the legasov tapes

black and white pass photo of Valery Legasov Valery Alekseevich Legasov was an inorganic chemist in the Soviet Union. He was the first deputy director of the Kurchatov Institute of Atomic Energy and he became famous as a member of the government commission that investigated the causes of the 1986 nuclear disaster at Chernobyl. Legasov had been warning the scientific and political communities of the dangers of the type of reactor used in Chernobyl for years, to the point of publishing an article about its dangers - important parts of which were redacted by censors.

Two years and one day after the disaster, Legasov took his own life, though not before recording a distillation of his side of the story onto five compact cassette tapes. The first four tapes feature only Legasov giving a recounting of the entire event, from the moment he learned of the accident to his final days at the Kurchatov Institute. The fifth tape features an interview with author Ales Adamovich.

The audio that was on these tapes seems to have been lost, but a transcript was made by Soviet prosecutors - it can be found here (I keep a copy). This transcript was translated into English by Yury Timofeyev, and the translation was edited by Juhi Ahluwalia, Tim Hughes and Jody Boyington; the fruit of their considerable labour can be found on their website.

The translators include images, links and notes in their version of the text, which is divided across several pages with finicky blog-style navigation. The unfortunate result is that this copy of the English text cannot be easily navigated and copied without clicking different menu items, scrolling through ten separate pages, and editing out the various annotations.

This is why I have copied the entire text to this page and edited it so a "clean" version is available. Furthermore, I am in the process of correcting irregularities, ambiguities and errors in the text. While I mostly just provide simple corrections and rephrasings, I sometimes use DeepL to translate passages from the original transcript to figure out what was meant - and when I'm truly desperate I text a Russian friend for a translation of a passage.

I regularly upload updates as I work my way through the whole thing, so somewhere in the text below you'll find a centred phrase that explains that everything that comes after is the uncorrected text, along with the date of the latest update. Like the original translation, this version of the text, in whatever shape it currently appears, is published under the CC BY-NC-SA 4.0 license.

I have generated an EPUB file of the text that is suitable for ereaders. It contains the above introduction and the original translation of the text, which I will replace with my revised version when I finish it.

Jump to tape: 1a | 1b | 2a | 2b | 3a | 3b | 4a | 4b | 5a | 5b

tape 1, side a

It never occurred to me in all my life that at the age I am now, being just into my fifties, I would be writing my memoir, nor that it would be so tragic, and in many ways confusing and incomprehensible.

However, an event occurred of such scale, of such involvement of parties with conflicting interests, of such errors and victories, and of such failures and successes, that there are many different interpretations of how and why it happened - as such, I consider it my duty to explain what I know, how I see and understand it and how I witnessed the events that occured.

26 April 1986 was a Saturday, a beautiful day and I was thinking of either going to my university department and finishing something there, or maybe letting things slide and going with my wife, Margarita Mikhailovna, and a friend to recreate somewhere, or of going to the party activists' meeting that was scheduled at 10 o'clock at the Ministry that supervises our Institute, The Kurchatov Nuclear Institute. As a matter of course, due to my nature and because of old habits, I called for a car and went to the activists' meeting.

Before the start of the meeting, Nikolai Ivanovich Yermakov, the head of the 16th head office of the Ministry of Medium Machine Building, under whose supervision our entire university was, walked up and said calmly but with some concern, that an unpleasant accident had happened at the Chernobyl Station.

The report of minister Efim Pavlovich Slavsky began - and it was quite dull, standard and mundane. We were all already used to how this very old yet good demagogue, with a loud confident voice, could narrate how good things were in our ministry, for an hour. All the metrics were perfect in his report: the best sovkhozes, the best enterprises, all goals had been achieved. Altogether this was like a victory speech.

At points, he would pause to criticize a chairman or a specialist for higher rates of workplace injuries, or poor financial performances, or for improper executions of technical operations within our ministry.

As usual, he praised the atomic energy program and the progress that had been achieved. However, in between his praise he somewhat abruptly mentioned that there had been an accident at Chernobyl. The station was under the supervision of our neighboring Ministry of Energy. Rather curtly, he stated that they had somewhat messed something up, and an accident of sorts had occurred there, but this would not stop the overall development of the atomic energy program. This was followed by a routine report that continued for two hours.

Around noon, a break was announced and I went up to the second floor, to the office of the Science Secretary Nikolay Sergeevich Babay to discuss the report. Immediately after me, Aleksandr Grigorjevich Meshkov, First Deputy Minister of Medium Machine Building, entered the room, quickly stated that a Government commission had been formed to investigate the Chernobyl accident, and that I had been assigned to that commission. I was told that the members of the commission should gather at Vnukovo airport at 1600 hours. I left the meeting immediately, called for a car and went to my university to find someone from the reactor team.

With great difficulty I managed to find the head of the department that developed and supported stations with RBMK reactors (the same type as at Chernobyl) - Alexander Konstantinovich Kulagin. He already knew about the disaster and that they had received a very serious alarm signal from the station the night before. The signal was encrypted according to defined procedure; during each and every deviation from normal operation, the station must inform the Ministry of Energy or whatever ministry it falls under about the situation by using a special code. In this case, they had received the following signal: "1-2-3-4"; which means that an event had occurred at the station that involved nuclear hazard, radiation hazard, fire hazard and explosive hazard, that is to say, all possible types of hazard.

It seemed to be the worst case scenario. He told me that, as planned in advance, teams were gathering to respond to each hazard and either go to the site itself or coordinate from a distance, and take over control of the station personnel. An appropriate team was gathered at night and approximately within three to four hours, they departed to the site. However, while they were on the way, new messages arrived from the station stating that the reactor (and this was reactor number 4 reactor) was mostly under control. The operators had tried to cool it down, but unfortunately, two people had already been killed. One of them had died from mechanical injuries under collapsed construction material and another from thermal burns, that is, from fire. No information was received about radiation-related injuries and this fact, while not conclusive, did calm us down somewhat.

After gathering all the necessary documentation and receiving from comrade Kalugin some explanation about the structure of the station and the possible issues that could occur, I dropped by my house. At this time my driver, as planned, brought my wife back from her job. We had to get in touch to solve some family issues, which of course remained unsolved. I told her that I was leaving on a work trip and that the situation was unclear so I could not say how long I would be away, and then I left for Vnukovo.

At Vnukovo, I found out that the head of the Government Commission was Boris Evdokimovich Scherbina, the chairman of the Bureau of Fuel and Energy. He was not in Moscow at the time but in another region where he was leading a Communist party asset meeting. We knew that he was on a flight over from there and that as soon as he arrived we would board the plane that had already been prepared for us, and then depart to the accident site.

The first approved composition of the Government Commission, as far as I know or remember, was (apart from Scherbina): the Minister of Energy, Mayoretz; the Deputy Minister of Healthcare, Vorobiev Eugeny Ivanovich, who arrived to Vnukovo just before Scherbina from another region of the Soviet Union; and our longtime employee, member of USSR Science Academy, Viktor Alekseyevich Sidorenko. The Deputy Chairman of the Government Nuclear Energy Supervision Bureau was also assigned to this commission. Additionally there were comrade Soroka, Deputy General Prosecutor of the USSR; and Fyodor Alekseyevich Scherbak, the head of one of the important divisions of Government Safety Committee (the KGB); also, the Deputy Chairman of the Ukrainian government, who would be at the site already; comrade Nikolayev; and the head of the Regional Executive committee, comrade Ivan Plyusch. This was the rough composition of the government commission that I remember as the initial one.

When Boris Evdokimovich arrived at Vnukovo he immediately boarded our plane and we flew out to Kiev. During the flight, our conversation was nervous. I was trying to explain to Boris Evdokimovich the accident at Three Mile Island in 1979. I wanted to prove to him that most likely the cause of that accident was in no way related to the Chernobyl accident because of fundamental differences in the construction of reactors. This is what occupied us on our hour-long flight.

In Kiev, after we got off our plane, what surprised us was a long line of black government cars and an anxious crowd of various Ukrainian chairmen, led by comrade Lyashko Aleksander Petrovich. They were all worried, and they didn’t have enough information; however, they all agreed that the situation was very bad. We didn’t get precise information here, so we got into our cars as quickly as we could and set off for the power plant. I was in a car with comrade Plyusch. The station was 140 kilometres from Kiev. The trip was in the evening. Having little information, we tried to prepare ourselves for all possible situations. Because of that our conversation was rather fragmented with long silences in between. Everyone was tense and anxious to get there quickly, to understand what had happened and to discover the scale of the disaster that we had to face.

Recalling this trip now, I can say that I had absolutely no idea that we were driving toward an event of a planetary scale, one that would most likely be remembered alongside famous events like the volcanic eruption at Pompei and other such catastrophes. We didn’t know this during the trip there - we were just guessing at the scale of the event. Would it be easy or difficult? In other words, our minds were entirely on the upcoming labour.

A few hours later, we got to Chernobyl. Although the power plant is called Chernobyl Station, it is situated 18 kilometres away from this regional city. It is a very green and very pleasant city, like a quiet countryside - this was the impression we got when driving through there. It was calm and peaceful there, all was ordinary.

Then we got onto a road that led to Pripyat, a nuclear city, where the builders and workers of the Chernobyl power plant lived. I will discuss the station itself, its history and operation a bit later so I won't disrupt the chronological order of this recording. In Pripyat we could feel the tension in the air. We arrived at the building of the city party committee in the central square. A hotel was nearby, a very good one, where the local authorities met us.

Mayorec was already there, having arrived before the Government Commission. A group of specialists was there also; they had arrived after the first call the previous night.

The first session of the Government Commission was immediately arranged. To our surprise, or at least to mine, we were not presented with sufficiently precise information of the situation in the plant or the city; the only precise report was about the accident, that it had happened in reactor number 4 while conducting a non-standard experiment of the turbo-generator operation when the turbine was in free run. Two explosions happened and caused the destruction of the reactor building. A considerable number of staff members was injured. The number was not precise, but it was clear that around 100 people had gotten radiation injuries. Two people had died, others were in hospital and the radiation conditions in the station were rather complex. The radiation conditions in Pripyat were considerably worse than normal, but at the time did not pose any significant danger to the people in the city.

The Government Commission's meeting was led very vigorously, in his usual manner, by Boris Yevdokimovich Shcherbina. We quickly organised members into groups, each with its own task.

The first group was led by Alexander Grigoryevich Meshkov and it started the investigation into the cause of the disaster. The second group, with comrade Abagyan in charge, had to organize all the dosimetric measurements around the station and in Pripyat, as well as in the closest surrounding areas, with the civil defence groups handling the rest. By this time General Ivanov had arrived; he would lead the civil defence group of that region and he had to organize preparatory measures for possible evacuation of civilians and for firsthand decontamination work. General Berdov, the head of the Ministry of internal affairs of the Republic, had to instate orders about which people could go inside the contaminated areas. As for myself, I was put in charge of the group that had to develop measures to localise the accident. The group led by Evgeny Ivanovich Vorobiev was assigned to handle all the medical problems.

When we were just nearing Pripyat, about 8 to 10 kilometers from it, I was struck by the appearance of the sky. There was a mulberry-coloured or even crimson glow visible above the station, which is opposite of what is usual for a nuclear power station. It is commonly known that nuclear power stations are very cleanly and exactingly run, with machinery and pipes that don’t exhaust anything visible into the atmosphere. If there's one thing a specialist knows about a nuclear power plant, it's that it does not exhaust any gases. This is its distinctive feature, if we're not speaking of complex technical aspects. But this one looked like a metallurgical factory or a giant chemistry plant with a huge crimson glow over half of the visible sky. This was very disturbing to us, and it made clear the extraordinary nature of the situation.

Immediately, it became evident that station management and the leaders of the Ministry of Energy were at odds. On one side most of the staff and leaders acted very bravely and were ready for any required action - the operators of 1st and 2nd blocks didn’t leave their posts, nor did the operators of the 3rd block, which was in the same building as reactor number 4. The various services of the station were on full standby. That is to say, one could contact any person and send any command or assignment - but how could the necessary course of action be determined before the arrival of the Government Commission?!

The Commission arrived at 20:20 on the 26th of April. There was no exact, predetermined plan of action - our Government Commission had to improvise. Firstly, the 3rd block was ordered to shut down. The 1st and 2nd blocks continued to work despite their internal rooms having a relatively high level of contamination which was in the tens or even hundreds of milliroentgens per hour. This internal contamination had happened because of the ventilation intake. It hadn’t been shut down in time and had drawn in some contaminated air where people continued to work.

This is why the first job of the first team that went in was to start the reactor shutdown procedure of the 1st and 2nd blocks. This was done by initiative of Alexander Egorovich Meshkov; he was the one to issue the command, not the station management or the Ministry of Energy. Execution of the command begun immediately.

Boris Scherbina had immediately called the NBC, which arrived very quickly with General Pikalov in command. Helicopter divisions were also incoming. These were based in Chernigov, onder the command of General Antoshkin who was the chief of staff of that Air Force division. They started flyovers above reactor number 4 to assess the situation.

During the first flight it became clear that the entire reactor had been destroyed. The upper reactor plate (nicknamed “Yelena”) that hermetized the reactor, was in an almost vertical position, slightly off kilter. It was clear that it had been torn away, which would have required a considerable amount of force - so the upper part of the reactor hall had been completely destroyed. On the roofs of the engine room and on station territory graphite blocks were scattered, some intact and some in pieces. Various parts of fuel assemblies were visible. Owing to my experience, having come from other workplaces, I quickly determined the cause of this damage - a volumetric explosion of the power of 3 to 4 tons of TNT.

The crater in the reactor produced a column of white smoke, several hundred metres long, most likely consisting of graphite combustion byproducts. Inside the crater, glowing spots of intense crimson were visible; it is difficult to say unequivocally what caused that glow. It could have been hot graphite blocks that had remained in place - seeing as graphite burns evenly, generating whitish burning products as an ordinary chemical reaction. The visible light, reflected in the sky, was the glow of hot graphite - that is how powerful it was.

Radiation levels were measured at different points in vertical and horizontal space around the reactor. As had been observed, a large amount of radiation had leaked out of reactor number 4, but at that time we were mostly worried about whether the reactor was still working. That is, was it generating short-lived radioactive isotopes or not? Because we needed that information immediately, a first attempt to measure the gamma and neutron fields was made. A military Armoured Personnel Carrier, property of the NBC, was used for this. The first measure showed that there was a powerful source of neutron radiation. This may have indicated that the reactor was still working.

To make sure of this, I had to get into that APC and go near the reactor. It appeared that within those powerful gamma radiation fields, the neutron channel of the measuring device wasn’t working, because it was affected by the powerful gamma rays, causing errors. That’s why the most precise information about the state of the reactor was gathered from the ratio of short-lived and long-lived isotopes of iodine-134 and -131. Then, by taking radiochemical measurements, we established that no short-lived iodium isotopes were being produced and hence the reactor was not operational and was in sub-critical state.

Multiple follow-up tests of gases over the next few days showed that no short-living isotopes were being produced. This convinced us that the fuel mass that was left after the explosion was in a sub-critical state. After performing these initial estimates about the reactor activity, other problems began to concern to us. First, the fate of the local population, and the number of members of station personnel that should remain at the station (and, in its current state, continue to service it). Second, we had to predict the possible behaviour of the fuel mass, possible outcome scenarios and appropriate courses of action to those scenarios.

By the evening of the 26th, all possible manners of flooding the core had been tried, though it resulted in nothing but high steam generation and the spread of water through the various transport corridors in the neighbouring unite. It was clear that the firemen who had extinguished the fires in the engine room had done it very quickly and professionally.

It is now sometimes said that many of those firemen received needlessly high radiation doses, because they were stationed in various places to monitor the situation and prevent the appearance of new fires. It is said that this was a poor and thoughtless decision - this is not true. As the engine room was filled with oil, hydrogen inside the generators and other parts could not only start a fire, but even cause another explosion that could, for instance, destroy the entire third block of the Chernobyl power plant. This is why the firefighters' actions were not only heroic but also very professional, thoughtful and correct. They did a very fine job taking the initial steps to localize the accident and prevented it from spreading.

The next question arose when it became clear that the crater of the wrecked fourth block was exhausting a lot of radioactive gas. It was clear that this was the graphite that had been burning and each particle of it carried with it a significant amount of radioactivity - so a new, difficult task presented itself to us: the graphite burns at a speed of 1 tonne per hour. There were 2500 tonnes of graphite in the fourth block, so the mass could continue to burn for 240 hours, accumulating radioactivity that could potentially contaminate a lot of territory through the spreading of the smoke.

The temperature inside the destroyed block would be limited by the temperature of the burning graphite, which is round about 1,500°C or slightly higher. This meant that a kind of equilibrium would be achieved: the uranium oxide fuel pellets would melt and stop producing additional radioactive particles. But the radioactivity that would be carried out with the smoke could heavily contaminate a considerable area of land. The severity of the radiation conditions meant that the reactor could only be approached from the air, and even then nothing could get closer than about 200 metres above the reactor. As such, we didn’t have any technical means to put the graphite fire out in a traditional way, for instance with water or foam.

We were forced to develop non-traditional ways of solving this problem. Our brainstorming session was conducted in constant consultation with Moscow, with whom one of us was constantly on the phone - for example Anatoly Petrovich Alexandrov. Numerous other scientists from the Institute of Nuclear Energy and the Ministry of Energy took active part in our discussions. All service providers, for example the firefighters, were also in constant contact with their Moscow counterparts. Starting on the second day we started receiving suggestions from abroad about various chemical mixtures that could be used on the burning graphite.

The logic behind our process of decision-making was as follows. First of all, we had to introduce as many boron-containing substances as was possible, so that under whatever conditions of fuel-mass movement, they would provide enough in the way of effective neutron absorbers. Happily, a sufficiently large amount (forty tonnes) of boron carbide was available from an uncontaminated stockpile, and it was quickly dropped into the reactor by helicopters. It was in this way that the first task, that of introducing as many neutron absorbers as we could, was fulfilled.

The second task was to drop down materials that would stabilize the temperature - this works by forcing energy generated by the decay of nuclear fuel to be spent on the induction of phase transitions in these materials. My first idea was to drop iron shot. The station had lots of it stockpiled - it was used in construction, to mix with concrete to weigh it down. Unfortunately, the place where the iron shot was kept had been affected by the initial outburst of radioactive particles and was contaminated, rendering it completely unusable. Either way, we didn’t know the temperature inside the core; if, for example, it were to be lower than the melting temperature of iron, dropping this material would not have been effective because the iron would not melt and the mass would not stabilise.

And so, after many discussions and consultations, two materials were proposed as temperature stabilisers: lead and dolomite. The first because it melts at low temperatures and because it has some ability to extract radioactive elements, on top of which it can act as a protective shield against gamma rays - these facts made it a good option. Of course there was a concern that if temperatures in the core were significantly higher than our estimates, say 1600-1700°C, the lead would just evaporate and be carried out of the reactor, causing additional contamination of the surrounding areas and rendering this measure ineffective.

Because of these concerns, a group of scientists from Donetsk, out of the Ministry of Energy of Ukraine, were placed under my supervision. They had Swedish branded (Ada company) devices including thermal cameras, and started constant flyovers of reactor number 4 to record the temperature of the surface. It was a very difficult task because the semiconductors used in these thermal cameras were heavily affected by the powerful gamma radiation that hit them, skewing the results drastically. As such, I advised to use additional thermocouple temperature measurements that would be conducted from the ground.

Eugeny Petrovich Razantzev took on this task in cooperation with helicopter pilots. The thermocouples were lowered from long halyards. Measuring the surface temperature in this manner was still an exceedingly difficult task.

Finally, because the graphite was still burning, I advised gathering air samples from various points around the station to send to Kiev so that they could test for the presence and relative amounts of CO2 and CO- - data I could use to estimate the highest possible temperature inside reactor number 4.

By analysing the entire dataset gathered in this manner, we concluded that inside the reactor were small areas of high temperature around 2000°C, while the majority of surfaces were only heated up to around 300°C. As such, it became clear that lead would be an effective measure. After all this study and based upon our conclusion, 2,400 tons of lead were dropped by helicopters, with high precision and great skill.

The amount of dropped lead grew from day to day. I was shocked by the speed and scale at which all the needed materials were delivered to fulfill this operation. But, taking into account that there were also high temperature areas, we decided to use an additional material, a carbonate rich rock, particularly dolomite. This would perform the same task as the lead in places where it was possible to stabilise the temperature by spending excessive energy on the decay of dolomite components. One of these components is Magnesium oxide - an oxide with relatively good thermal conductivity and, like lead, when it gets into place, it acts as a heat sink and transfers heat to all other metal construction elements.

But magnesium oxide, of course, is not a metal; it conducts heat more effectively and without corroding, and the oxides it forms interfere with the oxygen concentration in the combustion zone, contributing to the cessation of combustion. This was the reasoning that led to the introduction of this group of metals into the destroyed reactor.

Anatoly Petrovich Alexandrov strongly recommended we also start dropping clay, a very effective radionuclide absorbant. Should the uranium dioxide cells start to melt, large amounts of clay and sand would serve as a shield or filter that could contain at least part of the radioactive components.

It was immediately obvious to us that dropping anything from a height of 200 metres would create a complex situation around reactor number 4 - when 200 kilogrammes of material falls from a height of 200 metres it throws up dust, and that dust carries some amount of radioactive material. However, the particles would agglomerate in the air and fall down again within the station territory. This cloud would act as a kind of spoiler against the wind, trapping aerosol particles that would otherwise have been carried far away on the wind.

Judging by the quantity and dynamics of the radioactive exhaust from reactor number 4 our actions were quite effective. A considerable amount of radioactivity was localised and did not spread to a larger area, excepting the elements of Cesium and Strontium - the most easily melted elements.

It was the sum of these actions that allowed us to seal reactor number 4 and to create a layer of filtering materials, preventing the melting of the fuel by blocking a proportion of the endothermic reactions. This resulted in a considerable reduction of radioactivity spreading from reactor number 4 to a wider area.

These were the measures decided upon for containment. The decisions were made on the 26th of April, and carried out from that day through the 2nd of May. This was the period when we dropped the vast bulk of our decided-upon materials into the reactor. After the 2nd of May, we stopped the drops for some time. Then around the 9th of May, we resumed when a flaming spot was sighted while circling the reactor. It was either graphite or some metallic construction at a very high temperature. We dropped another 80 tonnes of lead; that was the last large drop.

As we were carrying out these operations to stabilise the temperature and create the filter layer, Boris Veneaminovich Gidaspov, a member of the Science Academy who had come to help the scientists that worked there (this was later, around the 10th of May), proposed an operation to suppress dust formation. Plastic bags were filled with special solutions, and the bags were dropped into the reactor. There they would burst and cover a significant area; the solution would then polymerise and solidify. The same thing was done to all surfaces that could produce dust. All these measures were, and I repeat myself, planned on the evening of the 26th of April. They continued until somewhere between the 12th and 15th of May, with the main drops ending, as I have said, on the 2nd of May.

This sums up our containment efforts. Of course, we continuously gathered air samples on filters to measure the amounts and the dynamics of the radioactivity that was being exhaust. Where the first cloud had carried off around 1000 curies of radioactivity a day, by the date of my second departure from Chernobyl, on May 12th, it was 100 curies a day and falling.

Of course, there was frequent disagreement about the accuracy and correctness of the measurements and calculations, which resulted in basic measurement consistency not being guaranteed at any given measuring point. I will say a few words about this later.

Earlier I described the work before and after the containment of the accident, but an even more essential element of the decision of our Government Commission on 26 April was the question of the population. Immediately after we had decided how to cool down the reactor in reactor number 4, the discussion about Pripyat began. On the evening of 26 April, the radiation levels were within permissable limits. Anywhere from one milliröntgen per hour up to a maximum of tens of milliröntgen per hour - obviously, this was not a healthy environment, but it did allow for some discussion about what to do next.

uncorrected version from here on out.
latest update: 2021-01-19

In these conditions, where on one side we had repetitive radioactivity measurements and on the other, the medics were limited by accepted order of things where the evacuation could only start when there was a risk of a person getting 25 biological roentgens per individual within some period of time. The evacuation was mandatory when a person could get 75 biological roentgens. But within 25 - 75 biological roentgens, the decision to evacuate lied with the local authorities. So in these conditions we started the discussion.

I must say that all physicists, especially Viktor Alekseevich Sidorenko, felt that the conditions would only change for the worse, and insisted on the mandatory evacuation. And the medics sort of supported this. Around 11 a.m. on the 26th of April, Boris Evdokimovich [Scherbina], after considering all our recommendations, decided to go ahead with the mandatory evacuation. After that, Ukraine representatives, comrade Plyusch and comrade Nikolaev, started to prepare for the evacuation of the city scheduled for the next day.

This by no means was an easy operation. Transport was needed; it was called from Kiev. Drivable roads had to be scouted to plan routes for the evacuation. General Berdov led this work, and also organized the task of informing the public so that they don’t come out of their houses. Unfortunately this meant that the information was disseminated only verbally - they visited each house, also posted notices. It seemed that not absolutely everyone was fully informed, because mothers with children were seen on the streets on the morning of the 27th.

At 11 a.m., we were officially informed that the whole city would be evacuated by 2 p.m.. All the transport had been gathered; all the routes had been identified; and at around 2-2:30 p.m. the entire city was empty. Except for the station workers, and some workers that were needed to operate public services.

The station personnel was transferred to a Pioneers camp “Skazochniy”, that was 10 km from Pripyat. The evacuation was fast and precise, despite being carried out in unusual conditions.

However, there were some issues. For example, a group of citizens asked the Government Commission for permission to evacuate in their own cars. There were a couple of thousand of such cars in the city. After some considerations, the Government Commission allowed them to use their cars. Perhaps that was a wrong decision, because some of those cars were contaminated, and the dosimetric posts had not yet been organized to control the contamination levels on such vehicles .

In such a way, many personal items that people took with them got out of Pripyat and carried the contamination with them. They, however, took a minimal number of items because they were hoping that the evacuation was temporary . However, I will repeat myself that the evacuation had been carried out at such a time when the radiation levels of Pripyat were not that high; and therefore the level of contamination of the items, as well as the people themselves, was also not high. It has become clear now that none of the almost 50,000 civilians of Pripyat, that were not at the station after the accident, had received any considerable amount of radiation.

That was the second line of defence- protection of the people. After that, more and more thorough dosimetric measurements of the situation were carried out. The isotope composition was analyzed more thoroughly. This was done by the services of Government Hydro-Metric Commission and by General Pikanow’s services, as well as the station services. I must say that both the dosimetry services and military had done great work, however, the most precise information we got came from the radiation institute laboratory that was set up onsite. It was led by comrade Petrov who had arrived here earlier. Dollezhal Research and Development Institute of Power Engineering (NIKIET) led by comrade Egorov supplied us with most precise data on isotope composition and on the spread of radioactivity. Based on their data, we adopted one or another decision.

It was clear that in the first few days, because of the way air masses were flowing and because of the material drops in the reactor, the contamination was spreading with the dust.


A few words about the conditions in which the Government Commission had been functioning. Some personal impressions of the time …

First and foremost I want to say that selecting Boris Eudokimovich Scherbina as the head of the Government Commission was a very good choice . That is because he has a good habit of carefully listening to the specialists, quickly gasping their point, and be immediately ready to make decisions. He is not in any way timid or sluggish at making decisions. This was very clearly seen in such an exceptional situation.

I will mention only one example of his work. Following the complex calculations about lead, Alexandrov, for example, couldn’t understand my reasoning for a long time, why that lead was needed. I tried to explain to him that there was no possibility of dropping iron shot because of the reasons I mentioned earlier. Because waiting for it to arrive would mean that we would have to stabilize the temperature on a much higher level when we wanted to do that on a lower level. According to my estimates, 200 tons of lead had been ordered but I immediately told Boris Eudokimovich that 200 tons won’t solve any problems. We would need around 2000 tons of lead to be dropped into the crater of the reactor. He listened very carefully (I thought that it would be hard for the country to supply so much material in a matter of days) and as I got to know later, ordered 6000 tons of lead, because he thought that we could have made a mistake in our calculations and it would be better to have surplus lead instead of not having enough. This is only a specific example.

The station personnel was also surprising in a way. They left very conflicting impressions. I have already spoken about that. We met people that were ready to do any job in any circumstances. Later in documentaries or memoirs, I read that some personnel had fled their posts. But the situation was complex. Especially after the evacuation, many people didn't know where their children, mothers were, because people had been evacuated in all directions. Some stayed in the villages they were evacuated to, others immediately got tickets and went to their relatives. But where did they go? This was making things more complicated. Nevertheless, all the station workers from the ordinary up to the ministerial staff, were ready for the most rigorous and courageous, so to say, actions. But what should those actions be? What did they need to do in such a situation? How should the work be planned and organised? From this perspective, there was no understanding of the steps that needed to be taken, neither from station personnel nor from the Ministry of Energy. And so I and the Government Commission had to take these decisions, come up with the action plan, get a clear understanding of the situation.

This confusion was seen even in small things. I remember the time when the Government Commission was still in Pripyat, we didn’t have enough respirators, personal dosimeters called TLDs, and even somewhat reliable pencil dosimeters, that would show some measurements. There were not enough of these devices for everyone who were involved in the work. Moreover, many of them either hadn’t been charged, or the people had not been instructed on how to use them and when to recharge them. This was quite unexpected.

We could only kick ourselves for not having external automatic dosimetry devices set up around the station, that would record the telemetry about radiation conditions within, say, 1 km, 2 km, 4 km and 10 km radius. So we had to send out a lot of people to assess the situation. There weren’t any radio-controlled aircraft equipped with dosimetric devices. So we had to send a considerable number of helicopters to take the measurements and investigate. It’s clear that a human is irreplaceable when one has to perform certain complex tasks like a cargo drop or some other operation involving large devices placed on a helicopter. But some simple, repetitive tasks could have been done by small crewless, radio-controlled aircrafts. This kind of equipment was not available at the time.

There were also issues with elementary culture. During the initial days in Pripyat, food was delivered: cucumbers, tomatoes, sausages, Pepsi-cola bottles, lemonades. All this was delivered to relatively dirty rooms, and was prepared for eating in the same place with bare hands. So even such a basic hygienic practice for eating was absent during the initial days. Later, after a few days, when the arrangements improved, proper dining tents were set up, proper sanitary and hygienic practices were put in place. Very basic, but it enabled keeping people's hands, and the food itself, safe from contamination.

During the initial days, all this hadn’t been organized and this was shocking. These were some of the smaller issues.

The Government Commission worked from Pripyat for the first few days. The headquarters were in the City party committee building. If we could, we would sleep in a nearby hotel. After the evacuation was completed, the Commission was still in Pripyat for a couple of days, but after that moved to the regional party committee building in Chernobyl and as well as into a military camp. Soon after, the working quarters were organized. The living accomodations, however, were placed in the city of Ivankov, which was 50 km from Chernobyl. It was clear that during such migrations there was no command centre prepared from which it would be possible to organise the work in such difficult conditions. All of this had to be invented and organized on the spot, successfully or otherwise.

On the second or third day, I think, I offered to organise an information group within the Government Commission. I invited two or three experienced journalists to it. They had to gather the needed information about the medical, technical, radioactive situation from the specialists in a quantity they needed, be it full or partial, deal with imprecisions when we ourselves didn’t have enough information. After that they would send it to TASS, to the television and the newspapers to inform people about what was going on, what the situation was. This wasn't rejected, but as far as I know, even now no such information group has been created.

tape 1, side b

On the 2nd of May, the Government commission was already in Chernobyl. Nikolay Ivanovich Ryzhkov and Egor Kuzmich Ligachev arrived at the exclusion zone. Their arrival had a great significance. One day prior to their arrival the Government commission had decided to continue the evacuation from an area within 30km radius around ChNS. This decision was based on a prediction of radioactivity spreading and analysis of current situation on the eve of the 2nd of May.

After our high-ranked guests had arrived, they deliberately started their visit from the places where evacuees had been placed. Then on the 2nd of May, they took part in the meeting carried out in the Chernobyl regional party committee together with comrade Scherbicky (who was here for the first time). Before that, the entire Ukraine Government was very actively and successfully represented by the Ukraine Chairman Deputy Nikolaev. This was a very important meeting. Firstly, thanks to our reports and I was a reporter, they understood the situation, understood that this was not an average accident but a high-scale disaster that will have long-term consequences, and that enormous amounts of work would be required to continue the localisation of reactor number 4 as well as to decontaminate the area and to build a shelter for the wrecked 4th block. An assessment of the situation was also needed, as well as considering the reactivation of the 1st, 2nd and 3rd blocks. And finally analyze the possibility of continuing the construction of 5th and 6th blocks. These questions were drafted out then. We also spotted an increase in radiation levels in Kiev and other cities which were quite some distance away from Chernobyl.

The party members and the government were quite worried about all this. That is why they came to personally sort these matters out at the location. After we had described the situation, the pivotal decisions were made. These decisions determined the entire order of organisational work for the rest of the period. The scale of the work, how all the organizations and the government itself perceived it.

The operative group led by Nikolai Ivanovich Ryzhkov was created and almost the entire Soviet industry was allocated to the disaster.

From that moment the Government Commission became only an administrative mechanism for that huge government work that was done under the control of the Operative group of the CCCPSU. The operative group held regular meetings where it was reported to about the radiation levels at each measurement point, all the details about the tasks being performed. In other words, I didn't know any big or small event that the Operative group of politburo didn't know about. Except for Nikolai Ivanovich Rizhkov, the Operative group consisted of Yegor Kuzmich Ligachev, comrade Scherbikov, comrade Vorotnikov, comrade Vlasov - the minister of foreign affairs, Vladimir Ivanovich Dolgikh - secretary of the CCCPSU who on behalf of the Central Committee supervised all the events performed within the ChNPP and in the field of atomic power as a whole. As it seemed to me, he was doing that 24\7 without leaving aside his assigned other tasks.

I must say that at multiple times that I attended the Operative group meetings, these meetings were held in a very calm and conservative manner. They tried as much as they could to base their decisions on the specialists’ point of view. However they also compared what many specialists say. In summary, for me it was an example of a correctly set up workflow. You know, I couldn't even assume that the Operative group would make such strong-willed purposeful decisions. These decisions were targeted solely to deal with the situation faster, lessen the consequences. The work was like a well organized science team.

First - carefully studying the available information. Preferably information obtained from multiple sources and there were cases when the military had provided information that was different from what the civil services had given. This was especially the case for the radioactive outbursts in reactor number 4 - different services had been providing different information in the first stages of localization.

For example, different groups in June provided different estimates of the radioactivity that had escaped reactor number 4.

In another instance, the GeoChem institute had provided report approved by academician Velikhov, that was based on their measurements that more than 50% of the reactor’s contents had escaped its core and the Chernobyl power plant territory. They had estimated a colossal plutonium spreading zone on the territory of the Soviet Union.

The second group of specialists, who was working under the instruction of Lev Dmitrievich Ryabev, consisted of radiation institute staff of Ministry of Medium Machinebuilding, was measuring the activity only in some hydro physical points around the station. And they estimated the escaped fuel by the activity within their measured points.

Of course, this was wrong. The self absorption was not taken into account as well as many other factors. But nevertheless, judging by this basic overview they also had concluded that around half of fuel was inside the reactor and another half had escaped.

FInally the third group of specialists, which in the most thorough way had researched all the maps from Government Hydro Metric service, integrated all the activity from land-based and air services, comparing that to data that was received from abroad. They could not get any more than 3-4% of radioactivity that had escaped reactor number 4.

All this information was accumulated in my sub-group and had practical effect on what actions and effort should we assign to decontamination and disposal works.

Because of these differences a commission had to be formed and Anatoly Petrovich was asked to be an arbitrator to search for mistakes. In the end it appeared that the GeoChem group was wrong, because their samples were taken in such a condition that they had included plutonium used in weapons coming from nuclear explosion period. These inaccuracies were accounted for, but that approach itself was not accurate.

Eventually all came to the following number: between 3% to 4% of the fuel was thrown out of reactor number 4 reactor. But during that period it created quite a tense situation. The Operative group itself however didn’t show any tension at all. They just constantly performed more measurements, more elaborations and tried their best to understand the actual conditions.

During this time the Operative group was constantly trying to provide maximum protection for the people and judging from possible degrees of contamination decide on a compensation amount that would be necessary for the evacuees. I repeat that and I personally was a witness to that. They made many decisions specifically to help people who were affected by this accident. This is true for each and any case.

Another thing that surprised me about the Operative group is that it never tried to be secretive about their decisions. For example, decisions of some sort were taken like the launch date of 1st and 2nd blocks, or sarcophagus completion time, or works on 5th or 6th blocks, or Pripyat conservation decisions. Such decisions were adopted, but if some experimental data appeared that showed that the conservation of Pripyat could be avoided and it could be decontamination and even inhabited later, then the Operative would change their decisions according to new data, without seeing something bad in that change.

Nikolai Ivanovich Ryzhkov had been on ChNPP many times . The Operative group had to take many decisions about accepting or rejecting help from abroad, that was proposed at some time.

I wanted to say that aloud. But now recalling those days of May, I must say that after N.I.Ryzhkov and E.K.Ligachev had visited the accident sites and verified the situation, we received a command: the composition of the Government commission should be changed.

Boris Eudokimovich [Scherbina] remained the leader of the Government commission, but a decision was made that all further work on the site would be performed by a second group. While the first group would go to Moscow, on the site the second group would be led by the chairman of the Ministry Council Ivan Stepanovich Silaev.

The entire group of the first Government commission departed, but Scherbina asked me and comrade Sidorenko to stay back for a while to finish the work. Sidorenko had to investigate the causes of the accident and I had- to finish the localization work on reactor number 4. Formally however I had to be replaced in Silaev’s team by Eugeny Petrovich Ryazantsev - deputy of the director of our Nuclear Energy Institute. He had arrived and then unexpectedly Eugeny Pavlovich Velikhov appeared in this group, I don’t even know on which command.

I must say a few words here...

Eugeny Pavlovich Velihov who as it seemed was watching too much TV about the “China syndrome”, arrived with concerns which I reported to Rizhkov and Ligachev. We were worried about the uncertainty of geometric shape of the remains of the reactor. It was clear that heat was being generated inside this fuel mass. The heating up could continue and some vertical movement of this fuel mass may occur. In particular, we were worried about two things: can that movement cause critical mass buildup in some region which would produce short-living isotopes. This was our first thing to worry about, however we were hoping that the large amounts of Boron (40 tons) that was dropped into the reactor would be more or less evenly mixed with the fuel and help prevent critical mass buildup. However we could not fully eliminate the possibility that such local “reactors” would appear. That was the first problem. And the second one was that the temperatures can be too high within these masses. Some construction elements of the lower part of reactor may not withstand that. Concrete may fail due to high temperatures. Part of fuel can get into the barboteurs, be it lower or upper one and we did not know at that time whether there was water or not. We feared that if a considerable amount of fuel gets there, then extensive vaporization would carry out additional radioactive aerosols and contaminate more territory.

These problems were what we were worried about. That’s why with Ivan Stepanovich Silaev, who by this time had replaced Scherbina, we decided to: first, get some information about the levels of water in the lower barboteur. This was a difficult task which was fulfilled heroically by the station personnel. And it was found that the water was indeed there. So the necessary measures were taken to remove that water from there. I want to stress that out once more: we removed the water just to avoid massive evaporation. It was absolutely clear to us that no explosion was possible, only evaporation that would carry out radioactive particles - that’s all.

So just in case, the water should be removed and in case the fuel mass would melt it’s way down into these rooms, we could pump the water back there, to cool the molten fuel masses.

These decisions were accepted and written down in session protocols. But then Eugeny Pavlovich appeared and started talking about this “China syndrome” and those barboteurs; - lower and upper ones, that they could melt through and some fuel could get through them into the soil and into the groundwater.

Groundwater was only 32 meters deep under the Chernobyl station. In this particular aspect the station was rather poorly placed. Should the fuel get there, it would contaminate a considerable part of water in Ukraine.

Probability of such an event was extremely low, nevertheless, as a preventive measure and after some debate, the work to prevent this was approved, despite most of specialists being in doubt whether it was needed or not. Nevertheless Eugeny Pavlovich insisted on performing this work that is constructing a concrete bed under the reactor . To accomplish this, miners worked very hard led personally by the minister of coal industry comrade Schadrin and his specialists led by comrade Brezhnev from the Ministry of special heavy building who created the required tunnels under reactor number 4. These tunnels were to be used to construct that concrete bed which had a cooling feature. This job was constructed and built in a very short period, but was completely useless, because no fuel got there and nothing had to be cooled.

Somewhere around the 10th day of May, Vyacheslav Dmitrievich Svetliy arrived, who was called by Velikhov. Svetliy brought a case with samples of various materials that had been melted using a laser or as a molten mass. This all had some psychological effect on Ivan Stepanovich Silaev and he authorized the works.

All in all these measures were excessive. But at the time it was understandable that they were preventative just in case some mass got through by accident. This also had a considerable psychological effect on the population, demonstrating that measures were being taken to protect the groundwater. But from my point of view, why I wasn’t an active supporter of this idea or even active opposer of it is because these jobs would require a lot of machinery to be concentrated in the zone. For that concrete supply had to be organized. Test what vehicles would be best-suited for the job within those conditions. Vehicle decontamination sites had to be organized and it had to be ascertained if they could even be fully decontaminated . What conditions should be prepared for the people that would work on that site and for how long should they stay there. And because the sarcophagus projects were just in the beginning of design stage, it was unclear what machinery and how much of it would it require.

But how to construct the concrete plate under the reactor - this was totally unknown to us. For me it seemed to be important that during this proactive stage the measures to supply people, to create proper living conditions for them, to gather experience for such a large scale work organisation. Because of that it seems that all the decisions were correct.

Entirely another case was when Eugeny Pavlovich proposed to construct another such plate under the wreck that was outside of reactor number 4. And it seemed to him that there was also a lot of fuel. For this he we would have to allocate another ten thousand of subway builders, get them here to do that work. In this case I could not stand it so I wrote a very angry letter together with Anatoly Pavlovich where we strongly objected this excessive allocation of people who would get high radiation doses when constructing that second plate. Of course there was no basis whatsoever to carry out such a work because we more or less knew where most of the radioactivity was distributed around each reactor zone.

Groundwater protection became one of our most important problems immediately around May. Because the Pripyat river by itself formed a considerable water basin, but even more - it was flowing into the Dnieper river. Well one does not have to explain about Dnieper. I will repeat myself that groundwater was relatively close to the surface under the station. So after it became clear that casualties of this accident were like hundreds of people, while tens were heavily injured and all the rest were curable - our main problem was to make sure the population safety around the Dnieper basin. This was sort of central, very important task. Ofcourse, water contamination measurements were carried out constantly.

tape 2, side a

Immediately, various solutions were proposed [for groundwater protection]. The first solution, whose planning was assisted by experts from Goskomgidromet and other regulatory organisations, as well as organisations such as Minvodkhoz, was to build an underground barrier surrounding all contaminated areas of the ChNPP, and to dig trenches, concrete them and make a kind of cuboid around the contaminated area to prevent contaminated water from leaving the site. Initially, even Italian equipment was purchased which would allow this project to be carried out at high intensity.

But then, more accurate surveys; more accurate evaluation of the radiation conditions in the water, of the migration of radionuclides in the water, together with tests on the Italian machinery itself and an assessment of its performance, showed that this solution was not justified. A more effective solution was put forward to the Minvodkhoz: to surround the entire contaminated territory with approximately 1450 wells, some of which would be measuring wells in which the radioactivity of the water flowing through wouldbe continuously measured; then, if necessary, contaminated water could be pumped out using special devices, preventing it from reaching the groundwater.

In practice, this then turned out to be the best decision, as all the wells had been built and the measuring wells showed that there was practically no penetration of contaminated water into the ground. To this day, I haven't heard of a single case where contaminated water had to be pumped out. So the barrier was built in the ground in only one place; the most contaminated area, and that was all. The wells are in place, are monitored and are functional.

Since the cooling pond at ChNPP ... Since after the release, some of the radioactivity got into the water, the next step to protect, say, the Dnieper sea [sic] and the entire water basin, was the construction of dams that included Celites, that is, substances capable of absorbing radioactive particles and radionuclides should they appear in the water in small or large rivers. Such protective dams were built and had a positive effect. So, water contamination never exceeded maximum permissible concentrations.

It must be mentioned that Ukrainian comrades initially came up with a plan to create a bypass canal that would divert all the water from the Pripyat river away from the Dnieper sea. This project would have cost billions and such a canal would have passed through Belorussia. It would have been very expensive. However, it would guarantee that no contaminated water got into the Kyiv Sea. But again, a commission led by comrade Voropaev was created. It thoroughly analyzed the situation. Even before this commission was created, I had been charged with assessing this project. Based on the simplest estimates that I could make, this commission seemed redundant, because with the system of wells and dams in place, the exchange of radioactivity between the water and silt would not pose any significant danger to the Dnieper sea. But then the commission did a much more thorough assessment and concluded the same thing as I did. Therefore, this project was rejected and as reality has shown, the project would have been economically impractical and would not have brought any additional benefits towards protecting the Dnieper basin.

People from Kiev took the correct measures at this time. They began to prepare for the possibility of using water from another source, from the Dniester, to supply the city and made all possible efforts to create additional artesian wells. In case the Dnieper’s water became contaminated above the permissible concentrations, the city could be supplied using alternate sources of water. All the preparatory work was done in a very quick and very organized manner. All this was readied but never went into action. Because neither before nor after the high water in spring did the waters of the Dnieper basin contain dangerous levels of contamination that would pose a threat to human health. What I mean is that, generally, there was no contamination in the river basin.

In the first few days, on separate spots of the river basin, it must be said, activity of up to 10-8 curie per litre was detected in some water samples. Secondly, silt, including that in the Dnieper basin, turned out to be contaminated. The most heavily contaminated silt was in the cooling pond beside the ChNPP but also further downstream along the Pripyat and the Dnieper. Radionuclide content in the silt is considerably elevated even today. But fortunately, nature itself acts in a way that silt holds the individual particles of radionuclides quite firmly. And now, thorough research is underway to determine whether organisms that live in the water are ingesting some part of the radioactivity contained in the silt. This research is still underway and will continue for quite a while. The initial conclusions are that fish living close to the riverbed do, without a doubt, carry some radioactivity in them but no disturbing symptoms have been discovered.

And the second situation, protecting the shore and rivers against the melting water [in spring] which carries away various debris contaminated with radioactive elements—wood chips or needles that fell in the contaminated forest—that could lead to rather significant radiation damage. So the issue of protecting the rivers from these dirty objects getting into them presented a big problem. And here, the Soviet Army played a big role in minimizing the possibility of these contaminated objects getting into the rivers, and in tackling the problem of cleaning and gathering [contaminated objects] from such contaminated areas. It was a serious problem and it was resolved by the army with great intensity.

Since I’ve already started talking about the army, then I must say that from the moment when the Soviet Army was charged with organizing the work, the scope of work was quite extensive, but the deployed chemical forces first had to scout and establish the contaminated area. The army was responsible for the work at the station itself and decontaminating villages, houses and roads in the 3-kilometre zone. They did a colossal amount of work.

While individual researchers had proposed various solutions for dust suppression, in the summer of 1986, one of the main challenges was preventing the spread of contaminated dust over large distances. To do this, a wide range of chemical solutions were tested that had to be practical, could cut off the contaminated areas while letting water through but, prevent considerable spread of dust. The creation of these solutions, their testing and their introduction across large areas—all this work fell to the army. This work was very meticulously organized.

An enormous amount of work was done by the army to decontaminate Pripyat. Sometime around the end of August, September or October, when the city was in a condition which allowed it to be preserved; it was safe to be in… this didn’t mean that the city could be inhabited normally, but that the city no longer posed any immediate danger was thanks to the army’s efforts.

Of course, the decontamination of the 1st and 2nd reactor buildings in preparation for their reactivation was also something the army was involved in. Decontamination of the interior, cleanup of the area, and of the roof, all this was done very actively and in difficult conditions, all while ensuring that not one of the soldiers or officers received [radiation] doses exceeding 25 rem . Later, the maximum dose was reduced.

Although, of course, there were cases, some amusing and some tragic, that I witnessed with my own eyes. One such unfortunate case was when some groups of soldiers had only a single dosimeter carried by their commander, who would estimate the [radiation] dose received by each soldier. These were rare cases, but they did happen. In one case, a commander was recording higher doses for soldiers who were working well—perhaps as an incentive to work harder and as an opportunity to complete their stay in the zone faster—and lower doses for soldiers who were working poorly. But when such cases became known, a scandal broke out. Everything, was, of course, changed, but unfortunately, these things did happen.

I never witnessed a single case where specialists from the SA [Soviet Army] or a USSR citizen, somehow trying to do their work, or felt like they were forced to do difficult or dangerous work. There could have been such cases but I never saw anything like it. On the contrary, I myself went to the dangerous areas of the 4th reactor building several times, to clarify reconnaissance data or to estimate the amount of work remaining for certain operations, and always had to take soldiers with me for help. I always asked them. When a group of soldiers was brought to me, I explained the conditions under which they would be working and said that I only wanted to work with those who were comfortable with it. And there never was a case—and there were many such occasions [when soldiers were asked to help]—where someone, as they say, remained in the ranks, and did not step forward to help us carry out various, sometimes very difficult, tasks. In these cases, a soldier was no different from a civilian who took part in these efforts.

As proposed by General Damiyanovich, a military centre was quickly established in the area surrounding the ChNPP to ensure that military specialists—the military units in charge of decontamination, measurement, and any other operations that the army had to do—would not act randomly; by trial and error, but more consciously. This military centre was organized, and worked on selecting appropriate measuring equipment, the most appropriate conditions and routes, on developing technological methods for decontamination. The presence of such a military centre played a large positive role as it allowed the work to be done sufficiently quickly and with minimal [radiation] doses. Although, generally, the cumulative doses were doubtless quite high due to the enormous amount of work, and the enormous number of people involved. But nevertheless, they were minimized thanks to the actions of the military centre, that worked in collaboration with scientific organisations of the USSR Academy of Sciences, the Institute of Nuclear Energy and Kiev research organisations. So, this centre played a big role.

Not only were the decontamination tasks performed incredibly quickly, the construction of the new residential villages, where the evacuees were moved, was also incredibly quick. The construction of the village Green Cape was astonishingly swift where the 1st and 2nd block staff, who were forced to work in shifts, were accommodated. The work was done not only quickly, but they also sought to do it properly and, in my opinion, tastefully.

At this point, I want to say that, particularly in the initial period, considering the tragedy of the situation, considering such despair, I would say, considering the lack of technical means, lack of experience in handling such a large scale catastrophe, confusion and uncertainty could have easily arisen in decision making. But it was not so. Somehow, irrespective of rank, irrespective of the task at hand, everyone worked like a finely-tuned team, especially in the initial days. The scientific part of the team, who were responsible for the correctness of decisions, made these decisions without the support of Moscow, Kiev, or Leningrad. Support in the form of consultations, in the form of various experimental verifications, in the form of the immediate arrival of any specialists called in ... Whenever we came to some reasonable scientific decisions, the leadership of the Government Commission was able to, with the help of the Operative Group or one of its members, instantly obtain all the necessary materials that we needed in order to implement it in a fantastically short time, literally within days, and sometimes hours.

I remember that on-site at Chernobyl was the chairman of the Government Planning Committee of Ukraine, Vitaly Andreyevich, working as part of the Operative Group—a remarkably calm person, energetic; who would understand things perfectly even before we had finished talking. He always listened to our scientific discussions—what we would talk about, what we would need—and reacted instantly. We needed liquid nitrogen to cool down the block after we concluded that we were dealing with a cyst, he responded with a smile that the required trains had already been ordered. The same was true for all materials, say, magnesium oxide, containing carbon. He got them all from the metallurgical factories of Ukraine or somewhere else, and all of these materials were delivered. It is difficult to overestimate the work of the supply group, which was organised by the chairman of the of the Gossnab of Ukraine—working on behalf of Vitaliy Andreyevich Solov, the chairman of Gosplan of Ukraine—who, sitting in Kiev, worked miracles to ensure that all the work was carried out in Chernobyl with all the needed materials even though the amount needed was, of course, ridiculous.

Along with technology and scientific materials, the huge army of people brought to the zone had to be provided with food, water, clothes, and dressing areas; laundry and cleaning had to be provided; inspections... This colossal task was organized; even now it is hard to imagine how. Of course, all this reminded me of the the war—which I remember from my childhood, and from accounts told by soldiers—that the logistics were certainly as, if not more, important than the work of those at the front lines, who worked on the decontamination itself, on measurements, diagnostics and various other things. They were responsible for providing all needed materials, living provisions; they played a vital role.

Speaking of such impressions, of such observations, I cannot leave unsaid that on the very first day of my stay at Chernobyl, I was struck by two things. Due to the nature of their work, I'm used to treating people in the KGB (Committee of Government Safety) as people that safeguard state secrets, that organize people who are cleared to work in especially secret and important roles, who coordinate services that allow for the protection of all documents, technical documentation, and correspondence, which ensures that state secrets are kept safe. This is how I mainly knew the KGB. However, from stories and literature, I also knew that a part of this committee was engaged in intelligence and counterintelligence work.

In Chernobyl, I met highly organized, very precise young people who fulfilled the tasks assigned to them in the best possible manner, and these tasks were not easy. The initial organization of clear and reliable communication; this was done practically within a day. On all [communication] channels, they worked quietly, calmly and very confidently. And I even saw a team of young people, led by Fyodor Alekseevich Scherbakov, working. But all this was done remarkably clearly and quickly. In addition, they were also responsible for ensuring that the evacuation was carried out without panic, without any sense of panic, any excess that would hamper normal work. And they did it. But how they did it, how they made it happen, I still cannot imagine because I only know the result of their work. Indeed, there was nothing that impeded the organization of this unusual and difficult operation. And I was just delighted with the technical equipment and the culture of competence within this group.

The direct opposite to the work of this group was the work of, for example, the Civil Defence group in the composition in which they operated in the initial days. It simply shocked me. It seems that we all often learn, retrain; a lot of brochures are produced; a lot of time is spent on each erprise. But it means taking into our own hands issues that fall within the sphere of Civil Defence. General Ivanov, who initially commanded this unit, in my opinion, simply failed. They did not know what to do; and if they received direct instructions, they did not demonstrate any influence, management skills or ability to remedy the situation. And these weren’t just personal impressions. This is how many felt, so to say, in a subtle way, that the work of the Chekists, though not conspicuous, was positive, whereas the negative, helpless work by Civil Defense was noticeable in the early days of these events. I cannot leave that unmentioned.

During the first days of the Chernobyl tragedy, the flaws in our information services were very evident. Even though we have Atomenergoizdat—formerly called Atomizdat—medical publishing houses, the “Knowledge” society, it turned out that prepared literature that could quickly be distributed among the people to explain, for example, what doses are extremely dangerous for humans, how to behave when a person is inside a zone of increased radiation exposure, a system that could correctly advise on what to measure, how to measure, how to treat fruits and vegetables, the surface of which could be contaminated with beta, gamma, alpha radiation—all this literature was totally absent. There were many books for experts, thick and accurate, well-written; these were stored in the libraries. But it was precisely such brochures, leaflets—same as the Japanese ships with their products like watches, voice recorders, video recorders—that were needed in those conditions. Which button to press, how long to wait, what to do. Almost no such literature was available, in the entire country.

I have already mentioned that I had proposed from the beginning to create a press group under the Government Commission that would correctly inform the population about the events that were happening, that would give the right advice. For some reason, this was not accepted. After Ryzhkov and Ligachev arrived at the disaster zone, journalists were allowed in. And a large army [of journalists] appeared there. But, you know, it is hard to say even now; it is probably good that it was allowed but it is bad that it was not organized properly. Why? The journalists arrived, a variety of them, most of them very good journalists. For example, a team from Pravda and the famous head of the science section Gubarev, Odinets, many good Ukranian journalists and documentary filmmakers appeared there. But I saw for myself how they would grab the most famous people there, and interview them about some specific issue. Sometimes, they managed to ask the Chairman of the Government Commission, or one of the members of the Commission, about some particular, specific topic. They, of course, spent most of their time on-site. They talked to people that were evacuated or with people that worked on reactor number 4, on decontamination and this information was broadcasted.

What they collected, what was published, of course, is of tremendous importance from a historical and archival point of view as live documentary material. And this is necessary and essential. But at the same time, because the information was presented from a particular, specific point of view each time, the nation did not get a daily or maybe at least weekly, depending on the state of events, idea of what was going on. Because information came out in separate blocks. The miners are working heroically there but there is no information about the level of radioactivity they work in; what is happening in the Brest region nearby, who is measuring it, and how. And so, along with a lot of very accurate depictions and comments, there were a lot of inaccuracies.

For example, the press spent a lot of time on the so-called “needle” which was fiddled with for a long time. It was an integral device that had to be placed into the belly of the wrecked 4th block and would have provided continuous information about the temperature there, about radiation fields and some other parameters. But, in practice, the effort to put this needle in the right place from a helicopter was huge; and nearly no information was received from it. There was zero information; well, it only confirmed what had been obtained by other simpler and more reliable methods. So this episode of installing the needle was described very elaborately and very, so to say, extensively.

At the same time, the enormous amount of work done by the dosimetrists, the modest work of young people, say, from Kurchatov Institute led by Shekalov or Borov or Vasiliev, the work of “Ryanovskaya” [РЯновская] group led by Petrov, the work of Kombanov who was there many times to test his dust suppression solutions, the logic of all the work, an analysis of the projects that were undertaken—this wasn’t described properly. And mainly, the chronology of the events themselves was not presented. In this situation, many people overheard things here and there and this led to exaggerated rumours; naturally about the number of people affected by radiation sickness, about the levels of contamination in Kiev and the extent of the affected area. Any pause in the subsequent construction of the sarcophagus was frequently interpreted as some sort of catastrophe, as a collapse of some structure, as the appearance of new emissions, or as proof that the reactor is suddenly working again, etc. So, no proper systematic information was provided on these questions. And this, of course, gave rise to all sorts of wrong and sensational, sometimes maybe not sensational but still inaccurate, depictions.

For several months, the extent of the emissions from reactor number 4 was debated, even in the science community. The fact is that experts—those working directly at the station, experts from Hydrometeorology service—had precisely measured the fallout dynamics. The first, the most powerful emission was the one that threw millions of curies of radioactivity in the form of noble gases and iodine at high altitude. And this emission was registered by almost all the countries of the world. Subsequently, there were a few days of active emission of radioactive particles, fuel, mainly due to the graphite burning. Then the emission of these fuel particles ceased around the 2nd of May. Then the fuel began to heat up due to a bead there; and there was a release of already fission products such as Caesium and Strontium until the 20-22 of May when the contaminated areas were known. And starting from the 3-4 to 5th of May, there was a constant decrease in the total radioactivity emitted from Reactor Building 4.

However, because radioactivity had been thrown out earlier, a large number of vehicles were spreading it on their tires across various areas. Dust transfer because of a dry summer was also enlarging the contaminated areas. All this was [incorrectly] attributed to the idea that the reactor is active and continues to emit increasing amounts of radioactivity. This created, so to say, a stressful environment for those who were working there, who were doing the decontamination.

Until such time as something was being thrown out of reactor number 4, redundant projects kept appearing, like creating a sort of a skull cap over reactor number 4. I fought against this project from May; an absolutely useless project. Nevertheless, various organisations were doing such things, creating such projects for an external shell that, if installed, would only complicate subsequent work on the construction of the shelter, and would not have had any effect on the release of aerosol radiation. But this talk of the reactor “smouldering”, emitting radioactivity in considerable amounts, were so strong that orders were given to manufacture various types of covers for it. They were designed, tested, but the matter ended when one of the last such constructions immediately crashed down while it was being lifted by a helicopter for testing, and was completely destroyed. That put an end to this sort of thing. These projects were devised under the influence of rumours, inaccurate information, and attempts were made to implement them. God forbid, had any of them been implemented, they would only have complicated future work.

I remember how during the war there were two types of daily communications which were published in our newspapers or TASS reports: where we recaptured German-occupied points, where we retreated, where we took a large number of prisoners, where we suffered a partial defeat. This was precise official communication which provided an account of the joyous and bitter developments on the front lines. That was accurate TASS information but along with it were many journalistic articles about specific battles, about specific people, about heroes at the home front, etc. So, [in Chernobyl] our press reported a lot of information of the second type, about people, about their impressions, about what was happening there, but reported very little, unlike the TASS regular, about what has happened so far and what has changed. This, in my opinion, was a defect in the communication system, firstly. And secondly, there were too few statements by expert scientists.

I recall, perhaps, only one statement by Professor Ivanov from Moscow Engineering-Physics Institute. A large article was published where he tried to simply explain what these REMs are, milliroentgens, at which levels they pose a real threat to human health, at which level they don’t, how to behave in conditions with increased radiation levels. This, as far as I can remember, was the only article that had a helpful, calming effect on others. But the number of such articles could certainly have been increased.

It seems to me that they were overly modest and careful when writing about what happened at the station itself, why the accident occurred, whose fault it was, whether the reactor was defective or the actions of the staff were wrong. Of course, much has been written about this and I myself was involved in describing the events that preceded the accident. But, in reality, I think that the full picture of exactly what happened, and how, is not entirely clear to anyone. On the whole, this extraordinary situation—not a trivial situation, a tragic situation, a difficult situation of immense magnitude—has shown that it requires not only the mobilisation of considerable communication resources, but also a very creative and skilful use of these resources, to ensure that the population receives information in the needed sequence and quantity, who can refer to the information with complete confidence, and most importantly, be able to use this information for practical purposes; or to indicate when to worry, and conversely, when to stay calm so that it is quite regular and not sudden. Altogether, these were extremely important questions.

Sometimes, I even think that an event of this magnitude could have had a special television and newspaper section consisting of two parts. The Chernobyl part of this section would be exclusively official, to provide precise information from the Government Commission at the time when this section is released; and the second part should be an emotional part, narrative with personal opinions. This, altogether, is a serious question about how to, and to what extent, cover such large, very unpleasant and difficult events that affect and alarm almost the entire population of the country, and not merely our country.

Since I have touched upon communication a little, mentioned the reactor a bit, it may be time when I can express some personal opinions about how on earth I got involved with this story, how I was connected to it, how I understood the history and quality of the development of nuclear energy and how I understand it now. Rarely have any of us really spoken frankly and accurate about this.

I graduated from the Faculty of Physicochemical Engineering of the Moscow Institute of Chemistry and Technology named after Mendeleyev. This faculty trained specialists, mainly researchers, who were to work in the field of nuclear industry, that is, be able to separate isotopes, to work with radioactive substances, to extract uranium from the ore, bring it to the needed condition, make nuclear fuel from it, to process nuclear fuel that had been removed from the reactor having a strong radioactivity component, to extract useful products from it as well as the dangerous and hazardous parts, to be able to compact them, bury them so that they would not harm humans, and use parts of radioactive resources for the national economy, medicine maybe. This is the group of specific subjects I trained on.

Then, I graduated from the Kurchatov Institute in the field of nuclear fuel reprocessing. Academician Kikoev tried to convince me to stay in postgraduate studies because he liked my graduate thesis. But my comrades and I agreed to work for a while at one of the nuclear plants to get some practical skills in the field that would later become the subject of our research. I was sort of the proponent of this idea and so I couldn’t accept the offer of postgraduate studies and left for Tomsk. I got into one of our closed cities where I participated in launching one of the radiochemical plants. That was very interesting. The exciting time when a young man begins practice. I worked at this plant for about two years. And then I was pulled out with the permission of the party (I was already a communist since my time at the institute) for my postgraduate studies at the same Kurchatov Institute.

With the encouragement of my friend and comrade Vladimir Dmitrievich Klimov, who worked there, I passed the candidate exams at the Tomsk Polytechnic Institute and left after passing the exams to work on my candidate thesis. My first candidate thesis was proposed to me, to tackle the problem of such a gas phase reactor that would contain gaseous uranium hexachloride as fuel and such problems, namely the problem of interaction at high temperatures of uranium hexachloride with construction materials. These were the problems that I was researching. After obtaining a lot of data, I wrote a large report that could have been the basis for my dissertation, or maybe it already was a complete dissertation.

But at this time, my comrade postgraduate Viktor Konstantinovich Popov informed me that in Canada, Professor Bartlett had done excellent, staggering chemist’s work on obtaining a true xenon compound, one of the noble gases. This information captured my imagination and I devoted all my subsequent professional work to synthesising such unusual compounds, using various physical methods, that would be powerful oxidizing agents, have a number of unusual properties which I was happy to work on, and on the basis on which it was possible to build a whole range of technological processes.

And this is how my professional work was progressing, which gave the ability to successively defend the candidate thesis, the doctoral thesis, dissertations. Later, with the development of these works, they were evaluated to elect me into the Academy of Sciences. The research part of the work was awarded the USSR State prize. The applied part was awarded the Lenin prize. So, this was my own professional work to which I managed to attract most interesting young people who with style, with good education and understanding, are still developing this extremely interesting area of Chemical physics—from which I’m sure will originate very many developments, important for practice and for education.

tape 2, side b

Successful work in this area attracted the attention of the director of the institute, and he moved me closer to himself, that is made a deputy director of the institute. The scientific responsibilities were limited to my own scientific work. As for the distribution of responsibilities that we had in the directorate, and still have, I was assigned the following tasks related to chemical physics, radiochemical physics, and the use of nuclear and plasma sources for technological purposes. This was the range of professional tasks that I was carrying out.

After Anatoly Petrovich Alexandrov was elected president of the USSR Academy of Sciences, he made me the first deputy director of the institute, entrusted me with several responsibilities regarding the management of the institute, but did not change my responsibilities in the scientific sphere. There were no new areas that I was responsible for.

As before, Eugeny Pavlovich Velikhov was fully responsible for the largest part of the institute’s work: plasma physics and controlled thermonuclear fusion. Vyacheslav Dmitrievich Pismienniy was made responsible for laser technology. Lev Petrovich Feoktistov, a very intelligent and talented man, was given the responsibility of matters of nuclear physics and its special practical applications. Anatoly Petrovich had a deputy for nuclear energy earlier, Eugeny Petrovich Ryazantsev. Before him, Viktor Alekseyevich Sidorenko worked as the director of the department of nuclear reactors. Now, Ponomaryov-Stepnoi became the first deputy director of nuclear energy who dealt with reactor construction.

I, of course, moved around in this circle, choosing my task. I was thinking about what should be the percentage of nuclear energy, and why it should be present in the Soviet energy sector. I was able to organize systematic studies related to the types of stations that should be built, their intended purpose, how they should be used wisely, whether they should only produce electricity or other energy sources [as well], in particular, hydrogen. Hydrogen energy became an area of my close attention.

All these were some unusual questions that complemented nuclear energy. Since Anatoly Pavlovich was himself a reactor man, creator or participant in the creation of many reactors, he needed me not as a reactor scientist, but as someone who, from the outside, could give unusual advice, find unconventional solutions. But all these solutions and advice did not concern the design of the reactors, which I never worked on. They concerned possible areas of use of those components that are in a nuclear reactor.

Because the questions of safety in nuclear energy are the most acute in various spheres of international public opinion, I was interested in comparing the real dangers, the real threats that nuclear energy carries to the threats of other energy systems. This is what I was passionately working on, mainly figuring out the dangers in sources of energy alternative to nuclear energy.

This, broadly, is the range of issues that I worked on professionally. Well, actively aid Anatoly Petrovich in the management of the institute, considering his occupation at the Academy of Sciences—planning the work of the institute, the regime of its work. I tried to establish such things that would bring the institute together, like the Kurchatov General Council, the institute’s general seminar, and setting up various publications that would, on order, sit on the desks of researchers so that they could quickly get all the news from their field. I tried to organize opportunities for comparing different points of view, different approaches to general problems of physics and energy. This I did with quite a lot of enthusiasm.

As for the physics and technology of reactors, it was a forbidden area for me—both because of my own education and because of the taboo imposed by Anatoly Pavlovich Aleksandrov and his subordinates working in this area. They really did not like interference in their professional work by outsiders. I remember how once Lev Petrovich Feoktistov, who had just started working at our institute, attempted to conceptually analyze questions about a more reliable reactor, a more interesting reactor, that would eliminate—this problem was worrying then—the production of such fissile materials that could be removed from the reactor and used in nuclear weapons. But his proposals were met with hostility; as well as the proposals about a new safer reactor from Viktor Vladimirovich Orlov who had come to the institute. They were somehow not considered by the existing reactor community.

Since I didn’t have administrative authority over this department but generally understood many specific details of what was going on, and because I was concerned, I began to suggest to the reactor department an engineering, not physical, approach to solving problems. But, naturally, I couldn’t considerably change this situation. And Anatoly Petrovich had such a humanly understandable and even likeable trait, namely, reliance on people with whom he has worked for many years. He trusted certain people who worked on, say, naval equipment, station machinery or specialized devices; and really didn’t like the appearance of new faces who could somehow bother him or make him doubt the decisions made earlier. This roughly is how things were.

In the scientific sphere, I chose a fascinating field for myself which I have already mentioned—chemical physics related to creating unusual substances, creating systems that would allow obtaining hydrogen in one way or another, linking places where hydrogen is obtained to nuclear energy generation sites. I passionately worked in this area with the involvement of external organisations. It had a very small share in the institute, both from a monetary and human resources perspective. The people there were active and interesting; many proposed a lot of unique solutions that triggered discussions. This created an impression that a lot of attention was being paid to it, but in reality, these were the activities of new people arriving into a new industry. But resources in the form of buildings, staff, funding allocated to this field were certainly not comparable to the money that went to…


I was a member of the Science and Technology Council of the Ministry of Medium Machine Building of the USSR, but I was not a member of the reactor unit of this council. So I did not know many details or specific discussions. The Science and Technology Council of the institute frequently held discussions about the conceptual issues in the development of nuclear energy, but very rarely were technical aspects talked about such as the quality of the reactors, the quality of fuel, the problems that were there. These matters were discussed either in reactor units of the Ministry or in the science and technology councils of the respective departments.

Nevertheless, the information I had convinced me that not everything was well in the development of nuclear energy, as it seemed to me. Because it was clear that our devices fundamentally weren’t very different from the western ones, say, in their concept; even surpassing them in some aspects. But they were painfully lacking in good control systems and extremely poor in diagnostic systems.

For example, the fact that I learnt that Ramsomson, an American, had analyzed the safety of nuclear power plants. He consistently looked for possible sources of issues that would lead to accidents, systematized them, and made probabilistic evaluations of events, estimates of the likelihood of an event leading to a release of radioactivity. We discovered this from foreign sources. I have not seen a single group in the Soviet Union that raised and considered these issues with any degree of competence.

The most active advocate of nuclear energy safety in our country was Viktor Alekseyevich Sidorenko. But I felt that his approach to the questions of safety was serious. Because he was truly familiar with how stations operated, with the quality of the manufactured equipment, with the problems that sometimes occurred at nuclear stations. However, his effort was mainly directed towards managing these situations: firstly, by organisational means; secondly, by a system for improving the documentation that must be at stations and with the designer; thirdly, he was quite concerned about creating supervisory bodies that would control the situation. All these he called organisational measures.

He and his associates showed great concern about the quality of the equipment that was supplied to the station. Recently, all of us became concerned about the quality of training and readiness of the personnel who design, build and operate nuclear power stations, because the number of facilities had sharply increased, but the quality of the personnel involved in this process had likely decreased and was decreasing before our eyes.

On these matters, I would say, Viktor Aleksandrovich Sidorenko was the leader of the people who were concerned. He didn’t get proper support in our ministry; every document, every step was painfully difficult. This is psychologically understandable because the institution in which we all worked was built on principles of the highest qualifications of people who were executing any operation with the highest responsibility. And, indeed, in the hands of qualified people that did their job well, our devices seemed both reliable and safe to operate. In this circle, concern about additional measures to increase the safety of the nuclear stations seemed a far-fetched issue, because the environment consisted of highly qualified people who were used to being relied on, and were convinced that safety issues are solved solely by skills and by precisely instructing the personnel that led the process.

Military acceptance was also extensive in our industry, so the quality of the equipment was high grade . All this had a reassuring effect. And even scientific work aimed at solving the most important issues of further improvement of stations, both in terms of safety and efficiency did not enjoy support.

More and more resources were spent on creating facilities that were not directly related to nuclear energy. Capacities were created for the production of players capacities for metallurgy and extractive metallurgy facilities. A large number of construction resources was spent on creating objects that were not related to the field of the department. Science organisations began to weaken, not strengthen. Slowly, once the most powerful in the country, they began to lose the standard of modern equipment. The staff began to age. Fewer young people joined. New approaches were not welcomed. Gradually, imperceptibly, but it was happening. The habitual rhythm of work persisted and the usual approach to solving problems prevailed.

I witnessed all this, but it was hard for me to intervene in the process purely professionally while general declarations on this subject were received with hostility. Because an attempt by a non-professional to bring some kind of insight into their work could hardly be acceptable.

All the time, new buildings, new stands and new people were required to do the work, because the number of devices was growing. But the growth was not qualitative but quantitative. Moreover, the new specialists reflected the standard of the design organisations in their qualifications. They often practised there. And a good reactor specialist was one who had mastered the design of a particular reactor, who could ably calculate, say, the zone, who knew all the accidents that happen at a station, who could come to any facility and assist in its physical and organisatorial launch, quickly figure out what was happening there, and report to the management of the institute or the Ministry.

And so a generation of engineers came up who were very competent, but not critical of the devices themselves, not critical of all the systems that were ensuring their safety; but mainly knew the systems and required an increase in their numbers. This situation was not normal for a science centre.

At the same time, numerous conversations on how to strengthen design organisations with such-and-such specialists and such-and-such approaches were heard at the Institute for a decade and a half, at professional or party levels. But in practice, the design organisations have not strengthened, except for one, but have remained at the same habitual level of carrying out their originally-assigned duties.

So the picture was like this: that everything is safe, and all that is needed is just increasing the number of known stands, increasing the number of people working using a known algorithm, and all would be fine.

The worm of doubt gnawed at me because, in my professional area, I felt that I should always do things differently. You must always do something new, and be very critical to what was done before you. Try to move aside and do something different than what was done before you. Risks could be taken in this work, and I did risk a lot. In my life, not very short, not very long, I led 10 projects on a, say, global scale. And I have to say that five of them had failed. I cost the government around 25 million roubles in these failed projects. These projects failed not because they were basically wrong. They were engaging and interesting. But it turned out that the materials needed were not there, or the material scientists didn’t want to, or could not, make them. Then, no organisation would take on the development of an unconventional compressor or an unconventional, say, heat exchanger, again driven by the lack of needed material or experience. As a result, essentially sound projects, when developed, turned out to be overly expensive, cumbersome, and not accepted for execution. This is how five out of ten projects became a failure.

Two of these ten projects, I am afraid, will have the same fate, and for roughly the same reasons. But three projects became very successful, where we found good partners, and where we put in the maximum effort, using the highest levels of the government, using the authority of Anatoly Pavlovich and the Central Committee of the party. As a result, one project alone, of the three successful projects that cost us 17 million roubles, began to generate an annual income of 114 million roubles.For four years now, the corresponding industry and technology have been working. To date, it has generated more than half a billion roubles of income for the Government, which more than covers that cost of 25 million roubles for the projects that failed. But the degree of risk in my own projects was quite high. Well, either 30, 50 or 70 per cent of risk is certainly high. But it also had an impressive impact once the work was complete.

In the field of reactors, my attention was drawn to the high-temperature-helium-cooled reactor, molten salt reactor, because I had not seen anything similar. It seemed new to me, although not entirely new because both of them had already been tried by the Americans. The gas-cooled reactors had been tried out by the Germans. These reactors had shown their considerable superiorities, in terms of efficiency, potential water consumption for cooling the reactor, and the range of uses of such reactors in technological processes. So they seemed novel to me, and, by the way, these reactors also seemed safer than the traditional ones. That is why I provided some sort of patronage for these areas, well, whatever I could provide within the bounds of the Institute’s authority. More than that, as part of professional work, I took some part in these areas. But traditional reactor engineering somehow did not interest me much, and it was not assigned to me, and it seemed rather boring.

Of course, I could not imagine at that time the level of danger, the scale of danger that was inherent in those old devices. But there was a nagging sense of anxiety. However, there were such giants, behemoths, experienced people that I thought they would not allow for something unpleasant. And since the literature, the most precise, was western, comparing western devices to our own, this allowed me to conclude in various books and articles that although there are many problems relating to the safety of existing devices, nevertheless, they are still less than the dangers of traditional energy; with its many carcinogenic substances released into the atmosphere, with radioactivity released into the atmosphere from coal seams. And I focussed on this.

I was certainly irritated by the situation that had developed between the Ministry and the science leadership. It was wrong. From talks, from documents, I knew that the original position was this. Our Institute was not part of the Ministry of Medium Machine Building. It stood beside it, as a separate independent organisation, and had the right to dictate its scientific requirements and positions. And the Ministry, after evaluating the scientific proposals, was technically obliged to execute them precisely. This was the partnership. Scientific proposals not being limited by the influence of those in power, and full opportunity for the execution of such proposals that the Ministry liked from an engineering point of view, was [the] correct [way of operating].

But then, history came to such a state where science became subordinate to the Ministry. The ministerial cadres grew up and acquired their own extensive engineering experience. It seemed to them that they already understood everything in the scientific arena. And so, the scientific spirit and the scientific atmosphere in reactor engineering gradually began to submit to the engineering will, as it were, to the ministerial will. I saw this; it bothered me. And it complicated my relationship with the Ministry when I tried to, not very carefully, speak out on this issue. And I could not win in these matters because, to the reactor people from the Ministry, I was a chemist, and this allowed them to not listen to my opinions carefully and to treat my suggestions as sort of fantasies. This was the general environment in which all this work was happening.

As for the RBMK reactor, you know, in reactor circles, it was considered a bad reactor. Viktor Alekseyevich Sidorenko had repeatedly criticised it. But this reactor was not considered bad because of safety reasons. From a safety point of view, it even stood out as being better, as I understood from the discussions. It was considered bad because of economic reasons. First, for higher fuel consumption; for higher capital costs; and for a non-industrial basis of its construction. Also worrying was the fact that it was an isolated Soviet line of development. Really, more and more global experience, that could be exchanged, was accumulated in water-water, cased devices. Operating experience, technical solutions that had been used, software, all these could be exchanged and adapted. But for RBMK reactors, all the experience was domestic. And if we took the accumulated statistics, then the statistics on the operation of RBMK reactors were minimal compared to the VVER. devices. This was just as worrying.

I, as a chemist, was worried about the huge potential for chemical reactions in these devices. There is a lot of graphite, a lot of zirconium and water. And under some anomalous conditions… In normal conditions, of course, the graphite comes into contact only with inert material which was ensured by appropriate technical solutions. A temperature at which a vapour-zirconium reaction could begin, accompanied by the generation of hydrogen was, in principle, unacceptable, be it routine work or technical conditions. Nevertheless, the potential reserve of chemical energy in a device of this type was maximal relative to, say, another comparable device. This too was a point of concern.

When I looked at this device, I was confused by, for example, an unusual and, in my opinion, insufficient construction of safety systems, that would work in extreme situations. Because the safety of the device in case of some abnormal behaviour… For example, a positive reactivity coefficient in this device, should it start to develop, become noticeable, then the operator, and only the operator, could lower the emergency rods. Or they could be lowered automatically after one of the sensors sent a command; there were several such safety systems. Or manually, using the special AZ-5 button to reset the emergency rods. This device did not have any mechanical rods (mechanical, well, it could work well or it could work badly) or other safety systems that would be independent of the operator, and would work solely based on the state of the zone. This created an uncomfortable situation. But still, some practical experience had already been accumulated. Specialists exhibited confidence in these aspects.

The speed of introducing safety systems was, as it seemed, insufficient. I heard often that specialists, Kramerov Aleksander Yakovlevich in particular, while discussing these problems with Anatoly Petrovich Aleksandrov, made proposals to the [reactor] designer to change the accident protection system (APS), to improve the APS of this device, and they were not rejected. But they [the safety systems] were developed very slowly. Moreover, by that time, the relationship between the science director and the chief designer became, well, quite tense.

For all new projects and new ideas, this design organisation fully recognized the authority of the Institute of Nuclear Energy, and readily consulted with it and maintained contact. But with regards to this particular device [RBMK], they considered themselves absolute creators and owners. They did not violate the formal order in which the scientific leadership was under the Institute of Nuclear Energy. In fact, this leadership was, to a large extent, nominal in nature. It was used for such cases when, say, key decisions were taken like whether to make the RBMK 1500, or whether to introduce a heat exchange intensifier to this reactor. For example, when there was a need to propose that the share of RBMK devices in nuclear energy be increased, then Anatoly Petrovich Aleksandrov’s support was required on this issue. These questions were discussed with the director. But in questions of specific technical policy or improvements to this device, the designer was unwilling to accept the Institutes’s point of view, not considering it to be a sufficiently-developed partner for it to be useful to the designer in his work.

In this context, I want to state an opinion, of which I am fully convinced, but which, unfortunately, is not shared by my colleagues, and leads to friction between us, sometimes quite dramatically. The thing is that, as far as I know, and it is logical, there is no concept of a science supervisor or chief designer in the developed industries in the West and the Soviet Union. I understand this myself; scientific stewardship is a problem.

For example, a scientific supervisor for aviation. Although it likely doesn’t exist, I could imagine it. It would be an organisation that would be responsible for the developmental strategy of aviation. How many small aircraft, how many large ones; whether to prioritise comfort when boarding or deboarding passengers, or the speed of travel between two points; whether to give preference to [the development of] hypersonic aircraft or supersonic ones; is ensuring comfortable and reliable operation of ground crew more important for safety, or the work of personnel onboard the aircraft; what should be the percentage of various types of aircraft. This kind of scientific management of aviation seems right to me.

But when it comes to the design of a [particular] aircraft, it must have a single owner. He must be the designer, the engineer and the science supervisor. All the power and all the responsibility must be in the same hands. I see this as an obvious fact.

At the time of the birth of nuclear energy, everything was sensible, because it was a completely new field of science - nuclear physics, neutron physics. The concept of science leadership came down to a system where the basic principles of constructing a device were given to the designer, and the science supervisor was responsible for those principles to be physically correct and safe. But it was the designer who implemented these principles, in constant, daily consultation with the physicists on whether any physical laws of the device were being violated.

All this was justified at the dawn of the nuclear industry. But as the design organisations have grown, when they have set up their own physics departments and calculation departments, then this system of dual ownership of the same device has come about—there is a science supervisor and a designer. In fact, there is triple ownership, because there is also a head office, or some deputy minister, who has the last word on a particular technical decision. Numerous councils, interdepartmental or departmental, created an overall atmosphere of joint responsibility for the quality of the device. This situation continues today. It, in my opinion, is wrong. I am still convinced that the science supervisor, the organisation of science supervisor which scrutinises projects and selects the best one, thereby defining the development strategy of nuclear energy... This is the function of the science supervisor, not creating a particular device with given properties. All this confusion has led to a great deal of irresponsibility which was exposed by the Chernobyl experience.

One way or another, the system of multiple owners... The system of a singular person being personally responsible for the quality of the device—with all the facilities it was installed in—was absent. And this caused appropriate alarm among professionals, in technical and engineering sense. Obviously, it was difficult for me to judge the merits and demerits of this or that device. However, the thing that I was able to achieve was to create an expert group that would perform an expert comparison between different types of devices, in terms of their economy, universality and safety.

The first two such consecutive works by experts were interesting. The idea of creating such an expert group and doing this work was mine. I helped organise this activity, and the actual work was done by Aleksander Sergeyevich Kachanov’s laboratory created specifically for this purpose. He, in my opinion, organised the work perfectly. Because his laboratory was a kind of cell that posed questions and formulated them physically; while the answers to these questions were given by specialists, not only from the various departments of the Institute but also from different institutes. As a result, a basis emerged that could be discussed widely, critiqued and supplemented. But this work was unfortunately suspended at the very beginning, initially because of a serious illness of Aleksander Sergeyevich Kachanov and an inability to find an equivalent replacement, and then because of the subsequent Chernobyl events.

The 26th of April 1986 caught the Institute of Nuclear Energy in a rather odd position. With the approval of the director of the Institute, with his full support, the first deputy was working on organising system-wide research on the structure of nuclear energy, an activity that was of little interest to the Ministry and was happening solely because of the support from Anatoly Petrovich Aleksandrov. The Institute did acquire a taste of it. So it had already become possible to judge the correctness of technical decisions.

At the same time, I managed to set up a laboratory for safety measures that evaluated the various dangers of nuclear energy compared to other types of energy. For the first time, there were specialists that took …


… soon it was necessary to literally fight for the correct implementation of every technological mode. This is when Aleksander Petrovich and Vyacheslav Pavlovich Volkov, director of the Kola and then the Zaporozhye nuclear power stations, recently told me about an episode, where a group of his comrades visited the Kola station, and witnessed, in his opinion, a complete disorder in the organisation of the technical process. What examples did he give? Say, a duty officer starts their shift. He would fill out all the measurement journals beforehand, all the parameters, even before the end of the shift. And then stared at the ceiling til the end of his shift, doing practically nothing. Maybe only the chief engineer of reactor control sometimes left his chair to carry out some operations. But apart from that, it was still and silent. No careful monitoring of the instrument, no attention to the condition of the equipment between planned preventive maintenance.

So his comrade, having arrived to get familiar with the work of this [Chernobyl] station, reported that everything was wrong there. The director of the station, Briukhanov said when Volkov called him, ‘What are you worried about? Yes, a nuclear reactor is like a samovar; much simpler than a heat station. And we have experienced personnel. Nothing will ever happen.’ Well, he [Volkov] was very wary. As he told me later, he called Veretennikov in the Ministry of Energy about this, then Shasharin, got as far as Neporozhniy, and then reported it to comrade Maryin at the Central Party Committee. But he was told, ‘Don’t stick your nose in the wrong place.’ Only Neporozhniy said, ‘I’ll go take a look”. He went, had a look, and said that everything was in order and that the information was wrong. And this was not long before the Chernobyl disaster.

I think that we should look at the work in other industries [as well]. I had to visit various chemical facilities. I was particularly horrified by a phosphorous processing plant in the Chemkent region. This phosphorous plant was something frightful, both from the perspective of the quality of technologic and the saturation with diagnostic devices. Terrible working conditions. Many supervisors that should have been on the staff were just absent. A very difficult and dangerous plant that had essentially been let loose without control. It was scary to see such a situation.

That’s why I understood the words of our Chairman of the Council of Ministers in a larger context, that it is not a feature of the development of nuclear energy that has come to this state, but a feature of the development of the national economy that has led to this. It didn’t take long for a confirmation of the correctness of my understanding of these words. In a few months, the Nahimov collision happened, such a severe disaster with the same carelessness and irresponsibility; then a methane explosion at a coal mine in Ukraine; a train collision in Ukraine—all these within a short time. All of this reflected a certain general serious technological inefficiency and indiscipline in almost all crucial areas of our work.

And now, the situation is indeed like in the Lev Nikolayevich Tolstoy’s story—“There are no guilty in the world.” When one looks at the chain of events, why someone acted in this way and another in that way and so on, it is impossible to point to a single culprit, an initiator of all the unpleasant events that led to the crime. Because it is a chain that links to itself. The operators made mistakes because they had to complete the experiment which they considered a matter of honour. This is what led them, and directed their actions. The plan for the experiment was drawn up very poorly, very imprecisely, and not authorised by the specialists by whom it should have been authorised. In my safe is a record of telephone conversations between the operators on the eve of the accident. Reading these records makes your hair stand on ends. One operator calls another and asks, “Valera, here in the program, it’s written what needs to be done, but then a lot of it is crossed out. What should I do?” And the second one answers, “You do what is crossed out.” Can you imagine? This is the level of document preparation for a facility as serious as a nuclear station. When someone crossed out something, the operator could interpret it as right or wrong and could perform arbitrary actions.

But again, it would be wrong to place all the blame on the operator, because someone made the plan, someone scribbled on it, someone signed it, and someone did not coordinate it. And the very fact that the station could independently perform any actions not authorised by the experts is already a defect in the relationship of the experts with this station. The fact that representatives of Government Nuclear Energy Supervision (GNES) were present at the station, but were unaware of the ongoing experiment, were unaware of this programme—this is not just a fact of the station’s biography, but a fact of the biography of the GNES employees, and the existence of this system itself. These are all the thoughts that come to mind in connection with the Chernobyl accident.

But let’s get back to the Chernobyl events, from which I have deviated so far. As far as I remember, I stopped the story at how I was struck by the precise work of our chekist [the KGB], who without any fuss, with very few people, did a lot of work to establish communications and bring order in the zone of the accident. Similar [good] words can be said to theMinistry of Internal Affairs of Soviet Union, and Ukraine as well, because the evacuation process, the rapid cordoning off of the zone, and quick establishment of regime and order, as much as possible—they did that very well. Although it must be said, there were separate cases of looting or intrusions into the zone with the aim of stealing. But the number of such attempts was small, and they were quickly suppressed.

The air force, the helicopter groups, worked very precisely. This was simply an example of superior organisation and ignoring any danger, working very carefully and accurately. All the crews always tried to do the assignments, no matter how difficult or complex the task was. The first days were especially difficult. An order was issued to prepare the sandbags. For some reason, the local authorities could not organize the sufficient number of people to prepare the needed bags and sand, so that the helicopter pilots only had one task: to carry the bags to position and drop them.

tape 3, side a

With my own eyes, I saw how the crew commanders, officers loaded the sandbags, attached them to the helicopters, flew to the target, dropped them, returned and did it all over again. So, on the 27th and 28th of April, neither the Ministry of Energy nor the local authorities could fully and precisely organize the work to supply materials that had to be dropped into the crater of the reactor. Around the 29th, a system for this was put in place. Quarries were prepared, the lead started to come in. People were assigned stations and then things went more smoothly.

Around this time, the helicopter people found a very effective way of operating by setting up an observation post on the roof of the Pripyat party committee building. From there, they monitored the crews that were above reactor number 4. I must say that this work was not safe because the pilot had to hover above the reactor, drop a considerably large load, and then leave quickly so as to not get an excessive dose of radiation and most importantly, drop exactly on target.

All this was well-coordinated, and if memory serves me correctly, then the numbers were as follows: tens of tonnes were dropped on the first day, then hundreds on the second and third day. And eventually, Major Antoshkin reported to us in the Government Commission’s evening meeting that on that day, they had dropped 1100 tonnes of materials. All in all, this quick and diligent work of the people that were delivering the materials resulted in the reactor being plugged around the 2nd of May. From that day on, the generation of radionuclides (of any considerable amount) from the crater reduced. Simultaneously, the military continued to do all the necessary recon operations.

The work of the Government Commission (GC) during the first days was as follows. Early in the morning, Boris Eudokimovich Scherbina would gather the members of the GC. All people responsible for the various operations would be invited. The meeting usually began with General Pekalov’s report presenting the radiation conditions within the station and the surrounding areas. Of course, the conditions were worsening every day. The already-scouted areas were showing higher radiation levels, and the number of such areas was increasing. The number was increasing because the scouts were visiting more and more new areas, while the old areas were receiving more and more radionuclide fallout. Overall, the situation was getting so complicated that it became clear that the scale of the operation had to be increased.

The first decontamination efforts began even while the conglomeration processes inside reactor number 4 were ongoing. But what did they boil down to? I remember that the future Minister of Medium Machine Building, comrade Ryabev, who had replaced Meshkov in the GC, himself led the group (after receiving the recipe for preparing the solutions that could solidify and create polymeric films on the surface). He organized a team in one of the industrial areas of Pripyat that would prepare these solutions. They then themselves went to the most contaminated areas and covered them with these solutions. At the same time, the group that I had called, led by comrade Schupak Aleksander Fyodorovich from our institute, was researching ways to inject these components into the soil in order to absorb the most mobile radionuclides, Caesium being one of them.

Then the phosphate solutions appeared. A group of scientists from Novosibirsk telegraphed me that it was necessary to use more tuff and Сelite. So we organized a supply of these materials from our Armenian and Transcarpathian deposits and shipped them in by trains. Using such Celite-containing materials was very beneficial: both when put into the soil for holding radionuclides, and also when mixed into the bodies of dams that were being built on small and large rivers.

I must say that, of course, there were many senseless things done in the course of this work. Not every work progress was documented, whether it had been completed or not. The commands were issued; however, the checks on how precisely they had been fulfilled were at times delayed. For example, when I visited the site after some time, I found out that the sorbents had been simply poured around the storm sewer when it would have been better to make a sort of pallet that could be quickly replaced after the sorbents became saturated with radionuclides. Lev Alekseyevich Voronin, who was in charge of the GC at that time, quickly understood me. He told me that he had issued appropriate orders, but I think those never got executed.

In addition, the intermittent changes in the composition of the GC led to a constantly changing plan of work. One GC would order a train of certain materials, then after the switch, the new one would order another train with different materials. Because of this many loaded train cars accumulated on transport routes.

Logistical issues started to arise and a separation register was made. According to that register, all the materials that had been tested would be handed over to the Army to use in decontamination tasks. On the other hand, the materials that needed testing were sent to the departments of the Ministry of Medium Machine Building. They were required to test the materials and create a report, and only after that they could be given to the Army to use on a large scale.

A lot of materials were used, our own Soviet were offered. But in the end, it all came down to the fact that the most effective measure was dust suppression, which in most contaminated areas meant just plain mechanical removal of the most contaminated debris. This mechanical removal was also done by robots that were acquired from, for example, the German Federal Republic. However, the use of robots was not successful because all the robots that were tested initially were either mechanically unable to operate among the wreckage, or they simply could not overcome the obstacles on large irregular surfaces. When on an even surface but inside strong radiation fields, their electronics, usually the control modules, failed making them inoperable. That’s why in the end, the most reliable method was to use radio-controlled bulldozers or just simple scraper bulldozers, our ordinary vehicles, cabins of which were reliably covered with lead to protect the driver. During the first stages, this was the most effective way where by using ordinary vehicles but with proper crew protection, it became possible to collect and dispose of the most contaminated debris, the most dangerous contaminations.

The next operation was applying a special layer to the already-cleared ground and concreting it. This operation was carried out. Powerful vacuum cleaners were used before the concreting; they cleaned up a lot of contaminated dust. Concreting, removing various лакусов [sic], which sometimes appeared to be unsuccessful. Then came the chemical solutions. The most interesting ones were those proposed by academy member Viktor Aleksandrovich Kabanov, preliminarily tested in the dust storm-prone regions of Central Asia. These solutions were meant to bond the dust particles together, but at the same time let moisture through, thus allowing the subsoil to exist normally. All the solutions that we tested appeared to be successful. V.A.Kabanov, with the help of the heads of the Ministry of Chemical Industry managed to organize production in Dzerzhinsk that was sufficient for our needs. These solutions were used extensively.

The most trivial cleaning methods also had a big effect: regular cleaning of roads, setting up points for decontamination of vehicles and people - all this became more and more organized and sophisticated as time passed.

Earlier I had started to talk about how the work in the Government Commission (GC) was organized. The work would start very early; at around seven or eight in the morning, the first meeting would be held. It was led by the chairman. Dosimetric conditions in the various parts of the district would be reported. Assignments would be issued, and the completed ones checked. After this, all the specialists would begin work on their assigned tasks; and in the late evening—at least when Scherbina was the chairman, around 10 in the evening—a summary was reported. Radiation conditions were evaluated, work status of dam construction, well construction, about acquiring appropriate equipment and vehicles, about the construction of the sarcophagus...all this information was heard, and operational decisions were made immediately. Regularly, several times a day, the leaders of the GC spoke to comrades Dolgikh Vladimir Ivanovich, Rizhkov Nikolai Ivanovich. All this was mandatory every day.

After Rizhkov and Ligachev arrived on the site, as I have already said but I will repeat myself, the original GC left. It was announced that it would be the permanent commision, and it would be replaced by a stand-in. However, Sidorenko and I stayed behind to finish the decontamination work while Sidorenko continued to investigate the role of Gosatomenergonadzor (USSR State Committee on Supervision of Safe Conduct of Work in Atomic Energy) in what had happened and what was going on now.

Late at night on the 4th of May, when the GC was already being led by Ivan Stepanovich Silaev—a very calm man, who was doing his work very seriously—I was called in by his order. It appeared that I had been summoned to Moscow to take part in the Politburo meeting that would take place on the 5th of May. I took the first available flight.

After I arrived at the institute, they met me, washed me, cleaned me as much as it was possible. Then I dropped by home, met my wife, who was of course very upset, and by 10 a.m. arrived at the Politburo, where in turns, I reported to Scherbina and comrade Ryzhkov about what was happening. The chairman of the Politburo, M.S.Gorbachev immediately warned me that, at that moment, he was not interested in the culpability and causality of the accident. He was interested in the current status of work, and the measures required from the government to resolve the situation faster.

At the end of the Politburo meeting, Mikhail Sergeyevich [Gorbachev] addressed heaven knows who, but apparently the ministers Brezhnev and Chazov who were at the meeting, asking them to return to the site and continue the work. After the meeting, I went to the office of B.E.Scherbina and asked whether this request was also addressed to me, or should I stay here in Moscow with the other GC to continue my current work? He replied: “Yes, you will stay here and continue your work”. So I went to the institute;but before I reached, my car phone rang and one of Scherbina’s subordinates told me that as per a request by Silaev to the General Secretary, I needed to go back to Chernobyl because Velikhov’s unilateral actions were, for some reason, worrying Ivan Stepanovich. So on the same day at 4 p.m., I flew out of Chkalovsk and once again arrived at Chernobyl where I continued my work.

The work went on as had been planned before, that is in three aspects: one, monitoring the state of reactor number 4, because the material drops had ended. Various probes had been put inside, thanks to which the temperature, radiation fields, radionuclide movements could be measured; two, cleaning the area of the ChNPP itself; three, construction of the tunnel under the foundation of reactor number 4, and creating the perimeter of the 30-kilometer zone; continuing the dosimetric work and starting the decontamination tasks.

At this time, both the Army and the regional organisations allocated builders for the construction of villages in which the evacuees could live. This was an enormous task that required moving masses of people, creating the necessary control systems and quickly planning the logistics and work.

Sometime around the 9th of May, it seemed to us that reactor number 4 had stopped living, breathing, burning. It was calm on the outside, and we wanted to solemnly celebrate our Victory Day late in the evening on the 9th. But unfortunately on that day, a small but very bright crimson spot was discovered inside reactor number 4. This was evidence that the temperatures were still high there. It was difficult to determine if they were the parachutes burning that had been used to drop the lead and other materials. In my opinion, it was unlikely. Most likely, it was a hot mass — as I understood it later — a mass of sand, clay and all the other things that had been dropped. We were of course upset. The 9th of May celebrations were ruined and we decided to drop another 80 tons of lead inside the crater. After that, the glowing stopped and the 9th of May was celebrated on the 10th of May in a calm and normal atmosphere.

I cannot leave unmentioned the huge role that Marshal Aganov played along with his engineering troops. Every time there was a need to get from one place to another, or to lay a hose, it was necessary to punch holes. And each time we needed a hole, they did the calculations before using military engineering tools — that is, shoot using a gun of the appropriate caliber—because there was a risk of the entire structure collapsing. It was imperative to make proper estimates and calculations. All this work was done by Marshal Aganov and his team with excellent precision and good organisation.

Even then, during those difficult days, despite everything we were, it may seem paradoxically, in good spirits. It was, of course, not because we were taking part in liquidation of the consequences of such a tragic event. The tragedy, of course, was the primary background against which everything was going on. But what caused the good spirits was the way the people had been working; how quickly they responded to our requests, how quickly various engineering scenarios were evaluated. And we had already begun, on the site, to consider the first options for constructing a dome over the destroyed block. Later, that work was assigned to comrade Batalin, the Deputy Chairman of the Council of Ministers. He took the leadership of the construction project in his hands. And subsequently the construction itself was assigned to the Ministry of Medium Machine Building.

Around the 9-10th of May, M.S.Gorbachev in a telephone call asked me personally to give him some sort of chronology of the events, a description of what was happening, because he was preparing to speak on the Central Television to the entire Soviet Union. So I started preparing a note in which I described all that was known by that time: how the events had developed, how the destruction of reactor number 4 had happened, what work had already been done, and what work was yet to be performed. I handed this note to E.P.Velikhov and I.S.Silaev. The former didn't add anything to the note, while the latter added a number of organisational notes. After that, all three of us signed that note and sent it to Gorbachev. It was partially used in his [TEXT UNAVAILABLE IN SOURCE].

I suppose what I am saying is that the institute, for the first time, managed to assemble a group of experts who looked at nuclear energy as a system, all elements of which should be equally efficient, equally safe and reliable; and depending on the size of one or the other element in the system, the quality of the entire nuclear energy system should be more or less optimum.

This work had only now begun. I have always thought that this is the correct approach. Figure out, together with the Energy Commission headed by Anatoly Petrovich, what percentage of energy should be in the form of nuclear energy in a given task. After that, evaluate what type of energy must be replaced with nuclear energy, then assess which regions are the most appropriate for it, and then define the requirements for the devices that will optimally fit the tasks that stemmed from the fuel and energy balance of the country. And then, after selecting appropriate devices, engineer them to comply with all the international safety standards.

These were the questions that I had.... well… I was involved in, at least during the statement of the problem and in the development of these works. It began quite successfully. But with the illness of Aleksander Sergeyevich Kochinov and after the subsequent events, everything has changed. Now once again, solely an engineering approach is used when one device is compared to another. Every specialist who invents either an upgrade for an existing system or an entirely new system must prove the benefits of such innovation. There is no standardised system of evaluation. Maybe someone is trying to create it now. In the last few months, I don’t know what is going on because after I formed the group, I was excluded from this work. It is hard for me to say what is going on there. At the end of the day, this group of course is made up of intelligent specialists, and maybe everything will fall into place.

For example, at the meeting on the 14th of June, Nikolai Ivanovich Ryzhkov said in his speech that this disaster did not seem accidental to him; that nuclear energy with a degree of inevitability was heading towards such a tragic event. I was shocked by the accuracy of these words. Although I had not been able to describe the issue in such a way, he did.

I really do want to understand these numerous cases. For example, at the Kola NPP when the main pipeline, the most important pipeline, was welded in such a way where the welders, instead of doing it normally, just put an electrode inside and lightly welded it from above. This could have resulted in a terrible disaster - the rupture of a large pipeline of the VVER device. This is the worst-case scenario leading to a complete loss of coolant and a meltdown of the core. Luckily, as I was later told by the director of the Kola NPP Volkov Aleksander Petrovich, the personnel were properly trained and very cautious. The operator had detected the first crack [defect in metal] despite the fact that it could not be seen with the naked eye. It is a noisy place; one can miss some auditory signals. Nevertheless the operator was so attentive that he spotted the anomaly on the main weld bead. An investigation was started. It was discovered that this was simply a hack job. The important pipeline had been carelessly quality-assured. They checked the documentation - all the signatures were in place. During the check, it turned out that not only had the welder signed that he had done the welding properly, but also gamma-flaw detector who had checked this weld bead, the weld bead that didn’t even exist. Of course, all this was done in the name of productivity. To weld more. And this hack job was just mind-boggling for us.

All this was rechecked at other stations—the same spots, the same weld beads—and not all was perfect. Frequent device stoppages, frequent cracks inside crucial structures, imperfect operation of gate valves, malfunctioning channels inside the RBMK reactors—all this was happening every year. A decade of talking about simulators, which are increasingly effective and are becoming commonplace in the West, and we still don’t have them in the Soviet Union. For at least five years, there have been long talks about creating diagnostic systems for the most critical equipment... nothing has been done.

I remember that the quality of engineers and other personnel running the stations was falling. But additionally, any person that had been on an NPP construction site was surprised at the potential of work being done so carelessly, even on such an important project. All these instances were in our heads as individual episodes. But when N.I.Ryzhkov said that nuclear energy was heading towards it, then this picture, created over multiple years, emerged before my eyes. I remembered that experts from my own institute were already used to what was happening during the construction of the nuclear power plants. I also remembered the Ministry with its strange concerns. This wasn’t a leader that led us, it was a leader that was just making ends meet, getting money, sending information up to the levels above, sending people to launches or acceptances.

As I recall, there is not one person, or group, who leads focused work on analyzing the situation in the nuclear energy industry—about how to change the usual practices of building stations, of supplying equipment—despite the fact that such individual episodes have been happening. For example, the many-years-long struggle of Viktor Alekseyevich Sidorenko, that was supported by academician Aleksandrov, resulted in a government resolution for the creation of Gosatomenergonadzor, representatives of which should be present at every station, and every enterprise that manufactures critical equipment for nuclear power stations. These representatives should grant permissions or stop the work depending on its quality. The same Gosatomenergonadzor should thoroughly review all the regulatory documents and improve them, while also verifying that all the regulatory requirements are met in practice. So this issue was somewhat resolved. But it was resolved in a very odd manner.

You know, similar to our current state quality control, a lot of ‘specialists’ appeared that were not involved in engineering or scientific activities. They gathered at the table and doled out houses and posts to themselves. But as is evident from the Chernobyl disaster, this organisational superstructure couldn’t actually improve the state of the nuclear energy industry because its authority was not defined properly. And the requirements they created were not ideal, not the ones that had to be created to make nuclear energy safer, but rather they were coming from the current situation that we had here, and from some Western experiences. This was a sort of combination of the Western experience with our own, with the level of the machine-building industry in the Soviet Union—which cannot fulfill certain requirements. All this left an impression of a sort of eclectic image—not coherent, not complex.

Many of the regulations, requirements and rules were complicated and very confusing; in some parts, contradictory. Maybe, at a glance, to figure out a contradiction one had to do additional work. Normally, everything would be stored on a single personal computer, in one or two disks, located next to the operator so that he could at any moment clarify something. In reality, all this was stored in old and used books. The operator had to go and search for them. This left a rather wretched impression. But it seemed to me that this wretchedness was not recognized by many... I had very few supporters.

Once a magazine called “Business Week” fell into my hands. This was, I think, in 1985. In it was an article criticizing the French for their active cooperation (an attempt of cooperation) with the Soviet Union in the field of nuclear technology. It was about a deal where we would increase the supply of natural gas to France while they would provide us with nuclear technologies: robots for repair works, loading and unloading operations, some diagnostic systems, a range of devices to make the technology of the construction and operation of a reactor more modern. But the author of this article, an American, criticized the French, said that they shouldn’t be doing it (for political reasons, economic reasons). But the article stated very precisely that: firstly, the Soviet Union has developed the physical fundamentals of nuclear energy on the same level as the rest of the world, but the technology gap to implementing those physical fundamentals is huge, and the French should not help the Russians in overcoming this gap. And above that article, there was a lousy illustration, in which in front of a half-wrecked cooling tower, a young moustached Frenchman is trying to explain to a Russian bear how to build those cooling towers, while the bear has put a finger in his mouth and hardly understands that the quality of the cooling tower is as essential to the quality of a nuclear station as the reactor itself. A very mean caricature it was. And I remember running around with this caricature, showing it to Meshkov, Slavsky, Aleksandrov; presenting it as a question that was very serious. The question of the gap between the physical concepts of what the reactor should be, and the poor-quality production of fuel, and the whole range of technological operations, many of which seem insignificant, and which are practiced at our stations.

You know, I was not met with understanding anywhere. Rather, A.P.Alexandrov called Kokoshin, the Deputy Director of the Institute for USA and Canada (he had a doctorate, a very interesting young man), and asked him to write a counter-article debunking the author, that things are nothing like that, and that Soviet nuclear energy is at par with the West, etc. However, that American article did say that although Soviet nuclear industry in terms of input capacity is not at the world-class level, the reactor concepts adopted in the Soviet Union are physically correct and sound, and that the Soviet reactor construction specialists are good. However, the technological support for this complex cycle is outdated. That’s why more staff is needed to operate our stations, there are many poor devices, many imprecisions in the operating systems that service the station. So this was indeed true, but nevertheless Anatoly Petrovich insisted that Kokoshin must write an article refuting these views. Luckily, Kokoshin had enough wisdom, or not enough time, to not write that article. For if it had appeared, it would have appeared in the Chernobyl days.

I want to emphasize that I was possibly the only one, among the people I spoke to, who acutely felt this concern. Others, who possibly knew the situation at the nuclear power plants much better, were sort of very calm about it. I once heard from Ponomaryev-Stepnoy Nikolai Nikolaevich (he was a Deputy Director of Nuclear Energy, now the First Deputy). He was working on a helium-cooled high-temperature reactor, and we considered this reactor as having the best technological capabilities for our national economy. It had high temperatures which meant that we could use it in metallurgy, chemistry and oil refining. That is, we considered it not as a competitor to nuclear energy but as an addition to it. But then, in a conversation, he said that RBMK reactors are very dangerous. And that is true. So in this sense, not an addition but actually an alternative to today's energy.

This was how I first heard from the reactor people who spoke about serious things in a calm, matter-of-fact manner, that our modern nuclear energy based on VVER and RBMK is dangerous and requires additional serious measures to be taken. As is my nature, I started to research this question and be more active in certain situations, to speak about the necessity of the next generation of reactors to be safer; say TTER reactors or liquid salt reactors that I was trying to present as the next steps towards safer reactors. But this caused a storm in the Ministry. A storm of indignation. Especially from Minister Slavsky who was literally stomping his feet, saying that these are different things, and that I am illiterate, that I don’t mind my own business, and that it is wrong to compare one reactor to another of a different type. This was a difficult environment.

Slowly, work progressed on alternative reactors. Slowly, we upgraded the existing reactors. But sadly, no proper scientific analysis of the actual situation took place to analyze all the possible problems and find ways to avoid them. I tried to set up a safety measures laboratory. It later became part of the Nuclear Energy Safety Department. But since Sidorenko was put in charge of this laboratory (the whole department), everything was routed towards developing documents, procedures and standards to make things better on existing nuclear power stations. And things never came to serious theory, to serious analysis, to serious strategies, which, all in all, was quite alarming.

The more nuclear power stations were built, the more real became the danger of something happening at some point in time. People had started sensing that. But the fight against these dangers was being fought on a case-by-case basis. Say, a steam generator breaks down at some station, and they start to think about how to change its design, and, of course, come up with a solution that improves the situation. Then something else happens. An RBMK channel bursts, so they start researching why this happened; is Zirconium to blame, or the operating state, or something else? And the quality of produced Zirconium becomes better, as well as of the pipes made out of it, or else the operating states become better, and everyone calms down until the next thing happens.

It seemed to me that this was not a scientific approach to solve the safety-related problems of nuclear energy. But because my professional occupation was in a different area, I was an observer integrating all this information that was entirely impossible to discuss in the ministry; because they were used to having very specific engineering discussions, such as how to replace one kind of steel with another, how to modify a technological system. All conceptual talks, all attempts at adopting a scientific, consistent approach towards this problem, they did not accept at all. This is how the situation was developing before the Chernobyl events.

Moreover, the number of enterprises who were involved in the production of various equipment for a nuclear power plant had also increased. The construction of Atommash had begun. Many young people arrived. As our press reported, the factory was built very poorly. The quality of specialists, that had yet to master their professions, left much to be desired. This was obvious and Komsomol themselves wrote many papers about it. They were helping to organize the headquarters under the Central Committee to help the development of the nuclear energy.

This also was visible at the stations. I was particularly disappointed after I visited several western stations. Especially after I saw the Loviisa station in Finland which was built according to our principles; it was basically our station. Only it was built by Finnish builders. Only they had discarded all of our automatic control systems and put in Canadian ones. A number of technological instruments had been replaced with either Swedish or their own, and ours had been taken out of operation. The procedures established at this station were sharply different from ours. Starting from the entrance to the station, its external signage, personnel training. This station had a proper training simulator where everyone had to undergo regular training, and the various situations that could arise at a reactor were simulated.

I was struck by the time this station put into carrying out a refueling. Very interestingly, the station staff consisted of 45 people, if I recall correctly, who had to plan the reloading operation; that is they planned who, of the people that didn't work at the station, had to participate in the reloading. They selected people, agreed on the time, arranged the needed tools, and decided the sequence of carrying out the procedure. This very thorough preparation for the refueling procedure took around half a year's time. But the refueling itself took only 18-19 days, while for us it takes around a month and a half, and upto two months at times. But the operational staff there is considerably smaller than in our stations. Outer cleanliness of the station, the number of equipment in the station laboratories, all this differed strikingly from our stations in the Soviet Union.

Yes, and I also wanted to talk about the administrative systems. As one remembers how our nuclear energy sector was structured: our Ministry of Energy with its directors, the Ministry of Medium Machine Building with its directors, the chief engineer, the science supervisor. Any expert from any level (from the laboratory supervisor to the director of the institute) could request information, interfere in the work of a station, write reports, propose something. There were countless industry councils where something was discussed. And all this was not very coherent, not orderly, and did not present to me as a unified, smooth work process. Instead, each time it was a response to some technical proposal, or to some accident, or to some pre-accident situation. This left an impression of disorder, and a widespread movement towards disorganized work in the field of nuclear energy.

This, by the way, I felt less keenly, because my own functions as a member of the Energy Commission were to determine the rate of commissioning nuclear power stations, the chronology of tasks, and the structure of nuclear energy. All these were prospective questions. As for ongoing activities, I was involved with them only indirectly because it was not my speciality, and they were never assigned to me. However, the more I learned about what was happening there, the more anxious I became. And when Nikolai Ivanovich Rizhkov in a politburo meeting spoke his words about how nuclear energy was inevitably moving towards a grave accident, immediately all these facts, accumulated over many years, somehow aligned in my mind, and his words highlighted that it really was so.

And in general, all the experts, scientists, at least at different times and from different platforms, talking about individual parts, said that we are on the road to a bad accident; Anatoly Pavlovich Aleksandrov said it, repeatedly citing striking examples of carelessness in the construction of nuclear power plants; Sidorenko said it, speaking about disorders in operation and documentation; the young specialists said it; the material scientists said it.

An unexpected problem occurred with, for example, specimens lowered into the Finnish station Loviisa. They showed that the reactor housing may not last for 30-40 years per the project parameters, but may function for substantially lesser time. Immediately desperate research began, that resulted in proposals on how to deal with the situation and prolong the life of the reactor housing.

tape 3, side b

All of this had such an irregular, sudden quality. On the one hand, it could be explained by the young age of this branch of technology, and to some extent it is; but on the other hand, it was a reflection of an overall incorrect manner of working in general. When Nikolai Ivanovich spoke his words, and they, like a light, retrospectively illuminated all the previous events, I realised that these were the right words. But I also realised that this was not specific to the nuclear energy industry, but rather the consequence of the way work was organized in general, to create, very quickly create, a new branch of technology that the national economy needs.

Here’s a way to organize work on construction sites: inconsistency in different types of production, say, the production of fuel elements; the machine-building equipment, the unpreparedness of builders to accept this equipment on time; garbage on construction sites; constant, incomprehensible changes in the number of construction staff (by construction I mean at nuclear power plants), at times too many, at others too few. Work, so to say, is progressing on the station, then abruptly stops because one or the other equipment is not there.

All this taken together was very unpleasant, and at the same time, hardly unique or specific to the nuclear energy industry alone. That is why the words of Nikolai Ivanovich Ryzhkov should be understood in a much wider context. And when I visited the Chernobyl station after the accident and saw what was happening there, I myself drew a precise and unequivocal conclusion, that the Chernobyl disaster is an apotheosis, the pinnacle of all the mismanagement that has been carried out for decades in our country.

Of course, what happened at Chernobyl has real, not abstract, culprits to blame. We already know now that the reactor’s Protection Control System (PCS) had a defect in it, and many scientists knew this, and they proposed ways to fix this defect. The Chief Designer, not wanting to do, so to say, quick, additional work, was in no hurry to change the Protection Control System.

Also, there are, of course, specific culprits. What went on at the Chernobyl station itself for many years: conducting, so to say, experiments the plans for which were made very carelessly and sloppily. Before conducting the experiments, there were no simulations of possible situations, that is the situations were not walked through—what will happen if there is a protection malfunction; what will happen if the process does not execute as planned; how should the staff react in one situation or the other; can the reactor be left running when the steam supply to the turbine is stopped; and if this is done, what could happen; what will happen if the main circulation pumps are switched on.

Common sense would suggest that all these cases had to be simulated before the experiment, be it this particular one or any other. But nothing of the kind, of course, was done. There was an absolute disregard of the viewpoint of the Chief Designer or the Science Supervisor. It needed a fight to…


Speaking of the conversations with Mikhail Sergeyevich Gorbachev. While in Chernobyl, I spoke with him thrice on the phone. This was rather odd. He, of course, would call the Second Deputy of the Government Commission, comrade Silayev Ivan Stepanovich, or maybe he would call Shcherbina and talk to him, but this was not in my presence. But sometimes when we were at Silayev’s, then Gorbachev would call. Ivan Stepanovich would tell him his point of view and then, when more detailed, specific, technical information was needed, he would ask, “To whom should I give the phone, Velikhov or Legasov?” And in the first call, he said, “Give the phone to Legasov.”

So I started talking to him. He, Mikhail Sergeyevich, spoke for two or three minutes. “What is going on there? I am very concerned about this problem. Already the name of Gorbachev is being tarnished all over the world because of this accident. Mass hysteria has begun. What is the real situation there?” In response to this, I outlined the situation for him; that basically—as it was after the 2nd of May; the call was around the 4th or 5th of May—the radiation emissions from the destroyed block have ceased, and the situation is currently under control. The scale of contamination in the areas adjacent to the Chernobyl station, as well as the scale of contamination around the world, is more or less known to us. It was already clear to us that people injured by radiation, except for those who worked at the Chernobyl station at the time of the accident, are expected to be unlikely; that the control of the population is thorough; that if the countries that came under the nuclear fallout from the accident took proper informational and sanitary measures, then there will be no real consequences to the health of the people.

This is what I said to Mikhail Sergeyevich on the 6th of May, not knowing that on the same day a session of the World Health Organization, specially assembled about this issue, had come to the same conclusion. That the accident did not pose any threat to the people in Western Europe and other countries. I also talked about the specific situation, where the heavily contaminated areas were, where the situation was more or less favourable, and how the work was progressing. He was satisfied with this conversation.

The next day, when we were at Ivan Stepanovich Silayev’s office again, the phone rang once more, and this time he asked for the phone to be given to Evgeny Pavlovich Velikhov. He began to ask him about the reasons for the accident, but Evgeny Pavlovich started giving very confusing explanations, and then quickly said that Valery Alekseyevich [Legasov] will explain this better, and handed the phone over to me. Perhaps I was too generous with the details, but I did explain why this accident had occurred. And at that moment, Mikhail Sergeyevich asked me to write a personal letter to him. And what surprised me was that I, specifically, had to send a letter about what had happened and what had to be reported. So I immediately sat down to write this letter, and after a few edits by Ivan Stepanovich Silayev, it was sent to Gorbachev that same night, signed by Silayev, Velikhov and me.

Ivan Stepanovich Silayev, during his term, paid the most attention to the construction work— arranging the concrete factories, arranging the shipment of concrete—because it was clear to him that the area around reactor number 4 had to be concreted as much as possible. He was very angry with, say, Makuhin, the First Deputy Minister of Energy and Electrification, who, it seemed to him, was working slowly; and he even made a quick decision to fire him. This decision was never implemented, but such words were said. It was Ivan Silayev who introduced the system of monetary rewards for doing the most dangerous tasks. And the most dangerous tasks during his term were to determine whether or not there was water inside the upper and lower bubblers, and in the rooms beneath the reactor hall because this was crucial. We were worried that some of the molten fuel would get there, and possibly lead to powerful vaporization which will carry out additional radioactivity. And we had to know whether those bubblers were empty or not. After that, we had to decide whether to leave them empty or to fill them with special concrete. So Ivan Stepanovich Silayev had to tackle all these issues.

It was quite hard to get to these bubblers because the adjacent corridors were flooded with water from the time when they were trying to cool down the reactor with water. The levels of radioactivity in that water were quite high, up to a curie per litre in some places and at certain points in time. The pumping devices were turned on and this water was pumped out. And yet, the gate valve that needed to be opened to determine if there was water inside the bubblers, was opened by one of the station workers in very difficult conditions. So in the evening, Ivan Stepanovich solemnly thanked him and gave him a package with a thousand roubles. He had obtained the necessary permission for it. And I saw the face of that man who, on the one hand, was very proud that he had managed to do this difficult task in such difficult conditions. However, on the other hand, it was plain to see how he crumpled that package of money, not like a prize. Basically, it was uncomfortable for him to refuse this money, but at the same time, the cash form of the prize itself did not really please him. Probably because indeed, especially during that period, people who fought with this accident sought to do their best, to do everything they could, without thinking about any kind of encouragement, be it material or moral. Everyone worked as a single collective, attempting to find the best solution.

During this time, it was frightening to look at comrade Konviz—he was from Hydroproject and the chief engineer of the station—because he, I think, never slept, not for a minute. And naturally, to find out how to access various rooms, everyone turned to him, either to his drawings or simply to his memory, to his experience.

Here I recall many such annoying episodes. You would look at the drawings and see an open corridor. You would start moving along this corridor and suddenly run into a wall. The wall was obviously built there because of some engineering considerations after the project was completed. It was not in the design, but it was there and not shown in any of the drawings. There were reverse cases as well, when, say, where should have been a wall according to the drawings, in reality, was a doorway. We encountered such cases as well.

It was particularly hard for the miners because, beneath the station territory, a large number of pipes and plates were buried in the ground. And so when they worked using their tunnelling shield or something similar, their way would appear to be clear when looking at the underground utility drawings. But when they began their work, they constantly ran into obstacles that were not shown in the drawings.

There were a lot of inconsistencies between the part of the documentation that was at the station and the reality in various places of the station and underground facilities. All this certainly gave an impression of gross neglect, of gross sloppiness towards maintaining documentation, which should be accurate and describe the state of building structures, and walkways, and electrical communications at every moment in time. Unfortunately, we came across this sloppiness quite often. At the same time, I want to highlight the fact that although these things are irritating when faced day after day, at that moment the people were so determined, they so wanted to complete their work, that all these past cases of sloppiness did not cause any fuss or outcry. All this receded into the background in front of the will to tackle the situation as quickly as possible.

The number of people staying at the site was increasing day by day because each group required new assistants, who came either with devices, or with documents, or with work tools that were needed to perform a task. This increase in the number of people required new ways of organizing work because it was no longer possible to personally give specific instructions and be done with it. That is why after the main problems had been solved (by main I mean protecting people from immediate danger and localizing the disaster itself), came the question of managing all these numerous groups of people who had gathered there at the suggestion of the Government Commission, according to the decisions of the Operative Group of the Politburo of the Central Committee, and stayed in ever-increasing numbers, along with their equipment, on the territory of the Chernobyl nuclear power plant.

It was necessary to simultaneously organize a number of tasks that were of completely different types. First of all, start the design of the covering that would later come to be called the ‘sarcophagus’. This design had to be done concurrently at the site and in the different design organizations located in cities across the Soviet Union, mainly in Moscow and Leningrad. It was necessary to immediately work on zone-wise decontamination, following the guideline of going from the most contaminated areas to the less contaminated ones. It was necessary to carry out a survey of the territory, to continue this reconnaissance, and to check how radioactivity was being spread by the wind, by the vehicles. It was necessary to tackle the issue of checking the equipment in the 1st and 2nd blocks, of checking the remaining structure and equipment in the 3rd block. It was necessary to assess the condition of all the rooms and areas on the entire Chernobyl station, its surrounding areas and roads. It was necessary to accommodate the army divisions as well as the various construction organizations that had arrived to help solve this situation. A proper management system had to be established for scientific research, design and execution of projects across all these very diverse areas of work. The management system for this complex mechanism was established gradually.

The first two groups, led by Boris Yevdokimovich Shcherbina and Ivan Stepanovich Silayev, were occupied exclusively with the most important and urgent tasks. Thanks to the arrival of comrade Voronin, the overall scheme of work management had started to form. A procedure for ordering materials was established already; a procedure for work fulfilment. It became clear that one group of researchers had to work solely on the tasks related to reactor number 4, while another would tackle its surrounding area. The third group—implementers, not researchers; these were mostly the army divisions— began decontaminating the rooms in the 1st and 2nd block, and also prepared for the construction of the sarcophagus, because the design was already in progress in Moscow.

Comrade Voronin was replaced by Yury Nikitich Maslyukov, and during his time a lot of work was done to build new premises, new villages for the evacuees. The treatment of roads had begun, and the initial preparations started in front of reactor number 4 for the construction of the sarcophagus. The sarcophagus itself had not yet been begun but the approaches to it had already been concreted. The most contaminated areas had either been cleared or concreted for the builders to begin their work on the sarcophagus construction.

When comrade Gusev came to the site with his team, the main design elements were being sketched out. It had already been decided to assign the construction of the sarcophagus to SU 605, a department in the Ministry of Medium Machine Building; and that a thorough assessment of the internal condition of reactor number 4 had to be carried out, of the structural soundness of its remaining building, so that the project could rely on some analysis, on some verified data.

And when comrade Vedernikov and his team replaced Gusev, the construction of the sarcophagus had already begun. Moreover, particularly under Vedernikov, with the participation of the group leader from the Institute of Nuclear Energy, comrade Tutnov, a decision was taken that made the construction of the sarcophagus easier and quicker. Because originally the plan was to build a dome made entirely of concrete over the wreckage. However, calculations showed that the time needed for the construction of the sarcophagus could be significantly reduced if the concrete dome—the reliability of which was being questioned, whether the design would hold its weight— is replaced by, so to speak, a pipe run. The pipe system of roof support would protect the sarcophagus against the possibility of radioactive dust being carried out. However, more radiation would escape through this top cover but it would be comparable to or even less than the total radiation on the site. The correct decision was made during the time of comrade Vedernikov.

And gradually, the following framework of work organization emerged. It came down to this that the research group from the Institute of Nuclear Energy together with experts (this group was successively led by experts such as Yury Vasilievich Svincev, Anatoly Mihailovich Polevoi, Tutnov as I have already said; next this group was led by comrade Kuharkin Nikolai Evgenievich. A lot of work was done when comrade Pologikh Boris Grigorievich led this group. Also, research groups under which particularly a lot of work was done were led by Kulakov, Borovoi, for example) had to—and this was their primary objective—thoroughly investigate the premises of reactor number 4. Firstly, find the fuel; determine how was it distributed. Secondly, install the maximum number of sensors that would ascertain the condition of reactor number 4.

Here I need to pay tribute to comrade Schekalov, the expert from the Institute of Nuclear Energy, and also to the experts from the Ukrainian (Kiev) Institute of Nuclear Research, who made great efforts to find the appropriate paths, put in the necessary sensors, and stretch cables to them. As for neutron sensors, they were the responsibility of CNIIP [Central Science Research and Project Institute] of the Ministry of Medium Machine Building. The experts from this institute were led by comrade Zhernov. Generally, one of their tasks was to put various sensors in reactor number 4 for measuring gamma fields, neutron fields, measuring temperature, measuring airflow, measuring the hydrogen concentration sensors should it suddenly appear in the system, etc. These sensors were placed in various spots. This was dangerous and hard work because they had to go inside the block every time and search for the most suitable spots that would reliably diagnose the condition of reactor number 4. This was one set of tasks.

At the same time, videos and photos of the rooms of reactor number 4 were taken continuously which allowed the engineers to select the proper solutions for the construction of the sarcophagus itself. During this, the project team from NIPIET - Leningrad Design Institute of the Ministry of Medium Machine Building, was working on-site in Chernobyl, and an array of design decisions, though the general design had been developed at the Institute, an array of design decisions were made there on the spot. An absolutely enormous amount of work was done by comrade Kurnosov, the chief engineer of this project and the chief engineer of the institute itself. He regularly found proper solutions when one or the other difficult situation arose.

And there were difficult situations. An attempt to pour concrete in an area was unsuccessful because there were rather large gaps through which the concrete flowed to the levels below. Methods to hold the concrete in place had to be thought of. Some supports were not strong enough and reinforcement was necessary. This harmonious work of the researchers and the designers, in the end, led to a reliable construction. That was one group of tasks.

Another set of tasks was performed by the construction experts from the Ministry of Energy who were building a temporary village called Green Cape (Zelyoniy Mis). Many prefabricated houses were ordered, made both in Finland and in the Soviet Union. And for the shift workers that had to work in the 1st and 2nd blocks, a very nice village was constructed with all the needed amenities: with houses, with shops, with cultural facilities. This village had been constructed literally in a few months. Boris Yevdokimovich Shcherbina was personally following the construction of this village, paying attention not only to the places to sleep after work, but also that there should be flowers, that the canteen worked as well as in any other part of the Soviet Union, and that the people felt comfortable there. These divisions of the Ministry of Energy had taken part in the construction of the village at Green Cape, and also in the construction of many stations for the decontamination of vehicles, quite a lot of which had gathered on the site by then.

The Government Commission itself had already been relocated by this time. The work was, as before, done in Chernobyl in the former regional Party Committee building, but the living accommodations were moved approximately 50 kilometres away from Chernobyl. The leaders of the Government Commission, as well as the various experts that were arriving to perform certain tasks, lived there.

A large group of researchers from various organizations of the Soviet Union, from the Academy of Sciences , from the Kurchatov Institute of Nuclear Energy(when I say Academy of Sciences , for example, I mean of course the GeoChem [ГЕОХИ] and the entire Ukrainian Academy of Sciences), this whole group of researchers was working on a detailed assessment of the radioactive contamination of the area. For this, they used both statistically reliable samples that were gathered on the site—followed by analysis in the radiochemical laboratories that had been deployed in Chernobyl, and some samples were sent to the institutes, the Radio Institute or the Institute of Nuclear Energy—and measurements of gamma fields made using helicopters. These surveys were done for both the total amount of gamma radiation and the isotope spectrum of gamma radiation. And correlations were found between the contents of individual isotopes, by using relative contents of which we could predict the concentration of, say, Plutonium that was released into the environment. Of course, samples of Plutonium, as well as other heavy alpha-active elements, were collected continuously to compare the data gathered by the helicopters and through the direct collection.

The responsibilities were distributed in such a way that everything that was outside of the 30-kilometre zone was controlled both from the air and from the ground by the Goskomgidromet [State Committee on Hydrometeorology] led by member-correspondent Yury Antonovich Izrael. I cannot exactly tell how much time he spent in Chernobyl, and took the most thorough part in data collection, their correct estimation, researching the history of the appearance of contamination spots. An enormous amount of work had been done and as a result, outside the 30-kilometre zone, we were receiving more and more precise maps that showed the degree of contamination of various areas.

And within that 30-kilometre zone, the talk was mostly about Caesium contamination, because several Caesium spots had appeared (these will be shown on the maps) and the creation of Caesium maps began in the period from the date of the accident until the 20th of May, after which the creation of such maps was stopped.

According to existing sanitary norms, decisions were taken that set the maximum limits [of radiation exposure] that allowed people to live in areas contaminated by certain isotopes. The local authorities acted according to these rules, either relocating people or letting them stay, switching to imported food, or declaring the area safe enough to live in and to use the land. At the same time, the Gosagroprom [State Agro-Industrial Committee] and the experts from the Ministry of Medium Machine Building were also carrying out analysis of various agricultural crops, determining the degree of their contamination, observing the forests and fields around the Chernobyl station, both within the 30-kilometre zone and around it.

As for the 30-kilometre zone itself, it was under the charge of the experts from the Ministry of Nuclear Energy, the experts from the Kurchatov Institute, experts from the Radium Institute and the experts from the Ukrainian Academy of Sciences.

In September, the work of the substitute Government Commission had ended. All the work was transferred to the revised composition of the first Government Commission (the one led by Boris Yevdokimovich Shcherbina) that had been approved. And subsequently, from September onwards, all the work on the site of the Chernobyl station and within the contaminated zone was the responsibility of the Government Commission. It made all the decisions, reviewed all the projects, all the comments, and led all the work.

The order of operations was approximately as follows. Around the beginning of September, the evacuation efforts had been generally completed and the evacuees were placed in the newly-constructed villages. Some of the station personnel got flats in Kiev city and some in Chernigov. All in all, the accommodation issues had been solved. A decision was made to build the city of Slavutych because it was clear from the beginning that the shift work method could only be used temporarily at the nuclear power plant. And so the design of the new city of Slavutych began; the city that would replace Pripyat as the permanent residence for the power engineers.

The period of August and September was a period of active preparation to launch the 1st and 2nd blocks of ChNPP. This launch was carried out successfully. Moreover, before launching these blocks, an entire complex of measures, developed by experts to further increase the safety of such type of stations, was implemented and tested; partially on the 1st block and fully on the 2nd block. This was sort of the main task in that period.

Concurrently with the preparation for the launch of the 1st and 2nd blocks, and with performing the launch operations, work was underway on the construction of the sarcophagus. The original deadline for this construction was at the end of September, but various issues that naturally come up prevented this work from being completed in time. But, I will repeat, this was because unforeseen circumstances cropped up constantly. There were very large gaps that could not hold the concrete, preventing it from hardening, and making it impossible to set up the base for the subsequent construction elements. There were problems with selecting the appropriate material (this, by the way, was the task given to the experts from Kiev, they were also employed at the end) that would close the gaps between the components of the pipe cover. It was necessary to design a forced ventilation system for the sarcophagus so that if there was not enough natural ventilation, it would be possible to remove heat by switching on the forced one.

All these issues were gradually solved during the design phase and were refined during the construction of the sarcophagus of reactor number 4. This construction was a separate saga in itself.

I will repeat that the project teams were working on the spot. The work was done with the help of two cranes made in the German Federal Republic by the firm Demag. The primary work was being done using these cranes, but still many finishing tasks, that would increase the reliability of the sarcophagus, had to be done by hand or by using various robotic devices. However, as I have already said, the robotic devices we had, be it our own or acquired from abroad, turned out to be practically useless in those conditions. Say, even if a robot had sufficiently reliable electronics, it could not overcome obstacles, that were the result of a large amount of wreckage of reactor number 4, and stopped. This was the reason they were unusable. If, however, the researchers received robots that had good all-terrain travel capability in the most difficult conditions, then their electronics would fail because of the high gamma radiation and they also stopped.

So there we were, trying to use robots to clean the contaminated roofs of buildings where the 3rd and 4th blocks were, and also the roof of the reactor, of the radioactive contamination. We tried to use robots but this generally was not very successful. The best technical devices were created by experts from NIKIMT. Yurchenko Yury Fedorovich was the director of this organization. He himself spent a lot of time on the site and under his leadership, the robots were created, tested and used. But, well, what kind of robots? Ordinary. Ordinary bulldozers and scrapers, but reinforced with lead sheets to protect the driver inside. And such vehicles were used to do the majority of decontamination work in the most difficult places. The army divisions were primarily used to decontaminate large areas of the station territory and the insides of the station buildings. They worked very diligently, with great speed and efficiency.

Of course, many things changed as time passed, our views and ways of working. I remember an episode well when we, with General Kuncevich, arrived at Pripyat. It seemed that it would be impossible to decontaminate this city because everywhere one went, there were very high levels of radiation, say, 700-800 milliroentgens per hour. This was the magnitude of doses that we measured with our devices. But then we did one thing. We broke off pieces of facing from one of the buildings and took them from Pripyat to Chernobyl. And it turned out that this facing was radiating 800 milliroentgens per hour but here [in Chernobyl], it radiated less than 10 milliroentgens per hour. So it became clear that the contamination sources were not widely spread, but rather there were local sources of contamination in Pripyat that created a general environment that made it seem like that decontamination was not possible.

After we figured this out, and after the most active isotopes had already decayed, then mainly around August-September, very active work began, carried out by the military organizations, to decontaminate Pripyat. And the city of Pripyat was considerably decontaminated by about the same time when the sarcophagus construction was ending.

While constructing the sarcophagus (it is still under construction), we solved the problem of how to close the gaps. The following decisions were taken. Dip asbestos sacks filled with polyethylene chips into appropriate solutions—this would produce foam—and then use these sacks to close the gaps on the roof of the sarcophagus. But even before the work on the sarcophagus ended, work began on checking the condition of the equipment in the 3rd block. The question arose about what to do with the 5th and 6th blocks. These were the questions we had.

Around October 1986, the situation regarding work distribution was very clear. US 605 of the Ministry of Medium Machine Building was completing the construction of the sarcophagus, which was later named ‘Shelter’. The builders from the Ministry of Energy were occupied with the construction of the shift village at Green Cape and some tasks related to the creation of a decontamination station inside the 30-kilometre zone and some work on the territory of the station itself. Minatomenergo led the work on the preparations to launch the 1st and 2nd blocks and had already started to gradually make their way into the 3rd block to assess its condition. The army divisions, together with the organizations of Ministry of Medium Machine Building, were cleaning the roofs of the building where the 3rd and 4th blocks of the Chernobyl NPP were. The military divisions were also continuing with the decontamination of the villages that were within the 30-kilometre zone. The research group, as I have already said, had divided its tasks as follows: researching the wreckage of reactor number 4; finding the fuel; and surrounding it with the maximum number of diagnostic devices.

The diagnostic devices were inserted from under reactor number 4. For the bubbler rooms, the diagnostic elements were inserted through holes drilled into the sidewalls that led to the reactor hall. And the bulk of the diagnostic devices were inserted from above, hung on special ropes inside the reactor hall.

At the same time, another group of researchers was occupied with another task, specifically, studying the migration of radionuclides inside the 30-kilometre zone and around it. We were concerned by the question: how deep do the radionuclides penetrate after they are deposited on the surface; how are they absorbed. Different techniques for the artificial absorption of radionuclides on surfaces were tested. The problems of preventing the radionuclides from getting into the Pripyat river were solved. Measures were taken to prevent the radionuclides from getting into the groundwater.

Within the last field, the actions were quite simple. Around 150 wells were constructed, both diagnostic and service wells. The diagnostic wells worked continuously and measured the radioactivity of the groundwater, and if required, the service wells could be turned on to pump out the contaminated water. But fortunately, during the entire period of work, and to this day, all the diagnostic wells have shown that the groundwater has always been clean, and the service wells have never been used.

Complex research was done in the cooling pond near the Chernobyl NPP, where the radioactivity of the water, as well as silt, was measured. and a lot of attention was paid to the condition of the Pripyat river itself, the Kiev reservoir. But it was very quickly discovered that the water itself did not have much contamination, but the silt was affected. And the concentration of radioactive elements in the silt under the cooling pond was up to 10-5 curie, while the concentration of radioactivity in the water was no more than 10-8 or 10-9 curie per litre.

tape 4, side a

But it was very quickly discovered that the water itself did not have much contamination, but the silt was affected. And the concentration of radioactive elements in the silt under the cooling pond was up to 10-5 curie while the concentration of radioactivity in the water was no more than 10-8 or 10-9 curie per litre. These were the maximum numbers.

A lot of dams was constructed, dykes, that were meant to hold the contaminated debris, foliage and all that had contaminated the surface of the water and prevent radioactivity from spreading along the Pripyat and the Dnieper. All this work was done by the Soviet Ministry of Water and by the Ukrainian Ministry of Water—done within a remarkably short time.

The dams were designed and built immediately but this was also accompanied by research work. Additionally, Celites were added into the bodies of dams—Celites, shipped from Armenia and Georgia, had a high sorption capacity—to capture all the microparticles and all the components of radioactive elements that were in the water and to prevent them from spreading further. As of today, we can say that this goal has been achieved.

Around the same time when the Government Commission was already final, led by Boris Yevdokimovich Shcherbina and there were no further substitutions or replacements, around that time, by a Government decision, a Coordinating Council for the Chernobyl issues was created in the Academy of Sciences, led by Anatoly Petrovich Alexandrov, and I was assigned as his First Deputy. The composition included heads of the main institutions associated with the work around Chernobyl and also leading experts, such as academician Sokolov, academician Mikhalevich and academician Trefilov, who were associated with particular tasks of ecological or technical nature related to the liquidation of the consequences of the accident.

It needs mentioning that when the work became organized like this, when the effort was distributed across various institutions and supervisors, then, of course, there was much more order and clarity than in the first days when all the emergency problems were solved but not all work had gone smoothly.

For example, the status of contamination on the roofs of buildings of the 3rd and 4th blocks was measured many times. And, each time considerably different figures and results were reported, from astonishingly high to relatively moderate. That’s why I personally and also the military specialists [had to go there]—who by this time had very successfully deployed a research centre at the village of Ovruch that allowed a large contingent of military specialists to consciously perform decontamination tasks, measurement tasks, all the tasks that they had been assigned. This centre was doing very extensive work on measuring radioactivity and the release of radioactivity, on wind transfer, on the dynamic conditions of various areas, and made a big contribution to the scientific research and practical plans of all this work done in Chernobyl. And these problems were not easily solved.

For example, not far from the station was a heavily contaminated forest (up to several roentgens per hour such radiation at the beginning it had) which was named the “Red Forest”. Here is the fate of this forest. Various suggestions were made. First, to not touch it and leave it as is with its radiation, counting on nature itself to somehow recycle it all, that is, the needles, that are the most contaminated, would fall off, after which the needles could be gathered and buried, while the tree trunks, branches, all these would remain relatively clean. The second proposal, conversely, was to burn this entire forest down and even experiments were carried out on burning parts of this contaminated forest. But these experiments showed that the products of combustion will nevertheless carry away a large amount of radioactivity with them. Finally, a decision was made to chop down part of the forest, transport it, bury it, and to simply convert the remaining area into a burial ground, to restrict access to it, which has been done. And the radioactive impact of the “Red Forest” on the city and its surroundings sharply decreased after the said operations were carried out.

A big discussion arose about the so-called Compton effect. Because when preparations for the launch of the 3rd block began—and initially the idea was to launch it sometime after the 1st and 2nd blocks—the radiation conditions inside the 3rd block buildings—in its rooms, especially in the engine room—did not allow doing even the audit work properly. The first assumption was that it is the internal contamination of the building. After decontamination was carried out, the level of activity in this room lowered but still remained relatively high, reaching tens and sometimes hundreds of milliroentgens per hour at certain spots and up to a roentgen per hour at other spots in the engine room. Then an initial assumption was made that the source of such high activity was the roof of the 3rd block on which was a lot of scattered fuel. And this was preventing the creation of acceptable radiation conditions. Because even though the more than 600 rooms of the 3rd block were cleaned, washed, the radiation condition in the engine room nevertheless remained quite high.

So we started taking various measurements using a specially-designed collimator, which showed that the activity on the roof is not the only source affecting the radiation conditions in the 3rd block. It was the neighbouring 4th block which because of the Compton effect—the reradiation and reflection of a part of the gamma rays coming out through the roof of reactor number 4—was the main source of the elevated radiation environment in the engine hall of the 3rd block. So many discussions were had on this topic, so many surveys, so many measurements, and in the end, it turned out that the main source of contamination was the contamination on the roof of the 3rd block. This was the main cause. Although, of course, the Compton effect had its share in the radiation environment; somewhere around 10 milliroentgens per hour and maybe even less than 10 milliroentgens per hour was radiated from reactor number 4. That's why a decision was made to completely replace the roof of the 3rd block, put in a new one with appropriate safety devices that would allow the necessary work to continue and launch the 3rd block of the Chernobyl NPP in time.

Around the same time when the fate of the 3rd block was decided—well, because of such conditions its launch had been delayed from summer, for when it was planned, to autumn—the necessity of setting up and launching work on the 5th and 6th blocks was very keenly discussed. These blocks were in very different states of readiness. The 5th block was almost ready and could practically be launched within a few months after decontamination, and the 6th block was in the initial stage.

There were considerable discussions. The public was protesting against the continued construction of the 5th and 6th blocks and their entering into service, because they felt that it was too much power, 6 gigawatts, on a single site, especially in abnormal radiation conditions. Ukraine’s energy demands dictated the need for introducing more and more power capacities. This question was discussed at the Government Commission and was escalated to higher levels, and ultimately it was decided to defer the issue and that in the next year, 1987, and possibly in 1988, no construction work will be done on 5th and 6th blocks. All the effort of decontaminators needed to be focussed on fully normalizing the conditions in the 3rd block and also on cleaning the construction base. There was a construction base on the territory where machinery and materials needed for the construction of the 5th and 6th blocks were stored. This base was quite contaminated. So to save the considerable amount of expensive equipment stored there, a special workshop was constructed at the Chernobyl Nuclear Power Plant, a decontamination workshop. And this workshop began to regularly decontaminate the most valuable equipment and send it to various parts of the Soviet Union for practical utilization.

At the time when active work began on the decontamination and launch preparation of the 3rd block, at the same time work truly unfolded not on the planning but the construction of the city of Slavutych. And the pace of construction was increasing all the time and this made a lot of sense because, after about 4-5 months of operating the 1st and 2nd blocks in a shift mode of work, it had become obvious that psychologically and even physically it was very hard work. Even with long breaks for rest, the operators still had to be at the control panel for 10-12 hours. There was a problem of prolonged separation from families, working in unusual conditions. All this created such problems that it became evident that the shift method, in this case, was certainly not optimal. It was a forced measure that had played a big role at the time when it was used. But to make it the primary method of work based on that, it was absolutely obvious that this was impossible. Therefore the speed of construction of the city of Slavutych, as the main city of power engineers, was greatly increased. For example, Boris Yevdokimovich Shcherbina, as I remember, made such trips almost every month to monitor how the construction of Slavutych is progressing, how equipping is moving along, how facilities are being outfitted. In other words, this issue was constantly under his control, as were all the other issues related to the Chernobyl accident.

Somewhere in the middle of 1987, in the summer of 1987, finally appeared robots made by our own Soviet hands. For example, robots made at the Kurchatov Institute of Nuclear Energy. These were reconnaissance robots which we couldn’t get in time from anywhere, from any country in the world. So we made these recon-robots ourselves that, in the most complicated geometrical conditions, in wreckage, in high radiation fields, could advance to practically any distance in a guided manner, and do radiation and thermal reconnaissance of the situation, provide the needed information. These robots have played a huge role even today because many interesting things have been discovered with their help regarding the questions related to the nature and consequences of the accident. But I am not sure that they will gather any additional information.

Another idea that I have repeatedly talked about and asked to be implemented—it has not been implemented yet—is the idea of creating flying robots, that is, radio-controlled aircraft models that would carry sensors on them. Sensors for radiation fields, sensors that could measure the composition of gas at various locations in the Chernobyl NPP. Well, so as to not use… [TAPE ERASED]

This text is for comrade Novikov Vladimir Mikhailovich, Dyomin Vladimir Fyodorovich and Sukhoruchkin Vladimir Konstantinovich. It is about an article that was requested to be written by the magazine Scientific American and must have a summarizing philosophical character. The provisional title of this article is “The reasons that led to the Chernobyl accident and its consequences”. The article should be based on my papers, comrade Dyomin’s papers, comrade Novikov’s papers, comrade Sukhoruchkin’s papers, but, nevertheless, these papers must be collated and processed in such a way that an integral philosophy emerges from them.

The first part of this article, I think, should be about the history of the development of Soviet nuclear energy, to remind that the world’s first nuclear power plant … [TAPE ERASED] … and the principle of safety provisions in this small 5-megawatt station. At that time, the entire protection system was copied, probably from … [TAPE ERASED] … that existed in the industrial reactors and was using accumulated military experience. Then the second station, Beloyarsk nuclear station, where graphite was used as an inhibitor, but that it was already a fast-neutron reactor, and such research, and well, describe its working principle.

Thereafter, talk about the Novovoronezh station, the 1st block of which has already been built as a nuclear station designed to be operated in a continuous mode with a civilian crew, and describe the protection systems that have been used at that station.

Then, we will need to mention that both during and after the construction of the Novovoronezh NPP, the policy of our government did not attach any particular importance to the development of nuclear energy; because it was believed that by using organic sources of fuel—coal from Donbass, gas from Saratov, and then the oil reserves—we would be able to fulfil all our industrial needs; and that the nuclear energy demonstrated at Obninsk, Beloyarsk and Novovoronezh stations was more in the way of scientific research that prepared us for some future.

Explain that this, in fact, was a miscalculation in terms of resources—the capacity of the Donetsk Basin to supply coal was overestimated—and also a miscalculation in terms of transport and ecology, because at the time we did not understand the extent of land transport if energy is based on organic sources or the extent of pollution including radioactive elements.

All this must be described. This is important because of this. It is important to say that an approximately 10-year delay in the development of nuclear energy in the Soviet Union was the first cause of the Chernobyl accident, the first swallow, the first knell. Why? Well because it was already clear in the 60s that it would be expensive and practically impossible to develop industry in the European part and provide it with electricity from organic sources. And that it was necessary to put nuclear energy sources into operation, to do this quickly. And so there appeared a kind of natural desire to somehow minimize the spending on the rapid development of nuclear energy. And here, at this moment, the main fundamental philosophical mistake in our approach to safety was made.

Any approach to nuclear safety of a technologically complex and potentially dangerous device must have three elements. First, make the device itself, say, a nuclear reactor maximally safe. Second, make the operation of this device maximally safe and reliable. But the word ‘maximally’, in both cases, can never mean a 100 per cent reliability. Equipment can never work at 100 per cent conditions specified by the project, and fully exclude all human error, accidental or perhaps even intentional. This is impossible.

And because this maximally-safe reactor and maximally-safe operation are not always a 100-per cent safe, then the philosophy of safety requires mandatory implementation of the third element—the element that presumes that an accident will happen; and that radioactivity and other dangerous material will get out of the device. And, for these cases, a mandatory element is enclosing the dangerous device in such a mechanism that would localize the accident which, despite low probability, could still happen. It would enclose the object in what is called a containment (maybe an underground option or other possible engineering options), but the most important for reliability is to have a system that does not rely on a geographical site. And in the event of unlikely but possible troubles, these troubles would not spread to the surrounding environment, as is the case with accidents in mines. This is the third element. In Soviet nuclear energy, precisely because of the pace that had to be quite high, because ten years had been lost, this third element, from my point of view, was criminally ignored.

In fairness, I must say that many experts of the Soviet Union spoke, and very actively spoke, against the construction of nuclear power plants without containments. In particular, the corresponding member of the USSR Academy of Sciences Viktor Alekseyevich Sidorenko in his doctoral thesis, and later in his book based on this doctoral thesis, was proving by all means available to him at the time, that containments were necessary. However, this point of view of the experts was not considered.

There is another definite circumstance to it. Nuclear energy in the Soviet Union has not emerged from the energy sector but from, as it were, the nuclear industry; where highly trained and disciplined personnel were used, where special military acceptance was in place for every piece of equipment; and consequently the reliability in this sphere of nuclear industry, both from personnel and equipment point of view, was very high. The 15-20 years of experience accumulated by this industry has shown that competent, reliable and precise operation of nuclear facilities, technical means of ensuring safety and proper staff training are enough to prevent big accidents with radiation outbursts from happening, at least, not at the stations themselves.

It was not taken into account that after the nuclear facilities move from limited industrial environment to wide usage in civil nuclear energy, the conditions will change drastically. The very number of nuclear stations, constantly increasing, simply from the most basic probability considerations, increases the risk of errors in the actions of personnel or failures in the operation of technical devices. So, from my point of view, this was a philosophical mistake; allowing operation of stations without an external localisation shelter. This mistake was fundamental.

Since when has this mistake begun to be corrected? Since the Soviet Union entered the foreign market and started constructing the first nuclear power plant for a foreign country, for Finland. As a customer, the Finnish side demanded, having studied international experience—and by this time, an international standard had developed requiring precisely the three elements of safety: a reliable reactor, reliable operation and mandatory containment. This third element was requested by the Finns. That is why the Finnish station was constructed with a cover. After this, the ice melted. The energy leadership started to regard the importance of this element with great understanding, although without fully realizing the seriousness of this issue themselves. And our design organizations started to work with containments.

The second consequence of the delay in the development of nuclear energy was the fact that there were insufficient production capacities for, say, VVER reactor shells. And it still is the most common type of reactor in the world. And its construction and operation can take into account not only our own experience but also the experience of the entire world community. So, the machine-building plants did not have enough capacity to produce the shells and other equipment for VVER reactors in the needed quantities. This is when a section of the energy community came out with a proposal. So as to not limit the plans to introduce new nuclear power capacities and considering the overload of the machine building industry, create a parallel branch in nuclear energy that would allow building sufficiently powerful reactors without using the shell concept, without burdening the machine building industry with the complex technology for manufacturing highly reliable reactor shells that are required for VVER reactors. This is how the idea of channel type RBMK reactor with graphite blocks, etc came about.

If the philosophy that mandatorily required a containment over any type of nuclear facility had been developed, then naturally RBMK, with its geometry, with its construction, as a device would simply not have appeared. It would be, so to say, outside international standards, outside international regulations. No matter how reliable or good it was in its other characteristics, it would not appear. But since this philosophy of mandatory containment was not adopted by the leadership of nuclear energy of the time, the RBMK reactor did appear.

This is why I believe that the beginning of the Chernobyl disaster must be counted from the slowdown of the development of nuclear energy in the late 50s and early 60s. After creating the first nuclear facility, we then slowed down the development of the technology of their creation, the consideration of all the safety issues related to the operation of these devices, and later we started to rush. And this rush led to a need to build more devices at the same cost. There was a need for saving. We started saving on containments. And once containment became optional, temptation arose to build another [reactor] line that would help the country without overloading the machine building industry. This is how the ideology of RBMK reactor appeared.

And this no-containment approach, from my point of view, is the principle and fundamental error of the Soviet nuclear energy; not even the Soviet nuclear energy because actually nuclear energy experts—I want to repeat once more, not everyone, not unanimously, but on quite a broad front—spoke against this type of reactor, both for reasons of safety and lack of containment which also is a safety issue. Already the first launch of this reactor in the first RBMK unit of Leningrad NPP has shown that such a large active zone, implemented in the way it has been, was very complex for the operator. During the initial launches of the first unit at the Leningrad nuclear station, there was a problem of instability of neutron flows and difficulty in managing them. This had to be changed on the go. The degree of fuel enrichment, a number of other technical measures had to be taken to make controlling the reactor easier. But yet, even after these measures—and all the experts in the Soviet Union knew this—from a control point of view, this reactor required a lot of attention from the operator and always was quite complex.

Besides, the very fact of the appearance of this RBMK device, from the perspective of international and generally normal safety standards, was illegal—the fact of its appearance. But, additionally, at least three major design mistakes were made in this device. The first design mistake was that there should be at least two emergency protection systems, as required by international standards and as common sense suggests. Moreover, one of the emergency protection systems should be based on physical principles different from the other one. And more importantly, from my point of view, one of the two systems must operate independently of the operator. This means, let’s say, one emergency protection system must be controlled by the operator automatically, semi-automatically or manually depending on the mode; and the second emergency protection system must work independently, whatever the circumstances of the operator may be, based only on an increase in parameters, say, neutron flow, power, temperature, etc and must automatically shut down the reactor. The RBMK reactor was not equipped with such a second protection system that was operator-independent and not part of the control system. This is a big mistake and had it not been made, the Chernobyl accident would not have happened.

And finally, the third design mistake, which is hard to explain, was that all the numerous emergency protection systems were accessible to the station staff. For example, there were no special double cyphers to turn off the protection systems where protection could be disabled only by using a double or even triple command—by an operator turning a key; by a simultaneous turning of a key by, say, the shift supervisor and maybe even by someone specifically responsible for safety; by a simultaneous turning of a key by the head of the station, the chief engineer or his deputy. Such technical means and devices which are generally used in many military systems, in missile complexes, in nuclear weapons, had not been used. This, of course, seems surprising and strange.

As I already said, the RBMK device is not easy to operate because instabilities, that are possible in principle, frequently occur in its working modes and this makes having simulators near every RBMK device more important. These simulators would allow continuous training of personnel to properly react when a deviation from normal operation occurs. However, for this particular device, as a matter of fact, there were no simulators.

It must be added, however, that a number of challenges with this reactor were solved very well. For example, a number of advantages of this device are already known, such as, firstly, indeed, the possibility of constructing the device without using machine building industry capacities—I mean the absence of a casing for the reactor; the possibility of refuelling the reactor while in operation allowed for having a high coefficient of power utilization in this reactor—the channel principle itself of this reactor; a number of other technical decisions—pumps that were highly reliable in this reactor. These were small advantages, of course, but nevertheless. Also, the fundamental lack of containment, as practice has shown, cannot be compensated by the tightly sealed compartments. And this issue turned out to be principle.

And, of course, it must be said that the positive reactivity coefficient in this device turned out to be unexpected for the physicists. This again was related to the first reason, the rush, with the necessity for a high pace of development of nuclear devices. Because, in principle, with the correct configuration of graphite and with less volume inserted into the zone, this graphite inhibitor could, of course, hold the vapour coefficient within allowable quantities. As practice has now shown, the sum of measures that have been taken for this reactor has made the vapour coefficient to be no more than one beta. And this value is already quite controllable and allows, with proper fast protection devices, to manage any processes. But this had not been done before and the device worked with values of positive reactivity coefficients much higher than a beta in the first place.

Secondly, what was calculated turned out to be significantly higher in practice than was accounted for because physical knowledge about this device was still not sufficient. This is the group of reasons that led to the trouble I wanted to speak about. And so, it's not about the operators …

Of course, the mistakes made by the operators are well known and there is no need to list them yet again. These mistakes themselves are monstrous. The actions of the station management are very hard to explain. Punishing the direct culprits of this disaster is correct because the actions did not meet regulatory requirements and showed inconsistency with the job requirements of the people who were acting in this situation. But still, this is the fault of the officials. But the main reason is not even the errors in the design of the reactor—which of course had their place and for which probably the respective specialists will have to answer—but the main reason is the violation of the basic safety principle for such devices. The lack of and the unprompted removal of the third element—placing dangerous devices in a kind of mandatory capsule that would limit the possibility of activity leaving the station or the device itself. This is the main reason for the magnitude of the accident. This is the thesis I want to be developed when we talk about the causes of the accident.

The next thesis relates to the particular specification of the design of the device, the defects in this design and the sequential description of the causes that led to the accident itself. First of all, it must be noted that this is an experiment that should not have been performed at a nuclear power plant, because the value of turbine coastdown at idle is something that should be measured on a special stand built by the designer of the turbine. And I want this to be underlined. Exactly there is where this question had to be experimentally verified. But it was not. This is what forced the station management, apparently out of good intentions, to perform this experiment— firstly.

Secondly, the absence of systematic thinking on the part of the station management involved with this case. When the first experiments in 1982 and 1983 showed that during a coastdown, the turbine does not maintain the necessary electrotechnical parameters to serve the station’s own needs, nobody even thought about solving this problem from the other side, more precisely, reducing the time needed for the backup diesel generators to start and output at the required levels. But they went in the direction of increasing the coastdown time of the turbine, when, at this time, there already were diesel generators that could output at the required electrotechnical levels two to three times quicker than those installed at the Chernobyl station. The most straightforward procedure would have been to replace the diesel generators at the Chernobyl power plant with those that would perform better and all that process of tests and checks would simply have become unneeded. This fact should be noted.

Now it is necessary to describe in detail how the experiment itself went, who approved it, who didn’t approve it, how procedures were violated and how the accident developed. Wherein, what is the most important element in this description? For some reason, many sources state that there was one explosion, or two explosions, or a hydrogen explosion, or a non-hydrogen explosion. As of today, it has been absolutely reliably established, and it must be unambiguously written, that there were two consecutive explosions, the second more powerful than the first. This must be noted.

Secondly, we cannot talk about the hydrogen explosion without mentioning that, in addition to the steam explosion, chemical energy related to interactions within all that molten mass was added. It must be said that all the quantitative assessments show that the power of the explosion was equivalent of around three to four tons of TNT. Today, this number can be called a reliably established number so that numbers like in tens of tons or kilotons, etc don’t go around. Three or four or up to ten tons of TNT, this is the maximum that can be said.

By the characteristics of the explosion, by the glow, by the dispersion, it is clear that the system had a volumetric-detonation explosion. There was a volumetric detonation. The explosion was volumetric in nature. This means that a rapid expansion of steam, constantly thermally heated, led to the damage that was witnessed. And further, figures of fuel release, they are less clearly known.

Then we must describe the accepted scenario of what happened in the reactor with the fuel: the time when it started heating, the time when it stopped heating, the cooling system and so on. And it is very important to describe the measures that were taken and their significance. For instance, did a one-day delay in taking action have any effect at all? On the first day, the 26th, except pouring water there at night, nothing was done on the night of the 26th. The dropping of, say, sand, dolomite, clay started around the 28th. The first drops were, it seems, at the end of the day on the 27th.

All this has to be thoroughly described because it is necessary to precisely write about the physical implication of each action. Because it was as follows. For example, firstly, per the thinking of the Government Commission, there was an option to not do anything and let the graphite burn. But that would mean ejection of radioactive graphite particles over large distances. The maximum rate of combustion under the temperatures we established (the temperature of graphite combustion) is around a ton per hour. So you can calculate. Given that there are 2,400 tons, the burning would have continued for 2,400 hours. In this time, there would be an emission of radioactivity in aerosol form over large distances. This meant that the graphite fire had to be extinguished first and foremost. This is why sand was used as a means to put out the fire.

tape 4, side b

Secondly, once there was sand, it meant that there was thermal insulation, bringing additional trouble from possible heating of the area. Hence, elements like dolomite and lead were introduced. Lead is difficult to oxidise; dolomite decays. Endothermically, lead takes heat to melt; dolomite also takes heat to melt; SiO2, sand itself, also takes heat to melt. This is how a lot of the heat was absorbed by endothermic processes.

And finally, elements such as clay, for example, served as filtering elements meant to prevent part of the radioactive isotopes from getting into the external environment. All this reasoning should be correlated with actual graphs: when what was emitted and when it stopped. In particular, it must be said that not all measures were prudent. For example, the injection of liquid nitrogen that was done per my proposal made around the 2nd of May and implemented around the 4th or 5th of May. This measure turned out to be pointless because when I had proposed it, the extent of the destruction of the reactor was not yet known and neither was known the natural air circulation, its natural flow. But after some time, we calculated that the airflow is so high that injecting and diluting it with liquid nitrogen would not have any effect. First of all, it leaked through the side gaps and practically passed by the reactor area that had the fuel; and secondly, its quantity was calculated entirely incorrectly. This is why we discontinued injecting liquid nitrogen. This measure did not prove to be useful in practice.

About lead, it must be noted that our initial plan was, of course, to put metal, iron shot there. The shot was on station territory but it was in a room that was heavily contaminated, making it impossible to load it into the helicopters. Also, we didn’t know the exact temperatures at various points of the destroyed Chernobyl reactor. Say, for the uppermost points, we found that the temperature range was around 300-350 degrees [Celsius]. For this temperature range, lead would be the most suitable element which would additionally act as a shield against radiation. For areas with higher temperatures that were located lower, we needed to deliver the metal, but then it would generate additional energy because of overoxidation. That is why we chose SiO2, sand, which would perform the same function, that is, melting, flowing in the same way as dolomite; because magnesium oxide [sic] is a relatively good conductor of heat, the most conductive among all ceramics. This is why all these measures were quite sensible.

Now, with the introduction of all these elements, such as lead, for example, we assessed if there would be lead contamination in the area. We calculated simply. 2400 tons of lead was dropped. The assumption was that all this lead will get into the hot zone and evaporate, which is impossible because most of it condensed at the upper levels. Then we assumed that even if all the lead evaporates, we took the 30-kilometre zone and derived that everything [contamination in this zone] would turn out to be less than the permissible concentrations. At least later, comrade Izrael, with his associates, measured lead concentration both in the air and on the ground. And it turned out that it was determined solely by the lead that comes from automobile exhaust pipes from leaded gasoline. And against this background, against the background of lead contamination, to detect lead contamination caused by the 2400 tons scattered around was almost impossible. And there was a lot of talk about lead poisoning. That is why the calculations had to be very precise accounting for all the measures that were taken.

Then a few words need to be said about the concepts for the sarcophagus construction. There were 17 projects but only two or three need be described. The first concept, the embanked mound, and why we rejected that. Then the second option, a sarcophagus but with a concrete dome; why we rejected that—because the structure wouldn’t withstand it. Why the concrete dome, which would certainly have been better, was replaced with a pipe run and a suitable metal roof. These circumstances need to be explained.

It is necessary to explain the following facts in this order. This is very important. No country in the world... and quite a few countries responded to our trouble, sent telegrams, proposals, etc. We became convinced that no country in the world had a proven, experimentally verified action plan for such a situation. This is the first circumstance.

The second one. There were no dosimeters with proper scales for minimum to maximum doses. There were no unmanned aircraft that could be fitted with the necessary measuring equipment at the time of the accident, in the beginning, to be precise. This forced us to use manned helicopters, which in turn caused additional radiation exposure for the people and made these flights dangerous because the helicopters could collide with some structure and lead to the destruction of, say, a neighbouring block.

Going back a bit, it has to be highlighted that the actions of the firemen were logical. Because many journalists, and in plays, write that the firemen needlessly stayed there for several hours and got exposed to high radiation doses as a result, etc. Their actions were rational. Because there was hydrogen in the generators in the engine room; there was engine oil. And they expected that the fire could spread to the 3rd block and cause damage there as well as in reactor number 4. This is why their actions were truly selfless and, most importantly, rational; and not just some pointless actions arising out of ignorance.

Further still, we must return to the fact that neither work nor reconnaissance robots were available in any country in the world. We bought and tried robots from other countries but they failed either because they could not overcome the obstacles in the destroyed block, or because they could not be controlled when electronics failed due to the high gamma fields. And only recently—this must also be described—have our own reconnaissance robots been developed at the Institute of Nuclear Energy.

It is necessary to talk about the management scheme for the process of liquidation, that is, about the separation of functions. There was a group that investigated the causes of the accident; a group that was occupied with decontamination and preparation for the launch of the first and second block; a group that worked on analysing what is being done in reactor number 4, the wreckage, diagnostics, research and other necessary things; a group that worked on the design for the sarcophagus itself; a group that worked on the construction of the sarcophagus; the army group that carried out the decontamination of the territory; a group that built new living spaces for the evacuated population; a group that worked on establishing decontamination posts to control transport and to wash and clean it. All this must be described in the most thorough and detailed manner.

After that, as I see it, there should be a section named “Current status” where it should be stated that there is a Coordination Council in the Academy of Sciences, that includes heads of departments responsible for the relevant type of work—Gosagroprom, Minsredmash, Minatomenergo, etc.—as well as leading scientists-experts from the fields of medicine, radiology, agriculture and so on. And that this Coordination Council systematically analyzes the situation related to all the circumstances around this Chernobyl accident. This organizational aspect should also be described.

Then, have a section by Vladimir Fyodorovich Dyomin wherein simply describe the following clearly. How many areas, and people, were affected and to what degree; what has already been restored and what hasn’t. All that is related to the consequences, from the injured people to the damage to the Red Forest, must be accurately and clearly described. The psychological factors arising out of the liquidation process must, under no circumstances, be forgotten. Because a whole array of illnesses found in people, a whole array of phenomena related to the personnel who survived this tragedy, were not related to radiation sickness. This was unambiguously established by the doctors. But nevertheless, the psychological shock and, say, because of that psychological shock, cardiovascular dystonia was found in a large number of experts and continues to be found up until now. The shift mode of work, all that was experienced, etc.—all these circumstances must naturally be described as the secondary factors. Here, the doctors have a lot of information and, I think, Vladimir Fyodorovich knows it well. If not, I can suggest all that is needed.

In the next section, after the consequences of the accident have been described, the current research and agricultural measures that are being carried out right now must be outlined. What has already been discovered, what is encouraging for us, that is, I mean, the accumulation of radioactive elements inside fish and animals that are inside the 30-kilometre zone, what is not frightening, what is useful, what is useless, the behaviour of the various tree species, all the Gosagroprom findings, only those that are currently very obvious—these should be described. And conclude this section about the consequences with such normal words—that this is a long-term program, that the consequences of this accident will manifest themselves for many, many years, and describe how they will manifest, and that the research front is a broad, so to say, rough plan. It is possible to safely talk about the programs that are led by Ruteny Mikhailovich Polevoy who established several of them. They can be regarded as the directions work should take. All this has to be done.

Talk about the various organizations that are involved both on the site and in their offices; about the medical radiology centre that has been created there. All of this, in my opinion, has to be described in this section as obvious and clear.

This section cannot be concluded with only the obvious and clear things. A whole variety of questions must be posed. For instance, we are not clear why there was not complete conformity in the decline of radioactivity in reactor number 4. In some areas, it reduced faster than predicted by the laws of radioactive decay. There are various theories but those are only theories. Therefore, we still cannot fully explain this phenomenon but there are such theories.

There are unsolved issues. For example, those remarkable photographs that are on my table, brought by Nikolai Nikolaevich Kuznetsov, where spruce has transitioned into pine form, that is, when spruce twigs start to branch in the same way as pines. And that we are starting to research the cause of this phenomenon which, it needs to be said, is not clear to us. And all this should be collected into a group of unanswered questions, where we have the facts but no full explanations for those facts. This, as it seems to me, should be recorded because it would be foolish to say that everything is already fully apparent to us, fully clear.

By the way, looking back, I want to say once again that the question of how positive reactivity was added is a matter of discussion. Because there are various ways that could lead to the addition of positive reactivity in such an uncontrollable reactor. None of them unequivocally corresponds to all the experimental facts; that is why discussions are ongoing. But actually, that doesn’t have particular significance. Because the main thing is that, in principle, it was possible to add positive reactivity with such a strong acceleration. This is the main thing while the specific details are not so important. Because the discussion itself shows that there were several ways to get the reactor to the state it was in.

After the section by Vladimir Fyodorovich, I see that Vladimir Konstantinovich must be involved in two ways. The first way is to briefly, clearly and plainly explain that, from the very beginning, the Soviet Union did not conceal anything. There are questions like why was it announced so late? Well, because no one knew exactly what had happened. No one wanted to start a panic or give out wrong information. And what international measures have been taken, what conventions have been adopted, what was the Soviet position on international cooperation. This part has to be stated as the completed part.

And further, to develop a philosophy that, as the experience of the Chernobyl accident shown, any device can cause trouble not only in the country where it is located but also in the neighbouring countries; and cause not only radiation damage but also economic and psychological losses in those countries. The questions of international inspections, quality checks of constructed facilities, etc, to create this international procedure ... it is necessary to express this desire and this, in my opinion, would be right.

Broadly, the international tasks section should be split into two parts. The first part should be about what the Soviet Union has done in the international arena—what material it has presented, whom it invited, who hosted, whose help it accepted and whose help it refused. And the second part should be about how it will be necessary to inspect, control and mutually verify the level of safety in nuclear energy in the international plan. I think that Vladimir Konstantinovich should develop these points.

And finally, the last but, from my perspective, the most important section. It should begin with the measures that are planned in the Soviet Union to increase the safety of nuclear energy. Well, they are listed in the reports presented at Vienna. They must be included. Such and such things are planned. Such and such things have been implemented. And then, from the position of Vladimir Mikhailovich Novikov, state that the level of device that we currently have is probably sufficient to ensure that Chernobyl does not happen again. Although, I must say that for those devices that do not have containments, these measures will probably not be enough. We need to think about some special measures to localize accidents for those 28 devices that don’t have containments.

It is clear that these localisation measures must be dynamic because it is economically and technically impossible to build containments over them. And these non-traditional dynamic localisation methods for possible accidents at such facilities need to be thought about by us today, well, mainly by the Soviet community because it is our problem; although we would happily cooperate internationally for this task. This is the problem. So this is what it is. Today, our measures are planned; such and such have been implemented and such and such issues worry us.

Next comes the philosophy. Can the Soviet Union, for example, limit the number of devices that are there, gradually put those that have no cover out of service, and hence, switch to fossil fuel. Kuzmin and my work can be used here that considers this particular question—whether it is possible to do without nuclear sources in our country which is so rich in fossil fuel—and shows that it is impossible. That we will need nuclear sources in an ever-increasing amount, firstly due to economic considerations, resources and secondly, environmental. And most importantly, emphasize that nuclear sources, as any previous sources, are not only the bearer of energy but also the bearer of new technology. It can be taken from my older works that we mostly use heat, radiation, today; but actually, it is possible to produce synthetic materials, to alloy, modify, remove impurities in nuclear sources more simply and more economically than is done today in, for example, chemical or metallurgical industry. This is one more proof that we cannot do without them.

And thereafter would be the concept, developed by Vladimir Mikhailovich, about what safe nuclear energy should look like. I will not talk about safe reactors because the requirements formulated by Novikov are very accurate. But the full cycle of nuclear fuel safety must be added to those requirements. And quantitative estimates must be made for the processing and enrichment plants, similar to those that were made for the reactor. Considering the latest accident in Brazil, it is even worthwhile to mention the use of radiopharmaceuticals and the forms of their use. It seems impossible to stop using them but how can their use be made safe.

The question should be thought through in such a way that the understanding of safe nuclear energy is as wide as possible and not limited only to the question of creating a safe reactor. And I would very much like to ask to make such a statement that, as of today, we do not have safe nuclear energy, or a concept of safe nuclear energy, or even a concept of a safe nuclear reactor that is completely ready. And since the number of such [nuclear] devices must increase, the problem becomes urgent. The time available to solve it is not too small but not too much either. It is about 15-20 years within which all the questions we are discussing here must be resolved. This, roughly, is the structure according to which all the material should be prepared. And I repeat that it should be based on the work we have previously done so that we refer to our own sources and not someone else’s.



Legasov: First of all, you would imagine that I have some special place in this whole story because I’ve been in the field of nuclear energy for 15 years. However, my position is somewhat distinctive. I am a radiochemist, that is, in the designing of reactors, for example, I am involved only from a position of being present at the board meetings to listen to the discussions, debates, etc. that happen there, from which I, of course, gain a perspective. But as you can understand from the talk, I am the director of my own department that supports the nuclear fuel cycle, that is, separating the isotopes, disposal of radioactivity… My position is of an external observer, as it were, and also of a participant.

But my participation in the events at Chernobyl was certainly justified because there was no reactor anymore, just its remnants which is my direct speciality. This is nuclear and non-nuclear chemistry. One must understand which processes are happening with the radioactive elements, how they differ from other processes, what can be introduced and what that will lead to. This may have been a truly random coincidence but this is really my direct speciality.

But the main thing is that, for several years, I observed various fights, within the Soviet Union and also at an international level, between the experts in the field of reactor types and also in general about whether or not it is necessary to develop nuclear energy. At the same time, under my leadership, work developed in the field of safety of chemical production, which also poses a great danger. So, from a strictly professional perspective, I understand the safety issues, and how to manage them, very well. This is why I am such a confusing figure; because, on the one hand, I know the questions of safety in their overall philosophical form, how they should be posed and solved, I know the nuclear fuel cycle and its external parts, and [on the other hand] I was an observer of the reactor saga.

Chernobyl began, in my opinion, conditionally of course, in 1961; that is, in the very year when Gagarin flew into space or at the time of the last highest achievement of Soviet science and technology. Although I generally believe that our science and technology has developed very successfully, by hook or crook, surprising the whole world with colossal achievements in almost all fields. And the pinnacle of these achievements was Gagarin’s flight into space. After that, we began to give way sharply in all fields, give way and just started to decline. This general downfall of Soviet technology, the reasons for which can be discussed extensively and for a long time, it was simultaneously the beginning of Chernobyl. This is not an abstract statement and not in the sense that we had begun to lower the general technical culture. Rather, it is a concrete statement.

The fact is that, as you know, the Soviet Union was the founder of nuclear energy. We built the first power plant in Obninsk near Moscow. Then we built the Beloyarsk Nuclear Power Station and the Novovoronezh Nuclear Power Station. And then stopped the development of nuclear energy. This was in the late 50s. Because such a belief prevailed that we have enough Donbass coal and that we don’t need to develop nuclear energy. So we, after pioneering its development, stopped its development for 10 years. And the three nuclear power plants, Novovoronezh, Beloyarsk and Obninsk were like playgrounds for scientists, where researchers solved their problems. These are three different types of reactors. They had their peculiarities that they [scientists] were researching. But nobody thought of nuclear energy as a large-scale phenomenon.

And at the same time, England first and then the United States of America began to develop their energy sector, not as separate nuclear power plants but as a nuclear power industry. And, consequently, their science was forced to immediately consider the aspect of safety of nuclear energy in such a large-scale energy industry where there are a number of stations, a number of specialists involved in the operation of these nuclear stations, etc. Whereas our Gosplan made a potent miscalculation, based on an assumption that we have enough fossil fuel that will last for a long time and that we would practically not need nuclear energy. But sometime around the 60s—61, 62, 63, around that time—it became evident that a miscalculation had been made. That the European part of the Soviet Union, where 80 per cent of the population and industry is concentrated, will not survive on shipped fuel; and Donetsk coal became too expensive and too little. And shipped fuel is quite expensive; economically, transportation-wise and environmentally expensive. It became clear that it is impossible not to develop nuclear energy. The European industry will not survive without it.

In fact, because of ecological reasons, and many people do not understand this, it is impossible not to develop [nuclear energy]. Supposing, for a moment, that we take a Politburo decision to shut down nuclear energy; we stop the presently-operating nuclear power stations and do not build new ones; then immediately, straightaway, as a result of this, the level of radioactive contamination of our territory and our people would increase incredibly. Just radioactivity; I’m not even talking about carcinogens and other things. Why? Well, because many radioactive elements have accumulated inside coal and oil seams over the centuries. Moreover, these are specifically the long-living isotopes and the most dangerous: alpha-active. For example, the Kansk-Achinsk coal basin, just in its upper layers, contains 2 million curies of alpha-active, long-living isotopes. As soon as we start to actively use the Kansk-Achinsk basin, we will start to saturate our own lungs with radioactive dust along the roads on which this coal is shipped and also when we burn it. Therefore, the fewer nuclear power plants and the more coal and oil ones we have, the higher the radioactive pollution will be under normal circumstances. This is a very obvious scenario.

Of course, it would be best to use what we all eagerly wish for, the alternative sources: thermonuclear, solar, НГД(sic), and the others. But, here, we must be honest with ourselves; that within the next 40-50 years, there will be nothing. Because even the best figures today show that, in solar energy, the cost of human labour will be a 100 times more for a unit of power, and the cost of materials a 150 times more, than coal and nuclear power plants. Undoubtedly, science will address this and things will improve but not by 100 or 150 times. Because of this, the share of alternative sources in the foreseeable period of 45-50 years will be 5-7 per cent. This share must be maintained in order to develop these energy sources but it cannot be the basis of energy [planning]. Thus, in this way, the inevitability of nuclear energy became apparent in the 60s but the pace was lost. And then, it became a scramble across Europe. But, money being limited, no investments were made for 10 years.

And here the fateful mistake was made, from which, specifically, Chernobyl began. What was this fateful mistake? The world accepts the normal standard of safety for any dangerous industry including nuclear power stations. This standard consists of three elements. One, make the reactor maximally reliable. Two, make the operation maximally reliable; trained staff, good discipline, easy-to-operate equipment, etc. And strive for maximum reliability everywhere. But, since the world understands that “maximally” does not mean 100 per cent and that there is always a chance of a technical component failing, even the most reliable one, or of a person doing something, by malice or ignorance or by accident, the third element is introduced. Three, all this dangerous industry with a maximally safe reactor, maximally safe operation, must compulsorily be encapsulated; enclosed in a containment as it is called in the West, placed under a cupola as we call it. So, if something, having a low probability but still, suddenly happens, it will remain limited to the area of the reactor itself. All the troubles will be restricted to the area.

And the main criminals... Of course. those who have already been convicted at Chernobyl are criminals because they committed unthinkable actions and they were convicted absolutely legally. Now the investigation, additional investigation is underway and, I think, will probably judge the designers of the RBMK reactor—at least they should be judged in my opinion—who made at least three grave mistakes in the design of this reactor. Grave mistakes. And perhaps they should bear criminal responsibility for it. This is my point of view but I don’t know how this will turn out.

But the main criminals are those leaders of energy in the 60s who despite the opinion of experts, and Soviet experts … Say, at our institute, there is corresponding member Sidorenko Viktor Alekseyevich; he is now the Deputy Chairman of Gosatomenergonadzor. He wrote a doctoral dissertation and later published a book at approximately that time, in which he proved the impossibility of having nuclear stations without containments, no matter the type, VVER or RBMK; that it was dangerous and criminal. But, as they say, they spat on him from the big bell tower [a Russian proverb that means to not care] because this made each station approximately 25-30 per cent more expensive. And since Gosplan strictly specified the funding for nuclear energy, this would mean 20-30 per cent fewer nuclear power plants would be built in a given time.


Legasov: No, as far as I know, Petrosyants was not specifically involved in these matters. It was the leadership of Gosplan at the time: comrade Baybakov, comrade Voloyants were involved, and comrade Slavsky was among the ones mainly responsible, and comrade Neporozhny. So this was the team: Neporozhny, Slavsky, Voloyants, Baybakov. However, Baybakov’s role was that he consulted Slavsky and Neporozhny as energy experts. And this wasn’t because there was no such knowledge. The knowledge existed; the experts, however, were not unanimous. Because in our Kurchatov Institute itself, the author of the development, Professor Feinberg Savely Moiseevich, now deceased, was advocating the possibility of a reactor without containment, particularly RBMK.

It is very important for me that you understand that had the international philosophy been adopted, had each reactor been inside a containment, then the RBMK reactor would simply not exist. Since it is a high power channel-type reactor and is assembled from many blocks, it would not fit inside any containment. And there wouldn’t be a designer's error because there wouldn’t be such a reactor. Now, about how it came to be and why. Since we were late by 10 years in the development of nuclear energy…


Legasov: Feinberg S.M. was a good physicist, of course, but he also got into this story. It was all tangled up.


Legasov: Anatoly Petrovich had nothing to do with the design of the RBMK reactor at all. But I will tell you about the role of Anatoly Petrovich Alexandrov later as objectively as I can. From my point of view, he bears some degree of guilt, of course, small. But he is too meritorious, has done too much for the country to talk about it in this way, but…


Legasov: No, that is just a mistake. He did say that about one of the reactors, the AST, a nuclear power plant of an entirely different type, which really is the safest of all that exist in the world today; about that he said that it can be put even in Red Square. I will talk about Aleksandrov’s role later but it is important for me that you understand that the main issue was the 10-year delay. Because once we were 10-years late, then before anything, the question arose ...

A line of cased reactors was developed in the world, similar to our water-water energy reactors VVER; like the one that had to be built near Minsk but will not be built now. But they required considerable machine-building capacities to build the case that the Soviet Union did not have. Building one case takes 2-3 years. And then the Atommash factory was specially built to make cases for such reactors.

The question arose that there are no cases, nuclear energy has to be developed, and then comrade Slavsky, the Minister of Medium Machine Building comes up with a proposal, in parallel with the VVER reactors…


Legasov: The VVER reactor is a large metal vessel in which the active zone is immersed in water. The water overheats; the pressure is 170 atm. The two-circuit system heats the water in the second circuit, and the water in the second circuit, turning into steam, drives the turbine. And the RBMK reactor is a single-circuit reactor. It has many zirconium channels in which water is heated using the fuel pellets and this water immediately enters the turbine and drives it. For this reason, in VVER reactors, power is limited by the size of the reactor vessel but in RBMK reactors, power is not limited by anything. Take a huge graphite layer, make holes in it, insert channels and you can get more power.

So, when it became clear that there is not enough of Soviet energy, then Efim Pavlovich Slavsky, the Minister of Medium Machine Building said, “There is a way to help the country.” Do you understand? This type of device came from the Ministry of Medium Machine Building where several such devices were built for special purposes and operated in the most unique way. There was military acceptance of each piece of equipment, specially trained personnel, the highest requirements, etc. These are the same industrial reactors that the Americans have. They also don’t have containments because they are large. But there are only four of them, the American ones. And the tracking and monitoring for each one of them are very high-class.

So, for the Ministry of Medium Machine Building and, in this sense, also for Anatoly Petrovich Aleksandrov, there was an impression that this reactor, if operated properly and with reliability, is very good and normal. But as soon as the first such reactor, the first one they plugged in near Leningrad, a 100 kilometres from Leningrad, the first such RBMK reactor... As soon as it began to run, right away it was discovered that the reactor was bad, that it was difficult to control, that its neutron fields started to “float”. The operators were all sweating; they could not control it because of its large size and the peculiarities of the nuclear processes. The level of fuel enrichment had to be changed, every time something… Well, altogether, from the moment it was launched, there were constant changes and alterations.

And yet, because 10 years had been lost and because the international philosophy that every device had to be inside a containment was not necessarily adopted, these devices were introduced into the national infrastructure. And they were built not by the Ministry of Medium Machine Building but by the Ministry of Energy. Kursk, Chernobyl, Smolensk NPPs, all use these RBMK reactors. However, in whispers, all the operators, all the engineers and experts were saying that this reactor is very difficult to control.

In economy, in cost per kilowatt-hour of energy, in fuel consumption, it was about the same as VVER, better in some ways, worse in others. But that it was more difficult to control became clear. But the main thing, and I keep coming back to this, the main crime committed was allowing a criminal philosophy into the Soviet nuclear energy, allowing stations, of any type, VVER or RBMK, to be built without containments. If there were containments, then RBMK would simply not exist; as it didn’t anywhere in the world, this type of reactor.

Another mistake was that with such technology, it is dangerous to not go the way the world is going. Because, after all, this is a dangerous technology. And when we are dealing with VVER-type reactors, we can use the entire world’s experience. Just think about it; we have a dozen such reactors, the Americans have 90 of them, the British have 40 and the French have 60. And each one accumulates experience and mistakes, and all of it belongs to all humankind. But RBMK, there was only the Leningrad station initially and, yes, Chernobyl and that’s all. This was all the experience and but we thought we knew enough; and there was no more information available to seek. And later it turned out that we knew very little about them. This was the so-called “road to development”. Firstly, it was domestic, which meant that it was not supported by any international experience. Secondly, SEV countries could not be consulted because they didn’t have such a device. The philosophy itself contradicted what we had at hand. And the design itself had, I’d say, at least three fundamental flaws. I find them monstrous, and have always found them monstrous. So don’t look at me as a person who… The fact is that our institute was divided about this reactor. And here I will speak about Anatoly Petrovich.

What is the monstrosity of his design mistakes apart from the containment philosophy? The monstrosity of the mistakes lies in the philosophy of safety. Why do I say this? Because the philosophy of safety does not depend on what you are dealing with, be it a nuclear reactor, a biological facility where viruses propagate, a chemical plant or something else. The specific technical decisions do depend but the philosophy does not vary. Because it has three elements: a maximally reliable device, a maximally reliable staff, and putting all this underground with maximum reliability, in a rock, under a containment. This is the philosophy that applies to any entity which makes the system reliable. But also with some reliable design… It requires that if you have some kind of emergency protection system which stops, say, a car, a train or something else, then you must have at least two protection systems. And they should be based on independent physical principles and one of the two systems should not depend on the operator. This is the law of the theory of safety.

Because, say, the operator suddenly becomes ill and he cannot press the button, or something else, then because of an overrun in parameters, because of anomalies, the second protection system should activate automatically.

The RBMK reactor has only one protection [system], unlike the VVER reactor, which is a flagrant violation of principles, the first mistake. Moreover, the designer to this day… If the designers of the RBMK reactor or my colleagues from my own institute heard me now, they would tear me to pieces because they think that I don’t understand the philosophy of safety. Since the emergency protection system consists of 211 rods that are lowered, they say that they have 211 [protection] systems, not two; because when they remove these 211 rods, each of which can absorb neutrons when lowered into the reactor, they say that there are 211 [safety systems]. But this is rubbish because all these rods are lowered by the operator; by the automatic system; by pressing a button, etc. And if the operator is killed, falls ill or dies, then all these 211 rods will remain in place. They still cannot understand this, or maybe this is just a self-defensive reaction. That is why they are after me with such terrible force in this aspect.

Moreover, when the Chernobyl accident happened, when it was necessary to make modifications, I immediately proposed an independent gas-based protection system, that is, injecting into the device sort of a gas capsule. I will not describe the whole thing in detail here. They accepted it very reluctantly, put it somewhere in their implementation plans for the 90s at the last moment, and began to correct the second mistake.

And the second mistake in the design, apart from there not being two protection systems but one, was that…

tape 5, side a

… it should be obvious even to a humanist that if power builds up at a certain rate, if it so happens that a problem escalates at a certain speed, then it is obvious that the protection system must act faster than this problem grows in the system. But theirs was five to six times slower.


Legasov: Yes, the reactivity increases by 13 times every second whereas the rod takes five or six seconds to descend. So they directed all their efforts towards harmonizing these speeds to make a dry channel. This is how much they clung to those bloody rods, mechanical, with the help of which… And they still can’t let go of them, while my proposal for gas-based protection was pushed to sometime in the distant future. And now it appears that it is impossible to make the rods move that fast after all. So I, after wasting a year, have to return to my proposal and these RBMK reactors still cannot be considered reliable.


Legasov: RBMK? 14 of them. All through, I want to tell you, and I don’t know if I am succeeding, that it is just about the philosophy of safety. Had the philosophy of safety been correct, then our experts would have, without a doubt, found technical solutions conforming to this philosophy. Because they are competent specialists, sensible people; they can make calculations and have other skills. But the problem is that they were put in such a situation. If the philosophy had specified mandatory containment, we would not have the RBMK reactor and this conversation wouldn’t be. Neither would there be 14 VVER devices “naked”, covered by nothing. And if a VVER explodes, and it can explode, the footprint would not be 80-90 kilometres; it would be 250 kilometres.


Legasov: No, we have 14 VVER devices without containments.


Legasov: No, 14 RBMKs without containments and 14 VVERs without containments.

And only when we had the containments, the stations being built for the last 5-6 years, the ones being designed now, and the ones that will be built, all are being built with containments. Where did this come from? As soon as we started selling stations to the Finns. The Finns, according to international requirements, said, “Give us containment; we won’t take it without containment.” And then came our first station with containment. And it is very good judging by its reactor parameters, and it is with containment. This makes it the best station in the world, “Loviisa”. After that, we started implementing this philosophy here. That is why the stations being built in the last 5-6 years, the Zaporizhia station in Ukraine... By the way, the station that was built near Minsk for you would have been built with containment.


Legasov: Well, the decision has already been made, an emotional one, so to say. But I should tell you that the Minsk station, in particular, wouldn’t pose any danger.


Legasov: Well, that is understandable. The decision has been made and what can we say about it now. But, in reality, there could be an accident. The reactor could explode. Anything can happen. But everything will remain inside the containment. This is what makes the Minsk station and the Finnish station distinct. Same as the Americans. They had an accident worse than this but everything remained inside the containment.

So this is the first violation of the philosophy.

What is the fault of Anatoly Pavlovich Alexandrov? The fault of Anatoly Pavlovich Alexandrov is that he, albeit reluctantly, consented. He was against it, objected to it together with the experts, but then went on to meet the stubborn requirements of State Planning Committee and the Ministry of Energy, that stations can be built without containments. At first, he opposed it greatly, he fought—and I can prove this documentarily—but then he gave up. But under what conditions? Under the mandatory condition of the most rigorous compliance with all regulations and such. And for the last 20 years, he spoke wherever he could, at the Politburo, etc. He demanded military acceptance; he demanded an improvement in the quality of equipment and so on. So he was fighting to make the likelihood of an accident at a station, knowing that there is no containment, minimal. He fought for it.

But yet, he, how should I tell you, well, didn’t want to die for this philosophy. This is his only fault. There is no other. Because in all other cases, he fought for the right things, even though it was difficult to fight. Because a group of experts—who, you know, are like “hurrah, go, go!”—they had so much influence that Sidorenko Viktor Alekseyevich, the director of the Department of Nuclear Reactors at our institute, the author of this doctoral dissertation and this book, was expelled from the institute. He had to leave the institute. Because his own colleagues didn’t understand him. But why didn’t they understand him? Because his colleagues got bonuses from the Ministry; because the institute was part of the Ministry of Medium Machine Building. Do you understand? They see the director, who is a corresponding member of the Academy of Sciences, and their [own] salary is lousy. If he doesn’t get a bonus of 100 roubles, he will survive. But I get only 180 and for me, a bonus of 100 roubles is important. If I “squeal” about the cost of these containments, then I will not get a bonus. If I say something wrong, I will not be published and my dissertation will fail.

This is how his own subordinates, brought up for years with such an ideology in that Ministry, could kick out their own superior. How? Well, they didn’t kick him out but made his work environment intolerable. However, he, together with Anatoly Petrovich, fought for quality once they lost with the containments. And he did a lot to bring about Gosatomenergonadzor, where he eventually went to work, to the organization that at least controlled the composition of the equipment that went there. Such were the conditions.

This is why Chernobyl—now do you see why I started from so far back?—it demonstrated that in the Soviet Union, even today after having survived Chernobyl, not a single dog understands this philosophy, that is so basic and simple, the three components of which I told you, even in the nuclear industry. And it has not been carried over to the chemical industry, where we could have a Bhopal at any moment, you see, because of this very reason of the wrong philosophy. There is not a single organization in the Academy of Sciences of the Soviet Union or in the national academies that could develop this philosophy. There is no capability to use the theory of risk and reliability of devices to anticipate possible consequences of such events and to prepare for them in advance.

So we have Chernobyl. As Nikolai Ivanovich Ryzhkov said in the Politburo meeting on the 14th of July when discussing the issue, “I have the impression that the country was slowly and steadily moving towards Chernobyl while developing its nuclear energy.” He was absolutely correct. We were moving towards Chernobyl. Only it should have happened, in my opinion, not at Chernobyl but at the Kola station, and a few years earlier; when it was discovered that in the main pipeline that carries the coolant, the welder, to get a bonus and to finish faster, just put electrodes inside and lightly welded them on top instead of welding the valve in the most critical spot. This was miraculously discovered and this, the most powerful disaster... we would have just lost the entire Kola Peninsula. And this could have happened a few years ago. And just by a miracle, it didn’t. And a station without containment would have contaminated everything. And our Kola Peninsula, a natural wonder, would have been destroyed.

I want to tell you all this so that you understand that the origin of the Chernobyl tragedy was in wrong philosophy which resulted from losing 10 years. And then to catch up, quickly, this option was proposed.

Then the transfer, unwarranted transfer of experience from the military industry to domestic infrastructure. The transfer was entirely unjustified. Because in the military industry, with a limited number of devices, strict military acceptance at multiple times—military acceptance at the manufacturer, military acceptance during the operation—multiple examinations, staff retraining, etc… And when you suddenly, with the same device, enter the domestic infrastructure where there is nothing similar—no simulators, no training systems, no training systems at all, not to mention the training systems for emergencies. Do you understand? This is how the conditions for such disasters were created. This is what I want to tell you today. But this is not for publication yet because they will take both your and my head off; mine first and then yours. Because nothing has changed so far.

Adamovich: That is what Adamov already told me, and Velikhov said the same. In fact, everything continues by inertia. I said the same to them but how can one get access to Gorbachev for a back-and-forth. They told me about their complete helplessness.

Legasov: Our general helplessness is again associated with the fact, and lies in the fact, that as long as there is a monopoly of a particular institution over the system, it will continue. For example, the Politburo correctly decided to create a relevant nuclear organization within the Academy of Sciences; because there is no alternative, no competition. But not everyone is in a hurry. The same is with Velikhov, for example. He, knowing this, is not in a hurry to create a strong and appropriate alternate organization.

Adamovich: [UNINTELLIGIBLE QUESTION] ... and which system controls all this apart from the Academy?

Legasov: Ministry of Medium Machine Building. It has everything. It has all the designers; everyone remained with them, whereas the Ministry of Energy is purely an operational institution. It only handles the operation, nothing more.

The Ministry of Power Engineering was the one who designed the equipment. The situation worsened because earlier there was the Ministry of Power Engineering which only made nuclear equipment. Now it has merged with Minmash. And nuclear equipment has become just one in a range of manufactured items. So the situation has only worsened. The probability of [another] Chernobyl has now increased.

Right now, I’m writing a note to Nikolai Ivanovich Ryzhkov, another one, where I say the same thing. “The probability increases day by day because of…” again, those devices without containment.

Adamovich: Which exist…

Legasov: …which exist. And people understand that they are dangerous. But what are they doing? They are trying to increase the reliability of the reactor so that there would not be an accident. But what does this ‘increasing the reliability of the reactor’ mean? It means adding more and more instruments to it, some additional diagnostics tools and so on. Moreover, this is being done on different devices at different times. And staff migration is quite high. So changes to the regulation are introduced for one device but not for another. On this, they do; on that, they don’t. Can you imagine? A shift manager moves from one facility to another thinking that things will be the same. Do you understand? That is why it is more probable now. Because people think they are doing a good thing by increasing the reliability of the device. But in reality, due to a lack of understanding of this whole philosophy, they are worsening the condition of the device.

Adamovich: [PART OF AN UNINTELLIGIBLE PHRASE] ...I understand that it is useless to write…

Legasov: Hope this isn’t confusing to you. It is only for myself. Just in case it is useful when you write. This means that it applies, in no less degree but more, to the chemical facilities where we still have such ugliness, much more than in the nuclear industry. And I sit and shiver. Indeed, even a person here is ill and I am lying down. Thank God, I am already cured. I feel sick thinking about exactly what is most likely to happen to us in the near future. So I just say what I’m afraid of, and I already am afraid. Because I already spoke at the Politburo once. I said that the next disaster will happen in South Kazakhstan, with phosphorus, when everything that lives within a 300-kilometre radius will die.


Legasov: But I said so at the Politburo. It went in one ear and out the other. But two weeks later, it happens in America, a phosphorous accident in two weeks. And then they paid attention. Do you understand? Thank God that it did not happen here or in a factory but on a railway tanker car transporting phosphorus. They had to evacuate 30,000 people because of this accident. So I just know that the next nuclear accident will be at the Armenian plant and the whole of Armenia will be affected. Then the next most likely is Bulgaria, Kozloduy. And the next most likely is Leningrad; it will certainly explode. These are the three nuclear stations. There will be a major chemical accident in Dzerzhinsk. It will be the largest chemical accident in history. And another big accident will be in Kuibyshev, a chemical accident. And in Shymkent in South Kazakhstan, there will definitely be an accident.

Adamovich: I will note all this down. And then…

Legasov: Check that. [dictates] Nuclear: Armenian, Leningrad, and Kozloduy, Bulgaria—these nuclear power stations that don’t have containments. Now the chemical accidents: an explosion at Dzerzhinsk, there will be a powerful explosion; then the same volumetric explosion at Kuibyshev and Shymkent at a phosphorus plant. An accident is possible in which organophosphorus compounds form, a single breath of which is lethal. Based on the wind rose, on dispersion, within a radius of 300 kilometres, with entry into China, all life will be destroyed.

All this is what I say [will happen] unless the necessary measures are taken. Moreover, the measures that can be taken to prevent this from happening are known. But the most demoralizing part, which makes one worried and sick, is that the measures needed are known. For example, I actually can today…

[ERASED], it means that the information came in a standard form. The system for warning the Ministry of Energy about an accident was adopted beforehand, long before the accident. And it was a coded system. The information came as a code. For example, certain numbers are sent: 1-2-3-4. 1 is a fire; 2 is radiation damage; 3 is a nuclear accident; 4 is a chemical hazard.

And teams had already been put in place beforehand. In case of such and such signal, at such and such place, assemble a specific emergency team to dispatch here in Moscow. In case of another situation, another team will assemble and so on. And so, on the night of the 26th of April, all four types of codes for all types of possible hazards appeared at the Ministry of Energy. There was a team for this. Accordingly, the Minister was called immediately, and all the listed experts who had to depart were summoned. Since this happened on the night between Friday and Saturday, some were at their dachas. So this process took two to three hours. But, at night, everyone gathered at the Ministry of Energy. Then another hour or so passed as the situation with the plane was ascertained, and this group of people flew out early in the morning to the location. I was not with this group when they left. And here, an unpleasant moment occurred.

They established a telephone connection and we started receiving information from the station contrary to the coded signals, not supporting them and even contradicting them. They started to say that they turned the cooling on, turned this or that on. This gave the impression that the reactor was live, that something serious had certainly happened.

In the morning, they had already reported that two people had died. But it was reported in such a way that one of them died from physical trauma while the second from chemical burns. Because there really was a fire. That was true indeed. One they just lost and—

Adamovich: [faintly audible] And he remained there.

Legasov: He remained there, buried in the sarcophagus, while the second one did actually die from chemical burns because a fire broke out in an area. But, at the same time, they didn’t report other things like the appearance of typical radiation injuries and so on. And during the first half of the day of the 26th, we were receiving such information that the staff are trying to deal with the situation that has arisen, that the device is out of control, and they are trying to get it back under control. This, roughly speaking, was the situation. But since the original signal was serious, the information was relayed to the Government and it established the Government Commission.

Adamovich: Who sent the first signal? They themselves?

Legasov: The station staff. The station director. So, on Saturday, early in the morning around ten, I went to the party meeting, where Slavsky, our elderly Minister of Medium Machine Building, was speaking.

Adamovich: What’s his name and patronymic?

Legasov: Efim Pavlovich.

Adamovich: He was the Minister of…?

Legasov: Medium Machine Building.

Adamovich: Medium, noting.

Legasov: So he presented a big report; he always made long reports. He praised nuclear energy, praised himself, praised his own Ministry, and said in passing, “ Chernobyl, we have had a signal. Something has happened but we, as always, will handle it.” and went on with his report. He finished his report. There was a break at 12 o’clock as I remember it now. During this break, Slavsky’s First Deputy, Meshkov Alexander Grigorievich, his First Deputy who was later fired because of this accident—

Adamovich: And he himself? He simply retired?

Legasov: Slavsky?

Adamovich: Yes.

Legasov: Well, how should I put this. They retired him. [They made him retire.]

Adamovich: Oh, I see. It was like that.

Legasov: Yes, it seems to be civilized. He left without punishment, so to say.

And so Meshkov Alexander Grigorievich came up to me and said that a Government Commission had been appointed and that I was included in it. And that I must be at Vnukovo, at the airport, at 4 o’clock to fly out. The head of the Government Commission was Boris Yevdokimovich Shcherbina. I immediately jumped into the car, went to the Institute and found experts on this type of reactor. I repeat that I myself am not a reactor man despite being the First Deputy Director of the Institute. But the Institute is huge. There is thermonuclear and nuclear physics, isotope separation and usage, radiochemistry and whatever the hell else.

My responsibilities included chemical physics, and separation of isotopes and substances, as well as the use of nuclear energy in the domestic infrastructure in the form of isotopes or something else. My department was the smallest. Apparently, that is why Anatoly Petrovich appointed me as the First Deputy, because I had no greed to pull resources towards my own tasks. Among the “giants”, among the reactor people or the thermonuclear people, I was the smaller, so to say, proprietor. That is why he put me in charge of management affairs, of resource management. He assigned me the post of the First Deputy and I worked for them for many years. I think it was out of these considerations; perhaps he had other considerations.

Anyway, I called the experts with the drawings of the reactor and all the information that could be gathered. Of course, I did understand the design of this reactor but not in as much detail as a member of the Government Commission would need to in such an emergency. I took all that I could carry with me and at 4 o’clock, I was at the airport. Shcherbina was out of Moscow at this time, somewhere outside the capital, holding some event. We waited for him. He arrived. I looked at the composition of the Government Commission—I can list this first composition if needed—and we flew out to Kiev.

On the way, I told Shcherbina the story of the accident at Three Mile Island in detail. This is what I did on the flight. I told him what had happened at Three Mile Island in America, what events took place there and what measures [were taken]. And the measures there were simple. They ran away. And didn’t go near that Three Mile Island station for three years. This is all they did. Well, actually, they did struggle to keep the hydrogen bubble from exploding. They were ventilating the hydrogen bubble. Having done that, they closed the entire thing and for three years, no one even went near the station. They lost 17 people there, the Americans. But not in the accident itself. In the accident, no one was killed or exposed to radiation. But because of panic. There was panic in the town. They rushed to their cars to evacuate themselves and, in the process, 17 people died in cars. This is how the Americans fled. And I told this story to Shcherbina on the plane.

We arrived at Kiev. There, led by Liashko, the head of the Ukrainian Government, was a huge crowd of black limousines. Gloomy faces. No one could explain what had happened. They said that things were probably bad. We got into the cars and set off. The journey was gloomy. There was no definite information. So the conversation was in the form of “Do you know?” “Yes” or “No”. I was in the same car as the head of Kiev Oblast Executive Committee, Plyushch, who was also a part of the Government Commission. What conversation was there to have?

Here, the measure of our ignorance, the measure of our misunderstanding of what had happened was expressed in such instances. That I, for example, even managed to drop by home to tell my wife that I was leaving on a business trip. But because I had been at the meeting dressed in my best suit, my best clothes, I left in the same clothes.

Adamovich: But you did understand?

Legasov: Oh well, I… That’s how much we were confused by the scale of the accident. Do you understand? To such as extent that I could not imagine the scale of this accident from the available information. And I have seen more than one accident. I already had 180 roentgens in me and, thank God, I knew how to act in situations like these. And the cavalcade of black cars, Chaikas and others, that were going there also reflected how little we knew and understood that day. It bore witness to that. Then, Shcherbina, after returning from there, smashed his deputation badge with a hammer before our own eyes. So that no one could use it. So contaminated it was that he personally smashed it to pieces with a hammer. Nothing else bothered him. Anyway… Also, there was an episode that I will talk about later.

We drove through Chernobyl. It lived a peaceful life, quietly, very peacefully. We arrived at Pripyat. A few kilometres before Pripyat… There are 18 kilometres between Chernobyl and Pripyat. So a few kilometres before Pripyat, say seven or eight, for the first time, I could not recognize a nuclear station. Because a nuclear power plant is easily distinguishable because of chimneys that don’t emit anything. Do you understand? This is the most distinctive feature of a nuclear facility when there is a chimney but it only serves to draw air from which only Krypton-85 is extracted, as I told you, and nothing else. And everything around is clean. But here, suddenly, there was a crimson glow in half the sky and white smoke streaming out of the reactor. This is not a nuclear station. My first impression was that I hadn’t come to a nuclear station.

We drove up to the building of the Pripyat City Committee of the Party, placed ourselves in a hotel nearby, where we stayed for about ten days in Pripyat itself, but the headquarters—

Adamovich: And the people had already been evacuated. They were taken away on Sunday.

Legasov: No. We arrived on the 26th at 8.20 pm. And at 8.40 pm, approximately, the first meeting of the Government Commission was held in Pripyat itself in the city committee of the party. This first meeting was simple and straightforward. Shcherbina assigned the duties.

He instructed Meshkov to gather a group of specialists, to be called from Moscow if needed, and investigate the cause of the accident. He charged me with developing the measures for liquidation; in other words, what to do. I was tasked with coming up with proposals on what to do. Suggestions. Because the final decisions were taken collectively by the Government Commission or by Shcherbina personally. He as the chairman made the decisions. But preparing proposals on what to do fell on my shoulders.

Vorobyov Evgeny Ivanovich, the former Deputy Minister of Health, who was later removed, his responsibility was to determine the number of people exposed to radiation, their fate and everything that had to do with people. And local authorities were a part of the Government Commission. For example, the head of the district executive committee, Plyushch, had to make preparations for the evacuation. These words were pronounced immediately and directly, “Prepare for evacuation.” And to carry out the tasks that I would define to limit the consequences of the accident.

The first thing to do was reconnaissance. Because the dosimetry service… By the way, here I will take a detour and say that dosimetry was poorly organized. Dosimetrists with devices, instead of assault rifles, should have been everywhere. As I wrote in the proposals: the first perimeter at the station itself, a second one at a kilometre from the station, then 3-kilometre and 10-kilometre perimeters. Within these, at every 100 metres, there should have been automatic devices that would generate audio and light signals in case of excess doses.

Adamovich: DP-5.

Legasov: Yes. But even DT-5 was not there in sufficient quantities when we arrived. So the main work was undertaken by Abaghian Armen Artavazdovich, the Director of VNIIAES, the Institute of Atomic Energy Stations, that is presently under the Ministry of Atomic Energy and was under the Ministry of Energy earlier.

Adamovich: Abaghian…

Legasov: Armen Artavazdovich, a good man. And, a little later, Egorov from the Adamov Institute but he arrived a day or two later. They started the work. Then Pikalov came with his services. Then the dosimetric reconnaissance began.

On the evening of the 26th, we did everything roughly. However, it was already clear on the 26th that the reactor was destroyed. And on the 26th, at 11.11 pm, there was another meeting of the Government Commission that considered two issues. The first was about the population. And here we had a sharp debate. Sidorenko Viktor Alekseyevich, who also was a member of the Government Commission from Gosatomenergonadzor, insisted on an immediate evacuation of the population. And I supported him. The medics objected. But the point here is that the procedure that had been established was this. The permission for evacuation is issued by the Ministry of Health of USSR; not the Council of Ministers or the Central Committee of the CPSU but the Ministry of Health.

The rules that they had worked out prior to this accident were as follows. By the way, there are no international rules even now. But the Ministry of Health had developed these rules. If there is a danger of a person receiving a dose of 25 rem immediately or within a certain amount of time, then the local authorities have the right to—have the right to but are not required to—carry out an evacuation. If there is a probability of receiving a dose of 75 rem or more, then the local authorities are required to carry out an evacuation. So, if there is no threat of receiving 25 rem, then no one has the right to carry out an evacuation. Between 25 and 75 rem is a matter for the local authorities. And above 75 rem, it is mandatory. These were the sanitary rules that existed at the time. Direct measurements were made in Pripyat. The explosion happened in such a way that Pripyat was bypassed from both sides [by the fallout]. Do you understand?

Adamovich: And it went to Belorussia.

Legasov: To Belorussia, one part, and the other went to Ukraine but in the other direction. And Pripyat appeared, at the time of the explosion, it appeared to be clean. There were less than 10 rem. This put the medics in a difficult position. According to their regulations, they did not have the right to declare an evacuation based on the data available to them at 11 pm. We, as experts, were saying that—

Adamovich: Tomorrow, there will be…

Legasov: That tomorrow, there will be 25 or more. Therefore, we must declare the evacuation right away. But that will be tomorrow, and right now there isn’t. And what if there isn’t [above 25 rem] tomorrow? What if something is done to the reactor tomorrow and the whole thing is over? How would we feel then? Would we be breaking the law? Altogether, there was such a lengthy argument and Shcherbina, to his credit, approved the decision to evacuate.

The medics did not sign the protocol. They signed it the next day at 11 am. But since Shcherbina had approved the decision, the local authorities had promptly begun the preparations. One thousand buses were called from Kiev, the routes were prepared, and locations where the evacuees would be taken were determined.

Unfortunately, there was no local broadcasting network to announce this. So General Berdov, who had arrived from Kiev, ordered that all policemen will go to every flat and inform that no one should go outdoors until the next day and should stay at home. Because in the houses, there were no—

Adamovich: So that there was no local…[inaudible]

Legasov: Well, I don’t know. I only know that the population was informed at night and early in the morning by going to all the flats and placing on duty—

Adamovich: 27th or...[inaudible]

Legasov: In the morning on the 27th and at night on the 26th.

Nevertheless, on 27th morning, there were women taking a walk with their children. This meant that they did not have time to inform some of the people or that they had come from somewhere else. People were going to the shops and the city was living its semi-usual life. But at 11 am, it was already fully official. After the medics signed, it was announced that the city is being evacuated. This showed our inexperience, of some sort... organisational, I would say.

I understood, I must tell you honestly, that I understood that the city was being evacuated permanently. But psychologically, somehow, I did not have the means, the strength, the ability to say this to people. Because I reasoned, for example, that if we say this to the people now, the evacuation will be delayed. But the radioactivity was already growing exponentially at this time. People will start to pack for too long. Do you understand? Something else will happen. But there was no time. That is why I advised, and Shcherbina agreed with me, to announce that we cannot tell about the precise duration of the evacuation yet.

Adamovich: [unintelligible]

Legasov: No, no such duration. He is wrong. Maybe someone understood it this way but it was announced like so, “Probably for a few days, maybe for a longer period…” It was announced in an indefinite form but it was announced in such a way that people could understand that they were leaving their city for a few days. Do you understand? That is why they packed lightly and left.

Then there was another mistake. Some residents asked to evacuate in their own cars and there were around 3,000 private cars in the city, around that number.

Adamovich: [Was it] banned?

Legasov: No, allowed. Boris Yevdokimovich probably made a mistake but it is hard to say. Say they allowed it and some cars left, some of the residents left in their own cars, but the cars were, of course, contaminated. On the other hand, people were contaminated; and their things were contaminated. Whether it made a big difference is hard to say.

The evacuation itself took place in an exceedingly organized manner. In two hours, as I recall, 45,000 of all the 51,000 residents were evacuated. Those needed to maintain the city and service the station remained. And the Government Commission itself remained in Pripyat. During this—this may not be for publishing or maybe it is—do you know what caught my eye? The party organisation was removed.

Adamovich: That is?

Legasov: Even during the war, when a retreat was planned from a city, it was already determined in advance who would remain undercover, who would be with the army, etc. But here everything was so quick and sudden that…


...there was no one to rely on, that is, the highest party authority. But this was for a few days, and after a few days, everything, of course, recovered.

Now, the station personnel, who were supposed to service the 1st and 2nd blocks in shifts, were transferred 50 kilometres away to the pioneer camp, Skazochniy. When I arrived there for the first time, I witnessed a grim scene because the first proper dosimetric posts were set up there. People were changing clothes. And it was such an unforgettable scene as one drove up to Skazochniy. Probably, there were a few thousand suits, civilian, hanging on trees. Because, of course—this is interesting—everyone arrives, the dosimetrists measure them and everyone’s clothes are contaminated. And I remember that my Finnish overcoat, which my wife chose for me after much thought, and my English suit…

Adamovich: On trees…[inaudible]

Legasov: Simply hung up on trees. And there you are, travelling by car for a long, long time and then you see such a scene in front of you—

Adamovich: Oh, just hung up...[inaudible]

Legasov: Just before Skazochny. It went like this. You approach the gates of the Skazochniy Pioneer Camp. The dosimetrist measures you. Says, "Undress." You undress. Take a few steps. You hang your suit on a tree, wherever you are. You are then given special clothing, like this one, blue or white. And you go into Skazochniy where you are assigned a bed, living space and other things. Then the next one arrives and so it goes on.

Adamovich: And then you drove past these suits?

Legasov: Yes, two or three times we went by these suits.

Adamovich: And then?

Legasov: Then they were destroyed, of course.

Adamovich: Destroyed?

Legasov: Of course, later they were all destroyed. Buried and destroyed.

Adamovich: [unintelligible]

Legasov: Leaves an impression. Yes. Like scarecrows all of them were hung. And there was another episode. Sidorenko and I, when we had moved to Chernobyl after spending a week in Pripyat, went to a shop—we were supposed to be the experts—to buy ourselves at least something, new underpants, undershirts, shirts. Do you understand? Something to change into. This is underwear that we were dreaming of. We went in and bought ourselves some very nice shirts. But when we returned to Skazochniy and measured them, they turned out to be more contaminated than the ones we were wearing. Even Chernobyl was quite…

Adamovich: [inaudible] ...this is in Chernobyl?

Legasov: Yes, there is contamination in Chernobyl itself.

Adamovich: But people were living in Chernobyl for seven more days.

Legasov: Sometime after the 2nd of May, they started to evacuate them. But in the end, I have to say this. The evacuation, the order of evacuation, doesn't matter from Pripyat or Chernobyl, was carried out in such a way that—it will be better for you if Ilyin or the other doctors say this—overall among the people who did not work at the station, just lived there, not a single person was injured because of delaying the evacuation by at least a day.

Another thing. Many residents later, in six or seven days, were drinking milk—

Adamovich: Where?

Legasov: Well, somewhere. Say from cows who—

Adamovich: In Chernobyl? [inaudible]

Legasov: In Chernobyl, near it, in your Belorussia, everywhere. Do you understand? Yes? That is because Iodine fell out first. Then the cows ate the grass with Iodine. Then gave us milk when they were milked later. And then those who drank Iodine, and children, in a large enough amount, they had greater stress on their thyroid gland. But there was no external radiation exposure or any other effect, so to say, on those people that were evacuated. There was nothing.

But coming back to Pripyat... As I said, on the 26th of April, at 11 pm, it was decided that the people will be evacuated the next day. But my colleagues and I were faced with the task of what to do next? What to do next?

Adamovich: Sorry, but the first commission, they must have then called. Was Shcherbina calling Moscow with you? Didn’t you report to Gorbachev and others, well, the situation?

Legasov: So, on that day and the following days, there was regular communication with Nikolai Ivanovich Ryzhkov and Vladimir Ivanovich Dolgikh. They were communicating, continuously, constantly. As far as I can imagine, but this is within my ability, Mikhail Sergeyevich Gorbachev, I spoke with him three times. And the first time with him—

Adamovich: Well, that’s interesting. What kind of conversation did you have with him?

Legasov: I probably cannot say because—

Adamovich: I will not write it down.

Legasov: Or I will. Not for the record but for understanding. So, I heard his first call… When I worked with Shcherbina, I never heard him speaking to Gorbachev. Whether he was or not, I just don’t know. I won’t lie. But when Silayev replaced Shcherbina, and I was left, then the entire Commission, the first composition of it, left.

Adamovich: [unclear]

Legasov: I was left behind. They left me. At first, Sidorenko left me, and Shcherbina asked me to stay. Then I was called to the Politburo meeting on the 5th of May. There I reported the situation. Then Silayev called Gorbachev himself and asked that I go back. So I was caught on the road and, after the Politburo, sent back again. But these are such personal things. And so, before the Politburo, before the 5th of May, when Shcherbina had already left and Silayev had arrived, this was the 3rd or 4th of May, I heard the first call from Gorbachev to Silayev and his conversation with him. This was the first one.

Were there conversations between Shcherbina and Gorbachev? I don’t think so. I think there were no conversations in the initial days but I may be wrong. Also, I think that Gorbachev’s first call to Silayev was sometime after the May holidays, on the 3rd or 4th of May. And I spoke with Mikhail Sergeyevich in the second, third and fourth calls. Velikhov spoke with him once, in my presence, on the situation. That was it. But usually, Ryzhkov and Dolgikh were in constant communication. They, so to say, maintained this connection.

Adamovich: [weakly and hardly understandable] But what did Gorbachev ask you…tell you…

No, I am turning off my—

[Recording interrupted]

Legasov: ...The director of ChNPP was in shock, from beginning to end.

Adamovich: [unclear]

Legasov: I saw him on the first day I arrived there. His last name was Bryukhanov, the director of the station. The last time I saw him was in the Politburo meeting on the 14th of July [transcript of the Politburo meeting] when the cause of the Chernobyl accident was being discussed. That’s where he was questioned. He was in shock all of the time. Not one sensible action or word could he utter. So he was in shock. What he is as a person and why he was in shock there… but there, he was an incapacitated man.

At the same time, Shasharin, the First Deputy Minister of Energy, under whom the station was at the time, was at a loss. He was at a loss because for him, the situation was, how do you say, not planned for. It was not clear what to do in it. And so he sought our help all the time on what to do. But he acted very eagerly and selflessly.

I will end here all my manipulations with you, so to say—there is a lot of talk about it—the logic, so the logic behind the decisions that were made is clear to you. The logic behind the adopted decisions was as follows.

We had to introduce an element that would absorb heat due to chemical energy and transform, in the same way we boil tea, would take away the heat and so on. Initially, I suggested dropping iron shot. Firstly, because it would melt and a sufficient amount of energy would be spent in melting it. Secondly, it would ensure that the heat transfers to the metal structures and then they would transfer the heat to the air faster. But the iron shot that we found at the station was contaminated with radioactivity. So it was impossible to load it into the helicopters, first of all. Second, at the high temperatures that we had measured at some points, the process would get reversed. The iron would oxidize and the temperatures would rise further still.

Adamovich: [unclear]

Legasov: That is why this option was discarded. For the places where the temperature was relatively low, say 200, 300, 400 degrees [Celsius], lead was used. It would melt there, absorb the heat and also act as a protective shield to some extent. At the same time, it would also be a kind of heat-conducting element. And we even thought that it would partially evaporate, cool down in the higher area and then flow down again. You know, sort of similar to Freon circulation in refrigerators. This would facilitate heat transfer. That's probably what happened.

I repeat, then there was a lot of talk about lead poisoning. But now they are preparing for me a precise report of analyses of all the soils from both within the 30-kilometre zone and beyond it. All that has been given to me so far shows no difference from Moscow to Minsk or anywhere else. Lead is everywhere but it is the one that comes from exhaust gases of vehicles. Do you understand? There is no excess. And doctors have never found any trace of lead in the people who were directly working there. That is idle talk; even though it is so very widespread.

We dropped dolomite there. That’s magnesium carbonate. It also decomposes the same way. The heat was absorbed and it broke down into magnesium oxide and carbon dioxide, which in turn reduced the supply of oxygen, as it is in firefighting. Do you follow? And magnesium oxide, the most heat-conducting of all ceramics, similarly carried the heat away.

And finally, sand. It played the role of iron but without the oxidisation. If the temperature is high, it melts and absorbs heat. Sand played a double role. On the one hand, it melted and we did find evidence of that. And it used the heat from the reactor to melt. It took away the heat so that the uranium won’t melt. Moreover, we added clay just for filtering. Whatever radioactive particles would escape, they would be filtered out. So the radioactive particles were filtered out by this layer. As western experts have shown after our report at the IAEA…

tape 5, side b

…report at the IAEA, the measures taken were innovative, even though they were actually devised on the fly. And now, they are recommended. To my surprise. I thought they would criticize us because there was no prior plan, everything was done on the fly. Now the British conference and the Vienna conference have ended, and our actions are officially recommended for the future as very effective and useful.

Adamovich: Did all the graphite there burn out?

Legasov: No.

Adamovich: Extinguished in some way…

Legasov: Yes, yes. Look, the fire ended—

Adamovich: It started at around four or five in the evening. The graphite started burning—

Legasov: Yes, it started to burn.

Adamovich: [Inaudible] …judging by these notes that I—

Legasov: The graphite started burning around the 26th or 27th—

Adamovich: No, hold on. On the 26th in the evening—

Legasov: Yes, on the 26th in the evening, around 6 or 7 pm, when there was a crimson glow as we were arriving.

Adamovich: Yes… [Inaudible]

Legasov: Correct. But the fire ended completely on the 2nd of May. Completely.

Adamovich: I see, so on the 2nd of May… [Unclear]

Legasov: But after the 2nd of May, there were traces of a glow a few times in some spots. Either graphite or metal structures were heating up. The last time this was observed was on the 9th or 10th of May. And that’s it. After that, nothing happened.

Adamovich: [Unclear] talked about nitrogen.

Legasov: About nitrogen. There is a lot of confusion in the international press, for example, that Velikhov was measuring something on the roofs around the 26th, Evgeny Pavlovich [Velikhov]. But he was at his dacha, drinking vodka, and was not aware of anything.

Adamovich: And he was not there on the 26th?

Legasov: He was not there. Yes, he wasn’t.

About nitrogen. This was during Silayev’s time when he has already arrived. It was I who proposed using liquid nitrogen for cooling. This proposal was stupid as practice ha showed. But what was my reasoning? I thought that the reactor shaft was intact. Do you see? And so if we add liquid nitrogen to the air—and we had, very quickly I must say, an entire train of nitrogen brought to us—then that cold air would cool the hot zone better. But then it turned out that the sidewalls of the reactor were wrecked. So all the nitrogen we supplied—and we did find a place for to supplying it—leaked out of the zone and cooled nothing. The natural air circulation was so strong that this nitrogen was like a drop in the ocean. That’s why we quickly discontinued this measure. And in the report I prepared for Vienna, to tell the truth, the Central Committee removed this phrase, but it was in the initial version, that among the ineffective measures was supplying liquid nitrogen.

Now, what else did I want to say about these measures? I repeat that they were invented in continuous phone conversations with Moscow, with experts who assessed, did the thermophysical calculations. For example, dolomite. Anatoly Petrovich Aleksandrov and my student, who called me just now, Silivanov, they thought about which material to use that would generate CO2 and also conduct heat. This is how we chose dolomite which was quickly shipped.

We received many telegrams from abroad, by the way. From these telegrams, I immediately realised that no one [in the world] was prepared for this kind of accident. Because, well, one telegram was just provocative, clearly provocative. It proposed to create another explosion by introducing nitrate mixtures there.

Adamovich: To blow up… [Unclear]

Legasov: If we were to do this, there would simply be another explosion. But there was only one such telegram.

Adamovich: What is this nitrate mixture?

Legasov: Explosives. Basically, they proposed to drop explosives. Obviously, people thought that we are panicking and suggested a solution of such and such composition, containing nitrate, to be dropped there. The water would immediately evaporate, leaving pure ammonium nitrate. And ammonium nitrate is an explosive in its pure form. Everything there would be blown to kingdom come. From one of the countries, Sweden I think it was, if my memory is correct, we got this provocative—

Adamovich: This was from Sweden?

Legasov: I think, yes, from Sweden, but I’m not sure. I cannot vouch for my memory. Perhaps it was not Sweden. But it was from abroad, this telegram. And a huge number of friendly telegrams, a great amount of benevolent advice: what to do, how to extinguish the fire and so on. But from the contents of the telegrams, it was apparent that all this was, you know, people dreaming up things, same as we were doing here. Do you understand? And not that they had any experience [to draw from].

Adamovich: People say that the Japanese proposed something like this, that we give them the Kuril Islands and they will extinguish everything.

Legasov: I am not aware of that.

Adamovich: Another thing is that Sakharov came… [Unclear]

Legasov: That didn’t happen for sure.

Adamovich: [Unclear]

Legasov: What didn’t happen didn’t happen. But the logic behind these actions was this. When the fire ended, when we established that the surface temperature, that was monitored, is not higher than 300 degrees Celsius, all actions targeted towards eliminating the fire itself and its spread ended. This doesn’t mean that the spreading of radioactivity ended.

Adamovich: But these hazardous… [Unclear]

Legasov: About the ratio [unclear] I will say later. Radioactive emissions were still going on but, of course, getting lesser and lesser until about the 20th of May. Because the zone was still hot. Some amount of aerosol particles were released with ascending airflows. And the caesium emissions that caused so much trouble in Belorussia, they were forming up until the 22nd, maybe even the 23rd of May. But getting less and less overall.

Adamovich: [Unclear]

Legasov: Mostly caesium and strontium.

Adamovich: But this muck—

Legasov: Yes. Because other such unpleasant things like plutonium, as we established, had a distribution radius of 12 kilometres. Nothing got farther than 12 kilometres from the station. But caesium and strontium, these emissions, they did spread to large areas. [Volume reduces, unclear]… the release of caesium because everything is hot there. Why caesium? Because of all the metals that were there, it is the most fusible. It evaporates at just above 700 [sic] degrees Celsius. It melts and has high volatilization [sic] of saturated vapours. That is why it spreads. Our main goal was to prevent 2,500 degrees there. This is the main accomplishment of those people who spent considerable time there in the initial days. We had to avoid reaching a temperature of 2,500 degrees. That was the main goal.

Adamovich: [Unclear]

Legasov: Because 2,500 degrees is the melting point of the uranium dioxide pellets, and the main radioactivity sits inside these pellets. So if the temperature reached 2,500 degrees, then it would not be three per cent of radioactivity that gets released but the entire 100 per cent. That means 30 times the contamination. The area, the extent of contamination, its intensity would increase by 30 times compared to what happened. By 33 times almost. Even more actually because nasty isotopes would spread, much heavier than caesium that we mentioned earlier. Do you understand?

And so the main purpose of our actions boiled down to not reaching 2,500 degrees. This is why Ryzhkov was constantly asking—what is the temperature? what is the temperature? how much did it increase? The maximum temperature recorded there was around 2,000 degrees. Then with all these measures, by dropping all kinds of materials, we began to lower it and reduced it to 300 degrees in the end. Now the maximum temperature there—activity still continues; not the reactor but its remnants are active—is somewhere around 60-70 degrees Celsius. Around that much. Do you understand?

Adamovich: But if left without supervision, can it—

Legasov: Oh, about leaving it unattended, I will talk later separately. Now about other things. So that there is an understanding. The main goal of all the actions…

Adamovich: I understand.

Legasov: …was to prevent 2,500 degrees.

Adamovich: All the uranium in there—

Legasov: It would have all melted and all the radioactivity—only three and a half per cent got out—one hundred per cent of the radioactivity would have gotten out and flown around the earth. Do you understand? The meaning.

Adamovich: How much of it was there in total?

Legasov: In total in the reactor? In this reactor, 1,700 tons.

Adamovich: Of uranium?

Legasov: Uranium yes, the fuel itself. This goal was achieved.

Adamovich: There were telegrams from Ryzhkov. You did not hear what kind of conversations happened with him, [they were] purely operational.

Legasov: I heard them, and talked with Ryzhkov. And I reported to him when they arrived with Ligachev. But with Dolgikh, I myself spoke on the telephone many times.

Adamovich: Was there a conversation about, maybe, what you would do, and you reported on that?

Legasov: Reported on what is being done. The question is what was needed from Moscow. Full approval of our actions; very calmly. But I was very pleased with all the conversations with Ryzhkov and with Dolgikh. They were very professional.