Soviet nuclear industry sources have said that domestic problems played a role, but the timing, 27 April, exactly two years after the Chernobyl accident, is clearly of major significance. His death was first officially announced on 29 April, but without any mention of the cause. Subsequently it emerged that he had taken his own life.
Legaslov, who was 51, led the Soviet delegation to the momentous IAEA Chernobyl post-accident review meeting in Vienna in August 1986, where his candid, detailed and lengthy exposition of the circumstances and consequences of the accident earned considerable respect and acclaim worldwide.
On 20 May, Pravda published extracts from his memoirs, which he had dictated into a recording machine in the period since the accident. These describe how he first heard of the accident just before going to a routine talk at his Institute to be given by a party activist. This was around 10am on 26 April (the accident had occurred in the early hours of that day). The speaker mentioned the Chernobyl event and added, “They have somehow messed things up there; there has been some kind of accident but it will not stop the development of nuclear energy.” Around midday Legasov learned that a government commission had been formed to deal with the accident and that he was on it.
The article below is extracted from the Pravda material.
The commission which Legsaov found himself on had to assemble at Vnukovo airport at 4pm on 26 April for departure to Kiev.
At Vnukovo airport Legasov found out that the leader of the commission would be Boris Shcherbina, deputy Chairman of the Council of Ministers and head of the Bureau for Fuel and Energy. During the flight, Legasov talked about the Three Mile Island accident with Shcherbina and concluded that, because of differences in reactor design, the causes of the Chernobyl accident were probably quite unlike those at TMI.
The commission was taken from Kiev to Pripyat (the nearest town to the nuclear station) where they learnt that, “as a result of two consecutive explosions, the building housing the reactor had been destroyed and several hundred people had been irradiated.” It was also reported that two men had perished and the remainder were in the town’s hospital. Radiation conditions were around normal in Pripyat.
A crimson glow was visible in the night sky 8-10 km from the plant.
Before the arrival of the commission at the site, which was at around 8pm on the 26th, the station staff and operators were “doing the best they could” and were still in post on units 1-3. But they were unable to assess the overall situation and there was no plan of action.
The first step taken was to shut down the third unit. The first and second units continued to operate despite high radiation levels caused by internal contamination due to the common ventilation system which had not been switched off at the time of the accident.
The external state of the reactor was examined from helicopters. A column of white smoke several hundred metres high belched out from the crater of the reactor. Inside there were large zones emanating a strong crimson glow. It was difficult to assess whether the glow was caused by incandescent graphite blocks that had remained after the explosion or by combustion of graphite, Legasov observed.
By the late evening of 26 April all the possible means of flooding the damaged reactor had been rejected because of worries about generating large volumes of steam and the possibility of the water spreading to the neighbouring units. On the same evening, the firemen accomplished the heroic task of putting out the turbine hall fire thus eliminating the danger of further fires and explosions that could have led to the destruction of the third unit.
During the 240 hours or so that Legasov estimated would be required for combustion of the whole graphite inventory of the core, a very large area would have become very heavily contaminated. Since radiation levels were high the fire could only be put out from the air, at a height of not less than 200m above the reactor.
Telegrams from abroad began to arrive over the next few days suggesting ways of handling graphite fires using carious chemical mixtures. After considerable deliberation, Legasov notes, the now famous mixture of lead and dolomite was selected as the temperature stabiliser.
By 2 May, the reactor was plugged. But on 9 May, just when it appeared that the damaged unit had stopped burning, a small but brightly glowing crimson spot was observed inside it. Legasov came to the conclusion that it was an incandescent mass of sand, clay and other material dropped on the core. It appears that this fire was extinguished by dropping a further 80 tons of lead.
EVACUATING PRIPYAT
In the very early stages, one of the most pressing problems for the commission was deciding what was best for the residents of Pripyat. The physicists wanted immediate compulsory evacuation and between 10pm and 11pm on the 26th, Shcherbina “having heard our discussions and believing our prognosis,” decided to evacuate the town the following day.
However, not everyone received the information, which was initially conveyed by word of mouth, because on the morning of 27 April, “mothers could be seen pushing prams and children were playing in the street – just like any other Sunday,” Legasov remarks. At 11am, however, the official announcement was made and the evacuation was carried out relatively smoothly.
A large group of people were allowed to leave the area in their own cars. Legasov considered, however, that this should not have been permitted because the cars were contaminated and washing facilities were not set up until later.
|
“” |
|
He concluded that the accident was the ‘apotheosis of all that was wrong in the management of the national economy and had been so for many decades.’ |
Dosimetry services were provided by the military and more accurate information on isotope compositions came from laboratories set up in the area.
Legasov found that the plant personnel were ready to do anything, but they had no real understanding of how to plan and organise. Assessment of the problem and implementation of operations had to be undertaken by the government commission.
During their first day in Pripyat the commission encountered shortages of respirators and personal dosimeters. There was no remote-controlled equipment for external dosimetry at the plant and therefore a large number of people had to be deployed to carry out these operations. There were no radio-controlled aircraft available equipped with dosimeters and therefore a considerable number of pilots were needed for measuring radiation levels. Initially, at least, no attention was paid to elementary health physics. In the first few days after the accident, food was stored in contaminated rooms and people were handling it with their bare hands.
At the beginning of May, a Politburo working party under Nikolai Ryzhkov was established, which in effect had the whole of Soviet industry under it. Legasov enthusiastically commends the way in which this working party handled daunting and complex problems, including contradictory information from experts.
The army was given the job of dealing with the plant itself and decontaminating the area within a 30km radius, including Pripyat. Legasov reports that the army personnel approached their tasks with great courage. Everyone was only too willing to assist him, he says.
As the initial problems were tackled “in those terrible days,” and thoughts turned to building the sarcophagus, Legasov describes the mood, paradoxically, as one of elation, arising from the way in which people responded so quickly, calmly and effectively to the challenges being faced.
CONCERNS ABOUT SAFETY
The memoirs however, also reveal his deep concerns about safety aspects of the Soviet nuclear industry. While Soviet equipment was, in certain conceptual respects, better than that from the West, “there was a marked shortage of control and diagnostic systems.” Also, rigorous analysis of nuclear power plant risk was almost exclusively the preserve of Western scientists and engineers. There was no organization in the USSR which could competently address these problems, he claimed.
Legasov singles out C A Sidorenko by name as a leading advocate of improved nuclear safety who was most active in pushing for better equipment quality and better training for designers, builders and plant operators. The number of power plants was increasing while the level of personnel training was falling. Yet Sidorenko’s views did not receive widespread support. The organizations concerned, themselves staffed by highly qualified people, believed that the problems could be tackled simply by raising the qualifications of personnel and issuing ever more detailed instructions.
Scientific organizations began to be weakened, the capacity to provide plants with up-to-date equipment declined, personnel began to age and new approaches were not welcomed. Gradually a pattern of work and responding to problems became entrenched. Legasov was aware of the trends but felt powerless to intervene since the “professionals in the field did not take kindly to outside interference.” A generation of engineers grew up who were well qualified but did not cultivate a critical attitude to the technology.
Although there were many problems connected with the safety of existing nuclear systems he had nevertheless been convinced that the risks from conventional stations were greater.
The RBMK reactor was considered by a number of engineers to be inferior from the economic point of view, but fairly good in terms of safety. As a chemist, however, Legasov was disturbed about the large quantities of graphite, zirconium and water in the system. He was also worried about the remarkably inadequate provision of safety systems which could operate under emergency conditions: introduction of the emergency protection rods was subject to operator intervention. There were no other protection systems completely independent of the operator and which were triggered exclusively by signals from the core instrumentation that could not be overridden. Proposals had been made to the designers about the need for changes in the protection system, but modifications were being developed with not great urgency, he notes.
LACK OF RESPONSIBILITY
A major underlying contributor to the Chernobyl accident, Legasov believed, was an attitude engendered by the lack of individual responsibility for quality. He mentions a number of examples (slipshod, welding, pipework defects, faulty valves, RBMK channel failures) and notes that after a decade of talk about training and five years, at least, of discussions on the development of systems for equipment diagnostics, nothing was done.
His calls for studies on safer reactor types (eg HTGR) were, he says, greeted with indignation and no efforts were made to identify in a rigorous and comprehensive way all the possible faults that could arise in nuclear plants and analyse them in detail.
He concluded that the accident was the “apotheosis of all that was wrong in the management of the national economy and had been so for many decades.”
But the blame was not a purely abstract concept. There were, in his view, genuine guilty parties. Designers had failed to modify reactor safeguard systems quickly enough, even when problems were recognized. One station director is quoted as saying that a nuclear reactor is like a samovar [kettle] “and much simpler than a conventional plant.”
Legasov refers to transcripts in his safe of conversations between operators from the night before the accident, which show that they were planning to carry out actions which had been crossed out in the operating manual. “The level of preparation of serious documents for a nuclear power plant was such that someone could cross out something, and the operator could interpret, correctly or incorrectly, what was crossed out and perform arbitrary operations,” Legasov observes.
But Legasov emphasises that it is not only operators that were to blame. He notes, for example, that although representatives of the regulatory body, Gosatomenergonadzor, were present at the plant they were not informed about the experimental programme.
| Legasov suicide |
| He concluded that the accident was the ‘apotheosis of all that was wrong in the management of the national economy and had been so for many decades.’ |
External weblinksNuclear Engineering International is not responsible for the content of external internet sites.Focus on Chernobyl
