Waking hungry on the morning of the 28th, the scientists went to the headquarters of the commission in Party Headquarters, where they were given a breakfast of sausages, white buns, lemonade and iodine tablets. When Fedulenko asked whether they should not have taken the iodine tablets earlier, he was told ‘better late than never’.
They reported to Legasov. Their task, he said, was to discover how the accident had occurred. The computer printouts and tape recordings were waiting for them in the bunker beneath the administrative block. He took two dosimeters out of his pocket and handed one to each of the two scientists.
They took a bus to the power station. It was shrouded in fog, a natural mist mingling with the vapour that still rose from the ruins of the fourth unit. Both scientists – especially Kalugin, whose whole life had been dedicated to RBMK reactors – were appalled to see all the mangled pipes and tanks exposed to the open air. They got off at the administrative building in front of the first unit and went down to the bunker. There they were met by Alexander Gobov, the director of research at Chernobyl and an old friend of Fedulenko’s. He gave them the logbooks from the fourth unit, printouts from the Skala computer registering one hundred parameters of data, and the tapes on which were recorded the voices of the operators as they conducted the tests.
Looking first at the logbooks, Kalugin saw that the reactor had been put onto low power twenty-four hours before the accident, with only thirteen control rods inserted into the core – two fewer than the minimum required – and that this clear breach of the guidelines had been ratified by the signature of the head of the shift. Turning to the printout from the computer, he saw that one minute before the accident had occurred, almost all of the boron control rods had been withdrawn from the core. The power of the reactor had been at two hundred megawatts. Thirty-six seconds after the test on the turbines had started, it had risen to six hundred megawatts. The AZ safety button had been pressed, and two hundred rods had started their descent into the core, but three seconds later the power had increased by a factor of three and the pressure in the reactor had doubled. Thereafter, the lines indicating neutron power and steam drum pressure ran vertically to the top of the paper.
Could it have been, Kalugin wondered, that as the control rods descended they had displaced the water in the base of the reactor, leading to a surge of positive reactivity? With growing dismay, he remembered that two years earlier this possibility had been raised at a meeting with his colleagues at Dollezhal’s institute, NIKYET. They had agreed that it was a remote possibility, but only if too many control rods were withdrawn. With the minimum of fifteen stipulated, such an uncontrollable leap in power could not occur.
Kalugin and Fedulenko then listened to the recording of the operators’ voices. At times they were muffled and indistinct, but the scientists could make out an agitated shout of ‘Press the button.’ Clearly the operators had been aware of a crisis. Next Gobov showed them photographs taken on the morning of the 26th, which showed not just the destroyed tanks, exposed pumps and piping, but the large blocks of graphite that had been thrown out by the explosion. It was incontrovertible evidence that the reactor had been destroyed. Gobov told them that in places the dosimetric readings were so high that fragments of the fuel itself must also have been ejected.
Kalugin and Fedulenko had seen enough to reach a preliminary conclusion. They telephoned Legasov, and soon after midday a telegram was sent to the Politburo in Moscow: ‘Cause of accident unruly and uncontrollable power surge in the reactor.’
Summoned back to Pripyat by Legasov, Kalugin and Fedulenko waited for the bus in front of the administrative block. It was now early afternoon, and the morning’s mist had been dispersed by the heat of the sun. They smoked and chatted while watching the helicopters make their bombing runs over unit 4. Several others were waiting for the same bus – some wearing military uniforms, others, like Kagulin and Fedulenko, dressed in civilian clothes. No one wore a mask or seemed worried about radiation. The damaged reactor was hidden from their view by the wall of the turbine hall, but Fedulenko noticed that every time a helicopter dropped a load of sacks into the reactor a dark grey cloud of smoke rose from behind the ventilation chimney. It floated almost to the top of the chimney; then the darker particles appeared to sink down to the earth again, while the lighter-coloured vapour rose above the chimney and was carried off to the north by a current of air.
After waiting in the open for more than a quarter of an hour, the group was picked up by an old Lvovsky bus. It was filled with dust and drove slowly past the fourth unit. Fedulenko had in his pocket a cloth mask that he had brought with him from Moscow, and though no one else was wearing a mask or respirator of any kind, he took it out and held it over his mouth and nose. Slowly the bus chugged past the damaged reactor. Another load of sand and clay dropped into the crater; another cloud of dark dust rose into the air.
Back at Party Headquarters, Kalugin and Fedulenko found that Legasov was less interested in their hypothesis about the cause of the accident and more in how to deal with its disastrous results. He described to them the action being taken and told them to calculate the likely effect upon the core. They returned to the hotel and went to work with a slide rule.
The next morning, the 29th, they were told that they were to move to the Pioneer camp. When they had been driven 3.5 kilometres from the power station, they got out to transfer to a less contaminated bus. It was an exceptionally beautiful day, and the air was fragrant with blossoms. It was almost impossible to believe that the new shoots of grass were already contaminated by radiation. While they were waiting, Fedulenko watched some peasants tilling their land with horse and plough, while others planted potatoes. No one had told them that they were wasting their time.
Anatoly Serotkin, the chief physicist from NIKYET, came up to Kalugin, his face expressing the utmost dejection. ‘Have you got a gun?’ he asked.
‘No. Why?’
‘I could use one.’
He reminded Kalugin of the meeting held two years before at which they had discussed the theoretical possibility of an accident of this kind. Shaking his head, Serotkin admitted how mistaken they had been to assume that the operators would observe the regulations. Had there not been reports about the lack of discipline in the nuclear power stations run by the Ministry of Energy? Had they not considered establishing commissions, run by their Ministry of Medium Machine Building to verify standards? Fedulenko was obliged to agree. He remembered the remark made by Fomin that it was as simple to run a reactor as a samovar.
As the second bus passed through Chernobyl, they saw the peasants who were being evacuated loading their belongings onto carts. Children were weeping; their mothers were distraught. What a triumph for socialism! This quiet country town, which had sat on its bluff above the Pripyat River since the twelfth century, with its wooden houses and onion-domed church, was now to be abandoned, probably for ever. Seeing this and feeling, like Serotkin, partly to blame for this catastrophe that had shattered the lives of so many innocent people, Kalugin wanted to lie on the floor of the bus to hide his shame.
4
At 10.00 a.m. on 1 May in Kiev the parade started on the wide curving boulevard, the Khreshchatyk. Brigades from the Pioneers, the Komsomol Youth Movement and sports teams, as well as garlanded young men and women in national costume, prepared to march past the party élite, who stood on the podium in front of Lenin’s statue. Next to General Secretary Vladimir Shcherbitsky stood a stern matron, Valentina Shevchenko, a deputy prime minister of the Ukraine. Other government and party leaders were drawn up in ranks around them, and on either side of the podium were seated veterans from the Great Patriotic War, and leading figures from the scientific and cultural world, as well as industrial leaders and record-breaking production workers. There were also honoured guests from abroad, including the representative of a Polish building combine that was building a hotel in Kiev. ‘On this festive day,’ he told a reporter, ‘I would like to wish the Ukraine’s working p
eople great success and clear skies over the planet.’
Some of those who had not gone to the Khreshchatyk or had fled the city watched the parade on television. Sergei Sklar, for example, remained at home not because he was worried about radiation but because the wind now coming from the north made it colder than it had been a few days before. He knew about the accident at Chernobyl; he had heard the announcement on ‘Vremya’ on 28 April, and had been told by friends who listened to the Voice of America that it was perhaps more serious than the authorities had admitted, but nothing had led him to suppose that either he or his wife or his eighteen-month-old son, Sergei, were in any danger. The day before, the little boy’s grandmother had taken him out for two or three hours in the open air, and seeing so many people smiling and dancing on the Khreshchatyk, he felt it must be safe enough for Sergei to be playing outdoors.
Yet, studying the crowds on the screen, he saw the occasional anxious expression among the smiling faces. He noticed, too, that a particularly gloomy look had replaced the usually genial countenance of General Secretary Shcherbitsky, standing on the podium with his grandson, and that he kept looking at his watch.
Then the telephone rang. It was a friend who warned Sklar that it was perhaps not as safe as they had supposed. Little Sergei was called indoors.
5
At 1.00 p.m., after the parade in Red Square in Moscow, Nikolai Ryzhkov held a meeting of the Politburo’s Chernobyl commission in the Kremlin. When reports were given on the measures taken in the wake of the accident, it was immediately apparent that the existing structures were not coping. The civil defence and the Ukrainian Health Ministry had been overwhelmed by the scale of the disaster. Urgent coded requests had been sent from the Belorussian Ministry of Health for radiological testing equipment and supplies of potassium iodide tablets. The decision was made to mobilize the army medical corps – Ryzhkov signed the decree – and to form a medical commission in Moscow under the auspices of the Ministry of Health, including Academician Ilyn and the celebrated haematologist Professor Andrei Vorobyov.
The commission also decided to form a new team to relieve Scherbina and Legasov, who were not only exhausted but had absorbed significant doses of radiation. Ryzhkov appointed another of his deputy prime ministers, Ivan Silayev, a man of considerable experience in the aircraft industry, and told him to be ready the next day to leave for Chernobyl. Two scientists from the Kurchatov Institute were chosen to replace Legasov: the second deputy director, his great rival, the atomic-fusion expert Academician Yevgeny Velikov; and Professor Eugene Ryzantzev, the head of the department for atomic safety, the superior to Drs Fedulenko and Kalugin.
Ryzhkov also heard that there were differences of opinion between the civil defence, the chemical troops and the Ministry of Health about whether further evacuation was necessary beyond the ten-kilometre exclusion zone. Other experts were therefore put on notice to fly to Chernobyl the next day. Finally, late in the afternoon, Ryzhkov decided that he himself, together with Yegor Ligachev, would fly to Chernobyl, and that evening he telephoned Gorbachev to tell him that the situation seemed sufficiently serious to warrant his personal attention.
As befitted their rank, Ryzhkov and Ligachev were met by the Ukrainian general secretary, Vladimir Shcherbitsky; a deputy prime minister; and the first secretary of the Communist party of the Kiev region, Grigori Revenko. They were led to a cavalcade of large black limousines, and driven at high speed and with a motorcycle escort to Party Headquarters in the town of Chernobyl, which since the evacuation of Pripyat on 29 April had been the command centre of the government commission. There they met with the large number of soldiers, scientists and engineers already working on the aftermath of the accident; together with ministers, deputy ministers and officials from Soviet and Ukrainian departments of state, the group that gathered at 3.00 p.m. before Ryzhkov and Ligachev amounted to 250 people.
On behalf of Scherbina, Legasov made his report. More than five thousand tons of sand, boron and lead had now been dropped over the burning reactor. As a result, the emission of radionuclides from the damaged reactor continued to decline. It was now only a little over two million curies per day – a high rate, certainly, but sufficient to suggest that smothering the reactor with sand was having the desired effect.
Following this optimistic line, the minister of energy and electrification, Mayorets, addressed the visiting leaders. ‘Dear comrades, members of the Politburo, Nikolai Ivanovich and Yegor Kuzmich, I am able to tell you that we have prepared the schedule for the reconstruction of the fourth unit and can assure you that it will be put back into operation by autumn, or winter at the latest. I can also assure you that the fifth unit will be launched on schedule.’ These assurances were met with applause.
Not all were so sanguine. General Pikalov’s assessment of the situation was grave. An area within fifteen kilometres of the power station and the station itself were both heavily contaminated and should be evacuated at once. There was also the danger that any rainfall would wash radioactive dust into the rivers, which fed the Dnieper and the Kiev reservoir.
Ligachev interrupted him. ‘And how long, Comrade General, will it take to clear up this contamination?’
‘Up to seven years.’
Ligachev exploded. ‘We’ll give you seven months! And if you haven’t done it by then, we’ll relieve you of your party card!’
‘Esteemed Yegor Kuzmich,’ said Pikalov. ‘If that is the situation, you needn’t wait seven months to take my party card. You can have it now.’
Pikalov’s pessimistic evaluation was confirmed by the maps that had been prepared by Professor Israel’s hydrometeorological committee, showing radioactive contamination outside the ten-kilometre zone. These showed deposits of plutonium 239 and 240 within a thirty-kilometre zone, while surface contamination by caesium 137 of over forty curies per square kilometre had been found beyond the thirty-kilometre zone, and even in territory to the north of Gomel in Belorussia. Some argued however, that the population was still in no danger of crossing the control limit of twenty-five rems. Distribution of iodine tablets would protect the thyroid from iodine 131, which had a half-life of only eight days. Caesium 137 on the ground had a half-life of thirty years, but if sensible measures were taken to ensure a supply of uncontaminated milk, the additional dose the populace would receive from the caesium would still be well within the prescribed limit.
Psychological factors had to be taken into account. The benefits of escaping additional contamination might be outweighed by the stress inherent in uprooting people from their homes. It was estimated that 116,000 people were involved. It should also be noted that those who had already been evacuated from Pripyat and the villages in the ten-kilometre zone had gone to territory hardly less contaminated than that which they had left – for example, the land around Narodici and Polesskoe. Some of the evacuees who had been sent there might as well have stayed at home.
Others were in favour of evacuation. The deputy chief of the civil defence, General Ivanov, had already prepared a contingency plan. He estimated that some of the villagers in the area could accumulate doses of six to eight rems, significant for adults and serious for children, and during the briefing the day before had recommended the evacuation of nine villages to Scherbina. Scherbina had put off a decision, but when Ryzhkov now asked what preparation had been made, Ivanov sent a note to the rostrum saying that if cattle were left behind, the area could be evacuated within a couple of hours.
Confused by this conflicting advice from the experts, Ryzhkov conferred with Scherbina, Revenko and Ligachev. They weighed the expense and the strain on resources of uprooting tens of thousands more people from their homes against the chance that if they remained some might be harmed by radiation. Finally a decision could no longer be postponed. Ryzhkov thumped his fist on the table. No more discussion! The town of Chernobyl and all the villages were to be evacuated: there would be a thirty-kilometre exclusion zone.
When Ryzhkov and Ligachev left the
town of Chernobyl that evening, the first buses were already arriving to remove the population. Their big black Zils, however, were too contaminated to leave the ten-kilometre zone; the prime minister and the secretary of the Central Committee had to return in smaller cars.
6
Although Velikhov and Ryzantzev had been sent to replace him, Valeri Legasov did not leave with Scherbina, but summoned Kalugin and Fedulenko to an urgent meeting. The most recent measurements taken by the chemical troops showed that on the very day that they had reassured the government that the reactor was under control, the emission of radionuclides from the damaged reactor had doubled from two million to four million curies per day. Rather than cooling down, the reactor core was getting hotter.
This gave Fedulenko the courage to criticize the whole idea of smothering the reactor with sand. ‘In my opinion, Valeri Alekseyevich,’ he said to Legasov, ‘it’s counterproductive. All that happens is that radioactive dust is thrown into the air.’
‘We heard a broadcast from Sweden,’ said Legasov, ‘that said that burning graphite should be smothered with sand.’
‘But uranium needs no oxygen for a chain reaction,’ said Fedulenko. ‘And the sand is unlikely to put out the graphite fire. We saw the video made by Poloshkin from the air. It shows that the core of the reactor is still largely blocked by the biological shield.’
‘It was blown aside by the blast …’