Midnight in Chernobyl: The Untold Story of the World's Greatest Nuclear Disaster

by Adam Higginbotham

The incident was classified top secret, and those directly involved were forced to sign gag orders by the KGB. Nikolai Steinberg would wait years before learning the truth about what had happened.

In the years that followed, there would be even more serious accidents at nuclear plants elsewhere in the Soviet Union, and all of them would be covered up.

While conducting tests before the two reactors could be brought into normal operation, the start-up teams of nuclear engineers in Ignalina and Chernobyl noticed a small but disturbing glitch. When they used the AZ-5 scram button to shut down the reactor, the control rods began their descent into the core, but instead of completing a smooth shutdown, the rods initially had the opposite effect: for a brief moment, reactor power rose instead of falling. The specialists discovered that the severity of this “positive scram” effect depended on the conditions inside the reactor at the moment the shutdown began—particularly on the ORM, the measurement indicating how many of the 211 control rods were withdrawn from the core. If more than 30 of these rods remained inserted when the scram began, the AZ-5 mechanism worked as intended, and the reactor would shut down quickly and safely. But when the total number of inserted rods fell below 30, the behavior of the reactor at shutdown became increasingly unpredictable, and the AZ-5 system struggled to do its job. With only 15 rods in, the technicians found that initial dampening of fission inside the reactor was marginal; it took six seconds before reactivity began to fall. And under some circumstances—7 rods or fewer—pressing the AZ-5 button might not shut down the reactor at all, but instead trigger a runaway chain reaction. If this happened, the increase in reactor power following an AZ-5 trip might be so great that it would no longer...

NIKIET circulated a notification of the positive scram effect to the senior managers of all RBMK plants. But, swept along in a blizzard of bureaucracy, tangled in secrecy, the news never reached the reactor operators. Nonetheless, as far as Anatoly Aleksandrov and the other nuclear chiefs were concerned, the redoubtable RBMK-1000—the Soviet national reactor—had been troubled by nothing more than temporary setbacks. By the time Viktor Brukhanov put his final signature on the paperwork to acknowledge completion of the fourth reactor of the V. I. Lenin nuclear power plant on the last day of 1983, the world still spoke of only one nuclear accident. And that humiliation belonged entirely to the United States.

the reactor designers devised what they called a “rundown unit”: a mechanism to use the momentum of the unit’s turbines to drive the pumps for those crucial seconds. The rundown unit was a crucial safety feature of Reactor Number Four and was supposed to have been tested before it was approved for use in December 1983. But Director Brukhanov had granted approval to skip the test, to meet his end-of-year deadline. And although similar trials had been attempted since, they had failed each time. By the beginning of 1986, the test was more than two years overdue, but the reactor’s first scheduled maintenance shutdown offered an opportunity to conduct the trial in real-world conditions. At two o’clock on Friday afternoon, with new modifications made to one of the unit’s two huge turbine generators, Turbine Number Eight, it had—at last—been ready to begin.

Yet the deputy chief engineer admitted a peculiar reservation about the reactor on which they all worked. For all his hours spent poring over the latest technical revisions and regulations, for all his mastery of thermodynamics and physics, Dyatlov said that there remained something unfathomable about the RBMK-1000: a nuclear enigma even he could never fully understand.

Shift Foreman Alexander Akimov, who would be responsible for supervising the test under the direction of Deputy Chief Engineer Dyatlov. In the strict technical hierarchy of the power plant, Akimov, an experienced reactor control engineer, was the senior member of the operational staff in the room. Dyatlov’s role was administrative: no matter how deep his nuclear expertise, he could no more take the controls of the reactor engineer’s desk than an airline executive could step onto the flight deck of one of his passenger jets and fly the plane himself.

As soon as the Kiev grid dispatcher gave permission, the operators had resumed the reactor’s long, controlled power descent and now held it steady at 720 megawatts—just above the minimum level required to perform the test. But Dyatlov, perhaps assuming that a lower power level would be safer, was adamant that it be conducted at a level of 200 megawatts. Akimov, a copy of the test protocol in his hands, disagreed—vehemently enough for his objections to be noted by those standing nearby, who heard the two men arguing even over the constant hum of the turbines from the machine hall next door. At 200 megawatts, Akimov knew that the reactor could be dangerously unstable and even harder to manage than usual. And the program for the test stipulated it be conducted at not less than 700 megawatts. But Dyatlov insisted he knew better. Akimov, defeated, agreed reluctantly to give the order, and Toptunov began to decrease power further. Then, at twenty-eight minutes past midnight, the young engineer made a mistake.

Before completing the change, he was supposed to choose a level at which the computer would maintain reactor power in the new operating mode. But, somehow, he skipped this step. The reactor proved as unforgiving as ever. Bereft of fresh instructions, the computer defaulted to the last set point it had been given: near zero.

The reactor was being poisoned, plunging into what the operators called a “xenon well.” At this point, with the reactor’s power stalled at its minimum, and more xenon accumulating all the time, nuclear safety procedures made the operators’ course quite clear: they should have aborted the test and shut down the reactor immediately. But they did not.

Finally, six long minutes after the fall in power had begun, Toptunov, terrified of losing his job, gave in to Dyatlov’s demands. The deputy chief engineer withdrew from the console, mopping sweat from his brow, and returned to his position in the center of the room.

But to do so they had withdrawn the equivalent of 203 of the unit’s 211 control rods from the reactor core.

In the control room, just as the staff was expecting to relax, the SIUR’s annunciator panel suddenly lit up with a frightening succession of alarms. The warning lamps for “power excursion rate emergency increase” and “emergency power protection system” flashed red. Electric buzzers squawked angrily. Toptunov shouted out a warning: Power surge!

The temperature inside the reactor rose to 4,650 degrees centigrade—not quite as hot as the surface of the sun.

In that moment, the core of the reactor was completely destroyed. Almost seven tonnes of uranium fuel, together with pieces of control rods, zirconium channels, and graphite blocks, were pulverized into tiny fragments and sucked high into the atmosphere, forming a mixture of gases and aerosols carrying radioisotopes, including iodine 131, neptunium 239, cesium 137, strontium 90, and plutonium 239—among the most dangerous substances known to man. A further 25 to 30 tonnes of uranium and highly radioactive graphite were launched out of the core and scattered around Unit Four, starting small blazes where they fell. Exposed to the air, 1,300 tonnes of incandescent graphite rubble that remained in the reactor core caught fire immediately.

At his post in the shadow of the main circulation pumps, Valery Khodemchuk was the first to die, vaporized instantly by the explosion or crushed beneath the mass of collapsing concrete and machinery. Inside Control Room Number Four, tiles and masonry dust fell from the ceiling. Akimov, Toptunov, and Deputy Chief Engineer Dyatlov looked about them in confusion. A gray fog bloomed from the air-conditioning vents, and the lights winked out. When they came back on, Boris Stolyarchuk noticed a sharp, mechanical smell, unlike any he had ever encountered before. On the wall behind them, the indicator lamps monitoring levels of radiation in the room abruptly turned from green to red.

Returning to the control room, Dyatlov took command. He gave orders to Shift Foreman Alexander Akimov to dismiss all nonessential personnel still at their posts, including Senior Reactor Control Engineer Leonid Toptunov, who had pressed the AZ-5 scram button. Then he told Akimov to activate the emergency cooling pumps and smoke exhaust fans, and gave instructions to open the gates of the coolant pipe valves. “Lads,” he said, “we’ve got to get water into the reactor.”

And from somewhere in the heart of the tangled mass of rebar and shattered concrete—from deep inside the ruins of Unit Four, where the reactor was supposed to be—Alexander Yuvchenko could see something more frightening still: a shimmering pillar of ethereal blue-white light, reaching straight up into the night sky, disappearing into infinity. Delicate and strange and encircled by a flickering spectrum of colors conjured by flames from within the burning building and superheated chunks of metal and machinery, the beautiful phosphorescence transfixed Yuvchenko for a few seconds. Then Tregub yanked him back around the corner and out of immediate danger: the phenomenon that had entranced the young engineer was created by the radioactive ionization of air and was an almost certain sign of an unshielded nuclear reactor open to the atmosphere.

Pravik and Shavrey, mere firefighters, had no equipment to measure radiation. Their walkie-talkies weren’t working.

Brukhanov heard that the instrument readings in the control room still showed coolant levels stuck at zero. He feared that they stood on the precipice of the most terrifying catastrophe imaginable: the reactor running dry of water. Nobody suggested to him that the reactor had already been destroyed.

Perevozchenko, Proskuryakov, and Kudryavtsev remained on the ledge for only as long as Yuvchenko held the door: a minute at most. But even that was too long. All three received a fatal dose of radiation in a matter of seconds. Even as his three colleagues staggered back into the corridor in shock, Yuvchenko wanted to have a look for himself. But Perevozchenko, a veteran of the nuclear submarine fleet, who knew very well what had just happened, shoved the younger man aside. The door slammed shut. “There’s nothing to see here,” he said. “Let’s go.”

The plant’s civil defense chief, Serafim Vorobyev, arrived in the bunker shortly after two in the morning.

Vorobyev drove back to the bunker and reported to Brukhanov the most conservative reasonable dosimetry estimate: the station was now surrounded by very high fields of radiation, of up to 200 r/h. It was essential, he said, to warn the people of Pripyat about what had happened. “We need to tell people that there’s been a radiation accident, that they should take protective measures: close the windows and stay inside,” Vorobyev told the director. But still Brukhanov stalled. He said he would wait for Korobeynikov, head of the plant’s radiation safety team, to make his own assessment. At 3:00 a.m., Brukhanov called his Party boss in Moscow and the Ministry of Internal Affairs in Kiev with a situation report. He described an explosion and a partial collapse of the turbine hall roof. The radiation situation, he said, was being clarified.

It was another hour before the chief of radiation safety arrived. Vorobyev stood by and listened to the man’s report in disbelief: his measurements revealed that radiation levels were indeed elevated, but they were a mere 13 microroentgen an hour. He claimed to already have performed a rough analysis and found that the radionuclides in the air were principally noble gases, which would quickly dissipate and therefore posed little threat to the population; there really wasn’t much to be concerned about. This assessment was apparently what Brukhanov had been hoping to hear. He stood and, looking around the room, declared darkly, “Some people here understand nothing and are stoking panic.” He left no doubt whom he was talking about. Yet Vorobyev knew that it was simply impossible to approach the station from any direction without passing through radiation fields tens of thousands of times higher than the radiation safety team reported. Every word he’d just heard must therefore be a lie—but his confidence in his own expertise and equipment had been shaken.

“There’s no mistake,” he told Brukhanov. “We must take action as the plan demands.” But the director cut him off. “Get out,” he said and pushed him away. “Your instrument is broken. Get out of here!”

In desperation, Vorobyev picked up the phone to notify the Ukrainian and Belarusian civil defense authorities. But the operator told him he had been forbidden from making long-distance calls. Eventually he managed to get a connection to Kiev on his direct line, which in their haste Brukhanov and his assistants had failed to have cut off. But when Vorobyev delivered his report, the civil defense duty officer who answered refused to believe that he was serious.

Yet as Toptunov and Akimov entered the plant infirmary, the water they had worked so hard to release gushed uselessly from shattered pipes around the smashed reactor. It spilled through Unit Four from one level to the next, running down corridors and staircases, slowly emptying the shared reserves needed to cool Unit Three, flooding the basement and the cable tunnels that linked them both, and threatening further destruction. Many more hours would pass, and other men would sacrifice themselves to the delusion that Reactor Number Four survived intact, before Director Brukhanov and the men in the bunker acknowledged their terrible mistake.

Vitali Sklyarov couldn’t sleep. The Ukrainian republic’s minister of energy and electrification

Boris Prushinsky—chief engineer of Soyuzatomenergo, the Ministry of Energy’s Department of Nuclear Power, and head of OPAS, the emergency response team recently created to respond to accidents at atomic stations—was at home in bed when he was woken by a call from the duty operator. She told him there had been an accident in Unit Four at the Chernobyl power plant. Then she read aloud the code signal used to signify its severity: Odin, dva, tri, chetyre. “One, two, three, four.” Prushinsky, barely conscious, struggled to recall what the numbers meant: A localized or general accident? A fire? Radiation? With casualties or without? It was no good. He grew impatient. “Tell me normally,” he said. “What happened?” It was 1:50 a.m.

The head of the USSR’s civil defense—the branch of the Soviet armed forces responsible for protecting civilians in the event of natural disaster, nuclear war, or chemical attack—was away at a conference in Lvov, in western Ukraine. The marshal found him by telephone and gave instructions to deploy immediately the mobile radiation reconnaissance unit of civil defense stationed in Kiev. He also alerted the special Soviet army brigade dedicated to dealing with radioactive contamination, based east of the Volga River, and arranged for men and equipment to be airlifted to Chernobyl. By the time he left Moscow to lead the operation, Colonel General Boris Ivanov, deputy commander of all civil defense forces in the USSR, understood that he was dealing with an explosion in the Chernobyl plant’s gas storage system and a fire in Unit Four. He planned to deploy his troops in accordance with existing plans to protect the workers and nearby population in the event of power station accidents: this was a scenario for which his staff had been specifically trained.

At 3:00 a.m., Vladimir Marin was still at home when his phone rang a second time. It was Viktor Brukhanov himself, calling from the bunker beneath the plant. The director confessed that there had been a terrible accident at the power station—but assured his boss that the reactor itself remained intact. Marin told his wife the news, then quickly dressed and ordered a car to take him to the Central Committee. Before leaving, Marin called his immediate superior, who then passed the message up through the Party hierarchy.

But over at Soyuzatomenergo, Georgi Kopchinsky and the other nuclear experts had already grasped that the reality might be far worse than anyone imagined. When they reached a shift supervisor at the station by phone, he had sounded incoherent and on the edge of panic. The agency’s director instructed him to find someone from the station’s senior management and tell them to phone Soyuzatomenergo immediately. Chernobyl’s deputy chief engineer for science was the first to call back. He calmly explained what he knew: Unit Four had been taken off-line for routine maintenance, and some kind of electrical tests were being carried out; exactly what, he couldn’t say. During those tests, an accident had occurred. But when asked about the progress of emergency cooling of the core—the vital work that would ensure Reactor Number Four could soon be repaired and brought back online—the Chernobyl engineer’s composure snapped abruptly. “There’s nothing left to be cooled!” he shouted. Then the line went dead.

comprehension? Sklyarov called First Secretary Scherbitsky once again and told him what he had. “Vitali Fedorovich,” Scherbitsky began, and Sklyarov braced himself. It was always a bad sign when the First Secretary used your patronymic. “You need to go there yourself.” Sklyarov, who had almost no interest in seeing a blazing nuclear plant at close quarters, tried to object. “The station is under the supervision of Moscow. It doesn’t belong to us,” he said. “The station might not be Ukrainian,” Scherbitsky replied, “but the land and the people are.”

The chief engineer, Fomin, who had approved the Unit Four turbine test without bothering to notify Brukhanov that it was taking place, appeared to be in shock. His commanding self-assurance had snapped with the finality of a rotten branch, and he sat, repeating the same question again and again, in the small voice of a forlorn child: “What happened? What happened?”

By eight in the morning, samples taken by technicians from the plant’s Department of Nuclear Safety revealed the presence of fission products and particles of nuclear fuel on the ground and in water around the station. This provided conclusive evidence that the core of the reactor had been destroyed and that radioactive substances had been released into the atmosphere.

The doctor in charge of the plant sick bay provided details of casualties so far. There was one dead and dozens of injured; it was clear that they had been exposed to enormous levels of radioactivity and undeniably exhibited the symptoms of radiation sickness. Yet the chief of the station’s external dosimetry, tasked with measuring radiation beyond the plant’s limits, insisted there was no need to evacuate Pripyat. Vorobyev, the head of civil defense for the plant, tried to interrupt to say—once again—that they had a duty to inform the city’s population of the accident, but this time Malomuzh cut him off. “Sit down,” he snapped. “It’s not up to you.”

Malomuzh instructed Brukhanov to give him a written situation report, which was then drafted by a handful of staff led by the plant Party secretary and brought to the director’s desk at around 10:00 a.m. The document was brief—a single typed page—describing an explosion, the collapse of the roof of the reactor hall, and a fire, which had already been completely extinguished. Thirty-four people involved in the firefighting were being examined in the hospital; nine had suffered thermal burns of varying degrees, and three were in critical condition. One man was missing, and another had died. There was no mention of any radiation injuries. The document stated that levels of radiation near Unit Four had reached 1,000 microroentgen per second—a tolerable 3.6 r/hr. But it failed to explain that this was the highest reading possible for the equipment used to take the measurements. It concluded with the assurance that the situation in Pripyat remained normal and that radiation levels there were being investigated. At the bottom, in the space provided, Brukhanov signed his name in blue ballpoint.

Led by Boris Prushinsky, the Ministry of Energy’s nuclear accident emergency response

So when the bus finally approached the fork in the road separating the city from the nuclear plant, and Prushinsky saw a militsia officer wearing a lepestok mask with his summer uniform, he was puzzled. The lepestok, or “petal,” was a Soviet-designed cloth respirator, which filtered radioactive aerosols from the atmosphere, and he couldn’t imagine why it might be necessary. But when the team reached Pripyat, someone from the plant was there to meet them and assured him that everything was under control. Relieved, Prushinsky checked into Hotel Polesia, an eight-story concrete building overlooking the central square, and went to lunch in the restaurant downstairs. Afterward, he ambled out onto the sunny hotel terrace and saw Director Brukhanov crossing the plaza toward him. “What’s the problem with the unit?” Prushinsky asked. Although the shell-shocked director would later continue to give his superiors contradictory information—and for several more hours tell others that Reactor Number Four remained intact—at this moment, Brukhanov acknowledged the truth.

“There is no unit anymore,” he said. Prushinsky was dumbfounded. He knew this man was no nuclear expert. But what he was suggesting was simply inconceivable. “Have a look for yourself,” Brukhanov said in despair. “The separators are visible from the street.”

it was not until later on Saturday afternoon that the report was delivered to Gorbachev.

“An explosion occurred in the upper part of the reactor chamber,” the cable read. “The roof and parts of the wall panels of the reactor compartment, several roof panels of the machine room . . . were demolished during the explosion and the roofing caught on fire. The fire was extinguished at 0330.” To a government that had developed a strong stomach for industrial accidents, this was familiar territory. Some sort of explosion, yes; a fire, which had already been put out. A serious incident, certainly, but nothing that couldn’t be contained. The main thing was that the reactor itself remained undamaged; a potential nuclear catastrophe had been averted. “The personnel of the AES are taking steps to cool the fuel core of the reactor. In the opinion of the Third Main Directorate of the USSR Ministry of Health,” the report stated, “it is not required to take special measures, including the evacuation of the population from the city.”

Circling the reactor at low altitude in the helicopter, Boris Prushinsky realized that Director Brukhanov had been right about the fate of Unit Four of the Chernobyl Atomic Energy Station. Yet the head of the nuclear emergency response team still found it hard to believe what he was seeing. The roof of the central hall had disappeared. Inside was a gaping black crater, where more than ten stories of walls and floors had been carved away as if scooped out from above by a monstrous spoon. The northern wall of the building had collapsed into a shambles of black rubble that tumbled out across the flat roofs of adjoining buildings and toward the station perimeter. Inside the ruins of the hall, he could see the tangled wreckage of the 120-tonne bridge crane, the refueling machine, the main circulation pumps, and the emergency core cooling tanks. The pilot tilted the helicopter to one side, so the plant photographer could shoot through the window. Prushinsky saw that the lid of the reactor—Elena, the two-thousand-tonne disc of concrete and steel designed to shield it from the outside world—was tilted upward to the sky. Beneath it, deep within the reactor vault, and despite the bright sunshine, he could make out the glowing lattice formed by the remaining fuel cells—and a single spot that burned a fierce yellow-red. As the helicopter banked away, Prushinsky forced himself to confront what his mind still refused to accept: Reactor Number Four had ceased to exist.

At a 4:00 p.m. meeting in the Party’s conference room in the White House, Chief Engineer Nikolai Fomin finally conceded that the efforts made by his men over the previous twelve hours to keep cooling water circulating through Reactor Number Four had been entirely in vain. He admitted that the reactor had been destroyed and pieces of highly radioactive graphite lay on the ground everywhere. Worse news was to come. That morning, station physicists had entered the contaminated control room of Unit Four and established that the control rods had not descended fully into the reactor before the explosion. They now suspected that the conditions for a new criticality would soon exist in whatever nuclear fuel remained inside the reactor vessel, initiating a new chain reaction—but this time, it would take place in the open air, and they would have no means of controlling it. When the reactor returned to life, it could bring fires and explosions and release waves of deadly gamma and neutron radiation into the atmosphere less than 2,500 meters from the edge of Pripyat. Their estimates suggested they had only three hours to intervene before the new criticality began—sometime after seven in the evening.

the radiation reading just beside the plant cafeteria, scribbled hastily in pencil: 2,080 roentgen an hour. “You mean milliroentgen, son,” the Party chief said. “Roentgen,” Logachev said. Logachev’s commander studied the map. He finished one cigarette and then lit another. “We need to evacuate the city,” he said.

“We have to evacuate the local population,” Prushinsky said. “Why are you being so alarmist?” Scherbina asked.

Academician Legasov listened as Scherbina took reports from Malomuzh—the regional Party boss—and Mayorets, the Soviet energy minister. But they provided no detailed information about the situation at either the plant or in the city and had no plan on how to deal with the consequences of the accident. They said only that during a turbine rundown experiment in Unit Four, there had been two explosions in quick succession, and the reactor hall had been destroyed. There were hundreds of injuries among the staff: two men were dead, and the rest were in the city hospital. The radiation situation in Unit Four was complex, and although levels in Pripyat had departed significantly from normal, they posed no threat to human health.

that something must be done—but what? And as dense clouds of radionuclides continued to roil into the sky above Reactor Number Four, the experts assembled in the White House still could not agree on whether to evacuate Pripyat. The civil defense radiation scouts had been taking hourly readings on the streets of the city since noon, and they found the figures alarming: on Lesi Ukrainki Street, less than three kilometers from the reactor, by midafternoon, they had recorded readings of 0.5 roentgen an hour; by nightfall, it was up to 1.8 roentgen. This reading was tens of thousands of times higher than normal background radiation, but the Soviet deputy minister of health insisted that it posed no immediate threat to the population. He pointed out indignantly that even after the still-undisclosed 1957 disaster in Mayak, the population of the secret city had not been told to leave. “They never evacuated people there!” he said. “Why do it here?”

more urgent was the state’s compulsion for secrecy. By daybreak on Saturday, the men of the militsia had sealed off the entire area with roadblocks, and the KGB then cut off the city’s long-distance telephone lines. By nightfall, the local lines were dead, too, and there had still been no radio broadcast to notify the citizens of Pripyat of the accident, let alone warn them to stay indoors or close their windows. Even so, in the event of an evacuation, Scherbina knew there would be no way of concealing the exodus of the fifty thousand residents of an entire atomgrad.

From Kiev, the Ukrainian prime minister had already unilaterally given orders to arrange transport—more than a thousand buses and trucks—for a possible evacuation of the city. Yet nothing would move without sanction from the top. And Scherbina wanted more information before making a decision. He resolved to wait until morning.