5

Chernobyl: From Accident to Sarcophagus

In many ways, Chernobyl was an accident waiting to happen, and some readers may interpret the following account as entirely in line with this view. What I will demonstrate in this chapter is more complicated, however. While there were warning signs that all was not well with the RBMK, the Chernobyl plant crew, and the Soviet nuclear industry in general, and while it is true that some ignored or minimized many of these warning signs, other people and organizations worked tirelessly to address them. Many people in the industry had to make difficult decisions under great uncertainty, and when they knew they couldn't achieve the optimum solution, zero risk, they tried to at least reduce the risk they saw. These decision makers did not have the clarity hindsight conveniently provides. When they couldn't get fire-resistant roof tiles in time, they had to decide whether to risk delaying a reactor's start-up, a delay that could cost them funds for salaries and workers’ bonuses in years to come. They had to decide whether to stop operating all reactors until every system had been upgraded, a decision that would have left many households dark, schools cold, and industrial facilities idle. And they had to decide whether to treat nuclear power plants as special or ordinary, with all the consequences this categorization entailed. Nobody made such decisions alone: teams, committees, councils, sectors, divisions, and other forums all debated these decisions, weighed options, disagreed, and compromised. Sometimes they got it right, sometimes they got lucky, and sometimes things went really badly. Catastrophically badly, as they did in the early hours of April 26, 1986, at Chernobyl's reactor number 4 (figure 5.1).

Figure 5.1 Destroyed reactor number 4 at Chernobyl. On April 26, 1986, an explosion completely destroyed reactor number 4 and ejected large amounts of highly radioactive debris into the plant's surroundings and high into the atmosphere, where wind and rain carried the fallout to regions near and far. Remediation work commenced immediately, despite the unprecedented levels of radiation.

Source: Photograph by Anatol Rasskazov, 1986. Courtesy of National Chernobyl Museum, Kiev, Ukraine.

In this chapter, I recapitulate the main stages of the accident itself—the explosion and immediate response, including the evacuation of the plant's satellite town. Next, I analyze the phase when a more specific emergency response strategy took shape and culminated in the completion of the reactor entombment (the sarcophagus). I scrutinize the protracted period of accident investigations, when reports were written, revised, and refuted. This period started during the extended emergency response phase, when the Soviet and international authorities assigned blame, and it continued after the sarcophagus was built. During this period, organizations operating nuclear power plants introduced safety improvements at their reactors, not always in a synchronized fashion. To fully examine the design issue, I reconsider the concerns that nuclear scientists raised about the RBMK before Chernobyl. Finally, I look at how the accident changed the nuclear power industry in the former Soviet Union.

The Accident

On April 25, 1986, the operators on duty in the control room of unit 4 at the Chernobyl nuclear power plant conducted a scheduled test.¹ They wanted to see whether, with their energy supply cut, the turbines would have enough momentum to supply electricity to the plant's systems for more than the 20 to 30 seconds the emergency diesel generators needed to start up.² To do the test, they had to switch off one of the safety subsystems.³ They planned to do the test just before the next regular maintenance shutdown.⁴ Their instructions stipulated a thermal power level of 700–1000 MW. If the power dropped below this margin, they were supposed to terminate the test and shut down the reactor immediately.

When the head of unit 4's control room staff, Aleksandr Akimov, started his shift in the afternoon of April 25, the reactor was in transition, a state that occurred whenever operators were either shutting it down or starting it up. In those situations, a reactor is typically less stable than during regular operation. In addition, during shift change, the incoming operators had to catch up with the logbook, assess the current state of the reactor, and prepare for the tasks allocated to their shift.⁵ Observers in Russia and the United States have noted that these moments in the control room are always challenging and often push the reactor operators’ skills to the limit.⁶

The operators at Chernobyl's unit 4 had begun to decrease the power level when the regional grid operator, Kievenergo, prohibited the reactor's shutdown due to high energy demand.⁷ Kievenergo did allow the operators to resume the scheduled test at 11:25 p.m., once the period of peak demand had passed.⁸ The operators then tried to raise the power level again, not realizing that the reactor had already entered the period of xenon poisoning, during which raising the power level is difficult if not impossible.⁹

To understand what happened next, we need a few additional technical details about the RBMK.¹⁰ The control rods that sit in water-filled, vertical channels in its graphite core are made of a neutron-absorbing material and serve to regulate the reactor's power level. When completely inserted into the core, as for example at start-up and shutdown (position D in figure 5.2), the control rods absorb all the neutrons emitted by the uranium fuel, and no nuclear fission can take place.¹¹ Reactor operators adjust the level of the control rods to increase, stabilize, or decrease the reactor's power level.¹² When operators raise them—that is, pull them partially out of the core—neutrons emitted by the fuel are free to interact with the moderator (the graphite). The moderator slows the neutrons down to a speed at which they are likely to split other nuclei, a process that eventually facilitates a nuclear chain reaction. Automatic controls regulate some control rods, others can be operated manually, and some are emergency rods programmed to react to signals indicating an accident.¹³

Figure 5.2 The chart shows the design and various possible positions of the RBMK's control rods. In an effort to raise the reactor's power level, operators at Chernobyl's reactor number 4 had pulled most of the control rods out very high, to a position labeled “prohibited” on the chart. When the operators initiated the automatic reactor shutdown (SCRAM), the control rods started moving down into the reactor core. Since they had been pulled out too far, their insertion did not shut down the nuclear reaction as intended, but instead introduced additional reactivity into the core. This led to the destruction of the reactor.

Source: Graphic design by Dane Webster.

The control rods in the RBMK consist of two parts, one boron-iron alloy part that absorbs neutrons, and another part (the so-called displacer, usually made of graphite or zirconium) that does not. When a control rod is pulled completely out of the core, only the part that facilitates the chain reaction remains in the core (position C in figure 5.2). This control rod design makes the reactor economically more efficient, because it prevents the control rod channel from filling up with water, which is a neutron absorber and would therefore slow down the chain reaction. If a control rod is pulled out too far, however (position A in figure 5.2), water floods the lower part of the empty channel and, due to its neutron-absorbing properties, reduces the reactivity in the core. When the control rod is subsequently reinserted (position B in figure 5.2), its nonabsorbing portion replaces the water and thus introduces additional reactivity to the core.

The operators at Chernobyl unit 4 completed the last part of the scheduled test, and at 1:23:40 a.m., one of them pushed the emergency shutdown button.¹⁴ The workers didn't think there was an emergency: while it may not be the most elegant way to shut down the reactor, RBMK operators habitually used the “scram” button under nonemergency circumstances to activate the reactor's automated shutdown, presumably as a shortcut to shutting it down manually. That night, the operators had pulled most of the rods almost all the way out as they tried to raise the reactor's power level. The control rods that remained partially inserted into the core added up to the equivalent of only eight or nine full control rods. This violated the instructions, which required the equivalent of fifteen control rods in the core at any given time.¹⁵ Once the operators activated the automated shutdown, more than 200 control rods started inexorably lowering, and the first part of each rod to enter the core was not the neutron-absorbing part but the graphite part. Replacing the neutron-absorbing water columns, the rods thus introduced additional reactivity into the core. In other words, the control rods that were supposed to terminate the chain reaction did just the opposite—they pushed it into an uncontrollable state. The operators could do nothing but watch: the system was automated and they could no longer intervene.

The introduction of additional reactivity to the core led to a rapid, uncontrollable power increase, prompting reactivity to rise exponentially.¹⁶ As the deputy minister of Energy and Electrification, Gennadii Shasharin, put it: “One thing is clear: the reactor bolted.” ¹⁷ The control rods made it only about halfway down their path. An immediate tenfold rise in power triggered the first warning signal, the second—which indicated a 100-fold rise in power—followed within three seconds.¹⁸ The latter signal (excess pressure) usually comes on when a coolant pipe in the reactor ruptures or suffers a major leak. The fact that these alarms went off is evidence that not all safety systems had been switched off, as initial reports would claim.¹⁹ Then the staff on duty heard a rumble “resembling a human moan.” ²⁰ This first explosion destroyed the reactor.²¹ According to Aleksandr Iadrikhinskii's authoritative report, a second explosion destroyed the reactor building.²²

The explosion ejected much of the graphite from the core of unit 4 into the plant's surroundings and set the rest on fire.²³ This fire not only distributed radioactive particles into the atmosphere but it jeopardized the electric communications that the plant's unit 4 shared with unit 3. Firefighters were the first to come to the plant after the explosion. Despite their inadequate equipment (the fire engines were not designed to fight fires at great heights and distances, and the firefighters had no protection against radiation), they managed to extinguish the fire completely by 5:00 a.m. Twelve received perilous doses of radiation, and six of them later died in a specialized clinic in Moscow.²⁴ Their work was crucial, since the consequences might have been far worse had the fire reached the adjacent reactor, unit 3, or reactors 1 and 2, neither of which was protected by fire-resistant construction materials.²⁵

The shift on duty gathered to drink an iodine-alcohol mixture, a stopgap measure to counteract the thyroid gland's uptake of radioactive iodine: “Diatlov [the plant's deputy chief engineer] prepared the solution with difficulty, because his hands were shaking, and drank.” ²⁶ The authorities didn't decide to distribute potassium-iodide tablets to the general population in the area affected by the disaster until May 6, when the greatest danger was already over.²⁷

The radiation-measuring instruments on hand continuously indicated the maximum on their scales; they were not calibrated to measure such high radiation levels. Other instruments with larger-scope gauges were kept in an area between units 3 and 4, and the explosion had made it impossible to reach them.²⁸ Eventually, other nuclear power plants would supply the required instruments, but too late to help those on duty that day.²⁹

The plant's director, Viktor Briukhanov, who rushed to the plant from his apartment in Pripyat, called Moscow to report the accident. However, at the time of his call, he did not—could not—give conclusive information on the gravity of the situation.³⁰

The very day the accident occurred, the Council of Ministers established a government commission at the Chernobyl site and appointed Boris Shcherbina its chairman.³¹ Shcherbina, a former minister for Construction in the Oil and Gas Industries, was deputy chairman of the Council of Ministers at the time of the accident and also headed the Council of Ministers’ powerful Bureau for the Fuel and Energy Complex. Shcherbina's commission included the minister of Minenergo, deputy ministers of Health, Internal Affairs, and Sredmash, Ukrainian leaders, a deputy attorney general, representatives from the Power Industry Workers’ Union and the KGB, and of course nuclear specialists. Clearly Moscow understood the extraordinary character of the situation.³²

Shcherbina's commission created several working groups and allocated responsibilities for specific tasks. Aleksandr Semenov, for example, at the time deputy minister of Minenergo, was put in charge of implementing a program to shut down Chernobyl's reactor number 4 and was given detailed deadlines for each step.³³ The government commission, Semenov's group, and other specialists serving on site were receiving high doses of radiation and consequently their membership had to be exchanged frequently.³⁴ The first fifteen airplanes transporting people to Chernobyl and flying the route Moscow-Kiev-Moscow had to clean their contaminated seats and discard some of them.³⁵

Minenergo set up its own working groups. Gennadii Veretennikov, the director of Soiuzatomenergo, headed a coordinating group in Moscow. Soiuzatomenergo already had a preapproved action plan in case an accident occurred at a nuclear power plant. Never implemented before, this action plan called for a team of experts to be dispatched to the accident site, and provided for around-the-clock support from Moscow.³⁶ Following this plan, on the morning of April 26, 1986, Boris Prushinskii, the chief engineer of Soiuzatomenergo, Armen Abagian, the director of Minenergo's nuclear research institute (VNIIAES), and Konstantin Polushkin, a leading representative of the RBMK's chief engineering institute (NIKIET), flew from Moscow to Kiev. Gennadii Shasharin, then first deputy minister of Minenergo, headed another working group directly at the Chernobyl site. Shasharin's group was responsible for analyzing the accident and for keeping the plant's remaining three reactors safe.

In immediate response to the accident, the Communist Party's Politburo established the Strategic Group under Nikolai Ryzhkov, then chairman of the Council of Ministers.³⁷ This group had the highest authority of all; it consisted of several Politburo members, ministers, and the president of the Academy of Sciences, Anatolii Aleksandrov.³⁸ It established a direct phone line to connect its members in Moscow and the government commission at the Chernobyl site. Members of the government commission also reported regularly in person to the Strategic Group in Moscow, in secret meetings, whose minutes have been to this day only partially declassified.³⁹

When nuclear specialists arrived at the Chernobyl site from Moscow, their first concern was whether the reactor could reach criticality again.⁴⁰ The explosion had destroyed both the control rods, which would have kept the chain reaction under control, and the core cooling system, which would have ensured the removal of decay heat. On the evening of April 26, the government commission ordered the shutdown of reactors 1 and 2. By the morning of April 27, all remaining reactors at Chernobyl were off line.⁴¹

On the day of the accident, almost 50,000 people were living in the town of Pripyat, in the immediate vicinity of the Chernobyl nuclear plant; almost 30 percent of them were children.⁴² Apparently, Chernobyl's director Briukhanov requested an evacuation when he first notified Moscow officials of the accident, and several other individuals also suggested an evacuation very early on.⁴³ According to the emergency response plan, the Ministry of Internal Affairs should have told the people of Pripyat to stay inside and shelter in place, but this did not happen.⁴⁴ Even if it had, those in the metropolis may not have listened: Kiev residents were holding May Day parades, celebrating outdoor weddings, and taking schoolchildren on field trips. The authorities had a heated and prolonged debate over evacuating the plant's satellite town, and on April 27 at 11:00 a.m., some 33 hours after the reactor exploded, they announced they would evacuate Pripyat and establish a 30-kilometer exclusion zone around the destroyed reactor.⁴⁵ Buses started leaving the town at 2:00 p.m. that day, and the evacuation was complete by 5:00 p.m.⁴⁶ Overall, more than 135,000 people left Pripyat and the surrounding areas.⁴⁷ By the evening of April 27 various working groups had arranged the delivery of 3,000 tons of lead and other necessary material to the site and the setup of two improvised concrete factories. Multiple medical centers provided support to the mitigation workers.⁴⁸

Initial Disaster Response

In the days that followed, additional groups at the local, regional, and republican level, as well as civil defense organizations and party commissions, all got involved in mitigating the disaster. The effort would continue until 1988, and about 30,000 people would take part.⁴⁹

The operation proceeded by trial and error rather than with a scientific approach, and a coherent strategy developed only slowly.⁵⁰ Specialists from other nuclear power plants, especially from Kursk and Smolensk, and some who had worked previously at the Chernobyl plant came to support or replace those at the accident site. Many recruits and nonspecialized hired workers were not familiar with radiologically dangerous environments.⁵¹ This was even more the case for the volunteers who started to pour in at the same time. The influx of willing but unorganized individuals posed new challenges for the accident mitigation management.⁵² One problem, for example, was the quantity of contaminated clothing, which overwhelmed the plant's specialized cleaners. Early on, no safe disposal sites existed for contaminated clothes and equipment.

Army helicopters dropped heavy sacks filled with a neutron-absorbing material on the destroyed reactor to secure it.⁵³ During 1,800 flights, these helicopters dropped more than 5,000 tons of material on the ruins of unit 4, in a desperate attempt to prevent the reactor from reaching criticality again.⁵⁴ The helicopters had no shielding against radiation; the pilots eventually started putting lead plates under their seats.⁵⁵

High radiation made robots, both Soviet and foreign, “go crazy” and malfunction; they had to be supplemented, and in some cases replaced by, so-called biorobots, soldiers donning protective lead outfits.⁵⁶ Photographs of these soldiers became some of the most notorious images of the Chernobyl cleanup efforts. Under extremely dangerous conditions, these “volunteers” shoveled graphite from the rooftop back into the ruins of reactor number 4, working for only a minute or two before they accumulated a lifetime dose of radiation and left the site.

On the fifth day after the accident, radioactive emissions from the reactor started to increase anew. One explanation for this phenomenon was that the material dropped on the reactor prevented adequate heat removal. Another was that when the heavy loads landed on the reactor's biological shield, which the explosion had lifted and which had landed back on its base at an angle, they made the shield shift slightly, possibly allowing the release of more radioactive material.⁵⁷ The Soviet delegation later told the IAEA that about 25 percent of the postaccident radioactive emissions occurred during the first day. Emissions then decreased over the next five days, only to rise again on days six to nine to 70 percent of the first day's release and then finally decrease to about 1 percent of the initial level.⁵⁸

Another threat was radioactive contamination of groundwater, which half of Ukraine's population depended on for drinking water.⁵⁹ A separate working group took on building an underground barrier under the entire plant, only to have its work later limited to the most dangerous areas.⁶⁰

The realization that the reactor, possibly the entire plant, and perhaps the entire area would have to be abandoned for good, only gradually sank in. For weeks after the initial explosion, top officials in Ukraine and at the central ministerial level still called for a rapid return to “normal operations.” ⁶¹

International media reports contributed to the confusion over how bad things really were: Scandinavian reindeer were mass-slaughtered, British sheep quarantined, and Greek agricultural products taken out of circulation (and swooped up by U.S. armed forces); German regions fought over the proper way to decontaminate lettuce.⁶² When the radioactive dust settled, the world had a new set of realities to live with: significant portions of Europe had been contaminated, so much so that authorities recommend limiting the consumption of wild mushrooms and berries to this day. The alarm over exposure to radiation was not misplaced. To mention just one of the accident's long-term health impacts, the rate of thyroid cancer in children exposed to radioactive iodine, especially in Belorus, Ukraine, and Russia, would increase significantly.⁶³

Constructing the Sarcophagus: Longer-Term Mitigation

To contain radiation within unit 4's remains, officials decided in May 1986 to build a concrete encasement (ukrytie). But construction of this so-called sarcophagus didn't begin immediately, apparently because the president of the Academy of Sciences, Anatolii Aleksandrov, and his deputy, Evgenii Veli­khov, disagreed about whether building it was dangerous.⁶⁴ Nikolai Ryzhkov, chairman of the Council of Ministers, ordered them to sort out their differences by the following day (May 20), and only then did construction start. Having witnessed this controversy, the deputy minister of Minenergo, Aleksandr Semenov, concluded: “Back then I, and I think other participants in this meeting, found it strange that two academicians and nuclear specialists could not give an unambiguous answer to a given task; it occurred [to me] that maybe not everything was well with nuclear science.” ⁶⁵ Sredmash took responsibility for the design and construction of the sarcophagus. Already in charge of most accident mitigation work, Sredmash had the full support of the military, which meant that it had battalions of soldiers at its disposal.⁶⁶ The Leningrad design and construction institute VNIPIET took on the role of project manager for the encasement.⁶⁷ Together, these entities completed the sarcophagus that November (figure 5.3).⁶⁸

Figure 5.3 The Chernobyl “Sarcophagus.” Facing the extreme conditions of a nuclear disaster, the Ministry of Medium Machine Building (Sredmash) led the national effort to cover the ruins of Chernobyl's reactor number 4 with a concrete entombment. By November 1986, armies of professionals, soldiers, and volunteers managed to complete the construction of the so-called Sarcophagus.

Source: Photograph by Volodymir Repik, 1986. Courtesy of National Chernobyl Museum, Kiev, Ukraine.

Construction workers built temporary housing in radiologically safe areas outside Pripyat. In July, they built the town Zelenyi Mys (Green Cape) on the banks of the Kiev reservoir to accommodate both the workforce that would maintain the remaining reactors and continue the cleanup around reactor number 4 and the nuclear specialists who flew in from Moscow and other nuclear power plants.⁶⁹ Simultaneously, construction began on new permanent living quarters for the nuclear plant workforce and their families.⁷⁰

Placing Blame for Chernobyl: Conflicting Reports

The Chernobyl disaster and the subsequent arguments about blame, accountability, and acceptable risk bear striking analogies to the Challenger accident Diane Vaughan has analyzed.⁷¹ As with the Challenger incident, which preceded Chernobyl by only a few months, Chernobyl prompted a heated discussion about whom to blame (engineers or managers in the Challenger case, operators or designers in the Chernobyl case) and about the legitimacy of earlier decisions regarding acceptable degrees of safety and redundancy. In retrospect, it may seem obvious where fault lies. But by considering each of the various accounts of the accident seriously, we can tease out sharply divergent scenarios, each of which has different implications for the nuclear power industry.

If human error alone caused the accident, as one of the influential accounts would have it, this exonerates the reactor designers to some extent: had the reactor operators followed procedure, everything would have been fine. But as the young Soviet antinuclear movement figured out pretty quickly, this argument can backfire once we acknowledge that human beings never follow all the rules all the time, not even in a nuclear reactor control room. If the design of a reactor lets rule violations, or even simple mistakes, escalate into a nuclear catastrophe, that reactor probably should not be operating.

Conversely, if a design flaw caused the accident, then the question arises why nobody fixed this flaw, especially if designers knew about it, as some evidence suggests. But the argument that the designers were irresponsible for not immediately fixing the problem doesn't withstand scrutiny either. Complex technological systems usually have innumerable problems, and even a modern probabilistic risk assessment expert will prioritize these problems by urgency, rather than suggest eliminating them all. We all operate and use imperfect systems on a daily basis. We know about flaws and know how to work around them (think of a quirky car, a buggy computer program, or annoying security protocols). In other words, a faulty control rod design does not mean a nuclear reactor cannot work, but it does require knowledgeable, skilled operators who understand how to compensate for the flaw, know their limitations, and are committed to safety above everything else, including plan targets, bonuses, and, yes, orders.

The contradictory reports on Chernobyl also raise the question of who had access to what information. Many serious critics have charged that the Soviet nuclear industry maintained undue secrecy, which implies that access to everything by anyone, full transparency, could have prevented Chernobyl. From there, it is a small step to more general statements about the advantages of transparent democratic systems and the inherent disadvantages of the secretive Soviet system. But the dichotomy is wrong: complete secrecy, like full transparency, does not exist. There will always be leaks and leakers, and there will always be restricted knowledge, in any political system, in any industry, and especially in the nuclear industry with its many sensitive, potentially dual-use areas of expertise. Our collective attention is better focused on who makes the rules that guard sensitive expertise and what processes we set in motion to administer these rules. As the reports and especially the whistleblowers’ accounts show, the Soviet nuclear power community was full of critical, outspoken, confrontational individuals who took considerable personal and professional risks to pinpoint problems and report them. But in a system without a free press or an independent regulator, they had to report them to their peers and their higher-ups. Chernobyl happened at a point in time when that restrictive system was starting to crack, even though it was still going strong. The accident investigation reports illustrate the contradictory dynamics affecting that system.

The Government Commission's Report

The report the government commission ultimately submitted to the Strategic Group was not its first. Shortly after the accident, Gennadii Shasharin, Boris Prushinskii, and Armen Abagian—all leading Minenergo experts—refused to sign the report the commission had prepared at the Chernobyl site.⁷² They argued it was impossible to arrive at a final conclusion after just one week. Their refusal to sign caused a scandal, and on May 13, Shcherbina, the chairman of the government commission, ordered Shasharin, Viktor Sidorenko (from the oversight committee Gosatomenergonadzor), and Valerii Legasov (from the Institute of Atomic Energy) to report to him in person in Moscow. He was putting together the final report, and he wanted these experts to sort out their differences so he could finish it.⁷³ Shasharin, who as first deputy minister of Minenergo was in charge of nuclear power plants, continued to see things differently from Sidorenko and Legasov, both members of the government commission.

Despite his inability to achieve unanimity, Shcherbina submitted his group's report to the Central Committee's Strategic Group in June 1986. Written in accessible, nontechnical language, it covered the development of nuclear power in the Soviet Union and described the Chernobyl plant before getting into the accident and mitigation measures.⁷⁴ The report concluded that the reactor operators, Leonid Toptunov and Aleksandr Akimov (both of whom died soon thereafter from acute radiation sickness), had directly caused the accident. It also made some general recommendations for increasing the safety of nuclear power plants.

Those who attended two meetings of the Interdepartmental Technical Council in June 1986 confirmed the government commission's version of events.⁷⁵ The actual scientific and technical reports on the accident were initially classified and were only declassified when foreign specialists started publishing their own analyses based on IAEA reports and material published in the Soviet Union prior to the accident.⁷⁶

Minenergo's Assessment

Shasharin considered the government commission's account of the accident premature, crafted when experts knew too little to draw definite conclusions or attribute blame. In particular, he took issue with the conclusion that the reactor operators on duty that night had directly caused the accident.⁷⁷ Analyzing the course of events with the help of reactor parameters recorded just before the accident, Shasharin concluded that there were no warning signals at the time the operator pushed the emergency shutdown button:⁷⁸

The operator activated … the reactor emergency shutdown system, he activated it before the warning and accident signals indicating a rise in power appeared, signals that would have triggered the emergency shutdown system automatically (it was not turned off). … But the emergency shutdown button … thrust [the reactor] into a prompt-critical state. … One publication stated that the operator confused the buttons. No, the operator pushed the right button. The situation was paradoxical … had the operator not pushed the emergency shutdown button, the reactor would have “extinguished” itself on its own, because the remaining reactivity was close to zero.⁷⁹

Well aware that many would perceive his critique of the government commission's conclusions as defending the ministry he represented, Shasharin was nevertheless determined to challenge the assessment that operators’ actions had led directly to the catastrophe. Human error, he acknowledged, could never be fully eliminated, even among highly qualified specialists. If one operator's mistake could lead to a reactor explosion, as the government commission's version claimed, then the antinuclear opposition was right and nuclear power should indeed be abandoned.⁸⁰ Shasharin's analysis highlighted deficiencies in the reactor design.⁸¹ He made that case several times in person to the government commission and in writing to both the Council of Ministers and Ryzhkov, the council's chairman.

Shcherbina had a copy of Minenergo's report, and he no doubt realized that it differed significantly from the one the members of his own commission had written.⁸² In the end, however, rather than presenting both versions in his own report, let alone trying to reconcile their incompatibilities, he chose to trust the authority of “big science.” ⁸³

The Central Committee's Decree

By the time the government commission reported to the Politburo's Strategic Group in early June 1986, the members of the latter already had alternative explanations at their disposal, and concluded that the efforts of Minenergo, Sredmash, and Gosatomenergonadzor to increase the safety of nuclear power plants were insufficient.⁸⁴ In particular, the Strategic Group lamented that plants had insufficient fire protection, outdated equipment, no simulator training for plant personnel, and a tense atmosphere. The Strategic Group's assessment marked the beginning of a protracted process of assigning blame and debating ultimately irreconcilable differences.

In a top-secret decree issued July 14, 1986, the Central Committee blamed the accident on organizational culture, a lack of a rigorous attitude toward personnel performance, and a lack of discipline in all organizations involved—a remarkable departure from the government commission's report.⁸⁵ A Pravda article that appeared on July 20, 1986 named those dismissed in the wake of the disaster but did not give all the decree's details.⁸⁶

Like the government commission, the Central Committee criticized Minenergo's leadership (specifically minister Maiorets and his first deputy Shasharin) and pointed out severe problems within the operating organization Soiuzatomenergo (specifically mentioning its director, Veretennikov). But the Central Committee also said the chief design engineer (NIKIET) and the scientific director (the Institute of Atomic Energy) had made serious mistakes and criticized Sredmash (specifically minister Slavskii and his first deputy Meshkov) for not having reacted to suggestions about improving the reactor's safety, despite being fully aware of the design's flaws.⁸⁷ The Central Committee attributed this passivity to Sredmash's lack of self-criticism and its narrow-minded, compartmentalized approach. It also identified an overly conciliatory attitude within Gosatomenergonadzor and singled out the agency's top managers Evgenii Kulov and Viktor Sidorenko. The decree argued that all of the aforementioned leaders knew about the problems but consciously decided not to address them. It also mentioned that the Central Committee had raised concerns about RBMK design deficiencies back in 1983 and that the Interdepartmental Technical Council had sent a mollifying response: “The assertion of the leaders of Sredmash and the Soviet Academy of Sciences that the reactors operating at nuclear power plants were absolutely reliable led to [an attitude of] underestimating the importance of developing accident response measures.” ⁸⁸ More self-critical than the agencies it criticized had been, the Central Committee charged some of its own departments with excessive leniency in controlling the activities of the ministries and agencies under their supervision. The Central Committee instructed the government commission, together with the State Committee for Science and Technology, Minenergo, Sredmash, the Academy of Sciences, and Gosatomenergonadzor, to work out and implement practical measures to modify operating RBMKs and to modernize those under construction. The committee made clear that it considered these design modifications a necessary complement to measures aimed at improving operator performance.⁸⁹

The Central Committee's decree not only distributed blame across the entire nuclear sector, identifying individuals and technical artifacts at fault; it also had manifest consequences for the careers of high-ranking industry managers. The Central Committee expelled the director of the Chernobyl plant from the Party for major mistakes and severe negligence in his work. It severely reprimanded Shasharin, for a lack of organization and poor personnel management, and it dismissed him from his position.⁹⁰ Shasharin's superior, minister Maiorets, who had only served in his position for about a year, got away with a strict reprimand on his record.⁹¹

Sredmash's deputy minister Aleksandr Meshkov lost his position. The committee reprimanded and dismissed the deputy director of Sredmash's chief design institute, NIKIET, Ivan Emelyianov, for underestimating the significance of nuclear safety concerns during the RBMK's design stage and for not reacting to critical comments and suggestions on how to improve the design, which, the decree said, “was one of the reasons for the accident at the Chernobyl nuclear power plant.” ⁹² For unsatisfactory supervision of safety in the nuclear power industry and a lenient attitude toward violations of norms and rules, the chairman of the oversight committee Gosatomenergonadzor, Evegenii Kulov, also received a severe reprimand and dismissal from his position.⁹³

The decree instructed both Sredmash's board (kollegiia) and Slavskii personally to pay due attention to scientific research and practical design work in order to increase reactor safety. It informed Aleksandrov, the director of the Institute of Atomic Energy, and president of the Soviet Academy of Sciences, and chairman of the Interdepartmental Technical Council, that he needed to eliminate all significant safety defects to guarantee that nuclear power plants would be completely safe.

Chernobyl also marked the end of Slavskii's reign: after almost thirty years in office, he resigned from his position as minister of Medium Machine Building in November 1986. I am unable to judge whether his resignation was forced or voluntary. Most likely, the Central Committee allowed this legendary manager of the Soviet nuclear complex to step down on his own initiative.⁹⁴

Containing International Consequences

As details about the disaster came to light, several European countries stopped imports from the Soviet Union and tourism plummeted. On May 6, 1986, the government set up a press conference for foreign journalists in Moscow and invited other countries’ ambassadors to visit Chernobyl. On May 14, Mikhail Gorbachev appeared on Soviet television—a measure intended to strongly influence public opinion.⁹⁵ Vladimir Dolgikh, secretary of the Central Committee, directed Minenergo's information service, Informenergo, to document the cleanup work, and the service sent its journalists and filmmakers to Chernobyl, where they meticulously recorded the remediation efforts.⁹⁶

In late August 1986, at an International Atomic Energy Agency conference in Vienna, a Soviet delegation presented the officially approved assessment of the accident, as well as a detailed account of potential medical and environmental consequences, to an international audience.⁹⁷ Valerii Legasov, deputy director of the Institute of Atomic Energy, led the Soviet delegation to the IAEA.⁹⁸ None of Minenergo's staff was invited to participate.⁹⁹ The journal Atomnaia energiia published the delegation's report the same year.¹⁰⁰ This report did not reflect the conflicting analyses of the accident discussed above. Instead, it clearly blamed the operators and charged them with violating operating instructions and with conducting unauthorized experiments. The report's greatest flaw is probably its date: when the Soviet delegation reported their conclusions to the IAEA, hundreds of experts were still on the Chernobyl site, trying to figure out what had actually happened.

Just before the first anniversary of Chernobyl, the Central Committee's Department for Heavy Industry and Energy began what it called counterpropagandistic activities (kontrpropagandistskie aktsii). The approaching anniversary had prompted increased press coverage abroad, most of which the party perceived as overly negative. It was concerned that the “demoralizing centers of imperialism” might use the occasion to launch yet another anti-Soviet campaign.¹⁰¹ The Central Committee supported the production of a series of movies, popular-scientific brochures on the promising future of nuclear power, and exhibitions in several pavilions at the All-Union Exhibition of the Achievements of the People's Economy (VDNKh), a prominent exhibition space in Moscow.¹⁰²

To confirm the official verdict of operator error one last time, the state began the trial of Chernobyl's top management in July 1987. As we saw in the introduction to the book, the court convicted the plant's operators and top managers but never tried the reactor designers, possibly because the Soviet Union did not want to risk losing its international prestige in the area of nuclear science and possibly for fear of lawsuits.¹⁰³

Unheeded Whistleblowers: The Long Controversy over the RBMK

The postaccident loosening and eventual elimination of censorship prompted several nuclear specialists to use new avenues for voicing their concerns, which in turn allows us to consider narratives that countered the official explanations.¹⁰⁴ It is safe to assume that these published accounts were only the tip of the iceberg and that most who put together reports on the Chernobyl disaster submitted them internally.¹⁰⁵ Many who later published their accounts first tried and failed to use official channels, which in part explains the accounts’ emotional, often accusatory tone.¹⁰⁶

During the years following Chernobyl, a number of nuclear specialists came forward with testimony about a controversy that predated the accident. They had warned about significant problems with the RBMK before Chernobyl and were not heard—or not heeded. To understand why, we need to take into account the closed nature of Soviet society and the symbiotic relationship between technical experts and the state. These factors, along with the gradual realization that what everyone had thought was forever—Party control, rational planning, and technical progress—was starting to crumble, explain a delay that would have been unfathomable in the media-obsessed Western world.¹⁰⁷

Anatolii Diatlov

One of the catalysts for this altered perception was Anatolii Diatlov, Chernobyl's deputy chief engineer, who published a letter from prison that reached the international community. In it, he gave a detailed description of the reactor construction and argued that construction flaws, not operators’ mistakes, had led to the explosion at Chernobyl.¹⁰⁸ Diatlov argued that the operators did not commit any mistakes; in pushing the emergency shutdown button, which was supposed to reliably cut off the nuclear chain reaction under any and all circumstances, they were following instructions. The operators, he wrote, were unaware of the RBMK's positive steam coefficient.¹⁰⁹ Some have dismissed Diatlov's account as self-interested; after all, he was one of the operators his explanation seeks to exonerate. His publications also contain a strong emotional component, but still, several independent nuclear experts familiar with the RBMK design have since confirmed Diatlov's assessment of its technical problems.

Vladimir Volkov

When nuclear specialists first proposed the RBMK design in 1965, reviews were none too encouraging.¹¹⁰ Among others, Ivan Zhezherun, Vladimir Volkov, and V. Ivanov, all physicists from the scientific director (the Institute of Atomic Energy), pointed out the design's dangers. Volkov in particular warned reactor designers in an internal report that experimental data for the RBMK was insufficient; he cautioned against operating it.¹¹¹

At first, the designers ignored Volkov's concerns and went ahead with the RBMK reactor at the Leningrad nuclear power plant, the country's first. In 1975, right after this reactor started up, it shut down automatically, which led a fuel channel to rupture and a small part of the core to melt.¹¹² The incident did not have catastrophic consequences, but operators observed a brief flash of reactivity when they inserted the control rods into the core.¹¹³ A commission consisting of representatives of the Institute of Atomic Energy and NIKIET analyzed the causes of the Leningrad accident and in 1976 issued a set of recommendations to improve the reactor's design.¹¹⁴ First and foremost, the commission recommended reducing the RBMK's steam coefficient by increasing fuel enrichment, reducing the quantity of graphite in the core, and introducing additional absorber rods. These experts also suggested design changes for the control rods and the creation of a fast emergency shutdown system.¹¹⁵ Sredmash did not pursue these recommendations at that time; it did so only as part of the post-Chernobyl modernization of RBMKs. As I have mentioned, Minenergo, the organization that would operate future RBMKs, had no access to the documentation on the Leningrad accident.

In 1983, during the physical launch of Chernobyl's unit 4, the start-up commission observed that when the control rods were lowered into the core to shut the reactor down, they initially contributed additional reactivity. The inspector from Gosatomnadzor (then still under Sredmash) acknowledged this fact and still approved the reactor for full operation.¹¹⁶ Designers updated the operators’ manual to specify how many control rods should be inserted at all times for safety, but they made no technical changes. In other words, operators could still pull out more than the prescribed number of control rods. Operators worked under the paradoxical expectation that they could competently operate a less-than-ideal reactor (that is, rely on their professional judgment and expertise) and at the same time obediently follow the rules.

After the Chernobyl accident, Volkov sent the report he had written to Aleksandrov back in the 1970s to the prosecutor's office. Almost instantaneously, by the first of May 1986, he was banned from entering his workplace, the Institute of Atomic Energy.¹¹⁷ Volkov promptly wrote letters to Mikhail Gorbachev, to the chairman of the Council of Ministers, Nikolai Ryzhkov, and to the attorney general, A. Rekunkov. In the letters, he argued: “The accident at the Chernobyl nuclear power plant was caused not by the actions of the operating personnel, but by the construction of the active zone and the lack of understanding of the processes taking place in it. … A loss of coolant in the active zone led to an increase of reactivity … which … led to the destruction of the reactor.” ¹¹⁸

Although some interpret Volkov's initiative as an attempt to prove the nuclear power plant operators’ innocence, he was also very critical of Minenergo. He argued that “Minenergo has operated nuclear power plants with RBMKs with an unstable core in terms of neutron physics, for quite some time, but [Minenergo] did not attribute due importance to the repeated warning signals [of dangerous, and dangerously fast, power increases] every time the emergency shutdown system was activated, and it did not demand a diligent examination of accidents.” ¹¹⁹

Nikolai Shteinberg

While possibly the first to blow the whistle on the RBMK's design and operation, Volkov was not alone. In 1989, Aleksandr Iadrikhinskii, a nuclear safety inspector from the Kursk nuclear power plant, submitted a report on the Chernobyl accident and the safety of RBMK reactors to the nuclear supervisory committee Gosatomenergonadzor.¹²⁰ This internal report prompted heated discussions in the nuclear expert community, and on February 27, 1990, in response to Gorbachev's initiative, Gosatomenergonadzor created a commission under Nikolai Shteinberg to reinvestigate the Chernobyl accident in light of Volkov's and Iadrikhinskii's reports.¹²¹ Shteinberg, former chief engineer at Chernobyl, would lead this prominent and authoritative commission in thoroughly reinvestigating the Chernobyl disaster.¹²² In January 1991, the group presented their conclusions, which clearly shifted the emphasis from blaming the personnel for operating mistakes to criticizing the designers for having allowed this reactor type to be built and operated in the first place.¹²³ What came to be known as the “Shteinberg report” had far-reaching effects. The report stated officially that Aleksandrov and Dollezhal had neglected to pursue the recommendations Volkov and his colleagues had made after the 1975 accident at the Leningrad plant and had effectively ignored the Interdepartmental Technical Council decision on reducing the positive steam coefficient.¹²⁴

As a direct result of the Shteinberg report's findings, the International Atomic Energy Agency revised its original accident analysis, the widely read and cited INSAG-1, which the agency had based mostly on the official Soviet report. The IAEA experts published a new document (INSAG-7) that included as appendixes both the Shteinberg report and another revisionist expert report from VNIIAES.¹²⁵ Nuclear experts understood the more nuanced findings of these revised reports and updated many publicly accessible Chernobyl accounts accordingly, but INSAG-7 never generated the same news storm as the initial reports from 1986 had.

However, within the Soviet, and later post-Soviet, nuclear community, the significance of Diatlov's writings, Volkov's efforts, and the Shteinberg report can hardly be emphasized enough. Apart from their specific findings, they created a blueprint for expert disagreement in public, and in the public media, that had simply not existed under Soviet rule—or that had entailed political consequences that few technical specialists were willing to risk.¹²⁶ Following Volkov's, Diatlov's, and Shteinberg's lead, several widely cited experts now voiced their disagreement with the official explanation of the Chernobyl accident. Let's turn to some of them next.

Boris Dubovskii

Boris Dubovskii was an experienced nuclear physicist who had cooperated with Kurchatov to start up the first Soviet experimental reactor in Moscow. Dubovskii served as the head of Sredmash's Nuclear Safety Inspection from 1958 to 1973, and he subsequently directed the Sector for Nuclear Safety at the Institute of Physics and Power Engineering (FEI) in Obninsk.¹²⁷ In an interview published in October 1994 in the popular Saint Petersburg weekly Smena, Dubovskii mentioned two predecessors of the Chernobyl accident that he said should have alerted the designers to problems.¹²⁸ One was the 1975 accident at the first RBMK in Leningrad, the other a similar accident in 1982 at the Chernobyl plant.¹²⁹

Sredmash leaders did not grant Dubovskii, even in his function as a nuclear safety official, access to investigation records for either accident. Based on his own analyses, he concluded that under certain circumstances the lower part of the RBMK core turned into a separate, explosive reactor.¹³⁰ At Leningrad in 1975 and at Chernobyl in 1982, according to Dubovskii, the reactor design prevented the proper release of excess steam.¹³¹ He also viewed the slow speed of the emergency shutdown mechanism as a problem that was especially dangerous for the lower part of the core. In his analysis of these earlier accidents, Dubovskii had suggested adding absorber rods in the lower core, but this proposal, like many others, was only realized after Chernobyl.¹³²

When Dubovskii stated publicly that he considered flaws in the reactor design, not the operators’ actions, responsible for the Chernobyl disaster, he was pushed into retirement.¹³³ His conclusion that until 1986, all RBMKs had operated without a regular safety system, let alone an effective emergency shutdown system, proved too heretical.¹³⁴

Undeterred, Dubovskii wrote a letter to Mikhail Gorbachev on November 27, 1989, in which he argued that it was “impossible to eliminate mistakes by the operators in the future,” and urged the General Secretary to look at “the real causes” of the Chernobyl accident.¹³⁵ In addition to the technical issues, for which he blamed the designers, however, Dubovskii also criticized the nuclear power industry's management system, which he said had lost an acute sense of responsibility and abandoned the rigid system of accountability the nuclear weapons project had had.

Viktor Sidorenko

Viktor Sidorenko had joined the Institute of Atomic Energy in 1952, right after graduating from the Moscow Power Engineering Institute (MEI). In 1983, he was head of the Institute's Sector for Nuclear Reactors, when his colleagues approached him with disconcerting news. Their computations showed that the graphite-water reactor being implemented at nuclear plants all over the country had a real, if improbable, potential to suffer a severe accident due to a design flaw in the control rods.¹³⁶ Sidorenko took this alarming report to the institute's leaders, who met it with conspicuous indifference. The reactor's design engineers at NIKIET declared that the problem was well known but highly unlikely to trigger an accident. Therefore, the institute leadership postponed mitigation until it was time for all control rods to undergo refurbishment.¹³⁷ Sredmash's top authorities, who also received the report, did not react either. Instead of requiring design changes, they held that more detailed operating instructions would ensure that this scenario would not occur.

When the Chernobyl reactor exploded, one of Sidorenko's colleagues reportedly told him, “That very thing happened.” ¹³⁸ By then Sidorenko was deputy director of Gosatomenergonadzor, and he recounts sarcastically what this evidence meant in the early glasnost era: the Communist Party did not interpret the existence of his earlier report as a demonstration that he had accurately diagnosed and reported a dangerous situation to the appropriate authorities. Rather, it charged him with unscrupulousness (besprintsipnost’): he knew and yet did not act on his knowledge.¹³⁹

The Central Committee's Sector for Nuclear Energy

At the time of the Chernobyl accident, Vladimir Maryin had been working in the Party's Central Committee apparatus for seventeen years. Representing the Sector for Nuclear Energy, he repeatedly confronted complaints about operating problems in RBMK reactors in the early 1980s. Simple factory defects often caused these problems, but they kept reactors from getting automated safety systems. Instead, operators had to work around nonstandard, partly defective equipment.¹⁴⁰

In May 1983, the Central Committee's secretary, Vladimir Dolgikh, invited Anatolii Aleksandrov, director of the Institute of Atomic Energy (IAE), and Evgenii Riazantsev, who had succeeded Sidorenko as director of the Sector for Nuclear Reactors at the IAE, to discuss the concerns that RBMK operating personnel had reported to the Central Committee's Sector for Nuclear Energy.¹⁴¹ Maryin and his close collaborator Georgii Kopchinskii prepared a list of questions for this meeting.¹⁴² They knew that Sredmash and the IAE were well aware of these problems, but the organizations’ indifferent response alarmed them.¹⁴³ When Maryin and Kopchinskii complained that the RBMK “conformed neither to international nor to national nuclear and radiation safety requirements,” Arkadii Volskii, the deputy director of the Central Committee's Department of Mechanical Engineering, dismissed their concerns by stating that “these deficiencies are well known and why worry people yet another time.” ¹⁴⁴ The Interdepartmental Technical Council convened on June 13, 1983, to discuss “The deficiencies in the operation of nuclear power plants with RBMK-1000 and the increase of these nuclear power plants’ reliability.” ¹⁴⁵ After that meeting, a frustrated Maryin concluded: “It should be noted that the administration of the Interdepartmental Scientific-Technical Council under the Ministry of Medium Machine Building [sic] did not consider the materials sent to them with the appropriate sincerity. Some questions were not even assigned to anyone for examination.” ¹⁴⁶

On August 16, 1986, the Central Committee and the Council of Ministers abolished the MVTS for its disastrous mishandling of these concerns.¹⁴⁷ In its place, the authorities created an Interdepartmental Scientific-Technical Council (MVNTS) as part of the State Committee for Science and Technology.¹⁴⁸ On February 8, 1988, the MVNTS came under the authority of the Council of Ministers’ Bureau for the Fuel and Energy Complex, and operated under Gospromatomnadzor's wings.¹⁴⁹

Chernobyl's Consequences

Chernobyl left a deep impact on every imaginable aspect of nuclear power. The disaster immediately affected the Soviet Union's economic development, personnel training, industry management, reactor designs, and, most importantly, the organizational structure of its entire nuclear sector. It profoundly affected political activism as well.

In contrast to the 1979 accident at the Three Mile Island nuclear power plant in the United States, the Soviet system controlled the mass media and for quite some time managed to suppress critical public discussion within its borders.¹⁵⁰ However, in 1986 and 1987, new Soviet citizen movements started to form as a direct reaction to the accident.¹⁵¹ Beginning around 1989, these environmentalists of a new generation gained access to the Soviet press, eventually forcing out censorship, and mobilized to oppose new nuclear power plant projects violently. In the period following the Chernobyl disaster, this activism radically tore open many previously stable elements of the nuclear industry.

The emergent antinuclear groups challenged the nuclear industry's culture of secrecy, the lack of information on and discussion about site selection, the methods used to determine and predict energy demand, the choice of reactors, the lack of support for alternative energy, state control of the media (including patronizing experts), as well as local authorities’ powerlessness and the complete lack of public participation in decision-making processes. By questioning the legitimacy of earlier technological choices, these groups also challenged the official historical narrative about the smooth and rational development of nuclear power in the Soviet Union. Chernobyl united people in fear and resistance, and mobilized them to oppose nuclear power.

The initial success of the antinuclear movement followed from a combination of changes in political strategy, most notably, Gorbachev's policy of transparency (glasnost). With the support of local politicians, Soviet society—in large part driven by the new environmentalist rhetoric—achieved a halt of construction of many nuclear power plants, even those near completion. Many regional authorities, most prominently the newly emboldened Ukrainian government, supported these movements by declaring a moratorium in 1990 on all nuclear power plants then under construction.¹⁵²

Planning and construction work were dropped for the Rostov, Bashkir, Tatar, Kostroma, Crimean, and Krasnodar nuclear power plants, for units 5 and 6 at Balakovo, unit 4 at the South-Ukrainian and Khmelnitskii nuclear plants, the nuclear heating plants at Voronezh, Gorky (Nizhnii Novgorod), and Arkhangelsk, as well as siting work for new nuclear power plants with a total capacity of 109,000 MW. The Central Committee decided to abandon the RBMK design and asked the Council of Ministers to submit an amended energy program.¹⁵³ Authorities changed siting policies for nuclear power plants, too: in addition to sufficient water supply and sufficient energy demand, post-Chernobyl policies required additional seismic tests, greater distance from urban centers, and ecological compatibility (environmental impact) studies for new nuclear plant sites.¹⁵⁴ At the same time, requirements that authorities considered preeminent in the past, such as the proximity of high-voltage power lines or large contingents of construction workers ready to deploy, lost importance. The Central Committee's July 14, 1986, decree also required that the Council of Ministers approve all future design and siting decisions.¹⁵⁵

As the entire Soviet industry collapsed in the late 1980s and early 1990s, energy consumption stagnated or decreased significantly, which rendered new nuclear power plants unnecessary. While some regions abandoned their nuclear ambitions after Chernobyl or tried to switch to alternative energy sources, other areas continued to depend heavily on nuclear power. In these areas, the energy supply situation soon forced politicians once again to resort to nuclear energy. Armenia, for example, closed its nuclear power plant after a severe earthquake in 1988, concerned about the facility's safety.¹⁵⁶ To keep warm, people cut down the national forests during the first winter without nuclear power, and the authorities subsequently restarted unit 2.¹⁵⁷

When the Soviet Union officially ended in December 1991, its successor states inherited a nuclear industry in disarray.¹⁵⁸ For instance, Lithuania, a small state that after independence temporarily generated a higher percentage of nuclear electricity than France, agreed to shut down its two RBMK-1500 reactors at Ignalina in exchange for accession to the European Union. They did so despite the fact that Sweden and Finland had already invested significant amounts of money and expertise in upgrading the reactors.

The first post-Soviet Russian government under Boris Yeltsin, while sympathetic to concerns over nuclear safety, in the end opted for a stable, long-term energy supply that included nuclear power.¹⁵⁹

Reforming Recruitment

The Chernobyl disaster also deeply affected discussions about training for the nuclear workforce: what responsibilities workers should have, whether their training was adequate, and to whom they were ultimately accountable. The post-Chernobyl era saw a marked increase in the number of accident simulators at nuclear power plants, and simulator training became mandatory for reactor operators.¹⁶⁰ This latter measure implicitly acknowledged that operator training had not been as good as it should have been before Chernobyl. When the nuclear safety law was rewritten after the accident, operator error featured prominently in it, and post-Chernobyl reactor operators found themselves in another paradoxical situation: on the one hand, they were now being trained to make better decisions in accident-like situations—that is, they were learning to better assess potentially dangerous situations and to react appropriately. On the other, instructors told them not to interfere with the automated systems because their actions could threaten the otherwise smoothly functioning technology. It is therefore unclear if the new system, with this contradictory conception of its human elements, was safer than the one it replaced.

In the wake of the disaster, authorities also thoroughly scrutinized recruitment policies for the nuclear power industry. In part this was a response to Minenergo's often criticized decision to appoint Nikolai Fomin, who was not a nuclear physicist or engineer, as chief engineer at Chernobyl. Fomin, who became chief engineer one and a half years before the accident, had not been Minenergo's first choice, however. The deputy minister of Energy and Electrification, Shasharin, and the head of the operating organization Soiuzatomenergo, Veretennikov, had both favored Vladimir Bronnikov, who had previously worked as deputy chief engineer at Chernobyl. He was an experienced operator and a highly qualified nuclear specialist who later became director of the Zaporozhye nuclear power plant.¹⁶¹ Minenergo had suggested Fomin, a good administrator, for a post as director of one of the Ukrainian nuclear power plants under construction.¹⁶² But the Ukrainian Communist Party objected to these plans, and as a result, Fomin became Chernobyl's chief engineer, with the prospect of replacing the director, Briukhanov, once he left for another position in Moscow.¹⁶³ Minenergo's managers agreed to the compromise because they expected the entire plant leadership to cooperate closely as a team.¹⁶⁴ In Minenergo's experience, a nuclear power plant's administration worked best if the top management, consisting of the director, the chief engineer, and their deputies, had training in different, mutually complementary areas. At the Chernobyl plant, the distribution of expertise was not ideal, but it was acceptable, Shasharin argued, because two of the deputy chief engineers were nuclear physicists and engineers. Unfortunately, Fomin did not consult his deputies before approving the test in unit 4.

In the end, however, the nuclear industry continued to rely on nonspecialists in addition to nuclear experts: there simply were not enough qualified specialists available. Chernobyl only exacerbated the problem, and the nuclear workforce not only in the Soviet Union, but worldwide, continues to experience a significant generation gap.

Reconsidering the RBMK

When evidence came to the fore that nuclear experts had had concerns about specific design features of the RBMK all along, most notably the positive steam coefficient, these revelations cast doubt on designers, and more broadly, on Soviet science. The Soviet Union was the only state that developed the graphite-water design into a power reactor—specialists elsewhere favored a light-water design at the time.¹⁶⁵ Aside from the problems mentioned above, the RBMK lacks a containment structure. Such a structure would have been costly and immensely complicated due to the enormous size of the core. What's more, it might not have prevented the disaster anyway.¹⁶⁶

Nuclear scientists questioned past choices, but shutting down all operating RBMKs as unsafe and eliminating a total of 14,000 MW of base-load electricity was simply not an option. Instead, scientists and engineers had to find ways to improve the safety of operating RBMKs.¹⁶⁷ The design modifications they implemented in the years following Chernobyl (for instance, modifying the construction of RBMK control rods and increasing fuel enrichment) provide a convincing argument in favor of the design-flaw story.¹⁶⁸

Reactor designers also introduced 70 to 100 additional absorber rods to decrease the positive steam coefficient, another modification prompted by Chernobyl but based on early experiences with the RBMK.¹⁶⁹ They also significantly increased the speed with which the emergency rods would fall into the core and improved the Control and Safety System (SUZ—sistema upravleniia i zashchity). If the underlying problems were well understood and these technical modifications were possible, why did it take so long to implement them? It is hardly surprising that organizational issues (turf wars and inertia, among others) constituted the nuclear industry's fundamental quandary.

Restructuring the Nuclear Power Industry

The USSR's first response to Chernobyl—before modifying the reactors or providing better training to their operators—was to restructure yet again the management of nuclear power. While it took about five years to implement technical modifications, and emergency training for RBMK operators only gradually improved after the accident, in the immediate aftermath of the disaster the authorities emphasized organizational modifications (figure 5.4).¹⁷⁰ As I have mentioned, deep mistrust toward established nuclear science and design engineering institutes ultimately led to the elimination of the influential Interdepartmental Technical Council. But the disaster profoundly affected every last organization involved with nuclear power.

Figure 5.4 In the 1950s, the Ministry of Medium Machine Building (Sredmash), which was in charge of Soviet nuclear weapons, managed the design and construction of nuclear power reactors. Once the Soviet leadership made a commitment to expanding the generation of electricity at nuclear power plants, in 1966, the Ministry of Energy and Electrification (Minenergo) took over responsibility for their construction and operation. After two decades of successful growth, the Chernobyl disaster threw the industry into crisis. One of the first reactions to the disaster was administrative reform: initially, a new ministry (Minatomenergo) was put in charge of managing nuclear power plants only. After three years, this ministry merged with the former Sredmash to form a new ministry for all things nuclear, which in slightly modified form and under changing names exists today. Source: Graphic design by Dane Webster.

Immediately following the accident, the new Ministry of Atomic Energy (Minatomenergo) began coordinating and managing all nuclear power plants, including the Leningrad and Ignalina plants and the Rovno nuclear plant (transferred from the Ukrainian Ministry of Power Engineering).¹⁷¹ Minatomenergo's infrastructure mirrored that of Soiuzatomenergo, the organization within Minenergo that had managed nuclear power plants. The new body also took over Minenergo's design, support, and other organizations relating to nuclear power, as well as some Sredmash design organizations.

Nikolai Lukonin, former director of the Leningrad and Ignalina nuclear power plants, became minister of atomic energy at the inception of the new ministry in 1986. Lukonin came from the Sredmash apparatus; his appointment reflected yet another attempt to transfer Sredmash's expertise and to ensure the new ministry's work would be of high quality.

In creating the new ministry, the Soviet government intended to concentrate all stages of design, construction, and operation under one roof.¹⁷² And yet, Sredmash continued to control the research and engineering organizations designing and developing nuclear reactors, the scientific research organizations in charge of determining the scientific direction, and all research and industrial structures connected with the manufacturing of the nuclear fuel for nuclear power plants. The fundamental division of labor thus remained unresolved. Minatomenergo and Sredmash both existed until June 1989, when the government decided to merge the two ministries into one Ministry of Atomic Energy and Industry (Minatomenergoprom). The creation of Minatomenergoprom was essentially a return to an all-powerful Sredmash—under a new name.¹⁷³ Vitalii Konovalov, a decorated industrial manager who had worked in the Sredmash apparatus since 1986, was appointed minister.¹⁷⁴ Viktor Sidorenko, who transferred from the oversight committee, became first deputy minister in charge of nuclear power engineering.¹⁷⁵

Minatomenergoprom organized and coordinated scientific research, design and engineering work, as well as construction work in the area of nuclear science, technology, and industry, including military objects. The ministry managed all organizations and enterprises within the nuclear energy branch, thus uniting all the scientific and production aspects of nuclear technology: uranium mining, enrichment processes, production of weapons-grade materials, production of nuclear fuel for power plants, construction and operation of nuclear power plants, and the reprocessing and storage of radioactive waste.¹⁷⁶

This ministry's primary concern was maintaining the country's nuclear complex as a unified whole. For that purpose, its leadership suggested creating the state corporation Atom, which would eventually turn into a joint-stock company. They argued that this corporation would correspond better with an emerging market economy, but ultimately it was an attempt to keep nuclear facilities beyond the territory of the Russian Federal SSR (namely, facilities in Ukraine, Lithuania, Kazakhstan, and other Soviet republics) united in one organization and under a single command.¹⁷⁷ After the Soviet Union disintegrated, Minatomenergoprom was dissolved without having implemented any of the structural changes it had suggested.¹⁷⁸ The new Ministry of Atomic Energy of the Russian Federation (Ministerstvo atomnoi energii Rossiiskoi Federatsii), also known as Minatom, took Minatomenergoprom's place.¹⁷⁹

Viktor Mikhailov, who had previously worked for the nuclear weapons complex, became minister of Minatom.¹⁸⁰ In November 1992, ministry authorities established a Commission for Nuclear Energy to coordinate its relevant subdivisions. Deputy minister Viktor Sidorenko chaired this commission and led its efforts to create a uniform technological policy, decide management issues, and prepare strategic plans for the nuclear industry.¹⁸¹ The commission worked until September 23, 1993, when Lev Riabev, who had succeeded Slavskii as Sredmash's leader in 1986, became first deputy minister and started coordinating all questions relating to the civilian nuclear industry.¹⁸² Minatom passed several important policies, including strategic plans for the development of the Russian nuclear power industry.¹⁸³

In March 1992, Russian President Boris Yeltsin established the agency Rosenergoatom within Minatom. The plan was to eventually turn Rosenergoatom into the operating organization for all Russian nuclear power plants, providing one general management for these plants, while they remained independent economic units.¹⁸⁴ Rosenergoatom managed and coordinated all nuclear power plants in operation, under construction, and in the planning stage, as well as all enterprises and organizations facilitating the operation of nuclear power plants.¹⁸⁵

During the initial period of its existence, Rosenergoatom had to focus on the safe operation of the nuclear power plants under its management, and particularly on modernizing several plants and improving their safety features.¹⁸⁶ By the end of the 1990s, subdivisions of Rosenergoatom had emerged—for example, for construction work, investments, long-term planning, design, and technological subsidiaries.¹⁸⁷ However, Rosenergoatom's mandate vis-à-vis the nuclear power plants did not stabilize until 2000; until then, Rosenergoatom remained a purely managerial organization.¹⁸⁸

Ukrainian Nuclear Institutions

It is beyond the scope of this book to explore the administration of nuclear energy in the Newly Independent States, but since Chernobyl happened in Ukraine, a short summary of the development of a Ukrainian nuclear power infrastructure is appropriate. In 1990, after imposing its moratorium, the Ukrainian SSR integrated organizations involved with nuclear power plants under a company called Ukratomenergoprom, which later took the Ukrainian name Derzhkomatom. After becoming an independent state in 1991, Ukraine lifted the moratorium in October 1993 and construction resumed at three sites.¹⁸⁹ Since then, the government has commissioned six new reactors with a power capacity of 1000 MW each, bringing the number of Ukraine's nuclear power reactors to fifteen.¹⁹⁰ In 2004, Ukraine generated more than 53 percent of its electrical power at nuclear plants.

In October 1996, the Ukrainian government created the state-owned National Atomic Energy Generating Company of Ukraine (Energoatom) to introduce a “uniform technical and economic policy in the field,” and alleviate the industry's grim economic situation.¹⁹¹ This organization managed all five Ukrainian nuclear power plants under the aegis of the Ukrainian Ministry of Fuel and Energy. This ministry, in turn, set the priorities for nuclear power within the national energy policy. It was the operating agency responsible for raising the power output at nuclear power plants, while guaranteeing the safe operation of all Ukrainian nuclear plants. Specifically, the Ministry of Fuel and Energy was in charge of assembling new nuclear power plants, reconstructing operating ones, buying nuclear fuel and disposing of radioactive waste, and training specialists for the nuclear power industry. In 2004, Energoatom employed about 38,000 people.

Energoatom closely collaborates with the International Atomic Energy Agency (IAEA), the European Union, the U.S. Department of Energy, the World Association of Nuclear Operators (WANO), and Russian nuclear organizations. The Russian Federation until recently provided all the nuclear fuel for the Ukrainian reactors and took back the spent fuel. It also supplied equipment and participated in the construction of unit 2 at the Khmelnitskii and unit 4 at the Rovno (Rivne) nuclear plants. For many years, a Russian-Ukrainian committee that included Russia's Rosenergoatom met twice a year and conducted joint inspections at Ukrainian nuclear plants. Starting in 1995, representatives of British Energy advised Energoatom on how to become a privatized corporation. Interestingly, this entity includes a broad spectrum of social services for Energoatom's employees, such as housing, cultural programs, and other services, which the Ukrainian Academy of Sciences’ Institute of Sociology helped develop.¹⁹² The corporation intended these measures to attract and retain a highly qualified workforce, but it found it challenging to continue them given the new economic realities of the post-Soviet era.

When the last reactor at Chernobyl shut down, a newly created suborganization of Energoatom, Atomremontservis, absorbed the plant's former employees. In 2001, the Ukrainian government decided to create a new “State Specialized Enterprise” that separated out all operations involving Chernobyl.¹⁹³ Subsequently, Energoatom stopped administering the closed plant. While this division nominally created a separate organization in charge of maintenance, safe decommissioning, nuclear fuel and radioactive waste management, monitoring, and the massively delayed Shelter project, this organizational split may cause the loss of valuable skills, experience, and postdisaster best practices not only for the Ukrainian nuclear sector, but for the nuclear industry worldwide.¹⁹⁴

Conclusion

The scope of the nuclear emergency at Chernobyl was unprecedented, and emergency response, accident mitigation, and decontamination work all proved extremely challenging—even chaotic—despite international support. Even though it was completely unprepared for a disaster of this magnitude, the centralized Soviet system worked surprisingly well. The state could draw on resources, supplies, and mitigation personnel that might not have been available, and would likely have been much more difficult to mobilize, in a less centralized system. Beginning on the day of the accident, this centralized system set up a coordinating structure with multiple task forces on site that regularly reported back to the center. The state drew on an army of conscripts and recruited, or “volunteered,” thousands of “liquidators” to help mitigate the disaster. Most importantly, however, Chernobyl constituted a watershed moment for the global nuclear power industry. A severe accident at a civilian nuclear facility was no longer a remote, hypothetical, and infinitesimally small probability. It had turned into a realistic possibility.

At different times after the accident, various and often contradictory assessments of the Chernobyl disaster enjoyed very different authority, and I have tried to give these assessments even-handed consideration. Taking a detailed look at the controversy that broke out over the technical design of the RBMK after Chernobyl has allowed me to trace the historical roots not only of the design choice, but also of this debate. The post-Chernobyl controversy also illustrates that while unified on the surface, the Soviet nuclear sector, and by extension the Soviet system in general, was anything but monolithic. The fact that after the accident, both antinuclear groups and nuclear specialists criticized the earlier decision to build RBMKs all over the country can help us understand how political power, distributed as it was, influenced design decisions in the Soviet nuclear power industry. This debate also marks a fundamental change in the ways technical experts related to the state and in how they interpreted their role vis-à-vis their own organizations, the broader public, and the country's rulers.

The Chernobyl disaster prompted massive changes in the Soviet and post-Soviet nuclear industry. It did not, unfortunately, have the same effect on the international nuclear industry. In part because the initial assessment that operator error was the main cause of the accident was so widely circulated, many Western nations, including the United States, concluded “this could never happen here.” Although the accident did prompt changes outside the Soviet Union, it was easy, and tempting, to interpret the disaster as the logical outcome of a corrupt political apparatus, a dysfunctional economic system, an outdated reactor design with insufficient, or insufficiently automated, safety features, and, most importantly, inept operators—both in the control room and at the management level. While Chernobyl was Soviet through and through—its reactor design, its reactor operators, and its institutional context—it was also a warning sign for nuclear industries elsewhere, a warning sign that those of us outside the former Soviet Union have ignored, perhaps arrogantly, certain that our own safety updates can wait until the next planned shutdown for maintenance.