“An Explosion Occurred in Power Unit No. 4”: The Story of Chernobyl in Documents

Image: The first photograph of Unit Four after the accident, shot from a helicopter by Chernobyl plant photographer Anatoly Rasskazov, at approximately 3.00pm on April 26 1986 (Anatoly Rasskazov/Ukrainian National Chernobyl Museum).

The primary research for Midnight In Chernobyl encompassed hundreds of hours of interviews with scores of eye-witnesses and experts, reporting trips to key locations in the story in both Russia and Ukraine, as well as letters, unpublished memoirs, contemporary reports, films, and photographs.

I also made use of documents held in numerous archives around the world, including London, Harvard, Washington DC, Moscow, and Kiev. One of the most significant sources of material was the Ukrainian National Chernobyl Museum in Kiev, where I was granted access to a collection of documents from numerous Soviet archives, which helped chart the official record of the Chernobyl disaster. These sources tracked the story over the course of more than 20 years, from the earliest Communist Party decisions about where to build Ukraine’s first nuclear plant to the engineering problems of maintaining the ‘Sarcophagus’ designed to entomb the wreckage of its doomed fourth reactor.

As part of a crash program of reactor building intended to help the USSR catch up with the swift growth of nuclear power engineering in the West, in September 1966 the Soviet Council of Ministers formally resolved to build a series of new atomic plants, including one in the Kiev region of Ukraine. Less than two years later, the leader of the Ukrainian Communist Party, Vladimir Scherbitsky, gave his approval for the construction of the new plant, then known as the Central Ukrainian Nuclear Power Station, near the old village of Kopachi, 18 kilometers from the district capital—the city of Chernobyl. The first reactor was due to come online in 1974, with a second due the following year. A new city to accommodate the workers form the plant and their families was built nearby, and named Pripyat.

By July 1980, the first two reactors were complete, with two more scheduled for completion soon afterward. When the next pair—reactors five and six—came online, the plant, by now known as the Chernobyl Atomic Energy Station, would become the largest nuclear power station on Earth.

But plans for a second phase of the Chernobyl plant were already in place, intended to add another six reactors to the complex. The potential environmental impact of such a colossal installation, and the radioactive effluent they would flush into the surrounding waterways, was such that the Ukrainian Academy of Sciences called for a dedicated scientific study of its potential consequences.

At around 1:25 a.m. on the morning of April 26, 1986, during an electrical system test being conducted as part of a routine maintenance shutdown, a massive explosion destroyed Reactor Number Four of the Chernobyl station. At some point after 10:00 a.m. that day, plant director Viktor Brukhanov signed an official accident report which listed the initial casualties including one dead and one missing. Yet, despite the increasingly obvious scale of the catastrophe, the director’s report, which was sent to his Communist Party superiors in Kiev and Moscow, dramatically underestimated radiation levels around the station, suggesting that the accident was far less serious than it was.

That night at 8:00 p.m., the Ukrainian Council of Ministers issued a secret order to prepare for a mass evacuation of the citizens of Pripyat, using 1125 buses gathered from Kiev and the surrounding area. The evacuation itself did not begin until the following afternoon, almost exactly 36 hours after the initial explosion.

The head of the Ukrainian Ministry of Internal Affairs (MVD), Ivan Gladush, reported to the Central Committee of the Communist Party of Ukraine that personnel and equipment of the Interior Ministry, the KGB, Civil Defense and Soviet Army—including 2900 men from the MVD alone—had already been directed toward the plant to help keep order and deal with the consequences of the accident. A Soviet level commission, headed by Deputy Prime Minister Boris Scherbina, had taken control at the scene.

An undated KGB report issued soon afterward indicated that by noon on Monday, April 28, levels of airborne radiation in the city of Rovno, more than 100 kilometers to the west of the power plant, had risen. In the streets of Pripyat, gamma radiation had risen to 0.57 Roentgen per hour—enough for an individual to receive the total permissible one-time dose allowed for Soviet troops in wartime in just ten hours.

By 9:00 a.m. on Tuesday April 29, 27,500 people had been evacuated from Pripyat, and those in the nearby city of Chernobyl were also beginning to leave. The Ukrainian Communist Party’s Department of Science and Education reported that crops and pastures in several districts of the Kiev Oblast’ were contaminated with radiation. 270 people had been hospitalized in Ukraine displaying possible symptoms of radiation poisoning, while a further 144 had been flown to Moscow, suffering from radiation sickness.

That same day, one of the members of the plant staff, 25-year-old Leonid Toptunov, the nuclear engineer manning the control desk of reactor number four at the moment of the explosion, sent a telegram from his room in the specialized radiological Hospital No. 6 in Moscow, to his mother in Estonia.

While the Communist Party in Moscow attempted to suppress news of the catastrophe, rumors about what had happened spread through cities in Ukraine.

On April 30, a report reached Ukrainian MVD headquarters that their informants in Zhitomir, Chernigov and Kiev witnessed citizens discussing the deaths of up to 600 people, that panic and looting had begun in the towns near the plant, and that even Soviet troops were no longer able to maintain order. A taxi driver in Kiev was overheard telling those around him that “the water in the Dnepr was completely contaminated” with radiation.

In fact, measurements recorded that same day by the Ukrainian Ministry of Health revealed that contamination had indeed spread throughout the land and waterways of the northern regions of the republic and that 468 people had so far been hospitalized following the accident, including 79 children: “thirty-eight people have already been diagnosed with radiation sickness.”

A separate, secret, report indicated that radioactive water from the Chernobyl plant had entered the Dnepr from the power station’s cooling pond, reaching the giant reservoir known as the Kievan Sea the day after the explosion and the city of Kiev itself on April 30. The authorities rapidly constructed a network of artesian wells and pumping stations to ensure the city a supply of fresh water, and built underwater dams to prevent the further spread of radioactive sludge downstream from the river beds.

By June 11, preparations were under way to build a fence 120km long around the perimeter of the newly-established Exclusion Zone surrounding the Chernobyl plant. Over 90,000 people had already been evacuated from the area; 201,000 students and schoolchildren had been sent to pioneer camps from the city of Kiev, and surrounding Oblast’. A hand-written note added to the report indicated that up to 150,000 people would require long-term medical observation; to fully understand the effects of radiation on the population “and to forecast morbidity,” the authors of the report recommended the organization of a scientific research institute dealing with issues of radiation protection.

However, the thumb of the centralized state had already been firmly placed on the scale. In a coded telegram sent from Moscow on May 21, the deputy minister of health of the USSR, Oleg Schepin, had intervened to cover up the extent of radiation exposure in the population. The message ordered Ukrainian health authorities to assign any patients exposed to ionizing radiation but not suffering from signs of acute radiation sickness a diagnosis that did not mention radioactivity at all, but instead stated that they were suffering from “occasional vascular dystonia.”This was a psychological complaint with physical manifestations—sweating, heart palpitations, nausea and seizures—triggered by the nerves or “the environment,” unique to Soviet medicine but similar to the Western notion of neurasthenia.

Similarly, in July 1986, the Politburo in Moscow heard the conclusions of a months-long investigation of the causes of the accident at the plant—the result of two separate inquiries headed by senior scientists and engineers including Valery Legasov, the first deputy director of the Kurchatov Institute of Atomic Energy and Alexander Meshkov, deputy chief of the Ministry of Medium Machine Building. This revealed the extent of the failures in the design of the RBMK reactors used in Chernobyl, and the failure—of both the leaders of the Kurchatov Institute of Atomic Energy and the Ministry of Medium Machine Building—to rectify them.

Yet the KGB took steps to ensure that none of these failings would be revealed to the public. The day after the Politburo meeting, a list (a copy of which, dated earlier that month, can also be found in the archives of the Ukrainian KGB) was circulated, enumerating the levels of classification assigned to 26 separate topics associated with the accident: the first item, designated “secret,” was “Information revealing the true reasons for the accident at ChAEhs unit No.4.”

And the following year, in September 1987, the head of the Government Commission overseeing the investigation and the liquidation of the consequences of the accident, Boris Scherbina, approved a similar decree ensuring that almost all data about the environmental impact of the accident be kept from the general public. This included information about damage to farm animals and forests, and concentrations of radioisotopes in water and soil samples, but also about areas of the USSR where radiation levels exceeded maximum permissible levels.

Two months later, the Soviet Minister of Health, Yevgeniy Chazov, provided a report to the Communist Party Central Committee outlining the ministry’s handling of the accident, providing a blizzard of statistics detailing its apparently swift response and comprehensive treatment of the victims of the disaster. He described the creation of an All-Union Scientific Center of Radiation Medicine to track and analyze the health of the populations affected by the accident, stating that to date they had not found any illnesses that they would attribute to radiation. An increase in circulatory disease and thyroid problems identified in those patients subjected to the study was attributed to other sources, including “the psychoemotional factor” which Chazov would describe in public as “radiophobia.” Chazov made no mention of the widespread incompetence and lack of preparedness as the ministry reported—when the accident response initially unfolded—to Prime Minister Nikolai Ryzhkov’s Chernobyl Operations Group.

But by July 1989, the unintended consequences of the Soviet policies of secrecy had helped to undermine Chazov’s assurances that the health effects of the disaster were minimal, resulting in a distrust of Soviet scientists and growing unrest in those areas of the Union most badly affected by radioactive contamination.

A letter sent to General Secretary Gorbachev and Ryzhkov, signed by the acting director of the All-Union Academy of Agricultural Sciences, pointed out the longstanding expertise of Soviet specialists in the field of radioactive contamination of the environment, and recommended responding to the crisis of public confidence with a more comprehensive approach to dealing with the wider impact of the accident. Enclosing 15 pages of suggestions on how to proceed, they even recommended a “package of work” designed to repopulate the 30 kilometer Exclusion Zone and safely return it to agricultural production. Yet public unrest intensified, and when the USSR finally disintegrated just over two years later, the Exclusion Zone remained an empty and fallow radioactive no-mans’-land.

Many of the political, social, environmental and economic costs of the accident then fell on the shoulders of the newly-independent government of the Republic of Ukraine. According to one estimate, the financial toll would reach a total of $128bn by 1997.

And, even then, the ruin of the reactor that exploded early on the morning of April 26th continued to represent a looming threat to the environment. In 1993, the deputy chief of the Ukrainian Academy of Sciences’ Interdepartmental Scientific and Technical Center outlined his concerns about conditions inside the Ukrytie—otherwise known as the Sarcophagus—which had been constructed over the wreckage of Reactor Number Four by Soviet engineers during the second half of 1986. Specialists feared that the nuclear fuel remaining inside the structure could not only leach yet more radionuclides into the groundwater, but also approach a new criticality, which—in the unlikely event that it took place, could result in an uncontrolled fission reaction, releasing further contamination into the atmosphere.

These conditions would not be fully resolved for more than 20 years, when a second steel tomb—the New Safe Confinement—was finally sealed over the decaying Ukrytie, in November 2016.