Chernobyl: The History of a Nuclear Catastrophe

Serhii Plokhy, a Harvard historian of Ukraine who was living less than 500 kilometers from the Chernobyl reactor at the time of the disaster, presents the first comprehensive history of the 1986 nuclear catastrophe, tracing events from the explosion to the plant's closure in December 2000. Drawing on newly opened Soviet archives and files from the Committee for State Security (KGB), Plokhy argues that the disaster was not merely a technological failure but the product of a dysfunctional political system whose consequences helped bring down the Soviet Union itself.

The book opens on April 28, 1986, at the Forsmark Nuclear Power Plant in Sweden, where a chemist named Cliff Robinson triggers a radiation alarm. Swedish authorities determine that the contamination originates from the Soviet Union, but three Soviet agencies deny any knowledge. Plokhy then turns back to the Twenty-seventh Communist Party Congress in February 1986, where General Secretary Mikhail Gorbachev called for a dramatic expansion of nuclear energy as part of uskorenie, his program to accelerate economic development. Viktor Briukhanov, the 50-year-old director of the Chernobyl Nuclear Power Plant, attended the congress as a delegate. The plant used RBMK reactors, a graphite-moderated design born from the Soviet military-industrial complex. Anatolii Aleksandrov, the chief scientific adviser behind the design, publicly claimed the reactors were safe enough to install on Red Square, but the RBMK lacked the concrete containment structures standard at Western plants.

Born in Tashkent in 1935 to a Russian working-class family, Briukhanov rose through the Soviet power industry before being appointed, at 35, to build and direct the Chernobyl plant. By 1986, the plant operated four reactors near Prypiat, a company town of nearly 50,000 people built for plant workers. Briukhanov warned that a serious mishap at the station could overwhelm the entire Soviet Union. KGB reports documented construction defects at the plant but received no response from authorities.

On the evening of April 25, 1986, operators prepared to shut down reactor No. 4 for routine maintenance. A turbine test aimed to determine whether a spinning turbine's momentum could generate enough electricity to cover a 45-second gap before emergency diesel generators activated. The test required disabling emergency safety systems. Deputy chief engineer Anatolii Diatlov oversaw the process. After a power grid dispatcher delayed the shutdown for nine hours, the midnight shift took over, led by Aleksandr Akimov with Leonid Toptunov as senior reactor engineer. Toptunov accidentally caused the reactor's power to plummet to near zero. Rather than abort, Diatlov approved continuing the test at 200 megawatts of thermal energy (MWt), far below the prescribed 760. To compensate for the buildup of xenon-135, a fission byproduct that absorbed neutrons and slowed the reaction, operators withdrew nearly all control rods from the core.

At 1:23 a.m. on April 26, the turbine test began. Thirty-six seconds later, Akimov ordered the AZ-5 emergency shutdown. As the control rods descended, their graphite tips displaced neutron-absorbing water in the upper core, triggering a catastrophic power spike through the positive void effect, a known design flaw in which steam voids accelerate rather than dampen the nuclear reaction. Power surged from 200 to over 30,000 MWt in seconds, causing a steam explosion that blew the 200-tonne upper biological shield through the roof. A second explosion destroyed much of the building and scattered radioactive graphite and fuel fragments across the grounds.

Firefighters arrived within minutes. Lieutenant Volodymyr Pravyk, 23 years old, radioed the highest alert. His crews climbed to the roofs, kicking aside glowing chunks of radioactive graphite without knowing what they were. The fire was contained by roughly 7:00 a.m., but the firefighters had absorbed lethal doses of radiation. At the plant, Briukhanov saw the destroyed reactor but could not accept what had happened. The only dosimeter with an adequate scale registered radiation exceeding 200 roentgens per hour, but the civil defense chief who reported this was dismissed. Officials deferred to a government commission not yet arrived, and no evacuation was ordered. That day, seven weddings took place in Prypiat, and residents played outdoors, unaware of the danger.

Boris Shcherbina, deputy chairman of the Soviet Council of Ministers, arrived to chair the commission on the evening of April 26. Scientist Valerii Legasov, first deputy director of the Kurchatov Institute of Atomic Energy, served as chief scientific adviser. After helicopter flights confirmed the reactor was destroyed and further explosions rocked Unit 4 that evening, Shcherbina phoned Premier Nikolai Ryzhkov, who approved the evacuation. The next afternoon, 1,125 buses evacuated approximately 44,460 people from Prypiat. They were told they would return in three days. They never did.

Helicopter pilots dropped sandbags, boron, lead, and clay into the reactor, absorbing extreme radiation with each sortie. Scientists feared the overheated core would burn through its foundations to the water table, contaminating the Dnieper River Basin. Divers drained approximately 20,000 tonnes of radioactive water from the flooded basement, and miners dug tunnels beneath the reactor by hand. The exclusion zone expanded to 30 kilometers, requiring the evacuation of more than 40,000 additional people.

The Soviet government maintained near-total silence for days. Not until the evening of April 28, after Swedish detection forced the issue, did Soviet television read a four-sentence bulletin acknowledging an accident. On May 1, despite elevated radiation, authorities proceeded with the May Day parade in Kyiv, with party leaders and children marching through contaminated air. Gorbachev's first televised address on Chernobyl came 18 days after the explosion and devoted more than half its length to attacking Western criticism.

Close to 600,000 people were mobilized as liquidators to clean up the disaster zone. Within three months, 29 people died of acute radiation syndrome, including firefighters Pravyk and Lieutenant Viktor Kibenok and reactor operators Akimov and Toptunov. Yefim Slavsky, the minister who oversaw the Soviet nuclear empire, directed construction of a concrete sarcophagus over the damaged reactor; approximately 200,000 workers completed the structure by November 1986. At the July 1986 Politburo meeting, the government officially blamed plant personnel, shielding the reactor designers, and Briukhanov was expelled from the party. In 1987, Briukhanov, chief engineer Nikolai Fomin, and Diatlov were tried in the exclusion zone and each sentenced to 10 years. Diatlov argued that his procedural violations could not have caused the explosion if the reactor had not been fundamentally flawed, but the court excluded evidence pertaining to reactor design. Legasov, who had presented a report to the International Atomic Energy Agency (IAEA) in Vienna, received international praise but faced retaliation for divulging too much about the Soviet nuclear program. His health deteriorated from radiation exposure, and he died by suicide on April 27, 1988, one day after the disaster's second anniversary.

In the years that followed, the disaster catalyzed political transformation. Ukrainian writers such as Ivan Drach and Oles Honchar linked nuclear safety to national survival, and ecological activism merged with the independence movement. Journalist Alla Yaroshynska exposed the secretly contaminated Narodychi district and won election to the Congress of People's Deputies. In November 1988, approximately 10,000 people gathered in Kyiv at the first mass rally not fully controlled by the Communist Party. The grassroots organization Rukh (Movement), founded with Chernobyl as a central cause, ultimately declared Ukrainian independence as its goal. On August 24, 1991, following a failed coup in Moscow, the Ukrainian parliament voted overwhelmingly for independence. A 1991 commission of nuclear scientists, led by Academician Yevgenii Velikhov of the Kurchatov Institute, concluded that RBMK design flaws, not operator error alone, predetermined the catastrophe, vindicating Diatlov's arguments at trial.

Independent Ukraine adopted generous social welfare laws for Chernobyl victims but could not sustain the costs amid economic collapse. In 1993, the same parliament that had voted to close the plant reversed course, lifting moratoriums on nuclear construction. After international negotiations that included Ukraine's surrender of its Soviet-era nuclear arsenal in exchange for security assurances under the 1994 Budapest Memorandum, Western governments pledged $2.3 billion toward decommissioning and replacement reactors. On December 15, 2000, President Leonid Kuchma officially closed the Chernobyl plant. Construction of a new 30,000-tonne steel arch shelter over the deteriorating sarcophagus began in 2010 and was completed in 2017 at a cost exceeding 3 billion euros. Plokhy concludes that the causes of the disaster, including authoritarian leaders pursuing great-power status while neglecting safety, remain present today, as most new reactors are being built under regimes with limited accountability. The half-life of cesium-137, one of the most harmful isotopes released, is approximately 30 years, but scientists estimate the contamination will harm the environment for at least 180 years; the half-life of plutonium-239, traces of which reached Sweden, is 24,000 years.