In 1986, reactor four of the Chernobyl nuclear power plant in Soviet Ukraine exploded, sending many billions of radioactive particles into the atmosphere, contaminating the surrounding area.
The fight to avert an even worse disaster was led by a chemist for the Kurchatov Institute of Atomic Energy, a man by the name of Valery Legasov, a tragic figure as much as he was a hero. His investigation into the Chernobyl disaster won him international acclaim even as it cost him his career and reputation back home, a cautionary tale about the consequences of ignoring uncomfortable scientific facts.
The Chernobyl Crisis
On April 26, 1986, technicians at the Chernobyl nuclear power plant in northern Soviet Ukraine performed an unauthorized safety test on the reactor four to simulate a power outage so they could develop procedures for maintaining reactor cooling until back-up power could be engaged.
The test was delayed for several hours, so the shift that had prepared for the test was rotated out and the test supervisor did not follow the established testing procedure.
This, combined with several critical design flaws in the Reactor Bolsho Moshchnosty Kanalny-, or RBMK-, type nuclear reactor led to a runaway nuclear reaction. The energy unleashed by this reaction vaporized the water that was cooling the reactor core, causing an explosion from the pressurized steam, rupturing the containment chamber for the reactor and exposing it to the open air. Without any cooling mechanism, the reactor core quickly caught fire, releasing tons of radioactive material into the atmosphere.
Valery Legasov and the Chernobyl Response
At the time of the accident, Valery Legasov was the First Deputy Director of the Kurchatov Institute of Atomic Energy and was assigned to the commission investigating the disaster.
Though Legasov did not lead the commission - the investigation was led by the head of the Bureau for Fuel and Energy and Deputy Chairman of the Council of Ministers, Boris Shcherbina - Legasov would become the public face of the effort to contain the disaster and the investigation into its cause.
Legasov was immediately confronted with the disorganization of the various Soviet departments connected to the disaster response. There wasn't enough necessary equipment for working amid the radioactive fallout from the reactor fire.
There weren't enough respirators or radiation detectors for workers on the site to use and Legasov had to turn to international experts--something unthinkable for Soviet officials at the time--for assistance in dealing with the graphite fire in the main reactor.
Legasov's abandonment of the long-standing Soviet practice of secrecy around such circumstances won him considerable praise from the international community, who saw Legasov's quick recognition of Soviet limitations and willingness to ask for help as a welcome voice of reason from an otherwise intransigent and tight-lipped bureaucratic government in Moscow.
Legasov also ordered the evacuation of the nearby city of Pripyat and officials established a 30 km Chernobyl Exclusion Zone, which is said to be unsafe for human habitation for the next 20,000 years as a result of the disaster.
Legasov's Report on the Chernobyl Disaster
Legasov and the rest of the commission issued a final report on the disaster that cited several causes for the disaster, but two were especially emphasized.
First and foremost was the RBMK-type reactor itself. Though widespread in the Soviet Union, the reactor design was prohibited outside of the Soviet Union.
According to the Nuclear Energy Institute, a trade group for nuclear power operators in the United States, "[b]ecause of the way the [RBMK reactor] used graphite where American reactors use water, when Soviet operators tried to reduce power the RBMK had a tendency to sharply increase power production instead. As overheating became more severe, power increased even more."
Legasov found that this flawed design should never have been allowed to operate and that no RBMK reactor can be considered safe.
The second key cause of the disaster was the incompetence of the plant personnel, especially deputy chief engineer Anatoly Dyatlov, who allegedly violated several key safety protocols when he executed the partial power shutdown of reactor four as part of an unauthorized test. That shutdown started the chain of events that led to the reactor explosion and subsequent crisis for which Dyatlov and plant personnel more broadly were entirely unprepared to deal with.
Soviet Response to Legasov's Report
In a July 3 meeting of the Soviet politburo on the Chernobyl crisis, the Soviet deputy energy minister, G.A. Shasharin, said that "The personnel had no idea that this type of reactor can release so much energy. We didn't know it either. We were enthusiastic about this reactor but never truly convinced of its safety. There was only one protective system, and everyone assumed that it was no good. The Smolensk and Kursk nuclear power plants, as well as the two near Leningrad, should also be shut down. They can't even be refurbished anymore."
Soviet premier Mikhail Gorbachev angrily lamented: "What isolated areas we have created in this country! The Central Committee declared everything to be a secret. The government doesn't even determine the locations for nuclear power plants or the types of reactors used. The entire system consisted of cajolery, boasting, deception, nepotism and the persecution of dissidents."
Gorbachev's words would turn out to be prophetic, as the Soviet state placed all the blame for the Chernobyl accident on the unauthorized actions of plant personnel, making no mention of the flaws in the RBMK-type reactors, which continued to operate in the Soviet Union and later in the Russian Federation to this day.
Valery Legasov was ostracised by the government for his speaking out about the dangers of the RBMK-type reactors and denied reappointment to the Kurchatov Institute of Atomic Energy. Disillusioned with his government's response to the crisis, Legasov hanged himself in his apartment nearly two years to the day after the Chernobyl disaster.
His friend, Vladimir Gubarev, was highly critical of Legasov's colleagues at the Kurchatov Institute who voted 128-100 to keep Legasov off the Institute's scientific council that Legasov once served on as its Deputy Director.
Noting how Legasov stayed at the Chernobyl site throughout the crisis, rather than be cycled out as the rest of his team was (to limit contamination), Gubarev said of the Kurchatov Institute: "I felt like saying to them that Legasov never left Chernobyl, but how come I did not see you there?"
Legasov was posthumously awarded the title of "Hero of the Russian Federation" by then-Russian President Boris Yeltsin on September 20, 1996, for his dedication to the truth during his investigation, even at great personal cost to himself.