HBO’s acclaimed Chernobyl miniseries has sparked new interest in the tragic sequence of events on that warm spring night of April 26, 1986 near the idyllic town of Pripyat that led to the world’s worst nuclear disaster. A combination of dreadful human errors and design flaws within the Soviet constructed reactor led to an uncontrolled power surge within the graphite core of Chernobyl’s RBMK Reactor Number 4, causing a catastrophic explosion and concomitant release of highly radioactive material. This invisible death, which possesses neither taste nor smell, still lingers in high concentrations at Chernobyl’s Exclusion Zone to this very day.
The catalyst for the explosion was a turbine shutoff safety test designed to see if the kinetic energy in the turbines could generate sufficient electricity to pump water coolant through the reactor’s core during the one-minute lapse before diesel generator backups could take over. The test had been performed on three previous occasions but had failed for various reasons, though the consequences of those prior failures were nowhere near as calamitous as Chernobyl’s fourth and final failed test.
Chernobyl’s Reactor Number 4 was completed in 1983. Emphasis was placed on speedy construction and completion while safety protocols were largely ignored or circumvented. The safety test that Chernobyl’s control room engineers were conducting that night should have been conducted in 1983 before, and not after, Reactor Number 4 opened for business.
Despite these and other shortcomings, the safety test had to be performed. The Cold War between East and West was still brewing and the Soviets were paranoid about the possibility of an attack against their reactors and their functionality in the event of sudden loss of power.
On June 7, 1981, just two years prior to the completion of Reactor Number 4, eight Israeli Air Force F-16A fighter bombers, each armed with two unguided Mark-84 2000lb bombs, attacked and obliterated Iraq’s Baghdad based Osirak nuclear facility. Israeli intelligence had determined that Iraq’s mercurial and bloodthirsty leader, Saddam Hussein, would have utilized the reactor to produce atomic bombs. Though Israel was heavily criticized for its actions at the time, subsequent developments would prove Israel’s intelligence assessment to be accurate.
Israel’s raid against Osirak heightened Soviet fears of vulnerabilities in its nuclear facilities and served as a catalyst for safety tests like the one performed at Chernobyl. Ironically, the greatest danger posed to the Soviet Union’s nuclear power plants was not an attack from the West but was rather the culture of corruption endemic to the Soviet socialist system. It was this culture of corruption that prioritized meeting deadlines and timetables over safety concerns. And it was this culture of corruption that placed emphasis on cheaper but less safe reactors over more expensive but safer reactors.
Graphite moderated, water cooled RBMK reactors of the type found at Chernobyl had several design flaws and were inherently unsafe making the Chernobyl disaster all but inevitable. The reactors were unstable in low power mode. The boron control rods, which are designed to control or slow down the reaction by absorbing neutrons, were tipped with graphite, which actually causes a temporary power surge when lowered into the core. This design defect was the final catalyst leading to the core’s explosion. And in a feature unique to Soviet RBMK reactors, the more steam generated in the core, the higher the reactivity, which in-turn produces more heat, which produces more steam leading to a vicious uncontrolled cycle. This feature is referred to as a “positive void coefficient.” In Western reactors, the void coefficient is negative, which means that more steam results in less reactivity. In addition, RBMK reactors lacked emergency safety containment vessels which are mandatory in Western reactors.
Many of these design defects were known to the Soviets but were ignored for the sake of expediency. The Soviets compounded their errors by waiting a full day before issuing evacuation orders for Pripyat’s residents and residents of surrounding areas despite known lethal radiation levels in the area. It was a demonstrable display of contempt for human life where state secrets prevailed over the wellbeing of Soviet citizens.
In the months following the Chernobyl disaster, Andranik Petrosyants, chairman of the State Committee for the Utilization of Atomic Energy, in an interview with the state propaganda outlet Tass, downplayed Soviet malfeasance but called for an international treaty that would outlaw attacks on power stations, such as that carried out by IAF F-16s on Osirak. It was a rather pathetic attempt at an old Soviet tactic to deflect from Soviet shortcomings and conflate two unrelated events – a nuclear accident caused by criminal negligence and a successful counter-proliferation effort that saved countless lives.
Even today, vestiges of the old Soviet mindset, of refusing to take responsibility and dabbling in delusional conspiracy, prevail. In response to the HBO production, the Russian government allocated $500,000 toward the production of a film whose version of the Chernobyl disaster is premised on the conspiracy-prone belief that a CIA spy penetrated Chernobyl’s Reactor Number 4 on the night of the accident to carry out sabotage. Some things will never change.