Chernobyl was a disaster — there is no doubt about that — but what lessons should we learn from it?
Though the catastrophic meltdown and explosion of the RBMK Reactor No 4 happened almost half a lifetime ago, when police states claiming to serve the workers ruled eastern Europe, the recent HBO mini-series Chernobyl has brought that time back to life.
Though partly fictionalised and sometimes wrong (according to survivors and experts), the basic facts are correct.
During an “experiment” aimed at improving safety procedures, Reactor No 4 responded erratically and attempts to bring it under control, including the extraction of virtually all control rods, were to increase the danger later.
The experiment should have been aborted at this point, but a bureaucratic adherence to a plan, coupled with a not-uncommon reluctance to challenge one’s superiors, led to continuance until an unexpected rapid power surge demanded an emergency shutdown or SCRAM. This would normally involve rapidly inserting control rods which absorb the neutrons without which the chain reaction in the fuel rods cannot continue.
In the RBMK, these were poorly designed, being only capable of slow insertion and having graphite tips which actually reflect neutrons back into the fuel rods (a moderator made of graphite, i.e. pure carbon, surrounded the reactor core to reflect neutrons back into the uranium fuel and drive the chain reaction). The result was to momentarily increase the overheating.
This increased steam pressure from the coolant water and the fuel rods seem to have disintegrated, blocking the control rod channels before insertion could be completed. The chain reaction went further out of control, power output continuing to rise to about ten times normal levels, according to some estimates.
The pressure build-up resulted in a steam explosion which caused further damage to the fuel rods and a loss of coolant…and more overheating. The graphite would have been burning by this time.
Three seconds later, a second explosion blew the core apart, stopping the chain reaction but exposing highly-radioactive material, some of it burning, some of it flying through the air, to the environment. This second explosion may have been like an atomic bomb which has not detonated fully but “‘fizzled”, supposedly impossible in properly-designed nuclear reactors.
This is covered well in Chernobyl, as is the heroism of many who lost their lives preventing a worse disaster, according to a highly-complimentary review by Hamish Johnston in Physics World.1 Johnston praises the courtroom scene where investigator Valery Legasov explains how a nuclear reactor works and the way design flaws contributed to the disaster.
While Legasov is a real character, the investigative journalist Ulana Khomyuk is fictional. Curiously not mentioned in Chernobyl is a real investigative journalist, Lyubov Khovalevskaya, who, as editor of the Chernobyl atomic energy plant newspaper Tribuna Enerhetyky, obtained secret documents which enabled her to break the story of the Chernobyl reactor’s serious problems a month before the accident.
According to the International Women’s Media Foundation,2 which awarded her its 1991 Courage in Journalism Award, Khovalevskaya “spent the next three years collecting official documents on the facility and entered the forbidden radioactive zone more than thirty times to interview workers and cooperative officials.
“Risking her own life, she reported the accident and aftermath extensively, pointing to its disastrous impact on the soil and water system and numerous victims and publishing documents the government was trying to keep secret.” Perhaps Khomyuk is based on Khovalevskaya, but the latter could have appeared as a real character in Chernobyl.
Some reviews have made much of the inaccuracies in Chernobyl. These, under the heading of “artistic licence”, are difficult to justify but detract little from the overall truth of its account of the causes and events of the accident.
On health effects, speculation is general anyway and Chernobyl brings little clarity or perspective. The direct deaths are known (28) and an estimate exists for deaths from thyroid cancer, almost entirely due to children absorbing radioactive iodine (I-131) from their milk. Iodine is essential for the thyroid gland to make thyroid hormone.
This cancer is nearly always curable but leaves survivors on lifelong medication. There have been some 5,000 cases in the region affected by fallout from Chernobyl with some fifteen deaths. Though the initial cause of I-131 release was the accident at Chernobyl, the bureaucracy is blameworthy for not distributing iodide tablets in time: these work by swamping the thyroid gland with harmless I-127.
Overall deaths definitely or most likely due to the accident number 43 at present. Illnesses and deaths among survivors do not seem much different from expected in unaffected populations: there is at worst a slight increase in cancers. The total number of excess cancers may be as little as 4,000, a tiny increase in risk given that about one third of people die from cancer.
According to the WHO,3 any increase in cancers will be undetectable. This is particularly so given the health decline in the former Soviet Union since its collapse in 1991.
Chernobyl was a disaster (except for local wildlife);4 people died unnecessarily; people’s lives were disrupted by displacement from their communities and fear of the future; the “Soviet” bureaucracy showed itself incapable of or uninterested in protecting its citizens, which may have accelerated its demise. The makers of Chernobyl have done a major service in informing or reminding us of this.
Many will conclude (as most of the Left did at the time and many still do today) that this means nuclear power is inherently unsafe. But, since that time, we have learnt much about the dangers of fossil fuel extraction and energy production.
Those are between 40 and 400 times as dangerous as nuclear power!
The review includes an embedded YouTube video (an episode of Going Nuclear with Scott Manley). This is particularly praising of the description of the science of the reactor “for the lay person” in the final court scene but goes into more details.