Guest post by Christine Horejs, Senior Editor Nature Reviews Materials
The new British-American miniseries ‘Chernobyl’, aired on HBO and Sky in May and June 2019, takes you on a dark ride through the insanity that accompanied the nuclear disaster of Chernobyl. Five haunting episodes depict the night and aftermath of the explosion of reactor 4, using the style of disaster films to vividly show how the combination of bad nuclear reactor design, irresponsible scientists, a totalitarian system and human error led to one of the biggest nuclear disasters, with devastating consequences within and outside the Iron Curtain.
In Eastern Austria, where I grew up, the weather was rather bad in the last days of April 1986. We children did not know at that time that the rain that fell on our sandbox in the garden carried radioactive waste.
On 26th April 1986, reactor 4 in the Chernobyl nuclear power plant in Soviet Ukraine had exploded. Once the news of the catastrophic nuclear accident spread across the Iron Curtain – on 28th April – we lost our sandbox for good, were fed iodine tablets by our parents and stopped drinking milk and eating berries or mushrooms. Many of the children growing up in Eastern Austria in the 1980s had thyroid problems later in their lives. I had to get my thyroid removed a few years ago – whether this is related to Iodine 131 released in Chernobyl and absorbed by my thyroid remains unclear. Indeed, many facts about Chernobyl have long remained in the dark, as neither the Americans (or Europeans) nor the Russians had an interest in telling the truth about nuclear disasters and the consequences of radiation for human health.
Three important books1,2,3, published over the last year, and a new HBO TV drama, now dissect every minute and (known) consequence of the Chernobyl accident. Being slightly obsessed with this topic, I read them all and I certainly could not wait to watch the HBO series. And, yes, ‘Chernobyl’ drags you right into the agonizing hours after the disaster and creates this feeling of horrifying fascination that often accompanies apocalyptic movies – but this time it is real (most of it)!
Many people are familiar with the ever reoccurring stories about Chernobyl – the spreading wildlife in the exclusion zone, the awkward selfies taken in front of deserted Pripyat or the liquidators as heroes of the Soviet Union. But this series is definitely something else. It not only shows how an RBMK reactor (like the one in Chernobyl) works or does not work and how high doses of radiation literally dissolve the human body, but also how totalitarianism and secrecy provided the basis for what happened at Chernobyl. In particular, the complete refusal of the scientists and politicians in charge to acknowledge the fact that the graphite core of reactor 4 had exploded and that high doses of radiation had been released, despite overwhelming evidence. Highly radioactive graphite pieces from the reactor core lying on the ground outside the reactor and nuclear engineers disbelievingly staring into the remains of the reactor core from the roof while their skins turn red. And yet, Nikolai Fomin, the chief engineer who approved the safety test that ultimately caused the explosion, constantly repeats that the “the core of an RBMK reactor cannot explode,” – like a prayer. Meanwhile, invisible radioactive particles fall on the town and people of Pripyat (the Atomgrad —atomic city – located 2km from the power plant) and accumulate high up in the clouds to make their way across Europe. It is this invisibility that creates the true horror of ‘Chernobyl’. You, the viewer, know, but the children playing in the radioactive dust and their parents gathering on a railway bridge in Pripyat to check out the burning reactor don’t. In the credits at the end of the series, we learn that none of the people on the railway bridge in Pripyat survived.
In ‘Chernobyl’, we experience the actual explosion from the window of the wife of the firefighter Vasily Ignatenko. At 01:23 on 26th April 1986, a bright light appears in the distance, followed by a massive thud leaving behind a bright blue flash in the night sky above the Chernobyl power plant (caused by radiation ionizing air). The few nuclear engineers present in the control room of the power plant anxiously look at each other. “What just happened,” asks Anatoly Dyatlov, deputy chief-engineer of the power plant and supervisor of the fatal safety test. The scene perfectly captures the essence of what went wrong during and after the Chernobyl disaster. The nuclear engineers remain paralysed after the accident, not comprehending its magnitude or cause. Similarly, the director of Chernobyl, Viktor Bryukhanov, who is brought in after the accident, wastes crucial time by convincing local politicians that the accident is under control and that he cannot be held responsible for any damage. Outside, one of the firefighters, who were called to Chernobyl right after the explosion, grabs a piece of the graphite core. What happens to his hand in an instant after he touched the piece of graphite is the stuff of zombie movies.
‘Chernobyl’ is mesmerizing owing to the sheer drama of actual facts. For example, biorobots (that is, human beings) have to clean up the roof of reactor 3 to make room for the concrete wall, which will become famous as the sarcophagus shielding the world from reactor 4. Even a rover designed to work on the moon failed in this radioactive environment. Each liquidator has only 90 seconds to shovel graphite pieces back into the open core of reactor 4. The graphite is so radioactive that exposure for longer would be fatal. Ninety seconds never felt so long.The reality of ‘Chernobyl’ could have maybe been even more emphasized by using Russian-speaking actors, as, sometimes, hearing a Russian nuclear engineer speaking English with a British accent seems slightly inappropriate for a historical drama set in Soviet Ukraine in the 1980s.
And then there is the very last episode – the trial. Valery Alekseyevich Legasov, a chemist, who, together with Boris Yevdokimovich Shcherbina, vice-chairman of the Council of Ministers, investigated the Chernobyl disaster, explains what went wrong during the safety test. Legasov theatrically illustrates the combination of errors that caused the explosion of reactor 4 using red and blue panels on a wooden board, to depict the factors that can speed up or slow down the nuclear reaction. He also explains two crucial design flaws of RBMK reactors: the dangerously high ‘positive void coefficient’ and the graphite tips of the control rods, which together make this reactor type inherently difficult to control. Cooling water absorbs neutrons, but once steam is generated, a bubble is created that does not absorb neutrons. This bubble void leads to a reduction in moderation, that is, neutrons are not slowed down, which can cause a runaway condition. RBMK reactors have the highest positive void coefficient of any commercial reactor ever designed. In addition, the ultimate stop button (AZ-5), which should theoretically shut down a reactor as all control rods are inserted at once, can – for a short time – increase the reactor power output, as in RBMK reactors, the rods initially displace coolant with their graphite tips before the neutron-absorbing boron is inserted. Thus, when the nuclear engineers in the control room of reactor 4 pressed the AZ-5 button to shut down a reactor out of control, they ultimately caused the explosion. If only the engineers operating the nuclear power plant would have known about this fatal flaw of the AZ-5 button – but they didn’t as this would have compromised the reputation of Soviet nuclear physics. These construction errors in combination with all the errors previously made during the safety test led to the nightmare that followed.
The episode perfectly rounds up the story, showing what actually happened in the control room before and after the accident (which is well in line with what has been reported in recent books1,2). But in reality, Legasov was not present at the Chernobyl show trial, and even if he had been there, I doubt that he would have openly criticised Soviet science. At an International Atomic Energy Agency meeting in August 1986 Vienna, he had reported that it was only human error that caused the explosion. One wonders why there is the need to introduce fiction in a story that certainly does not lack dramatic historical figures and facts. Especially, because this might open up the room for criticism – as it already happened in the Russian media. Despite these flaws, ‘Chernobyl’ is definitely worth watching and forces you to comprehend the destructive combination of nuclear power going out of control and an authoritarian system – not only for Chernobyl-obsessed people like me, but for all present and future children of the nuclear age.
1 Serhii Plokhy. Chernobyl, the history of a nuclear catastrophe. 2018
2 Adam Higginbotham. Midnight in Chernobyl. 2019
3 Kate Brown. Manual for Survival: A Chernobyl Guide to the Future. 2019
Watch the Chernobyl miniseries here.