Playing With Fire at Chornobyl: After 36 Years the Nuclear Site is Again in Danger

Ukrainian National Chornobyl Museum resembling the reactor that suffered the catastrophic failure (reactor core surrounded by blue) by Jorge Láscar/Creative Commons.

For 36 years things had been quiet at Chornobyl. Not uneventful. Not safe. But no one was warning of “another Chornobyl” until Russian forces took over the site on February 24 of this year.

Russia’s invasion of Ukraine first took their troops through the Chornobyl Exclusion Zone, where they rolled armored vehicles across radioactive terrain, also trampled by foot soldiers who kicked up radioactive dust, raising the radiation levels in the area.

As the Russians arrived at the Chornobyl nuclear site, it quickly became apparent that their troops were unprotected against radiation exposure and indeed many were even unaware of where they were or what Chornobyl represented. We later learned that they had dug trenches in the highly radioactive Red Forest, and even camped there.

After just over a month, the Russians pulled out. Was this to re-direct troops to now more strategically desirable — or possibly more reasonably achievable — targets? Or was it because, as press reports suggested, their troops were falling ill in significant numbers, showing signs of radiation sickness? Those troops were whisked away to Belarus and the Russians aren’t talking. But rumors persist that at least one soldier has already succumbed to his exposure.

Plant workers at the nuclear site, despite working as virtual hostages during the Russian occupation and in a state of perpetual anxiety, where shocked that even the Russian radiation experts subsequently sent in, were, like the young soldiers, using no protective equipment. It was, said one, a kind of suicide mission.

What could have happened at Chornobyl — and still could, given the war is by no means over and the outcome still uncertain — could have seen history repeat itself, almost 36 years to the day of that first April 26, 1986 disaster.

Yet, Chornobyl has no operating reactors. So why is it still a risk? Doesn’t the so-called New Safe Confinement (NSC) structure protect the site?

The $2.3 billion NSC was built to cover over the original and crumbling old sarcophagus that had encased the lethal cargo left behind after the April 26, 1986 explosion of Unit 4.

Supposed to last just 100 years, that still inadequate timeframe was thrown into jeopardy as a reported firefight broke out prior to the Russian takeover. Fears arose that the shocks and vibrations of repeated shelling and artillery fire could cause the NSC to crack or crumble.

Housed inside the NSC is the destroyed Unit 4 as well as 200 metric tonnes of uranium, plutonium, irradiated dust, solid and liquid fuel, and a molten slurry of uranium fuel rods, zirconium cladding, graphite control rods, and melted sand.

The fuel lump from Unit 4, sitting inaccessible on a basement floor, remains unstable. In May 2021, there was a sudden and baffling escalation of activity there and a rise in neutrons, evoking fears of a chain reaction or even another explosion.

All of these volatile fuels and waste inventories still depend on cooling pumps to keep them cool. And those cooling pumps depend on power.

However, not everything at the site is within the NSC.

Units 1, 2 and 3 are not yet fully decommissioned and likely won’t be until at least 2064. Even though their fuel has been cooling for 20 years, it cannot go indefinitely without power. And managing it necessitates skilled, and unharried, personnel.

Loss of power threatens the ISF-1 spent nuclear fuel pool where much of the waste fuel is still stored. As nuclear engineer, Dave Lochbaum, described it in an email, “If forced cooling is lost, the decay heat will warm the water until it boils or until the heat dissipated by convective and conduction allows equilibrium to be established at a higher, but not boiling, point.

“If the pool boils, the spent fuel remains sufficiently cooled until the water level drops below the top of the fuel assemblies.”

At that point, however, adds Union of Concerned Scientists physicist, Ed Lyman, “a serious condition in the ISF-1 spent nuclear fuel pool” could occur. “However, because the spent fuel has cooled for a couple of decades there would be many days to intervene before the spent fuel was exposed.”

At the time of the invasion, workers at the site had been engaged in moving the full radioactive waste inventory from all 4 of the Chornobyl reactors, from the common fuel pool to the ISF-2 facility where it will be dismantled and put into long-term storage casks. It is unclear whether this operation was halted, but likely so.

Fire also remains a significant risk at the site. The massive 2020 wildfire that reached the perimeter of the Chornobyl plant site, occurred in April, well before the dry season. Military combat clearly invites the risk of igniting a lethal fire.

Indeed, the entire region, known as the Chornobyl Exclusion Zone, is a tinderbox. As Dr. Tim Mousseau and his research team discovered, dead wood and leaf litter on the forest floors is not decaying properly, likely because the microbes and other organisms that drive the process of decay are reduced or gone due to their own prolonged exposure to radiation.

As leaf litter and organic matter build up, the risk of ignition increases. There have been several hundred fires in the Zone already, sometimes, incomprehensibly, deliberately started. The explosions of war fighting could spark another. Indeed, stories did emerge about fires during the Russian occupation, their origin unclear.

But even without military attacks or destruction of the site, it was still at risk, especially when offsite power was lost, twice, raising fears of a potential catastrophe if emergency on-site power — consisting of diesel generators — did not work or ran out of fuel. Later reports revealed that plant workers had taken to stealing Russian fuel to keep those generators running.

Meanwhile, the State Nuclear Regulatory Inspectorate of Ukraine (SNRIU) had lost complete contact with its Chornobyl workforce. As days dragged into weeks, the SNRIU legitimately worried that an exhausted workforce, going without shift changes and operating under duress and potentially fear, could lead to mistakes that could prove deadly.

It was, after all, human error that had contributed to the first Chornobyl catastrophe.

On March 17, the SNRIU reported, “There is no information on the real situation at the Chornobyl NPP site, as there is no contact with the NPP personnel present directly at the site for the 22nd day in a row without rotation.”

Radiation monitors had remained off since the Russian occupation, leaving authorities and the public in the dark should there be any significant release of radioactivity as a result of damage at the site inflicted by military conflict or other causes.

Repeating a warning that had become a daily one on the SNRIU website, the agency concluded: “Given the psychological, moral, and physical fatigue of the personnel, as well as the absence of day-time and repair staff, maintenance and repair activities of equipment important to the safety of the facilities at the Chornobyl NPP site are not carried out, which may lead to the reduction of its reliability, which in turn can lead to equipment failures, emergencies, and accidents.”

Finally, a month into the occupation, a partial shift change was allowed. Workers could go home and rest. But almost immediately, the Russians attacked the nearby worker town of Slavutych, terrorizing the workforce and leaving at least three dead according to press reports.

Some personnel, including security guards, chose to stay on at the site. With good reason, they perhaps feared that the Russian occupying force would behave irresponsibly at a site that houses lethal cargos.

Sure enough, on March 24 stories emerged that Russian forces at Chornobyl may have “looted and destroyed a laboratory near the abandoned Chernobyl nuclear power plant that was used to monitor radioactive waste,” according to CNN and other news sources.

The laboratory, which conducts research into radioactive waste management, houses radioactive materials that may then have fallen into Russian hands.

The State Agency of Ukraine for Exclusion Zone Management, which announced the attack, went further in wishing “the enemy today…will harm himself, not the civilized world.”

And now here we are, just days away from the 36th commemoration of that terrible day in 1986. Still watching. Still waiting. Still holding our breath. The war is neither over, nor won by either side. The Chornobyl site, possibly now more radioactive than in the immediate past, sits like a ticking time bomb. Along with too many unanswered — and unanswerable — questions.

Who will protect it? Will it be spared further assault? And will the word Chornobyl come to mark a new nuclear catastrophe 36 years after the first?

“Chornobyl” is the Ukrainian spelling of the Russian “Chernobyl”.

Linda Pentz Gunter is the editor and curator of and the international specialist at Beyond Nuclear.