Ukrainian Nuclear Disaster Scientist Talks Worst-Case Wartime Scenarios

Amid the horrors of the past 39 days of Russia’s all-out war on Ukraine, Olena Pareniuk finds a rare moment of absurd humor.

“I wanted to be the expert in radiation safety, but I didn’t want that much experience,” Pareniuk says, laughing at the thought.

Unfortunately, Pareniuk, 35, has no choice.

As a senior researcher for Ukraine’s Institute for Safety Problems of Nuclear Power Plants, it’s Pareniuk’s job to investigate what happens after a disaster at a nuclear power plant. She’s spent years researching the aftermath of both the 1986 explosion and fires at the Chernobyl Nuclear Power Plant and the extensive damage to the Fukushima Daiichi Nuclear Power Plant in Japan in the wake of a tsunami in 2011.

But after Feb. 24, when Russia launched its massive assault on Ukraine and subsequently took over Chernobyl and shelled Europe’s largest nuclear power plant in the southern Zaporizhzhya region, she’s had new nightmares to ponder along with ceaseless questions about worst-case scenarios that she is tired of thinking about. 

MARCH 10, 2022: Maxar satellite imagery closeup of Chernobyl Nuclear Power Plant in Ukraine., Satellite image (c) 2022 Maxar Technologies.

All this has occurred while Pareniuk has had to also worry about the safety of her family, which includes her husband serving in the Ukrainian military, and her three-year-old son, who has been terrified by the shockwaves of Russian bombardment.

“What is the worst-case scenario for Chernobyl?” she says, repeating a question she is often asked. “What’s the worst-case scenario for Zaporizhzhya and also, Kharkiv? There is a research facility in Kharkiv and Kharkiv is constantly being bombed by the Russians and it’s also a nuclear facility. So people are also asking what is the worst-case scenario for that facility? I don’t want to do that. I don’t want to imagine the worst-case scenarios.”

Pareniuk lost the luxury of not considering future worst-case scenarios on the morning of Feb. 24.

She was at home in Kyiv and, by the time she woke up, Ukraine was abandoning the Chernobyl Nuclear Power Plant ahead of advancing Russian troops.

“I woke up by 7 a.m.,” she said. “There are people who should maintain laboratories and they were over there. So, early in the morning, they were waking up and then they were forced by the Ukrainian army to get on buses, and then they were evacuated from the exclusion zone.”

APRIL 15, 2021 – Employees stay in front of the monitors at the central control panel of the New Safe Confinement at the Chornobyl Nuclear Power Plant (ChNPP), Kyiv Region, northern Ukraine., Volodymyr Tarasov/ Ukrinform/Future Publishing via Getty Images

The ensuing Russian occupation of the plant, the site of the world’s worst nuclear power plant disaster where massive amounts of radioactive materials are still stored, “was really, really, scary because it was obvious they were not following the rules for visiting the exclusion zone,” said Pareniuk.

Russian troops were not wearing protective gear to prevent contamination from radioactive dust. The trucks and tanks and other vehicles they drove through the exclusion zone kicked up so much of the contaminated dust, said Pareniuk, “that our detectors were actually detecting the increase of the dose rate and it was because the Russian machines were lifting up the radioactive dust.”

They cut off the electrical supply needed to cool the water chilling spent nuclear fuel rods and, Ukrainian officials have said, stored vehicles, ammunition, and rocket-launching systems at the site that could have contributed to spreading radioactivity in the event of an accident or conflict. A large amount of the remaining radioactive material is stored in three buildings. 

“If the integrity of these three buildings is injured,” said Pareniuk, “that means that radioactivity may leak into the environment. It might contaminate the soil. There is quite a lot of really highly radioactive dust inside the new system.”

The radioactivity, she said, could also leak into the air, and, depending on the wind direction, contaminate either Ukraine, Belarus, Poland, or Russia. Perhaps even more dangerous for Ukraine, she said, is the potential to contaminate Ukraine’s drinking water supply.

The site sits along the Pripyat River, which runs into the Dnipro River, the main source of drinking water for Ukraine.

“So if it gets into the water, it could cause an ecological catastrophe,” she said.

This map showing the radioactive contamination in the region a decade after the catastrophe at Chernobyl also shows how the plant sits along the main waterway that runs through Ukraine and provides drinking water for millions of people., CIA handbook via Wikicommons

There was also the human and infrastructural toll that took place while Russians, who have since left, occupied both the Chernobyl plant and the nearby town, the site of nuclear research facilities.

The April 1986 accident at Chernobyl was, Pareniuk pointed out, largely the result of a lack of safety culture in the old USSR and mistakes made by employees under duress.

While a normal working shift for those maintaining the plant, now undergoing decommissioning, is about 12 hours, Pareniuk said that Russian occupiers kept about 150 workers in the plant for weeks on end, at gunpoint, in dire conditions. They were forced to sleep on floors and fed poor quality food with no ability to leave.

About 10 kilometers to the east, in the town of Chernobyl, Russians looted research labs, stealing radioactive material and other equipment, smashing much of what was left behind.

“My colleagues spent quite a lot of time and effort in equipping and buying everything for the lab, and they just destroyed it,” Pareniuk said. “So it’s really painful.”

Meanwhile, some soldiers of the National Guard of Ukraine, who were captured by Russian forces during the opening stage of the invasion on Feb. 24, are now believed to be held captive in Russia and Belarus, according to Lyudmyla Denisova, the Ukrainian Parliament Commissioner for Human Rights. In a statement published on her Facebook page, Denisova said that according to the wife of one of those troops, “the prisoners are starving and not given water. At present, nothing is known about their health.”

Such actions, said Denisova, “grossly violates the conditions of the Geneva Convention on the treatment of prisoners of war, in particular Article 26 of the Convention, which guarantees proper food for prisoners of war.” 

Before the Russians left, reports about their troops experiencing acute radiation sickness after digging trenches in the Red Forest rocketed around the world. Pareniuk said she is in the camp of those who don’t buy into that story.

“I would say because they were digging the trenches in the Red Forest, it will pose a danger because if you would do it without protective gear and without a respirator, you would inhale radioactive dust, and it will really increase the probability of the person having cancer,” she said. “It’s not enough to cause acute radiation syndrome.”

While the Russians have left, and the plant is back in the hands of Ukraine and safely operating, there are lingering concerns, said Pareniuk.

In addition to the fear that Russia might launch missile attacks against the facility, Pareniuk said their retreating troops left behind mines in the exclusion zone, making her job of analyzing the lasting fallout of the Chernobyl disaster impossible.

A map of the exclusion zone at a checkpoint near Chernobyl. , Tiia Monto/wikiommons

“I’m just a scientist,” she said. “I’m doing my research. I’m minding my own business and I have quite a lot of sampling points all over the exclusion zone. It’s the beginning of spring, the beginning of the vegetation season. So I would normally start my experiments by now in the forest of the exclusion zone. But the territory is mined and we don’t know how to take care of all of those mines on the territory.”

The Ukrainian military, she said, has issued warnings.

“They said please don’t go to the forests. You can use this route. And that’s it. So just please be very careful. And we were warned and my colleagues who work in the territories that were mined probably will have to wait for military professionals to get there.”

Pareniuk said she likely won’t take any chances.

“Probably I will skip the season,” she said.

As troubling as the Russian occupation of Chernobyl was, Pareniuk said the attack on the Zaporizhzhya Nuclear Power Plant, the largest in Europe, presented an even greater danger.

“I was woken up at 1 a.m. by my friend who’s also the official and she was calling me and she said ‘you know, they’re shooting a missile at a working nuclear power plant.’ So it was probably the most terrible couple of minutes in my life,” said Pareniuk. “Nuclear power is not just a toy, and it’s not something that you use for nuclear terrorism. So we shouldn’t play with this because we were already trying to take care of the Chernobyl accident and also to take care of the Fukushima accident. We don’t want people to cause another nuclear accident.”

After that call, “I was just sitting in the armchair shaking and reading the news and also reading some messages from my friends for a little bit more,” she said.

Luckily, she said, the Russians hit the first unit at Zaporizhzhya, which was a maintenance building, not any of the reactors or fuel rod storage facilities.

Still, the idea that Russians would fire into a nuclear power plant was impossible to fathom, especially given the history of Chernobyl.

“They were shooting at a working nuclear power plant with a cannon,” she said. “I wouldn’t believe it. If aliens landed on my lawn, It would be okay for me, but I would never, ever believe if someone would tell me that here in Ukraine, in the former Soviet Union, someone would just shoot. We’ll just take a tank and shoot into the working nuclear power plant because, you know, here in the former Soviet Union, we have this history of Chernobyl. All of us are affected by Chernobyl. All of us know people who got the sickness, who died because they were affected by Chernobyl and I have no idea how can you even imagine doing something like that?”

Pareniuk, who was born a year after the Chernobyl disaster and spent two years researching the effects of the Fukushima Nuclear Power Plant disaster, said her training quickly kicked in.

“My friend was asking me can you please estimate the consequences if we will have the explosion in Zaporizhzhya,” she said. “So I was just sitting there and trying you know, to calculate the consequences. I was checking the wind direction. I was checking the weather because it’s really affecting the distribution of the radioactive material. Yeah, I was trying to prepare for a nuclear accident.”

Though there was no damage to the nuclear power facilities, and no radiation leaks, Pareniuk said she is breathing no sighs of relief. As long as Russian troops occupy the facility, the dangers at Zaporizhzhya will not go away.

“Russian troops are still there and we are still expecting that nuclear accident,” she said.

Six power units generate 40-42 billion kWh of electricity making the Zaporizhzhia Nuclear Power Plant, the largest nuclear power plant not only in Ukraine, but also in Europe, Enerhodar, Zaporizhzhia Region, southeastern Ukraine, July 9, 2019., Dmytro Smolyenko/Future Publishing via Getty Images

While Russians claim they are not interfering and are even letting workers take normal shifts, Pareniuk says the same concerns about overwhelming pressure increasing the chances for a deadly mishap still exist.

“People are working under constant psychological pressure, because it’s impossible again, to work in a normal way when you know that there are armed people in the facility and that there are some people with guns who might be shooting into your family,” she said.

There are other nuclear power plants in Ukraine. All told, six of them are now under Russian control and nine others are still in Ukrainian hands. Pareniuk worries that those facilities could come under attack. There is also concern about the Kharkiv Institute of Physics and Technology, which Ukraine officials say contains nuclear materials and an experimental reactor. Russian troops fired on that facility three times last month, according to authorities in Ukraine.

“They bomb our cities,” she said. “They could easily bomb a nuclear power plant. I mean, even if it’s not Zaporizhzhya, they could bomb South Ukrainian Nuclear Power Plant. They could bomb Rivne. Even here in Chernivsty is about almost near the border with Romania and we have constant air raids here, so we have to hide in the basement.”

Despite not wanting to think about worst-case scenarios, Pareniuk said she can’t help it.

“Of course I do,” she says with a laugh. “It’s my job.”

Then she ran down some of those scenarios.

“The worst-case scenario for the Zaporizhzhya Nuclear Power Plant is a nuclear explosion,” she said. “In that case, all of Europe will be contaminated. We will have an exclusion zone, in Europe. In Turkey. Everywhere.”

Rafael Grossi, Director General of the International Atomic Energy Agency (IAEA), points on a map of the Ukrainian Zaporizhzhia nuclear power plant as he informs the press about the situation of nuclear power plants in Ukraine during a special press conference at the IAEA headquarters in Vienna, Austria on March 4, 2022. , JOE KLAMAR/AFP via Getty Images

While “highly unlikely” to occur, such a disaster could be touched off by a couple of factors, she said. One is if the Russians shot a missile at one of the working units. Another is if a nuclear operator makes a mistake because of the psychological pressure.

“If this guy would push the wrong button, it might, you know, bring us the Chernobyl scenario,” she said. “Of course, the reactors we have at Zaporizhzhya are much, much safer than Chernobyl, but I mean, it’s a nuclear reactor.”

And the worst case in Chernobyl, should the facility be hit by a Russian missile?

“I will be greedy now,” she said. “Ukraine was building the new safe environment for like 15 years. It’s a really complicated building. And it costs like a couple of billions of dollars. And we don’t really want anyone to destroy it.”

But, if it were destroyed, “there will be dust in the air and then it will depend on the wind direction. It can take it to the territory of Ukraine, it can take it to the territory of Russia. So it depends on the wind.”

And then there is concern about the radioactive dust contaminating the Pripyat River and contaminating the Dnipro River.

The difference in the worst-case scenarios for Zaporizhzhya and Chernobyl is one of timing and intensity, said Pareniuk.

“In the case of Zaporizhzhya, the worst-case scenario will be immediate,” she said. “There would be an explosion and then, in a couple of days, we will have the contamination of large territories in the northern hemisphere.”

A disaster at Chernobyl would take longer to wreak havoc.

“In Chernobyl, in a really worst-case scenario, we will have the contamination of Dnipro and this contamination will be distributed. Not that fast. It will be quite slow, but then again, it’s radiation. You cannot smell it. You cannot see it. It would be really difficult even to detect this distribution of contamination. If our drinking water will be contaminated, the disease rate and the amount of cancer cases in our population will of course increase.”

Map of nuclear reactor sites in Ukraine.,

Pareniuk’s work to assess the ongoing fallout of the Chernobyl disaster and the potential of future ones comes as she tries to comfort a toddler deeply frightened by the sights and sounds of war.

After Russia launched its attacks, Pareniuk said the family packed up and moved out of Kyiv, to her parent’s home in Zhytomyr.

“It was very scary,” she said. “We packed everything. We took our cat. We took our friends. And usually, it takes us about like one and a half hours from our house in Kyiv to our house in Zhytomyr, but that time, it took us about eight hours to drive. And I was trying to give some food and some water to my son and then we just realized that we didn’t eat and we didn’t drink anything. And then we decided that you know, it’s healthy to drink water. so we should drink.”

It took a while, said Pareniuk, for the shock of escaping from Russia’s attack on Kyiv to wear off.

“It was very difficult to speak to each other,” she said. “You are not speaking. I mean, of course, you need to communicate with people. You’re like asking, ‘can I have a glass of water?’ Or ‘we should go to sleep now.’”

The stay in Zhytomyr, however, was short-lived.

Her primary school, where she spent 11 years studying as a child, was destroyed by aerial bombardment. It was just 500 meters from where she was staying.

“I felt the house shaking,” she said. “The windows were shaking. So I took my son, and he was so scared. He was just, you know, holding me and he wasn’t speaking. He just started to speak. And he was asking me, ‘just please, hold me and don’t let me go.’ So I was hugging him for a night and then in the morning, we decided that we needed to go to Chernivsty. So of course it’s not that scary as living in Kyiv or living in Mariupol or living in Kharkiv, but I got enough of it. My son started laughing only after probably a couple of days after we came here.”

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Howard Altman

Senior Staff Writer

Howard is a Senior Staff Writer for The War Zone, and a former Senior Managing Editor for Military Times. Prior to this, he covered military affairs for the Tampa Bay Times as a Senior Writer. Howard’s work has appeared in various publications including Yahoo News, RealClearDefense, and Air Force Times.