Chernobyl Experts Say Russia Could Set Off a Nuclear Disaster

Before Russian troops crossed the border into Ukraine last month, Olena Pareniuk and Kateryna Shavanova worked at Chernobyl studying microorganisms in the exclusion zone and those living in the radioactive lava inside the site’s collapsed No. 4 reactor. Both are currently in Ukraine (Shavanova is in Kyiv while Pareniuk is near Chernivtsi). Writing together, they corresponded with TIME earlier this week about the dangers that Russian military activity poses to Chernobyl and the country’s nuclear infrastructure, and the possible consequences of an accident. This conversation has been condensed and edited for length and clarity.

What are the current risks at the Chernobyl site?

The vital need is to rotate the staff of the Chernobyl nuclear power plant. The staff, who are still at the Chernobyl nuclear power plant, came in on February 23. The enemy has not allowed any opportunity to change the staff, who are psychologically and physically exhausted due to the lack of rotation and the constant pressure caused by armed people. This can lead to loss of control over the safety of the facility and the inability to respond to internal and external initial events such as fire, which in turn can lead to severe radiation effects.

In addition, the connection with the automated control system and the accurate data on the radiation status of the Chernobyl nuclear power plant has been lost. From 11:22 on March 9, 2022, there has been no electricity supply at the Chernobyl plant. According to plant’s management, an additional supply of diesel fuel for diesel power plants has been delivered to the site, providing emergency power supply for spent nuclear fuel storage facilities, as well as the New Safe Confinement facility. On Monday Ukrainian staff managed to restore electricity supply, but on Tuesday there were interruptions again. The main risk of the Chernobyl Exclusion Zone is not radiation, but Russian troops.

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What is the worst case scenario at Chernobyl?

In case of a complete power outage, there is a risk of disabling the safety of important systems and equipment, in particular: ventilation, heat dissipation, technological, and radiation control systems. The possibility of remote control over nuclear and radiation safety indicators at storage facilities, the New Safe Confinement facility, and other facilities will be lost. Operators will be unable to control the level and temperature of water in spent nuclear fuel storage pools.

There are long-lived radionuclides in the spent nuclear fuel storage, which in case of an accident can get into the Kakhovka Reservoir, and further along the Dnipro river into the Black Sea. A huge area would be contaminated by radiation for thousands of years. If there is an accident with one power unit or one container for spent fuel, depending on the direction of wind the radioactive cloud will affect Russia, Bulgaria, Greece, Romania, and other border countries.

What are the risks to Ukraine’s other nuclear reactors?

Zaporizhzhya power plant and the city of Energodar are still under the control of Russian military units. There haven’t been changes to the condition of power units: two units are working, two power units are under repair (№ 1 and № 6), the rest are stopped. There are seven nuclear sites at Zaporizhzhya: six nuclear power units and a spent nuclear fuel storage facility are equivalent to about 20 Chernobyls! This is a huge amount of nuclear material, which is now out of [Ukraine’s] control, [and] even of the International Atomic Energy Association. This is a danger not only for Ukraine, but to nearby countries. Other Ukrainian nuclear power plants are under Ukraine’s control, but the country is at war and the situation is changing very quickly.

What is the likelihood of a major nuclear incident due to the fighting?

Right now, Chernobyl and Zaporizhzhya are under direct threat. Russian troops continue to grossly violate the requirements of radiation safety and security, which worsens the radiation situation and contributes to the spread of radioactive contamination outside the Chernobyl Exclusion Zone. Destruction of the Chernobyl confinement structure in case of the explosion is highly probable and may lead to the release of highly radioactive dust into the environment.

At Zaporizhzhya, the threat depends on the direction of the wind at the time of the possible accident. During the recent fighting, the wind blew to the southeast, towards Crimea, Melitopol, Rostov, Turkey, the Black Sea. And the Black Sea connects with the Mediterranean, and therefore, radioactive contamination in case of an accident will spread throughout the basin and harm many more countries.

The problem is that the accident at the Zaporizhzhya nuclear power plant [ZNPP], if it happens, may be quite different from what happened at Chernobyl. The construction of reactors at ZNPP is much safer than at Chernobyl, but the Chernobyl accident was addressed by the entire Soviet Union. Now, in the conditions of hostilities, the elimination of the accident will be complicated, and Ukraine simply does not have the resources to do it. We will not even discuss the risks of disrupting the integrity of the Zaporizhzhya reactors—because these are six power units, and each of them can do as much damage as Chernobyl, polluting the air of the entire Northern Hemisphere.

It is impossible to predict in any way how events will move forward. Russians are crazy, violating all international agreements. No one with common sense will enter the territory of a nuclear plant with artillery weapons. For us, as experts who helped overcome the consequences of the Fukushima accident, such behavior does not even fit into our understanding of the world. For us, it’s as if the river flowed up in the sky by itself or the sky turned orange. Anything can happen [with] those who have a diseased brain. This nuclear material can fall into anyone’s hands and anything can be done with it.