Kiev warns that Russian soldiers may have planted explosives on two power plant blocks at the Zaporizhia nuclear power plant. The IAEA wants to investigate the suspicion. An explosion could release radioactive radiation.

In the first few months of the Russian occupation of the Zaporizhia nuclear power plant in spring 2022, the Ukrainian operator Energoatom reported that the Russian army had probably mined the site. After the dam wall of the neighboring Kakhovka reservoir was destroyed in early June – presumably by the Russian army – Kiev announced that the occupiers had also mined the power plant’s cooling pond. Now the Ukrainian general staff has warned that Russian soldiers have also attached “explosive device-like objects” to two blocks of the nuclear power plant.

The International Atomic Energy Agency (IAEA), on the other hand, reported at the end of June that it had found no signs of mines or other explosives at the nuclear power plant. Now IAEA Director General Rafael Grossi has stated that experts from the agency needed access to other areas of the nuclear plant for a more thorough inspection to rule out the possibility that explosive devices could be attached there.

Weak point cooling system

Ukrainian nuclear safety expert Olha Kozharna emphasizes that mining important areas of cooling poses a direct threat to the power plant. The water in the cooling pond plays a crucial role in this. It is used to cool the fuel elements in the reactors so that they do not melt due to overheating.

The six units of the Zaporizhia NPP have not been in operation since last autumn. Five of them are in a cold shutdown. Dmytro Humenyuk from the Center for Nuclear and Radiation Safety of Ukraine explains that the reactors still have to be cooled because the fuel elements continue to give off heat, but the water can no longer evaporate. However, if the cooling system were to be destroyed and the water drained away, according to the experts, an accident would occur after eight days.

The sixth reactor, however, is in hot shutdown, here the cooling water can reach up to 280 degrees and would quickly evaporate in the event of a leak. Then, according to experts, there were only 27 hours to prevent the radiation from escaping. I think all this – all this blackmail and threats – is happening to stop the counter-offensive of the Ukrainian army in this region,” says Olha Kozharna.

Fukushima scenario in Zaporizhia?

A blast in any part of the cooling system at the Zaporizhia NPP could trigger a Fukushima-like scenario, experts say. In 2011, as a result of an earthquake and subsequent tsunami flooding, the cooling of three reactors at the Japanese nuclear power plant was interrupted. This resulted in a core meltdown and the release of nuclear radiation.

“An evacuation zone was then created, which people had to leave. But three years later, they returned due to low levels of radiation, and now only a third of that zone remains,” explains Mark Zheleznyak, professor at Fukushima University’s Institute of Environmental Radioactivity (IER).

Zheleznyak considers the potential danger in Zaporizhia to be smaller than in Fukushima: “There would be no radiation catastrophe because radioactive iodine cannot be released in a switched-off unit,” emphasizes the scientist and advises not to panic and not to Buy potassium iodide tablets, which are designed to protect the thyroid from radioactive iodine.

2.5, 20 or 550 kilometers radius affected?

The Center for Nuclear and Radiation Safety of Ukraine has published two scenarios for a possible accident at the nuclear power plant. In the first, the reactor’s one meter thick protective shell remains intact and only the equipment underneath melts.

This could happen if the power went out completely or the cooling system was damaged. According to the scientists, in such a scenario, an area of ​​2.5 kilometers around the nuclear power plant would be exposed to radiation. “This would basically only affect the personnel of the power plant. In this case, people should only stay outdoors within a protection zone. Iodine prophylaxis is not necessary,” says a statement from the center.

The other scenario would be a reactor accident with a damaged containment. “In this scenario, radiation exposure will affect a larger area and have worse consequences. The area of ​​contamination depends on weather conditions,” the center explains.

According to calculations by Ivan Kovalets, an expert in environmental informatics from the National Academy of Sciences of Ukraine, an area of ​​up to 20 kilometers around the power plant could be affected by serious consequences, depending on the wind strength and direction. “In this case, immediate evacuation of people is required,” said the expert.

But even in areas up to 550 kilometers away from the power plant, there could be certain consequences for people’s health. “But at such distances, there is no need for immediate countermeasures or evacuation,” Kowalez said.