When Russia first occupied the Zaporizhia nuclear power plant in early 2022, Ukrainian operator Energoatom reported that Russian forces had likely mined the site. After the nearby Kakhovka Dam was destroyed in early June – allegedly by Russian forces – Kiev announced that Russia had also planted landmines in the power plant’s cooling ponds.
Military forces in Ukraine are now warning that Russian soldiers are also said to have attached “explosives-like objects” to two blocks of the power plant.
At the end of June, the International Atomic Energy Agency reported that it had found no evidence of mines or other explosives in the power plants. IAEA Director-General Rafael Mariano Grossi has announced that agency experts now need access to more parts of the plant to conduct a more thorough inspection and rule out the presence of explosives.
The cooling system is Zaporizhia’s weakest point
Olha Kosharna, a Ukrainian nuclear safety expert, has stressed that the placement of landmines in key cooling segments poses a direct threat to the power plant. She added that the water in the cooling pool plays a crucial role in cooling the fuel rods in the reactor, preventing them from overheating.
Nikopol is doubly threatened by the Zaporizhia nuclear power plant
This browser does not support the video element.
The Zaporizhia nuclear power plant consists of six units that have been out of service since last autumn. Five blocks are in “cold shutdown” – a state in which they no longer generate electricity.
Dmytro Humeniuk of Ukraine’s State Scientific and Technical Center for Nuclear and Radiation Safety explained that while the reactors still need to be cooled because the fuel rods are still giving off heat, the water cannot evaporate. If the cooling system were destroyed, water could leak out, and the expert estimated that a nuclear accident would occur within eight days.
According to experts, the sixth reactor is still in a “hot shutdown”, in which power plant blocks generate thermal electricity – although the IAEA had already ordered the cold shutdown four weeks ago. In this case, the cooling water can reach a temperature of 280 degrees Celsius and would evaporate in the event of a leak. That would give experts just 27 hours to prevent radiation from escaping.
“I think all these blackmails and all these threats serve to stop Ukraine’s counter-offensive in the region,” Kosharna said.
Is a disaster like Fukushima possible?
Experts believe an explosion in any part of Zaporizhia’s cooling system could lead to a disaster like the one in Fukushima, Japan. In 2011, an earthquake and subsequent tsunami disrupted the cool-down sequence of three reactors at the Fukushima Daiichi Nuclear Power Plant, resulting in a nuclear meltdown that released radiation.
“An evacuation zone was then set up, which people had to leave. They returned three years later because of the low radiation, and now the zone has been reduced to a third,” said Mark Zheleznyak, visiting professor at the Institute of Environmental Radioactivity at Fukushima University.
Zheleznyak assumes that the risk potential in Zaporizhia is lower than in Fukushima. “There wouldn’t be a radiation catastrophe because a shutdown block can’t emit radioactive iodine,” he said, advising against panicking and buying iodine tablets, which are designed to protect the thyroid from radioactive iodine.
How much of the area is at risk?
The Ukrainian Center for Nuclear and Radiation Safety has developed two possible scenarios in the event of a nuclear accident at the Zaporizhia nuclear power plant.
In the first scenario, the reactor’s 1 meter thick protective shell remains intact while the underlying equipment melts. This can happen if the power fails completely or the cooling systems are damaged. Experts estimate that in such a scenario, an area of about 2.5 kilometers around the power plant would be contaminated with radiation.
“Basically, only personnel working at the power plant would be affected,” the center said in a recent statement, adding that those individuals would have to leave the area. “Iodine prophylaxis is not necessary.”
‘The world needs to do something’: Nuclear power plant workers
This browser does not support the video element.
The other scenario assumes a nuclear accident with a damaged containment. “In this scenario, the radiation would affect a much larger radius and have far more serious consequences. The contaminated area would depend on weather conditions,” the center explained.
Ivan Kovalets is an environmental modeling expert at the National Academy of Sciences of Ukraine. He calculated that, depending on wind strength and direction, an area of up to 20 kilometers around the nuclear power plant could be severely affected.
“In that case, an immediate evacuation would be required,” Kovalets said. Even people living up to 550 kilometers from the power plant could be exposed to health risks. “However, at such distances there is no need for immediate countermeasures or evacuations,” he added.
This article was originally published in German.