Greenpeace analysis of nuclear power plant vulnerability during military conflict

Greenpeace analysis of nuclear power plant vulnerability during military conflict – Key Findings

Key findings of the Greenpeace analysis are:

● The Zaporizhzhia plant, like all reactors, with hot highly radioactive fuel, requires constant electrical power for cooling even when shut down. When the electricity grid fails and the reactor is in a station black out, there are backup diesel generators and batteries, but their reliability over a longer period of time cannot be guaranteed. There are unresolved on-going issues with the Zaporizhzhia emergency diesel generators, which have an estimated fuel stock on site for only seven days.

● Official data from 2017 reported that at Zaporizhzhia there were 2,204 tons of high level spent fuel – 855 tons of which were in highly vulnerable spent fuel pools. Without active cooling, they risk overheating and evaporating to a point where the fuel metal cladding could ignite and release most of the radioactive inventory.

Zaporizhzhia, like all operating nuclear power plants, requires a complex support system, including the permanent presence of qualified personnel, power, access to cooling water, spare parts and equipment. Such support systems are severely compromised during a war.

● The nuclear reactor buildings of Zaporizhzhia have a concrete containment protecting both the reactor core, its cooling system and the spent fuel pool. However, such containment cannot withstand the impact of heavy munitions. The plant could be hit accidently. It seems unlikely that the plant would be targeted deliberately, given that the nuclear release could severely contaminate neighbouring countries including Russia. Still, this cannot be entirely ruled out.

● In the worst-case scenario, the reactor containment would be destroyed by explosions and the cooling system would fail, the radioactivity of both the reactor and the fuel pool could then freely escape into the atmosphere. This risks making the entire plant inaccessible because of the high radiation levels, which could then lead to a further cascade of the other reactors and fuel pools, each spreading large quantities of radioactivity into different wind directions over several weeks. It could make a large part of Europe, including Russia, uninhabitable for at least many decades and over a distance of hundreds of kilometres, a nightmare scenario and potentially far worse than the Fukushima Daiichi disaster in 2011.

● It takes a long time to bring a power plant in operation into a stage of passive safety which does not require further human intervention. When a reactor is shut down, the residual heat from the radioactivity decreases exponentially, still it remains very hot and requires cooling over a period of 5 years before it can be loaded into concrete dry storage containers which remove their heat through natural circulation of the air outside the container. Shutting down a reactor might progressively decrease the risks over time, but it does not solve the problem.

https://www.greenpeace.org/static/planet4-international-stateless/2022/03/6805cdd2-nuclear-power-plant-vulnerability-during-military-conflict-ukraine-technical-briefing.pdf—