ENS Expert Explains What’s Going On In Chernobyl

Prof. Dr. Attila Aszodi (Budapest University of Technology and Economics, Hungary) explains in his blog the possible consequences of the recent loss of electricity supply in Chernobyl, Ukraine.


A continuous electricity supply of nuclear power plants is vital.

This also applies to shut-down reactors, given that the spent fuel that has been irradiated contains radioactive material, the decay of which generates heat, and this heat must be removed continuously. If this is not ensured, the spent fuel may overheat after a period of time depending on its decay power and cooling conditions, which could damage it and release radioactive material into the environment.

Another reason for the need for a continuous supply of electricity is that it is essential to monitor the processes inside the nuclear installation, and this is only possible if the measurement systems and the visualisation of the measurements can be kept operational.

Communication channels between operators and between operators and the authorities also need to be maintained, which also requires electricity.

These aspects make it essential to have a continuous electricity supply to the installations.

On 9 March 2022, reports from the Chernobyl site indicated that the connection to the external electricity grid had been lost, and that power to the facilities could only be supplied by the emergency diesel generators. According to the Ukrainian operator, these have a reserve of 2 days of diesel fuel. Some sources have predicted that after 2 days, this could result in a large radioactive release. However, the International Atomic Energy Agency has said that there is no immediate emergency and that months are available.

What we can really expect?

This can be assessed from the information released by Ukrainian Authorities in the so-called European stress test following the 2011 Fukushima accident. This Ukrainian report states that the interim storage facility for spent fuel at Chernobyl, the so-called ISF-1 facility, can ‘survive’ for about 2 months without active cooling – i.e. it is guaranteed to keep the fuel under water. This is a plausible figure.

Continue reading more on Prof. Aszodi’s blog “chainREACtion”.