According to the Ukrainian operator Ukrenergo, the power supply to the nuclear site was completely cut off by Russian military actions. The International Atomic Energy Agency has nevertheless confirmed that there is no major safety risk.
A situation described as “abnormal”, but not cause for concern. Just hours after announcing the power outage at Ukraine’s Chernobyl nuclear site, the International Atomic Energy Agency (IAEA) was quite reassuring.
According to the UN agency, the incident that took place early Wednesday morning has “no major impact on security”.
No more active reactors on the site
An overly reassuring tone from the nuclear police officer? Far from there. If the name remains synonymous with concern for Europeans today, Chernobyl is no longer the nuclear site of the time of the 1986 disaster.
“The situation is indeed abnormal,” Ludovic Dupin admits on BFMTV. The spokesman for the French Nuclear Energy Association, however, agrees with the IAEA’s view that “there is no immediate danger as there are no more reactors operating at Chernobyl”.
The factory’s last reactor was actually decommissioned in 2000, and has not been fully functional since. “You shouldn’t call it a power station, you should call it an old power station,” says Dominique Greneche on our antenna. For the nuclear physics physician and international expert, “the risk from a power failure is zero”.
Vigilance at the fuel storage basin
The operator Ukrenergo has indicated that the continuation of hostilities makes it impossible to restore the line at this stage. As a result, the emergency diesel generators took over to “ensure the site’s vital activity for a maximum of 48 hours”.
“After that, the stored fuel cooling systems will stop,” Ukrainian Foreign Minister Dmytro Kuleba warned.
“On the other hand, there is a monitoring facility that is a pool of spent fuel that needs to be cooled,” Ludovic Dupin points out, “so you need an electrical system to cool it.”
The release of radioactive particles is considered “unlikely”
Currently, 20,000 fuel assemblies are stored in the site’s storage pool. However, given the time elapsed since the accident in 1986, “the pool’s heat load and cooling water volume are sufficient to ensure efficient heat dissipation without electricity,” estimated the International Atomic Energy Agency.
“The loss of electricity at Chernobyl is worrying, but it is extremely unlikely that the basins will become empty through evaporation,” James Acton, co-director of the nuclear policy program at the Carnegie Endowment for International Peace, said on Twitter. “This process is slow and mitigation measures should be simple […] in general, the risks in operating Ukrainian nuclear power plants are much greater than in Chernobyl.”
“Even if the emergency diesels run out of fuel, the water is enough to cool the spent fuel so that it does not exceed 70°C,” said Ludovic Dupin, who rejected any risk of releasing radioactive particles. “When it evaporates, the fuel shouldn’t be above 300°C or 1,000 degrees before it starts to melt,” he finally adds.