The International Atomic Energy Agency has lost contact with the data systems of Ukraine’s Chernobyl power plant, which, despite being closed since 2000, has remained without power due to the presence of Russian forces. This undermines the guarantee of a constant energy supply for this type of installation and is of concern for the security of the nuclear materials stored inside.
“Ukraine informed the International Atomic Energy Agency (IAEA) of the blackout at the Chernobyl nuclear power plant. Rafael Mariano Grossi – director of the IAEA – indicates that the event violates a key security pillar on guaranteeing an uninterrupted energy supply. In this case, the IAEA sees no critical safety impact”.
This is the message that the IAEA tweeted this Wednesday, followed by another where it indicates that “the heat load of the spent fuel storage pool and the cooling water volume of the Chernobyl nuclear power plant are sufficient to remove heat efficiently without requiring a power supply”.
Of the seven fundamental pillars of nuclear security recently presented by Grossi, the Russian occupying forces in Ukraine had already failed two at the Zaporizhia plant (working without external pressure and reliable communications), and now at Chernobyl, they violate a third: “guarantee the external power supply from the grid for all nuclear sites”.
Professor Geraldine Thomas, from Imperial College London and director of the Chernobyl Tissue Bank, stressed: “Since the Chernobyl power plant has been closed since 2000, the spent fuel rods stored there have been refrigerated for 22 years. Therefore, they will not produce significant amounts of heat, making radiation release highly unlikely.”.
“In the unlikely event that this happens – he adds – it would only affect the most immediate local area, so it would pose no threat to Western Europe: there would be no radioactive cloud. The factory workers are a highly skilled group of people, and the greatest threat to their well-being is lack of food and rest, as a result of being prevented from leaving the factory, rather than radiation”.
For his part, Mark Wenman, professor of nuclear materials also at Imperial College, recalls that the last unit of the Chernobyl reactor was closed more than 20 years ago and units 1 and 2 between 1991 and 1996, “which means that the heat produced by the fuel in the storage pools will have been significantly reduced over a period of 20 to 30 years”.
“Also, the fuel storage tanks are very deep and it will probably take weeks for the water to calm down, even without the cooling pumps working. Also, we hope there will be enough time for power to the cooling systems to be restored.“says the expert.
Loss of communication with the central
In any case, Wenman considers it to be a “disturbing fact” and also “Disturbingly, the IAEA’s communications with headquarters have been lost, making it much more difficult to get up-to-date information on the situation. Fire is another risk to the plant in general, but this is less of a concern because the worst radioactivity is in the fuel, which is protected by being underwater.”.
Professor Claire Corkhill, Professor of Nuclear Material Degradation at the University of Sheffield (UK) adds: “In the absence of electricity supply available at the Chernobyl site, the security of the nuclear materials stored there raises several concerns. Spent nuclear fuel generates heat through radioactive decay and requires constant cooling, which is achieved by pumping fresh water into the ponds. Without electricity, this water could slowly evaporate, potentially leading to contamination of the building with low levels of radioactive isotopes.”.
“It is essential that radiation monitoring systems are able to continuously monitor the situation inside Reactor 4 so that we can be aware of any potential issues with the exposed nuclear fuel residing there.“, he underlines.
“Another serious concern is the maintenance of the ventilation system in the structure called the New Safe Sarcophagus.“, according to Corkhill, “this prevents further degradation of Reactor Number 4 and the hazardous nuclear fuel exposed within, and is essential for the future decommissioning of the site. If this structure is not supplied, we could witness the total failure of the dismantling program of 1.5 billion euros to permanently secure the site.”.
Mark Foreman, professor of nuclear chemistry at Chalmers University of Technology in Sweden, points out that by cutting the power lines to Chernobyl, the site will have to rely on its own generators, which will have a limited supply of diesel or gas. Considers the event to be much less serious than the power outage on the site which caused the Fukushima nuclear accident.
“Although the fuel in the rafts must be kept cold, the last Chernobyl reactors were shut down years ago, so the heat generation in the spent fuel stored in their rafts will be much lower than that of the fuel in the Fukushima reactors, which have been in operation very recently. I think that, although it is important to prevent the cooling ponds from drying out, the consequences of them drying up would be much less than the Chernobyl accident of 1987 or the more recent one in Japan.“, it is said.
Foreman thinks the drying up of the ponds will pose a greater threat to workers than to the general public:Additionally, the loss of ventilation will reduce the site’s ability to manage radioactive dust and protect employees, and I strongly suspect that conditions for employees will deteriorate. They may find it much more difficult to enter certain areas without full protective clothing and have a harder time putting them on and taking them off. Parts of the work may be out of reach of workers until power is restored”.