The International Atomic Energy Agency (IAEA) has reported that the Chernobyl Nuclear Power Plant (NPP) has been disconnected from the grid and has lost power.
The development comes two weeks after Russian forces took control of the site, the agency’s director-general Rafael Mariano Grossi said. He expressed concern at the news, as the “secure external power supply to the grid for all nuclear sites” was one of the seven indispensable pillars of nuclear safety and security outlined by him at a meeting of the IAEABoard of Directors on March 2.
However, the director general said the IAEA agreed with the Ukrainian regulator that the disconnection would not have a critical impact on essential safety functions at the site, where the radioactive waste management facilities are located.
The IAEA said that with regard to the site’s spent fuel storage facility, the amount of cooling water in the basin is sufficient to maintain effective heat dissipation from the spent fuel without electricity supply. The site also has backup emergency power with diesel generators and batteries.
Nevertheless, a lack of power is likely to further deteriorate operational radiation safety at the site and create additional stress for technical experts and security guards who actually “live there around the clock,” Director General Grossi added.
“Day by day we see a deteriorating situation at the Chernobyl nuclear power plant, especially for radiation safety and for the personnel managing the facility under extremely difficult and challenging conditions,” he said.
“I reiterate my urgent appeal to the forces effectively controlling the factory to respect internal radiation protection procedures, facilitate the safe rotation of personnel and take other important steps to ensure safety.”
Commenting on the statement from the IAEA, Professor Claire Corkhill, chair of nuclear material degradation at the University of Sheffield, said there are “several concerns” regarding the safety of nuclear material at Chernobyl, the first being the spent fuel from reactors 1 and 3 stored in the cooling pond.
“This material produces heat through radioactive decay and requires constant cooling, which is achieved by pumping fresh cool water into the ponds. Without a power supply, this water could slowly evaporate, potentially leading to contamination of the building from low levels of radioactive isotopes,” Corkhill said.
“It is essential that radiation monitoring systems are able to constantly monitor the situation in reactor 4 so that we can be aware of potential concerns about the exposed nuclear fuel contained there.
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“Another serious concern is the maintenance of the ventilation system in the New Safe Confinement structure. This prevents further degradation of reactor number 4 and the hazardous exposed fuel contained therein, and is essential for the future decommissioning of the site. If there is no power for this structure, we could see the complete failure of the 1.5 billion euro decommissioning program to make the site safe once and for all.
Director-General Grossi said the IAEA also recently lost remote data transmission from its security systems installed to monitor nuclear materials at the Chernobyl nuclear power plant and another Ukrainian nuclear power plant now controlled by Russian forces, the Zaporizhzhya Nuclear Power Plant.
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He expressed concern about the sudden interruption of data flows to the IAEA headquarters in Vienna from sites where large amounts of nuclear material are present. The reason for the outage was not immediately clear, the IAEA said, adding that it continues to receive such data from other nuclear facilities in Ukraine, including three other power plants.
While there were technical features to ensure data was stored locally, the storage capacity and operational status of the monitoring systems remained uncertain, Grossi said.
Through technical safeguards, the IAEA checks that countries are complying with their legal obligations to use nuclear materials and technology only for peaceful purposes.
University of Bristol materials professor Tom Scott says he agrees with the IAEA that spent nuclear fuel in Chernobyl’s storage ponds does not pose a ‘substantial risk’.
“The fuel in these pools is decades old and therefore very little waste heat is generated,” says Prof. Scott. “This low heat load added to the very large volume of water in the cooling baths means that the heat coming from the fuel can be safely dissipated even without power to circulate the water.”
He added that it is still important that the situation continues to be actively reported to the IAEA, and that any communication disruptions should be repaired quickly.
