The world’s nuclear safety watchdog has lost contact with the captured Zaporizhzhia power plant in Ukraine, just hours after warning of a potential disaster in Chernobyl.
The International Atomic Energy Agency (IEAA) said it was unable to access data from systems installed at both plants to monitor nuclear material after they were seized by Russian forces.
Ukraine has 15 nuclear reactors, eight of which were operating as of Wednesday. The Zaporizhzhia plant is the largest of its kind in Europe.
Russian forces shelled the plant last Thursday, sparking fears of a “nuclear catastrophe”.
Security footage from the site showed a blaze breaking out in one of the buildings, prompting alarm across the world before the fire was extinguished and officials said the facility was safe.
Radiation levels around the plant remain normal while repairs are being carried out on a block damaged by fighting with Russian troops, authorities said.
In a statement, IAEA chief Rafael Grossi said he was “concerned about the sudden interruption of such data flows to the IAEA’s Vienna headquarters from the two sites, where large amounts of nuclear material are present in the form of spent or fresh nuclear fuel and other types of nuclear material”.
It was not clear what had caused the disruption, the IAEA said, adding that transmissions from other nuclear facilities in Ukraine, including its three other operational nuclear power plants, were continuing.
The status of the equipment that had stopped transmitting was "uncertain", it said.
Ukraine’s national security service last week accused Russian forces of firing rockets at a physics institute in the city of Kharkiv that contains nuclear material and a reactor.
They warned that a strike on the nuclear facility could lead to “large-scale ecological disaster”.
The US and its western allies have heavily criticised Russia over its shelling of the plant, with 15 envoys at the United Nations (UN) expressing “grave concern” and shock.
Linda Thomas-Greenfield, the US ambassador to the United Nations, said last Saturday that nuclear facilities “cannot become part of this conflict”.
She added: “Reliable electricity is vital for the nuclear facility, as are back-up diesel generators and fuel. Safe transit corridors must be maintained.
“Russia must halt any further use of force that might put at further risk all 15 operable reactors across Ukraine – or interfere with Ukraine’s ability to maintain the safety and security of its 37 nuclear facilities and their surrounding populations.”