Experts at the International Atomic Energy Agency (IAEA) have been unable to determine what caused a fire at the Zaporizhzhya nuclear power plant in the southern Ukrainian city of Enerhodar.
The fire broke out in the cooling system of the plant on Sunday, with Russia and Ukraine blaming each other for the incident.
The head of the IAEA, Rafael Grossi, said experts accessed the cooling tower area on Monday.
They had assessed that it was unlikely that the primary source of the fire began at the base of the cooling tower, he said.
“During the team’s visit to the cooling tower, it determined that the damage was most likely concentrated on the interior of the tower at the water nozzle distribution level, located at roughly ten metres high.’’
Experts were unable to access the water nozzle distribution level or the base of the cooling tower, due to safety concerns.
Samples of debris, including burnt and molten plastic, had been collected from the site, Grossi said.
“The lingering odour from the fire was assessed by the team and determined that in the absence of a sulphur smell, was more likely caused from burning plastic.
“Neither tyre nor drone remains were observed during the walk down,’’ he said.
According to the Russian version of events, the fire was caused by a combat drone.
Meanwhile on the Ukrainian side the head of the military administration in Nikopol, not far from the contested power station.
It cited unnamed sources as saying the Russians set fire to car tyres in the cooling tower.
Grossi emphasised that the nuclear safety of the plant was not affected, as the cooling towers were not currently in operation.
There were not required as part of the cooling mechanism for the reactors, which were all in a state of cold shutdown.
“The team conducted radiation monitoring in the area of the cooling towers and the reactors and confirmed no signs of elevated radiation levels,’’ he said.
The IAEA would continue its investigations into the fire after additional review and access to the water nozzle distribution level and the cold-water basin, Grossi added.
Russia seized Europe’s largest nuclear power plant shortly after the start of its full-scale invasion of neighbouring Ukraine and has occupied it since then.
Both sides accused each other of attacks on or sabotage of the plant.
Russia had recently complained repeatedly of Ukrainian drone attacks.
Due to safety concerns, the reactors were already shut down in 2022 but still needed to be cooled.
