Zelenskyy and UN warn of heightened risk at Ukrainian nuclear plant

The plant is under Russian military control (AP)

Ukraine’s president and the head of the UN nuclear agency have warned over increased safety risks at the Russia-occupied Zaporizhzhia Nuclear Power Plant in southern Ukraine, which lost its external power supply more than a week ago as the war raged around it.

Emergency diesel generators are providing power for crucial cooling systems for the facility’s six shutdown reactors and spent fuel, and there is no immediate danger to Europe’s biggest nuclear plant, according to International Atomic Energy Agency (IAEA) director-general Rafael Mariano Grossi.

However, “it is clearly not a sustainable situation in terms of nuclear safety”, he said.

The back-up generators have never needed to run for so long, according to Ukrainian leader Volodymyr Zelenskyy.

“The generators and the plant were not designed for this,” Mr Zelenskyy said late on Tuesday, describing the situation as “critical”.

Zaporizhzhia is one of the 10 biggest nuclear plants in the world, and its fate amid the fighting has caused fears of a potential nuclear catastrophe. Russian forces seized it days after the full-scale invasion of neighbouring Ukraine began on February 24 2022.

The Vienna-based IAEA has been walking a tightrope in the war, eager to maintain access to nuclear facilities and issuing warnings about the dangers without angering either side. Ukraine has four nuclear plants, though Zaporizhzhia is the only one in Russian hands.

Mr Grossi said that Zaporizhzhia’s emergency generators were coping with the extra strain so far.

He added: “The current status of the reactor units and spent fuel is stable as long as the emergency diesel generators are able to provide sufficient power to maintain essential safety-related functions and cooling.”

An IAEA team at the plant reported that it has fuel reserves ensuring the generators can operate for more than 10 days, with regular off-site supplies maintaining this level.

“Nevertheless, it is extremely important that off-site power is restored,” Mr Grossi said, adding that he was in touch with Russian and Ukrainian officials about how to swiftly reconnect the plant to the grid.

As Russia’s invasion churns across the Ukrainian countryside, the Zaporizhzhia facility has repeatedly been caught in the crossfire.

It lost its off-site power for the 10th time during the war on September 23, when its only remaining power line was damaged by military activity about a mile from the plant, the IAEA statement said.

Eight emergency diesel generators are operating, with nine additional units in standby mode and three in maintenance, according to the IAEA.

It said that over the past week, the plant has been alternating those in use and servicing idle generators in an effort to ensure continuous availability.