Zelenskyy raises alarm about power outage at Zaporizhzhia nuclear plant

Ukraine's president and the head of the UN nuclear watchdog have sounded the alarm about safety risks at the Russia-occupied Zaporizhzhia Nuclear Power Plant (NPP) in southern Ukraine, which lost external power supply more than a week ago as the war continues to rage around it.

Emergency diesel generators are providing power for crucial cooling systems for the facility's six non-operational reactors and spent fuel and there is no immediate danger to Europe's biggest NPP, the International Atomic Energy Agency’s (IAEA) Director General Rafael Grossi said.

But "it is clearly not a sustainable situation in terms of nuclear safety," he said.

The backup generators have never needed to run for so long, Ukrainian President Volodymyr Zelenskyy pointed out.

"The generators and the plant were not designed for this," Zelenskyy said in comments late on Tuesday, describing the situation as "critical".

Zelenskyy blamed Russian artillery for cutting the power line to the Zaporizhzhia plant, but Kremlin spokesman Dmitry Peskov said it was Ukrainian shelling.

Peskov told reporters Wednesday that it was "stupid to accuse the Russian side of shelling the plant it controls."

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

"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," he said in a statement late Tuesday.

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," Grossi said, adding that he was in touch with Russian and Ukrainian officials about how to swiftly reconnect the plant to the grid.

Caught in the crossfire

As Russia's full-scale invasion continues 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 23 September, when its only remaining power line was damaged by military activity about 1.5 kilometres 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.

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 in the earliest days following the invasion of Ukraine on 24 February 2022.

Ukraine has four nuclear plants, though Zaporizhzhia is the only one in Russian hands.

Tensions surrounding the plant's safety have added to broader concerns about the course of the war, which shows no signs of ending after a US-led effort this year to stop the fighting amounted to nothing.