War against Ukraine: Europe's largest nuclear power plant forced to switch to emergency generators after losing power

The atomic power plant is the largest of its kind in Europe.

​Ukraine's Zaporizhzhia Nuclear Power Plant spent hours operating on emergency diesel generators after losing its external power supply for the seventh time since Russia's full-scale invasion of its neighbour, the head of the UN nuclear watchdog said.

"The nuclear safety situation at the plant [is] extremely vulnerable," Rafael Grossi, head of the International Atomic Energy Agency (IAEA), said in a tweet.

Hours later, national energy company Ukrenergo said on Telegram it had restored the power line that feeds the plant.

A general view of the Russian-controlled Zaporizhzhia nuclear power plant in southern Ukraine. Picture: Andrey Borodulin/AFP via Getty Images

"We must agree to protect [the] plant now, this situation cannot continue," Mr Grossi said, in his latest appeal for the area to be spared from the fighting between Ukrainian and Russian forces.

IAEA staff are deployed at the plant, which is occupied by Russian troops.

The plant's six nuclear reactors are protected by a reinforced shelter able to withstand an errant shell or rocket. But a disruption in the electrical supply could disable cooling systems essential for the reactors' safety. Emergency diesel generators can be unreliable.

Fighting, especially artillery fire, around the plant, which is Europe's largest atomic power station, has fuelled fears of a disaster like the one at Chernobyl in 1986.

Then, a reactor exploded and spewed deadly radiation, contaminating a vast area in the world's worst nuclear catastrophe.

Energoatom, Ukraine's state nuclear company, blamed Russian shelling for the loss of the last high-voltage transmission line to the plant in Russian-occupied southern Ukraine, about 300 miles from Kyiv.

The facility is "on the verge of a nuclear and radiation accident", Energoatom warned.

Mr Grossi said it was the seventh time the plant had lost its outside power supply since Russia's full-scale invasion in February last year.

The Zaporizhzhia Nuclear Power Plant is one of the ten biggest atomic power stations in the world.

Russian officials have begun training for a planned evacuation from the plant of 3,100 staff and their families, a representative of Energoatom said last week.