A view shows the Zaporizhzhia Nuclear Power Plant
Reuters

The Zaporizhzhia nuclear power plant has enough water to cool its reactors for "several months" from a pond located above the reservoir of a nearby dam that has broken, the U.N. atomic watchdog said on Tuesday, calling for the pond to be spared.

The major Soviet-era dam near the Russian-held nuclear plant in southern Ukraine was breached on Tuesday, unleashing flood waters across the war zone in what both Ukraine and Russia said was an intentional attack by the other's forces.

The dam's reservoir provided water used for the essential cooling of the six reactors at Europe's biggest nuclear power plant as well as of spent fuel and emergency diesel generators that have had to be used repeatedly when external power fails.

"There are a number of alternative sources of water. A main one is the large cooling pond next to the site that by design is kept above the height of the reservoir," International Atomic Energy Agency (IAEA) chief Rafael Grossi said in a statement issued in response to the breach of the Kakhovka dam.

Water from the pond should provide enough cooling water for "some months", Grossi said, adding that his agency would confirm that "very shortly". In a second statement later the IAEA said the pond was full and had enough water for "several months" since the plant's six reactors are currently shut down.

"It is therefore vital that this cooling pond remains intact. Nothing must be done to potentially undermine its integrity. I call on all sides to ensure nothing is done to undermine that," Grossi said.

While Grossi had already been due to visit the Zaporizhzhia plant next week, that visit had now become essential and would go ahead, he said. Russian forces took over the plant shortly after the Feb. 24, 2022 invasion of neighbour Ukraine.

Grossi later tweeted he would lead a rotation of the IAEA staff at Zaporizhzhia with a "reinforced team" - suggesting the number of staff there will increase from a number that diplomats said is now about three.

Although Ukraine had prepared for situations like the dam burst, Grossi said late on Tuesday: "This is making an already very difficult and unpredictable nuclear safety and security situation even more so."