IAEA chief welcomes cold shutdown of all Zaporizhzhia nuclear plant reactor units

A view of the Zaporizhzhia Nuclear Power Plant from the bank of Kakhovka Reservoir near the town of Nikopol in Ukraine. Reuters

The safety of the Russian-controlled Zaporizhzhia nuclear power station in Ukraine remains fragile, but the change to a cold shutdown of all six reactor units, accomplished on Saturday, is a good development, according to the UN nuclear watchdog director.

Drones attacked Zaporizhzhia, Europe’s largest nuclear power station, on Sunday, damaging a reactor building in the deadliest such incident since November 2022, but nuclear safety was not jeopardised, according to the International Atomic Energy Agency.

According to IAEA Director General Rafael Grossi, with the conclusion of the winter heating season in adjacent Enerhodar, where the majority of plant personnel reside, unit 4 was transferred from hot shutdown on Saturday, putting “all six reactor units” to cold shutdown for the first time since late 2022.

“I welcome this development which has been recommended by the Agency for some time, as it enhances the overall safety of the facility,” Grossi’s statement said.

Cold shutdown allows for an “additional response margin of several days before the cooling of the nuclear fuel in the reactor might be challenged,” he added.

The reactor would also need less cooling water than in hot shutdown, he said, an issue that grew more challenging following the destruction of the Kakhovka Dam in June.

However Grossi said the situation at the nuclear plant remained “extremely fragile,” noting a team of IAEA experts had heard 16 rounds of outgoing artillery fire in less than half an hour on Saturday, and several drone strikes had targeted the facility over the past week.

The cold shutdown did not address the “fundamental issue of a recent sharp deterioration of the situation at the plant,” he said. “Without a doubt, nuclear safety and security at this major nuclear facility remains very precarious.”

Moscow and Kyiv have repeatedly accused one another of targeting the plant since Russia seized it weeks after it invaded Ukraine. Both countries requested an emergency meeting of the IAEA’s Board soon after Sunday’s attack.