U.N. warns of reactor crisis risk

Burst dam in Ukraine steadily draining cooling reservoir

KYIV, Ukraine — The largest nuclear power plant in Europe faces “a relatively dangerous situation” after a dam burst in Ukraine and as Ukraine’s military launches a counteroffensive to retake ground occupied by Russia, the head of the United Nations nuclear watchdog said Tuesday.

Rafael Mariano Grossi, the head of the International Atomic Energy Agency, spoke to journalists in Kyiv just before leaving on a trip to the Zaporizhzhia Nuclear Power Plant. The plant has been in the crossfire repeatedly since Russia launched its war on Ukraine in February 2022 and seized the facility shortly after.

Grossi said he met with Ukrainian President Volodymyr Zelenskyy to discuss the perils facing the nuclear plant, which grew more serious after the Kakhovka Dam burst last week. The dam, further down the Dnieper River, helped keep water in a reservoir that cools the plant’s reactors.

Ukraine has said Russia blew up the dam, something denied by Moscow, though analysts say the flood likely disrupted Kyiv’s counteroffensive plans.

Grossi said the level of the reservoir that feeds the plant is dropping “quite steadily” but that it didn’t represent an “immediate danger.”

“If there was a break in the gates that contain this water or anything like this, you would really lose all your cooling capacity,” Grossi said.

Ukraine recently said it hoped to put the last functioning reactor into a cold shutdown — a process in which all control rods are inserted into the reactor core to stop the nuclear fission reaction and generation of heat and pressure.

When asked about Ukraine’s plans, Grossi noted that Russia controlled the plant and it represented “yet again, another unwanted situation deriving from this anomalous situation.” Ukrainian workers still run the plant, though under an armed Russian military presence. The IAEA has a team at the plant.

Asked about the Ukrainian counteroffensive, Grossi said he was “very concerned” about the plant potentially getting caught again in open warfare.

“There shouldn’t be any military equipment or artillery or amounts of ammunition, an amount that could compromise the security of the plant,” Grossi said. “We do not have any indication at this point. But it could not be excluded.”