U.N. Nuclear Official Visits Zaporizhzhia Plant to Assess Safety

Rafael Mariano Grossi, the director general of the International Atomic Energy Agency, visited the Zaporizhzhia Nuclear Power Plant on Thursday after the destruction of a dam in southern Ukraine that compromised a key source of water used to cool the plant’s reactors.

But Mr. Grossi said that there was currently enough water in a cooling pond to ensure the plant’s safety, at least for the time being. In a serious of video clips posted on Twitter shortly after his visit, Mr. Grossi could be seen standing in front of that pond, which had been a major concern after the Nova Kakhovka dam was destroyed last week.

“One of the most serious consequences of the destruction of the Nova Kakhovka dam has been the decrease in the level of water which is needed to cool the nuclear power plant behind me,” he said, adding, “With the water that is here the plant can be kept safe for some time.”

Mr. Grossi and a team from the I.A.E.A., the United Nations’ nuclear agency, arrived at the Russian-occupied power plant earlier on Thursday. It lies near the front line and inside territory controlled by Russian forces and there have long been concerns about maintaining the safety of nuclear reactors caught in the middle of active battle.

Before his visit, Mr. Grossi said that he would cross the front line to investigate conditions at the plant and spend several hours touring the facility. His trip was delayed slightly because of safety concerns.

Like other nuclear power plants, the Zaporizhzhia plant is designed to be resilient but has come under fire numerous times during the war. The most recent concerns arose last week when the destruction of the Kakhovka dam on the Dnipro River caused water to drain from a reservoir that feeds a giant pond at the nuclear facility.

Water from that pond is used to cool the power plant’s reactors to avoid a meltdown, as well as spent fuel, so part of Mr. Grossi’s visit, he said, was to assess the water levels in the pond and how quickly the supply to it could be restored.

Estimates of how long existing water in the pond could last have varied. On Tuesday, Mr. Grossi said that there “could be water for a few weeks or maybe a month or two.” After visiting the site on Thursday, he did not immediately give a clearer assessment of the time frame.

The visit was the third by the I.A.E.A. team, led by Mr. Grossi, to the Zaporizhzhia plant since the start of Russia’s full-scale invasion of Ukraine in February 2022. As he and his team departed the site, clambering over the segments of a destroyed bridge that mark the line between Ukrainian and Russian forces, Mr. Grossi recorded another video update.

“We believe that we have gathered a good amount of information for an assessment of the situation,” Mr. Grossi said in the video. “And we will continue permanently monitoring the situation there in order to help prevent a nuclear accident.”

An additional concern had been the precise depth of the water remaining in the Kahkovka reservoir itself, which has been rapidly draining since the dam was destroyed. Before he arrived at the plant, Mr. Grossi said that there was a discrepancy between water level readings taken at a thermal power plant near the reactors and measurements taken in the reservoir itself. Knowing the water depth matters for calculations about how best to resupply the cooling pond.