KYIV, Ukraine — A slow-motion crisis has been unfolding at a giant nuclear power plant in Russian-occupied southeastern Ukraine.
The failure of a high-tension power line in an area of combat is raising the risk of an eventual failure of cooling systems that keep nuclear fuel from melting down in the switched-off reactors at the plant, in Zaporizhzhia.
Since Wednesday, the site has operated on backup diesel power to cool the reactors. While external power to the facility has been cut several times during the war, the current outage is the longest yet.
Russia and Ukraine have differing explanations of why electrical power was lost and why it has still not been restored. Russia says Ukrainian artillery severed the line and renders repairs too dangerous. Ukraine says Russia created the crisis as a ploy to justify connecting the plant to the Russian power grid to restart the facility, despite copious wartime risks.
The power loss poses no immediate risk of a meltdown or an explosion. But it removes another layer of safety measures from a plant already operating on a razor-thin margin for error.
“This situation is critical,” Bruno Chareyron, scientific adviser to the Commission for Independent Research and Information on Radioactivity, a French nonprofit, said of the plant’s operation for days on backup diesel power.
“The problem is, with this war, people get used to it,” he said. “It’s very dangerous that people are used to a situation that is absolutely not normal” for the operation of a nuclear power plant.
When the Russian army invaded Ukraine in 2014 and again in 2022, it advanced into a landscape full of Soviet-legacy nuclear sites, including uranium mines, nuclear research laboratories, the Chernobyl disaster zone and active nuclear power plants. All were put at risk by combat.
But the Zaporizhzhia nuclear power plant has caused perhaps the most alarm. Russian troops fought their way into the plant in March 2022, damaging administrative buildings and striking some equipment with small-arms fire. The plant has been on a front line since. All six reactors were shut down in September 2022.
In 2023, an explosion in a dam drained the plant’s primary source of cooling water, elevating worries about the risk of a meltdown as the site pivoted to drawing water from a smaller cooling pond and wells.
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