Chernobyl site running on backup power supply

Ukrainian government officials said Wednesday that damage by Russian forces had left the defunct Chernobyl nuclear power plant “disconnected” from outside electricity, leaving the site of the worst nuclear accident in history dependent on power from diesel generators and backup supplies.

The International Atomic Energy Agency (IAEA) said Wednesday that there was no need for immediate alarm over the condition of the decommissioned plant, where workers have safeguarded nuclear waste since the Chernobyl disaster of 1986. But officials said the situation around the site remained a source of grave concern.

Russian troops have occupied the facility since the early days of the invasion last month. The IAEA, a United Nations agency, said the loss of power violated a “key safety pillar” but said it saw “no critical impact on safety” at this time because the amount of water in cooling ponds and around radioactive waste was sufficient to keep the nuclear material under control, even without continuous power to the plant. Part of the reason is that the used fuel assemblies are old and not as dangerous as they once were.

The American Nuclear Society, a professional group, agreed. “The loss of power is a serious matter but it does not pose a threat to the public,” it said in a statement.

Russia’s Energy Ministry said Wednesday that Belarus, whose border is near the Chernobyl facility, was working on restoring power from its own grid.

Still, there were deep worries in the nuclear community about the long-term fate of the facility, which is staffed by several thousand workers who oversee the plant and its fuel and waste storage, as well as other nuclear plants in Ukraine.

The shelling last week of a different, operating nuclear power facility caused a fire at a training building, and led to calls from U.S. President Joe Biden to the embattled president of Ukraine, Volodymyr Zelenskyy. Biden later denounced the military action, at the Zaporizhzhia nuclear complex in southern Ukraine, as “reckless.”

Early Wednesday, Ukraine’s nuclear regulator said backup generators had fuel to operate for 48 hours, and painted a dire picture of what could happen if the plant remained off the power grid for longer than that. The less dire statements from the IAEA followed, and some other experts generally played down the risks.

A former plant employee with knowledge of conditions, speaking on the condition of anonymity out of fear for his safety, said that in addition to the diesel generators, safety systems are powered by batteries and other backup means.