Ukraine Nuclear Plant Equipment Forced to Run on Diesel Fuel Amid Strikes

Ukraine's Zaporizhzhia nuclear power plant lost all of its external power on Wednesday because of damage from shelling, forcing the site to rely on backup diesel generators for its safety and security functions, according to a top official from the United Nations' nuclear watchdog.

Rafael Grossi, director general of the International Atomic Energy Agency (IAEA), said on Twitter that the watchdog's team at the plant informed him about the loss of access to external power, adding that this is the second time it has happened in five days.

"This repeated loss of #ZNPP's off-site power is a deeply worrying development and it underlines the urgent need for a nuclear safety & security protection zone around the site," Grossi wrote.

In an update posted several hours later, he said the IAEA's team had informed him that external power was restored. The plant's operator said that shelling damage to "a far off substation" caused the outage, "highlighting how precarious the situation is," Grossi tweeted. "We need a protection zone ASAP."

Russian forces captured the Zaporizhzhia plant early after Russian President Vladimir Putin's invasion of Ukraine began last February, which brought IAEA concerns and condemnation from world leaders. Reports of shelling and other dangerous activity around the plant, for which Russia and Ukraine have traded accusations of responsibility, have ramped up fears in recent months about a potential nuclear disaster.

Ukraine's state nuclear operator, Energoatom, said in a Telegram post on Wednesday that a Russian rocket attack damaged the plant's Dniprovska substation, which is in the Dnipropetrovsk region. The substation's transmission line was disconnected as a result, pushing the Zaporizhzhia plant into "full blackout mode" and causing the diesel generators to kick in automatically.

"Russian shelling and damages to the energy infrastructure, which is related to the operation of nuclear plants, are the same manifestations of nuclear terrorism just like direct shelling of ZNPP, and lead to the same consequences and threats of a radiation accident," Energoatom said. "The invaders continue to disdain the nuclear and radiation safety of the largest nuclear power plant in Europe, threatening the world with a radiation disaster."

The fact that the plant was forced to rely on its diesel generators for even part of Wednesday could be a cause for concern. Energoatom chief Petro Kotin told The Associated Press last month that the generators are the Zaporizhzhia site's "last defense before a radiation accident." The station has enough fuel to run the generators for only 10 days, Kotin said.

The plant was also forced to rely on its diesel generators on Saturday because of shelling, which Grossi called "tremendously irresponsible" in a statement, that cut off its external power. Even though the plant's six reactors are currently in "cold shutdown," an electricity supply is still required to keep the reactors cool and carry out other security functions, the IAEA said.

Newsweek reached out for comment to the IAEA and Russia's Defense Ministry.