Fighting in the vicinity of the plant has led to acute worries of a potential catastrophe and to calls from many world leaders for UN nuclear experts to be allowed to visit the site.
Russian and Ukrainian officials traded blame for shelling at the plant, which they said had resulted in the disconnection from the power grid — the first time it has ever been cut off. Officials, including Ukrainian President Volodymyr Zelensky, have warned that such a disconnection itself could lead to an extremely dangerous situation by disrupting the plant’s normal operation and potentially making it difficult to cool the reactors.
“The actions of the invaders caused a complete disconnection of the ZNPP from the power grid — for the first time in the history of the plant,” Ukraine’s nuclear energy company, Energoatom, said in a statement.
On Thursday morning, the mayor of Enerhodar, where the plant is located, said the city was on the “verge of a humanitarian disaster” as shelling left it without electricity or water. He later said officials were working on restoring power to the city.
The Russian-installed “governor” of the occupied region, Yevhen Balytskyi, blamed Ukraine’s military for the outages. The charge was echoed by Russia’s RIA Novosti news agency, which said shelling by Ukrainian forces caused a network to short-circuit, resulting in “a blackout in the Zaporizhzhia region.”
Inside Ukraine’s captured nuclear plant, explosions and constant fear
The nuclear plant is now being powered from a neighboring geothermal plant, and Russian-held Enerhodar was expected to get its power back in a few hours, a spokesman for Energoatom said.
Ukrainian plant workers have continued to keep the nuclear site operational while under the control of the occupying authorities.
The Zaporizhzhia plant is a major source of power for Ukraine. Before the Russian invasion on Feb. 24, it provided one-fifth of Ukraine’s electricity and nearly half of its nuclear energy.
US Undersecretary of State Bonnie Jenkins, a senior official responsible for arms control and international security, told reporters Thursday she was aware of reports of a power outage but could not independently confirm them.
Jenkins renewed calls for the Russian military to vacate the plant and allow international nuclear experts to visit, saying a power outage can have an “immediate impact, obviously” for Ukraine’s citizens.
In a statement, Rafael Mariano Grossi, director general of the International Atomic Energy Agency, the UN nuclear watchdog, said the plant twice lost power during the day but that it was currently back on.
Grossi said the incident further underscored the “urgent need for an IAEA expert mission to travel to the facility.” He said he was prepared to go there himself in the coming days.
“Almost every day there is a new incident at or near the Zaporizhzhia nuclear power plant,” he said. “We can’t afford to lose any more time. I’m determined to personally lead an IAEA mission to the plant in the next few days to help stabilize the nuclear safety and security situation there.”
On Tuesday, Zelensky called for international pressure to compel the occupying Russian forces to leave the plant and the surrounding area. “We need to put pressure on Russia, give them an ultimatum from the international community that they should leave,” Zelensky said, adding: “This is dangerous for the whole world.”
Experts have been struggling to understand whether the damage at the plant was due to deliberate sabotage or perhaps the result of a mistake by soldiers in the area. They said having IAEA inspectors on-site would improve the situation.
“At a minimum, the IAEA can assess the safety of the plant,” said Jon Wolfsthal, a former senior director for arms control and nonproliferation at the National Security Council during the Obama administration.
“It can determine whether or not there’s been any damage to the reactor containment,” Wolfsthal said. “It can determine whether the backup safety systems are online and functioning. It can provide assurance to the Ukrainians and to the Russians and to the nearby population, and the rest of Europe, that there are still multiple backup systems in place or alert the world if those systems are not in place.”
Karina Tsui and Robyn Dixon contributed to this article.