Power has again been restored at the Zaporizhzhia nuclear facility, reducing worries about an accident at one of the war’s most sensitive sites. But the head of the United Nations’ atomic watchdog warned that Ukrainian workers were under yet more intense pressure as Moscow tries to assert further control of the plant.
While Ukrainian engineers have continued to operate the plant under the watch of Russian soldiers, Moscow recently said it was nationalizing the facility. The effort is part of a broader bid to claim, in a parade of formalities designed to give the moves a sheen of legitimacy, that parts of Ukraine are now Russian. The nuclear plant sits in one of four Ukrainian provinces that President Vladimir V. Putin declared this month had been annexed to Russia — a move that has been widely rejected and condemned as illegal.
Late Friday, Rafael Mariano Grossi, the director general of the International Atomic Energy Agency, said in a statement that employees at the nuclear plant were now facing “unacceptable pressure” to sign employment contracts with the Russian nuclear energy company, Rosatom, in defiance of Kyiv.
That pressure only adds to the stresses on the workers that Ukrainian officials have been warning about for months, saying that Russian soldiers had subjected already fatigued staff to harsh interrogations and torture.
Holding the plant gives Moscow a military advantage but also significant leverage over Ukraine’s energy infrastructure. Russian authorities could also, in theory, connect the facility to their grid, funneling power south to Ukrainian territory that Moscow has seized.
Amid the continuing management struggle between Moscow and Kyiv, Ukraine’s nuclear power company said this week that Russia had kidnapped another senior official from the plant, expressing fears he could be forced to disclose information about Ukrainian personnel working there. The head of the plant had previously been detained and released.
Ukraine’s state energy company, Energoatom, said on the Telegram messaging app on Saturday that it had set up a hotline for workers at the plant that could be used by “everyone who has information about cases of kidnapping and torture” by Russian authorities.
Despite Russia’s claims to have nationalized the plant, the International Atomic Energy Agency says that it views the plant as Ukrainian, since the U.N. charter does not recognize illegal annexations.
In a “much-needed development,” the Ukrainian engineers who have been working at the Zaporizhzhia site under intense Russian pressure have managed to restore backup power, ending the plant’s reliance on diesel generators. Most nuclear power plants consider diesel generators a last line of defense to be used only in extreme circumstances.
It was the second time in recent days that shelling had cut power lines that feed the cooling systems for the plant’s six reactors, all of which are shut down.
The war marks the first time that a nuclear facility has become an active battle zone. Russia has stationed troops and artillery at the plant since seizing it in March. Ukrainian authorities say the Russians have shelled nearby cities from the plant’s grounds, aware of the risk of returning fire. A waste storage site has been hit several times, and power lines have been a frequent target. Each side has blamed the other for the attacks.
“Working in very challenging conditions, operating staff at the Zaporizhzhia Nuclear Power Plant are doing everything they can to bolster its fragile off-site power situation,” Mr. Grossi said. “Restoring the backup power connection is a positive step in this regard, even though the overall nuclear safety and security situation remains precarious.”
The Zaporizhzhia plant is not providing electricity to Ukraine’s grid, given that its reactors are shut down. But it needs its own power source for safety reasons. Workers have been wrestling for weeks with how to provide that.
Mr. Grossi said that efforts to restart one of the reactors for that purpose would begin on Saturday in a process that would take several days. In addition, more diesel fuel has arrived, from both the Ukrainian and Russian side of the front line, to power Zaporizhzhia’s generators for at least 10 days should the plant again be cut off, he said.