The complex was disconnected Thursday due to fires at a nearby ash pits, causing the last remaining power line connecting to Ukraine’s energy grid to disconnect twice, Energoatom said in a statement.
“The actions of the invaders caused a complete disconnection of the ZNPP (Zaporizhzhia nuclear power plant) from the power grid — the first in the history of the plant,” it wrote.
Later on Thursday, the Russian-installed regional governor said that “at the moment, the power supply to all cities and districts of the Zaporizhzhia region has been restored” from the plant after earlier disruptions.
The official, Yevhen Balytskyi, blamed Ukrainian military action for the earlier outages. “As a result of a strike by the armed formations of Ukraine on power lines in the area of the Zaporizhzhia NPP, the territory of the security zone of the 750 kV overhead line caught fire. The fire was provoked by a short circuit on power lines,” he said.
In a separate statement, Ukraine’s State Inspection of Nuclear Regulation, which cited the nuclear operator Energoatom, said a power line from the plant was disconnected due to hostilities in the area.
As a result, one of the nuclear power units at the plant had also been disconnected, it said.
The complex has six reactors, but only two are operational at the moment.
It is unclear whether there is currently any disruption to the power supply at the plant. CNN has previously been told that there are 18 diesel generators at the plant as back-up sources of power to the reactors.
The nuclear plant, which is Europe’s largest, has been under Russian control since March. Clashes around the complex have sparked widespread concern and fears of a disaster.
Ukraine has accused Russian troops of using the plant as a shield, risking a potential disaster at the plant. The Kremlin has in turn repeatedly accused Ukrainian forces of shelling the plant.
Calls have also grown for inspectors from the International Atomic Energy Agency (IAEA) to visit the plant. “We are very, very close to that [an agreement with Russia],” IAEA Director General Rafael Grossi told France 24 on Thursday.
A ‘dangerous situation’
But Thursday’s disconnection has raised concerns that Moscow is attempting to divert electricity produced at Zaporizhzhia to Russian-occupied parts of Ukraine.
This view was put forward on Monday by Energoatom chief Petro Kotin, who accused Russia of trying to disconnect the plant from the Ukrainian grid “and then try to reconnect it to Russian system,” in an interview with CNN.
He said the only way to do that would require a full shutdown of the plant “and a full cut of all lines which are connected to the Ukrainian system. Because the frequencies right now are different, Russian frequency and Ukrainian frequency — we are synchronized with European system, and they’re synchronized with Russia.”
He however warned that once the fourth line was damaged, “then we will have blackouts more through the whole plant,” he said, describing it as a “dangerous situation” because the plant would be reliant on only diesel-powered generators, which are unreliable “because they need fuel for their work, and also … they have limited capacity to constantly be in work mode.”
Top US State Department official Bonnie Jenkins warned on Thursday that Russia’s actions at the plant “have created a serious risk of a nuclear incident, a dangerous radiation release that could threaten not only the people and environment of Ukraine, but also affect neighboring countries and the entire international community.”
Jenkins, who is Undersecretary of State for Arms Control and International Security, called for Russia to cease its military activities around the plant, stressing the importance of an IAEA visit.
While she was unable to confirm that the plant had been disconnected from the grid, she reiterated concerns “about turning off any of the other power plants.”
CNN’s Sam Kiley, Bex Wright and Jennifer Hansler contributed to this report.