Sunday, the Ukrainian operator Energoatom announced that the last active reactor at the Zaporizhzhia nuclear power facility in southern Ukraine has been completely shut down and disconnected from the grid.

"Arrangements for its cooling and transfer to a cold state are underway," Energoatom said, adding that the sixth — and last operating — reactor at the plant had been powering the facility's internal needs in recent days because "all transmission lines linking the Zaporizhzhya NPP to the Ukrainian power system were damaged due to Russian shelling."

The U.N. nuclear watchdog had warned on Friday that this may occur as a result of fresh shelling surrounding Europe's largest nuclear complex. The director general of the International Atomic Energy Agency, Rafael Mariano Grossi, stated that it was "absolutely necessary" to establish "a nuclear safety and security protection zone" surrounding the site, emphasizing that a nuclear power station "can never be used as a pawn of war."

The plant was taken by Russian soldiers in March, but Ukrainian personnel has continued to run it.

Energoatom stated that the plant's internal needs will be met by diesel generators whose service life is constrained by the availability of technological resources and diesel fuel. The operator stated that it is taking "all possible measures to organize the supply of additional batches of diesel fuel" to the facility.

Energoatom stated that to prevent an emergency at the power plant, the Russian shelling of the transmission lines connecting the ZNNP to the power grid must cease and a demilitarized zone must be established around it.