By Tom Balmforth and Max Hunder
KYIV (Reuters) -Ukraine said on Wednesday it might have to shut down the Russian-occupied Zaporizhzhia nuclear plant to avoid a disaster and called on residents in areas near the embattled facility to evacuate for their own safety.
Europe's largest nuclear plant has been disconnected from the Ukrainian electricity grid after shelling cut its external power lines. Moscow and Kyiv accuse each other of shelling the plant and risking a nuclear disaster.
Shutting down the vast, six-reactor nuclear plant would pile further strain on Ukraine which is bracing for a winter of energy shortages as the war rages on in its east and south.
Russia's occupation of the plant has fuelled fears it might try to link up the facility to its own power grid, but the head of Ukraine's state nuclear power company has said that is technically difficult.
"The option of switching off the station is being assessed, if conditions necessitating the station to be switched off arise," Oleh Korikov, acting head of Ukraine's State Nuclear Regulatory Inspectorate, told a news briefing.
He said the facility was supplying its own electricity needs, but that backup diesel generators would have to be fired up if it remained disconnected, though he gave no time frame.
It would be extremely difficult to replenish the reserves of diesel because of Russia's Feb. 24 invasion, he said. Moscow's troops captured the plant in early March but it is still operated by Ukrainian technicians.
"We could potentially reach a situation where the diesel runs out, which would cause an accident involving the damage of the active zones of the reactors, which would cause the expulsion of radioactive substances into the environment," he said.
"This would have consequences not only for the territory of Ukraine, but also cross-border consequences," he said.
Deputy Prime Minister Iryna Vereshchuk urged Ukrainians living near the plant to evacuate.
"Find a way to get to (Ukrainian) controlled territory," she wrote on Telegram.
The weeks-long crisis around the plant prompted inspectors from the International Atomic Energy Agency to travel to the site last week, braving shelling. Two inspectors have remained at the plant indefinitely.
In their report, the IAEA said on Tuesday that the situation was unsustainable and that there would be a risk of disaster unless the shooting stopped. But it did not ascribe blame for the damage or set out a detailed plan for what should happen next.
The IAEA report called for the immediate establishment of a nuclear safety and security protection zone, but it did not set out a detailed plan of how that should be brought about and what each side's responsibilities should be, an adviser to Ukrainian President Volodymyr Zelenskiy, told Reuters.
"The key part is missing in (IAEA director general) Mr. Grossi's report: There is no definite algorithm of what we must do," the official, Mykhailo Podolyak, told Reuters.
"It says both sides have to negotiate, but it doesn't say that Russian troops must vacate the Zaporizhzhia nuclear power plant. It doesn't mention a 10-15 km demilitarisation area" and it doesn't include the threat of specific sanctions against Russia, he said.
Russia was also critical of the report, with President Vladimir Putin saying it failed to say that Ukraine was to blame for shelling on the site. The Russian Foreign Ministry requested "additional explanations" from the IAEA.
(Additional reporting by Pavel Polityuk; Writing by Conor Humphries and Tom Balmforth; Editing by Tomasz Janowski and Philippa Fletcher)