By Guy Faulconbridge and Anastasia Lyrchikova
MOSCOW (Reuters) -External power must be restored to the vast Soviet-built Zaporizhzhia nuclear power plant in southern Ukraine which is being cooled by emergency diesel generators after an external line was severed during fighting, Russia said on Wednesday.
Fighting and intense drone and artillery war around several vast Soviet-era nuclear power stations in Ukraine have repeatedly triggered grave warnings from the United Nations' nuclear agency about the danger of a major nuclear accident.
The plant's Russian-installed management said that backup electricity supply was sufficient for now and that radiation levels were normal, but that it was important that external power was restored as soon as possible.
"The situation at the station is under control," said Yevgeniya Yashina, a spokeswoman for the plant, adding that the staff at the plant knew what to do and that radiation levels were normal.
RISK OF MELTDOWN
The Russian management said that Ukrainian shelling cut the last remaining power line, the high-voltage Dneprovskaya line, on September 23 and that Ukrainian shelling was preventing its repair. Ukraine said that Russian shelling was preventing the restoration of external power.
Power is needed to pump water around the plant to cool the reactors and spent fuel, the International Atomic Energy Agency (IAEA) said.
"Europe’s largest nuclear power plant has been without external power for more than a week now, which is by far the longest lasting such event during more than three and a half years of war," IAEA Director General Rafael Grossi said.
The Russian management said the emergency generators were sufficient for now and that only some were being used. All equipment was functioning as normal, it said.
The Zaporizhzhia plant has six Soviet-designed VVER-1000 V-320 water-cooled and water-moderated reactors containing Uranium 235. All reactors are currently shut down so are cooler than usual.
The risk is that without any power - external or supplied by the emergency generators - the nuclear fuel which sits just 500 km (300 miles) from the site of the world's worst nuclear accident, the 1986 Chornobyl disaster, would not be cooled and would risk a meltdown.
"The current status of the reactor units and spent fuel is stable as long as the emergency diesel generators are able to provide sufficient power to maintain essential safety-related functions and cooling," Grossi said.
"It is extremely important that offsite power is restored."
Russian forces seized the plant in 2022 shortly after President Vladimir Putin sent tens of thousands of troops into Ukraine. Russia has controlled the plant ever since.
(Reporting by Reuters, Writing by Guy Faulconbridge; editing by Andrew Osborn and Aidan Lewis)
