By Anastasia Lyrchikova
MOSCOW (Reuters) -Russia's state nuclear power corporation has reported that turbine blades broke at a plant where the company has installed two reactors of a type it is also building in Turkey and plans to construct in Hungary.
Rosenergoatom, which runs Russia's nuclear power stations, said it was not clear what caused the blades to break, forcing the shutdown of a unit at the Leningrad nuclear power plant west of St Petersburg on Sunday.
"The main thing now is to understand the reason for the destruction of the blades. This is a new phenomenon," said Alexander Shutikov, head of Rosenergoatom. He said repairs should be completed by Dec. 22.
The unit where the problem occurred was built in 2018 with a next-generation VVER 1200, a pressurised water reactor. Units of this type are being built by Russia at the Akkuyu nuclear power plant in Turkey and are planned for the Paks-2 plant in Hungary. Russia has already supplied them to Belarus.
Shutikov said the blades that failed were part of a 1,200-megawatt high-speed steam turbine. The turbines are produced by businessman Alexei Mordashov's Power Machines сompany.
Power Machines said turbines of the same type had operated without problems since 2016 at four power units. It said it was taking all steps to restart the affected unit as soon as possible and working with specialists from the plant to investigate the causes and identify defects.
"Based on the results, conclusions will be drawn and compensatory measures will be determined," it said in reply to a request for comment from Reuters.
Rosatom, the parent of Rosenergoatom, said similar turbine models are in operation at another unit of the Leningrad plant and in the southern Voronezh region. The company said it always investigates and corrects any malfunction.
"Since turbines are not part of the 'nuclear island' of the plant, their malfunctioning has no impact on nuclear safety, as all reactor equipment is functioning as intended," it said.
(Reporting by Anastasia Lyrchikova, writing by Mark Trevelyan; Editing by Cynthia Osterman, William Maclean)