Russia’s nuclear utility Rosenergoatom (part of Rosatom) reported that unit 5 at the Leningrad NPP had been shut down after blades broke on the turbine installed at the VVER-1200 reactor. Rosenergoatom said it was not clear what caused the blades to break, but was investigating the cause. "The main thing now is to understand the reason for the destruction of the blades,” said Rosenergoatom Director Alexander Shutikov. “This is a new phenomenon.”. He added that the blades that failed were part of a 1 high-speed steam turbinesupplied by Alexei Mordashov's Power Machines (PM) сompany. He said repairs should be completed by 22 December.
According to PM, turbines of the same type had operated without any problems since 2016 at four power units. The company said it was 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," PM told Reuters.
Similar turbines operate at Leningrad unit 6. "Since turbines are not part of the 'nuclear island' of the plant, their malfunction has no impact on nuclear safety,” Rosatom said. “All the reactor equipment is functioning as intended."
Currently Leningrad NPP has four units in operation – units 3&4 with Soviet RBMK-1000 reactors, as well units 5&6 with new VVER-1200 units. Units 5&6 replaced units 1&2 with RBMK-1000 reactors, which were decommissioned in 2018 and 2020. New VVER-1200 units (7&8) will replace units 3&4.
Image: Leningrad nuclear power plant (courtesy of Rosatom)