First criticality means the plant achieved a controlled, self-sustaining nuclear fission chain reaction for the first time.
Rosatom said the plant, a 1,085-MW Generation III+ pressurised water reactor, or VVER, will now undergo a series of tests before nuclear regulator Rostechnadzor can approve a phased increase in power levels and commercial operation.
Rosatom said Leningrad 2-2, north of St Petersburg on the Gulf of Finland, is scheduled for commercial operation in 2021. It will replace Leningrad-2, a 925-MW Soviet-designed light water graphite reactor, or RBMK, which has been in commercial operation since February 1976 and is scheduled to be permanently shut down.
The identical Leningrad 2-1 unit, which began commercial operation in October 2018, replaced, Leningrad-1, which began commercial operation in November 1974 and was permanently shut down in December 2018. Leningrad-1 was also a Soviet-era RBMK.
Commissioning of Leningrad 2-2 will mean Russia’s fleet of Generation III+ units will increase to four. The others are Leningrad 2-1, Novovoronezh 2-1 and Novovoronezh 2-2.
According to International Atomic Energy Agency statistics, Russia has 38 nuclear power reactors in commercial operation and four under construction. In 2019 the nuclear fleet provided almost 20% of the country’s electricity production share.