Rosatom said the gross power of the 1,085-MW Generation III+ pressurised water reactor, or VVER, has been increased to 240 MW, or 20%, with the turbogenerator synchronised with the east European electric power grid.
Power will now be increased in steps to 100% with tests and inspections carried out at each power level.
After the completion of this pilot operation phase, the plant will be stopped for inspection of equipment and inspection by nuclear regulator Rostechnadzor.
Rosatom said the plant is scheduled to begin commercal operation in 2021.
The plant, construction of which began in 2010, was brought to its minimum controlled power level and achieved first criticality in August.
Over the next six months the plant will go through the stages of power startup, pilot operation and comprehensive tests.
Leningrad 2-2, north of St Petersburg on the Gulf of Finland, 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.