Russia has today brought unit 1 of the Leningrad Phase II nuclear power plant to the minimum controllable power level, state nuclear corporation Rosatom has announced. The assembly of the reactor vessel for the unit, which is in Sosnovy Bor in western Russia, was completed in early January.

Leningrad plant workers mark the milestone (Image: Rosatom)

The existing Leningrad plant site has four operating RMBK-1000 units, while Leningrad II will have four VVER-1200 units. The new unit will be the second to come on line in Russia this year - Rostov 4, which is near the city of Volgodonsk, was connected to the grid on 1 February.

Andrey Petrov, director general of Rosatom's plant operator subsidiary Rosenergoatom said achieving minimum controlled capacity is "the final link in the whole chain of operations" conducted during the physical start-up of a reactor unit, which for the new Leningrad reactor started on 8 December.

"The high-quality and timely execution of all the planned work allowed us to bring the reactor to a critical state in a safe and timely manner," Petrov added.

Leningrad NPP Director Vladimir Pereguda added in the same Rosatom statement it was "symbolic" that the plant started the new year with a new record to its name - producing 1 terawatt hours of electricity.

The first unit at the existing Leningrad plant was constructed to help serve Moscow International Airport, he said, adding: "And now, before our very eyes, the most powerful power unit in the Leningrad NPP family has been born, which will increase this achievement."

Tests at the new unit next week will include checking the neutron-physical characteristics of the first fuel loading, as well as confirming the reliability of the operation of the control and safety mechanisms of the reactor installation, according to the statement.

Operator personnel will then prepare the unit for power start-up and pilot operation, which are to start in the spring, it added.

Preparations for the physical start-up of Leningrad II unit 1 began on 8 December, with the start of the loading of 163 nuclear fuel assemblies into the reactor.