Russian nuclear utility Rosenergoatom (a subsidiary of state nuclear corporation Rosatom) has assembled the reactor vessel for unit 1 of the Leningrad Phase II NPP, under construction in Sosnovy Bor in western Russia.

The VVER-1200 is expected to achieve first criticality later in January. "The reactor is fully assembled, sealed and ready for hydraulic tests of the first and second circuits, during which we will once again check the equipment of the reactor installation, and finally confirm its density, “Alexander Belyaev, chief engineer of Leningrad NPP, said in the company statement. “After that, it will be possible to start the reactor at the minimum controlled power level."

Testing of the passive heat removal system of Leningrad II-1 was finished in late August, and fuel loading began in December. The existing Leningrad plant site has four operating RMBK-1000 units, which will be replaced by Leningrad II with four VVER-1200 units.