Wedoany.com Report-Sept. 12, The lower tier of the internal containment building has been successfully installed at the third new unit under construction at the Leningrad nuclear power plant in Russia. The circular structure, with a diameter of 44 meters, height of 10 meters, and weighing 227 tonnes, was placed in a carefully coordinated operation that took eight hours. Rosatom noted that the tier had been pre-assembled on a slipway near its permanent location, reducing the need for assembly and welding at height. The next step will involve welding the tier in its final position.

Yevgeny Milushkin, Deputy Director for Capital Construction at Leningrad NPP-2, said: “Together with the general contractor, we carefully worked out all the stages of the upcoming operation, and also used the experience of constructing the previous two units in terms of engineering solutions. As a result, the complex technological lifting at the 3rd power unit was carried out with high quality.”

The Leningrad nuclear power plant is one of the largest in Russia, with a total installed capacity of 4,400 MWe. It supplies more than 55% of the electricity demand of St Petersburg and the Leningrad region, which corresponds to approximately 30% of all electricity in northwest Russia.

The first two units at the plant, Leningrad 1 and Leningrad 2—both 1,000 MWe RBMK units—have been shut down, in 2018 and November 2020 respectively, after decades of operation. To maintain power supply in the region, new VVER-1200 units have been constructed at the adjacent Leningrad II site. The fifth and sixth units, Leningrad II-1 and Leningrad II-2, have already started operations, securing the region’s electricity needs through the 2080s. Units 7 and 8, also referred to as Leningrad II-3 and Leningrad II-4, will replace the older third and fourth units as they are retired in the coming years.

Construction of unit 7 began in earnest in March 2024 with the pouring of the first concrete, marking the start of the main construction phase. This new unit is designed for a 60-year service life, with a potential extension of 20 years, ensuring long-term reliability and stability of the regional power supply.

The installation of the lower tier represents a key milestone in the construction process, demonstrating the application of advanced engineering methods and lessons learned from previous units. Once completed, the new units will integrate into the Leningrad II plant, supporting continuous electricity generation and enhancing energy security for the surrounding regions.