At the construction site of Russia’s Leningrad NPP, the main excavation work has been completed to develop a foundation pit for the nuclear island of power unit 7. The nuclear island comprises a complex of buildings and structures related to the operation and maintenance of the nuclear reactor.

The seventh and eighth VVER-1200 units at Leningrad NPP (also known as Leningrad-II 3&4) are expected to start construction in 2024 and 2025for completion by 2030 and 2032. First concrete for unit 7 is planned for June 2024, the foundation of unit 8 will be laid in May 2025. Currently Leningrad NPP has four units in operation – units 3&4 with Soviet RBMK-1000 reactors, as well units 5&6 with new VVER-1200 units. Units 5&6 replaced units 1&2 with RBMK-1000 reactors, which were decommissioned in 2018 and 2020. The new units 7&8 will replace units 3&4.

“Developing the foundation pit for a nuclear island is a large-scale work at the initial stage of construction,” said Evgeniy Milushkin, Deputy Director for Capital Construction and Head of the Leningrad-II Capital Construction Department. The dimensions of the pit are 196 by 266 metres. During the construction process, about 660,000 cubic metres of soil were removed from the pit.

Milushkin said 50 people, 30 vehicles and 15 special mechanisms were involved in the work. Next, specialists will begin installing drainage for the buildings and structures of the nuclear island.

“Since 30 August, the general contractor for the construction of new power units at Leningrad-II, Titan-2, has been constructing a pit for the turbine island, said Konstantin Khudyakov, Titan-2 Director of the programme for LNPP units under construction. “Specialists will have to deal with 348,000 cubic metres of soil. The work is planned to be completed by November 2023.”

The vertical layout and construction of an upland ditch for drainage of surface water are being completed at the construction site. The arrangement of areas for the passage of vehicles and personnel, the installation of temporary outdoor lighting and temporary fencing is continuing.


Image courtesy of Rosatom