Workers have successfully completed the concrete foundation pit for the reactor of unit 8 at Russia’s Leningrad nuclear power plant.
The first nuclear safety-related concrete for the VVER-1200 unit is planned to be poured next year.
Accelerated Construction Timeline
Rosenergoatom, the operational division of the Russian state nuclear corporation Rosatom, announced that the construction of the pit was finished in about two months, two-and-a-half months ahead of schedule.
Titan-2, the general contractor responsible for the new power units at the Leningrad plant, carried out the work.
Technological Advancements in Construction
In June, the foundation pit for unit 8’s reactor building was completed two weeks ahead of schedule.
“The technology for constructing the concrete foundation pit included a multi-layer drainage system – lean concrete, sand, porous concrete,” explained Konstantin Khudyakov, director of the Leningrad NPP Facilities Programme of JSC Concern Titan-2.
“A special membrane then cut off the drainage system before the concrete preparation.”
Upcoming Construction Phases
The next phase involves lightning protection and waterproofing, to be completed by the end of August. Following this, the screed will be installed.
Evgeny Milushkin, deputy director for capital construction at Leningrad II, stated that these preparations will allow specialists to start reinforcing the foundation slab in October.
The steel reinforcement will form a robust framework, enhancing the slab’s strength, paving the way for the crucial concreting operation of the reactor building’s foundation.
Importance of the Leningrad Plant
The Leningrad plant is among the largest in Russia, with an installed capacity of 4400 MWe, providing over 55% of the electricity demand for St Petersburg and the Leningrad region, equating to 30% of northwest Russia’s total electricity.
Transition from RBMK to VVER Units
Leningrad units 1 and 2, both 1000 MWe RBMK units, were shut down in 2018 and 2020, respectively. As these units were decommissioned, new VVER-1200 units commenced operations at the nearby Leningrad II plant.
These new units (Leningrad II-1 and Leningrad II-2) have a service life of 60 years, ensuring power supply continuity until the 2080s. Units 7 and 8 will replace the retiring units 3 and 4 in the coming years.
Milestones and Future Plans
The pouring of the first concrete for unit 7 in March marked the beginning of the main construction phase for the new power unit, which is designed to operate for 60 years, with a potential 20-year extension.
The foundation slab for this unit comprises approximately 5500 cubic metres of concrete.
Recently, Rosatom reported that work on the reactor building is progressing two-and-a-half months ahead of schedule, with the foundation concreting already finished.
Leningrad units 7 and 8 (Leningrad II-3 and Leningrad II-4) are slated for commissioning in 2030 and 2032, respectively.