Construction of spray pools – two artificial reservoirs of 124 metres long, 74 metres wide and 4.5 metres deep – has begun at Leningrad NPP unit 7 (also known as Leningrad-II unit 3). Specialists from general contractor Titan-2 are completing development of the pit and are installing formation drainage. Work on reinforcing the foundation slab of the first pool is planned to begin in August.
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 (also known as Leningrad-II 1&2). Units 5&6 replaced the RBMK-1000 reactors at units 1&2, which were decommissioned in 2018 and 2020. New VVER-1200 units (7&8), now under construction, will replace units 3&4. Unit 7 is scheduled to begin operation in 2030 and unit 8 in 2032.
“We have to consistently create the bottom and walls of each artificial reservoir, waterproof them, protect tanks from leaks, as well as lay distribution pipelines for supplying and discharging water, and install spray nozzles and control systems,” said Konstantin Khudyakov, director of the programme for Leningrad NPP facilities at Titan-2. “Considering the importance of these tanks for the safe operation of the unit, the work ahead is responsible and extensive. We plan to complete construction and installation work at these facilities in 2027. Before the physical start of the unit, the spray pools must undergo the necessary tests and confirm their readiness for operation.”
Spray pools part of the water supply system for power units of with VVER-1200 reactors, are important for safety. They are needed to remove heat from critical components – pumps, units, heat exchangers, and parts of auxiliary systems.
“Spray pools are not simple construction projects,” explained Evgeny Milushkin, Deputy Director of the Leningrad NPP and Head of the Capital Construction Department of the Leningrad-II NPP. “In fact, each of them will consist of an open and a closed section. This complex design will prevent water being lost in the event of hypothetical natural disasters (tornado or hurricane) or man-made incidents. To be able to quickly replenish the pools with water, we will connect them to a reserve pool, which we will build nearby.”
