The process sees 60 tonnes of chemically demineralised water brought into the reactor vessel through the pressure compensator through the main circulation pipeline of the primary circuit. The water removes any impurities as well as checking that everything has been installed correctly and verifying the operability of the pump units in normal operation and safety systems.
Director of the Kursk NPP Andrey Osharin said that based on the results "we can verify that the installation was carried out correctly and the process equipment is ready for commissioning work”.
Oleg Shperle, Vice President of ASE JSC, Project Director for the construction of the Kursk NPP, said: "This is the first of numerous equipment inspections ... the next stage of post-installation cleaning is hydraulic testing and circulation flushing of the primary circuit of the reactor installation of the first power unit. These operations will prepare the first power unit of Kursk NPP-2 for physical start-up.”
Kursk II is a new nuclear power plant in western Russia, about 60 kilometres (37.5 miles) from the Ukraine border, that will feature two VVER-TOI reactors, the latest version of Russia's large light-water designs. They have upgraded pressure vessels and a higher power rating of 3300 MWt that enables them to generate 1300 MWe gross.
Construction of the first unit began in 2018, its polar crane was installed in October 2021 and the reactor vessel in June 2022. Concreting of the outer dome of the first unit was completed in August.