At power unit No. 6 PWR-1200 of the Leningrad NPP, the first in its history refueling of nuclear fuel was successfully completed. The operation was carried out during a scheduled major overhaul.

According to Alexander Belyaev, chief engineer of LNPP-2, refueling operation was carried out to replace part of the spent assemblies with fresh ones and to rearrange partially burnt assemblies and reactor control and protection system elements in the reactor core.

“A distinctive feature of PWR units in comparison with RBMK units is that all work with nuclear fuel on them is performed only when the reactor is shut down. This is due to its design: a pressurized water reactor is a pressure vessel. It is decompressed only during repairs. The design of channel reactors makes it possible to reload a separate technological channel at a nuclear reactor operating at rated power,” explained Alexander Belyaev.

During the refueling, specialists removed fuel assemblies with nuclear fuel from the reactor core 163 and moved them to the spent fuel pool. After confirming the integrity of the reactor vessel and its internals, 115 fuel cartridges were loaded back into the reactor, and 48 cartridges were replaced with new ones.

To provide the biological protection of personnel and the reliability of cooling of fuel assemblies, the work was performed by the "wet" method, under a layer of water, using a refueling machine. The nuclear power plant personnel controlled all processes remotely.

Power unit No. 6 PWR-1200 LNPP has been disconnected from the grid since December 25 last year. In addition to checking the reactor and working with fuel, specialists will have to check the steam generators, the main circulation pipeline and related pumps, the steam turbine plant, as well as the APCS equipment and safety systems equipment. The completion of the overhaul at unit 6 is planned for mid-February. Also on January 11, 2022, power unit No. 5 of the PWR-1200 Leningrad NPP was put into scheduled medium repair. Work on it will last until the end of February.

The radiation situation at the industrial site and in the Leningrad NPP observation area is within the limits of natural background values.