The first scheduled large-scale inspection of the reactor was successfully completed at the VVER-1200 power unit No 5 of the Leningrad NPP. It took place as part of the scheduled preventive maintenance of the unit. The tests have confirmed that the state of the metal of the reactor vessel, as well as of its welded joints and anti-corrosion surfacing, has not changed since the unit was first put into commercial operation in October 2018.

“Studies have proven that after 20,000 hours of operation, the most important equipment of the unit is ready to continue its work safely under the current operational conditions. The experts found no changes in the metal (such as corrosion, cracks, cracking and hidden internal defects),” – Chief Engineer at LNPP-2 Aleksandr Belyaev underlined.

The equipment was checked using an automated control system developed specifically for the new generation VVER-1200 reactors of the Leningrad NPP. Operators-defectoscopists performed their work using highly sensitive sensors and manipulators remotely, under a layer of water. This provided a safe working environment for them.

The assessment of the state of the reactor was carried out following the complete extraction of its nuclear fuel. At the end of the inspection, the nuclear scientists loaded the fuel assemblies (FA) with fuel into the reactor again. At the same time, 42 spent fuel assemblies were replaced with assemblies with fresh fuel. The rest of the fuel assemblies were rearranged in accordance with the reloading scheme based on the performed neutron-physical calculations.

As for the present moment, the Leningrad NPP is undergoing a scheduled preventive maintenance at the VVER-1200 power unit No. 5. Its main task is to improve the reliability of the technological systems in the next overhaul period and to ensure the operational efficiency and safety of the power unit. The repairs are scheduled to go on until early January next year.