Unit 1 of Russia's Kalinin NPP completes scheduled maintenance ahead of schedule

Unit 1 of Russia's Kalinin Nuclear Power Plant has been restored to rated power operation after completing equipment modernization and planned major overhaul. The unit was connected to the grid on August 27, 2026, with maintenance work completed two days ahead of the original schedule.

Kalinin NPP is a nuclear power plant under Rosenergoatom, located in Udomlya, Tver Oblast, Russia. During this maintenance period, plant personnel and experts from Atomenergoremont completed nuclear fuel reloading, preventive maintenance of the reactor plant and turbine-generator unit, metal condition inspection of major equipment, and diagnostic testing of heat exchange tubes in 2 of the 4 steam generators, among other tasks.

In addition to routine maintenance, 8 equipment modernization initiatives were implemented at Unit 1, involving certain components and process systems, aimed at maintaining the unit's safety level, equipment reliability, and operational performance. Over 12,000 various tasks were completed throughout the entire maintenance cycle, with approximately 2,000 professionals participating in the related work.

According to estimates, the optimization of the maintenance schedule will result in approximately 45 million kWh of additional electricity generation. Based on a per capita monthly electricity consumption of 200 kWh, this amount of electricity could meet the monthly demand of approximately 225,000 people.

Kalinin NPP has a total of 4 VVER-1000 pressurized water reactor units, each with an installed capacity of 1,000 MW. The plant accounts for approximately 82% of the total electricity generation in Tver Oblast, 14% of the generation in the Central Federal District of Russia, and about 15% of Rosenergoatom's total electricity output.

The plant stated that the radiation background at the Kalinin NPP site and surrounding areas is currently at normal operational levels for the units and does not exceed natural background values.