Unit 4 of Russia's Balakovo Nuclear Power Plant Shut Down for Planned Major Overhaul

On September 26, 2026, Unit 4 of the Balakovo Nuclear Power Plant, which is part of the Electric Power Division of Rosatom State Atomic Energy Corporation, was formally disconnected from the grid and entered the stage of preventive major overhaul and modernization upgrade in accordance with the established approved plan. Conducting preventive maintenance on a regular basis is a core routine measure for Russian nuclear power plants to maintain a high level of safety margin for equipment and ensure continuous and stable power grid supply.

Alexey Portnov, Head of the Maintenance Management Department of the Balakovo Nuclear Power Plant, stated that as a key battle in the final stage of the plant's 2026 major overhaul, this overhaul round has planned multiple major equipment upgrade projects, with key scope covering the comprehensive replacement of valves and piping components in the spray pond, as well as the comprehensive replacement of the original lens-type expansion joints with new bellows expansion joints in the service water system, thereby enhancing the system's pressure-bearing capacity and fatigue resistance life.

In terms of the scope of the unit overhaul, Unit 4 will strictly implement standardized overhaul procedures. In the reactor building, a comprehensive disassembly and inspection of the reactor proper will be carried out, along with the complete unloading of spent fuel from the core and the reloading of some new fuel assemblies; in the turbine generator building, the focus will be on advancing the deep overhaul of the high-pressure cylinder of the steam turbine, as well as extracting the generator rotor for intermediate generator maintenance.

The entire overhaul round will cumulatively implement more than 15 special equipment modernization modifications, specifically including the comprehensive software and hardware upgrade of servers, switches, and terminal equipment of the unit information and computing system, the precise updating of temperature monitoring instruments, and the comprehensive renovation of the fire protection system and process technical water pipelines. The on-site maintenance work has mobilized more than 2,000 professional technical personnel. In addition to the plant's own team, it has also deeply integrated elite personnel from the general contractor "Balakovoatomenergoremont," multiple cross-plant backbone branches under Atomenergoremont, AER, the BalakovoVEM specialized electrical installation engineering team, and the Non-Destructive Testing Center.

At present, the radiation monitoring data in the Balakovo Nuclear Power Plant site and surrounding controlled areas are fully within the normal operating range of the unit, with no abnormal fluctuations observed in the environmental dose rate, remaining consistent with the long-term natural background radiation levels in parts of European Russia.

The Balakovo Nuclear Power Plant is located on the left bank of the Saratov Reservoir in Saratov Oblast and is affiliated with Rosenergoatom. It is one of the largest and most modern backbone power enterprises in Russia. The plant is equipped with 4 modernized upgraded VVER-1000 (improved V-320 type) pressurized water reactor units with an installed capacity of 1,000 megawatts (MW) each, which were successively connected to the grid and put into operation in 1985, 1987, 1988, and 1993 respectively. The plant contributes more than one quarter of the electricity generation of the Volga Federal District, and its power transmission covers a wide range of core industrial and densely populated areas, including the Volga River basin, central Russia, the Urals, and Siberia.