On the night of 31 December 2025 to 1 January 2026 the first power from the new VVER-TOI reactor at Kursk NPP-2 entered the Unified Energy System of Russia. The unit, the lead of four planned VVER-TOI blocks at the replacement station, began generation at an initial 240 megawatts before an orderly increase to higher output levels.
Kursk NPP-2
The VVER-TOI design, which stands for water-water power reactor, typical, optimised, informatized, is a modern evolution of Russia’s pressurised water reactor family. The units are classed as Generation 3+ and deliver improved safety and economics compared with older VVER-1000 plants. Rated at about 1,250 MW, the VVER-TOI includes both passive and active safety systems and a domestic melt localisation trap known as ULR. International assessments, including those at expert level within the IAEA, have said the technology provides strong containment of severe accident products.
Construction work on the first unit began with the pouring of the first concrete in 2018. Project planners had anticipated a sooner commissioning, but construction and commissioning timetables adjusted to reflect regional security challenges and wider events over the past several years. Rosatom and plant management have said those challenges were met without halting progress.
Rosatom director general Alexey Likhachev noted that the region had frequently featured in national news and that teams working on the project had continued their work under difficult conditions. President Vladimir Putin visited the site in August 2025 and described the construction as impressive, highlighting its continuation despite a tense security environment.
The on-grid synchronisation was performed by Valery Yakushev, shift supervisor of the electrical shop, who said the unit had finally found its purpose and that being part of the start-up was an honour. Rosenergoatom CEO Alexander Shutikov confirmed that the plant is undergoing comprehensive trials and that power will be increased stepwise to 35–40 percent of design capacity as part of the planned commissioning sequence. Full confirmation of performance and compliance with regulatory standards will follow review by Rostekhnadzor.
Kursk NPP has long been a central node in the region’s power system. The wider station currently supplies more than 90 percent of industrial electricity demand in the Kursk region and accounts for roughly 35 percent of installed capacity across the Chernozem region. The new VVER-TOI units are intended to replace four RBMK-1000 reactors built in the 1970s and 1980s, delivering higher output and longer equipment life spans, with a projected operational life measured in decades and serviceability improvements over previous generations.
Industry specialists point to several benefits from bringing the new unit online. The project supports energy security, adds low-carbon generation to the grid and modernises the plant site with contemporary safety features. The replacement programme will see station output rise by about 20 percent relative to the period when all four RBMK units were online.
With the first generator now producing electricity, project teams will continue staged tests and regulatory verifications ahead of commercial operation. The successful initial synchronisation marks a milestone in the station’s long-term transition to modern reactor technology and in the regional supply of reliable, low-carbon electricity.
Key Takeaways:
- Russia connected the first VVER-TOI reactor unit of Kursk NPP-2 to the national grid on the night of 31 December 2025 to 1 January 2026.
- The new unit began output at 240 MW and will be ramped to 35–40 percent before full-power commissioning.
- Kursk NPP-2 will replace ageing RBMK units and use advanced safety systems including a Russian melt localisation trap evaluated by IAEA experts.
- The project strengthens regional energy security and adds low-carbon capacity to Russia’s grid.
