The first ever VVER-TOI reactor at unit 1 of Russia’s Kursk-II NPP has begun pilot industrial operation. Power will gradually be increased from 408 MWe to the nominal level of 1,250 MWe.
The VVER-TOI (water-cooled power reactor – standard optimised informatised) has improved technical and economic indicators: compared with previous generation VVER-1000 reactor. The capacity is increased by 25%, to 1250 MWe. The service life of the main equipment is doubled. The project involves the use of a combination of passive and active safety systems.
Kursk-II will replace the currently operating Kursk NPP, which comprises four ageing RBMK reactors (two of which are now closed) with four new units comprising Generation 3+ VVER-TOI reactors. Unit 2 is expected to begin operation in 2027 and the construction and commissioning of units 3&4 are planned for 2042.
“Pilot operation is a decisive stage. It confirms compliance with the design of power unit systems and equipment under different operating conditions,” said Rosatom Director General Alexei Likhachev. “At Kursk-II we are building the most powerful power units in Russia according to the VVER-TOI project. And with the transition to pilot operation, the first nuclear giant is already one step away from full commissioning. This is a great achievement of the entire team at Kursk NPP-II and [nuclear utility] Rosenergoatom, which, on a daily basis, brings the commissioning of the power unit closer to commercial operation.”
Since connection of the unit to the grid in December 2025, the station team has conducted a set of tests and received approval from regulator Rostechnadzor for transition to the pilot operation stage, confirming safety and compliance with international standards. Further tests and neutron physics studies will take place after which, the system operator will have to confirm its readiness to accept full power. Rostechnadzor will then have to certify the power unit’s compliance with the high standards required for modern nuclear power units.
