Unit 1 at Russia’s Kursk-II NPP, the world’s first VVER-TOI reactor, has achieved full power during pilot operation. Design tests will now confirm that the parameters and performance characteristics of systems and equipment correspond to the design values, in the run up to commercial operation.
Since grid connection and commissioning in December 2025, specialists have increased the rated power of the reactor plant, from 40% to 100%. Since then, the unit has supplied more than 570 GWh of electricity to the network.
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.
“At each stage, our specialists carried out a set of tests to check the compliance of the parameters and characteristics of the operation of systems and equipment with the design values and verified their reliable and safe operation,” said Kursk NPP Director Alexander Uvakin. “At 100% power, we will once again study the neutron-physical characteristics of the core, study the behaviour of the reactor installation in various scenario conditions, test in-reactor control systems, test the mode of complete de-energisation of the unit, check the effectiveness of biological protection, as well as the radiation situation at the NPP.”
ASE Vice President and Director of the project for the construction of the Kursk NPP, Oleg Shperle, noted: “Reaching 100% of design capacity is the final stage of the process of commissioning unit 1 of Kursk-II NPP. We can already confidently say that the unit has confirmed the correctness of the solutions adopted in the VVER-TOI project, the high quality of the equipment manufactured and the construction and installation work performed.”
The final conclusion on the readiness of the new heavy-duty VVER-TOI unit for industrial operation will be issued by nuclear utility Rosenergoatom’s acceptance committee after confirmation of the readiness of all launch complex facilities by regulator Rostechnadzor. The power unit is planned to be put into commercial operation later this year.
The projected annual electricity generation units 1&2 of Kursk-II is 19.5 TWh. The final plan for Kursk-II is for four VVER-TOI which will increase output by a total of 20%. Construction of the four units is included in the general plan for Russian electric power facilities until 2042, approved by the Government in December 2024. In total, 38 new power units are to be built in Russia during this period, including projects in seven new regions.
