The first stage of concreting has been completed for the internal cavity of the BREST-OD-300 reactor under construction at the Siberian Chemical Combine (SKhK – Sibirskovo Khimicheskovo Kombinata) in Seversk, Tomsk region as part of the pilot demonstration power complex (ODEK – Opitno Demonstratsionovo Energo-Kompleksa). ODEK is being built as part of the strategic industry Proryv (Breakthrough) project to demonstrate a closed nuclear fuel cycle. As well as BREST, ODEK includes on-site nuclear fuel cycle facilities including a module for fuel fabrication and refabrication and a module for reprocessing and recycling irradiated fuel. The fuel fabrication unit began operation in December 2024.
The lead-cooled BREST-OD-300 fast neutron reactor has an integrated layout. The vessel is not an all-metal structure, like that of the VVER light water reactor, but a metal-concrete structure, inside of which metal cavities are mounted for the placement of the core and primary circuit equipment. The space between these cavities will be filled in stages with concrete, which becomes part of the supporting structure, while simultaneously performing the functions of thermal and radiation protection.
“The design of the reactor vessel has no precedents in world practice. The integrated layout of BREST-OD-300 made it possible to apply this solution, which will give the installation additional safety and reliability,” noted ODEK Director Dmitry Zozulya.
At the same time, preparations for the installation of reactor equipment continue at the site. All equipment is manufactured by Russian enterprises from special high-strength materials. Earlier in 2026, the installation of a pipeline system connecting the central and four peripheral cavities of the BREST-OD-300 reactor plant housing was completed. This made it possible to close the first circuit, where lead coolant will circulate, transferring heat from the core located in the central cavity to steam generators installed in the peripheral cavities.
To train operating personnel, a full-scale simulator has been created at the SKhK training and information centre, simulating the operation of a power unit with a BREST-OD-300 fast reactor.
