The second stage of the containment for Russia’s lead-cooled Brest-OD-300 fast reactor has been completed at the construction site on the territory of the Siberian Chemical Combine (part of Rosatom’s fuel company TVEL). The Brest-OD-300 reactor is part of the pilot demonstration power complex (ODEK - Opitno Demonstratsionovo Energo-Kompleksa), which is being developed under the Breakthrough (Proryv) project intended to demonstrate closed fuel cycle technology.
The ODEK project also includes a module for fabrication and refabrication of nuclear fuel (MFR) and a module for reprocessing irradiated fuel. The reactor is scheduled for grid connection in 2027; the MFR is almost completed and planned for commissioning this year; construction of the reprocessing unit is planned for 2025-2026 for commissioning in 2030.
The newly installed containment section along with rigging equipment weighs 184 tonnes. The weight of the installed unit together with rigging equipment is 184 tons. The containment of the Brest-OD-300 reactor consists of three blocks and provides an additional barrier to protect the reactor installation and follows the boundary of the coolant circuit.
The total mass of the enclosing structure is 429 tonnes, of which 312 tonnes have already been installed. The first block was installed in December 2023 - January 2024. The third enlarged unit is planned to be installed in the reactor shaft in December 2024. As a result, the height of the structure will be 17 metres, and the cavity will be filled with special, heat-resistant concrete, providing strength to the metal-concrete frame of the housing, inside which the reactor will operate.
The advantage of fast neutron reactors is the ability to efficiently use secondary products of the fuel cycle for energy production (in particular, plutonium). At the same time, having a high breeding rate, fast reactors can produce more potential fuel than they consume, and can also burn highly active transuranium elements (actinides) for energy production. The Brest-OD-300 reactor will supply its own main energy component – plutonium-239, by producing it from the uranium-238 isotope, which comprises more than 99% of natural uranium ore. Currently the fissile uranium-235 isotope used to produce energy in thermal reactors comprises only 0.7% of natural uranium. The introduction of fast reactor technologies will greatly increase the efficiency of using natural uranium.
Unlike traditional VVER reactors, the Brest-OD-300 reactor has an integral layout. The VVER reactor vessel is an all-metal structure, and the primary circuit equipment (steam generators, main circulation pumps, etc.) is connected to it through the main circulation pipelines. The Brest-OD-300 reactor vessel, however, is a metal-concrete structure, in which metal cavities are provided to hold the primary circuit equipment and the space between the cavities is gradually filled with concrete. Also, compared with the VVER vessel, the Brest-OD-300 vessel is a larger, the delivery of which is possible only in sections and its final assembly is possible only at the construction site.
Image courtesy of SCC
