The fourth and final metal shell of the peripheral cavity for the BREST-OD-300 lead-cooled fast neutron reactor has been installed at the construction site. The BREST-OD-300, being built at the Siberian Chemical Combine (SKhK – Sibirskovo Khimicheskovo Kombinata) in Seversk, Tomsk region, is part of the pilot demonstration power complex (ODEK – Opitno Demonstratsionovo Energo-Kompleksa), under the Breakthrough (Proryv) Project intended to demonstrate closed fuel cycle technology. As well as Brest, ODEK also includes on-site nuclear fuel cycle facilities including a module for fuel fabrication and refabrication and a module for reprocessing and recycling irradiated fuel.
Installation of the final metal shell of peripheral cavity was carried out using a self-propelled Liebherr crane with increased load capacity. In August and September, the metal shell of the central cavity of the reactor unit, as well as the first three metal shells of the peripheral cavity, were delivered to SKhK. The total weight of the components, which were manufactured at the factories of Rosatom’s Mechanical Engineering Division is more than 1,000 tonnes.
“At the moment, the body of the BREST-OD-300 reactor unit is approximately 70% assembled,” noted Ivan Babich, a representative of the management of the ODEK Complex at SKhK. “In 2026, it is necessary to form a lead coolant circulation circuit, complete concreting of the housing, and install all the main internal devices. Completion of work to assemble the reactor vessel is scheduled for the end of 2026.”
At the next stage, the peripheral cavities of the reactor will be connected to the shell of the central cavity, already installed in September 2025, to form a closed circuit for the circulation of the lead coolant. Steam generators, main circulation pumps, coolant purification system equipment and other in-hull equipment will subsequently be located inside this circuit. The central cavity shell is designed to accommodate the core basket and fuel assemblies.
In December 2025, at the site of the All-Russian Research Institute for the Operation of Nuclear Power Plants (VNIIAES – Vserossiiskii Nauchno Issledovatelskii Institut po Expluatatsii Atomnikh Elektrostantsii), comprehensive tests of a full-scale simulator for the BREST-OD-300 project were completed.
The Institute for the Safe Development of Nuclear Energy of the Russian Academy of Sciences (IBRAE – Institut Problem Bezopasnovo Razvitiya Atomnoi Energetiki) is responsible for modelling the reactor core and primary circuit of a power unit with lead coolant); the NA Dollezhal Scientific Research & Design Institute of Power Engineering (NIKIET – Nauchno Issledovatelskii i Konstruktorskii Institut EnergoTekhnikh imeni NA Dollezhal) developed an automated process control system for the power unit: and JSC Instrument-Making Plant Vibrator (PZV – Priborostroitelnyy Zavod Vibrator) manufactured simulators for the unit and backup control panels.
“An analytical simulator developed by VNIIAES has already been installed and put into operation at SKhK,” noted Egor Klevtsov, head of the ODEK personnel training department. “This is a key technical training tool, since in accordance with federal regulations and rules, personnel training must be completed before the physical start-up of the power unit using a full-scale simulator.”
VNIIAES chief expert Evgeniy Grigoriev said until April 2026 the full scale simulator will be continuously modified and debugged. “In April, the simulator will be disassembled, packaged and transported to Seversk, Tomsk region, to the Siberian Chemical Combine. Acceptance tests will take place, and after that personnel training will begin.”
