Rosatom installs two 95-tonne separator-superheaters at BREST-OD-300

Rosatom has installed two separator-superheaters in their design positions in the turbine hall of the BREST-OD-300 lead-cooled fast neutron reactor. Each unit is 16 metres tall and weighs 95 tonnes.

Concrete pouring for the foundation of the reactor's turbine and generator began in May at Seversk, in Russia's Tomsk region. Rosatom says construction of the turbine unit foundation will be completed by the end of the year, allowing installation of the power unit turbine.

A separator-superheater prepares steam for the turbine's low-pressure cylinder, protecting turbine blades from water droplet erosion and improving the efficiency of the steam turbine unit, Rosatom said.

Construction began in 2021 with 2026 as the initial target

The 300 MWe BREST-OD-300 is part of Rosatom's Proryv, or Breakthrough, project to enable a closed nuclear fuel cycle. It will be the main facility of the Pilot Demonstration Energy Complex at the Siberian Chemical Combine site. The complex will demonstrate an on-site closed nuclear fuel cycle with a facility for the fabrication and re-fabrication of mixed uranium-plutonium nitride nuclear fuel, as well as a used fuel reprocessing facility.

Construction began in 2021, and the initial target date for operation was 2026. In October 2025 the last roofing truss was moved into place on the turbine hall and the 143-tonne metal shell for the central cavity — more than 14 metres tall with a diameter of 8 metres — was installed. The four peripheral cavity shells were installed at the end of 2025, when the reactor vessel was reported to be approximately 70% assembled. A full-scale control-room simulator was commissioned in July.

Initial operation to focus on performance

Initial operation of the demonstration unit will focus on performance, and after 10 years or so it will be commercially oriented, according to Rosatom. Under the plan, if it is successful as a 300 MWe (700 MWt) unit, a 1,200 MWe (2,800 MWt) version, the BR-1200, will follow.

WNA paper lists 20.6 t fuel load and 1.05 breeding ratio

The World Nuclear Association information paper on fast neutron reactors describes the design as a fast neutron reactor of 700 MWt, 300 MWe, with lead as the primary coolant, at 540°C, and supercritical steam generators. It uses mixed uranium and plutonium nitride fuel, the fuel load being 20.6 t. The core breeding ratio is 1.05, effective enrichment is about 13.5%, and the fuel cycle is quoted at 5-6 years with partial refuelling at about 10 months.