Specialists from Russia’s Central Research Institute of Mechanical Engineering Technology, NPO TsNIITMASH (part of Rosatom’s Mechanical Engineering Division) have created a new heat-resistant steel of the austenitic class. It is intended for the primary circuit of the planned large-scale lead-cooled fast reactor – the BR-1200. The operating temperature of a reactor will be 500-600 degrees Celsius The development of the new corrosion-resistant type of steel was carried out within the framework of the strategic industry Proryv (Breakthrough) project aimed industrial implementation of a closed nuclear fuel cycle based on fast neutron reactors.
“The development is based on our many years of experience in creating materials for installations with heavy liquid metal coolants using computer modelling, said Sergey Logashov, Director of the Institute of Materials Science within TsNIITMASH. “The resulting material combines the radiation and corrosion resistance necessary for the primary circuit of the BR-1200, thermal stability at temperatures up to 600 degrees Celsius and, most importantly, exceeds the long-term strength characteristics of the reference steel EP302 (currently used for NPPs operating in contact with liquid metal coolant).”
TsNIITMASH specialists also tested the technology of laser welding of austenitic and martensitic-ferritic steels in homogeneous and heterogeneous combinations. It is expected that these combinations will be used in the manufacture of critical equipment elements of the BR-1200. Research has shown that the use of laser welding can significantly increase the productivity of manufacturing welded structures compared with traditional arc methods, while maintaining high quality welded joints. The new technology can also be implemented for existing reactor plants, both VVER and RITM.
The combination of these developments – new high-tech materials and welding technologies – brings closer the successful implementation of the BR-1200 project as another Generation IV Russian nuclear project. The prototype of the BR-1200 is the experimental demonstration BREST-OD‑300, which is being built in the city of Seversk, as part of an experimental demonstration energy complex.
An industrial energy complex consisting of a two-unit NPP with BR-1200 reactor units is also planned to be built in Seversk. In accordance with the industry roadmap, commissioning of the first unit is planned for 2036, the second for 2038. The commissioning of the BREST-OD-300 reactor plant will allow the solution to be scaled up in the field of closed fuel cycle in more powerful gigawatt-class reactors.
