Concept art of a tank type sodium-cooled fast reactor. (Image: MHI)

The Japanese government has chosen Mitsubishi Heavy Industries (MHI) to head up the conceptual design and research and development of a demonstration sodium-cooled fast reactor, the Tokyo-based engineering firm announced recently.

MHI is to oversee the work in partnership with Mitsubishi FBR Systems Inc. (MFBR), an MHI Group engineering company established in 2007 to develop and design fast breeder reactors.

Conceptual design work is scheduled to commence in fiscal year 2024, with operation of the unit slated for the 2040s.

Reactor roadmap: According to MHI’s announcement, in the strategic roadmap for fast-reactor development adopted by the Japanese Cabinet in December 2018, a policy was defined to assess the efficacy of several types of technologies to be developed following a competition among private-sector companies. The roadmap was subsequently revised by the Cabinet in December 2022, at which time two decisions were made: (1) to select a sodium-cooled fast reactor as the target of the conceptual design of the demonstration unit and (2) to select a manufacturer to serve as the core company in charge of the reactor’s design and requisite R&D.

Natrium, a 345-MWe sodium fast reactor with a molten salt energy storage system, was developed by TerraPower and GE Hitachi Nuclear Energy. TerraPower is planning to build the first Natrium demonstration reactor by 2028 with 50-50 cost-shared funding of about $2 billion from the Department of Energy’s Advanced Reactor Demonstration Program. And for the requisite data and testing of reactor components to support that deployment, TerraPower is looking to Japan—a country with decades of experience developing sodium fast reactor designs and testing infrastructure.