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Toshiba

Toshiba

🇯🇵 Tokyo, JP · Active

Toshiba is a Japanese electronics and engineering group formed in 1939 by the merger of Shibaura Seisakusho and Tokyo Denki, with roots in a company set up in 1875. Its nuclear business sits in Toshiba Energy Systems & Solutions. With Japan's Central Research Institute of Electric Power Industry it designed the 4S, a small sodium-cooled fast reactor; talks with the US Nuclear Regulatory Commission about a 4S for Alaska ran from 2007 to 2011 before the effort was dropped, and in 2026 Zap Energy said it would base a fission product on the design. Toshiba bought Westinghouse for $5.4 billion in 2006, and Westinghouse's bankruptcy in March 2017 caused heavy losses. A consortium led by Japan Industrial Partners took Toshiba private in 2023.

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Sector
Fission, Supply chain
Technology
Heat-pipe microreactor, Sodium fast reactor
Role
Reactor developer, Supplier

Terms

Heat-pipe microreactor
Heat moved by sealed heat pipes rather than pumped coolant or forced convection. No primary pumps and no coolant loop, which suits very small transportable reactors. Heat-pipe describes how heat is moved, not the neutron spectrum. Moderator and fuel vary by design: some designs are fast and unmoderated, others use a graphite or beryllium oxide moderator, with TRISO or metal fuel, usually HALEU.
Sodium fast reactor
Liquid sodium coolant with a fast, unmoderated neutron spectrum. Sodium carries heat superbly at atmospheric pressure, but burns in air and reacts violently with water. Large sodium-cooled cores can have a positive sodium void effect that the core design must offset. Fuel is typically metal alloy or mixed-oxide.

Designs

Design Developer Approach Electrical output per unit Size class Licensing stage
4S Super-Safe, Small and Simple Toshiba Sodium fast reactor 10 MWe planned Microreactor No milestone recorded
MoveluX Toshiba Heat-pipe microreactor 3 to 4 MWe planned Microreactor No milestone recorded

Related companies

Sources