U.K.-based Cavendish Nuclear, a subsidiary of Babcock International, will work with Amentum on the next phase of work supporting the decommissioning of Japan’s Monju prototype fast reactor under a contract awarded by the Japan Atomic Energy Agency.
Under the contract, Alkali Metal Processing Ltd., a joint venture between Cavendish Nuclear and Amentum, will construct, commission, and secure regulatory permissions for a new facility in the U.K. to treat nonradiological sodium coolant removed from the reactor. The sodium coolant is to be converted into sodium hydroxide for general industrial reuse.
Located in Fukui Prefecture, Monju was a sodium-cooled, MOX-fueled fast reactor with three primary coolant loops. Plagued by incidents and limited operation (it has been reported that the reactor operated for only 250 days since reaching criticality in 1994), the Japanese government decided in December 2016 to end the Monju project and decommission the reactor.
According to Cavendish, the award builds on a previous contract that focused on the design and engineering phase of the U.K.-based project and represents a key milestone in the decommissioning program and the companies’ collaborative relationship with the JAEA.
The Alkali Metal Processing joint venture is now moving forward with construction, installation of process equipment, and preparations for operation, working with locally based supply chain partners. Cavendish added that the approach draws on both companies’ experience gained from the decommissioning of the U.K.’s Dounreay prototype fast reactor, which shares design similarities with Monju.