Amentum and Cavendish Nuclear are working together to assist the decommissioning of the Monju Prototype Fast Reactor (PFR) in Fukui Prefecture, Japan.
Under a contract from the Japan Atomic Energy Agency (JAEA), the two companies are constructing a facility in the UK to treat sodium coolant material removed from the reactor. The end product, sodium hydroxide, will be recycled for industrial use.
Design, construction, operation and final dismantling of the treatment plant is expected to take place over a 10-year period.
“We will draw on our knowledge and experience from previous sodium treatment projects to help execute the sodium removal plan, enabling JAEA to proceed with the decommissioning of Monju,” says Amentum Senior Vice President Andy White. “Dealing safely and effectively with legacy sites protects the environment and is an essential prerequisite for further investment in nuclear technologies to assist with the transition to a net zero carbon economy.”
The Monju sodium does not present any significant radiological concern but does require careful treatment and handling to minimize the hazards associated with reactive alkali metal.
Similar in design to the Prototype Fast Reactor at Dounreay in the UK, the Monju plant was intended to use up spent nuclear fuel from Amentum’s nuclear power stations. It began operations in 1994 and was shut down in 2010. Amentum and its UK heritage firms have been working at the Dounreay site in the Scottish Highlands for more than two decades, managing highly complex decommissioning, demolition and clean-up projects.
“It is encouraging that JAEA can now engage in this important project with Cavendish Nuclear and Amentum which have a high level of technology based on their experience in the UK. JAEA wishes that the relationship between us will be further enhanced,” says JAEA President Koguchi Masanori.