Japan’s Monju Fast Breeder Reactor Officially Shut Down For Good

13 Dec (NucNet): The Japan Atomic Energy Agency has filed an application with the Nuclear Regulation Authority for approval of a decommissioning plan for its prototype Monju fast breeder reactor in Fukui Prefecture, southwest Japan, the Tokyo-based industry group Japan Atomic Industrial Forum (JAIF) said. The application is required by law and as a result the Monju FBR is now officially classified as permanently shut down, JAIF said. The NRA has established a safety oversight team to monitor activities at the Monju site. Decommissioning and dismantling is scheduled to be finished by 2047 and cost $3.2bn (€2.86bn). JAIF said the immediate priority is to remove the fuel, which will be done by March 2023. JAIF said the government has not yet specified any alternative destination for the spent fuel, but said officials will work out details of the transportation plan before the fuel is completely removed from the reactor. In earlier statements, JAIF said this might happen by 2022. JAIF said the reactor’s sodium coolant will also be removed from Fukui Prefecture. Monju is a 246-MW sodium-cooled fast reactor designed to use mixed fuel rods of uranium and plutonium and to produce more fissile material than it consumes. Monju reached criticality for the first time in 1994, but it has mostly been offline since 1995 when 640 kg of liquid sodium leaked from a cooling system, causing a fire. Monju was allowed to restart in May 2010 after JAEA carried out a review of the plant’s design, and its safety procedures, which were shown to be inadequate. However, operation was again suspended in August 2010 after a fuel handling machine was dropped into the reactor during a refuelling outage. Monju is a 246-MW sodium-cooled fast reactor at the Tsuruga nuclear power station. It was designed to use mixed fuel rods of uranium and plutonium and to produce more fuel than it consumes. Regarded as the core facility of the government’s policy for nuclear fuel recycling, Monju is different from conventional nuclear power plants, which use water as coolants. Monju uses sodium as the coolant, meaning more sophisticated technology is required for its operation.