5 Nov (NucNet): The state-run Japan Atomic Energy Agency (JAEA) is “not fit to operate” the Monju prototype fast breeder reactor (FBR) because it has repeatedly failed to correctly carry out inspections of the plant, Japan’s nuclear regulator has said.
According to the Japan Atomic Industrial Forum (Jaif), the Nuclear Regulation Authority (NRA) has recommended that the Ministry of Education, Culture, Sports, Science and Technology – the ministry with authority over JAEA – find another operationor to replace JAEA within six months.
Jaif said the recommendation has no force of law, but the ministry is required to respond to it.
Jaif did not give any details of the inspection failures, but said the NRA had referred to “repeated insufficient inspections of equipment”.
In May 2013 JAEA president Atsuyuki Suzuki resigned after the NRA prevented the restart of Monju due to inspection deficiencies. In November 2012 it was revealed that JAEA had failed to conduct regular inspections on almost 10,000 out of a total 39,000 pieces of equipment at Monju. Some of these included safety-critical equipment. In January 2013, the NRA ordered JAEA to change its maintenance rules and inspection plans.
The NRA said the organisation responsible for the Monju FBR should have the technological capability to perform its operations precisely and “other abilities required to secure safety”. A party to replace JAEA should be identified, the NRA said.
If a suitable party cannot be identified, the future of the Monju FBR should be reviewed, including the possibility of decommissioning it, Jaif quoted the NRA as saying.
Jaif said the NRA is expected to discuss its recommendation in more detail at a scheduled meeting next week.
Monju is a 246-megawatt sodium-cooled fast reactor at the Tsuruga nuclear power station in Fukui Prefecture, southwest Japan.
In December 1995, just months after the reactor first started power transmission, it was shut down when 640 kg of liquid sodium leaked from a cooling system, causing a fire. There were no injuries and no radioactivity escaped plant buildings, but the incident was compounded by JAEA’s attempts to cover up the scale of the damage.
Monju was allowed to restart in May 2010 after JAEA carried out a review of the plant’s design, as well as safety procedures, which were shown to have been inadequate. However, operation was again suspended in August 2010 after a fuel handling machine was accidentally dropped in the reactor during a refuelling outage. The device was retrieved almost one year later.
The JAEA took over Monju operations from the Japan Nuclear Cycle Development Institute, which was created in 1998 through a reorganisation of Power Reactor and Nuclear Fuel Development Corporation.
Monju uses mixed fuel rods of uranium and plutonium, and is made 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. Monju reached criticality for the first time in 1994, but it has mostly been offline since 1995.
