Japan is expected to decommission its prototype fast-breeder nuclear reactor at Monju in Fukui Prefecture, which has faced a series of technical, economic and safety problems since first achieving criticality in 1994, including a serious leakage of sodium coolant and fire in 1995. The reactor had only been operational for 250 days before the Fukushima accident in March 2011, which resulted in all of Japan’s reactors being closed down, pending safety checks.
Revelations of a massive number of equipment inspection failures in 2012 and subsequent lax management practices led the Nuclear Regulation Authority (NRA) to conclude last November that the operator, the Japan Atomic Energy Agency, was not qualified to safely operate the reactor. However, the Ministry of Education, Culture, Sports, Science and Technology, which oversees the Monju project, has been unable to find a new operator.
The ministry then considered other ways it could continue operation, but the government now appears to favour scrapping it, not least because of the heavy cost involved. The Ministry estimated it will require at least JPY580bn ($5.7bn) to restart the reactor, including funds needed to upgrade the facilities to meet new safety requirements introduced after the Fukushima disaster. This assumes that it would take about 10 years to complete the work to refurbish the facilities, and another five or six years to accumulate data by running the reactor.
The government decided on 21 September to rethink its policy. "Regarding the Monju project, we will fundamentally review it by the end of the year, including (the option of) scrapping it," Chief Cabinet Secretary Yoshihide Suga said during a meeting of ministers. Suga said a panel to discuss Japan’s fast-reactor development policy will be launched and the fate of the Monju reactor will be discussed there. The project has already cost more than JPY1,000bn and has also led to concern over the build-up in stocks of plutonium, which the reactor was meant to burn.
However, the government continues to support plans to burn plutonium-uranium mixed oxide fuel (mox) in conventional reactors as a way to consume plutonium, despite public opposition amid safety concerns. Local media quoted “sources close to the matter”, as saying the government is likely to continue fast-reactor development by using the Joyo experimental reactor in Ibaraki Prefecture created as the first stage of the fast breeder reactor development project. Japan may also consider partnering with France to develop a fast reactor, the sources said.