TOKYO — The operator of the Monju prototype fast-breeder nuclear reactor on Wednesday submitted a plan to decommission the trouble-plagued facility over the next 30 years.The submission of the latest plan to the Nuclear Regulation Authority is likely to mark a step forward but a number of problems remain over the dismantling of the reactor in Fukui Prefecture, central Japan. In particular, a location to receive the spent nuclear fuel is yet to be determined.
The government had originally hoped the Monju reactor would serve as a linchpin for nuclear fuel recycling efforts as it was designed to produce more plutonium than it consumes while generating electricity.
But it experienced a series of problems, including a leakage of sodium coolant in 1995 and a very high number of equipment inspection failures in 2012, and has barely operated over the past two decades.
Under the latest proposal, the Monju operator — the Japan Atomic Energy Agency — plans to divide the 30-year period through 2047 into four phases. In the first phase, nuclear fuel will be extracted from the reactor core and other places by March 2022, followed by the second phase in which the operator prepares to decommission pipes and pumps where sodium coolant has circulated.
The agency will begin scrapping the reactor in the third phase but has not disclosed detailed working processes from this point.
In the first decommissioning of a fast-breeder reactor in Japan, some 26,700 tons of solid radioactive waste are expected to be produced. The local government is calling on the operator to take spent nuclear fuel and sodium out of the prefecture swiftly.
After the central government decided to scrap the reactor in December last year, the Fukui prefectural government expressed concern over the agency taking the decommissioning role as it had been judged unqualified to operate the reactor safely by the NRA.
In response, the government beefed up oversight functions and the agency accepted external experts from electric utilities and manufactures to play central roles in decommissioning works.
Prior to the plan’s submission, the agency concluded on Tuesday an agreement on safety measures and regional development plans with the Fukui prefectural government and the city of Tsuruga, which hosts the reactor.