Nuclear reactor operator submits 30-year plan to scrap trouble-prone Monju facility

Kyodo

The operator of the Monju prototype fast-breeder nuclear reactor submitted a plan Wednesday to decommission the trouble-plagued facility located in Fukui Prefecture.

The most recent plan presented to the Nuclear Regulation Authority lays out a 30-year time frame to complete the project despite a number of problems that remain unresolved, including where to store the spent nuclear fuel.

The government had originally hoped the Monju reactor would serve as a linchpin for its nuclear-fuel-recycling efforts as it was designed to produce more plutonium than it consumed.

But it experienced a series of problems, including a leakage of sodium coolant in 1995 and equipment failures in 2012. The plant has only operated intermittently over the past two decades.

Under the latest proposal, the facility’s operator, the Japan Atomic Energy Agency, plans to divide the 30-year disassembly 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 whereby pipes and pumps where sodium coolant was circulated will be disassembled. The agency will begin the primary scrapping of the reactor in the third phase.

In what is to be the first decommissioning of a fast-breeder reactor in the nation, some 26,700 tons of solid radioactive waste is expected to be produced. The local government is calling on the operator to swiftly remove the nuclear fuel and sodium from the prefecture.

After the central government decided to scrap the reactor in December last year, the Fukui Prefectural Government expressed concern over JAEA’s leading role as it had been judged unqualified to operate the reactor safely by the Nuclear Regulation Authority.

In response, the government beefed up oversight over the effort and the agency accepted external experts from electric utilities and manufacturers to play central roles in the decommissioning work.

Prior to the plan’s submission, the agency on Tuesday concluded an agreement on safety measures and regional development plans with the Fukui Prefectural Government and the city of Tsuruga, which hosts the reactor.