Time to shutter Monju

The long-stalled project to commercialize fast-breeder reactor technology has been kept alive by the Abe administration in its plan for the nation’s new basic energy policy. Thus the government once again has missed the opportunity to shutter the Monju prototype reactor — which has been inoperative for most of the past two decades — and to rethink its pursuit of the nuclear fuel cycle based on reprocessing of spent nuclear fuel for consumption at the fast-breeder reactor and other nuclear power plants.

Although the plan says the government will push for a “thorough reform” of Monju’s operator, the Japan Atomic Energy Agency, and aim to wrap up the fruits of its research, the track record of the project’s history raises serious doubts about its prospect.

The fast-breeder reactor has been touted as “dream” nuclear energy technology that produces more plutonium than it consumes — supposedly a boon for the resource-scarce Japan. But most other nations around the world have given up on commercializing the technology due to technical difficulties, including those involved in the use of sodium as coolant, and the massive costs involved.

Japan spent nearly ¥1 trillion on the Monju prototype reactor in Tsuruga, Fukui Prefecture, but the plant has been hit by a series of troubles after it first reached criticality in 1994, including a sodium coolant leak and a subsequent fire the following year and its operator’s attempt to cover up the extent of the accident.

Last year, revelations of safety inspection failures prompted the Nuclear Regulation Authority to issue an order to halt preparatory work for its restart. While the prospect for its future operation remains dim, it costs ¥20 billion each year just to maintain the facility.

Monju has been the core component of the government plan to reprocess spent nuclear fuel from the nation’s nuclear reactors into plutonium-uranium mixed-oxide (MOX) fuel to be consumed again for nuclear power generation.

But the path of the nuclear fuel cycle program has been fraught with a series of setbacks, delays and doubts.

The operation of Monju has been halted for much of the time since 1995, and completion of a spent nuclear fuel reprocessing plant in Rokkasho, Aomori Prefecture, has been delayed for years due to a host of technical glitches and other problems, with its construction costs having already tripled to around ¥2 trillion.

As the Monju project has stalled, the government has pushed for the so-called pluthermal program, in which MOX fuel would be used at ordinary light-water reactors at nuclear power plants, as a stopgap measure to keep up the quest for the nuclear fuel cycle.

But while the fast-breeder reactor can keep using recycled fuel after repeated reprocessing, MOX fuel used at light-water reactors can be reprocessed only once more at most for reuse at such reactors — a cost-inefficient program given the massive expense needed for reprocessing of spent fuel.

Before the March 2011 triple meltdowns at Tokyo Electric Power Co.’s Fukushima No. 1 nuclear power plant, four nuclear power plants in Japan, including the Fukushima plant, had started using MOX fuels after several years of delay. The restart of some MOX-capable reactors are now under safety review by the Nuclear Regulation Authority after most of the nation’s nuclear power plants were shut down in the wake of the Fukushima disasters.

Meanwhile, Japan already possesses a total of 44 tons of plutonium — a product of past reprocessing either at experimental domestic facilities or at overseas facilities using spent fuel from domestic nuclear power plants.

To dispel international fears of proliferation of nuclear materials, Japan, as the sole nonnuclear power that engages in commercial operation to reprocess spent fuel, has pledged that it will not own any plutonium that has no specific use. But the government’s scenario of consuming plutonium stockpiles as MOX fuel at up to 18 reactors at nuclear power plants around the country has been thrown in doubt by the post-Fukushima situation.

The start of operations at the Rokkasho reprocessing plant will only produce more plutonium whose prospect for consumption is uncertain.

The stalemate of the fast-breeder reactor project clearly throws the whole nuclear fuel cycle policy in doubt. But while Monju has been idled for years, policymakers have been unwilling to review the policy. Even the previous Democratic Party of Japan-led administration said it will maintain the program when it called for a phaseout of nuclear power generation by the end of 2030s.

The policymakers fear that declaring an end to the nuclear fuel cycle program could put the nuclear power generation itself in paralysis. About 3,000 tons of spent nuclear fuel from reactors around Japan have been shipped to the storage facility in the Rokkasho complex for future reprocessing.

Aomori Prefecture accepted the spent fuel on promises by the national government and the power industry that the prefecture will not be the final disposal site for nuclear waste.

A 1998 agreement between the parties require the power companies to “swiftly take necessary and appropriate steps” including the transfer of spent fuel out of the Rokkasho complex if the reprocessing program becomes difficult, raising the prospect of massive stockpiles of spent fuel without storage space.

But what the government and the power industry should do is end the policy to push the nuclear fuel cycle project — whose key components are clearly in doubt — and concentrate on finding solutions to these and other problems that could emerge from the ending of the policy, rather than rely on skewed rhetoric aimed at justifying pursuit of the program on the grounds that it will lead to solutions to the related problems.

Keeping the long-dormant Monju project alive without a serious review — along with the pursuit of the much-doubted nuclear fuel cycle program — will only add to people’s distrust of the government policy on nuclear energy. The government is urged to think twice about its decision.