Monju and the nuclear fuel cycle

Media reports that the government is finally weighing whether to pull the plug on the Monju fast-breeder reactor in Tsuruga, Fukui Prefecture, due to the massive cost needed to restart the long-dormant facility, should come as no surprise. Once touted as a “dream reactor” for an energy-scarce country that produces more plutonium than it consumes as fuel, Monju has been a nightmare for national nuclear power policy for the past two decades. The sole prototype reactor for this kind of technology has been in operation a mere 250 days since it first reached criticality in 1994. It has mostly been offline since a 1995 sodium coolant leak and fire. Its government-backed operator has been declared unfit by nuclear power regulators to run the trouble-prone reactor, and the education and science ministry, in charge of the project, has not been able to find a viable solution.

More than ¥1 trillion in taxpayer money has so far been spent on Monju, and maintenance alone costs ¥20 billion a year. Restarting the reactor under the Nuclear Regulation Authority’s new safety standards would cost another several hundred billion yen, including the expense of replacing its long-unused fuel as well as its aging components — though there would still be no guarantee that it would complete its mission of commercializing fast-breeder reactor technology.

The Abe administration may think that writing off the ill-fated costly project, even with the projected ¥300 billion cost of decommissioning the facility over 30 years, will help win more public support for its policy of seeking to reactivate the nation’s conventional reactors — most of which remain idled in the wake of the 2011 meltdowns at Tokyo Electric Power’s Fukushima No. 1 plant — once they’ve cleared the NRA screening. Public concerns over the safety of nuclear energy remain strong after the Fukushima disaster, with media surveys showing a large portion of respondents still opposed putting the idled reactors back online.

If it is going to decide to decommission the Monju reactor, however, the government should also rethink its pursuit of the nuclear fuel cycle — in which spent fuel from nuclear power plants is reprocessed to extract plutonium for reuse as fuel. Monju, which runs on plutonium-uranium mixed oxide (MOX) fuel, has been a core component of the program. As Monju remained dormant for more than 20 years, the government and power companies have shifted the focus of the policy to using MOX fuel at regular nuclear power plants. The No. 3 reactor at Shikoku Electric Power’s Ikata plant in Ehime Prefecture, which resumed operation in August, runs on MOX fuel. The government apparently thinks the Monju program is no longer essential to the policy.

But the nuclear fuel cycle itself has proven elusive, and some say the policy has already collapsed. It is still nowhere in sight when the nuclear fuel reprocessing plant in Rokkasho, Aomori Prefecture — another key component in the program and whose construction began in 1993 — will be ready for operation.

After its scheduled completion in 1997 has been delayed by more than 20 times due to a series of technical glitches and other problems, its construction cost has ballooned three times the original projection to ¥2.2 trillion.

If indeed the Rokkasho facility is completed and starts reprocessing spent fuel from power plants across the country, the Ikata power plant is currently the only one in operation that consumes plutonium-uranium fuel. It’s not clear how many more will be up and running in the years ahead given the slow pace of restarting the idled reactors, and the Rokkasho facility operating without a sufficient number of reactors using MOX fuel would only add to Japan’s stockpile of unused plutonium — which has already hit 48 tons.

If it’s the cost problem that’s finally spelling doom for the Monju project, the government and power companies should also consider the cost-efficiency of the nuclear fuel cycle program, including the extra cost of reprocessing spent fuel into MOX fuel. They should also think about whether the program is compatible with the government’s stated policy — though its commitment may be in doubt — of seeking to reduce Japan’s dependency on nuclear power as an energy source.

Monju has drifted on for years after its future was clearly in doubt. A decision now to terminate the project seems sensible. Such a decision should also prompt the government to stop and consider whether its nuclear fuel cycle still makes sense.