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.