Japan is apparently finally pulling the plug on Monju, an experimental reactor plagued by accidents, cover-ups, cost overruns, and other problems that have idled it for all but a few months since it came online in 1994. Japanese media report that at an extraordinary evening meeting today, the nation's cabinet decided to set up a committee to explore decommissioning Monju, which was supposed to play a key role in burning plutonium accumulating in spent fuel of Japan’s conventional nuclear power reactors.
Monju was intended to burn plutonium typically blended with natural or reprocessed uranium and produce, or breed, more fissile fuel than it consumes. It was once seen within the global nuclear research community as a bold experiment, as similar breeder reactor programs elsewhere were halted.
But high hopes for Monju, which for security reasons sits on an isolated spit of land ringed by mountains on the Sea of Japan coast, came crashing to Earth just months after the reactor achieved criticality—a self-sustained nuclear reaction—in April 1994. The following December, it suffered a massive sodium coolant leak and a resulting fire. The Japan Atomic Energy Agency (JAEA), the plant's operator, tried to cover up the accident—vastly exacerbating its impact. Continuing accidents and safety issues have kept Monju offline ever since, except for a brief period in 2010.
Last November, Japan's Nuclear Regulation Authority recommended stripping JAEA of responsibility for operating Monju because of persistent safety issues. Japan's utilities soured on the fast breeder concept long ago, so no other potential operators stepped forward. And citizens' groups have long urged scrapping Monju, which has cost Japan's taxpayers $10 billion.
A final decision on Monju won't be reached until the end of this year.