It's been operating for only 250 days since 1995.
The Japanese government has officially approved the decommissioning of the 280 MW plutonium-burning Monju fast-breeder reactor (FBR), which has been operating only 250 days since its commissioning in 1995, according to Enerdata.
The Japan Atomic Energy Agency (JAEA) proposed a plan to carry out the dismantling of the idled reactor and the government endorsed it.
Here's more from Enerdata:
The Monju FBR is a MOX- fed reactor which was supposed to produce more fuel than it consumes and thus help Japan with energy security and nuclear waste management.
Instead, the Monju reactor run only 205 days in 1995 before being stopped due to a sodium leak, and another 45 days in 2010 before being stopped again due to refuelling equipment falling into the reactor vessel.
At that point, the Japanese Nuclear Regulation Authority (NRA) did not allow it to restart and stated that the JAEA was not competent to operate the facility.
Estimations of the decommissioning are expected to total at least Yen375bn (US$3.2bn) and and the process will take at least 30 years.