The prototype Monju fast breeder reactor has been finally shut down. The Japan Atomic Energy Agency is reported to have filed an application with the national regulator, the Nuclear Regulation Authority, to approve a decommissioning plan for the reactor.

The decision to decommission the reactor was announced in December 2016, shortly after a study concluded that it would take eight years to bring the reactor back online and that it would cost ¥540 billion (about $4.82 billion) to operate it. Decommissioning and dismantling the reactor is estimated to cost $3.2 billion. According to the current plan, removal of the fuel is expected to be completed in 2023 and the reactor will be dismantled by 2047.