Japan's nuclear watchdog has approved a detailed plan for decommissioning the Monju prototype fast-breeder nuclear reactor.
Dismantling of the plant in Fukui Prefecture, central Japan, will take 30 years to complete.
The Nuclear Regulation Authority approved the plan submitted by the Japan Atomic Energy Agency at a regular meeting on Wednesday.
It calls for dismantling the reactor in 4 phases, ending by March, 2048.
The first phase aims to remove all the nuclear fuel in about 5 years, and is expected to start this year in July.
Questions remain about whether fuel removal from a fast-breeder reactor can be done safely. Removal and safe disposal of liquid sodium coolant is also a concern, as it burns furiously in contact with air or water.
The cost of the decommissioning is estimated to exceed 3.5 billion dollars, and it could go higher if earthquake proofing measures are included.
The government decided in December 2016 to scrap the reactor after a series of accidents and other safety problems.
The Monju was once considered a pillar of Japan's nuclear fuel recycling policy. The project has cost taxpayers 9.4 billion dollars so far.