Procedures for Decommissioning and Contaminated Water and Treated Water Management at TEPCO's Fukushima Daiichi NPS

Efforts to decommission damaged nuclear reactors have been continued at Tokyo Electric Power Company (TEPCO)'s Fukushima Daiichi NPS. Since all units achieved cold shutdown condition in December 2011, the units have all remained stable and under control up until now.

Procedures for decommissioning Tokyo Electric Power Company (TEPCO)'s Fukushima Daiichi NPS are unprecedentedly challenging. The Government of Japan takes the initiative to carry out measures safely and steadily in line with the Mid- and Long-term Roadmap towards the Decommissioning of Tokyo Electric Power Company Holdings' Fukushima Daiichi NPS (Mid- and Long-term Roadmap). Specifically, efforts have been made for the removal of fuel from spent fuel pools, fuel debris retrieval, measures for contaminated water, disposal of the ALPS treated water, treatment and disposal of waste, and demolition of reactor facilities, etc.

In December 2019, the Mid- and Long-term Roadmap was revised and the method of fuel debris retrieval for the first unit was finalized. The finalized plan is to commence with trial retrieval of the fuel debris from Unit 2 first, and then expand the scale of the retrieval work in stages. For completing the decommissioning by 2041 to 2051, decommissioning procedures will continuously be implemented while placing top priority on ensuring safety.¹

1. In September 2024, with the start of trial retrieval of fuel debris, the process moved on to Phase 3, the period from the start of fuel debris retrieval up to the completion of decommissioning.

• Included in this reference material on February 28, 2018
• Updated on March 31, 2025