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Status of Fuel Removal from Spent Fuel Pools
The spent fuel pool in the upper part of each reactor building stores fuel rod assemblies that have been used to generate electric power. To reduce the risk from these spent fuel rods, the actual removal of the fuel from the accident-hit reactor buildings, or preparations therefor, are being carried out.
What Are Spent Fuel Rods?
Fuel rods that have been used to generate electric power in a nuclear reactor are replaced with new fuel after they are no longer usable. The replaced fuel rods are spent fuel. Since the spent fuel rods continue to generate heat, they are cooled for stable storage.
Status of Fuel Removal in Each Unit
Unit 1 Status
Survey of internal state
Removal of rubble
(operating floor)
Construction of a large cover
Removal of rubble
(overhead crane, etc.)
Installation of
a fuel handling facility
Removal of fuel
Completed
At Unit 1, removal of rubble from the center portion on the north side of the operating floor, at the upper part of the reactor building, was begun in January 2018.
Work to support the overhead crane and fuel handling machine on the south side of the operating floor was completed in November 2020.
Goiong forward, we plan to construct a large cover that emcompasses the entire building and remove rubble from under the cover.
Unit 2 Status
Survey of internal state
South side of reactor building
Installation of "fuel removal platform
/front chamber/opening/runway girder"
Installation of
a fuel handling facility
Removal
of fuel
Completed
Fuel handling equipment will be installed in preparation for the commencement of fuel removal by FY2026.
Unit 3 Status
Survey of internal state
Removal of rubble
Installation of
a fuel handling facility
Removal
of fuel
Completed
Removal of all fuel from Unit 3 was completed in February 2021.
Unit 4 Status
Survey of internal state
Removal of rubble
Installation of
a fuel handling facility
Removal
of fuel
Completed
Removal of all fuel assemblies from Unit 4 was completed in December 2014.
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Unit 5 Status
The status of the 1,542 fuel rod assemblies is as follows. [As of September 25, 2025]
・Removal completed: 22
・Stored in the spent fuel pool: 1,520
(Spent fuel : 1,352, Fresh fuel: 168)
Secure space in the common pool transfered from Unit 5 spent fuel pool have been making, and the preparations were completed and then the removal of the spent fuel from the Unit 5 spent fuel pool have commenced on July 23, 2025.
In order to proceed with the removal work to the extent that it does not affect the Unit 2 and Unit 1 fuel removal works, the Unit 5 removal work will be temporarily suspended after the start of the Unit 2 fuel removal in FY2026. -
Unit 6 Status
The status of the 1,884 fuel rod assemblies is as follows. [As of September 25, 2025]
・Removal completed: 1,456
・Stored in the spent fuel pool: 198 (Fresh fuel)
・Stored in the fresh fuel storage: 230 (Fresh fuel)
The transfer of the spent fuel stored in the Unit 6 spent fuel pool (1,456 fuel rod assemblies in total) to the common pool was completed on April 16, 2025.
The status of progress on the mid- to long-term roadmap (decommissioning and contaminated water measures team meetings/secretariat conferences) is updated in monthly progress reports and other materials.
See the “Spent fuel pool measures” materials here for details.