Fukushima Unit 2 Decommissioning

The decommissioning work at unit 2 of Fukushima Daiichi has been moving at a significant pace in recent years. Unit 2 was spared from the kind of hydrogen explosion damage that ripped through units 1, 3, and 4. This provided more opportunities to install equipment and work in some areas of the building.

Unit 2 has had a handling building installed along the side of the refueling floor level in the same area as the damaged blow-out panel. This access provided the means to remove equipment and decontaminate the refueling floor level. Even with this extensive work completed, the radiation levels on the refueling floor are unsafe for workers.



Spent Fuel Removal Scheduled: FY 2024-2026
Fuel Debris Removal Scheduled: FY 2021*
Fuel debris removal appears to have been deferred since this date was reported earlier in 2021


Spent Fuel Removal

There is a detailed plan for remote removal of the spent fuel from unit 2’s pool.

Airlock building installed to gain access to the refueling floor and for clean-up activities.


Initial plans involved removing the roof and walls of the refueling floor in order to install a building to remove the spent fuel. This plan was scrapped by 2019 for safety reasons and was replaced with a plan that left the original building largely intact but installed a second platform onto the refueling floor level.

fukushima daiichi unit 2 spent fuel removal building

Spent fuel removal building published by TEPCO in 2019


This defueling building includes a negative air pressure system with HEPA filtration and a hatch to transport spent fuel casks down to the ground level. Internal equipment including cranes and a rail system will be operated remotely.

fukushima daiichi unit 2 fuel removal crane and rail

Fuel cask removal rig and rail to be installed inside unit 2’s refueling floor.



Unit 2 Spent Fuel Removal Articles

Fukushima Daiichi Unit 2 Spent Fuel Pool Inspected
Fukushima Unit 2 Spent Fuel Pool Inspection
SimplyInfo.org Annual Report; Unit 2
Fukushima Unit 2 Has A Spent Fuel Removal Plan
Fukushima Unit 2 Spent Fuel Removal Plan May Drastically Change
Fukushima Unit 2 Refueling Floor Inspection Results
Fukushima Unit 2 Refueling Floor Work Progresses, Poses Risks
Fukushima Unit 2 Wall Removal Begins
Fukushima Unit 2 Decomm Progresses
TEPCO Erects Mystery Platform Around Unit 2 Fukushima Daiichi

Fuel Debris Removal

TEPCO has completed multiple inspections inside the reactor pedestal of unit 2. At least a portion of the fuel debris is located there. A future inspection to attempt to remove samples of fuel debris is planned with a deferred start date due to the pandemic. An elaborate plan to use a retractable arm and a series of hot cells to remove the fuel debris from the pedestal is in place. Research and development work began before the pandemic including a fully constructed robot arm, a hot cell, and some other equipment. We detailed this plan in our 2021 annual report.


The diagrams below from TEPCO and IRID help illustrate the fuel removal process.


fukushima unit 2 fuel debris removal tunnel

An access tunnel is planned to be installed inside the reactor building to provide a contained route from the containment hatch to the hot cell and airlock cells.
fuel debris would be moved from containment through the tunnel. The fuel debris is packed into a shielded container, then moved out through the delivery cell.



fukushima unit 2 fuel debris removal rail and hatch

The above diagram shows the retractable arm inside containment and the interface between the containment wall and the fuel debris removal cells.


fukushima unit 2 fuel debris removal hot cell tunnel

The above diagram explains the secure tunnel that will be used to route fuel debris out of the reactor building. The top left image shows a prototype created for testing. This tunnel also has to bridge from outside the reactor building to the containment structure to avoid placing additional load on the building.


fukushima unit 2 fuel debris removal hot cell tunnel

The images and diagrams above show an isolation room and robot that would be used to open the X6 hatch into containment in an isolated manner. This would prevent the release of radioactive dust. Photos of the isolation room are from a test run with the equipment at unit 5.


fukushima unit 2 fuel debris removal arm

Above diagram of the retractable arm design. that will be installed in containment to remove fuel debris. The end of the arm can be equipped with different cutting and collecting devices.



Unit 2 Fukushima Daiichi fuel removal arm

Photo of the actual retractable arm device being completed in the UK.



Fukushima unit 2 fuel removal mockup

Mockup of the reactor pedestal and rail at one of the R&D facilities.




Fukushima unit 2 fuel debris transit container

Example of the shielded container that will be used to collect and store fuel debris.



Fukushima unit 2 fuel debris glovebox

Glove box portion of the Unit 2 fuel removal system.


Fukushima unit 2 fuel debris spray arm

Debris inside the Unit 2 hatch will need to be removed.


Unit 2 Fuel Debris Removal Articles

New Damage Found At Fukushima Daiichi Unit 2
Fukushima Unit 2 Fuel Debris Plan Further Confirmed
2020 SimplyInfo.org Annual Report; Unit 2
Fukushima Daiichi Unit 2 Containment Inspection
SimplyInfo.org; New Clues To Melt Through At Unit 2
TEPCO Confirms Our Theory On Fukushima Unit 2
Fukushima Unit 2 Extended Timeline
Fukushima Unit 2; New Containment Panorama Photos
Fukushima Unit 2 Fuel Debris Inspection Results
TEPCO To Poke Fukushima Unit 2 Fuel With A Stick
SimplyInfo.org: Unit 2 Fuel Debris Report
SimplyInfo.org Analysis Of Fukushima Unit 2 Pedestal Inspection 2018
Fukushima Unit 2 Inspection Happens Friday
Fukushima Unit 2 To Be Scope Inspected In January
TEPCO Revises Fukushima Unit 2 Radiation Readings
Fukushima Unit 2 Decomm Progresses
Fukushima Unit 2 Confirmation Of Damage Found
Scorpion Dies In Fukushima Unit 2, Sends Back Data
Scorpion Enters Fukushima Unit 2
Scorpion Robot To Make Suicide Mission Inside Fukushima Unit 2
Fukushima Unit 2 High Radiation Damages New Robot
Fukushima Unit 2 New Radiation Readings From TEPCO
Fukushima Unit 2 Robot May Not Go In Due To Dangerous Conditions
Fukushima Unit 2 Failure Point Found!
What The New Fukushima Unit 2 Inspection May Indicate
Fukushima Unit 2 Containment Inspection Starts Jan 18th
Fukushima Unit 2 Containment Inspection, What You Need To Know
Fukushima Unit 2 Containment Inspection Preparation Starts
Fukushima Unit 2 Containment Repair Research Underway
Fukushima Unit 2 Containment Inspection To Happen Early 2017
First Fukushima Unit 2 Muon Scans Dispute New Scan Results
Fukushima Unit 2 Muon Scan Not So Conclusive
Fukushima Unit 2 Muon Scan Shows No Fuel In Reactor

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