Fuel Removal from Unit 2 Spent Fuel Pool
The spent fuel pool in the upper part of the reactor building stores fuel rod assemblies that were used to generate electric power. Hydrogen explosions occurred in Units 1, 3, and 4, whereas Unit 2 was spared such an explosion because hydrogen escaped through the partially collapsed walls of the reactor building. Currently, various strategies are being studied in preparation for removal of fuel from the spent fuel pool of Unit 2.
Unit 2 Status
Progress Status
Step 1: Survey of internal state
Operating floor surveys were conducted on the way to fuel rod removal.
Step 2: Construction of a fuel handling facility (access gantry+front chamber) on the south side of the reactor building
Studies and work are proceeding on construction of a fuel handling facility (access gantry+front chamber).
Step 3: Installation of a fuel handling facility
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Step 4: Removal of spent fuel
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Completed
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Surveys inside Reactor Building
In preparation for removal of fuel from the spent fuel pool of Unit 2, a room called a front chamber was built on the west side of the Unit 2 reactor building. Then in June 2018, an outer wall opening was completed on the west side of the building. Survey work inside the operating floor has now been conducted in advance of studies on measure to suppress scattering of radioactive materials when the upper part of the reactor building is dismantled.
Construction of a Fuel Handling Facility (Access Gantry+Front Chamber) on the South Side of the Reactor Building
The first priority in devising the fuel removal method is ensuring the safety of the surrounding area. After studies were conducted based on various risk scenarios, it was decided to revise the plans calling for dismantling of the upper part of the reactor building, given the downward trend in air dose rates on the operating floor. Following the revision, a fuel handling facility (access gantry+front chamber) is being constructed for transporting fuel rod assemblies out of the building on the south side. By connecting the front chamber and the building, a fuel removal system will be carried in and set up on the operating floor, and fuel will be removed by remote operation. Since this method does not involve dismantling of the upper part of the building, work can be performed in a state in which dust, including radioactive materials, is controlled.
