Example of method 3 "Retrieving fuel debris from the side”

ⅰ) Challenges and reference information : (2) Install barrier

Task(s): Installation of barrier based on the dose rate and allowable load of the floor, and equipment specification inside the barrier.

Arrangement of work environment to install barrier for preventing release of radioactive substance
Securement of necessary area on 1st. floor
Condition of damage and difference in level on 1st. floor
Design of areas for barrier assembly and temporary storage of materials on 1st. floor
Monitoring of radiation after installing barrier

Plant information	Atmospheric environment inside PCV (temp, dose rate, etc.) Plain view (Unit 1) Plain view (Unit 2) Plain view (Unit 3)

Assumptions and prerequisites	Assume that the rubbles are removed and decontamination work proceeds in 2020 when fuel debris retrieval starts No shielding or air tight function for boundary by the container covering operation floor is counted Effective dose rate outside the PCV - Operation floor :1mSv/h - Operation areas except for operation floor : 3mSv/h - Passageway inside the building : 5mSv/h

Transportation of barrier (Disassemble into the parts to be transferred.)
Assembly and installation of barrier
Design of transportation, shielding equipment, ventilation facility, etc. inside the barrier
Installation of ventilation facilities
Maintenancing boundary when carrying in and out equipment from/to the barrier etc.

Plant information	Plain view (Unit1) Plain view (Unit2) Plain view (Unit3)

Assumptions and prerequisites	Allowable load of 1st. floor : 1.2t/㎡ Size of equipment which should be transported through passageway : Width 1.2m, Height 3m or less Use existing opening, hatch, and stairs inside the reactor building for accessing each floor and delivering the equipment to each floor. No new openings, in principle, shall be created on the outer wall of the building. (Seismic resistance and leakage prevention of radioactive materials shall be considered when creating new openings.) Total weight of equipment installed on the operation floor shall be minimized in consideration of seismic safety.

Assumptions and prerequisites

Allowable load of 1st. floor : 1.2t/㎡
Size of equipment which should be transported through passageway : Width 1.2m, Height 3m or less
Use existing opening, hatch, and stairs inside the reactor building for accessing each floor and delivering the equipment to each floor.
No new openings, in principle, shall be created on the outer wall of the building.
(Seismic resistance and leakage prevention of radioactive materials shall be considered when creating new openings.)
Total weight of equipment installed on the operation floor shall be minimized in consideration of seismic safety.