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

Index > Challenges and Plant information : Overview of methods ｜Example of method 3 "Retrieving fuel debris from the side” > (3) Create opening on the side of PCV

ⅰ) Challenges and reference information : (3) Create opening  on the side of PCV

Task(s): Cutting, boundary under narrow high dose rate, countermeasure against dose rate increase.

(3) Create opening on the side of PCV - Major challenges on the actual method

(1)Prior preparation (2)Install barrier (3)Create opening on the side of PCV (4) Install equipment and access (5)Dismantle and remove internal structures (6)Retrieve fuel debris (7)Transport canister (8)Clean-up equipment

PCV cutting Boundary maintenance

  • Method for cutting work under the environment of high dose rate, narrow and crowded with structure outside PCV (Out of scope of the cutting and dust collection technology written in the RFP)
  • Maintenance of boundary during installing a new opening on PCV
  • Control Method of atmospheric environment inside PCV after installing a new opening on PCV
Plant information

Countermeasure against dose increase

  • Process of wastes during removing internal structures and PCV
  • Management of dose rate increase when installing the opening on the side of PCV
Assumptions and prerequisites
  • Air dose rate inside the PCV/RPV
    - Dose rate inside the PCV 100Gy/h
    - Dose rate inside the RPV 1kGy/h
  • Effective dose rate outside the PCV
    - Operation floor : 1mSv/h
    - Operation areas except for operation floor : 3mSv/h
    - Passageway inside the building : 5mSv/h
  • Withstand load / Dimensional limit of access routes.
    - Withstand load of floor and passageway : 1.2t/㎡
    - Dimensional limit of floor and passageway : W 1.2m･H 3m
  • Allowable load / size of access routes.
    - Allowable load of floor and passageway : 1.2t/㎡
    - Size of equipment which should be transported through passageway : W1.2m, H3m or less
→(4) Install equipment and access