Example of method 2 "Retrieving fuel debris from the top (mobile platform)”

ⅰ) Challenges and reference information : (5) Install equipment and access

Task(s): Installation of equipment, transporting control and management of ventilation inside the boundary.

(5) Install equipment and access - Major challenges on the actual method

(1)Prior preparation (2)Install barrier (3)Remove shield plug (4)Remove PCV/RPV upper head (5)Install equipment and access (6)Dismantle and remove internal structures (7)Retrieve fuel debris (8)Collect fuel debris and Transfer canister (9)Clean-up equipment

Installation of equipment

  • Installation and stabilization of the cutting, transporting equipment required for post-process
    - Dismantling and removal of internal structures
    - Retrieving fuel debris
    - Storage of fuel debris and transfer of canisters
    - Remote detachment
  • Maintenance of equipment and actions to trouble
Plant information
Assumptions and prerequisites
  • Allowable load of operation floor and passageway : 1.2t/㎡
  • Size of equipment which should be transported through passageway : Width 1.2m, Height 3m or less
  • Overhead crane specification (Rated load 100t)
  • Air dose rate inside the PCV/RPV
    - Dose rate inside the PCV 100Gy/h
    - Dose rate inside the RPV 1kGy/h
  • PCV exterior effective dose rate
    - Operation floor : 1mSv/h
    - Operation areas other than operation floor : 3mSv/h
    - Passageway inside the building : 5mSv/h
    - Total weight of equipment installed on the operation floor shall be minimized in consideration of seismic safety.

Control of Transportation

  • Operation range of works that workers conduct directly or remotely
  • Method for operating, monitoring and controlling the transport of equipment
Plant information
Assumptions and prerequisites
  • Allowable load of operation floor and passageway : 1.2t/㎡
  • Size of equipment which should be transported through passageway : Width 1.2m, Height 3m or less
  • Overhead crane specification (Rated load 100t)
  • 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
    - Total weight of equipment installed on the operation floor shall be minimized in consideration of seismic safety.

Set-up of Ventilation

  • Design of required air quantity and specification of ventilation facilities
  • Installation of ventilation/exhaust equipment
  • Prevention of radiological release into external environment
  • Exchanging air ventilation filter
Plant information