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

ⅰ) Challenges and reference information : (7) Retrieve fuel debris

Task(s): Methods of monitoring operation and arranging environment for cutting.

(7) Retrieve fuel debris - 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

Cutting method

  • Method to cut fuel debris
⇒Cutting and dust collection technology
Plant information
Assumptions and prerequisites
  • Fuel debris could be large melted lump depending on its location.
    Also, contents of the compound vary widely depending on the location.
    Some of those may be mainly consist of fuel material and some may be metal.

Status check for fuel debris etc.

  • Method for monitoring fuel debris retrieval work etc.
  • Lighting method for monitoring
  • Identification of fuel debris
⇒Visual and measurement technology
Plant information
Assumptions and prerequisites
  • Air dose rate inside the PCV/RPV
    - Dose rate inside the PCV 100Gy/h
    - Dose rate inside the RPV 1kGy/h
  • Visibility inside PCV/RPV is very low due to no lighting provided

Environmental effect

  • Environmental effects and impacts when retrieving fuel debris
  • Method for collection of cut chip etc.
⇒Cutting and dust collection technology
Plant information