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” > (6) Retrieve fuel debris

ⅰ) Challenges and reference information : (6) Retrieve fuel debris

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

(6) Retrieve fuel debris - 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

Cutting method

  • Method to cut fuel debris
  • Scope of retrieval (Confirm the feasibility of cutting inside of RPV)
⇒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
  • Hydrogen accumulation in upper side of PCV
⇒ Visual and measurement technology
Plant information
Assumptions and prerequisites
  • PCV/RPV interior air dose rate
    - PCV interior dose rate 100Gy/h
    - RPV interior dose rate 1kGy/h
  • Visibility inside PCV/RPV is very low due to no lighting provided
  • Give consideration to the possibility of the accumulation of hydrogen gas inside PCV/RPV when cutting fuel debris or internal structures

Environmental effect

  • Environmental effects and impacts when retrieving fuel debris
  • Method for collection of cut chip etc.
⇒Cutting and dust collection technology
Plant information
→(7) Transfer canister