Application field and the issues on "Visual and measurement technology”

Index > Application field ：Retrieve fuel debris

ⅰ) Application field：Retrieve fuel debris

Requirements on application

Challenges on steps

  • Observation method for retrieval work
  • Lighting method
  • Identification of fuel debris
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
  • Effective dose rate outside the PCV
    - Operation floor : 1mSv/h
    - Operation areas except for operation floor : 3mSv/h
    - Passageway inside the building : 5mSv/h

Visual technology

  • Long time operation under condition of much higher dose rate than that in Prior preparation
  • Verification of status and location of fuel debris and internal structures by panoramic or detailed observation
    Visual technology :
    - camera
    - Endoscope
    - Fiber scope etc.
Plant information
Assumptions and prerequisites
  • PCV/RPV interior air dose rate
    - PCV interior dose rate 100Gy/h
    - RPV interior dose rate 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

Measurement technology

  • Long time operation under condition of much higher dose rate than that in Prior preparation
  • Measurement of radiation or detection of hydrogen concentration
    Measurement technology ：
    - radiation measurement （gamma-ray, neutron ray）
    - Ultrasonic wave detection
    - radionuclide analysis
    - thermography
    - Detector of hydrogen concentration, etc.
Plant information
Assumptions and prerequisites
  • PCV/RPV interior air dose rate
    - PCV interior dose rate 100Gy/h
    - RPV interior dose rate 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
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