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

Index > Application field：Prior preparation｜Application field and the issues on "Visual and measurement technology”

ⅰ) Application field ： Prior preparation

Requirements on application

Challenges on steps

Verification of the following
  • Condition of existing shield plug
  • Condition of PCV/RPV upper head
  • Location, shape and condition of internal structures
  • Location, shape and condition of fuel debris
  • Condition of hydrogen accumulation
  • Condition of radiation dose rate
  • Condition of dust　measurement
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

  • Approach into the narrow place with high dose rate
  • 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
  • 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

Measurement technology

  • Approach into the narrow place with high dose rate
  • 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
  • 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
→Application field ： Retrieve fuel debris｜Application field and the issues on "Visual and measurement technology”