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

(7) Retrieve fuel debris - Major challenges on the actual method

Cutting method

Method to cut fuel debris

⇒Cutting and dust collection technology

Plant information	Specification of canister Location and amount of fuel debris Fuel debris properties Atmospheric environment inside PCV (temp, dose rate, etc.) Some 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	Atmospheric environment inside PCV (temp, dose rate etc.） Schematic diagram for internal structures Plain view (Unit1) Plain view (Unit2) Plain view (Unit3) Dimension and weight of internal structures

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

Environmental effect

• Environmental effects and impacts when retrieving fuel debris
• Method for collection of cut chip etc.

⇒Cutting and dust collection technology

Plant information	Atmospheric environment inside PCV (temp, dose rate etc.） Fuel debris properties

→(8) Collect fuel debris and Transfer canisters