Review and down-selection of NDE technologies suitable for ITER cooling water system remote weld inspections

ITER In-Vessel Components (IVCs) will have limited lifetimes and need to be maintained and/or replaced during the operational life of ITER. IVCs are attached to the plant cooling water system via pipework to enable active cooling of the components during plasma operations. When maintenance is required, Remote Handling Systems (RHS) will be used to remotely cut the connecting pipework as the environmental and space constraints are not suitable for humans. The components will then be transferred into the Hot-Cell Facility where they can be inspected, refurbished or disposed. During reinstallation, remote rewelding of the pipes will be required. The integrity of the remotely welded joints must be demonstrated remotely by the means of Non-Destructive Evaluation (NDE) to ensure the weld quality requirements are met. Establishment of a weld acceptance process that can be applied to all remote welds across ITER is therefore required. In this study, applicable NDE technologies for ITER remote weld inspection are reviewed. Scoring criteria is defined and Eddy Current Testing (ECT) and Phased Array Ultrasonic Testing (PAUT) were selected as the most suitable technologies for the defined use cases.