The link between risk-informed in-service inspection and inspection qualification

A growing need exists for a quantitative measure of inspection effectiveness as an input to quantitative risk-informed in-service inspection (RI-ISI). A Probability of Detection (POD) curve could provide a suitable metric, but there can be significant problems associated with generating realistic POD curves by practical trials. The ENIQ inspection qualification methodology is used to provide high confidence that an inspection system will achieve its objectives, but is not designed to provide a quantitative measure of the type that can be used in RI-ISI analysis. This paper describes the results of a project set up to investigate approaches to quantifying the confidence associated with inspection qualification. The project applied quantification approaches in a pilot study and produced guidelines on how to relate inspection qualification results, risk reduction and inspection interval.