Reliability considerations of NDT by probability of detection (POD) determination using ultrasound phased array

Reliable assessment procedures are an important aspect of maintenance concepts. Non-destructive testing (NDT) methods are an essential part of a variety of maintenance plans. Reliability aspects of NDT methods are of importance if quantitative information is required. Different design concepts e.g. the damage tolerance approach in aerospace already include reliability criteria of NDT methods. NDT is also an essential part during construction and maintenance of nuclear power plants. This paper will show the results of a research project designed for POD determination of ultrasound phased array inspections of real cracks. The continuative objective of this project is to generate quantitative POD results and to integrate these results in a probabilistic damage assessment concept. The distribution of the crack sizes of the specimens and the designed inspection instruction will be discussed, and results of the ultrasound inspections will be presented. Furthermore, additional considerations for POD determination of phased array inspections of real cracks will be discussed. In the context of the results, the remaining uncertainty of the inspections has to be taken into consideration for failure analysis.