Studies on the quantification of NDE reliability

For fifteen years the U.S. Nuclear Regulatory Commission has been funding the Pacific Northwest Laboratory to conduct studies to quantify and make improvements in the reliability of NDE for the inservice inspection of light water reactors. These studies have focused on various aspects of the inspection process including the ultrasonic equipment, inspection procedure, personnel, flaw types, flaw location, flaw orientation, flaw size, material, and component geometrical effects. These studies have included laboratory parametric studies, round robin studies and participation in international studies. These studies have produced an engineering data base for performance demonstration criteria and for developing recommendations to limit the influence and effects of these variables on the reliability of the inspections being performed on light water reactor components. Current studies on risk-based inspections are expected to form the basis for improved ISI programs. This paper will highlight the most significant aspects of the work performed and describe work that is still in progress