High-Resolution X-Probe for 12.9 Mm (0.51") Diameter 1600 Tubing

Abstract

A new high-resolution (HiRes) X-probe was designed to improve the performance of the X-probe for detection and characterization of lay-up induced, localized IGA in 12.9-mm diameter 1600 tubing at the Bruce Nuclear Generating Station. The new probe contains two rows of twelve coils versus the original X-probe's three rows of eight coils and improves profiling, circumferential resolution and characterization of volumetric flaws. This higher coil density per row leads to better detection of localized volumetric flaws and short circumferentially oriented cracks as well as superior characterization of volumetric flaws, when compared to the original X-probe. These changes to the probe design had an impact on the qualification of the probe, since they introduced modifications to an essential variable: number of coils, i.e., coil density. In February of 2008, after several prototypes, studies and field trials, the equivalency of the two probes was demonstrated for flaw detection. This paper summarizes these efforts and the improvements made with respect to the original X-probe, and with successive generations of the HiRes X-probe prototypes. The results presented here demonstrate superior resolution and flaw discrimination for the examination of 12.9-mm diameter I600 SG tubing, which should also be applicable to tubing of similar diameters.