SI - Dresden Service Water Engineering Evaluations and G-Scan Inspections

Abstract

In 2005, Structural Integrity Associates, Inc. (SI) assisted Dresden nuclear station in locating and characterizing a leak in a 54 inch buried service water pipe using long range guided wave ultrasonics (G-Scan™) inspection and engineering evaluations. The SI support to Dresden permitted the magnitude of degradation that had produced the leak to be understood and permitted structural integrity assessments of the piping to be made that allowed the plant to continue to operate safely until one of the two Dresden units was scheduled for an outage. At that time, both Dresden units were brought down, the line was dewatered, and a non-metallic structural repair was applied to the leak location as well to other locations with lesser degradation that had been detected during the original inspection. An overview of the G-Scan™ method and details of the subject inspection and analysis are discussed.