Ultrasonic Inspection Experience of Steam Generator Tubes at Ontario Hydro and the TRUSTIE Inspection System

Abstract

Ontario Hydro have been using ultrasonic test (UT) technique to inspect steam generator(SG) tubes since 1993. The UT technique has higher sensitivity in detecting flaws in SG tubes and can characterize the flaws with higher accuracy. Although an outside contractor was used initially, Ontario Hydro has been using a self-developed system since 1995. The TRUSTIE system (Tiny Rotating Ultra Sonic Tube Inspection Equipment) was developed by Ontario Hydro Technologies specifically for 12.7 mm outside diameter (OD) tubes, and later expanded to larger tubes. To date TRUSTIE has been used in all of Ontario Hydro's nuclear generating stations inspecting for flaws such as pitting, denting, and cracks at top of-tubesheet to the U-bend region.