Inspection experience in determining fabrication flaws in a reactor pressure vessel using SAFT-UT

Pacific Northwest National Laboratory has examined U.S. reactor pressure vessel material in order to measure the density and size of fabrication flaws. The Pressure Vessel Research User Facility (PVRUF) vessel at Oak Ridge National Laboratory was inspected using the Synthetic Aperture Focusing Technique for Ultrasonic Testing field data acquisition system. An inspection methodology was developed specifically for recording small fabrication flaws. This methodology was used to detect and characterize 2500 indications in the PVRUF vessel. Rules were developed and applied to the detection process. The characterization steps have been documented. The spatial dependence of the indication density shows the greater concentration of fabrication flaws in the weld metal and heat affected zone compared to the base metal