Patent Number: 062228978
Section: abstract

Scan methods of inspecting piping and welds of a pipe elbow in a reactor pressure vessel of a boiling water reactor are disclosed. The scan apparatus includes a motor connected to a scan head having two ultrasonic transducer probes each including an ultrasonic transducer, a transducer arm connected to each transducer probe, a scan platform having an arcuate cutout, and a connector connecting each transducer arm to the scan platform. The scan head allows the transducer probes to remain substantially in contact with the pipe elbow while the scan head traverses the pipe elbow. The scan apparatus further includes a pivot arm connecting the scan platform to a pivot pin. The method includes the steps of positioning the scan head and the transducer probe such that the ultrasonic transducer is substantially in contact with the pipe elbow surface. Then moving the scan head axially along the pipe elbow in a first direction while maintaining the ultrasonic transducer in substantial contact with the pipe elbow surface. Then incrementally rotating the probes, in a raster type manner, and moving the scan head axially along the pipe elbow in a second direction. The steps are repeated until the entire pipe elbow surface has been inspected.