Ultrasonic Waveguide Transducer for ...

An ultrasonic imaging system based on the waveguide technique was developed to provide in-service inspection of reactor core and mechanical components in sodium-cooled fast reactors (SFR). By using the ultrasonic waveguide technique, we overcome the major technical challenge in developing an under-sodium viewing (USV) system that can sustain the high-temperature, high-radiation, and corrosive environment. The developed ultrasonic waveguide transducers (UWTs) show high detection sensitivity with minimal background noise by effectively reducing spurious echoes and mode conversions. The performance of UWTs was demonstrated in liquid sodium up to 650?F (343?C). C-scan images of a target were successfully developed from both time-of-flight and amplitude variations of the reflected echoes. The ultrasonic waveguide imaging system demonstrates a capability of detecting defects with 1mm in width and 0.5mm in depth under sodium. The developed imaging system would have broad applications for industries, energy or manufacturing, involving harsh environments.