Research on ultrasonic detection technique of fuel rod failure

Single- and pair-wafer ultrasonic probes were developed. Through the study on the change of ultrasonic signal during fuel rod failure, the detection method and pattern of probe were determined. The results show that fuel rod failure can be identified through the difference of ultrasonic echo amplitude on the acoustic range of 15-20 mm. Compared with single-wafer probe, pair-wafer probe can detect the fuel rod failure more easily, and can effectively detect the minimum amount of water with 0.2 mL. (authors)