Ultrasonic testing of nuclear fuel rod welds and clad (LWBR Development Program)

Ultrasonic techniques were developed utilizing commercially available equipment as a part of the work required in the LWBR Core Manufacturing program for assurance of fuel rod weld integrity and for measurement of fuel rod clad thickness and clad thickness eccentricity. The need for the highest possible resolution and the undesirability of transducer to rod contact dictated the use of a water immersion technique with pulse-echo instrumentation for both weld and clad thickness ultrasonic tests. For the weld test, both longitudinal wave and shear wave inspections were employed with the transducers shuttled together back and forth longitudinally across the weld zone as the fuel rod was rotated. For the clad thickness test, only the longitudinal wave inspection was used with a helical scan pattern along the full length of the clad