UT-4 - AN AUTOMATIC ULTRASONIC TESTER FOR CLOSURES OF HANFORD I&E FUELS

摘要

The most likely route for water entry to the core of a Hanford AISi canned fuel element is through the closures' weld beads and braze layers. An ultrasonic tester—UT-4—was developed to inspect the closures' braze layers for possible water paths. Several test modes were tried during development, but a longitudinal wave system gave the best results. The final product was- a tester capable of resolving the first return echoes from a 16 mil or larger diameter defect located 30 mils or more from the exterior surface of the jacket. A testing station built around the UT-4 will automat¬ically measure the defect, pass or reject the fuel element, and record test results.