Melt behavior of aluminum clad rods

摘要

Since the Li-Al alloy cores in control rods used to control production reactors are susceptible to corrosion by heavy water, they were clad with Al. This paper reports results of an experimental and numerical study of the behavior of control rods heated to the point of clad and rod-core failure. Results show that the core of the rod melts first; the clad fails only after significant additional heating. Once the rod breaks and drops to the bottom of the quartz tube in the furnace, the lower section of the rod fails by ''poker-chipping'' downward as the topmost portion fails before the portion below it. Part of the core in the remaining top of the rod relocates immediately after rod separation, leaving a hollow tube of Al which also melts upon further heating.