In-Reactor Tests of Externally Pressurized, Short, Unsupported Lengths of Zircaloy Tubing (AWBA Development Program)

摘要

Results are reported for an in-reactor, short time test of externally pressurized, unsupported lengths of Zircaloy-4 tubing simulating axial gaps in a fuel element pellet stack. Stability of unsupported cladding over fuel stack axial gaps is a design concern for light water breeder reactors because of the desire to maximize neutron economy by minimizing cladding thickness and tightly spacing fuel rods. In turn, both of these design features limit allowable rod prepressurization due to LOCA concerns. The test investigated the tendency of tubing to deform into an axial gap. Four types of Zircaloy-4 tubing having various outside diameters and wall thicknesses were tested: three in the stress relief annealed condition, one recrystallization annealed. (ERA citation 08:026097)