Interim report on the effect of hot die size process variables upon grain growth in aluminum alloy 8001 cladding

摘要

Three hot die size (HDS) fuel elements charged for the HDS equivalency test, PT-IP-781-A, failed during irradiation (August, 1965) as a result of severe ledge and groove corrosion. Examination of comparison pieces revealed that ledge and groove corrosion was the most severe at the top of the downstream end of the downstream ten pieces as positioned in the process tube. In the case of HDS fuel, the downstream end is the top or cap end of the piece as it is fabricated. It was speculated that ledge and groove corrosion could be an interaction between the HDS fuel assembly process and reactor operation. For this reason, studies were initiated to determine the effect of HDS process variables upon ledge and groove corrosion in out-of-reactor tests. This report summarizes the results of testing to determine the effect process variables have upon grain size and hardness of the aluminum cladding.