Fuel Assembly Tests under Normal Conditions of Transport

Tests of a surrogate pressurized water reactor fuel assembly have been conducted simulating normal conditions of truck and rail transport to measure the strains and accelerations on the fuel pins and accelerations on the assembly. The assembly was subjected to vibrations and shocks imposed by shakers and on a truck for an over-the-road test. These tests were performed to assess the strains on individual fuel rods subjected to normal conditions of transport. The magnitude of these strains can be used for an assessment of the margin of safety relative to the elastic limit of the cladding. This is important for predicting the integrity of zirconium-alloy fuel pins that may be degraded due to high burnup or long-term aging in a storage facility.Results of three sets of tests of the assembly are reported. The strains imposed on the fuel pins for the normal conditions of transport were extremely low. Strains measured on the surrogate fuel rods were consistently very low—well below the elastic limit of irradiated Zircaloy-4. Conclusions based on these results along with a fatigue evaluation are discussed.