DEFORMATION BEHAVIOR OF ZIRCALOY-4 CLADDING IN A SPENT FUEL POOL ACCIDENT

摘要

Despite the low frequency of events leading to a lossof-cooling function and a loss-of-coolant accident (LOCA)at a spent fuel pool (SFP) and the postulated slow accidentprogression, the potential risk of SFP-LOCA is thought tobe significant owing to the inventory higher than that in thereactor and the lack of containment around the SFP. Todevelop and validate a cladding deformation modelleading to burst based on a realistic SFP-LOCA scenario,burst tests of as-received Zircaloy-4 cladding wereconducted under a wide range of postulated SFP-LOCAconditions. The internal pressure of test rods, the heatingrate and the air ratio in a steam environment were variedin the tests as parameters. The relationship between themeasured shape of the burst opening, circumferential burststrain, burst pressure, burst temperature, burst time andazimuthal difference in the cladding temperature wasdiscussed. The results obtained in this study were alsocompared with the published data obtained from thereactor LOCA conditions.