LENGTH DEPENDENCE OF FeCrAl ACCIDENT-TOLERANT FUEL CLADDING UNDER SIMULATED LOSS-OF-COOLANT ACCIDENT TESTING

摘要

The safety of the accident-tolerant fuel (ATF)cladding candidates, must be assessed undersimulated conditions of the loss-of-coolant accident(LOCA). During LOCA, the temperature of thecladding and the internal pressure of the fuel rodsincrease under an oxidizing steam environment.Under these conditions, the cladding experiencesmechanical loading due to the internalpressurization, which eventually causes tube burstbefore quenching. Simulated LOCA tests use 12-inchlongtube segments which are inconvenient for theirradiated ATF cladding candidate of FeCrAl alloysdue to the high radiation doses. Therefore, it is usefulto reduce specimen size. This study investigates theeffect of tube specimen length on burst behavior ofthe FeCrAl tubes using the severe accident testingsystem (SATS) at Oak Ridge National Laboratory(ORNL). Specimens of various lengths were subjectedto heating experiments until the burst occurred.Specimen surfaces were engraved for strainmeasurements after the burst, and the tube lengtheffect on the failure behavior of the FeCrAl alloyswere investigated by comparing samples of differentlengths. Results are interpreted based on changes inthe tubes’ burst characteristics.