Senior engineer, Research and Development Center, Westinghouse Electric Corporation, Pitts-burgh, PA
Senior engineer, Westinghouse Electric Corporation, Columbia, SC
Pages: 18 Published: Jan 1989
Expanding mandrel (Simulated Fuel Expansion or Simfex) pellet-cladding interaction (PCI) simulation tests were performed on unirradiated Zircaloy-2, Zircaloy-4, zirconium-lined Zircaloy-2, Zircaloy-3A alloy-lined Zircaloy-2, and graphite-lined Zircaloy-4 tubing with high-purity argon and iodine. SIMFEX tests were also performed on irradiated Zircaloy-4 cladding in iodine. Sensitivity tests were performed on unirradiated unlined Zircaloy-4 tubing in order to establish SIMFEX test conditions that simulate PCI. Test variables included test temperature, core compression rate (or sample strain rate) and iodine partial pressure. SIMFEX test parameters that simulate PCI cover a wide range of test conditions. At a given temperature, these test conditions depend on core compression rate and iodine partial pressure. Iodine SIMFEX tests on unlined unirradiated and irradiated Zircaloy-4 showed that the PCI simulation test conditions produce fractures similar to fuel rod ramp tests. The zirconium-lined Zircaloy-2, Zircaloy-3A alloy-lined Zircaloy-2 and graphite-lined Zircaloy-4 tubing exhibited excellent resistance to simulated PCI failure. Similar diameter fracture strains were exhibited by the zirconium-lined Zircaloy-2 and Zircaloy-3A alloy-lined Zircaloy-2 while significantly higher diameter fracture strains were measured on the graphite-lined Zircaloy-4 tubing. The results of these tests will be used to discuss iodine stress corrosion cracking liner performance mechanisms.
zirconium, Zircaloys, cladding, tubing, iodine, fracture, strain, deformation, temperature, rate, cracks, stresses, fuels, expansion, testing, graphite, pellet-cladding interaction (PCI)
Paper ID: STP18885S