Status of LOCA Performance Tests of HANA-6 Cladding

HANA (High performance alloy for nuclear application) alloy was developed in order to meet the global demand for an extension of the fuel discharge burn-up to more than 70 GWd/MtU. Several lead test rod (LTR) and lead test assembly (LTA) programs have been successfully conducted in commercial reactors. US NRC recently issued new LOCA criteria (10CFR50.46c) to address recent research finding related to high burn-up fuel. According to 10CFR50.46c, an analytical time limit on breakaway oxidation should be determined and periodically confirmed based on an acceptable experimental technique. In addition, an analytical limit on peak cladding temperature (PCT) and integral time at temperature (ITT) have been proposed to ensure maintaining the cladding ductility under LOCA condition. In this regard, LOCA performance tests of HANA-6 cladding with development of new test systems were being performed to develop LOCA analytical models. In this paper, status of LOCA performance tests was summarized. Current status of LOCA performance tests of HANA-6 cladding is summarized as follows. 1. The high temperature oxidation of HANA-6 was lower than at 1000 .deg. C, but, similar at above 1050 .deg.C in comparison with CP correlation. 2. The breakaway oxidation analytical time limit of HANA-6 cladding could be above 5000 seconds. Additional tests will be performed by using new test system to comply with RG 1.222. 3. For post-quench ductility test, production of qualified hydrogen pre-charged samples and qualification of new test system are being performed.