High-temperature oxidation and mechanical strength under a loss-of-coolant accident (LOCA) were investigated using irradiated and unirradiated fuel cladding. Cladding from fuel rods irradiated up to 49 GWD/MTU in a Japanese commercial PWR and unirradiated cladding, most of which was preoxidized and precharged with hydrogen to simulate high burnup fuel, were subjected to the tests. High-temperature oxidation tests showed that the oxidation weight gain for irradiated cladding was equal to, or slightly lower than, that for unirradiated material. Preoxidized cladding showed less oxidation weight gain, and no effect of hydrogen absorption on oxidation behavior was observed. The mechanical tests (uniaxial strength and ductility) after a thermal sequence simulating a LOCA showed comparable behavior with that of unirradiated cladding, due to the recovery of the irradiated microstructure. These test results suggest: (1) there is no adverse effect of irradiation on the high-temperature oxidation behavior; and (2) radiation damage in cladding is eliminated during a LOCA condition.

The Water Reactor Fuel Performance Meeting (WRFPM) held in Asia has merged with TopFuel in Europe and LWR Fuel Performance in the United States to form the globally most influential conference in the field of nuclear fuel research. WRFPM2023 is organized by Chinese Nuclear Society (CNS) in cooperation with the Atomic Energy Society of Japan (AESJ), Korean Nuclear Society (KNS), European Nuclear Society (ENS), American Nuclear Society (ANS), the Interna-tional Atomic Energy Agency (IAEA) with the support from China Nuclear Energy In¬dustry Corporation (CNEIC) and TVEL. Conference Topics: 1. Advances in water reactor fuel technology and testing 2. Operation and experience 3. Transient and off-normal fuel behaviour and safety related issues 4. Fuel cycle, used fuel storage and transportation 5. Innovative fuel and related issues 6. Fuel modelling, analysis and methodology