关键词：燃耗；覆层；污染；快中子；HFIR反应器
摘 要：Safe transport and long term storage of used nuclear fuel requires that the fuel clad material remains structurally sound. Understanding the impact of irradiation on new and high burn-up fuel cladding materials is critical to make this assessment. There is, therefore, a need to establish the relationship between the behavior and performance of unirradiated cladding and actual irradiated cladding. ORNL is addressing this linkage with an experiment designed to simulate high-burnup used fuel cladding by irradiating cladding material in the High Flux Isotope Reactor (HFIR). Fast neutron irradiation of pre-hydrided zirconium-alloy cladding in the HFIR at elevated temperatures is being carried out to simulate the effects of high burnup on used fuel cladding. Test results from irradiated, prehydrided metallic materials will be used to benchmark test results of high-burnup used fuel cladding. Additionally, samples free of alpha contamination can be provided to researchers/students in universities without hot cell facilities to support the Department of Energy Office of Nuclear Energy Used Fuel Disposition Campaign (UFDC). This approach is designed to provide well-controlled neutron irradiation of pre-hydrided materials in the desired temperature range (200-350 degrees C) similar to the service temperatures of boiling water reactors (BWRs) and pressurized water reactors (PWRs). The clad hydrogen content is in the range of 400-800 weight parts per million (wppm), which is similar to what has been observed for high-burnup used fuel cladding in PWRs.