EVALUATION OF STRATEGIES FOR OBTAINING HIGH FLUENCE MATERIALS TO ASSESS IRRADIATION-ASSISTED DEGRADATION OF PWR INTERNALS

摘要

One of the key technical issues for nuclear power plant operation up to 80 years is high-fluence irradiation-assisted degradation (IAD) of reactor internals composed of austenitic stainless steels. High-fluence IAD may become more severe at neutron damage levels approaching or exceeding 80 displacements per atom (dpa) accumulated during operation up to 80 years. There are several potential approaches for developing a technical basis related to IAD to support extended reactor operation up to 80 years. The approaches considered in this paper include using data from existing research programs and generating additional data from ion irradiation, fast reactor irradiation, near-light water reactor (LWR) spectrum irradiation, and near-LWR spectrum further irradiation of harvested ex-plant materials. For each of the potential approaches considered, this paper summarizes both the technical and non-technical benefits and drawbacks. Technical considerations are associated with the representativeness of the approach to the actual irradiation exposure in a PWR, while non-technical considerations include level of effort, schedule and project complexity.