NSUF 10-242: Low Fluence Behavior of Metallic Fuels
Metallic nuclear fuels are important part of development of various reactors (e.g. fast and research reactors). Currently, new metallic fuels are under development for the Advanced Fuel Cycle Initiative (AFCI) for use in fast reactors that will be utilized for actinide transmutation, and for the Reduced Enrichment for Research and Test Reactors (RERTR) program. This proposal is focused on providing key, in-pile data that is necessary to support the development of metallic fuels and their claddings, either as input to the predictive model or to augment the out-of-pile experiments and their validation. The program will focus on low fluence irradiations utilizing the newly installed hydraulic shuttle irradiation system (HSIS) within ATR. Currently, there is little or no data that exists for low fluences of metallic fuels. However, it is known that the changes that lead to fuel degradation starts at very low burn-up (e.g. < 0.9%). The changes that we will examine in metallic fuels by low fluence, including defect formation, fission product nucleation, constituent redistribution and microstructural degradation will have a profound effect on overall performance of metallic fuels.The objective of the proposed program is understand the U-Zr and U-Mo based metallic fuel behavior with low fluence irradiation testing. A range of fluence (1 x 10-5 to 1 dpa) and temperatures (50° to 750°C) will be explored with various exposure time. Samples to be irradiated will include prefabricated TEM disks, diffusion couples and multiples. Samples are specifically designed for post-irradiation characterization and comparison to out-of-pile experimental observations (i.e., on-going programs at universities and INL or critical literature). Characterization of post-irradiation will focus on early defect formation, evolution of phase constituents and microstructure, and the impact of radiation enhanced diffusion in fuels and fuel/cladding systems.Findings from the proposed program will have several broad impacts. First, this program will mark the first systematic experiments at low fluence for metallic fuels. Initial changes in microstructure of the fuel and fuel/cladding assemblies will provide critical information that will have a significant effect on long-term behavior of metallic fuels. In other words, for understanding and modeling the fuel performance, the knowledge gained from this study will provide “initial” condition within the irradiation. Also the use of pre-fabricated diffusion couples will enhance the chance of successfully acuquiring controlled data on radiation enhanced diffusion for fuel-related materials. Finally and most importantly, detailed scientific findings from this study will provide thermo-kinetic parameters that are critical and required for predictive modeling capability for AFCI and RERTR programs.A strong collaborative team among university and national laboratory has been assembled for the proposed program, ranging from ATR experiments, metallic fuels, fuel/cladding interactions, materials characterization, multiscale materials modeling. The proposed ATR program is designed for three years of tasks. During the first year, we will focus on experimental design and pre-fabrication of specimens to be tested. The second year tasks will include the irradiations in the HSIS at ATR, and PIE. The third year will involve the remaining PIE and documentation of findings.
Additional Info
| Field | Value |
|---|---|
| Abstract | Metallic nuclear fuels are important part of development of various reactors (e.g. fast and research reactors). Currently, new metallic fuels are under development for the Advanced Fuel Cycle Initiative (AFCI) for use in fast reactors that will be utilized for actinide transmutation, and for the Reduced Enrichment for Research and Test Reactors (RERTR) program. This proposal is focused on providing key, in-pile data that is necessary to support the development of metallic fuels and their claddings, either as input to the predictive model or to augment the out-of-pile experiments and their validation. The program will focus on low fluence irradiations utilizing the newly installed hydraulic shuttle irradiation system (HSIS) within ATR. Currently, there is little or no data that exists for low fluences of metallic fuels. However, it is known that the changes that lead to fuel degradation starts at very low burn-up (e.g. < 0.9%). The changes that we will examine in metallic fuels by low fluence, including defect formation, fission product nucleation, constituent redistribution and microstructural degradation will have a profound effect on overall performance of metallic fuels.The objective of the proposed program is understand the U-Zr and U-Mo based metallic fuel behavior with low fluence irradiation testing. A range of fluence (1 x 10-5 to 1 dpa) and temperatures (50° to 750°C) will be explored with various exposure time. Samples to be irradiated will include prefabricated TEM disks, diffusion couples and multiples. Samples are specifically designed for post-irradiation characterization and comparison to out-of-pile experimental observations (i.e., on-going programs at universities and INL or critical literature). Characterization of post-irradiation will focus on early defect formation, evolution of phase constituents and microstructure, and the impact of radiation enhanced diffusion in fuels and fuel/cladding systems.Findings from the proposed program will have several broad impacts. First, this program will mark the first systematic experiments at low fluence for metallic fuels. Initial changes in microstructure of the fuel and fuel/cladding assemblies will provide critical information that will have a significant effect on long-term behavior of metallic fuels. In other words, for understanding and modeling the fuel performance, the knowledge gained from this study will provide “initial” condition within the irradiation. Also the use of pre-fabricated diffusion couples will enhance the chance of successfully acuquiring controlled data on radiation enhanced diffusion for fuel-related materials. Finally and most importantly, detailed scientific findings from this study will provide thermo-kinetic parameters that are critical and required for predictive modeling capability for AFCI and RERTR programs.A strong collaborative team among university and national laboratory has been assembled for the proposed program, ranging from ATR experiments, metallic fuels, fuel/cladding interactions, materials characterization, multiscale materials modeling. The proposed ATR program is designed for three years of tasks. During the first year, we will focus on experimental design and pre-fabrication of specimens to be tested. The second year tasks will include the irradiations in the HSIS at ATR, and PIE. The third year will involve the remaining PIE and documentation of findings. |
| Award Announced Date | 2010-06-09T00:00:00 |
| Awarded Institution | None |
| Facility | None |
| Facility Tech Lead | Alina Zackrone |
| Irradiation Facility | None |
| PI | Yongho Sohn |
| PI Email | [email protected] |
| Project Type | Irradiation/PIE |
| RTE Number | 242 |