NSUF 21-4304: Assessing the Radial Thermal Conductivity Change in FBR MOX Fuel
Radial variations in temperature and burnup result in nonuniform microstructural evolution in nuclear fuels, which includes both changes in grain structure and fission product distribution. These changes affect the fuel’s properties, which have a direct impact on fuel performance. Although thermal conductivity is often predicted with modeling, experimentally measured thermal conductivity data of irradiated fuels is scarce and often averaged over large measurement volumes. A thermal conductivity microscope (TCM) can be used to collect local measurements (~50 μm) to capture the variation across different regions on a fuel pellet. These measurements can be directly related to the local microstructure to study its impact on the thermal conductivity. Previously awarded RTEs worked to characterize the micro and nano-scale solid fission products in a 13.7% FIMA sample of mixed oxide (MOX) fuel. These investigations provided detailed characterizations of the fission products in different regions of the fuel, including their three-dimensional (3D) structure at three radial locations. This project aims to link these 3D microstructures to thermal properties in a sample of MOX fuel. The TCM will be used to collect measurements at the different radial locations. These measurements will be compared to conductivities predicted by the models generated from the 3D reconstruction, which will validate the accuracy of the model. This will improve our understanding of the thermal conductivities of the fuel matrix and solid fission products in MOX fuel, which will aid future modeling efforts. Since MOX is a promising candidate for the Generation IV sodium cooled fast reactor (SFR), accurate models depicting its response to irradiation and varying conditions could promote its implementation over other fuel types. With an expected timeline of two months, this project will significantly advance the current understanding of the impact of fission product distribution on thermal conductivity in MOX fuel.
Additional Info
| Field | Value |
|---|---|
| Abstract | Radial variations in temperature and burnup result in nonuniform microstructural evolution in nuclear fuels, which includes both changes in grain structure and fission product distribution. These changes affect the fuel’s properties, which have a direct impact on fuel performance. Although thermal conductivity is often predicted with modeling, experimentally measured thermal conductivity data of irradiated fuels is scarce and often averaged over large measurement volumes. A thermal conductivity microscope (TCM) can be used to collect local measurements (~50 μm) to capture the variation across different regions on a fuel pellet. These measurements can be directly related to the local microstructure to study its impact on the thermal conductivity. Previously awarded RTEs worked to characterize the micro and nano-scale solid fission products in a 13.7% FIMA sample of mixed oxide (MOX) fuel. These investigations provided detailed characterizations of the fission products in different regions of the fuel, including their three-dimensional (3D) structure at three radial locations. This project aims to link these 3D microstructures to thermal properties in a sample of MOX fuel. The TCM will be used to collect measurements at the different radial locations. These measurements will be compared to conductivities predicted by the models generated from the 3D reconstruction, which will validate the accuracy of the model. This will improve our understanding of the thermal conductivities of the fuel matrix and solid fission products in MOX fuel, which will aid future modeling efforts. Since MOX is a promising candidate for the Generation IV sodium cooled fast reactor (SFR), accurate models depicting its response to irradiation and varying conditions could promote its implementation over other fuel types. With an expected timeline of two months, this project will significantly advance the current understanding of the impact of fission product distribution on thermal conductivity in MOX fuel. |
| Award Announced Date | 2021-06-07T15:52:02.793 |
| Awarded Institution | Idaho National Laboratory |
| Facility | Advanced Test Reactor |
| Facility Tech Lead | Alina Zackrone |
| Irradiation Facility | None |
| PI | Casey McKinney |
| PI Email | [email protected] |
| Project Type | RTE |
| RTE Number | 4304 |