NSUF 23-4780: Microstructural Defect Induced Thermal Conductivity Reduction in Uranium Nitride and Thorium Nitride
We propose to investigate thermal conductivity variation of uranium nitride (UN) and thorium nitride (ThN) after proton irradiation. UN is known to have a better thermal conductivity than traditional oxide fuels, which could lead to a more efficient energy transport and lower local temperature. This advantage, in addition to a higher fissile density, superior thermophysical properties, and a high melting point, makes UN a promising candidate of accident tolerant fuels. Thermal conductivity variation of UN after irradiation has not been investigated in detail. We propose to fill this knowledge gap. Microstructure defects including point defects and dislocation loops will be introduced to UN (and ThN as the benchmark) by using proton irradiation at Texas A&M University, and characterized using TEM and EELS at INL. Their impacts on thermal transport will be measured using spatial-domain thermoreflectance technique at INL. Computational work will be performed to provide better understanding of the defect generation and evolution, and the scattering mechanisms of thermal carriers and defects and electron-phonon coupling in UN. The proposed work will provide an important step towards enabling control of thermal transport under irradiation by understanding the fundamental microstructural mechanisms responsible for degradation of thermal transport properties of UN.
Additional Info
| Field | Value |
|---|---|
| Abstract | We propose to investigate thermal conductivity variation of uranium nitride (UN) and thorium nitride (ThN) after proton irradiation. UN is known to have a better thermal conductivity than traditional oxide fuels, which could lead to a more efficient energy transport and lower local temperature. This advantage, in addition to a higher fissile density, superior thermophysical properties, and a high melting point, makes UN a promising candidate of accident tolerant fuels. Thermal conductivity variation of UN after irradiation has not been investigated in detail. We propose to fill this knowledge gap. Microstructure defects including point defects and dislocation loops will be introduced to UN (and ThN as the benchmark) by using proton irradiation at Texas A&M University, and characterized using TEM and EELS at INL. Their impacts on thermal transport will be measured using spatial-domain thermoreflectance technique at INL. Computational work will be performed to provide better understanding of the defect generation and evolution, and the scattering mechanisms of thermal carriers and defects and electron-phonon coupling in UN. The proposed work will provide an important step towards enabling control of thermal transport under irradiation by understanding the fundamental microstructural mechanisms responsible for degradation of thermal transport properties of UN. |
| Award Announced Date | 2023-09-14T13:39:39.467 |
| Awarded Institution | None |
| Facility | None |
| Facility Tech Lead | Alina Zackrone, Lin Shao |
| Irradiation Facility | Accelerator Laboratory |
| PI | Zilong Hua |
| PI Email | [email protected] |
| Project Type | RTE |
| RTE Number | None |