NSUF 14-513: Lattice structure evolution in ion irradiated UO2.
Uranium dioxide is one of the most complex oxide materials due to the unstable stoichiometry resulting from rapid and reversible oxygen ion mobility. As the most commonly used nuclear fuel, there has been significant research to understand defect structure in the UO2 complex following nuclear reactor irradiation. Characterization of UO2 stoichiometry has been undertaken since 1950s and is still far from complete. Despite large empirical databases for UO2, there is a lack of scientific understanding of its property evolution under irradiation. This proposed research and experiment will enrich the scientific basis of radiation induced damage formation in UO2, the ultimate goal being the understanding of the irradiation microstructure evolution starting from the point defect scale. Transmission Electron Microscopy (TEM) has been utilized to study extended structure changes and microstructure evolution. Ion beam irradiations create displacements and displacement networks, gas bubbles and several other microstructure changes to model nuclear reactor damage. Using ion accelerator, it has been possible to isolate these defects and study their evolution with increasing dose. Extended X- ray Absorption Fine Structure (EXAFS) measurements have shed significant insight into the local chemistry evolution surrounding uranium ion from irradiation damage. With the aforementioned defect characterization techniques this project will attempt to focus on the following scientific points: 1. The local chemistry and atomic structure evolution with ion irradiation in UO2 using ion beam methods and a possible reactor irradiation experiment 2. The relation between atomic structure defects and point defects to the longer range microstructural damage in irradiated UO2 3. The differences in resulting damage structure changes when irradiated with varying incoming ions including protons, helium ions and krypton ions The project is expected to be completed before end of year 2014 with conclusive results about microstructure and lattice structure evolution, correlation between various length scales and implanted ion dependent defect morphology.
Additional Info
| Field | Value |
|---|---|
| Abstract | Uranium dioxide is one of the most complex oxide materials due to the unstable stoichiometry resulting from rapid and reversible oxygen ion mobility. As the most commonly used nuclear fuel, there has been significant research to understand defect structure in the UO2 complex following nuclear reactor irradiation. Characterization of UO2 stoichiometry has been undertaken since 1950s and is still far from complete. Despite large empirical databases for UO2, there is a lack of scientific understanding of its property evolution under irradiation. This proposed research and experiment will enrich the scientific basis of radiation induced damage formation in UO2, the ultimate goal being the understanding of the irradiation microstructure evolution starting from the point defect scale. Transmission Electron Microscopy (TEM) has been utilized to study extended structure changes and microstructure evolution. Ion beam irradiations create displacements and displacement networks, gas bubbles and several other microstructure changes to model nuclear reactor damage. Using ion accelerator, it has been possible to isolate these defects and study their evolution with increasing dose. Extended X- ray Absorption Fine Structure (EXAFS) measurements have shed significant insight into the local chemistry evolution surrounding uranium ion from irradiation damage. With the aforementioned defect characterization techniques this project will attempt to focus on the following scientific points: 1. The local chemistry and atomic structure evolution with ion irradiation in UO2 using ion beam methods and a possible reactor irradiation experiment 2. The relation between atomic structure defects and point defects to the longer range microstructural damage in irradiated UO2 3. The differences in resulting damage structure changes when irradiated with varying incoming ions including protons, helium ions and krypton ions The project is expected to be completed before end of year 2014 with conclusive results about microstructure and lattice structure evolution, correlation between various length scales and implanted ion dependent defect morphology. |
| Award Announced Date | 2014-08-11T00:00:00 |
| Awarded Institution | None |
| Facility | None |
| Facility Tech Lead | Yaqiao Wu |
| Irradiation Facility | None |
| PI | Mahima Gupta |
| PI Email | [email protected] |
| Project Type | RTE |
| RTE Number | 513 |