NSUF 12-382: Atom Probe Tomography to Study the Effect of Surfaces on the Chemistry of Depleted UO2
It is widely known that microstructural changes influence the thermal performance of nuclear fuels. One mechanism that plays a pivotal role in the microstructural evolution of fuel is absorption and release of oxygen at the surface in uranium dioxide UO2. Changes in the microstructure, specifically at the surface, lead to a change in the efficiency of the transport of phonons or lattice vibrations. Atomic level experiments are needed to help explain the role that free surfaces play in altering the chemistry and thus the thermal transport properties in UO2. The objective of this proposed research is to study the effect of chemistry changes on the microstructure of nuclear fuel. The goal is to elucidate the fundamental material-physics underlying the connection between the migration of surface atoms and microstructural evolution. The proposed research utilizes atom probe tomography (APT) to study changes in surface chemistry in single crystal depleted UO2. In order to characterize the precise chemical and spatial distributions at the surface in UO2, laser-assisted atom probe tomography (APT) in conjunction with the focused ion beam (FIB) system available at CAES will be used. The FIB system will be used to prepare site-specific samples that target various depths from the surface to fabricate atom probe tips. Each sample analyzed will be reconstructed using the IVAS software (available both at CAES and PI Manuel’s laboratory at the University of Florida) to study the chemical changes in single crystal UO2 at the surface. Samples will be studied in the late summer or early Fall 2012. Final results will then be published in peer-reviewed journal articles. It is expected that these results will provide new insight into the spatial and chemical distribution at the surface of UO2, allowing for the correlation with atomic-level simulations and/or the ability to link with mesoscale structure-property relationships.
Additional Info
| Field | Value |
|---|---|
| Abstract | It is widely known that microstructural changes influence the thermal performance of nuclear fuels. One mechanism that plays a pivotal role in the microstructural evolution of fuel is absorption and release of oxygen at the surface in uranium dioxide UO2. Changes in the microstructure, specifically at the surface, lead to a change in the efficiency of the transport of phonons or lattice vibrations. Atomic level experiments are needed to help explain the role that free surfaces play in altering the chemistry and thus the thermal transport properties in UO2. The objective of this proposed research is to study the effect of chemistry changes on the microstructure of nuclear fuel. The goal is to elucidate the fundamental material-physics underlying the connection between the migration of surface atoms and microstructural evolution. The proposed research utilizes atom probe tomography (APT) to study changes in surface chemistry in single crystal depleted UO2. In order to characterize the precise chemical and spatial distributions at the surface in UO2, laser-assisted atom probe tomography (APT) in conjunction with the focused ion beam (FIB) system available at CAES will be used. The FIB system will be used to prepare site-specific samples that target various depths from the surface to fabricate atom probe tips. Each sample analyzed will be reconstructed using the IVAS software (available both at CAES and PI Manuel’s laboratory at the University of Florida) to study the chemical changes in single crystal UO2 at the surface. Samples will be studied in the late summer or early Fall 2012. Final results will then be published in peer-reviewed journal articles. It is expected that these results will provide new insight into the spatial and chemical distribution at the surface of UO2, allowing for the correlation with atomic-level simulations and/or the ability to link with mesoscale structure-property relationships. |
| Award Announced Date | 2012-08-31T00:00:00 |
| Awarded Institution | Idaho National Laboratory |
| Facility | Advanced Test Reactor |
| Facility Tech Lead | Alina Zackrone, Yaqiao Wu |
| Irradiation Facility | None |
| PI | Michele Manuel |
| PI Email | [email protected] |
| Project Type | RTE |
| RTE Number | 382 |