NSUF 17-917: Pore size distribution in U-Mo fuel irradiated to high burnup
Attaining fundamental understanding of fuel performance requires detailed characterization of irradiated fuels under variety of irradiation conditions. Such characterization was previously limited by instrumentation available for highly radioactive samples. Significant advancements in understanding of irradiated fuel performance during irradiation started to occur with implementation of stat-of-the-art equipment in nuclear fuels field. The main objective of this proposed research is to apply scanning electron microscopy (SEM), transmission electron spectroscopy (TEM), and focused ion beam (FIB) nano-tomography techniques to perform a detailed microstructural examination on the monolithic U-10wt%Mo fuel irradiated to high burnup. It is know that high burnup microstructure is dominated by micron sized fission gas bubbles distributed randomly throughout the microstructure. Therefore, the main features of interest in this project are fission product precipitate morphology and chemistry, and pore size distribution. FIB nano-tomography will be used to attain better understanding of the porosity in irradiated U-Mo fuels and determining the total porosity in the fuel. 3D reconstruction of the acquired 2D images will allow us to discover if the porosity is interconnected, which could lead to breakaway swelling. It is imperative to establish the onset for interconnection of the porosity to better understand the end of life irradiation properties of the U-Mo fuel. The crystallography and fission gas bubble behavior observed in U-Mo fuel will be investigated in TEM. Since TEM has the disadvantage of only being able to study relatively small areas as compared to FIB nano-tomography, it will be used to validate the data. As part of this objective, 4 block lift-outs and 2 TEM lamella will be prepared in FIB, which will be followed by FIB nano-tomography of the blocks and TEM examination of the lamella. The acquired data will be reconstructed to produce 3D volume, which will then be used as an input to MARMOT.
Additional Info
| Field | Value |
|---|---|
| Abstract | Attaining fundamental understanding of fuel performance requires detailed characterization of irradiated fuels under variety of irradiation conditions. Such characterization was previously limited by instrumentation available for highly radioactive samples. Significant advancements in understanding of irradiated fuel performance during irradiation started to occur with implementation of stat-of-the-art equipment in nuclear fuels field. The main objective of this proposed research is to apply scanning electron microscopy (SEM), transmission electron spectroscopy (TEM), and focused ion beam (FIB) nano-tomography techniques to perform a detailed microstructural examination on the monolithic U-10wt%Mo fuel irradiated to high burnup. It is know that high burnup microstructure is dominated by micron sized fission gas bubbles distributed randomly throughout the microstructure. Therefore, the main features of interest in this project are fission product precipitate morphology and chemistry, and pore size distribution. FIB nano-tomography will be used to attain better understanding of the porosity in irradiated U-Mo fuels and determining the total porosity in the fuel. 3D reconstruction of the acquired 2D images will allow us to discover if the porosity is interconnected, which could lead to breakaway swelling. It is imperative to establish the onset for interconnection of the porosity to better understand the end of life irradiation properties of the U-Mo fuel. The crystallography and fission gas bubble behavior observed in U-Mo fuel will be investigated in TEM. Since TEM has the disadvantage of only being able to study relatively small areas as compared to FIB nano-tomography, it will be used to validate the data. As part of this objective, 4 block lift-outs and 2 TEM lamella will be prepared in FIB, which will be followed by FIB nano-tomography of the blocks and TEM examination of the lamella. The acquired data will be reconstructed to produce 3D volume, which will then be used as an input to MARMOT. |
| Award Announced Date | 2017-04-26T10:13:05.897 |
| Awarded Institution | None |
| Facility | None |
| Facility Tech Lead | Alina Zackrone |
| Irradiation Facility | None |
| PI | Zheng Zhang |
| PI Email | [email protected] |
| Project Type | RTE |
| RTE Number | 917 |