NSUF 18-1276: Towards characterizing the microstructural evolution in nuclear fuel via neutron diffraction
The objective of this project is to characterize an aspect of the microstructural evolution in nuclear fuel, namely changes in the crystal structure, by means of neutron powder diffraction. Developing advanced nuclear fuels is central to deploying advanced nuclear systems that have significant advantages over light water reactors in terms of efficiency, waste generation, proliferation resistance, and safety; advanced reactors cannot function without advanced fuels. Knowledge of advanced fuel performance in advanced reactors is critical to demonstrating and deploying these systems. The relationship between metallic fuel microstructure and fuel performance is, in general, not well understood regarding the effects of crystallographic distortions during irradiation. The initial microstructure of fuel is often either not well controlled or specified incorrectly. Both cases may lead to suboptimal performance. Specifically, studies of irradiated uranium alloy systems showed sensitivity to texture in the samples where they observed lattice constant growth in the [010] crystallographic direction during irradiation with a corresponding lattice constant shrinkage in the [100] crystallographic direction. In this project, we will characterize crystal structures of fresh and irradiated metallic fuel samples by neutron powder diffraction. Neutron and x-ray diffraction are routinely used in material science to improve material performance through understanding and subsequent tailoring of microstructure to achieve desired outcomes. These bulk diffraction methods are complimentary to electron-beam methods, which allow precise location specific analysis, but with very small volumes (nm^3). This work, in addition to answering specific questions about the behavior in a model fuel system, would demonstrate the utility of neutron diffraction in understanding and improving the performance nuclear fuels, creating new data streams that will benefit all fuel and material development programs and provide data suitable for benchmarking and validation of modeling and simulation (M&S) codes required to accelerate the fuel qualification process.
Additional Info
| Field | Value |
|---|---|
| Abstract | The objective of this project is to characterize an aspect of the microstructural evolution in nuclear fuel, namely changes in the crystal structure, by means of neutron powder diffraction. Developing advanced nuclear fuels is central to deploying advanced nuclear systems that have significant advantages over light water reactors in terms of efficiency, waste generation, proliferation resistance, and safety; advanced reactors cannot function without advanced fuels. Knowledge of advanced fuel performance in advanced reactors is critical to demonstrating and deploying these systems. The relationship between metallic fuel microstructure and fuel performance is, in general, not well understood regarding the effects of crystallographic distortions during irradiation. The initial microstructure of fuel is often either not well controlled or specified incorrectly. Both cases may lead to suboptimal performance. Specifically, studies of irradiated uranium alloy systems showed sensitivity to texture in the samples where they observed lattice constant growth in the [010] crystallographic direction during irradiation with a corresponding lattice constant shrinkage in the [100] crystallographic direction. In this project, we will characterize crystal structures of fresh and irradiated metallic fuel samples by neutron powder diffraction. Neutron and x-ray diffraction are routinely used in material science to improve material performance through understanding and subsequent tailoring of microstructure to achieve desired outcomes. These bulk diffraction methods are complimentary to electron-beam methods, which allow precise location specific analysis, but with very small volumes (nm^3). This work, in addition to answering specific questions about the behavior in a model fuel system, would demonstrate the utility of neutron diffraction in understanding and improving the performance nuclear fuels, creating new data streams that will benefit all fuel and material development programs and provide data suitable for benchmarking and validation of modeling and simulation (M&S) codes required to accelerate the fuel qualification process. |
| Award Announced Date | 2018-02-01T14:19:47.72 |
| Awarded Institution | None |
| Facility | None |
| Facility Tech Lead | Gordon Kohse |
| Irradiation Facility | None |
| PI | Kevin Tolman |
| PI Email | [email protected] |
| Project Type | RTE |
| RTE Number | 1276 |