Microstructure, Thermal, and Mechanical Properties Relationships in U and UZr Alloys (Final Report)

Technical Report · Mon Jun 01 04:00:00 EDT 2020

DOI:https://doi.org/10.2172/1632268· OSTI ID:1632268

Okuniewski, Maria A. ^[1]; Tomar, Vikas ^[2]; Bai, Xianming ^[3]; Deo, Chaitanya ^[4]; Beeler, Benjamin ^[5]; Zhang, Yongfeng ^[6]

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1. Purdue Univ., West Lafayette, IN (United States); Purdue University
2. Purdue Univ., West Lafayette, IN (United States)
3. Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)
4. Georgia Institute of Technology, Atlanta, GA (United States)
5. North Carolina State Univ., Raleigh, NC (United States)
6. Univ. of Wisconsin, Madison, WI (United States)

Uranium-zirconium (U-Zr) alloys are candidate fuel systems for transmutation based reactors that can be used to burn long-lived minor actinides and fission products in fast spectrum reactors. Metallic fuels have also been gaining more recent attention for applications as accident tolerant fuels, as well as for use in small modular reactors. This research focused on a “science-based” approach to capture the connections between U and U-Zr alloys’ three-dimensional (3-D) microstructure, thermal properties, and mechanical properties through closely coordinated experiments and modeling efforts from the unirradiated to the irradiated fuels. Advanced characterization and modeling techniques were used to understand irradiation-induced microstructural evolution and its direct impact on the thermal and mechanical properties of U and U-Zr fuel. Closely coordinated experiments and modeling were performed to provide crucial data that does not currently exist. Overall, this research spanned multiple length and time scales within the models and experiments. The scope of the research encompassed the understanding of the irradiation effects in U and various U-Zr alloys with particular attention paid to three task areas: (1) microstructural evolution, (2) in-situ/ex-situ thermal and mechanical properties, and (3) multiscale modeling connections to microstructure, thermal, and mechanical properties. This research resulted in (1) the 3-D characterization of neutron irradiated U-Zr fuel in multiple phase regions to better understand fission gas swelling and constituent redistribution, (2) development of a microstructural model linking thermal and mechanical properties via in situ Raman and nanoindentation, (3) and mesoscale phase field modeling was coupled with the AEH method in the MOOSE framework was used to calculate the effective thermal conductivities of U-Zr fuels consisting of α-U and δ-UZr₂ heterogeneous microstructures.

• Research Organization: Purdue Univ., West Lafayette, IN (United States); Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Georgia Institute of Technology, Atlanta, GA (United States); North Carolina State Univ., Raleigh, NC (United States); Univ. of Wisconsin, Madison, WI (United States)
• Sponsoring Organization: USDOE Office of Nuclear Energy (NE)
• DOE Contract Number: NE0008558
• OSTI ID: 1632268
• Report Number(s): NEUP--16-10821; 16-10821
• Country of Publication: United States
• Language: English

Related Subjects

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
microstructure
nuclear fuel
thermal properties
uranium-zirconium