NSUF 16-637: TEM Microstructural Characterization of Irradiated UO2 Fuel

INL has undertaken the effort to characterize a variety of fuel systems, including but not limited to U-Mo, UCO, MOX, U-Pu-Zr, and U-Zr fuels. These characterization efforts are possible in part due to the utilization of the Focused Ion Beam tool in characterization of irradiated fuels. Very little TEM data has been reported on UO2 fuels, which are typically used for commercial power production. The objective of this proposal is to conduct a comprehensive TEM investigation of this fuel system. Irradiated UO2 fuel is currently located in EML and is available for characterization work. The FIB analysis of the fuel has been scheduled as part of the programmatic work but it doesnt include TEM investigations. It is known that a radial temperature gradient is present in UO2 fuels, which can result in varying microstructures across the fuel pellet. Understanding what key features are present in the microstructure is important to validate ongoing modeling efforts supported by DOE NE. By creating multiple TEM lamella across the radial part of the fuel sample, microstructure of the fuel can be be studied to understand the effects of irradiation on UO2. Proposed defects to be studied include the high burnup rim structure of UO2 fuels (if present), chemical composition and size of precipitates, defect production such as voids, pores, and dislocations, chemical composition of the UO2 fuel radially, and any other defects created. These findings will be used as an input for existing models being developed at the INL and for validation of such models. 6 days of FIB time and 10 days of TEM time are requested to achieve objectives of the proposal.

Additional Info

Field	Value
Abstract	INL has undertaken the effort to characterize a variety of fuel systems, including but not limited to U-Mo, UCO, MOX, U-Pu-Zr, and U-Zr fuels. These characterization efforts are possible in part due to the utilization of the Focused Ion Beam tool in characterization of irradiated fuels. Very little TEM data has been reported on UO2 fuels, which are typically used for commercial power production. The objective of this proposal is to conduct a comprehensive TEM investigation of this fuel system. Irradiated UO2 fuel is currently located in EML and is available for characterization work. The FIB analysis of the fuel has been scheduled as part of the programmatic work but it doesnt include TEM investigations. It is known that a radial temperature gradient is present in UO2 fuels, which can result in varying microstructures across the fuel pellet. Understanding what key features are present in the microstructure is important to validate ongoing modeling efforts supported by DOE NE. By creating multiple TEM lamella across the radial part of the fuel sample, microstructure of the fuel can be be studied to understand the effects of irradiation on UO2. Proposed defects to be studied include the high burnup rim structure of UO2 fuels (if present), chemical composition and size of precipitates, defect production such as voids, pores, and dislocations, chemical composition of the UO2 fuel radially, and any other defects created. These findings will be used as an input for existing models being developed at the INL and for validation of such models. 6 days of FIB time and 10 days of TEM time are requested to achieve objectives of the proposal.
Award Announced Date	2016-04-11T00:00:00
Awarded Institution	None
Facility	None
Facility Tech Lead	Alina Zackrone, Yaqiao Wu
Irradiation Facility	None
PI	Brandon Miller
PI Email	[email protected]
Project Type	RTE
RTE Number	637