NSUF 16-642: APT 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. While very little TEM data has been reported on UO2 fuels, which are typically used for commercial power production has been published, no atom probe tomography (APT) data has been published. The objective of this proposal is to conduct a comprehensive APT 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 APT 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 APT tips across the radial part of the fuel sample, the chemical composition of precipitates in the fuel can be studied to understand the effects of irradiation on UO2. The APT data can provide chemical composition and size of precipitates. 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, 10 days of TEM time, and 10 days of LEAP 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. While very little TEM data has been reported on UO2 fuels, which are typically used for commercial power production has been published, no atom probe tomography (APT) data has been published. The objective of this proposal is to conduct a comprehensive APT 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 APT 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 APT tips across the radial part of the fuel sample, the chemical composition of precipitates in the fuel can be studied to understand the effects of irradiation on UO2. The APT data can provide chemical composition and size of precipitates. 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, 10 days of TEM time, and 10 days of LEAP 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	Yaqiao Wu
Irradiation Facility	None
PI	Brandon Miller
PI Email	[email protected]
Project Type	RTE
RTE Number	642