NSUF 25-5224: High resolution characterization of U3Si2 fuel rodlets using Transmission Electron Microscopy and Atom Probe Tomography

U3Si2 has received attention due to its larger thermal neutron absorption cross section and increased uranium density as compared to other fuels like UO2. The uranium density and thermo-physical properties of high uranium content uranium silicides (U3Si2 and U3Si) make them an attractive material from both an economic and safety perspective as a replacement for UO2. There is data scarcity for understanding performance of U3Si2 fuel under irradiation especially on microstructural changes and fission product distribution under the reactor condition. The proposed work suggests using Transmission Electron Microscopy (TEM) and Atom Probe Tomography (APT) to investigate the microstructure of the rodlets focusing on fuel constituent redistribution zones within the rodlet as well as the FCCI region. TEM will be key in understanding the crystallographic structure of the different phases like U3Si2, UO2 and USi post irradiation and understood with preliminary characterizations. APT will help in understanding chemical variations within redistribution zones and the decomposition phases in irradiated U3Si2 fuel. The scientific questions we want to address in this work is on the microstructural changes in U3Si2 fuel in radial directions as well as the chemistry and distribution of fission products along the radial direction of fuel. A similar study for the fuel and cladding chemical interaction (FCCI) region will be carried out.

Informações Adicionais

Campo	Valor
Award Announced Date	2025-08-06T10:06:11.753
Awarded Institution	Idaho National Laboratory
Facility Tech Lead	Alina Montrose
Irradiation Facility
PI	Sohail Shah
PI Email	[email protected]
Project Type	RTE
RTE Number	None