Date of Award


Document Type

Open Access Thesis


Mechanical Engineering


College of Engineering and Computing

First Advisor

Travis W. Knight


U3Si2 is currently being considered as a possible replacement for the current light water reactor fuel, UO2. U3Si2’s high melting temperature, high uranium density, and high thermal conductivity are favorable in accident conditions, such as a loss of coolant accident. Improved accident performance is further expected when paired with a SiC/SiC cladding, since it provides relatively high strength and a high oxidation resistance.

Modeling of U3Si2 and SiC/SiC in reactor is currently very important since much of their behavior is still unknown. By implementing models that describe the properties of U3Si2 and SiC/SiC into INL’s fuel performance code BISON, performance of this fuel/cladding combination can be compared to that of the standard UO2/Zircaloy. Included in these material models is a preliminary thermal creep model for U3Si2 based off of recent compressive creep data.

In addition to the fuel performance analysis, due to the brittle nature of the monolithic SiC layer that surrounds the cladding, an in depth analysis on stresses in the cladding is done. Specifically performance during PCMI, when large interfacial pressures cause significant stresses in the cladding, and the effect of varying pelletcladding gap widths are analyzed.


© 2018, Ray A. Freeman