High temperature steam oxidation dynamics of U3Si2 with alloying additions: Al, Cr, and Y

Uranium silicides are considered for advanced technology reactor fuels due to their enhanced thermal conductivity and high uranium density (U3Si and U3Si2) compared to traditional UO2. Susceptibility to oxidation and wash out, in the event of a cladding breech, could limit the potential for deployment of silicides as accident tolerant fuels. Mitigating the water reaction for U3Si2 could enable its use as an accident tolerant, high uranium density fuel or as a composite fuel constituent. Reported here is the impact of alloying additions of Al, Cr and Y on the high temperature, steam oxidation response of U3Si2. In addition to the thermogravimetric response, as melted microstructures, phase compositions and post oxidation analysis are also presented. The investigation shows steam oxidation dynamics are altered, from non-alloyed U3Si2, under thermally ramped conditions. However, additional alloy development of these fuel forms is necessary for further consideration as candidate accident tolerant fuels in water-cooled reactor designs.