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.