| Abstract Scope |
The uranium-silicide compound, U<sub>3</sub>Si<sub>2 </sub>, is under consideration as a potential replacement for conventional uranium dioxide fuel. Despite the large number of studies on the uranium-silicon system, there is concern regarding the accuracy and completeness of our understanding of the 40-66 at.% silicon region of phase diagram. The Uranium-Silicon phase diagram is characterized by seven intermetallic compounds (U<sub>3</sub>Si, U<sub>3</sub>Si<sub>2,</sub> USi, U<sub>3</sub>Si<sub>5 </sub>, USi<sub>1.88 </sub>, USi<sub>2 </sub>, and USi<sub>3</sub>) of which only U<sub>3</sub>Si is well understood. In this work, experimental techniques for thermal and compositional analysis, and crystal structure determination were coupled with computational predictions for the characterization of the six intermetallic compounds U<sub>3</sub>Si<sub>2 </sub>, USi,U<sub>3</sub>Si<sub>5 </sub>, USi<sub>1.88</sub>, USi<sub>2 </sub>, USi<sub>3</sub>, and additional compounds between U<sub>3</sub>Si<sub>2 </sub>, and USi<sub>2 </sub>. Information such as phase transitions, homogeneity ranges, and crystal structures were used, along with critically assessed literature data, to construct a thermodynamic database describing the U-Si system utilizing the CALPHAD method. |