Previous research has shown that multi-principal element alloys (MPEAs) using chromium, molybdenum, niobium, tantalum, titanium, vanadium, and zirconium can form stable body centered cubic (BCC) structures across a large temperature region (25-1000 °C). This is the same structure and space group as ? phase uranium (U) which has shown desirable behavior in previous alloy fuel research. It is hypothesized then that the MPEA alloying approach can be used to produce a uranium bearing alloy that is a stable BCC phase throughout anticipated operating regions of power producing reactors. Candidate elements were assessed using Monte Carlo n-Particle (MCNP) analysis to determine uranium densities necessary to make the alloy a viable fuel compared to conventional fuel forms. Following neutronic considerations, materials property databases and empirical predictors were used to determine compositions with a high potential of forming a BCC solid solution alloy. The final four alloys were MaNbTaU2, MoNbTiU2, NbTaTiU2, and NbTaVU2 and were cast using arc-melting of raw elemental foils and chunks. Characterization of the fabricated alloys included scanning electron microscopy (SEM), x-ray diffraction (XRD), energy dispersive x-ray spectroscopy (EDS/EDX), and transmission electron microscopy (TEM). The results showed a two-phase system with a U-rich matrix phase around the refractory precipitates. The U phase was found to contain varying concentrations of the alloying elements and was a BCC ?-U phase. These results warrant further research on these alloy compositions to identify ideal compositions for use as an advanced alloy fuel.
