b'Multi-principalActinide bearing multi-principal element alloys that could be used for Element Alloy Fuelshigh temperature reactor fuel were fabricated for the first time.for Fast Reactors T his research explored the fabrication and microstructure of a uranium (U) bearing multi-principal element alloy for use as a high-assay low enriched uranium fuel material. The incentive of these compositions was to create an alloy system that remains single phase body-centered cubic from room temperature through anticipated operation temperatures to improve fuel performance and predictability. Previous research has shown that multi-principal element alloys using chromium, molybdenum (Mo), niobium (Nb), tantalum (Ta), titanium (Ti), PROJECT NUMBER:vanadium (V), and zirconium can form stable body-centered cubic structures across 21A1057-007 a large temperature range (25-1000C). This is the same structure and space group TOTAL APPROVED AMOUNT:as gamma phase uranium that has shown desirable behavior in previous alloy fuel $125,000 over 1 year research. These elements, along with uranium, were assessed through materials property databases, and predictors were used to determine compositions with a high PRINCIPAL INVESTIGATOR:potential of forming a solid solution alloy. These compositions were also analyzed Geoffrey Beausoleil II using Monte Carlo n-Particle analysis to determine uranium densities necessary CO-INVESTIGATORS: to make the alloy a viable fuel. These two approaches resulted in a down selection Nathan Jerred, INLof four alloys: MoNbTaU, MoNbTiU, NbTaTiU, and NbTaVU. These alloys were James Zillinger, INL fabricated using spark plasma sintering of raw elemental powders and through arc Xiaofei Pu, INL melting of raw elemental foils. Characterization of the fabricated alloys included scanning electron microscopy, x-ray diffraction, and energy dispersive x-ray spectroscopy. The results showed that mixing and consolidation through powder methods, ball milling, and spark plasma sintering was inadequate for producing a homogenized alloy with all elements remaining mostly segregated from each other. The arc-melted samples, however, produced a two-phase system with the uranium forming a body-centered cubic matrix phase around a body-centered cubic solution of the other alloying elements. While this work did not yield its intended result, the processing did allow for a uranium rich body-centered cubic phase to form and could lend itself to improved opportunities for future fuel fabrication development.TALENT PIPELINE:Abdullah Weiss, student at Texas A&M University38'