A study was made of the preparation of a uranium - 10 w/o niobium alloy by the bomb reduction of a suitable form of niobium and uranium tetrafluoride with calcium. A compound with a probable formula of Na₂NbOF₅ proved to be most satisfactory as the source of niobium. High yields and good metal-slag separations were obtained. Chemical analysis and density determinations showed the composition to be 10 ± 0.5 w/o niobium. Fifteen pounds of alloy were melted in BeO and cast into a graphite mold.