Uranium-niobium alloys play an important role in the nation's nuclear stockpile. It is possible to chemically quantify this alloy at a micron scale by using a technique know as wavelength dispersive spectroscopy. This report documents how this technique was used and how it is possible to reproduce measurements of this type. Discussion regarding the accuracy and precision of the measurements, the development of standards, and the comparison of different ways to model the matrices are all presented.

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.

A satisfactory procedure is described for the analysis of uranium-niobium alloys containing up to 25% niobium. It is based on the separation of the niobium from uranium by dissolving the cupferron complex of the former element into chloroform. After the evaporation of the solvent from the combined organic extracts, the niobium is ignited to the pentoxide. The uranium is afterwards precipitated from the remaining aqueous solution by the addition of ammonium hydroxide after the wet oxidation of organic matter. Absorptiometric procedures are included for the determination of the small amounts of uranium co-extracted with the niobium and the trace amounts of unextracted niobium. (auth).