THE POLAROGRAPHIC DETERMINATION OF HEXAVALENT URANIUM IN URANIUM OXIDES THE DETERMINATION OF OXYGEN URANIUM RATIOS

A method was developed for the determination of uranium(VI) in high- purity uranium oxides. Oxide samples are dissolved in hots concentrated phosphoric acids and then, the uranium(VI) is determined polarographically in a sulfuric-phosphoric acid medium with a dropping mercury electrode. The method provides an accurate means for determining oxygen-uranium ratios in high purity nominal uranium dioxide and has been applied a the analysis of raw urandium dioxide, fuel pellets used in the PWR Core 1 blankets and a variety of oxides prepared for development work on ceramic fuel materials. The relative precision of the method at the 95% confidence level is plus or minus 4%, and the range of the method is from 0.2 to 20.0% uranium(VI) in the high-purity uranium oxides. (auth)