Title: Radiometric determination of /sup 233/U in thorium
Abstract: An alpha spectrometric method has been developed for the determination of trace levels of /sup 233/U in a thorium matrix. Uranium is selectively removed from thorium and other macro-impurities (except Fe) by passage through an AGl-X8 anion exchange resin in the Cl/sup -/ form. Further purification of uranium for removal of iron is accomplished by passage through an AGl-X8 anion exchange resin in the NO/sup -//sub 3/ form. Natural uranium is used as both a carrier and an internal yield correcting standard. The assay is relatively interference free, except for inherent uranium, which can be tolerated up to 1800 ppM, with only a 1% negative bias. Three duplicate assays in the range of 0.1 to 55 ppM /sup 233/U can be performed to a relative standard deviation of +- 7.1%, or better in approximately twelve hours (including counting).