Internal Standards Applied to Isotopic Ratio Measurements of Uranium and Plutonium

Application of internal standards to measurement of isotopic ratios in analyses of uranium and plutonium has yielded improvement in precision and accuracy of about a factor of 5 for single filament analyses of nanogram-sized samples. These results emphasize the desirability of producing the necessary enriched isotopes in sufficient quantity and purity to foster the widespread application of the technique. It will have especially significant impact on nuclear safeguards programs.