Methods of precise uranium and plutonium determination

The Davies and Gray redox method modified by Eberle was proved for the potentiometric determination of uranium. An accuracy of +-0.02 rel.% was obtained for batches of 200 to 300 mg U. Pu was determined following oxidation by AgO surplus in HNO3 environment. The AgO surplus was decomposed by amidosulfonic acid and Pu was reduced by a surplus of titrated solution of Fe(II). The amount of Fe(II) which did not react was determined by ceric salt titration; the error in the determination of a 13 mg Pu/g solution was 0.037 rel.%. The methods applied were proved on simulated mixtures of U and Pu. (M.K.)