METHOD FOR PREPARING STABLE URANIA-PLUTONIA SOLS

1307090 Stable urania-plutonia sols UNITED STATES ATOMIC ENERGY COMMISSION 2 Oct 1970 [6 Oct 1969] 46878/70 Heading C1A Stable urania-plutonia sols having minimal oxidation-reduction between the tetravalent ionic species, U (IV) and Pu (IV), are prepared by mixing a crystalline, nitrate-stabilized, tetravalent urania sol with a nitrate-stabilized polymeric, tetravalent plutonia sol formed by the extraction of nitrate ions with a waterimmiscible alcohol from a plutonium nitrate solution, and thereafter removing excess nitrate ions from the mixed sol by solvent extraction, e.g. with 0À1-0À2 M n-lauryltrialkylmethylamine in dodecane. The preferred average crystallite size of the nitrate-stabilized tetravalent urania sol is 35-100 Š and that of the stable urania-plutonia sol is about 40 Š. The water-immiscible alcohol used to form the plutonia sol is preferably an aliphatic alcohol, e.g. n-butanol, n-hexanol or 2-ethyl-1-hexanol. The plutonia sol is preferably prepared by contacting a 0À13 M plutonium nitrate - 0À12 M nitric acid solution with n-hexanol, extracting nitrate until the nitrate/plutonium mole ratio is about 3, converting the solution to a sol by heating at about 100‹ C., cooling to about 24‹ C. and re-extracting nitrate with n-hexanol until the NO 3 -/Pu mole ratio is about 1À0.