MANUFACTURE OF PUO2 CONTAINING CRYSTAL

A method for manufacturing Pu2-containing crystals by oxidizing plutonium in a heavily contaminated nitric acid starting solution to Pu6+, precipitating ammonium plutonyl carbonate containing crystals by reaction with ammonium- and carbonate ions and subsequent separating and calcining of these crystals. The nitric acid solution with the oxidized Pu6+ as well as carbonate and/or acetate ions and NH3 are dosed into an aqueous starting solution of ammonium carbonate or ammonium acetate in a concentration such that the mol ratio of carbonate and/or acetate ions to the Pu6+-ions in the solution is at least 4:1 and plutonium containing carbonato- or acetato complex compounds which remain dissolved in the receiver solution, are formed, while difficult-to-dissolve metal hydroxide compounds are precipitated. Thereupon NH3 and carbonate ions are added to precipitate the ammonium plutonyl carbonate containing crystals.