Trennprozesse mit polymerharzen bei der wiederaufarbeitung von kernbrennstoffen

Abstract

After an overview of the applications of ion‐exchangers in reprocessing, our present investigations using macroporous resins are reported. A polystyrene‐divinylbenzene tributylphosphate copolymerisate resin (Levextrel‐TBP Bayer AG.) as stationary phase was used for the extraction chromatography of actinides. Distribution coefficients of U, Pu, Np, Am in 0.1 to 6 M HNO3 solutions were measured. A loading capacity up to 140 g Pu/1 resin was achieved in equilibrium with solutions containing 20 g Pu/1 and 6 M HNO3. Elution using 3 bed volumes of 0.3 M HNO3 at 50°C and a flow rate of ca. 1 cm/min removed more than 99.5% of Pu from the resin. A process for separation of plutonium from americium and fluoride was developed. Studies on the removal of tributyl‐ and dibutyl phosphate from aqueous product and waste streams by macroporous styrene‐divinylbenzene copolymers (without functional groups) are described. The process developed is routinely used for purification of radioactive solutions in the laboratory‐scale reprocessing facility MILLI in Karlsruhe. Loadings of 200 g TBP per liter resin and separation of TBP to less than 2ppm in the aqueous effluent solutions can be achieved.