[en] A review is given concerning the published knowledge about the chemistry of ruthenium in nitric acid solution with special reference to nitric acid nuclear fuel solutions. Possibilities of the spectroscopic description of the different existing ruthenium complexes are discussed and papers are presented dealing with the estimation of the proportions of the different ruthenium compounds in nuclear fuel solutions. Finally, arguments are derived for the preparation of ruthenium-containing model solutions, which adequately simulate the composition of real nuclear fuel solutions. (author)

[en] A method is described for the preparation of solutions of nitrosyl nitrate complexes of ruthenium. Ruthenium chloride has been transformed into ruthenium tetroxide which reacted with nitrogen oxides in nitric acid and formed ruthenium nitrosyl nitrate. The solution has been labelled with ¹⁰⁶Ru and spectrophotometrically investigated. The extraction behavior of the ruthenium complexes with neutral organic phosphorous compounds has been investigated as a function of the acid and salt concentration of the solution and compared with that of other fission products. (author)

[en] Because dimethylglyoxime (DMG) is suitable for the selective separation of palladium from nuclear fuel reprocessing waste solutions the radiation resistance of pure DMG and of DMG sorbed on activated charcoal was studied. Irradiation was carried out at 20-40 ₀C using a ₆₀Co gamma source with a dose rate of 0.6 - 1.7 Gy/s in the dose range 2 kGy to 5 MGy. The radiolytic products were determined by different methods and the G values determined. It has been shown that DMG is relatively radiation resistant up to doses of about 100 kGy. At higher doses the reactive NOH-groups of DMG are partially destroyed and cannot react with palladium. However, in the separation process of palladium from radioactive waste solutions these doses will not be reached so that complications due to insufficient radiation resistance of DMG can be excluded. (author)