Abstract: The invention relates to a process for improving the effectiveness of the removal of zirconium from an aqueous, zirconium-containing nuclear fuel and/or fertile material solution in nitric acid in a liquid-liquid extraction process.Accordingly, the object of the invention is to improve the removal of zirconium from the reprocessing solutions and, at the same time, to simplify the course of the process. The invention seeks to improve decontamination of the uranium product and the plutonium product while, at the same time, reducing the outlay involved.According to the invention, this object is achieved in that, in a process step carried out before the first extraction of the nuclear fuels and/or fertile materials, the zirconium is converted from the dissolved state into a filterable or centrifugable solid phase by the use of an adsorbent from the group of inorganic ion exchangers and is removed from the aqueous solution together with the adsorbent.

Abstract: A liquid-liquid two-phase extraction process in which a feed solution is introduced into an intermediate stage of a multistage extraction apparatus. The solution is water and one or more valuable material to be recovered by extraction. An organic extractant is introduced into one end of the apparatus. The extractant is a solvent and flows through the apparatus. The valuable material is extracted from the feed solution to provide a charged organic phase. An aqueous extractant having water is introduced into another end of the apparatus to wash the charged organic phase. The aqueous extractant flows through the multistate extraction apparatus countercurrent to the extractant and contributes to the aqueous phase. The organic extractant is divided into at least two streams prior to introducing the organic extractant into the apparatus. Each stream is introduced into the apparatus at different stages, both ahead of the intermediate stage.

Abstract: A process for the separation of substances hindering the recovery of the fissionable materials uranium and plutonium and for the separation of the fissionable materials to be recovered in a reprocessing process for spent, irradiated nuclear fuel- and/or fertile materials. A second and a third wash of the organic phase is performed for residual ruthenium separation and residual zirconium separation, and there is a repetition of the Pu stripping step with simultaneous electrolytic reduction of Pu(IV) to Pu(III). The second and third wash solutions or the aqueous phase employed for the repetition of plutonium stripping, respectively, each contains a high concentration of product uranyl nitrate. The aqueous run-off from the second and third washes and from the repetition of the Pu stripping step is indirectly fed back into the aqueous fuel solution employed in the first extraction step of the reprocessing method by first feeding these run-offs to an intermediate treatment.

Abstract: A process for the separation of neptunium from an organic phase, which is developed in the recovery of irradiated nuclear fuel and/or fertile material. The organic phase contains uranium-, plutonium- and neptunium ions, tritium in the form of tritiated water and fission products in ionic form, as well as an organic extraction agent dissolved in diluent. After a first wash step, and before the organic phase is further fed to a uranium-plutonium separation or to a uranium-plutonium coreextraction, the organic phase is brought into contact with an aqueous solution containing diluted HNO.sub.3, butyraldehyde and a low concentration of sulfamic acid in countercurrent flow as a second wash step for the selective reduction of Np (VI) to Np (V) and for selective stripping of Np (V), with respect to U and Pu, from the organic into an aqueous phase.