The use of hydroxyiminoalkanoic acids including at least four carbon atoms as anti-nitrous agents in operations of reductive stripping of plutonium. The invention may be useful in any method for processing spent nuclear fuels that includes one or more operations of reductive stripping of plutonium and, more particularly, in the PUREX method as implemented in modern nuclear fuel processing plants, as well as in processes derived therefrom.

Provided herein are separation processes for metal ions present in aqueous solutions based on methods involving liquid-liquid extraction. The separation process involves a chelator that can selectively bind to at least one of the metals at a relatively low pH. This can be used, for example, for recovery and purification of actinides from lanthanides, separation of metal ions based on their valence, and separation of metal ions based on the pH of the extraction conditions.

The use of hydroxyiminoalkanoic acids including at least four carbon atoms as anti-nitrous agents in operations of reductive stripping of plutonium. The invention may be useful in any method for processing spent nuclear fuels that includes one or more operations of reductive stripping of plutonium and, more particularly, in the PUREX method as implemented in modern nuclear fuel processing plants, as well as in processes derived therefrom.

Provided herein are separation processes for metal ions present in aqueous solutions based on methods involving liquid-liquid extraction. The separation process involves a chelator that can selectively bind to at least one of the metals at a relatively low pH. This can be used, for example, for recovery and purification of actinides from lanthanides, separation of metal ions based on their valence, and separation of metal ions based on the pH of the extraction conditions.

A cation adsorbent of an embodiment includes tungsten oxide particles having a BET specific surface area in a range of 0.82 m.sup.2/g or more and 820 m.sup.2/g or less. The cation adsorbent is added to a solution to be treated containing cations being recovery objects, and the cation adsorbent adsorbing the cations is precipitated. The generated precipitate is separated from the solution to recover the cations.

Apparatuses, processes and methods for the separation, isolation, or removal of radioactive isotopes from liquid radioactive waste, these processes and methods employing a plurality of microspheres. In some embodiments, the processes and methods further include the vitrification of the separated isotopes, generally with the plurality of microspheres. Vitrification is often a step in a larger scheme of preparing the radioactive isotopes for long-term storage or other disposition.

The proposed invention relates to processes of extraction and concentration of radio nuclides and can be used in radiochemical technologies when processing liquid radioactive wastes.

A method for extraction of americium from liquid radioactive wastes and its separation from rare-earth elements comprises simultaneous extraction of americium and rare-earth elements from radioactive nitrate solution with neutral solution of organic extracting agent in polar fluorinated organic solvent, washing of saturated with metals organic phase, selective re-extraction of americium. N,N,N,N-tetraalkyl-amide of diglycolic acid is used as an extracting agent and solution containing 5-20 g/L of complexon, 5-60 g/L of nitrogen-containing organic acid and 60-240 g/L of salting-out agent is used as a solution for re-extraction of americium.

Technical effect is the extraction of americium from acidic liquid radioactive solutions and its separation from all rare-earth elements in a single extraction cycle.

Uses of cyclic amine monoamides for extracting uranium(VI) and/or plutonium(IV) from an acidic aqueous solution, as well as for totally or partially separating uranium(VI) from plutonium(IV) from an acidic aqueous solution. A method for treating an aqueous solution resulting from the dissolution of spent nuclear fuel in nitric acid to extract, separate and decontaminate uranium(VI) and plutonium(IV) in a single cycle and without resorting to any operation of reducing plutonium(IV), and wherein a cyclic amine monoamide or a mixture of cyclic amine monoamides is used as extractant. The cyclic amine monoamides have formula (I):

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An object to be decontaminated contaminated with radioactive material, e.g., contaminated soil or water, is introduced into eluting solvent and dissolved, and the radioactive material is separated from the object to be contaminated by elution of the radioactive material into the eluting solvent. The eluting solvent containing the radioactive materials dissolved therein and the object to be decontaminated are separated into solid and liquid. The soil after solid-liquid separation and from which the radioactive material is removed is collected, and the eluting solvent after solid-liquid separation and a separated liquid containing contaminated water are introduced into an electrolysis tank and electrolyzed. Metal ions such as those of the radioactive materials are deposited on the cathode in the electrolysis tank. Hydrogen containing tritium generated in electrolysis is collected in the electrolysis tank. The hydrogen is moved to the outside of the electrolysis tank and trapped.

An object to be decontaminated contaminated with radioactive material, e.g., contaminated soil or water, is introduced into eluting solvent and dissolved, and the radioactive material is separated from the object to be contaminated by elution of the radioactive material into the eluting solvent. The eluting solvent containing the radioactive materials dissolved therein and the object to be decontaminated are separated into solid and liquid. The soil after solid-liquid separation and from which the radioactive material is removed is collected, and the eluting solvent after solid-liquid separation and a separated liquid containing contaminated water are introduced into an electrolysis tank and electrolyzed. Metal ions such as those of the radioactive materials are deposited on the cathode in the electrolysis tank. Hydrogen containing tritium generated in electrolysis is collected in the electrolysis tank. The hydrogen is moved to the outside of the electrolysis tank and trapped.