Preparation method of organic-phase plutonium and organic-phase neptunium standard solution

Abstract

The invention belongs to the technical field of analysis of uranium, neptunium and plutonium in radioactive liquid and particularly relates to a preparation method of an organic-phase plutonium and organic-phase neptunium standard solution. The preparation method includes the following steps of preparation of nitric acid-hydrofluoric acid, preparation of an organic-phase reagent, aampling of standard substances, dissolution of a standard plutonium substance sample, plutonium sample evaporation, preparation of an organic-plutonium standard, neptunium standard sampling, neptunium standard sample evaporation, organic-phase addition and preparation of organic-phase neptunium standard. The uncertainty of the organic-phase plutonium standard prepared by adopting the method is 0. 069%, and the uncertainty of the organic-phase neptunium standard is 1.08%. The preparation method can be used for preparation of relevant series standard solutions in a method for direct determination of the low-concentration uranium, neptunium and plutonium in posttreatment samples and thus meets the need for direct determination of organic phases uranium, neptunium and plutonium in posttreatment process feed liquors.

Description

technical field [0001] The invention belongs to the technical field of analysis of uranium, neptunium and plutonium in radioactive liquids, and in particular relates to a method for preparing standard solutions of organic phase plutonium and organic phase neptunium. Background technique [0002] When the graphite crystal pre-diffraction X-ray fluorescence method is used to measure low-enriched uranium, neptunium, and plutonium in radioactive material liquids, it is necessary to draw uranium, neptunium, and plutonium working curves, which requires the preparation of uranium, neptunium, and plutonium standard solutions. The common method for preparing the standard solution of organic phase neptunium and organic phase plutonium in China is to determine the weighing amount of the standard substance through calculation according to the distribution coefficient of neptunium and plutonium in TBP, and adjust the neptunium and plutonium in the solution to a suitable value after dissol...

AI Technical Summary

Problems solved by technology

The common method for preparing the standard solution of organic phase neptunium and organic phase plutonium in China is to determine the weighing amount of the standard substance through calculation according to the distribution coefficient of neptunium and plutonium in TBP, and adjust the neptunium and plutonium in the solution to a suitable value after dissolution. In the valence state of TBP extraction, the solution is then evaporated to near dryness, and enough TBP is added to re-extract it into the TBP solution, but this method does not consider the loss of the extraction separation process

The UK Atomic Energy Authority, Swinbrun and McGowan used concentrated low-burnup plutonium nitric acid solution to prepare plutonium nitrate by solvent extraction, ion exchange chromatography, peroxide or oxalate precipitation and oxalate dissolution, but the organic phase plutonium and The preparation of organic phase neptunium standard has not been reported