The α nuclide slurry is the radioactive slurry deposited at the bottom of the storage tank during the long-term storage of the waste liquid in the reprocessing process of uranium-plutonium fuel cycle.The α nuclide slurry seriously restricts the decommissioning process of the old tank farm which urgently needs to be treated and disposed of but there is no treatment and disposal method for engineering application in China at present.For the follow-up large-scale industrial treatment and disposal,a plant has formulated a technical route for the acid dissolution of transuranic nuclides in α nuclide slurry,and the analysis of total Pu in the acid-soluble samples of the α nuclide slurry is one of the important data.Due to the complex chemical composition and high salt content of the α nuclide slurry,there is no standard and mature analytical method for the total Pu in the α nuclide slurry.In this study,the acid solution samples in the treatment and disposal of the α nuclide slurry were studied,the separation,purification and liquid scintillation measurement of Pu in the mud acid-soluble samples were studied according to the complexing properties of Pu4+cations and organic matter,the Pu in the acid solution samples was extracted by TiOA-xylene organic system,and the Pu activity concentration in the acid-soluble samples was measured by liquid scintillation,finally a mature and reliable method for the analysis of total Pu in the acid-soluble samples of the α mud was formed.The results showed that TiOA-xylene had strong extraction ability for Pu,but poor extraction performance for U,and could not extract Am.The acidity of the sample had limited effect on the extraction efficiency,and the ideal acidity of the extraction was about 4.0 mol·L-1,and the recovery rate of Pu extraction was 99.23%.The cation of Pu was the most stable in aqueous solution with Pu4+.The reduction performance of Fe2+adjusted the high valence state of Pu to the tetravalent state.The oxidation of NaNO2 oxidized Pu(III)to Pu(IV).After the separation and purification of Pu in the sample,the liquid scintillation counter was used to measure it,which was of high accuracy and good stability.Therefore,the basic conditions of this method has been established for accurate and rapid analysis in the treatment of intermediate α nuclide slurry.
万方数据
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