The Purex thermodynamics of plutonium(IV) and uranium(VI) macroconcentrations coextraction into tri-n butylphosphate: new data and new models
The Purex thermodynamics of plutonium(IV) and uranium(VI) macroconcentrations coextraction into tri-n butylphosphate: new data and new models
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钚 (IV) 和铀 (VI) 常量共萃取成磷酸三正丁酯的 Purex 热力学：新数据和新模型
DOI：
10.1016/0022-3115(95)00003-8
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
V. Vlasov
中科院分区：
文献类型：
--
作者：
E. Renard;A. Chizhov;V. Vlasov
现代世界范围内的Purex技术（乏核燃料后处理）是基于在硝酸水溶液和磷酸三丁酯（TBP）有机（正链烷烃）溶液的系统中对锕系元素（U，Pu）进行溶剂萃取。为了建立一个通用的数学过程模型，首先需要了解铀（VI）、钚（IV）和硝酸的平衡分布数据。此外，还应包括所有技术（“专门知识”）操作领域，特别是含锕系元素有机相的所谓强酸和弱酸以及高温和室温擦洗。为了丰富Purex数据库的额外信息，Pu（IV）平衡分配系数的新原始值（0.06-28克/升），U（VI）（0.18-150 g/l）和硝酸（0.01-10.5 mol/l）（在所有情况下-平衡的水相浓度）-在可靠的有机溶液均匀性下（即没有“第三”相形成现象）。这些结果包括20和30体积% TBP（在正十二烷中）在25和60°C下的数据。所有金属含量的分析都是使用原始的同时测定U和Pu的伽马能谱程序进行的。利用所得数据和已知结果（不少于700个“系统”类型的“U（VI）-Pu（IV）-水-硝酸-TBP-正十二烷”），建立了简单的回归方程（两个三次多项式级数），其精度优于± 8%，可用于计算上述三个组分的分布。所有组分的分配系数（D）的浓度依赖性方程的一般形式为：In [公式：见正文]，其中i+K+m <$3; n = Pu，U，HNO 3。高性能型号推荐用于操作程序的开发-作为当今Purex性能的改进剂。
The modern worldwide Purex technology (spent nuclear fuel reprocessing) is based on solvent extraction of actinides (U, Pu) in a system with aqueous nitric acid solutions and organic (n-paraffins) solutions of tri-n-butylphosphate (TBP). To the creation of a universal mathematical process model contributes - first of all - the knowledge of uranium(VI), plutonium(IV) and nitric acid equilibrated distribution data. Further should be included the field of all the technological (“know-how”) operations, in particular, so-called strong-and-weak-acid and high-and-ambient-temperature scrubs of the actinide bearing organic phase. To enrich the Purex data base with additional information the new original values of equilibrium distribution coefficients of Pu(IV) (0.06–28 g/l), U(VI) (0.18–150 g/l) and nitric acid (0.01–10.5 mol/l) (in all the cases - equilibrated aqueous phase concentrations) - at reliable organic solution homogeneity (i.e. without “third” phase formation phenomena) were obtained. Those results include data at 25 and 60°C, of 20 and 30 vol% TBP (in n-dodecane). All the analyses of the metal content were performed using original gamma-spectrometric procedure of simultaneous U and Pu determination. Using both obtained data and known results (no less than 700 “systems” type of “U(VI)-Pu(IV)-water-nitric acid-TBP-n-dodecane“) the simple regressive equations (two third-power polynominal series) were developed, which with an accuracy better than ± 8% permit to calculate the distribution of the three mentioned components. The developed equations of the concentration dependence of the distribution coefficients (D) for all the components have the general form: In [Formula: see text] , where i+K+m⩽3; n = Pu, U, HNO3. The high performance models are recommended for development of operating programs - as a modifier of today's Purex performance.