Actinyl(VI) Speciation in Concentrated Sodium Chloride Solutions.

Runde, W. ; Neu, M.

Technical Information Center Oak Ridge Tennessee

关键词: Sodium chlorides;    Evaluation;    Aqueous solutions;    Actinide compounds;    Thermodynamics;   

RP-ID  :  DE2001763298

学科分类：工程和技术（综合）

美国|英语

来源: National Technical Reports Library

【 摘 要 】

Thermodynamic parameters and sorption coefficients provide the fundamental database for the mathematical abstraction of environmental transport of actinides. We have been investigating the chemistry of the hexavalent actinides, U and Pu, in the solid state in concentrated salt (NaCl) solutions representative of conditions within geologic salt formations, sites for nuclear waste disposal. Chloride complexation is proven to play an important role for actinyl(VI) volubility and speciation. We investigated U(VI) and Pu(VI) equilibria with the predominant inorganic ligands hydroxide and carbonate in the presence of chloride. We used a number of spectroscopic techniques (UV-vis-NIR, Raman, FTIR, NMR, XAS) and Xray diffraction to characterize solution species and solid phases as a function of pH, carbonate concentration, and ionic strength.