Development of Fundamental Data on Chemical Speciation and Solubility for Strontium and Americium in High-Level Waste: Predictive Modeling of Phase Partitioning During Tank Project Summary, 2001.

Felmy, A. R. ; Choppin, G. ; Dixon, D. A.

Technical Information Center Oak Ridge Tennessee

关键词: Waste processing;    Americium;    Strontium;    NTA;    EDTA;   

RP-ID  :  DE2004833733

学科分类：工程和技术（综合）

美国|英语

来源: National Technical Reports Library

【 摘 要 】

In this research program, Pacific Northwest National Laboratory and Florida State University are investigating the speciation of Sr and Am/Cm in the presence of selected organic chelating agents (ethylenediaminetetraacetic acid (EDTA), N-(2-hydroxyethyl) ethylenediaminetriacetic acid (HEDTA), nitrilotriacetic acid (NTA), iminodiacetic acid (IDA), citrate, and oxalate) over ranges of hydroxide, carbonate, ionic strength, and competing metal ion concentrations present in high-level waste stored intanks at Hanford and other U.S. Department of Energy (DOE) sites. The project comprises integrated research tasks that approach the problem ofchemical speciation using macroscopic thermodynamic measurements of metal-ligand competition reactions, molecular modeling studies to identify structures or complexes of unusual stability, and mass spectrometry measurements of complex charge/mass ratio that can be applied to mixed metalchelate systems. This fundamental information thenis used to develop thermodynamic models designed to predict changes in chemical speciation and solubility resulting from various tank processing conditions. In this way we can develop new approaches that address fundamental problems in aqueous speciation and, at the same time, provide useful and practical information needed for tank waste processing.