Chemical Speciation of Strontium, Americium, and Curium in High Level Waste: Predictive Modeling of Phase Partitioning During Tank Processing. Annual Report June 1, 2002 through May 31, 2003

摘要

The objective of this research project is to measure the effects of organic chelate complexation on the speciation and solubility of Sr and trivalent actinides under strongly basic, high carbonate conditions, similar to those present in high-level waste tanks at U.S. Department of Energy storage sites. We proposed, (1) extension to important chelates not previously studied$ (2) studies of completing metal ions$ and (3) specific studies using Am(III)/Cm(III). The chelate complexation studies would extend our previous research on EDTA, HEDTA, NTA, and IDA to citrate and oxalate. In addition, we propose to address the possible formation of mixed ligand-ligand complexes for Eu(III) in EDTA-HEDTA, EDTA-NTA, HEDTA-NTA, and ligand-carbonate solutions. The fundamental data on chemical speciation and solubility will be used to develop accurate thermodynamic models which are valid to high ionic strength.