Carbonate and hydrolysis complexation studies of actinyl ions towards understanding the environmental behavior of U, Np, and Pu

A fundamental understanding of the solubility and sorption behaviors of key actinide ions is critical in evaluating the potential migration or retention of radionuclides from a long-term waste repository site. Knowledge of the species likely to form and accurate thermodynamic constants for the formation of these species are required for modeling studies. We are using multinuclear NMR, Raman, Vis/NIR, EXAFS, and x-ray diffraction to study the aqueous behavior of hexavalent and pentavalent U, Np, and Pu ions, and their hydroxo and carbonato complexes