Monday, June 18, 2007 - 9:05 AM
The Peregrins (Boise Centre on the Grove)

Identifying americium speciation for advanced separations

Leigh R. Martin, Bruce J. Mincher, and Nicholas C. Schmitt. Idaho National Laboratory, Idaho Falls, ID

The separation of Am from Cm and the lanthanides is still one of the most challenging separations facing analytical chemistry, as well as any proposed advanced fuel cycle. Despite significant advances in soft donor extractants for the separation of the trivalent actinides the required separation factors have yet to be reliably demonstrated. Americium displays a wide variety of redox chemistry which could be utilized to develop improved separations systems. To implement this approach, we have to fully understand the chemistry of these different oxidation states in solution. One way is to study the optical absorbance spectra of these species. Although the optical absorbance spectra of all americium species are relatively well established, due to the sensitivity limitations of this technique low millimolar solutions of Am are usually required. These concentrations represent a significant radiological hazard and as such, have limited these techniques for use in studying the chemistry of Am. With the application of a Liquid Waveguide Capillary Cell we have been able to study the chemistry of these oxidized species of Am with lower concentrations and smaller sample volumes. The benefits and limitations of this approach to studying the optical absorbance spectra of Am species will be discussed.