Abstract
UV-Visible spectroscopy can be utilized in an on-line fashion to directly measure the concentration and speciation of special nuclear materials, such as uranium and plutonium, thus allowing real-time process control and tracking for the solvent extraction processes. Attributing UV-Visible data to process conditions is complex due to uranyl nitrate speciation, thus efforts focus on characterizing the system encompassing 0.01–1.26 M U and 0.01-8 M HNO3. Results suggest dominant speciation changes from low (0.01 M) to high (>6 M) HNO3, and peak shifts in the high (>1 M) uranyl system imply an ingrowth of species not present at lower uranyl concentrations.
ACKNOWLEDGEMENTS
This work was performed under the Nuclear Forensics Graduate Fellowship Program which is sponsored by the U.S. Department of Homeland Security's Domestic Nuclear Detection Office and the U.S. Department of Defense's Domestic Threat Reduction Agency. Additional funding was provided by DOE contract No. DE-FG07-08ID14927. The authors thank Tom O'Dou and Trevor Low for their help and dedication in laboratory radiation safety.