Chemistry Department Seminar: Tenure Track Candidate
Shining a Light on Plutonium Separations"
“How do chemists avoid adding harsh redox agents during separations?” This is a problem that touches on almost every aspect of large-scale chemical processing. This concern recently (2014) caught the eye of everyone in actinide separations when a waste drum over-pressurized, failed, and released substantial quantities of plutonium (Pu) and americium (Am) throughout the environment. A positive outcome from this tragic event was motivation to change actinide processing methods. Toward this end, an alternative method combining photochemistry, electron transfer reactivity, and separations is proposed to remove Pu from U without the addition of conventional redox agents. First, the use of photochemistry as a “switch” for reduction of Pu4+ Pu3+ and UO22+ U4+ in HCl(aq) is demonstrated. Second, the photogenerated Pu3+(aq) and U4+(aq) are easily separated using anion exchange chromatography. This substitution keeps harsh redox agents out of process waste streams, reducing the threat of waste container failure promoted by unwanted side-reactions and pressurization. Hopefully these results inspire others to explore photochemical actinide separations, especially as a tool to improve the safety, efficiency, and effectiveness of actinide processing efforts.
*This seminar counts towards the chemistry major seminar attendance requirement.