While they have had a significant impact on recent world history and geopolitics since the discovery of nuclear fission in 1939, appropriate frameworks to completely describe the chemistry of the actinide series are still emerging. The original “Actinide Hypothesis”, which provided the framework for Glenn T. Seaborg’s 1951 Noble prize, is being reframed to account for emerging bonding interactions observed for the transplutonium actinides. The classical, coordination chemistry framework used to describe actinide purification in the ubiquitously used Plutonium, Uranium, Redox Extraction (PUREX) process fails to describe this solvent extraction chemistry during industrial implementation. The modifications to our understanding of transplutonium and PUREX chemistry are enabled by coupling experimental measurements with computational modeling that could not previously be completed due to the significant resources needed to address the multi-electron and relativistic complications associated with the actinides. This presentation will span from the highly fundamental to the more applied applications of actinide science. By using a combination of radiotracer (i.e less than micromolar amounts of actinides detected by using their radioactive decay) techniques and advances in computational chemistry, the fundamental chemistry of the berkelium, californium and einsteinium elements can be probed in more precise ways than previously considered. Regarding applied research, understanding the chemistry controlling the PUREX process provides a means of predicting which trace metals might be co-recovered with the uranium and plutonium bulk product. The trace metal fingerprint can be indicative of the type of process used, the scale of the process and potentially even the specific site where material was produced. In this latter project, understanding the supramolecular chemistry controlling the PUREX process impacts our ability to predict what types of trace metal signatures can arise from various processing facilities. These studies provide new frameworks for studying the chemistry of the heaviest actinides to inform bonding across the periodic table; and to inform safe, secure implementation of nuclear energy.
Host: Prof. Henry S. LaPierre (email@example.com)