Synchrotron-based X-ray techniques for radioactive materials research: Understanding the chemical behaviour of radionuclides in solution

Treatment of spent nuclear fuels (SNFs) is one of the critical issues in the world’s nuclear power industry. The international consensus thus far is that the SNFs are supposed to be reprocessed to extract reusable nuclides (e.g., Pu or U) by solvent extraction, or buried deep in the ground to permanently isolate them from human contact. The basic- and applied research related with these SNFs treatments always requires fundamental information on the chemical behaviour of radionuclides in solution, since most chemical processes relevant to the treatment of SNFs (e.g., solvent extraction or geological disposal) occur in solution.
As one of the powerful experimental probes for radioactive materials research, synchrotron-based X-ray techniques have been extensively employed for the last few decades. This seminar will focus on the application of synchrotron-based X-ray methods to the study of radionuclides in solution systems, including the following three sub-topics: (1) X-ray absorption spectroscopy (XAS) and high energy X-ray scattering (HEXS) for characterizing the hydrolytic species of tetravalent cerium (Ce(IV)) in aqueous solution, (2) X-ray absorption spectroscopy for understanding the redox behaviour of actinides in aqueous solution, (3) multiple spectroscopic (XAS and UV-visible-NIR) and quantum chemical approach for acquiring structural information of individual chemical species in the mixed system.