About the event
Decarbonization of the energy sector – the role of complex oxides in nuclear energy applications
The ongoing decarbonization efforts in the United States require a combination of various energy technologies with a low carbon foot print, including nuclear energy. A summary of recent progress in nuclear materials chemistry involved in the synthesis and performance of advanced nuclear fuels, as well as their disposal to increase the safety and efficiency of the nuclear energy sector will be presented. Utilization of wet-chemical, innovative synthesis approaches in combination with a wide range of characterization tools, facilitate a better understanding of the structure-property relationships of advanced nuclear fuel and its waste forms. This knowledge is applied to tailor and fine-tune materials with targeted functionality that relies on a well-defined set of physical properties, with a strong emphasis on the versatile sol-gel technique. Such approach enables to fabricate a large variety of feedstock for high-performance nuclear fuels for current and future reactor types (LWRs, SMRs, HTGRs), while suppressing airborne radioactive particles. Several classes of materials will be discussed, including complex oxides as potential nuclear waste forms that have received an increased focus of attention due their unconventional response to radiation damage enabling to study their order/disorder transition which is heterogeneous across different length scales. In addition, the systematic understanding of the role of defects as well as dopants such as Mn, Cr towards the enhanced performance and safety of high-performance UO2 fuel candidates will be discussed. Besides novel fuels, research aimed to advance the current state of the art for nuclear waste management will be presented. Ongoing efforts at UCI are supported by the recently established cluster of nuclear chemistry laboratories in combination with the TRIGA reactor and characterization facilities and will be briefly introduced.
1. J. Shamblin, M. Feygenson, J. Neuefeind, C. Tracy, F. Zhang, S. Finkeldei, D. Bosbach, H. Zhou, R. Ewing, M. Lang; “Probing disorder in isometric pyrochlore and related complex oxides” Nature Materials 15 (2016) 507.
2. S. Finkeldei, J. Kiggans, R. Hunt, A. Nelson, K. Terrani; “Fabrication of UO2-Mo composite fuel with enhanced thermal conductivity from sol-gel feedstock” Journal of Nuclear Materials 520, (2019) 56.
3. S. Finkeldei, M. Stennett, P. Kowalski, Y. Ji, E. de Visser-Tynova, N. Hyatt, D. Bosbach, F. Brandt; “Insights into the fabrication and structure of plutonium pyrochlores” Journal of Materials Chemistry A 8 (2020) 2387.
Sarah Finkeldei received her Diploma in Chemistry (equivalent to a master’s degree) from the RWTH Aachen. During her PhD she studied pyrochlore oxides as potential nuclear waste forms in the Institute of Nuclear Waste Management at the Helmholtz Research Center Juelich, Germany. She received her PhD with honors from the RWTH Aachen University in 2014. During her time as a postdoctoral researcher in the Helmholtz Center in Juelich, she led a collaborative project with Prof. Rodney Ewing (Stanford University) and Prof. Maik Lang (UT Knoxville) on long-term matrix corrosion of spent nuclear fuel. In August 2017 Sarah became a member of the Nuclear Fuel Materials Group at the Oak Ridge National Laboratory as a postdoctoral researcher and worked under the supervision of Dr. Kurt Terrani and Dr. Andrew Nelson for the Advanced Fuels Campaign of DOE. In July 2019 Sarah joined the Department of Chemistry at the University of California, Irvine as Assistant Professor where her research funded by DOE via NEUP and BES CEM is dedicated to advanced nuclear fuel forms and nuclear waste management.