CE Seminar: Metal Organic Frameworks for Removal of Xe/Kr from Nuclear Reprocessing Plants

Title: “Metal Organic Frameworks for Removal of Xe/Kr from Nuclear Reprocessing Plants”
Abstract: During reprocessing, fission-product noble gases are released when the fuel cladding is breached and any fuel processing is performed. Two of these gases are radioactive xenon (Xe) and krypton (Kr). Although Xe is generated as fission product, by the time the fuel is reprocessed, all the radioactive isotopes have decayed to very low concentrations. Never-the-less, non-radioactive Xe is at a higher concentration than Kr. Krypton has two long-lived isotopes 81Kr [t1/2 = 2.1 x 105 y] and 85Kr [t1/2 = 10.7 y]. Of these, 85Kr is the isotope of regulatory concern and cannot be freely released if fuel younger than roughly 30 y is processed. In an operating reprocessing plant, 85Kr is diluted with process air making its removal difficult because of the low concentrations. The existing technology is cryogenic distillation which is costly and energy consuming. We at PNNL, focused on room temperature separation of Xe and Kr from nuclear reprocessing conditions using novel porous sorbents, which shown to be more effective and cheaper.

Speaker Bio: Dr. Thallapally currently is a scientist working on the development of Hierarchical porous materials for Energy and Environmental applications including gas storage, separation heating and cooling and so on. He is major contributor for DOE – EERE collaborative project with PNNL on crystalline solids for Hydrogen storage applications and played a major role in The Alliance for Collaborative Research in Alternative Fuel Technology (ALL-CRAFT) program on materials for Methane Storage Applications. His work has been highlighted in several external press including Science Editorial Choice and Chemical Engineering News, and Chemical Communications. Dr. Thallapally’s research interests include Carbon Sequestration, nanostructured materials, catalysis, crystallography and crystal engineering.