Uranium in Ionic Solutions: From Seawater to Molten Salts
Abstract: There are 4.5 billion tons of uranium in seawater but at an extremely low concentration of ∼3.3 ppb. Polymeric sorbents grafted with functional chemical groups can fish out uranium from the sea. I’ll discuss how we use classical molecular dynamics simulations coupled with free-energy simulations to understand the binding between chemical groups and the uranyl group, taking into account the water molecules, the Ca2+ ions, and the Na+/Cl- ions explicitly.
The second story is about uranium for molten salt reactors. Molten chloride salts are one of the two main choices to dissolve nuclear fuels for fast-spectrum molten-salt reactors, as a generation IV reactor design. U(III)/U(IV) ratio has to be controlled carefully to avoid corrosion of the reactor materials. I’ll discuss the difference between U(III) and U(IV) ions in molten NaCl, MgCl2, and NaCl-MgCl2 salts from first principles molecular dynamics simulations as well as identify the optimal mole fraction of UCl3 in NaCl based on a heat transfer figure-of-merit.
Bio: De-en Jiang is a professor of chemistry at University of California Riverside. He received his BS and MS degrees from Peking University and earned a PhD in chemistry from University of California Los Angeles in 2005. He worked at Oak Ridge National Laboratory first as a postdoc (2006) and then as a staff scientist before joining UCR in 2014. His research focuses on computational materials chemistry for energy and the environment. In nuclear energy research, he first worked on atomistic simulations of uranium extraction from seawater and is now modeling physiochemical properties of molten uranium chloride salts for fast-spectrum molten salt reactors. He received the Presidential Early Career Awards for Scientists and Engineers in 2010. According to Google Scholar, his 300+ peer-reviewed publications have been cited over 17,000 times; his h-index is 71