P05 - Ab Initio Modeling of Magnetite Surfaces for Plutonium Retention
DescriptionIn many countries, thick steel casks are used for the containment of high-level radioactive waste in deep geological repositories. In contact with pore-water, steel corrodes forming mixed iron oxides, mainly magnetite at the surface. After tens of thousands of years, casks may breach allowing leaching of the radionuclides by pore-water. The magnetite can retard dissolved radionuclides either by adsorption or structural incorporation [1,2]. Our goal is to better understand these interaction mechanisms by using computer simulations alongside experiments . Energetically favourable termination and stoichiometry of possible (111) Fe3O4 surfaces at repository relevant conditions are revealed based on Kohn-Sham density functional theory with Hubbard correction (DFT+U) for Fe 3d electrons . Further, classical molecular dynamics (MD) simulations are applied to investigate the interaction at the water-magnetite interface. Moreover, after determining the U value to describe Pu 5f electrons, ab initio MD simulations of sorption structures on expected magnetite (111) surfaces are performed.
 T. Dumas et al., ACS Earth Space Chem. 2019, 3, 2197-2206.
 R. Kirsch et al., Environ. Sci. Technol. 2011, 45, 7267-7274.
 E. Yalçintaş et al., Dalton Trans. 2016, 45, 17874-17885.
 A. Kéri et al., Environ. Sci. Technol. 2017, 51, 10585-10594.
TimeTuesday, June 2719:30 - 21:30 CEST