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 [3]. 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 [4]. 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.
[1] T. Dumas et al., ACS Earth Space Chem. 2019, 3, 2197-2206.
[2] R. Kirsch et al., Environ. Sci. Technol. 2011, 45, 7267-7274.
[3] E. Yalçintaş et al., Dalton Trans. 2016, 45, 17874-17885.
[4] A. Kéri et al., Environ. Sci. Technol. 2017, 51, 10585-10594.
TimeMonday, June 2611:20 - 11:50 CEST
Event Type