Large-scale computational modeling of the chemical behavior of actinide elements at interfaces
EMSL Project ID
29990
Abstract
High performance parallel computational resources and scalable software has enabled computational chemistry to model actinides at various interfaces, in the presence of multiple ligands in solution, and to obtain a basic understanding of actinide sorption and redox behavior in the subsurface as well as in solutions critical to minimize the generation of new radioactive waste from fuel reprocessing. We propose to study the influence of the local environments on sorption, redox mechanisms and oxidation state stability of actinides in solution, especially for nanoparticle and colloid formation, and at solution/mineral interfaces. We believe that computational chemistry methods that integrate electronic structure and classical techniques provide invaluable information that will make currently existing surface complexation and field-scale models more accurate, and will provide critical guidance that could enhance the effectiveness of separations schemes.We propose to study the actinides thorium through curium in their relevant oxidation states: 1) with nitrate, carbonate, sulfate and phosphate aqueous co-contaminants, interacting with mineral interfaces that including magnetite, quartz, and goethite, 2) forming colloidal or nanophase actinide hydroxides, hydrous oxides and oxides in aqueous solution, and 3) incorporated in actinide containing oxides and minerals. We propose to study these systems with atomistic simulations, using quantum and classical mechanical models through molecular dynamics. We will use Gaussian and Car-Parrinello plane-wave density functional theory (DFT) with relativistic scalar and spin-orbit effects, and will properly account for the influence of the local molecular environment by using a variety of methods including solvent reaction fields, explicit inclusion of solvents, and hybrid point-charge models for extended systems. Ab initio and classical molecular dynamics simulations will be performed to obtain a continuous description of the molecular- and meso-scale reactivity and redox behavior of the actinides in ground water conditions and with co-contaminants as well as for models of reprocessing solutions, and to study the properties of colloids and nanoparticles.
Project Details
Project type
Capability Research
Start Date
2008-10-03
End Date
2011-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members
Related Publications
Hydration Shell Structure and Dynamics of Curium(III) in Aqueous Solution: First Principles and Empirical Studies
Atta-Fynn R, EJ Bylaska, GK Schenter, and WA De Jong. 2011. "Hydration Shell Structure and Dynamics of Curium(III) in Aqueous Solution: First Principles and Empirical Studies." Journal of Physical Chemistry A 115(18):4665-4677. doi:10.1021/jp201043f
Cerium Oxyhydroxide Clusters: Formation, Structure, and Reactivity
Aubriet F, JJ Gaumet, WA De Jong, GS Groenewold, AK Gianotto, ME McIIwain, MJ Van Stipdonk, and CM Leavitt. 2009. "Cerium Oxyhydroxide Clusters: Formation, Structure and Reactivity." Journal of Physical Chemistry A 113(22):6239-6252. doi:10.1021/jp9015432