Multiscale Modeling of Radiation Effects in Novel Nuclear Waste Forms
EMSL Project ID
40085
Abstract
The safe immobilization of high-level nuclear waste is one of the major challenges facing humanity today. This multi-scale computational effort aims to obtain a fundamental understanding of equilibrium and non-equilibrium atomic-level defect processes and their influence on microstructure evolution and property changes in ceramic nuclear waste forms. Computational methods will be synergistically integrated with experimental studies (by Ian Farnan at Cambridge University) to study dynamic processes associated with defect formation and migration, defect interactions, evolution of nanostructures, phase transformations, and effects of localized electronic excitations. Density functional theory, ab initio molecular dynamics, classical molecular dynamics, and kinetic Monte Carlo techniques will be combined to study the formation and migration of defects and the dynamics of defect interactions, nanostructure evolution, and phase transformations. The objective is to develop fundamental understanding and models of electronic excitations, atomic-level defects, defect/property relationships, and dynamics of defect processes in ceramic structures that support the rational development of novel waste forms. Our long range goal is to perform multiscale modeling from the atomistic to the continuum scale to develop predictive models of waste form materials performance in extreme environments. Experimental study of these processes by our collaborators will provide a macroscopic understanding and enable validation of simulations. However, the microscopic details will be inaccessible to experiment due to coupling of multiple mechanisms, transient nature of the phenomena observed, and small time and distance scales associated with the phenomena. Multi-scale modeling and simulation starting at the ab initio level and ranging to the mesoscale and continuum level is needed to shed light on fundamental mechanisms. The proposed work is well aligned with DOE and EMSL missions, Hanford clean up efforts and the Science of Interfacial Phenomena theme. It is also aligned with the emphasis placed on sustainable nuclear power in the President's 2010 state of the union address.
Till date our research in this area involved classical molecular dynamics (MD) simulations of defect accumulation in small ceramic systems. In the proposed work, we will increasingly use ab initio molecular dynamics calculations of defect creation processes and massively parallel classical molecular dynamics simulations of swift heavy ion irradiation of ceramics using the thermal spike model. The resources requested are consistent with the scope of this work.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2010-10-12
End Date
2011-10-16
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members