A New Multiscale Approach to Nuclear Fuel Simulations: Atomistic Validation of Kinetic Method

Abstract

A key issue for fuel behavior codes is their sensitivity to values of various materials properties, many of which have large uncertainties or have not been measured. Kinetic mesoscale models, such as those developed at Argonne National Laboratory within the past decade, are directly comparable to data obtained from in-reactor experiments. In the present paper, a new multiscale concept is proposed that consists of using atomistic simulation methods to verify the kinetic approach. The new concept includes kinetic rate-equations for radiation damage, energetics and kinetics of defects, and gas/defect-driven swelling of fuels as a function of temperature and burnup. The quantum and classical atomistic simulation methods are applied to increase our understanding of radiation damage and defect formation and growth processes and to calculate the probabilities of elemental processes and reactions that are applicable to irradiated nuclear materials.