We study the coupled thermal transport, oxygen diffusion, and thermal expansion of a typical nuclear fuel element consisting of UO(2+x) fuel and stainless-steel cladding. Models of thermal, mechanical and chemical properties of the materials are used in a series of finite-element simulations to study the effect of the coupled phenomena on the temperature profile, oxygen distribution and radial deformation of the fuel element. The simulations include

We present thermodynamic models of point defects formation in fluorite-type oxides with important technological applications, such as hypostoichiometric ceria CeO(2-x) and plutonia PuO(2-x). The concentrations of defect species were calculated at different temperatures and partial pressures of oxygen. To highlight some of the current capabilities of the approach, a number of example applications, including the calculation of defect configuration

To address the complexity of the phenomena that occur in a nuclear fuel element, a multi-scale method was developed. The method incorporates theory-based atomistic and continuum models into finite element simulations to predict heat transport phenomena. By relating micro and nano-scale models to the macroscopic equilibrium and non-equilibrium simulations, the predictive character of the method is improved. The multi-scale approach was applied to