A MULTIDIMENSIONAL AND MULTIPHYSICS APPROACH TO NUCLEAR FUEL BEHAVIOR SIMULATION

Important aspects of fuel rod behavior are inherently multidimensional in addition to being complicated multiphysics problems. However, many current fuels modeling tools are strictly 2D axisymmetric or even 1.5D. This paper outlines the capabilities of a new fuel modeling tool able to analyze either 2D axisymmetric or fully 3D models. The need for multiphysics, multidimensional modeling is then demonstrated through a set of example problems. The first, a 10-pellet rodlet, demonstrates the viability of the solution method employed. This example highlights the effect of our smeared cracking model and also shows the multidimensional nature of discrete fuel pellet modeling. The second example relies on our multidimensional, multiphysics approach to analyze a missing pellet surface problem. As a final example, we show a 5-pellet rodlet simulation coupled to lower-length-scale simulations of bubble growth.