الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
It is a challenging multiphysics challenge to comprehend how nuclear fuel reacts to radiation. This topic involves irradiation physics, neutronics, material science, structural mechanics, chemistry, heat transmission, and thermal hydraulic systems. Fuel modelling is often carried out using mathematical simulations because of the complex nature and interconnection of the physics and modelling associated. Modern, complicated, and comprehensive fuel modelling algorithms are now feasible because of improvements in computer software and hardware. Nuclear fuel performance modelling and simulation is a critical task for nuclear fuel design optimization and safety analysis in both transient and ordinary situations. The fuel performance is a complicated phenomenon which involves thermal, mechanical and irradiation mechanisms and requires special Multiphysics modules. In this thesis, a fuel performance model was developed using the COMSOL Multiphysics platform. The modeling was done for a 2D axis-symmetric geometry of a UO2 fuel pellet in E110 clad for VVER-1200 fuel. The modeling considers all relevant phenomena including heat generation and conduction, gap heat transfer, elastic strain, mechanical contact, thermal expansion, grain growth, densification, fission gases generation and release, fission products swelling, gap/plenum pressure, and clad thermal and irradiation creep. The model was validated using a through both comparing one code to another of pellet centerline and surface temperature in case of constant power in addition to a validation of fission gas release (FGR) predictions. This proved the capability of the model to generate previously published VVER nuclear fuel performance parameters. A sensitivity study was also carried out to evaluate the implications of the uncertainties in certain of the modelling variables. The model is then used to predict the VVER-1200 fuel performance parameters on account of burnup such as: Temperature profiles, gap width, fission gases emission and the plenum pressure. A compilation of related material and thermomechanical models were conducted and included in the modeling to allow the user to investigate different material/performance models. Although the model was developed for normal operating conditions, it can be modified to include off-normal operating conditions.