CEA develops the PLEIADES software environment in cooperation with EDF and Framatome to simulate fuel elements behavior under normal and off-normal conditions. PLEIADES can be viewed as a fuel performance code based on a multidimensional and on a multiphysics approach. ALCYONE, the PLEIADES code dedicated to PWRs fuel elements, already provides a coupling scheme with thermal diffusion, oxygen thermal diffusion and calculation of local thermodynamics equilibria. Recent works lead to the development and the integration in PLEIADES of a phase-field model to couple these three physical phenomena with liquid-solid phase change. Depending on the thermodynamic conditions, the fuel composition and the amount of oxygen, it can be required to simulate also the gas phase in the system, even at temperatures lower than liquidus. However, the current modelling provided in PLEIADES does not take the gas phase into account.
The goal of this work is then to develop a new phase-field model to simulate simultaneously the phase changes phenomena with the gas phase occurring in the PWR fuel with thermal diffusion, oxygen thermal diffusion and local chemical equilibria in the fuel.
To perform this work, the candidate will be deeped into the high-level scientific environment of the Laboratoire du Simulation du comportement du Combustible of the Département d’Etudes du Combustible at the CEA Cadarache research facility. Moreover, this work could be submitted in a peer-reviewed journal.