Development and investigation of thermal-hydraulic behavior of new reactor safety features. Investigation on molten metal 3D simulation

To enhance the current core catcher technology and therefore the safety of light water reactors, it is crucial to deepen the knowledge on corium spreading resulting from a severe accident and to be able to simulate it properly. In the following study, we focus our attention on the three-dimensional Volume of Fluid (VOF) multiphase model towards the spreading of molten metal, which is released from the crucible vertically falling onto the flat metal plate. Unlike the previous simulations of the topic, we try to simulate a spreading phenomenon closer to the severe accident scenario and fully driven by the gravity force alone. From that point forward, the simulation results were compared to the available data from a previous set of experiments done by Ogura et al (2018). This kind of comparison allows us to see the drawbacks and short coming of the simulations under such severe condition and provide characterizations for the simulation improvement. As the simulations are driven closer to the real case scenario, experiments to help that extension were built to work parallelly with the available database. (author)