Numerical Study on Relocation Process of Al, Fe, and Pb by Using the Moving Particle Semi-Implicit Method During Severe Accident of Reactor

Reactor safety is one of the essential parts of reactor research, especially to appropriately respond when melts down occurred during a severe accident. In this study, the relocation process of Al, Fe, and Pb was simulated by using the Moving Particle Semi-Implicit method to study the relocation mechanism of the liquids when they experienced an interaction between liquids at high temperatures. It is obtained that, to reach the stratified condition, Pb- Al needs 0.63 seconds, Al-Fe and Al-Pb need 1.14 seconds, and Fe-Al needs more than three seconds. Overall, the results indicate that the difference in viscosity and density between two liquids influences the time to reach the stratified condition. The greater the density difference between two liquids, the faster the stratification process.