抄録
For improvement of Severe Accident (SA) codes, a detailed core relocation process has to be clarified because the numerical methods in SA codes for analyzing the core relocation process is simplified. Especially, it is very important to understand precisely the melting behavior of fuel elements including fuel rods, fuel channel boxes and control rods. Then we have been developing the numerical method for analyzing fundamental melting behavior of the fuel elements based on the original POPCORN code. The POPCORN code was developed in Japan Atomic Energy Agency (JAEA) based on the Moving Particle Semi-implicit (MPS) method. In the present study, we introduced the numerical analysis models for phase change, surface tension and multi components to the original POPCORN code. This paper shows an outline of the simulation methods and results of numerical simulations, it was confirmed from the present results that melting behavior called candling can be simulated numerically.