Numerical simulations on melting behavior of simulated fuel elements based on particle method

Nagatake, Taku ; Yoshida, Hiroyuki  ; Takase, Kazuyuki; Kurata, Masaki 

As for improvement of Severe Accident (SA) codes, a detailed core relocation process has to be clarified because higher prediction results are obtained by numerical methods in the SA codes. Especially, it is very important to understand precisely the melting behavior of fuel elements. 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 methods for phase change, surface tension and multi components to the original POPCORN code. This paper shows outline of simulation methods and results of numerical simulations. From the results, melting behavior called candling can be simulated numerically.