Development of numerical simulation method to evaluate heat transfer of fuel debris in air cooling, 6; Effect of effective thermal conductivity model in analysis of thermal behavior in PCV

Uesawa, Shinichiro  ; Ono, Ayako ; Yamashita, Susumu   ; Yoshida, Hiroyuki  

To evaluate the thermal behavior of fuel debris of porous media in PCVs of TEPCO's Fukushima Daiichi Nuclear Power Station for air cooling, JAEA has developed a numerical simulation method with JUPITER. In this presentation, we report the numerical simulation results of the thermal behavior in the PCV considering three effective thermal conductivity models for fuel debris. The results showed the temperature and the velocity distributions and the heat removal amount from the fuel debris were different for each model. It is important to understand the internal structure of the fuel debris and choose the appropriate effective thermal conductivity model for the analysis of the thermal behavior because the model affects the simulation results.