多次元ナトリウム燃焼解析コードAQUA-SFの過酷事故解析への適用

-上向きスプレイ燃焼実験検証解析-

抄録

A modification of multi-dimensional sodium fire analysis code AQUA-SF has been carried out so as to investigate a sodium fire under a severe accident condition inside a reactor containment of sodium cooled fast reactor. The GGDH (Generalized Gradient Diffusion Hypothesis) turbulence model and a radiation model for sodium droplets was newly implemented to the AQUA-SF code. A validation study has been conducted through a benchmark analysis of an upward spray combustion experiment. This paper describes detailed influencing factors in the validation. The temperature distributions are almost the same between the results of the previous and GGDH turbulence models since there is no significant difference in turbulence energy. However, the turbulence analyses shows more reasonable temperature distribution than a laminar analysis dose. The radiation model for sodium droplet increases heat transfer to structure and hence gas temperature and pressure decrease. Consequently, it has been confirmed that the experimental results is simulated reasonably by the newly introduced models in the AQUA-SF code.