Presentation Information
[2F11]Evaluation of hydrogen behavior in lower level of BWR reactor building during severe accidents(3) Sensitivity study of hydrogen concentration in a ceiling cavity
*Tomohisa Yuasa1, Miki Saito1, Kimitoshi Yoneda1, Yoshihisa Nishi1, Ryo Morita1, Kunihiro Tomita2, Yoshihiro Matsuto2, Satoshi Mizuno3, Takumi Nameki3 (1. CRIEPI, 2. ATENA, 3. TEPCO HD)
Keywords:
severe accident,BWR,reactor building,GOTHIC code,hydrogen leakage
Sensitivity analyses were conducted to evaluate the hydrogen behavior in the ceiling cavity on lower floor with the GOTHIC model. The effects of geometric, fluid and heat transfer parameters were evaluated. The vertical and horizontal distance from the leak point to the ceiling cavity were the parameters with the highest sensitivity to the hydrogen concentration in the ceiling cavity, and that the closer the distance, the higher the hydrogen concentration. In addition, within the range of condition in this analysis, referred to the licensing basis, the hydrogen concentration in the ceiling cavity did not increase, concentrate, nor exceed the flammable criteria, and that the hydrogen concentration was higher in the ceiling area upstream from the ceiling cavity.