Study on the separation distance in the HTGR hydrogen production system (GTHTR300C)

Nishihara, Tetsuo ; Kunitomi, Kazuhiko ; Murakami, Tomoyuki

An accidental release of hydrogen is the most important safety issues in the HTGR hydrogen production system because the hydrogen production plant is close to the reactor building. Evaluation of the hydrogen dispersion around the reactor building is necessary to perform the safety assessment against hydrogen explosion. Numerical analyses for diffusion using the STAR-CD are carried out to survey the effect of inventory, pipe diameter, existence of wall and so on. Maximum horizontal distance from the release point to the explosive hydrogen cloud is compared each other. Blast overpressure is evaluated by Multi-Energy Method. The available energy of explosion is calculated using the results of diffusion analysis. Coupling the numerical analyses of the hydrogen diffusion and the blast overpressure derives a precision separation distance between the hydrogen production plant and the HTGR. The plant layout of the HTGR hydrogen production system can be optimized by using this proposed method.