The Safety Implication of Hydrogen Production and Explosion for KFDP

According to national fusion road map, Korea is going to establish engineering foundation such as associated design techniques, analysis techniques, and fabrication techniques by 2020. The plan to build a demonstration plant in 2030 is being promoted. Even though the blanket type of Korea Fusion DEMO Plant (KFDP) is not specified clearly yet, H2O seems a competitive coolant for the demonstration plant to confirm technical feasibility. In case in-vessel Loss Of Coolant Accident (LOCA) is handled by using water cooling method, hot dust of Be, W, and C consisted of Plasma Facing Component (PFC) could react with steam and produce hydrogen. The hydrogen produced by above reaction could explode by reaction with oxygen. In such a scenario the structural integrity would be a prime concern. In case of the hydrogen produced at a vessel wall, it is also expected that steam and air ingress into the vessel can disturb the formation of flammable mixture. From these motivations, we preliminarily reviewed the effects resulting from hydrogen explosion induced by the PFC materials, for instance, hot dust of Be, W, and C react with steam. In this study, the explosion induced by a tritium plant is excluded because tritium system design is not yet specified