Safety features of modular high temperature gas-cooled reactors (MHTGR)

The following design features which satisfy fundamental safety design objectives of an MHTGR are analyzed: (i) inherent safety features to reactivity effect: (ii) passive decay heat removal: and Oil) multiple barriers. Several events have been identified to be the bounding, hypothetical accidents for the MHTGR. The important accident sequences leading to severe accidents are ingress of a large amount of water or air into the core. The analyses of severe accident scenarios have shown that even the harm of fuel element predicted to occur by chemical reaction after a hypothetical large amount of water ingress into the core or air ingress into the core will not result in major impact on the environment due to the integrity of fuel particles remained. Therefore, it would not be necessary to require an emergency plan to evacuate nearby inhabitants.