Protection Against Internal Hazards in the Design of Nuclear Power Plants

Internal hazards have to be considered in the design of items important to safety in a nuclear powerplant. The objective is to provide appropriate features to prevent internal hazards and mitigate their effects toensure that safety is not compromised. This Safety Guide provides recommendations to regulatory bodies, nuclearpower plant designers and licensees on hazard assessment (including for combinations of hazards) and designconcepts for protection against internal hazards in nuclear power plants, in order to meet the requirementsestablished in IAEA Safety Standards Series No. SSR 2/1 (Rev. 1), Safety of Nuclear Power Plants: Design. Thefollowing internal hazards are reviewed in this Safety Guide: fires, explosions, missiles, pipe breaks, flooding,collapse of structures and falling objects with a focus on heavy load drop, electromagnetic interference and releaseof hazardous substances originating from within the site boundary.