Safety Guide NS-G-1.7 is a revision of an earlier Safety Guide, Safety Series No. 50-SG-D2. This and other new Safety Guides recommend how to meet the design requirements established in Safety Standards Series No. NS-R-1. Safety of Nuclear Power Plants: Design. Its technical conent is based on the most recent operational experience and has been extended to cover the design of plants in relation to internal explosions. The appendices provide guidance for the design and upgrading of fire detection and suppression systems.

Internal hazards have to be considered in the design of items important to safety in a nuclear power plant. The objective is to provide appropriate features to prevent internal hazards and mitigate their effects to ensure that safety is not compromised. This Safety Guide provides recommendations to regulatory bodies, nuclear power plant designers and licensees on hazard assessment (including for combinations of hazards) and design concepts for protection against internal hazards in nuclear power plants, in order to meet the requirements established in IAEA Safety Standards Series No. SSR 2/1 (Rev. 1), Safety of Nuclear Power Plants: Design. The following 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 release of hazardous substances originating from within the site boundary.

This publication is a revision of the former safety standards given in Safety Series No. 50-SG-D4, dealing with protection against missiles and the consequences for the safety of nuclear power plants. This revised publication also includes other internal hazards: collapse of structures and falling objects, pipe whips, jet effects and flooding.

The technical content of this guide is based on the most recent operating experience and has been extended to cover the design of plants in relation to internal explosions. The appendices provide guidance for the design and upgrading of fire detection and suppression systems.

"Internal hazards have to be considered in the design of items important to safety in a nuclear power plant. The objective is to provide appropriate features to prevent internal hazards and mitigate their effects to ensure that safety is not compromised. This Safety Guide provides recommendations to regulatory bodies, nuclear power plant designers and licensees on hazard assessment (including for combinations of hazards) and design concepts for protection against internal hazards in nuclear power plants, in order to meet the requirements established in IAEA Safety Standards Series No. SSR 2/1 (Rev. 1), Safety of Nuclear Power Plants: Design. The following 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 release of hazardous substances originating from within the site boundary."--Publisher's description.