Preface This is the first edition of CSA N393, Fire protection for facilities that process, handle, or store nuclear substances. Users of this Standard are reminded that the site selection, design, manufacture, construction, installation, commissioning, operation, and decommissioning of nuclear facilities in Canada are subject to the Nuclear Safety and Control Act and Regulations. Authorities having jurisdiction may impose requirements additional to those specified in this Standard. In Canada, this Standard will come into force on the date specified by the nuclear facility licence or licence condition handbook. For nuclear facilities licensed prior to the publication of this Standard, the design and construction requirements of this Standard will not be retroactively applied to existing structures, systems, and components, but the operational requirements (e.g., general requirements, concepts, programs, operations, analyses, emergency response) of this Standard will apply. Fire protection concepts and performance levels are detailed in Clause 5, and more detailed requirements for achieving these concepts and performance are provided in Clauses 6 to 12. Clause 9 has been created to cover special hazards. In addition, where noted, explanatory material has been added in Annex A to clarify the content. The CSA N-Series Standards provide an interlinked set of requirements for the management of nuclear facilities and activities. CSA N286 provides overall direction for management in developing and implementing sound management practices and controls, while the other CSA nuclear standards provide specific technical requirements that support the management system. This Standard works in harmony with CSA N286 and does not duplicate the generic requirements of CSA N286; however, it may provide more specific direction for those requirements. Scope 1.1 This Standard provides the minimum fire protection requirements for the design, construction, commissioning, operation, and decommissioning of facilities which process, handle, or store nuclear substances, including structures, systems and components, and other hazardous substances that directly relate to the nuclear substances being regulated. This Standard does not cover fire protection for nuclear power plants, which is covered by CSA N293. Note: See Clause A.1 for further clarification on what facilities are covered under this Standard. This Standard applies to all nuclear facilities where it is referenced as a licence condition or included in the licence condition handbook. 1.2 In this Standard, \"shall\" is used to express a requirement, i.e., a provision that the user is obliged to satisfy in order to comply with the standard; \"should\" is used to express a recommendation or that which is advised but not required; and \"may\" is used to express an option or that which is permissible within the limits of the standard. Notes accompanying clauses do not include requirements or alternative requirements; the purpose of a note accompanying a clause is to separate from the text explanatory or informative material. Notes to tables and figures are considered part of the table or figure and may be written as requirements. Annexes are designated normative (mandatory) or informative (non-mandatory) to define their application.