N290.5-06 (R2011)

1 Scope 1.1 This Standard covers the design, procurement, qualification, construction, installation, inspection, and documentation of CANDU nuclear power plant electrical power and instrument air systems. These systems are considered safety support systems. 1.2 Electrical power and instrument air systems of CANDU nuclear power plants include all structures, systems, equipment, and components of the electrical power and instrument air systems that are necessary for the operation of safety-related systems. 1.3 Electrical power systems consist of the Class I, II, III, IV, and other electrical systems that are required to meet the nuclear safety requirements of plants. 1.4 Instrument air systems consist of the components of the plant instrument air system and other associated compressed gas systems that are necessary for the operation of safety-related systems. 1.5 The requirements of this Standard take into account and are consistent with the safety-related requirements of nuclear power plants. 1.6 In CSA Standards, "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; "may" is used to express an option or that which is permissible within the limits of the standard; and "can" is used to express possibility or capability. 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.