N290.2-17

1.1 This Standard applies the design, qualification, installation, operation, maintenance, inspection, and documentation of the emergency core cooling (ECC) system for new and existing water-cooled nuclear power plants. 1.2 This Standard also applies to all support systems required to ensure that the ECC system is able to maintain adequate heat transfer for as long as necessary to maintain the release of radioactive material within reference dose limits by limiting fuel failure. This Standard includes requirements for the layout of plant structures to provide a recovery flow path to the ECC pumps. 1.3 This Standard outlines the specific requirements for ECC system, and is used in concert with CSA N290.0, which outlines general requirements for safety systems. 1.4 This Standard uses the term “ECC system” to refer to either a single system or multiple systems depending on the plant design. 1.5 This Standard does not address the assessment of plant or system operation following beyond design basis accident. Requirements and guidance regarding beyond design basis accident are provided in CSA N290.16. 1.6 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. 1.7 In this Standard, “shall be considered” or “shall consider” means that the user evaluates the impact and documents any decisions. Note: Examples can include no action, operating procedures, and design features.