This is the second edition of CSA N290.2, Requirements for emergency core cooling systems of nuclear power plants. It supersedes the previous edition published in 2011. This Standard is one of a series of standards on reactor control systems, safety systems, and instrumentation for nuclear power plants.
Changes to this edition include the following:
a) New requirements, guidance, and recommendations have been added to address lessons learned in response to the Fukushima Daiichi event. This edition has been updated to align the Standard with CNSC REGDOC-2.5.2.
b) Clause 5.14 of the previous edition of this Standard was relocated to an informative Annex of this edition to provide guidance for debris interceptor design without constraining future design options. Further guidance regarding design considerations for addressing water hammer were included in this edition based on operating experience.
The CSA N-Series Standards provide an interlinked set of requirements for the management of nuclear facilities and activities. CSA N286 provides overall direction to management to develop and implement sound management practices and controls, while the other CSA Group nuclear Standards provide technical requirements and guidance 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.
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.
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.
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.
This Standard uses the term ECC system to refer to either a single system or multiple systems depending on the plant design.
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.
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.
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.