Requirements for nuclear safety-related structures
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This is the third edition of CSA N291, Requirements for nuclear safety-related structures. It supersedes the previous edition published in 2015 under the title, Requirements for safety-related structures for nuclear power plants and 2008 under the title, Requirements for safety-related structures for CANDU®nuclear power plants. The title has been changed to reflect more accurately the scope.
Note: CANDU®(CANada Deuterium Uranium) is a registered trademark of Atomic Energy of Canada Limited (AECL).
There have been many changes throughout this edition; the most significant changes are as follows:
• clarification of the scope, specifically for storage of radioactive waste material;
• addition of new clauses on testing of welding materials and rebar splice materials;
• addition of new clauses on beyond design basis and design extension conditions;
• addition of new clauses on personnel qualifications for: visual inspection, non-destructive examination, welding, concrete construction inspection, and non-metallic liner and coatings inspection.
• modification and addition of new clauses to clarify the requirements for a formal, detailed construction inspection and testing program;
• addition of new clauses on aging management; and
• updates to tests and test frequencies tables for concrete materials, concrete, and grout.
This Standard specifies requirements for the material, analysis and design, construction, fabrication, inspection, examination, and aging management of safety-related structures constructed of structural steel, reinforced concrete, and reinforced masonry. The minimum design requirements specified in this Standard follow the requirements of CSA A23.3, CSA S16, CSA S304.1, and the National Building Code of Canada. Additional requirements reference the CSA N287 series and the CSA N289 series of Standards.
This Standard provides a general definition of safety-related structures rather than a comprehensive listing of all safety-related structures. The analysis and design of structures cover static and dynamic loads, and the loads, load factors, load combinations, and safety criteria cover service loads and abnormal/environmental loads. This Standard also covers the design and analysis of irradiated fuels and radioactive waste storage structures.
The CSA N-Series of Standards provides 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.
The users of this Standard are reminded that an authority having jurisdiction (AHJ) such as the Canadian Nuclear Safety Commission might impose additional requirements to those specified in this Standard.
This Standard specifies requirements for the material, analysis and design, construction, fabrication, inspection, examination, and aging management of nuclear safety-related structures. Nuclear safety- related structures covered in this Standard are
a) structures that support, house, or protect safety systems in nuclear power plants;
b) structures or their elements, where failure of the structures or their elements, would impede the function of safety systems;
c) structures and their elements that are required for the safe operation and/or safe shutdown of the reactor in nuclear power plants;
d) structures for the storage of wet irradiated fuel; and
e) structures for the storage of dry irradiated fuel and other radioactive waste material as agreed with the AHJ.
1) Not all elements of the structures described in Item e) are necessarily considered safety-related and therefore such elements are not governed by this Standard.
2) The structures described in Item e) can include, but are not limited to structures for storage of high-level radioactive waste material, where high-level is as described in Clause A.7 of CSA N292.0, and where the structure requires a design life greater than 50 years.
This Standard does not apply to concrete containment structures covered in the CSA N287 series or the pressure-retaining systems and components covered in CSA N285.0/N285.6.
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.