Preface

This is the first edition of CSA N285.0 S1, Supplement No. 1 to N285.0:23, General requirements for pressure-retaining systems and components in CANDU nuclear power plants (technology neutral requirements). This Supplement is to be used in conjunction with CSA N285.0. This Supplement is organized and structured in the same format as CSA N285.0. The pressure-retaining concepts in CSA N285.0 have been adapted and modified as indicated in this Supplement to provide technology neutral pressure-retaining requirements. Users of this Supplement 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. The Canadian Nuclear Safety Commission might impose requirements in addition to those described in this Supplement. The CSA N-Series Standards provide an interlinked set of requirements for the management of nuclear facilities and activities. The CSA N286 Standard provides overall direction to management to develop and implement sound management practices and controls, while the other CSA nuclear Standards provide specific technical requirements that support the management system. This Supplement was prepared by Task Force J — Technology Neutral Requirements, under the jurisdiction of the Technical Committee on CANDU Nuclear Power Plant Pressure-Retaining Systems and Components and the Strategic Steering Committee on Nuclear Standards, and has been formally approved by the Technical Committee.

Scope

S1-1.1 [Replace this clause with the following] This Supplement establishes requirements for

1. code classification of the pressure-retaining systems identified in Clause S1-1.2
2. construction of i) vessels; ii) piping systems; iii) pumps; iv) valves
3. metallic containment boundary components; vi) component supports; vii) core support structures; viii) non-metallic core components and assemblies; ix) fittings
4. other pressure-retaining components used in nuclear power plants
5. in-service inspection, modification, repair, and replacement activities for the items in b) above. S1-1.2 [Replace this clause with the following] Except for Clause S1-1.3, this Supplement applies to the items in Clause S1-1.1 for systems that have been designated by the licensee as important to safety, including a) safety systems
6. safety support systems
7. other systems whose failure might lead to nuclear safety concerns (e.g., process and control systems). S1-1.3 [Replace this clause with the following] This Supplement does not apply to a) containment structures that are covered in the CSA N287 series of Standards, but does apply to metallic containment components
8. system complementary design features that are covered in CSA N290.16
9. sensing elements of instruments. S1-1.4 [Replace this clause with the following] This Supplement does not apply to portable assemblies of pressurized items that are temporarily connected to a system or component to enable testing, venting, draining, calibration, or other maintenance activities, provided that they a) do not reduce the ability of a system to perform its design safety function
10. are under surveillance when connected and are removed upon completion of their function
11. and are constructed to Standards deemed by the licensee to be suitable for the application.

Note: Safety analysis, environmental qualification programs, or seismic qualification may be used to satisfy the conditions in this clause. S1-1.5 [Replace this clause with the following] In this Supplement, "shall" is used to express a requirement, i.e., a provision that the user is obliged to satisfy in order to comply with the Supplement; "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 Supplement. 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 (nonmandatory) to define their application. S1-1.6 [Replace this clause with the following] The values given in SI units are the units of record for the purposes of this Supplement. The values given in parentheses are for information and comparison only. The units in this Supplement may be converted in accordance with the ASME BPVC, Section III, NCA- 1150