This is the third edition of CSA N289.4, Testing procedures for seismic qualification of nuclear power plant structures, systems, and components. It supersedes the previous editions published in 2012 and 1986.
The major changes to this edition include the following:
a) This Standard was re-structured to consolidate all sub-clauses for the following topics: purchaser’s scope, testing lab’s scope, testing methods, and documentation.
b) The distinction of proof vs. fragility testing was elaborated and enhanced guidance was provided to remove any ambiguity.
c) More explanation was added on the differences between required response spectrum, test response spectrum, required input motion, and table input motion.
d) Requirements related to the disposition of the anomalies found during seismic testing were elaborated.
e) The requirements on seismic aging prior to the seismic testing was made consistent with international practice.
f) Application of the static side load as one of the methods of testing was elaborated.
g) Annex F was improved by clarifying several aspects, such as
i) affidavit replaced by engineer’s certification;
ii) introduction of separate tables for Category A & B valves;
iii) relief valves separated from other valves;
iv) a comprehensive list of available methods of seismic qualification;
v) clarity on use of side load testing; and
vi) clarity regarding hard mounted and line mounted components, including definitions of these terms.
h) The previous Annexes D and E have been combined into one Annex (now Annex D).
Standards in the CSA N289 Series of Standards were initiated in response to the recognition on the part of the utilities and industries concerned with nuclear facilities in Canada of a need for consistent standards for seismic design and qualification of nuclear structures, systems, and components (SSCs) of nuclear power plants. Users of this Standard should recognize that it has the force of law only when adopted by the Canadian Nuclear Safety Commission (CNSC) or the appropriate authority having jurisdiction (in countries other than Canada).
The purpose of this Standard is to provide a basis for the development of specifications for seismic qualification by testing, and to aid purchasers, suppliers, and testing laboratories in selecting the appropriate test method(s) for performing acceptable seismic qualification tests that meet a quality and standard commensurate with the safety principles necessary to comply with the Canadian nuclear safety philosophy.
The CSA N289 Series consists of five separate Standards. Some of the objectives of each Standard are summarized as follows:
a) N289.1-18, General requirements for seismic design and qualification of nuclear power plants, provides guidelines for identifying structures and systems requiring seismic qualification based on nuclear safety considerations;
b) N289.2:21, Ground motion determination for seismic qualification of nuclear power plants, determines the appropriate seismic ground motion parameters for a particular site;
c) N289.3:20, Design procedures for seismic qualification of nuclear power plants, provides design requirements, criteria, and methods of analysis for:
i) determining the design response spectra and ground motion time-histories to be used in the analysis;
ii) establishing design criteria for structures, systems and components (SSCs), and supports that require seismic qualification; and
iii) performing seismic analyses, including the effects of the soil-structure-interaction;
d) N289.4:22, Testing procedures for seismic qualification of nuclear power plant structures, systems, and components, provides design requirements and methods for seismic qualification of specific components and systems by testing methods; and
e) N289.5-12, Seismic instrumentation requirements for nuclear reactors and nuclear facilities, establishes the requirements for seismic instrumentation and for seismic-related inspection of structures and systems before and after a seismic event.
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 can provide more specific direction for those requirements.
Users of this Standard are reminded that the design, manufacture, construction, commissioning, operation, and decommissioning of nuclear facilities in Canada are subject to the provisions of the Nuclear Safety and Control Act and its Regulations. The Canadian Nuclear Safety Commission (CNSC) can therefore impose additional requirements to those specified in this Standard.
1.1 Structures, systems, and components requiring seismic qualification This Standard defines the processes and requirements for performing seismic qualification by testing and presents the test methods, and related content as applicable, that may be used for the seismic qualification of the nuclear power plant structures, systems, and components (SSCs). Seismic qualification by testing is typically used for SSCs that will be performing both an active function and that are required to change state during or following a seismic event in order to perform a safety function, while maintaining structural and/or pressure-boundary integrity or seismic category B per CSA N289.1, Clause 220.127.116.11. Seismic testing can identify contact chatter or unauthorized change of state of contact in electrical and I&C components during seismic excitation.
1) Clause 5.3 of CSA N289.1 specifies acceptable seismic qualification methodologies, including qualification by analysis, testing, or a combination thereof and qualification by similarity, depending on the nature and complexity of the SSC.
2) Some mechanical and electrical components are inherently seismically rugged (see Clause 18.104.22.168 of CSA N289.1 or Clause D.6 of this Standard) and do not need to be tested to demonstrate seismic capability.
3) Seismic categories are defined in CSA N289.1, Clause 5.2.3.
1.2 Specification development
This Standard is intended to provide a basis for developing specifications for seismic qualification of SSCs by testing, or by a combination of analysis and testing, and to aid component purchasers, suppliers, and testing laboratories in selecting the appropriate test method(s) for performing a seismic qualification test. The specification provides the basis for the development of the test plan by the testing laboratory.
1.3 Acceptable test methods
This Standard presents several acceptable test methods with the intent of permitting the user to make a judicious selection from among the various options. In making such a selection, the user of this Standard should choose those test methods that best recognize the characteristics of a particular SSC and the seismic environment under which it is required to perform its function.
1) It should be recognized that seismic qualification forms only a portion of the overall equipment qualification program. It is important that the qualification program for a component include consideration of all operational loadings and conditions (e.g., seismic, environmental, aging impact, thermal and mechanical stresses, deformation, etc.) for which the component must demonstrably meet its SSC functionality objectives.
2) Tests performed in accordance with the requirements of IEEE/IEC 60980-344 and which satisfy the test specification written as per CSA N289.4 may be considered acceptable.
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.