Draft Details

1.1 Inclusions

This Standard specifies the requirements for an EQ program for nuclear power plants (NPPs) (see Figure 1). The EQ program comprises a set of planned and coordinated activities establishing auditable assurance that equipment will

perform safety functions in a harsh environment following the DBA(s) for which it is credited; and

meet or exceed its functional and performance requirements, taking into consideration the effects of normal service.

Note: While this standard focuses on EQ programs for NPPs, it provides guidance that may be useful for other nuclear facilities, including research reactors and non-reactor facilities where EQ considerations apply

1.2 Exclusions

Equipment demonstrated to be in a mild environment after a DBA are not subject to the requirements of this Standard.

DEC survivability assessments are outside the scope of an EQ program. However, this Standard provides optional guidance (see Annex B) on how to demonstrate, with reasonable confidence, that equipment and instrumentation credited to operate during DEC will be capable of performing their intended safety function(s) under the expected environmental conditions.

Notes:

Post-DBA harsh environment conditions addressed by an EQ program are a subset of service conditions required to be addressed as part of overall equipment qualification. Service conditions can also include seismic vibration, severe weather, external floods, electromagnetic interference and radio frequency interference, and fire. Equipment qualification to demonstrate performance in these conditions is outside of this Standard’s scope. For further guidance on equipment qualification, see IEC/IEEE 60780-323.

For general requirements on beyond design basis accidents (BDBAs), see CSA N290.16.

1.3 Facility lifecycle considerations

This Standard presents the requirements for establishing and preserving EQ to confirm the adequacy of the equipment to meet its design intent. This considers:

the effects of aging on equipment’s ability to perform its safety function(s) during and following a DBA;

the need to minimize common-cause unsafe failures under accident conditions;

the preservation of EQ during maintenance or modification of equipment and systems; and

the procurement of equipment and components.

Note: Although life extension projects can change the design life of the plant, maintaining EQ program as detailed in this Standard, including the change control process, will provide adequate guidance for continued operation. For example, temporary changes in safety functions during different operational states might exist during life-extension projects.

1.4 Conflicts

In cases of conflict between this Standard and other Standards which it references, this Standard takes precedence.

1.5 Terminology                                                                      

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.