IEEE Std 323:2003 pdf free download

IEEE Std 323:2003 pdf free download.IEEE Standard for Qualifying Class 1 E Equipment for Nuclear Power Generating Stations.
3.17 service conditions: Environmental, loading, power, and signal conditions expected as a result of
normal operating requirements, expected extremes (abnormal) in operating requirements, and postulated
conditions appropriate for the design basis events of the station.
3.18 service life: The time period fom initial operation to removal from service.
3.19 significant aging mechanism: An aging mechanism that, under normal and abnormal service conditions, causes degradation of equipment that progressively and appreciably renders the equipment vulnerable to failure to perform its safety function(s) during the design basis event conditions.
4. Principles of equipment qualification
4.1 Qualification objective
The primary objective of qualification is to demonstrate with reasonable assurance that Class IE equipment for which a qualified life or condition has been established can perform its safety function(s) without experiencing common-cause failures before, during, and after applicable design basis events. Class 1E equipment, with its interfaces, must meet or exceed the equipment specifcation requirements. This continued capability is ensured through a program that includes, but is not limited to, design control, quality control, qualification, installation, maintenance, periodie testing, and surveillance. The focus of this standard is on qualifica-
tion, although it affects the other parts of the program.
For equipment located in a mild environment for meeting its functional requirements during normal environmental conditions and anticipated operational occurrences, the requirements shall be specified in the design/purchase specifications. A qualified life is not required for equipment located in a mild environment and which has no significant aging mechanisms. When seismic testing is used to qualify equipment located in a mild environment, pre-aging prior to the seismic tests is required only where significant aging mechanisms exist (see 6.2.1.1). A maintenance/survillance program based on a vendor’ s recommendations, which may be supplemented with operating experience, should ensure that equipment meets the specified requirements.
4.2 Qualified life and qualified condition
Degradation with time followed by exposure to environmental extremes of temperature, pressure, humidity, radiation, vibration and, if applicable, chemical spray and submergence resulting from a design basis event condition can precipitate common-cause failures of Class IE equipment. For this reason, it is necessary to establish a qualified life for equipment with significant aging mechanisms. The qualified life determination must consider degradation of equipment capability prior to and during service. Inherent in establishing a qualified life is that a qualifed condition is also established. This qualified condition is the state of degradation for which successful performance during a subsequent design basis event was demonstrated.