IEEE 379-2014 pdf download

IEEE 379-2014 pdf download.IEEE Standard for Application of the Single-Failure Criterionto Nuclear Power Generating Station Safety Systems.
actuation desice: A component or assembly of components that directly controls the motive powcr (electricity. compressed air, hydraulic fluid. etc.) for actuated equipment.
NOTE—Esanipics of actuation des ices arc circuit brcakcrs. relays, and pilot valvcs.
ainiliar supporting Ieaturrs: Systems or components that provide scrvics (such as cooling, lubrication. and energy supply) required br the safely systems to accomplish their safety functions
channel: An arrangement of components and modules as required to generate a single protective action signal when required by a generating station condition. A channel loses its identity where single protective action signals are combined.
common-cause (allure (CCF): Loss of function to multiple sIntetures. systems. om components due to a shared root cause.
design basis events: Postulated events used in the design to establish the acceptable pcrfumsancc requirements for the structures, systems, and components.
detectable failures: Failures that can be idcntiticd through periodic testing or that can be revealed by alarm or anomalous indication. Component failures that are detected at the channel. division, or system level arc detectable failures.
NOTE—ldenmiliablc. bui raondctcctahk failurcx are failures i&niiiicd by analysis thai cannot he detected through periodic testing or resealed by alarm or anomalous indication.
execute features: The electrical and mechanical equipment and interconnections that perform a function. associated directly or indirectly with a sat’ety function upon receipt of a signal from the tense and conunand feamres The scope of the CxccutC katurcs extends from the sense and command katures output to. and including, the actuated equipment-to-proccsa coupling.
NOTE- – In some instances. iwotcctive actions may be pctfotnioi by execute featutes that respond directly to the process conditions (c.g. check salves and self-actuating relief valves).
failure: The termination of the ability of an item to perform its required function.
periodic lest: A test performed at scheduled intersals to detect failures and verify operability.
protection sstem: The pars of the sense and command features insolved in generating those signals used primarily for the reactor trip system and engineered safely features,
protection. eaction: The initiation of a signal within the sense and command features, or the operation of equipment within the execute features. fur the purpose of accomplishing a safety function.
redundant equipment or sYstem: A piece of equipment or a system that duplicates the essential function of another piece of equipment or system to the extent that either may perform the required function. regardless of the state of operation or failure ot’thc other.
NOTE Duplication of essenual functions can be accomplished by the use of idenucal equipment, equipment disentily. or functional diversity.
safety function: One of the processes or conditions (e.g.. emergency negative reactivity insertion, post- accident heat removal, emergency core cooling, post-accident radioactivity removal, and containment isolation) that is essential in maintaining plant parameters within acceptable limits established for a design basis event,
NOTE —A safety function is achieved by the completion of all required protective actions by the reactor trip system or Lhc engineered safety features, or both. concurrent with the completion of all required protective actions by the attsiliaiy supporting features.
safety group: A given minimal set of interconnected eononents, modules, and equipment that can accomplish a safety function.
safety system: A system that is relied upon to remain functional during and following design basis events to assure one of tlse follossing:
— The integrity of the reactor coolant pressure boundary
The capability to shut down the reactor and maintain it in a safe shutdown condition
— The capability to prevent or mitigate the consequences of accidents that could result in potential of site exposures comparabk to regulatory guidelines 1l121n
NOTE I—The classification of safety electrical equipment is Class I E as defined in IEEE Std 603.
NOTE 2—This definition of sofas’ wstens agrees with the defmition of safrts’-reiated intern used by the Code of Federal Regulations in Title tO, part 30.2 [BlJ.
sense and command features: The electrical and mechanical components and interconnections involved in generating those signals associated directly or indirectly with the safety functions. The scope of the sense and command features extends from the measured process variables to the execute features input terminals.
shared systems: Structures. systems. and components that ean perform functions for more than one unit in multiunit stations.
NOTE—This detinition includes the following:
Systems that are simultaneously shared by both units
— Time sequential sharing or systems that would he shared by two units at cliticrent times according to the sequence of events
— Systems that would only be used by one unit at any given time but that could be disconnected from that unit and placed in the other unit on demand.