IEEE 497-2010 pdf free download – IEEE Standard Criteria for Accident Monitoring Instrumentation for Nuclear Power Generating Stations.
3. Definitions
The following definitions apply specifically to this standard. For other definitions, see The Authoritative
Dictionary of IEEE Standards Terms , Seventh Edition [B4].
3.1 accident analysis licensing basis:
The portions of the licensing basis documentation that describe the design basis events (including anticipated operational occurrences), the thermal-hydraulic response of the plant, and the subsequent response of the safety systems.
3.2 accuracy: A nseasure of the degree by which the actual output of a device approximates the output of an ideal device nominally perfonning the sane function.
3.3 anticipated operational occurrence IA()O): Those conditions of normal operations that are expected to occur one or more times during the life of (be nuclear power unit and include. but are not limited to. loss of power to all recirculation pumps. tripping of the turbine generator set isolation of (he main condenser. and loss of all offsite power tsee Title 10 CFR. Part 5018 lOJL
3.4 auxilIary supporting features: Systems or components that provide services tsuch as cooling. lubrication, and energy supply t required for the safety systems to accomplish their safety functions.
3.5 common cause failure: Multiple failures of structures, systems, or components as a result of a single phenomenon.
3.6 contIngency actions: Alternative actions taken to address unexpected responses of the plant or conditions beyond its licensing basis f for exansple. aclions taken for multiple equipment failuret’O.
3.7 critical safety functions: Those safety functions that are essential to prevent a direct and immediate threat to the health and safety of the public. These are accomplishing or maintaining of:
— Reactivity control
— Reactor core cooling
— Reactor coolant system integrity
— Primary reactor containment integrity
— Radioactive effluent control
3.8 current sahw: That magnitude of a variable that is associated with the present time and is available for display within the respotise time limits of an information display channel.
3, design basis event WIlE: Postulated events specified by the safety analysis for the station to establish the acceptable performance requirements of the structures and systems
3.10 display channel: An arrangement of electrical and mechanical components or modules, or both. from the measured process variable to the display device as required to sense. process. and display conditions within the generating station (see Figure II.
3.11 display channel failure: A situation where the information displayed disagrees, in a substantive manner i that is, where the maximum error within which the information must be conveyed to the operator has been exceededj with the actual conditions of the plant.
3.12 display segment: The electrical components or modules in an infonnation display channel that receive the processing electronics output and process the signal for input to the applicable display device. The display segment may include data validation algorithnn. storage of digital display graphics. and analog or digital display devices (see Figure I).
3.13 electrical power source: The electrical and mechanical equipment and their interconnections necessary to generate or cons’en power. Specific criteria unique to the Class lE power system are given in IEEE Std 30S-l99lP.IEEE 497 pdf download.