IEEE 497-2010 pdf download IEEE Standard Criteria for Accident Monitoring Instrumentation for Nuclear Power Generating Stations
3. Definitions
For the purposes of this document, the following terms and definitions apply. The IEEE StandardsDictionary: Glossary of Terms & Definitions should be referenced for terms not defined in this clause.
accident analysis licensing basis: The portions of the licensing basis documentation that describe thedesign basis events (including anticipated operational occurrences), the thermal-hydraulic response of thenuclear power generating station, and the subsequent response of the safety systems.
accuracy: A measure of the degree by which the actual output of a device approximates the output of anideal device nominally performing the same function.
analog sensor: The portion of a channel that responds to changes in a plant variable or condition andconverts the measured process variable into an electric, optic, or pneumatic signal.
anticipated operational occurrence (AOO): Those conditions of noral opcrations that are cxpected tooccur one or more times during the life of the nuclear power generating station and include, but are notlimited to, loss of power to all recirculation pumps, tripping of the turbine generator set, isolation of themain condenser, and loss of all offsite power.
auxiliary supporting features: Systems or components that provide services (such as cooling, lubrication.
and energy supply) required for the safety systems to accomplish their safety functions.
common cause failure: Multiple failures of structures, systems, or components as a result of a singlephenomenon.
contingency actions: Alternative actions taken to address unexpected responses of the plant or conditionsbeyond its licensing basis (for example, actions taken for multiple equipment failures).
current value: That magnitude of a variable that is associated with the present time and is available fordisplay within the response time limits of an information display channel.
design basis event (DBE): Postulated events specified by the safety analysis for the station to establish theacceptable performance requirements of the structures and systems.digital sensor: A device used for measuring process variables that operates on the basis of discretenumerical techniques in which the measured variables are represented by coded pulses or states.
display channel: An arrangement of electrical and mechanical components or modules, or both, from themeasured process variable to the display device as required to sense, process, and display conditions withinthe nuclear power generating station.
NOTE-See Figure 1.
display segment: The electrical components or modules in an information display channel that receive theprocessing electronics output and process the signal for input to the applicable display device, such as avideo display unit (VDU) or indicator (IND). The display segment may include data validation algorithms.storage of digital display graphics, and analog or digital display devices.
NOTE–See Figure 1.