Document: NUREG-0800
Document ID: 8c755ba5-45e1-492e-b36c-5fa2fa5b3e29
Document Type: srp
Title: Appendix 7-A
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0525/ML052500545.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7
CFR Part: 
CFR Title: 

Content:
ments. • To confirm that calibration intervals and methods established are consistent with safety analysis assumptions. B. Branch Technical Position 1. Introduction Instrumentation and control (I&C) safety systems control plant parameters to ensure that safety limits will not be exceeded under the most severe design basis accident or transients. Instrument setpoints and allowable Appendix 7-A Rev. 4 — June 1997 BTP HICB-12-3 values for these I&C safety system functions are chosen so that potentially unsafe or damaging process excursions (transients) can be avoided and/or terminated before plant conditions exceed safety limits. Accident analyses establish the limits for critical process parameters. These analytical limits, as established by accident analyses, do not normally include considerations for the accuracy (uncertainty) of installed instrumentation. Additional analyses and procedures are necessary to ensure that the actual trip setpoint of each safety control function is appropriate. Instrument channel uncertainties in these analyses are based upon the characteristics of installed instrumentation, the environmental conditions present at the instruments' installed locations, and process conditions. A properly established setpoint will initiate a plant protective action before the process parameter exceeds its analytical limit. This, in turn, ensures that the transient will be avoided and/or terminated before the process parameters exceed the established safety limits. Similar calculations and reviews are performed as necessary to verify the setpoints for non-safety systems or procedural action points for safety and non-safety systems. 2. Information to be Reviewed The information to be reviewed consists of (1) a description of the setpoint program, procedures, and analytical results, (2) engineering information for the installed instrumentation, (3) supporting analyses, and (4) requirements and operating history for the instrument maintenance and