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:
significance of various types of setpoints important to safety may differ, and thus one may apply a less rigorous setpoint determination method for certain functional units and limiting conditions of operation. The use of a graded approach allows a less-rigorous setpoint determination method based on the safety significance of the instrument function. However, the grading technique chosen by the applicant/licensee should be consistent with the standard and should consider all known applicable uncertainties regardless of setpoint application. Additionally, the application of the standard, using a "graded" approach, is also appropriate for non-safety system instrumentation maintaining design limits in the technical specifications. Appendix 7-A Rev. 4 — June 1997 BTP HICB-12-5 Basis for Instrument Calibration Intervals The applicant/licensee should evaluate the effects of extended calibration intervals on instrument uncertainties, equipment qualification, and vendor maintenance requirements to ensure that an extended surveillance interval does not result in exceeding the assumptions stated in the safety analysis. Generic Letter 91-04 Enclosure 2, "Guidance for Addressing the Effect of Increased Surveillance Intervals on Instrument Drift and Safety Analysis Assumptions," provides acceptable guidance for justifying extended calibration intervals through the use of data analysis, monitoring and assessment. 4. Review Procedures The setpoint analysis methodology and assumptions should be reviewed to confirm that an acceptable analysis method is used and that the analysis parameters and assumptions are consistent with the safety analysis, system design basis, technical specifications, plant design, and expected maintenance practices. The following factors should be emphasized in the review: • The relationships between the safety limit, analytical limit, the allowable value, the setpoint, the as-found limit and the as-left limit. • The basis for selection of the trip