Document: NUREG-0800
Document ID: 1da20040-18d5-4c75-9863-5f578a9d73a5
Document Type: srp
Title: Revision 5 - March 2007
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070550078.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7
CFR Part: 
CFR Title: 

Content:
o safety may differ, and thus a less rigorous setpoint determination method for certain functional units and limiting conditions of operation may be applied. 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 and bound 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. Basis for Instrument Calibration Intervals The applicant/licensee should evaluate the effects of extended calibration intervals on instrument uncertainties, equipment qualification, and vendor maintenance provisions to assure 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. This approach has been used for plants to accommodate a 24-month fuel cycle change. For changes to surveillance test intervals for reasons other than a 24-month fuel cycle, the submittals have followed the risk informed approach and followed the guidance of Regulatory Guides 1.174, 1.177, and 1.200. 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