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:
ability, hysteresis, dynamic response, environmental qualification, calibration reference, and calibration intervals should be listed for each instrument type. • Instrument loop diagrams showing all hardware elements of the instrument loop(s). • Instrument and tubing layout drawings and installation details showing locations and elevations of instruments and tubing relative to a reference datum, as well as the points where the instrument interfaces with the monitored process. • For digital instrumentation, the configuration database for the instrumentation functions, and identification of digital elements (hardware and software) where error could be introduced in the measurement. (For example, errors that could result from analog-to-digital or digital-to-analog conversion or from numerical methods used in the software (e.g., curve fitting).) The description of assumptions required by ISA-S67.04 Part I should include the environmental allowances (temperature, pressure, humidity, radiation, vibration, seismic, and electrical) for the instruments. Analysis Supporting Establishment of Setpoints and Instrumentation Tolerances The applicant/licensee should document the bases and the calculations of measurement uncertainties. The methods by which setpoints are calculated should conform to the guidance of Draft Reg. Guide DG-1045. Statistical Guidelines for Instrument Uncertainty In the review of uncertainties in determining a trip setpoint and its allowable values, the NRC staff typically uses 95/95 tolerance limits as an acceptable criterion. That is, there is a 95% probability that the constructed limits contain 95% of the population of interest for the surveillance interval selected. Guidelines for Graded Approach Section 4 of ISA-S67.04 Part I states that the safety 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