Document: NUREG-0800
Document ID: 43123a17-321c-4751-b3ba-9ba5e9b0b364
Document Type: srp
Title: Draft Revision 6 – August 2015
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1515/ML15159A726.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7
CFR Part: 
CFR Title: 

Content:
mation, provided the Category 1 instrumentation is isolated from the Category 2 instrumentation using qualified isolation devices. Guidance on the application and qualification of isolation devices is provided in SRP BTP 7-11. Range Deviations from the range values identified in Revisions 2 and 3 of RG 1.97 may be acceptable if supported by analyses demonstrating that the indication would remain on scale with appropriate margins for any design basis event or accident for which the instrumentation might be required for operator information. An appropriate margin should include allowance for analytical uncertainties and instrumentation uncertainties. However, RG 1.97 identifies that, for a limited number of functionally significant variables (e.g., containment pressure, primary system pressure); instrument ranges should extend beyond values that the selected variables can attain under limiting conditions. Guidance on uncertainties is provided in SRP BTP 7-12. The ranges and footnotes for radiation and meteorological instrumentation that are provided in Revision 3 of RG 1.97 should be applicable for plants using Revision 4 of RG 1.97. Applicants and licensees using Revision 4 should document differences from the Revision 3 ranges and footnotes for radiation and meteorological instrumentation. Minimizing Measurements To the extent practicable, the same instruments should be used for accident monitoring as are used for normal operations of the plant. In cases in which a single display may indicate the reading of more than one instrument, the intent of this recommendation is met if the same variable and same display are used for accident monitoring even though the sensor(s) providing the signal are different. Alternate Instrumentation The use of alternate instrumentation to monitor variables different from those identified in RG 1.97, Revisions 2 and 3, is acceptable, provided that all three of the following criteria are met: (1) The alternate instrumentation fulfills the