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:
tivities," provides guidance on determining that the quality of the PRA, in total or the parts that are used to support an application, is sufficient to provide confidence in the results such that the PRA can be used in regulatory decision making for light-water reactors. 3. Definitions ISA-S67.04-1994, Part I, Section 3 and Figure 1 provide acceptable definitions (except as noted by Regulatory Guide 1.105, Revision 3, and RIS-2006-17) of setpoint terminology and relationships between trip setpoint, allowable value, analytical limit, LSSS, and safety limit. The following additional definitions are provided for reviewer guidance: A. Acceptable as-found band: It is the band around the nominal trip setpoint or previous as-left setting of the instrument within which the as-found setpoint is expected to fall. The band accounts for the uncertainties associated with factors such as instrument reference accuracy, measurement and test equipment (MT&E), readability, normal environment effect, and drift of the instrument BTP 7-12-4 Revision 5 - March 2007 components that are being tested, and it accounts only for the duration between the tests. The width of the band is established by the Deviation Limit (DL), which may be asymmetrical relative to the reference value (nominal setpoint (NSP) or previous as-left) and defines the deviation (from the previous as-left value or NSP) that is expected to occur during the test. It should be noted that the DL must not include the setting tolerance (ST). B. As-left tolerance band or acceptable as-left band: It is the band around the nominal trip setpoint (LSP) - or around any value which is more conservative than the LSP - within which the as-left setpoint must fall at the conclusion of a channel test. The band accounts for the as-left tolerance, which some licensees define as leeway given to instrument technician or calibration tolerance or setting tolerance. Setting tolerance can be based upon particular uncertainties such as reference