Document: NUREG-0800
Document ID: fe8ec6c2-e960-404c-854f-55c77bde1672
Document Type: srp
Title: NUREG-0800
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML2400/ML24005A077.pdf
Revision Date: 2024-05
Chapter: 7
Section ID: 7
CFR Part: 
CFR Title: 

Content:
signal in such a system reaches the final actuation device only through the equipment that performs control functions, then the reviewer should determine whether all the SSCs in that pathway have been assigned to the SSC category of most safety significance. Acceptance Criteria for Safety-Significance Determinations The three safety-significance determination categories7 below should reasonably conform to the criteria below. If the applicant uses risk insights (e.g., from a site-specific PRA) to demonstrate that an SSC is less safety significant than these criteria would indicate, the NRC staff should review these on a case-by-case basis. The following acceptance criteria apply: a. High safety significance: safety-related SSCs that perform safety-significant functions SSCs in this category have one or more of the following characteristics:  They are credited in the FSAR to perform design functions that contribute 7 The safety-significance determination categories used in this BTP are consistent with SECY-18-0090. BTP 7-19-15 Revision 9 — May 2024 significantly to plant safety.  They are relied upon to initiate and complete control actions essential to maintaining plant parameters within acceptable limits established for a DBE or to maintaining the plant in a safe state after it has reached safe shutdown.  Their failure could directly lead to accident conditions that may have unacceptable consequences (e.g., exceeding dose guidelines) if no other automatic systems are available to provide the safety function or no preplanned manual operator actions have been validated to provide the safety function. b. Lower safety significance: safety-related SSCs that do not perform safety-significant functions, and SSCs that are not safety related that do perform safety-significant functions SSCs in this category have one or more of the following characteristics:  They provide an auxiliary or indirect function in the achievement or maintenance of a safety-related