Document: NUREG-0800
Document ID: 39eaebb5-884c-4731-895a-8df4686b7293
Document Type: srp
Title: REGULATORY TREATMENT OF NONSAFETY SYSTEMS FOR PASSIVE
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1403/ML14035A149.pdf
Revision Date: 2023-06
Chapter: 19
Section ID: 19.3
CFR Part: 
CFR Title: 

Content:
staff reviews the applicant’s analysis of accidents related to NRC deterministic performance requirements such as 10 CFR 50.62 and 10 CFR 50.63 to identify any nonsafety-related SSCs that have been credited in the analyses and confirms that these SSCs have been included in the scope of the RTNSS program (RTNSS “A”). 2. The staff reviews the applicant’s determination of safety functions that must be satisfied to maintain the plant in a safe stable shutdown condition1 in the post 72-hour period and following seismic events, and the methods for achieving those safety functions. The staff verifies that nonsafety-related SSCs relied upon to achieve those functions have been included in the scope of the RTNSS program (RTNSS “B”). 3. The staff reviews the applicant’s description of the Seismic Margins Analysis (SMA) documented in Chapter 19 of the FSAR to identify any nonsafety-related SSCs that have been credited in the SMA. The staff confirms that any nonsafety-related SSCs that are relied upon to meet the acceptance criteria for the SMA have been included in the scope of the RTNSS program (RTNSS “B”). 4. The staff responsible for review of the applicant’s PRA reviews the results of the focused PRA sensitivity studies as described in SRP Section 19.0, “Probabilistic Risk Assessment and Severe Accident Evaluation for New Reactors,” Revision 3. The staff confirms that nonsafety-related design features or functional capabilities with mitigation capability sufficient to reduce the CDF or LRF below the Commission goals when credited in the focused PRA have been identified as risk-significant and included in the scope of the RTNSS program (RTNSS “C”). 5. The staff responsible for review of the applicant’s PRA use information in Chapters 15 and 19 of the FSAR pertaining to initiators of transients and accidents affecting the nuclear steam supply system, and consult as necessary with reviewers of those sections, to verify that the applicant has