Document: NUREG-0800
Document ID: ecf7a8d4-0097-4a93-8609-630545f03f70
Document Type: srp
Title: REGULATORY TREATMENT OF NONSAFETY SYSTEMS FOR PASSIVE
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1308/ML13081A756.pdf
Revision Date: 2023-06
Chapter: 19
Section ID: 19.3
CFR Part: 
CFR Title: 

Content:
rd Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants: Integral Pressurized Water Reactor Edition,” Revision 0 (Draft for Comment), January 2013.” Some examples of this “graded approach” are: • RTNSS “B” SSCs may have testing and inspections, tests, analyses, and acceptance criteria (ITAAC) because of the augmented design standards they must meet; whereas, testing and ITAAC for other RTNSS SSCs would be unlikely. • Functional capabilities of some RTNSS “C” SSCs may have higher risk-significance than functional capabilities of other RTNSS “C” SSCs. RTNSS “C” SSCs performing the function with higher risk-significance would normally receive a more rigorous review. Area of Review – Identification of SSCs in the Scope of the RTNSS Program The staff reviews the process used by the applicant to determine which nonsafety-related systems in the facility design should be subject to regulatory treatment and under what conditions that treatment should apply. The staff verifies that the implementation of the RTNSS process follows the scope, criteria, and specific steps described in SECY-94-084 and SECY-95-132, which are discussed in RG 1.206. In particular, the staff verifies that the applicant has applied the RTNSS scoping criteria described in Section I of this SRP appropriately. 1. The 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