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
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Content:
provided in the ACM. III. REVIEW PROCEDURES The general procedures for the review of RTNSS SSCs for all passive light water reactors are given in the following paragraphs. In applying these procedures to the review of RTNSS SSCs in the designs of small modular reactors that rely on passive safety systems, the staff uses a graded approach described in NUREG-0800, Introduction – Part 2, “Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants: Light Water Small Modular Reactor Edition, Revision 0,” January 2014 (ADAMS Accession No. ML13207A315). 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. 19.3-9 Revision 0 – June 2014 • 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 SSCs 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