Document: NRC Regulatory Guide
Document ID: b3da4d67-03d8-4f52-b04b-8e76d142c857
Document Type: regulatory_guide
Title: Guidance for a Technology-Inclusive, Risk-Informed, and Performance-Based Methodology to Inform the Licensing Basis and Content of Applications for Licenses, Certifications, and Approvals for Non-Light Water Reactors + HISTORY - HISTORY 05/2019 – Issued DG-1353 , Proposed Revision 0
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1831/ML18312A242.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.233
CFR Part: 
CFR Title: 

Content:
onservative assumptions. The safety classification categories used in NEI 18-048 for non-LWRs are defined as follows: • safety related: o SSCs selected by the reactor designer from the SSCs that are available to perform the required safety functions to mitigate the consequences of DBEs to within the LBE F-C target and to mitigate DBAs that only rely on the SR SSCs to meet the 10 CFR 50.34 dose limits using conservative assumptions o SSCs selected by the reactor designer and relied on to perform required safety functions to prevent the frequency of BDBE with consequences greater than the 10 CFR 50.34 dose limits from increasing into the DBE region and beyond the F-C target 8 The methodology in NEI 18-04 includes a different definition and means to identify SR SSCs for non-LWRs from those used in the deterministic approaches for LWRs. Additionally, “nonsafety-related” is used in NEI 18-04 but is not a defined term in NRC regulations and has different meanings depending on the context in which it has been used in guidance documents and specific applications. As used in this RG and NEI 18-04, the term “nonsafety-related” means SSCs or an SSC that is not safety-related. NEI 18-04 includes a glossary to help alleviate some of the issues that will arise because of differences in terminology. Applicants referencing this RG are expected to use the terminology in NEI 18-04 and, as needed, identify exceptions to and exemptions needed from NRC regulations. DG-1353, Page 16 • nonsafety-related with special treatment (NSRST): o non-SR SSCs relied on to perform risk significant functions; risk-significant SSCs are those that perform functions that prevent or mitigate any LBE from exceeding the F-C target or that make significant contributions to the cumulative risk metrics selected for evaluating the total risk from all analyzed LBEs o non-SR SSCs relied on to perform functions requiring special treatment for DID adequacy • nonsafety-related with no special