Document: NRC Regulatory Guide
Document ID: db0c5d18-2d27-4720-8935-40b402e52f9a
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:
takeholders and the Commission’s directions related to the Commission paper will be reflected in the final RG. 5 The definitions of some phrases used in NEI 18-04 are different from the same phrases used in NRC regulations and guidance developed for LWRs. The terms “AOO” and “DBE” are examples of similar terms having different definitions. The methodology in NEI 18-04 also includes a different definition and means to identify SR SSCs from those used in the deterministic approaches for LWRs. 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 11 NEI 18-04 describes an expanded role for probabilistic risk assessment (PRA) for non-LWRs beyond current 10 CFR Part 52 requirements or Commission policy for potential applications under 10 CFR Part 50. Before the first introduction of the design-specific PRA, a designer needs to develop a technically sound understanding of the potential failure modes of the reactor concept, how the reactor plant would respond to such failure modes, and how protective strategies will be incorporated into formulating the safety-design approach. A designer can use safety-analysis methods appropriate to early stages of design, such as failure modes and effects analyses and process hazard analyses. Designers may likewise use the design criteria from RG 1.232 and confirm or refine them throughout the design process to develop the final PDC provided in an application. These techniques provide industry-standardized practices to ensure that such early-stage evaluations are systematic, reproducible, and as complete as the current stage of design permits. The subsequent use of the PRA by the designer is used to develop or confirm the events, safety functions, key SSCs, and adequacy of DID; and