Document: NRC Regulatory Guide
Document ID: acab976c-e936-49be-8c59-865767973599
Document Type: regulatory_guide
Title: Guidance for a Technology-Inclusive Content of Application Methodology to Inform the Licensing Basis and Content of Applications for Licenses, Certifications, and Approvals for Non-Light-Water Reactors (Rev. 1)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2319/ML23194A194.pdf
Revision Date: 2023-09
Chapter: 
Section ID: RG-1.253
CFR Part: 
CFR Title: 

Content:
P ISG, DANU-ISG-2022-02, “Site Information,” (Ref. 26), contains additional guidance on one acceptable approach to determining the scope and level of detail of the site information to be provided. h. Addition: In addition to the information that NEI 21-07, Revision 1, states applicants should include in SAR Chapter 2, applicants should identify and describe the non-PRA analysis and calculation methodologies used to establish their licensing bases. A change to any of the evaluation methodologies used in the licensing basis is one of the criteria in the existing facility change process (e.g., 10 CFR 50.59); therefore, for the facility change process to be effective, the licensing basis needs to describe these evaluation methodologies. DG-1404, Revision 1, Page 18 4. Licensing Basis Events Section C.3 of NEI 21-07, Revision 1, provides guidance on the information related to the LBE selection methodology and the summary of LBEs (AOOs, DBEs, BDBEs, and DBAs) to include in a SAR. After identifying the LBEs, Chapter 3 of a SAR following NEI 21-07, Revision 1, should describe the systematic and reproducible process and methodology used to select the LBEs, and the specific analysis and evaluation of the selected LBEs for the proposed design. The analyses in this chapter are primarily described in terms of event sequences consisting of an initiating event, the plant response to the initiating event (which includes a sequence of successes and failures of mitigating systems), and a well-defined end state. Chapter 3 should also describe the process used to group and condense the many event sequences considered in the PRA into event sequence families that are used to define the AOOs, DBEs, and BDBEs. It is important to note that the term “event sequence” is used here, instead of the term “accident sequence” used in LWR PRA standards, because the scope of the LBEs also includes AOOs and initiating events that do not result in radioisotope releases. It also important to