Document: NRC Regulatory Guide
Document ID: 239cc7c1-f2cb-46cc-945d-8009db28aa6c
Document Type: regulatory_guide
Title: General Site Suitability Criteria for Nuclear Power Stations + HISTORY - HISTORY 12/2023 – DG-4034 , Proposed Revision 4 12/2011 – DG-4021 , Proposed Revision 3 02/1995 – DG-4004, Second Proposed Revision 2 11/1992 – DG-4003, Proposed Revision 2 (Rev. 4)
Source: NRC Regulatory Guide Division 4
Source URL: https://www.nrc.gov/docs/ML2312/ML23123A090.pdf
Revision Date: 2023-10
Chapter: 
Section ID: RG-4.7
CFR Part: 
CFR Title: 

Content:
exposure period, the siting of a reactor might not be determined by population-density considerations but would instead be governed by the regulatory requirement in 10 CFR 100.21(b) for reactors to be located distant from densely populated centers with more than about 25,000 residents.. However, an advanced reactor with estimated doses below 1 rem at the site boundary over the month following the assumed postulated accident could be sited within towns with populations of no more than approximately 25,000 residents. Similar to the description in section C.2 of RG 1.183 for LWRs, non-LWR applicants must also provide a defensible technical basis for the deterministic source term used for the siting analysis and justification of an alternative to the existing guidance in section C.1.4 of this RG (i.e., limited population density out to 20 miles from a reactor). The technical basis must be supported by sufficient experimental and empirical data, be verified and validated, be documented in a scrutable form that facilitates public review and must be peer reviewed by qualified subject matter experts. The following subsections offer guidance on specific elements to consider in developing such a source term for use in the siting analyses, including performing an event assessment, establishing a radionuclide release, considering uncertainty, and demonstrating adequate defense in depth. (a) Performance of an Event Assessment and Selection of an Event or Events to be used for the Siting Analysis To adequately justify the source term used for the siting analysis, an event assessment must be performed for the plant design basis. For the siting analysis, an applicant is required by 10 CFR 50.34(a)(1), 10 CFR 52.17(a)(1)(ix), or 10 CFR 52.79(a)(1)(vi), as applicable, to provide an assessment and evaluation of the SSCs that bear significantly on the offsite dose evaluation factors. In performing this assessment, an applicant is required (e.g., by 10 CFR 50.34(a)(1)(ii)(D)) to assume