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:
from consideration. If an event is precluded by some aspect of the design or an analytical assumption, that should be noted and justified. (b) Establish Radionuclide Release(s) from the First Barrier Applicants should provide a safety analysis that demonstrates compliance with the requirements in 10 CFR 50.34(a)(1), 10 CFR 52.17(a)(1)(ix), or 10 CFR 52.79(a)(1)(vi), as applicable, to justify a finding of reasonable assurance of adequate protection of public health and safety even under the worst credible accident conditions. Recognition of the potential for a radiological source term—including activation of coolant/deposits, fission gas release, local failures (defects that are unlikely but credible over a sufficient sample size, channel blockages, etc.) and other relevant phenomena—is an important aspect of defense in depth to ensure that both prevention and mitigation of the full spectrum of credible adverse conditions that bear on public health and safety are considered. (Additional discussion on defense in depth considerations is provided in Section A-4, “Defense in Depth,” below.) Therefore, the siting analysis should assume a radionuclide release from the innermost barrier (typically the fuel). Methods for determining the release of radionuclides should use conservative estimates of the radionuclide release(s) from the first barrier (and potentially intermediate barriers) to result in a source term and offsite consequences that are bounding for all credible events. In many cases, a single analysis may adequately bound all other DBA analyses, and a single source term can be used for the siting analysis, similar to the approach used for non-power reactor applications submitted to the NRC that have used a maximum hypothetical accident analysis, as described in NUREG-1537, “Guidelines for Preparing and Reviewing Applications for the Licensing of Non-Power Reactors.”k Use of a single, bounding accident analysis does not prevent an applicant from