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:
on in final safety analysis report,” if the DBA does not involve the equivalent of significant core damage such as that resulting from a major accident. Those regulations require an assumed “major accident”f for demonstrating the adequacy of traditional containment structures to confirm that doses at the boundaries of the exclusion area and LPZ are below the siting reference values provided in the regulations, a dose of 25 rem TEDE. Applicants using a methodology like that described in RG 1.233 would use the licensing-basis events categorized as design-basis events (DBEs) and beyond-design-basis events (BDBEs) to estimate potential offsite doses for use in determining the distance out to which the population density should be less than 500 ppsm.g The estimated doses from DBEs and BDBEs are calculated for the 30-day period following the initiation of the release to determine the distance at which the dose to a hypothetical individual would exceed 1 rem TEDE. The calculation of offsite doses should be in accordance with NRC-accepted methodologies, including associated computer models for the plant response to an accident, the performance of various barriers to the release of radioactive materials, and the atmospheric dispersion of any released radioactive materials to areas surrounding the plant.h Demonstrating that the population density for a subject site does not exceed 500 ppsm within the circular area defined by a radius of twice the distance at which the 1 rem TEDE is estimated for potential DBEs and BDBEs is sufficient to meet the requirements of 10 CFR 100.21(h). If an applicant can show that no DBEs or BDBEs result in an offsite dose exceeding 1 rem TEDE for the 30-day 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.