Document: NRC Regulatory Guide
Document ID: 5e2766ae-dd3b-4b1a-a6bb-48bde2dcbf97
Document Type: regulatory_guide
Title: Performance-Based Emergency Preparedness for Small Modular Reactors, Non-Light-Water Reactors, and Non-Power Production or Utilization Facilities
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1808/ML18082A044.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.242
CFR Part: 
CFR Title: 

Content:
w, or may be evaluated over a range of distances from the site boundary. A-3.6 Probabilistic Dose Aggregation The method for aggregating doses from different source terms, given consideration of their frequencies, should be identified. For example, analyses with design-basis-accident source terms may simply present dose-distance curves conditional upon the occurrence of the source term without consideration of frequency. For beyond design basis accidents (BDBA), dose-distance results may be aggregated using frequency information developed as described in Appendix B to evaluate the likelihood of exceeding a TEDE of one rem as a function of distance. The likelihood of exceeding a TEDE of one rem due to variability in meteorological conditions should be discussed. Methods used to compare the dose assessment results (which would be characterized by a distribution reflecting variability in meteorological conditions) to the dosimetric criteria (which is a single dose value) should be identified. For example, the dosimetric criteria may be compared to the mean, median, maximum, or some other statistic of the distribution. Because there can be uncertainties in each of the analyses supporting the evaluation, any significant uncertainties that could affect this comparison should be identified and characterized. DG-1350, Appendix A, Page A-4 Figure A-1. Analyses to Support Radiological Dose Assessment for EPZ Size Evaluation •Identify release scenarios and evaluate source term information as described in Section A-3.1 and Appendix B. 1. SOURCE TERM •Develop meteorological data for atmospheric transport and dispersion modeling as described in Section A-3.2. 2. METEOROLOGICAL DATA DEVELOPMENT •Identify and parameterize an atmospheric transport, dispersion, and deposition model as described in Section A-3.3. 3. ATMOSPHERIC TRANSPORT MODEL •Model the potential exposures to offsite populations as described in Section A-3.4. 4. EXPOSURE MODEL •Estimate potential doses to