Document: NRC Regulatory Guide
Document ID: f0baf50b-5bb7-4783-b2f9-9586e09c97e1
Document Type: regulatory_guide
Title: Preparation of Environmental Reports for Nuclear Power Stations + HISTORY - HISTORY 02/2017 – DG-4026 , Proposed Revision 3 09/2014 – Periodic Review of Revision 2 – Revise (Rev. 3)
Source: NRC Regulatory Guide Division 4
Source URL: https://www.nrc.gov/docs/ML1611/ML16116A068.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-4.2
CFR Part: 
CFR Title: 

Content:
earby bodies of water on short-term dispersion estimates should be provided. The meteorological data used as input to the models should be provided. Long-Term Dispersion Estimates The applicant should provide estimates of annual average atmospheric dispersion (χ/Q) and deposition (D/Q) at appropriate locations (e.g., site boundary, nearest vegetable garden, nearest residence, nearest milk animal, and nearest meat cow in each 22½-degree direction sector within a 5-mi radius of the site), at points of maximum individual exposure, and at points within a radial grid of sixteen 22½-degree sectors (e.g., centered on true north, north-northeast, northeast) and extending to a distance of 50 mi from 7 Carbon dioxide (CO2) equivalents is a metric used to compare the emissions of GHG based on their global warming potential (GWP). GWP is the total energy that a gas absorbs over a period of time, compared to carbon dioxide. Carbon dioxide equivalent is obtained by multiplying the amount of the GHG by the associated GWP. DG-4026, Page 50 the station. A set of data points should be located within each sector at increments of 0.25 mi out to a distance of 1 mi from the plant, at increments of 0.5 mi from a distance of 1 to 5 mi, at increments of 2.5 mi from a distance of 5 to 10 mi, and at increments of 5 mi thereafter to a distance of 50 mi. Estimates of χ/Q (undecayed and undepleted; depleted for radioiodines) and D/Q radioiodines and particulates should be provided at each of these grid points. Regulatory Guide 1.111, “Methods for Estimating Atmospheric Transport and Dispersion of Gaseous Effluents in Routine Releases from Light-Water-Cooled Reactors” (Ref. 47), presents criteria for characterizing atmospheric dispersion and deposition conditions for evaluating the consequences of routine releases. The applicant should describe the methods for generating these χ/Q and D/Q values. The applicant should provide a detailed description of the model inputs, including the