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:
n members of the public and if so, estimate the nature and magnitude of the impact. The scope of the review should include an analysis of radiation-exposure pathways to biota. In the ER, the applicant should include the following: • Pathways identified in Section 5.9.1 of this RG. • Biota to be evaluated. The biota to be considered are those species of local flora and local and migratory fauna defined as “important” (Table 2-1) and whose terrestrial and/or aquatic habitats provide the highest potential for radiation exposure or the applicant should specify surrogates for aquatic species (e.g., fish, invertebrates, and algae) and for terrestrial species (e.g., muskrats, raccoons, herons, and ducks). DG-4026, Page 104 • An estimation, considering exposure pathways and the distribution of facility-derived radioactivity in the environs, of the following: (1) the maximum radionuclide concentrations that may be present in important local flora and local and migratory fauna and (2) the internal dose rates (millirad/year) that may result from those concentrations. Values of bioaccumulation factors, concentration ratios, and transfer factors used in preparing the estimates should be based on site-specific data, if available; otherwise, values from the literature may be used. The applicant should tabulate and reference the values of bioaccumulation factors used in the calculations. Dose rates to important local flora and local and migratory fauna that receive the highest external exposures should be provided along with a description of the calculational models. The bioaccumulation factor for aquatic organisms is the value of the ratio: (concentration in organism)/(concentration in water). The soil-to-plant concentration ratio is the ratio of plant concentration (dry weight)/(the concentration in dry soil). The feed-to-organism transfer factor is the ratio of (concentration in fresh tissue)/(daily intake of the radionuclide by the organism). Values of bioaccumulation