Document: NRC Regulatory Guide
Document ID: e5306f4f-dc8c-4f60-a71c-af7ad4080384
Document Type: regulatory_guide
Title: Aquatic Environmental Studies for Nuclear Power Stations + HISTORY - HISTORY 12/2014 – DG-4023 -Proposed New Guide
Source: NRC Regulatory Guide Division 4
Source URL: https://www.nrc.gov/docs/ML1318/ML13186A085.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-4.24
CFR Part: 
CFR Title: 

Content:
ecology resources (e.g., freshwater mussels) and special aquatic sites, further narrows the field of possible sites, and increases confidence in how well the resulting field of sites avoids sensitive resources. The ROI may be screened initially at a coarse scale (e.g., 1:250,000) to identify candidate areas that best exclude areas dedicated to ecological management (e.g., national wildlife refuges, critical habitat for federally listed species, important habitat for state-listed protected species, designated EFH, and state sanctuaries, reserves, preserves, wildlife, or natural areas), as well as other sensitive and important aquatic habitats such as estuaries. One approach could be to identify candidate areas to be screened more closely by overlaying a polygon approximating the size of a nuclear reactor site showing protected species and smaller aquatic areas that were indiscernible at the coarser scale. Analysts may reposition the polygon multiple times over the map to identify a suite of candidate sites for further investigation. Applicants could then compare candidate sites using specific qualitative and quantitative criteria. Criteria may include numbers of known occurrences of federally or state-listed species; scientific reports or professional judgment on the amount and quality of freshwater, estuarine, or marine habitats; distance from aquatic habitats; and other pertinent species or habitat attributes. Applicants may score criteria and compare candidate sites using composite scores. Scoring criteria should reflect information that is as uniform in detail and accuracy as possible among candidate sites. Analysts should review scores for possible biases derived from differing quality of available data. For example, the number of known occurrences of federally and state-listed species may vary from site to site depending on how well analysts in each geographic region have characterized them in the past. Analysts should justify the criteria selected and