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:
s therefore DG-4034, Page 40 important in site selection to consider potential effects on the routes and times of movement of immature individuals. Some species migrate in central, deeper areas, while others use marginal, shallow areas. Rivers, streams, and estuaries are seldom laterally homogeneous in depth, current velocity, and habitat type. Thus, the determination of adequate zones of passage should be based on both width or cross-sectional area criteria and knowledge of the specific migratory requirements of important species. Narrow reaches of water bodies should be avoided as sites for intake or discharge structures. A zone of passage should be provided that will permit normal movement of important species and maintenance of the harvestable crop of economically important populations. The width or cross-sectional area of a water body at a proposed site, relative to the general width or cross-sectional area in the portion of the water used by migrating species, should be estimated. Suggested minimum zones of passage range from one-third to three-fourths of the width or cross-sectional areas of narrow water bodies.5 Site evaluations should also assess the potential for blockage of movements of important terrestrial animal populations and the availability of alternative routes that would allow the species to maintain their breeding populations. 2.3.4 Entrainment and Impingement of Aquatic Organisms Several variables, including site characteristics and intake structure design and placement, determine the potential for impingement of organisms on cooling water intake structures and entrainment of organisms through the cooling system. 2.3.4.2 Relevant Statutes and Regulations • Fish and Wildlife Coordination Act, as amended; • Magnuson-Stevens Fishery Conservation and Management Act, as amended; • Clean Water Act section 316(b), as implemented in o 40 CFR Part 9, “OMB Approvals Under the Paperwork Reduction Act;” o 40 CFR Part 122, “EPA Administered