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:
epted engineering practices. For multipurpose impounded lakes and reservoirs, consumptive use should be restricted so that the magnitude and frequency of drawdown will not cause unacceptable damage to important habitats or be inconsistent with the management goals for the water body. In areas with complex ground water hydrology, or with aquifers that are or may be used for domestic or industrial water supplies or for irrigation water, the suitability of a site for a specific plant design can be determined only after a reliable assessment of the potential impacts of the reactor on the ground water. Site environmental parameters, which include hydrological and meteorological characteristics, should be comparable to those used in the plant probabilistic risk assessment and environmental analysis. Statistical techniques and numerical modeling (e.g., the 7Q10 low-flow condition) should be used, if applicable, to extend and complement the period of record to help identify the expected minimum flow for the region. If the water supply is not adequate for the plant, then other sources of water need to be identified. DG-4034, Page 34 If applicable, potential sources of cooling water should also be screened by their capacity to meet intake flow limitations specified in CWA section 316(b), as implemented by the EPA in 40 CFR Parts 9, 122, 123, 124, and 125. CWA section 316(b) identifies criteria based on type of water body in order to reduce environmental impact. It is typically administered by State programs. Although management of surface water quality is important, water quality is not generally a determining factor in assessing the suitability of a site, since adequate design alternatives can be developed to meet CWA requirements and the Commission’s regulations implementing NEPA. The following are examples of potential environmental effects of station construction and operation that should be assessed: • physical and chemical environmental alterations in habitats of