Document: NUREG-1555
Document ID: b5d0daf9-9138-4935-a8fb-b1fed4498171
Document Type: esrp
Title: DISCHARGE SYSTEM
Source: NUREG-1555
Source URL: https://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr1555/initial/
Revision Date: 2007-10
Chapter: 5
Section ID: 5.3.2
CFR Part: 
CFR Title: 

Content:
the receiving water body. Responsibility for making this determination (or for reassigning the responsibility) rests with the EPA. NUREG-1555 5.3.2.2-6 October 1999 Discharge system impacts on aquatic biota may result from the effects of thermal, chemical, and physical alterations to the receiving water body. Major alterations are usually confined to a limited discharge area (the mixing zone), whereas lesser alterations may extend over a larger portion of the receiving-water body. Adverse effects on biota that are transported through, migrate through, or are attracted to the mixing zone may be acute or chronic, and impacts may be reflected as changes in the populations of “important” species and in the structure and function of the ecosystem. The reviewer should take the following steps to evaluate the impacts of the plant’s discharge system: (1) Determine whether the applicant has provided a current NPDES permit with a 316(a) determination (if required) or equivalent State permits and supporting documentation. If these documents are not available, are not current, or do not reflect conditions during the license-renewal term, continue the analysis at Step (2). Otherwise, prepare a statement for the SEIS describing the potential for discharge impacts to aquatic biota at the site that ` summarizes the permitting documents reviewed ` states that the required current NPDES permit and 316(a) determination are available and current ` concludes that there are no discharge impacts to aquatic organisms that may occur as a result of plant-cooling-system discharges to receiving water bodies. (2) If “important” aquatic species are present and are susceptible to heat shock resulting from plant- cooling-system discharges to the receiving water bodies such that the effects will be detectable or may destabilize or noticeably alter population levels, then continue the analysis at Step (3). Other- wise, prepare a statement for the SEIS describing the potential for thermal