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:
hase I for new facilities. • Information on National Pollutant Discharge Elimination System (NPDES) permits for the proposed site and/or current NPDES permit for existing units sited in proximity to the proposed units. • Description of the susceptibility of important aquatic species at specific life stages to entrainment, and impingement in conjunction with operation of the plant cooling-system and entrainment or impingement rates from operation of the plant using data from studies as discussed in RG 4.24, including existing historical data from studies from co-located or nearby nuclear or fossil units. • Discussion of stock assessments, if available and appropriate, as a metric for impact to the species for those important species potentially affected by station operation. • Discussion of species and habitats that may be adversely affected by periodic operations, (e.g., thermal backwashing). • Discussion of species that may be affected by potential adverse effects from recirculation of heated effluent from the plant-discharge system, and altered hydrodynamic characteristics including altered circulation or current patterns. Discussion of habitats affected by the cooling- water system including bottom scouring near the discharge. DG-4026, Page 86 • Discussion of the temperature tolerance, duration of exposure, and avoidance behavior of susceptible important aquatic species in relation to thermal discharge, including heat shock and cold shock, at all affected life stages. This discussion should be based on a model, map and description of the thermal plume and should include variation seasonally and throughout the water column. • Description of any potential changes to vectors causing aquatic species disease as a result of thermal discharges. • Description of any potential changes to numbers of nuisance, invasive, and introduced species, including fish, aquatic vegetation and benthic invertebrates (e.g., Corbicula spp. or Mytilus spp.) onsite or in the