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:
hydrologic alterations resulting from station operation. For example, the applicant should discuss alterations in water levels and groundwater heads; alterations in flow rates and circulation patterns caused by diversion, intake, and discharge structures; and alterations in erosion, deposition, and sediment transport characteristics. • The effects of these alterations on the quantity and availability of water within the ROI. For example, the applicant should assess, as applicable, how hydrologic alterations affect river discharge (including changes in the seasonal variation of flow) or groundwater discharge to wetlands. • The effects of effluent discharge on the water quality of the receiving waterbodies. Thermal, chemical, and radiological effects should be evaluated. • The proposed actions to minimize the effects of the hydrologic alterations. • Applicable standards and regulations. When a mathematical model is used to evaluate the effects of hydrologic alterations, the applicant should describe the conceptual basis for the model (including the rationale for eliminating plausible DG-4026, Page 83 alternative conceptualizations), the assumptions used in developing the model, the range of applicability of the model, input data used, the basis for boundary conditions, parameter estimation and calibration procedures followed, and estimates of uncertainty in model forecasts. The applicant should provide sufficient data to permit staff evaluation of modeling results, including input files used to obtain the model results and a description of any post-modeling analyses used by the applicant. 5.2.2 Water-Use Impacts The applicant should identify those water uses and water users discussed in Chapter 2 of this RG that are potentially affected by the changes in the quantity and/or availability of water resulting from hydrologic alterations. The applicant should evaluate the water-use impacts by quantifying the anticipated reduction in water-supply reliability for