Document: NRC Regulatory Guide
Document ID: eb3f5778-b26b-4ba0-9962-f7101bddfff7
Document Type: regulatory_guide
Title: (Rev. 3005)
Source: NRC Regulatory Guide Division 4
Source URL: https://www.nrc.gov/docs/ML0037/ML003739900.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-4.8
CFR Part: 
CFR Title: 

Content:
e or seasonal temperature requirements of the species to be protected. 2.1.5 Heat Treatment of Circulating Water System Limits should be provided for the magnitude and duration of temperature increase (AT) in intake and receiving waters above normal operating levels which result from special uses of heated water, such as heat treatment of the condenser and deicing of water intake structures. Limits may be required to maintain discharge water temperature increases to acceptable levels above ambient or to' control fish attraction to the warmed intake structure. 2.2 Hydraulic 2.2'1 Intake Velocity Maximum limits on intake approach and screen face velocities should be .specified where a potential exists for impingement on intake screens of numbers of individuals of important species that may result in an unacceptable impact on the species population or the ecological system. Intake water velocities should be based on swimming speeds and behavioral patterns which in fluence impingement susceptibility. 22.2 Discharge Velocity Limits on discharge velocity should be established where bottom scouring is a potential problem, where sfcific discharge velocities are necessary for optimum mixing conditions, or where circulation in the receiving water is affected by the discharge velocity. 2.2.3 Withdrawal and Drawdown Restrictions Limits on total withdrawal from the water supply should be established where water level or discharge is important for protection of organisms in the station vicinity and in upstream and downstream waters and to prevent undesirable alteration of the circulation of the supply water body. Limits on water drawdown may be needed for lakes and reservoirs that undergo large fluctuations in water level due to hydroelectric or flood control operations or other causes. Limiting conditions for operation should be estab lished for .chemical releases (including biocides) associated with all plant discharge water systems, for other plant-related chemical usages such