The Use of Closed-Cycle Cooling at New Nuclear Power Stations and Its Potential Impact on the Aquatic Environment

On December 18, 2001 U.S. EPA published regulations implementing new requirements under section 316(b) of the Clean Water Act for large new thermo-electric power facilities.  The regulations establish proportional flow requirements and implement design technologies to minimize impingement and entrainment of fish and shellfish.   Most importantly the regulation has resulted in the adoption of closed-cycle wet cooling systems for almost all proposed thermo-electric power plants including all new nuclear facilities.  The effect of this regulation on new nuclear station design is discussed.  Employing closed-cycle cooling at new facilities and its effect on the fishery is considered with an emphasis on the impact of withdrawal and the consumptive use of water resulting from the use of evaporative closed-cycle cooling systems.  Because of the significant consumption of water associated with this cooling technology areas of the U.S. with high water demand and/or limited supply have experienced difficulty the siting of new nuclear facilities. The loss of water results in a loss or alteration of aquatic habitat.  This and other sources of impact to the fishery due to close-cycle cooling such as impingement, entrainment, and thermal effects need to be considered when assessing impact.  Opportunities for research and monitoring at new power stations are also discussed.