Evaluation and Optimization of Cooling Water Use in Nuclear Power Generation

As the world is facing a global challenge in declining fresh water resources and increasing demand, there are indisputable needs for conservations through sustainable strategies and practices on water use. In the power generation industry, traditionally, the majority of the consumptive water use is expended in the cooling cycle as evaporative water losses. This paper evaluates the different cooling technologies and operation strategies considered by the North Anna Power Station, who proposes to build a nuclear power generation unit located on an existing cooling reservoir, Lake Anna, to minimize water consumption and adverse impacts on lake temperature, lake levels, and downstream flows. The method of thermal and water budget analyses used to estimate water consumption and responses on the lake level and downstream flow releases are discussed. Results of the analysis indicate that, for a 1500 Megawatt nuclear unit, a hybrid, wet-dry cooling tower system in combination with changes in reservoir operation strategy could reduce long-term water consumption from about 28 cfs to less than 19 cfs as compared to a conventional once-through cooling system. These results suggest that the hybrid cooling tower technology has the potential to significantly reduce water consumption by thermoelectric power plants, thereby reducing consumptive use impacts on reservoir levels, recreational users as well as downstream flows and associated fisheries.