DESIGN AND SITING CRITERIA FOR ONCE-THROUGH COOLING SYSTEMS BASED ON A FIRST-ORDER THERMAL PLUME MODEL

摘要

The processes which control the distribution of excess temper-ature in the heated plume resulting from the discharge of a heated effluent into a natural waterbody are discussed, and the relative importance of each process for various plant design and environmental conditions is assessed. The distributions of excess temperature, and the time-temperature history of exposure of organisms entrained into the thermal plume resulting from the discharge of condenser cooling water from a 1000 MWE nuclear power plant, are given for several alternate sets of design criteria for the discharge structure It is shown that, in order to minimize adverse effects on natural water bodies used to supply condenser cooling water flow for once-through cooling systems, the power plant should be located on a waterway having large dilution capacity, and the discharge structure should be designed to promote rapid dilution of the heated effluent by the cooler receiving waters Intake structures should be designed to provide for low intake velocities, and to provide an effective means of diverting fish and other aquatic organisms away from the Intake. Time of travel of the condenser cooling water flow from the condensers to the point of discharge should be kept small, in order to minimize the time of exposure of entrained organisms to the maximum temperature rise.