The Atmospheric Effects of Thermal Discharges into a Large Lake

Abstract

Concern for the biological and ecological effects of heated water has resulted in legal actions that will prevent power companies from dumping the waste heat from the majority of their new generating units into rivers and lakes. Many nuclear- and fossil-fueled plants now under construction, and even some now online, are being required to change from once-through cooling systems to other methods, such as wet cooling towers, cooling ponds, and spray canals, despite higher costs and lower thermal efficiencies. Yet, these alternate cooling procedures are not without their own environmental problems.

The primary weather change due to once-through cooling on a large water body is a small local increase in fogginess at the plant outfall. But the relative probability of significant local meteorological effects is much higher with alternate cooling procedures, since these reduce the area of heat and moisture transfer. It is therefore concluded that, from a meteorological point of view, the least undesirable way to dispose of waste heat is by using once-through cooling on large water bodies.