A cooling pond is a man-made body of

water Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as ...

primarily formed for the purpose of cooling heated water and/or to store and supply cooling water to a nearby

power plant A power station, also referred to as a power plant and sometimes generating station or generating plant, is an industrial facility for the generation of electric power. Power stations are generally connected to an electrical grid. Many p ...

or industrial facility such as a petroleum refinery, pulp and paper mill,

chemical plant A chemical plant is an industrial process plant that manufactures (or otherwise processes) chemicals, usually on a large scale. The general objective of a chemical plant is to create new material wealth via the chemical or biological transfor ...

steel mill A steel mill or steelworks is an industrial plant for the manufacture of steel. It may be an integrated steel works carrying out all steps of steelmaking from smelting iron ore to rolled product, but may also be a plant where steel semi-fi ...

or smelter.

Overview

Cooling ponds are used where sufficient land is available, as an alternative to

cooling tower A cooling tower is a device that rejects waste heat to the atmosphere through the cooling of a coolant stream, usually a water stream to a lower temperature. Cooling towers may either use the evaporation of water to remove process heat and ...

s or discharging of heated water to a nearby

river A river is a natural flowing watercourse, usually freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the ...

or coastal bay, a process known as “once-through cooling.” The latter process can cause thermal pollution of the receiving waters. Cooling ponds are also sometimes used with air conditioning systems in large buildings as an alternative to cooling towers. The pond receives

thermal energy The term "thermal energy" is used loosely in various contexts in physics and engineering. It can refer to several different well-defined physical concepts. These include the internal energy or enthalpy of a body of matter and radiation; heat, ...

in the water from the plant’s condensers during the process of energy production and the thermal energy is then dissipated mainly through evaporation and

convection Convection is single or multiphase fluid flow that occurs spontaneously due to the combined effects of material property heterogeneity and body forces on a fluid, most commonly density and gravity (see buoyancy). When the cause of the c ...

. Once the water has cooled in the pond, it is reused by the plant. New water is added to the system (“make-up” water) to replace the water lost through evaporation. A 1970 research study published by the U.S. Environmental Protection Agency reported that cooling ponds have a lower overall electrical cost than

s while providing the same benefits. The study concluded that a cooling pond will work optimally within 5 degrees Fahrenheit of natural water temperature with an area encompassing approximately 4 acres per megawatt of dissipated thermal energy.

Examples

Lake Anna Lake Anna is one of the largest freshwater inland reservoirs in Virginia, covering an area of , and located south of Washington, D.C., in Louisa and Spotsylvania counties (and partially in Orange County at the northern tip). The lake is easil ...

is a cooling pond in

Virginia Virginia, officially the Commonwealth of Virginia, is a state in the Mid-Atlantic and Southeastern regions of the United States, between the East Coast of the United States, Atlantic Coast and the Appalachian Mountains. The geography an ...

, which provides cooling water for the North Anna Nuclear Generating Station. This pond has recreational uses such as fishing, swimming, boating, camping, and picnicking as well as being a cooling pond for the nuclear plant. * The cooling pond at the

Chernobyl Nuclear Power Plant The Chernobyl Nuclear Power Plant (ChNPP; ; ), is a nuclear power plant undergoing decommissioning. ChNPP is located near the abandoned city of Pripyat in northern Ukraine northwest of the city of Chernobyl, from the Belarus–Ukraine bor ...

(Pripyat, Ukraine) has abundant wildlife, despite the radiation present in the area. There are some accounts of wels catfish ''(Silurus glanis)'' growing up to 350 pounds and having a lifespan of up to 50 years in the area. * The Columbia Energy Center in Pacific, Wisconsin is a coal fired power plant with a capacity of 1000 MW. A dual cooling system is used for heat rejection that consists of a cooling pond and two cooling towers. The pond and towers are connected in a parallel arrangement to help dissipate thermal energy at expedited rates. * In 1994 the reactor at

Yongbyon Nuclear Scientific Research Center The Nyongbyon Nuclear Scientific Research Center is North Korea's major nuclear facility, operating its first nuclear reactors. It is located in Nyongbyon County in North Pyongan Province, about 100 km north of Pyongyang. The center produ ...

, North Korea, was under U.S scrutiny and its nuclear fuel rods were taken out of the reactor and placed in the facility's cooling pond. The fuel rods have since been removed. * At the 2.05 MW Ashford A power station Kent, UK, cooling water for the oil-fired engines was obtained from, and returned to, cooling water ponds. The principal cooling mechanism in the ponds was by convection from the water surface. * At the 89 MW Back o’ the’ Bank power station in Bolton UK the cooling water was cooled in 4 spray ponds. The small size of the spray droplets improved the heat transfer, increased evaporation, and led to more effective cooling. Each cooling pond had a capacity of 0.75 million gallons per hour (0.95 m³/s). Make up water was abstracted from the nearby River Tonge. In about 1950 a hyperbolic reinforced concrete cooling tower was built with a capacity of 2.5 million gallons per hour (3.15 m³/s), with cooling range of 15 °F (8.3 °C). However, there were complaints that operation of the cooling tower let to problems with ice in cold weather as water vapour from the tower froze as fine particles. * In 1963 the UK’s Central Electricity Generating Board (CEGB) was researching the possibility of using warmed cooling water from power stations to support fish-farming both for recreational use and for food. At Grove Road power station in London water was cooled in wooden natural draft cooling towers and fell into cooling water ponds. The CEGB introduced carp ( Cyprinus carpio),

grass carp The grass carp (''Ctenopharyngodon idella'') is a species of large herbivorous freshwater fish in the family Cyprinidae, native to the Pacific Far East, with a native range stretching from northern Vietnam to the Amur River on the Sino-Russi ...

, silver carp and Tilapia into the cooling water ponds; the fish grew rapidly in the warm water (up to 27 °C).

References

{{pond * Cooling technology Ponds Water pollution

Overview

Examples

See also

References