Power-generation plants

Del y for Dec y. Nuclear power plants generate radioactive xenon and krypton as products of the fission reactions. Although these products ate trapped inside the fuel elements, portions can leak out into the coolant (through fuel cladding defects) and can be released to the atmosphere with other gases through an air ejector at the main condenser. 

The utilities in our modern society are so much a part of our lives that it is hard to imagine how we survived without them. An electric power plant generates electricity to heat and light our homes in addition to providing power for the television, refrigerator, and electric toothbrush. When our homes were heated with wood fires, home-made candles were used... 

Suppose 10,000 V, j (e.g., from an electrical power plant generator) is input to a transformer where the number of secondary turns is 75 times more than the number of primary turns. Then the voltage from the secondary will be 75 X 10,000 = 750,000... 

A nuclear power plant generates electricity in a manner similar to a fossil fuel plant. The fundamental difference is the source of heat to create the steam that turns the turbine-generator. A fossil plant relies on the combustion of natural resources (coal, oil) to create steam. A nuclear reactor creates steam with the heat produced from a controlled chain reaction of nuclear fission (the splitting of atoms). 

Ocean thermal energy conversion (OTEC) power plants generate electricity by exploiting the difference in temperature between warm water at the ocean surface and colder waters found at ocean depths. To effectively capture this solar energy, a temperature difference of 35°F or more between surface waters and water at depths of up to 3,000 feet is required. This situation can be found in most of the tropical and subtropical oceans around the world that are in latitudes between 20 degrees north and 20 degrees south. 

Nuclear power plants generate electricity in much the same way fossil fuel power plants do. Water is heated to create steam that can be used to turn electricity-generating fur bines. The fundamental difference between these two types of power pi ants i s th e fuel used to h eat th e water. A fossil fuel plant burns fossil fuel, such as coal or petroleum, but a nuclear plant, such as the one shown in this chapter s opening photograph, uses the heat created by nuclear fission to heat the water. 

In 1991 coal furnished 55% of the total hiel required to generate electricity in the United Slates. One ton of coal consumed by a power plant generates approximately 2000 kilowatt hours of electricity. Then current consumption of 772 million tons/year for electricity generation was expected lo rise to close to 1.3 billion tons by the year 2030. Clean eoal technologies will be mandated. Even after installation of considerable environmental correction equipment, coal remains the least expensive of the fossil fuels by a wide margin. The cost lo generate a million Blu of energy for petroleum is 2.63 for natural gas. SI. 18 and for coal, S0.77. U.S. recoverable coal... 

In comparison to the cost of fossil-nuclear energy, solar power plants generate electricity at 12-20 /kWh. When using solar energy, the fuel is free and inexhaustible. Another potential of solar energy is economical if it was decided to cover 10 million American homes with solar roofs, this decision alone would trigger the biggest economic expansion of the decade (if not the century ). 

Nevertheless, present-day nuclear power plants generate saturated steam and operate with turbines designed to eject liquid at various stages of expansion. 

Another important combustion reaction occurs when coal is burned to produce energy. Coal is called a fossil fuel because it contains the remains of plants that lived long ago. It is composed primarily of the element carbon. Coal-burning power plants generate electric power in many parts of the United States. The primary reaction that occurs in these plants is between carbon and oxygen. 

A power plant generates 2.76 x 10 megawatt hours (MWh) of electricity per year by burning 1.66 x 10 tons of a low-grade coal containing 3.2% sulfur and 15.4% ash. The ratio of fly ash to bottom ash is 0.65 and the plant s particulate collection efficiency is 85%. Determine the amount of each pollutant (particulates, NO4 and SO2) emitted per year in pounds/kilowatt-hour for the coal-fired power plant. 

Samples collected neeur municipal-industrial activities at Fort Myers exhibited petroleum contamination representative of heavy residual fuel oil used for electric power plant generators. 

Electric cars are recharged at night by electricity from local power plants. If local power plants generate electricity by burning fossil fuels, why are electric cars more environmentally sound than conventional gas (petrol)-burning cars ... 

Nuclear Energy Reactors An uncontrolled fission chain reaction can be adapted to make an atomic bomb, but controlled fission can produce electric power more cleanly than can the combustion of coal. Like a coal-fired power plant, a nuclear power plant generates heat to produce steam, which turns a turbine attached to an electric generator. 

Megawatt - One thousand kilowatts, or 1 million watts standard measure of electric power plant generating capacity. 

As of December 1994, there were at least 157 coal-fired boiler imits at 92 power plants with wet scrubbing systems operating. These plants are located in at least 32 states [66,72-75]. Additional scrubbers are planned or under construction in order to achieve compliance with the Clean Air Act requirements. As of 1996, the operating scrubber systems at coal-fired power plants generated approximately 21.4 million metric tons (23.8 million tons) of FGD sludge aimuaUy [71-80]. 

What pollutants do nuclear power plants generate ... 

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