Nuclear power plants produce energy through the fission of uranium or uranium and plutonium. Control rods control the reaction so that the plant produces only enough energy to heat water and generate steam. The steam acts on a turbine, which runs a generator to produce electricity. Although nuclear power plants became more controversial in the United States after a near disaster at the Three Mile Island nuclear power plant in Pennsylvania in 1979, some scientists and environmentalists have started touting the positive effects of nuclear power plants in relation to other forms of energy, especially fossil fuel energy.
Because nuclear power plants do not burn fossil fuels, they do not produce carbon dioxide, which is the primary contributor to global warming. Whereas power plants burning fossil fuels pollute the environment with substances that cause acid rain--nitrogen oxides and sulphur oxides--nuclear power plants do not. A small amount of uranium can release a large amount of energy; according to Max W. Carbon, Emeritus Professor of Nuclear Engineering at University of Wisconsin-Madison, "The nuclear energy in a pound of uranium is three million times the energy released in burning a pound of coal." The result is less strip mining to reach the uranium in the earth (strip mining can disrupt wildlife and negatively impact groundwater).
Plants that use fossil fuels discharge particulates into the air, a type of air pollution that is associated with lung cancer and respiratory diseases, according to the World Resources Institute. Nuclear power plants, in contrast, do not have as a by-product any type of soot or particulates. Although nuclear power plants do emit some radioactivity, this amount is inconsequential during normal operation, according to Daniel D. Chiras, an environmental scientist.
Chiras reports that the transportation costs of fuel are also less for nuclear power plants because of the concentrated nature of uranium. In the 1970s, nuclear power plants in the United States were cheaper than other forms of power plants; but in the 1980s, stricter governmental regulations and environmental lawsuits raised the cost of operating nuclear power plants. In the United States today, according to Chiras, the cost of electricity generated by a nuclear power plant is two times the cost of electricity produced by a coal plant. Max Carbon, however, predicts that nuclear power will eventually become cheaper than fossil fuel energy, as environmental regulations aiming to cut down carbon emissions raise the operating costs of fossil fuel plants.