Creating nuclear energy
• Nuclear power accounts for about 20 percent of the total electricity generated in the United States, about as much as that used in California,Texas and New York, the three most populous states.
• It comes from the nucleus (core) of an atom, tiny particles that make up every object in the universe and require enormous energy to be held together.
• When the atoms are split into smaller atoms (nuclear fission), they release energy that can then be used for other purposes, such as heating water to create steam that turns electricity-generating turbines.
• The fuel most widely used by nuclear plants for fission comes from uranium, a nonrenewable metal found in rocks all over the world. Once uranium is mined, it is processed into U-235, because its atoms are easily split apart.
• During nuclear fission, a small particle called a neutron hits the uranium atom, causing it to split and release a great amount of energy as heat and radiation. More neutrons also are released, creating a chain reaction.
• The uranium fuel is formed into ceramic pellets, each about the size of a fingertip. Each one produces the same amount of energy as 150 gallons of oil. These energy-rich pellets are stacked end-to-end in 12-foot metal fuel rods. A bundle of fuel rods is called a fuel assembly.
• Fission generates heat in a reactor just as burning coal does in a boiler, turning water into steam. The steam pressure turns huge turbine blades, which in turn drive generators that make electricity. Afterward, the steam is changed back into water and cooled in a separate structure at the power plant called a cooling tower. The water is then recycled.
• Like all industrial processes, nuclear power generation has by-product wastes: radioactive waste and heat.
• Radioactive wastes are the principal environmental concern for nuclear power. The irradiated fuel assemblies are highly radioactive and must be stored in specially designed tanks resembling large swimming pools (water cools the fuel and acts as a radiation shield) or in specially designed dry storage containers. Most nuclear fuel is stored underwater.
• The United States Department of Energy’s long-range plan is for this spent fuel to be stored deep in the earth in a geologic repository, at Yucca Mountain, Nev.
Source: The U.S. Energy Information Administration, a division of the Department of Energy.“