Control rods can then be inserted into the reactor core to reduce the reaction rate or withdrawn to increase it. The heat created by fission turns the water into steam, which spins a turbine to produce carbon-free electricity. All commercial nuclear reactors in the United States are light-water reactors. This means they use normal water as both a coolant and neutron moderator. These reactors pump water into the reactor core under high pressure to prevent the water from boiling. The water in the core is heated by nuclear fission and then pumped into tubes inside a heat exchanger.
Those tubes heat a separate water source to create steam. The steam then turns an electric generator to produce electricity. At the center of the reactor is the core, which contains uranium fuel. The uranium fuel is formed into ceramic pellets. Each ceramic pellet produces about the same amount of energy as gallons of oil. These energy-rich pellets are stacked end-to-end in foot metal fuel rods. A bundle of fuel rods, some with hundreds of rods, is called a fuel assembly.
A reactor core contains many fuel assemblies. The heat produced during nuclear fission in the reactor core is used to boil water into steam, which turns the blades of a steam turbine. As the turbine blades turn, they drive generators that make electricity. Nuclear plants cool the steam back into water in a separate structure at the power plant called a cooling tower, or they use water from ponds, rivers, or the ocean.
The cooled water is then reused to produce steam. Nuclear reactors in the United States may have large concrete domes covering the reactors, which are required to contain accidental releases of radiation. Not all nuclear power plants have cooling towers. Some nuclear power plants use water from lakes, rivers, or the ocean for cooling. As of December 31, , 94 nuclear reactors were operating at 56 nuclear power plants in 28 states.
Thirty-two of the plants have two reactors, and three plants have three reactors. Learn more about the U. This is the energy that produces heat inside a reactor, which in turn is used to generate steam, and ultimately creates electricity. For more than 60 years, nuclear energy has provided the world with reliable electricity.
Today, more than reactors are operating in more than 30 countries. More nations are exploring the use of nuclear energy, particularly as electricity demand increases and concerns about climate change rise. International Atomic Energy Agency. World Association of Nuclear Operators. Radiation is energy in motion. There are many natural sources of radiation that we live with safely every day such as cosmic radiation from the sun.
It is not possible for a nuclear energy plant to explode like a bomb, these plants are designed to produce electricity safely and reliably. If you stood at the site boundary for a whole year, you would receive less than a quarter of the radiation from a chest x-ray. Who Operates the Plant? Other fuels, such as plutonium and thorium, can also be used.
A single pellet contains as much energy as there is in one tonne of coal. A typical reactor requires about 27 tonnes of fresh fuel each year. In contrast, a coal power station of a similar size would require more than two-and-a-half million tonnes of coal to produce as much electricity. Like any industry, the nuclear industry generates waste. However, unlike many industries, nuclear power generates very little of it — and fully contains and manages what it does produce.
The vast majority of the waste from nuclear power plants is not very radioactive and for many decades has been responsibly managed and disposed of.
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