What is Nuclear Power???
Nuclear power plants use the amazing power of the atom to generate electricity with a very low fuel cost and much less pollution than fossil fuel plants. However, the planning, building, and operating of a nuclear power plant is a long, costly, and very complex process.
Constructing ??
After an order is received to start working on a nuclear power plant, the long multi-year process begins. The most important part of a plant is the nuclear reactor. That is where the nuclear reactions take place. During these reactions radiation is released. To make sure that none of this radiation is released into the environment, the building that houses the reactor must be made to hold it in. The reactor is housed in a dome-shaped building made with extremely thick walls of concrete and steel. The building must be strong enough to stand even if a jet plane crashed into it!!
The engine house is the building where the control and computer rooms are located. In the control room, engineers constantly keep watch over the entire power plant. If something were to go wrong, an alarm would sound and by the simple push of a button the problem would be automatically fixed. In the computer room, many computers are constantly recording information on every little thing that happens in the power plant. The construction of the buildings, the reactor, and the complex electrical network needed to run the power plant could take years. Then electricity can be generated.
Uranium, the most common fuel, is placed in rods in the reactor's core. Free neutrons are released into the core. When a neutron hits the nucleus of a uranium atom, fission occurs, tremendous amouts of heat are released. When the nucleus was split 2 or 3 neutrons were set free. Those, in turn, split the nuclei of other atoms, setting more neutrons free. A chain reaction takes place in the core creating large amounts of heat. A coolant circulates around the rods of uranium in the core. The most used coolant is water, but newer plants use liquid metal instead.
The Generating Process
Billions and trillions of atoms, tiny little particles, make up all matter. Inside of an atom, there is a core, or nucleus made up of protons and neutrons. When the nucleus of an atom is split, nuclear fission occurs. That is what happens in the core of a nuclear reactor, and is the start of the process of generating electricity in a nuclear power plant.
As you might have guessed, the coolant is used to keep the reactor from getting too hot. It is also needed in the generation process. The coolant absorbs the heat produced by fission. It travels through tubes until it reaches the steam boiler. Pressure inside the tubes prevents the coolant from boiling. At the steam boiler, the heat from the coolant passes through the tube walls and heats up sea water. The sea water was pumped in from a nearby river or stream. The heated sea water boils into steam. The steam travels through pipes to a turbine. The steam causes a turbine to turn, which then turns a generator to create electricity. (Back to Generating page for more information) After the coolant releases its heat in the steam boiler, it circulates back around toward the reactor's core. A pump keeps the coolant circulating so that none of its radioactivity can escape.
If the core reaches the point where it is too hot, control rods are moved down into it. The control rods are made of an element that absorbs excess neutrons. When the control rods are moved into the core, they absorb neutrons, slowing down the chain reaction. When this happens less fission occurs and the heat is reduced.
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