How Nuclear Energy Facilities Work

Mighty power from tiny atoms

A nuclear energy facility is not all that different from coal, oil, or gas fueled plants. The main difference is that at a nuclear energy facility, the heat used to make steam is produced by fission.

a_fissionFission is the splitting of atoms into smaller parts. Some atoms, themselves tiny, split when they are struck by even smaller particles, called neutrons. Each time this happens more neutrons come out of the split atom and strike other atoms. This process of energy release is called a chain reaction. The nuclear energy facility controls the chain reaction to keep it from releasing too much energy too fast. In this way, the chain reaction can go on for a long time.

Few natural elements have atoms that will split in a chain reaction. Iron, copper, silver and many other common metals will not split, or fission. There are isotopes of iron, copper, etc. that are radioactive. This means that they have an unstable nucleus and they emit radioactivity. However, just being radioactive does not mean that they will fission, or split. But uranium will. So uranium is suitable to fuel a nuclear energy facility.

What radioactive means

Radioactivity means giving off radiation. Radiation is a spontaneous emission of energy from the nuclei of atoms. It is naturally occurring, but it is also a byproduct of the fission process. Uranium is radioactive and when it splits, the atoms that are produced are also radioactive. Also, some metals that do not split when struck by a neutron will absorb the neutron and then become unstable or radioactive.

Heat makes it work

As atoms split and collide, they heat up. The nuclear energy facility uses this heat to create steam. The pressure of the expanding steam turns a turbine which is connected to a generator. Click on the drawings below to see animated versions of a pressurized water reactor and boiling water reactor.

Pressurized Water Nuclear Energy Reactor

Pressurized Water Nuclear Power Reactor

Getting a charge out of it

After the steam is made, a nuclear energy facility operates much like a fossil fuel plant: the turbine spins a generator. The whirling magnetic field of the generator produces electricity. The electricity then goes through wires strung on tall towers you might see along a highway to an electrical substation in your neighborhood where the power is regulated to the proper strength. Then it goes to homes and businesses providing electricity to power lights, heaters, air conditioners, computers and more.

Safety first

The Nuclear Regulatory Commission (NRC) makes sure nuclear power plants in the United States protect public health and safety and the environment. The NRC licenses the use of nuclear material and inspects users to make sure they follow the rules for safety.

Since radioactive materials are potentially harmful, nuclear energy facilities have many safety systems to protect workers, the public and the environment. These safety systems include shutting the reactor down quickly and stopping the fission process, systems to cool the reactor down and carry heat away from it and barriers to contain any radioactivity and prevent it from escaping into the environment

Clean air

One of the greatest benefits of nuclear energy is that it produces emissions-free energy. The big towers many people associate with nuclear energy are actually for cooling water used to make steam. (Some other kinds of plants have these towers, too.) The towers spread the water out so as much air as possible can reach it and cool it down. Most water is then recycled into the plant. The puffs you see coming out of a cooling tower are just clouds of water vapor.

Learn more

It's fun to study about nuclear energy. To learn more about this fascinating science, please visit the Nuclear Energy Institute and the Nuclear Regulatory Commission's websites. Some of the material on this page is from these organizations — we thank them for their help.