FAQ's
How does a nuclear power plant work?
Steam power plants, whether they are coal or nuclear, use heat to make electricity. They operate like a giant tea kettle, turning water into steam which is then used to turn a generator to make electricity. The only difference between coal and nuclear power plants is that nuclear plants use uranium as the fuel to produce the heat instead of coal.
In a nuclear power plant reactor, water is heated by a process called nuclear fission.
- Uranium atoms are split when they are struck by neutrons.
- When the atoms split, they release heat, along with two or three more neutrons.
- These neutrons then strike other uranium atoms, again causing the atoms to split, release heat and again, two or three more neutrons. This is called a chain reaction.
Heated water travels from the reactor to the steam generators.
- The water flows through thousands of tubes in the steam generators and then flows back to the reactor.
- The tubes become hot and transfer the heat to a second system of water that is transformed into steam.
The steam then spins the turbines, which are tied to the generators, which produce electricity.
First in safety
A series of barriers and safety systems within the plant keeps radioactivity from normal operations inside. The building that contains radioactive fuel and the reactor has thick concrete and steel walls and flooring. The building, or containment, acts as a barrier. It surrounds the reactor and other equipment in contact with highly radioactive materials. The containment structure extends well below the ground. The reactor vessel, where fission takes place, is a thick steel cylinder that contains the fuel assemblies.
All nuclear plants are conservatively designed and built with many safety systems and emergency back-ups.
Operations
As a nuclear plant, Palisades uses mildly enriched uranium as a fuel to heat water and produce steam that turns turbines to produce electricity.
The uranium is contained as pellets in bundles of fuel rods submerged in water inside the steel-reinforced reactor vessel. Subatomic particles, neutrons, strike the uranium nuclei in a controlled reaction called fission. As the nuclei split, heat is released, which boils water and produces steam for the turbines.
Operators control the rate of the reaction (and the amount of heat produced) by raising and lowering control rods inside the uranium bundles. The control rods are made of a material that absorbs neutrons and can be lowered completely into the bundles when it is necessary to shut the reactor down.
Spent nuclear fuel is stored safely on-site in federally approved dry casks awaiting shipment to a federal nuclear waste repository in Nevada. The U.S. Department of Energy estimates it will begin taking spent fuel by 2010.
The U.S. Nuclear Regulatory Commission (NRC) regulates all nuclear plants, including the issuance of operating licenses. Inspections and tests are performed routinely as a requirement for maintaining an operating license. Periodic training sessions keep Palisades operators familiar with new or changed regulations and procedures.
