According to the Nuclear Energy Institute, American nuclear power plants operated at an average daily capacity factor of better than 98% over the first 14 days of August, helping to provide the energy that kept the nation’s citizens cool during the summer’s worst heat wave. Nuclear power’s best day was August 1st, when the plants made an average capacity factor of 99.6% for the day.
Capacity factor is a measure of power plant efficiency, and describes the amount of electricity the power plant generated compared to the amount that it could have generated at continuous full power operation during the same period.
There are currently 104 nuclear power plants operating in 31 states in the United States. Together, they can produce up to 100,125 megawatts of electricity, enough to meet the annual electricity requirements of approximately 62 million Americans.
Nuclear power plants account for nearly 11 percent of the nation’s total electricity generation capacity. However, due to the fact that they operate at high levels of efficiency and reliability, these plants produce almost 20 percent of the total annual electricity supply of the United States.
At present, nuclear energy is the United States’ third biggest producer of electricity, and the nation’s biggest non-fossil fuel electricity source. Many alternative energy proponents see nuclear power as the most important type of non-fossil fuel for the next century or longer.
Nuclear plants, like other types of power plants, generate electricity by boiling water into steam which turns the turbines that produce electricity. However, nuclear plants don’t burn a substance to generate the heat. Instead, they use uranium fuel got from solid ceramic pellets that have been packed together in long, vertical tubes, and generate electricity through the process known as fission.
Fission is the splitting of atoms. In the case of nuclear power plants, it is the splitting of uranium in a nuclear reactor. Bundles of the uranium ceramic pellet tubes are inserted into the reactor. The splitting of an atom creates a burst of energy given off via the subatomic particles’ binding energies being broken.
Nuclear fuel consists of two types of uranium, U-238 and U-235. Most of the uranium in nuclear fuel is U-238, but U-235 atoms are easier to split because a U-235 nucleus is unstable. As the nuclei break up, they release neutrons. As free neutrons collide with uranium atoms, those atoms also split, releasing yet more neutrons and heat. This process creates a chain reaction which becomes self-sustaining.
Rods inserted among the tubes holding the uranium fuel control the nuclear reaction. Inserted or withdrawn to varying degrees, the rods speed up or slow down the reaction.
Water separates the fuel tubes in the reactor, and the heat created in the fission reactions converts the water into steam. The steam drives a turbine, and the turbine spins a generator to create electricity.
As new electricity peak-demand records were set during the first two weeks of August, nuclear power plants operated at very high efficiency levels to help electrical grids meet the huge demands, says the NEI.
“When the dog days of August barked, U.S. nuclear power plants were the most efficient producers of electricity on the nationwide grid, churning out massive emission-free supplies of electricity to meet demand,” said Marvin Fertel, NEI’s chief nuclear officer and senior vice president.
Nuclear Energy Institute (PR NEwswire), “Operating at 98% Efficiency, U.S. Nuclear Plants Play Vital Role in Beating Sweltering Heat Wave”