Nuclear plants currently generate about 20 percent of U.S.
electricity. In fact, The U.S. is the world leader in nuclear capacity
and generation. There are currently 61 active nuclear plants with 99
nuclear reactors spread across 30 states in the U.S. The U.S.
Nuclear Regulatory Commission issues 40-year licenses for
commercial reactors. In addition, operators of nuclear reactors have
the opportunity to apply for a 20-year license extension, upping the
potential lifespan of a reactor to 60 years.
While nuclear is considered a reliable and low-carbon resource, it
does have potential risks associated with it -- chiefly safety issues.
Since the 2011 Japanese earthquake, tsunami and subsequent
nuclear accident at Fukushima, seismic analysis and the potential
for damage to a U.S. nuclear plant from an earthquake has been
under review. AEP’s Cook Plant was among an initial group of 10
plants required to complete the analysis. The 10 plants, including
Cook, must submit a detailed risk analysis to the NRC by June 30,
AEP’s Donald C. Cook Nuclear Plant
How nuclear power is generated
- Enriched uranium pellets fill metal fuel rods. These rods are placed in the reactor core.
- The uranium pellets are made of billions of atoms. Each atom contains a nucleus that consists
of protons and neutrons. During fission, when a uranium atom splits, it releases neutrons that
hit and split other uranium atoms. When more neutrons are released than absorbed in other
atoms, the fission becomes self-sustaining. This is called a chain reaction. The energy from the
splitting of atoms produces tremendous heat.
- Control rods stop and start fission. Control rods are made of materials that absorb neutrons.
When they are inserted into the reactor core, they stop the chain reaction by absorbing the
extra neutrons. When the control rods are removed, the extra neutrons resume splitting the
atoms and the fission process begins again.
- Boric acid also controls fission. Boric acid, which is dissolved in the primary system water, also
absorbs neutrons. The fission can also be controlled by changing the concentration of boron in
- Concrete and steel protect from radiation. Radioactivity is released during the fission process.
The containment building’s thick concrete and steel walls shield the public from radiation.
- Thousands of gallons of water absorb the heat from the fission. The primary system is
pressurized so water flowing through the pipes will not boil.
- Heat is transferred from the primary system pipes to the secondary system pipes changes
water into steam. Heat, not water or radioactivity, passes between these closed-loop systems.
- The steam in the secondary system turns the turbine fan blades. The turbine shafts are
connected to the rotor that also turns inside the generator.
- Electromagnetism makes electricity. As the generator rotor turns, coils of wire spin in a
magnetic field. This produces electricity in an outer set of coils. The electricity flows to a
transformer. The transformer increases the voltage so the electricity can travel long distances.
- Intake pipes draw over a million gallons of water per minute into a condensing system. As the
water enters the condenser, heat from the steam in the secondary system transfers to the third
system. As the steam in the secondary system cools it changes to water that is pumped back
to the steam generator. The clean condensing system water discharges through pipes. This
safe, efficient process produces electricity 24 hours a day, 365 days a year.
Nuclear power at
Nuclear power is an
important resource in our
energy portfolio. AEP’s
2,191MW Donald C. Cook
Nuclear Plant in
Bridgman, Mich., provides
low-cost electricity to I&M
customers. Together, the
two units produce enough
energy to power
approximately 1.5 million
homes and represent
approximately 48 percent
of I&M’s power generation
portfolio. In 2005, the
plant received license
extensions from the
the units to run an
additional 20 years
beyond the duration of
their original operating
licenses – until 2034 and