Nuclear Power Frequently Asked Questions

Nuclear energy is:

Clean. Nuclear energy is one of the cleanest power sources today. Nuclear power plants produce no greenhouse gases and are America’s largest source of carbon-free electricity.

Reliable. Nuclear power plants consistently generate large amounts of electricity to meet customers’ energy needs, even during periods of extreme heat or cold when electricity demand increases. In fact, nuclear energy provides electricity to one in five businesses and homes in the U.S.

Always-on. Nuclear energy facilities generate electricity around-the-clock, only taking a break every 18 to 24 months to refuel.

An economic driver. Duke Energy’s nuclear plants support local economies through jobs and tax revenues. Plus, nuclear employees give time, talent and financial support to local schools, service agencies, arts programs, civic and environmental organizations and more.

• Redundant, engineered safety systems that are frequently tested 
• Plant personnel that are trained extensively to manage situations that might arise, including “what if” scenarios.
• Detailed and comprehensive emergency plans that are practiced throughout the year in coordination with local, state and federal emergency management officials to ensure plans, equipment and personnel can appropriately respond to an emergency.
• Reactor operators that are rigorously trained and carefully screened. Operators have stringent standards on continuing training, which is one week out of every five weeks.
• Well-trained, armed security forces to protect all U.S. plants 24 hours a day.
• Multiple physical intrusion barriers including concrete structures and razor wire fences that surround the plants.
• Advanced surveillance equipment which continuously monitors areas around the plants.
• Low concentration of fuel (uranium-235) which makes it physically impossible for a commercial nuclear power plant in the U.S. to explode like a nuclear bomb.

Duke Energy operates 11 nuclear units in the Carolinas at six plant sites.  Our nuclear fleet generates about half the electricity provided to our customers in the Carolinas.

Affordable, reliable and clean nuclear energy has been part of Duke Energy's generation mix for more than 50 years and Duke Energy intends to renew the operating licenses of the nuclear plants it operates for an additional 20 years to support the company's net-zero carbon goal.

Nuclear plants operated by Duke Energy, like all U.S. nuclear power plants, are built to withstand a wide variety of external forces, including hurricanes, tornadoes, fires, floods and earthquakes.

• Duke Energy's nuclear plants are safe and meet all Nuclear Regulatory Commission (NRC) requirements for safe operation. Duke Energy-operated nuclear plants meet their current seismic design bases and have a safe 40-plus year record for operating safely.
• Nuclear plants have sensitive instrumentation to detect seismic activity (earthquake-induced motions) at the site and procedures to require shutting down the units when low levels of ground motion are detected.
• Nuclear plants are designed to withstand earthquake-induced ground motions, and the seismic factors of their designs must meet national codes, standards and NRC regulations, which are more stringent than commercial office building requirements. Compliance with these standards and regulations ensures there is a substantial margin with respect to earthquakes.
• Detailed and comprehensive emergency plans are practiced throughout the year in coordination with local, state and federal emergency management officials to ensure our plans, equipment and personnel can appropriately respond to an emergency or abnormal event.

The physical attributes of nuclear power plants, along with well-trained and highly-skilled security forces, are integrated into the overall station design to ensure the safe operation of the plant and to protect against extraordinary events.

Additionally, the U.S. nuclear industry has implemented a program of continuous improvement based on lessons learned from worldwide operating experience to better protect our plants in the event of an emergency.

• After the 1979 Three Mile Island accident, significant changes were made to emergency planning requirements and emergency operating procedures. Human factor issues were addressed by now requiring every nuclear station to have a replica of its control room for training purposes. New requirements for hydrogen control were added to help prevent explosions inside of containment, along with new requirements for enhanced control room displays of the status of pumps and valves. Modifications were also made to the Resident Inspector Program, which now requires at least two full-time NRC inspectors to be on site at each nuclear power plant.
• Since the events of Sept. 11, 2001, the NRC required U.S. nuclear operators to revamp their disaster plans to deal with the potential loss of large areas of the plant after extreme events. The NRC now requires licensees to have important equipment available and staged in advance, in addition to new procedures and policies to deal with an emergency. It was also proved, using sophisticated computer modeling by some of the world’s leading structural engineers, that critical structures at nuclear plants can withstand a jetliner impact without releasing radiation.

• Duke Energy has a detailed cybersecurity plan for its nuclear stations and continues to perform plan assessments, update the plan and implement new standards/controls.
• Duke Energy complies with all cybersecurity orders and programs related to nuclear operations and, through national and industry networks, remains abreast of new information. 
• Safety and control systems at U.S. nuclear power plants are not connected to the Internet. Unlike industries for which two-way data flow is critical (e.g., banking), nuclear power plants do not require incoming data flow. 
• Nuclear power plants have security attributes (technologically advanced detection, insider mitigation programs and behavior testing) not found at other critical infrastructure, and safety system functions are securely protected from cyber attack.
• Nuclear plants are protected from grid instability with backup power supplies that provide for safe reactor shut down in the event of a blackout.

The NRC initially licenses U.S. nuclear power plants to operate for 40 years. After the initial operating license, current federal regulations permit nuclear plant owners to renew their plants’ license for an additional 20 years. To renew a license, the NRC must be satisfied the plant can operate safely for an additional 20 years. All Duke Energy nuclear plants have renewed licenses. 

Some nuclear power plant licensees, including Duke Energy, are now submitting applications to renew the operating licenses of nuclear power plants a second time for an additional 20 years. Continuous upgrading and replacement of parts and systems, rigorous NRC oversight and learnings from research and operating experience will ensure nuclear energy facilities continue to operate safely. Learn more about the NRC license renewal process.

The federal government has responsibility for permanently disposing of used nuclear fuel.  Duke Energy continues to support the government's efforts to fulfill its obligation to accept and manage used nuclear fuel. 

Until a permanent disposal facility is licensed, used nuclear fuel is safely and securely stored at plant sites in storage pools or specially designed dry storage containers. 

Duke Energy has more than 40 years of experience handling used nuclear fuel. Our employees are well-trained, environmentally conscious professionals who take pride in their work.

If all the used fuel produced in nearly 50 years of U.S. nuclear power plant operations was stacked end to end, it would cover a football field to a depth of less than 10 yards. Ninety-six percent of this material could be recycled.

Radiation is a natural part of our environment. We receive radiation from the sun, minerals in the earth, the food we eat and building materials in our houses. Even our bodies give off small amounts of radiation. Some radiation also comes from manmade sources such as medical and dental X-rays, televisions and smoke detectors.

The amount of radiation a person receives is measured in millirems. The average person receives about 620 millirems of radiation each year — about 80 percent comes from natural sources and the rest from manmade sources.

Nuclear power plants contribute a very small amount of radiation to the environment which is carefully monitored, meets established regulations and is reported to the appropriate local, state and federal agencies. A person living next to a nuclear plant will receive less than one additional millirem per year due to plant operations.

Visit the U.S. Environmental Protection Agency’s website to enter RadTown USA, an interactive tool to help you learn about radiation sources and radiation-treated items.

The white cloud — or plume — is simply water vapor being released from the plant's cooling towers. Some of Duke Energy's plants use lakes to cool the water, so cooling towers are unnecessary. Lake or river water flows through thousands of tubes to cool steam and turn it back into water. It is then discharged down a long canal (for further cooling) and eventually enters the main part of the lake or river. The lake or river water does not mix with other water used at the plant.

At other plants, the cooling water is circulated through cooling towers to remove the extra heat it has gained. The water is pumped to the top of the cooling towers and pours down through the structure. At the same time, a set of fans at the top of each tower pulls air up through the condenser water to cool it even more. The condenser water then flows back into the turbine building to begin condensing steam again.