Frequently Asked Questions

Nuclear energy is:

• Safe and secure. Nuclear power plants are designed, built and operated with extensive safety and security measures to protect the public, plant workers and the environment. To ensure the safety of nuclear power plants, the U.S. nuclear industry is heavily regulated with strict guidelines from the Nuclear Regulatory Commission (NRC).
• 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 and affordable. Nuclear energy can reliably generate large amounts of electricity around-the-clock to meet customers’ energy needs. In fact, nuclear power provides electricity to one in five businesses and homes in the U.S. Nuclear power plants are also the lowest-cost provider of large-scale electricity, producing baseload electricity for about 2.14 cents per kilowatt-hour.

Safety and security are the highest priority of the nuclear industry. To protect our nuclear power plants, each nuclear station has strictly controlled safety and security programs and features, including the following:

• Redundant engineered safety systems are maintained in operable condition and frequently tested to ensure the safe operation and condition of the plants at all times.
• Plant personnel are trained extensively to cope with abnormal situations that might arise, including “what if” scenarios.
• Detailed and comprehensive emergency plans 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 or abnormal event.
• Reactor operators are rigorously trained and are subjected to careful screening. Operators have stringent standards on continuing training, which is one week out of every five weeks.
• Well-trained, armed security forces protect all U.S. plants 24 hours a day.
• Multiple physical intrusion barriers consisting of concrete structures and razor wire fences surround the plants.
• Advanced surveillance equipment continuously monitors areas around the plants.
• Safety system functions protect plants from cyber-security attacks.
• Low concentration of fuel (uranium-235) makes it physically impossible for a commercial nuclear power plant in the U.S. to explode like a nuclear bomb.

Additionally, all nuclear plants are built to withstand a wide variety of external forces, including hurricanes, tornadoes, fires, floods and earthquakes.

The three nuclear stations owned and/or operated by Duke Energy provide about half of our total electrical generation in the Carolinas.

Duke Energy began generating electricity with nuclear energy in 1973, when the first unit at Oconee Nuclear Station, in Seneca, S.C., went into operation. A second and third unit followed in 1974. Oconee Nuclear Station’s three nuclear reactors are capable of providing more than 2,538 megawatts (MW) of electricity.

In the early 1980s, McGuire Nuclear Station’s two units on Lake Norman in Huntersville, N.C., began operating, providing 2,200 MW of electricity.

In the mid 1980s, Catawba Nuclear Station’s two units in York, S.C., began operating, providing 2,258 MW of electricity.

Over the course of our nuclear fleet’s operating lifetime, the seven units we operate have safely and reliably generated more than 1.5 billion megawatts of electricity.

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.

• Each nuclear unit can be safely shut down in the event of a severe earthquake as part of the plant design.
• Plants are built to withstand earthquakes of the magnitude equivalent to or greater than the largest known earthquake for the region where they are located.
• Key safety systems in the plant are designed to withstand the ground motion that would result from a design basis earthquake. Engineers and scientists calculate the potential for earthquake-induced ground motion using a wide range of data. They review the impacts of historical earthquakes up to 200 miles away from each plant site, with careful study given to those within 25 miles. All of this information is used to determine the maximum potential earthquake that could affect the site. For Duke Energy plants, this is based on the Charleston earthquake that occurred in 1886.
• Each plant has sensitive instrumentation to detect seismic activity and alert operators if it is necessary to shut down the plant or take other precautionary measures.
• Safety at nuclear plants in the U.S. is based on the defense in depth philosophy, where multiple barriers and redundant safety systems ensure the safe operation and condition of the plants at all times.
• 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 build 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. Similarly, the NRC requires all new nuclear plants to be able to withstand the direct impact of a fully fueled commercial jetliner.
  

On Friday March 11, Japan was struck by a magnitude-9 earthquake. Fukushima’s safety systems survived the earthquake, but the ensuing tsunami caused the site to lose normal and emergency power, resulting in the site losing cooling system capabilities and thus causing the nuclear accident.

Our industry takes our commitment to the safe operation of nuclear energy facilities very seriously, and as the full extent of Fukushima accident is learned, more long-term corrective measures and assessments will be taken to better protect nuclear plants in the U.S.

To ensure that reactors in the U.S. could respond to an event similar to what occurred at Fukushima, the U.S. nuclear industry has already taken the following actions.

• Assessed each plant’s ability to maintain safety during extreme events, including the loss of significant operational systems caused by natural events, fires, aircraft impact or explosions.
• Assessed each plant’s ability to respond to a total loss of off-site power by confirming that we have adequate materials and procedures in place.
• Assessed each plant’s ability to respond to floods, including their impact on systems inside and outside the plant.
• Performed walk-downs and inspection of important equipment needed to respond successfully to fires and floods.
• All U.S. nuclear stations underwent detailed inspections by the NRC as follow-up to the Fukushima event. Information from this review will also be used to evaluate the readiness of U.S. nuclear plants to respond to similar events.

For more information on the situation in Japan, please visit the Nuclear Energy Institute website.

Cyber security has been an area of increased activity over recent years, and Duke Energy has completed many tasks and projects related to cyber security as part of its nuclear security programs. Since the terrorist attacks of Sept. 11, 2001, U.S. nuclear stations have been subject to several NRC orders related to cyber security, including 10 CFR 73.54, "Protection of digital computer and communication systems and networks,” which is currently being implemented. It requires each licensee to provide high assurance that digital computer and communication systems and networks are adequately protected against cyber attacks.

• Duke Energy has a detailed cyber security plan for its nuclear stations and continues to perform plan assessments, update the plan and implement new standards/controls as necessary.
• Duke Energy complies with all cyber security orders and programs related to nuclear operations and, through national and industry networks, remains abreast of new information related to cyber security.
• Safety and control systems at U.S. nuclear power plants are not connected to the Internet.
• 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.
• Unlike industries for which two-way data flow is critical (e.g., banking), nuclear power plants do not require incoming data flow.
• 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.

Duke Energy’s Oconee Nuclear Station received its extended license in May 2000, making it the second nuclear plant in the U.S. to do so. Catawba and McGuire Nuclear Stations both received their extended licenses in December 2003.

The NRC has already granted license renewals to dozens of nuclear plants. Since no nuclear plant has operated long enough to explore renewal after the additional 20 years, there is still a possibility for further license extension.

The federal government has responsibility for permanently disposing of high-level waste (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 35 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 “waste” could be recycled.

President Obama has appointed a Blue Ribbon Commission to re-evaluate fuel storage, and Duke Energy continues to support the government's efforts to fulfill its obligation to accept and manage used nuclear fuel. Until a national repository or recycling is available, utilities will continue to safely and securely store used fuel at nuclear stations.

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 gets is measured in millirems. The average person receives about 360 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.

Visit the U.S. Environmental Protection Agency’s website to enter RadTown USA, an interactive tool used to explore a virtual community of houses, schools, laser light shows, construction equipment, flying planes and moving trains. Each place in RadTown helps you learn about radiation sources or radiation-treated items you might find there.

The white cloud — or plume — is simply water vapor being released from the plant’s large cooling towers. Some of Duke Energy’s plants in North Carolina and South Carolina use lakes to cool the water, so the large 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.

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.

Although renewable energy sources, like wind and solar power, are important resources for the country’s energy mix, only nuclear power is capable of producing large amounts of electricity 24 hours a day, 365 days a year.

While Duke Energy is also investing in wind and solar farms, large baseload plants — like nuclear — are an important part of our mission to provide clean, affordable, reliable electricity.

In December 2007, Duke Energy submitted a combined construction and operating license (COL) application to the NRC for the proposed 2,234-megawatt (MW) Lee Nuclear Station in Cherokee County, S.C. This site was selected following a comprehensive study to identify plant locations across Duke Energy’s service area in the Carolinas.

Following a thorough evaluation of new reactor technologies, Duke Energy selected the Westinghouse AP1000® for the proposed new nuclear station. The Westinghouse AP1000 reactor is an advanced passive pressurized water reactor (PWR), featuring innovative passive safety systems and proven Westinghouse PWR technology — which is currently in use at McGuire and Catawba nuclear stations.

Westinghouse is partnering with The Shaw Group Inc., a global engineering, design, construction and operations firm, on engineering work for this project. See our Technology section for more information.

To meet our customers’ energy needs, Duke Energy is continuing licensing work for the Lee Nuclear Station to ensure clean, reliable and new nuclear generation is available as part of the future energy mix. Duke Energy anticipates receiving the COL in the 2013 time frame.

Project development has been under way since the license application was filed with the NRC, including the following activities.

• We removed existing structures from previous construction on the Cherokee County site. We reused 63,725 cubic yards of concrete for crusher-run in road beds, as well as riprap around site ponds. In addition, we recycled steel from old buildings and sent 6,200 gross tons for reuse.
• We conducted a detailed siting study to select transmission routes to connect existing Duke Energy transmission lines to Lee Nuclear Station.
• We performed a detailed assessment of the potential water needs for the proposed plant. This evaluation required analysis of numerous factors, such as available water sources, needs of upstream/downstream water users and station requirements. In light of the drought that affected the region, we worked closely with local, state and federal agencies to conduct an additional review. As a result of this assessment, we determined the addition of a third cooling water source — another industrial pond — could provide additional backup water during a prolonged drought while minimizing impact on other water sources.
  

It’s premature to draw conclusions about the impact of the Fukushima accident on the U.S. new nuclear plant construction. New reactor projects are in the early stages and there is sufficient time to incorporate lessons learned from the events in Japan as more is learned. Projects awaiting their COLs from the NRC are expected to proceed.

Nuclear energy has and will continue to play a key role in meeting America’s energy needs. Duke Energy is continuing with development activities for the proposed Lee Nuclear Station and anticipates receiving the COL in the 2013 time frame.