What Exelon Nuclear Plants Do

Exelon operates nuclear power plants across the United States that generate electricity by splitting uranium atoms in a controlled reaction. The heat from that reaction boils water into steam, which spins turbines connected to generators — the same basic process as coal or natural gas plants, but powered by nuclear fission instead of burning fuel. Exelon is one of the largest nuclear operators in the country and sells the electricity its plants produce to regional power grids and utilities.

The company does not sell power directly to homeowners. Instead, your local utility buys electricity from Exelon's plants (or from other sources) and delivers it to your home through power lines. If you live in the Midwest, Mid-Atlantic, or parts of the Northeast, some of the electricity on your bill may have come from an Exelon nuclear facility.

Key Takeaways

  • Exelon operates nuclear plants in Illinois, Pennsylvania, New York, and Maryland that produce electricity for regional power grids.
  • The company's plants use uranium fission to heat water into steam, which drives turbines to generate power without burning fossil fuels.
  • Exelon sells electricity wholesale to utilities and grid operators, not directly to consumers.
  • Nuclear plants run continuously at high capacity, providing steady baseload power to the grid around the clock.
  • Exelon's plants are regulated by the Nuclear Regulatory Commission and subject to strict safety and security requirements.

Where Exelon's Nuclear Plants Are Located

Exelon operates 14 nuclear reactors across four states. In Illinois, the company runs the Braidwood, Byron, Peach Bottom, and Quad Cities stations. Pennsylvania hosts the Peach Bottom and Three Mile Island plants. New York has the Nine Mile Point facility, and Maryland operates the Calvert Cliffs station. Each location has one or more reactors, and each reactor is a separate generating unit.

The specific location of a plant matters because it determines which utility companies and grid operators buy its power. A plant in Illinois feeds electricity into the Midwestern grid, while a Pennsylvania plant supplies the PJM Interconnection, which covers the Mid-Atlantic region. The grid operator in each region balances supply and demand across all power sources — nuclear, coal, natural gas, wind, and solar.

How Exelon's Plants Connect to Your Power Bill

When you pay your electric bill, you are paying your local utility for the electricity delivered to your home. That utility sources power from multiple generators, which may include Exelon nuclear plants, natural gas plants, wind farms, or other sources. The utility does not tell you which power plant supplied your specific kilowatt-hours — the grid mixes all sources together.

However, if you live in a state where utilities must disclose their power mix, your bill or the utility's website will show what percentage of electricity came from nuclear, coal, natural gas, renewables, and other sources. That percentage includes power from Exelon plants operating in your region. Some utilities also offer programs that let you pay a premium to support renewable energy or other specific sources, but these are separate choices you make with your utility, not with Exelon.

The Regulatory Oversight of Exelon's Operations

The Nuclear Regulatory Commission (NRC) is the federal agency that licenses and inspects every nuclear plant in the United States, including all of Exelon's reactors. The NRC sets safety standards, reviews plant designs, and conducts unannounced inspections to verify that plants follow those standards. Exelon must renew its operating licenses periodically — typically every 20 years — and the NRC can deny renewal or impose restrictions if safety concerns arise.

Beyond the NRC, state utility commissions regulate the rates that utilities pay for electricity from Exelon's plants. These commissions review contracts and cost structures to protect consumers from paying excessive prices. Environmental agencies also monitor nuclear plants for compliance with water quality and emissions rules, though nuclear plants produce no carbon dioxide or air pollution during operation.

How Nuclear Plants Provide Steady Power to the Grid

Unlike solar panels that only work during daylight or wind turbines that depend on weather, nuclear plants run continuously at full capacity 24 hours a day, 365 days a year — as long as they are operating safely. This steady output is called baseload power, and it forms the foundation of the grid's electricity supply. Exelon's plants typically run at capacity factors above 90 percent, meaning they produce power at their rated output more than 90 percent of the time.

The grid operator in your region uses this predictable supply to balance demand. When electricity demand rises in the evening, the grid can rely on nuclear plants to maintain steady output while other sources ramp up or down. This stability is one reason utilities contract for nuclear power alongside renewable sources that fluctuate with weather and time of day.

Decommissioning and Plant Closures

When a nuclear plant reaches the end of its operating life or becomes uneconomical to run, Exelon must shut it down and decommission it — a process that involves removing radioactive fuel, decontaminating equipment, and eventually dismantling the reactor. The NRC oversees decommissioning to may support it is done safely. Exelon has closed several plants in recent years, including Three Mile Island Unit 1 in 2019 and Byron Station in 2024.

Decommissioning can take 10 to 20 years and costs hundreds of millions of dollars. Exelon sets aside money in a decommissioning trust fund during the plant's operating life to pay for this work. The NRC reviews these funds to may support they are adequate. After decommissioning is complete, the site may be released for other uses or kept under long-term monitoring if any radioactive material remains.

Nuclear Waste Storage and Disposal

Nuclear plants produce radioactive waste during operation. Spent fuel rods — the uranium that has been used up in the reactor — are stored in pools of water at the plant site to cool and shield radiation. After several years in the pool, spent fuel can be moved to dry storage casks, which are large steel and concrete containers that hold the fuel safely for decades. Exelon's plants use both wet and dry storage methods.

The federal government is responsible for permanent disposal of spent nuclear fuel, but no permanent repository currently operates in the United States. Until one is built, plants must store their waste on-site. This is a point of ongoing debate, and some communities near nuclear plants have concerns about long-term storage. The NRC regulates all storage methods to may support they remain safe.

Frequently Asked Questions

Can I choose to buy electricity from Exelon's nuclear plants?

Not directly. You buy electricity from your local utility, which sources power from multiple generators. Some utilities offer green energy programs where you pay extra to support renewable sources, but these programs do not let you select a specific power plant or company. You would need to ask your utility whether it offers a nuclear-specific program, which is uncommon.

Are Exelon's nuclear plants safe?

Exelon's plants operate under strict NRC safety standards and are inspected regularly. The NRC can shut down a plant if safety violations are found. Like all nuclear plants, they carry inherent risks, and communities near plants have different views on that risk. The NRC's role is to may support plants meet federal safety requirements, not to declare them risk-free.

What happens to the area around a nuclear plant when it closes?

After decommissioning is complete, the site is typically released for other uses or kept under monitoring if radioactive material remains. Some former plant sites have been redeveloped for industrial, commercial, or recreational purposes. The NRC must approve the final status of the site before it can be released from nuclear regulation.

How much of the electricity in my region comes from Exelon's plants?

That depends on which utility serves you and which Exelon plants are in your grid region. Your utility's website or bill should show the breakdown of power sources in your area. You can also contact your utility directly to ask what percentage of their power comes from Exelon or other nuclear operators.

What is the difference between Exelon and the utility that sends me my bill?

Exelon generates electricity at its nuclear plants and sells it wholesale. Your local utility buys that electricity (along with power from other sources) and delivers it to your home through power lines, then bills you for what you use. Exelon does not bill consumers directly or operate the distribution network in your area.