The average age of U.S commercial nuclear power reactors that were operational as of March 2026 is approximately 44 years.
The oldest operating reactor is Nine Mile Point Unit 1 in New York State, which entered commercial service in December 1969. The newest reactor to enter service is Vogtle Unit 4 at the Alvin W. Vogtle Electric Generating Plant in Georgia, which began commercial operation in April 2024. The third-youngest operating reactor is Vogtle Unit 3, which began commercial electricity generation in July 2023.
The U.S. Nuclear Regulatory Commission licenses new commercial nuclear reactors to oper-ate for 40 years. Reactors licensed for 40 years can apply for a 20-year operating license extension, extending their operations to 60 years. The NRC can grant a second 20-year operating license extension, extending a total operational life to 80 years.
As of March 2026, there are 57 nuclear power plants in the United States with 96 reactors capable of producing about 103,581 megawatts of generator nameplate capacity. Those reactors produce approximately 20% of the electricity consumed in the U.S.
In comparison, there are 219 coal power plants in the United States with 462 generators at about 188,952 MW of generator nameplate capacity.
Utility-scale power plants have a total nameplate electricity generation capacity of at least 1 MW.
A power plant may have one or more generators, and some generators may use more than one type of fuel.
The U.S. nuclear industry today employes approximately 80,000 workers, according to the Department of Energy.
Records show the first full-scale commercial nuclear power plant in the U.S. went online in December 1957. It was the Westinghouse Electric Corp. plant for the Duquesne Light Co. at Shippingport, Pennsylvania.
Research has shown that the first reactor design developed in the United States was set to produce substantial amounts of electric power for household and commercial use. The process was the pressurized water reactor, which used water under high pressure as the moderator-coolant. This “light-water” design used enriched uranium fuel elements in the form of rods or plates at temperatures of about 300 degrees Celsius.
The launch followed the idea that the country began to embrace atomic-nuclear energy in the 1950s. On Dec. 8, 1953, President Dwight Eisenhower gave his “Atoms for Peace” speech, emphasizing the need for an international program of civilian uses of atomic energy.
Four years after that, on Dec. 2, 1957, the Shippingport Atomic Power Station began supplying electricity