The United States has the most installed nuclear generating capacity of any country in the world, according to International Atomic Energy Agency data compiled by the US Energy Information Administration. The US, along with France, China, Russia and South Korea, account for more than two thirds of the roughly 376 gigawatts of nuclear capacity operating worldwide across 416 reactors in 31 countries.

US utilities currently operate 94 nuclear reactors, the world's largest fleet, producing about 19 percent of US electricity generation and roughly 30 percent of all nuclear electricity generated globally. Most of the country's operating nuclear capacity was built between 1967 and 1990, following the 1957 launch of the Shippingport Atomic Power Station in Pennsylvania, the country's first commercial nuclear plant. The US fleet posted a capacity factor of 92 percent in 2024, reflecting improved efficiency in managing planned and unplanned outages at reactors nationwide.

France operates the second largest fleet with 57 reactors and 63 gigawatts of capacity, generating close to 65 percent of its electricity from nuclear power. China has the fastest growing reactor fleet, with 28 additional units under construction that would eventually push its total installed capacity above France's once complete.

The comparison illustrates the scale of the existing US nuclear base as utilities weigh new investment in reactor uprates, license renewals and small modular reactor projects to meet rising electricity demand from data centers and other large industrial customers.

Source: U.S. Energy Information Administration - https://www.eia.gov/todayinenergy/detail.php?id=65904