The United States operated 96 commercial nuclear reactors at 57 power plants across 28 states as of March 2026, together supplying nearly 20% of the nation's electricity. The fleet remains the largest single source of carbon-free power on the U.S. grid.

The reactor count reflects a fleet that has shifted from contraction toward extension. License renewals are keeping long-serving units in service well past their original timelines, with Duke Energy's Robinson plant in South Carolina cleared to run through 2050, two decades beyond its prior expiration. Other operators are pursuing similar extensions across the fleet.

Capacity additions are coming largely from existing reactors rather than new construction. About 30 planned uprates are identified through 2030, including three applications in 2026, 16 in 2027, and eight in 2028. If approved and implemented, those uprates would add roughly 2.5 gigawatts of generating capacity without building a single new reactor.

Restarts add another source of recovered capacity. The Nuclear Regulatory Commission approved restarting Holtec's Palisades plant in Michigan, the first restart of its kind, and Constellation's Crane Clean Energy Center in Pennsylvania is set to return in 2027.

The numbers describe a fleet being squeezed for more output through regulatory and engineering measures. With load growth accelerating from data centers and electrification, utilities are extending licenses, raising reactor power levels, and reviving shuttered plants to keep nuclear's share of generation steady or growing.

Source: Nuclear Energy Institute - https://www.nei.org/news/state-of-the-nuclear-industry-2026