The U.S. nuclear fleet continues to post industry leading reliability, operating at a capacity factor of about 92 percent, according to Nuclear Energy Institute data. The figure measures how much electricity plants actually produce relative to their maximum potential, and it places nuclear well above other large scale generation sources. The average annual capacity factor reached 91 percent in 2025.

The fleet's 94 reactors generate close to 20 percent of the nation's electricity, a share that has held steady even as overall demand rises. Nuclear's consistent output makes it a baseload complement to variable wind and solar generation and to grid storage.

Operators are moving to squeeze more output from existing plants. Roughly 30 power uprates are planned through 2030, including three applications in 2026, 16 in 2027, and eight in 2028. Uprates increase the licensed generating capacity of a reactor without building new units, offering a faster route to added supply.

The combination of high capacity factors, license renewals that extend plant lifespans, and planned uprates points to a fleet positioned to deliver more electricity from its current footprint. As demand from data centers and electrification grows, the reliability metrics underscore why utilities and large power buyers are increasingly turning to nuclear for firm, around the clock generation.

Source: Nuclear Energy Institute - https://www.nei.org/resources/statistics/us-nuclear-generating-statistics