Nuclear energy continues to anchor the U.S. electricity system, supplying close to a fifth of the nation's power from a fleet that runs more consistently than any other generation source. The country's 94 operating reactors produce almost 20 percent of total U.S. electricity and account for the largest share of carbon-free generation on the grid.

The fleet's defining strength is reliability. U.S. nuclear plants operate at capacity factors above 90 percent, meaning they run near full output the vast majority of hours in a year. That figure is the highest of any electricity source and far exceeds the capacity factors of wind, solar, and most fossil generation, which makes nuclear a dependable base of supply as intermittent renewables expand.

That steadiness has taken on new importance as demand climbs. Electricity consumption is rising at a rate not seen in decades, propelled by data centers, AI computing, and broader electrification. Because nuclear plants deliver constant output regardless of weather, utilities and large power buyers increasingly view existing reactors and their planned uprates as a way to add firm, round-the-clock capacity without adding emissions.

The role of the current fleet is expanding accordingly. License renewals now extend many reactors toward 60 and 80 years of operation, preserving generation that would otherwise retire. With more than 8 gigawatts of additional capacity possible through uprates and restarts, the data underscores how central the established nuclear fleet has become to plans for meeting surging electricity demand while holding carbon output down.

Source: U.S. Energy Information Administration -- https://www.eia.gov/nuclear