Nuclear generation accounts for approximately 19 percent of United States electricity output based on 2026 estimates, drawn from a national grid producing roughly 4,400 terawatt-hours annually across about 1,250 gigawatts of installed capacity. The most recent confirmed Energy Information Administration figure, published in the February 2026 Electric Power Monthly, placed nuclear at 18 percent of utility-scale generation for 2025.

The share has held remarkably steady across two decades, which is notable given that almost no new capacity entered service during most of that period. Stability came from uprates at existing units and from sustained high capacity factors rather than from fleet expansion. Plant Vogtle Units 3 and 4 in Georgia represent the only large reactors added in recent years, contributing roughly 2,200 megawatts combined.

Nuclear's position in the generation mix is now being tested by load growth rather than by competition. Data center electricity demand alone is projected to move from 31 gigawatts in 2025 to 66 gigawatts within two years, and the incremental supply required exceeds what the existing nuclear fleet can provide without additions.

Federal activity has responded to that arithmetic. The Department of Energy announced financing in June 2026 for long-lead supply chain items covering 10 planned large-scale reactors, alongside restart support for the 800 megawatt Palisades station and the 835 megawatt Crane project.

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