The American nuclear fleet hit an all-time high in 2025: 785.6 TWh generated by 94 operating reactors, accounting for roughly 29% of total global nuclear output. It is the highest figure ever recorded for the United States, reinforcing the country’s position as the world’s leading nuclear power producer in terms of both installed capacity and actual generation.
The figure comes from World Nuclear Association data and aligns with findings published by the U.S. Energy Information Administration, which in March 2026 certified 2025 as a record year for overall U.S. electricity generation — reaching 4.43 TWh in total, up 2.8% from 2024. Nuclear power contributed steadily throughout the year, holding a share of around 18–19% of the national electricity mix. As of May 2026, that share stood at 18.3%, with peaks of 59.5% in New Hampshire and 55.5% in New Jersey and Illinois.
The growth outlook extends well beyond U.S. borders. The International Energy Agency projects new global nuclear generation records every year through 2030, driven by new reactor commissioning in China, restarts in Japan, and improved availability in France. On February 9, 2026, Japan restarted Unit 6 at the Kashiwazaki-Kariwa plant, offline since 2011 — a move the EIA expects to shift generation away from fossil fuels, primarily natural gas, which covered 33% of Japan’s electricity in 2024, toward zero-emission sources.
On the technology front, the United States is opening a new chapter. In March 2026, the Nuclear Regulatory Commission issued a construction permit for TerraPower’s Natrium reactor, a sodium-cooled unit with a net output of 345 MWe — expandable to 500 MWe for up to five and a half hours via molten salt thermal storage — to be built in Kemmerer, Wyoming, on the site of a decommissioned coal plant. It is the first construction permit ever granted in the United States for a next-generation advanced reactor. The project, co-funded by the Department of Energy under the Advanced Reactor Demonstration Program with an initial $80 million, has also become a magnet for private investment: in January 2026, Meta signed an agreement to prepay for energy supply and support Oklo’s 1.2 GWe nuclear campus project in Ohio, while in June 2026 Walmart signed its first-ever nuclear power purchase agreement, securing around 176 MWe from Constellation’s Dresden plant in Illinois.
The convergence of major tech corporations and nuclear producers marks a genuine shift in the energy market. This is not merely about decarbonization — it reflects real, urgent demand fueled by the explosive growth of data centers. Nuclear delivers where other sources fall short: reliability, energy density, and a minimal land footprint. If IEA projections hold and ongoing construction projects are completed on schedule, global nuclear output by 2030 could surpass current levels by a significant margin, returning the technology to the center of the energy debate — backed by data, not promises.
