Nuclear power plants operate in 32 countries, with 417 reactors running worldwide as of 2024. The vast majority are concentrated in just a handful of nations: the United States, France, China, Russia, and South Korea together account for roughly two-thirds of all operational reactors. Within the U.S., 94 reactors spread across 28 states generate about 18% of the country’s electricity.
Countries With the Most Reactors
The United States has the largest nuclear fleet in the world with 94 operating reactors. France and China are tied for second with 57 each, though France gets a far greater share of its electricity from nuclear power (67%) compared to China (about 4.5%), which has a massive overall grid. Russia operates 37 reactors, South Korea has 26, and India runs 20. Canada, the United Kingdom, Spain, and the Czech Republic round out the top ten.
Nuclear’s share of a country’s electricity varies enormously. France relies on it for two-thirds of its power. The Czech Republic gets about 40% from nuclear, and South Korea around 32%. In the U.S., the figure is closer to 18%. China’s percentage is small only because its total energy consumption is so enormous; in absolute terms, Chinese reactors produced over 417,000 gigawatt-hours in 2024.
Another 62 reactors are currently under construction globally, with China leading that expansion by a wide margin.
Where U.S. Nuclear Plants Are Located
U.S. nuclear plants are heavily concentrated in the eastern half of the country, especially the Southeast and the Great Lakes region. Illinois leads all states with six operating plants (11 reactors total), including Braidwood, Byron, and LaSalle. South Carolina operates four plants, Pennsylvania has four, and Georgia is home to Plant Vogtle, the largest nuclear facility in the country with four reactors producing about 4.5 gigawatts of capacity.
Other states with significant nuclear capacity include Alabama, North Carolina, Tennessee, New York, New Jersey, Florida, Virginia, and Texas. A few western states have plants too: Arizona’s Palo Verde facility (3.9 GW) was the nation’s largest before Vogtle’s expansion, California still operates the two-reactor Diablo Canyon plant (2.2 GW, providing about 9% of the state’s electricity), and Washington state runs the Columbia Generating Station.
States with just a single reactor include Kansas (Wolf Creek), Missouri (Callaway), New Hampshire (Seabrook), Minnesota (Monticello and Prairie Island, both small), Nebraska (Cooper), Mississippi (Grand Gulf), Louisiana (River Bend and Waterford), and Wisconsin (Point Beach). The Nuclear Regulatory Commission maintains an interactive map on its website where you can click on any plant to see its exact location and regulatory details.
Nuclear Power Across Europe
Twelve European Union countries currently operate nuclear reactors: France, Spain, Finland, Sweden, Belgium, Bulgaria, the Czech Republic, Hungary, the Netherlands, Romania, Slovenia, and Slovakia. France dominates, with its 57 reactors producing more nuclear electricity than the rest of the EU combined.
The trend in Europe has been mixed. Germany permanently shut down its last three reactors in April 2023, completing a phase-out that began after the Fukushima disaster. Lithuania closed its nuclear facilities in 2009. Meanwhile, several Eastern European countries continue to invest in nuclear capacity, and the UK (no longer in the EU) still operates 9 reactors.
China’s Rapid Expansion
China’s nuclear plants are clustered along its eastern and southern coastlines, where population density and electricity demand are highest. Guangdong province in the south and Jiangsu province near Shanghai have some of the heaviest concentrations. Shandong, on the northeastern coast, also hosts multiple facilities. This coastal positioning is no accident: reactors need enormous volumes of water for cooling, and seawater provides a ready supply without competing with freshwater resources used for agriculture and drinking.
China is building new reactors faster than any other country and has plans to roughly double its nuclear capacity over the next decade.
Why Plants Are Built Where They Are
Nuclear power plants can’t go just anywhere. The most important requirement is access to a large, reliable water source. Reactors generate intense heat, and cooling systems need millions of gallons of water per day. That’s why nearly every nuclear plant sits on an ocean coastline, a major river, or a large lake. In the U.S., you’ll notice clusters along the Great Lakes, the Atlantic coast, and major river systems like the Mississippi and Tennessee.
Seismic stability is another major factor. Regulators require detailed geological surveys of any proposed site, including analysis of earthquake history and fault lines. Each plant must be designed to safely shut down during the strongest earthquake considered possible for that location. Soil composition matters too, since the ground needs to support enormous concrete structures without shifting.
Regulators also evaluate how groundwater and nearby waterways could be affected if radioactive material were accidentally released. Sites where contamination could easily reach underground water tables or flow into rivers require extra precautions or may be ruled out entirely. Population density plays a role as well: plants need buffer zones around them, which is why you won’t find reactors in the middle of major cities.
New Sites on the Horizon
The next wave of nuclear construction in the U.S. centers on small modular reactors, which are compact enough to fit on smaller sites and can be manufactured in factories rather than built entirely on location. The Department of Energy is partnering with a group of municipal utilities to deploy a commercial small modular reactor at Idaho National Laboratory. A second project involves the Tennessee Valley Authority working to permit a small modular reactor at its Clinch River site near Oak Ridge, Tennessee.
These smaller designs could eventually open up locations that wouldn’t work for traditional large-scale plants, including retired coal plant sites that already have grid connections and cooling water infrastructure in place.