Most observers of the global energy system are familiar with the general storyline of nuclear power. The United States, the Soviet Union, and France rapidly developed their commercial nuclear power industry after World War II. Belgium, Sweden, Ukraine, South Korea, and other nations also made nuclear power a key source of electricity generation. The number of new reactor starts (connections to the grid) roughly tripled from the mid-1960s to the mid-1980s.
The tide quickly turned. New reactor starts plummeted to the low single digits by the 1990s due to rising costs, public opposition, disasters at Three Mile Island and Chernobyl, and most recently by relatively cheap and abundant alternatives such as natural gas, solar, and wind. Reactor retirements began to outnumber new connections to the grid. Over the past 20 years, 107 reactors were retired as 100 started operation.1 Reactor retirements were concentrated in the United States, Germany, and the United Kingdom.
New reactor starts increased in the 2010s as some countries looked to replace fossil fuels to reduce greenhouse gas emissions, improve domestic energy security, and reduce the potential impact of intermittent renewable sources on grid reliability. The nuclear power industry has touted a new generation of “small modular reactors” that will be reliable, safe, and cost-effective, although these potential benefits have yet to be demonstrated at scale. In countries like Russia and China, new reactors enjoy generous government financial support and favorable regulatory environments.
The balance between reactor starts and reactor retirements is reflected in the trend in the number of reactors in actual operation and their generation capacity. A peak level of more than 430 reactors was sustained from 1995 through 2010. In early 2024 there were 416 operating reactors with a generation capacity of about 375 gigawatts (GW).
Countries exhibit distinct patterns of reactor starts. The United States shows bursts of activity in the 1970s and again in the 1980s, followed by rapid retrenchment. China’s nuclear program began much later than most but now accounts for many of the new nuclear reactors in the world.
1 World Nuclear Association, “Plans For New Reactors Worldwide,” June 27, 2024, Link
