Nuclear power is making a global return, International Energy Agency Executive Director Fatih Birol said, pointing to expansion across the Americas, Europe and Asia. More than 400 nuclear reactors are operational in 31 countries, with about 70 more under construction.

"I am 100% sure nuclear is coming back," Birol said. "It's seen as a secure electricity generation system, and we will see that the comeback of nuclear will be very strong, both in the Americas, in Europe and in Asia."

Nuclear power produces about 10% of the world's electricity and accounts for about a quarter of all low-carbon power sources. Reactors have seen steady improvements, adding more safety features and becoming cheaper to build and operate.

The United States operates 94 reactors, accounting for about 30% of global nuclear electricity generation, and is increasing efforts to develop nuclear capacity with a goal of quadrupling it by 2050. "The world cannot power its industries, meet the demands of artificial intelligence, or secure its energy future without nuclear power," Undersecretary of State Thomas DiNanno said.

China operates 61 reactors and has nearly 40 more under construction, with the aim of surpassing the U.S. to become the global leader in nuclear capacity. Russia has built 20 reactors worldwide and is constructing one nuclear plant in Egypt. In Japan, 15 reactors have been restarted after a review of lessons from the earthquake and tsunami that damaged the Fukushima plant, and 10 more are in the process of getting approval to restart.

"The momentum we are seeing today is the result of a growing recognition that reliable, low-carbon electricity will be essential to meet the world's rising energy demand," International Atomic Energy Agency Director General Rafael Grossi said. South Africa has the only nuclear power plant on the African continent, and several other African nations are exploring nuclear technology.

In Europe, nuclear energy accounted for about a third of the continent's electricity in 1990 and now accounts for about 15%. The European Commission views nuclear as part of clean energy, along with wind and solar, to achieve climate goals, and the EU is considering the development of Small Modular Reactors expected to become operational in the early 2030s. France has 57 reactors at 19 plants and relies on nuclear for nearly 70% of its electricity; in 2022, President Emmanuel Macron announced plans to build six new pressurized water reactors. Belgium repealed a law that had demanded the closure of its reactors and extended their lifespan, while Sweden and Finland have spearheaded nuclear power in their countries.

Other European nations have moved in the opposite direction. Germany switched off its last three reactors in 2023, and Germany, Austria and Italy have outlawed the use of nuclear energy. Spain plans to shut down its seven operational reactors between 2027 and 2035.

The 1986 Chernobyl disaster slowed development of nuclear power in Europe and elsewhere. Reactor No. 4 at Chernobyl exploded on April 26, 1986, while Ukraine was still part of the Soviet Union, contaminating nearby areas and spewing radiation across Europe. The 2011 Fukushima disaster in Japan further diminished the appetite for nuclear power. Ukraine now generates about half of its electricity from nuclear plants.