What Is Nuclear Energy, and Why Is It Making a Comeback?

KUALA LUMPUR, 21 AUGUST 2026 —

Energy security concerns augmented by recent years of war in Ukraine and the Middle East have fueled a global resurgence of nuclear energy. In Asia, Europe, and elsewhere, governments are looking to nuclear energy as a stable power source in the face of geopolitical uncertainty, increasing electricity demand, and accelerating climate change. This includes the United States, which recently signed a thirty-year civil nuclear cooperation agreement with Saudi Arabia, though it has yet to go into effect. This resurgence marks a stunning reversal. Nuclear power development stalled after high-profile accidents such as the 1979 Three Mile Island meltdown and the 1986 Chernobyl disaster fueled public fears of the technology. “This is the brightest moment for nuclear power globally in a couple of decades,” Vijay Vaitheeswaran, senior fellow and director of CFR’s Energy and Climate Program, told CFR. “Energy for development and prosperity is extremely important… and we have a climate crisis as well as a challenge of local emissions. So nuclear, and more of it, would be a very good thing if the challenging economics of new plants can be overcome.” As of 2024, there are 417 nuclear power reactors operating across 31 countries, with dozens more under construction, according to the International Atomic Energy Agency (IAEA) [PDF]. Together, they supply roughly 9 percent of the world’s electricity, a share that energy experts expect will grow in the coming decades as countries expand their nuclear commitments to meet booming demand. CFR examines what’s driving renewed global interest in nuclear energy, which countries use it most, and the debate over its risk—including weapons proliferation. Nuclear energy is generated through nuclear fission, the process through which the nucleus of an atom splits into two or more nuclei, releasing large amounts of energy, mostly as heat and radiation. In a nuclear power plant, this heat is used to produce steam, which drives turbines connected to electric generators. Nuclear reactors are commonly fueled by uranium-235, a naturally occurring isotope of uranium. The result is low-carbon electricity. Nuclear-generated electricity prevents more than 470 metric tons of carbon dioxide emissions from entering the atmosphere that would otherwise come from fossil fuels, according to the Nuclear Energy Institute. However, the waste produced by nuclear power plants is radioactive and requires careful, long-term storage, fueling debate about nuclear energy as a clean climate solution. The development of civilian nuclear power became an international focus in the early 1950s, according to the IAEA [PDF]. In 1951, the Experimental Breeder Reactor-I in Idaho became the world’s first reactor to generate usable electricity from nuclear fission. However, nuclear power development slowed [PDF] in the United States in the 1970s and 1980s due to increased concern over reactor safety, waste disposal, and other environmental effects. Experts say a combination of factors is driving nuclear energy’s comeback, which gained significant momentum in 2023, when more than twenty countries committed to tripling their global nuclear energy capacity by 2050. Energy diversification. Geopolitical instability has underscored countries’ need to diversify their energy sources. Russia’s 2022 invasion of Ukraine exposed Europe’s dependence on Russian natural gas imports, while the Iran war has disrupted global oil and gas markets this year, highlighting the vulnerability of relying on fossil fuel supply chains to meet energy needs. Although the push for nuclear energy was already well underway before the Iran war began in February 2026, experts say these geopolitical conflicts have likely accelerated the process. Climate goals. This summer’s record-breaking heat and devastating wildfires have once again raised alarms about climate change. Faced with such mounting pressures, governments around the world are expanding their use of low-carbon electricity sources—such as nuclear, solar, and wind—to lower greenhouse-gas emissions and meet their climate goals. In a high-case scenario, the IAEA projects that global nuclear capacity will nearly triple by 2050, up from 377 gigawatts (GW) to 992 GW. In a low-case projection, capacity would increase by about 50 percent. Advocates of nuclear power point out that it provides 24/7 power regardless of the weather, while low-carbon alternatives like wind and solar rely on energy-storage technologies like batteries to provide reliable power to the grid. However, mining and refining uranium—the primary fuel source for nuclear energy—and building nuclear power plants requires large amounts of money and energy. Even so, the environmental gains outweigh the upfront costs required to build a nuclear energy plant, Vaitheeswaran told CFR. “Compared to something like coal, nuclear has very low climate or local emissions, and that’s very attractive in an age of great concern about climate change,” he said. AI demand. Nuclear energy presents a way to reduce the strain put on electrical grids by the rapidly expanding use of artificial intelligence (AI). Data centers accounted for roughly 50 percent of total electricity demand growth in the United States in 2025, according to the International Energy Agency. In the United States and globally, nuclear energy is seen as one way to meet this added demand. Major tech and AI infrastructure companies—including Amazon, Google, Meta, and Microsoft— have signed at least one nuclear deal in 2026. Before their recent interest in nuclear, these U.S. companies were the main force developing clean energy in the country with wind and solar power purchase agreements, he added. Just five countries produce more than 70 percent of the world’s nuclear electricity generation capacity: the United States, China, France, Russia, and South Korea, according to the U.S. Energy Information Administration. The United States leads in nuclear energy production, accounting for about 30 percent of global electricity generation. The Trump administration aims to further increase production, with the goal of quadrupling U.S. nuclear capacity from 100 to 400 GW by 2050—close to the total amount of nuclear power currently generated worldwide. To achieve this, the administration plans to expedite the construction of ten large-scale commercial nuclear reactors by up to three years, with complete designs under construction by 2030. It also intends to encourage the building of more small modular reactors, compact nuclear fission plants that,… (AI-assisted rewrite, based on the original source)

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