How Many Countries Use Nuclear Power? A Global Overview of Nuclear Energy

Nuclear energy stands as a significant source of electricity worldwide, playing a crucial role in the global energy landscape. Since the first commercial nuclear power stations began operating in the 1950s, nuclear technology has evolved to become a key component of low-carbon energy production. Currently, around 9% of the world’s electricity is generated from nuclear sources, utilizing approximately 440 power reactors across the globe. Furthermore, nuclear energy contributes about one-quarter of the world’s low-carbon electricity, making it the second-largest source of low-carbon power after hydropower.

Beyond electricity generation, over 50 countries operate approximately 220 research reactors. These reactors are instrumental in various fields, including research, the production of medical and industrial isotopes, and training. This broad utilization underscores the diverse applications of nuclear technology in the modern world.

Nuclear technology harnesses the energy released from splitting atoms of certain elements, a process first developed in the 1940s. Initially, during World War II, research was focused on military applications. However, in the 1950s, the focus shifted towards the peaceful applications of nuclear fission, particularly for power generation. The ability to control nuclear fission paved the way for civil nuclear power. For a deeper dive into the history, explore the History of Nuclear Energy.

Today, civil nuclear power boasts approximately 20,000 reactor-years of operational experience. Nuclear power plants are currently operational in 31 countries, plus Taiwan, showcasing a widespread adoption of this technology. Through interconnected regional transmission grids, many more countries indirectly benefit from nuclear-generated power, especially in Europe.

The nuclear industry has transformed from its early days in the 1960s, when distinct boundaries existed between Eastern and Western industries. Today, international collaboration and commerce are hallmarks of the nuclear sector. A reactor being constructed in Asia might incorporate components from a multitude of countries, including South Korea, Canada, Japan, France, Germany, and Russia. Similarly, the nuclear fuel cycle is globally interconnected, with uranium sourced from countries like Australia or Namibia potentially powering a reactor in the UAE, after undergoing processing stages in various European and Asian countries.

The applications of nuclear technology extend far beyond just providing low-carbon energy. It plays a vital role in controlling diseases, aiding medical professionals in diagnosis and treatment, and powering ambitious space exploration missions. These diverse uses highlight the central role of nuclear technologies in global sustainable development efforts. For more detailed information, refer to Nuclear Energy and Sustainable Development.

Key Nuclear Energy Statistics

In 2023, nuclear power plants globally supplied 2602 TWh of electricity, an increase from 2545 TWh in 2022, indicating a continued growth in nuclear electricity production.

In 2023, fourteen countries generated at least 25% of their electricity from nuclear power. France leads in nuclear energy reliance, with approximately 70% of its electricity derived from nuclear sources. Ukraine, Slovakia, and Hungary also heavily depend on nuclear power, with about half of their electricity production coming from nuclear energy. Japan, historically reliant on nuclear power for over a quarter of its electricity, is expected to return to similar levels as reactors restart.

Nuclear Power Developments in 2024

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Global Nuclear Power Overview

Nuclear power development is a global phenomenon, with activities spanning across continents. For detailed information on specific countries, the Country Profiles section in the World Nuclear Association’s Information Library provides extensive resources.

Note: World figures include Taiwan, contributing 17.2 TWh in 2023 and operating one reactor as of January 2025.

† Under Construction figures include units with suspended construction: Angra 3 (Brazil), Ohma 1 and Shimane 3 (Japan), Khmelnitski 3&4 (Ukraine).

‡ Ukraine 2023 electricity generation estimated.

This table details the nuclear power landscape across the globe, showing the number of countries actively involved in nuclear energy. As of 2023, 31 countries plus Taiwan operate commercial nuclear power plants, contributing to the global supply of electricity. Furthermore, the table highlights countries with reactors under construction, planned, or proposed, indicating a continued interest and expansion in nuclear energy worldwide. Emerging nuclear energy countries like Bangladesh and Turkey are also making strides in establishing their first nuclear power plants, signaling a potential increase in the number of countries utilizing nuclear energy in the future. For more insights into these developing nations, see Emerging Nuclear Energy Countries.

Enhanced Reactor Performance

The operational efficiency of nuclear reactors has significantly improved over time. Over the past four decades, there has been a notable increase in the proportion of reactors achieving high capacity factors, demonstrating enhanced reliability and performance.

Figure 4: Long-term trends in capacity factors (source: World Nuclear Association, IAEA PRIS). Alt text: Line graph illustrating the long-term trend of nuclear reactor capacity factors, showing improvement and stabilization over the years.

Interestingly, recent data indicates no significant age-related decline in the average capacity factor of reactors over the last five years, suggesting effective maintenance and upgrades are sustaining performance even in older plants.

Figure 5: Mean capacity factor 2018-2023 by age of reactor (source: World Nuclear Association, IAEA PRIS). Alt text: Bar graph comparing the mean capacity factor of nuclear reactors by age group from 2018 to 2023, indicating consistent performance across different reactor ages.

The Growing Need for New Electricity Generation

Globally, there is a pressing need for new electricity generating capacity. This demand is driven by the necessity to replace aging fossil fuel power plants, particularly coal-fired plants that are significant sources of carbon dioxide emissions, and to meet the increasing electricity demands of growing economies. In 2022, fossil fuels still accounted for 61% of global electricity generation. Despite the growth and support for intermittent renewable energy sources, the contribution of fossil fuels to power generation has remained relatively stable over the last 15 years (66.5% in 2005).

The International Energy Agency (IEA) provides annual energy scenarios. The IEA’s World Energy Outlook 20231 outlines a Net Zero Emissions by 2050 Scenario (NZE), aiming to limit global temperature increase to 1.5°C while ensuring universal access to modern energy by 2030. This NZE scenario projects a significant increase in nuclear capacity, reaching 916 GWe by 2050, highlighting the crucial role of nuclear energy in achieving global climate goals. Further details are available on the IEA Scenarios and the Outlook for Nuclear Power information page.

Beyond Power Plants: Other Nuclear Reactors

In addition to commercial power reactors, approximately 220 research reactors are operational in over 50 countries, with more under construction. These reactors serve vital roles in research, training, and the production of medical and industrial isotopes, demonstrating the broad utility of nuclear technology beyond electricity generation.

Nuclear reactors are also critical for marine propulsion, primarily in major navies. For over five decades, nuclear power has been essential for submarines and large surface vessels. Over 160 ships, mainly submarines, are powered by around 200 nuclear reactors, accumulating over 13,000 reactor-years of experience in marine applications. While many nuclear submarines from the Cold War era have been decommissioned by Russia and the USA, the technology remains vital for naval operations.

Russia also operates a fleet of nuclear-powered icebreakers and is expanding this fleet. Furthermore, Russia has deployed a floating nuclear power plant in the remote Arctic region of Pevek, utilizing reactors adapted from icebreaker technology to provide power to the grid.

Explore more about the diverse applications of nuclear technology beyond power generation on the The Many Uses of Nuclear Technology page.

Notes & References

References

1. OECD International Energy Agency, World Energy Outlook 2023 [Back]
2. OECD International Energy Agency Statistics [Back]

General references

World Nuclear Association, World Nuclear Performance Report 2023

Related Information

Nuclear Energy and Sustainable Development
World Energy Needs & Nuclear Power
Plans For New Reactors Worldwide
The Many Uses of Nuclear Technology
What is Uranium? How Does it Work?
Financing Nuclear Energy