Nuclear Energy

This article was first published in July 2020. We revised this page in August 2026 to reflect the change in how primary energy is measured.

As the world attempts to transition its energy systems away from fossil fuels towards low-carbon energy sources, we have a range of energy options: renewable energy technologies such as hydropower, wind, and solar, as well as nuclear power. Nuclear energy and renewable technologies typically emit very little CO 2 per unit of energy production and are also much better than fossil fuels at limiting local air pollution.

However, while some countries invest heavily in increasing their nuclear energy supply, others are shutting down their plants. Therefore, nuclear energy's role in the energy system is very specific to each country.

How much of our energy comes from nuclear power? How is its role changing over time? In this article, we look at levels and changes in nuclear energy generation worldwide and its safety record in comparison to other sources of energy.

Nuclear power generation has existed since the 1960s but saw massive growth globally in the 1970s, 1980s, and 1990s. The interactive chart shows how global nuclear generation has changed over the past half-century.

Following fast growth during the 1970s to 1990s, global generation has slowed significantly. In fact, we see a sharp dip in nuclear output following the Fukushima tsunami in Japan in 2011 [we look at the impacts of this disaster later in this article] , as countries took plants offline due to safety concerns.

Some countries get no energy from nuclear — or aim to eliminate it completely — while others get most of their power from it.

This interactive chart shows the amount of nuclear energy generated by country. France, the USA, China, Russia, and South Korea all produce relatively large amounts of nuclear power.

We previously considered nuclear output in terms of energy units — how much each country produces in terawatt-hours. However, to understand how large a role nuclear plays in the energy system, we need to consider total energy consumption.

Note that this data measures primary energy in terms of total energy supply . For more details, read how primary energy measurement has changed across our charts .

Note that this is based on nuclear energy's share in the energy mix. Energy consumption represents the sum of electricity, transport, and heating. We look at the electricity mix below.

In the section above, we examined the role of nuclear power in the total energy mix, which includes electricity, transport, and heating. Electricity is only one component of energy consumption.

Since transport and heating tend to be harder to decarbonize – they are more reliant on oil and gas – nuclear and renewables tend to have a higher share in the electricity mix versus the total energy mix.