Over the past two months, the World Nuclear Association (WNA) has released two documents, the World Nuclear Performance Report tracking nuclear construction and energy output across the globe and the World Nuclear Fuel Report outlining three supply and demand scenarios and assessing the availability of uranium supplies through 2040. Both current performance and future projections show upward trends.
The WNA identified record-high electricity generation at nuclear facilities worldwide as the main achievement of 2024, with 2,667 TWh produced, up from 2,601 TWh the previous year. This figure surpassed the previous record of 2,660 TWh set in 2006. Since 2012, North America has led the world in nuclear power generation. Europe, which held the top position in the first half of the 2000s and remained roughly on par with North America in the latter half of the 2000s and early 2010s, has now fallen to third place, overtaken by Asia as well. A 40 TWh increase in the European output in 2024 — driven by French reactors returning to service after temporary outages in 2022 and 2023 — was insufficient to reverse this trend.
2,667 TWh
Global nuclear energy output in 2024
Asia showed the largest growth in generation capacity and is now in second place in terms of output, closely approaching North America. In other regions, including Russia and Eastern Europe, nuclear energy output in 2024 remained virtually unchanged compared to 2023.
As of the end of 2024, there were 440 operational reactors worldwide with a combined electrical capacity of 398 GW — three reactors and 6 GW more than in 2023.
The report notes that in 2024, some reactors in Japan (19 GW), India (less than 1 GW), and other countries (11 GW) did not generate electricity because their operations are currently suspended. Thus, the total electrical capacity of reactors that actually produced electricity in 2024 was 369 GW, which is 1 GW more than the previous year.
Pressurized water reactors are the most numerous worldwide (313), with their number increased by five in 2024 compared to 2023. Boiling water reactors rank second (60), remaining unchanged from 2023. The number of heavy water reactors decreased by one to 46. Graphite-moderated reactors also declined by one, totaling 10 in 2024.
Historically, many reactors were commissioned in the 1970s and 1980s, while new construction slowed significantly in the 1990s and 2000s. In the 2010s, the pace of new additions began to rise again. Consequently, the global fleet now includes growing numbers of both ‘young’ (under 15 years old) and ‘elderly’ (over 42 years old) reactors. However, the core of the operational nuclear fleet still consists of mid-life units (15 to 42 years old). Notably, Rosatom is currently building power units with a design life of 60 years, extendable by another 20 years.
Last year, construction began on nine reactors, six in China and one each in Egypt, Pakistan, and Russia. In Russia, first concrete was poured for Unit 3 of Leningrad II on March 14. By September of this year, workers had installed the first tier of the reactor building’s inner containment shell and begun preparations for the turbine building foundation.
As of the end of 2024, 63 units were under construction worldwide, including four in Russia: three with VVER reactors and one Generation IV fast neutron reactor.
Seven reactors were connected to the grid for the first time in 2024, three in China and one each in the United States, France, India, and the UAE. Construction timelines for these units varied significantly. The best result was achieved at Zhangzhou 1 (China), with only 61 months elapsed from first concrete pouring to grid connection. The longest construction period was for Flamanville 3 (France), which took 204 months. On average, the units connected in 2024 took 114 months — just under 10 years — to build. It should be noted that the construction start date for Unit 1 of the Shidao Bay Nuclear Power Plant had to be determined using satellite imagery, as no official announcement of first concrete pouring was made.
Construction of most units currently being built began within the last seven years. Only the prototype fast breeder reactor (PFBR) and Rajasthan 8 with a PHWR (both in India) have been under continuous construction for over 10 years. Other units with construction periods exceeding 10 years experienced, or are still experiencing, construction delays or suspensions.
Four reactors were permanently shut down in 2024: Pickering Units 1 and 4 (Canada), Maanshan Unit 1 (Taiwan), and Kursk Unit 2 in Russia. In summary: seven units were connected to the grid and four retired in 2024, resulting in a net positive balance.
In 2024, seven units were connected to the grid and four retired, resulting in a net positive balance.
Last year, the global average nuclear capacity factor — the ratio of actual output to maximum possible output — reached 83%, up 1% from the previous year. Africa showed the greatest improvement in the capacity factor. Both units of the continent’s only operating nuclear plant, Koeberg, passed scheduled maintenance and retrofit one after another. Unit 1 was under maintenance from December 2022 to November 2023, and Unit 2 from December 2023 to December 30, 2024. The two units were overhauled ahead of a planned 20-year life extension.
Capacity factors remained flat in North America but declined slightly in other regions. “As observed in previous years, there is no overall age-related decline in nuclear reactor performance, in terms of average capacity factors achieved by reactors of different ages. This includes reactors that have operated for 40 years and longer, which is a positive indication for the potential of reactors to continue to function well when entering periods of extended operation,” the report says.
The future of the nuclear sector was further analyzed in the 22nd edition of the World Nuclear Fuel Report. It presents three scenarios for global nuclear power expansion, and all were revised upward compared to the 2023 projections.
According to the reference scenario, global installed nuclear capacity (398 GW as of June 2025) will grow to 746 GW by 2040 (60 GW higher than the 2023 forecast). In the upper scenario, capacity will reach 966 GW (35 GW higher), and 552 GW (66 GW higher) in the lower scenario.
Consequently, uranium demand will also rise. WNA experts estimate that nuclear power plants will need 68,920 tonnes of uranium in 2025. In the reference scenario, demand will grow to just over 150,000 tonnes by 2040; the upper scenario requires more than 204,000 tonnes, while the lower scenario still needs over 107,000 tonnes.
The key challenge is that uranium supply from primary sources (mines) does not cover projected demand, even when combined with supply from secondary sources. Mining companies face two major obstacles: insufficient investment and excessively long licensing timelines (8 to 15 years) for new uranium mines.
Speaking at the World Atomic Week in Moscow in late September, Sama Bilbao y León urged authorities to shorten these timelines to accelerate production at already identified but not yet operational mines. “Uranium is fortunately a resource that is quite abundant in all continents, but obviously we need to invest in the exploration of this resource and in the extraction. And related to that is to work together with regulators and the agencies that are permitting these mines to optimize and accelerate the process of permitting these mines,” she said at a press briefing.
She clarified her point: “Obviously, this does not mean cutting any corners. I mean we still need to make sure that we do due diligence and we make sure that we assess all the things that need to be assessed in order to permit the mine. But let’s do that in a very efficient manner.”
Photo by: Strana Rosatom newspaper
