Number of Operating Reactors Drops – Taiwan Completes Nuclear Phaseout

WNISR, January 2026

In 2025, four new reactors with a total capacity of 4.4 GW were connected to the grid—two in China and one each in India and Russia—while seven totaling 2.8 GW were closed—three in each Belgium and Russia, and one in Taiwan completing the nuclear phaseout in the country. Thus, 2025 saw the lowest number of new startups since 2017 and should also be compared to the expected number of grid connections of 13 at the beginning of the year.

After three units closed in Belgium and with no new startups, the number of operating reactors in the European Union dropped below one hundred, to 98. The year also saw—at minus three units—the largest net negative startup/closure balance since post-Fukushima year 2012. As the average unit size of newly started reactors largely exceeded the average of the closed ones—the three closures in Russia cumulate only 33 MW—net startup/closure balance was slightly positive at just above 1.5 GW. To put this into perspective: China alone added an estimated 275 GW of solar capacity in the first eleven months of 2025 [1], over one hundred times the combined capacity of 2.5 GW of the two new reactors connected to the Chinese grid during the year. [2] This also means that the net capacity balance outside China was slightly negative by around 1 GW.

The global capacity in operation—installed capacity minus reactors in Long-Term Outage (LTO)—remains virtually stable at 369 GW with two new units entering the LTO category. [3]

There is still not a single commercial nuclear power reactor construction underway on the entire American continent. In the European Union, the only unit under construction is the Mochovce-4 reactor in Slovakia that originally started building in 1985.

China dominates the building activities with 36 active construction projects at home, more than half of the world total of 66 as of 1 January 2026. Over the year, the cumulated number increased by seven—entirely due to China [4]—while the number of units under construction outside China remained stable. [5]

Of the total of 66 units being built in 11 countries, 63 (95 percent) are either in nuclear-weapon states (50) or are implemented by companies controlled by nuclear-weapon states in other countries (13). Just the three building sites in South Korea fall outside this category. And only the three nuclear weapon states China, France, and Russia—the latter being by far the largest international builder with 20 units in progress outside its borders—are in the course of building commercial reactors abroad.

The number of building countries declined by almost one third, from 16 to 11, in just two years, with several countries having completed their last construction project (France, United Arab Emirates, United States), or suspended if not terminated construction (Argentina, Brazil, Japan [6]), while only one country was added to the list (Pakistan). Only eight of the 31 countries currently operating commercial nuclear plants are building new ones, while three are newcomer countries (Bangladesh, Egypt, Türkiye) in the course of building their first reactors, all implemented by the Russian nuclear industry.

There were 11 construction starts in 2025—the largest number since pre-Fukushima year 2010—of which nine were implemented in China. Russia and South Korea kicked off the remaining two building sites.

Thus, the basic trend has not changed since 2020: globally, 51 units got underway in that period, of which 35 (69 percent) in China, one by Chinese companies in Pakistan, and 14 implemented by the Russian nuclear industry in Egypt, India, Türkiye, or at home. Russia also began building four of the units in China. Over the entire six-year period, Chinese and Russian companies have been the only builders worldwide with official reactor construction starts, except for one project officially launched in South Korea.

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