The nuclear sector is seeing one of its strongest construction pipelines in decades as World Nuclear Association data shows 80 reactors under construction worldwide, with 88,230 MWe of capacity, the highest in history.
Another 123 reactors, totaling 110,232 MWe, are listed as planned. A further 311 reactors, representing 286,394 MWe, sit in the proposed column.
The current fleet is still the anchor. WNA lists 438 operable reactors with 400,680 MWe of capacity and estimated 2025 uranium requirements of 68,920 tonnes, equal to 81,273 tonnes U3O8.
WNA’s 2025 fuel report projects global uranium requirements rising to just over 150,000 tonnes by 2040 in its reference scenario. Its upper scenario puts the figure above 204,000 tonnes.
The data, in other words, does not only measure nuclear ambition. It shows where ambition becomes recurring demand.
China
The global construction count is heavily concentrated.
China accounts for 39 reactors under construction, totaling 44,842 MWe. That is nearly half of the world’s under-construction reactor count in the WNA table. China also has 41 planned reactors and 144 proposed reactors, making it the dominant visible pipeline in both committed and speculative categories.
WNA separately says most reactors under construction or planned are in Asia.
The US shows the opposite shape. It remains the largest operating nuclear market in the WNA table, with 94 operable reactors and 96,952 MWe. But the same table lists no US reactors under construction, none planned, and 25 proposed.
Pipeline vs. fleet
The combined under-construction, planned, and proposed pipeline totals 484,856 MWe. That is larger than the 400,680 MWe WNA lists as currently operable worldwide.
But those categories do not carry the same weight. WNA treats planned reactors as projects that have moved through some mix of approval, financing, or formal commitment, generally with an expected operating window inside 15 years.
Proposed reactors are looser. They are tied to specific programs or sites, but WNA warns their timing is highly uncertain.
Even the construction line needs context. WNA says its under-construction total includes suspended units, naming Angra 3 in Brazil, Ohma 1 and Shimane 3 in Japan, and Khmelnitski 3 and 4 in Ukraine.
The bullish reading also runs into fleet aging. WNA says new nuclear plants entering service in recent years have largely been balanced by older plants retiring. Its reactor plans page says that over the past 20 years, 111 reactors were retired while 101 started operation.
The current fleet is performing better than the retirement math suggests. Nuclear reactors generated 2,667 TWh of electricity in 2024, beating the previous 2006 record of 2,660 TWh, according to the World Nuclear Performance Report cited by World Nuclear News.
But the WNA reactor table still puts nuclear’s 2024 share at about 9% of global electricity.
Uranium
For investors and policymakers, uranium may be the cleaner read than reactor totals.
A proposed reactor may never reach first concrete but an operating reactor has a fuel cycle attached to it. Once a new reactor enters commercial operation, the demand becomes a recurring procurement need.
That is why the WNA fuel report matters more than the social-media excitement around the 80-reactor headline. The 2025 estimate already places reactor uranium requirements at about 68,920 tonnes, and the reference case points to just over 150,000 tonnes by 2040.
The pressure is not only mining. WNA’s fuel report says Russia’s war in Ukraine and related geopolitical factors have affected uranium supply, conversion, enrichment, and fuel fabrication.
The reactor pipeline is large enough to matter. But the data’s most important distinction is not between today and tomorrow. It is between optional capacity and unavoidable demand.
The 311 proposed reactors may help shape long-term expectations, especially if governments keep nuclear inside energy-security and decarbonization plans. WNA-linked reporting on national targets said most growth to 2030 comes from reactors already under construction, planned projects drive expansion to 2035, and proposed or government-driven programs account for capacity growth after 2035.
That timeline makes the market risk clearer. The farthest-out reactor numbers carry the most uncertainty, while uranium demand from the existing fleet is already present and demand from completed construction would be added on top.
Nuclear’s next test is not whether the pipeline looks large on a table. It is whether the fuel system can meet the part of the table that stops being optional.
Information for this story was found via the sources and companies mentioned. The author has no securities or affiliations related to the organizations discussed. Not a recommendation to buy or sell. Always do additional research and consult a professional before purchasing a security. The author holds no licenses.
