Nuclear power is in the middle of a global comeback. After years of stagnation following the 2011 Fukushima disaster, new construction is accelerating, governments are signing pledges to expand capacity, and the industry produced roughly 2,618 terawatt-hours of electricity in 2024. About 70 reactors are currently under construction in 15 countries, and a landmark international agreement aims to triple nuclear capacity by 2050.
How Much Electricity Nuclear Provides Today
Nuclear plants generated approximately 2,618 terawatt-hours of electricity worldwide in 2024, according to the IAEA’s reactor database. That makes nuclear one of the largest sources of low-carbon electricity on the planet, behind hydropower but ahead of wind or solar individually in many regions. The global fleet consists of around 440 operating reactors spread across more than 30 countries.
France still leads in nuclear reliance, generating the majority of its electricity from its reactor fleet. Other countries with high nuclear shares include Slovakia, Ukraine, Hungary, and Belgium. The United States operates the most reactors of any single country and remains the world’s largest nuclear electricity producer in absolute terms, though nuclear accounts for roughly 18 to 19 percent of U.S. generation.
Where New Reactors Are Being Built
China dominates new construction with 37 reactors currently underway, totaling nearly 43,000 megawatts of capacity. That’s more than half the global construction pipeline on its own. India and Russia each have 6 reactors under construction, and the remaining projects are scattered across countries including Turkey, Egypt, Bangladesh, and several in Eastern Europe.
This wave of construction reflects a shift in how governments view nuclear energy. At COP28 in late 2023, 25 countries endorsed a declaration committing to triple global nuclear capacity from 2020 levels by 2050. Signatories included the United States, France, Japan, the United Kingdom, Canada, South Korea, and the United Arab Emirates, along with countries like Poland, Ghana, and Morocco that don’t yet operate nuclear plants but plan to. The declaration explicitly recognized that climate models show tripling nuclear capacity is necessary to reach net-zero emissions by mid-century.
Extending the Life of Existing Plants
Building new reactors is only part of the picture. Many countries are choosing to keep their existing plants running far longer than originally planned. In the United States, 78 reactor units have already received licenses to operate for 60 years, up from their original 40-year terms. Six units have been approved for operation to 80 years, and reviews for additional plants are ongoing or expected.
These extensions require operators to demonstrate that aging components can be managed safely over the longer timeframe. The focus is on physical degradation: whether concrete, cables, and reactor vessels will hold up under decades of additional neutron bombardment and thermal stress. For the U.S. fleet, life extensions are a practical necessity. Many of these reactors were built in the 1970s and 1980s, and replacing their output with new construction would take decades and cost far more than keeping them running.
The Cost Challenge
New nuclear remains expensive compared to renewables, and this is the industry’s biggest obstacle. The U.S. Energy Information Administration estimates that an advanced nuclear plant entering service in 2030 would produce electricity at roughly $126 to $134 per megawatt-hour. Onshore wind comes in around $26 to $32, and solar at $19 to $30. That makes new nuclear four to six times more costly per unit of electricity than the cheapest renewables.
These figures don’t tell the whole story, though. Wind and solar are intermittent, meaning they only generate power when conditions allow. Nuclear runs around the clock at high output, which gives it value as “baseload” power that doesn’t depend on weather or time of day. Still, the cost gap is wide enough that most private investors won’t finance new nuclear plants without substantial government support, loan guarantees, or long-term power purchase agreements. Large projects in the U.S. and Europe have a track record of running years behind schedule and billions over budget.
One area generating significant interest is small modular reactors, or SMRs. These are factory-built units with lower upfront costs and shorter construction timelines, at least in theory. Several designs are in advanced licensing stages in the U.S., Canada, and the UK, though none are producing commercial power in Western countries yet.
Uranium Supply and Fuel Costs
Uranium prices have climbed sharply in recent years, reflecting growing demand expectations and supply uncertainty. Spot prices hovered around $81 to $82 per pound in early 2025, a significant increase from the $20 to $30 range that persisted through much of the 2010s. Investment funds have been actively buying physical uranium, with Sprott’s uranium fund (the world’s largest) increasing its holdings and triggering additional speculative buying.
On the supply side, the U.S. government announced $2.7 billion in contracts to establish domestic uranium enrichment capabilities, particularly for a specialized fuel called high-assay low-enriched uranium that next-generation reactors will need. Canada approved its first in-situ recovery uranium mining operation, a technique that extracts uranium without traditional open-pit or underground mining. These moves reflect a broader push among Western nations to reduce dependence on Russian nuclear fuel services, which have historically dominated the global enrichment market.
The Nuclear Waste Milestone in Finland
One of nuclear power’s longest-standing criticisms is the lack of a permanent solution for spent fuel. That is about to change. Finland’s Onkalo facility, built deep into bedrock on the country’s western coast, is on track to become the world’s first operational deep geological repository for spent nuclear fuel. Operator Posiva has stated it aims to begin final disposal in 2026.
The concept is straightforward: spent fuel is sealed in copper canisters, surrounded by clay, and buried roughly 400 meters underground in stable rock formations that have remained geologically quiet for nearly two billion years. If Onkalo operates successfully, it will serve as proof of concept for similar repositories being planned in Sweden, France, Canada, and other countries. The U.S., by contrast, has struggled for decades to site a permanent repository, with the proposed Yucca Mountain facility in Nevada remaining politically stalled.
Fusion: Still a Long Way Off
Nuclear fusion, the process that powers the sun, is sometimes discussed alongside conventional nuclear power, but the two are on completely different timelines. The ITER project in southern France, the world’s largest fusion experiment, has its schedule set for first plasma in late 2025, though the project has faced repeated delays and cost overruns since construction began. Even if ITER succeeds, it is a research device, not a power plant. Commercial fusion electricity is still decades away at best.
Several private companies are pursuing smaller, faster approaches to fusion, but none have demonstrated net energy gain at a scale relevant to power generation. Fusion remains a long-term research bet rather than a factor in today’s energy planning.
What’s Driving the Shift
Three forces are converging to push nuclear back into favor. The first is climate policy: nuclear produces electricity with virtually no carbon emissions during operation, and policymakers increasingly accept that renewables alone may not decarbonize grids fast enough. The second is energy security, sharpened by Europe’s experience after Russia’s invasion of Ukraine exposed the risks of dependence on imported natural gas. The third is surging electricity demand from data centers, artificial intelligence, and electrification of transportation and heating, all of which require reliable, round-the-clock power.
Whether nuclear can deliver on these expectations depends largely on whether the industry can solve its cost and construction problems. China is building reactors on budget and on schedule. Western democracies, so far, mostly have not. The next decade will determine whether the current wave of political support translates into actual megawatts on the grid, or whether nuclear’s revival remains more aspiration than reality.