Nuclear energy provides about 10% of the world’s electricity, but its share has been shrinking for two decades even as climate concerns grow. The reasons are primarily economic: new nuclear plants cost roughly four times more per unit of electricity than solar or wind. Beyond cost, long construction timelines, unresolved waste storage, complex licensing, and persistent public unease have all slowed nuclear expansion.
The Cost Gap Is Enormous
The single biggest barrier to nuclear energy is price. According to the U.S. Energy Information Administration’s 2025 outlook, a new advanced nuclear plant entering service in 2030 would produce electricity at about $134 per megawatt-hour in today’s dollars. Onshore wind comes in at roughly $32, and utility-scale solar at about $38. That means nuclear electricity costs more than three times what renewables cost, even before accounting for the financial risks that make investors nervous.
These numbers reflect the full lifecycle: construction, fuel, operations, maintenance, and financing over 30 years. Nuclear plants do run reliably for decades and produce power around the clock, which has real value. But the upfront capital required is so large, and the payback period so long, that private investors and utilities increasingly choose cheaper, faster alternatives. A solar farm can be financed, built, and generating revenue in under two years. A nuclear plant takes a decade or more just to construct.
Construction Takes Years, Sometimes Decades
Building a nuclear reactor is one of the most complex construction projects on Earth, and timelines frequently spiral out of control. Among reactors that connected to the grid in 2024, construction times ranged from about five years for China’s Zhangzhou 1 reactor to 17 years for France’s Flamanville 3. India’s Kakrapar 4 took over 13 years. The U.S. Vogtle 4 reactor in Georgia took just over 10 years, arriving billions of dollars over budget.
China has managed to build reactors in five to seven years by standardizing designs and maintaining a continuous pipeline of projects. Most other countries lack that institutional experience. When a nation builds only one reactor every few decades, the workforce, supply chains, and regulatory knowledge erode between projects. Each new plant becomes a “first of a kind” all over again, with predictable delays and cost overruns. Many reactors currently listed as under construction worldwide have had periods where work was simply suspended, sometimes for years.
No Country Has Opened a Permanent Waste Site
Every nuclear plant produces spent fuel rods that remain dangerously radioactive for thousands of years. The scientific consensus is that deep geological repositories, essentially tunnels carved hundreds of meters into stable rock, are the safest long-term solution. But as of 2025, not a single country on Earth has an operational repository for high-level nuclear waste.
Finland is closest: its Onkalo facility is built and awaiting final approval to begin accepting waste. Sweden plans to start emplacement around 2035, France between 2027 and 2028, and Canada by 2031. The United States spent decades and billions of dollars developing Yucca Mountain in Nevada, only to see the project defunded and its licensing process suspended indefinitely. Germany, which decided to phase out nuclear power entirely, doesn’t expect a repository until sometime between 2046 and 2068.
In the meantime, spent fuel sits in cooling pools and dry cask storage at reactor sites around the world. This interim storage is considered safe for decades, but it was never meant to be permanent. The inability to solve the waste question feeds public distrust and gives political opponents a concrete, visible argument against new plants.
Licensing and Regulation Are Slow by Design
Nuclear reactors require extensive government review before a single shovel hits dirt. In the United States, the Nuclear Regulatory Commission asks prospective applicants to plan for a multi-year licensing process that includes pre-application activities, formal application review, and safety evaluations. The NRC uses proposed milestone dates for budget and resource planning, and the process can stretch across several years even before construction begins.
This isn’t arbitrary bureaucracy. Nuclear accidents carry consequences that no other energy source matches: large-scale land contamination, mass evacuations, and cleanup costs that can reach hundreds of billions of dollars. Regulators move cautiously because the stakes justify caution. But the result is that a utility deciding to build a nuclear plant today might not see it operating until the late 2030s, while energy markets, technology, and politics could shift dramatically in the interim. That uncertainty discourages investment.
Decommissioning Adds Hidden Costs
When a nuclear plant reaches the end of its life, you can’t just turn it off and walk away. Decommissioning involves removing radioactive components, decontaminating structures, and managing waste. Cost estimates range from $130 million to $477 million per reactor, depending on the size, design, and regulatory requirements of the country involved. Some nations plan to seal reactors in a “safe storage” phase for decades before fully dismantling them, stretching the process out by 50 to 100 years.
Plant operators are typically required to set aside funds during the reactor’s operating life to cover these eventual costs. But estimates have historically been too low, and the financial burden adds another layer of uncertainty for anyone considering a new build.
Fuel Supply Depends on a Few Countries
Nuclear plants run on uranium, and the global supply is concentrated in a handful of nations. In 2024, Kazakhstan alone produced 39% of the world’s mined uranium, followed by Canada at 24% and Namibia at 12%. Together, those three countries account for about three-quarters of global production. Australia and Uzbekistan round out the top five.
This concentration creates geopolitical risk. Kazakhstan’s uranium industry has deep ties to Russian state nuclear companies, which also dominate global uranium enrichment and fuel fabrication. For countries that view energy independence as a security priority, building reactors that depend on fuel supply chains running through geopolitical rivals is a hard sell. Solar panels and wind turbines, once manufactured, run on sunlight and air.
Public Opinion Remains Divided
Nuclear energy has never enjoyed comfortable public support. Gallup polling shows that even before the 2011 Fukushima disaster in Japan, Americans were roughly split: in 2001, 49% said nuclear was necessary to solve energy problems while 46% said the dangers were too great. After Fukushima, opposition edged ahead at 48% to 46%. When asked specifically about building a nuclear plant in their area, opposition has been stronger: a 2007 poll found 59% somewhat or strongly opposed, with 44% strongly opposed.
Support has ticked upward in recent years as climate concerns grow and tech companies seek reliable carbon-free power for data centers. But decades of association with Chernobyl, Fukushima, and Three Mile Island have created a deep reservoir of public wariness that translates directly into political resistance. Elected officials in many democracies see little upside in championing nuclear projects that take longer than their terms in office and carry the risk of spectacular failure.
Small Modular Reactors: A Possible Shift
The nuclear industry’s best hope for changing the equation is the small modular reactor. These are factory-built units roughly a quarter to a third the size of conventional reactors, designed to be manufactured on assembly lines and shipped to sites, potentially cutting construction time and cost dramatically.
Progress is real but slow. Multiple SMR designs are moving through licensing, siting, and early construction phases across several countries. The OECD’s Nuclear Energy Agency tracks these projects and notes substantial advancement from concept to ground-breaking. However, no SMR design has yet reached full commercial operation in a Western market. The first deployments will be “first of a kind” projects, which historically cost more and take longer than their developers promise. Whether SMRs can actually deliver electricity at prices competitive with renewables remains unproven at scale.
The technology is promising enough that major tech firms and governments are placing bets on it. But the pattern of nuclear energy’s history is one of optimistic projections followed by sobering reality, and SMRs still need to prove they can break that cycle.