Five Myths of Fusion

Nuclear Fusion: The Myths and the Facts

Nuclear fusion energy is a clean, efficient, powerful, and bountiful source of power that will revolutionize the world. But you might not have known that—you might have heard that it’s dangerous, wasteful, unnecessary, and worst of all, an unattainable dream. But fusion is far from impossible. It’s the same nuclear process that powers our sun, and it has the potential to power everything we do here on Earth. In fact, we're closer than ever to making that a reality.

With the increasing negative effects of fossil fuel reliance, human civilization needs fusion now more than ever. Fortunately, the innovators working to make fusion a reality have never had more momentum.

But nuclear fusion continues to be plagued by misunderstandings about both its benefits and its feasibility. Many misconceptions stem from pop culture and from conflating nuclear fusion with nuclear fission. It’s long past time to set the record straight by correcting the myths about nuclear fusion.

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Fusion Myth No. 5: Nuclear fusion and fission are the same thing

Nuclear fusion and fission are fundamentally different reactions—opposite in mechanics, distinct in fuel, and worlds apart in the waste they leave behind. Understanding that difference starts with what each process actually does to an atom.

In nuclear fission, a neutron strikes the nucleus of a heavy element, uranium or plutonium, splitting it apart and releasing heat—a lot of it. That heat is used to boil water, drive steam turbines, and produce electricity. That’s right—the end result of all that nuclear complexity is basically steam power with extra steps!

Fusion works differently than fission. Instead of splitting nuclei apart, fusion forces hydrogen isotopes together under extreme heat and pressure until they fuse to produce helium—releasing enormous amounts of energy that can be harnessed to produce electricity.  

The sun, for example, is a giant natural fusion reactor that’s constantly shoving hydrogen nuclei together, producing the heat and light that reach us across 93 million miles of space.

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Fusion Myth No. 4: Nuclear fusion is too dangerous

The last half of the twentieth century ingrained the potential dangers of nuclear power in our collective minds. A handful of high-profile accidents—Chernobyl, Three Mile Island, Fukushima—raised fears of meltdown and loss of control. Those fears, amplified by fictional nuclear disaster tropes, left a lasting impression. But the reality today is that safety is the defining priority of everything involving nuclear energy—how reactions are controlled, how facilities are operated, and how materials are handled and stored. Yet the stigma persists.

That stigma has attached itself to both fission and fusion—unfairly in both cases. Nuclear fission is statistically one of the safest forms of energy production, comparable to solar and wind, and far safer than fossil fuels or even hydroelectric power, whose risks are less often scrutinized.

Fusion is even safer than fission, and the reasons come down to how the reaction behaves. Fission relies on a chain reaction. Each split atom releases neutrons that trigger more splits, creating a self-reinforcing cascade. Without precise engineering controls, that cascade can escalate rapidly, releasing dangerous amounts of heat. Fusion doesn’t work that way. It requires extremely precise conditions to sustain the reaction. If those conditions deviate, the reaction simply stops. It can’t escalate.

Accidents and disasters in the past have given us the most powerful tool of all: experience. That experience, built through decades of fission, is what makes fusion the logical next step. Fission developed the materials science, engineering expertise, and regulatory frameworks that fusion now builds directly upon.

But with all that said, nuclear fusion isn’t just a future source of electricity. It has the potential to save lives. At SHINE, we’re developing fusion-based systems to produce medical isotopes critical for diagnosing heart disease and for the detection and treatment of certain cancers. To understand how SHINE's founder thinks about what fusion can do for medicine, read about this SXSW panel discussion here.

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Fusion Myth No. 3: Solar and wind energy are better than nuclear fusion energy

For decades, nuclear energy has been overlooked as a clean energy solution in favor of solar and wind. That dismissal has extended to fusion in particular, where a familiar objection has been, “If we have renewable energy, why do we need fusion?”

The short answer is that a truly green energy infrastructure needs nuclear power—fission today, and ultimately fusion. The reasons why come down to reliability. Renewables, for all their value, are inherently intermittent, and the world requires power that can be counted on around the clock.

Solar and wind energy are useful and important renewable energy sources, but unlike nuclear energy, they are limited by their environment. Solar panels can only generate electricity when sunlight is available, and wind turbines only when there’s sufficient wind. And both must store electricity in batteries to compensate for their inherent downtime. Likewise, hydroelectric energy can only be gathered from sites with significant water flow. Nuclear operates continuously, at a capacity factor of roughly 92% compared to 25-35% for wind and solar. And it can do so just about anywhere you can build a reactor.

On clean energy credentials, fusion compares favorably to renewables, and then some. Nuclear fusion doesn't directly produce greenhouse gases, and unlike fission, it produces no long-lived radioactive waste. Its fuel supply is equally compelling—effectively limitless and extraordinarily energy-dense. Deuterium, the primary fuel, is extracted from ordinary water. One gallon of seawater contains enough to produce as much energy as 300 gallons of gasoline.

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Fusion Myth No. 2: Nuclear fusion will create too much waste

Nuclear energy has a reputation for creating dangerous radioactive waste. True enough, used nuclear fuel from fission does consist of radiotoxic materials that can remain highly radioactive for hundreds of thousands of years. These materials, classified as high-level waste, must be carefully handled and stored.

But the volume of that waste may surprise you. The entire U.S. stockpile—more than 90,000 metric tons accumulated since the 1950s—would fit on a single football field at a depth of less than 10 yards. Compare that to a single 1,000-megawatt coal plant, which produces vastly more waste and pollution—about 500,000 metric tons of ash and more than 6 million metric tons of CO2 every year.  And unlike nuclear waste, that pollution doesn’t decay.

Fusion's waste profile goes even further in defying expectations. Unlike fission, it produces no long-lived high-level waste at all. There is one nuance worth noting: By volume, a fusion power plant would actually produce more waste byproducts than a fission reactor. But that waste is much shorter-lived, less hazardous, and far easier to handle and store.

For fission, though, the bigger challenge isn't volume—it's duration. Fission's high-level waste requires isolation for hundreds of thousands of years, and the U.S. has yet to establish a permanent disposal pathway. But that picture is changing thanks to recycling. Countries like France have been recycling used nuclear fuel for decades, recovering around 96% of reusable material and converting the remaining waste into glass through vitrification. This significantly reduces the volume requiring permanent storage.

Unfortunately, when it comes to recycling used nuclear fuel, the U.S. has lagged behind. But for the first time in decades, federal initiatives, private investment, and bipartisan support are aligning to help bring practical recycling solutions to scale.

And fusion has a role to play in that effort too. SHINE is testing how fusion-generated neutrons can transmute—i.e., transform at the atomic level—long-lasting radioactive isotopes into stable or shorter-lived forms. This pathway could shrink residual high-level waste and significantly shorten its required isolation period from millennia to decades. It could also recover valuable isotopes and metals—including materials used in medicine and advanced manufacturing—from what was once considered waste.

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Fusion Myth No. 1: Fusion energy is 30 years away

That’s a line both fusion's proponents and critics alike have repeated for decades. Fusion reactions were first achieved in the 1930s, soon after the discovery of the neutron by James Chadwick in 1932. Work has been ongoing to produce fusion energy since the end of World War II, when atomic scientists first developed reactor designs such as the tokamak. But for all that effort, fusion energy has seemed to be perpetually just around the corner, making it seem to critics as little more than a pipe dream.

Why that is may have more to do with funding than engineering hurdles. Since the 1950s, funding for fusion research has followed a boom-and-bust model, with bursts of government and private investment spurring progress, then drying up and stalling it.  The unique challenges of replicating the sun's power on Earth have proven difficult to sustain financially over the long haul. However, that’s changing in dramatic ways, driven not just by new investors, but by mounting pressure to decarbonize, secure energy supplies, and meet surging global electricity demand.

The scientific picture has also shifted meaningfully in recent years. In 2022, the National Ignition Facility achieved a landmark milestone, producing more energy from a fusion reaction than was used to trigger it. Since then, the NIF has repeated and surpassed that result, most recently achieving a fusion energy yield more than four times the energy consumed. On the private sector side, Commonwealth Fusion Systems has validated key magnet technology for its SPARC tokamak and is advancing toward a net energy demonstration. In fact, dozens of private companies, backed by nearly $10 billion in cumulative investment, are now pursuing commercial fusion through a range of technical approaches.

These are real and significant developments. But a scientific milestone is not a commercial system. Moving from net energy gain to reliable, grid-scale power requires sustained operation, durable materials, and fully integrated fuel and power systems—an engineering and economic challenge that extends well beyond any single breakthrough.

Nuclear fusion energy holds extraordinary promise—abundant, low-pollution power for a world that urgently needs it. At SHINE, we're not waiting for that future to arrive. We're building toward commercial energy at scale through markets where fusion creates value today, with each application driving down costs along the way.

Watch the SXSW panel discussion on what it actually means to make fusion work.