Fusion versus Fission
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Fusion vs Fission

Is the most climate-friendly nuclear technology the one we already have?
December 24, 2022

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Earlier this month, researchers at Lawrence Livermore National Laboratory used 192 lasers firing for billionths of a second to fuse hydrogen atoms in a tiny gold capsule into helium. For the first time, this experiment released more energy than the laser energy aimed at the capsule (although still just a fraction of the overall energy used). The announcement generated its own self-sustaining reaction of pundits speculating about cheap, limitless, carbon-free power. But moving from one experiment to something that can affordably power a city remains a monumental challenge. Which presents us with a climate dilemma: Should we invest in fulfilling the promise of fusion or improving and scaling nuclear fission technology that has already avoided emissions and saved lives?

• • •

Fusion’s Payout Is Worth It

1.  Limitless Fuel. The same technologies that enrich uranium to make fuel for today’s nuclear fission reactors can also produce explosive material for nuclear bombs. Fusion reactions, on the other hand, can use hydrogen isotopes found in nature. Seawater alone contains enough fusion fuel to power humanity’s needs for hundreds of thousands of years.

2.  Less of A Toxic Legacy. A fusion power station would generate low-level radioactive waste, more in fact by volume than fission. However, its waste should be less radioactive, and for a shorter time, than the dangerous and long-lived waste from a fission reactor.

3.  The Odds Are Actually Getting Better. There are now many horses in the fusion race. The Lawrence Livermore experiment, and the multi-billion dollar ITER fusion effort in Europe, are governmental affairs. But there are also around 35 private companies globally pursuing fusion power, according to the Financial Times. These have raised nearly $5 billion in total, with over half coming in just the last 18 months. Some are pursuing the same laser fusion technology as Lawrence Livermore, while others are exploring magnetic systems, a combination, or other approaches. We only need one of them to succeed.

private companies investing in fusion energy technology

 • • •

Fission Isn’t Perfect
But It Pairs Well with Renewables

1.  Pricey . . . But Reliable. Although wind and solar farms are much cheaper to build than nuclear reactors, energy grids need the reliable, always-on power that only nuclear – and fossil fuels – can provide. Nuclear power could be key to bridge the last 10 to 20% gap in a zero-emissions world, researchers from the Carnegie Institution for Science found. But fusion power is unlikely to be cheaper than fission anytime this century. Each of Lawrence Livermore’s tiny hydrogen capsules cost hundreds of thousands of dollars to produce, and its lasers are so powerful they damage themselves every time they fire.  And they only fire a few times a year. In a commercial reactor, this would need to happen every few seconds.

2.  Scary . . . But Far Less Deadly Than Coal or Gas. Much is made of fusion’s “clean” reaction, but fission power stations are already much cleaner and safer than fossil fuels. Accounting for deaths from air pollution and accidents, natural gas facilities kill 70 times—and coal 600 times—as many people as nuclear power stations. In 2013, NASA scientists calculated that nuclear power has saved over 2 million lives since its introduction last century, by avoiding air pollution deaths. And despite its massive infrastructure, fission uses about the same resources as renewables.

3.  Slow . . . But Quicker Than Something That Doesn’t Exist. Siting and commissioning a nuclear power station is an expensive, decades-long process. Don’t expect fusion power stations to be any different, or even much more efficient, warns the Bulletin of the Atomic Scientists. But even those calculations are academic. Sandia National Laboratories fusion engineer Michael Cuneo points out that it usually takes around 40 to 50 years to widely adopt a new source of energy. The world needs to wean itself off carbon power sources long before then.

material footprint of different energy sources

Nakagawa, N et al. 2022. Life cycle resource use of nuclear power generation considering total material requirement. Journal of Cleaner Production.

• • •

What To Keep An Eye On

1.  Government Funding. Experts estimate bringing fusion technology to maturity will cost tens of billions of dollars more, at least. And that kind of investment has to involve governments. And given the progress, there is some enthusiasm to dig deep. Last year, the Biden Administration pledged $50 million for a fusion pilot plant by 2032. The US currently funds fusion to the tune of around $500 million annually—half of which goes straight to ITER.

2.  New Fission Technologies. Even as fusion inches forward, fission science isn’t standing still. The Bill Gates’ funded startup TerraPower is hoping to break ground next year in Wyoming on a safer and cleaner fission reactor using molten sodium. This is likely to be delayed, as it will use fuel made in Russia, which is subject to sanctions due to its invasion of Ukraine.

3.  A Global Return to Fission.  Conventional nuclear reactors are enjoying a renaissance, spurred in part by the gas price shocks from the Ukraine war. India wants to commission 20 new plants within a decade, and China already has 20 new power stations under construction. (It is even planning one for a proposed moonbase). 

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