What’s fueling the commercial fusion hype?

Recent White House and Energy Department pronouncements on speeding up the “commercialization” of fusion energy are so over the top as to make you wonder about the scientific competence in the upper reaches of the government.

In April 2022, the White House launched what it called a “bold decadal vision” for a 10-year program to “accelerate the realization of commercial fusion energy.” The “bold” part is the proposal, in questionable analogy with high-speed computing, to do in parallel all the development steps that are typically done sequentially to bring a new technology to the market. According to the White House, this parallel processing would include: technology development, preparing a regulatory system (including rules for fusion reactor exports), securing the supply chain, identifying high-value markets, training a diverse workforce, and gaining public support, all “to support the rapid scale-up of fusion energy facilities.”

The special attraction of fusion is of course that it offers a potential source of abundant carbon-free energy that does not generate radioactive nuclear waste. But just because it would be nice if controlled fusion could work doesn’t mean it’s on the verge of doing so. The hard truth is that scientists and engineers don’t even know yet whether controlled fusion can be achieved to make useful work, at least anywhere outside the sun (and other stars, of course).

A historical perspective is useful to understand where the hype about commercial fusion is coming from.

We have known about fusion powering the sun since Hans Bethe explained it in 1939. This was also almost exactly when Otto Hahn and Fritz Strassmann discovered uranium fission (and Lise Meitner and her nephew Otto Frisch explained it). Then in 1942, Enrico Fermi and a small number of co-workers demonstrated a controlled fission chain reaction in a squash court at the University of Chicago. Fermi spent about $50 million in today’s dollars on building his 20-foot-tall atomic pile.

More than 80 years later, the corresponding control-of-fusion principle has yet to be demonstrated experimentally and the US government already made $35 billion in cumulative fusion expenditure—with probably a comparable investment abroad—without yet knowing what works.

The White House’s approach to attain success appears based on the idea that enthusiasm and coordination of all diverse stakeholders backed up with enough money can solve a so-far-unsolved scientific problem. Administration spokespersons mention projects that were successfully accelerated in this way, like the 1969 trip to the moon. Sure, this was indeed a hugely successful monumental project at the time, but no one involved doubted it was possible to do. All the necessary component technologies, like rockets and communications, were in hand on a smaller scale. In the case of fusion power reactors, no one is yet sure what they would look like, let alone if they will turn out to be possible and practicable.

The main research track today in fusion energy is “magnetic confinement”—configuring magnetic fields to keep in place a plasma of thermonuclear fuel 10 times hotter than the sun’s core within a donut-shaped magnetic “bottle.” Dozens of such machines—known as “tokamaks,” a Russian-language transliteration for toroidal chamber with axial magnetic field—have been built around the world since the 1950s, but none got close to demonstrating a net energy gain. Controlled fusion, it turns out, is an extremely difficult problem. To solve it, fusion experts have concluded the key is to have a large enough facility.

The world’s largest experimental fusion machine—ITER (initially the International Thermonuclear Experimental Reactor, also meaning “the way” in Latin)—is nearing completion in France. It is a highly complex scientific and engineering project. ITER publicity describes the building housing the reactor as “slightly taller than the Arc de Triomphe in Paris,” and that the building foundation will support some 400,000 metric tons—“more than the weight of New York’s Empire State Building.” Started in 2006, ITER is a 35-country megaproject that was supposed to be completed in 2016 at a cost of $6 billion. The reactor is currently projected to start up in 2025, but even that appears to be an optimistic date, as is the total budget estimate of about $22 billion.

The initial design objective is to produce a fusion plasma with thermal power 10 times greater than the injected thermal power. Even if successful, this net power output would not yet be the fusion equivalent of Fermi’s 1942 experimental nuclear pile, which proved the controlled fission concept. Nor would ITER’s more ambitious subsequent goal of maintaining this plasma for eight minutes. To get to proof of principle would likely take another step or an upgrading of ITER.

The Lawrence Livermore National Laboratory’s weapons laboratory pursued another approach of “internal confinement,” to create a fusion reaction at its National Ignition Facility (NIF) and claimed it could have power application. NIF uses light pulses from a concentric battery of powerful lasers to heat a small target containing a tiny bead of frozen thermonuclear fuel. This is, in effect, a miniature (secondary) thermonuclear bomb, with the lasers playing the role of the triggering fission reactions (primary). The light heats the container material sufficiently to ablate and swiftly compress the fuel to the point of detonation, which lasts some billionths of a second. The experiment was directed primarily at developing a useful diagnostic tool for weapons research. In power application, you would have to repeat the explosions at an extraordinarily fast rate, which is a tall order.

Despite its lack of promise for civilian use, the Energy Department and the White House have used the Livermore controlled fusion experiment results to boost the effort to harness fusion power for civilian purposes. In December 2022, Energy Secretary Jennifer Granholm announced with great fanfare that a laser pulse ignited a fusion reaction that produced more energy than was supplied by the light beams: “This milestone moves us one significant step closer to the possibility of zero carbon abundant energy powering our society …  a huge step forward to the president’s goal of achieving commercial fusion within a decade.” (Update: In less than nine years from now.)

In her energy balance, however, the energy secretary forgot to account for the energy it took to create the laser beams. This energy input, when added, drastically reverses her conclusion, with the fusion output then amounting to only about one percent of the input. This is not disqualifying from a scientific point of view, but it obviously is in a power generating application. Still, this hasn’t stopped the Energy Department from including Livermore’s fusion ignition experiment in a promotional video on the “7 moments that changed nuclear energy history.” The clip claims “[t]he Lab was the first to produce more energy from a fusion reaction than was used to start the process,” again forgetting the energy it took to power the lasers.

Most people in the field still pin their hopes on the international ITER project for advancing the possibility of fusion power. One thing we know already is that, if a magnetic confinement fusion power reactor ever works, it will be huge and expensive. This contrasts with current thinking in energy policy that inclines to a more decentralized electrical system powered by more affordable and flexible generators. With fusion power being so difficult to demonstrate—even in principle—it will likely suffer a much longer time between proof of principle, if we ever get there, and significant commercial application. So, forget the Energy Department’s parallel processing path promise.

A recent White House announcement on fusion had a link to an Atlantic Council discussion on fusion. In it, former Energy Secretary Ernie Moniz, a physicist, said he drew confidence about the prospects of fusion power from knowing that $5 billion of private capital has been invested. This showed him that “somebody must think this has got a good chance of working.” At the same time, if true, the funders who committed the $5 billion were surely drawing confidence from the fusion physicists’ enthusiastic claims. This circular reasoning does make one wonder.

It’s not surprising that the fusion research community at the Energy Department is gushing with enthusiasm for commercialization of fusion and the near-term prospect of building pilot plants and revolutionizing electricity generation. But as with any big-bet investment, some perspective about the possibilities and risks involved is in order. Where is the US government agency that will provide such a perspective?