“Can Small Fusion Energy Start-Ups Conquer the Problems That Killed the Giants?”
by W. Wayt Gibbs
Scientific American, November 2016
Proposed article headline: New Roads to Fusion Energy
Cover potential/cover lines: Fusion Energy Gets Hot / potential cover art: illustration of the stellarator or one of the other new experimental reactors now running (see illo on last page); conceptual art based on the Sun; or some amalgam of the two.
Summary: A steady stream of disappointing news from two megaprojects in conventional approaches to fusion—NIF at Livermore, which bombards tiny fuel pellets with huge lasers, and ITER in France, which aims to finally get a near-commercial-scale tokamak going sometime in the next decade—reinforces the old canard that fusion is the energy source of the future…and always will be.
Yet physicists and outside investors are now expressing more genuine excitement about the prospects for fusion energy than they have for perhaps a generation. An impressive stream of encouraging news has been emerging from a handful of startups and national labs, where physicists are making rapid headway on several alternative paths to fusion. This article will survey these new roads to fusion, the likely obstacles that lie on each one, and the chances each has of delivering a source of energy that is practical, clean, affordable, and inexhaustible. The article will mention the latest on NIF and ITER, but only in passing.
News pegs: In mid-December, the first full-scale stellarator went online in Germany. Wendelstein 7-X looks like no fusion reactor before; it is designed to use geometry, rather than complex control systems, to contain a million-degree burning plasma. In 2016, American scientists from the Princeton Plasma Physics Labs, MIT, and their collaborators at the Max Planck Institute will replace the startup helium plasma in this billion-euro machine with hydrogen fuel to get fusion going in earnest.
This year, ARPA-E increased funding for alternative fusion technology research, including experiments at Sandia National Labs on MagLIF fusion, which combines magnetic implosion with laser heating to force frozen deuterium to fuse into helium. I’ve previously covered MagLIF for Nature and Discover, but in a recent follow-up interview with the program’s PI at Sandia, I learned that the team expects in 2016 to hit scientific breakeven—100 kJ yield in a single shot, generating as much energy as is put into the fuel—by ramping the electrical current on their Z machine up from 19 million amps to 25 MA and boosting the laser energy. That milestone would likely be sufficient to win approval to upgrade the machine to the 50–60 MA size needed to achieve true breakeven yields. Design work on the upgrade is already well underway. In December, Sandia announced it has started construction on Thor, a new, more compact version of Z that will accelerate work on MagLIF.
Among the private-sector startups, General Fusion in Vancouver, BC (just two hours from Seattle by car) has raised $100m, including more than $27m in new investment this year and $20m from Jeff Bezos, to build a novel reactor that compresses fuel to the incredibly high density and temperature required by firing lots of synchronized pistons, which create a collapsing spherical shock wave. In December, GF opened up hundreds of gigabytes of data gathered from its plasma experiments to the public and invited computationally skilled fans to find patterns and come up with a predictive model. It’s offering a $20,000 prize for the best submission. A previous crowdsourced design project GF ran generated 60 submissions from 17 countries in just a month.
In my backyard, Helion Energy in Redmond received a $4m grant from ARPA-E this year to continue work on its pulsed plasma system, which is similar in some ways to the Sandia MagLIF approach but doesn’t use lasers and is far more compact and thus cheaper to build. Helion’s approach is unusual in using helium instead of tritium in the fuel mix. This gets around the issue of tritium radioactivity and supply. (The helium is a product of the fusion, so is recycled within the reactor itself.)
Tri Alpha Energy, in Los Angeles, has been very quiet until recently but has started talking to selected reporters—Miles O’Brien just filmed an interview there for an upcoming NOVA episode on nuclear fission energy—and is reporting surprising progress. Its system uses a pair of opposing, 10-meter-long “plasma cannons” that fire smoke-ring-like bursts of plasma at one another at upwards of 1 million kph. When they collide, they merge into a fast-spinning vortex, which is stabilized in the center by crossed neutral particle beams. In August, the company announced that the reactor was containing the plasma for as long as its power supply held out—a very impressive achievement in fusion research. In 2016, Tri Alpha plans to build a bigger test reactor that can hold the plasma in place longer and allow it to reach higher temperatures. The company aims to achieve temps of 3 billion (!) Kelvins, high enough to fuse hydrogen and boron, an unusual reaction that offers advantages over D-T fusion—most notably it doesn’t spew out high-energy neutrons that irradiate anything nearby and erode metal components.
And there are other, smaller startups out there as well, such as a much-hyped but secretive supercompact design under development at Lockheed Skunkworks, plus promising academic projects, such as the ARC reactor design at MIT, which would use new ultraefficient superconductors to shrink a tokamak in size (and cost and construction time) by a factor of 10.
In December, Bill Gates and other billionaire philanthropists announced the Breakthrough Energy Coalition, which is expected to provide funding to one or more fusion energy projects. I will interview Gates or other members of the coalition to find out whether they view fusion as one worthy investment for their multibillion-dollar fund.
This could be an amazingly illustrated, timely, comprehensive physics/energy tech article that does a better job than previous popular media have done in actually explaining the physics behind these schemes and assessing their problems and long-term commercial feasibility. I propose allocating 10 pages for the piece so that we can have several good-looking photos and explanatory diagrams, along with a total of about 4,000 words, including sidebars and pull-quotes.
Consumer benefit re policy, legal, personal implications: Fusion could be the ultimate energy source: a form of nuclear energy that is carbon-free, produces very little pollution (mainly during construction and decommissioning), inherently safe (zero meltdown risk; even explosions would be largely benign) and able to supply 24/7/365 power to the grid in any nation without raising proliferation worries. In principle, its fuel is essentially inexhaustible, but in practice, tritium production would have to ramp up to support a fusion fleet, and because tritium is mildly radioactive this raises some policy issues, which I could mention briefly. The most pressing policy question for fusion energy is whether there is any realistic hope of coming online fast enough and at a large enough scale to help the world curtail CO2 emissions before midcentury. The smart money says probably not, but maybe. Financial support for fusion research would have to ramp up dramatically to have a real hope of meeting that goal.
Possible art: [See example photos and illos on pages that follow of the W7-X stellarator; the Z-300 upgrade design for the Z machine at Sandia; a diagram of how MagLIF works; General Fusion’s piston-driven implosion reactor (nice little video here); Tri Alpha’s plasma cannon reactor; Helion Energy’s helium-recycling reactor; MIT’s small ARC design vs. the ginormous ITER reactor.
Proposed author: I would like to write this. I’ve followed fusion research since studying the physics of fusion energy at Cornell in the early 1990s, and I’ve toured the D-IIID tokamak at General Atomics, the NIF at Livermore, and (in October) the Alcator C-Mod tokamak at MIT. I’ve covered fusion for SA, Nature, and Discover, and I’m thoroughly up to speed on the complex physics of the MagLIF, MCF, and ICF approaches to fusion. I have cultivated high-level sources at Sandia. I’m well positioned in Seattle to visit General Fusion in Vancouver, Helion Energy in Redmond, and Tri Alpha Energy in L.A. to get exclusive inside details on their progress and business situations. And I’m a constitutionally skeptical reporter, which is an asset when covering a topic like this that tends to get kid-glove treatment by the media. My stance will be one of hope for fusion’s success but realism about the tough road it must travel en route to commercialization.
Date: 29 December 2015
[photos and illustrations appended to pitch email]