Has Fusion Really Had Its "Wright Brothers" Moment?

If it had ever left the spotlight, nuclear fusion is certainly now back. There have recently been new books, big announcements from small fusion companies, and the widely-shared news of a new record for energy produced at the National Ignition Facility, at the U.S. Lawrence Livermore National Laboratory in Livermore, Calif. The result, a yield of 1.3 megajoules, has garnered headlines calling it a "breakthrough" and a "milestone" and likening it to a "Wright Brothers" moment. The latest advance, we're told, puts laser-ignited nuclear fusion at a new "threshold." (Remember too, though, NIF researchers had also hit a "turning point" of fusion ignition in 2014-one year after IEEE Spectrum proclaimed NIF the "brightest hope" for the field.)

It can be difficult, in other words, to know what to believe about the latest fusion news. Go back a few years, and there's an eerily similar news cycle, with previous milestones and promises of progress. As the joke goes, fusion is always 40 years away.

With that in mind, we spoke with Charles Seife, a professor of science journalism at NYU and author of the 2008 book Sun in a Bottle: The Strange History of Fusion and the Science of Wishful Thinking.

IEEE Spectrum:
What do we mean by a "milestone" in fusion?

Charles Seife:
A milestone is a significant point along the path towards an end. When people think of fusion, the ultimate end in everyone's mind-or at least in the public's mind-is some sort of reactor, hopefully hooked up to the grid, that will generate power through fusion. What one would hope in fusion energy is some sort of necessary step that marks some sort of threshold in that path towards that goal. And I think one of the key problems with NIF's announcement is, it really isn't a milestone on that path at all. In fact, it's pretty clear that NIF is not an energy project, even though it's been touted as such.

Spectrum:
Right, it was sold as this thing for nuclear weapons testing.

Seife:
That's right. It depends on whom you're selling it to. NIF was sold to the public and sold largely to Congress as a step along the way towards fusion energy. Early on, the rhetoric was about converting this into something that would generate power. When it became obvious NIF wouldn't do it directly, they had all sorts of hybrid models, where NIF was basically used as a neutron source to get power out of bombardment of uranium. So yes, NIF was definitely sold to some people as an energy project. Anything that dealt with the public tended to dwell on energy and not weapons. However, to the more savvy people, it was supposed to be stockpile stewardship. And the problem with that, is that if you look carefully, even that doesn't make sense. What is it really doing toward stockpile stewardship? If you look really carefully-and people will admit this, if you push them hard enough-the point of this was to give some sort of project around which you can have weapons designers still work. You're doing the same calculations and equations, same kind of modeling for work, the same coding. So it's exercising the same muscles as designing weapons. Fundamentally, what NIF really is, is a project to keep that resource alive. One can say that that's a reasonable goal on some level, but you really have to dig to get that out. And that makes of course the question of "Does this ignition milestone matter?" more salient, because the threshold of ignition is not that important when it comes to this weapons design issue. It really is a self-licking ice-cream cone. They're creating a threshold, which looks good, but really doesn't have any purpose other than being able to declare that you've reached ignition, because it doesn't move you any closer towards the goal of energy, doesn't move you any closer towards the goal of better stockpile stewardship, and it doesn't move you any closer the goal of retaining people better. It's just great. It's nice that you did it.

Charles SeifeSigrid Estrada

Spectrum:
Do you think that they're learning anything? It seems like they have been steadily increasing the energy over the years.

Seife:
I think they're learning a few things around the edges, I think, for example-and this is classified, so I don't know the details about it-but there was some sort of mystery about energy balance. There were different-than-expected yields because of some unknown phenomenon, and they apparently figured that one out. Omar Hurricane did comment on that in opaque terms a number of years ago. They're also learning [the] engineering. I understand that they're able to get the fluence of laser light through the optics higher than expected. And one of the major issues [is] that from the very beginning, the skeptics were saying, "Look, you're going to be destroying your optics every shot, and this is very expensive to replace, what are you doing?" And so I gather that they've got some adaptive optics, stuff that is helping keep the lifetime of optics going for a while. But the question is, where can it be useful elsewhere? To be fair, as you know, basic physics research to solve a physics problem off in left field will often have knock-on effects elsewhere. So I don't want to diminish that. But this is not fundamental science as far as I can tell.

"They're creating a threshold, which looks good, but really doesn't have any purpose other than being able to declare that you've reached ignition."
-Charles Seife

Spectrum:
Is there any value to having these kinds of announcements in the press every couple of years? "We've reached a new milestone, we've got more helium being produced." "Now, we've got 70% of the injected energy being emitted." Is there any value in getting in the news for funding future research? Or is it a Boy Who Cried Wolf situation?

Seife:
Yeah, I tend to follow the latter course. And if you think about it, I mean, with NIF in particular, they turned one of the biggest scientific failures-in terms of money, in modern times-into a success. If you remember, a few years ago, they announced a huge breakthrough, when in fact, it was firing at about one percent yield of what you expected in the design. [Acc. to their 2014 Nature letter, 1.9 megajoules total laser energy in, less than 20 kilojoules energy out. -Ed.] I think it's deceptive. I think it's bordering on fraud on the taxpayers. One could argue that NIF helped keep Livermore alive and that unless you keep these results going in the public, that there won't be a justification to keep these labs alive. But I don't buy it. I still think that it's necessary for scientists to be honest about what they're doing. And if society doesn't like what they're doing, it is their job to convince Congress members that the public is wrong, or move on to something else that's not government funded.

Spectrum:
Let me ask you about how this relates to other efforts for fusion. I know that there was a credulous story in the New York Times [...and, to be fair, IEEE Spectrum has given smaller fusion startups some positive press too -Ed.] about some smaller private fusion things that were maybe seeing results. And also, obviously, there's [the International Thermonuclear Experimental Reactor,] ITER, which is always getting pushed back another year.

Seife:
Actually, lately, ITER has been on schedule. For the first time, it is creeping towards completion. But first, I think of all the schemes, NIF is the least likely to lead to energy. Forget about the accounting tricks, which they all do. Even if you have break-even laser-light-to-fusion output, and even if you grant them that they'll be able to collect that energy, you're still losing 85 to 90% of your energy. Then you've got to manufacture your hohlraums, you've got to manufacture your pellets and inject it. And all of that is energetic. Once you account for all of that stuff, it is just not going to happen. It's just impractical.

Spectrum:
I've always been confused at how the scheme actually is going to transfer energy, presumably to water in the way that a fuel rod would.

Seife:
That is something to be worked out later. Again, when you talk about milestones, that's the sprint towards the end of a marathon. I don't think we're even close to that.

Spectrum:
I think a lot of people feel this way: Fusion has nonproliferation potential, it has potential for clean energy, it's the kind of thing that in a vacuum, you would want to see the government investing in at a large scale. But on the other hand, it hasn't worked. It's not going to work in time to be a large source of renewable energy. What are we doing here?

Seife:
It's a question of priorities. Just in terms of national labs, would you prefer to see a NIF or would you prefer to see next-generation CLIC [Compact Linear Collider] or ... something like that, which is of equal complexity and cost? Obviously, it's easier to sell something with weapons. And it's also easier to sell something with energy. I think that's the game that the Livermore people have played for a long time, and they've been playing it very, very well. But I think, sadly, it's close to a zero-sum game. And I think that other fields are suffering.

"When you talk about milestones, that's the sprint towards the end of a marathon. I don't think we're even close to that."
-Charles Seife

Spectrum:
Why do you think it's zero-sum?

Seife:
Historically, a very good example of this is the International Space Station. The International Space Station won its funding by one vote the very same day that the [Superconducting Super Collider] was voted down. And there's a lot of feeling that the backing of one caused the destruction of the other. With national labs, I mean, if you look at Brookhaven versus Jefferson National Lab, it's always been which one is going to get funded? The [U.S.] Office of Science [and Technology Policy] is going to have a set of priorities, and they're not going to be able to fund everything they want. And things get killed. (I should be careful there because NIF is not under the Office of Science, if I recall correctly, or at least most of their funding is not.) And if NIF were removed from the priority list, I would hope that it would go elsewhere. But as you know, it doesn't always work that way.

Spectrum:
Is there anything that you think is important to bring to the public's attention with regard to these new results?

Seife:
Generally speaking, I think what you have to do is keep an eye on what the goal is, short term and long term, and make sure that those goals don't shift. And I think the NIF PR has been very good at shifting the milestones in subtle ways. You can make these energy ratios look very favorable, when in fact they're not. You've got to make sure that the terms aren't changing, that there's always kind of a fixed goal. And you measure your success by the goal that you've set out before you do your experiment. That's good science.