JUDY WOODRUFF: But first: the hunt to create fusion energy. While many people remain worried about pursuing further development of nuclear power, some researchers believe nuclear fusion could hold the key to clean and plentiful energy.
There have been many false starts before, but some scientists see real reason for hope that this path will eventually pay off.
Miles O’Brien has a report for our weekly segment The Leading Edge, a co-production in this case with NOVA and his special, “The Nuclear Option.”
MILES O’BRIEN: In Southern California, this complex, power-hungry machine is hard at work on a seemingly quixotic mission, akin to catching lightning in a bottle. It is a plasma generator. Its builders hope it’s a key step in the long journey to the Holy Grail of energy production: fusion.
MICHL BINDERBAUER, Tri Alpha Energy: Fusion is nature’s preferred way of making power.
MILES O’BRIEN: Michl Binderbauer is chief technology officer for a startup called Tri Alpha Energy that is making a $500 million bet on fusion.
MICHL BINDERBAUER: Think of this like a mini-sun, a very hot mini-sun, and it radiates. And it’s that radiation that is intercepted on the surface of the machine, and then it becomes heat, and then you can process that into electricity.
MILES O’BRIEN: The promise, no less than limitless power, with virtually no greenhouse gases or radioactive waste. If that sounds too good to be true, it is. No one knows that better than nuclear engineer Steve Dean.
STEVE DEAN, Fusion Power Associates: Fusion is not low-tech. It’s not going to be easy to prove that it’s reliable, maintainable, cost-effective, because it is complicated.
MILES O’BRIEN: Dean is president of Fusion Power Associates, a foundation focused on research and education. He joined the fusion industry in 1962, working for the U.S. Atomic Energy Commission, which coordinated and funded the U.S. fusion effort.
STEVE DEAN: To me, it seemed like it was something I could spend my career on, and we would have electricity on the grid by the time I retired.
STEVE DEAN: That’s what I thought. So, it didn’t happen that way.
MILES O’BRIEN: Fusion is as old as the cosmos. It is the nuclear reaction that takes place in our sun and all the other stars in the universe. In a fusion reaction, hydrogen atoms collide at high speed, fusing together, forming a helium atom, releasing one neutron.
Since the mass of the helium atom is less than the combined mass of the two atoms that collided in the first place, energy is released.
The dawn of man-made fusion broke over the Pacific in 1952, with the first explosion of a hydrogen bomb.
MICHL BINDERBAUER: The hydrogen bomb was a quick success. And so a derivative of that was euphoria. In a few more years, we could do civilian energy production out of fusion. And while there were glimmers of hope along the way, we all now know, painfully, that hasn’t happened.
MILES O’BRIEN: In the 1950s and ’60s, researchers looked for ways to control, confine and sustain fusion so that it could be used as an energy source. They tried newly invented lasers, a U.S. design called stellarator, and then a Russian design called tokamak, a big circular racetrack that uses powerful electromagnets to suspend and accelerate particles, prompting fusion-generating collisions.
Over the years, they have gradually answered many of the questions.
STEVE DEAN: Right now, there are still physics issues that have to be proven, but the physics is very well-known. The only thing that isn’t known is, when you do something that’s a little bit more closer to a power plant, whether something new will show up in the physics. You can’t really predict that.
MILES O’BRIEN: That’s what this huge project is all about. It is the biggest tokamak ever designed, under construction in France, the International Thermonuclear Experimental Reactor, or ITER, a joint project of 35 nations, including the U.S.,
It is the first engineering test of a fusion power plant. ITER is a $14 billion endeavor that is six years late and $10 billion over budget. It is designed to one day use 50 megawatts of electricity to generate 500 megawatts for 15 minutes.
STEVE DEAN: At some point, in order to get to a power plant, you have to build what we call an engineering test reactor, or something that really works, that’s putting out lots of fusion energy and has a lot of the engineering that’s needed for a power plant. And ITER and the tokamak are the — is the only track that’s at that stage.
MAN: Three, two, one, zero.
MILES O’BRIEN: But there is a lot of fusion progress on a smaller scale. Teams in Germany, China and South Korea have recently reported longer, sustained fusion reactions than ever before.
Tri Alpha is the largest of about a dozen startups trying to make it work.
MICHL BINDERBAUER: We partner up with some of the best and brightest in the field.
MILES O’BRIEN: Michl Binderbauer began his work in academia, but believes the private sector might have a better chance of success.
MICHL BINDERBAUER: It made us lean. It made us focused. It made us an organization that was nimble to react to small changes quickly and think on our feet very quickly. And I would attribute part of our success to exactly that.
STEVE DEAN: And they’re also building on many more years of physics understanding and progress. And so they can be smarter now, whereas, in the past, a lot of times, their ideas were interesting, but there wasn’t any physics basis for having confidence.
MILES O’BRIEN: The fundamental fusion problem is, it is not easy to get nuclei to collide and fuse. They are all positively charged, so they naturally repel each other, like two magnets.
MICHL BINDERBAUER: So, we use magnetic fields to provide that magnetic bottle, if you will, into which you put the charged clouds of particles.
The gas wants to escape and distribute out, and we’re holding that in with magnetic force. This is not like how it’s done in the sun, where you have massive gravity, it does the same job. So, here, it’s all electromagnetic fields.
MILES O’BRIEN: It takes a lot of energy to create those magnetic fields. In fact, the real challenge in fusion is creating plasma that generates more energy than it takes to make it in the first place. Historically, scientists have opted to go big, like ITER.
STEVE DEAN: One event makes a very small amount of practical energy. You have to have billions of these events. That means you have lots of things — these things happening in a large volume.
MILES O’BRIEN: Tri Alpha is taking a different approach that wouldn’t require such a huge structure. The idea is to fire two football-shaped plasma clouds at each other at supersonic speeds.
At the center of the chamber, they collide violently, fusing into a larger football. Additional particles are fired at right angles, making the plasma ball spin like a well-thrown pass.
MICHL BINDERBAUER: The particles always come in like this, and they go into the rotation of the main object. So, it feeds in like this to maintain that rotation rate.
MILES O’BRIEN: The rotation suspends the plasma in place. They are testing constantly, sometimes 50 times a day. Each shot requires about 20 megawatts of electricity, enough to power all the lights and appliances in 5,000 homes, but for only a few-thousandths-of-a-second.
Gleaning data from a hot ball of nothing that lasts for much, much less than the blink of an eye requires a lot of clever testing tools.
MICHL BINDERBAUER: Ultimately, physics is an experimental science, right? And, as such, it relies on hard-core evidence coming out of an experiment. At the stage where we are at, we are dabbling a fine line between learning what works and tweaking that and advancing it another step.
MILES O’BRIEN: Binderbauer believes a commercial fusion system will be available in a decade.
MICHL BINDERBAUER: Our great-great-great-grandkids are going to live in a world powered by fusion almost exclusively.
MILES O’BRIEN: But industry graybeards like Steve Dean are less willing to make such predictions. After all, fusion energy has remained decades away for many decades.
Is it inevitable, in your view?
STEVE DEAN: Yes.
MILES O’BRIEN: Just a matter of time?
STEVE DEAN: I think it’s just a matter of time. I used to say, in my lifetime. Then I started saying in my children. And now I think, before it’s of wide-scale use, it being at least my grandchildren.
STEVE DEAN: I can’t predict.
MILES O’BRIEN: Right now, we do not have an energy crisis to spur the effort, but we do have a climate crisis. Fusion remains an alluring, yet still elusive way to power the planet the same way nature does.
Miles O’Brien, the PBS NewsHour, Foothill Ranch, California.
Fusion animation by Jorge Cham/ Princeton Plasma Physics Laboratory. Additional video provided by Max Planck/Institute for Plasma Physics and ITER.