The Decibel - Everything you need to know about fusion energy

Episode Date: February 13, 2023

Fusion – the act of deriving energy by smashing atoms together – has long been the stuff of science fiction. But thanks to a recent scientific breakthrough, there has been an increase in public excitement that one day, we might be able to use this as a continuous, clean source of energy.The catch? We might not get the technology before our 2050 net-zero climate goals arrive.Science Reporter Ivan Semeniuk explains exactly how fusion works and the Canadian efforts that are working to take this theory and turn it into a viable and widespread energy source.Questions? Comments? Ideas? Email us at [e-mail]

Okay, so stars run on fusion energy, don't they? That's right. So does that mean that fusion scientists are trying to, I guess, like build a star on Earth? Yeah, that's an accurate description in many ways. And that's why it's so hard. Today, science reporter Ivan Semenik and I are going to talk about fusion. The promise of it is massive. Continuous, clean energy.

Only one problem. The technology's not quite there yet. But we're getting closer. Late last year, the U.S. Secretary of Energy announced a big breakthrough. Last week at the Lawrence Livermore National Laboratory in California, scientists at the National Ignition Facility achieved fusion ignition. It's the first time it has ever been done in a laboratory anywhere in the world. Today, Ivan is back on the show to break down the science and give us a reality check on the future of fusion.

I'm Maina Karaman-Wellms, and this is The Decibel from The Globe and Mail. Ivan, it's great to have you here again. Thank you so much for joining me. Thank you. So in the very simplest terms possible, what is nuclear fusion? Good question. Nuclear fusion is a reaction that essentially involves building larger or heavier elements out of smaller ones. And when that happens, the process actually liberates energy.

The most achievable form of fusion, the kind of fusion that's happening in stars, most stars, is when hydrogen is turned into helium. So the lightest element in the universe is turned into the second lightest element in the universe. And there are some versions of that that are achievable on Earth, including two forms of hydrogen, or two isotopes, we call them, deuterium and tritium. That's about the easiest kind of fusion to do. You put them together with enough force and in the process liberate a huge amount of energy, which is the basis of a fusion reactor.

Okay. So why do we want to do this in terms of like there's a lot of different ways to get energy? Like why are we putting our time and attention into this? There are lots of ways to get energy, but fusion is a kind of holy grail that is hard to resist. It would be a kind of power that doesn't emit carbon, that would be, you know, offering you a continuous load, you know, kind of uninterrupted power. It doesn't require, for the most part, any special substance that only a few countries control, you know, like oil or uranium, that sort of thing. Terium especially is very accessible because it's found in nature.

You can distill it out of water. Tritium is a little bit harder to get, but it can be done. Canada has one of the largest non-military supplies of tritium on the planet, just by chance, because the CANDU reactors, which we have in Ontario, and there's one in New Brunswick that provide regular power, they produce tritium as a byproduct. And, you know, the idea is you would have the energy without the cost of climate change. Another advantage of fusion, and this is what sets it apart from renewables, for example, like solar and wind and so on, there's a limit to how much solar energy you can gather just because of how much space you need to spread out those solar panels or how many wind turbines you can set up. Fusion is in a neat little box, so its footprint

is very tiny, and that's another attractive aspect of that form of energy. So for people who take the long view, you know, how is civilization going to be powered for hundreds of years from now, often fusion is seen as the ultimate solution. Okay, so that kind of takes care of the clean part. The other thing that people say is it's a continuous supply of energy. How is it continuous? Well, in the sense that you're not waiting for the sun to shine or for the wind to blow. It's uninterrupted as long as you maintain that reaction however you're going to maintain the reaction. Okay. And when we talk about nuclear power plants, there's always the risk of a meltdown.

Is that a risk with fusion? In this case, no. So one of the other advantages of fusion is it's so difficult to make it work that the minute conditions aren't quite right, it'll shut itself off. So you don't have a situation where a reaction could go out of control and have sort of that classic meltdown situation the way we saw with Chernobyl or other kinds of disasters, Fukushima and so on. So that sort of situation is not an issue with fusion because it just stops. Okay. So we already do have nuclear power plants, as we said. How is fusion different from the power then that we currently generate in those plants? Conventional nuclear plants rely on fission. That means they take a

larger atom. In fact, usually uranium, which is the largest, heaviest naturally occurring element, uranium kind of wants to break itself down. It's radioactive. And in the process, that releases some energy. And that energy is then turned into heat, which then runs a generator. So that's the basic principle of a fission-powered nuclear reactor. So fusion is different in the sense that it's the opposite process, and the byproduct is helium, which is easy to deal with, unlike the byproducts of nuclear fission, which would be more radioactive waste, which you have to deal with. I would say, though, it would be a mistake to come away thinking that fusion does not involve any radioactive waste, which you have to deal with. I would say, though, it would be a mistake to come away thinking that fusion does not involve any radioactive materials, because tritium,

one of the fuels that you need to start it, is radioactive. And over time, if you're running a fusion reactor, the parts of the reactor, the walls, the pieces, and so on, whatever is near where the energy is being released, would start to become irradiated. And over time, you would have to find ways to manage and dispose of those parts. So there still is some nuclear waste there to deal with, although not to the same degree that you might have with fission. Okay. Basically, when we're talking about these two different things, so fission, which is what our nuclear power plants currently use, is about big radioactive atoms breaking down. Fusion is the opposite because this is about smashing atoms together to make a bigger one, which then gives us

energy. So let's get into that process, Ivan, which I imagine is complicated, but hopefully we can do this on a high level. How does fusion work? There are different approaches to fusion, but the bottom line is you need to have that fuel, usually the deuterium and the tritium, and get it to the right conditions. And by right conditions, I mean millions of degrees, millions of degrees, actually hotter than the sun because you have less pressure to work with,

so you have to make up for it with more temperature. Millions of degrees. This is hard to comprehend. Yeah, actually over 100 million degrees for the kinds of reactors that we're talking about today. So, you know, there's no container for something that hot. However, one approach is something called a tokamak, which is like, imagine a donut,

a metal donut encased in magnets. And the magnetic field can keep a loop of this high temperature plasma rolling around inside the donut in a way that it doesn't touch the sides. And if you get it to the right temperature and you energize it enough, this electrified plasma will start to undergo fusion reactions. And then you have the energy coming out of it. That's one way of doing it. Another way, and this got a lot of attention in December, is you take a little fuel pellet, frozen deuterium and tritium, and you implode it with a remarkable amount of energy. So in this case, you take a laser beam and blast the target with so much energy that the target implodes, and momentarily you have the conditions required

for fusion. That's what was done at the National Ignition Facility, and they claimed and have shown that they were the first to cross what's called the net energy threshold. In other words, the energy produced in the fusion reaction when they imploded their little pellet, kapow, the energy that came out was greater than the energy that went in. This was a breakthrough in December. So we've never done this before then. It was. That has never happened before. So that is remarkable. But what, of course, is maybe not as widely known is that even though it produced more energy than it absorbed from the laser, it still took quite a bit more energy than it absorbed from the laser, it still took quite a bit more energy than that to run the laser. So it's still not at the point where, you know,

that facility couldn't run itself. It's still drawing lots and lots of power from the grid to do these experiments. So basically, so this breakthrough that we saw in December, the kind of end result energy that went in was less than the energy that was expelled. But really to create that initial energy that went in, you needed a lot more energy to do that then. Absolutely. So it demonstrates, you know, this threshold for fusion, but it doesn't bring you to a working power plant yet. We'll be back in a moment. Okay, so once we've got the energy that has been created,

so these atoms have collided, they've created a bigger atom, there's energy expelled there. How do you actually capture that energy that's released? So what happens is most of the energy is streaming out in the form of neutrons. So these are, you know, you've got the helium as a byproduct, but also the neutrons. The neutrons are moving very fast. They're carrying away most of the energy just in the form of their movement. Imagine there's a collision of a bunch of things, and you just see a small little piece of shrapnel flying off at high speed.

That's the neutron. That neutron then collides with something else. It imparts its energy by transferring it in a collision with something else that creates heat. And, you know, as the heat spreads out, you can harness that heat. A lot of fusion reactors also, the plan is to have another built-in step where those neutrons, as they're streaming out, collide with lithium, another element. And it turns out when you irradiate lithium with high-speed neutrons, as they're streaming out, collide with lithium, another element.

And it turns out when you irradiate lithium with high-speed neutrons, you can produce more tritium. So the idea is you also need to have your reactor breeding its own tritium supply so that you don't run out and you can continue the reaction. So there's a lot to accomplish there. Yeah, there's a lot going on. And then at the end of all of that, you still have to harness the heat and then, you know, put it to a conventional generator and make electricity. Wow. Okay. You mentioned these tokamak reactors before. So when we were talking about these reactors, just how big are these

things? They can be different sizes. But, you know, if you go back a few decades, when people were wondering how big would one have to be to get to net energy, that's where things got a little bit complicated. You know, there are tokamaks around the world right now. Even Canada used to have one. It's since been discontinued. That was run by Hydro-Quebec when Canada was doing fusion experiments. Just outside of Montreal? Just outside of Montreal and Varennes. There are others around the world. These are places where fusion has been achieved, but not at the net energy level, not where you get more energy coming out. So the calculations would show that if you have a bigger magnet operating in a larger size reactor, you can get to net energy. That's the principle behind

ITER, which is this giant tokamak international project being constructed in France. And it's designed to be the first tokamak to get to net energy. I think the thing that really impresses you is the size of it. You know, this is the kind of thing that almost looks like the size of an airport terminal. It won't be until later this decade that there's plasma running through the machine, and not until the 2030s, where they're really trying to get to get to net energy, where they're doing fusion with tritium. So that's exactly what has motivated private companies to look for alternate solutions. And so are we seeing those private companies popping up now? We are. And, you know, of course, the motivation has always been there,

especially as ETER started to slow down or as more things got complicated and kind of pushed the timelines further and pushed the cost up. Increasingly, people who are looking for fusion as a real energy solution would be thinking, there's got to be a better way. There's got to be another way. And one of the most promising of all, I would say, is something that's just emerged kind of in the last five years or so with this company, Commonwealth Fusion Systems, which is actually a spinoff from a class, like a graduate class

at MIT, where the professor, Dennis White, who's a transplanted Canadian, he realized that a new kind of material for making magnets was likely to become easier to get a hold of. So that led to some very interesting designs. And sure enough, by the time they were ready to start testing those designs, high temperature superconducting materials were becoming very available in a very handy way. So what they did was around 2021, they debuted their first magnet and showed that they could produce a higher magnetic field than it had ever been done anywhere on earth. That's fascinating. So he's actually kind of, they ended up kind of working into the future with stuff they didn't actually have available yet, but down the road,

they did. Down the road, they did. So the material appeared, the magnet was made, and now they could say, okay, so this is a magnet at the strength you would need at ITER, but it's much smaller. So now you could scale down the entire plan. Instead of having a building the size of an airport terminal, we need something that's like a high school gym. That's a big difference. And now it starts to seem like maybe that's economically practical. This is really interesting. So there's stuff currently happening right now

to try to move this sector forward. I wonder, is Canada active in this sector at all, Ivan? I know you mentioned that the fusion program in Canada was discontinued in the 90s, but is there anything that's, I guess, picked up since then? There's lots happening in Canada. Of course, it's amazing how many, if you look around in the fusion community,

it's amazing how many Canadians you find wherever they are in the world. You know, one Canadian who's passed away now, Norm Rostoker, was based in California, had a different idea for how you could kind of create a plasma that generated its own magnetic field in a self-contained way, almost like blowing a smoke ring inside this chamber. This sounds like something out of Star Trek. Oh, yeah. All these ideas. In Canada, there's a company that has also been working on this for quite a while, actually 20 years now. General Fusion is a company based in Vancouver.

The reactor they envision would have this kind of spinning vortex of liquid metal. So imagine hot liquid metal spinning around almost like in a can. And inside that, you can inject some plasma, which is already very hot, very energized. Then around the can, you've got these pistons, literally like a piston in a car engine that suddenly compress. They squeeze the metal, the metal squeezes the plasma, and for an instant, you can have fusion. And then the whole cycle repeats. You can imagine this chucking along, these pistons going, going, going, and you might have this almost like a car engine version of fusion. So lots of players are jumping in with their own ideas, and it's not quite clear yet who will really get there first,

and if someone can get to a place where it looks like practical energy. So we know that fusion is possible. We're still working on scaling it up so that it can be a viable source of energy for our electrical needs. But Ivan, I want to ask you about the timeline here. Because when we talk about actually moving over from non-renewable energy sources, right, Canada has some pretty ambitious goals when it comes to reducing our fossil fuels, lowering our carbon emissions. We want to get to net zero by 2050. Could fusion help us reach our climate goals? Could fusion do the trick? I'm really glad you asked this because certainly

the way, because there's been so much excitement lately, it's often presented in light of, you know, here's a world challenged to get off carbon. Here seems to be a ready-made solution. Is this going to just solve our problems? Will fusion be our escape hatch out of climate change? And then we just don't have to worry. We'll still have unlimited energy. It's unlikely that that's the way it's going to work. Maybe these first demonstration machines will start popping up as early as 2025 or a little bit later in this decade. Maybe there will even be working reactors in the 2030s.

Maybe there will be working power plants in the 2040s. That would be incredibly exciting, optimistic, incredibly exciting. But even then, if you start and think, okay, how many of those power plants would you need to really make a dent in the energy demands that the world will have by the 2040s, as we approach 2050, it would take hundreds and hundreds of such power plants. By 2050, it won't yet be at a level that's really making a significant difference to our energy generation. What may be the best way to think about fusion is that it could be the long-term solution that we really need to run civilization for centuries.

Ivan, this was fascinating and complex, but also very, very cool. Thank you so much for taking the time to talk to me today. Thank you. More power to fusion. That's it for today. I'm Mainika Raman-Wilms. Our producers are Madeline White, Cheryl Sutherland, and Rachel Levy-McLaughlin. David Crosby edits the show. Kasia Mihailovic is our senior producer,

and Angela Pichenza is our executive editor. Thanks so much for listening, and I'll talk to you tomorrow.