What's the difference between fission and fusion? What are the drawbacks to fission power? Why is fusion power so challenging? Join Jonathan, Joe and Lauren as they explore the ins and outs of fusion power.
Male Speaker 1: Brought to you by Toyota. Let's go places. Welcome to Forward Thinking.
Jonathan: Welcome everyone to Forward Thinking, the audio podcast where we think about the future, talk about what is to come. Today we are going to talk a little bit about fusion and what that is. I am Jonathan Strickland.
Lauren: I'm Lauren Vogelbaum.
Joe: And I'm Joe McCormick.
Jonathan: And so fusion, yeah. We're talking about nuclear reactions, and you guys might be familiar with the fact that the world has lots of nuclear reactors already, so why are we talking about fusion as being in the future? And the reason for that is that the nuclear reactors that are out there, the majority of them, the ones that are actually generating power that we use -
Joe: The majority of them.
Jonathan: Well, because there are experimental ones.
Joe: Okay. All the ones that are hooked up to a grid.
Jonathan: Yeah, are fission based, which is where you are essentially making atoms split apart, and in the case of nuclear fission you're using a type of uranium, and the uranium is going through radioactive decay which gives off a lot of heat.
Joe: And why uranium is because it's heavy, right? It's a huge atom.
Jonathan: Well, it's heavy and it does decay, right? Especially when you're getting it, the specific type of radium used in nuclear reactions is different than if you just found unrefined uranium. This is refined uranium that decays at a predictable rate, and as it decays it spontaneously causes other atoms in the uranium to decay, so it starts, once the reaction starts, it kind of maintains itself for a certain amount of time. And what you're essentially doing is you are submerging these radioactive uranium rods in water, which converts the water into steam that then turns steam turbines. It's not terribly efficient, but it does generate an awful lot of electricity.
Lauren: It's more efficient than, say, a coal generator that is burning coal to heat water into steam to turn turbines.
Jonathan: Right, it's more efficient than coal combustion, and you're generating an entirely different kind of waste. Instead of greenhouse gas emissions, you've got this kind of nuclear material that's radioactive and harmful to humans, and will be radioactive.
Lauren: And most other things.
Jonathan: Yeah. Radioactive for a very long time, as it turns out, but we'll talk in another episode of this show, we'll talk about a way of trying to use that nuclear waste in a smart way.
Joe: Okay, so what happens in these reactions? We say that we're splitting a heavy atom, right? Why does that create so much energy? I bet this has something to do with Einstein, doesn't it?
Jonathan: Yes it does. Well, you know, for one thing, you're talking about mass and mass converting into energy. You've heard of a little equation, E=MC squared?
Joe: Right, and that tells us that matter and energy are in some way equivalent, right? That one can produce another.
Jonathan: Right. If you go back far enough, according to the big bang theory, there was a point where energy and mass were one thing and then they kind of split apart, so they are intrinsically connected to one another. So if you were to convert matter into energy, you would get a lot of it, because you take that mass and you multiply it by C squared. C squared, that's the speed of light squared. So a little bit of mass times the speed of light, which is pretty big, and you square that, then you get the equivalent amount of energy out. That's a lot of energy for just a tiny bit of mass, so even on the atomic level you're talking about lots of energy when you have these reactions. Now that's fission. Fusion is something different. Fusion is what happens in the sun.
Joe: And all other stars.
Lauren: It's when instead of splitting atoms, you are -
Jonathan: Fusing them. Yeah, celestial stars by the way, not celebrities.
Lauren: Movie stars?
Jonathan: Yeah, not movie stars.
Lauren: Bruce Willis can't do this?
Jonathan: And as much as I would go on about how the sun is a mass of incandescent gas -
Lauren: A gigantic nuclear furnace?
Jonathan: Yeah, where hydrogen is built into helium at a temperature of millions of degrees, which is a song that They Might Be Giants made popular. It was actually a song that was on a science album for kids. I have the original track. It's amazing. But They Might Be Giants actually went back and corrected that because of course scientists later found that that's kind of an oversimplification of what the sun is.
Joe: Did you ever hear the Megadeath cover?
Jonathan: Going on, and ignoring Joe, so fusion is when you are fusing two atoms together. Generally speaking you want to start with light atoms and fuse them, and the way you have to do this is, well, there are certain fundamental forces that are in the universe. You've got an electromagnetic force, that's one of them, and then there's the strong nuclear force. Strong nuclear force, that's the force that holds the subatomic particles together, and it's really really strong, but it works on incredibly short distances. So, when it comes into effect, it's incredibly strong.
Joe: Okay, but so, in a fusion reaction, you're taking little hydrogen atoms, the smallest atoms there are, a single proton, and you're fusing them together to create helium atoms, which have two protons, right? If we have, say, a hydrogen balloon, why doesn't this happen inside the balloon? Why don't the hydrogen atoms spontaneously fuse together to create helium atoms?
Jonathan: All right, that distance is a really big problem, because when I'm saying really close distance, I'm talking really really close distance.
Lauren: One trillionth of a millimeter I think is how close things have to be to fuse.
Jonathan: Now, those protons that are in a hydrogen atom, they have a positive charge, right? So positive charges don't like each other. Like charges repel one another.
Lauren: Right, like if you take two positive ends of a magnet and try to smush them together.
Jonathan: Yeah, you're going to feel the push. It'll feel like it's pushing against you. So, what you have to do is you have to actually get those atoms close enough, you have to overcome the electromagnetic force so that the strong nuclear force takes hold, which requires you to put a lot of energy into the system for this to work. Now, with the sun, that energy ends up being gravity and heat. You've got this intense amount of heat in the sun. It's stripping the protons of their electrons. It's becoming a plasma. A plasma is an ionized gas, and it's exactly what it sounds like. You've got ions, these are charged atoms because they have either gained or lost an electron, in this case lost electrons, and those electrons roam freely throughout the plasma. So anyway, you have to create plasma first, so you have to pour energy into it.
Joe: Plasma, it's like fire. It's incredibly hot.
Jonathan: Saying that plasma is like fire is like saying a thimble of water is like an ocean. Yes, but it doesn't get the scale.
Lauren: It's very hot and very pressurized.
Jonathan: Right, so you've got this incredibly hot, these incredibly hot atoms that are getting closer and closer to each other, you're forcing them together, and then if they get close enough that strong nuclear force is going to be strong enough to bind them two together. Now, here's the really interesting thing. The mass of that new nucleus, in the case of hydrogen becoming helium, the mass of that new nucleus is actually less than the product of the two hydrogen nuclei.
Joe: Oh, that makes me wonder if that mass went somewhere.
Jonathan: It did. That mass that is lost when these two nuclei fuse together to make one nucleus is converted into energy, which is energy in the form of heat. So again, if you create a fusion reaction, it creates a lot of heat, which can, depending on how you use it, can actually create more reactions down the line, like in say the sun. So, the challenge here, you've got the E=MC squared again, so you get a lot of energy for this tiny little subatomic particle, this nucleus, that is slightly less mass than the product of the two nuclei that formed it, you get a lot of energy out of that, but you have to pour a lot of energy into the system first to even get to that fusion reaction, and that's the problem that we have right now, is the idea of, how do we do this in such an efficient way that the energy we get out makes sense compared to the energy we pour in.
Lauren: Is greater, or significantly greater, yeah.
Jonathan: Now, if we can do that, if we can figure that out, fusion has some amazing promises.
Joe: You're talking about as an energy source, as a source of great electricity, like fission.
Jonathan: Right, exactly. If we can get to the point where we have solved the problem of getting more energy out of this process than we have to create to put into it, then because we're talking about things like hydrogen, you could end up with an energy surplus pretty quickly.
Joe: Well, don't they say, the amount of energy you get out of a fusion burn is hundreds of millions of times more than the energy you get from an equivalent fossil fuel burn.
Jonathan: Depending on how many reactions you're talking about, I think it's actually four million times, if I think about it, if you're talking about one single reaction, it's like four million times the amount of energy you would get out of burning coal or oil, and that's incredible, right? I mean, that's like these tiny little reactions that do require a lot of energy to start them.
Joe: And no carbon emissions, right?
Joe: And plentiful resources, right? So if you want to make a fusion reactor here on Earth, what do you have to put into it?
Jonathan: Well, first you've got to create a reactor that can withstand a tremendous amount of heat.
Joe: Oh right, we'll get there in a minute, but what is the fuel? It's two isotopes of hydrogen, right? And an isotope means that it's an atom of that element with a different number of neutrons.
Jonathan: Yeah, you have to get that to fuse them together, yes.
Joe: And the two you need are deuterium and tritium, correct?
Lauren: Yeah, those are the ones that are currently being used, yeah.
Joe: Those are not hard to get at all, from what I read. Deuterium is just abundant in the ocean, you scoop up some ocean water in a glass and there's deuterium in it, right?
Jonathan: Yeah, I've often refused to go into the ocean because it was just lousy with deuterium.
Lauren: Just rife with it.
Jonathan: But no, yeah, that's -
Joe: You go to the beach and smell the deuterium in the air.
Lauren: The other, I think, is created from lithium so it's a little bit more expensive to produce. Currently the two different kinds of fusion reactors that they use both use have deuterium and tritium reactions and they're working on some that are deuterium deuterium reactions, which would be a lot easier because since the tritium is made from lithium it's kind of expensive.
Jonathan: Yeah, then you could just use the seawater, essentially.
Joe: In any case, the fuel is totally abundant.
Lauren: Sure, much more so than, for example, uranium.
Joe: Or fossil fuels.
Jonathan: Right, so there you have an energy surplus, which would be an amazing and kind of unimaginable world compared to the one we live in right now.
Lauren: Right. If electricity is free, then we can do as much as we want.
Joe: Well, maybe not free, because there are some challenges, right?
Jonathan: Right, so there's the challenge of building a reactor that's going to withstand the heat.
Joe: Right, if it's this great a deal, why aren't we doing it yet?
Jonathan: That's part of it, is that it's expensive to build a reactor that can withstand the tremendous amount of heat that would be given off, and again, the reaction here, the fusion reaction, that heat that you are generating, you are doing the same thing with that heat that you would do with the fission reactor. You're using it to heat up water to turn steam turbines.
Joe: Right, it's not magic.
Jonathan: Yeah, the fusion doesn't just automatically create electricity and suddenly all the lights go bright in the entire city, it's actually turning steam turbines still.
Lauren: Right, but we are talking about a hundred million kelvin, something along that magnitude, like actually like six times hotter than the sun, I believe.
Joe: Oh, what I read was 20 times.
Lauren: 20 times?
Joe: Than the core of the sun.
Jonathan: Yeah, see, the core of the sun and the surface of the sun are the two different temperature.
Joe: Right, so fusion reactions go on in the core of the sun -
Lauren: But it's got its tremendous gravity to help it out. Here on earth, we don't have that kind of gravity.
Joe: Right. The sun is a pressure cooker, and our reactor would not be a pressure cooker, right? Not in the same way at least. So you've got to find a way to contain this heat, and obviously, if you think about it, if this is something that is causing hydrogen atoms to fuse together, and you put it against any material surface, it's going to melt it. It's going to cause major damage that the reactor won't be able to sustain itself. So what do you do?
Jonathan: You have to contain that plasma in some way.
Joe: In a way that it doesn't have contact with the outer walls of the containment chambers.
Jonathan: Right, and there are two main methods that we've used to try and control plasma. Each way has multiple versions of it, but the two main ways were using lasers, or as I used to say on tech stuff, lasers.
Lauren: That's inertial confinement.
Jonathan: yes, and then there's using magnetism. So you're trying to contain the plasma so that the reactions are happening exactly where you want them to. Heat is not something that radiates out indefinitely, so it dissipates very quickly, actually, so you can have a very intensely hot reaction happening at a very localized point and not melt the surface of the earth. It's not like we suddenly see the fusion reaction go out of control and goodbye Seattle. It's not quite that dramatic.
Lauren: Hopefully not, yeah.
Jonathan: But the magnetism one is the one that I think has received the most attention recently. That's the method that was used at the Joint European Torus, or JET reactor.
Joe: Torus, that's a word, it means donut, basically, right?
Jonathan: Okay. It actually means bear claw.
Joe: It does, right? The torus, it's a shape, it's a three dimensional shape that's sort of like what we would call a donut.
Lauren: Yeah, well it turns out that the easiest way to get plasma to flow, this crazy hydrogen plasma to flow through this magnetic field, is in a donut shape, and we're talking about a donut that's like 100 feet tall, weighs 23,000 tons, and is made of some million parts.
Jonathan: Yeah, it's the Homer Simpson dream donut.
Jonathan: So JET, the Joint European Torus, it used this magnetic confinement method and at its height was able to produce reactions where they would get a little over half the amount of energy they needed to start the reaction. So in other words, their efficiency was somewhere around the mid 60 percentile, so that's not great. Obviously you're losing energy.
Joe: It's very promising, but you can't use that yet.
Jonathan: Yeah, that wouldn't be a power generator, that would be a power sink, because you would always be putting more power into starting the reaction than you were getting out of the reaction, but there are other facilities that are similar to the JET one that are in various stages of construction right now that may give off way more energy than it was required to start, like the International Thermonuclear Experimental Reactor, or ITER, which is in France, but it's supposed to generate ten times more power than it requires to start the fusion process. So, even then, it's just the beginning, right? Ten times what you put into it sounds great, but we only hopefully go up from there.
Joe: Fusion is one of those funny things that for years and years people have been saying it's right around the corner, and we've never gone around that corner yet.
Jonathan: It's always 20 to 50 years away.
Lauren: Like all super fancy technology.
Jonathan: Right, it's one of those things like the singularity, it's always 20 to 50 years away.
Joe: But we have made real progress.
Jonathan: We have.
Joe: We are a lot closer than we used to be.
Jonathan: And we do need to take just a quick moment to talk about cold fusion, which is -
Joe: Well, "cold fusion".
Jonathan: Well, we don't even have to say the quote, it's an accepted term for something that is unproven scientifically.
Lauren: That is imaginary, yeah.
Joe: People who advocate it don't like that term anymore, do they? They try to hide it under different terminology.
Jonathan: Yeah, Ponds and Fleishman, the pair of physicists who became famous for experiments that they thought proved, or at least indicated, that cold fusion is a thing, and by the way cold fusion is this idea that you can create fusion reactions among certain light atomic elements at close to room temperature. So that energy barrier that you need to make the reactions start goes away.
Joe: Well, and, I mean if this were true, it would be a miracle. It would just -
Jonathan: We would have limitless energy right now.
Lauren: It would be Doc Brown's Mr. Fusion right now on the back of the -
Jonathan: Right, everyone could have a fusion reactor at home that would provide more than enough power to run absolutely everything all the time every day, and there would never be, there wouldn't be a need for an electric grid anymore.
Joe: Right, you can see why people would want it, but it's just -
Jonathan: The problem is that the science just doesn't seem to work out. But Ponds and Fleishman did some studies that initially seemed very promising. A few labs even reported that they had replicated the results, but upon further examination, it seemed like all the results were brought into question. There were questions about measurement techniques, about the equipment that was actually being used to take measurements, about the fact that some of the results were falling within the margin of error, which means that you can't really be sure that you're looking at a result. The whole thing that they were saying was that they were getting more energy out of a reaction than they expected. It was beyond what science would tell you would happen based upon what was going on, but it hasn't borne any fruit, despite the fact that both Ponds and Fleishman, for many years, continued to really work in this. They originally called it N-fusion. That's not a joke, that really is true. They called it N-fusion.
Joe: Like tea?
Jonathan: No, the letter N, and then fusion, which is weird because if you know anything about N-rays, N-rays were something that some scientists believed were a thing until they tried to look into it and realized there was nothing there. N-rays were these things that existed until you looked for them and then they didn't, so it seems funny to me that you would call it N-fusion with N-rays being such a big scandal in the scientific community. But anyway, cold fusion, yeah, it just didn't seem to have any merit to it, and there have been a lot of people that have looked into it since then. There are plenty of people out there on the internet who really hope that it turns out that cold fusion really does have something to it, and it may make sense. That would solve everyone's problems.
Lauren: It is a lovely dream.
Jonathan: For energy, yeah. Sadly, from my own personal perspective I think you might as well wish for fairies and clap your hands, based upon the scientific evidence that we have in front of us. Now that's not to say that someone won't find some way of making it work in the future. Maybe they will, but based upon what we know right now, it seems unlikely. Incredibly unlikely.
Joe: Yeah, but this doesn't mean, now here's one of the main reasons I think we needed to bring this up is that people hear about the failures of cold fusion and that makes them think, "Oh, fusion, it's a pipe dream.
Lauren: Fusion is, yeah, sure. All fusion.
Joe: Hot fusion has serious potential.
Jonathan: Yeah, hot fusion is definitely one of those things that could work if we get the system efficient enough, like if ITER, if the International Thermonuclear Experimental Reactor does in fact work out, then that will show that fusion is a viable means of generating energy. We know it's legitimate, the sun is there, but whether or not we can harness it in a way that makes sense is still the question. It does look promising, but even the optimists are still saying it's 30 or 40 years away.
Joe: Well not, what is it here; Lockheed Skunkworks says that they can make fusion work in the next few years.
Jonathan: Well yeah, but then it'll only work in Area 51.
Jonathan: Anyway, it's a really interesting concept. I really hope it does work out. It would be a huge benefit, and the idea of, think about it, if you're using this method to create energy then you suddenly, the whole question about how do we create clean energy is answered and we don't have to, things like wind turbines and solar farms, which are problematic right now -
Lauren: Inefficient, relatively.
Jonathan: They're relatively inefficient, you have to find very specific places to be able to harness that kind of stuff, and there's a question of whether or not the amount we could harvest would meet our demand. This would answer all those questions immediately. We would easily meet our demand for at least the foreseeable future. Never say never. Eventually we could get to a point where even fusion might seem like, "Well, we need the next big thing."
Joe: Well, at that point we'd probably be off planet Earth.
Jonathan: We'd just be harnessing the stars themselves.
Joe: Which we are going to talk about at some point.
Jonathan: Yeah, we will, but not today. Today we're going to wrap this up. So guys, if you have enjoyed this, if you have suggestions for future topics, if you want to chime in on the discussion about fusion and if you want to say that I'm a denier because I don't think cold fusion is going to work, you can let us know. We have our website at fwthinking.com. You can read our blogs, you can watch the videos, you can listen to the podcast, and of course there are the links to all of our presences on various social networks. You can find us on Facebook, Twitter, and Google Plus. We look forward to hearing from you, and we will talk to you again really soon.
Male Speaker 1: For more on this topic and the future of technology, visit fwthinking.com. Brought to you by Toyota. Let's go places.
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Duration: 23 minutes
Topics in this Podcast: nuclear fusion