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Going Nuclear

Apr 10, 201323 min
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Episode description

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.

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Transcript

Speaker 1

Brought to you by Toyota. Let's go places. Welcome to Forward Thinking. Welcome everyone to Forward Thinking, the audio podcast where we think about the future talk about what is to come. Today, we're going to talk a little bit about fusion and what that is. I am Jonathan Strickland, I'm Lauren Vocaldon, and I'm Joe McCormick. And so fusion. Yeah,

we're talking about nuclear reactions. And uh, you guys might be familiar with the fact that the world has lots of nuclear reactors already, So why aren't we talking about fusion as being in the future. Uh, And the reason for that is the nuclear reactors that are out there, I mean the majority of the ones that are actually generating power than well, because there are experimental all the

ones that are hooked up to a grid. Yeah, are fission based, which is where you are essentially, you're you're making Adam split apart. In the case of nuclear fission, you're using a a type of uranium, and the uranium is is going through radioactive decay, which gives off a lot of heat. Uranium it's it's because it's heavy, right, it's a huge atom. Well, it's it's heavy it's heavy and and it does decay right like, especially when you're

getting it. The specific type of uranium used in nuclear reactions is different than just like if you found unrefined uranium. It's this is refined uranium that that decays at a predictable rate and as it 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 you're you're submerging these 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. It's more efficient than say a coal generator that is burning coal to heat water into steam to turn Yeah, it's it's more

more efficient than coal combustion. And uh, you know, you're generating an entirely different kind of waste instead of instead of greenhouse gas emissions, you're you've got this kind of nuclear material that's radioactive and harmful to humans, and we'll be radio radioactive for a very long time, as it turns out. But well, we'll talk about in another episode of this of this show, we'll talk about kind of a way of trying to use that nuclear to waste in a a in a smart way. Okay, So what

happens in these reactions? We we say that we're splitting a heavy atom? Right, Yeah? Why does that create so much energy? I bet this has something to do with Einstein, doesn't? Yes? It does. Well, you know, for for one thing, you're talking about mass and mass converting into energy. You've heard of a little equation equals mc squared, right, and that that tells us that matter and energies are in some way equivalent. Right, Yes, one can produce another, right if

you 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. And so if you were to convert matter into energy, you 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 these reactions. Now that's fission. Uh. Fusion is something different. Fusion is what happens in the sun. So you know, right, yes, yes, Uh,

it's when instead of splitting atoms, you are fusing them. Yeah. Celestial stars, by the way, not stars. Um first, well, it's do this and and and As much as I would love to go on about how the Sun is a massive incandescent gas, the gigant techniclear fairness, where hydrogen is built into helium and a temperature millions of degrees. Uh. 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 science has later found that that's kind of an oversimplification of what the sun is cover going on and ignoring Joe. Uh. 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. Okay, You've got an electromagnetic force, that's one of them. And then there's the strong nuclear force. Now, strong nuclear force, that's the force that holds these sub atomic particles together. And it's really really strong. But it were works on incredibly short distances. Okay, so when it when it comes into effect,

it's incredibly strong. Okay. But so in a fusion reaction, you're you're taking little hydrogen atoms, the smallest atoms that there are, 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 fused together to create

helium atoms? All? Right? That distance is a really big problem because when I'm saying really close distance, I'm talking really really close to one trillion of a millimeter, I think,

is how close things have to be diffused. 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, right right, Like, So if you take two positive ends of a magnet and try to smooh them together, Yeah, you're gonna feel that push. It'll 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. Uh. 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 um it's and those electrons roam freely throughout the plasma. So anyway you've got you have to create a plasma first, so you have to pour energy into it. Plasma it's like fire. It's incredibly hot. Saying that plasma is like fires like saying a fumble of water is like an ocean, yes, but not but it doesn't get

the scale. Yeah, so very pressurized. Right, So you've got you've got this incredibly hot uh, 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. Uh, 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. So that makes me wonder if that mass went somewhere it did? You've that that mass that is lost when these two atoms, these two nuclei fused 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 you know, depending on how you use it, can actually help create more reactions down the line, like in say the sun. Um. So the challenge here, you've got the the equals mc squared again, so you get a lot of energy for this tiny little sub atomic particle that you know, this nucleus that is slightly less mass than

the product of the two nuclear that formed it. You get a lot of energy out of that, but 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 energy we pour in now, or it's significantly greater. Yeah, if we if we can do that, if we can figure that out, fusion has some amazing promises you're talking about as an energy sources, as a source of just great electricity like vission. Right exactly. If if we can get to the point where we have solved the problem of 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. Yeah. Well, don't they say, I mean the amount of energy you get out of a fusion burn is it's hundreds of millions of times more than the energy you get from an equivalent fossil fuel burn. Depending on how many reactions you're talking about. I think it's actually four million times if I think about it, like if you're talking about one single reaction, it's like four million times the amount of energy would

get out of burning coal or oil. And I mean that's incredible, right, And I mean that's like the the you know, these tiny little reactions that do require a lot of energy to start them. No, no carbon emissions, right right, and uh, plentiful resources. Right. So how if you want to make a fusion reactor reactor here on Earth, what do you have to put into it? Well, at first, you've got to create a reactor that can withstand tremendous amount of heat. All right, we'll get there in a minute.

But what is the fuel. It's it's two isotopes of hydrogen, and an isotope means that it's a it's an atom of that element with a different number of neutrons. Yeah. Yeah, you have to get that to fuse them together. Yes, and you and the two you need are deuterium and tritium. Yeah, those are the ones that are currently being used. Yeah. Those are not hard to get at all. From what I read like, deuterium is just abundant in the ocean. You you scoop up some ocean water and a glass

and there's deuterium in it, right, Yeah. I've often refused to go into the ocean because it was just deterium with it. Yeah yeah, but now yeah, that's and smell the deuterium in the air. The other I think is a created from from lithium, I believe, and so it's a little yeah yeah, so it's it's a little bit

more expensive and to produce. Currently, the two different kinds of of fusion reactors that they use both have a deuterium and tritium reactions, and they're working on some that are a duty arium deuterium reactions, which would be a lot easier because since the tritium is made from lithium, it's kind of expensive, and then you could just use

the seawater essentially. In any case, the fuel is totally abundant, right, much more so than for example, uranium, right fuels exactly, So then that there you have an energy surplus, which would be an amazing and kind of like unimaginable world compared to the one we live in right now. So I etricity is free, then we can do as much as we want, Well, maybe not free, because there are some challenges, right, right, right, So there's the challenge of

building a reactor that's going to withstand the heat. If it's this, if it's this greater deal, why aren't we doing it yet? 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're generating, you're doing it. You're 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. It's not magic, yeah, yeah, the fusan the fusion doesn't just automatic create electricity and suddenly all the lights go bright in the entire city. It's actually turning steam turbine. But we are talking about like a hundred million kelvin something on that magnitude like actually like six times hotter

than the Sun, I believe times. Then the core of the Sun, well, see the core of the Sun, and so the fusion reactions go on in the core of the Sun. And so but it's got its tremendous gravity to help it. Out here on Earth, we don't have that kind of gravity. So, right, the Sun's a pressure cooker, and our reactor would not be a pressure cook 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 like um, if this is something that's causing hydrogen atoms to fuse together and you put it against any material surface, it's going to melt it. You know, it's it's going to cause major damage that the reactor won't be able to sustain itself. So what do you do. You have to contain that plasma in some way, in a way that it doesn't have contact

with the outer walls of the containment chamber. 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 we're using lasers or as I used to say on textuff lasers, that's that's inertial confinement, yes uh. And then there's h using magnetism. So you're trying to contain the plasma so that it's the reactions are happening exactly where you want them to. It's not going to. I mean, heat is not something that radiates

out indefinitely, so it dissipates very quickly. Actually, so you can have a very intensely hot reaction happening and a very localized point and not melt the surface of the earth. You know. It's not not like we suddenly see the fusion reaction go out of control and goodbye, you know, Seattle. It's not not quite that that dramatic. But but but the magnetism was the one that I think has received the most attention recently. That's the method that was used

at the joint European Taurus or Jet reactor. And then for us, that's the word. It means doughnut basically, right, Okay, it does, Actually it means bear claw. Now, Taurus is a it's a shape. It's a three dimensional shapes like what we would call it donut. Yeah. Yeah, Well, it turns out that the easiest way to get plasma to flow this this crazy hydrogen plasma to flow through this

magnetic field is in a donut shape. And we're talking about a doughnut that's like a hundred feet tall, ways twenty three thousand tons um and is made of some million parts. So yeah, it's the Homer Simpson dream donut. Yes, yes so. Uh so JET the Joint European Taurus UH used this magnetic confinement method and UH and at its at its height, was able to produce reactions where they would get a little over half the amount of energy

they needed to to start the reaction. So, in other words, their efficiency was somewhere around in the mid sixty percentile. So that's not great. I mean, obviously you're you're losing energy. It's very promising, it's pretty cool, but yeah, yeah, you couldn't. 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 EITER, which is in France, but its supposed to generate ten times more power that requires to to start the fusion process. So if it's you know, even even then it's just the beginning, right, ten times

what you put into it is. It sounds great, but uh, but we only hopefully go up from there. Sure, fusion is one of those funny things that for years and years people have been saying it's right around the corner, and it's never We've never gone around that corner. Yet it's always it's always twenty to fifty years away. It's why all super fancy technology. Yeah, it's one of those things where, like like the singularity, it's always twenty to

fifty years away. But we have made real progress. We have, we have we're a lot closer than we used to be, and we do need to take just a quick moment to talk about cold fusion. Which is cold fusion well, we don't even have to say the quote. I mean, it's it's an accepted term for something that is unproven scientific. Imagine people who people who advocate it don't like that term anymore, do they? That they try to like hide

it under different terminology. Pons and Fleischmann, the paraphysicists 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 so so that energy barrier that you need to make the reaction start goes away. Well, I mean, and if this were true, it would be

a miracle. It would just I mean, we would have limitless energy right now. It would be Doc Browne's mr fusion on the back of it. Would Yeah, I mean we would. 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 even be a need for an electric grid anymore. You can see why people would want it. Yeah, The problem is that the science just doesn't seem to work out.

But Ponds and Fleishman did some, uh 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. Um. The whole thing that they were saying was that they were getting more energy out of a reaction than they expected. Like it was it was beyond what the 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 Fleischmann for many years continued to uh to to really work in this They they originally called it infusion. That's not a joke, that really is true. Uh, they call

it infusion. It was t that not like the letter in an infusion, which is weird. Which is weird because if you know anything about if you if you know anything about in rays, in rays were something that, uh that some scientists believed were a thing until they tried to look into it and realized there was nothing there like in rays where these things that existed until you

looked for them, and then they didn't. So it seems to me, it seems funny to me that you would call it in fusion within rays being such a big scandal in the scientific community. But anyway, uh, cold fusion. Yeah, it just didn't seem to have any merit to it. And there have been a lot of people who 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 makes sense, right, Like that would solve everyone's problems 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, like, well, incredibly unlikely. But this doesn't mean now Here's one of the main reasons I think we needed to bring this up is that, um, people hear about the fail years of cold fusion, and they that makes them think, oh, fusion, it's a fusion. Hot fusion has serious potential, right Yeah, No, hot fusion is definitely one of those things that could work if

we get the system efficient enough. Like if I turn, if the International Thermonuclear Experimental Reactor does in fact work out, then that will show that fusion is a viable means of generating energy. And that, and we know it's legitimate, the son's there, but but whether or not we can harness it in a way that makes sense is still the question. Uh. It does look promising, but even even the optimists are still saying it's, you know, thirty forty

years away, So, uh, what is it here? Lockheed skunk Work says that they can make fusion work in the next few years. Well yeah, but then it'll only work in area fifty one anyway, So it's a really interesting

con sept. I really hope it does work out. It would be a huge benefit and the idea of you know, think about it, if you're if you're using this this method to create energy, then you suddenly that the whole question about how do we create clean energy is answered and we don't have to you know, things like wind turbines and solar farms, which are you know, problematic right now,

inefficient Relatively they're relatively inefficient. You have to find very specific places to be able to harness that kind of stuff. And uh, you know, there's a question of whether or not the amount we could harvest would meet our demand. This would answer all those questions. Me we would easily meet our demand. For at least the foreseeable future. You know, never say never. Eventually we could get to a point where even fusion might seem like, well, we need the

next big thing. But at that point we'd probably be off planet Earth and yeah, we just be harnessing the stars themselves, which we are going to talk about at some point, yeah we will, but not today. Today, we're going to wrap this up. So guys, if you have enjoyed this, if you have of 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 gonna work, you

can let us know. We have our website at f w thinking dot com. You can read our blogs, you can watch the videos, you can listen to the podcasts, and of course there are the links to all of our presences on various social networks, so you can find us on Facebook, Twitter, and Google Plus. We look forward to hearing from you, and we will taught to you again really soon. For more on this topic and the future of technology, visit forward thinking dot com, brought to you by Toyota. Let's go places

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