WEBVTT - How a Fusion Reactor Would Work 0:00:04.120 --> 0:00:07.160 Get in touch with technology with tech Stuff from how 0:00:07.200 --> 0:00:13.880 stuff works dot com. Hey there, and welcome to tech Stuff. 0:00:13.920 --> 0:00:17.119 I'm your host, Jonathan Strickland. I'm an executive producer with 0:00:17.120 --> 0:00:20.959 how Stuff Works and I love all things tech. And 0:00:21.000 --> 0:00:25.000 in our last episode, I described how nuclear fission reactors work. 0:00:25.520 --> 0:00:29.319 There are several different kinds of nuclear fission reactors, but 0:00:29.360 --> 0:00:32.680 they all depend upon the process of radioactive decay and fission. 0:00:33.120 --> 0:00:35.519 And that's when you have a heavy atom that splits 0:00:35.560 --> 0:00:39.599 into smaller atoms after some sort of process such as 0:00:39.640 --> 0:00:43.080 absorbing and incoming neutron, and as a result, it releases 0:00:43.200 --> 0:00:46.080 energy as a byproduct. That energy can then be used 0:00:46.080 --> 0:00:48.400 to heat up water into steam and drive a steam 0:00:48.479 --> 0:00:52.040 turbine to generate electricity. So listen to the last episode 0:00:52.040 --> 0:00:54.920 for a full rundown of that. But now we're gonna 0:00:54.960 --> 0:00:59.840 turn our focus to fusion. Now, with fusion, two or 0:01:00.000 --> 0:01:04.760 more lighter atoms are fused together to form a heavier atom, 0:01:05.240 --> 0:01:08.240 and they release a lot of energy in the process, 0:01:08.360 --> 0:01:11.400 more energy than you would get from a fission reaction. 0:01:11.840 --> 0:01:15.560 And rather than relying on heavy radioactive isotopes like uranium 0:01:15.560 --> 0:01:19.000 two thirty five or plutonium two nine, is fuel you 0:01:19.000 --> 0:01:24.240 would be using really light atoms that aren't themselves necessarily radioactive, 0:01:24.720 --> 0:01:28.640 But doing so isn't as easy as it sounds. Fusion 0:01:29.360 --> 0:01:33.919 is the process through which stars emit energy, like stars 0:01:33.959 --> 0:01:37.319 in the galaxy, not on Hollywood Boulevard. The Sun is 0:01:37.360 --> 0:01:41.800 basically an enormous fusion reactor, and the Sun is massive. 0:01:42.720 --> 0:01:45.720 How massive you might ask, Well, if you look at 0:01:45.720 --> 0:01:48.400 our solar system, and if you add up all the 0:01:48.480 --> 0:01:53.280 mass represented inside that solar system, the Sun would account 0:01:53.360 --> 0:01:57.400 for nine nine point eight six per cent of all 0:01:57.600 --> 0:02:01.920 of that mass. All of the planets, moons, asteroids, and 0:02:01.960 --> 0:02:04.880 other material would make up less than one per cent 0:02:05.120 --> 0:02:09.120 of the mass of the solar system. One million earths 0:02:09.160 --> 0:02:12.120 could fit inside the Sun. The Sun has a diameter 0:02:12.240 --> 0:02:16.600 of one million, six four kilometers or more than eight 0:02:16.639 --> 0:02:20.760 hundred sixty seven thousand miles, and most of the sun, 0:02:21.400 --> 0:02:26.200 like sevent of it, is made out of hydrogen. Most 0:02:26.240 --> 0:02:29.440 of the remaining mass is helium, and the process of 0:02:29.480 --> 0:02:34.200 fusion inside the Sun's core turns hydrogen into helium. It 0:02:34.280 --> 0:02:38.960 fuses hydrogen together and forms helium as a result at 0:02:39.000 --> 0:02:42.480 a temperature of millions of degrees. According to the song 0:02:42.560 --> 0:02:45.240 why does the sun shine which was made popular by 0:02:45.280 --> 0:02:48.720 They Might Be Giants. However, I should point out that 0:02:48.800 --> 0:02:52.000 song also has some inaccuracies, as we would no longer 0:02:52.080 --> 0:02:55.520 say the Sun is a mass of incandescent gas, which 0:02:55.520 --> 0:02:59.000 is why they Might be Giants. Eventually revised the song 0:02:59.080 --> 0:03:01.640 with an updated verse and called why does the Sun 0:03:01.919 --> 0:03:05.280 really shine and says the sun is a miasma of 0:03:05.320 --> 0:03:11.040 incandescent plasma. But let's move on to understand solar fusion, 0:03:11.120 --> 0:03:14.359 we need to know how stars form. And yes, then 0:03:14.560 --> 0:03:17.359 this actually ends up being really important because it illustrates 0:03:17.360 --> 0:03:21.920 the parameters necessary to make fusion work. So before you 0:03:21.960 --> 0:03:25.880 have a star, you've got clouds of dust and gas 0:03:25.880 --> 0:03:29.160 out in space, just floating around in the same general area. 0:03:29.360 --> 0:03:32.600 Then you get some sort of gravity disturbance, which could 0:03:32.639 --> 0:03:35.320 be caused by any number of things, such as a supernova. 0:03:36.240 --> 0:03:39.240 This ends up causing some of that gas and dust 0:03:39.280 --> 0:03:42.280 to clump together, and the particles are starting to move 0:03:42.320 --> 0:03:45.640 closer and closer in with each other. And as all 0:03:45.720 --> 0:03:50.120 this mass moves closer together, the force of gravity begins 0:03:50.160 --> 0:03:53.680 to pull them in more tightly. You know, gravity depends 0:03:53.760 --> 0:03:57.200 upon mass and distance, so as this mass gets concentrated, 0:03:57.280 --> 0:04:00.520 it starts to create a gravitational pull gas it's drawn 0:04:00.880 --> 0:04:04.720 inward into the core of this mass, and as the 0:04:04.840 --> 0:04:10.520 pressure increases from the gravity pulling things inward, the mass 0:04:10.560 --> 0:04:14.720 begins to heat up and the clump then begins to rotate. 0:04:14.800 --> 0:04:18.640 This heat starts to move stuff around, and there's rotation 0:04:18.680 --> 0:04:22.159 in the universe anyway, so you get some rotation of 0:04:22.240 --> 0:04:26.920 the mass of stuff, and this starts to flatten out 0:04:27.080 --> 0:04:30.800 into a disc. That process actually draws in more dust 0:04:30.960 --> 0:04:34.440 and gas that gets drawn inward and the mass continues 0:04:34.520 --> 0:04:37.200 to heat up. Now skip ahead about a million years. 0:04:37.400 --> 0:04:40.159 You've done a million years of this process where this 0:04:40.320 --> 0:04:45.320 disc has continuously been sucking up more dust and gas 0:04:45.360 --> 0:04:49.000 through gravitational pull and heating up over and over more 0:04:49.040 --> 0:04:52.320 and more, and the core of the disc has become 0:04:52.440 --> 0:04:56.200 a dense structure that we would call a proto star. Now, 0:04:56.240 --> 0:05:00.320 proto stars can turn into full blown stars, or they 0:05:00.400 --> 0:05:04.359 might not. It depends all on how much matter is around, 0:05:04.400 --> 0:05:08.640 how much mass can they accumulate. So if there's enough 0:05:08.960 --> 0:05:11.760 mass in the form of gas and dust, the protostar 0:05:11.839 --> 0:05:14.520 will pull it inward heat up even more, and once 0:05:14.560 --> 0:05:17.479 the temperature hits around seven million degrees kelvin which is 0:05:17.520 --> 0:05:20.640 equal to about twelve point six million fahrenheit or nearly 0:05:20.680 --> 0:05:25.599 seven million celsius. Fusion will begin. Hydrogen atoms will be 0:05:25.680 --> 0:05:29.360 stripped of their electrons because they have far too much energy, 0:05:29.880 --> 0:05:33.640 and the intense temperature and pressure will cause them to 0:05:33.760 --> 0:05:38.640 fuse together to form helium atoms, and that process releases energy. 0:05:38.839 --> 0:05:44.880 The nuclear fusion creates a strong outward pressure, so if 0:05:44.880 --> 0:05:49.080 there were no other boundaries on this system, the protostar 0:05:49.120 --> 0:05:52.320 would just expand to the point where it dissipates. However, 0:05:53.000 --> 0:05:58.600 there's still that incredible gravitational pull that counteracts the expansion 0:05:58.760 --> 0:06:02.800 from nuclear fusion, and the young star will still pull 0:06:02.839 --> 0:06:06.719 in more material. If the protostar collects a sufficient amount 0:06:06.839 --> 0:06:10.640 of mass, the temperature will remain hot enough to sustain fusion, 0:06:10.680 --> 0:06:13.560 and the protostar will release a jet of gas called 0:06:13.600 --> 0:06:17.520 a bipolar flow. That flow will push away gas and 0:06:17.640 --> 0:06:20.200 dust from the star. Some of that stuff could potentially 0:06:20.200 --> 0:06:23.440 clump together to form stuff like planets and moons, But 0:06:23.480 --> 0:06:27.159 if the protostar doesn't accumulate enough mass, the protostar will 0:06:27.200 --> 0:06:30.640 not become a fully fledged star. Instead will turn into 0:06:30.680 --> 0:06:33.159 what is called a brown dwarf. So we see that 0:06:33.240 --> 0:06:39.120 fusion occurs under intense temperatures and intense pressures. The same 0:06:39.240 --> 0:06:42.560 is true if we want to create fusion on Earth. 0:06:43.120 --> 0:06:46.520 So what is actually going on with a fusion reaction? 0:06:46.520 --> 0:06:49.760 I mean, I know that we take two atoms of 0:06:49.880 --> 0:06:52.880 hydrogen and we push them together real hard in a 0:06:53.040 --> 0:06:56.440 very high temperature, high pressure environment, and we get helium. 0:06:56.480 --> 0:06:59.440 But how does that release energy, especially after you need 0:06:59.520 --> 0:07:02.240 so much inergy to make it happen in the first place. Well, 0:07:02.240 --> 0:07:04.640 I'm going to give a very simplistic answer to this, 0:07:04.760 --> 0:07:08.520 but please know that in reality, the real answer, if 0:07:08.520 --> 0:07:12.640 you really boil it down, it's ridiculously complicated. So this 0:07:12.720 --> 0:07:16.280 is a very high level look at what is going on, 0:07:16.840 --> 0:07:18.840 But to go into more detail would require a very 0:07:18.880 --> 0:07:22.440 deep understanding nuclear physics. I frankly do not possess a 0:07:22.520 --> 0:07:26.760 deep understanding of nuclear physics. I have a cursory understanding, 0:07:27.000 --> 0:07:29.680 but I can sort of explain from a very very 0:07:29.720 --> 0:07:33.720 general level. So fusion involves binding those two lighter atoms 0:07:33.720 --> 0:07:35.920 to make a heavier atom. So let's say we've got 0:07:36.040 --> 0:07:39.640 atoms number one and atom number two, and we combine 0:07:39.680 --> 0:07:43.520 them together and we get atom number three. However, we 0:07:43.600 --> 0:07:47.360 see that atom number three's mass is not the same 0:07:47.960 --> 0:07:50.640 as if we added up the mass of atoms one 0:07:50.680 --> 0:07:54.760 and two together. Right, So if we said that the 0:07:54.800 --> 0:07:57.320 mass of atom one is one and the massive atom 0:07:57.360 --> 0:08:00.200 two is one, the massive atom three might actually end 0:08:00.240 --> 0:08:05.640 up being one point eight, but not too so how 0:08:05.800 --> 0:08:08.920 is that possible? After all, matter, just like energy, cannot 0:08:08.960 --> 0:08:13.360 be created or destroyed. Ah, but you can convert it. 0:08:13.960 --> 0:08:16.600 And this is where a real Einstein comes into play. 0:08:16.920 --> 0:08:21.640 His name was Einstein. Einstein's famous equation E equals mc 0:08:21.800 --> 0:08:24.920 squared tells us that if you were to convert mass 0:08:25.040 --> 0:08:28.040 into energy, the amount of energy you would get would 0:08:28.080 --> 0:08:32.000 be you take you take a mass, and you multiply 0:08:32.120 --> 0:08:36.240 that times the speed of light squared. And the speed 0:08:36.240 --> 0:08:38.960 of light is a really big number, like a huge number, 0:08:39.000 --> 0:08:41.240 and then you've just gone and squared it. You multiplied 0:08:41.240 --> 0:08:44.640 that huge number by itself. Then you take that even 0:08:44.760 --> 0:08:48.720 bigger number and multiply that by however much stuff you 0:08:48.800 --> 0:08:51.520 have the mass of the stuff, and that tells you 0:08:51.559 --> 0:08:54.880 how much energy would be produced. It is an enormous 0:08:54.920 --> 0:08:58.679 amount of energy represented in a very tiny amount of mass. 0:08:58.720 --> 0:09:02.680 So the missing mass from this fusion process isn't really missing, 0:09:03.000 --> 0:09:06.680 it's converted from mass to energy, and that is why 0:09:06.760 --> 0:09:10.960 fusion reactions are so powerful. The amount of mass lost 0:09:11.000 --> 0:09:13.840 in the fusion process is tiny, but even so that 0:09:13.880 --> 0:09:17.520 generates an enormous amount of energy. Now, like I said, 0:09:18.440 --> 0:09:21.160 there's an overly simple way of describing what is going on. 0:09:21.760 --> 0:09:23.960 We can get into quantum mechanics, we can get into 0:09:24.000 --> 0:09:27.960 nuclear physics, and I would be totally lost. And so 0:09:28.040 --> 0:09:31.560 there are a lot of details that I am glossing over, 0:09:31.600 --> 0:09:33.800 but at least gives a hint as to why fusion 0:09:33.840 --> 0:09:38.520 power is so tantalizing because it could potentially produce so 0:09:38.640 --> 0:09:41.280 much energy we could put to use in doing things 0:09:41.360 --> 0:09:45.040 like creating electricity. But there are other reasons why fusion 0:09:45.200 --> 0:09:47.199 is really attractive as well, and I'll go into those 0:09:47.240 --> 0:09:49.720 in just a moment, but first let's take a quick 0:09:49.760 --> 0:10:00.360 break to thank our sponsor. So here's the idea for 0:10:00.679 --> 0:10:04.679 a nuclear fusion reactor. You would start with some isotopes 0:10:04.880 --> 0:10:08.120 of hydrogen. Now I mentioned isotopes in the previous episode, 0:10:08.120 --> 0:10:10.120 but just to catch you up in case you haven't 0:10:10.160 --> 0:10:13.959 heard it, isotopes are whord we use to describe atoms 0:10:14.200 --> 0:10:17.360 of the same element, but those atoms have different number 0:10:17.400 --> 0:10:20.400 of neutrons from each other. The number of protons has 0:10:20.440 --> 0:10:23.280 to remain the same for these atoms, because otherwise you 0:10:23.280 --> 0:10:26.080 would have a totally different element. But neutrons have a 0:10:26.080 --> 0:10:28.959 neutral charge. They do not affect the chemical properties of 0:10:29.000 --> 0:10:32.719 the element, but they do change the atomic mass of 0:10:32.760 --> 0:10:36.920 the atoms. The two isotopes of hydrogen most frequently used 0:10:36.920 --> 0:10:42.280 for hydrogen fusion reactions are deuterium and tritium. Now first, 0:10:42.640 --> 0:10:44.719 before I talk about deuterium and tritium, let me talk 0:10:44.760 --> 0:10:49.239 about protium. That's hydrogen one. That's the most common isotope 0:10:49.280 --> 0:10:54.000 of hydrogen. It consists of a single proton and an electron, 0:10:54.559 --> 0:10:59.440 no neutrons, and protium makes up about nine of all 0:10:59.480 --> 0:11:02.120 the hydrogen and found on Earth. Most of that hydrogen, 0:11:02.120 --> 0:11:06.600 by the way, is locked in with other stuff, hydrocarbons 0:11:06.720 --> 0:11:11.360 in particular. Then you have deuterium. Deuterium has one proton 0:11:11.679 --> 0:11:14.560 and one neutron in the nucleus, and it has one 0:11:14.600 --> 0:11:18.520 electron orbiting the nucleus. So it's like protium, excepted has 0:11:18.559 --> 0:11:22.600 a neutron. So some of the hydrogen in the water 0:11:22.800 --> 0:11:26.760 on Earth is deuterium. Like one atom out of every 0:11:26.800 --> 0:11:30.320 six thousand, five hundred hydrogen atoms or so, then you 0:11:30.360 --> 0:11:33.800 have tritium that is hydrogen three. It has one proton, 0:11:34.080 --> 0:11:38.720 two neutrons, and one electron. Now, tritium can occur in 0:11:39.080 --> 0:11:43.840 very trace amounts on Earth in the atmosphere, but it 0:11:43.960 --> 0:11:48.320 is exceedingly rare. It's typically only found in the tiniest 0:11:48.360 --> 0:11:51.560 amounts in the atmosphere after hydrogen atoms have interacted with 0:11:51.600 --> 0:11:55.880 cosmic rays, so there's no easy way of getting hold 0:11:55.920 --> 0:12:00.439 of it. But we can tots make tritium ourselves. That 0:12:00.480 --> 0:12:04.360 does involve irradiating other stuff, so I don't recommend taking 0:12:04.360 --> 0:12:07.240 it on as a d I Y project. Also, tritium 0:12:07.280 --> 0:12:10.600 itself is radioactive. It has a half life of about 0:12:10.640 --> 0:12:16.240 ten years, so tritium, while while deuterium is not radioactive, 0:12:16.280 --> 0:12:21.200 tritium is. Fusion reactors would probably have to rely upon 0:12:21.320 --> 0:12:26.520 deuterium tritium reactions, which would create a helium four atom 0:12:26.600 --> 0:12:30.679 and a neutron. Now, if we could manage deuterium deuterium 0:12:30.679 --> 0:12:35.600 reactions just fusing to deuterium atoms together, that would be 0:12:35.640 --> 0:12:38.000 for the best because that would produce a helium three 0:12:38.040 --> 0:12:41.320 isotope plus a neutron, and the results would be preferable 0:12:41.360 --> 0:12:45.720 to the deuterium tritium. Because deuterium occurs naturally on Earth 0:12:45.960 --> 0:12:48.280 means we don't have to make it. We can actually 0:12:48.320 --> 0:12:51.160 harvest it from the oceans if we wanted to. Plus, 0:12:51.480 --> 0:12:55.360 deuterium isn't radioactive, tritium is, and the reaction would yield 0:12:55.520 --> 0:12:59.560 more energy than a deuterium tritium reaction. But on the 0:12:59.600 --> 0:13:02.640 downs side, the amount of energy we would need to 0:13:03.120 --> 0:13:08.640 initiate a deuterium deuterium reaction is so great that it 0:13:08.800 --> 0:13:12.240 is prohibitive right now and possibly always will be. We 0:13:12.400 --> 0:13:17.640 just don't have the capability of creating that. Helium four, 0:13:17.679 --> 0:13:22.120 by the way, UH consists of two protons and two neutrons. 0:13:22.160 --> 0:13:24.520 Helium three is an isotope that only has one neutron 0:13:24.600 --> 0:13:28.960 with those two protons. So where's the problem. We know 0:13:29.120 --> 0:13:31.360 what's happening with fusion, but why can't we make it 0:13:31.440 --> 0:13:34.160 a reliable reactor? Why can't we make a fusion reactor 0:13:34.280 --> 0:13:37.559 right now that produces more energy than it requires to operate? Now, 0:13:37.640 --> 0:13:40.320 first you have to create the conditions that allow fusion 0:13:40.320 --> 0:13:43.480 to happen in the first place. Fusing nuclei together means 0:13:43.480 --> 0:13:46.800 you have to overcome the repulsive force you encounter when 0:13:46.840 --> 0:13:49.400 you try to smush together two particles with the same charge, 0:13:49.880 --> 0:13:52.040 and by repulsive, I don't mean they're disgusting. I mean 0:13:52.080 --> 0:13:55.720 they repel each other. Like if you take two magnets 0:13:55.720 --> 0:13:58.280 and you try and put the north end of each 0:13:58.320 --> 0:14:00.840 magnet next to each other, you'll feel them resist that, 0:14:00.880 --> 0:14:05.640 they'll push against each other because like charge repels, like 0:14:06.240 --> 0:14:10.440 opposite charges attract, So a positively charged particle will attract 0:14:10.440 --> 0:14:13.839 a negatively charged one, but the same charge repels and 0:14:14.280 --> 0:14:18.439 to positively charged particles like protons, are going to resist 0:14:18.480 --> 0:14:21.720 getting smushed together. They repel one another. You have to 0:14:21.800 --> 0:14:24.440 overcome that tendency, so you have to heat up the 0:14:24.520 --> 0:14:28.400 hydrogen to millions of degrees kelvin. That amount of energy 0:14:28.440 --> 0:14:31.720 will strip the electrons away from the hydrogen atoms, turning 0:14:31.720 --> 0:14:35.200 the atoms into nuclei, which would make a protium just 0:14:35.280 --> 0:14:38.800 become a proton all by itself, but deuterium, you would 0:14:38.800 --> 0:14:42.360 have a proton and a neutron together, and hydrogen would 0:14:42.440 --> 0:14:47.120 change from gas form into plasma. Plasma is the most 0:14:47.160 --> 0:14:50.600 plentiful form of matter in the universe, because again that's 0:14:50.640 --> 0:14:53.320 what stars are made of, and we've already established how 0:14:53.520 --> 0:14:56.880 massive stars can be keep in mind, the Sun is 0:14:56.880 --> 0:14:59.640 not the biggest kind of star we've ever seen, so 0:15:00.560 --> 0:15:04.160 it's the most plentiful stuff. It's essentially an ionized gas, 0:15:04.200 --> 0:15:07.360 meaning that has free roaming part of electrons and nuclei 0:15:07.480 --> 0:15:10.600 inside of it. Now, to get hydrogen to those temperatures, 0:15:10.640 --> 0:15:13.560 to heat up hydrogen enough to turn it into a plasma, 0:15:13.880 --> 0:15:17.240 we use powerful technologies and typically we use stuff like 0:15:17.360 --> 0:15:22.320 lasers or microwaves and ion particles to heat up the 0:15:22.400 --> 0:15:25.560 material to a temperature high enough where we can actually 0:15:26.040 --> 0:15:30.480 turn it into plasma. Then we have to use some 0:15:30.600 --> 0:15:36.120 form of containment to push all of those nuclei together 0:15:36.680 --> 0:15:40.000 big time. We have to really squish them in so 0:15:40.040 --> 0:15:43.200 that they are within one time's tent to the negative 0:15:43.440 --> 0:15:48.000 fifteen meters to fuse together. They had to be so 0:15:48.240 --> 0:15:51.680 darn close to each other. And we don't have the 0:15:51.760 --> 0:15:56.240 benefit of having an intense gravitational force like the Sun 0:15:56.320 --> 0:16:00.200 has because of it's so massive. The gravity that the 0:16:00.240 --> 0:16:04.600 Sun exerts is so strong that it that that condition 0:16:04.680 --> 0:16:07.160 is natural in the core of the Sun. We can't 0:16:07.200 --> 0:16:10.840 replicate that on Earth. We don't have the control of gravity, 0:16:10.880 --> 0:16:13.360 so we have to use something else, and we typically 0:16:13.480 --> 0:16:17.760 use stuff like magnetic fields or lasers or ion beams 0:16:17.760 --> 0:16:20.320 in order to do that. I'll explain how in just 0:16:20.400 --> 0:16:23.680 a moment, but first let's take another quick break to 0:16:23.800 --> 0:16:34.720 thank our sponsor. All right, let's talk about magnetic confinement. 0:16:36.080 --> 0:16:39.960 That means we're using magnetic and electric fields to manipulate 0:16:40.000 --> 0:16:43.240 the plasma to squish it into a tiny mass, and 0:16:43.560 --> 0:16:46.480 it also heats it up in the process. The International 0:16:46.640 --> 0:16:50.440 Thermonuclear Experimental Reactor, or at least that's what was formerly 0:16:50.480 --> 0:16:55.040 known as also called it and France relies on that approach. 0:16:55.440 --> 0:16:58.960 Actually these days they say that i t e R 0:16:59.120 --> 0:17:03.200 no longer stands International Thermonuclear Experimental Reactor. Instead they say 0:17:03.320 --> 0:17:07.120 it is a reference to the Latin phrase for the way, 0:17:07.520 --> 0:17:12.800 probably because the word thermonuclear sounds super scary. But this reactor, 0:17:13.000 --> 0:17:16.600 which is a research project meant to explore the possibilities 0:17:16.680 --> 0:17:20.760 of using magnetic confinement to produce fusion reactions that will 0:17:20.800 --> 0:17:25.000 release more energy than it requires to initiate, has was 0:17:25.040 --> 0:17:29.200 called a tacomac. That's a specific kind of reactor has 0:17:29.200 --> 0:17:31.399 an arrangement of magnets that are sort of in the 0:17:31.400 --> 0:17:35.040 shape of a of a doughnut or or toroid. And 0:17:35.320 --> 0:17:38.880 this kind of reactor would first convert hydrogen gas into 0:17:38.880 --> 0:17:45.040 plasma using microwaves, electricity, and neutral particle beams, and then 0:17:45.080 --> 0:17:49.520 those superconducting magnets would create an extremely powerful magnetic field 0:17:49.600 --> 0:17:53.560 compressing the plasma, and because plasma has an electric charge, 0:17:53.600 --> 0:17:57.560 it's going to respond to these magnetic fields. The amount 0:17:57.560 --> 0:18:01.000 of power needed to start the fusion process, according to it, 0:18:01.480 --> 0:18:06.120 will be about fifty megawatts, but the fusion process would 0:18:06.200 --> 0:18:11.159 produce five hundred megawatts, meaning the thermal output power should 0:18:11.160 --> 0:18:15.320 be ten times greater than the heating input power, so 0:18:15.359 --> 0:18:19.040 you get a tenfold return on your power investment. That 0:18:19.080 --> 0:18:23.639 sounds pretty sweet, but itder itself will not produce electricity, 0:18:23.720 --> 0:18:26.600 at least not first anyway, it's meant to be a 0:18:26.640 --> 0:18:31.280 research facility for the design and testing of fusion technologies. Now, 0:18:31.320 --> 0:18:34.720 if it were a fusion power facility and it was 0:18:34.760 --> 0:18:38.679 beyond research and development, the thermal energy generated from the 0:18:38.720 --> 0:18:42.520 fusion reaction would be used again to heat water into 0:18:42.560 --> 0:18:46.520 steam and push steam turbines, just like a nuclear fission 0:18:46.520 --> 0:18:49.520 reactor or even a cold power plant does. But would 0:18:49.520 --> 0:18:51.840 be really really good at this because it would be 0:18:51.840 --> 0:18:54.640 producing so much energy you could heat up a lot 0:18:54.680 --> 0:18:57.680 more water. You could drive more steam turbines than other 0:18:57.800 --> 0:19:01.320 forms of steam turbine generators, and so you can generate 0:19:01.400 --> 0:19:04.080 quite a bit of electricity from the amount of energy 0:19:04.160 --> 0:19:08.240 you are producing through these reactions. In addition, because we're 0:19:08.359 --> 0:19:12.840 pretty sure we're limited to do tterium tritium reactions, I 0:19:13.000 --> 0:19:15.600 turn would also serve as a test facility to look 0:19:15.600 --> 0:19:20.240 at the feasibility of creating tritium breeder reactors. So a 0:19:20.280 --> 0:19:25.360 breeder reactor creates the materials you need for a different 0:19:25.359 --> 0:19:29.000 type of reaction. So the the reactor is in what 0:19:29.160 --> 0:19:32.400 is called a vacuum vessel, and that vacuum vessel will 0:19:32.440 --> 0:19:36.560 have lithium blankets lining the inside of it, and those 0:19:36.600 --> 0:19:41.040 blankets will actually absorb energy given off by this reactor 0:19:41.119 --> 0:19:45.120 during the fusion process, and as a result, when you 0:19:45.400 --> 0:19:52.280 bombard lithium with radioactive energy, essentially it produces tritium. So 0:19:53.000 --> 0:19:56.520 that way you can actually create part of the fuel 0:19:56.600 --> 0:20:01.040 you need for future reactions as a byproduct of this process, 0:20:01.119 --> 0:20:05.440 and then you keep on going. But that's magnetic confinement. 0:20:05.480 --> 0:20:09.000 There's actually another way we could use to keep plasma 0:20:09.040 --> 0:20:12.480 confined so that fusion reactions can occur and that is 0:20:12.520 --> 0:20:17.840 called inertial confinement. That one uses ion beams or laser 0:20:17.880 --> 0:20:21.959 beams to confine and squeeze the plasma. The National Ignition 0:20:22.000 --> 0:20:26.320 Facility at Lawrence Livermore Laboratory in the United States uses 0:20:26.520 --> 0:20:29.920 that methodology, and the n i F reactor would use 0:20:31.320 --> 0:20:34.960 two different laser beams to focus on a single point. 0:20:35.800 --> 0:20:38.399 And it's inside a chamber. You've got this big chamber 0:20:38.440 --> 0:20:42.199 called the whole rom h O H L R A 0:20:42.480 --> 0:20:45.439 U M is the spelling for that, and the chambers 0:20:45.480 --> 0:20:50.240 specifically designed for radiant energy. That chambers ten ms in diameter. 0:20:50.240 --> 0:20:54.040 It's pretty big. So what happens at the one focal 0:20:54.080 --> 0:20:56.760 point where all those lasers are aimed at. Well. At 0:20:56.760 --> 0:21:00.199 that point will set a tiny pellet of duteri um 0:21:00.280 --> 0:21:04.480 tritium and it's encased in a plastic cylinder. The one 0:21:05.440 --> 0:21:08.919 laser beams will pour one point eight million jewels of 0:21:09.000 --> 0:21:13.240 power into this cylinder. This creates an enormous amount of heat. 0:21:13.520 --> 0:21:16.600 It also emits X rays as a result, and this 0:21:16.680 --> 0:21:21.120 will help convert that pellet into a plasma. The lasers 0:21:21.320 --> 0:21:25.840 compress this plasma and fusion occurs. The fusion reaction will 0:21:25.840 --> 0:21:28.640 be over in less than in an instant like one 0:21:28.760 --> 0:21:32.679 millionth of a second, but that reaction should produce about 0:21:32.760 --> 0:21:36.240 fifty to one hundred times more energy than what was 0:21:36.320 --> 0:21:40.080 needed to initiate the reaction in the first place, so 0:21:40.200 --> 0:21:44.080 the return on energy would be incredible, much more than 0:21:44.160 --> 0:21:48.159 the magnetic confinement which was ten times right. So a 0:21:48.200 --> 0:21:52.560 series of experiments eventually got the plasma to produce more 0:21:52.720 --> 0:21:56.560 energy than it required to initiate, but the project never 0:21:56.680 --> 0:22:00.000 reached full ignition. They never got to the point where 0:22:00.080 --> 0:22:04.560 they fully ignited the fuel, where you had full fusion. 0:22:05.440 --> 0:22:08.639 Are research is ongoing at the facility, but the early 0:22:08.640 --> 0:22:11.640 optimistic hopes that full ignition would be reached by late 0:22:13.000 --> 0:22:16.560 obviously proved to be too ambitious. Now, one day it 0:22:16.600 --> 0:22:20.360 may prove to be an effective process to use as 0:22:20.600 --> 0:22:25.240 a way to generate the energy necessary to drive electrical generators, 0:22:25.240 --> 0:22:27.199 but a lot more work has to be done to 0:22:27.280 --> 0:22:30.919 achieve goals and create a sustainable approach. A sustainable approach, 0:22:30.920 --> 0:22:33.040 by the way, if you think about that setup where 0:22:33.040 --> 0:22:35.919 you have a hund lasers focused on one little point, 0:22:36.160 --> 0:22:39.280 how do you make that something that you can continuously 0:22:40.480 --> 0:22:45.040 do so that you can keep generating energy and create 0:22:45.080 --> 0:22:50.600 electricity while you would have multiple pellets inside the chamber, 0:22:51.080 --> 0:22:55.040 and the lasers would focus on one after another and 0:22:55.680 --> 0:22:59.200 initiate fusion for each of those in order to generate 0:22:59.280 --> 0:23:04.399 the energy did to create electricity, So we got a 0:23:04.400 --> 0:23:06.639 long way to go. And like Eider, the n i 0:23:06.720 --> 0:23:09.840 F was not intended to be a power plant itself. 0:23:09.880 --> 0:23:12.000 It was a research and testing ground still is a 0:23:12.040 --> 0:23:16.919 research and testing grounds for technology for various uh applications, 0:23:16.920 --> 0:23:21.040 not just nuclear power but also nuclear weapons. Research goes 0:23:21.080 --> 0:23:24.239 on there. Uh Now it might that research might one 0:23:24.280 --> 0:23:27.480 day make fusion reactors practical. A fusion reactor like the 0:23:27.520 --> 0:23:30.800 one in i F research could lead to would generate 0:23:30.840 --> 0:23:33.919 electricity the same way the Eider based reactor would. In 0:23:33.960 --> 0:23:36.600 other words, it would be used to generate energy that 0:23:36.640 --> 0:23:39.240 would heat up water to turn into steam. So it 0:23:39.280 --> 0:23:43.040 all comes back down to steam turbines. Seems like almost 0:23:43.080 --> 0:23:47.240 all the major ways we generate electricity, with the exception 0:23:47.280 --> 0:23:50.960 of something like direct solar power, has some variation of this. 0:23:51.880 --> 0:23:55.240 While we haven't cracked the nut on fusion reactors, it 0:23:55.320 --> 0:23:59.280 does remain a tantalizing goal. Deuterium is more plentiful than 0:23:59.320 --> 0:24:02.000 stuff like your name two thirty five and it's not radioactive. 0:24:02.600 --> 0:24:06.680 Tritium is radioactive, but we'd create that from energy given 0:24:06.720 --> 0:24:10.080 off during fusion reactions, and so we could have breeder 0:24:10.119 --> 0:24:13.800 reactors produced the fuel supply needed for various power plants, 0:24:14.080 --> 0:24:16.760 and the stuff we'd used to generate the tritium is lithium, 0:24:16.840 --> 0:24:19.719 and we are lousy with lithium. Is that is not 0:24:19.760 --> 0:24:21.840 hard to get hold of at all. The amount of 0:24:21.840 --> 0:24:24.399 fuel we would need for fusion reactions in general is 0:24:24.440 --> 0:24:26.800 a fraction of what we would need for a fission 0:24:26.960 --> 0:24:29.239 based nuclear power plants. So that's the other nice thing 0:24:29.240 --> 0:24:31.960 about is that you don't need as much stuff to 0:24:32.040 --> 0:24:34.560 generate the energy you want to generate, right, You don't 0:24:34.560 --> 0:24:37.560 have to go mining for uranium two thirty eight and 0:24:37.600 --> 0:24:40.760 then enriching that so that you have enough uranium two 0:24:40.760 --> 0:24:44.240 thirty five to have a sustainable nuclear reaction, and the 0:24:44.240 --> 0:24:47.920 amount of radiation produced by such reactors would be less 0:24:47.920 --> 0:24:51.199 than the natural background radiation we typically encounter in our 0:24:51.240 --> 0:24:53.400 day to day lives, and that's a nice change from 0:24:53.560 --> 0:24:57.800 fission based nuclear reactors. There's also no combust bustion with 0:24:57.800 --> 0:25:00.240 a nuclear fusion plant. There's also no combust in with 0:25:00.280 --> 0:25:03.159 a fission nuclear power plant, at least not if everything 0:25:03.240 --> 0:25:06.480 is working properly, so you aren't burning stuff and you 0:25:06.520 --> 0:25:09.920 don't cause any pollution that way, And unlike fission reactors, 0:25:10.000 --> 0:25:13.800 fusion reactors would not produce high level nuclear wastes. You 0:25:13.840 --> 0:25:16.440 would still have low level nuclear waste, and that's still 0:25:16.480 --> 0:25:18.760 something you have to be concerned about, but that in 0:25:18.800 --> 0:25:21.400