WEBVTT 00:00:00.656 --> 00:00:02.959 Well, I have a big announcement to make today, 00:00:02.959 --> 00:00:05.132 and I'm really excited about this. 00:00:05.132 --> 00:00:07.460 And this may be a little bit of a surprise 00:00:07.460 --> 00:00:10.714 to many of you who know my research 00:00:10.714 --> 00:00:12.869 and what I've done well. 00:00:12.869 --> 00:00:16.273 I've really tried to solve some big problems: 00:00:16.273 --> 00:00:18.740 counterterrorism, nuclear terrorism, 00:00:18.740 --> 00:00:22.388 and health care and diagnosing and treating cancer, 00:00:22.388 --> 00:00:24.852 but I started thinking about all these problems, 00:00:24.852 --> 00:00:29.412 and I realized that the really biggest problem we face, 00:00:29.412 --> 00:00:31.660 what all these other problems come down to, 00:00:31.660 --> 00:00:35.302 is energy, is electricity, the flow of electrons. 00:00:35.302 --> 00:00:38.421 And I decided that I was going to set out 00:00:38.421 --> 00:00:41.803 to try to solve this problem. NOTE Paragraph 00:00:41.803 --> 00:00:45.775 And this probably is not what you're expecting. 00:00:45.775 --> 00:00:47.427 You're probably expecting me to come up here 00:00:47.427 --> 00:00:49.006 and talk about fusion, 00:00:49.006 --> 00:00:50.986 because that's what I've done most of my life. 00:00:50.986 --> 00:00:54.252 But this is actually a talk about, okay -- 00:00:54.252 --> 00:00:56.876 (Laughter) — 00:00:56.876 --> 00:00:59.843 but this is actually a talk about fission. 00:00:59.843 --> 00:01:01.369 It's about perfecting something old, 00:01:01.369 --> 00:01:04.019 and bringing something old into the 21st century. NOTE Paragraph 00:01:04.019 --> 00:01:08.644 Let's talk a little bit about how nuclear fission works. 00:01:08.644 --> 00:01:10.388 In a nuclear power plant, you have 00:01:10.388 --> 00:01:13.036 a big pot of water that's under high pressure, 00:01:13.036 --> 00:01:14.554 and you have some fuel rods, 00:01:14.554 --> 00:01:16.923 and these fuel rods are encased in zirconium, 00:01:16.923 --> 00:01:19.793 and they're little pellets of uranium dioxide fuel, 00:01:19.793 --> 00:01:23.949 and a fission reaction is controlled and maintained at a proper level, 00:01:23.949 --> 00:01:27.100 and that reaction heats up water, 00:01:27.100 --> 00:01:29.925 the water turns to steam, steam turns the turbine, 00:01:29.925 --> 00:01:31.855 and you produce electricity from it. 00:01:31.855 --> 00:01:34.635 This is the same way we've been producing electricity, 00:01:34.635 --> 00:01:38.100 the steam turbine idea, for 100 years, 00:01:38.100 --> 00:01:41.121 and nuclear was a really big advancement 00:01:41.121 --> 00:01:42.701 in a way to heat the water, 00:01:42.701 --> 00:01:47.156 but you still boil water and that turns to steam and turns the turbine. NOTE Paragraph 00:01:47.156 --> 00:01:50.972 And I thought, you know, is this the best way to do it? 00:01:50.972 --> 00:01:53.772 Is fission kind of played out, 00:01:53.772 --> 00:01:56.627 or is there something left to innovate here? 00:01:56.627 --> 00:01:59.212 And I realized that I had hit upon something 00:01:59.212 --> 00:02:03.516 that I think has this huge potential to change the world. 00:02:03.516 --> 00:02:07.007 And this is what it is. NOTE Paragraph 00:02:07.007 --> 00:02:09.612 This is a small modular reactor. 00:02:09.612 --> 00:02:14.316 So it's not as big as the reactor you see in the diagram here. 00:02:14.316 --> 00:02:16.719 This is between 50 and 100 megawatts. 00:02:16.719 --> 00:02:18.340 But that's a ton of power. 00:02:18.340 --> 00:02:21.789 That's between, say at an average use, 00:02:21.789 --> 00:02:26.930 that's maybe 25,000 to 100,000 homes could run off that. 00:02:26.930 --> 00:02:29.508 Now the really interesting thing about these reactors 00:02:29.508 --> 00:02:31.633 is they're built in a factory. 00:02:31.633 --> 00:02:33.596 So they're modular reactors that are built 00:02:33.596 --> 00:02:35.941 essentially on an assembly line, 00:02:35.941 --> 00:02:38.100 and they're trucked anywhere in the world, 00:02:38.100 --> 00:02:40.411 you plop them down, and they produce electricity. 00:02:40.411 --> 00:02:43.853 This region right here is the reactor. NOTE Paragraph 00:02:43.853 --> 00:02:46.164 And this is buried below ground, which is really important. 00:02:46.164 --> 00:02:48.877 For someone who's done a lot of counterterrorism work, 00:02:48.877 --> 00:02:51.573 I can't extol to you 00:02:51.573 --> 00:02:54.358 how great having something buried below the ground is 00:02:54.358 --> 00:02:58.397 for proliferation and security concerns. NOTE Paragraph 00:02:58.397 --> 00:03:01.910 And inside this reactor is a molten salt, 00:03:01.910 --> 00:03:04.688 so anybody who's a fan of thorium, 00:03:04.688 --> 00:03:06.014 they're going to be really excited about this, 00:03:06.014 --> 00:03:11.096 because these reactors happen to be really good 00:03:11.096 --> 00:03:13.680 at breeding and burning the thorium fuel cycle, 00:03:13.680 --> 00:03:15.731 uranium-233. NOTE Paragraph 00:03:15.731 --> 00:03:18.301 But I'm not really concerned about the fuel. 00:03:18.301 --> 00:03:21.525 You can run these off -- they're really hungry, 00:03:21.525 --> 00:03:24.957 they really like down-blended weapons pits, 00:03:24.957 --> 00:03:27.821 so that's highly enriched uranium and weapons-grade plutonium 00:03:27.821 --> 00:03:28.854 that's been down-blended. 00:03:28.854 --> 00:03:32.246 It's made into a grade where it's not usable for a nuclear weapon, 00:03:32.246 --> 00:03:35.397 but they love this stuff. 00:03:35.397 --> 00:03:37.180 And we have a lot of it sitting around, 00:03:37.180 --> 00:03:38.822 because this is a big problem. 00:03:38.822 --> 00:03:40.939 You know, in the Cold War, we built up this huge arsenal 00:03:40.939 --> 00:03:43.279 of nuclear weapons, and that was great, 00:03:43.279 --> 00:03:45.734 and we don't need them anymore, 00:03:45.734 --> 00:03:49.078 and what are we doing with all the waste, essentially? 00:03:49.078 --> 00:03:51.493 What are we doing with all the pits of those nuclear weapons? 00:03:51.493 --> 00:03:53.394 Well, we're securing them, and it would be great 00:03:53.394 --> 00:03:55.138 if we could burn them, eat them up, 00:03:55.138 --> 00:03:57.139 and this reactor loves this stuff. NOTE Paragraph 00:03:57.139 --> 00:04:00.161 So it's a molten salt reactor. It has a core, 00:04:00.161 --> 00:04:03.935 and it has a heat exchanger from the hot salt, 00:04:03.935 --> 00:04:08.005 the radioactive salt, to a cold salt which isn't radioactive. 00:04:08.005 --> 00:04:10.652 It's still thermally hot but it's not radioactive. 00:04:10.652 --> 00:04:12.432 And then that's a heat exchanger 00:04:12.432 --> 00:04:15.725 to what makes this design really, really interesting, 00:04:15.725 --> 00:04:18.733 and that's a heat exchanger to a gas. 00:04:18.733 --> 00:04:21.277 So going back to what I was saying before about all power 00:04:21.277 --> 00:04:24.270 being produced -- well, other than photovoltaic -- 00:04:24.270 --> 00:04:28.168 being produced by this boiling of steam and turning a turbine, 00:04:28.168 --> 00:04:30.688 that's actually not that efficient, and in fact, 00:04:30.688 --> 00:04:33.064 in a nuclear power plant like this, 00:04:33.064 --> 00:04:37.872 it's only roughly 30 to 35 percent efficient. 00:04:37.872 --> 00:04:40.409 That's how much thermal energy the reactor's putting out 00:04:40.409 --> 00:04:42.062 to how much electricity it's producing. 00:04:42.062 --> 00:04:44.987 And the reason the efficiencies are so low is these reactors 00:04:44.987 --> 00:04:46.693 operate at pretty low temperature. 00:04:46.693 --> 00:04:48.448 They operate anywhere from, you know, 00:04:48.448 --> 00:04:52.141 maybe 200 to 300 degrees Celsius. 00:04:52.141 --> 00:04:56.140 And these reactors run at 600 to 700 degrees Celsius, 00:04:56.140 --> 00:04:58.845 which means the higher the temperature you go to, 00:04:58.845 --> 00:05:01.741 thermodynamics tells you that you will have higher efficiencies. 00:05:01.741 --> 00:05:05.415 And this reactor doesn't use water. It uses gas, 00:05:05.415 --> 00:05:07.893 so supercritical CO2 or helium, 00:05:07.893 --> 00:05:09.334 and that goes into a turbine, 00:05:09.334 --> 00:05:11.195 and this is called the Brayton cycle. 00:05:11.195 --> 00:05:13.669 This is the thermodynamic cycle that produces electricity, 00:05:13.669 --> 00:05:16.099 and this makes this almost 50 percent efficient, 00:05:16.099 --> 00:05:18.989 between 45 and 50 percent efficiency. 00:05:18.989 --> 00:05:20.660 And I'm really excited about this, 00:05:20.660 --> 00:05:23.173 because it's a very compact core. 00:05:23.173 --> 00:05:27.309 Molten salt reactors are very compact by nature, 00:05:27.309 --> 00:05:30.614 but what's also great is you get a lot more electricity out 00:05:30.614 --> 00:05:33.359 for how much uranium you're fissioning, 00:05:33.359 --> 00:05:35.438 not to mention the fact that these burn up. 00:05:35.438 --> 00:05:37.030 Their burn-up is much higher. 00:05:37.030 --> 00:05:39.008 So for a given amount of fuel you put in the reactor, 00:05:39.008 --> 00:05:41.364 a lot more of it's being used. NOTE Paragraph 00:05:41.364 --> 00:05:44.549 And the problem with a traditional nuclear power plant like this 00:05:44.549 --> 00:05:48.821 is, you've got these rods that are clad in zirconium, 00:05:48.821 --> 00:05:51.550 and inside them are uranium dioxide fuel pellets. 00:05:51.550 --> 00:05:53.724 Well, uranium dioxide's a ceramic, 00:05:53.724 --> 00:05:56.940 and ceramic doesn't like releasing what's inside of it. 00:05:56.940 --> 00:05:59.241 So you have what's called the xenon pit, 00:05:59.241 --> 00:06:01.345 and so some of these fission products love neutrons. 00:06:01.345 --> 00:06:02.592 They love the neutrons that are going on 00:06:02.592 --> 00:06:04.992 and helping this reaction take place. 00:06:04.992 --> 00:06:07.968 And they eat them up, which means that, combined with 00:06:07.968 --> 00:06:10.205 the fact that the cladding doesn't last very long, 00:06:10.205 --> 00:06:11.919 you can only run one of these reactors 00:06:11.919 --> 00:06:16.447 for roughly, say, 18 months without refueling it. 00:06:16.447 --> 00:06:21.038 So these reactors run for 30 years without refueling, 00:06:21.038 --> 00:06:23.758 which is, in my opinion, very, very amazing, 00:06:23.758 --> 00:06:25.711 because it means it's a sealed system. 00:06:25.711 --> 00:06:28.582 No refueling means you can seal them up 00:06:28.582 --> 00:06:31.495 and they're not going to be a proliferation risk, 00:06:31.495 --> 00:06:33.766 and they're not going to have 00:06:33.766 --> 00:06:36.270 either nuclear material or radiological material 00:06:36.270 --> 00:06:38.582 proliferated from their cores. NOTE Paragraph 00:06:38.582 --> 00:06:41.646 But let's go back to safety, because everybody 00:06:41.646 --> 00:06:45.424 after Fukushima had to reassess the safety of nuclear, 00:06:45.424 --> 00:06:47.974 and one of the things when I set out to design a power reactor 00:06:47.974 --> 00:06:51.526 was it had to be passively and intrinsically safe, 00:06:51.526 --> 00:06:54.005 and I'm really excited about this reactor 00:06:54.005 --> 00:06:56.334 for essentially two reasons. 00:06:56.334 --> 00:06:59.278 One, it doesn't operate at high pressure. 00:06:59.278 --> 00:07:02.519 So traditional reactors like a pressurized water reactor 00:07:02.519 --> 00:07:04.951 or boiling water reactor, they're very, very hot water 00:07:04.951 --> 00:07:08.358 at very high pressures, and this means, essentially, 00:07:08.358 --> 00:07:11.222 in the event of an accident, if you had any kind of breach 00:07:11.222 --> 00:07:14.263 of this stainless steel pressure vessel, 00:07:14.263 --> 00:07:16.535 the coolant would leave the core. 00:07:16.535 --> 00:07:19.574 These reactors operate at essentially atmospheric pressure, 00:07:19.574 --> 00:07:23.480 so there's no inclination for the fission products 00:07:23.480 --> 00:07:26.052 to leave the reactor in the event of an accident. 00:07:26.052 --> 00:07:28.370 Also, they operate at high temperatures, 00:07:28.370 --> 00:07:31.249 and the fuel is molten, so they can't melt down, 00:07:31.249 --> 00:07:35.827 but in the event that the reactor ever went out of tolerances, 00:07:35.827 --> 00:07:38.137 or you lost off-site power in the case 00:07:38.137 --> 00:07:41.327 of something like Fukushima, there's a dump tank. 00:07:41.327 --> 00:07:45.798 Because your fuel is liquid, and it's combined with your coolant, 00:07:45.798 --> 00:07:48.169 you could actually just drain the core 00:07:48.169 --> 00:07:50.350 into what's called a sub-critical setting, 00:07:50.350 --> 00:07:52.304 basically a tank underneath the reactor 00:07:52.304 --> 00:07:54.264 that has some neutrons absorbers. 00:07:54.264 --> 00:07:58.054 And this is really important, because the reaction stops. 00:07:58.054 --> 00:08:00.718 In this kind of reactor, you can't do that. 00:08:00.718 --> 00:08:04.199 The fuel, like I said, is ceramic inside zirconium fuel rods, 00:08:04.199 --> 00:08:07.190 and in the event of an accident in one of these type of reactors, 00:08:07.190 --> 00:08:09.327 Fukushima and Three Mile Island -- 00:08:09.327 --> 00:08:12.222 looking back at Three Mile Island, we didn't really see this for a while — 00:08:12.222 --> 00:08:15.708 but these zirconium claddings on these fuel rods, 00:08:15.708 --> 00:08:18.537 what happens is, when they see high pressure water, 00:08:18.537 --> 00:08:21.094 steam, in an oxidizing environment, 00:08:21.094 --> 00:08:23.166 they'll actually produce hydrogen, 00:08:23.166 --> 00:08:26.094 and that hydrogen has this explosive capability 00:08:26.094 --> 00:08:28.304 to release fission products. 00:08:28.304 --> 00:08:30.518 So the core of this reactor, since it's not under pressure 00:08:30.518 --> 00:08:32.782 and it doesn't have this chemical reactivity, 00:08:32.782 --> 00:08:36.256 means that there's no inclination for the fission products 00:08:36.256 --> 00:08:37.990 to leave this reactor. 00:08:37.990 --> 00:08:40.255 So even in the event of an accident, 00:08:40.255 --> 00:08:43.973 yeah, the reactor may be toast, which is, you know, 00:08:43.973 --> 00:08:45.632 sorry for the power company, 00:08:45.632 --> 00:08:47.732 but we're not going to contaminate large quantities of land. 00:08:47.732 --> 00:08:51.744 So I really think that in the, say, 00:08:51.744 --> 00:08:53.872 20 years it's going to take us to get fusion 00:08:53.872 --> 00:08:56.092 and make fusion a reality, 00:08:56.092 --> 00:08:58.673 this could be the source of energy 00:08:58.673 --> 00:09:01.347 that provides carbon-free electricity. 00:09:01.347 --> 00:09:03.005 Carbon-free electricity. NOTE Paragraph 00:09:03.005 --> 00:09:06.350 And it's an amazing technology because 00:09:06.350 --> 00:09:09.180 not only does it combat climate change, 00:09:09.180 --> 00:09:10.684 but it's an innovation. 00:09:10.684 --> 00:09:13.751 It's a way to bring power to the developing world, 00:09:13.751 --> 00:09:16.230 because it's produced in a factory and it's cheap. 00:09:16.230 --> 00:09:18.366 You can put them anywhere in the world you want to. NOTE Paragraph 00:09:18.366 --> 00:09:21.622 And maybe something else. 00:09:21.622 --> 00:09:24.143 As a kid, I was obsessed with space. 00:09:24.143 --> 00:09:26.886 Well, I was obsessed with nuclear science too, to a point, 00:09:26.886 --> 00:09:29.286 but before that I was obsessed with space, 00:09:29.286 --> 00:09:31.197 and I was really excited about, you know, 00:09:31.197 --> 00:09:33.071 being an astronaut and designing rockets, 00:09:33.071 --> 00:09:35.157 which was something that was always exciting to me. 00:09:35.157 --> 00:09:38.563 But I think I get to come back to this, 00:09:38.563 --> 00:09:41.864 because imagine having a compact reactor in a rocket 00:09:41.864 --> 00:09:44.694 that produces 50 to 100 megawatts. 00:09:44.694 --> 00:09:47.971 That is the rocket designer's dream. 00:09:47.971 --> 00:09:51.702 That's someone who is designing a habitat on another planet's dream. 00:09:51.702 --> 00:09:53.706 Not only do you have 50 to 100 megawatts 00:09:53.706 --> 00:09:58.119 to power whatever you want to provide propulsion to get you there, 00:09:58.119 --> 00:09:59.518 but you have power once you get there. 00:09:59.518 --> 00:10:03.039 You know, rocket designers who use solar panels 00:10:03.039 --> 00:10:05.998 or fuel cells, I mean a few watts or kilowatts -- 00:10:05.998 --> 00:10:07.591 wow, that's a lot of power. 00:10:07.591 --> 00:10:10.036 I mean, now we're talking about 100 megawatts. 00:10:10.036 --> 00:10:11.209 That's a ton of power. 00:10:11.209 --> 00:10:13.496 That could power a Martian community. 00:10:13.496 --> 00:10:15.093 That could power a rocket there. 00:10:15.093 --> 00:10:17.800 And so I hope that 00:10:17.800 --> 00:10:19.921 maybe I'll have an opportunity to kind of explore 00:10:19.921 --> 00:10:24.588 my rocketry passion at the same time that I explore my nuclear passion. NOTE Paragraph 00:10:24.588 --> 00:10:27.578 And people say, "Oh, well, you've launched this thing, 00:10:27.578 --> 00:10:30.142 and it's radioactive, into space, and what about accidents?" 00:10:30.142 --> 00:10:33.175 But we launch plutonium batteries all the time. 00:10:33.175 --> 00:10:35.294 Everybody was really excited about Curiosity, 00:10:35.294 --> 00:10:37.895 and that had this big plutonium battery on board 00:10:37.895 --> 00:10:40.014 that has plutonium-238, 00:10:40.014 --> 00:10:42.414 which actually has a higher specific activity 00:10:42.414 --> 00:10:46.158 than the low-enriched uranium fuel of these molten salt reactors, 00:10:46.158 --> 00:10:49.661 which means that the effects would be negligible, 00:10:49.661 --> 00:10:51.113 because you launch it cold, 00:10:51.113 --> 00:10:54.824 and when it gets into space is where you actually activate this reactor. NOTE Paragraph 00:10:54.824 --> 00:10:56.132 So I'm really excited. 00:10:56.132 --> 00:10:58.669 I think that I've designed this reactor here 00:10:58.669 --> 00:11:02.574 that can be an innovative source of energy, 00:11:02.574 --> 00:11:06.255 provide power for all kinds of neat scientific applications, 00:11:06.255 --> 00:11:08.783 and I'm really prepared to do this. 00:11:08.783 --> 00:11:11.550 I graduated high school in May, and -- 00:11:11.550 --> 00:11:15.698 (Laughter) (Applause) — 00:11:15.698 --> 00:11:17.749 I graduated high school in May, 00:11:17.749 --> 00:11:20.589 and I decided that I was going to start up a company 00:11:20.589 --> 00:11:22.957 to commercialize these technologies that I've developed, 00:11:22.957 --> 00:11:25.814 these revolutionary detectors for scanning cargo containers 00:11:25.814 --> 00:11:28.094 and these systems to produce medical isotopes, 00:11:28.094 --> 00:11:31.542 but I want to do this, and I've slowly been building up 00:11:31.542 --> 00:11:33.795 a team of some of the most incredible people 00:11:33.795 --> 00:11:35.982 I've ever had the chance to work with, 00:11:35.982 --> 00:11:38.744 and I'm really prepared to make this a reality. 00:11:38.744 --> 00:11:41.841 And I think, I think, that looking at the technology, 00:11:41.841 --> 00:11:47.191 this will be cheaper than or the same price as natural gas, 00:11:47.191 --> 00:11:48.991 and you don't have to refuel it for 30 years, 00:11:48.991 --> 00:11:51.718 which is an advantage for the developing world. NOTE Paragraph 00:11:51.718 --> 00:11:54.840 And I'll just say one more maybe philosophical thing 00:11:54.840 --> 00:11:56.769 to end with, which is weird for a scientist. 00:11:56.769 --> 00:11:59.263 But I think there's something really poetic 00:11:59.263 --> 00:12:03.062 about using nuclear power to propel us to the stars, 00:12:03.062 --> 00:12:05.817 because the stars are giant fusion reactors. 00:12:05.817 --> 00:12:08.158 They're giant nuclear cauldrons in the sky. 00:12:08.158 --> 00:12:11.555 The energy that I'm able to talk to you today, 00:12:11.555 --> 00:12:13.650 while it was converted to chemical energy in my food, 00:12:13.650 --> 00:12:16.838 originally came from a nuclear reaction, 00:12:16.838 --> 00:12:19.614 and so there's something poetic about, in my opinion, 00:12:19.614 --> 00:12:22.583 perfecting nuclear fission 00:12:22.583 --> 00:12:26.302 and using it as a future source of innovative energy. NOTE Paragraph 00:12:26.302 --> 00:12:28.253 So thank you guys. NOTE Paragraph 00:12:28.253 --> 00:12:33.238 (Applause)