Well, I have a big announcement to make today, and I'm really excited about this. And this may be a little bit of a surprise to many of you who know my research and what I've done well. I've really tried to solve some big problems: counterterrorism, nuclear terrorism, and health care and diagnosing and treating cancer, but I started thinking about all these problems, and I realized that the really biggest problem we face, what all these other problems come down to, is energy, is electricity, the flow of electrons. And I decided that I was going to set out to try to solve this problem.
今天我要隆重宣布一件事情, 我真的很兴奋。 在座很多了解我一直以来的研究 和工作的人 可能会有点小吃惊。 我一直在尝试解决一些大问题: 比如反恐,核恐怖活动, 还有医疗保健,癌症的诊断和治疗, 然而当我开始思考这些问题, 我意识到,我们面临的最大问题, 也是所有其他问题的根源, 是能源,电力,电子的流动。 我决定我要着手 来试着解决这一问题。
And this probably is not what you're expecting. You're probably expecting me to come up here and talk about fusion, because that's what I've done most of my life. But this is actually a talk about, okay -- (Laughter) — but this is actually a talk about fission. It's about perfecting something old, and bringing something old into the 21st century.
这可能有些出乎大家的意料。 大家可能觉得我站在这里 是来讲核聚变的, 因为那才是我这一生中大多数时候做的事情。 但其实我想讲的是,好吧~~ (笑声) 其实我想讲的是核裂变。 是关于如何将古老的东西完善, 然后把它们带入21世纪,古为今用。
Let's talk a little bit about how nuclear fission works. In a nuclear power plant, you have a big pot of water that's under high pressure, and you have some fuel rods, and these fuel rods are encased in zirconium, and they're little pellets of uranium dioxide fuel, and a fission reaction is controlled and maintained at a proper level, and that reaction heats up water, the water turns to steam, steam turns the turbine, and you produce electricity from it. This is the same way we've been producing electricity, the steam turbine idea, for 100 years, and nuclear was a really big advancement in a way to heat the water, but you still boil water and that turns to steam and turns the turbine.
让我们先简要的谈一谈核裂变的原理。 在核电厂里, 你会看到 一大锅水,在一个高压的系统里, 你还会看到一些燃料棒, 这些燃料棒是被锆包裹, 它们是小球状的二氧化铀燃料, 裂变反应是受到控制的,被维持在一个恰当的程度, 这个反应使水加热, 然后水变成蒸汽,蒸汽带动涡轮机, 然后就可以发电了。 用蒸汽带动涡轮旋转,跟我们 100年来一直沿用的发电方法是一致的, 但是用核能来给水加热 却真是一个巨大的进步, 但我们仍然需要烧水,让水变成蒸汽来带动涡轮机。
And I thought, you know, is this the best way to do it? Is fission kind of played out, or is there something left to innovate here? And I realized that I had hit upon something that I think has this huge potential to change the world. And this is what it is.
我在想,这真的是最好的办法了吗? 裂变在这一过程中真的是物尽其用了, 还是留下了一些创新的空间? 我意识到我碰到了一些东西, 我觉得这些东西具有改变世界的巨大潜力。 这个就是我要展示的。
This is a small modular reactor. So it's not as big as the reactor you see in the diagram here. This is between 50 and 100 megawatts. But that's a ton of power. That's between, say at an average use, that's maybe 25,000 to 100,000 homes could run off that. Now the really interesting thing about these reactors is they're built in a factory. So they're modular reactors that are built essentially on an assembly line, and they're trucked anywhere in the world, you plop them down, and they produce electricity. This region right here is the reactor.
这是一个小型的单元反应堆。 它不像你在这张图里看到的反应堆那么大。 发电量在50-100兆瓦。 但那已经是很大的能量了。 按平均用电量来算, 这个电量大概能供给两万五千到十万个家庭。 这些反应堆真正有趣的地方在于 他们是在工厂里制造出来的。 所以说它们本质上 是在装配线上组装起来的单元反应器, 然后再由大卡车运送到世界各地, “扑通”放在地上,然后就开始发电。 这个区域就是反应堆。
And this is buried below ground, which is really important. For someone who's done a lot of counterterrorism work, I can't extol to you how great having something buried below the ground is for proliferation and security concerns.
它是埋在地下的,这个非常重要。 对于那些从事反恐行动的人来说, 不用我宣扬, 大家也知道能把东西埋在地下有多好, 出于对核扩散和安全性的考虑。
And inside this reactor is a molten salt, so anybody who's a fan of thorium, they're going to be really excited about this, because these reactors happen to be really good at breeding and burning the thorium fuel cycle, uranium-233.
在这个反应器里面是一种熔盐, 如果有人很喜欢钍的话 他们一定会对这个感到很兴奋, 因为这个反应堆恰好在 钍燃料的增殖燃烧转化循环中有很好的表现, 经过一系列变化钍的最终产物是铀233。
But I'm not really concerned about the fuel. You can run these off -- they're really hungry, they really like down-blended weapons pits, so that's highly enriched uranium and weapons-grade plutonium that's been down-blended. It's made into a grade where it's not usable for a nuclear weapon, but they love this stuff. And we have a lot of it sitting around, because this is a big problem. You know, in the Cold War, we built up this huge arsenal of nuclear weapons, and that was great, and we don't need them anymore, and what are we doing with all the waste, essentially? What are we doing with all the pits of those nuclear weapons? Well, we're securing them, and it would be great if we could burn them, eat them up, and this reactor loves this stuff.
但是我并不关心燃料的问题。 它们可以很容易被消耗掉。我要讲的是,这些反应堆很“饥饿”, 它们很喜欢那些经过混合掺杂浓度变低的核弹头, 核弹头含有高浓度的铀和武器级别的钚, 但它们经过掺杂浓度都变低了, 以致它们不再适合用作核武器。 但是这些反应堆却很喜欢它们。 而且我们现在有很多这样的闲置的核弹头, 这是一个大问题。 大家都知道,冷战的时候,我们建了巨大的核武器兵工厂, 当时觉得很棒, 但现在我们不再需要了, 那我们应该怎么从根本上处理这些核垃圾呢? 怎么来处理那些核弹头呢? 好吧,我们可以把它们保护起来,但如果 我们可以把它们烧掉,或者“吃”掉,那就太棒了, 而这个反应堆就很喜欢这些东西(可以把它们“吃”掉)。
So it's a molten salt reactor. It has a core, and it has a heat exchanger from the hot salt, the radioactive salt, to a cold salt which isn't radioactive. It's still thermally hot but it's not radioactive. And then that's a heat exchanger to what makes this design really, really interesting, and that's a heat exchanger to a gas. So going back to what I was saying before about all power being produced -- well, other than photovoltaic -- being produced by this boiling of steam and turning a turbine, that's actually not that efficient, and in fact, in a nuclear power plant like this, it's only roughly 30 to 35 percent efficient. That's how much thermal energy the reactor's putting out to how much electricity it's producing. And the reason the efficiencies are so low is these reactors operate at pretty low temperature. They operate anywhere from, you know, maybe 200 to 300 degrees Celsius. And these reactors run at 600 to 700 degrees Celsius, which means the higher the temperature you go to, thermodynamics tells you that you will have higher efficiencies. And this reactor doesn't use water. It uses gas, so supercritical CO2 or helium, and that goes into a turbine, and this is called the Brayton cycle. This is the thermodynamic cycle that produces electricity, and this makes this almost 50 percent efficient, between 45 and 50 percent efficiency. And I'm really excited about this, because it's a very compact core. Molten salt reactors are very compact by nature, but what's also great is you get a lot more electricity out for how much uranium you're fissioning, not to mention the fact that these burn up. Their burn-up is much higher. So for a given amount of fuel you put in the reactor, a lot more of it's being used.
这个反应器是一个熔盐反应堆。它有一个堆芯, 还有一个热交换器在放射性热盐 和非放射性冷盐之间进行热量交换。 热力学上来讲是热的,但它实际上不具有放射性。 正是这个热能交换器 使得这个反应堆的设计特别引人关注, 这是一个气体热交换器。 回到我之前讲的,所有的电, 除了光电池产生的, 都是由水蒸汽带动涡轮旋转产生的, 事实上这种方法效率不是很高, 像这样一个核电厂, 发电效率大概只有30%到35%, 也就是说反应堆产生的热能只能 转化成30%到35%的电能。 效率这么低的原因是这些反应堆 是在非常低的温度下进行操作的。 它的操作温度 大概在200到300摄氏度之间。 而这种反应堆的操作温度在600到700摄氏度之间, 热力学上来说温度越高, 效率越高。 并且这个反应堆不需要用水。它用的是气, 是超临界态的二氧化碳和氦气, 然后这些气体会达到涡轮机, 这个过程被称作“布雷顿循环” 。 这是一种热力学循环,能产生电流 可使发电效率接近50%, 介于45%到50%之间。 这让我很兴奋, 因为这是一个体积非常小的堆芯。 熔盐反应堆天生体积就很小, 更棒的是等量的铀 裂变能产生更多的电, 更不要说那些燃耗。 它们的燃耗要高很多。 所以如果向反应堆投加给定量的燃料, 消耗的燃料会更多。
And the problem with a traditional nuclear power plant like this is, you've got these rods that are clad in zirconium, and inside them are uranium dioxide fuel pellets. Well, uranium dioxide's a ceramic, and ceramic doesn't like releasing what's inside of it. So you have what's called the xenon pit, and so some of these fission products love neutrons. They love the neutrons that are going on and helping this reaction take place. And they eat them up, which means that, combined with the fact that the cladding doesn't last very long, you can only run one of these reactors for roughly, say, 18 months without refueling it. So these reactors run for 30 years without refueling, which is, in my opinion, very, very amazing, because it means it's a sealed system. No refueling means you can seal them up and they're not going to be a proliferation risk, and they're not going to have either nuclear material or radiological material proliferated from their cores.
像这样一个传统的核电厂有一个问题, 就是这些燃料棒是被锆合金包裹的, 燃料棒里面才是二氧化铀燃料小球。 二氧化铀是一种陶瓷材料, 然而陶瓷材料不容易释放它内部的东西。 所以我们有一种叫做氙坑的东西, 这些裂变产物中的某些很喜欢中子, 它们喜欢那些 能帮助反应持续进行的中子。 它们会“吃”掉这些中子, 再加上燃料棒外的金属涂层并不持久, 这就意味着,这些反应堆 大概只能运行18个月,在不添加燃料的情况下。 而这些反应堆,在不添加燃料的情况下,可以运行30年, 在我看来,这是非常令人吃惊的, 因为这就意味着,这将是一个密封的体系。 不用添加燃料意味着这些反应堆可以被密封起来 然后就没有核扩散的风险, 不会有 核物质或者放射性物质 从堆芯扩散出来。
But let's go back to safety, because everybody after Fukushima had to reassess the safety of nuclear, and one of the things when I set out to design a power reactor was it had to be passively and intrinsically safe, and I'm really excited about this reactor for essentially two reasons. One, it doesn't operate at high pressure. So traditional reactors like a pressurized water reactor or boiling water reactor, they're very, very hot water at very high pressures, and this means, essentially, in the event of an accident, if you had any kind of breach of this stainless steel pressure vessel, the coolant would leave the core. These reactors operate at essentially atmospheric pressure, so there's no inclination for the fission products to leave the reactor in the event of an accident. Also, they operate at high temperatures, and the fuel is molten, so they can't melt down, but in the event that the reactor ever went out of tolerances, or you lost off-site power in the case of something like Fukushima, there's a dump tank. Because your fuel is liquid, and it's combined with your coolant, you could actually just drain the core into what's called a sub-critical setting, basically a tank underneath the reactor that has some neutrons absorbers. And this is really important, because the reaction stops. In this kind of reactor, you can't do that. The fuel, like I said, is ceramic inside zirconium fuel rods, and in the event of an accident in one of these type of reactors, Fukushima and Three Mile Island -- looking back at Three Mile Island, we didn't really see this for a while — but these zirconium claddings on these fuel rods, what happens is, when they see high pressure water, steam, in an oxidizing environment, they'll actually produce hydrogen, and that hydrogen has this explosive capability to release fission products. So the core of this reactor, since it's not under pressure and it doesn't have this chemical reactivity, means that there's no inclination for the fission products to leave this reactor. So even in the event of an accident, yeah, the reactor may be toast, which is, you know, sorry for the power company, but we're not going to contaminate large quantities of land. So I really think that in the, say, 20 years it's going to take us to get fusion and make fusion a reality, this could be the source of energy that provides carbon-free electricity. Carbon-free electricity.
但是让我们再来谈一谈安全性,因为每个人, 在日本福岛核事故以后都想要对核能的安全性进行重新评估, 所以在我着手设计一个核能反应堆的时候 我考虑的一个问题就是,这个反应堆本身必须是安全的、温和的, 我对这个反应堆感到很兴奋, 本质上有两个原因, 第一,反应堆所需的操作压力并不高。 传统的反应堆,像那些增压水反应堆 或者沸水反应堆,都会用到温度很高的水 并且压力很高,这就意味着, 一旦遇到事故, 只要这个不锈钢承压容器有一点点缺口, 冷冻剂就会从堆芯逸出。 而我的这些反应堆基本上是在大气压下运行的, 所以在事故中,那些裂变产物 不大会离开反应堆。 并且,这些反应堆是在很高的温度下运行的, 燃料已经是熔化态,所以不会出现熔毁, 但是如果出现反应超出反应堆耐受性的情况 或者装置外电源断电 像福岛事故那样,就必须有一个核废料贮藏罐。 因为燃料是液态的,并且和冷冻剂在一块儿 实际上,我们可以仅仅把堆芯中的液体 排到一个叫做亚临界的环境, 就是在反应堆下面的一个贮藏罐 里面有一些中子吸收器。 这个很重要,因为这样一来反应就会终止。 对这种反应堆,我们就不能那样处理。 它用的燃料,我之前说过,是包在锆合金燃料棒里面的陶瓷材料, 在事故中,这种类型的反应堆 像福岛和三哩岛—— 回头看三哩岛核泄漏,我们很久都没有再看到这样的事故了—— 但是包裹在这些燃料棒上的锆合金涂层, 会发生的是,当它们遇到高压水, 蒸汽,在一个氧化环境中, 它们会产生氢气, 氢气具有爆炸性, 会释放裂变产物。 所以这个反应堆的堆芯,因为不受压力 而且没有化学反应活性, 裂变产物不会倾向于 离开反应堆。 所以即使是在事故中, 哦,是的,反应器可能会被烧毁,那样的话 对核电厂就只好说声抱歉了, 但是大范围的核污染是不会发生的。 所以,我真的觉得, 我们会用20年的时间 来使聚变成一个现实, 这可以成为一个种能源 提供无碳电力。 无碳电力,
And it's an amazing technology because not only does it combat climate change, but it's an innovation. It's a way to bring power to the developing world, because it's produced in a factory and it's cheap. You can put them anywhere in the world you want to.
是一个非常令人惊叹的技术, 因为它不仅可以防止气候变化 而且还是一种创新。 是一个把能源带到正在发展的国家的方法, 因为它可以在工厂里很便宜的制造出来。 你可以把它放到世界上任何一个你想放的地方。
And maybe something else. As a kid, I was obsessed with space. Well, I was obsessed with nuclear science too, to a point, but before that I was obsessed with space, and I was really excited about, you know, being an astronaut and designing rockets, which was something that was always exciting to me. But I think I get to come back to this, because imagine having a compact reactor in a rocket that produces 50 to 100 megawatts. That is the rocket designer's dream. That's someone who is designing a habitat on another planet's dream. Not only do you have 50 to 100 megawatts to power whatever you want to provide propulsion to get you there, but you have power once you get there. You know, rocket designers who use solar panels or fuel cells, I mean a few watts or kilowatts -- wow, that's a lot of power. I mean, now we're talking about 100 megawatts. That's a ton of power. That could power a Martian community. That could power a rocket there. And so I hope that maybe I'll have an opportunity to kind of explore my rocketry passion at the same time that I explore my nuclear passion.
呃,也许还有一些其他的用途。 在我还是个小孩子的时候,我对太空很着迷。 好吧,到某一阶段的时候,我对核科学也很着迷 但是在那之前,我对太空很着迷, 我很兴奋地,你知道 想成为一个宇航员或者火箭设计师, 这一直以来都让我非常激动与兴奋。 所以我觉得我要回到我小时候的梦想, 试想一下,如果把这个便携式小型反应堆安装在火箭上, 而且它能产生50-100兆瓦的电。 那是一个火箭设计师的梦想。 那是一个想要在另一个星球设计一个栖息地的人的梦想。 你不仅仅拥有50-100兆瓦的电力 来提供能使你到达那里所需的推进力,你想发动多少就发动多少, 而且一旦你到达了那里,你仍然拥有很大的电能。 你知道,有一些用太阳能电池板 或者燃料电池的火箭设计师只能获得几瓦或几千瓦的电 哇,那已经是很多电了。 但是现在我们谈的是100兆瓦。 那真是太多太多的电能了。 那都可以为一个火星人社区供电了。 那可以驱动一个火箭达到这个社区。 所以我希望 也许我也会有机会来探索 我的火箭梦,在我探索我的核电梦的同时。
And people say, "Oh, well, you've launched this thing, and it's radioactive, into space, and what about accidents?" But we launch plutonium batteries all the time. Everybody was really excited about Curiosity, and that had this big plutonium battery on board that has plutonium-238, which actually has a higher specific activity than the low-enriched uranium fuel of these molten salt reactors, which means that the effects would be negligible, because you launch it cold, and when it gets into space is where you actually activate this reactor.
也有人会说:”哦,好吧,你发射了这个东西 到太空,它是具有放射性的,那要是发生了事故怎么办?“ 但是我们不是一直在发射钚电池嘛。 大家都对”好奇号“火星探测器感到很兴奋, 那个探测器上就有一个很大的钚电池, 用的是钚238, 它其实比这些熔盐反应堆里的低浓度铀燃料 具有更高的比活度, 这就意味那些影响几乎可以忽略不计, 因为我们是在它还未启动的时候就发射出去了, 当到达太空后,我们才真正激活这些反应堆。
So I'm really excited. I think that I've designed this reactor here that can be an innovative source of energy, provide power for all kinds of neat scientific applications, and I'm really prepared to do this. I graduated high school in May, and -- (Laughter) (Applause) — I graduated high school in May, and I decided that I was going to start up a company to commercialize these technologies that I've developed, these revolutionary detectors for scanning cargo containers and these systems to produce medical isotopes, but I want to do this, and I've slowly been building up a team of some of the most incredible people I've ever had the chance to work with, and I'm really prepared to make this a reality. And I think, I think, that looking at the technology, this will be cheaper than or the same price as natural gas, and you don't have to refuel it for 30 years, which is an advantage for the developing world.
所以我很激动。 我觉得我设计的这个反应堆 可以成为一个能源革新, 为各种各样非常棒的科学应用提供能源, 我已经准备好了来开发这项技术。 我在五月份时高中毕业, (笑声)(掌声)—— 我五月份已经从高中毕业了, 我当时决定要创立一家公司 来使我的很多发明商业化, 比如革命性的探测器来扫描货物集装箱, 还有那些可以生产医用同位素的系统, 但是现在我还是想做这个,我已经慢慢建立了一个团队 团队里都是一些不可思议了不起的人 我从未有机会和这样的人一起工作, 现在我已经准备好要将这个变为现实。 我想,我想,从技术角度来看, 这会比天然气便宜,或者价格差不多。 而且30年不需要添加燃料, 这对于正在发展中的国家来说是一个好处。
And I'll just say one more maybe philosophical thing to end with, which is weird for a scientist. But I think there's something really poetic about using nuclear power to propel us to the stars, because the stars are giant fusion reactors. They're giant nuclear cauldrons in the sky. The energy that I'm able to talk to you today, while it was converted to chemical energy in my food, originally came from a nuclear reaction, and so there's something poetic about, in my opinion, perfecting nuclear fission and using it as a future source of innovative energy.
最后我要再说一点,算是一个比较哲学的东西, 来结束我的演讲,或许对于一个科学家来说这可能有点奇怪, 但是我觉得这是一个很有诗意的东西, 用核能驱动把人类带到其他星球, 因为那些星球本身就是巨大的核聚变反应堆。 它们就像是太空中沸腾的巨型核能汽锅。 我今天能在这里演讲所需要的能量, 尽管是从我食物中的化学能转化而来, 但最初的能量还是源于核反应, 所以在我看来,这是一些很诗意的东西: 使核裂变的更完美 然后将它作为未来新能源。
So thank you guys.
谢谢大家。
(Applause)
(掌声)