Nearly everyone in the world is part of some community, whether large or small. And all of these communities have similar needs. They need light, they need heat they need air-conditioning. People can't function very well when it's too hot or too cold. They need food to be grown or provided, distributed and stored safely. They need waste products to be collected, removed and processed. People in the community need to be able to get from one place to another as quickly as possible. And a supply of energy is the basis for all of these activities. Energy in the form of electricity provides light and air-conditioning. Energy in the form of heat keeps us warm. And energy in chemical form provides fertilizer; it drives farm machinery and transportation energy.
全世界几乎每个人都是社区的一部分, 不管这个群体是大是小。 所有的这些社区都有类似的需求。 他们需要照明, 他们需要热量, 他们需要空调。 当太热或太冷时,人们不能很好的工作。 他们需要食物的供给, 配送和安全存储。 他们需要垃圾回收,移除和处理。 社区的人们需要能够 尽可能快的从一个地方 到另一个地方。 能源供应是所有这些活动的基础。 以电力存在的能源, 提供了照明和制冷。 以热能存在的能量, 让我们保持温暖。 化学能源提供了肥料; 它驱动农业机械并运输能源。
Now, I spent 10 years working at NASA. In the beginning of my time there in 2000, I was very interested in communities. But this is the kind of community I was thinking of -- a lunar community It had all of the same needs as a community on Earth would have, but it had some very unique constraints. And we had to think about how we would provide energy for this very unique community. There’s no coal on the Moon. There's no petroleum. There’s no natural gas. There's no atmosphere. There’s no wind, either. And solar power had a real problem: the Moon orbits the Earth once a month. For two weeks, the sun goes down, and your solar panels don't make any energy. If you want to try to store enough energy in batteries for two weeks, it just simply isn't practical. So nuclear energy was really the only choice.
我在NASA工作了10年。 2000年我刚开始工作时, 对社区非常有兴趣。 但我在思考的是, 这种类型的社区—— 一个月球社区。 它有地球上社区所有的同类需求, 但它有一些非常独特的约束条件。 我们需要想出如何 为这个非常独特的社区 提供能源。 月球上没有煤炭, 没有石油, 没有天然气, 没有大气层, 也没有风。 而太阳能有个真正的问题: 月球每月环绕地球一周。 有两周,太阳落山后, 你的太阳能面板无法产生任何能源。 如果你想要用电池存储足够两周的能源, 压根儿不现实。 所以核能源确实是唯一的选择。
Now, back in 2000, I didn't really know too much about nuclear power, so I started trying to learn. Almost all of the nuclear power we use on Earth today uses water as a basic coolant. This has some advantages, but it has a lot of disadvantages. If you want to generate electricity, you have to get the water a lot hotter than you normally can. At normal pressures, water will boil at 100 degrees Celsius. This isn't nearly hot enough to generate electricity effectively. So water-cooled reactors have to run at much higher pressures than atmospheric pressure. Some water-cooled reactors run at over 70 atmospheres of pressure, and others have to run at as much as 150 atmospheres of pressure. There's no getting around this; it's simply what you have to do if you want to generate electricity using a water-cooled reactor. This means you have to build a water-cooled reactor as a pressure vessel, with steel walls over 20 centimeters thick. If that sounds heavy, that's because it is.
2000年的时候,我对核能所知不多, 于是我开始学习。 我们今天在地球上使用的几乎所有核能 都用水作为基本冷却剂。 这个方法有一些优势,但也有很多不足。 如果你想要产生电, 你得让水温比正常情况下 高很多。 在正常气压下,水在100度沸腾。 这还不足以有效的发电。 所以水冷反应堆必须在比大气压 更高的压力下运行。 一些水冷反应堆的运行压力 超过70个大气压, 另一些则高达150个大气压。 这是不可避免的; 如果你想要使用水冷反应堆产生电力, 就必须这样做。 这意味着你必须建造一个水冷反应堆 作为压力容器, 有超过20厘米厚的钢墙。 如果这听起来很重,那确实因为它很重。
Things get a lot worse if you have an accident where you lose pressure inside the reactor. If you have liquid water at 300 degrees Celsius and suddenly you depressurize it, it doesn't stay liquid for very long; it flashes into steam. So water-cooled reactors are built inside of big, thick concrete buildings called containment buildings, which are meant to hold all of the steam that would come out of the reactor if you had an accident where you lost pressure. Steam takes up about 1,000 times more volume than liquid water, so the containment building ends up being very large, relative to the size of the reactor.
如果发生事故,反应堆内部压力泄漏, 情况会变得更糟。 如果你有300摄氏度的液态水, 突然间减压, 它不会保持在液态太久, 而是会快速蒸发成蒸汽。 所以水冷反应堆建 在又大又厚的混凝土建筑内, 称为安全壳建筑, 假如你在事故中失去了压力, 它可以用来储存所有 从反应堆中泄漏的蒸汽。 蒸汽的体积大约是液态水的1000倍, 所以安全壳建筑最终相对反应堆 会变得非常庞大。
Another bad thing happens if you lose pressure and your water flashes to steam. If you don't get emergency coolant to the fuel in the reactor, it can overheat and melt. The reactors we have today use uranium oxide as a fuel. It's a ceramic material similar in performance to the ceramics we use to make coffee cups or cookware or the bricks we use to line fireplaces. They're chemically stable, but they're not very good at transferring heat. If you lose pressure, you lose your water, and soon your fuel will melt down and release the radioactive fission products within it.
假如你失压,另一件坏事是 水变成蒸汽。 如果你没有给反应堆中的 燃料提供紧急冷却剂, 它会过热而融化。 我们现在的反应堆使用 铀氧化物作为燃料。 它是一种陶瓷材料,在性能上类似于 我们用来制作咖啡杯或炊具的陶瓷, 或我们用来排列壁炉的砖。 它们的化学性质比较稳定, 但热传导性能不佳。 如果你失去压力,失去水, 很快你的燃料就会融化 并释放其中的放射性裂变产物。
Making solid nuclear fuel is a complicated and expensive process. And we extract less than one percent of the energy for the nuclear fuel before it can no longer remain in the reactor. Water-cooled reactors have another additional challenge: they need to be near large bodies of water, where the steam they generate can be cooled and condensed. Otherwise, they can't generate electrical power. Now, there's no lakes or rivers on the Moon, so if all of this makes it sound like water-cooled reactors aren't such a good fit for a lunar community, I would tend to agree with you.
制造固体核燃料是 一个复杂而昂贵的过程。 在核燃料不能再留在反应堆之前, 我们只提取了不到1%的能量。 水冷反应堆还面临着另一个挑战: 它们需要靠近大型水源, 在那里,它们产生的蒸汽 可以冷却和凝结。 否则,它们无法产生电力。 月球上没有湖水和河流, 所以听起来水冷反应堆 对于月球社区并不是很合适, 我倾向于同意你的看法。
(Laughter)
(笑声)
I had the good fortune to learn about a different form of nuclear power that doesn't have all these problems, for a very simple reason: it's not based on water-cooling, and it doesn't use solid fuel. Surprisingly, it's based on salt.
我幸运地了解到 有另外一种形式的核能 没有所有这些问题, 因为一个非常简单的原因: 它不基于水冷却,也不使用固体燃料。 让人惊奇的是,它是基于盐的。
One day, I was at a friend's office at work, and I noticed this book on the shelf, "Fluid Fuel Reactors." I was interested and asked him if I could borrow it. Inside that book, I learned about research in the United States back in the 1950s, into a kind of reactor that wasn't based on solid fuel or on water-cooling. It didn't have the problems of the water-cooled reactor, and the reason why was pretty neat. It used a mixture of fluoride salts as a nuclear fuel, specifically, the fluorides of lithium, beryllium, uranium and thorium. Fluoride salts are remarkably chemically stable. They do not react with air and water. You have to heat them up to about 400 degrees Celsius to get them to melt. But that's actually perfect for trying to generate power in a nuclear reactor.
有天,我在一个朋友的办公室工作, 我注意到书架上的 这本书《液体燃料反应堆》。 我产生了兴趣,问他是否能借读。 在那本书中,我了解到美国在 1950年代的研究, 一种不以固体燃料或水冷却为基础的 反应堆。 它没有水冷反应堆的这些问题, 原因很简单。 它使用氟化盐的混合物作为核燃料, 也就是锂、铍、铀和钍的氟化物。 氟化盐在化学上非常稳定。 它们不会跟空气和水反应。 你需要把它们加热到400摄氏度 才能让它们融化。 但这对于在核能反应堆里发电来说 是非常完美的。
Here's the real magic: they don't have to operate at high pressure. And that makes the biggest difference of all. This means they don't have to be in heavy, thick steel pressure vessels, they don't have to use water for coolant and there's nothing in the reactor that's going to make a big change in density, like water. So the containment building around the reactor can be much smaller and close-fitting. Unlike the solid fuels that can melt down if you stop cooling them, these liquid fluoride fuels are already melted, at a much, much lower temperature. In normal operation, you have a little plug here at the bottom of the reactor vessel. This plug is made out of a piece of frozen salt that you've kept frozen by blowing cool gas over the outside of the pipe. If there's an emergency and you lose all the power to your nuclear power plant, the little blower stops blowing, the frozen plug of salt melts, and the liquid fluoride fuel inside the reactor drains out of the vessel, through the line and into another vessel called a drain tank. Inside the drain tank, it's all configured to maximize the transfer of heat, so as to keep the salt passively cooled as its heat load drops over time. In water-cooled reactors, you generally have to provide power to the plant to keep the water circulating and to prevent a meltdown, as we saw in Japan. But in this reactor, if you lose the power to the reactor, it shuts itself down all by itself, without human intervention, and puts itself in a safe and controlled configuration.
这是真正的魔力所在: 它们不需要在高压下运行。 这就是最大的不同。 这意味着你不需要用到 又重又厚的钢制压力容器, 它们不需要用水来冷却, 在反应堆里没有任何东西 会像水一样,在密度上有大的改变。 所以反应堆周围的安全壳可以小得多, 也可以安装得很紧密。 不像固体燃料如果停止冷却就会融化, 这些液态氟化物燃料已经在一个 低得多的温度下融化了。 在正常的操作中,在反应堆容器的 底部有一个小塞子。 这个塞子是由一块冷冻盐制成的, 你可以把冷却的气体吹到管子外面 来保持它的冷冻状态。 如果发生紧急情况,你失去了核电站的 所有电力, 小鼓风机不吹了, 冻住的盐块融化了, 反应堆内的液态氟燃料 会从容器中通过管道排出, 然后进入另一个叫做排水槽的容器中。 在排水槽内部,所有的配置 都是为了最大限度地传递热量, 使盐在其热负荷随时间下降时 保持被动冷却。 在水冷反应堆中, 你通常必须为核电站提供电力, 以保持水的循环,防止熔毁, 就如我们在日本福岛 核事故中看到的那样。 但在这个反应堆中, 如果你失去了反应堆的能量, 它会自动关闭,不需要人工干预, 并将其置于安全可控的配置中。
Now, this was sounding pretty good to me, and I was excited about the potential of using a liquid fluoride reactor to power a lunar community. But then I learned about thorium, and the story got even better. Thorium is a naturally occurring nuclear fuel that is four times more common in the Earth's crust than uranium. It can be used in liquid fluoride thorium reactors to produce electrical energy, heat and other valuable products. It's so energy-dense that you could hold a lifetime supply of thorium energy in the palm of your hand. Thorium is also common on the Moon and easy to find. Here's an actual map of where the lunar thorium is located. Thorium has an electromagnetic signature that makes it easy to find, even from a spacecraft.
我觉得这个想法不错, 我对使用液态氟化反应堆 为月球社区提供能源的 潜力感到兴奋。 但后来我了解了钍,故事就变得更好了。 钍是一种天然的核燃料, 地壳中含量是铀的四倍。 它可用于液态氟钍反应器中 产生电能、热量等有价值的产品。 它的能量密度如此之大, 你可以把一辈子的钍能量 储存在你的手掌里。 钍在月球上也很常见,很容易找到。 这是月球上钍元素分布的真实地图。 钍的电磁特征使得它很容易被发现, 甚至在宇宙飞船中也能发现。
With the energy generated from a liquid fluoride thorium reactor, we could recycle all of the air, water and waste products within the lunar community. In fact, doing so would be an absolute requirement for success. We could grow the crops needed to feed the members of the community even during the two-week lunar night, using light and power from the reactor. It seemed like the liquid fluoride thorium reactor, or LFTR, could be the power source that could make a self-sustainable lunar colony a reality.
用液态氟钍反应堆产生的能量, 我们可以在月球社区中回收所有的 空气,水和废弃物。 事实上,这样做是成功的绝对必要条件。 即便在两周之久的月球黑夜中, 我们也可以使用 来自反应堆的照明和电力 来种植能满足社区所有成员的粮食。 看起来液态氟钍反应堆,简称LFTR的 能源能够让自给自足的月球殖民地 成为现实。
But I had a simple question: If it was such a great thing for a community on the Moon, why not a community on the Earth, a community of the future, self-sustaining and energy-independent? The same energy generation and recycling techniques that could have a powerful impact on surviving on the Moon could also have a powerful impact on surviving on the Earth. Right now, we're burning fossil fuels because they're easy to find and because we can. Unfortunately, they're making some parts of our planet look like the Moon. Using fossil fuels entangles us in conflict in unstable regions of the world and costs money and lives.
但我有个简单的问题: 如果这对于月球社区是如此伟大的事情, 为什么不在地球上建立 一个社区,一个未来的社区, 一个自我维持和能源独立的社区。 同样的能源生产和回收技术 可能会对在月球上生存产生强大的影响, 也同样对地球的生存有强大的影响。 现在,我们在燃烧化石燃料, 因为它们易于开采,并且因为我们能够。 不幸的是,它们让地球的 某些部分变得像月球。 使用化石燃料使我们卷入了 世界不稳定地区的冲突, 导致金钱和生命的损失。
Things could be very different if we were using thorium. You see, in a LFTR, we could use thorium about 200 times more efficiently than we're using uranium now. And because the LFTR is capable of almost completely releasing the energy in thorium, this reduces the waste generated over uranium by factors of hundreds, and by factors of millions over fossil fuels. We're still going to need liquid fuels for vehicles and machinery, but we could generate these liquid fuels from the carbon dioxide in the atmosphere and from water, much like nature does. We could generate hydrogen by splitting water and combining it with carbon harvested from CO2 in the atmosphere, making fuels like methanol, ammonia, and dimethyl ether, which could be a direct replacement for diesel fuels. Imagine carbon-neutral gasoline and diesel, sustainable and self-produced.
如果我们使用钍,情况可能会大不相同。 可以看到,在LFTR中, 我们用钍的效率 比今天使用的铀高200倍。 因为LFTR几乎可以完全释放 钍的能量, 这减少了数百倍的铀废料, 还有数百万的化石燃料。 我们仍然需要为汽车 和机器提供液体燃料, 但是我们可以从大气中的 二氧化碳和水中产生 这些液体燃料,跟自然界中的过程一样。 我们可以通过将水分解产生氢 并与大气中的二氧化碳里的碳结合, 制造甲醇、氨和二甲醚等燃料, 可以直接替代柴油。 想象一下碳中性汽油和柴油, 可持续和自生产。
Do we have enough thorium? Yes, we do. In fact, in the United States, we have over 3,200 metric tons of thorium that was stockpiled 50 years ago and is currently buried in a shallow trench in Nevada. This thorium, if used in LFTRs, could produce almost as much energy as the United States uses in three years. And thorium is not a rare substance, either. There are many sites like this one in Idaho, where an area the size of a football field would produce enough thorium each year to power the entire world.
我们有足够的钍吗? 是的,没错。 事实上,在美国,我们50年来储存的钍 就有3200吨, 目前埋在内华达州的一条浅沟渠中。 这些钍,如果用在LFTR中, 它可以产生几乎相当于 全美国使用三年的能源。 钍也不是稀有物质。 爱达荷州有很多这样的地方, 一个足球场那么大的区域 每年就能生产出足够的钍 来为整个世界供能。
Using liquid fluoride thorium technology, we could move away from expensive and difficult aspects of current water-cooled, solid-fueled uranium nuclear power. We wouldn't need large, high-pressure nuclear reactors and big containment buildings that they go in. We wouldn't need large, low-efficiency steam turbines. We wouldn't need to have as many long-distance power transmission infrastructure, because thorium is a very portable energy source that can be located near to where it is needed. A liquid fluoride thorium reactor would be a compact facility, very energy-efficient and safe, that would produce the energy we need day and night, and without respect to weather conditions. In 2007, we used five billion tons of coal, 31 billion barrels of oil and five trillion cubic meters of natural gas, along with 65,000 tons of uranium to produce the world's energy. With thorium, we could do the same thing with 7,000 tons of thorium that could be mined at a single site.
采用液态氟钍技术, 我们可以摆脱目前水冷、 固体燃料铀核电昂贵和困难的一面。 我们不需要大的,高压的核反应堆 和大型围堵建筑。 我们不需要大型、低效的汽轮机。 我们不要拥有 长途输电基础设施, 因为钍是一种非常便携的能源, 可以被直接运送到需要它们的地方。 液态氟钍反应堆将是一个紧凑的设施, 非常节能和安全, 将产生我们日常所需的能量, 而无需考虑天气条件。 2007年,我们使用了50亿煤, 310亿桶石油, 和5万亿立方米的天然气, 还有65000吨铀 来生产全世界所需的能源。 有了钍,我们在一个地点 开采7000吨的钍就能做到同样的事情。
If all this sounds interesting to you, I invite you to visit our website, where a growing and enthusiastic online community of thorium advocates is working to tell the world about how we can realize a clean, safe and sustainable energy future, based on the energies of thorium.
如果你们对这些很有兴趣, 欢迎访问我们的站网站, 那里有一个日益壮大、 热情高涨的钍在线社区, 致力于告诉世界我们如何 才能实现清洁、安全 和可持续的,基于钍的 未来能源。
Thank you very much. (Applause)
谢谢。 (鼓掌)