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  • Well, I have a big announcement to make today,

    我今天要發表一個重大聲明

  • and I'm really excited about this.

    我感到很興奮

  • And this may be a little bit of a surprise

    各位可能會感到驚訝

  • to many of you who know my research

    因為很多人對我過去的研究

  • and what I've done well.

    及成果相當瞭解

  • I've really tried to solve some big problems:

    我曾努力解決一些重大問題:

  • counterterrorism, nuclear terrorism,

    反恐怖主義、核子恐怖主義、

  • and health care and diagnosing and treating cancer,

    醫療保健、診斷治療癌症

  • but I started thinking about all these problems,

    但我開始思考這些問題時

  • and I realized that the really biggest problem we face,

    我意識到我們面臨的最大問題

  • what all these other problems come down to,

    也是所有問題的根源

  • is energy, is electricity, the flow of electrons.

    就是能源,也就是電流, 電子的流動

  • And I decided that I was going to set out

    我決定要開始

  • to try to solve this problem.

    嘗試解決這個問題

  • And this probably is not what you're expecting.

    以下可能並非各位期待的

  • You're probably expecting me to come up here

    你們可能希望我到這裡

  • and talk about fusion,

    來談核聚變

  • because that's what I've done most of my life.

    因為那是我目前做最多的事

  • But this is actually a talk about, okay --

    但我今天真正要說的是…

  • (Laughter) —

    (笑)好…

  • but this is actually a talk about fission.

    我今天真正要說的是-核裂變

  • It's about perfecting something old,

    把老東西變得更完美

  • and bringing something old into the 21st century.

    把老東西帶入21世紀

  • Let's talk a little bit about how nuclear fission works.

    先簡單說明核裂變的原理

  • In a nuclear power plant, you have

    核電廠裡有個

  • a big pot of water that's under high pressure,

    很大的高壓水箱

  • and you have some fuel rods,

    及一些燃料棒

  • and these fuel rods are encased in zirconium,

    這些燃料棒,用鋯封裝了

  • and they're little pellets of uranium dioxide fuel,

    小小的二氧化鈾燃料丸

  • and a fission reaction is controlled and maintained at a proper level,

    核裂變反應會控制在適當水準

  • and that reaction heats up water,

    將水加熱

  • the water turns to steam, steam turns the turbine,

    水變成蒸汽,蒸汽推動渦輪

  • and you produce electricity from it.

    電就產生了

  • This is the same way we've been producing electricity,

    我們一直採用相同方式發電

  • the steam turbine idea, for 100 years,

    蒸汽渦輪已用了100年

  • and nuclear was a really big advancement

    以加熱水的方法而言

  • in a way to heat the water,

    核能真是巨大的進步

  • but you still boil water and that turns to steam and turns the turbine.

    但還是要燒水,變成蒸汽推動渦輪

  • And I thought, you know, is this the best way to do it?

    我想,這是最好的方式嗎?

  • Is fission kind of played out,

    核裂變是不是落伍了

  • or is there something left to innovate here?

    還是可以繼續創新呢?

  • And I realized that I had hit upon something

    我意識到一個想法

  • that I think has this huge potential to change the world.

    有巨大的潛力可以改變世界

  • And this is what it is.

    這個想法是這樣的

  • This is a small modular reactor.

    這是個小型模組化反應爐

  • So it's not as big as the reactor you see in the diagram here.

    不像那張圖裡的反應爐那麼大

  • This is between 50 and 100 megawatts.

    介於50到100百萬瓦

  • But that's a ton of power.

    但仍是很大的功率

  • That's between, say at an average use,

    在一般情況下

  • that's maybe 25,000 to 100,000 homes could run off that.

    可供2萬5千至10萬個家庭使用

  • Now the really interesting thing about these reactors

    這些反應爐真正有趣的地方在於

  • is they're built in a factory.

    是工廠生產出來的

  • So they're modular reactors that are built

    模組化反應爐

  • essentially on an assembly line,

    是在生產線上建造出來的

  • and they're trucked anywhere in the world,

    然後運到世界各地

  • you plop them down, and they produce electricity.

    丟著就可以發電了

  • This region right here is the reactor.

    這個區域就是反應爐

  • And this is buried below ground, which is really important.

    是埋在地底下的,這很重要

  • For someone who's done a lot of counterterrorism work,

    對從事反恐工作的人來說

  • I can't extol to you

    我的言語難以形容

  • how great having something buried below the ground is

    埋在地下有多美好

  • for proliferation and security concerns.

    因為沒有核子擴散和安全問題

  • And inside this reactor is a molten salt,

    反應爐裡面是熔解的鹽

  • so anybody who's a fan of thorium,

    在座如果有 釷元素的粉絲

  • they're going to be really excited about this,

    一定會很興奮

  • because these reactors happen to be really good

    因為這種反應爐最擅長

  • at breeding and burning the thorium fuel cycle,

    釷燃料循環 的滋生和燃燒

  • uranium-233.

    最後產生鈾-233

  • But I'm not really concerned about the fuel.

    我真正關心的不是燃料

  • You can run these off -- they're really hungry,

    因為總會用完的,反應爐很餓

  • they really like down-blended weapons pits,

    反應爐很喜歡稀釋的核武原料

  • so that's highly enriched uranium and weapons-grade plutonium

    像高濃縮鈾和及核武級的鈽

  • that's been down-blended.

    加以稀釋

  • It's made into a grade where it's not usable for a nuclear weapon,

    降到不可能用來作為核武

  • but they love this stuff.

    模組化反應爐很愛吃這個

  • And we have a lot of it sitting around,

    而我國有一大堆

  • because this is a big problem.

    這是個大問題

  • You know, in the Cold War, we built up this huge arsenal

    冷戰時期我們儲備了

  • of nuclear weapons, and that was great,

    大量的核武,太棒了

  • and we don't need them anymore,

    我們再也不需要核武了

  • and what are we doing with all the waste, essentially?

    這些留下來的垃圾該怎麼辦?

  • What are we doing with all the pits of those nuclear weapons?

    核武裡的核物質要怎麼處理?

  • Well, we're securing them, and it would be great

    我們要確保其安全

  • if we could burn them, eat them up,

    如果能燒掉、吃掉,那就太棒了

  • and this reactor loves this stuff.

    這個反應爐就愛這樣

  • So it's a molten salt reactor. It has a core,

    熔鹽反應爐有個核心

  • and it has a heat exchanger from the hot salt,

    還有熱交換器,把熱量由

  • the radioactive salt, to a cold salt which isn't radioactive.

    「熱鹽」,即放射性鹽 傳到「冷鹽」,即無放射性的鹽

  • It's still thermally hot but it's not radioactive.

    冷鹽還是很熱,但沒有放射性

  • And then that's a heat exchanger

    熱交換器

  • to what makes this design really, really interesting,

    是這種反應爐設計最有趣的地方

  • and that's a heat exchanger to a gas.

    這種熱交換器用的是氣體

  • So going back to what I was saying before about all power

    我剛說了,產生所有的能量前

  • being produced -- well, other than photovoltaic --

    除了光電池外…

  • being produced by this boiling of steam and turning a turbine,

    都要燒水,產生蒸汽,推動渦輪

  • that's actually not that efficient, and in fact,

    如此效率並不高,事實上

  • in a nuclear power plant like this,

    傳統的核電廠

  • it's only roughly 30 to 35 percent efficient.

    效率大約只有30到35%

  • That's how much thermal energy the reactor's putting out

    這是反應爐產生的熱能

  • to how much electricity it's producing.

    與實際產生電力的比值

  • And the reason the efficiencies are so low is these reactors

    效率這麼低的原因是這些反應爐

  • operate at pretty low temperature.

    在低溫下運轉

  • They operate anywhere from, you know,

    運轉溫度介於

  • maybe 200 to 300 degrees Celsius.

    約攝氏200到300度

  • And these reactors run at 600 to 700 degrees Celsius,

    新型反應爐高達攝氏600到700度

  • which means the higher the temperature you go to,

    溫度越高

  • thermodynamics tells you that you will have higher efficiencies.

    依據熱力學原理,效率就越高

  • And this reactor doesn't use water. It uses gas,

    而且這個反應爐不用水,改用氣體

  • so supercritical CO2 or helium,

    用超臨界二氧化碳,或是氦氣

  • and that goes into a turbine,

    氣體直接進入渦輪

  • and this is called the Brayton cycle.

    稱為布雷頓循環

  • This is the thermodynamic cycle that produces electricity,

    是個產生電的熱力學循環

  • and this makes this almost 50 percent efficient,

    效率接近50%

  • between 45 and 50 percent efficiency.

    在45%到50%之間

  • And I'm really excited about this,

    我真的感到很興奮

  • because it's a very compact core.

    因為這個核心相當小

  • Molten salt reactors are very compact by nature,

    熔鹽反應爐本來就很小

  • but what's also great is you get a lot more electricity out

    另外也很棒的,是會得到更多的電

  • for how much uranium you're fissioning,

    比等量的鈾分裂還多

  • not to mention the fact that these burn up.

    更不用提燃耗了

  • Their burn-up is much higher.

    新反應爐的燃耗比率高多了

  • So for a given amount of fuel you put in the reactor,

    放進等量的燃料

  • a lot more of it's being used.

    利用到的多了很多

  • And the problem with a traditional nuclear power plant like this

    傳統的核電廠有個問題

  • is, you've got these rods that are clad in zirconium,

    燃料棒用鋯包著

  • and inside them are uranium dioxide fuel pellets.

    裡面是二氧化鈾燃料丸

  • Well, uranium dioxide's a ceramic,

    二氧化鈾已燒結為陶瓷

  • and ceramic doesn't like releasing what's inside of it.

    陶瓷不太會釋出內部的東西

  • So you have what's called the xenon pit,

    氙氣會累積

  • and so some of these fission products love neutrons.

    有些核裂變產物很喜歡中子

  • They love the neutrons that are going on

    很喜歡周圍這些中子

  • and helping this reaction take place.

    並幫助反應進行

  • And they eat them up, which means that, combined with

    會將其侵蝕掉,再加上

  • the fact that the cladding doesn't last very long,

    包覆層不太耐用

  • you can only run one of these reactors

    所以傳統反應爐

  • for roughly, say, 18 months without refueling it.

    補充燃料一次大約只可燒18個月

  • So these reactors run for 30 years without refueling,

    新式核反應爐可用30年 不用補充燃料

  • which is, in my opinion, very, very amazing,

    我覺得非常非常驚人

  • because it means it's a sealed system.

    因為這意味著一個全封閉的系統

  • No refueling means you can seal them up

    不用補充燃料表示可以封起來

  • and they're not going to be a proliferation risk,

    就不會有核子擴散的風險了

  • and they're not going to have

    不會有…

  • either nuclear material or radiological material

    核子物質或放射性物質

  • proliferated from their cores.

    從內核洩漏出來

  • But let's go back to safety, because everybody

    再回到安全問題

  • after Fukushima had to reassess the safety of nuclear,

    福島事故後,大家都重新評估 核能安全

  • and one of the things when I set out to design a power reactor

    我開始設計新型反應爐的理念之一

  • was it had to be passively and intrinsically safe,

    就是必須為被動安全和本質安全

  • and I'm really excited about this reactor

    我對新型反應爐感到很興奮

  • for essentially two reasons.

    有兩個重要原因:

  • One, it doesn't operate at high pressure.

    第一,不必在高壓環境中運轉

  • So traditional reactors like a pressurized water reactor

    傳統反應爐,如壓水式反應爐

  • or boiling water reactor, they're very, very hot water

    或沸水式反應爐

  • at very high pressures, and this means, essentially,

    都有高熱高壓的水,這表示

  • in the event of an accident, if you had any kind of breach

    一旦發生事故

  • of this stainless steel pressure vessel,

    當不銹鋼壓力容器出現裂縫

  • the coolant would leave the core.

    冷卻劑就會從內核中洩漏出來

  • These reactors operate at essentially atmospheric pressure,

    新型反應爐在一般大氣壓力下運轉

  • so there's no inclination for the fission products

    核裂變產物不太可能

  • to leave the reactor in the event of an accident.

    會在事故中洩漏

  • Also, they operate at high temperatures,

    而且反應爐在高溫運轉

  • and the fuel is molten, so they can't melt down,

    燃料本就是熔化的,所以不會熔毀

  • but in the event that the reactor ever went out of tolerances,

    即使這個反應爐真的撐不住了

  • or you lost off-site power in the case

    或像福島那樣失去外部電源

  • of something like Fukushima, there's a dump tank.

    我們還有排汙槽

  • Because your fuel is liquid, and it's combined with your coolant,

    因為燃料是液體,混合了冷卻劑

  • you could actually just drain the core

    事實上可把整個內核

  • into what's called a sub-critical setting,

    排入亞臨界裝置

  • basically a tank underneath the reactor

    基本上就是反應爐下的水槽

  • that has some neutrons absorbers.

    裡面有中子吸收劑

  • And this is really important, because the reaction stops.

    這很重要,因為連鎖反應停止了

  • In this kind of reactor, you can't do that.

    傳統反應爐無法做到這點

  • The fuel, like I said, is ceramic inside zirconium fuel rods,

    它的燃料是包在鋯燃料棒裡的陶瓷

  • and in the event of an accident in one of these type of reactors,

    以下幾種反應爐如果發生事故

  • Fukushima and Three Mile Island --

    例如福島和三哩島…

  • looking back at Three Mile Island, we didn't really see this for a while

    回顧三哩島,我們好久沒關心了…

  • but these zirconium claddings on these fuel rods,

    燃料棒外面的鋯包覆

  • what happens is, when they see high pressure water,

    遇到高壓的水

  • steam, in an oxidizing environment,

    或蒸汽,並處在氧化環境中

  • they'll actually produce hydrogen,

    實際上會產生氫氣

  • and that hydrogen has this explosive capability

    氫氣有可能爆炸

  • to release fission products.

    釋放核裂變產物

  • So the core of this reactor, since it's not under pressure

    新式反應爐內核不處在壓力狀態

  • and it doesn't have this chemical reactivity,

    而且沒有這種化學反應性

  • means that there's no inclination for the fission products

    就表示不太可能讓核裂變產物

  • to leave this reactor.

    洩漏出反應爐

  • So even in the event of an accident,

    所以一旦發生事故

  • yeah, the reactor may be toast, which is, you know,

    是的,這個反應爐會燒壞,就是說

  • sorry for the power company,

    電力公司,抱歉了

  • but we're not going to contaminate large quantities of land.

    但它不會汙染大片土地

  • So I really think that in the, say,

    所以我真的覺得

  • 20 years it's going to take us to get fusion

    這可給我們20年過渡時間

  • and make fusion a reality,

    讓核聚變成為現實

  • this could be the source of energy

    這種能源

  • that provides carbon-free electricity.

    提供了無碳的電力

  • Carbon-free electricity.

    無碳電力

  • And it's an amazing technology because

    這是非常令人驚歎的技術

  • not only does it combat climate change,

    不但可對抗氣候變遷

  • but it's an innovation.

    更是個創新

  • It's a way to bring power to the developing world,

    可將能源帶給開發中國家

  • because it's produced in a factory and it's cheap.

    因為是在工廠生產的,所以很便宜

  • You can put them anywhere in the world you want to.

    可裝置在任何地方

  • And maybe something else.

    接下來我要談一些別的

  • As a kid, I was obsessed with space.

    小時候我對太空非常癡迷

  • Well, I was obsessed with nuclear science too, to a point,

    嗯,我對核子科學也非常著迷

  • but before that I was obsessed with space,

    但在那以前,我對太空很著迷

  • and I was really excited about, you know,

    我很興奮

  • being an astronaut and designing rockets,

    希望能當太空人和設計火箭

  • which was something that was always exciting to me.

    總是讓我很興奮

  • But I think I get to come back to this,

    我覺得可以重拾童年夢想

  • because imagine having a compact reactor in a rocket

    只要火箭裡裝個小型反應爐

  • that produces 50 to 100 megawatts.

    可發電50到100百萬瓦

  • That is the rocket designer's dream.

    這是火箭設計師的夢想

  • That's someone who is designing a habitat on another planet's dream.

    也是外星基地設計師的夢想

  • Not only do you have 50 to 100 megawatts

    不只有50到100百萬瓦電力

  • to power whatever you want to provide propulsion to get you there,

    提供給以任何動力推進的飛行器

  • but you have power once you get there.

    甚至到目的地之後,也有電可用

  • You know, rocket designers who use solar panels

    相較原先火箭設計師利用太陽能板

  • or fuel cells, I mean a few watts or kilowatts --

    和燃料電池,只有幾瓦到幾千瓦…

  • wow, that's a lot of power.

    哇,那可是好多電力

  • I mean, now we're talking about 100 megawatts.

    我們談的是100百萬瓦

  • That's a ton of power.

    這是超多的電力

  • That could power a Martian community.

    夠為整個火星社區供電了

  • That could power a rocket there.

    足以為火箭供電

  • And so I hope that

    所以我希望有機會

  • maybe I'll have an opportunity to kind of explore

    在探索核能的同時

  • my rocketry passion at the same time that I explore my nuclear passion.

    也有機會探索我熱愛的火箭

  • And people say, "Oh, well, you've launched this thing,

    有人會說,「你發射的這個東西,

  • and it's radioactive, into space, and what about accidents?"

    它有輻射,發生事故怎麼辦?」

  • But we launch plutonium batteries all the time.

    其實太空船一直在用鈽電池

  • Everybody was really excited about Curiosity,

    大家都對探測火星的好奇號很興奮

  • and that had this big plutonium battery on board

    它上面就裝了一個這麼大的鈽電池

  • that has plutonium-238,

    用的是鈽-238

  • which actually has a higher specific activity

    它的反應活性

  • than the low-enriched uranium fuel of these molten salt reactors,

    比熔鹽反應爐的低濃度鈾燃料更高

  • which means that the effects would be negligible,

    表示它的影響可以忽略

  • because you launch it cold,

    因為發射時反應爐還沒啟動

  • and when it gets into space is where you actually activate this reactor.

    進入太空後才會啟動

  • So I'm really excited.

    我真的很興奮

  • I think that I've designed this reactor here

    我想我已設計出這個反應爐

  • that can be an innovative source of energy,

    這是創新的能源

  • provide power for all kinds of neat scientific applications,

    可為各種了不起的科學應用供電

  • and I'm really prepared to do this.

    我已經準備好這麼做了

  • I graduated high school in May, and --

    五月我就要高中畢業了…

  • (Laughter) (Applause) —

    (笑聲)(掌聲)…

  • I graduated high school in May,

    五月我高中畢業後