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,