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核废料危害大吗?

What's Nuclear Waste?

你以前在《辛普森一家》或其他电影看过的
So you’ve seen episodes of The Simpsons or other movies,
核废料泄露液体的情况
where the nuclear waste is leaking,
那些泛着绿光的核废料
and it’s glowing green
或许会赋予你超能力 或许会杀死你
and it either gives you super powers or it kills you,
或许先给你超能力再杀死你
or maybe one and then the other.
[音乐]
[MUSIC]
事实上这是不可能发生的
That’s not actually what happens.
这位是迈克
THIS IS MIKE.
大部分核废料里面的固体材料
Most of the solid materials in nuclear waste,
它们就是那样的……它们是固体
they’re just that… they’re solid.
它们不会泄露流出来
They don’t leak.
他是麻省理工的核科学家
HE’S A NUCLEAR SCIENTIST AT MIT.
而且 即使是核废料里的液体材料
And even the liquid materials in nuclear waste,
储存它们的容器也异常坚固
those containers are so robust
实际上我们已经做过相关实验 还拍了视频
that we actually have tests that we’ve done that are on video
你可以去YouTube上找来看
and you can go out and watch on YouTube,
我们把储存箱浸在航空煤油里
doused them in jet fuel and
用一辆火车向放有储存箱的火车冲过去
putting them on a train and running another train at them
撞向固定着金属钉的水泥墙
with a metal spike aimed at a concrete wall,
把它们从直升机上扔下来
or dropping them off of a helicopter,
这就是对储存箱做过的各种实验
these are the sorts of tests that we do for nuclear waste containers,
它们必须在每种实验下都完好无损才行
and they have to survive every single one.
所以不会发生随手扔点什么东西
It’s like we can’t throw anything at these containers
就把储存箱砸烂了
that gets them to break apart.
核能是有风险的
NUCLEAR POWER HAS RISKS.
你的第一反应是恐惧
Your immediate reaction is fear,
这是很正常的
and that’s a natural reaction.
人都有战斗或逃跑的本能反应
We’re all built with a fight or flight
这是有原因的
response for a reason,
这些本能保障我们的安全
it’s kept us out of danger
所以我们没有被动物吃掉
and it’s why the human race still exists,
所以人这一物种依然存在
is we haven’t been eaten to death.
但是核能也有优点
BUT NUCLEAR POWER ALSO HAS BENEFITS.
我们之所以称核能为清洁能源替代品
The reason we call nuclear a clean energy alternative
是因为我们使用核能时
is that it does not emit CO2,
它不释放二氧化碳
carbon dioxide, when you use it.
当你实际使用核能时
When you actually use the fuel,
它绝对不会产生二氧化碳
it produces absolutely no CO2.
有些关于核能的事
AND THERE ARE ABOUT NUCLEAR ENERGY
会让你大吃一惊
THAT MIGHT SURPRISE YOU.
吃一根香蕉的辐射是住在核电站50英里内
Eating one banana gives you 11 times as much radiation
一年所接受的辐射的11倍
as living within 50 miles of a nuclear plant for a year.
如果你住在煤电厂附近
If you live near a coal power plant,
你受到的辐射
you get 30 times as much radiation
是住在核电站附近的30倍
as you do if you live near a nuclear plant.
所以我们做了这个视频来解释:
SO WE MADE THIS VIDEO TO EXPLAIN SOME OF THEM.
发电厂的重点是发电
The point of a power plant is to make electricity,
它们都是通过加热水产生蒸汽
and they all do so by heating up water
来驱动涡轮机发电的
to make steam to drive a turbine.
叶轮驱动一个像汽车或者发电机那样的交流发电机转动
That turbine drives an alternator, like what’s in your car or a generator,
这样就产生了电能
and that’s what produces electricity.
核能加热水的方式是
The way nuclear power heats up water
像铀-235这样的裂变原子
is that these fissile atoms, like uranium-235,
在受到中子撞击后发生分裂
split apart when neutrons hit them.
被称为裂变产物的碎片释放大量能量
And the fragments, called fission products, release a lot of energy.
碎片不断撞击周围的原子 使它们发热
They bounce around the other atoms, heating them up,
加热了周围的水流 形成蒸汽
and water flows around them making steam
蒸汽驱动叶轮 进而产电
that drives a turbine and makes electricity.
反应堆的运行中止
Nuclear waste is all the leftover stuff
或者燃料耗尽的时候
when you’re done running the reactor,
剩下的东西就是核废料
or you’re done using the fuel.
废料包含前面提到的裂变产物
This includes those fission products that we talked about,
因为吸收了一些中子
the structural materials nearby
所以变成放射性物质的反应器结构材料
that have absorbed some of the neutrons and become radioactive,
以及我们不希望进入外界的任何放射性物质
and anything else radioactive that we don’t want to get to the outside world.
放射线会损伤你的细胞 你的遗传物质
Radioactivity can damage your cells, your DNA,
最终导致癌症
and eventually cause cancer.
那么问题来了
The question is, though,
接受多少辐射才能导致这样的后果?
how much radiation does it take to do this?
答案是要远超过
And the answer is a whole lot more
我们每天承受的自然辐射
than the amount we naturally tolerate everyday.
我们在充满辐射的世界已经发生了进化
We’ve evolved in a constantly radioactive world.
有来自宇宙的 大地的 空气的辐射
There’s radiation coming from space, from the ground, from the air.
你吃的食物里面有钾和碳14
The food you eat containspotassium, carbon-14.
它们都是天然放射性同位素
They’re all naturally radioactive occurring isotopes.
你房子的装修材料也有放射性
The building materials from your house, they’re radioactive.
自然中有很多背景辐射
There’s a lot of natural background radiation
所有生物都进化到适应背景辐射了
that all of life has evolved to tolerate.
未封装的核废料产生的辐射
The radiation from un-contained nuclear waste
远超人的承受范围
is way more than the body can tolerate.
幸运的是 一旦它们被封存好
Luckily for us, when it’s properly contained,
能接受到的辐射总量几乎为零
the amount that we’re exposed to is next to nothing.
废料被储存的金属燃料棒中 称为“燃料展平”
It’s contained within metal fuel rods, called fuel flattening.
金属燃料棒被打包成燃料组
Those are contained in fuel assemblies,
这些燃料组被封存进
and those fuel assemblies are
铜 不锈钢或混凝土容器
sealed up in either copper, stainless steel, or concrete containers.
所以有多重封装确保
So there’s multiple barriers
所有东西都被包裹在废物储存器中
keeping everything inside that waste container.
我不排斥住在核废料处理站附近
I’d gladly live next to a nuclear waste burial site.
目前 我们封存核废料
Right now, we seal up nuclear waste
然后就地储存在发电厂
and store it onsite at the power plants,
但我真正希望看到的是
but what I’d really like to see us do
可以从废料里提取些有价值的东西
is get some value out of that waste.
你认为反应器里有多少燃料是真正被利用了的?
So how much of the fuel do you think actually gets used in the reactor?
90%
90%?
80%?70%?60%?50%?40%?都不是!
80? 70? 60? 50? 40? No?
只有5%!
5%!
只有5%的燃料被真正利用了
5% of the fuel is actually used,
反应器里95%的燃料都成为了废料
95% of the useful fuel exits the reactor as waste.
所以你可能会想 我的天啊
So you might be wondering, well jeez ,
为什么反应堆的燃料利用效率这么差?
why are reactors so bad at utilizing their own fuel?
这是因为即使只有5%
It’s ’cause even that 5%
也会产生被称为“中子毒物”的产物
ends up making things called neutron poisons,
“中子毒物”从其它反应物那夺走了
because they take neutrons away
应与这些物质产生铀裂变的中子
from what otherwise would make uranium split apart.
现在利用化学手段
Now, you can, chemically,
把那些裂变产物分离出来
separate out those fission products
然后回收燃料重新使用
and recycle the fuel as fresh fuel,
这个实际在法国 日本等其他国家已经实现了
and this is actually done in France, Japan, most other countries.
美国情况很特殊
The US is quite unique
我们的法律禁止再加工
in we have laws against reprocessing.
所以你可能会惊讶于
So you might be surprised at how much other valuable
废物里居然有如此多值钱的东西
stuff there is in”waste”.
金 银 铂 铑 钌
Gold, silver, platinum, rhodium, ruthenium.
一些其他的废弃产物
Some of the other waste products,
比如钚-238和锶-90
like plutonium-238 and strontium-90,
它们通常用在远离太阳的地方推进航空器
are used to power spacecrafts that go too far from the sun,
因为那里无法使用太阳能
where you can’t use solar power.
核反应还有很多其他有价值的副产物
There are a bunch of other valuable by-products of a nuclear reaction.
比如氢的同位素——氚
There’s tritium, an isotope of hydrogen,
还有失去一个中子的氦的同位素——氦-3
and helium-3, an isotope of helium that’s missing a neutron.
它们在黑市的价格分别是每公斤3万和5.3万美元
The street value of those gases are $ 30,000 and $ 53,000 a kilogram.
氦-3很有利于检测难检出的中子
Helium-3 is really good at detecting neutrons, which is usually tricky to do,
因此它十分有价值 我们太需要它了
and it’s so valuable, and we need it so much,
甚至于到月球开采它 在经济上都是可行的
that it’s economically feasible to mine it on the moon.
向月球发射火箭
It actually makes economic sense
采集氚-3带回地球
to send a rocket to the moon,
真的有很大的经济意义
accumulate helium-3 and bring it back to Earth.
如果可以从已有的反应器中得到它们
If we could get that from the reactors we already have,
那就真是太好了
that would be fantastic.
早晚有一天会实现的 迈克早晚有一天
IT REALLY WOULD, MIKE. IT REALLY WOULD.

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视频概述

核能有很广阔的前景,但谈到核能就不得不面对核废料的问题。那么核废料从哪来?如何处理?它真的对人类有很大威胁吗?

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翻译译者

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审核员_DB

视频来源

https://www.youtube.com/watch?v=IGRMGmPw3Kw

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