Let's take a peek at a future powered by nuclear!
This is a little weird.
We can radically cut climate change emissions and leave a safe clean world for the future.
We don't need to invent anything new!
We just need to stop wasting time with distractions like nuclear power.
Come on!
Let's build the future we all want to see!
To understand why nuclear power has so much potential requires some effort.
It requires you to exercise a little bit of study.
Which part of this is doable, and could be safe, and could be acceptable in our society,
and which part of this is not?
And there's a collage of images that the anti-nuclear movement will throw you,
usually of nuclear weapons.
I hate nuclear weapons.
I never want to see nuclear weapons used.
I have no interest in that- But I do want to see nuclear power used to make my life,
and my children's lives, and your children's lives safer and better.
Think of the sun's heat on your upturned face on a cloudless summer's day.
From 150,000,000 kilometres away- we recognize its power.
When was the last time you watched Cosmos with Carl Sagan?
Recently actually.
Yeah?
I showed it to my kids a couple years ago.
Empire Strikes Back and Cosmos were probably
two of my formative influences of the age of 6.
The Sun is the nearest star- a glowing sphere of gas.
The surface we see an ordinary visible light is at 6,000 degrees centigrade.
But in its hidden interior- Super hot gas pushes the Sun to expand outward.
At the same time The Sun's own gravity pulls it inward to contract.
A stable equilibrium between gravity and nuclear fire.
Atoms are made in the insides of stars.
The atoms are moving so fast, that when they collide, they fuse.
Helium is the ash of The Sun's nuclear furnace.
The Sun is a medium-sized star, its core is only lukewarm 10,000,000 degrees.
Hot enough to fuse hydrogen, but too cold to fuse helium.
There many stars in the galaxy more massive yet,
that live fast and die young in cataclysmic supernova explosions.
Those explosions are far hotter than the core of the Sun.
Hot enough to transform elements like iron into all the heavier ones,
and spew them into space.
Long before the Earth, our home, was built- stars brought forth its substance.
Our planet, our society, and we ourselves, are built of star stuff.
Now, two of the things that were created in supernova are thorium and uranium.
These were different because they were radioactive and they kept some of that
energy from the supernova explosion stored in their very nuclear structure.
And some of this thorium and uranium was incorporated into our planet.
Sinking to the center of the world, and heating our planet.
Liquid iron circulating around the solid part of the core as Earth rotates- acts like a
wire carrying electric current.
Electric currents produce magnetic fields, and that's a good thing.
Our magnetic field protects us from the onslaught of cosmic rays.
A bigger deal- the magnetic field is deflecting the solar wind.
If you don't have a magnetic field deflecting the solar wind, over billions of years your
planet ends up like Mars.
Because the solar wind will strip off a planet's atmosphere,
without the protective nature of the magnetic field.
So if we didn't have the energy from thorium inside the Earth we would be on a dead planet.
The decay of radioactive elements in the core keeps it moving.
Let's talk about radioactivity.
Because I had an erroneous notion of what radioactivity was.
I thought, that if you had something that had like a half-life of a day, and you had
something had a half-life of a million years, it meant that the dude that was radioactive
for a day is like brr-r-r-r-r-r-r-r for a day and then, ooop, I'm done.
And the dude with the half-life for a million years is like brr-r-r-r-r-r-r-r for a million
years, and then done.
Ok, so you go- Which one of these is more dangerous?
Well definitely the one that's got a half-life of a million years because that's got to be,
like, radioactive forever, and the dudes that's radioactive for a day that's not a big deal,
right?
Completely wrong!
Ok?
Utterly backwards.
The dude who is radioactive for a day is really, really radioactive!
The dude who is radioactive for a million years is hardly radioactive at all.
Which one of those two is more dangerous?
The one that's radioactive for a day.
By a long shot!
Ok?
So you're radioactivity is directly, and inversely proportional to your half-life.
If somebody goes to you here's stuff that's got half-life of a million years- scary huh?
You go, here give it to me, I'm going to put it in my hand.
It's not going to hurt me.
Agghh!
It's not going to hurt me.
Here's stuff with a half-life of a day- you want to hold it?
No!
No, keep it away from me man!
That stuff is hot!
But it's going away fast too, right?
Got a longer half-life?
Less dangerous.
And I want to tear my hair out because what I haven't mentioned is radioactive waste.
With all out radioactive waste?
The main problem is radioactive waste.
Close down all those reactors, now.
With solar and wind and geothermal- Geothermal.
What's green energy?
And they go- Geothermal's green energy.
Okay, do you you know where geothermal comes from?
No.
Comes from the decay of thorium inside the Earth.
Oh.
Is geothermal renewable?
Yes.
Ok, then thorium's renewable.
No it's not you're using it up!
Well, you're using up thorium as it decays inside the Earth.
Any argument for geothermal, if it is rigorously pursued, is an argument for the renewability
of thorium as an energy resource.
The majority of American geothermal is harvested in the state of California, which has most
of its geothermal energy harvested in the Imperial Valley.
A typical Imperial Valley geothermal plant
produces 40 tons of radioactive waste, every day.
And they're saddled with all our radioactive waste, who do we think we are, Bob?
Geothermal is creating 200 times the volume of radioactive waste
that nuclear reactors do, per watt of power.
I don't wanna wear a dosimeter.
Don't want to calculate rems and sieverts.
I don't wanna see no clean-up crew.
Or get zapped before I hear the news.
We can get the heat from Earth and Sun.
And hook the wind to make the engines run.
If common sense could only start- a chain reaction of the human heart-
What a wonderful world this would be!
Coal and gas plants are able to release radioactive material to the environment in much greater
amounts than a nuclear plant would ever possibly be allowed to, because they are considered
what's called N.O.R.M.
- Naturally Occurring Radioactive Materials.
For instance, when you go frack a shale and you pull gas out,
a lot of radon comes out with that too.
Burn the gas that radon being released.
Nobody counts that radon against the gas.
If they did, the regulatory commission would shut the gas plant down.
Same with coal.
And they've spent a lot of money to make sure that regulatory agencies do not regulate N.O.R.M.
for a coal or gas plant the way they regulate radioactive emissions from a nuclear plant.
If they did we would be shutting down all our coal and gas plants- based on radioactivity
alone.
A fear of radiation, probably, is the basis of most fear of nuclear power in general.
What is radiation?
It's simply the idea that there are certain nuclei that radiate things from them.
In the process of changing to something else they radiate something.
Modern physics and chemistry have reduced the complexity of the sensible world
to an astonishing simplicity!
Three units put together in different patterns make, essentially, everything.
The proton has a positive electrical charge.
A neutron is electrically neutral.
And an electron an equal negative electrical charge.
Since every atom is electrically neutral, the number of protons in the nucleus must
equal the number of electrons far away in the electron cloud.
The protons and neutrons together make up the nucleus of the atom.
If you're an atom and you have just one proton- You're hydrogen.
2 protons- helium.
3- lithium.
All the way to 92 protons- in which case your name is uranium.
For any given element, the number of protons must remain the same.
But the number of neutrons may vary.
The atomic weight of an atom is the number of protons plus the number of neutrons.
Natural uranium may contain 142, 143 or 146 neutrons.
That means- Uranium has 3 natural isotopes.
U-234, U-235, and U-238.
Some elements, such as tin, have a great number of natural isotopes.
Others, such as aluminum, have only 1.
Most isotopes are stable.
They would never spontaneously change their atomic structure.
But some isotopes are constantly changing.
They're busy being radioactive.
Given enough time, this Radium-88 isotope will shed energy and change.
This is how isotopes in the Earth itself emit radiation.
The geiger counter detects their presence.
A cloud chamber makes these rays visible to the naked eye.
Each new vapor trail shows that another atom has thrown off a fragment from its nucleus.
Each atom does this only once before becoming a different isotope.
This activity appears to go on endlessly.
That's because there's billions of atoms in that tiny sample.
You can't turn decay on and off.
If we can turn radioactive decay on and off we can do all kinds of things
that we've never figured out how to do, I don't think we ever will.
Because we simply can't influence the state of the nucleus like that.
Hit it with a hammer.
Boil it in oil.
Vaporize it.
The nucleus of an atom is kind of sanctuary.
Immune to the shocks and upheavals of its environment.
The atoms of each unstable element decay to constant rate.
These mouse traps represent atoms that are radioactive.
Every once in a while, a mousetrap's spring breaks down and snaps shut.
A tiny bit of mass is converted into energy, as an atom
changes spontaneously into a lighter isotope.
Thorium has only one isotope, Thorium-232.
It has a 14 billion year half-life.
Ok, so when the universe is twice as old as it is now,
thorium will have only decayed one half-life.
So based on what I just told you about radioactivity,
what does that tell you about how radioactive thorium is?
Not very.
It's hardly at all.
Ok, uranium, two isotopes.
Uranium-235, Uranium-238, both of course the radioactive.
U-238 has a 5 billion year half life.
That's pretty old, that's about how old the Earth is.
That's how old the earth is, that's how old the universe is.
Uranium-235 on the other hand, much shorter half-life, 700 million years.
This is a handful of these uranium-oxide fuel pellets.
You see in the picture, the guy's got gloves on.
And so you think- He's got gloves on to protect him from the uranium oxide?
But now that I've taught you about the true nature of radioactivity, you might go- I dunno
Kirk I'm not so sure that stuff's so dangerous after all...
And you would be correct!
He's not protecting himself from the uranium- He's protecting the uranium from himself.
That stuff has to stay super pure and super clean, and you don't want to get any of your
oils, or grease, or sweat on nuclear fuel that's going to go inside a fuel rods, so,
that's what the gloves are for.
Knowing that some atoms could spontaneously change, in 1939
scientists tried firing a neutron into the nucleus of a uranium atom, the heaviest
and least stable atom found in nature.
Instead of a minor change, from one isotope into another,
the uranium atom split into two parts.
When an atom is so unstable that it can be split into two by hitting it with a neutron,
we call that "FISSILE".
When the fissile uranium atoms split apart, those two parts combined were light than the
original uranium atom.
The missing mass was converted into energy.
Also released were two neutrons.
One free neutron has become two free neutrons.
Now we have two neutrons.
This implied a nuclear chain reaction in uranium.
Obviously that's not what we want to do in reactors.
Most reactors are completely incapable of sustaining that kind of neutron multiplication.
You reach a point where only one fission is causing another fission and that is the notion
of CRITICALITY.
It's a state of balance.
When you want to bring the reactor power you bring it to super-criticality,
to a certain level.
You up to you get to where you want to be, and then you level out at criticality.
And one of the things I had wondered about for the longest time is
it seems like this is such a precise balance.
How would it be possible, in an engineered machine,
to attain such an absolute perfect situation of balance?
And what I found my great interest was-
the NEGATIVE TEMPERATURE COEFFICIENT OF REACTIVITY.
The reactor will become more reactive as it gets cooler and less reactive as it gets hotter.
This notion of a chain reaction has perhaps been used a number of times to scare people
about how nuclear fission reactions really take place in a reactor, as if they are an
uncontrolled expansion of the number of fission events.
That's not really what happens in a reactor.
Somebody wondered one time- Ok, billion years ago that means there's a lot more Uranium-235
and natural nuclear reactors might have been possible.
When you generate electricity from nuclear power you make 200 new elements that never
existed before we fissioned uranium.
We found in Africa, at a place called Oklo, in the Gabon [Africa], 2 billion years ago,
there were scores of natural nuclear reactors there.
That were nothing more than uranium ore in the rock
and the water would come in and it would lead to a nuclear reaction.
And these reactors ran for hundreds of millions of years.
So we did not invent nuclear fission, alright?
It was done long, long, long before we were here, and very successfully.
Back when the earth was formed there was a lot more Uranium-235 then there is now.
Uranium-235 is like silver and platinum.
Can you imagine burning platinum for energy?
And that's what we're doing with our nuclear energy sources today,
we're burning this extremely rare stuff,
and we're NOT burning the Uranium-238 and the Thorium.
Your uranium in Saskatchewan is so rich you don't even have to enrich it.
It's extremely powerful.
Caldicott is wrong.
There is no natural source of isotopically enriched uranium.
Natural uranium's isotopic ratios are identical- everywhere on Earth.
The amount of uranium in the world finite.
If all electricity today was generated with nuclear power
there would only be a 9 year supply of uranium left in the whole world.
In reality, there is no more a constrained uranium supply,
than there is a constrained seawater supply.
Uranium is water soluble, and it passes from the Earth's mantle, to the crust, to the ocean.
Every year, the ocean contains more uranium than the previous year.
What Caldicott refers to as "a 9 year supply of uranium" is in fact an infinite supply.
Harvesting uranium from seawater is impractically expensive today, but that will undoubtedly
change should our uranium mines ever be exhausted.
I'm offering you to drill on one of the great undeveloped fields of little Boston.
Those areas have been drilled.
No they haven't.
My straw reaches across the room.
We're pretty inventive when it comes to harvesting natural resources.
I drink your milkshake!
I drink it up!
We are never going to run out of uranium.
It is quite literally a renewable resource.
For all the difference that distinction makes.
We need to have a realization that
we've got about 35 years worth of oil left in the whole world.
We're going to run out of oil.
As a natural resource, the appeal of thorium over uranium,
is that thorium has zero environmental cost to acquire.
We can power our civilization on thorium without opening a single thorium mine.
It is already a plentiful byproduct of existing mining operations.
We need thorium and he needs somebody to get rid of Thorium.
It's found in tailings piiles.
It's found in ash piles.
Let me tell you how this stuff was discovered-
There was a guy named Glenn Seaborg who worked at Berkeley Labs in 1942.
This was the guy who had discovered plutonium.
He thought- I wonder if we could hit thorium with a neutron and turn it into something?
And you gotta remember, fission had been discovered like three years earlier,
so they were still in the very beginnings.
Well, he got this grad student, you know, everyone who's been a grad student knows what
it's like when the professor says: All right, I want you to go to the nuclear lab and turn
on the neutron bombardment system, and expose this sample and find out what happenes.
Yep, I've done it sir.
I have made something new.
Thorium did absorb the neutron, it became Uranium-233.
Isn't that cool?
Seaborg said yes, absolutely.
Ok, now let's take the next step... poor little grad student...
hit it with a neutron, and see if it will fission.
Because I think it'll fission just like Uranium-235.
Ok, yes sir.
Goes off, does the experiment, comes back and says: Yep.
You're right.
It did fission.
You're correct, it is a new form of nuclear fuel.
And Seaborg poped the really really, really important question, he said-
Now I want you to go figure out how many neutron came off when it fissioned.
Because if that number is below 2... we really don't have a story here.
Sir the number is 2.5.
Seaborg looks at his grad student, this is December 1942, and he said-
You've just made a 50 quadrillion-dollar discovery.
Seaborg was at absolutely right.
He had figured out that thorium could serve as an essentially unlimited nuclear fuel.
There really were 3 options for nuclear energy at the dawn of the nuclear era.
Only one of the materials in nature is naturally fissile, and that's Uranium-235,
which is a very small amount of natural uranium, about 0.7%.
This was the form of uranium that could be utilized directly in a nuclear reactor.
Most of the uranium was Uranium-238.
This had to be transformed into another nuclear fuel called plutonium before it could be used.
And then there was thorium.
And in a similar manner, to Uranium-238, it also had to be transformed
into another nuclear fuel, Uranium-233, before it could be used in a reactor.
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