It's less than one percent of uranium, it's about 0.7 percent uranium.

Hardly at all. That's why it is still around. Uranium, two isotopes uranium 235, uranium 238 both of course are radioactive.

Uranium hexafluoride is a gas.

Uranium tetrafluoride is in solution.

He is not protecting himself from the uranium, he's protecting the uranium from himself.

And then we get to uranium.

They took natural uranium, and they separated those two isotopes, highly enriched it in uranium 235.

It's going to stay in solution. But the uranium will come out as uranium hexafluoride, a gas.

And uranium 233 is being consumed but the neutrons from the fission are making new uranium 233.

It became uranium 233. Isn't that cool?

Large uranium reserves for nuclear fission still exist.

Uranium is used in the production of nuclear power.

Here's the decay chain that uranium 232 is on.

like uranium, plutonium, and everything else when they decay.

So, uranium, which is very big, wants to split.

You're fissioning uranium 233, but you're making a new one.

This is a handful of these uranium oxide fuel pellets.

You hit the salt with fluorine gas, and what'll happen is... There's uranium tetrafluoride, four fluoride ions, and there's uranium hexafluoride, six fluoride ions.

Now What about thorium and uranium? Both are naturally occurring materials.

The uranium and plutonium took on a gas form to escape.

Uranium 233, if you hit it with a neutron it will fission.

And with current reactor technology we really don't have very much uranium.

And you have the uranium mining that you have to deal with.

So they started looking at it, and it turns out, no, it's a really bad idea, because as you made the uranium 233, you were always making uranium 232.

Because I think it'll fission. I think it'll fission just like uranium 235.

Their major asset for developing nuclear weapons is the Natanz uranium enrichment facility.

It doesn't have anything to do, in specifics, with centrifuges, with uranium enrichment.

The radioactivities are mixture of Uranium and Plutonium used in Hiroshima and Nagasaki.

We could use thorium about 200 times more efficiently than we're using uranium now.

They say to me, We're going to run out of uranium. I said, OK.

You've got this core fluid, a lithium beryilium salt, with uranium tetrafluoride in there.

So now, you've just refueled your core salt with uranium tetrafluoride. Cool trick, huh?

India and Pakistan developed nuclear weapons secretly by enriching uranium in nuclear energy facilities.

Well, uranium dioxide's a ceramic, and ceramic doesn't like releasing what's inside of it.

They'd take uranium 235 from less than one percent up to like 90 plus percent.

Now, plutonium is a different chemical element than uranium, so they can be chemically separated.

Take nuclear weapons, take them apart, take the uranium out, burn it up, make electricity!

Coal contains small amounts of uranium and thorium. They go up the stack, they're dispersed.

It breathes this uranium as it goes along, so it's kind of like a candle.

Interestingly enough, they also do this with uranium and chromium, and various other toxic metals.

Now, let's say we were looking at uranium 235 as if it was its own thing.

You can see that uranium 235 is on par with the abundance of silver and platinum.

But this is how they made the uranium for the first nuclear weapon used in war.

At that rate, the known reserves of uranium would last for only 10 to 20 years.

So really quickly they were going, OK, we can work with uranium 235, that seems OK, we can work with plutonium, that seems OK, but this uranium 233 stuff has bad news for making a nuclear weapon.