[ExI] EP and Peak oil.

John K Clark jonkc at att.net
Fri Apr 4 17:42:32 UTC 2008

"Keith Henson" <hkeithhenson at gmail.com>

> I don't think you understand the problem.  Neutrons plus depleted uranium
> equals weapons grade plutonium

I know.

> better than any made in the cold war.

You're right, I don't know what that means.

> Why does it [plutonium] scare you?

Besides being far more toxic than uranium a Plutonium economy world probably
require breeder reactors, and they have a much higher energy density than a
regular reactor and that means it's inherently more dangerous with less
margin of error.  A conventional reactor uses Uranium as fuel in which the
U235 has been enriched from the naturally occurring .7% concentration to
about 4%,  you need about 85% to make a bomb.

A breeder uses weapons grade plutonium as a fuel, and lots of it. Also, a
conventional reactor uses water as a coolant and to slow down the neutrons,
a breeder uses molten sodium that burns in the air and explodes in the
presents of water. After a short time in operation this hot liquid sodium
becomes intensely radioactive.  And that's not just a theoretical danger, in
1996 a leak in a sodium pump destroyed the newest and largest breeder
reactor in Japan, if it wasn't in a containment building it could have been
a human disaster. It's already an economic disaster of several hundred
million dollars.

> Unless you take the trouble to make plutonium without Pu 240 in it, the
> stuff isn't suitable for bombs.

The very first nuclear bomb at Trinity had lots of Pu 240 in it as did the
bomb that destroyed Nagasaki. When the bomb makers realized it was hard
to make pure Pu 239 it created a crisis, they discovered that because of the
pre-detonation caused by that contaminate the gun method of assembly
wouldn't work for Plutonium. But they soon found a substitute, implosion,
and that worked just fine thank you very much.

And I Don't understand what you are trying to say. First you say reactors
are dangerous because they produce Plutonium then you say they're not.

> The problem is you can make pure Pu 239 if you set up to do so.

Yes if you limit the time the U238 is in the neutron flux, but it's seldom
done because it limits yield, better to be clever in the way you assemble
the Plutonium to critical mass.

> How do you think the space elevator could be used in the place of
> microwaves?

Boy that's a tough question! I'll have to think about that.

> Making antimatter and bring it down in a bag is a *joke.*

I could be wrong but I believe I read somewhere that scientists have
discovered another way of sending energy down a wire.

> Even if it could be, an elevator has to come down close to the
> equator and > there isn't much demand for power there.

Not now but things change, it's not unreasonable to think industry might
move to where energy is cheap.

 John K Clark

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