From: Eugene.Leitl@lrz.uni-muenchen.de
Date: Sat Jun 02 2001 - 04:44:21 MDT
"Eliezer S. Yudkowsky" wrote:
> *Bzzt.* No fair challenging Damien Sullivan's documented facts unless you
*Bzzt* yerself. Okay, it was the best thing I could think of while on
the tail end of several bottles of beer, before staggering off to bed.
Okay, it was no good, let's try it again. First: you don't have to
use coal. We've still got plenty of gas and oil, and the methane
alone will last long enough that we can think of something else,
like a hydrogen and solar economy.
So, the argument is already contrieved. Not too many people are
still using coal, and none of them have to use coal, and be it for
a little price premium.
Gas doesn't contain radioactive isotopes, nor does oil (it can be cleaned
of sulfur, vanadium, and other toxic crap, unfortunately, the aromates in
it are intrinsically carcinogenic, and if you got hydrocarbons into the
air, it makes very funky photosmog if the insolation and atmospheric conditions
are right -- methane is way cleaner here).
Secondly: we've got electrostatic dust filters and gas scrubbers, and
whatnot on those coal plants that are still in operation. Sure, we don't
have that in China, but which kinds of nuclear reactors do you think they
have in China? A lot of their hardware is either bought in Russia, or
made domestically using Russian blueprints and Russian experts. Given
how many nuke plants they would have to need, and what the technical standards
are going to be, you can't compare the numbers with the current release
rate of best Western facilities. If you thought firing sulfur and metal-rich
coal plants in China was bad, wait until they phase them out with nuke
plants. Whoa, betty! Watch lots of monkey engineers hoisting them with
their own petards.
Okay, let's have a gander at the real numbers. I'm still handicapped due
to the fact that my xDSL is still not delivered (but, at least a definite
delivery date was announced), and my flat is still not fit to live in, which
is another handicap so the best thing I could pull up with the modem was:
http://www.physics.isu.edu/~alber/coal.html
Okay, it says coal contains on the average about 1.3 ppm uranium and
3.2 ppm thorium. To start with, mentioning radioisotopes in context of
coal firing is a red herring. The real issues lay elsewhere:
http://www.fetc.doe.gov/products/power/enviro/pm25/emissions/psi.html
You might check out the 7 MByte .pdf whopper at the bottom, I haven't
though, as my bandwidth is virtually zero. See, I never said coal
was nice. Coal is evil, don't fire coal. Try methane, in a pinch oil,
if you can't get methane. Don't use coal, it's bad.
Back to uranium/thorium. There are about 4 g of uranium in a tonne of
granite (4 ppm, I guess), uranium ore has about 3000 ppm (3 kg/tonne)
and coal can supposedly contain up to 400 ppm uranium (interesting,
some coals lay within an order of magnitude of Oz ore grade, assuming
you can filter out the bulk of the ash).
Okay, let's pluck it apart:
W. Alex Gabbard, a nuclear physicist at Oak Ridge (Tenn.)
National Laboratory, did a little
Noticed the source?
calculating. According to the Environmental
Protection Agency figures, an average ton of coal
contains 1.3 parts per million uranium and 3.2 parts
per million of thorium. Both naturally
occurring trace metals are radioactive. Of the uranium,
So what, potassium-40 is radioactive too, and so is the
radon accumulating in a not well ventilated concrete building.
Smoke detectors are radioactive, grandpa's radium watch and
Swiss tritium watches are radioactive, steel is radioactive
(thanks to recycled activated structural material and medical
C60 sources), the uranium glass goblets over there are
radioactive, firestarter's pyrophoric spark metal is radioactive,
the granite slab I stand on is radioactive, the transatlantic
flight gives me extra exposure to cosmic rays, my body is
radioactive, too.
roughly 0.71 percent is U-235, the
fissionable variety used by nuclear power plants.
What a whopper, and from a fedral no0klear fisizist. The kind of
isotope is totally irrelevant, unless you're nearby criticality.
Whether U-235 or U-238, the decay rates are about the same. Things do
become very different if you have a slightly subcritical piece,
where the spontaneous fission rate is way elevated. If you go
near such a slightly subcritical assembly, your body water acting as
a moderator will cause the block of uranium acquire a blue aura.
If you see that aura, smell the ozone, and feel the block rapidly
warming to the touch, and jump back immediately you've got about
two weeks still to live, most of them minus hair, most of the
skin and on severe painkillers. So if you find a slightly subcritical
piece of fissibles on the road, don't pick it up. Use long tongs,
at least.
Moreover, global combustion of 2,800 million tons of coal
that year released 8,960 tons of thorium
and 3,640 tons of uranium, of which 51,700 pounds was U-235.
More meaningless numbers, as the real issues are toxicity, not
radioactivity. Notice he mentions U-235 again, oh my god, one could
think that is as bad as plutonium. Nevermind that people routinely
shoot tons of depleted uranium ammo into the landscape, especially
during military operations (thankfully, people are starting talking
tungsten instead, though it misses some critical nastiness, and a
bit of radioactive contamination is admittedly irrelevant, when you're
trying hard to turn thy neighbour into shredded meat sprayed in the
landscape, while he's attempting just the same practical joke on you).
Now that stuff is not diluted, and you have a pretty good chance of
getting a lungful of uranium smoke, which is probably not very good
for you -- as a heavy metal, uranium is toxic, and it *is* slighly
radioactive.
Ironically, in 1982, 111 U.S. nuclear power plants
used 540 tons of nuclear fuel to generate
Ironically, this is absolute bullcrap.
To start with, to harm you, you have to be hit by a bit
of speeding nuclear matter hitting and breaking your DNA,
which creates a harmful mutation, which is not caught by
the immune system, which is not detected during your health checks
so it grows into a malignant tissue, metastases and offs you
in a thinkably nasty way. The best way to do it, is to incorporate
the about-to-decay nuclei, and to hold onto them as long as possible.
It also depends on the decay rate of the particular isotope, as
some are hot, and some are not. Some isotopes are being extremely
enrichened and retained in the body (radiodine in the thyroid,
especially susceptible are children in iodine-depleted (due to
washout in the last glacial -- Ukraine is severly iodine
depleted, and the traditional diet does not include lots
of sea fish, nor did they have iodide/jodate tablets for
emergencies), which just soak up the stuff quantitatively,
radiostrontium in the bone, where it irradiates the bone
marrow (apart from the gonads the most susceptible tissue,
along with thyroids and hair follicles) from maximum
proximity, and similiar).
Natural uranium is not particularly radioactive (well, I wouldn't put
a kg of it under my pillow for every night, but otherwise it's
perfectly harmless, if you ever go to visit a military base ask them
to show you a piece of depleted uranium ammunition, it's rather
heavy and blows sparks, if you scratch it, as finely dispersed
uranium is pyrophoric -- a nice side effect for armor breaking
ammo, though the crew doesn't particularly mind anymore, after
a jet of liquid metal has bounced a bit inside the metal box),
nor it is particularly bioavalable.
The same applies to a freshly made fuel rod. You can grind it up,
make uranium from it and fashion (rather expensive, since enrichened)
uranium ammo from it, it would contaminate the landscape in exactly
the same way as depleted uranium ammo does, provided you stay
subcritical all along the way. (If not, god help you -- I see
lots of Cherenkov glow in your future).
Now a spent fission fuel rod is another matter entirely. To start with,
a fair fraction of uranium (or thorium, if you're trying to be exotic)
is gone. The rest of it, if you separate it, and clean it up really
peachy clean (some funky short-lived uranium isotopes including),
it would be just another perfectly bland bit of uranium. Now the
rest of it, it's pretty evil stuff. It consists of a wide range of
elements, most of them isotopes so hot they literally glow in the
dark and need to be stored underwater, to act both as a shield
and to cool them down, lest they warp and melt spontaneously. If
you get a load of this stuff while still fresh into the wind,
you can do surprising amounts of damage. So whatever is
going to get you, it's certainly not going to be thorium or uranium.
If this is indeed the piece most people mention when they say "radioactivity
release through coal plants blah blah" it's not just misleading, this is
actively planted piece of misinformation, concocted by a government
physicist in a national laboratory, probably a trained nuclear physicist.
I'm pretty much appalled, I must admit.
electricity. Thus, "the release of nuclear
components from coal combustion far exceeds the
entire U.S. consumption of nuclear fuels," Gabbard
notes in the fall issue of the OAK RIDGE
NATIONAL LABORATORY REVIEW.
> can cite better documented facts from sources that are visibly more
> objective. Otherwise the whole argument just reduces to "Did not", "Did
> too".
Tru enuff, tru enuff.
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