RE: Radioactive Fossils

[Bob Flood <bflood@SLAC.Stanford.EDU>]

At 02:23 PM 5/11/99 -0500, you wrote:

>....by collecting the uranium residue from coal combustion, significant
>quantities of fissionable material can be accumulated. ...
>Consequently, fissionable nuclear fuel
>is available to any country that either buys coal from outside sources or
>has its own reserves. The material is potentially employable as weapon fuel
>by any organization so inclined.

Not really. The coal-burning process does not separate U-235 from U-238,
and therefore the fissionable isotope won't any more readily available to
construct a weapon than it would be from uranium ore. And uranium ore would
be a much easier way to acquire raw material for the isotope separation
necessary to produce bomb-grade material. So coal plants don't pose a
nuclear weapons hazard.

>....In short, naturally occurring radioactive species released by coal
>combustion are accumulating in the environment 

You might mention that these materials are being released to and
accumulating BACK in the environment, the one from which they originated.
The materials are concentrated at the time of release, but given the
weathering processes they will be subject to, that will change over time.

It is important to note that the imposition of emission controls and the
improvements in precipitators has offset the increased use of coal over the
past decades, which means that the amount of materials (radioactive or not)
being emitted into the atmosphere today is about what was being emitted
many decades ago. Therefore, the nation has been exposed to this threat for
a period equal to at least the typical life expectancy. If we were going to
see significant (meaning at least detectable) impact on human health, I
think we would have seen it by now.

===================================
Bob Flood
Dosimetry Group Leader
Stanford Linear Accelerator Center
(650) 926-3793
bflood@slac.stanford.edu
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