From: yergeau@cornu.phy.ulaval.ca (Francois Yergeau)
Newsgroups: sci.environment,sci.energy,sci.physics
Subject: Re: Is nuclear energy "polluting"? (was Re: Is car pooling for real?
Date: 29 Jul 92 01:52:31 GMT
Organization: Universite Laval, Quebec

In article <sgmmytc@dixie.com> jgd@dixie.com (John De Armond) writes:
>carl@aoa.aoa.utc.com (Carl Witthoft) writes:
>>In any case, it would seem
>>that nuke plants are the only type which are actively, rather than
>>passively, dangerous when shut down.  That is, any building can 
>>collapse on you, but only a nuke is full of bad stuff.
>
> [stuff deleted]
>It will be much
>more cost-effective to refurbish the facility and run it for 
>another 40 or 50 years.

Hopefully, that could be, but when?  Currently, old plants are
decommissioned, and more modern ones, when they reach the end of their
life, will be considered old and outdated.  For instance, current
design efforts in the U.S. tend to favor so-called "inherently safe"
designs.  If these ever become mainstream, the older BWR designs might
be seen as relatively unsafe and it might not prove cost-effective to
_transform_  them (as opposed to simply refurbish) into the newer
designs. Anyway, I'm all for recycling.

>Let's take a look at a few other power sources:
>
>Soot burners (coal):
>
> [good comments about how nasty coal burners are deleted]
>
>Hydro:
>
>Dam structure remains.  Impounded water and sediment may also remain.
>Sediment will contain concentrated toxins from the years of collection.

I tend to disbelieve this proposition.  Actually, just the reverse
happens when the basin is initially filled: mercury trapped in the soil
of the flooded forest floor is released in the water, and toxic fish
results.  This pollution (which was there to begin with, but was
natural and hidden) washes out over a time frame of 10 to 20 years.  It
does not get concentrated, just the opposite.  Think of it, once the
basin is filled, the average flow is just the same as before the dam
was built, although admittedly over a wider area.

>May not be feasable to remove the dam and powerhouse after decomissioning
>leaving a ugly, hazardous structure.  Hazardous from things like 
>people falling off it and hazardous from the risk of failure.

Ok then, just refurbish it and go for another 50 years, as proposed
above for nuclear plants.  Actually, it even makes more sense than for
nukes because, while one nuclear plant can often be replaced by another
one built 100 meters away, no such option exists for hydro dams.  And
if you don't refurbish, at least open the vanes, and turn your dam into
a mere mound of dirt and concrete, no more dangerous than a cliff in
the mountains.

>Flushing out a few miles of primary piping in a nuke plant looks 
>positively benign in comparison.

Why then is it so damn expensive to do it right now?  In current or
constant dollars, the cost is pretty high, and the problem of disposing
permanently of the high-level waste is not even solved for good.  The
latter is, IMHO, the sore point of the whole nuclear industry.

-- 
Francois Yergeau (yergeau@phy.ulaval.ca) |  Quand le doigt montre la lune,
Centre d'Optique, Photonique et Laser    |  l'imbecile regarde le doigt.
Departement de Physique                  |               -proverbe chinois
Universite Laval, Ste-Foy, QC, Canada    |