On Sat, Mar 01, 2008 at 12:27:45AM -0500, Bob Axtell wrote:

Need some snippage...

> > On Fri, Feb 29, 2008 at 05:31:53PM -0500, Bob Axtell wrote:
> >
> >> Byron Jeff wrote:
> >>
> >>> On Fri, Feb 29, 2008 at 03:21:59AM -0500, wouter van ooijen wrote:
> >>>
> >>>
> >>>>> The difference between naturally occurring radioactive
> >>>>> materials and nuke waste is ONLY in terms of the level of
> >>>>> radiation coming out of it.
> >>>>>
> >>>>>
> >>>> Dunno what 'nuke waste' is (waste after an exploding nuke?), I was
> >>>> talkinmg about what's left of the fuel rods after their lifetime. That
> >>>> stuff is *very* different from natural uranium ore, for a starter it is
> >>>> chemically different: there is a significant amount of plutonium in it.
> >>>>
> >>>>
> >>> Actually there isn't going to be. All fuel rods would be reprocessed and
> >>> all of the useful fuel would be put back into new fuel rods.
> >>>
> >>> According to this site:
> >>>
> >>> http://www.uic.com.au/wast.htm
> >>>
> >>> Only 3% of the rod is actual waste and the other 97% (depleted uranium
> >>> mixed with plutonium) would be extracted and reused.
> >>>
> >>>
> >>>
> >>>>> It actually has less total radiation over time. Some of the
> >>>>> materials are producing a higher RATE of radiation, but they
> >>>>> have a shorter half life, so over all, they will produce less
> >>>>> total energy than the original substance.
> >>>>>
> >>>>>
> >>>> Again I doubt if this is true, but for the sake of argument let's accept
> >>>> it for now. So the radiation which would otherwise occur over a very
> >>>> long time is now concentrated in let's say a few 100 years. I don't
> >>>> think the people living in those few 100 years will like that.
> >>>>
> >>>>
> >>> I would agree with you if the waste were made into a statue that was placed
> >>> in a open public park. But when buried under hundreds of meters of solid
> >>> rock, the residual radiation effect is minimal. That's why the EPA's
> >>> estimate for Yucca Mountain for the first 10,000 years was so important,
> >>> because virtually all of the highly radioactive waste products would have
> >>> decayed by then.
> >>>
> >>> BAJ
> >>>
> >>>
> >> My main objection to nuclear power is simply that it seems obvious to me
> >> and many others that capturing
> >> solar energy to generate electricity would result in minimal damage to
> >> anything. And we wouldn't even NEED
> >> a Yucca Mtn.
> >>
> >
> > Unfortunately that's a very narrow view. Two major points:
> >
> > 1) At the efficiency levels that solar converts to electricity, it takes
> > more energy to create solar panels than they produce.
> >
> > 2) Solar panels have nasty stuff in them too. They cause issues in both
> > production and waste.
> >
> >

> er.. I didn't think I said PV arrays, I said solar energy. Concentrating
> the sunlight into a heat source to run a turbine or stirling engine is
> more efficient, and for a large generating system would be more
> practical. 

Solar tower. OK. I went and reread the Wikipedia article here:

http://en.wikipedia.org/wiki/Solar_updraft_tower

>A nuclear generation plant and a concentrated solar generation plant have
>two main differences: 

>(1) during the night, no electricity can be generated at the solar plant;
>and (2) no hazardous waste is generated, EVER. 

(1) is not technically true. As long as some type of heat storage (heating
water for example) is possible, generation can continue after the Sun has
set.

>Aside from that, the very same workers are
> needed by both types of plants.

> The solar plant would cost much less initially than the nuke plant,

The article debates that. The big problem with the Solar tower is that the
collector requires huge expanses of surface area is order to work. That
drives up the costs significantly.

With nuclear the vast majority of the cost is regulartory. A streamlined
approval process of a standard plant design would significantly reduce the
initial cost of building a nuclear power plant.

As for the waste issue, we've been over it multiple times. I do realize
that risks are involved. I'm not dismissing them. I know that accidents
occur. But I believe that by super overengineering the containment system
those risks are significantly reduced.

The point that's missing here is that the nuclear genie is already out of
the bottle. The US already has 9% of its electricity generated by nuclear.
France is upwards of 90% nuclear. Canada is at 15% or so.

Another approach is to consider a different type of reactor: the molten
salt reactor (MSR). You can take a long read here:

http://en.wikipedia.org/wiki/Molten_salt_reactor

The key points are that it burns virtually all of its fuel onsite, so there
are minimal waste products. The other point is that none of the waste
products have long half lives (all less than 30 years), so after 10 half
lives the waste is less radioactive than its original fuel source. The next
point is that the salts operate is low pressure environments, so no
explosions are possible. Finally the liquid fuel is temperature self
regulating, so if it gets too hot, it slows down the reaction.

The biggest problems seems to be possible corrosive effects and the fact
that fuel is so efficient that there's very little money in fueling the
plants.

> its
> fuel costs are almost zero; and
> maintanence would be much less.
> 
> I have a client who builds steel buildings. He uses tracking solar PV
> arrays and batteries to run his entire
> business- even some spot welding machines. He's been in business for
> several years, and never bought
> a dime's worth of power from the local utility; in fact, no power lines
> are even routed to his yard.
> Yes, we are in Tucson, AZ- and we have a LOT of sun.
> 
> OK, I'll bite. I have heard that PV array yarn before. I'd sure like to
> find out where that comes from.
> Fill me in. From what I have seen, your statements are unsupportable.

I have to call a mea culpa. I dropped that statement in from something I
read a while ago without reresearching it. I was wrong. This 1997 article
points to reasonable payback periods for solar panels:

http://www.csudh.edu/oliver/smt310-handouts/solarpan/pvpayback.htm

BAJ
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