----- Original Message ----- 
From: "Phil Hays" <[EMAIL PROTECTED]>
Newsgroups: gmane.science.general.global-change
To: "globalchange" <[email protected]>
Sent: Saturday, December 29, 2007 1:15 AM
Subject: [Global Change: 2314] Re: Public Awareness of Energy Issues


>
> On Dec 28, 11:49 am, Phil Randal <[EMAIL PROTECTED]> wrote:
>
> http://www.comics.com/comics/frazz/archive/images/frazz200712087309.jpg
>
> If you want a serious discussion, start with this:
>
> How much crustal rock has more available energy per kg as uranium and
> thorium than coal has for combustion?
>
> A rough answer is plenty good enough.
>

From http://nuclearinfo.net/
"A 1000 MW coal power station requires about 8,600,000 kg of coal per day, 
compared to 74 kg per day of uranium for the equivalent sized nuclear power 
plant."

From http://www.theoildrum.com/story/2006/8/7/195721/3132?page=1
"As of the beginning of 2005 ... Reasonable Assured Reserves recoverable at 
less than $US130/kgU (or $US50/lb U3O8) = 4.7 million tonnes."

From http://en.wikipedia.org/wiki/Coal#World_coal_reserves
"At the end of 2006 the recoverable coal reserves amounted around one 
exagram (1 × 1015 kg or 998 billion tons),"

One tonne is 10^3 kg so that's 4.7 x 10^9 kg uranium vs 1 x 10^15 kg coal, 
but for electricity production 8.6 x 10^6 kg coal is equivalent to 7.4 x 
10^1 kg uranium, so current coal reserves are equivalent to 8.6 x 10^9 kg 
uranium, or nearly twice current uranium reserves.

So my rough answer is "your average kg lump of Earth's crust has almost 
twice the energy available for coal combustion as for uranium fission 
(closer to 80% more, assuming I've correctly kept track of all my powers of 
ten)".

Add thorium to that, and from 
http://www.grida.no/climate/ipcc/emission/071.htm, "This extractable thermal 
energy would be some 60 times larger if reprocessing and fast breeder 
reactors are used (Ishitani and Johansson, 1996)."

-dl 



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