Re: Nuclear Power vs CO2

[Mr Jo <mjo@scs.unr.edu>]

Dr. Weiner,
I did not have a clear answer when I was asked to compare CO2 production (of
full fuel cycles) between uranium (mining, processing, use, and disposal) and
coal (mining, burn, and disposal). Do you have any information about that? I
would like to know if you or anyone can help me on that topic. Thank you. M. Jo

"Weiner, Ruth" wrote:

> Carbon dioxide is, of course, produced by complete burning  of carbon
> compounds.  Thus, for example, natural gas (methane) would produce 2.75
> pounds of CO2 per pound of methane (that's 44/16).  Burning octane (C8H16)
> -- a surrogate for gasoline -- completely produces 3.15 pounds of CO2 per
> pound of octane.  The amount of CO2 produced by burning coal or oil is
> directly proportional to the amount (weight or number of carbon atoms) in
> the fuel, and  that varies somewhat from coal to coal and a little from oil
> to oil.  By contrast, the only CO2 produced in a nuclear power plant would
> be if there were ancillary power (or heat) produced by burning a
> carbonaceous fuel and maybe a little bit from oxidation of C-14 produced by
> fission.  Heat for buildings, gasoline for workers to get there, and
> essentially non-power-generating fuel combustion would of course be the same
> for a nuclear power plant as a fossil fuel plant, as would the CO2 from
> ordinary human breathing.  So there is no way a nuke could even come close.
> In sum: CO2 production is an integral product of fossil fuel power
> generation but only a very small incidental by-product of nuclear power
> generation.
>
> To calculate the CO2 from a coal-fired plant, figure that the thermal
> efficiency is about 42% and the capacity is about 60%, look up the heat of
> combustion of coal (BTU/pound or BTU per gram) and the carbon content of a
> bituminous coal (kind of a US average), divide the energy output (kwh
> converted to appropriate units) by 0.252, divide by the heat of combustion
> to get grams unit time, and multiply by the fractional carbon content and
> then by 44/12 (44 is the molecular weight of CO2).  I used to give this as a
> final exam problem.
>
> Clearly only my own opinion.
>
> Ruth F. Weiner, Ph. D.
> Sandia National Laboratories
> MS 0718, POB 5800
> Albuquerque, NM 87185-0718
> 505-844-4791; fax 505-844-0244
> rfweine@sandia.gov

========================================================
Myung Chul Jo, MS, CHP
EH&S, Mail Stop 328
University of Nevada, Reno
Reno, Nevada 89557
(775)784-4540
(775)784-4553 fax
mjo@scs.unr.edu


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