AW: [ RadSafe ] Fast neutron reactors

[Bernard L. Cohen]

    The important advantage of fast neutron reactors is that they give 
more neutrons for each neutron inducing a nuclear reaction, enough to 
produce more fuel (by converting Uranium into Plutonium) than they 
consume in producing energy.Thus a fast neutron breeder reactor system 
would eventually derive useful energy from nearly all of the original 
Uranium, rather than the 1% or so of the the original Uranium as in 
current reactors.
    The fast neutron system derives energy from the plutonium it 
produces, whereas present reactors bury it with spent fuel, adding to 
the radwaste problem. There is a lot more to the effect of fast neutrons 
on the radwaste problem than can be discussed briefly here.
>
> "Fast reactors can extract more energy from nuclear fuel than thermal reactors do because their rapidly moving (higher energy) neutrons cause atomic fissions more efficiently than the slow thermal neutrons do. This effectiveness stems from two phenomena. At slower speeds, many more neutrons are absorbed in nonfission reactions and are lost. Second, the higher energy of a fast neutron makes it much more likely that a fertile heavy metal atom like uranium 238 will fission when struck. Because of this fact, not only are uranium 235 and plutonium 239 likely to fission in a fast reactor, but an appreciable fraction of the heavier transuranic atoms will do so as well. "
>
> >From the commentary the following quote summarizes the consequence: 
>
> "Yes, reprocessing spent nuclear fuel in fast reactors can indeed solve the 'waste problem'. It will allow more than 99% of the energy in uranium to be used -- unlike today's reactors, which utilize less than 1%."
>
> Kind regards, Rainer
>
> Dr. Rainer Facius
> German Aerospace Center
> Institute of Aerospace Medicine
> Linder Hoehe
> 51147 Koeln
> GERMANY
> Voice: +49 2203 601 3147 or 3150
> FAX:   +49 2203 61970
>
>  
>
> ________________________________
>
> Von: radsafe-bounces at radlab.nl im Auftrag von Steven Dapra
> Gesendet: Sa 29.11.2008 17:28
> An: radsafe at radlab.nl
> Betreff: [ RadSafe ] Fast neutron reactors
>
>
> Nov. 29
>
>         According to a book review in "Health Physics News" (Nov. 2008; p. 9, col.
> 3), fast neutron reacxtors will minimize waste and make better use of
> uranium resources.  How will such reactors reduce rad waste and use uranium
> more efficiently?
>
> Steven Dapra
> sjd at swcp.com
>
>
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-- 
Bernard L. Cohen
Physics Dept., University of Pittsburgh
Pittsburgh, PA 15260
Tel: (412)624-9245  Fax: (412)624-9163
e-mail: blc at pitt.edu  web site: http://www.phyast.pitt.edu/~blc