Hi Olin, Yes, I agree that both breeding and non-breeding reactors leave a lot of energy in the fuel. However, I think that a breeder is a bit different in the sense that it converts an unusable fuel into a usable fuel. I don't know all the physics but I would imagine that one could rig up a breeder reactor system (including a secondary plutonium reactor) which could get more energy out of the U235+U238 combination than you could get out of the original U235 in a hypothetical U235->Fe reactor. Sean On Fri, Nov 21, 2008 at 5:09 PM, Olin Lathrop wrote: > Sean Breheny wrote: >> If you take the total matter+energy input to a breeder reactor, and >> the matter+energy output, they are still equal. Mass is taken from >> U235 and U238 and converted into some heat, some useful energy, and >> mass of Pu, which can then be further used to end up with more energy >> and less mass. > > If you're extracting energy based on nuclear reactions, you're leaving > energy on the table unless your spent fuel is 100% iron. In all the > processes in use today, including the breeder chain, we are leaving a > **lot** of energy on the table. Breeders just ever so slightly less so. > > > ******************************************************************** > Embed Inc, Littleton Massachusetts, http://www.embedinc.com/products > (978) 742-9014. Gold level PIC consultants since 2000. > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist