Re: How Do the Europeans Get Rid of Nuclear Waste?

Michael Moroney wrote:
>
> Uncle Al <UncleAl0@xxxxxxxxxxxxx> writes:
>
> >Michael Moroney wrote:
> >>
> >> Dumb question: Is it possible to create a reactor design where the
> >> reactor has an inner and outer set of fuel rods? The inner portion works
> >> as a normal reactor except it produces an excess of neutrons which escape
> >> into the outer portion. The outer portion is "spent" fuel rods which
> >> can't maintain a chain reaction by themselves, but are constantly
> >> irradiated by neutrons from the inner portion and are more thoroughly
> >> "burned up" and produce more energy than if they were just removed.
> >> The outer portion is not needed for the inner portion to function (excess
> >> neutrons would be just lost without it)
> >>
> >> Refueling would be removing outer fuel rods, moving inner to outer and
> >> adding new fuel to inner. Maybe even three or more layers (fuel is
> >> "more spent" as you go outward)
>
> >How could neutron irradiation of neutron-rich beta-decay isotopes help
> >things any? All you will accomplish is making them decay faster, on
> >the average, into slower beta-decay isotopes of the next element up.
> >It's a waste of neutrons and a very slow way to get back to uranium
> >from, say, lanthanum.
>
> You don't understand. You have "spent" fuel rods with beta decaying
> fission products, leftover uranium and actinides. You essentially
> irradiate it with neutrons, and while many are lost to the beta decaying
> fission products, others either fission the uranium or the actinides and
> we get more energy from a given fuel rod with the net effect of fewer fuel
> rods per unit of energy produced. And the ones that are produced are more
> "burnt up". Nobody is suggesting trying to reproduce the "s" process in
> a reactor.

"Spent fuel rods" must be replaced primarily because they swell. Few
compounds and elements are as dense as the uranium or plutonium
compounds used to fabricate the rod. As fission proceeds the fuel
elements swell as their composition changes and their average density
decreases. Dimensional change plus chance of rupture dictate their
replacement. One doubts there is much more than 10% burn to
replacement. You've been hornswoggled, my boy. The fission products
as such are a physical nuisance and a nice profit center torn from
taxpayers' wallets. New fuel! Always new fuel!

--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz.pdf
.