[extropy-chat] Energy & Global Warming [was: Partisans and EP]

[Jordan Hazen]

On Sun, Feb 11, 2007 at 09:14:00PM -0800, spike wrote:
> > bounces at lists.extropy.org] On Behalf Of Anders Sandberg
> > Subject: Re: [extropy-chat] Energy & Global Warming [was: Partisans and
> > EP]
> > 
> > 
> > spike wrote:
> > > Cool calculation Anders!  The neutrons that are captured hafta be much
> > > lower energy than MeV if I understand the process correctly.
> > 
> > Yes, I just checked up the physics. They have to be thermalized by several
> > bounces down to 0.025 eV, which produces a speed of 2.2 km/s. At that
> > speed they have a big cross-section. Still, the speed is three orders of
> > magnitude larger than the movement of the nuclei, so I see no problem with
> > sloshy targets...
> 
> Ja, a fraction of an eV is what I recalled, altho my recollections from
> physics lectures are... very old now, my young friend.  {8^D  Sloshy targets
> are fine, I agree, but in Pu solution makes the ions too rarified to get
> very many captures in our lifetimes.  Solutions are another three orders of
> magnitude more rarified than a liquid metal, if my vague recollections of
> typical solubility of heavy metal salts are any better than my physics
> memory.


Molten salt reactors, which circulate UF4 dissolved in (mostly) LiF,
seem like a good compromise candidate between molten metals vs.
aqueous solutions.  Oak Ridge operated one for many years.

  http://nuclear.inl.gov/gen4/msr.shtml

  http://en.wikipedia.org/wiki/Molten_salt_reactor

This allows for on-stream reprocessing as well, and be fueled by
uranium, thorium, or other actinides, including transuranic wastes
from other reactor types.

-- 
Jordan.