Re: Tap the supervolcanoes to prevent a worldwide catastrophy
From: G. R. L. Cowan (gcowan_at_eagle.ca)
Date: Thu, 13 Jan 2005 11:12:35 -0500
Ed Earl Ross wrote:
> G. R. L. Cowan wrote:
> > Ed Earl Ross wrote:
> >>habshi wrote:
> >>> Geothermal is probably renewable as it is based on radiocative
> >>>decay in the earth
> >>The source of geothermal heat is hotly debated.
> > By you, maybe.
> http://www.geology.sdsu.edu/how_volcanoes_work/Heat.html ...
> ...The debate is about how much heat various sources provide. Some say
> any fission reaction within the core would have long past used all
> its fissionable material.
Oh, OK. You have been the victim of a strawman.
There was some talk a few years ago about uranium fissioning,
yielding 200 MeV of energy per atom, at the Earth's core.
I saw no evidence this talk was not totally stupid.
But arguments you may have read to the effect that it
*was* totally stupid, while probably correct, do not imply
-- and the strawman argument would be the pretense that they do --
that thermal power within the Earth cannot come from uranium.
If not fissioned, it produces heat by another mechanism --
alpha decay -- and while this yields only IIRC 43 MeV per atom,
it happens on the same timescale as the age of the Earth
and cannot be hurried. So while, as your SDSU link says,
radioactive decay power within the Earth isn't the ~100 TW
it must once have been, it will still be in the tens of terawatts
for billions of years to come -- including ~0 TW of fission.
Also see http://www.aip.org/png/html/neutrino.htm .
-- Graham Cowan
How individual mobility gains nuclear cachet