From: utzoo!decvax!cca!Ciccarelli@PARC-MAXC@sri-unix
Newsgroups: net.space
Title: Re: Reactors on the Moon
Article-I.D.: sri-unix.3304
Posted: Thu Sep 16 09:53:09 1982
Received: Fri Sep 17 03:19:54 1982

On Earth, nuclear reactors are (by some arguments) a cost-effective power source
compared to alternatives.  On the Moon, *no* such advantage exists when
compared to the obvious competitor: sunlight.  Consider the following criteria:

[Generator site]
  Nuclear:  If you build it "dirty" and unshielded (as suggested), its users must
be some distance away, at least outside the crater.
  Solar:  No site restrictions.  Power is generated where needed, without long
transmission lines.  Move the power station when you need to; it's not "hot",
large, or heavy (especially with photovoltaics). 

[Fuel]
  Nuclear:  (a) Launch it from earth, *if* your citizens and the rest of the world
don't object to the possibility of an unexpected "hot" shower if the launch
vehicle fails, or (b) Find it (if it exists), mine it, and set up and power a
separation plant on the moon (not worth considering).
  By the way there's the nasty detail of reprocessing breeder output.  Presumably
this involves robots or highly-paid humans, not to mention a plutonium
remanufacture facility.  Sounds complex...
  Solar:  Spread a thin reflective sheet, or set up your photovoltaics!  No hot
waste to reprocess, either.

[Electrical generator]
  Nuclear: (and Solar) could run a turbine (such a solar turbine has been
proposed for an orbiting solar power satellite), but turbogenerators have to be
shipped from Earth until you can make them "up there", and they have certain
economies of scale (lower efficiency when made smaller).
  Solar: Photovoltaics would be much easier (than turbines) to make "locally", 
since no iron is involved and silicon is plentiful.  They are usable in ANY size;
just connect enough cells in series and/or parallel to provide the desired voltage
and current.  They have NO moving parts, aren't "hot", and are easily relocated. 
There's no downtime or power reduction during repairs since you can replace
modules without shutting down others in the array.

[Industrial process heat, i.e. for smelting and reduction of rocks]
  Nuclear:  Heat can't be used directly without shielding (if you expect to have
humans anywhere nearby...).  This means electrical conversion (lossy) and
reconversion to heat or RF.  Why bother...?
  Solar:  Easier than power generation; just aim mirrors at whatever needs the
heat.  Turns on and off instantly; not true for a reactor.


...Lastly, I abhor the "run it till it melts down, then bury it" school of
engineering.  The same goes for the "launch the wastes into the sun"
suggestions.  Why *create* these problems in the first place, when obviously
better paths exist?  I'll be damned if I'd like to be the 22nd-century lunar
homesteader who happens to encounter your (oops, mistakenly unmarked)
plutonium waste dump.

/John