From: utzoo!decvax!yale-com!leichter
Newsgroups: net.misc
Title: Re: Cosmos A-bomb? - (nf)
Article-I.D.: yale-com.618
Posted: Sat Jan  8 10:25:22 1983
Received: Sun Jan  9 02:08:48 1983
References: hp-pcd.565

	Could the materials in the Russian nuclear-powered sattelite
	be used to build an A-bomb?

Tough to answer.  Large power reactors use slightly-enriched uranium (about
5% U235 if I remember right).  Going from that to weapons-grade enrichment
(25% ?) is almost as hard as starting from uranium ore.  There are, however,
two problems with respect to the satellite.  (Ah, spelled it right that time.)

	Small reactors often use more highly enriched uranium for efficiency.
	(In fact, there may be some limitation on the smallest workable reac-
	tor for a given enrichment.)  I remember reading about this for the
	reactors used in nuclear subs.

	As a reactor runs, it turns the U238 in the fuel into plutonium.
	Plutonium is every bit as useful for making bombs, and can be removed
	from the mixture fairly easily by chemical means (while separating
	out isotopes is very tough).

So, just to start off, one would need to know the enrichment of the original
fuel load, and how long it's been running as a reactor - and probably a lot
more information about HOW it was designed and run so as to be able to cal-
culate how much plutonium is likely to be in there.

On the other side, it's very unlikely that the stuff would come down in one
piece.  When the last Cosmos crashed in Canada, they gathered up literally
hundreds of pieces of radioactive material.  Whether the core of the reactor
is engineered such that it is likely to produce a piece containing a usable
amount of material when it breaks up, I don't know; it seems unlikely.  (The
core isn't a solid piece of uranium; it's made up of many small pieces with
cooling material and perhaps control rods running through it.  It seems
likely that it would disintegrate.  This would leave our putative terrorists
with the problem of gathering this stuff up in competition with the cleanup
crews that would have all the advantages - more people, better equipment,
ability to work publically.  I suppose if it all came down in Libya, you
might have a different situation.)

Anyway, that particular danger strikes me as remote - a terrorist group's
chances of getting bomb material this way strikes me as considerably less
likely than their ability to steal it.
							-- Jerry
						decvax!yale-comix!leichter