keith (01/07/83)
#N:hp-pcd:6400009:000:934 hp-pcd!keith Jan 7 11:12:00 1983 I was watching the CBS news report this morning (7 JAN) regarding the Soviet satellite (no, not Poland) that was about to come down upon our heads. The principal concern is the nuclear reactor aboard the satellite which carries some amount of Uranium (I think). The report covered the obvious hazard of radioactive material being distributed in a populated area, but the reporter also speculated about the possibility of the Uranium being recovered by some terrorist who would then fashion it into a A-bomb. My question is: Is this reasonable? I don't know much about the workings of reactors that go up in space, but I seem to remember assurances given by earth-bound power companies that reactor grade material can't be made into weapons grade material without a considerable amount of work. Sounds like a hardware problem, Keith M. Taylor Corvallis, Oregon hplabs!hp-pcd!keith
leichter (01/08/83)
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
henry (01/10/83)
The fission fuel aboard space reactors is usually, I think, highly enriched to minimize the size and weight of the reactor. I don't think those reactors operate for sufficiently long periods to generate useful amounts of plutonium, but the original fuel might be rich enough to qualify as "bomb grade". But as Jerry Leichter points out, it's likely to come down in lots of small, well-scattered pieces. Moreover, since said pieces come from a reactor that has been operating for a while, they will be *highly* radioactive and very dangerous to handle. This does not seem like a very practical source of materials for bombs.