Well, it's in the news again. Dear Leader sez it's just unacceptable, totally unacceptable, for the Iranians to be enriching uranium.
Thing is, their uranium enrichment program isn't particularly important to their nuclear weapons program. A uranium bomb is too heavy to put onto a missile warhead, and the resulting bomb has relatively little power compared to modern thermonuclear devices.
The core of Iran's nuclear program is their plutonium extraction process, which in turn is based around the heavy water reactor that they are building near the heavy water plant that they just finished building -- a heavy water plant, I might add, which is identical to the one Pakistan used as part of their nuclear weapons program, and the satellite photos I've seen of the reactor under construction seem to show it's identical to Pakistan's weapons reactor also. But I forget, these are being built with our "ally's" help (Pakistan's help), so Dear Leader must focus on the civilian nuclear program to distract attention from the fact that it is our "friends" who are giving Iran the bomb...
The civilian program (the light water reactor and the uranium enrichment program) is important to Iran's long-term weapons program, but only as a means of gaining experience with nuclear technology. Their actual weapons program is elsewhere, being built with the help of our "friends", an inconvenient fact that nobody seems willing to point out.
-Badtux the Thermonuclear Penguin
I'm going to have to disagree with you about a Uranium bomb being too big to fit on a missile. If anything, a Uranium bomb may be smaller than a Plutonium bomb [1]. Consider, for example, the Fat Man (Plutonium) versus the Little Boy (enriched Uranium). For a gun type bomb, which the Little Boy was, it can be put on a moderately large missle. However, Plutonium devices are all implosion type devices, and tend to be a bit larger (I can give some reasons, but I'd perfer not to do it out in public like this.).
ReplyDelete[1] "Hi guys!" (Standard greetings to the spooks who may be reading this, based on the keywords.)
There are some indications that some of Pakistan's Plutonium based devices may have been fizzles, due to some of the above aluded to problems.
As for the destructive power released, both Little Boy and Fat Man were about 10 Kt, which is adequate to wipe out a large portion of a city, if detonated at the correct position. It's certainly true that thermonuclear devices may have a SIGNFICANTLY enhanced yield (The Soviets had a 100 Mt design, and actually tested a 63 Mt scaled down version of it. Plus, there was that Castle Bravo test shot the Americans did that sort of got out of hand at about 15 Mt.). Most of these are based on a (multi-stage) Teller-Ulam/Shakarov design, although there are some indications that there may be other ways of achieving the boost.
Dave
You forgot the world's smallest detonator for a uranium bomb, Dave. Get uranium enriched enough, and you can take two lumps of uranium, one in your left hand and one in your right hand, smash them together, and BOOM! It'd be the world's most powerful suicide bombing.
ReplyDeleteOf course, that's like saying that if I had a billion dollars, I'd retire to the Bahamas. Enriching uranium is *hard*. Iran's current or proposed centrifuge cascade hasn't a hope or a prayer of ever enriching uranium to that point.
-BT
Oh, I never said (or, at least, I never intended to say) that enriching Uranium to weapons grade was easy. It's an incredibly hard thing to do. There's only a little over one percent mass difference between the stuff that goes "Boom" and the stuff that just sits there, and that's not much of a different. So, it takes MANY trips through the enrichment centrifuges, and you end up with a HUGE pile of waste before you get anything even remotely close to bomb grade (and, that's if you don't spring a leak and burn the place to the ground with the pyrophoric Uranium).
ReplyDeleteOf course, it can, and has, been done. My understanding is that we mostly originally used calutrons for the production, although production was later switched over to gasseous diffusion (in one of the world's largest buildings, which was necessary to contain the length of piping necessary).
So, given the difficulty, I have to wonder why the administration is making such a big deal out of Uranium enrichment when they're also working on the breeder reactor to produce Plutonium.
As for the world's smallest detonator, slapping the two halves together will definitely work as a suicide weapon (as Louis Slotin proved), but it will mostly result in a fizzle as the device blows itself apart before much energy is released.
http://en.wikipedia.org/wiki/Louis_Slotin
There have been a surprising (well, at least to me) number of criticality accidents, and none of these have resulted in a nuclear explosion.
http://en.wikipedia.org/wiki/Criticality_accident
http://www.csirc.net/docs/reports/la-13638.pdf
Dave
P.S. So you're saying that I won't see you in the Bahamas in about 20 years?
Dave
"Although Iran began developing its nuclear program in the 1950s, it was slow to progress until late in the 1960s, when the U.S.-supplied 5MW thermal research reactor (TRR) went online at the Tehran Nuclear Research Center (TNRC). In 1973, spurred by an influx of oil revenues, the Shah of Iran embarked on an ambitious goal of modernizing the country and building its image abroad..."
ReplyDeleteHistory