Regarding the ease or difficulty of making a nuclear bomb once you have the fissionable materials, I was thinking after my first post that there could be some metallurgical issues with shaping uranium into the required shapes. I dunno. If so, it might at least make it difficult for some schmoe who has just bought a couple of sub-critical masses on the black market to vaporize downtown wherever. But it probably still wouldn’t require a full-scale Manhattan Project effort…if you have the weapons-grade material, at least not if it’s uranium.
(Does plutonium have to be detonated by implosion, or could it be set off in a gun-type bomb as well?)
Thank you ME, this was becoming a debate and I thank you for setting it back on track. (that 9/11 has all of us hot).
My point is and was, once you have weapons grade plutonium or uraniuim then you in effect have a loaded gun that you can point at the international commumity. Saddam has not proved himself worthy of carrying this responsibilty in my book.
But, though it is the HARD part. is is a critical part. There are many things you can do with weapons grade atomic matter. (Sell it to terroist?). It should not be taken lightly.
Once again, I believe that once the US obtained it in 1945, it was only a few short weeks that they used it twice. What would stop a determined state from using it today.
To once again answer the OP. Yes it is hard. But to obtain it is to invite destruction of your fellow man.
A question about critiacl mass - If I have two 0.9 critical mass 238 half sphears and a wooden seperator - if I pulled out that seperator and the sphears came together - how long before it would go bang?
My understanding is that if the two hemispheres were brought in contact slowly, there will be an increase in temperature or a tiny explosion which will break up the lump. If you want a big explosion you need to do it faster using an explosive.
There was an insanely stupid accident in a Japanese nuclear fuel processing plant a few years ago. Workers poured buckets of refined uranium into a container, exceeding critical mass. The result wasn’t a multi-megaton explosion but just an intense chain reaction. The workers were killed by the radiation but other people in the facility survived.
Further to scr4’s answer, I don’t think wood would be a terribly good neutron absorber, maybe you should try something a bit heavier.
Wasn’t there an accident during the Manhattan project where a scientist (the name Slotkin springs to mind) had two hemispheres of uranium/plutonium held apart by a screwdriver? The thing slipped and he fatally irradiated himself. Others in the room survived, IIRC. There wasn’t a massive explosion.
And to answer te original point, we can’t possibly count on Iraq not having access to the knowledge of how to build nuclear weapons, and we can’t possibly count on Iraq not having the facilities to build nuclear weapons -either can be obtained. We have to assume he has both - at which point, the scarcity of payload materials is the single stumbling block.
Yes, folks, it’s not trivial to design and build an atomic bomb. Unfortunately, especially now that the cat’s out of the bag, design isn’t as tough an issue as it once was. Have people forgotten the Princeton undergraduate who designed an A0-bomb as his thesis – a real design, not a schematic – and had it slapped with a “classified” rating? Or the magazine circa twenty years ago that published detailed designs for atomic bombs? Or Tom Clancy’s note in the back of The Sum of All Fears about how easy he foun it to gat all the information he needed to design a working bomb? As Richard Rhodes said in The Making of the Atomic Bomb, “Every nation that has set out to build an atomic bomb has succeded on the first try.” Even though bomb design is not trivial, it is apparently surprisingly attainable by an educated and determined searcher. Saddam Hussein didn’t need an immense research team and a huge budget to design a working bomb. So I think the OP still stands, and it’s why so many nations are dragging their feet over war with Iraq – he doesn’t have the fissile material, and it’s what he really needs. I don’t want to see him get it, either, but how is the situation different from the way it has been for the past 11 years?
And why can’t we use this same excuse to invade North Korea? They already have the fissile material.
As for building the weapon, the practical considerations are large: Controlled atmosphere machining isn’t all that casual an excercise. Further, you have to at least try to avoid crapping-up your machinists, as the level of skill needed is quite high and sick machinists don’t do their best work. That’s not so easy, either. Still, it should be well within Iraq’s capabilities. One of the more difficult issues with implosion-type weapons is that you have to control the detonation of the explosives very carefully. A simple crack in one of the explosive lenses can cause a squib. Make one of the detonater lines an inch too long; Squib. Mis-match the charges; Squib. Wrong shape of charge; Squib. There are many ways to get a squib. For each bomb design, there’s just one way of getting it right. The damn things are on the verge of not working at all, and it requires careful and precise work to make an implosion nuke go “Bang”.
“Gun” type nukes are pretty straight forward, OTOH. The main factor against gun-type nukes is size; They tend to be larger than implosion weapons.
If Saddam has arlready figured out how to solve all the above problems, and only needs to acquire & machine the fuel, we’re at risk. Getting the fuel is merely an excercise in logistics. A difficult one, but not insurmountable. After that, it’s just a matter of time and willpower.
I read his book. He did not design the bomb from scratch. In fact, he didn’t design all that much of it at all. His trick was figuring out how to wheedle classified information out of the people who had actually done the design.
For example, the types and configuration of the explosives for the bomb are classified. So our enterprising student called the chemical manufacturer and asked for the information, and they accidentally gave it to him (or perhaps he misrepresented his reasons - I can’t remember now. I read the book about 15 years ago).
Making an effective nuclear bomb is NOT as simple as just dropping a couple of masses together. Tranquilis has it right - nuclear bombs are simple in basic concept, hideously complex to make work.
And the Manhattan project was divided into two parts - the fissile material was not manufactured at Los Alamos, as I recall. Los Alamos was responsible for designing the bomb itself, and it was a massive effort, even though the simple ‘you just need a critical mass’ explanation that’s floating around this thread was known well before WWII.
Nonetheless, Iraq apparently has the plans for a nuclear bomb, and they have the machining capability to make it. All they lack is fissile material, and they’re building the centrifuges to create that now.
Plutonium is easier to work with for making a basic gun-barrel type weapon, but you need a breeder reactor to get the plutonium. The Israelis took exception to such a thing in 1981, when they flattened the Osiraq facility then under construction in Iraq. It annoyed the French, too, who were building the facility, and who had supplied France with 27.5 pounds of fissile U-235, which as best I can tell was never returned.
The Israeli reaction was widely derided as a horribly intrusive and unprovoked attack. It especially pissed the French off, who were in the process of building the reactor for Iraq. If Iraq has in fact been pursuing its nuclear program for nearly forty years with only a couple of setbacks such as that attack and the Gulf War, then perhaps I’m beginning to understand why Bush and Blair are beginning to sound a little bit anxious.
It is arguable whether it is easy or not to develop the technology to make the Bomb in house. But what prevents Saddam to buy it out from some people from China, Pakistan or Russia ??
It is much easier to buy the technology (and even the techonologists) than to get the fissionable material out of any country !!! Pakistan’s nukes are supposedly copied from China (don’t have any cites - sorry). And Saddam has been selling a lot of Oil to China ( sorry no cite again - but if anyone wants use google)
So what really deters Saddam is to get the fissionable material out of any country !! What am I missing here ??
Tranquilis and manhattan, it shpould be bvious that my question as rhetorical. And it’s not a question of stability – it’s a question of intent. Once upon a time we started getting hysterical about Korea’s possessing material. I’m still not clear on why that changed. Certainly we don’t trust the Koreans a lot, or else we’d tear up the minefield on the border.
Sam Stone – whether he designed the bomb" from scratch" or not isn’t the point. He designed it, and he did wheedle senstive information about explosives and other things.(I didn’t rad he bok, but 've read xcerpts). This does nt make me feel any better.
CalMeacham: Well, it doesn’t make me feel better either, but on the other hand we don’t know what key pieces were missing from his bomb design, because it WAS classified. We don’t know for sure if it was workable, because when he submitted the paper a veil of secrecy was clamped over the whole thing.
Andy_Fl: Remember the ‘Axis of Evil’? One of the reasons those countries were lumped together was because of the synergy they bring to each other. North Korea has advanced short, medium, and soon Intercontinental ballistic missiles. Iraq has an advanced nuclear program (from what I understand, more advanced than Iran’s). Iran also has missiles, and may have fissile material (so might North Korea).
So if the U.S. had intelligence that these three countries were beginning to cooperate, then you’ve got a huge problem, because between the three of them they could come up with some pretty horrific weapons, both nuclear and otherwise.
But yeah, the big worry now is probably that Saddam is either A) close to refining his own fissile material), or B) collecting it on the black market.
The latter is hard to do, because weapons-grade material is tracked very carefully. Unfortunately, there is some that has been manufactured and can no longer be accounted for, but we really don’t know if it’s anywhere near Iraq.
The Axis of Evil is about countries NOT people !!! The poor Highly Technological people of Russia are more prone to give the technology to Iraq. If you are not following news (there was a story on NPR) the next attemted terrorism attack may well be in combination with Cyber Terrorism. The Cyber terrorists are not from the Axis of Evil, but some poor Tech guy from Russia!!!
The OP still stands.
Richard Rhodes’ book Dark Sun, about the development of the hydrogen bomb, goes into the workings of fission weapons as well. Reactor-bred plutonium-239 is unsuitable for an assembly-type bomb because of contamination with Pu-240, which will cause premature detonation. So you have to make a working implosion-type bomb, with all the complications of explosive lenses, detonators, etc. For that matter, building an efficient breeder reactor isn’t like brewing moonshine. In addition, the metallurgy of plutonium is an chemist’s nightmare. So although a plutonium bomb is conceptually simple, it’s a case of “the devil is in the details”.
U-235 based assembly bombs are much easier to design, but the raw material is very hard to obtain. The sheer scale of gas-diffusion plants is daunting, and there are any number of technical and engineering problems that have to be solved to build one.