While watching Dr. Strangelove and allowing my thoughts to drift to George W’s missile defense plan, the following question occurred to me: Does a nuclear weapon detonate when struck by another missile? For example, if a plane carrying nuclear weapons is shot down, does the desired nuclear effect occur? Alternately, if we shoot down a nuclear weapon in the upper reaches of the atmosphere, can we expect mostly cloudy skies with a chance of radioactive showers?
I apologize if this question has already been posted but a search of the boards turned up many nuclear references.
I believe the conventional explosives inside the warhead are positioned in an exact way so as to go off at the same time. The people who assemble the warheads have to have these explosives go off very exact, or else the ‘boom’ isn’t as big. The nuke might go off if hit by a conventional explosive while armed, but it won’t be as big as it was planned to be.
No, I’m not a nuclear physicist, I just read Tom Clancy and other related fiction.
Nuclear warheads are generally designed not to detonate unless they are deliberately set off. There have been a number of accidents involving crashes of aircraft carrying nuclear weapons as well as some “incidents” involving missiles, and so far at least there do not appear to have been any accidental nuclear detonations, though there have been some cases where there was some level of radioactive contamination. I would think a successful “Star Wars”-style intercept of a nuclear missile would pose more of a threat of radioactive contamination of some degree than it would of a full-scale nuclear explosion.
Short answer: no fusion is going to occur.
where the plutonium ends up, well… don’t think about it.
For those who remember the ‘neutron bomb’ (aka ‘enhanced radiation device’ - love the term) - this was a 1960’s attempt to ensure that the interceptor would trigger detonation - by creating a radiation field around the warhead (to create critical mass)
as to star wars - I guess we’ll have to get all enemies to use use single-warhead missles, tell us when/where they will be launching them, and put GPS beacons in them… :rolleyes:
Correct detonation of a nuclear device relies heavily upon the precise implosion of two sub-critical masses. Whether these masses serve as the principal component of the bomb or just as the “trigger” for a thermonuclear fusion device, the implosion must be near perfect to attain the compression required. An ABM impact could not possible produce the sort of concussion needed to cause this.
There was a show on The History Channel recently dealing with Broken Arrows (lost nukes). They covered this accident. It was very interesting. It’s already been said, but it bears repeating. It is extremely difficult to get a nuclear weapon to go off. Everything has to be timed perfectly to achieve a nuclear chain reaction. Quite a number of tests in the '50s and early '60s were no-yield fizzles because of this. Worst case scenario, high explosives in the warhead explode scattering plutonium from the missile. Bad news for anyone who comes in contact with it, but not anything as bad as a nuclear explosion.
Neutron bombs were designed to kill men in tanks. It was found that tank armor was actually very radiation resistant, and vehicle crews could easily survive a nearby tactical nuclear blast. Neutron bombs were designed to create high energy neutrons to penetrate tank armor and kill the crews.
And to the OP: No, nuclear bombs aren’t delicate. You can’t hit them with a hammer and make them go off… (Stupid tv movies like ‘atomic train’ make me want to gouge my eyes out, even though I’m not even anywhere near being a physicist…)…
There’s a very specific process that has to happen to allow a proper nuclear detonation… getting hit with an ABM equivelant to getting nailed with a sledge hammer, it’ll just fall apart… Although if the radioactive core is damaged, it might spread some stuff around.
Besides a very precise explosion you have a few other things preventing an accidental nuclear detonation.
The nuclear fuel is kept separate in two sub critical masses. When the weapon is intentionally detonated the two masses are brought together and the precise explosion everyone is talking about happens. If a nuke is hit by an interceptor the two masses have virtually no chance of being brought together in a proper fashion.
In addition to the conventional explosives used to compress the nuclear fuel an initiator is used to add a flood of particles to the mix to kickstart the chain reaction. There is a chance that a critical mass of nuclear fuel will spontaneously initiate a chain reaction but it’s not a very good chance and even if it did you’re not likely to get the maximum yield from the bomb (atom splitting doesn’t happen as fast or as efficiently). The initiator helps things along a great deal. Being an electronically controlled device it’s not going to do anything unless specifically told to do so. Getting smashed up in flight won’t accidentally set it off.
Add it all together and you have no problem with detonating a nuke accidentally. Intercept away!
The gun-type fission weapons - a la the Hiroshima bomb - are not nearly as inherently safe as the implosion type.
Had the B-29 carrying the Hiroshima bomb crashed, it might very well have set off the charge propelling the “plug” into the core, in turn setting off the weapon. Which is why the propelling charge wasn’t inserted until late in the flight towards Hiroshima.
Of course, this primitive design isn’t used anymore. Later gun-type designs (such as nuclear artillery shells) used all sorts of fancy tricks to get to supercriticality, all of which had to work flawlessly.
A rogue nation lashing up a rough-and-ready nuke might decide to go for a gun type weapon, but if you have the technical savvy to put together a missile, you’ll want to build a fancier nuke than that.
Yeah, Steven Seagal said to the stripper in “Under Siege” the nukes wouldn’t go off when they blew the submarine holding them away with the Missouri’s big guns… so if an actor said it, it’s gotta be true (actually appears to be one of the few movie facts that have turned out to be true :D)
