# "Dirty Bomb"

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not good enough, Ali. You have to provide a direct reference or quote. Why should we take your word for granted?

I don't have the proof however I can recall watching a program based on this on fox news in late 2002.

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you thought a dirty bomb was a nuke. how wouln't a nuke hurt many people?

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you thought a dirty bomb was a nuke. how wouln't a nuke hurt many people?

I'm not talking about conventional nukes. I'm talking about someone trying to use an explosion to try enact a conventional nuke.

Like the Americans nuked the Japanese I mean so what? its the survival of the fittest its evolution same as every where else in the animal kingdom, we are mammals after all. People should stop crying about it take it on the chin an move on. The dominant species will always survive.

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only because people have learned to restrain themselves.

Like the Americans nuked the Japanese I mean so what? its the survival of the fittest its evolution same as every where else in the animal kingdom, we are mammals after all. People should stop crying about it take it on the chin an move on. The dominant species will always survive.

Ever heard of MAD (mutually-assured destruction)? In the event of another atomic bomb, this is a very real possibility, but even more so back in the cold-war days. We learned to restrain ourselves because humans are smart enough to realize that, in our desire to dominate others, we could ultimately destroy ourselves.

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I'm not talking about conventional nukes. I'm talking about someone trying to use an explosion to try enact a conventional nuke.

That's not what a dirty bomb is. A dirty bomb is a conventional explosion used to disperse radioactive material.

AIDS has killed more people than house fires, so why have a fire department?

Like the Americans nuked the Japanese I mean so what? its the survival of the fittest its evolution same as every where else in the animal kingdom, we are mammals after all. People should stop crying about it take it on the chin an move on. The dominant species will always survive.

The Japanese aren't a seperate species.

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you seriously can't see the difference here? compare the rates instead. mosquitoes have been around a LOT longer than nukes.

Like the Americans nuked the Japanese I mean so what? its the survival of the fittest its evolution same as every where else in the animal kingdom, we are mammals after all. People should stop crying about it take it on the chin an move on. The dominant species will always survive.
that is very insensitive. if you continue to make such comments like that and the comments this thread, i predict a short membership for you. my predictions are usually correct, btw. i am just trying to help you out.

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That's not what a dirty bomb is. A dirty bomb is a conventional explosion used to disperse radioactive material.

No indeed, nuclear weapons genrally have some kind of conventional explotion to start with anyway, to force the lumps together...

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No indeed, nuclear weapons genrally have some kind of conventional explotion to start with anyway, to force the lumps together...

You can't just stick some explosives around a pile of uranium and make a nuclear bomb. It takes quite a bit of knowledge to put them in the right place for it to reach critical density when the explosives go off.

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You can't just stick some explosives around a pile of uranium and make a nuclear bomb. It takes quite a bit of knowledge to put them in the right place for it to reach critical density when the explosives go off.

I am well aware of this haveing been taught it in a lecture last year. But the principle that they DO have a conventional explocive still stands.

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Like the Americans nuked the Japanese I mean so what? its the survival of the fittest its evolution same as every where else in the animal kingdom, we are mammals after all. People should stop crying about it take it on the chin an move on. The dominant species will always survive.
Wow, your posts just get worse and worse. I gave one verbal warning. Implying that the Japanese aren't human or even mammalian is racist and for that you get a formal warning. Please don't EVER think that will be tolerated here. Take the time as you type to think about what you're saying.

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Yeah...I've always been told the Dirty Bomb threat was a conventional explosive device intended to scatter radioactive material over an area.

The issue is that while we assume its hard for terrorists to aquire nuclear weapons (only evidenced in that they haven't used any yet) that it may be possible and much cheaper/easier to aquire material unsuitable for a nuclear reaction, but still highly radioactive.

Klynos:

Yes they both utilize conventional explosives but I think the key differences, (that explosives in a nuke only serve to cause critical mass as a precursor to the actual very large nuclear reaction/explosion vs. a device who's total explosive output is no more than the chemical reaction of the conventional explosives themselves) make the simularities moot. Technically, a nuclear bomb can be triggered without conventional explosives, its just a convienant way to achieve critical mass.

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Wow, your posts just get worse and worse. I gave one verbal warning. Implying that the Japanese aren't human or even mammalian is racist and for that you get a formal warning. Please don't EVER think that will be tolerated here. Take the time as you type to think about what you're saying.

I wasn't trying to say the "Japanese aren't human" I was trying to say we humans have evolved from animals so like Darwin said its the survival of the fittest, take ancient civilizations for instance [Persians, Sumerians, Aztecs ect...].

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the whole idea of a dirty bomb is to disperse an extremely radioactive material of a wide area.

...

the isotope might render an area uninhabitable for many generations.

You can't have both. Activity is $A = \lambda N$ If it's extremely radioactive due to a short half-life it decays away rapidly. If you want to render an area uninhabitable for many generations you need a moderate half-life (e.g. several years) and to be extremely radioactive you need a fair amount of the material, which needs to also have a long biological half-life to be dangerous - otherwise you ingest and excrete it without it decaying.

(This concept was one of my board questions for nuke teaching qualification; the media reporting at Three Mile Island of "extremely radioactive" material being a problem for generations bugged the hell out of the physics dept head. When I took over, I used the same question on boards. So did my replacement.)

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Im uncertain about this Explosive not necesarily required to detonate a nuclear weapon, I think it IS needed.

else you simply get a meltdown (China Syndrome).

think of Chernobyl for example, 8 tons of radioactive fuel was blown a kilometer skywards, it wasnt a Nuclear explosion though, it was more akin to a "dirty bomb" where water instantly became super heated , expanded and That was the mechanical means of the actual explosion.

8 tons of fuel is well in excess of that needed for critical mass, it won`t explode though, not as a Nuke would anyway

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For a nuclear explosion, you do need a conventional explosive. As YT has pointed out, if you don't have the insanely high density, the freed neutrons simply cannot be absorbed in time and you don't get a self sustaining chain reaction leading to an explosion. What you will get, however, is a critical mass in which enough neutrons do get generated to remove the need for a separate neutron source. In this case, the mass of material will get insanely hot and you will get a meltdown, but then this molten mass of metal will disperse and quickly become subcritical.

In a nuclear device, you have subcritical masses which are fused together around a neutron source thanks to conventional explosives. The masses are under such extreme pressure and forces that they fuse into a solid, supercritical mass. Due to the high density of the supercritical mass, the neutrons released are immediately absorbed and very few of them make it out of the 'fuel'. This high density of material causes the explosion to happen. Just because you have a critical mass does not mean you will get an explosion. If that were the case, then nuclear power plants would simply not be possible. (As they run when their fuel supply reaches a critical mass and becomes self sustaining).

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Just because you have a critical mass does not mean you will get an explosion. If that were the case, then nuclear power plants would simply not be possible. (As they run when their fuel supply reaches a critical mass and becomes self sustaining).

They even go supercritical at times...

What's often misssed is that there is not only a critical mass, but a critical geometry that is required for a chain reaction.

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Klynos:

Yes they both utilize conventional explosives but I think the key differences' date=' (that explosives in a nuke only serve to cause critical mass as a precursor to the actual very large nuclear reaction/explosion vs. a device who's total explosive output is no more than the chemical reaction of the conventional explosives themselves) make the simularities moot. Technically, a nuclear bomb can be triggered without conventional explosives, its just a convienant way to achieve critical mass.[/quote']

Which was the point I was trying to make.

some interesting points esspecially on the http://people.howstuffworks.com/dirty-bomb3.htm page...

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Klynos:

Yes they both utilize conventional explosives but I think the key differences' date=' (that explosives in a nuke only serve to cause critical mass as a precursor to the actual very large nuclear reaction/explosion vs. a device who's total explosive output is no more than the chemical reaction of the conventional explosives themselves) make the simularities moot. Technically, a nuclear bomb can be triggered without conventional explosives, its just a convienant way to achieve critical mass.[/quote']

Which was the point I was trying to make.

Still, a critical mass does not mean that a device will explode like a nuclear bomb. All a critical mass means is that it has the neccessary mass to support a self-sustaining chain reaction. You still need the critical density in order for the chain reaction to ensue. Nuclear power plants all around the world have a critical mass of uranium/plutonium in their reactor cores. Yet these plants aren't exploding like a nuclear bomb. (In reality, they physically cannot explode like a nuclear bomb). The use of conventional explosives in a device is required in order to acheive the critical mass and density needed for a chain reaction explosion.

Now you can use hydraulics or other very ineffecient methods, but those haven't been tried in any successful manner and would require a very large building to provide the forces needed.

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Ever watched 24? Awsome program. This page explains what a dirty bomb is. I hope i'm not fueling some sort of terrorist attack here guys ???

http://science.howstuffworks.com/dirty-bomb1.htm

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There was an interesting BBC program on the topic. The dirty bomb was 'exploded' in Trafalgar Square. The BBC program claimed it would cause the evacuation of the city around the explosion site for 10 years. The number of deaths would be small but the disruption to the city large and the cleanup bill would be immense.

They estimated the number of deaths but I forget the number. I believe it was less than 50.

Dirty bombs exploding over the major cities would create havoc, but not many deaths.

I believe the Japanese during WW2 may have had a plan similar to this. LA was their target. The uranium coming from Germany was intercepted.

But really, what's at Trafalgar Square anyway but pigeons, tourists and those double deck red buses.

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Art students, tons of them. It's also in middle of well, everywhere else, that's why it'd be a big issue, not just the square itself but all the stuff around it.