[constant thinker]

U-238 isn't very dangerous. U-238 has a half-life of around 4.46 × 10⁹. It's used in tank shells in the form of depleted uranium.

It's actually used as radiation shielding in some nuclear reactors I believe.

There is probably a wikipedia entry on it. Search for it on http://wikipedia.org/.

[Borek]

It's used in tank shells in the form of depleted uranium.

Keel of racing-yachts - must be massive, but as small as possible, depleted uranium is relatively cheap and has high density.

[xiankai]

this wiould be because they will have create them by themselves and not because they will steal them from some place. Dont believe that all the terrorists are not educated poor Arabs. There are also rich maniacs in our world and people with knoledge about these weapons. They are the real big threat.   

if we're thinking terrorists building nuclear bombs here, maybe we can look at Iran and Korea, where whole governments may be dedicated to making bombs. (they may not, but its the possibility that we are worrying about) They are truly the biggest threats, what can a ban do against them?

It makes me think back to Richard Feynman and what it must have been like when they were doing the research, and making the bomb for the first time. If they could do it, then I suppose if you get enough smart people together, they'll be able to do it too. The only thing that can be done is to limit the materials which are used to make nuclear bombs.

that was during a war, and a government war budget is huge, especially the US.

The ban must start from the high purity 99,99 U-238, Thorium (especially them), Cobalt, Berillium, Cesium, Graphite and Polonium. Then we'll see.

if you must, research on the usefullness of these materials for other uses first. you must have an open mind, especially when the benefits outweight the risks.

[constant thinker]

Now that you bring up North Korea and Iran, I would be more afraid of either of the 2 countries giving terrorists highly radioactive materials that they don't need anymore. That's a very plausible scenario, and one that would make a dirty bomb an imminent threat.

[CGB_Spender]

Will you ever understand, that banning U-238 doesn't change anything, as it is of no use for nuclear terrorists?
Graphite ban is especially ridiculous, but I think I can overbid you here... We have to ban water! Water always contain traces of heavy water, which is used in nuclear reactors. If we ban water we can be finally safe.

First of all Borek, relax. We just talking here, there is no reason to get angry and agressive. I am just telling my opinion here.

Allow me to disagree with your opinion that U-238, has no use for terrorists. It can easyly be pu-239. The real problem is not how someone can do it Pu-239, the real problem is the protective meassures that someone must take for doing this. The creation of Pu-239 is ridiculous easy. If someone has U-238, then he has the first material for create the basic material for his fission bomb. And thats SOMETHING serious i believe. As i said with the banning of U and Th, we will not be 100% safe, but at least we will close some holes. 

I will overlook your hironic comments for water. I am sure you are smart enough for understand the difference between materials that can become materials for a fission bomb and the water or even the heavy water that has no use if you dont have U-238.

I have nothing else to add. I said my opinion and i let the other <<judge>> it. We are living in dangerous times and nothing is science fiction today. Everything is possible and even if we close some holes thats something than doing nothing at all. I will repeat that i really wish all these are my imagination and only as you Borek said before some posts. I really want to believe that you are correct my friend.

- Best CGB_Spender.     

[pantone159]

Allow me to disagree with your opinion that U-238, has no use for terrorists. It can easyly be pu-239.

The creation of Pu-239 is ridiculous easy.

No, the creation of Pu-239 is VERY HARD and it CANNOT be done (to any useful degree) without a nuclear reactor, which implies that one already has real fissionable materials (i.e. U-235).  U-238 is NOT of any use to terrorists at all.

[Alberto_Kravina]

Banning graphite? Do you mean that everybody has a device to build nuclear weapons in his peicil case (a pencil) ?

As Borek said, I think that it would be a complete nonsense to ban these elements

[constant thinker]

I have to agree with Mark K. I personally think without a nuclear reactor, it'll be extremely hard if not possible. Now with the reactor it becomes easy.

If it's easy for the average person to do CGB_Spender, then how will they do it without a nuclear reactor? Is there a method I'm not aware of that doesn't require a nuclear reactor.

[Borek]

how will they do it without a nuclear reactor?

My take is that CGB doesn't know anything about physics/chemistry involved, yet for some reason he thinks these things must be easy. It is enough to add one proton to U-238 to convert it to plutonium and you hear they do these things (like bombarding with protons or neutrons) in labs every day, so it must be easy. Well, maybe not very easy, but easy enough. You are not going to convince him that it is not true.

[CGB_Spender]

My take is that CGB doesn't know anything about physics/chemistry involved, yet for some reason he thinks these things must be easy. It is enough to add one proton to U-238 to convert it to plutonium and you hear they do these things (like bombarding with protons or neutrons) in labs every day, so it must be easy. Well, maybe not very easy, but easy enough. You are not going to convince him that it is not true.

You know Borek, maybe you are correct and i dont know anything about physics/chemistry involved... But i am surprised that a well educated person like you that knows almost anything, dont realise that a creation of a nuclear reactor from civillians or terrorists is not science fiction. Of course and its very hard, if not impossible to do U-238 to Pu-239 without a reactor. But what about if someone build one? And before you starting laugh, i want to say that i dont mean a high-tech, huge reactor like these that exist in Nuclear factories. If someone obtains grafhite, cadmium, Be, Heavy water, some neccessary chemicals for the separation of Pu from H.Water in big amounts and protective uniforms he can do it. He can build a small reactor in his back yard that would do U-238 to Pu-239. He/They just need knoledge, money, space for the reactor and time. Science fiction? Maybe...   

[Will]

He/They

He/They/She

Science fiction? Maybe...

Maybe definately!

[constant thinker]

Actually I think a group of people could do it with sufficient knowledge and resources. It's plausible but HIGHLY unlikely. They are more likely to raise red flags with the government and their neighbors before coming close to completion. Plus you need to have someone monitoring 24/7.

I personally see it being so hard that no one could do it with out blowing themselves up, or giving themselves a lethal dose of radiation. Also, I'm sure pretty much anyone with knowledge to build a reactor doesn't have the courage to do it, or the resources for that matter.

To me, I'm not worried. It's just not a threat that someone could whip up a nuclear reactor for that purpose even given the materials. I think it would be next to impossible to do. If a terrorist wants material like that, they will probably steal it from some under regulated and funded nuclear power plant in a developing country or USSR break away. Alternatively they may buy it on the black market.

[pantone159]

Actually I think a group of people could do it with sufficient knowledge and resources.

NOT with just U-238, though.  U-235 is an essential piece you can't do without!

[CGB_Spender]

NOT with just U-238, though.  U-235 is an essential piece you can't do without!

  I dont understant. In a U-238 reactor, you dont need U-235 at all. The -235 isotope has nothing to do with the transubstantiation of U-238. Heres whats happening:

U-238 + 1n ---> U-239 (emits a beta particle) ---> Ne-239 (emits a beta particle) ---> Pu-239

[Will]

Ne-239

No such isotope of neon exists, that I know of anyway. I think you probably meant Np-239.