What is it used for? Where does it come from?
It’s almost pure U238, depleted of U235, so useless for weapons. It comes from weapons production. Since most Uranium is U238 (only 2% or so is U235), there’s lots of worthless (at least for weapons) Uranium left over after you make your bombs. It’s very dense, and very hard, so useful for shooting at things (so I guess it’s still good for weapons, just not ones that go “boom”).
Sorry, the U-235 content of natural Uranium is only about .7%
It’s still at least somewhat radioactive, though, and inhaled dust from it might be responsible for the “Gulf War syndrome” many vets suffer from. That, or plain old chemical poisoning from it: It is a heavy metal, after all.
^
Actually U-238 is the main “fuel” in the third stage of a three stage nuclear device. It can undergo fast fission.
To the OP; DU is employed to defeat armour. Being hard and dense means it can for the same weight pack a heavier punch then say steel or tungsten. It is also pyrotechnic (hope I got the term right) whereby it tends to cause sparks; this is useful as said sparks can set off the ammunition racks in a tank.
As for its toxity; it is toxic and can cause cancer in one circumstance,if it is inhaled while burning. The only realistic time that is going to happen is when it is penetrating the hull of a vehical and I think the crew of that vehical will have bigger worries.
But it is also used in armor. When a tank with depleted uranium armor is burning, anyone near the tank or responding to scene of the burning tank may be exposed to burning DU. Not to mention the DU rounds that are in the burning tank. So there are plenty of ways to be exposed to burning DU without actually being inside a tank hit with a DU round.
When a Soldier returns from combat and is going through all of the post deployment medical screening, he is asked at least two dozen times if he has been near or inside burning vehicles, including going inside them to rescue injured Soldiers or just being in the area.
It melts at approx 2000[sup]0[/sup]F and boils at approx 7500[sup]0[/sup]F.
How how does a burning tank get?
A liquid doesn’t have to actually reach the point of vaporization for small quantities of the material to evaporate. Consider water-- it can evaporate at room temperature. The boiling point merely notes the maximum temperature that it can reach without turning into a gas (at a given pressure).
One unique aspect of DU is that it is a self-sharping weapon; i. e., the nose on impact with armor causes it fracture in such a way as to remain “pointy”.
To lower this down to a more layman level (as a layman, myself) uranium, like any other atomic element, has what’s called “isotopes”.
An isotope, to put it simply, is an atom that has a different count of neutrons than the charged particles that make up its chemical characteristics (proton = positive charge / electron = negative charge). That is, uranium, being element number 92, has 92 protons, 92 electrons, but its neutron count differs, depending on which isotope you’re dealing with.
Uranium-238, is very weakly radioactive; It’s half-life being almost 4.5 billion years. This is the isotope of uranium (it has 146 neutrons, 146 + 92 = 238) that is most abundant in the earth by a huge amount. U235, as stated above, occurs to a much lower percentage, and also U234, even less so. And all this is chemically bonded to other elements, so it has to be separated.
To make a nuke, you need the more unstable isotope of the element – U235 – to reach critical mass as the uranium splits, and all those free neutrons fire themselves at other U235 atoms, and cause them to split, and so on – a fissile chain reaction.
The energy of fission, the amount of mass that is converted into pure energy, is massive as dictated by E=MC^2. This is why nukes are so powerful considering their size. We’re converting mass into energy. It’s a nuclear reaction, not chemical, like TNT.
This just doesn’t work well with U238. But since U238 contains a very small amount of U235, if you purify it enough (the hard part), it becomes fissile, and you have weapons-grade Uranium, but a shit-load of U238 (depleted uranium) left over.
Hopefully I didn’t botch that up too much.
This actually happens with chemical reactions, too. It’s just that in chemical reactions, the mass change (and hence, energy release) is tiny.
It’s actually less radioactive than non-depleted uranimum.
The main toxicity of DU is not radiation but chemical - it is extremely bad for your kidneys. It’s far more likely to cause kidney failure due to chemical toxicity long before any residual radiation will cause cancer.
Ahh, of course.
Not saying that Bear_Nenno is wrong; but could someone clarify this. I remember when this was a big issue about 10 years ago; this was mentioned and NATO claimed that there was no risk; but they did start screening soldiers.
Just to add, the process of purifying U235 is called enrichment, or enriched uranium.
It’s great for armour piercing rounds fired by large calibre weapons.
It’s self sharpening, so if it breaks, it breaks sharp. And it’s autopyriphic, meaning it bursts into flames. It’s also pretty cheap.
I think you meant " …for the same volume…"
Well, yes, of course, but it’ll still click on a Geiger counter. And what radioactivity it does have is mostly alpha particles, which are the worst kind if the material is inside of you (eaten or inhaled).
It’s the same thing.
For a given weight, a DU projectile is smaller, hence more penetrating.