Their proportion is about 0.7% to 99.3%,
respectively.
Nuclear reactors require U235 to produce
energy,
therefore, the natural uranium has to be enriched to
obtain the isotope U235 by removing a large part of the U238.
What is left after the extraction of these isotopes
is called Depleted Uranium.
This exists in large quantities and is almost
always used in the production of weapons.
DU is 0.7 times as radioactive as natural
uranium.
These include tank armor and anti-tank shells from
30mm to
120mm (diameter of the Sabot encasing the DUTP) in diameter.
DU is softer than tungsten which means it
does not shatter when hitting a hard target.
The Germans will not allow DUTP ammo
to be fired in practice on their soil.
In the U.S. it can only be fired at
EPA-certified gunnery ranges.
When it hits an armored target it is compressed to
high pressure which
transforms it into a pyrophoric (burns when in contact w/ oxygen)
agent.
The pyrophoric DU burns its way through the armor
creating spall.
Du in this state has a tendency to fragment
as it passes into the tank interior and will burn through
human tissue in the same manner as White Phosphorous.
It also produces toxic fumes, which are
one of the suspects in the Gulf War Syndrome.
Millions of rounds of 30mm DUTPs were fired be the
U.S.
Air Force’s A-10 attack aircraft
during the Gulf War.
The U.S. Navy discontinued use of DUTPs in it’s Phalanx
CIWS in 1988 because of health concerns about it’s radioactivity.
Also, used in the M-1 Abrams' tank armor and main battle round.
However, the U.S. Army refuses to discontinue it’s
use.
Since DU has a half-life of 4.5 billion years,
there is very little decay of those DU materials.
DU is a suspected cause of some GWS cases.