On Wed, 20 Apr 2005 14:41:36 -0700, Bob May wrote:
What is depleted uranium depleted of?
I've always thought that this stuff is the byproducet of the nuke bomb
industry where the valuable U-235 is removed from the not valuable U-238
which isn't radioactive.

U-238 is radioactive, it has a half-life of 4.5 billion years.

I'll also note that granite is radioactive yet we build buildings with it
without concern.

It's detectable, but that doesn't mean that it's a problem. A chunk of
granite is less interesting to a Geiger counter than a smoke detector is.