"Bob May" wrote in message
...
What is depleted uranium depleted of?

U235

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.

Correct.

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

And the basements of houses built on granite fill up with Radon.
There's plenty of radioactive fallout from the 50s, the CO2 in the air is
has Carbon-14, water has tritium, potassium-40 occurs in natural potassium,
which is everywhere, including bannanas and people. Space is full of natural
fusion reactors, the earth has Van Allan belts, recently we got hit with a
massive cosmic ray burst, etc.