I have a small piece of graphite from the first nuclear reactor, CP-1, which was built under the Stagg Field spectator stands at the University of Chicago as part of the Manhattan Project in 1942. It's encased in clear plastic, and I was given it as a memento of some meeting or other.
I've always wanted a piece of diffusion barrier to go with it. Diffusion barrier is the material used in Oak Ridge's gaseous diffusion plants, which separated uranium isotopes in the Manhattan Project.
They've got a surplus of that stuff. It can't be all that radioactive; clear plastic should take care of any hazard. And I need a piece for my desk. I'll bet there are a lot of other geeks out here that would want one, too. That's how they could get rid of it.
But I suppose it's still classified. Sigh.