Unless they have changed the regulations in the past year, you are not
required to have a license for all radioactive materials. Sources in the
microcurie range are excepted. Sealed, low level sources are excepted. I am
speaking generally because their are exceptions to the exceptions. In some
cases you can have as much of an isotope that you want without a license. A
notable example is Radium. If you have the money you can buy all the Radium
you want. Of course I would advise against keeping any of it around unless
you really know what you are doing.
If Dick Sullivan needed a license for Uranium Nitrate, he would not be
able to buy it unless he gave his supplier a copy of his license.
I have maybe 300 gm of Uranium Nitrate in a little brown bottle. If you
put a GM probe up against the side of the bottle, it will kick the needle over
pretty good, but we are talking about maybe 50 mrem at the surface and thats
not a lot. Three feet away (1 meter about) it is essentially undetectable
with a survey meter (GM variety).
After I made my first uranium print, I decided to see if there was any
detectable radiation from the finished print. I picked up nothing at the
surface of the print with a standard GM survey meter. Of course, if you
put a uranium print (uranotype) in a gamma scintillation spectromemter
you would be able to easily detect uranium and all of the decay products.
But that is a different matter because we are now talking about nanocurie
levels.
Bob Schramm