If you want to study the effects of radiation on animals, insects etc I can see going there.
Otherwise it's just not worth the trouble even doing it legally.
The effects of exposure to multiple isotopes can be a DNA altering experience.
One screw up is all it takes.
If something happens there's no going back.
There are countless places that are cheaper, cooler, easier, and less of a hassle to do.
Of coarse I do look forward to the epic "I got busted at Chernobyl" thread
Carry on...