Re: Too far, and too hazardous . . .
One depository per state would be the way to go. Transporting a hot radio-hazard overland for hundreds, perhaps in excess of a thousand, miles for storage is just asking for a disaster. The less it's moved, the less chance something will happen to it.
Of course the only drawback I see to the logic is that the best place would be centrally located in the state -- which, for Ohio, is somewhere right under my chair...
Dan