[caddywompus]

Ah that is true. In that case the danger would be in the tracking and storage of fuel elements. Assuming re-fueling is required infrequently enough that a regulator organization could keep tabs on them. Although in that case the danger would be the tracking and safe storage of the fuel elements.

[nielu]

As far as i understand some of the small reactors are designed to be fueled only once in their lifetime - in the factory.