The book Command and Control by Eric Schlosser is one of the best I've read on any subject. He intersperses the history of nuclear command and control with the AR missile silo near disaster story. Top notch reporting all around.
Edit: s/Europes/German. Don't know about other european countries. And would think of it as unlikely for Greece, Italy, Portugal, and Spain itself. They wouldn't import from there, and keep the good stuff for themselves, anyway :-)
For a non-critical bomb exploding the bomb material actually has a pretty short half life on the order of a few decades or so I believe, so even if you did nothing at all the debris would naturally decay down to background levels fairly quickly (i.e. it would not be some catastrophic thing that ruins a part of the planet for centuries).
You are probably thinking of the tritium neutron trigger, which has a half-life of 12 years and has to be replenished to keep the warhead operational.
I'm not sure what the plans are for making new weapons in a few decades as the current ones decay into uselessness--there's likely some kinda provision in nuclear weapon treaties.