"Well according to what I was taught at the US Army's school for Nuclear, Biological and Chemical Warfare, this is true, but they can be brought back with some maintenance upgrades by a trained technician."
Wouldn't you also need things like bomb-grade uranium or plutonium? It's not like you can get that stuff at Wal-Mart or Home Depot...
A suitcase nuke is self contained. It already has the fissionable material (probably Uranium 235) to go boom! But the other components degrade over time, the technician would be addressing this in order to bring the device online for a possible detonation. The uranium doesn't go bad.
It's a suitcase nuke, it already has the plutonium.