[Southack]

"It depends on the trigger, and the style. Tritium is typically used. Some may even use the polonium style, but that won't last much longer. However.. The big thing is, maybe they can be refueled by the bad powers. I bet NK has quite a bit of Tritium now."

That's all incorrect. Tritium is **not** a trigger material, by the way. Tritium is a booster.

[elchrio]

Booster yes.. The old style had the neutron source go off at max pressure from the urchin design. However, moderns typical have an external neutron cyclotron outside of the assembly.

However, a gun-style does not need the boosting.