[DB]

They are conventional explosives that can be used to detonate a nuclear device. There are many other uses as well.

The nuclear material for a nuclear weapon is the hard part not the conventional explosives to detonate it.

[endthematrix]

Actually the explosives used to detonate Saddam's bomb was difficult to produce (into a nuclear detonator)

The explosive is press formed, molded or machined into a lens shape to be used cylindrically around the round implosion device. It's just not packing explosives next to uranium, but much more complicated than that.