However, I hate dumbed down science as displayed by this quote:

"A successful nuclear detonation requires a properly timed and triggered conventional blast that splits atoms, setting off the nuclear chain reaction that produces the massive explosions associated with atomic bombs."

A nuclear device consists of at least two sub-critical mass lumps of fissionable material that are brought together by the conventional blast to form a critical mass of material. The conventional blast does not split atoms. Those atoms are splitting spontaneously within the fissionable material and it's only the density and total mass of the final blob of splitting atoms that causes the uncontrolled nuclear chain reaction.

The conventional explosives are formed around the sub-critical masses in such a way that those masses of fuel fuse together into a single dense mass during detonation. The timing and distribution of the conventional charges are so critical that even a single one of them not working right can cause the materials to not combine properly. It's not surprising, if the NK's had an actual bomb, that it may have malfunctioned however, the track record of nuclear tests around the world have shown that most work on the first try.

Art