[smag999]

My opinion? The North Koreans already filled this tunnel with High Explosives from a side tunnel and will detonate a few thousand tons of conventional explosive underground then claim they have a nuke.

[Tulane]

I think scientists in the surrounding coutries will be able to determine fairly easily whether or not is a nuke...but that is just a guess.

[freebird5850]

Also, exploding large amounts of TNT is used for calibrating measuring equipment to determine actual yield of the nuclear device when it is detonated.

[NJ_gent]

"My opinion? The North Koreans already filled this tunnel with High Explosives from a side tunnel and will detonate a few thousand tons of conventional explosive underground then claim they have a nuke."

Unlikely this would be possible. We can measure the size of the blast via seismic analysis, and it's not easy to fake a nuclear detonation. They'de need to ship in an unimaginable amount of explosive materials unnoticed and pack them into an enormous area inside a mountain.