NK Nuke Test May Be Dud

This is being reported by Austin Bay, among others:

It looks like a small, less than one kiloton device — the articles says 550 tons. 1000 tons is a kiloton. (The Hiroshima bomb was the equivalent of 13 to 15 kilotons.) I say “looks like.” The Russians say they are one hundred percent certain Pyongyang tested a device.
Such a small boom means this could have been a failed test (they wanted a larger explosion). I doubt the NoKos have the sophistication to produce a small, efficient “low yield” nuclear weapon.