How very interesting. Not what I expected at all. Maybe Kimmie is finding the big boom a little more difficult than expected? No comment beyond that...watching closely...BTT...
There is a report to that effect in local media here. It says that NK researchers purposely put less than weapon's grade Plutonium(more than 7% of Pu240), ensuring the explosion, but resulting in far less yield(TNT 400 ton) than desired(4 kilo ton.) This is because they have been making exaggerated report of their progress to Kim Jong-il to keep him satisfied. However, they were worried quite a lot about the day when they are asked to perform the nuclear test. Basically their detonator was far from perfect. Their solution to this serious predicament was to use Plutonium with too much Pu240. This way, the bomb will explode whether the detonator works properly or not.
I think Kimme is finding it pretty expensive to build these things - bet he's running out of money.