The land of the flighty

[--Pete]

Hi,

That's not hard. I could make a device with photo strobes, a metal salad bowl and green dishwashing liquid!

You probably could. The advances in electronics and explosives since the days of the Manhattan Project are such that consumer grade materials now are better than the best they had to work with then. But, really, a gun type bomb (like the original uranium bomb) is very low tech. You're not going to fit a bunch of them on an ICBM MIRV bus, but a fifty foot private boat could carry one with no problem at all. As a matter of fact, the original was delivered by B29 (IIRC) that only needed to be slightly modified.

As to determining whether the test occurred at all and was successful, that's not so easy. Underground testing was developed precisely so that a minimum of radiation would be released to the outside, so that the heat and blast signature would be contained, and (when done right) so that seismographic monitoring of the shock waves would give a misleading indication of the yield. The idea then was not to let your enemies (at that time, the USSR and the USA, depending on where you sat) know that you'd conducted a test, much less how it worked out. So, either the Koreans pulled off a successful test using good underground test techniques, or they pulled off an unsuccessful test (and the techniques don't matter). And most of us will never know which.

--Pete