Comment by NoMoreNicksLeft
5 days ago
>Why is that?
One, nobody exactly allows independent observers so we only really get seismo readings from those tests. And they don't make alot of sense. Yields should've been higher for plutonium cores, it's not lightweight stuff. And I wouldn't put it past them to have somehow pulled a fast one to fool foreign intelligence agencies (though stockpiling thousands of tons of high explosives fake a successful nuclear test seems beyond farcical). Just seems wrong.
> though stockpiling thousands of tons of high explosives fake a successful nuclear test seems beyond farcical
Would that even work? I'd expect there to be obvious spectral differences, making such deception unrealistic.
I don't know if the seismic signature from a 10 kiloton nuclear explosion underground is different from 10,000 tons of actual TNT exploded underground, but there was also radioactive gas evidence of North Korean testing:
https://www.armscontrol.org/blog/2013-04-26/ims-detects-radi...
The xenon isotopes involved have short half lives so if they were not produced by a nuclear explosion, they would have had to be released simultaneously by e.g. reprocessing a "hot" fresh batch of irradiated uranium at the same time as the underground explosion. This is not impossible, but it looks increasingly convoluted compared to an actual nuclear test.
Also, contra the upthread assertion that "Yields should've been higher for plutonium cores, it's not lightweight stuff," there is nothing about plutonium that drives high yield. The United States manufactured a large number of low yield (1.7 kiloton) plutonium warheads in the late 1950s:
https://en.wikipedia.org/wiki/W25_(nuclear_warhead)
If North Korea aimed to make missile-deliverable weapons from the beginning (which makes sense because they don't have heavy bombers like the Cold War powers did at the beginning of their arms race), it also makes sense that their weapons tests would be focused on validating compact/lightweight designs instead of trying for high yield.