[credit_guy]

> Then you just make sure you have enough spent fuel that when you're ready for that part, you can get 3+ cores' worth in a hurry.

Lots of things about nuclear weapons are classified, but we can use some declassified numbers from the Manhattan project. The ratio of uranium fuel to plutonium end result was about 4000 to 1 [1].

  > Approximately 4000 pounds (1814.36 kg) of uranium were needed to produce 1 pound (0.45 kg) of plutonium.

At 6.2 kg per core, 3 cores would require 74 tons of uranium. That's about 50% more than what a plant like the Maanshan nuclear power plant (the one we are talking about here) would burn in one year. Except, or course, that commercial reactors burn uranium to a high degree, so the spent fuel is exactly worthless for weapons purposes. You need to burn the fuel 10 times less to have a chance to extract weapons grade Plutonium. So, that dash for 3 bombs would take 15 years, if by some miracle you could use the reactors 100% of the time only for the purpose of creating spent fuel for the plutonium production. Of course, the problem is that you'd need to buy that fuel from some suppliers, and the suppliers are going to ask questions why you are burning 10 times more fuel then you should (they are most likely legally obligated to report you if they suspect anything non-kosher is going on).

[1]https://www.nps.gov/articles/000/manhattan-project-science-a...

[NoMoreNicksLeft]

I suspect that the minimum qty of plut is far lower, at least for a simple device. They don't need multi-megaton, after all. I suspect the minimum qty is down around or just under 2kg per core. This is more or less an open secret, Taiwan would be aware of that (but, so would China).

Your other numbers check out though, best I can tell.