> It's because of the way the weapons are designed, which requires a CNWDI clearance to know, so your curiosity is not likely to be sated.

While that's true, the information that is online is surprisingly detailed.

For example, this series "Nuclear 101: How Nuclear Bombs Work"

https://www.youtube.com/watch?v=zVhQOhxb1Mc

https://www.youtube.com/watch?v=MnW7DxsJth0

Having once had said clearance limits my answers.

And if they really want to know: https://www.energy.gov/nnsa/working-nnsa