Personally, I find this more sphincter tightening than any nuclear weapon. With a nuke, you can just walk towards it, and end up nice and dead in a little bit. No mess or fuss (well… depending on distance from the epicenter, possibly very messy and fussy, but it doesn’t last long). Just dead. With these kinds of infrastructure killers, you have to deal with fucking Mad Max if you’re unlucky. I’d choose the dirtnap. You could easily put one together for like $500 in material. I have PDFs of the original research on them. They’re not very complicated devices.
They basically make a big boom turn into a fart, and in return some of that energy is converted into a massive EMP. Or whatever load you want, as long as it can handle a power source that rivals or surpasses lightning.
