A nuclear bunker buster I believe. See the scintillations around the fireball around the 1:40 mark, which appear about the same time as the sound arrives. It seems to me to be unlikely to be protons because of the large cross section of charged particles through air, but neutrons don’t normally trigger a CCD camera unless there’s some source of secondary emission, maybe a plastic window or something over the lens. Anyway, I’m not a nuclear expert. My question is, just how crazy is this establishment??