lol. try getting chatgpt to explain to you how nuclear fission chain reactions work, after feeding it the statistics of how small atomic nuclei are compared to the dimensions of the electron shells. i'm pretty sure one of the "biases" they program into them is that whatever the government says can't be contradicted even if the science isn't valid. i know a fair bit about big numbers and probability and this is why i understand that explosive nuclear fission is bullshit. nothing can withstand the heat of a kilogram of plutonium going into meltdown, and the dispersion it will create will make it little more than a dirty bomb. you want big explosions, there's plenty of options, plastic explosives are pretty awesome, and you can direct them with shape charges that direct the explosive force in one direction. you can also use even solid carbon if you have an explosive that produces enough heat to cause that carbon to vaporise. but it's a fire bomb. it will behave similarly to a fire storm, in that it will cause flammable materials to vaporise rapidly and create a massive chaotic expanding fireball.