I don't know how much needs to be packed, since I don't study this, but it's probably something like taking 1/16 of the whole Earth and packing it inside a pea in order to make a blackhole strong enough to devour the Earth.
Brb, waiting for scientists to take THAT much material for a project.
Srsly, no one's going to go: ohey, let's take all our nuclear fuel and pack it into one bomb and see how big we can make it. Yeah awesome, lol.
Pro scientists are not retards. They're not going to do such a thing. Science is not your enemy.