Cobalt bomb

Hypothetical salted nuclear bomb

A cobalt bomb is a type of "salted bomb": a nuclear weapon designed to produce enhanced amounts of radioactive fallout, intended to contaminate a large area with radioactive material, potentially for the purpose of radiological warfare, mutual assured destruction or as doomsday devices. There is no firm evidence that such a device has ever been built or tested.

This keyword could refer to multiple things. Here are some suggestions: