Could a (regional or global) fallout of radioactive material be a "bonus" disaster effect of an asteroid impact? My reasoning for how such a scenario maybe could be possible:
A) Some asteroids maybe consist of lots of radioactive heavy metals because they were initially formed by ejecta from the cores of planets during planetary collisions. Maybe even an airburst of a rather small such an asteroid could cause widespread dangerous radiak fallout?
As I understand it, Earth's initial uranium has fallen into the core. The uranium mines dig into concentrated deposits of uranium in the crust which came from uranium rich asteroids.
B) If any kind of asteroid large enough hits a uranium rich part of the Earth crust (making it the second one on the same spot), it could maybe eject much of Earth's own uranium and thus cause a dangerous fallout?