For anyone who is wondering the alloy metal that is radioactive is Technetium #43. It is weird it has no stable isotopes, and is only one of two radioactive elements that proceed non radioactive elements. As far as I am concerned it exists only to be different.
Promethium #61 it is so rare that it really has no practical uses outside the lab. There is most likely less than a kilogram of the stuff in the entire planet.