re: Addressing the Unthinkable
I'm not sure at what point this subject was declared "unthinkable." Radiation has always been a possible hazard. Even discounting nuclear attack, there are also possible hazards from nuclear reactors or other accidents. A dirty bomb is one of the most feasible attack methods by terrorists, although the psychological damage will probably far outweigh any physical damage.
I've had references and radiation detection equipment for quite a while now. Check E-bay.