Some education is in order (not really just for you personally, but for the public in general). You don’t need to enrich radioactive material to make a dirty bomb. You need to enrich it to make a nuclear weapon. A dirty bomb is just a conventional explosive laced with radioactive material. The idea is to use the conventional explosion to spread the radioactive material over a wide area.
Now, not to minimize the actual danger, but a dirty bomb is really in actual physical terms no more dangerous than a conventional explosive. The amount of radioactivity that would be released in a dirty bomb is minimal. You probably get more radiation from a typical dental x-ray than you would if you lived near a city where a dirty bomb was detonated.
The real danger of a dirty bomb (beyond of course the loss of life and property damage caused by the conventional explosion) is the psychological terror and panic it would create. Education is the way to combat this. Most people hear “radioactivity” and think of radiation poisoning, cancer, etc. The truth is that there is a natural level of radioactivity that we are all exposed to every day. In addition to this, various medical procedures, scanners at airports, and other sources add to this natural level. A dirty bomb would necessarily use low-level radioactive material. A terrorist group with access to more dangerous material would undoubtedly use such material to make a nuclear explosive, which would obviously be much more dangerous.
Yes - thanks for the clarifications. ISIS can wreak havoc with dirty bombs that disrupt and cause panic.