What are sources of radioactive material?
There has been a lot of speculation about where terrorists could get radioactive material to use in a dirty bomb. The highest-grade radioactive materials are present in nuclear power plants and nuclear weapons sites. However, increased security at these facilities would make theft of these materials extremely difficult. It is far more likely that radioactive materials used in a dirty bomb would come from low-level radioactive sources. These sources are found in hospitals, on construction sites and at food irradiation plants. They are used to diagnose and treat illnesses, sterilize equipment, inspect welding seams, and irradiate food to kill harmful microbes. Most of these sources are not useful for constructing a dirty bomb.
