Radiological Emergencies from the Malevolent Use of Radiation Sources

A National Emergency Plan was set up in Italy after the Chernobyl accident, to cope with the following nuclear risk sources: accidents in foreign nuclear power plants or aboard nuclearpropelled ships, falling of satellites using nuclear power units, transportation of radioactive materials. Moreover, this plan gives the general requirements of the emergency preparedness and response to be implemented into the local planning (Provincial Emergency Plan), on the basis of reference accidents for research reactors, nuclear power and reprocessing plants (shut down) in Italy. However in the National Emergency Plan are not considered, neither for local scale nor for the national one, the accidents with radiation sources, used for a wide variety of purposes in industry, medicine and research. Besides, after the events of 11 September 2001, it is raised the awareness of the risks created by radiation sources, because of their potential use for malevolent purposes (exposure of public to radiation or use of a source in a radiological dispersion device, commonly referred to as “dirty bomb”). Moreover, for a terrorist action, the personal danger from handling powerful radiation sources can not be seen as an effective deterrent. It is clear that a re-evaluation of risks involved and a planning of the interventions to protect the public is needed as also stated by the requirements set up in the new standard proposed by the IAEA. In this paper the radiological consequences of radioactivity dispersion by using conventional explosive have been evaluated for the main applications of radioactive sources.