Risk assessment of external events in nuclear facilities.

After the Chernobyl accident, a National Emergency Plan of protective measures for radiological emergencies has been set up in Italy to cope with nuclear risks which require actions at national level. Since the Italian nuclear power plants are, at present, not operational, the most relevant nuclear risk source identified in the National Emergency Plan is related to an accident occurring in a nuclear power plant near the Italian borders. However, risks related to severe accidents to other nuclear facilities present in Italy, such as provisional radioactive waste deposits or research centers are not taken into account in the Plan. In this paper the hypothetical radiological impact of a severe external event in a spent fuel storage pool has been evaluated, as this event appears to be one of those with the most severe consequences.