Natural catastrophes impose the largest toll in terms of human fatalities and economic consequences. If only human-made accidents are considered, the energy sector is the second-largest contributor, with transportation causing about 60% of all mortalities (EC, 1995). Risks of severe accidents in all energy chains should not be neglected, however, as they have the potential to cause large-scale and long-term impacts to human health, to the environment and to the whole of society. Severe accidents also tend to have broad media coverage and to attract the attention of the population and different stakeholders.