Risk: accounting for an uncertain future

Nuclear technologies have been historically characterized by unique risks, in which the deviation between scientific estimates of risk and risk as perceived by the general public has been large. In the context of decision making in circumstances involving life risks, there is no satisfactory conceptual mode of analysis and no adequate notion of optimality on which to base a formal model of public policy making. Consequently, policy options for nuclear waste management decisions must be defined in the absense of formal models. This requires a balancing of precautionary or preventative measures against potentially catastrophic outcomes. Decisions are made using detailed scenario analyses focusing on the consequences of events rather than their likelihood. Such a scenario-based analysis ignores probabilities and involves subjective elements. This type of approach is tantamount to a rejection of mechanistic models of decision making. (JMT)