Issues in comparative risk assessment of different energy sources

Abstract

The environmental and health impacts of different energy systems, particularly those associated with the production of electricity, are emerging as significant issues for policy formulation in the coming decades. There is, however, concern about the appropriate choice of electricity generating systems, particularly from environmental and human health viewpoints. This, together with the emerging need of many countries to define their energy programmes for the next century, have provided the basis for a renewed interest in the application of tools and techniques of comparative risk assessment in the decision–making process concerning energy planning. The methodologies for risk assessment that have been developed - particularly those for which health impacts are detailed - are extensive, and are now often used as useful tools for comparing the health impacts of various energy systems. There still remains, however, a number of methodological and procedural uncertainties for which improvements are desirable in order to strengthen the applicability of such techniques. Key issues in this regard include: the definition of fuel cycle boundaries; time dependencies of the risk estimates; regionalization of risk estimates; availability and reliability of databases; environmental indicators of risk; uncertainties in risk estimates and aggregate indicator for decision making. This paper reviews the current status of comparative risk assessment for different energy systems used in the generation of electricity with particular emphasis on the issues outlined above.