Taking uncertainties into account in risk assessment: the example of the GRNC

Taking uncertainties into account has become an essential stage in the risk assessment process. The lack of scientific knowledge can, however, make it difficult to perform an uncertainty analysis. It is then necessary to rely on subjective knowledge, that is, expert judgment, to determine the distributions to be used in the uncertainty analysis. Moreover, the characterization of the results of these calculations must be based on theories not yet clearly understood in the field of radioecology. Finally, the communication of the results to the public and to decision-makers is a crucial but sensitive step. These difficulties are illustrated with examples of radioactive and chemical risk assessments by the Nord-Cotentin Radioecology Working Group for emissions, effluents and discharges from the Nord-Cotentin nuclear facilities. (author)