Protection des organismes non-humains contre les radiations en eau douce - Effet de la dépendance au temps pour les évaluations graduées de l'exposition

Titre de la revue : Ecological Modelling Volume : 206 N° : 3-4 Pagination : 360-368 Date de publication : 01/08/2007

The ERICA's European framework that have been proposed to assess the exposure of biota to radionuclides is based on tiered approach: the Tier 1 assesment is based on equilibrium assumptions (constant radioactive releases over time, equilibrium at the interfaces water-suspended matter and water-biota); the Tier 2 assessment allows to use time-dependent and site-specific data to perform a more precise evaluation. The objective of this paper was to compare these two tiers in the context of routine releases from nuclear power plants in freshwater ecosystems. The Loire River where 14 nuclear power plants (NPPs) operate was chosen as a case study and the trnasport of 60Co in the river, its partition between water and suspended particles and its bioaccumulation was calculated under equilibrium and time-dependent assumptions respectively. Using this case study allowed to quantify the overpredictions linked to conservatismes assumed in Tier 1. Recommendations were identified on when Tier 2 approach is actually needed.