Comparison of radioactive and chemical risks : a new method to assess the global impact of nuclear facilities effluents on freshwater ecosystems

Titre du congrès :SETAC Europe 16th Annual Meeting Ville du congrès :La Hague Date du congrès :11/05/2006

An innovative method has been developed to assess the impact of radioactive contaminants on chronically exposed freshwater ecosystems in a comparative way to chemical impacts. Liquid effluents routinely released in watercourses by nuclear power plants under normal operating conditions represent one of the typical cases for application of such ERA methods as they are a mixture of radioactive substances and conventional chemicals. The novel methodological point corresponds to the combination of the radiological ecotoxicity data with a fate model of radionuclides in surface waters in order to solve the problem of unit that is stressor specific: radiological dose of energy delivered to the tissue for the radionuclides and exposure concentration in water for chemicals. The method allows to take account for the different impact pathways of aquatic species: external irradiation from water and sediment, internal irradiation by various types of radiation with specific biological effectiveness. Results are presented for different radioactive substances traditionally listed into any discharge authorization from a nuclear power plant.