A model for assessing the radiological impacts of deep sea disposal of radioactive wastes: development of the model and preliminary results

A new numerical model has been developed in France to assess the radiological consequences of low level radioactive waste disposal on the sea bottom of the Atlantic Ocean. It is a box model covering the world ocean with a finer resolution in the North Atlantic and near the Nuclear Energy Agency dumpsite. The main processes involved in the nuclides transfer from the drums to man are modelled or parameterized: time variations of the nuclides release, advection and diffusion by the ocean fluid, adsorption-desorption on particles, sedimentation and burial of sediments, transfers through organisms living in the sea (fishes, crustaceans, molluscs, seaweeds, plankton,...). The dose equivalent to critical group members and the collective dose equivalent are assessed. A sensitivity analysis of the model has been performed to assess the reliability of the dose calculations. An intercomparison exercise has been achieved with two other independent models on a benchmark problem