Radionuclides transport simulation for D.F.D.S.M.A. Saligny site

In the Saligny site the only aquifer geological formation appears to be the barrenian calcite. To reach this level, located at 80 m depth, the radionuclide have to penetrate the system formed of loesses and red clay as well as the Aptiene and Eocene deposits. Early studies demonstrated that radionuclide migration from repository into the aquifer is only possible due to the modification of the flow properties of the materials in unsaturated zone. The saturate zone model is extended to an area of 9.0 km x 9.0 km bordered on South by the Danube River-Black Sea Canal, on West by Danube River, on North by Tibrin Valley. and on East by a N-S line passing through Saligny town. A conductivity value of 5 m/day was assumed. 99 Tc was the radionuclide chosen to simulate the transfer over a 250 year period. A mesh was introduced with the cell size of 150 m. Piezometric measurements carried out on Saligny site showed the correlation between levels in Danube River and the piezometric levels in the repository zone. Simulations were performed with MODFLOW code based on two assumptions regarding thr piezometric charge. It is found that Tc-99 reaches the Canal in 72 years. The distribution of Tc-99 concentration and the aspect of contaminant plume after a 60 year span are presented. The results regarding the transit time in aquifer, and the concentration distributions obtained in the two assumptions are discussed