Abstract: The low level liquid waste discharge scheme was studied with the normal operation of a nuclear facility in Jiangsu coast. A mesoscale radionuclide migration diffusion numerical model was established using the hydrodynamic (HD) and Advection-Dispersion (AD) modules of the simulation software MIKE21. The radionuclide migration and distribution of tritium at oceanic mesoscale were simulated in consideration of the distance from the shore, the sewage outfall azimuth, adverse wind direction, and other conditions. The preliminary results indicated that it would be advantageous to migration and diffusion of the radionuclide when the sewage outfall is set at the northeast location of the river mouth with no less than 30 km away from the shore.

Key words: low level liquid waste, MIKE21, numerical simulation, tidal field, radioactive nuclide, migration and diffusion