Abstract: With an engineering example, we calculate and analyse the transport and diffusion of liquid effluent from nuclear power plants in the receiving water body, by a two-dimensional numerical simulation method based on depth averaging. The calculated tidal level, flow rate and flow direction are in good agreement with the measured hydrological test data, which truly reflect the hydrodynamic characteristics of the engineering area. Then, We analyze the impact mechanism of residual current on the nuclide dilution process. The results show that with the increase of residual current, the influence range of concentration field gradually shifts to the direction of residual current, which has a significant impact on the concentration distribution in the engineering area. It should be paid attention to in the environmental impact assessment process.

Key words: Nuclear power plant, Liquid effluent, Numerical simulation, Concentration distribution, Residual current