A model of ~(90)Sr distribution in the sea near Daya Bay Nuclear Power Plant in China

摘要

The impact on the environment of radionuclide release from nuclear power plants has attracted increased attention, especially after the accident at Fukushima Daiichi Nuclear Power Plant in Japan. Based on the mechanisms of adsorption/desorption at solid/liquid interfaces and a surface micromorphology model of sediments, a theoretical expression of the distribution coefficient K_d is derived. This coefficient has significant effects on the distribution of radionuclide in seawater, suspended sediment and seabed sediment. K_d is then used to simulate ~(90)Sr transport in the sea near the Daya Bay Nuclear Power Plant. The simulation results are compared with field measurements of tidal level, current velocity, suspended sediment concentration and ~(90)Sr concentrations in the same period. Overall, the simulated results agree well with the field measured data. Thus, the derived expression for K_d is capable of interpreting realistic adsorption/desorption processes. What's more, conclusion is drawn that about 40% ~(90)Sr released by Daya Bay Nuclear Power Plant will be adsorbed by suspended sediment and 20% by seabed sediment, only about 40% ~(90)Sr will remain in the sea near Daya Bay Nuclear Power Plant in South China Sea.