Study on vertical migration of 137Cs in marine sediment of Daya Bay
大亚湾沉积物中137Cs纵向迁移研究

As a long\|lived and critical artificial radionuclid, 137 Cs from GNPS(Guangdong Nuclear Power Station) plays an important role in the study of monitoring and assessing marine radioactivity in Daya Bay. Marine sediment is the final repository for 137 Cs in marine environment. The study on vertical migration of 137 Cs in marine sediment is important to make proper assessment for radionuclides impact on Daya Bay from GNPS. A quantitative vertical migration model for radionuclides in sediment presented in the paper. The mechanism of transport happened in the sediment\|water interface through sedimentation, diffusion and sorption\|desorption, etc. is taken into account comprehensively. The modeling analysis was conducted on the migration and distribution of 137 Cs versus the depth based on data of 4 samples of sediment cores, and the trend of 137 Cs migration and accumulation in the future was predicted.