The awareness of emission pattern of radionuclides is necessary for the assessment of their impact on people's health. In this paper, the distribution of 226Ra in the Gorgan Bay water body was investigated. This experience could help scientists predict the distribution of 226Ra in the aquatic environment. Two models predicted the distribution of 226Ra in the sediments at various points along the Gaz River estuary to Gorgan Bay. These predictions were then compared with actual measurements of 226Ra activity taken at the same locations. Model 1 is based on the framework proposed by the International Atomic Energy Agency, while Model 2 is a concentric model developed by the authors. Model2 can be used for the wastewater pools of nuclear centers and can predict well how radium spreads in a quiet environment without interference. The average specific activity of 226Ra in sediments for experimental data, Model1 and Model2 was 14.75, 14.99 and 15.24 Bq kg-1, respectively. The mean value of relative error for Model1 and Model2 was %7.18 and %3.29, respectively. The 226Ra diffusion patterns using models 1 and 2 at the study area are very near to the obtained results. According to these models and measurement results, the concentration of 226Ra is highest in deposits near the Gaz River's mouth, and its amount decreases with distance from its mouth. The good prediction of 226Ra concentration in sediments by these models shows that it can be used in other non-turbulent environments.
