9th INTERNATIONAL SYMPOSIUM ON ATMOSPHERIC SCIENCES (ATMOS), İstanbul, Türkiye, 23 - 26 Ekim 2019, ss.279-289
The Chernobyl Nuclear Power Plant (NPP) catastrophe of 1986 has been a milestone in the use of nuclear power for energy generation. Extensive amounts of research has been published on the atmospheric dispersion of radionuclides released from such accidents to estimate the radio-ecological impacts on human, animal and plant life. Despite all technological and scientific developments, there is still a significant amount of uncertainty on simulating the dispersion of radionuclides released from Chernobyl NPP. Majority of this ambiguity is associated with the three-dimensional structure of the meteorological conditions prevailing during the time of the accident and the vertical distribution pattern of the release. Currently, there is no definitive decision on the mixing height and vertical distribution of release from the Chernobyl accident. Based on this premise, this study focuses on various possible release patterns of the radioactive species along the vertical dimension and evaluates the potential differences in the atmospheric dispersion patterns of radionuclides with particular reference to Cs-137. For this purpose, some release pattern functions along the z-axis (such as uniform, exponential, log-Pearson and cumulative distribution function) are used to simulate the dispersion of Cs-137 released from the accident site. Simulations were conducted by using a Lagrangian particle dispersion model (FLEXPART). Model results originating from each release function were compared with each other and further verified with ground level measurements.