Estimation of the radionuclides emission region using trajectory and atmospheric dispersion models

A three-dimensional trajectory model has been developed to estimate the emission area of radioisotopes measured at the international monitoring stations of the Comprehensive Nuclear-Ban Treaty Organization (CTBTO). Calculated backward trajectories were compared with measurements of the European Tracer Experiment (ETEX). These trajectories generally moved toward the original release point and detected within the release duration of the tracer experiment. However, the comparative results had uncertainties with regard to starting time and the height of the tracer in the backward trajectory model. An atmospheric dispersion model based on the Fields of Regards (FOR) technique was used to reduce the uncertainties of trajectory model and to improve the accuracy of detective technology. The simulated results generated by the trajectory and atmospheric dispersion models together were agreed better with the measurements compared to those obtained from the trajectory model alone.