Application of a new approach in an analytical model to simulate the dispersion of a radioactive pollutant

The contribution of this work is focused on presenting a new approach to dispersion models of radioactive pollutants, that is, pollutants that undergo chemical reactions. The model uses the two-dimensional advection-diffusion-reaction equation to represent the dispersion of the pollutant in the Atmospheric Boundary Layer and to denote the chemical reaction that the pollutant suffers is included a source term in the advection-diffusion equation. This study presents a new analytical solution for the transient two-dimensional advection-diffusion-reaction equation by the combination of the methods of separating variables with the Generalized Integral Laplace Transform Technique (GILTT). The validation of the new model is made using experiment data carried out close to the site of Angra dos Reis nuclear power plant, in Brazil. The results of the three-dimensional pollutant concentrations are compared with the ones obtained by the GILTT method with a Gaussian assumption in the y direction (called here as GILTTG). The numerical results show that the predicted concentrations of the proposed model are close to the GILTTG concentrations, with the gain of not having to perform a numerical inversion in the time variable, resulting in a fast time response, which is very important in the prevention of environmental impacts.