Development of an Lagrangian particle dispersion model for impact assessment

In this study, a short range particle dispersion model is developed for estimating dose in the case of transient and short term releases from nuclear reactors. The model is based on Langevin equation. Three ways of computing turbulence velocities are incorporated in the model such as Hanna's scheme based on similarity theory (Hanna, 1982), the diffusivities derived from sonic anemometer using eddy covariance method and from Pasquill-Gifford classes. In order to use Hanna's similarity method, the model uses meteorological observations from multiple level instrumented tower for the computation of similarity variables such as friction velocity, Obukhov length, convective velocity scale etc. The eddy covariance method is used provided sonic anemometer data is available