Prediction of radiological dispersal from sabotage incidents involving high explosive

The intentional dispersal of radioactive material from a nuclear facility by use of explosive can result in severe radiological consequences. In many situations, it is important to be able to predict the magnitude and direction of this dispersal for (a) evacuation and sheltering decisions and (b) to estimate the potential size of the cleanup operation. Most commonly used predictive methods do not trace the cloud trajectory through its rise to a thermally-equilibrated height but, instead, assume a stabilized height and map the dispersal from this origin. A calculational method which more realistically describes this close-in behaviour has been developed. This procedure predicts the cloud height as a function of downwind distance and existing meteorological conditions. Comparisons of these predictions with experimental data are presented. In addition, the model provides estimates of downwind ground deposition and dose to exposed personnel. The results of these predictions are also presented