Coastal dispersion conditions near the southwestern tip of Africa: a system for evaluation and prediction.

Abstract

A system is presented to monitor the local meteorology and to predict the dispersion of effluents from a nuclear power station situated on the coast near the southwestern tip of Africa. A computerized weather station forms the basis of the system and provides spatial definition of wind profiles and dispersion indices near the coastal interface by interpolation between a sensor array. The meteorological system measures winds, temperature structure and turbulence indices at the 10-m level at five remote points and in the 10- to 80-m layer at the main coastal station. To provide a system for evaluation and prediction of effluent trajectories, a real-time three-dimensional puff dispersion model was developed. The meteorology input to the model is automatically verified and updated at 15-min intervals. Model results are presented under complex weather conditions to show how time and space changes in the local wind field are handled. To assist weather forecasters supporting the nuclear emergency plan, a simple tabular display enables a view of the dispersion climatology over 24-h (coastal) and 7-d (synoptic) cycles. These results are presented to contrast the different scales of circulation and for comparison within the nuclear industry to assist health physicists in deciding appropriate levels of meteorological support for emergency plans.