Ground-based remote sensing profiling and numerical weather prediction model to manage nuclear power plants meteorological surveillance in Switzerland

摘要

The meteorological surveillance of the four nuclear power plants inSwitzerland is of first importance in a densely populated area such as theSwiss Plateau. The project "Centrales Nucléaires etMétéorologie" CN-MET aimed at providing a new security tool basedon one hand on the development of a high resolution numerical weatherprediction (NWP) model. The latter is providing essential nowcastinginformation in case of a radioactive release from a nuclear power plant inSwitzerland. On the other hand, the model input over the Swiss Plateau isgenerated by a dedicated network of surface and upper air observationsincluding remote sensing instruments (wind profilers andtemperature/humidity passive microwave radiometers). This network is builtupon three main sites ideally located for measuring the inflow/outflow andcentral conditions of the main wind field in the planetary boundary layerover the Swiss Plateau, as well as a number of surface automatic weatherstations (AWS). The network data are assimilated in real-time into the finegrid NWP model using a rapid update cycle of eight runs per day (oneforecast every three hours). This high resolution NWP model has replaced theformer security tool based on in situ observations (in particular onemeteorological mast at each of the power plants) and a local dispersionmodel. It is used to forecast the dynamics of the atmosphere in theplanetary boundary layer (typically the first 4 km above ground layer) andover a time scale of 24 h. This tool provides at any time (e.g. startingat the initial time of a nuclear power plant release) the best picture ofthe 24-h evolution of the air mass over the Swiss Plateau and furthermoregenerates the input data (in the form of simulated values substituting in situ observations)required for the local dispersion model used at each of the nuclear powerplants locations. This paper is presenting the concept and two validationstudies as well as the results of an emergency response exercise performedin winter 2009.