Development of a Remote Sensing Meteorological Network assimilated to a fine grid NWP model for the Nuclear Power Plants Security in Switzerland

Each of the four nuclear power plants in operation in Switzerland is currently equipped with one meteorological tower (up to 110 m height) and standard ground based instruments which yield the basic data input to a gaussian-dispersion model. The latter is being used as short term weather forecast tool in case of a power plant accident.

MeteoSwiss is currently in charge of upgrading this security tool. It is intended to use the advantage / peculiarity that the four nuclear power plants are all located on the Swiss Plateau at short distance each from another, and with wind fields channeled towards the NE to SW direction due to the presence of the Jura mountains on the NW and the Swiss Alps on the SE.

The new security tool is based on the development of a high resolution NWP model linked to a meteorological network instrumented with ground based and remote sensing equipment. It will predict the dynamics of the atmosphere in the planetary boundary layer (e.g. up to 2 km above ground level) over the Swiss plateau, using the remote sensing instruments that are wind profilers, passive microwave instrument for temperature profiling, as well as a sodar for low level wind field. The measuring sites of the network will be located so to generate the ideal database, the latter being assimilated in real time as data input / boundary conditions for the fine grid NWP model.

Two major goals are foreseen: • This decision making tool that includes the meteorological network and the fine grid NWP model will at any time (e.g. starting from the initial time of a nuclear power plant accident) give the best picture of the one day-evolution of air masses over the entire Swiss plateau. • The fine grid NWP model will furthermore generate the necessary data input for the local dispersion model, the latter being specifically designed for each of the four nuclear power plants location respectively.