The role of the Finnish Meteorological Institute

The Finnish Meteorological Institute is responsible for the dispersion forecasts for the radiation control in Finland. In addition to the normal weather forecasts the duty forecaster has the work station based three dimensional trajectory model and the short range dispersion model YDINO at his disposal. For expert use, dispersion and dose model TRADOS is available. The TRADOS, developed by the Finnish Meteorological Institute and by the Technical Research Centre of Finland, includes a meteorological data base that utilizes the numerical forecasts of the High Resolution Limited Area Model (HIRLAM) weather prediction model. The transport is described by three-dimensional air-parcel trajectories. For each time step the integrated air concentrations as well as dry and wet deposition for selected groups of radionuclides are computed. In the operational emergency application only external dose rates are computed. In the statistical version also individual and population dose estimates via several external and internal pathways can be made. The TRADOS is currently run under two separate user interfaces. The trajectory and dispersion model interface includes ready-made lists of the nuclear power plants and other installations. The dose model has a set of release terms for several groups of radionuclides. There is also a graphical module that enables the computed results to be presented in grid or also isolines. A new graphical user interface and presentation lay-outs redesigned as visual and end-user friendly as possible and with the aim of possible and with the aim of possible adoption as a Nordic standard will be installed in the near future. (orig.)