Forecast of local meteorological conditions in an emergency adaptation of a prognostic model to Speedi

SPEEDI (System for Prediction of Environmental Emergency Dose Information) is a computer code system for the real-time assessment of an accidental release from a nuclear power plant in Japan. In this study to improve SPEEDI's capability, a prognostic hydrodynamic model, a so-called Boussinesq hydrostatic equation system, has been examined for the purpose of introducing a forecast function into SPEEDI. A system which has the forecast capability will provide a time margin to predict dose distributions and to alert and initiate off-site countermeasures. It thus has a great advantage compared with a real-time system