SPEEDI Network System SPEEDI network system features a central information-processing computer that is connected to the MEXT, METI, NSC, Off-site Emergency Centers, related local governments, and the Japan Weather Association. NUSTEC is prepared for emergencies by regularly collecting meteorological data from AMeDAS of the Japan Weather Association, data from meteorological stations and monitoring posts maintained by each local government. Should an accident occur at a nuclear facility, SPEEDI predicts wind direction and velocity, concentration of radioactive materials in the atmosphere and on the ground surface and external exposure dose , as well as edits the dose rate data from monitoring posts into graphycal forms. These information will serve as the technical basis to be utilized by MEXT, local governments and related organizations for their disaster prevention actions. Airborne Surveys of Radiation Radioactive plumes emitted during accidents can be detected promptly and effectively through airborne surveys of radiation. NUSTEC is developing two systems - rapid and detailed - for airborne surveys.