Studies on emergency preparedness

After the TMI-2 reactor accident, researches and developments concerning emergency preparedness were carried out during 1980∼1985 in Japan. Among them, the development of SPEEDI, a system for real time prediction of dose equivalent of the public due to radioactive gases released at a reactor accident, and ARSAS, an aerial survey system with a helicopter for radiation fields in such an accident were planned as two main projects. Both of them have been successfully accomplished. Both systems have high reliability due to excellent system design, practical devices in software and hardware, well equipped data bases, and calculational models validated by field experiments. Although SPEEDI followed an example of ARAC in USA, it has specialities including wind prediction and dose calculation. A practical version as a network system is being prepared, while further researches are being carried on for wide application. Characteristic features of ARSAS are wide range response to exposure rate, accuracy of positioning, software for data processing and analysis, etc. The system is in use for research purpose. (author)