This report describes the design, construction and experiences with the SPEEDI (System for Prediction of Environmental Emergency Dose Information) which is applied to predict the environmental dose due to the accidental release of radioactive substances into the atmosphere. It is essential for these kinds of systems to predict the realistic dose as soon as possible in an emergency.The emphasis have been, therefore, put on what kinds of data could be available for input in real-time, what kinds of models are applicable for the realistic and urgent simulations, and what kinds of output are effective for the monitoring for the countermeasures in the design of the system.
The present report shows how these design concepts have been taken into account and practiced, and also refers to the problems appeared through the experiences with the system in applications.
