User's manual for EXTREME: Expert support tool for responding to a nuclear emergency

Risk Analysis Research Group, Nuclear Safety Research Center

When a nuclear emergency occurs at a nuclear power plant (NPP), protective actions such as evacuation and sheltering are implemented to reduce radiation exposures to the public around the vicinity areas of the NPP. The necessity of the protective actions should be judged, taking into account the various types of information from the on-site and the off-site with reflecting the drastically change of accident situation. Japan Atomic Energy Agency has developed EXTREME (EXpert support Tool for Responding to a nuclear EMErgency) to enable quick and consistent assessments for supporting decision-makers during the response phase after a nuclear emergency occurred. The tool implements simplified models for assessing accident progression, environmental transport, and radiation doses to the public. This tool is also available as a PC-based graphical user interface (GUI) for easy operation by users. This report describes the usage of the developed support tool, focusing on the GUI configuration and the flow of calculations. It is expected that this support tool will effectively assist decision-makers in making judgments and decisions regarding protective actions during the response phase in a nuclear emergency.