Generating feasible strategies in nuclear emergencies - a constraint satisfaction problem

RODOS is a Real-time On-line DecisiOn Support system intended for use throu ghout a nuclear emergency, extending into the longer term. In this paper we concentrate on the early phases in which decisions on sheltering and evacu ation have to be taken quickly and under many pressures. RODOS is designed to assist off-site emergency management by formulating and structuring the evaluation of possible combinations of countermeasures. Because there can b e very many such combinations to be evaluated, an expert system has been de veloped to eliminate those that do not satisfy certain constraints dependin g on factors such as the wind direction and evacuation practicalities. The system uses the ILOG solver constraint satisfaction package and its high-le vel programming library to reduce the number of strategies to a manageable fraction. This allows a later careful evaluation of the remaining alternati ves.