Assessment of Inspection Strategies for Fuel Cycles with the Decision Support System STRASSY

The international safeguards applied to civilian nuclear installations include physical tests and verifications of nuclear material accounts. As part of the continuing effort to improve these safeguards, a decision support system has been developed over the past three years at the Radioactive Material Security Department of the French IPSN. The aim of the system is to find any diversion of nuclear material which will not be detected within a limited period of time by a given inspection strategy. For this, plan generation techniques have been adapted to our problem and a simple model of temporal aspects that allows the efficient treatment of the purely temporal constraints involved has been designed. As an example of the results of the method a fuel assembly diversion scenario is presented.