SYSTEM DYNAMICS APPROACH FOR THE EVALUATION OF SABOTAGE PROTECTION AT NUCLEAR FACILITIES

A system dynamics model is developed to assess physical protection against sabotage at nuclear facilities, which has emerged as a significant issue since the events of September 11 2001. The system dynamics model assesses the associated risk as well as determining whether or not the protection system could successfully thwart the intruder. The sabotage protection framework is comprised of four main components; detection, delay, response and recovery. The evaluation of sabotage protection for the nuclear facilities requires wholly dynamic approaches including decision-making, response, and mitigation processes. Computational tools are being developed for sabotage protection capacity evaluation of nuclear facilities using the system dynamics approach, which has been used for war game simulation in the military. The model consists of five modules; input module, dynamics module; evaluation module, data module and output module. Two different simulation modes are designed; interactive mode and one-through automatic simulation mode. In the interactive mode, the analyst will act as an intruder against facility personnel responding exactly according to the sabotage protection procedures, while in the one-through automatic simulation mode hundreds of simulations are performed. This paper introduces a method to evaluate sabotage protection effectiveness using system dynamics simulation technique. The proposed simulation approach has various advantages; identifying vulnerable paths against sabotage event, evaluating effectiveness of current sabotage protection system, and supporting cost benefit decision making in choosing alternative options to upgrade or modify the physical protection system. This simulation approach is capable of assessing the full spectrum of sabotage protection processes, from intrusion to mitigation of and recovery from radiological consequence at various nuclear facilities. This methodology can assess the facility response at different stages of the sabotage event and can provide feedback to time-dependent facility conditions for the evaluation process. Efforts are underway to develop a detailed model for the evaluation module, and for the verification and validation of modules and case studies to demonstrate the feasibility and applicability of this simulation approach to evaluate sabotage protection effectiveness for a broad spectrum of nuclear facilities.