Simulated-based vulnerability assessment for placement of detection systems within gamma irradiation facility

Abstract

Physical Protection Systems (PPS), for use in gamma irradiation facilities require optimal sensor placement to provide the highest probability of interruption (P I ) as well as cost effective design. This research will present a simulation-based vulnerability assessment using the EASI (Estimate of Adversary Sequence Interruption) Model to determine the four possible detection system designs for one adversary path that targets Category I radioactive sources (Cobalt-60). A Monte Carlo Simulation (10,000 iterations) was used to measure the uncertainty of the results. The results show that Configuration D (Optimized) achieves P I = 0.880 ± 0.002 using 3 sensors while Configuration B (Distributed) achieved P I = 0.882 ± 0.000 using 6 sensors. The optimized configuration will provide 99.8 % of the best possible protection for a system with approximately 50 % less complexity. Configuration A (Perimeter-Only) failed to meet security criteria (P I = 0.750 < 0.80). Statistical analysis confirmed significant differences between configurations (p < 0.001). This methodology provides a quantitative framework for PPS design optimization