Year
2025
Abstract
The increasing threat of malicious acts such as bombing, sabotage, or theft involving radioactive materials such as 90Strontium, 137Cesium, 60Cobalt, and 192Iridium raises significant concerns due to the potential direct or indirect harm to public health and safety through radiation exposure. A robust Physical Protection System (PPS) is critical to mitigating these threats, emphasizing its core functions detection, delay, and response. An effective PPS must be designed to counter adversary tactics and capabilities comprehensively. This study evaluates the effectiveness of the PPS at a hypothetical radiotherapy center in Tanzania under a sabotage scenario. The evaluation employs the Adversary Sequence Diagram (ASD) and the EASI (Estimate of Adversary Sequence Interruption) model to calculate the Probability of Interruption (PI), a key metric for PPS effectiveness. Additionally, the Probability of Neutralization (PN) by the response force is assumed to approach unity, serving as a second metric to calculate the overall Probability of Effectiveness. Key parameters analyzed include detection probabilities, delay times, communication delays, and response force action times along the adversary’s path toward the sabotage target. The study identifies vulnerabilities within the existing PPS and proposed redesigns to address these gaps, with subsequent analyses validating the improvements. This work provides a foundational framework for policymakers, including regulatory bodies, to enhance the design, implementation, and evaluation of PPS in radiological facilities, ensuring the secure management of radioactive materials against evolving threat in Tanzania.