Nuclear security system effectiveness assessment using bounded analysis approach: a case study of different adversary scenarios

A security issue on nuclear facilities will give a significant effect on national security, economy, public health, or the combination among them. The evaluation of physical security effectiveness is done by considering it as a probability that the system will defeat an adversary at a particular time. This research examined the effectiveness of Physical Protection Systems (PPS) of a nuclear research reactor in Indonesia, as a role model facility. Three possible adversary scenarios were assessed. Estimation of Adversary Sequence Interruption model was implemented to assess the physical security system. The estimation of the effectiveness of physical-cybersecurity combination was done by Bounding Analysis Approach. The effectiveness of security system with cyber system working properly was assessed and compared with the system receiving cyber attacked. The results showed that the system effectiveness is high (0.839, 0.949, and 0.837, respectively). The results showed that the assessment method is effective to examine whether a security element is working effectively or not in such facility. This work will be useful as base guidelines for nuclear regulatory body and licensee for the application and evaluation of PPS and provision of countermeasure strategies in RSG GAS, and for further benefit, it can be used by nuclear facilities.