Dynamic Probabilistic Risk Assessment for Cyber Security Risk Analysis in Nuclear Reactors

The increasing adaptation of nuclear power plants to incorporate software-based components along with digital communication networks in their operation has resulted in improved control, automation, monitoring and diagnostics, while simultaneously opening those power plants to a new dimension of risk, cyber-attacks. Additionally, the attackers have become more knowledgeable about the vulnerabilities associated with such software systems and network architectures. Hence there is a need to systematically study and quantify the risks associated with cyber-attacks on NPPs and the existing cyber defenses. In this paper we present a dynamic probabilistic risk assessment (DPRA) framework for nuclear power plants in the context of cyber security. In addition to stochastic events such as component failures, the framework implements cyber-attacks along with defenders' i.e., the plant operators, and the attackers' behaviors and their interactions in a game theory-based framework.