Safety and security assessment of overall I&C architectures

Modern digital instrumentation and control (I&C) systems are highly interconnected, making it challenging to analyse and demonstrate that the overall I&C system architecture as a whole does not contain dependencies detrimental to safety. Nuclear regulation calls for successive levels of protection independent of each other—the principle of Defence-in-Depth (DiD)—also for the I&C architecture. The aim of the SEARCH project is to develop methods and tools for assessing the safety and security of technical design solutions related to overall I&C architectures. Different analysis methods are effectively connected to a shared plant model—of the plant as a whole—making it possible to verify DiD related requirements on, e.g., functional separation or fault tolerance. A specific focus is on broadening the scope in which model checking can effectively be used. In terms of security requirements—instead of focusing on specific security technologies—the aim is to integrate safety and security aspects on the system level assessment.