Part 1 establishes the foundation by explaining how nuclear power plants operate, how safety is enforced through layered engineering and physical principles, and also how digital control systems support these protections. By looking at reactor control logic, trust assumptions in safety architectures, and the realities of legacy industrial design, it becomes clear that cybersecurity risk comes not from a single vulnerability, but from the interaction of multiple small decisions over time. These elements on their own do not cause failure, but they shape an environment in which trust can be misused.
