Cyber Security Controls in Nuclear Power Plant by Technical Assessment Methodology

Nuclear power plants rely on interconnected digital systems to monitor equipment, support plant operations, manage engineering activities, and protect people and the environment. These systems must be secured carefully because a cyber incident can affect operational reliability, safety functions, or the availability of essential services. This paper presents a technical assessment methodology for reviewing cybersecurity controls in a nuclear power plant. The approach considers governance, asset identification, network separation, access management, secure configuration, monitoring, incident response, backup and recovery, supplier security, and staff awareness. It proposes a structured process that begins with defining the assessment scope, collecting evidence, evaluating controls against recognised guidance, identifying gaps, and prioritising corrective actions according to risk and safety significance. The methodology is intended for authorised, non-disruptive assessment and emphasises coordination between cybersecurity specialists, instrumentation and control engineers, operations staff, and safety personnel. It does not recommend intrusive testing of live safety systems. A disciplined assessment can improve visibility of weaknesses, strengthen defence in depth, and support continuous improvement while preserving nuclear safety and operational continuity.