Secure Data Transmission in National Grid: A Data Diode-Based Approach for Transmitting Telemetering Data from Station SCADA to Grid in Nuclear Power Plants

In nuclear power plants, cybersecurity is paramount due to the critical nature of the infrastructure and the high stakes associated with any data breach or system compromise. This case study presents a robust Grid Communication Software (INuGriS) developed to simultaneously acquire data from station SCADA and Intelligent Electronic Devices (IEDs) and transmit it securely to Load Dispatch Centres. Utilizing a data diode, the software ensures unidirectional data flow, eliminating the risk of external cyber threats infiltrating plant systems. Compliance with standards such as IEC 60870-5-101, IEC 60870-5-104, and IEC 61850 ensures interoperability and secure communication across diverse protocols. The software architecture addresses redundancy, diversity, high availability, failure reporting and easy configurability while employing strict access control and isolation. Currently the system is deployed in one of the latest Indian Nuclear Power Plants and is planned to be used in all NPCIL upcoming projects.