Cybersecurity threat modeling for small modular reactor stations

Small Modular Reactors (SMRs) are an emerging nuclear energy technology offering the potential to reduce industrial loads on the electric grid to improve frequency stability and power quality. These compact nuclear facilities provide reliable energy, especially in remote areas. However, integrating SMRs into the bulk electric system introduces new cyber-physical vulnerabilities, including increased exposure to cyberattacks and potential cascading disruptions. This paper introduces a Cyber-Informed Design framework tailored to Cyber-Physical Energy Systems incorporating SMRs. The framework employs attack trees to model threat scenarios and identify vulnerabilities across four functional layers of SMR stations. We apply the threat modeling approach to a reference architecture and map the attack paths to the MITRE ATT&CK for Industrial Control Systems to provide insights into improving the resilience of cyber-physical energy systems.