Plan alignment and operational interfaces in nuclear security event response: evidence from Türkiye’s all-hazards emergency management system

Nuclear security event response within all-hazards systems requires coordination among emergency management, regulatory, law enforcement, technical and forensic actors operating under distinct mandates. This study examines how nuclear security event response is specified within Türkiye’s national emergency management system. Based on structured documentary analysis of publicly available planning, regulatory, strategic and review documents, the study applies the Four C framework to assess communication, coordination, collaboration, and cooperation across institutional interfaces. The findings show that Türkiye’s planning architecture provides a coordinated basis for radiological emergency response. However, nuclear security events are less clearly specified as a distinct response problem. Partially specified interfaces include command transition, forensic evidence management, security-sensitive information sharing, detection-to-response activation, and international notification timing. The study does not assess operational performance or classified capabilities. It provides a case-based diagnostic of how formal plan alignment may not translate into clearly specified operational response arrangements when nuclear security events require emergency management, regulatory, law enforcement, technical, and forensic functions to operate simultaneously.