This work presents the framework and status of the development of a basic principle integrated pressurized water reactor (iPWR) small modular reactor (SMR) simulator designed to be an open-source tool to support computer security academic studies, capacity building activities, innovative SMR concept of operations, and digital instrumentation and control. This simulator aims to provide a test environment for integration and evaluation of novel and emerging digital technologies in the nuclear sector such as artificial intelligence, digital twins and smart sensors. Reference plant processes will be simulated to investigate the safety-security interface, show the application of the IAEA computer security guidance, demonstrate the effects of cyber-physical (blended attacks) and cyber-attacks, and reproduce the relevant digital communication channels and network protocols. The simulator has been developed using a modular framework to allow further integration of passive and inherent safety features or the replacement of the iPWR core by an advanced reactor core. Software (Docker) containers are used to simplify replication and deployment of the simulator. Ease of replication and deployment provides for quick instantiation of single or multi-unit reactor sites in different physical locations for analyzing the impact of a centralized fleet management, and its nuclear security implications. Results from simulation and analysis of a potential strategy of redundant and independent communication channels between remote supervision centers and local control systems are discussed here.