IEC 62859:2016 provides a framework to manage the interactions between safety and cybersecurity for nuclear power plant (NPP) systems, taking into account current IEC standards addressing these issues and the specifics of nuclear I&C programmable digital systems. This standard establishes requirements and guidance to: - integrate cybersecurity provisions in nuclear I&C architectures and systems, which are fundamentally tailored for safety; - avoid potential conflicts between safety and cybersecurity provisions; - aid the identification and the leveraging of the potential synergies between safety and cybersecurity.