Cyber security consideration on I and C system development process

Instrumentation and control (I and C) systems in nuclear power plants collect sensor signals installed in plant fields, monitor plant performance and status, and generate signals to control instruments for plant operation and protection. Recently, digital systems of I and C are required to be protected from cyber threats. It has been reported that several plants have been attacked and malfunctioned by outside intruders. To cope with cyber attacks, various studies have been proposed in IT and plant industries. From 2006, regulatory guides and industry standards for cyber security have been published. Therefore, these guides should be strongly considered in the development process of a digital system. Our framework refers to the system development life cycle described in RG 1.152. The main activities of RG 5.71 are included in the framework appropriately. This approach supports the consistent application of system features for cyber security by incorporating the security requirements required in the operation and maintenance phases into the initial phase of development process. It is expected that the application of the framework to a new plant system design may comply with both RG 1.152 and 5.71