An analytical method for developing appropriate protection profiles of Instrumentation & Control System for nuclear power plants

A very important target of Instrumentation & Control System used in nuclear power plants is to ensure the safe operation of these plants. Until recently, an analog technology has been used for this purpose; however, this is now being replaced by the digital technology. Such replacement is facilitated by the wide use of real-time distribution of data that are collected by sensor devices of machine-to-machine technology. This, however, provides possibility of exposing Instrumentation & Control System to cyber-attack, as was the case for the Iranian Bushehr nuclear power plant, which the centrifuge was destroyed by the malicious code, Stuxnet. Therefore, security products which are exclusively developed for the prevention of cyber-attack on nuclear power plants are particularly needed in the development and operation of Instrumentation & Control System. However, the currently available security guidelines for such Instrumentation & Control System cover only security policies and protocols, without any specific reference urgent issues of cyber-attack. This paper proposes an implementable Instrumentation & Control System analysis model having focus on cyber security and technology evaluation. The model has been already implemented in reactor protection systems that is operating in Republic of Korea.