Industrial control system was designed mainly in the form of analog in early days. However, necessity of digital system engineering is increasing recently because systems become complicated. Consequently, stability of digital systems is improved so most industrial control systems are designed with digital. Because Using digital design of Industrial control system is expanded, various threatening possibilities such as penetration or destruction of systems are increasing enormously. Domestic and overseas researchers accordingly make a multilateral effort into risk analysis and preparing countermeasures. In this paper, this report chooses common security requirement in industrial control system and nuclear control system through relevant guidelines analysis. In addition, this report suggests the development plan of nuclear cyber security system which will be an essential ingredient of planning approvals.