Research and Application of SIS Design and Fault Tree Analysis of Nuclear Power Plant

In the process of instrument and control design of nuclear power plants, the safety classification are usually determined according to the process functions of the system, the supervision requirements of safety supervision departments and laws and regulations to ensure the safety and reliability of the system in operation. Safety-related control functions are usually handled centrally through safety-level DCS (Discrete Control System). However, this method is relatively expensive for small control systems scattered all over plant that can be controlled locally. For safety-related control loop, in order to improve the economy of nuclear power plant construction under the premise of ensuring the safe operation of the system, this paper proposes a method of using SIS design and fault tree analysis to carry out safety validation for local discrete control system of nuclear power plant, thus reducing I/O (Input/Output) points in DCS system, improving economy and improving the safety of local control system.