Design Of Reactor Protection System

The full digital distributed control system(DCS)invents in the 1970 s,after more than 40 years of continuous development and improvement,its function and performance improve greatly.Domestic thermal power plants have had many years of DCS operation experience and the reliability of the system equipment has had been verified.Because of the particularity of the nuclear power plant,the DCS system of the nuclear power plant is required higher reliability.Especially its reactor protection system,which requires that it can perform appropriate controls and provide automatic protection to prevent the unsafe and abnormal operation of reactors and provide the trigger signals to mitigate the consequences of accident conditions(i.e.extreme accident conditions)during the steady and transient power operation(i.e.normal operation,moderate frequency failure and rare accident conditions).The design of the reactor control and protection system follows the following principles:1)The design of reactor numerical control system should be based on the existing design concept of mature digital instrument and control system,combined with the process flow,parameter limit,control logic,get them into overall consideration and comprehensive layout.2)Reactor control and protection function is the core of reactive control and safe and stable operation of nuclear power plant.The safety requirements of nuclear power plant are embodied in the definition of system function level,and different function levels require different software / hardware design of numerical control system.3)The hardware construction of the reactor numerical control system needs to do different hardware configuration according to the different function classification,in order to meet the requirements of multi-channel,multi-redundancy configuration (including power supply design)and network design,the security network isolation should be examined in the implementation of logic function of 1E level.4)In order to improve the reliability of the software and avoid the common mode failure?get through the V&V verification,the software design of the reactor numerical control system realizes the configuration of the normal numerical control system,the on-line maintenance and periodic test of the system,and design the functions of channel bypass,self-diagnosis,priority,deviation alarm should be taken into consideration at the same time.Based on the analysis of the control logic,hardware structure and implementation model of control of the traditional reactor control protection system in nuclear power plant,combined with the structural characteristics of DCS and the design principle of the reactor control system,to research the design idea and structure of reactor control system.At the same time,some methods,ideas and analytical results are given to the software functional reliability verification of the reactor safety level control system.All the results of the analysis are applied to the research and development of the safety grade DCS in the domestic nuclear power plant.