Design And Implementation Of Liquid Level Control System Of Nuclear Power Plant

China’s nuclear power industry is facing a historical opportunity of development.Like othercountries in the world,China also needs the more economical and more secure nuclear technology topromote the sustainable development of nuclear energy.Although China has been developed nuclearpower for more than30years,there is still a certain gap in the need of the development of thenational economy and the progress of nuclear technology.The mechanisms need to be innovated andthe advanced technologies needs to be used to promote the nuclear power construction.Liquid levelcontrol system of moisture separator reheater drain tank,as the key instrument&control equipmentof conventional island part, plays an important role of regulation in the normal operation of nuclearpower plant.This paper is about the design and implementation of level control system based on DCS.Through the design, the former control mode of moisture separator reheater drain tank in QinshanNuclear Power Plant has changed to mature, reliable, advanced DCS control system, to meet therequirements of liquid level control. Independent control and operating functions (hand/automaticfunction) of normal steam trap regulating valve and emergency steam trap regulating valve havebeen realized. Pressure signals,temperature signals and feedback signals of the drain tank regulatingvalve have been added. Complete process parameters of running equipment and selfdiagnosisfunction have been provided.In the paper firstly the basic function and key technique of I/A Series control system ofFOXBORO have been studied; on the basis of mastering the basic principle and function of thesystem, with normal/emergency drain valve of MSR drain tank as the control object,the projectimplementation has been carried out with the application of I/A system,to which the key is hardwareconfiguration and system configuration.The design and implementation of control system, can improve the availability ratio, reduce thedefect rate of equipment, achieve the " zero defect" target, and meet the needs of the safe operationof power plant in long term.