Treatment and Analysis of SG Level Control Problems in Nuclear Power Plant Startup and Low Power Stage

Abstract

Steam generator level is the key and difficult point of nuclear power plant control. Improving the automation level of Steam generator level control can reduce the workload of nuclear power operators, reduce human errors and improve the work efficiency of operators. In the start-up and shutdown stage and low power stage of a GEN-II nuclear power plant, Steam generator is supplied with water by ASG system and operators manually operated control SG level. In a GEN-III nuclear power plant, Steam generator is supplied with water by AAD system in the start-up/shutdown stage, and SG level is automatically controlled by ARE Start-up control valve, thus it has realized the automatic control of SG level under all working conditions of the nuclear power plants and improved the intelligent level for the nuclear power plants. In the start-up and shutdown stage and low power stage of the nuclear power plants, the steam flow and feed water flow are extremely small, the measurement is inaccurate, and the conventional cascade control of SG level and feed water flow cannot be adopted. This paper mainly introduces the principle, test validation and optimization, problems and solutions of SG level automatic control in the start-up and shutdown stage of the GEN-III power plants.