System Modeling And Dynamics Analysis For BWR Nuclear Power Plant

As clean energy, Nuclear power technology has been relatively mature. With the characteristic of strong supply capacity, security and reliability, Nuclear power has become an important part of the strategy of national energy and electricity. Construction and operation of nuclear power plant can ease the demand for energy in the world today, but it also bring security risks. Especially after Japan’s Fukushima nuclear accident, people pay more and more attention on the safety of boiling water reactor nuclear power plant.BWR plant allow coolant saturated boiling, Therefore, the stability of the two-phase flow problems was concerned. Research of two-phase flow instability is significant for the safety of nuclear power system and accident analysis.The complexity and importance of the nuclear power plant system determines it can’t be tested directly. Therefore, to establish an accurate and complete BWR model is of great significance to the study of dynamic characteristics and two-phase flow instability problems of BWR. In this paper, the mechanism model of Boiling Water Reactor nuclear power plant is built up with the thermal hydraulic software RELAP5, including the reactor coolant System and main feedwater system Then, the steady and transient state analysis of the model was done. On the basis, simulation and analysis of two-phase flow instability phenomenon of boiling water reactor was done. The main content of this paper and results are as follows:1. BWR nuclear power plant modeling:through establishing the compute node and writing the RELAP5input card, complete the BWR nuclear power plant reactor core cooling system and main feedwater loop system modeling.2. BWR nuclear power plant model validation:compare the steady state calculation result with the actual operating data to ensure model accuracy and reliability. The result of dynamic verification meets the laws of physics, further determine the validity of the model.3. BWR control system modeling:based on the model, establish the BWR reactor power plant control system, and complete the real-time simulation of variable conditions and fault conditions, which verify the regulatory functions and disturb resistance capacity of control system.4. Analysis of two-phase instability phenomenon of BWR:establish BWR natural circulation model, do the two-phase flow instability simulation and analysis its influencing factors.