Investigation Of Nuclear Power Plant Simulation Estimate Platform(NPPSEP)

With the significant development of nuclear energy,more safety and economy efficiency are demanded for nuclear power plant.To fulfill this task,simulation technology is widely used to enhance the safety and economy of nuclear power.The simulation can be applied in safety analysis,independent evaluation,design verification of advanced main control room,accidents release action researching,operators training and teaching,etc.In this study,Nuclear Power Plant Simulation Estimate Platform(NPPSEP),which is based on international standard thermal-hydraulic system code coupled with visual human-machine interface,is developed.Besides,NPPSEP can be used for other relevant researches in nuclear engineering.As an important part of real-time,full-scope,entire functional simulation of nuclear power plant,steam system of the secondary loop which is coupled with the primary loop system,is considered for the impact on the reactor in safety analysis.Especially for marine nuclear power plant,considering the limit of marine space configuration and the rapidly varying of duty working,the safety of nuclear power system has an important relation with the steam system of the secondary loop.Due to international standard best-estimate system code RELAP5 is developed for transient simulation of reactor coolant systems,it is the first part of this study to develop the turbine model and the condenser model which can represent accurately system dynamic characteristics.The improved turbine model which is based on the characteristics of steam flow and work in the stage of turbine considers adequately the impact of internal configuration parameters and oblique shock which is developed by no-equilibrium characteristic of wet steam in turbine.At the same time according to the configuration and heat transfer of condenser,the condenser model is developed.In the second part of this study,coupling between RELAP5 code and new model is investigated.RELAP5 code is modified for simulation requirements.These modifications which update the system model used in RELAP5 include the read of model parameters,code coupling and dynamic output of calculation results.It has been verified that the simulation of entire nuclear power plant can be realized in this modified version of RELAP5 code without any sacrifice of original functions.In the third part,the study is focused on visual human-machine interface of NPPSEP,which provides users to visual system model,data input window and human-machine communication.Visual human-machine interface of NPPSEP which is designed in MVC(Model-View-Controller)mode,coupling with db4o(object-orientation database),VectorControl.Net3.0 SDK technology and GDI+(Graphics Device Interface Plus)technology,is developed by C#language.Users can design system simulation nodalization scheme of nuclear power plant by plotting tool and visual components base,and data card which is generated exactly and effectively without considering complicated rule of data card by data input window,is called by RELAP5 code.During the transnt of RELAP5,users can control calculation by inputing,and dynamic curve of calculation results can also be shown to users.The project is used to manage SVG files,data files and data card,which make work saved and reused.At last,NPPSEP is applied in the following relevant studies based on the Integrated Pressurized Water Reactor IP200:simulation analysis of system dynamic characteristics in the case of rapidly varying duty working in the two-constant control method(main coolant average temperature constant,steam pressure constant),and simulation of accident condition which is tripped in the transient.The results indicate that NPPSEP has wide applications in both academic and engineering fields.In conclusion,this work independently modifies international standard best-estimate system code RELAP5,and updates system model of secondary loop in RELAP5.Internal coupling interface in RELAP5 code can be used to couple with other simulation programs,and also provide theory base for other systems model in RELAP5,which will realize rapidly system simulation for nuclear power plant by the RELAP5 code.NPPSEP which is developed based on the modified version of RELAP5 coupling with visual human-machine interface,is used to simulate the entire nuclear power plant.In addition,this PC based version of simulation system is able to deliver wider engineering applications.