Study On The Three-dimension Transient Coupling Code Of Supercritical Water-Cooled Reactor

As one of the six nuclear energy systems of the Generation IV concept systems. SCWR is a once through circulatory system. The supercritical pressure water get into steam turbine after heated by the core. It has some advantages such as simple structure, high thermal efficiency and building on existing technology. Reactor physics analysis is mainly used for the calculation of nuclear reactor fission energy and it is an important basis for accident analysis. Reactor thermal hydraulic analysis mainly refers to the analysis of the primary coolant heat transfer characteristics and flow characteristics. Supercritical water cooled reactor is as the study object, combined with Spatial-Time Neutron Kinetic Equations and Two Group Diffusion Equation, based on deterministic coupling method to create a three-dimensional transient supercritical water cooled reactor coupling procedures. More precise analysis of transient supercritical water cooled reactor safety features is obtained. At the same time, it provides a theoretical basis for Spatial-Time Neutron Kinetic Equations and Two Group Diffusion Equation are applied to supercritical water-cooled reactors transient coupling temporal dynamics calculations, and it lays a good foundation for engineering of supercritical water reactor.Three-dimensional steady-state supercritical water reactor power distribution program are calculated by solving Diffusion equation and time kinetic equation. Solving Diffusion equation to obtain steady-state power distribution and solving Spatial-Time Neutron Kinetic Equation, obtaining physical three-dimensional transient power calculation program. Through the thermal program calculations, solving the mass, energy and momentum conservation equations, at transient and accident conditions, obtaining the core parameter characteristics. Through the establishment of axial heat conduction model to obtain pellets and cladding surface temperature. Heat transfer coefficient is calculated using the Watts ccnvective formula. The three-dimensional physical preparation program is coupled with the single-channel thermal procedure to obtain a three-dimensional physical and thermal coupling procedure.In steady state conditions, given initial power conditions, the use of three-dimensional coupling procedures to calculate the distribution of the coolant temperature, moderator temperature, power, cladding temperature inside the reactor core characteristics. In the design of different power and different flow conditions, heat engineering and the physical parameters of the core distribution are obtained.In transient conditions, based on the result of steady state, under the condition of partial loss of feedwater flow analysis, reactor coolant pump shaft card, during normal operation control rod is withdrawn and some transient and accident conditions, the reactor core fluid parameters and cladding temperature are calculated. Under the conditions of the safety control system, getting the security features.of the core. Through the preparation process, and the supercritical water cooled reactor three-dimensional coupling program studies, concluded:under the transient and accident conditions,getting the fluid thermal parameters by the three-dimensional thermal physics coupling program the maximum cladding temperature meet safety standards.While the results obtained by the three-dimensional coupled program are comparative with the results by the one-dimensional coupled program,analysis shows that the difference between the one-dimensional coupling results and the three-dimensional coupling results. It lays the foundation to get a better and more accurate understanding of the actual working conditions of supercritical reactor safety features, and provide a reference for other type of reactor calculation analysis.