Coolant Hydrodynamics in the PWR Reactor Core with TVS-Kvadrat of Various Designs

. The paper presents the results of experimental studies of the hydrodynamics of the coolant in the core of the PWR reactor with fuel assemblies “TVS-Kvadrat” of various designs. Experimental studies of hydrodynamics consisted in studying the velocity fields and the process of cross-flow of coolant between adjacent fuel assemblies “TVS-Kvadrat” of various designs in homogeneous and mixed cores on large-scale experimental models, including fragments of two adjacent fuel assemblies “TVS-Kvadrat” and a gap between them. The test models differ in the number of installed grids, this is due to the fact that in a homogeneous core the hydraulic load along the height of the fuel assemblies is identical, and in a mixed core the hydraulic load is uneven due to the different number of installed grids. The hydrodynamics of the coolant has been studied on an aerodynamic open-loop based on the theory of hydrodynamic similarity, using individually calibrated pneumometric sensors. Based on the data obtained, the fields of local axial and transverse velocities in various sections along the length of the studied section of the test models have been constructed. The fields of local dimensionless transverse and axial flow velocities in the fuel bundles and the gap between the fuel assemblies “TVS-Kvadrat” of the PWR reactor core have been studied. Peculiarities of the process of transverse flow between adjacent “TVS-Kvadrat” of a homogeneous and the mixed core of the PWR reactor have been revealed. The results of experimental studies have been transferred to the developer of “TVS-Kvadrat”, that is  JSC “Experimental Design Bureau of Mechanical Engineering named after I. I. Afrikantov”,  for further use in justifying the design and operating modes of a nuclear power plant.

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