Experimental Activities on Thermal Hydraulics of Heavy Liquid Metal Flow in Typical Elements of Nuclear Power Stations

The report presents the results of an experimental study of the thermal hydraulics of a heavy liquid-metal coolant in the elements of a reactor installation. Hydrodynamics and heat transfer are considered in the coolant flow in a model assembly of vertical rods and in a T-junction. These tasks are important both from the point of view of justifying the design solutions of a reactor plant with a heavy liquid-metal coolant, and from the point of view of verification of calculation codes. The results of an experimental study of the temperature distribution in the 7-rod experimental model of a fuel assembly with spacer grids are presented. To create a thermal heterogeneity, a heating zone was created in one of the rods. The evolution of the temperature field is studied with the variation of the mutual location of the heated, measuring rods and the spacer grid. Validation measurements of fluid velocity profiles and its pulsations in a similar flow in a similar geometry of a water coolant have also been carried out. Results of experimental study of mixing of liquid metal with different temperatures in a T-junction also are presented. The liquid with higher temperature was injected through the branch of the T-junction. Data on wall temperature evolution for the mixing of hot and cold liquids were obtained for different ratios of flow rates of main and side flows. Experimental data on fluctuational and spectral structure of temperature field in the mixing zone were obtained for different flow conditions. Results obtained may serve as a basis for construction of experimental data base for verification of CFD.