Experimental investigation of spacer grid effect on shear stress distribution in models of fuel assemblies
N.A. Pribaturin1,2, P.D. Lobanov2, V.V. Randin2, O.N. Kashinsky2, A.S. Kurdyumov2, M.A. Vorobyev2, S.M. Volkov2
1Novosibirsk Branch of Nuclear Safety Institute RAS, Novosibirsk, Russia
2Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia
Keywords: experiment, fuel assembly, fuel element, shear stress, spacer grid
Abstract
To assess the spacer grid effect on the liquid flow disturbance, the shear stress on the surface of a vertical rod - a fuel element simulator - was measured in seven-rod models of fuel assemblies differing in spacer grid sizes, diameter of rods (fuel element simulators), and relative distance between them. Data on axial distribution of shear stress are presented. An increase in the averaged and pulsation wall shear stresses directly behind the grid due to liquid flow disturbance and extinction of this effect far from the grid is shown. The results of this research can be applied to verify the design codes used in hydrodynamic predictions of reactors.
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