LAUSR

Several variants of intensifier grids which have a positive influence on the equalization of the coolant parameters over a section of an assembly as well as on the enhancement of critical heat-emission are proposed for intensifying heat-and mass-transfer in connection with the increase in the power of operating power-generating units with VVER. A large volume of experimental studies of the efficiency of different types of intensifier grids has been conducted at the National Research Center Kurchatov Institute. Among the intensifier grids studied is the developed universal intensifier spacer-grid. The investigations were performed on 37-pin models of VVER-1000 fuel assemblies. The influence of the grid spacing on the critical heat flux was studied. The dependence of the hydraulic resistance of a grid on the size of the deflector was studied. The experimental studies can be used to develop intensifier grids with new designs and to verify computational models and codes.