HYDRODYNAMICS OF GAS-LIFT PUMP WITH LEAD COOLANT

A gas-lift probe is an element of cladding failure detection system of perspective lead cooled reactor. Its function is local measurement of gaseous fission product activity into coolant and the defective fuel assembly localization. The transit time of gaseous fission products from the defect to the place of activity measurement depends on the flow rate of the coolant through the gas-lift probe. Since most fission products have a short half-life period, their delivery time to the measuring vessel should be minimal. Therefore, the calculation of the flow rate of the coolant, as well as the transit time of gaseous fission products in the lifting path of the gas-lift probe is an actual task. A computational methodology of the hydraulics of the gas-lift probe with a lead coolant is presented in this work. The calculation results of two-phase flow characteristics in a reactor gas-lift probe and in the tested model in NIKIET experimental setup are presented. It is obtained the significant difference between the coolant flow rate in the tested model and in the reactor probe at the same gas flow rate. The reasons for these differences are defined.