Estimating the Required Flow Rate to Lift an Absorber in the Shutdown System of Nuclear Reactors

Many of the research reactors use electro-magnetic force or hydraulic force to lift and grab an absorber in the shutdown system. When the shutdown system actuation signal occurs, the lifting force is stopped and the absorber drops in order to shutdown the reactor. The present study deals with the shutdown system using hydraulic force to lift the absorber at a predetermined position. The required flow rate to lift the absorber is the key design parameter. The pressure drop while the operating fluid flows around the absorber and the buoyancy force determine the required flow rate. The detailed calculation procedure to obtain the required flow rate and the experimental result will be shown in the present paper