Centrifugal pump performance under simulated two-phase flow conditions

This paper presents test results from centrifugal pump performance testing using nitrogen-water flow to simulate steam-water two-phase conditions. The results are compared with the predictions of the RELAP4/MOD6 pump performance model which is based on experimental data obtained from tests conducted on a small (radial-flow) pump. The purpose of this investigation is to obtain the two-phase characteristics of a mixed-flow pump and to evaluate the prediction capability of the pump model commonly used to analyze the thermal-hydraulic response when applied to a postulated loss-of-coolant accident in a light water reactor. Test results indicate that pump two-phase degradation is much less than that predicted by the RELAP4 model