Two-phase performance of scale models of a primary coolant pump. Final report

Scale models of PWR primary coolant pumps were tested in steady and transient two-phase flows in order to generate a data base to aid in the development and assessment of pump performance models for use in computer codes for the analysis of postulated Loss-of-Coolant Accidents (LOCA). This report summarizes and unifies the single and two-phase air/water and steam/water performance data on the relatively high specific speed pumps [4200 rpm (US gpm) /sup 1/2//ft /sup 3/4/] tested in these programs. These data are compared with those acquired from tests on the lower specific speed Semiscale pump [926 rpm (US gpm)/sup 1/2//ft/sup 3/4/] to better understand the mechanism of performance degradation with increasing void fraction. The study revealed that scaling down the size of the pump while maintaining the same design specific speed produces very similar performance characteristics both in single and two-phase flows. Effects due to size and operating speed were not discernible within the range of test conditions and within experimental uncertainties. System pressure appears to affect the rate of degradation as a function of void fraction. The report includes a survey of the existing two-phase pump performance correlations. A correlation synthesized from the B and W, C-E and Creare two-phase data is also presented