Development of a pump performance model for an integral effect test facility

Modeling methods for the reactor coolant pumps of the existing integral facilities are reviewed from the viewpoint of scaling, single- and two-phase characteristics. A series of separate effect tests was performed for the pumps of the ATLAS (Advanced Thermal-hydraulic test Loop for Accident Simulation) in order to obtain a complete set of single-phase homologous curves in all the quadrant operating regions. Besides the friction loss tests for the sheared shaft and the locked rotor conditions were conducted to extend the homologous curves to the limiting cases. A method which can take into account the two-phase degradation effects of the ATLAS pumps was suggested as a first approximation based on similarity principles. The present data and model can completely replace the pump input model of the MARS 3.1 code both for single- and two-phase conditions.