Complete and homologous pump characteristics for a reactor coolant pump

A reactor coolant pump is subjected to various abnormal operating modes, so the pump supplier has to provide all the transient pump characteristics to a user. Complete or homologous pump characteristics are the best forms including transient hydraulic information for an abnormally operating pump. Until now, there has been no consideration in the systematic test procedures to obtain the complete or homologous pump characteristics through a hydraulic test. No further research has been done on the relationships among the constant heads in complete pump characteristics. Likewise, no additional discussion has taken place on the direct transformation of the homologous pump characteristics into the complete pump characteristics. In present paper, a mathematical model is introduced to explain how the constant head curves in the complete pump domain are connected to each other. This means that other constant head curves can be obtained without additional hydraulic testing once a constant head curve is obtained for the full flow rate and speed range. It is also shown that the complete pump characteristics can be obtained from the homologous pump characteristics by another mathematical model. For homologous pump characteristics, even though differently enveloped test matrices that consist of different level sets of flow rate and speed are applied in hydraulic testing, the same homologous pump characteristics are obtained. These results indicate that a low-enveloped test matrix is sufficient to obtain the homologous pump characteristics.