| Nuclear reactor coolant cycling pump (RCP), called as the"Heart"of the reactor, is the equipment which provides the power to transfer of the coolant and discharge the heat. It is the component of the pressure boundary of the first circuit in reactor. Impeller, the key part of RCP running with high-speed, need to keep operating long-term, safely and reliably in the environment with high-temperature, high-pressure and strong-radiation as the importance for the integrity of the RCP's operation, successful transportation of the coolant, and the safety of whole reactor. Consequently, fatigue characteristic is very important for impellers to ensure the operation with high safety and reliability in life.This paper mainly studies of fatigue analysis system of impellers of RCP basing on the material, structural shape, manufacture and working environment. FEM technology is used to analyze the factors which will affect the fatigue of impellers. Firstly, the Pro/e and inventor software are used to get the 3D model of the Andritz RCP. Secondly, a three dimensional flow through passage of this RCP is simulated by the numerical simulation software-CFX. Then the stress response analysis results of the impeller are obtained by ANSYS. At last, the professional fatigue analysis software Fe-safe is used to take a fatigue life calculation by importing these results, and finally a reliability analysis is operated to the calculation result of the fatigue life. This paper achieves modeling the complex parts such as the impeller and guide vanes in RCP. During the process of 3D numerical simulation by using Fluent, the steady and unsteady conditions are simulated and a steady flow field distribution and the performance prediction of the RCP are obtained. Moreover, we can obtain the real flow situation (the transient flow field inside the RCP) and the water cycling power force of the blade by unsteady simulation. During the process of stress response analysis of the impeller by ANSYS, the stress response of the water cycling power force and centrifugal force are mainly considered. The results show that the part with higher stress in the blade is near the hub where fatigue phenomenon easily occurs. Because the temperature does not change unobvious inside pump and high-temperature only affect the allowable stress of the impeller, the high-temperature stress can be ignored normally. The influence of the high-temperature to the impeller's fatigue can be studied by defining a temperature parameter in Fe-safe. The fatigue life distribution and safety factor are obtained through the fatigue calculation under the superimposed load of all stress loadings. The results show the part near the hub has a lower fatigue life value which agrees with the actual situation. These results provide a theoretical basis to the fatigue design of the impeller. At last, the reliability analysis of the fatigue life is completed after the reliability calculation of fatigue life.This paper constructs a wholly fatigue life reliability analysis system of the RCP's impeller. This analysis process can provide a theoretical basis for the design and manufacture of the RCP's impeller. Meanwhile, it puts forward some suggestions and proposed solutions for the fatigue design and fatigue prevention of the RCP's impeller. Based on this analysis process, it may help to give a safety assessment and to confirm whether the impeller of RCP can keep operating with long-term, safety and reliability.
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