Uncertainty Quantification of Spray Nozzle Fatigue Analysis Under Transient Load

In this paper, the randomness concept of input parameters is introduced into the design of nuclear equipment, and the uncertainty analysis of input parameters is carried out for fatigue analysis. Taking the pressurizer spray nozzle as the research object, considering the random fluctuation of temperature and pressure of the transient load, the reliability and distribution of the fatigue usage are obtained by performing fatigue analysis according to the fatigue analysis method of nuclear power equipment with Monte Carlo sampling method. Taking section No.3 as an example, the thermal analysis and stress analysis models are established. Through the parameter sensitivity analysis, the relative sensitivity of the fatigue usage to each input parameter is obtained. From the results, it is clear which parameters have a significant impact on the results. The results can further optimize the structural design of the nuclear power equipment and improve its fatigue resistance, which has great application value to the life extension of nuclear power equipment.