Analysis on Validity of Test Data of Primary Circuit Pressure Boundary Leakage Rate

The primary circuit pressure boundary gas leakage rate test of a research reactor is interfered by small volume, equipment cooling water and other factors, and there are extreme sample points in the test data. On the basis of not changing the test method, the effectiveness of the test results is ensured by using the significance test and variance analysis of the regression model. The test method draws lessons from the test method of containment leakage rate of PWR. In this paper, three commonly used methods for calculating the leakage rate of the containment, including ANSI/ANS-56.8, RCC-G-1988, and ПНАЭГ-10-021-90, are used for calculation and analysis. The results show that the calculation results of the three methods are basically the same. By analyzing the independence, normality and variance property of residuals in linear regression model, the influence of regression diagnosis on the calculation results is discussed. At the same time, for the problems of heterogeneity of variance, autocorrelation and extreme sample points found in regression diagnosis, the final results are modified by combining the residual weighted least square method and removing extreme sample points, and the reliability of the results is improved. The analysis method in this paper has been applied to nuclear safety review.