COMPUTATIONAL INVESTIGATION OF THE EFFECT OF HYDRAULIC AND NONDESTRUCTIVE TEST PARAMETERS ON THE STRENGTH RELIABILITY OF THE HEAT EXCHANGER TUBES OF A STEAM GENERATOR

摘要

The results of calculations of the probability of a leak appearing in the tube band of steam generator in a WER-440 reactor system during operation are presented. The MAVR-1.1 computer code is used to calculate the probability of the formation of a leak and rupture of one of the heat exchanger tubes. The binomial distribution is used to determine the probability of the number of tubes that do not satisfy the plugging criterion. A leak in a tube bank is calculated as a sum of leaks in individual tubes. The probability of such a leak is calculated as a random sum. The calculations show that the parameters of test measures (pressure of the hydraulic tests, reliability of nondestructive testing for defects) and the sequence in which they are performed have a large effect on the failure probability of a tube bank during reactor operation. The computational results and the experience gained in operating steam generators show that the algorithm and the method developed for computing the leak probability could be helpful for estimating the strength reliability of heat exchanger tubes.