Evaluating foreign object damage in steam generator tubes

摘要

Foreign objects in the steam generator secondary de vary widely in material, size and shape. These an move as a result of the fluid flow, and wear out the steam generator tube through frictional contact between the tube and foreign object. This wear damage can be prevented by removing the foreign objects from the tube, but it is not always possible to remove the foreign objects with the current maintenance technology. It is very difficult to estimate the amount of wear that takes place under various conditions because the prediction for wear of the steam generator tubes includes many uncertainties such as size and location of the foreign objects. Testing is the best way to evaluate steam generator tube integrity. However, the test method may be inefficient from an economic point of view due to high costs. If an analytical method with enough conservatism is developed and applied to the prediction of wear of the steam generator lubes, this can be resolved economically without the use of tests. Analysis of damage caused by foreign objects in steam generator tubes was carried out by a computer program which can predict the remaining life of the tubes due to foreign object damage.