Postulated Degradation Mechanisms of Steam Generator Tubing in Water-Cooled Small Modular Reactors

Abstract

Nuclear steam generators are large stand-alone components in a nuclear power plant and, in the early years, degradation of the tubes was a major problem. The time spent on repairs caused significant economic losses in terms of lost power production. As a result, research and development into this problem led to a better understanding of the tube degradation mechanisms in the current fleet of nuclear power plants. In many of the new small modular reactor concepts, the steam generator is designed to be integral within the reactor pressure vessel, and the primary and secondary water flows are on the shell side and tube side, respectively, and this is reverse to that of traditional nuclear steam generators. This change may cause the known tube degradation mechanisms to manifest in different ways. This work provides some insight into how the traditional degradation mechanism may manifest in the new concepts of small modular reactors.