Flow-Accelerated Corrosion Wear of Power-Generating Equipment: Investigations, Prediction and Prevention: Part 3. Managing the Flow-Accelerated Corrosion of Pipelines and Equipment

The third part of this review1 discusses matters concerned with managing the flow-accelerated corrosion of power-generating equipment’s and pipelines' components. The importance of these matters tends to increase with increasing the capacity of power plant units and the time for which they have been in operation. The article considers the capabilities of object-oriented software packages aimed at providing information support to the personnel (PSSPs) in regard to scheduling in-service inspections for timely revealing cases of close-to-inadmissible flow-accelerated corrosion-induced thinning. The prospects of using PSSPs for minimizing the carryover of iron-containing products of general flow-accelerated corrosion into the process circuit of NPP units are shown. The list of parameters and characteristics necessary for numerically estimating the thinning rates and residual life of pipelines and equipment susceptible to flow-accelerated corrosion is determined. The possibility of using some PSSPs to predict the thinning of process circuit component walls taking into account the effect of cavitation and droplet impingement erosion on the metal is pointed out. The need to optimize the scheduling of in-service inspections of near-seam zones of welded connections used in the pipelines of the condensate–feedwater and wet steam paths of power units is substantiated. It is pointed out that work is underway for fitting the Russian NPP units with PSSPs able to define— based on calculation results, data of in-service inspections, and other information—a priority list of components to be subjected to first-priority or next scheduled in-service inspection and to schedule repair (or replacement) of components susceptible to intense thinning. It is shown that the use of stainless steels for making the components of pipelines and equipment operating in the secondary circuit of NPP power units is often an excessive measure for preventing the occurrence of inadmissible local flow-accelerated corrosioninduced thinning and for minimizing the concentration of iron in feed water. The prospects for comprehensively solving the flow-accelerated corrosion problems by implementing appropriate measures at the designing, construction, and operation stages are considered. The main topical practical objectives for coping with the problem of flow-accelerated corrosion in power engineering are formulated.