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Flow accelerated corrosion (FAC), which is a main cause of pipe wall thinning of carbon steel piping in nuclear power plant, is synergistically influenced by multiple factors, such as material, flow dynamics and water chemistry.
To take adequate measures for FAC mitigation during piping design and plant operation, it has to be understood that not only a single factor but also changes in multiple factors may synergistically affect on FAC behavior of carbon steel.
Especially, FAC mitigation by applying water chemistry improvement is effective, because FAC mitigation effect in broad area can be obtained by water chemistry improvement, which is easier to take measures.
On the other hand, the effect of water chemistry improvement on FAC mitigation has to be understood in each condition, because FAC mitigation effect is different in each condition.
Test apparatus we used in our FAC experiment enable us systematic FAC data acquisition under various combinations of multiple factors, with real time monitoring of thickness of specimen and in-situ ECP measurement.
FAC mitigation effect by water chemistry improvement in each region under various combinations of material and flow dynamics, and plant operation, are considered, based on FAC experiment results.
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