Abstract
Pipe wall thinning in power plants has been managed for maintaining plant integrity and safety with great importance. At present, the management is based on thinning rate and residual lifetime evaluation using pipe wall thickness measurement results. For more safety and improvement in the management, prediction model of thinning phenomena (FAC: Flow Accelerated Corrosion, LDI: Liquid Droplet Impingement) has been constructed in CRIEPI, and to utilize these models to actual plant piping management easily, prediction software "FALSET" is developed. By using this software, it is able to evaluate wall thinning of various pipe elements and layouts. However, as concerns FAC of separation and union pipe, FALSET has function to evaluate only T-tube. Thus, at present, there is no way to evaluate FAC of T-joint that has curvature at junction. In this study, for progress in FALSET, numerical analysis was conducted and wall thinning profiles (Geometry factor) of T-tube and T-joint was evaluated by using CRIEPI model. As a result, it was found that thinning rate of T-joint is about one-half of T-tube regardless of flow pattern.
