Computational Fluid Dynamics Analysis for Flow Accelerated Corrosion in CANDU6 Feeder Pipes

CANDU6 plant management over a long time period includes various ageing and degradation mechanisms like Flow Accelerated Corrosion (FAC) manifested mainly at first and second elbow of CANDU6 outlet feeders. FAC take place at all CANDU6 built before 2000 year with feeders made from SA106 grade B low alloy carbon-steel (with low Chromium at ∼ 0.02%). Open Source Computational Fluid Dynamics (CFD) method is used in the paper to investigate the feeder's wall thinning process taking place mainly due local flow conditions in complex 3D geometrical configurations. The 380 outlet feeders grouped in 2.5" (320) and 2.0" feeders (60). The objective of this paper is to help, as much as possible, to focus investigation on most probable maximum thinning rate locations through 3D distribution of some thermal-hydraulic (TH) parameters. Application of CFD methods in CANDU6 nuclear reactors implies the knowledge of real plant operating data like: long term time averaged channel power and mass flow as well as temperature, pressure, pH etc. allowing the optimization and cost reduction of wall thinning monitoring process at CANDU6 Nuclear Power Plants. (author).