IAEA CRP meeting discusses findings in Flow Accelerated Corrosion (FAC) research and modelling
2014-06-26 | As nuclear power plants age, piping and components may degrade causing piping and equipment failures due to Flow Accelerated Corrosion (FAC), the thinning of the inside wall of steel piping due to turbulent and fast flowing water or wet steam. Participants from 12 countries met in Erlangen, Germany in the first week of June to discuss recent progress in an IAEA coordinated research project (CRP) on the elaboration of FAC guidelines and benchmarking of prediction tools to help effectively reduce the number of piping and equipment failures caused by FAC.
FAC is a chemical effect that is primarily influenced by pH, hydrodynamics, oxygen, and temperature. As FAC wears away protective films (oxide layer) of piping and leads to corrosion of underlying metal, wall thinning in piping and vessels may cause sudden ruptures in high and moderate energy systems, resulting in plant shutdowns or other events and may risk personnel safety and affect safety and non-safety related equipment by leaking steam and water.
Seventeen countries participate in the CRP which aims to benchmark commercially available software programs (BRT-CICERO, CHECWORKS, COMSY, and RAMEK) that are used to predict FAC-related pipe wear. Fourteen research team members met at AREVA headquarters in Erlangen, Germany from 4-6 June to present their findings. Team members modelled and predicted wear rates for three real nuclear power plant (NPP) systems and results were compared and discussed. In the next phase of the project, models using actual wall thickness measurements, obtained from the NPPs in question, will be adjusted to further predict future wear rates at a later point in time, and to compare results of the various programs to actual wear rates obtained at that later point in time. FAC Guidelines, containing research results, are being prepared and will be published as a Nuclear Energy Series publication following the completion of the project.
Further details on the project can be found here