Sludge Deposit Mapping for Steam Generators

Abstract

During plant operation, corrosion products from feedwater, drain and condensate system accumulate on the secondary side of steam generator in form of scaled deposits around the tubes and sludge piles on top of the tubesheet. These deposits increase potential for corrosion, affect fluid flow and reduce heat transfer efficiency of the steam generator. Using data obtained during periodical eddy current examination of steam generator tubing, information on sludge deposit location and thickness is extracted from low frequency absolute channels. Sludge deposits can be detected over the whole length of the inspected tube. Using automatic analysis deposit results are provided within 36 hours after the inspection. Results are imported in Sludge Mapping software and presented in 3D visualization of steam generator. Both PWR and VVER steam generator visualization is supported. Sludge mapping software provides visual information on sludge deposit thickness using color code and by calculation position of sludge indication, software draws the indication on the location within the steam generator where indication was found. Sludge mapping software provides information on heavy sludge loading areas of steam generator and can help with tracking of sludge build-up over time that can be used for optimizing steam generator maintenance. This paper presents INETEC’s Sludge Mapping solution, its functionality and features for visualization of sludge deposit location and thickness within the steam generator.