Analysis of Eddy-Current Testing and Metallographic Examinations for Corrosion Damages of Heat Exchanging Tubes in NPP Steam Generators

2020;
: pp. 7 – 15
https://doi.org/10.23939/jeecs2020.01.007
Received: January 16, 2020
Revised: April 21, 2020
Accepted: May 07, 2020
1
Lviv Polytechnic National University
2
Lviv Polytechnic National University
3
Lviv Polytechnic National University

This paper represents the mechanism for corrosion damages of heat exchanging tubes (HET) of a steam generator PGV-1000 for various operational conditions. It was determined that corrosion damages locate mainly at the bottom of the steam generator bundled tubes. An investigation into the corrosion damages of HET was conducted in terms of PGV-1000 steam generator. The results of eddy-current testing (ECT) for steam generator HET performed by two different ECT systems “TEDDY-8”, “MIZ-30” were analyzed and compared to the results of metallographic examination of defects. It was determined that the percentage of rusted metal according to the metallography data in the absolute majority of analyzed defects surpassed the ECT ones. The difference is equal to 10-15% in most cases and up to 25% in some cases. It was proved that the thin-walled HET should not have significant or penetrating defects for ensuring the reliable operation of PGV-1000 HET, which is the most important task to do at a nuclear power plant (NPP).

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T. Kovalenko, S. Lys, V. Vostres. Analysis of eddy-current testing and metallographic examinations for corrosion damages of heat exchanging tubes in NPP steam generators. Energy Engineering and Control Systems, 2020, Vol. 6, No. 1, pp. 7 – 15. https://doi.org/10.23939/jeecs2020.01.007