Defects in the Metal of Welded Joints of Collectors to Steam Generators in Nuclear Power Plants

Authors

  • Galya Dimova Technical University of Sofia, Bulgaria

DOI:

https://doi.org/10.7546/CRABS.2025.01.14

Keywords:

nuclear power plants (NPPs), steam generators, defects, long term operation

Abstract

This article presents a study of the metal of coolant collectors' welded joints to steam generators in nuclear power plants. During the operation of nuclear power plants of the VVER-1000 type, metal defects were found in the collectors' welds to the steam generator body. The general cause for the defects' occurrence and development is the combination of: 1) the influencing stresses, and 2) the corrosively aggressive working environment. The specific manifestation and development of defects differs across different NPPs. This study focuses on examining the on-site working conditions. It describes observations on the occurrence and development of defects in the metal of the welded joints and possible facility degradation scenarios. The resulting data come from actual observations spanning a 30-year-period. This information is important for the safe operation of steam generators in NPPs. The data can be used for probabilistic safety analyses at NPPs as well as for NPP lifetime extension.

Author Biography

Galya Dimova, Technical University of Sofia, Bulgaria

Mailing Address:
Technical University of Sofia,
Technical College – Sofia,
Department of Energy and Mechanical Engineering,
Studentski complex, 8 Kliment Ohridski Blvd,
1756 Sofia, Bulgaria

E-mails: dimova@tu-sofia.bg,
gtdimova@abv.bg

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Published

29-01-2025

How to Cite

[1]
G. Dimova, “Defects in the Metal of Welded Joints of Collectors to Steam Generators in Nuclear Power Plants”, C. R. Acad. Bulg. Sci., vol. 78, no. 1, pp. 119–125, Jan. 2025.

Issue

Section

Engineering Sciences