Classifiability analysis of indications by eddy-current testing of nuclear power plant heat-exchanger tube

2009 ◽  
Author(s):  
Jan Grman ◽  
Livia Syrova
Keyword(s):  
Heat Exchanger ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Eddy Current ◽  
Nuclear Power ◽  
Eddy Current Testing ◽  
Heat Exchanger Tube ◽  
Current Testing ◽  
Exchanger Tube

Signal Processing Schemes for Defect Identification and Sizing From Signal of Eddy Current Testing in Nuclear Power Plant

2010 ◽  
Author(s):  
Shuxia Tian ◽  
Zhenmao Chen ◽  
Dongli Zhang ◽  
Qiang Geng
Keyword(s):  
Signal Processing ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Eddy Current ◽  
Nuclear Power ◽  
Eddy Current Testing ◽  
Neural Network Approach ◽  
Current Testing ◽  
Analysis Strategy ◽  
Welding Line

In this paper, signal processing schemes developed for upgrading the Eddy Current Testing (ECT) system utilized for In Service Inspection (ISI) of Steam Generator (SG) tubes of a nuclear power plant are presented. Schemes for the wobbling noise recognition, signal indication extraction, signal classification, and the separation of mixed signals are proposed. The schemes are applied to both signals measured in a SG mock-up and signals from short tube test-pieces measured in a laboratory environment. It is demonstrated that the methods work well even for mixed signals in the support plate region of SG tubes. As it is possible to adjust the position of a signal point based on the signature of the support plates, noise signals from a welding line or a bending zone can be recognized based on the information of design and manufactory. The mixed signals of defects and support structures are processed by using a similarity analysis strategy and the identification of defect signals is performed by means of both a neural network approach and a statistic method. Satisfactory results are obtained for the processing of measured signals.

Recent Design Technologies of Moisture Separator Reheater

2009 ◽  
Author(s):  
Jun Manabe ◽  
Jiro Kasahara ◽  
Toshiki Kojima ◽  
Issaku Fujita
Keyword(s):  
Heat Exchanger ◽  
Nuclear Power ◽  
Tube Bundle ◽  
Current Model ◽  
Temperature Oscillation ◽  
Separation Performance ◽  
Heat Exchanger Tube ◽  
Water Test ◽  
Moisture Separator ◽  
Exchanger Tube

This paper introduces the development of the current model Moisture Separator Reheater (MSR) for nuclear power plant (NPP) turbines, commercially placed in service in the period 1984–1997, focusing on the mist separation performance of the MSR along with drainage from heat exchanger tubes. A method of predicting the mist separation performance was devised first based on the observation of mist separation behaviors under an air-water test, then developed for the application to predict under the steam conditions, followed by the verification in comparison with the actual results of a steam condition test. The instability of tube drainage associated with both sub-cooling and temperature oscillation, which may adversely affect the seal welding of tubes to tube sheet owing to thermal fatigue, was measured on an existing unit both to clarify the behaviors and to develop a method to suppress them. Both methods were applied to current model MSR and the effectiveness of the methods was demonstrated. A new concept MSR for 1,700 MW class APWR units is put in perspective based on the technologies, alongside a multidisciplinary optimum design evaluating the heat exchanger tube bundle.

Development of Atlas of Defects of Steam Generators Heat Exchanging Tubes of NPPs With WWER and Analysis of Testing Results

2008 ◽  
Author(s):  
Murat Bakirov ◽  
Sergei Chubarov ◽  
Nikolay Trunov
Keyword(s):  
Eddy Current ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Eddy Current Testing ◽  
Basic Method ◽  
Steam Generators ◽  
Current Testing ◽  
The World

The basic method of the operational inspection of metal of heat exchanging tubes (HET) of steam generators (SG) is eddy-current multifrequency method all over the world. The greatest distribution was received variant with eddy-current testing (ECT) by use of a bobbing probe on the Russian nuclear power plants (NPP). Tubes with the defects which a subject to plugging are defined by results of lead operational ECT over the certain algorithm. SG resource is settled and replacement is required at achievement of a limit on number of the plugged tubes [1].

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