scholarly journals Development of an Eddy Current Test Configuration for Welded Carbon Steel Pipes under the Change in Physical Properties

2021 ◽  
Vol 12 (1) ◽  
pp. 93
Author(s):  
Azouaou Berkache ◽  
Jinyi Lee ◽  
Dabin Wang ◽  
Duck-Gun Park
Keyword(s):  
Carbon Steel ◽  
Physical Properties ◽  
Eddy Current ◽  
Nuclear Power ◽  
Power Plants ◽  
Experimental Results ◽  
Steel Pipe ◽  
Safety Level ◽  
Test Configuration ◽  
Current Test

Carbon steel pipe is used in various industries, including nuclear power plants. Due to the daily cyclic operation of the pipe over time, environmental influences, and extreme working conditions, the probability of developing small fine cracks in the welded areas of the pipes increases. For that reason, it requires earlier assessment, and providing adequate inspection and evaluation of the weld area of the pipes used in such an installation is crucial to increase the safety level. In this paper, two different probe configurations were used to assess the integrity of the girth weld of the SA106 carbon steel pipe welded by gas tungsten arc welding. The conventional eddy current probe was initially used, but as it had some limitations, a new probe configuration was proposed to overcome these constraints. Numerical simulations using the finite element method were performed, based on the real measurement of the physical properties of the specimen, to complement the experimental data. In addition, the experimental results were successfully reproduced by the simulations. Simulation and experimental results show that the proposed probe configuration allows adequate inspection.

Parametric Study on Determining Optimal Eddy Current Testing Method for Inspection of Steam Generator Tubes in SMART Plant

2010 ◽  
Author(s):  
Dae-Kwang Kim ◽  
Sung-Jin Han ◽  
Hak-Joon Kim ◽  
Sung-Jin Song ◽  
Yun-hang Choung
Keyword(s):  
Steam Generator ◽  
Eddy Current ◽  
Nuclear Power ◽  
Power Plants ◽  
Eddy Current Testing ◽  
Pressurized Water Reactor ◽  
Pressurized Water ◽  
Current Testing ◽  
Current Test ◽  
Testing Condition

The SMART (System-integrated Modular Advanced ReacTor) is small sized integral type pressurized water reactor designed by KAERI (Korea Atomic Energy Research Institute), Korea. But, shape of steam generator (SG) in SMART plant differs from those in operated nuclear power plants (NPPs). Especially, SG tubes in SAMRT plant is helical type with around 600 mm of innermost diameter and thickness of 2.5 mm which is thicker than general NPPs one. For providing integrity of SG tube in SMART plant, new types of ECT method are needed because eddy current testing (ECT) is one of widely adopted method for inspection of SG tubes in NPPs. Therefore, in this study, we investigate optimal conditions or parameters for detecting and evaluating of flaws in the SG tubes in SMART plant by simulation of ECT signals with various testing condition or parameter such as frequency, coil gap and etc. From the simulated ECT signals optimal eddy current test condition or parameters are proposed.

Strain Rate Effects in SA-106 Carbon Steel Pipe

1982 ◽  
Vol 104 (1) ◽  
pp. 31-35 ◽  
Author(s):  
D. Peterson ◽  
J. E. Schwabe ◽  
D. G. Fertis
Keyword(s):  
Carbon Steel ◽  
Yield Strength ◽  
Strain Rate ◽  
Tensile Properties ◽  
Nuclear Power ◽  
Power Plants ◽  
Experimental Modeling ◽  
Steel Pipe ◽  
Strain Rate Effects ◽  
Rate Effects

Experiments were performed to measure the effect of strain rate on the tensile properties of SA-106 carbon steel pipe, in support of analysis and experimental modeling of postulated pipe whip in nuclear power plants. It was observed that increasing the strain rate from 4 × 10−4 to 4 s−1 raised the yield strength by approximately 30 percent.

scholarly journals Evaluation of the Limit State of a Six-Inch Carbon Steel Pipe Elbow in Base-Isolated Nuclear Power Plants

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8400
Author(s):  
Sung-Wan Kim ◽  
Da-Woon Yun ◽  
Bub-Gyu Jeon ◽  
Dae-Gi Hahm ◽  
Min-Kyu Kim
Keyword(s):  
Carbon Steel ◽  
Nuclear Power ◽  
Power Plants ◽  
Base Isolation ◽  
Low Cycle Fatigue ◽  
Limit State ◽  
Steel Pipe ◽  
Cycle Fatigue ◽  
Pipe Elbow ◽  
Isolation Systems

The installation of base isolation systems in nuclear power plants can improve their safety from seismic loads. However, nuclear power plants with base isolation systems experience greater displacement as they handle seismic loads. The increase in relative displacement is caused by the installed base isolation systems, which increase the seismic risk of the interface piping system. It was found that the failure mode of the interface piping system was low-cycle fatigue failure accompanied by ratcheting, and the fittings (elbows and tees) failed due to the concentration of nonlinear behavior. Therefore, in this study, the limit state was defined as leakage, and an in-plane cyclic loading test was conducted in order to quantitatively express the failure criteria for the SCH40 6-inch carbon steel pipe elbow due to low-cycle fatigue failure. The leakage line and low-cycle fatigue curves of the SCH40 6-inch carbon steel pipe elbow were presented based on the test results. In addition, the limit state was quantitatively expressed using the damage index, based on the combination of ductility and energy dissipation. The average values of the damage index for the 6-inch pipe elbow calculated using the force−displacement (P–D) and moment−relative deformation angle (M–R) relationships were found to be 10.91 and 11.27, respectively.

Dynamic Testing of High Density Polyethylene Vent and Drain Configurations

2012 ◽  
Author(s):  
Douglas Munson ◽  
Timothy M. Adams ◽  
Shawn Nickholds
Keyword(s):  
Carbon Steel ◽  
High Density Polyethylene ◽  
Nuclear Power ◽  
Power Plants ◽  
Dynamic Testing ◽  
High Density ◽  
Steel Pipe ◽  
Labor Costs ◽  
Service Water ◽  
Hdpe Pipe

For corroded piping in low temperature systems, such as service water systems in nuclear power plants, replacement of carbon steel pipe with high density polyethylene (HDPE) pipe is a cost-effective solution. HDPE pipe can be installed at much lower labor costs than carbon steel pipe, and HDPE pipe has a much greater resistance to corrosion. This paper presents the results of the seismic testing of selected vent and drain configurations. This testing was conducted to provide proof of the conceptual design of HDPE vent and drain valve configurations. A total of eight representative models of HDPE vent and drain assemblies were designed. The models were subjected to seismic SQURTS spectral acceleration up to maximum shake table limits. The test configurations were then checked for leakage and operability of the valves. The results for these tests, along with the test configurations, are presented. Also presented are the acceleration data observed at various points on the test specimens.

Evaluation of Wall-Thinning in Pipes Using Laser-Generated Guided Waves

2006 ◽  
Vol 326-328 ◽  
pp. 705-708
Author(s):  
Jong Ho Park ◽  
Joon Hyun Lee ◽  
Min Rae Lee
Keyword(s):  
Carbon Steel ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Guided Waves ◽  
Single Mode ◽  
Steel Pipe ◽  
Wall Thinning ◽  
Structural Fracture ◽  
Local Wall Thinning

Local wall thinning is one of the major causes for the structural fracture of pipes of nuclear power plants. Therefore, assessment of local wall thinning due to corrosion is an important issue in nondestructive evaluation for the integrity of nuclear power plants. In this study, lasergenerated guided waves were used for pipe inspection, where a laser beam illuminated through linear slit array was used as the transmitter and the air-coupled transducer was used as the receiver. Slits was used in order to enhance the mode-selectivity of guided waves, since the space of slits is equal to the wavelength of the generated wave. The air-coupled transducer detected the selected single mode by turning its detection angle that was calculated from the relations between the wave propagation velocity in air and the phase velocity in dispersion curves. Experimental results for a 4- mm thick carbon steel pipe showed that the detection of the specific mode was useful in the distinction of the wall-thinning thickness in the carbon steel pipe.

RevospECT® PRO Software for Automated Interpretation of Results and Automatic Tracking of Defects during Eddy Current Inspection of Heat Exchangers

NDT World ◽  
2021 ◽  
pp. 21-23
Author(s):  
Denis Shorikov ◽  
Aleksandra Melnikova
Keyword(s):  
Eddy Current ◽  
Heat Exchangers ◽  
Nuclear Power ◽  
Power Plants ◽  
Level Ii ◽  
Unique System ◽  
Self Study ◽  
Software Product ◽  
Eddy Current Inspection ◽  
Automated Interpretation

The eddy current NDT method has been successfully used at Russian nuclear power plants for more than 20 years, but there are still problems with assessing the reliability of the results. Software product of Zetec Inc. (USA) RevospECT® Pro allows you to automatically analyze and compare the monitoring results of the same object, obtained at different times, which allows you to track the development of defects. Thanks to a unique system for collecting and analyzing information, its ability to self-study, RevospECT® Pro is able to make decisions on its own, replacing the level II specialist in full.

Load Factor for Evaluating Non-Planar Flaws in Carbon Steel Piping Using Limit Load Methodology

2016 ◽  
Author(s):  
Phuong H. Hoang
Keyword(s):  
Carbon Steel ◽  
Nuclear Power ◽  
Power Plants ◽  
Pipe Wall ◽  
Local Strain ◽  
Limit Load ◽  
Evaluation Methodology ◽  
Load Factor ◽  
Wall Thinning ◽  
Steel Piping

Non-planar flaw such as local wall thinning flaw is a major piping degradation in nuclear power plants. Hundreds of piping components are inspected and evaluated for pipe wall loss due to flow accelerated corrosion and microbiological corrosion during a typical scheduled refueling outage. The evaluation is typically based on the original code rules for design and construction, and so often that uniformly thin pipe cross section is conservatively assumed. Code Case N-597-2 of ASME B&PV, Section XI Code provides a simplified methodology for local pipe wall thinning evaluation to meet the construction Code requirements for pressure and moment loading. However, it is desirable to develop a methodology for evaluating non-planar flaws that consistent with the Section XI flaw evaluation methodology for operating plants. From the results of recent studies and experimental data, it is reasonable to suggest that the Section XI, Appendix C net section collapse load approach can be used for non-planar flaws in carbon steel piping with an appropriate load multiplier factor. Local strain at non-planar flaws in carbon steel piping may reach a strain instability prior to net section collapse. As load increase, necking starting at onset strain instability leads to crack initiation, coalescence and fracture. Thus, by limiting local strain to material onset strain instability, a load multiplier factor can be developed for evaluating non-planar flaws in carbon steel piping using limit load methodology. In this paper, onset strain instability, which is material strain at the ultimate stress from available tensile test data, is correlated with the material minimum specified elongation for developing a load factor of non-planar flaws in various carbon steel piping subjected to multiaxial loading.

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