Application of ultrasonic wave propagation imaging method to automatic damage visualization of nuclear power plant pipeline

2010 ◽  
Vol 240 (10) ◽  
pp. 3513-3520 ◽  
Author(s):  
Jung-Ryul Lee ◽  
Hyomi Jeong ◽  
Chia Chen Ciang ◽  
Dong-Jin Yoon ◽  
Seung-Suk Lee
Keyword(s):  
Wave Propagation ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Ultrasonic Wave ◽  
Nuclear Power ◽  
Imaging Method ◽  
Ultrasonic Wave Propagation ◽  
Damage Visualization

Damage Imaging of Pipes in Nuclear Power Plants Using Torsional Guided Wave Modes

2013 ◽  
Vol 577-578 ◽  
pp. 661-664
Author(s):  
Zhao Xiang Wei ◽  
Hong Xu ◽  
Hong Yuan Li
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Power Plants ◽  
Guided Waves ◽  
Axial Position ◽  
Imaging Method ◽  
Long Distance ◽  
Torsional Mode ◽  
Damage Imaging

Ultrasonic guided waves can propagate a long distance in pipeline with little attenuation. This means the damage in nuclear power plant can be detected from a remote single position. In the paper, the propagation of the guided waves are analyzed for the nuclear power plant pipes, and the axisymmetric torsional mode T(0,1) is chosen as the detection mode. An imaging method based on the synthetic focusing algorithm is used to obtain the damage information. The method is then verified by the finite element model. Results illustrate that the damage can be detected and located accurately by the damage imaging method. Not only the axial position, but also the circumferential position can be located simultaneously.

scholarly journals FEA-Based Ultrasonic Focusing Method in Anisotropic Media for Phased Array Systems

2021 ◽  
Vol 11 (19) ◽  
pp. 8888
Author(s):  
Seongin Moon ◽  
To Kang ◽  
Soonwoo Han ◽  
Kyung-Mo Kim ◽  
Hyung-Ha Jin ◽  
...  
Keyword(s):  
Wave Propagation ◽  
Ultrasonic Wave ◽  
Elastic Constants ◽  
Grain Orientation ◽  
Phased Array ◽  
Ultrasonic Imaging ◽  
Anisotropic Media ◽  
Imaging Method ◽  
Ultrasonic Wave Propagation ◽  
Propagation Paths

Traditional ultrasonic imaging methods have a low accuracy in the localization of defects in austenitic welds because the anisotropy and inhomogeneity of the welds cause distortion of the ultrasonic wave propagation paths in anisotropic media. The distribution of the grain orientation in the welds influences the ultrasonic wave velocity and ultrasonic wave propagation paths. To overcome this issue, a finite element analysis (FEA)-based ultrasonic imaging methodology for austenitic welds is proposed in this study. The proposed ultrasonic imaging method uses a wave propagation database to synthetically focus the inter-element signal recorded with a phased array system using a delay-and-sum strategy. The wave propagation database was constructed using FEA considering the grain orientation distribution and the anisotropic elastic constants in the welds. The grain orientation was extracted from a macrograph obtained from a dissimilar metal weld specimen, after which the elastic constants were optimized using FEA with grain orientation information. FEA was performed to calculate a full matrix of time-domain signals for all combinations of the transmitting and receiving elements in the phased array system. The proposed approach was assessed for an FEA-based simulated model embedded in a defect. The simulation results proved that the newly proposed ultrasonic imaging method can be used for defect localization in austenitic welds.

MARS-KS Code Analysis of the Pressure Wave Propagation Test 0 Performed at the PMK-2 Test Facility

2014 ◽  
Author(s):  
Xin-Guo Yu ◽  
Ki-Yong Choi ◽  
Chul-Hwa Song ◽  
Istvan Trosztel ◽  
Ivan Toth ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Wave Propagation ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Pressure Wave ◽  
Nuclear Power ◽  
Initial Conditions ◽  
Test Facility ◽  
Plant Safety ◽  
Nuclear Power Plant Safety

The pressure waves might be expected in the nuclear reactor systems due to sudden rupture of a pipe, quick opening or closure of a system valve. If generated, they can result in large mechanical loads on the RPV internal structures and pipelines, threating their integrity. This kind of phenomena is an important issue and a limiting accident case for the nuclear power plant safety, which requires extensive analysis to ensure the nuclear power plant safety. To study these phenomena, four PWP (Pressure Wave Propagation) tests have been performed in the PMK-2 test facility in MTA EK. In addition, these tests have been used to assess the capability of the MARS-KS code in simulating the PWP phenomena. Then, an input model representing the PMK-2 test facility was developed to simulate the tests. The MARS-KS simulation results are then compared with the test results. The comparison shows that the MARS code can well simulate the PWP frequencies and the initial pressure peaks as well. After the qualified assessment, the MARS-KS code is then deployed to conduct the sensitivity analysis on the effect of the break size, break time, coolant initial conditions on the PWP phenomena. The sensitivity analysis on the break sizes shows that the pressure wave amplitude is relevant to the break times: the shorter the break opening time is, the faster the pressure. The sensitivity analysis on the break sizes shows that the larger the break size is, the higher the pressure peak is.

Ultrasonic Wave Propagation Analysis in Cast Stainless Steel with Solidification Grain Structure Predicted by Cellular Automaton Finite Element Approach

2021 ◽  
Author(s):  
Masaki Nagai ◽  
Shan Lin ◽  
Kazuyuki Nakahata
Keyword(s):  
Finite Element ◽  
Stainless Steel ◽  
Wave Propagation ◽  
Cellular Automaton ◽  
Ultrasonic Wave ◽  
Nuclear Power ◽  
Power Plants ◽  
Solidification Structure ◽  
Grain Structure ◽  
Ultrasonic Wave Propagation

Abstract Several components of nuclear power plants are made of cast austenitic stainless steel (CASS) because of its high corrosion resistance and strength. The inservice inspection based on ultrasonic testing (UT) has to be conducted for CASS components in accordance with fitness-for-service codes such as the Japan Society of Mechanical Engineers Rules on Fitness-for-Service for Nuclear Power Plants. However, a high-accuracy evaluation of flaws in CASS components through UT is difficult because the ultrasonic waves are scattered and attenuated by coarse grains and their beam is distorted by the anisotropy resulting from the grain orientations. Numerical simulations are useful and reasonable ways for better understanding the ultrasonic wave propagation behavior in CASS. To effectively achieve this, the simulation model should include a three-dimensional (3D) grain structure. If a casting simulation can predict the solidification structure in a CASS, the wave propagation could be simulated also for a more realistic situation. In this study, we predicted the solidification structure of statically CASS by using a cellular automaton coupled with the finite element method and fed this structure into an explicit finite element model for simulating the propagation of waves emitted by angle beam probes. Afterward, these simulated wave propagations were compared with those measured by a 3D laser Doppler vibrometer, showing almost good agreement between predicted and experimental results.

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