An Online Monitoring Technique for Long-Term Operation Using Guided Waves Propagating in Steel Pipe

2017 ◽  
Vol 3 (4) ◽  
Author(s):  
Francesco Bertoncini ◽  
Mauro Cappelli ◽  
Francesco Cordella ◽  
Marco Raugi
Keyword(s):  
Power Plants ◽  
Guided Waves ◽  
Variable Temperature ◽  
Complex Structure ◽  
Guided Wave ◽  
Ultrasonic Waves ◽  
Nuclear Industry ◽  
Steel Pipe ◽  
Primary Circuit ◽  
Term Operation

Nondestructive testing (NDT) techniques are widely used as a reliable way for preventing failures and helping in the maintenance design and operation of critical infrastructures and complex industrial plants as nuclear power plants (NPPs). Among the NDT techniques, guided waves (GWs) are a very promising technology for such applications. GWs are structure-borne ultrasonic waves propagating along the structure confined and guided by its geometric boundaries. Testing using GWs is able to find defect locations through long-range screening using low-frequency waves (from 5 to 250 kHz). The technology is regularly used for pipe testing in the oil and gas industry. In the nuclear industry, regulators are working to standardize monitoring and inspection procedures. To use the technology inside an active plant, operators must solve issues like high temperatures (up to more than 300 °C inside a light-water reactor's primary piping), high wall thickness of components in the primary circuit, and characteristic defect typologies. Magnetostrictive sensors are expected to overcome such issues due to their physical properties, namely, robust constitution and simplicity. Recent experimental results have demonstrated that magnetostrictive transducers can withstand temperatures close to 300 °C. In this paper, the GW technology will be introduced in the context of NPPs. Some experimental tests conducted using such a methodology for steel pipe having a complex structure will be described, and open issues related to high-temperature guided wave applications (e.g., wave velocity or amplitude fluctuations during propagation in variable temperature components) will be discussed.

Guided Waves As an Online Monitoring Technology for Long Term Operation in NPPs: New Experimental Results on a Steam Discharge Pipe

2017 ◽  
Author(s):  
Francesco Bertoncini ◽  
Mauro Cappelli ◽  
Francesco Cordella ◽  
Marco Raugi
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Guided Waves ◽  
Complex Structure ◽  
Theoretical Background ◽  
Guided Wave ◽  
Experimental Results ◽  
Primary Circuit ◽  
Term Operation

Guided Wave (GW) testing is regularly used for finding defect locations through long range screening using low-frequency waves (from 5 to 250 kHz) [1]-[3]. Magnetostrictive sensors can overcome some issues, which usually limit the application to Nuclear Power Plants (NPPs) [4], like for example, high temperatures [5]-[6], high wall thickness of components in the primary circuit, and characteristic defect typologies. The authors have already shown the basic theoretical background, some simulations and some first experimental results concerning a real steel pipe, used for steam discharge, having a complex structure. Collecting more experimental data with a novel test campaign on the same pipe its complex structure results as a useful benchmark for the application of GWs as Non Destructive Techniques (NDT). Experimental measures using a symmetrical probe and a local probe in different configurations (pulse-echo and pitch-catch) indicate that GW testing with magnetostrictive sensors can be reliably applied to long-term monitoring of NPP components.

Guided Waves as an Online Monitoring Technology for Long-Term Operation in Nuclear Power Plants: Experimental Results on a Steam Discharge Pipe

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Mauro Cappelli ◽  
Francesco Cordella ◽  
Francesco Bertoncini ◽  
Marco Raugi
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Guided Waves ◽  
Complex Structure ◽  
Theoretical Background ◽  
Guided Wave ◽  
Experimental Results ◽  
Term Operation

Guided wave (GW) testing is regularly used for finding defect locations through long-range screening using low-frequency waves (from 5 to 250 kHz). By using magnetostrictive sensors, some issues, which usually limit the application to nuclear power plants (NPPs), can be fixed. The authors have already shown the basic theoretical background and simulation results concerning a real steel pipe, used for steam discharge, with a complex structure. On the basis of such theoretical framework, a new campaign has been designed and developed on the same pipe, and the obtained experimental results are now here presented as a useful benchmark for the application of GWs as nondestructive techniques. Experimental measures using a symmetrical probe and a local probe in different configurations (pulse-echo and pitch-catch) indicate that GW testing with magnetostrictive sensors can be reliably applied to long-term monitoring of NPPs components.

Guided Waves in Pitch-Catch Configuration: A Theoretical Framework to Steer Toward Experimental Tests

2020 ◽  
Author(s):  
Francesco Cordella ◽  
Mauro Cappelli ◽  
Francesco Bertoncini
Keyword(s):  
Theoretical Analysis ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Guided Waves ◽  
Oil And Gas ◽  
Theoretical Background ◽  
Guided Wave ◽  
Nuclear Industry ◽  
Discharge Pipe

Abstract Guided waves testing allows a long-range screening in pipes of different types and represents an effective and powerful non-destructing technique for defect detections using a limited number of points of measures. This kind of testing hence represents an appealing technique not only for the Oil and Gas industries but also for the Nuclear Industry, in particular regarding the Structural Health Monitoring of Nuclear Power Plants components. Another point of strength of this technique is that it can be applied in different configurations as the pulse-echo (the same probe is used both for transmission and signal receiving) or the pitch-catch (two symmetric probes are used one for the signal transmission and the second one for the signal receiving). In this way, the guided wave testing with magnetostrictive sensors can be reliably used for the short and long-term monitoring of Nuclear Power Plants components. The objective of this paper is to establish a strong theoretical background to pave the way for a robust experimental investigation. In particular, after the characterization through a general theoretical analysis, the focus is on a real steam discharge pipe with a high mechanical complexity used for many years in a research facility and now dismissed. The experimental method applied is the pitch-catch configuration of two magnetostrictive sensors. Preliminary experimental results conducted on a real complex steam discharge pipe are consistent with the theoretical analysis.

Development of On-Line Health Monitoring System for Pipes in Nuclear Power Plants

2006 ◽  
Vol 321-323 ◽  
pp. 441-444
Author(s):  
Heung Seop Eom ◽  
Sa Hoe Lim ◽  
Jae Hee Kim ◽  
Young H. Kim ◽  
Hak Joon Kim ◽  
...  
Keyword(s):  
Health Monitoring ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Guided Waves ◽  
Guided Wave ◽  
Wave System ◽  
Ultrasonic Guided Wave ◽  
On Line ◽  
Series Of Experiments

This study was aimed at developing an effective method and a system for on-line health monitoring of pipes in nuclear power plants by using ultrasonic guided waves. For this purpose we developed a multi-channel ultrasonic guided wave system for a long-range inspection of pipes and a few techniques which can effectively find defects in pipes. To validate the developed system we performed a series of experiments and analyzed the results.

Study on Damage Mechanism of Pipe Using Ultrasonic Wave and Acoustic Emission Technique

2007 ◽  
Vol 353-358 ◽  
pp. 2415-2418
Author(s):  
Jin Kyung Lee ◽  
Sang Ll Lee ◽  
Joon Hyun Lee
Keyword(s):  
Acoustic Emission ◽  
Carbon Steel ◽  
Ultrasonic Wave ◽  
Guided Waves ◽  
Damage Mechanism ◽  
Ultrasonic Waves ◽  
Steel Pipe ◽  
Thin Wall ◽  
Acoustic Emission Technique ◽  
Velocity Transmission

A study on corrosion evaluation by using ultrasonic waves and acoustic emission technique is presented. The experimental equipment was established to improve the corrosion process of carbon steel pipe. The carbon steel pipe was under 473K temperatures and 10Mpa pressure conditions, and ultrasonic wave and acoustic emission techniques were used to inspect the degree of corrosion after a certain period of time. Ultrasonic bulk waves are limited by the poor time resolution when used in the measurement of corrosion depth in thin wall structures because the corroded surfaces cause unclear echo signal edges. Therefore, in this study, the ultrasonic guided waves were generated on the pipe because the thickness of pipe was thin. Various wave modes were subsequently generated on the pipe to evaluate the implications of corrosion thinning on group velocity, transmission and reflection amplitudes. The amplitudes of the transmitted and the reflected waves are influenced by couplent material. In order to reduce the effect of coupling acoustic emission sensor was used. Acoustic emission technique has lots of parameters to evaluate the corrosion besides amplitude parameter. Among parameters energy, count, and frequency were useful parameters to measure the degree of corrosion inside the carbon steel pipe under 473K temperatures.

Non-Invasive On-Line Monitoring for Nuclear Power Plants Using Guided Waves Propagating in Steel Pipes With Different Types of Structural Complexity

2016 ◽  
Author(s):  
Francesco Bertoncini ◽  
Mauro Cappelli ◽  
Francesco Cordella ◽  
Marco Raugi
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Guided Waves ◽  
Structural Complexity ◽  
Ultrasonic Waves ◽  
Steel Pipes ◽  
Non Invasive ◽  
Different Types ◽  
On Line

On-line monitoring for installed piping in Nuclear Power Plants (NPPs), as well as for Oil & Gas and other kind of plants, is crucial to early detect local ageing effects and locate single defects before they may result in critical failures. All the actions able to prevent failures are of great value especially if non-invasive and allowing an In-Service Inspection (ISI). In particular the Long Term Operation (LTO) and Plant Life Extension (PLEX) may be invalidated from radiation, thermal, mechanical stresses besides their own ageing. Hence on-line monitoring techniques are of much interest especially if they assure the required safety levels and at the same time are simple and cost-effective. Guided Waves (GW) satisfy these requirements since they are structure-borne ultrasonic waves that propagate themselves without interfering along the same pipe structure, which in turns through its geometric boundaries serves as a confining structure for the GW used to test its integrity. The frequencies used for GW testing extend up to 250 kHz, thus allowing a long-range inspection of pipes (tens of meters in favorable circumstances). The experimental conditions (e.g. temperature, complex piping structure, wall thickness, materials) have to be considered since they strongly affect the results but GW generated through magnetostrictive sensors are expected to overcome such issues due to their robustness and positioning ease. In this paper, new experimental tests conducted using the proposed methodology for steel pipes having different types of structural complexity are described.

scholarly journals Prognostics and Health Management in Nuclear Power Plants: An Updated Method-Centric Review With Special Focus on Data-Driven Methods

2021 ◽  
Vol 9 ◽  
Author(s):  
Xingang Zhao ◽  
Junyung Kim ◽  
Kyle Warns ◽  
Xinyan Wang ◽  
Pradeep Ramuhalli ◽  
...  
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Health Management ◽  
Nuclear Industry ◽  
Data Availability ◽  
Data Driven ◽  
Special Focus ◽  
Prognostics And Health Management ◽  
Term Operation

In a carbon-constrained world, future uses of nuclear power technologies can contribute to climate change mitigation as the installed electricity generating capacity and range of applications could be much greater and more diverse than with the current plants. To preserve the nuclear industry competitiveness in the global energy market, prognostics and health management (PHM) of plant assets is expected to be important for supporting and sustaining improvements in the economics associated with operating nuclear power plants (NPPs) while maintaining their high availability. Of interest are long-term operation of the legacy fleet to 80 years through subsequent license renewals and economic operation of new builds of either light water reactors or advanced reactor designs. Recent advances in data-driven analysis methods—largely represented by those in artificial intelligence and machine learning—have enhanced applications ranging from robust anomaly detection to automated control and autonomous operation of complex systems. The NPP equipment PHM is one area where the application of these algorithmic advances can significantly improve the ability to perform asset management. This paper provides an updated method-centric review of the full PHM suite in NPPs focusing on data-driven methods and advances since the last major survey article was published in 2015. The main approaches and the state of practice are described, including those for the tasks of data acquisition, condition monitoring, diagnostics, prognostics, and planning and decision-making. Research advances in non-nuclear power applications are also included to assess findings that may be applicable to the nuclear industry, along with the opportunities and challenges when adapting these developments to NPPs. Finally, this paper identifies key research needs in regard to data availability and quality, verification and validation, and uncertainty quantification.

Application of Metallographic Methods for Thermal Ageing Evaluation on Samples from Primary Piping of NPP

2017 ◽  
Vol 891 ◽  
pp. 60-66
Author(s):  
Jana Petzová ◽  
Martin Březina ◽  
Miloš Baľák ◽  
Mária Dománková ◽  
Ľudovít Kupča
Keyword(s):  
Material Properties ◽  
Nuclear Power ◽  
Power Plants ◽  
Operating Temperature ◽  
Thermal Ageing ◽  
Primary Circuit ◽  
Degradation Mechanisms ◽  
Reliable Operation ◽  
Term Operation

During a long-term operation of nuclear power plants (NPP), the changes of structural material properties occur. To ensure the safe and reliable operation, it is necessary to monitor and evaluate these changes mainly on components from primary circuit of NPPs. One of the dominant ageing mechanisms of NPP components besides the radiation embrittlement and the fatigue loads is the thermal ageing. The thermal ageing is the temperature, material and time dependent degradation mechanisms due to long-term exposure at the operating temperature of 570 K.This paper describes the project for thermal ageing monitoring at primary piping in NPP Bohunice Unit 3. There are summarized the results obtained from evaluation of original primary piping material.

Cumulative Second Harmonic Generation of Ultrasonic Guided Waves Propagation in Tube-Like Structure

2016 ◽  
Vol 24 (03) ◽  
pp. 1650011 ◽  
Author(s):  
Weibin Li ◽  
Mingxi Deng ◽  
Younho Cho
Keyword(s):  
Second Harmonic Generation ◽  
Harmonic Generation ◽  
Polyvinylidene Fluoride ◽  
Guided Waves ◽  
Second Harmonic ◽  
Cumulative Effect ◽  
Guided Wave ◽  
Ultrasonic Waves ◽  
Material Nonlinearity ◽  
Fundamental Wave

Second harmonic generation of ultrasonic waves propagating in unbounded media and plate-like structure has been vigorously studied for tracking material nonlinearity, however, second harmonic guided wave propagation in tube-like structures is rarely studied. Considering that second harmonics can provide sensitive information for structural health condition, this paper aims to study the second harmonic generation of guided waves in metallic tube-like structures with weakly nonlinearity. Perturbation method and modal analysis approach are used to analyze the acoustic field of second harmonic solutions. The conditions for generating second harmonics with cumulative effect are provided in present investigation. Flexible polyvinylidene fluoride comb transducers are used to measure fundamental wave modes and second harmonic ones. The work experimentally verifies that the second harmonics of guided waves in pipe have a cumulative effect with propagation distance. The proposed procedure of this work can be applied to detect material nonlinearity due to damage mechanism in tube-like structure.

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