scholarly journals A Short-Time Approach for Fatigue Life Evaluation of AISI 347 Steel for Nuclear Power Energy Applications

2021 ◽  
Vol 11 (23) ◽  
pp. 11405
Author(s):  
Tobias Bill ◽  
Ruth Acosta ◽  
Christian Boller ◽  
Kai Donnerbauer ◽  
Lukas Lücker ◽  
...  

AISI 347 austenitic steel is, as an example, used in nuclear energy piping systems. Piping filled with superheated steam or cooled water is particularly exposed to high stresses, whereupon local material properties in the pipes can change significantly, especially in the case of additional corrosive influences, leading to aging of the material. In the absence of appropriate information, such local material property variations are currently covered rather blanketly by safety factors set during the design of those components. An increase in qualified information could improve the assessment of the condition of such aged components. As part of the collaborative project “Microstructure-based assessment of the maximum service life of core materials and components subjected to corrosion and fatigue (MiBaLeB)”, the short-time procedure, StrainLife, was developed and validated by several fatigue tests. With this procedure, a complete S–N curve of a material can be determined on the basis of three fatigue tests only, which reduces the effort compared to a conventional approach significantly and is thus ideal for assessing the condition of aged material, where the material is often rare, and a cost-effective answer is often very needed. The procedure described is not just limited to traditional parameters, such as stress and strain, considered in destructive testing but rather extends into parameters derived from non-destructive testing, which may allow further insight into what may be happening within a material’s microstructure. To evaluate the non-destructive quantities measured within the StrainLife procedure and to correlate them with the aging process in a material, several fatigue tests were performed on unnotched and notched specimens under cyclic loading at room and elevated temperatures, as well as under various media conditions, such as distilled water and reactor pressure vessel boiling water (BWR) conditions.

2018 ◽  
Vol 170 ◽  
pp. 03005 ◽  
Author(s):  
P. Kauffmann ◽  
M.-A. Ploix ◽  
J.-F. Chaix ◽  
C. Gueudré ◽  
G. Corneloup ◽  
...  

The inspection and control of sodium-cooled fast reactors (SFR) is a major issue for the nuclear industry. Ultrasonic solutions are under study because of the opacity of liquid sodium. In this paper, the use of leaky Lamb waves is considered for non-destructive testing (NDT) on parallel and immersed structures assimilated as plates. The first phase of our approach involved studying the propagation properties of leaky Lamb waves. Equations that model the propagation of Lamb waves in an immersed plate were solved numerically. The phase velocity can be experimentally measured using a two dimensional Fourier transform. The group velocity can be experimentally measured using a short-time Fourier transform technique. Attenuation of leaky Lamb waves is mostly due to the re-emission of energy into the surrounding fluid, and it can be measured by these two techniques.


2019 ◽  
Vol 9 (1) ◽  
pp. 3778-3781
Author(s):  
M. S. Mohammed ◽  
K. Ki-Seong

Ultrasonic non-destructive testing signal can be decomposed into a set of chirplet signals, which makes the chirplet transform a fitting ultrasonic signal analysis and processing method. Moreover, compared to wavelet transform, short-time Fourier transform and Gabor transform, chirplet transform is a comprehensive signal approximation method, nevertheless, the former methods gained more popularity in the ultrasonic signal processing research. In this paper, the principles of the chirplet transform are explained with a simplified presentation and the studies that used the transform in ultrasonic non-destructive testing and in structural health monitoring are reviewed to expose the existing applications and motivate the research in the potential ones.


Author(s):  
F. Hedin ◽  
J. C. Legendre

Lifetime management of EDF PWR vessels and pipings are one of the main technical key points of safety and competitivness. This paper describes the EDF global approach in this field, which is applied to the nuclear fleet i.e 58 nuclear power plants, and particularly to the first 34 three loops, as far as lifetime is concerned: • operating procedures and routine maintenance, special maintenance and ten years safety reassessment, • engineering analysis, based on feed back experience, scientific knowledge, degradations mechanisms, causes and consequences management, • operating loadings decrease, • complementary deterministic and cost-benefit analysis, • fit for service justifications, • anticipation strategy to prepare future, based on Non Destructive Testing investigations, ability to repair and/or to replace components, in situ expertises, ... Some examples are given: lifetime management of reactor vessels heads and bottom penetrations of pressure vessels, fit for service of cast stainless steel primary pipings, primary nozzles and auxiliary pipings special maintenance.


2020 ◽  
Vol 6 (8) ◽  
pp. 76
Author(s):  
Claudia Daffara ◽  
Riccardo Muradore ◽  
Nicola Piccinelli ◽  
Nicola Gaburro ◽  
Tullio de Rubeis ◽  
...  

Three-dimensional (3D) imaging and infrared (IR) thermography are powerful tools in many areas in engineering and sciences. Their joint use is of great interest in the buildings sector, allowing inspection and non-destructive testing of elements as well as an evaluation of the energy efficiency. When dealing with large and complex structures, as buildings (particularly historical) generally are, 3D thermography inspection is enhanced by Unmanned Aerial Vehicles (UAV—also known as drones). The aim of this paper is to propose a simple and cost-effective system for aerial 3D thermography of buildings. Special attention is thus payed to instrument and reconstruction software choice. After a very brief introduction to IR thermography for buildings and 3D thermography, the system is described. Some experimental results are given to validate the proposal.


Atomic Energy ◽  
2012 ◽  
Vol 113 (1) ◽  
pp. 57-63
Author(s):  
Yu. G. Dragunov ◽  
B. P. Strelkov ◽  
A. A. Arefyev ◽  
A. S. Mokrousov ◽  
N. G. Roshchin

2002 ◽  
Author(s):  
◽  
Kevin M. Dugmore

The experiments and their results contained herein will form the basis for the development of a portable non-destructive testing device for composite structures. This device is to be capable of detecting any of a variety of defects and assessing their severity within a short time


2020 ◽  
Vol 405 ◽  
pp. 165-170
Author(s):  
Michal Kapusňák ◽  
Michal Hajas ◽  
Marek Adamech

By the non-destructive testing of a dissimilar weld joint (DWJ) of cold collector DN 1100 (CC) on a steam generator, indications were found on inner-side cold collector’s surface at the root position of the examined weld. All the identified indications were very similar in shape and form, therefore, it was decided to cut out a part of the damaged site from this type of DWJ DN 1100 and get the obtained ring (real piece of material) for complex metallographic analysis. This paper briefly describes the results and recommendations found for the future reference during the next long‑term operation induced ageing and degradation of critical steam generator parts in NPP Bohunice Unit 4. There are summarized the results obtained from evaluation of original DWJ material.


2021 ◽  
pp. 20-26
Author(s):  
V. M. Ushakov

Topical aspects of non-destructive testing (NDT) of equipment and pipelines of power units of nuclear power plants (NPP) are considered. Non-destructive testing is an integral part of the entire life cycle of a nuclear power plant. Briefly analyzed documentation and types of non-destructive testing at the stage of manufacturing equipment and pipelines. Power of ultrasonic testing of welded joints of pipelines with a thickness of 2 to 6 mm. The main points of drawing up technological maps of non-destructive testing are noted. A brief analysis of the application of non-destructive testing in accordance with the requirements of the regulatory documents of the Russian Federation and the safety standards of the International Atomic Energy Agency is provided. It is shown that in recent years there has been a tendency to expand the role of NDTs from the classical approach of detecting and assessing defects to the use of NDTs in the study of metal degradation and ageing processes during the operation of NPP equipment and pipelines.


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