Effect of Shot Peening on the Surface Oxidation of P92 Steel in the Steam Environment at 600°C

2021 ◽  
Author(s):  
Yuhui Huang ◽  
Fu-Zhen Xuan
Keyword(s):  
Monitoring System ◽  
Nuclear Power ◽  
Power Plants ◽  
Surface Oxidation ◽  
Vibration Monitoring ◽  
Stress History ◽  
P92 Steel ◽  
Industrial Structures ◽  
Fatigue Monitoring ◽  
Vibration Fatigue

Abstract A vibration fatigue monitoring system has been developed by Framatome to assess, in real time, the evolution of industrial structures, systems and components lifetime expectancy. Its originality comes from the fact that only one or a few acceleration measurements are necessary to re-construct the complete stress history in the whole structure, including on welds or bolted connections that could not have been directly instrumented. From this stress history, a fatigue analysis with a rainflow counting algorithm is conducted and the cumulative usage factor of each weld or bolt is determined. The remaining life duration is then estimated. The method has been numerically and experimentally validated in that sense that the reconstructed stress histories were successfully compared to direct stress calculations and measurements. The system was then installed on five industrial structures submitted to transient dynamic excitations. It is expected that it will soon find further applications notably in monitoring vibrations induced during power plants transients that may induce some temporary resonance of piping equipment. Finally, the vibration monitoring system can also be combined with a thermal fatigue monitoring system, many of which are already deployed, at least on nuclear power plants, and the reconstructed stresses might include both thermal and mechanical effects. Installing such a fatigue monitoring on a set of sensitive systems and components could be a valuable brick in the present trend of building digital twins of power plants or other industrial structures.

A Method for Monitoring Vibrational Fatigue of Structure and Components

2021 ◽  
Author(s):  
Nadim Moussallam ◽  
Rainer Ziegler ◽  
Rudolph Juergen ◽  
Steffen Bergholz
Keyword(s):  
Monitoring System ◽  
Nuclear Power ◽  
Power Plants ◽  
Vibration Monitoring ◽  
Stress History ◽  
Industrial Structures ◽  
Digital Twins ◽  
Fatigue Monitoring ◽  
Vibration Fatigue ◽  
Rainflow Counting

Abstract A vibration fatigue monitoring system has been developed by Framatome to assess, in real time, the evolution of industrial structures, systems and components lifetime expectancy. Its originality comes from the fact that only one or a few acceleration measurements are necessary to re-construct the complete stress history in the whole structure, including on welds or bolted connections that could not have been directly instrumented. From this stress history, a fatigue analysis with a rainflow counting algorithm is conducted and the cumulative usage factor of each weld or bolt is determined. The remaining life duration is then estimated. The method has been numerically and experimentally validated in that sense that the reconstructed stress histories were successfully compared to direct stress calculations and measurements. The system was then installed on five industrial structures submitted to transient dynamic excitations. It is expected that it will soon find further applications notably in monitoring vibrations induced during power plants transients that may induce some temporary resonance of piping equipment. Finally, the vibration monitoring system can also be combined with a thermal fatigue monitoring system, many of which are already deployed, at least on nuclear power plants, and the reconstructed stresses might include both thermal and mechanical effects. Installing such a fatigue monitoring on a set of sensitive systems and components could be a valuable brick in the present trend of building digital twins of power plants or other industrial structures.

Environmental Fatigue and Fatigue Monitoring System in Korea

2016 ◽  
Author(s):  
Myung-Hwan Boo ◽  
Kyoung Soo Lee ◽  
Hyun-Su Kim ◽  
Chang-Kyun Oh
Keyword(s):  
Monitoring System ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Structural Integrity ◽  
Safe Operation ◽  
Web Environment ◽  
Nuclear Plants ◽  
Fatigue Monitoring ◽  
License Renewal

In accordance with the recommendation of USNRC and the U.S. license renewal experiences, the effect of reactor coolant environment on the fatigue life has to be considered for the continued operation of operating nuclear power plants as well as for the design of new plants in Korea. The reason is that it is very important to maintain the structural integrity and reliability of the nuclear power plants against the fatigue failure during operation. Fatigue monitoring system has been considered as a practical way to ensure safe operation of the nuclear power plants in terms of the fatigue. The fatigue monitoring system evaluates various plant conditions and their effects on the monitored location to give quantified value that indicates accumulated fatigue damage up to date. From this, the authors have developed a fatigue monitoring system, named NuFMS (Nuclear Fatigue Monitoring System) in web environment and has been being applied widely to Korean nuclear plants. In this paper, overall configuration and characteristics of the NuFMS are described in detail.

Research on Fatigue Monitoring System Development for Nuclear Power Plant

2017 ◽  
Author(s):  
Zhao Chuanli ◽  
Chen Yinqiang ◽  
Xu Feng ◽  
Ji Yuanyuan ◽  
Wang Jiangguo
Keyword(s):  
Monitoring System ◽  
Fatigue Damage ◽  
Nuclear Power ◽  
Power Plants ◽  
System Development ◽  
Monitoring Systems ◽  
Operational Load ◽  
Fatigue Monitoring ◽  
On Line ◽  
The Difference

Fatigue is the major aging mechanism for pipelines and components that are subject to transient during plant operation. In order to avoid abrupt accidents caused by fatigue failure, it is necessary to adopt corresponding techniques to monitor components condition due to fatigue damage. Experience shows that on-line fatigue monitoring system is the most effective way to monitor fatigue damage status of pressure-retaining boundary subjected to operational loads in real-time for NPPs. Several commercial fatigue monitoring systems have been put into application in the nuclear power plants. In this paper, the difference of the international fatigue monitoring systems were compared. As the key technologies of fatigue monitoring system development, the processing of operational load data and the stress influencing function development at monitored locations were researched in the paper. Furthermore, in order to study on the methodologies of the key issues of the system development, the experimental facility was established to improve the knowledge on fatigue monitoring system development for two kinds of input data modules, and the reasonability of the different methods in the study was proved reciprocally. Finally, the on-line fatigue monitoring system for pipelines was established to evaluate actual fatigue damage status.

Development of 1500-r/min 75-Inch Ultra-Long Last Stage Blades for Nuclear Steam Turbine

2017 ◽  
Author(s):  
Deqi Yu ◽  
Jiandao Yang ◽  
Wei Lu ◽  
Daiwei Zhou ◽  
Kai Cheng ◽  
...  
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Large Scale ◽  
Vibration Monitoring ◽  
Steam Turbines ◽  
Element Analysis ◽  
Rotating Blade ◽  
Lifetime Analysis ◽  
Computational Fluid Dynamics Cfd ◽  
Last Stage

The 1500-r/min 1905mm (75inch) ultra-long last three stage blades for half-speed large-scale nuclear steam turbines of 3rd generation nuclear power plants have been developed with the application of new design features and Computer-Aided-Engineering (CAE) technologies. The last stage rotating blade was designed with an integral shroud, snubber and fir-tree root. During operation, the adjacent blades are continuously coupled by the centrifugal force. It is designed that the adjacent shrouds and snubbers of each blade can provide additional structural damping to minimize the dynamic stress of the blade. In order to meet the blade development requirements, the quasi-3D aerodynamic method was used to obtain the preliminary flow path design for the last three stages in LP (Low-pressure) casing and the airfoil of last stage rotating blade was optimized as well to minimize its centrifugal stress. The latest CAE technologies and approaches of Computational Fluid Dynamics (CFD), Finite Element Analysis (FEA) and Fatigue Lifetime Analysis (FLA) were applied to analyze and optimize the aerodynamic performance and reliability behavior of the blade structure. The blade was well tuned to avoid any possible excitation and resonant vibration. The blades and test rotor have been manufactured and the rotating vibration test with the vibration monitoring had been carried out in the verification tests.

A 12 MM/S RMS Screening Vibration Velocity for Pipes Using ANSI-OM3 Standard and Regulatory Design Rules

2005 ◽  
Author(s):  
Se´bastien Caillaud ◽  
Yannick Pons ◽  
Pierre Moussou ◽  
Michae¨l Gaudin
Keyword(s):  
Correction Factor ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Vibration Monitoring ◽  
Vibration Velocity ◽  
Concentrated Mass ◽  
Design Rules ◽  
Velocity Relationship ◽  
Regulatory Design

ASME ANSI-OM3 standard is dedicated to the assessment of piping vibrations for nuclear power plants. It provides an allowable zero-to-peak velocity, which is derived from a stress/velocity relationship, where corrections factors (C1, C2K2, C3, C4 and C5) and an allowable stress σal are introduced. In the ANSI-OM3 standard, the C4 correction factor depends on the pipe layout and on its boundary conditions, and is calculated for a few cases. In a former work, it was proposed to extend this factor to a larger number of pipe setups. Besides, the correction factor C1, which stands for the effect of concentrated mass, is established on a given set-up: a clamped-clamped straight pipe span on its first vibrating mode. C1 is then supposed to be conservative on any piping layout. Finally, allowable velocities derived from the ANSI-OM3 stress/velocity relationship may be very conservative. One way to reduce this conservatism is to introduce regulatory design rules. For a larger set of pipe geometries, a new set of C1 and C4 correction factors are computed using weight and pressure designs. Using these numerical results, allowable velocities can be calculated. Then, we propose here to check if a screening vibration velocity of 12 mm/s rms is fulfilled. For the 181 geometries on 3708, which do not meet the criterion, a seismic design checking is applied. Finally, by this way, 99.7% of the tested geometries, which are supposed to be acceptable with respect to static and seismic designs, display allowable velocities above 12 mm/s rms and the minimum allowable vibration velocity is 11.2 mm/s. This screening vibration velocity of 12 mm/s commonly used for vibration monitoring of piping systems in EDF nuclear power plants is then supported.

scholarly journals Slope monitoring system for nuclear power plants

2019 ◽  
Vol 347 ◽  
pp. 86-94 ◽  
Author(s):  
Yonghee Lee ◽  
Weon-Hack Choi ◽  
Seok-Chul Kim
Keyword(s):  
Monitoring System ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Slope Monitoring

Effects of Flow Accelerated Corrosion on Piping Steady-State Vibration Evaluations

2003 ◽  
Author(s):  
Brian J. Voll
Keyword(s):  
Steady State ◽  
Nuclear Power ◽  
Power Plants ◽  
Pipe Wall ◽  
Vibration Monitoring ◽  
Accelerated Corrosion ◽  
Monitoring Programs ◽  
Wall Thinning ◽  
Piping Systems ◽  
Flow Accelerated Corrosion

Piping steady-state vibration monitoring programs were implemented during preoperational testing and initial plant startup at most nuclear power plants. Evaluations of piping steady-state vibrations are also performed as piping and component failures attributable to excessive vibration are detected or other potential vibration problems are detected during plant operation. Additionally, as a result of increased flow rates in some piping systems due to extended power uprate (EPU) programs at several plants, new piping steady-state vibration monitoring programs are in various stages of implementation. As plants have aged, pipe wall thinning resulting from flow accelerated corrosion (FAC) has become a recognized industry problem and programs have been established to detect, evaluate and monitor pipe wall thinning. Typically, the piping vibration monitoring and FAC programs have existed separately without interaction. Thus, the potential impact of wall thinning due to FAC on piping vibration evaluations may not be recognized. The potential effects of wall thinning due to FAC on piping vibration evaluations are reviewed. Piping susceptible to FAC and piping susceptible to significant steady-state vibrations, based on industry experience, are identified and compared. Possible methods for establishing links between the FAC and vibration monitoring programs and for accounting for the effects of FAC on both historical and future piping vibration evaluations are discussed.

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