scholarly journals Diagnosing nuclear power plant pipe wall thinning due to flow accelerated corrosion using a passive, thermal non-destructive evaluation method: Feasibility assessment via numerical experiments

2022 ◽  
Vol 386 ◽  
pp. 111542
Author(s):  
Chris Nash ◽  
Pranav Karve ◽  
Douglas Adams
Keyword(s):  
Power Plant ◽  
Numerical Experiments ◽  
Nuclear Power ◽  
Evaluation Method ◽  
Pipe Wall ◽  
Accelerated Corrosion ◽  
Feasibility Assessment ◽  
Non Destructive Evaluation ◽  
Flow Accelerated Corrosion ◽  
Non Destructive

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.

An Analytical Solution for Piping Non-Planar Flaws

2014 ◽  
Author(s):  
Phuong H. Hoang ◽  
Chee W. Mak
Keyword(s):  
Cross Section ◽  
Nuclear Power ◽  
Pipe Wall ◽  
Axial Loading ◽  
Limit Load ◽  
Element Analysis ◽  
Axial Section ◽  
Accelerated Corrosion ◽  
Pressure Limit ◽  
Flow Accelerated Corrosion

Recent studies on the effect of multi-axis loading on piping non-planar flaws indicate that the ASME Section XI, Appendix C pressure limit load approach for planar axial flaws can be used for evaluation of non-planar flaws provided that the effect of multi axial loading is to be considered. Finite element analysis results presented in this paper also indicate that bending limit load for planar circumferential flaws can be used for evaluation of non-planar flaws subjected multi axial loading. These studies used idealized uniformly thin rectangular flaws whose projected flaw geometry on pipe cross section and on pipe axial section are the same as the circumferential flaw geometry and the axial flaw geometry defined ASME B&PV, Section XI Appendix C. Sample problems with actual pipe wall thinning flaws due to flow accelerated corrosion and pitting in nuclear power plant are utilized for a comparison of the proposed methodology with various methodologies currently used by the industry for locally thinning pipe flaw evaluations.

scholarly journals On-Line Monitoring of Pipe Wall Thinning by a High Temperature Ultrasonic Waveguide System at the Flow Accelerated Corrosion Proof Facility

Sensors ◽  
2019 ◽  
Vol 19 (8) ◽  
pp. 1762 ◽  
Author(s):  
Se-beom Oh ◽  
Yong-moo Cheong ◽  
Dong-jin Kim ◽  
Kyung-mo Kim
Keyword(s):  
High Temperature ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Pipe Wall ◽  
Accelerated Corrosion ◽  
On Line ◽  
Waveguide System ◽  
Flow Accelerated Corrosion ◽  
Shear Horizontal

Pipe wall thinning and leakage due to flow accelerated corrosion (FAC) are important safety concerns for nuclear power plants. A shear horizontal ultrasonic pitch/catch technique was developed for the accurate monitoring of the pipe wall-thickness. A solid couplant should be used to ensure high quality ultrasonic signals for a long operation time at an elevated temperature. We developed a high temperature ultrasonic thickness monitoring method using a pair of shear horizontal transducers and waveguide strips. A computer program for on-line monitoring of the pipe thickness at high temperature was also developed. Both a conventional buffer rod pulse-echo type and a developed shear horizontal ultrasonic waveguide type for a high temperature thickness monitoring system were successfully installed to test a section of the FAC proof test facility. The overall measurement error was estimated as ±15 μm during a cycle ranging from room temperature to 150 °C. The developed waveguide system was stable for about 3300 h and sensitive to changes in the internal flow velocity. This system can be used for high temperature thickness monitoring in all industries as well as nuclear power plants.

Human reliability in non-destructive inspections of nuclear power plant components: modeling and analysis

2019 ◽  
Vol 7 (2B) ◽  
Author(s):  
Vanderley Vasconcelos ◽  
Wellington Antonio Soares ◽  
Raissa Oliveira Marques ◽  
Silvério Ferreira Silva Jr ◽  
Amanda Laureano Raso
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Human Factors ◽  
Nuclear Power ◽  
Power Plants ◽  
Failure Modes ◽  
Cooling System ◽  
Human Reliability ◽  
Non Destructive ◽  
Plant Components

Non-destructive inspection (NDI) is one of the key elements in ensuring quality of engineering systems and their safe use. This inspection is a very complex task, during which the inspectors have to rely on their sensory, perceptual, cognitive, and motor skills. It requires high vigilance once it is often carried out on large components, over a long period of time, and in hostile environments and restriction of workplace. A successful NDI requires careful planning, choice of appropriate NDI methods and inspection procedures, as well as qualified and trained inspection personnel. A failure of NDI to detect critical defects in safety-related components of nuclear power plants, for instance, may lead to catastrophic consequences for workers, public and environment. Therefore, ensuring that NDI is reliable and capable of detecting all critical defects is of utmost importance. Despite increased use of automation in NDI, human inspectors, and thus human factors, still play an important role in NDI reliability. Human reliability is the probability of humans conducting specific tasks with satisfactory performance. Many techniques are suitable for modeling and analyzing human reliability in NDI of nuclear power plant components, such as FMEA (Failure Modes and Effects Analysis) and THERP (Technique for Human Error Rate Prediction). An example by using qualitative and quantitative assessesments with these two techniques to improve typical NDI of pipe segments of a core cooling system of a nuclear power plant, through acting on human factors issues, is presented.

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