Structural integrity assessments of power plant components: the R5 and R6 procedures

1994 ◽  
Author(s):  
P.J. Budden
Keyword(s):  
Power Plant ◽  
Structural Integrity ◽  
Integrity Assessments ◽  
Plant Components

scholarly journals Accelerated Creep Life Assessment of In-Service Power Plant Components

2019 ◽  
Vol 293 ◽  
pp. 03001
Author(s):  
Saud Hamad Aldajah ◽  
Mohammad Mazedul Kabir ◽  
Mohammad Y. Al-Haik
Keyword(s):  
High Temperature ◽  
Power Plant ◽  
Structural Integrity ◽  
Elevated Temperatures ◽  
Sem Analysis ◽  
Life Assessment ◽  
High Temperature Creep ◽  
Creep Life ◽  
Temperature Creep ◽  
Plant Components

Structural metals used in plant components are subject to aging from a combination of fatigue, creep, and corrosion. Exposure to elevated temperatures promotes creep. Aged metals lose toughness, or the ability to absorb energy at stress above the yield point and cannot endure an occasional high load without fracturing. Creep is one of the most critical factors for determining the structural integrity of components. The main objective of the current study is to assess the remaining creep life of various 20-year old power plant engineering components such as the high temperature fasteners. Due to time constraints, the approach followed in this study was to utilize the accelerated high temperature creep testing in addition to Scanning Electron Microscopy (SEM) analysis to assess the remaining life of 4 different samples. The accelerated high temperature creep tests were conducted at a stress level of 61 MPa and at a temperature of 1000°C for samples Sample 1 (original), Sample 2, Sample 3 and Sample 4; these samples were collected from different parts of the power plant. SEM analysis was carried out for all the samples. The results of the accelerated high temperature tests were compared to similar materials’ theoretical creep data using Larson Miller curve. The Larson Miller actual creep lives of the tested samples were much higher than the experimental ones, which suggest that the samples are critically aged. SEM analysis on the other hand, showed that all samples have high percentage of creep voids

Overview of the JEA Code of Fracture Toughness Requirements for Nuclear Power Plant Components

2006 ◽  
Author(s):  
Minoru Tomimatsu ◽  
Seiji Asada ◽  
Takashi Hirano ◽  
Hideo Kobayashi
Keyword(s):  
Fracture Toughness ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Energy Use ◽  
Evaluation Method ◽  
Structural Integrity ◽  
Charpy Impact ◽  
Test Methods ◽  
Plant Components

The Japan Electric Association Code, JEAC 4206, “Method of Verification Tests of the Fracture Toughness for Nuclear Power Plant Components” was originally published in 1973 in order to prescribe test methods, fracture toughness requirements and acceptance standards for materials used in nuclear power plant components. The code was recently revised so as to incorporate a new method to evaluate the structural integrity of reactor vessels with upper shelf Charpy impact energy (USE) less than 68J, based on the results of the researches performed as national projects by the Japan Power Engineering and Inspection Corporation and so on. In this paper, some contents of the code, which are applicable for reactor vessels, such as J integral based integrity evaluation method for reactor vessels with low USE including predicting J resistance curves (J-R curves) by using USE and temperature, and methods to evaluate integrity against pressurized thermal shock events and to determine pressure temperature limits, are overviewed.

Validation of Constraint-Based Methodology in Structural Integrity: Current Issues and Best Practice Handbook

2002 ◽  
Author(s):  
K.-F. Nilsson ◽  
N. Taylor ◽  
S. Bhandari ◽  
D. Siegele ◽  
D. Lidbury
Keyword(s):  
Power Plant ◽  
Nuclear Power ◽  
Best Practice ◽  
Structural Integrity ◽  
State Of The Art ◽  
Structural Components ◽  
Local Approach ◽  
Ductile Tearing ◽  
Two Parameter ◽  
Plant Components

The paper presents an assessment of existing constraint-based procedures for as-received and aged nuclear power plant components, which has been performed as part of the European project VOCALIST. Current analytical procedures and gaps in understanding and limitations in constraint-based procedures are summarized and a First Best-Practice Handbook for constraint-based procedures is outlined. This handbook is based on case studies provided by the VOCALIST partners. The cases are selected to provide an overview of the state-of-the art methods include two-parameter and local approach analyses for cleavage and ductile tearing of different structural components.

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.

Development of an Integrity Evaluation System on the Basis of Cooperative Virtual Reality Environment for Nuclear Power Plant

2004 ◽  
Author(s):  
J. C. Kim ◽  
J. B. Choi ◽  
Y. H. Choi
Keyword(s):  
Virtual Reality ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Pressure Vessel ◽  
Evaluation System ◽  
Nuclear Power ◽  
Structural Integrity ◽  
Reactor Pressure Vessel ◽  
Virtual Reality Environment ◽  
Reactor Pressure

Since early 1950’s fracture mechanics has brought significant impact on structural integrity assessment in a wide range of industries such as power, transportation, civil and petrochemical industries, especially in nuclear power plant industries. For the last two decades, significant efforts have been devoted in developing defect assessment procedures, from which various fitness-for-purpose or fitness-for-service codes have been developed. From another aspect, recent advances in IT (Information Technologies) bring rapid changes in various engineering fields. IT enables people to share information through network and thus provides concurrent working environment without limitations of working places. For this reason, a network system based on internet or intranet has been appeared in various fields of business. Evaluating the integrity of structures is one of the most critical issues in nuclear industry. In order to evaluate the integrity of structures, a complicated and collaborative procedure is required including regular in-service inspection, fracture mechanics analysis, etc. And thus, experts in different fields have to cooperate to resolve the integrity problem. In this paper, an integrity evaluation system on the basis of cooperative virtual reality environment for reactor pressure vessel which adapts IT into a structural integrity evaluation procedure for reactor pressure vessel is introduced. The proposed system uses Virtual Reality (VR) technique, Virtual Network Computing (VNC) and knowledge based programs. This system is able to support 3-dimensional virtual reality environment and to provide experts to cooperate by accessing related data through internet. The proposed system is expected to provide a more efficient integrity evaluation for reactor pressure vessel.

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