Application of Microfocus Rod Anode in Qualification of Tube-to-Tube-Sheet Welds in Steam Generators

2010 ◽  
Vol 132 (5) ◽  
Author(s):  
P. R. Vaidya ◽  
D. Narain ◽  
Sunil Kumar
Keyword(s):  
Heat Exchangers ◽  
Radial Direction ◽  
Axial Direction ◽  
Tube Sheet ◽  
Steam Generators ◽  
Leak Test ◽  
X Ray ◽  
Nondestructive Examination ◽  
Macroscopic Examination ◽  
Random Section

Tube-to-tube-sheet (TTS) welds, occurring in heat exchangers, condensers, and steam generators, are exempted from volumetric nondestructive examination, such as radiography or ultrasonic tests, due to their geometry. An approach of stricter quality control at qualification stage is adopted, apart from tests like liquid penetrant test and leak test applied to production welds. For qualification purpose, a mock up block is destructively examined for weld quality by microscopy and/or macroscopic examination. This paper shows that it is possible to carry out radiography of TTS welds using microfocal x-ray unit with back-throw type rod anode attachment, which sends radiation in nearly radial direction. It demonstrates the use of the same technique for the qualification weld block also. It further shows that the qualification weld slices can be radiographed in axial direction to enable 100% volumetric examination. Besides, it will make metallography more effective and meaningful; instead of a random section, it can then address the plane with a flaw using the help from radiography test. The paper suggests that the code adopt radiography in addition to metallography during qualification for better quality assurance.

Analysis of Vibration Caused by Electromagnetic Force on Stator End-Winding of Large Dry Submersible Motor

2013 ◽  
Vol 416-417 ◽  
pp. 428-432
Author(s):  
Li Shan ◽  
Xiao Wei Cheng ◽  
Yong Fang ◽  
Xiao Hua Bao
Keyword(s):  
Electromagnetic Field ◽  
Steady State ◽  
Transition State ◽  
Electromagnetic Force ◽  
Radial Displacement ◽  
Radial Direction ◽  
Axial Direction ◽  
Axial Displacement ◽  
Force Density ◽  
Submersible Motor

This paper investigates the vibration which caused by electromagnetic on the stator end-winding of the large dry submersible motor. Firstly, the electromagnetic field which included transition state and steady state is researched by 3-D FEM. Secondly, the electromagnetic force which lead to vibrations of end-winding is calculated by numerical method, it can be obtained that where endured the largest force density along the slant part of end-winding. Finally, the radial displacement and the axial displacement of the slant part which caused by vibrations is studied, the analysis results show that the axial displacement is larger than the amplitude of radial displacement. It indicates that the slant part of end-winding will be more easily damaged at axial direction than radial direction.

Influence of Structure of Electrode Array on Logging. The Resistivity Logging Response through Casing of Structure of Electrode Array

2014 ◽  
Vol 1006-1007 ◽  
pp. 990-993
Author(s):  
An Ling Wang ◽  
Fu Ping Liu
Keyword(s):  
Radial Direction ◽  
Recurrence Formula ◽  
Electrode Array ◽  
Axial Direction ◽  
Formation Model ◽  
Line Equation ◽  
Metal Casing ◽  
Resistivity Logging ◽  
Important Significance ◽  
Computing Speed

Because difference of formation model affects the potential distribution on the metal casing, the resistivity logging response can be obtained through casing by measuring the potentials on the metal casing. In fact, the logging responses are the comprehension effects of complex formation and metal casing, so that in the coefficients of transmission line equation (TLE), we should consider the effects of formation model in radial-direction. In the following, for the formation taking on six-layer in axial-direction, and step in radial-direction, the resistivity logging responses through casing are researched and discussed, and given the recurrence formula to compute potential. Draw the curve of the resistivity logging response through casing of six-layer formations. The conductivity of formation is computed is very approximating to that of formation model. The computing examples also show that this method has a fast computing speed (the run time of computing example is less than 1s). For analysis the logging response of six-layers and block formations, and the design of logging instruments, the research is important significance and useful.

Residual Stress Measurements in Inconel Alloy 600 Tubing Using an Advanced X-ray Instrument and Cr Kβ Radiation

1984 ◽  
Vol 28 ◽  
pp. 275-279
Author(s):  
D. P. Ivkovich ◽  
C. O. Ruud ◽  
D. J. Snoha
Keyword(s):  
Residual Stresses ◽  
Heat Exchangers ◽  
Nuclear Reactors ◽  
Electric Power Research Institute ◽  
Alloy 600 ◽  
State University ◽  
Pennsylvania State University ◽  
Inconel Alloy ◽  
X Ray ◽  
Hoop Stresses

Residual stresses in an inconel alloy 600 U-bend tube, used in heat exchangers in nuclear reactors, were studied using an advanced x-ray instrument developed at The Pennsylvania State University. The work funded by the Electric Power Research Institute (EPRI) mapped both the axial and circumferential (hoop) stresses on the outside surface of the tube. The residual stresses, inherent in the fabrication of the U-bend tubes, are a major contributor to stress corrosion cracking.

Proven Concepts for LLW-Treatment of Large Components for Free-Release and Recycling

2007 ◽  
Author(s):  
Lena Bergstro¨m ◽  
Maria Lindberg ◽  
Anders Lindstro¨m ◽  
Bo Wirendal ◽  
Joachim Lorenzen
Keyword(s):  
Steam Generator ◽  
Heat Exchangers ◽  
Tube Bundle ◽  
Pilot Project ◽  
Initial Weight ◽  
Steam Generators ◽  
Huge Number ◽  
Material Recycling ◽  
Waste Production ◽  
Sampling Program

This paper describes Studsvik’s technical concept of LLW-treatment of large, retired components from nuclear installations in operation or in decommissioning. Many turbines, heat exchangers and other LLW components have been treated in Studsvik during the last 20 years. This also includes development of techniques and tools, especially our latest experience gained under the pilot project for treatment of one full size PWR steam generator from Ringhals NPP, Sweden. The ambition of this pilot project was to minimize the waste volumes for disposal and to maximize the material recycling. Another objective, respecting ALARA, was the successful minimization of the dose exposure to the personnel. The treatment concept for large, retired components comprises the whole sequence of preparations from road and sea transports and the management of the metallic LLW by segmentation, decontamination and sorting using specially devised tools and shielded treatment cell, to the decision criteria for recycling of the metals, radiological analyses and conditioning of the residual waste into the final packages suitable for customer-related disposal. For e.g. turbine rotors with their huge number of blades the crucial moments are segmentation techniques, thus cold segmentation is a preferred method to keep focus on minimization of volumes for secondary waste. Also a variety of decontamination techniques using blasting cabinet or blasting tumbling machines keeps secondary waste production to a minimum. The technical challenge of the treatment of more complicated components like steam generators also begins with the segmentation. A first step is the separation of the steam dome in order to dock the rest of the steam generator to a specially built treatment cell. Thereafter, the decontamination of the tube bundle is performed using a remotely controlled manipulator. After decontamination is concluded the cutting of the tubes as well as of the shell is performed in the same cell with remotely controlled tools. Some of the sections of steam dome shell or turbine shafts can be cleared directly for unconditional reuse without melting after decontamination and sampling program. Experience shows that the amount of material possible for clearance for unconditional use is between 95 – 97% for conventional metallic scrap. For components like turbines, heat exchangers or steam generators the recycling ratio can vary to about 80–85% of the initial weight.

Mechanical Model of Non-Magnetic Particles Centrifugal Separation in Magnetic Fluid

2013 ◽  
Vol 820 ◽  
pp. 225-228
Author(s):  
Tong Li ◽  
Jing Tao Wei ◽  
Ji Li
Keyword(s):  
Centrifugal Force ◽  
Magnetic Fluid ◽  
Mechanical Model ◽  
Radial Direction ◽  
Magnetic Particles ◽  
Axial Direction ◽  
Separation Mechanism ◽  
Centrifugal Separation

It is difficult to sort fine non-magnetic particles only by the buoyancy of magnetic fluid. Therefore, based on the magneto hydrostatic separation, the centrifugal separation under the condition of centrifugal force would be an effective method to improve the efficiency. By establishing the mechanical model of centrifugal separation in magnetic fluid, this paper analyzes the kinematical equations of non-magnetic particles in three directionstangential direction, radial direction, and axial direction, and then theoretically explores the separation mechanism of this method.

Preparation of Rare Earth Doped ZnO Nano Particles and Investigation on their Optical Properties

2011 ◽  
Vol 230-232 ◽  
pp. 992-995 ◽  
Author(s):  
Bing Cheng Xia ◽  
Rui Fang Zhang ◽  
Hua An ◽  
Yan Hong Zhao ◽  
Xiao Jing Wang
Keyword(s):  
Rare Earth ◽  
Axial Direction ◽  
Nano Particles ◽  
Ultraviolet Region ◽  
X Ray ◽  
Transmission Electron ◽  
Doped Zno ◽  
Rare Earth Doped ◽  
La Doped ◽  
Diffuse Spectrum

Rare earth doped ZnO particles were synthesized by low temperature hydrothermal method. They showed fine pin-shaped growing along the C axial direction with the diameter about 9-48 nm. The structures of zinc oxide and La doped ZnO were characterized through X-ray powder diffraction (XRD), transmission electron microscope (TEM), Uv-vis diffuse spectrum (UV – vis DRS). Our results indicated that the doping of La results in the crystal cell of ZnO inflating, the band gap shift up to the ultraviolet region with the increase of La doping concentration.

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