bluuebunny/crossref_metadata_2025 huggingface dataset:
Stress Analyses of Intermediate Heat Transfer Loop
Authors: Oh Chang H. , Kim Eung Soo , Sherman Steven
Published: July 2009

The Department of Energy and the Idaho National Laboratory are developing a Next Generation Nuclear Plant (NGNP) to serve as a demonstration of state-of-the-art nuclear technology. The purpose of the demonstration is two fold 1) efficient low cost energy generation and 2) hydrogen production. Although a next generation plant could be developed as a single-purpose facility dedicated to hydrogen production, early designs are expected to be dual purpose. While hydrogen production and advanced energy cycles are still in its early stages of development, research towards coupling a high temperature reactor with electrical generation and hydrogen production is under way. Many aspects of the NGNP must be researched and developed in order to make recommendations on the final design of the plant. Parameters such as working conditions, cycle components, working fluids, and power conversion unit configurations must be understood. A number of configurations of the power conversion unit were demonstrated in this study. An intermediate heat transport loop for transporting process heat to a High Temperature Steam Electrolysis (HTSE) hydrogen production plant was used. Helium, CO2, and a 80% nitrogen, 20% helium mixture (by weight) were studied to determine the best working fluid in terms cycle efficiency and development cost. In each of these configurations the relative component sizes were estimated for the different working fluids. Parametric studies were carried out on reactor outlet temperature, mass flow, pressure, and turbine cooling. Recommendations on the optimal working fluid for each configuration were made. Engineering analyses were performed for several configurations of the intermediate heat transport loop that transfers heat from the nuclear reactor to the hydrogen production plant. The analyses evaluated parallel and concentric piping arrangements and two different working fluids, including helium and a liquid salt. The thermal-hydraulic analyses determined the size and insulation requirements for the hot and cold leg pipes in the different configurations. Mechanical analyses were performed to determine hoop stresses and thermal expansion characteristics for the different configurations.
Investigation of Effect of Pre-Strain on Very High-Cycle Fatigue Strength of Austenitic Stainless Steels
Authors: Ogawa Takeshi , Nakane Motoki , Masaki Kiyotaka , Hashimoto Shota , Ochi Yasuo , Asano Kyoichi
Published: July 2009

The austenitic stainless steels have excellent mechanical and chemical characteristics and these materials are widely used for the main structural components in the nuclear power plants. A part of structural components using these materials is considered to have strain-history by machining, welding and etc in the process of manufacturing and these parts would be hardened because these materials have a remarkable work-hardening property. On the other hand, conventional studies for the fatigue strength used to be investigated by the results of fatigue tests applying normal specimens without the effect of hardening by pre-strain. This paper describes the effect of large pre-strain on very high cycle fatigue strength of the materials in consideration for the evaluation of strength of actual structures in the nuclear power plants. In order to achieve this purpose, the fatigue tests were carried out with strain hardened specimens. The material served in this study was type SUS316NG. Up to ±20% pre-strain was introduced to the round bar shaped materials by tension and compression load test, and the materials were mechanically machined to the hourglass shaped smooth specimens. On the other hand, the pre-strain of some specimens were introduced after machining so as to study the influence of roughness of the surface of the specimens for the fatigue property. Fatigue tests were conducted by ultrasonic and rotating-bending fatigue test machines and conditions were decided by preliminary examinations to control temperature elevation of the specimen during the fatigue test. The S-N curves obtained from fatigue tests show that increase in magnitude of the pre-strain cause increase in the fatigue strength of the material and this relationship is independent of type of the pre-strains of tension and compression. Though all specimens were fractured by the surface initiated fatigue crack, only one specimen was fractured by the internal crack and so-called “fish-eye” was observed on the fracture surface. However, the internal fracture of the SUS316NG does not cause sudden drop of the fatigue strength. Also, the Vickers hardness tests were carried out to discuss the relationship between fatigue strength and hardness of the pre-strained materials. It is found that the increase in fatigue limit of the pre-strained materials strongly depend on the hardness derived from the indentation size equals to the scale of stage I fatigue crack.
Measurement of Local Flow Parameters in Vertical Upward Bubbly Flow at Normal- and Micro-Gravity Conditions
Authors: Kamura Akihiko , Fukuhara Yutaka , Hazuku Tatsuya , Takamasa Tomoji
Published: July 2009

This study aims at the measurements of the axial developments of flow parameters such as void fraction profile, interfacial area concentration and Sauter mean diameter of adiabatic nitrogen-water bubbly flows in a 9 mm-diameter pipe by using a stereo image-processing method at normal- and micro-gravity conditions. The flow measurements were performed at four axial locations (axial distance from the inlet normalized by the pipe diameter, z/D = 5, 20, 40 and 60) at various flow conditions of superficial gas velocity (0.00840–0.0298 m/s) and superficial liquid velocity (0.138–0.914 m/s). The effect of gravity on radial distribution of bubbles and the axial developments of two-phase flow parameter was discussed in detail based on the obtained data and the visual observation.
Lattice Design of Dedicated Synchrotron for Proton Therapy
Authors: Hosseinzadeh M. , Ghergherechi M. , Feghhi S. A. H. , Mohammadzadeh A. , Afarideh H.
Published: July 2009

A compact model of synchrotron accelerator facility is proposed for the treatment of deep seated tumors with proton therapy. The extracted beam from the existing C-30 cyclotron is first injected into the model of synchrotron. The injected beam is specified with its longitudinal plane as well as its horizontal and vertical emittances. For this design to be compatible with the cyclotron C-30 the synchrotron should be kept compact and the number of magnet components must be low. The modeled synchrotron layout is designed using the computer codes MADX and AGILE in order to accelerate the injection proton ions from 30 MeV to a maximum extraction energy of 250 MeV with magnetic rigidity of 2.433 Tm. In this lattice arrangement with phase advance of about 90 degrees in two horizontal and vertical planes doublet cells are utilized. This ring consists of two long straight sections for RF and injection/extraction equipment, as well as four short straight sections. For chromaticity correction two families of sextupoles are used. To prohibit emittance growth, a matching at injection in longitudinal plane was performed. The proton beam energy spread of 2% can be improved to 0.1% at injection by using the designed achromatic system. For the proton beam acceleration a RF cavity with an approximate voltage of 160 volts with a frequency in the range of 2.3 up to 14 MHz is used.
Gas Magnification of Multi-Gap Resistive Plate Chamber
Authors: Wu Yue-Lei , Hu Hua-Si , Li Yi-Chen
Published: July 2009

A Monte Carlo model, simulated energy deposit in six gaps of multi-gap resistive chamber (MRPC) irradiated by a 6.771Mbq 60Co gamma source, was built in MCNP code. The MRPC primary current, which was too low to be measurable with existing instruments, only was derived from the simulation. The MRPC operation current, after gas avalanche magnifying, was measured employing a PCI-1714A/D DAQ card. The magnification factor, about (0.8±0.12) × 107, was obtained when the operation gas mixture is 5.3% iso-C4H10 and 94.7% C4H2F4, HV is 14kV and the counting rate is about 3Hz/cm2.
Underground Nuclear Power Parks: Power Plant Design Implications
Authors: Mahar James M. , Kunze Jay F. , Myers Carl W.
Published: July 2009

The siting of nuclear power plants underground, along with associated reprocessing, fuel manufacturing, and high level waste disposal facilities offer many advantages. Security costs are substantially less, radiative package transportation issues are eliminated, and political issues of high level waste storage and disposal are largely eliminated. Keeping the site preparation costs to a minimum requires that the underground facilities accommodate several power producing units (nominally 6 GW or more). However, significant redesign and placement of components can make it possible to accomplish most of the underground excavation with tunnel boring machines. These latter issues are addressed in this paper.
Potential Adverse Flow Effects at Nuclear Power Plants
Authors: Chen Pei-Yin , Sekerak Patrick , Scarbrough Thomas , Wu Cheng-Ih
Published: July 2009

In recent years, the nuclear industry experienced adverse flow effects that caused structural damage to safety-related and nonsafety-related components as a result of flow-induced acoustic resonance in both Boiling Water Reactor (BWR) and Pressurized Water Reactor plants. In particular, fatigue failures and cracks in steam dryers occurred in certain BWR plants during the extended power uprate operation with generation of loose parts that can adversely affect safety-related components within the reactor vessel and the reactor coolant system. The acoustic resonance occurs when the main steam line flow exceeds a critical value such that the vortices over the cavity of the closed side branch pipe are excited by the acoustic modes of the stagnant fluid in the branch. The occurrence of this phenomenon is highly dependent on plant-specific operating conditions and the piping as-built configuration. The U.S. nuclear industry has initiated extensive activities to address this phenomenon in BWR plants. The staff of the U.S. Nuclear Regulatory Commission (NRC) has been monitoring generic industry activities, as well as reviewing the evaluation of potential adverse flow effects that might result from power uprates at current operating plants, and during the design certification and licensing of new reactors. This paper discusses operating experience with adverse flow effects at nuclear power plants from the acoustic resonance phenomenon, industry actions to address and resolve the phenomenon, and NRC staff review activities related to this issue.
Non-Linear Design Verification of Nuclear Power Piping According to ASME III NB/NC
Authors: Zeng Lingfu , Jansson Lennart G.
Published: July 2009

A nuclear piping system which is found to be disqualified, i.e. overstressed, in design evaluation in accordance with ASME III, can still be qualified if further non-linear design requirements can be satisfied in refined non-linear analyses in which material plasticity and other non-linear conditions are taken into account. This paper attempts first to categorize the design verification according to ASME III into the linear design and non-linear design verifications. Thereafter, the corresponding design requirements, in particular, those non-linear design requirements, are reviewed and examined in detail. The emphasis is placed on our view on several formulations and design requirements in ASME III when applied to nuclear power piping systems that are currently under intensive study in Sweden.
Overview of EDF Life Cycle Management and Nuclear Asset Management Methodology and Tools
Authors: Hai¨k P. , Fessart K. , Remy E. , Lonchampt J.
Published: July 2009

The long term management of a production asset raises several major issues among which rank the technical management of the plant, its economics and the fleet level perspective one has to adopt. Decision makers are therefore faced with the need to define long term policies (up to the end of asset operation) which take into account multiple criteria including safety (which is paramount) and performance. In this context, EDF “PWR Durability I & II” research projects have consecutively been launched, since 2001, at EDF - Research & Development in order to develop methods and tools for EDF fleet. The aim of this paper is to summarize and analyze the research work that has been performed by EDF - R&D (in the field of decision making for nuclear power plant maintenance and operation) during the past seven year, in order to characterize the issues that have been or could be addressed with the developed methodology and tools. As a result, in this paper, we first remind the reader of the EDF overall methodology for asset management and its adaptations to plant-level life cycle management and to fleet-level component major replacement or capital investment management. We then focus on the three software tools that implement this methodology in order to allow decision makers, in several different contexts (life-cycle management, plant level operation and maintenance optimization, major component replacement ...) to define, evaluate and analyze long term plant operation and maintenance policies, major component replacement policies and capital investment strategies. We also show how the methodology and the software tools were used, from 2003 to 2007, on several pilot case studies. Examples of technical and economic results obtained for two pilot case studies (one at the plant level, the other at the fleet level) are described as well as the kinds of conclusions one can draw from them in order to help decision makers evaluate and analyze long term asset management strategies or compare different plants. We also analyze the added value of probabilistic evaluations and of our “rolling-up” process that allows to take into account interactions between the components of the plant or between the plants. Finally, we propose a classification of issues that can be addressed with our methodology and tools and introduce some perspectives for our future work.
An Semi-Empirical Model of Turbulent Convective Heat Transfer to Fluids at Supercritical Pressure
Authors: Jackson J. Derek
Published: July 2009

Recently, there has been a renewed interest in heat transfer to fluids at supercritical pressure because of the consideration now being given to the Supercritical Pressure Water-cooled Reactor (SPWR). This will supply high temperature ‘steam’ to turbines at pressures well above the critical value. The particular feature of fluids at pressures just above the critical pressure which makes them of special interest is that as they change from being liquid-like to gaseous the transition occurs in a continuous manner over a narrow band of temperature without the discontinuous behaviour encountered when phase occurs in fluids at sub-critical pressure. However, when heat takes place within fluids at supercritical pressure, extreme non-uniformities of physical and transport properties can be present. The governing equations for flow and convective heat transfer have to be written in a form which takes account of the temperature dependence of the properties. They are complicated, highly non-linear and strongly inter-dependent. The proportionality between heat flux and temperature difference found in constant property forced convection no longer exists. Also, the effectiveness of heat transfer can be very sensitive to imposed heat flux. Particular problems arise due to the non-uniformity of density by virtue of the fluid being caused to accelerate where the bulk density is falling or as a consequence of the flow field and turbulence being modified by the influence of buoyancy. Severe impairment on heat transfer can be encountered due to such effects. The requirements for achieving similarity and the approach to the correlation of data on heat transfer to fluids at supercritical pressure are matters that need to be carefully considered and soundly based. This necessitates representing the general form of the governing equations and the boundary conditions in non-dimensional form to identify the parameters that are involved. In this paper, an extended model of turbulent heat transfer to fluids at supercritical pressure is presented which utilises a semi-empirical multiplier to account for the combined effects of flow acceleration and buoyancy.
Warranty Test for a High-Pressure Turbine Retrofit Using Process Data Reconciliation in Accordance With VDI 2048
Authors: Langenstein Magnus , Riehm Steffen , Hansen-Schmidt Jan
Published: July 2009

The mathematical and statistical approach called “process data reconciliation in accordance with VDI 2048 [1, 2]” • calculates thermal reactor power; • performs warranty tests with on-site operational instrumentation only (without additional instrumentation). with an accuracy of approximately 0.4%. Process data reconciliation based on VDI 2048 is a mathematical-statistic approach that makes use of redundant process information. The overall process monitored continuously in this manner therefore provides hourly process information of a quality equal to acceptance measurements [3 – 10]. At a NPP in Germany a warranty test for a high pressure turbine retrofit was performed in 2007 exclusively using this method. In this paper, the approach and the results of the warranty test are described.
The Plant Feature and Performance of DMS (Double MS: Modular Simplified and Medium Small Reactor)
Authors: Kawabata Yukiko , Matsuura Masayoshi , Hirako Shizuka , Hoshi Takashi
Published: July 2009

The Japan Atomic Power Company has initiative in developing the DMS concept as a 400MWe-class light water reactor. The main features of the DMS relative to overcoming the scale demerit are the miniaturization and simplification of systems and equipment, integrated modulation of construction, standardization of equipment layouts and effective use of proven technology. The decrease in primary containment vessel (PCV) height is achieved by reducing the active fuel length of the DMS core, which is about two meters compared with 3.7 meters in the conventional BWR. The short active fuel length reduces the drop in core pressure, and overcomes the natural circulation system. And by using the lower steam velocity in the upper plenum in the reactor pressure vessel (RPV), we can adopt a free surface separation (FSS) system. The FSS eliminates the need for a separator and thus helps minimize the RPV and PCV sizes. In order to improve safety efficiency, developing an Emergency Core Cooling System (ECCS) for the DMS was considered. The ECCS configuration in the DMS was examined to achieve core coverage and economic efficiency from the following. 1: Eliminating high-pressure injection systems. 2: Adopting passive safety-related systems. 3: Optimizing distribution for the systems and power source for the ECCS. In this way the configuration of the ECCS for the DMS was established, providing the same level of safety as the ABWR and the passive systems. Based on the results of Loss of Coolant Accident (LOCA) analysis, core cover can be achieved by this configuration. Therefore, the plant concept was found to offer both economic efficiency and safety.
Research Studies in Support of Nuclear Power Plant Life Management
Authors: Bie´th Michel R. , Contri Paolo
Published: July 2009

The analysis of the plant operating practice in European countries shows a growing interest in plant life management programs (PLIM), integrating nuclear safety, economic and knowledge management issues in operating procedures and tools able to support optimised decision making. Such a trend is considered essential in market economies where optimised asset management is becoming imperative, keeping safety at the highest possible level. It is recognised that only an integrated approach to the management of some key safety and non-safety programs could guarantee full control on the plant assets, providing also invaluable frameworks for refined plant overall safety assessment, even in the long term, beyond the plant design life. The PLIM programs specifically address and control ageing phenomena, support optimisation of maintenance strategies, plan major plant reconstruction works, drive plant staff knowledge management and optimise economic resources. R&D is essential to support this development process of PLIM models, especially in the analysis of both the technical issues related to all types of component ageing, and in the challenging integration of safety and non-safety programs, such as in the case of maintenance optimisation, spare part management, staff ageing, and component obsolescence. The European Commission took important initiatives in contributing and supporting this R&D effort in selected PLIM areas, in the framework of the EURATOM programme, both by “direct actions” i.e. projects managed and executed by its Directorate General Joint Research Centres (JRC) and by indirect actions i.e. funding selected projects, managed by the Directorate General Research (RTD). This paper outlines the JRC’s priorities in the current 7th Framework Programme in relation to R&D tasks for PLIM methods to support the highest safety level at member NPPs and appropriate decision-making tools, also in view of long-term safe operation of the European plants. Some results made available by the on-going research programs are also shortly described, in the areas of PLIM models and operational indicators respectively.
Tensile Strain Capacity of Pipelines for Strain-Based Design
Authors: Liu Bing , Liu X. J. , Zhang Hong
Published: July 2009

Traditional pipeline design methods presented in various codes are usually based on limit stress criteria. However, these methods may be inapposite to modern steels, especially for displacement controlled loads such as ground displacement load. The design of pipelines for plastic strain should account for both tension strain limit and compression strain limit along the axial direction of the pipe. In tension, the issues relate to the failure modes of plastic collapse or fracture. Tensile axial strain of the pipe often results in rupturing. The capacity of tensile axial strain of the pipe is affected by a large number of factors: D/t ratio, Y/T ratio, internal pressure, girth weld effect, and defect size and location. Consequently, full solutions for tensile strain limits related to above-mentioned factors do not yet exist in codes and standards. In recent years, a number of projects have been funded to develop a quantitative determination of tensile strain limits in China. This paper covers the technical basis of the procedures. The development of the quantitative approach to tensile strain limits involves both experimental tests and finite element analyses, and the process is as follows. Firstly, a series of curved wide plate tests under the axial tensile strain have been done, especially including more than 60 girth weld specimens with not only buried or surface defects but also various defect-sizes and defect-locations. Based on these test data and other available experiment data of full scale tests under the axial tensile strain and internal pressure loading, a valid finite element model has been found. Then a total of 110 finite element analyses produced a lot of data for a wide range of material, D/T ratios, various defect sizes or locations, buried or surface defects, and various internal pressures. So some parametric equations can be developed from finite element analyses. The safety factors and appropriate limits for the parametric equations have been identified against much more experimental data. It is believed that the approach to axial tensile strain limit presented in this paper may lay the initial basis for the quantitative determination of tensile strain limits to pipelines.
Remote Monitoring of TBG’s Cathodic Protection
Authors: Teixeira Paulo L. B. , Hasselmann Stella A.
Published: July 2009

This paper describes TBG’s practice in developing and establishing a System to monitor the Cathodic Protection System of the Bolivia Brazil Gas Pipeline. Monitoring is performed by the Central Station located at Rio de Janeiro – RJ – Brazil. The Cathodic Protection System uses 41 Rectifiers, mounted along the gas pipeline and it is responsible to control the electrochemical corrosion caused by the soil. Good performance shown by the system, allows TBG to modify the inspection period from once a week to once a month.
Virginia Pilot Project for Incorporating GPS Technology to Enhance One-Call Damage Prevention
Authors: Kieba Max , Tahamtani Massoud , Ayers Shane , Wilhite Herb , Pevarski Rick
Published: July 2009

Excavation continues to be a leading cause of damage to underground facilities in the United States. Excavation damage was cited as the cause in 20% of the significant pipeline incidents in 2007. Effective damage prevention programs are necessary to protect underground facilities and to ensure public health and safety, environmental protection and continuity of vital services. Central to all damage prevention efforts is effective communication of accurate and timely information among excavators, one-call centers and underground facility operators. In 2005, the Commonwealth of Virginia, federal government, industry and other key stakeholders in the U.S. initiated a pilot project to enhance the one-call damage prevention process through the use of global positioning system (GPS) technology. Virginia was chosen as the location for the Project due to its mature, active and inclusive damage prevention program. Additionally, coincident with the implementation of the Pilot Project, Virginia’s one-call center developed and implemented enhanced mapping capabilities that complemented the Project technology. Certainly, the potential for application of the technology in all states was a driving consideration throughout the Project. Phase I of the Virginia Pilot Project, completed in December 2007, focused on improving the locational accuracy of facility locate requests submitted by excavators to the one-call center. This was achieved by the development and use of electronic white-lining. The Project Team combined existing cell phone, Internet and GPS receiver technologies with the development of specific software applications and enhanced one-call processes. Project data indicate significant improvements were achieved in one-call process costs and efficiencies. These improvements enhance the benefits of such programs to all stakeholders and significantly improve underground facility safety. This paper describes the results from Phase I and the minimum requirements for implementing the technology. The results will be shared and promoted nationwide to encourage other one-call centers to consider incorporating the processes. The paper also describes the status of subsequent, related phases of the Pilot Project. Phase II will involve the application of GPS technology to locating instruments and the development of electronic locator manifests. Phase III will involve the integration of GPS and mapping technologies on excavating equipment. Finally, the paper describes the relevance to other damage prevention programs in the U.S. and other countries.
SmartBall™: A New Approach in Pipeline Leak Detection
Authors: Fletcher Richard , Chandrasekaran Muthu
Published: July 2009

Early detection of leaks in hazardous materials pipelines is essential to reduce product loss and damage to the environment. Small undetected leaks can result in very high clean-up costs and have the potential to grow to more serious failures. There are a variety of methods that can detect leaks in pipelines, ranging from manual inspection to advanced satellite based imaging. Typically, most operators opt for a combination of CPM where available, and direct observation methodologies including aerial patrols, ground patrols and public awareness programs that are designed to encourage and facilitate the reporting of suspected leaks. Permanent monitoring sensors based on acoustic or other technologies are also available. These methods can be costly, and none can reliably detect small leaks regardless of their location in the line. SmartBall is a radical new approach that combines the sensitivity of acoustic leak detection with the 100% coverage capability of in-line inspection. The free-swimming device is spherical and smaller than the pipe bore allowing it to roll silently through the line and achieve the highest responsiveness to small leaks. It can be launched and retrieved using conventional pig traps, but its size and shape allow it to negotiate obstacles that could otherwise render a pipeline unpiggable. The SmartBall technology was originally developed and successfully implemented for the water industry, and now refined for oil and gas pipelines over 4-inches in diameter. SmartBall has been proven capable of detecting leaks in liquid lines of less than 0.1 gallons per minute where conventional CPM methods can detect leaks no smaller than 1% of throughput. Development work is continuing to reduce the detection threshold still further. Whereas traditional acoustic monitoring techniques have focused on longitudinal deployment and spacing of acoustic sensors, the SmartBall uses only a single acoustic sensor that is deployed inside the pipeline. Propelled by the flow of product in the pipeline, the device will record all noise events as it traverses the length of the pipeline. This allows the acoustic sensor to pass in very close proximity to any leak whereby the sensor can detect very small leaks, whose noise signature can be clearly distinguished from any background noise.
X100 (Grade 690) Helical-Welded Linepipe
Authors: Bai Dengqi , Collins Laurie , Hamad Fathi , Chen Xiande , Klein Randy , Zhou Joe
Published: July 2009

During the past ten years, linepipe development activities around the world have been focused on high strength steels for Arctic gas transmission. The incentive for this work has been the potential for greater transportation efficiency and lower construction costs associated with the use of higher strength steels. The present paper describes the successful production of both 9.8 mm × 762 mm diameter and 12.7 mm × 1067 mm diameter Grade 690 linepipe. The alloying concept, thermomechanical controlled processing, and the resultant microstructures and mechanical properties will be presented. The key processing parameters which control the microstructure and mechanical behavior of the steels will also be discussed.
The Effect of Microstructure on Pit-to-Crack Transition and Crack Growth in an X-52 Pipeline Steel in Near-Neutral pH Environment
Authors: Fang B. , Eadie R. , Chen W. , Elboujdaini M. , Han E.-H.
Published: July 2009

X-52 pipeline steel specimens that had been pitted using a passivation/immersion technique were cyclically loaded in a near-neutral pH solution sparged with 5% CO2/balance N2 gas mixture at a peak normal stress of 109% of the yield strength (YS), a stress ratio, R, of 0.8, and a frequency of 0.0001 Hz. Blunt cracks were seen to have initiated from the corrosion pits. There were many more cracks on the radial transverse (R-T) surface than on the axial transverse (A-T) surface. On the R-T surface, there were a lot of non-metallic inclusions particularly at mid-wall in this steel and these resulted in the nucleation of large pits that were particularly prone to pit-to-blunt-crack transition. At higher peak normal stress, 109% of YS, compared to previous studies at a little lower stresses, there was more rapid crack formation on the R-T surface. In the end, the cracks along the large elongated inclusions penetrated into the steel samples and led to failure. The crack path was transgranular in nature and the fracture surface displayed quasi-cleavage features. Analysis revealed that the pit depth to width ratio for individual pits was a little higher than that for linked pits, however, the ratio of crack depth to crack mouth width was observed to be much larger than the ratio for the linked pits. Strong preferential dissolution was believed to be responsible for the pit nucleation from these non-metallic inclusions, with the plastically deformed regions at the pits acting as the anodic phases.
Monitoring Acoustic Noise in Steel Pipelines
Authors: Meinert Dieter , Gorny Michael , Pollmann Ansgar , Chen Jie-Wei , Garbi Andrea
Published: July 2009

A system is under development to permanently monitor the acoustic noise transported in a steel pipe. Using different kinds of sensors it is attempted to identify its sources. Initial goals are detection and, if possible, prevention of severe damage to the pipeline, mainly induced by third-party interference. With growing experience it should be possible to identify several much weaker sources of noise, and even detect significant changes in the general noise background. This will finally lead to a permanently monitored, semi-intelligent pipeline with reduced need for inline-inspection.
A New Approach to Work Safety Awareness for Pipeline Construction Workers
Authors: Araripe Celso , Hocayen de Paula Eliane , Serricchio Cla´udio
Published: July 2009

One of the greatest difficulties faced by Work Safety teams is keeping workers committed to and focused on safety practices in their day-to-day work. With time, the worker tends to become accustomed to the way safety information is fed to him and he becomes indifferent, allowing lapses that can result in incidents and/or accidents. In order to break the routine that provokes such lapses, PETROBRAS/ENGENHARIA/IEDT developed the HSE (Health, Safety and Environment) MOBILE project, using educational-and-artistic tools for training in the field; a much more enticing method than conventional presentations in training rooms. The dynamic approach includes 15-minute theater-and-video presentations at the worksite and conveys messages of awareness and prevention related to Health, Safety and Environment – HSE. The goal: encouraging workers’ attentiveness and commitment to safety practices. The HSE MOBILE project aims to prevent lapses of safety practices and to reduce the number of incidents and accidents through the use of HSE points considered priority for the construction of pipelines. An analysis of the performance record in HSE shows that the Mobile HSE project has two distinct benefits. It improves behavior and attitude in the field, by increasing the perception of risk and recognizing work safety. It also produces positive results in audits by reducing the number of accidents.
Developing a Common Model for Predicting the Wax Deposition in Crude Pipelines
Authors: Miao Qing , Jiang Baoliang , Huang Qiyu , Jiang Zhengfeng , Hu Sen
Published: July 2009

Wax Deposition commonly occurs in hot waxy crude oil pipelines. How to precisely predict the wax deposition is significant to the safe operation of pipelines. Presently the applied way to predict wax deposition in crude pipelines is mainly through numerical solutions by using the wax deposition mathematical model aimed at pipelined crude and relevant pipeline parameters, in which creating a precise wax deposition model plays an important role. Because wax deposition strongly depends on the composition of crude, most parameters in wax deposition model have to be determined through laboratory loop tests. Previous practices show that loop tests not only take a long time but also consume a large amount of crude sample. To obtain a precise model all the above had to be done in the past. Many wax deposition loop tests aimed at different crude oils have been carried out in our laboratory and, more importantly, a great deal of test data have been collected and analyzed. Now, based on our new research results on mechanism of wax deposition in crude pipelines and test data of up to 9 representative crudes, a common rule about wax deposition available to most crudes and their tests on loop has been excitedly discovered. It has resulted in the development of a new practical and more efficient mathematical model, which no longer needs long-time loop tests and large amount of crude sample and could be commonly or generally used on wax deposition prediction of most crude oils in pipelines. In this paper, how to discover the common rule about wax deposition of most crudes is introduced in detail. Also, a verification case for the application of the new model on a practical crude pipeline in China has been implemented by comparing the prediction results according to the new model with the operational data from the field during 7 pigging cycles. It is necessary to emphasize that the crude selected in this case for verifying is not among the 9 crudes used to establish the new model. The verification results show that the average error of prediction using the new model is only −4.215% and the maximal error is −20%, which are far better than ±30% by value in average prediction error tolerated on engineering application of wax deposition prediction around the world currently. So the results are very successful and encouraging and imply a prospective application.
The Research of Character of Control Valve on Pipeline
Authors: Gong Jing , Cai Jian
Published: July 2009

Regulating valves are the important components of control system on oil pipeline. The opening of the valves is changed to regulate flow and pressures of pipelines. Operating characteristic of valves is the most important factor influencing the regulating quality, and the distortion is great in actual operation with the variation of working conditions. Beginning with the inherent flow and resistance characteristics of regulating valves, the coefficient of discharge was adjusted considering the influence of fluid viscosity. The relationship between the deformity characteristics of valves and ratio of pressure cut down or turndown ratio was discussed. The system made up by a pump, a valve and a tank was an example to analyze the factors affected the operating characteristic of valves in the actual operation. The influences of different closing valve times, different closing valve laws and different ratio of pressure cut down or turndown ratio on the operating characteristic of valves were analyzed by simulation using Visual Basic program. The results indicated that the operating characteristics of valves were different. And the method of two-stage closing valve was adopted according to the changes of operating characteristic of valves by different closing valve time, different shutting valve laws. The distortion degree of valves in the operation of pipeline was decreased mostly. Then the selection measures of regulating valves were discussed. The factors influencing operating characteristic of valves were analyzed comprehensively. Theory criteria can be provided for selecting regulating valves of pipeline correctly. It is also the key to stable and economically operation control of pipelines.
Study on Buried Pipeline Security and Early-Warning System in Landslide Area Based on Fiber Bragg Grating Sensors
Authors: Liu Jianping , Wang Hongju , Hao Jianbin , Chen Pengchao , Ai Muyang
Published: July 2009

Compared with electric sensors, Fiber Bragg Grating (FBG) sensors are immune to electromagnetic interference, corrosion resistant, small in size and light in weight. Therefore, FBG sensors are easy to bury into geotechnical soil mass, measuring strain and temperature simultaneously. Focused on buried pipeline integrity, a type of sensing network made up of FBG sensors is introduced in this paper, monitoring pipeline strain, landslide surface displacement and inner displacement. An application of the sensing network to a huge landslide affecting a gas mainline is also introduced. The field experimental data show that, the FBG sensors have many advantages such as good real-time monitoring ability, flexible to develop sensing network, convenient to realize long-term monitoring. Moreover, the FBG sensors give reliable long-term monitoring data of pipeline strain and surface and inner displacement of the landslide, which provide the basis to evaluate pipelines integrity affected by landslides.
Inspection of Buried Gas Pipeline Using Ultrasonic Guided Waves
Authors: Wei Yao , Wang Weibin , Wang Yuqin , Liu Guichun , Liu Guangwen , Wang Kun
Published: July 2009

Ultrasonic Guided Wave testing is now widely used for the inspection of buried pipelines. The principle, characteristics and application of the inspection were introduced. As an example, pipelines in gas station were tested on-site and the reliability of testing results was verified by excavation. A comparison result showed that the ultrasonic guided waves can make it reality to test on site quickly, and has wide prospect.
Subsea Pipelaying Simulation by the “Situa-Petropipe” Software: A User Friendly Alternative
Authors: da Silva Danilo Machado Lawinscky , Albrecht Carl Horst , Jacob Breno Pinheiro , Masetti Isaias Quaresma , Barros Claudio Roberto Mansur , Saad Arthur Curty
Published: July 2009

Currently, Petrobras (the Brazilian state oil company) performs numerical simulations of pipelaying operations employing commercial software, such as OffPipe [1]. However, such tools presents restrictions/limitations related to the user interface, model generation and analysis formulations. These limitations hinder its efficient use for analyses of installation procedures for the scenarios considered by Petrobras, using the BGL-1 barge (owned by Petrobras) or other vessels, considering for instance particular types of stingers depending on depth and pipeline, with different lengths and geometries adapted to certain laying conditions in S-Lay procedures. Therefore, the objective of this work is to present the development and application of a tailored, in-house non-commercial computational tool in which the modules follow Petrobras users’ specifications, in order to overcome the limitations for specific needs and particular scenarios in the simulation of several types of pipeline procedures. Such tool, called SITUA-PetroPipe, presents a friendly interface with the user, for instance allowing the complete customization of the configuration of laybarge and stinger rollers. It also includes novel analysis methods and formulations, including the ability of coupling the structural behavior of the pipe with the hydrodynamic behavior of the vessel motions under environmental conditions.
Pipeline Integrity Management: An Approach to Geotechnical Risks
Authors: Oliveira Hudson Re´gis
Published: July 2009

Linear works, such as highways, power lines, gas and oil pipelines among others, as well as other types of engineering works can be threaten by natural hazards, such as landslides, floods, erosions, earthquakes, hurricanes, seaquakes and others, which may lead to great environmental impacts, very high sum of money lost and even deaths. Aiming to reduce geological and geotechnical risks, preventive or corrective actions can be executed from the design phase to the operational and maintenance stages in pipelines. In the last phase, an integrity management plan can be adopted to mitigate residual risks not covered on the design and construction phases. One of the alternatives to implement a gas pipeline integrity management is found in the code “Managing System Integrity of Gas Pipelines” – ASME B31.8S (2005). However, this code has some limitations in actions concerning to prevention, identification and correction of geological and geotechnical problems. This paper presents information about geotechnical risks in transmission pipelines and tools applied in identification, prevention and correction of geotechnical problems in pipelines, as well as, others that can potentially be applied in pipelines. A basic pipeline integrity management plan focused on geotechnical risks is proposed in the paper, transcribed as a contribution to ASME B31.8S Code. This plan is composed by actions: from identification, prevention, evaluation and analysis to correction of geotechnical instabilities in pipelines. It is composed by a flowchart with all actions selected for the geotechnical risk care. The plan was developed based on directions set in ASME B31.8S Code, including Brazilian, Italian and Canadian experiences.
Development of the Risk Based Guidelines for Natural Gas Transmission Pipelines Projects
Authors: Cardoso Ca´ssia , de Oliveira Luiz Fernando , Faertes Denise
Published: July 2009

The design standards of gas pipeline NBR 12712 and ASME B31.8, although having their own safety factors, had not incorporated explicitly the risk concept for the population in their definitions. However, the orientation of the Brazilian Environment Agencies is that the risk level of transportation activity for gas pipelines must be controlled to the health and the safety of the population. These facts can create a critical management situation because a gas pipeline can be in compliance with the design standards and not in relation to the criteria of the Environment Agencies. In this scenario, the establishment of risk based design guidelines becomes an essential action. In this article, a methodology for the elaboration of these guidelines is presented. We analyze not only the influences of the main operational and design parameters on the risk, but also the impact of the main risk acceptability criteria for the approval of the gas pipelines operation license. The result of this article is an excellent decision management tool on the management and the viability evaluation of this type of project and its application provides important technical knowledge to definitions of routes, operational and design parameters, and the optimized selection of risk reduction measures.
Investigation of a Non-Destructive Method to Characterize Material Mechanical Properties of Pipelines in Service
Authors: Le Bastard Avigae¨le , Batisse Re´mi , Gaschignard Vincent
Published: July 2009

In the frame of Pipelines Integrity Management, a better knowledge of actual materials properties of pipelines in service can save money by avoiding the cut and interruption of gas transit thanks to a more realistic defect assessment at failure. Different ways have to be explored to improve this knowledge on materials. One is based on the development of adapted correlations, well validated, to get from the poor material data available, the material properties which are required to analyse the defect behaviour. Another one is to use directly on field a non-destructive mechanical characterization tool. This paper focuses on non-destructive characterization by indenter method. This method is a succession of micro-indentations made by a spherical tungstene carbide indenter. From the ball displacement and stress applied during the load phase, tensile mechanical properties and toughness of the material are estimated. As the depth of the indenter displacement in steel is about 300 μm with no creation of micro-cracks, the test is considered as non-destructive. Hence, measurement can be made on operating pipelines without cut or interruption of gas transit. Gaz de France’s R&D Division has led laboratory and field-testing to evaluate the accuracy of the indenter tool and the ease and reliability to use it in-ditch conditions. Results on determination of actual tensile properties and toughness by indentation are presented, compared with results from destructive tests on standard specimens. Residual stresses and anisotropic effect on the indenter results are slightly investigated. Finally, all results are discussed to estimate the relevancy of this method for the Pipeline Integrity Management and some perspectives are given.