bluuebunny/crossref_metadata_2025 huggingface dataset:
NPP Bulk Equipment Dismantling Problems and Experience
Authors: Gelbutovskiy Alexander B. , Cheremisin Peter I. , Epikhin Yuri A. , Troshev Alexander V. , Balushkin Eugeny V.
Published: April 2011

NPP bulk equipment dismantling problems and experience are summarized. “ECOMET-S” JSC is shown as one of the companies which are able to make NPPs industrial sites free from stored bulk equipment with its further utilization. “ECOMET-S” JSC is the Russian Federation sole specialized metallic LLW (MLLW) treatment and utilization facility. Company’s main objectives are waste predisposal volume reduction and treatment for the unrestricted release as a scrap. Leningrad NPP decommissioned main pumps and moisture separators/steam super heaters dismantling results are presented. Prospective fragmentation technologies (diamond and electro-erosive cutting) testing results are described. The electro-erosive cutting machine designed by “ECOMET-S” JSC is presented. The fragmentation technologies implementation plans for nuclear industry are presented too.
Hydrogen Production From a PV/PEM Electrolyzer System Using a Neural-Network-Based MPPT Algorithm
Authors: Nafeh Abd El-Shafy A.
Published: April 2011

The electrolysis of water using a polymer electrolyte membrane (PEM) electrolyzer is a very vital and efficient method of producing hydrogen (H2). The performance of this method can be significantly improved if a photovoltaic (PV) array, with maximum-power-point (MPP) tracker, is utilized as an energy source for the electrolyzer. This paper suggests a stand-alone PV/PEM electrolyzer system to produce pure hydrogen. The paper also develops the different mathematical models for each constituent subsystem. Moreover, the paper develops the suitable maximum-power-point tracking algorithm that is based upon utilizing the neural network. This algorithm is utilized together with the action of the PI controller to improve the performance of the suggested stand-alone PV/PEM electrolyzer system through maximizing the hydrogen production rate for every instant. Finally, the suggested hydrogen production system is simulated using the Matlab/Simulink and neural network toolbox. The simulation results of the system indicate the improved relative performance of the suggested hydrogen production system compared with the traditional case of direct connection between the PV array and the PEM electrolyzer.
Exploiting Synergies Between the UK and Japanese Geological Disposal Programmes
Authors: Scourse Ellie , Kawamura Hideki , McKinley Ian G.
Published: April 2011

The early ’80s UK programme for deep geological disposal of high-level radioactive waste was advanced and at the stage of characterising potential sites. When this project was put on hold in the mid ’80s, much expertise in this field was lost. In Japan R&D in the ’80s resulted in major generic safety assessments to demonstrate feasibility in the ’90s. This led to the establishment of NUMO (Nuclear Waste Management Organization of Japan) and the initiation of siting based on volunteerism. This novel approach required more flexible methodology and tools for site characterisation, repository design and safety assessment. NUMO and supporting R&D organisations in Japan have invested much time and effort preparing for volunteers but, unfortunately, no discussions with potential host communities have yet developed to the point where technical work is initiated. Presently, the UK is moving forward; with the NDA RWMD (Nuclear Decommissioning Agency Radioactive Waste Management Directorate) adopting a NUMO-style volunteering approach and a flexible design catalogue. Communities have already shown interest in volunteering. The situation is thus ideal for collaboration. The paper will expand on the opportunities for the UK and Japan to benefit from an active collaboration and discuss how this can be most efficiently implemented.
Ethics of the Management of Low and Intermediate Radioactive Wastes Generated by Cernavoda NPP: A Challenge for the Romanian Specialists
Authors: Barariu Gheorghe
Published: April 2011

This paper presents the design criteria and the prerequisites for the development of the Radioactive Waste Treatment Plant - RWTP which will comply with L/ILW Final Repository requirements to be built near Cernavoda NPP. The RWTP will be designed to satisfy the main performance objectives in accordance to IAEA recommendation and on basis of the Repository’s Waste Acceptance Criteria resulted from the local conditions. One of the most important technological aspect is related to the selection of technologies, which implies, on the one hand, the impact on present generation respectively incineration, radwaste transfer from the SS drums to CS drums, SS drums super compaction and spent filter cartridges cutting, and on the other hand, technologies that isolate for 300 years the tritium and C-14 in the Repository with impact for the next generations. The Saligny Repository will be commissioned in 2014 and in order to accept radwastes from Cernavoda NPP it is necessary that the radwastes are suitably treated for long–term radionuclides isolation. The conditions and requirements including many uncertainties and constraints reduce the possibilities to select the suitable treatment technologies for the Waste Treatment Plant designed for the radwastes generated by Cernavoda NPP, this selection being a critical case due to the limited storage capacity of existing Radioactive Waste Storage Facility. The necessary Radioactive Waste Treatment Plant implies a detailed analysis including ethical aspects of the selected technologies.
Current Mercury Distribution and Bioavailability in Floodplain Soils of Lower East Fork Popular Creek, Oak Ridge, Tennessee, USA
Authors: Han Fengxiang X. , Su Yi , Monts David L.
Published: April 2011

The objectives of this study were to investigate the current status of mercury distribution, speciation and bioavailability in the floodplain soils of Lower East Fork Poplar Creek (LEFPC) after decades of US Department of Energy’s remediation. Historically as part of its national security mission, the U.S. Department of Energy’s Y-12 National Security Facility in Oak Ridge, TN, USA acquired a significant fraction of the world’s supply of elemental mercury. During the 1950s and 1960s, a large amount of elemental mercury escaped confinement and is still present in the watershed surrounding the Y-12 facility. A series of remediation efforts have been deployed in the watersheds around the Oak Ridge site during the following years. The sampling fields were located in a floodplain of LEFPC of Oak Ridge, TN, USA. A series of surface soils (10–20 cm) were sampled from both wooded areas and wetland/grass land. Two 8×8 m fields were selected in the woodland. Five profiles each consisting of three layers were randomly taken from each field. The three layers were the surface layer at 0–10cm, subsurface layer at 50–60 cm, and bottom layer at 100–110 cm. Soil in both wood and wetland areas was well developed with a clear B horizon. The present study clearly shows that the total mercury in floodplain soils of LEFPC significantly decreased after the series of remediation. This study confirmed the long-term effectiveness of these remediation actions, especially after excavation of highly contaminated floodplain soils. However, the average total mercury level of all soil samples collected are in the range of 50–80 mg/kg, still significantly above toxic level (> 5mg/kg). Furthermore, contrary to conventional believing, the major mercury form in current soils of this particular area of floodplain of LEFPC is mainly in non-cinnabar mercury bound in clay minerals (after decades of remediation). The floodplains can act both as a medium-term sink and as long-term sources. Native North American earthworms (Diplocardia spp.) and adjacent soils were taken from each spot in each field. Our results show strong linear relationships between mercury concentrations in earthworms (both mature and immature groups) and non-cinnabar mercury form, while cinnabar mercury is less bioavailable to native earthworms. Earthworms may be used as a potential mercury ecological bio-indicator (bio-marker) for demonstrating mercury bioavailability and ecotoxicity in the ecosystem. The long-term stability, mobility and bioavailability of mercury contaminants in these floodplains still needs to be monitored continuously and closely.
Recent Developments and Trends in Requirements Management Systems
Authors: Suzuki Satoru , Ueda Hiroyoshi , Fujisaki Kiyoshi , Ishiguro Katsuhiko , Tsuchi Hiroyuki , Vomvoris Stratis , Gaus Irina
Published: April 2011

In a recent international meeting, five radioactive waste disposal organizations (NUMO/Japan; NAGRA/Switzerland; ONDRAF/NIRAS/Belgium; POSIVA/Finland; SKB/ Sweden) have discussed the status and developments of RMS in their respective programs. The majority have already implemented an IT-based system, or, are testing and developing such systems. The level of detail of requirements depends on the stage of the program. Those approaching the license application have integrated all components of the repository concept, including the processes for the operational phase. Requirements management is closely associated with the quality management system. Combining requirement and decision-tracking has been expressed as an explicit goal for some programs. Caution was expressed regarding the expectations for the RMS being developed. There is a risk that such systems are perceived as expert systems that can derive decisions, which then will be unquestionably accepted. It is nevertheless recognized that they can be of great help in communicating with the various stakeholders and with relative ease demonstrate how their requirements have been considered and satisfied with the proposed repository systems. Further efforts need to be undertaken to integrate the requirement management systems, and the processes that they represent, in the day-to-day operations of the organizations. First positive experiences of the latter are reported.
Treatment of Low-Level Radioactive Waste by Plasma: A Proven Technology?
Authors: Deckers Jan
Published: April 2011

Large amounts of actual and historical low level radioactive waste, with varying characteristics, are stored and generated from the operation and maintenance of nuclear power plants, the nuclear fuel cycle, research laboratories, pharmaceutical and medical facilities. Virtual all of these waste streams can be treated by the plasma technology resulting in a final product free of organics, liquids and moisture, and meeting without a doubt the acceptance criteria for safe storage and disposal. The plasma is a highly desirable heat source. Its high temperature of up to 10.000 °C can treat the radioactive waste as is. The inorganic materials are melted into a glassy slag, containing most of the radioactive isotopes, while the organic material is vaporized into a syngas and subsequently oxidized in an afterburner. This technology is very suitable for historical waste containing mixtures of inorganic, organic, liquids, sludge, etc, with almost no waste preparation and with minimal risk for radioactive contamination and exposure. Plasma technology offers a high volume waste reduction factor (VRF) that minimizes the volume and overall costs of waste storage and disposal. In addition, as plasma technology can recondition previously conditioned waste packages that no longer meet the present acceptance criteria for final disposal, it offers a solution to the growing demand for improved quality of final waste forms. As such, plasma technology is of great value, not just to waste producers but to future generations as well. This paper describes further the principles of plasma, the different waste feed systems, off-gas treatment, operational experience and future plasma plants.
Effect of Fracture Speed on Ductile Fracture Resistance: Part 2—Results and Application
Authors: Duan Da-Ming , Zhou Joe , Shim Do-Jun , Wilkowski Gery
Published: April 2011

One of the many aspects of natural gas pipeline design and material selection is the consideration of propagation and arrest of high-speed axial ductile fracture in the line pipes. Understanding the material ductile fracture behavior is essential for establishing an integrated fracture control plan. This is particularly important for pipelines of high design pressures utilizing large-diameter and high-grade line pipes. The procedure of Battelle Two-Curve Method (TCM) has been most commonly used in ductile fracture analysis in the prediction of fracture speed and minimum arrest toughness for axially running cracks. In the past decades, discussions and research have been in that the TCM approach, among with others, could not accurately predict either fracture speed or minimum arrest fracture toughness for high-grade pipes, and with pipe grade increasing the prediction errors are getting larger. Recent research work at TransCanada indicates that for a better prediction of pipeline ductile fracture, understanding the basic material mechanical behavior and its fundamental fracture mechanism is essential. One of the important findings of the work is that pipe material fracture toughness is not a constant as being commonly treated, rather the fracture toughness, in terms of both steady-state CTOA and steady-state DWTT fracture energy is fracture speed dependent, being decreasing with increasing fracture speed. Corresponding modifications have been made to the traditional TCM by introducing speed-dependent fracture toughness. The improved model gives much better predictions in both fracture speed and toughness for high grade pipes. This paper presents recent work at TransCanada, together with its industry partner Engineering Mechanics Corporation of Columbus (EMCC), on high-speed pipe-material fracture testing technique (using the modified back-slot DWTT specimen) and high-grade material testing data. The test data supports the predictions of early published work on speed-dependent fracture toughness. The fracture speeds obtained from the modified back-slot DWTT specimens were very close to actual full-scale pipeline ductile fracture speeds and this in turn enhanced the applicability of the modified TCM model.
Improvements in the Accurate Estimation of Top of the Line Internal Corrosion of Subsea Pipelines on the Basis of In-Line Inspection Data
Authors: Huyse Luc , van Roodselaar Albert , Onderdonk John , Wimolsukpirakul Boonchouay , Baker Jackson , Beuker Thomas , Palmer Johannes , Jemari Nija Amri
Published: April 2011

The cost for repair or replacement of subsea pipelines is much higher than for onshore pipelines. To a large extent, the repair or replacement decision hinges on the outcome of fitness-for-service analyses that are in turn based on the results of in-line inspections. It is therefore of utmost importance to obtain in-line inspection data that are as accurate as possible. It has been reported in the literature that MFL tools may significantly exaggerate the localized wall loss for wet gas lines subject to top of the line corrosion. This paper reports the results of a study on a Chevron asset that was initiated to compare the performance of various inspection methods. Upon completion of the in-line inspections, a section of the pipeline was recovered off the ocean floor and subsequently replaced. The defect population of the recovered pipeline section together with the high-definition automated ultrasonic testing (AUT) results built the reference of the performance test of several inline inspection techniques like magnetic flux leakage (MFL), ultrasonic (UT) and a recently developed technology for accurate measurement of shallow internal corrosion (SIC) that is based on eddy current (EC) technology. The improvements in defect sizing that resulted from this investigation are reported.
A Formula for Success: Research Impacts Realized Because of Strong Industry and Government Collaboration
Authors: Merritt James , Smith Robert
Published: April 2011

The U.S. Department of Transportation’s Pipeline and Hazardous Materials Safety Administration (PHMSA) has built and deployed a consensus-based, collaborative and co-funded research program that is bringing technology to market and helping to strengthen pipeline integrity worldwide. As the principle arbiter of on-shore pipeline safety issues at the federal level PHMSA has aggressively initiated an extensive range of research, development and demonstration projects to make pipelines safer. Significant progress is being accomplished while working with other international administrations, federal agencies, state and local governments, industry partners and academia focused on enhancing pipeline system integrity. This research enterprise is designed to be consistent, predictable and transparent to all stakeholders. Current PHMSA Pipeline Safety R&D Program managed research, development and demonstration (RD&D) projects are producing desired results focused on technologies, enhancing standards and regulations along with providing general knowledge needed to address critical safety and integrity functions. These investments are addressing better diagnostic tools, testing of unpiggable pipes, stronger materials, improved pipeline locating and subsurface mapping, prevention of outside force damage, and leak detection. PHMSA Pipeline Safety R&D Program utilizes consensus building on the technical gaps and challenges for future RD&D through facilitating government and industry pipeline stakeholder’s road mapping efforts. The recent Government/Industry R&D forum confirms progress is being made toward safety and integrity in some areas. However, new challenges seen from the recent construction boom is raising old questions along with new technology challenges with alternative fuels and climate change. This paper will discuss the impacts realized from the execution of PHMSA’s research program to develop technology, strengthen consensus standards and to generate and promote new knowledge since 2002.
A Study on Multi-Data Source Fusion Method for Petroleum Pipeline Leak Detection
Authors: Liang Wei , Zhang Laibin
Published: April 2011

This paper describes a new approach of data source fusion based on process fusion entropy for leak detecting of product pipelines. Data sources are either single-channeled or multi-channeled: single-channeled data sources can be structured or semi-structured process steady entropy, whereas multi-channeled sources are singular spectrum entropy and power spectrum entropy. In order to develop data sources fusion systems for pipeline leak detection in real-time contexts, we need to study all issues raised by the matching paradigms. This challenging problem becomes crucial with the dominating role of the internet. Classical approaches of data integration, based on schemas mediation, are not suitable to the pipeline SCADA (Supervisory Control and Data Acquisition) environment where data is frequently modified or updated. Therefore, we develop a loosely integrated approach that takes into consideration both steady and transient states which must be separated correctly in order to integrate new data sources. Moreover, we introduce a process fusion entropy-based Multi-data source Fusion Method (MFM) that aims to define and retrieve conflicting data from multiple data sources.
Qualification Strategy for FAST-Pipe™ for High Pressure Gas Pipelines
Authors: Salama Mamdouh M.
Published: April 2011

Because major reserves for natural gas are often remotely located from potential market, its transportation requires larger diameter pipes operating at high pressures. In order to reduce cost, high strength steels (≥ X80) have been advanced to reduce the wall thickness of the pipeline and thus lower materials, transportation and construction costs. However, producing large diameter high pressure pipelines of these steels creates significant challenges that can only be met by very few steel suppliers. This paper presents the qualification results of an alternative technology that will reduce cost even more than high strength steels while using conventional steel such as X70. This technology, which is designated as Fiber Augmented Steel Technology Pipe (FAST-Pipe™), involves hoop winding dry glass fibers over conventional steel pipes (e.g. X70) to provide the required high pressure capacity. The steel thickness is selected to mainly satisfy axial and bending load requirements. Following a proof-of-concept of the FAST-Pipe™, a detailed qualification program was developed based on a decision and risk analysis strategy that incorporates key elements of the industry technology qualification guidelines (DNV RP A203 and API 17N). The qualification program involved addressing fifteen design, construction and operational parameters. The paper presents the FAST-Pipe™ concept, discusses its advantages and summarizes the results of its qualification program.
A Case Study of the Crack Sizing Performance of the Ultrasonic Phased Array Combined Crack and Wall Loss Inspection Tool on the Centennial Pipeline, the Defect Evaluation, Including the Defect Evaluation, Field Feature Verification and Tool Performance Validation (Performed by Marathon Oil, DNV and GE Oil & Gas)
Authors: Hrncir T. , Turner S. , Polasik S. J. , Vieth P. , Allen D. , Lachtchouk I. , Senf P. , Foreman G.
Published: April 2011

GE performed an ultrasonic phased-array (USCD DUO) in-line inspection (ILI) survey of a 24-inch and 26-inch products pipeline. The primary purpose of this ILI survey was to detect and characterize stress corrosion cracking (SCC). A dig verification was subsequently performed throughout 2008 in order to establish a higher level of confidence in the detection and depth-sizing capabilities of this technology. Presented herein is an overview of the USCD technology and experience, the method used for validating the ILI survey results, enhancements to the ILI data analysis, and the impact on managing the integrity of the subject line section.
Research on Acoustic Emission In-Service Inspection for Large Above-Ground Storage Tank Floors
Authors: Lin Mingchun , Kang Yewei , Wang Weibin , Zhang Lei , Sun Yi
Published: April 2011

Much manpower is needed and a lot of materials are wasted when the floor of large above-ground storage tank (AST) is inspected with conventional methods which need to shut down the tank, then to empty and clean it before inspection. Due to the disadvantages of that, an in-service inspection method using acoustic emission (AE) technology is presented. By this mean the rational inspection plan and integrity evaluation of tank floors can be constructed. First, specific inspection steps are established based on the acoustic emission principle for large AST’s floors and the practical condition of AST in order to acquire the AE corrosion data. Second, analysis method of acoustic emission dataset is studied. Finally, maintenance proposes are provided based on results of analysis for the corrosion status of the tank floors. In order to evaluate the performance of our method, an in-service field inspection is practiced on product oil tank with a volume of 5000 cubic meters. Then a traditional inspection procedure using magnetic flux leakage (MFL) technology is followed up. Comparative analysis of the results of the two inspection methods shows that there is consistency in localizing the position of corrosion between them. The feasibility of inservice inspection of AST’s floors with AE is demonstrated.
Pipeline Leakage Recognition Based on the Projection Singular Value Features and Support Vector Machine
Authors: Wang Mingda , Zhang Laibin , Liang Wei , Hu Jinqiu
Published: April 2011

Identification of negative pressure waveform is the key of pipeline leakage detection. The feature extraction and the choice of the classifier are two main contents to solve the recognition problem. In this paper, a new feature extraction method based on the Projection Singular Value is presented. First of all, the two orthogonal singular value decomposition matrixes of the typical leakage waveform are extracted as the standard bases. Then the projection singular value features of the other pressure wave matrixes are extracted by being projected to the two standard bases. As the pipeline leakage is a small probability event, it is difficult to obtain the leakage samples. A multi-classification Support Vector Machine, which has the advantage of small sample learning, is constructed to classify these features in this paper. The field experiments indicate that the leakage detection based on this feature extraction and recognition model has a higher accuracy of leakage recognition.
The Alberta Experience With Composite Pipes in Production Environments
Authors: Grzyb David W.
Published: April 2011

The Energy Resources Conservation Board (ERCB) is the quasi-judicial agency that is responsible for regulating the development of Alberta’s energy resources. Its mandate is to ensure that the discovery, development, and delivery of Alberta’s energy resources takes place in a manner that is safe, fair, responsible, and in the public interest. The ERCB’s responsibilities include the regulation of over 400,000 km of high-pressure oil and gas pipelines, the majority of which is production field pipeline. ERCB regulations require pipeline licensees to report all pipeline failures, regardless of consequence, and thus a comprehensive data set exists pertaining to the failure frequency and failure causes of its regulated pipelines. Analysis has shown that corrosion is consistently the predominant cause of failure in steel production pipeline systems. Corrosion-resistant materials, such as fibre-composite pipe, thermoplastic pipe, and plastic-lined pipe have long been explored as alternatives to steel pipe, and have in fact been used in various forms for many years. The ERCB has encouraged the use of such materials where appropriate and has co-operated with licensees to allow the use of various types of new pipeline systems on an experimental basis, subject to technical assessment, service limitations, and periodic performance evaluations. This paper will review the types of composite pipe materials that have been used in Alberta, and present statistical data on the length of composite pipe in place, growth trends, failure causes and failure frequency. As the purpose of using alternative materials is to improve upon the performance history of steel, a comparison will be done to determine if that goal is being achieved.
The Remaining Life Prediction and Internal Inspection Interval Analysis for Large-Scale Crude Oil Storage Tank
Authors: Shuai Jian , Han Kejiang
Published: April 2011

As an important production facility, storage tank plays a more and more important role in the storage and transportation of crude oil and chemical product. The remaining life prediction of storage tank is to forecast the thinning trend of plate thickness, and forecast remaining life on the premise that remaining strength of storage tank meets the tank operation and safety requirements. Maximum corrosion depths of tank bottom plate obey the maximum extreme value distribution. Based on maximum extreme value distribution and statistics of corrosion data, the calculation formula of the remaining life prediction for large-scale crude oil storage tank was obtained by formula derivation. Compared with API STD 653 and EEMUA 159, the inspection interval specified by China standard SY/T 5921 is relatively conservative. The remaining life of a certain crude oil storage tank (tank A) in china is determined by the remaining life of tank bottom plate. The remaining life of tank A at the reliability of 0.99, 0.999 and 0.9999 are 25 years, 20 years and 17 years, respectively. For the acceptable failure probability of 1×10−4, the inspection interval of tank A can be extended from required 5–7 years specified by China standard SY/T 5921 to 17 years. The remaining life of crude oil storage tank predicted by the method proposed in this paper can be used as an important reference in the determination of inspection interval and tank’s maintenance.
A Review of Crack Detection In-Line Inspection Case Studies
Authors: Bates Neil , Lee David , Maier Clifford
Published: April 2011

This paper describes case studies involving crack detection in-line inspections and fitness for service assessments that were performed based on the inspection data. The assessments were used to evaluate the immediate integrity of the pipeline based on the reported features and the long-term integrity of the pipeline based on excavation data and probabilistic SCC and fatigue crack growth simulations. Two different case studies are analyzed, which illustrate how the data from an ultrasonic crack tool inspection was used to assess threats such as low frequency electrical resistance weld seam defects and stress corrosion cracking. Specific issues, such as probability of detection/identification and the length/depth accuracy of the tool, were evaluated to determine the suitability of the tool to accurately classify and size different types of defects. The long term assessment is based on the Monte Carlo method [1], where the material properties, pipeline details, crack growth parameters, and feature dimensions are randomly selected from certain specified probability distributions to determine the probability of failure versus time for the pipeline segment. The distributions of unreported crack-related features from the excavation program are used to distribute unreported features along the pipeline. Simulated crack growth by fatigue, SCC, or a combination of the two is performed until failure by either leak or rupture is predicted. The probability of failure calculation is performed through a number of crack growth simulations for each of the reported and unreported features and tallying their respective remaining lives. The results of the probabilistic analysis were used to determine the most effective and economical means of remediation by identifying areas or crack mechanisms that contribute most to the probability of failure.
Evolution of Triax Magnetic Flux Leakage Inspection for Mitigation of Spiral Weld Anomalies
Authors: Feng Qingshan , Sutherland Jeff , Gu Bill , Wei Yao , Tao Cui
Published: April 2011

With an overall objective for broad and confident integrity management of the PetroChina Pipeline Company’s pipeline network, we illustrate the impact of a collaborative effort between PetroChina and GE Oil & Gas for the inspection and mitigation of spiral weld anomalies, particularly for new advanced assessments of features oriented along and within the spiral weld. Tool configuration, sensor types and the role of novel data analysis techniques including magnetic vector component measurements, is presented as a set to address a broader variety of spiral weld threats, while ensuring a high level of operational robustness and reliability. This paper describes some of the science behind the art, and describes the fundamentals of MFL magnetics and it’s evolution as an ILI technology into the 21st century for spiral weld anomaly inspection.
Development of Failure Criteria for Predicting Tearing of Wrinkled Pipe
Authors: Ahmed Arman Uddin , Cheng J. J. Roger , Zhou Joe
Published: April 2011

Onshore steel pipelines, particularly buried in cold region, often subjected to extreme geo-environmental conditions, where significant inelastic deformation may occur resulting in localized wrinkles. Under continued deformation, there is a possibility of excessive cross-sectional deformation at wrinkle locations, eventually leading to fracture or damage in the pipe wall. A recent field fracture and failed laboratory specimens under monotonic load history address the necessity of conducting a comprehensive research program to better understand this unique failure mode. Initial results have indicated that even under monotonic loading, significant strain reversals can occur at sharp fold of the wrinkle. These strain reversals were identified as one of the key factors to trigger this unique failure mechanism. This paper addresses the development of failure criteria used in the finite element (FE) model of plain pipes subjected to sustained monotonic axial and bending deformation with or without internal pressure. In conjunction with the strain reversal criterion, the critical equivalent plastic strain was used as the fracture or damage initiation limit in the numerical analyses. Results obtained from the full-scale test of an NPS16 pipe were used to calibrate the FE model. Results obtained from the numerical analyses have shown that the proposed criteria predict the onset of fracture at sharp fold of the wrinkle with reasonable accuracy.
Determination of Pipe Girth Weld Fracture Toughness Using Sent Specimens
Authors: Pisarski Henryk G.
Published: April 2011

This paper reviews the basis for the use of SENT or SE(T) specimens as described in DNV RP F108, their limitations and aspects about specimen preparation testing and analysis procedures that need to be addressed in order to standardise the test better. Examples are given comparing the effect of crack tip constraint in a SE(T) specimen with a circumferential crack in a pipe subjected to axial straining and axial strain plus internal pressure. The variations in crack front straightness, the effect of specimen geometry on the J resistance curve as well as the accuracy of the J estimation procedure are presented. The use and limitations of CTOD estimation procedure based on measurement of crack mouth opening displacement as a fracture toughness parameter is discussed.
Rational Stress Limits and Load Factors for Finite Element Analyses in Pipeline Applications: Part I—Linear Elastic Stress Limit Development
Authors: Lin Bisen , Biel Richard C.
Published: April 2011

In this paper, a rational stress limit based on the von Mises equivalent stress is established for pipelines subjected to internal pressure. This stress limit is based on the ASME pipeline Code’s design margin for the service and location of the installation [1, 2]. These Codes are recognized by 49 CRF192 [5]. Both capped-end and open end conditions are considered. The single value of stress limits can be derived by classical hand calculations for use in assessing the results of a finite element analysis (FEA). Two application examples are presented showing studies done with the ABAQUS [3], a commercial (FEA) software. A stress limit was first found using classical hand calculations and verified by a simple finite element model. The linearized stresses at some critical locations were then compared to the established stress limit, and multiples, for the assessments of membrane, membrane plus bending, etc. stresses. This paper is not intended to revise or replace any provision of ASME B31.8 [2]. Instead, it provides a rational stress limit that may be used in the assessment of detailed FEA analyses of pipelines and the associated components.
Effect of Deposit Composition on the Mechanical Properties and Cracking Tendency of Cellulosic-Covered SMAW Weld Deposits
Authors: James Matthew J. , Quintana Marie A. , Weaver Robert J. , Savrin Tamara , Narayanan Badri
Published: April 2011

This investigation utilizes test electrodes manufactured with boron at different levels (including no boron). The design of these electrodes is identical with the exception of the intentional changes highlighted. Gapped bead on plate (GBOP) testing is used to determine the relative propensity of the electrodes for weld metal cracking. Test electrodes are also evaluated for deposit composition, CVN impact toughness, strength, and hardness on pipe joints. This work also uses a non boron-containing test electrode whose deposit composition has been modified such that its carbon equivalent is the same as one of the boron-containing electrodes. This serves to separate the influence of the specific element boron from the influence of general carbon equivalent/hardenability on the tendency for cracking. The results indicate that the effect of changes in boron and carbon equivalent over the range tested and in this specific electrode design is very slight. In most cases, the effect is not significant when compared to the amount of variation observed in the testing. In essence, the signal was lost in the noise. In terms of susceptibility to hydrogen assisted cold cracking (HACC) — the area of most concern — there appear to be other factors that are much more influential than those tested. If the goal is to minimize the cracking sensitivity of cellulosic weld metal, simply eliminating the use of boron is not the answer. More work is required to identify these other factors and quantify their effect.
Assessment and Management of SCC in a Liquid Pipeline: Case Study
Authors: Cazenave Pablo , Tandon Samarth , Gao Ming , Krishnamurthy Ravi , Peverelli Romina , Moreno Ochoa Carlos , Diaz Soli´s Esau´
Published: April 2011

Stress corrosion cracking (SCC) is a major concern for most gas and oil pipeline operators. Extensive efforts continue to be made to develop strategies for a better management of the problem. The quantification of the life cycle and risk of SCC rupture for a post inspection integrity assessment requires knowledge of (1) Quality of Inspection, namely POD (Probability of Detection), POI (Probability of Identification) and Actual Sizing Tolerance (2) Material and Metallurgy; (3) Appropriate Assessment Methods; and (4) Crack Growth Rates. Previous experience gained from the crack detection inspections showed POD and POI for deep cracks are generally high, with sizing limited up to 40% wt. The uncertainty in sizing for shallow cracks is usually higher, and may not meet the specified tolerance at a specified certainty and confidence level. POD, POI and sizing accuracy can be affected by the inspection operation including speed, other defects and geometry irregularity along the pipeline. Therefore, the qualification of the tool inspection performance directly impacts on the reliability of the assessment and serves as the basis for a reliable assessment. In this paper, an approach for managing high pH SCC in a 30″ × 340 Km oil pipeline in Mexico is presented. The approach consists of a comprehensive verification excavation plan, a strict in-ditch NDT investigation protocol, statistical models for POD, POI and sizing tolerance analyses, and an appropriate assessment methodology supported by the material testing program. With all the results obtained from application of the approach, the integrity management strategies are developed. An action plan for future integrity is established and being refined from time-to-time prior to next inspection.
Environmental Impact Mitigation on the Gasduc-3 Project
Authors: d’Oliveira Celso A. , de Paula Eliane H. , Freire Dilian A. D.
Published: April 2011

This paper approaches the environment impact mitigation measures adopted in the Cabiu´nas-Reduc-3 project (Gasduc-3), completed in January 2010. This high complexity project has great strategic importance to the Company and for the extension of natural gas offer in Brazil. Due to the large size of the project and its interference with environmentally sensitive areas, several programs and actions have been carried out in the influenced areas what allowed the team to conclude Gasduc-3 and, at the same time, follow through with the premise of sustainable development.
Critical Buckling Strain in High Strength Steel Pipes Using Isotropic-Kinematic Hardening
Authors: Fathi A. , Cheng J. J. Roger , Adeeb Samer , Zhou Joe
Published: April 2011

High strength steel pipes (HSSP) have become more popular recently for highly pressurized pipelines built to transport natural gas from remote fields to energy markets. Material tests on HSSP showed significant material anisotropy caused by the pipe making process, UOE. A combined isotropic-kinematic hardening material model is developed based on observations made on longitudinal and transverse stress strain data of HSSP. This material model combines linear isotropic hardening with Armstrong-Fredrick kinematic hardening and can be easily calibrated by longitudinal and transverse tension coupon test results. The proposed material model is used to show how considering material anisotropy affects the critical buckling strain of HSSP in the longitudinal direction. Finite element (FE) models are developed to simulate one pressurized and one unpressurised HSSP tested under monotonic displacement-controlled bending. Isotropic and anisotropic material modeling methods are used for each HSSP models. In the isotropic material model, longitudinal stress-strain data of HSSP material is used to define the stress-strain relationship. In the anisotropic model combined hardening material model, calibrated by longitudinal and transverse HSSP stress-strain data, is used. Critical buckling strain predictions by isotropic and anisotropic models of these pipes are compared with test results and also with some available criteria in standards and literatures. These comparisons show that anisotropic models give predictions closer to test results.
U.S. Federal, State, and Local Permitting Requirements and Expectations for Oil Pipeline Repair: Assuring Compliance and Streamlining the Permitting Process
Authors: Walker Rachel E.
Published: April 2011

This paper examines regulations for oil pipeline repair and considers some best practices to streamline permitting and assure compliance in the U.S. In the U.S., the federal government does not regulate construction or abandonment for oil pipelines, as it does with natural gas pipelines through the Federal Energy Regulatory Commission (the FERC). Instead, a number of federal, state, and local authorities have jurisdiction over oil pipelines and may regulate these activities differently. Because oil pipelines cross many jurisdictional boundaries, applicants find it challenging to navigate permitting requirements. For example, determining which permits are required for pipeline repair in U.S. waters can be difficult because, while such waters are defined by federal statute, the application of those rules is not uniform in all jurisdictions. In this paper, we present best practices for assuring compliance and streamlining the permitting process for oil pipeline construction, routine maintenance and repair in the U.S. To the extent possible, best practices mimic the FERC process, promote dialogue between regulators and oil pipeline companies, and foster a more transparent and effective environmental regulatory process. This paper presents the challenges encountered by the oil pipeline industry as a result of multiple agencies regulating the repair of oil pipelines. The paper then presents some discussion of the regulatory process and approaches to addressing challenges associated with this process. Following best practices to meet regulatory requirements is not only efficient and cost effective, but also helps assure long term regulatory compliance which affects the success of both small and larger scale projects.
A Study on the Standard System of Pipeline Operation
Authors: Liu Bing , Shui Biyuan , Liu Lingli
Published: April 2011

Standardization, as the basis of pipeline, plays an important role in the sound development of pipeline operation and ensures its safety and efficacy on technology. It has become an important and pressing task to build up an appropriate standard system for the application of pipeline operation, in view of which, this article has made an in-depth analysis of the present standardization status of pipeline operation application and the problems in existing standard systems, put forward the principles for the standard of pipeline operation within the oil and gas industry and the established standard system for the application of pipeline operation. This project is intended to make the standard work better and move R&D into the development of standard system.
Integrity Management Program for Geo-Hazards in the OCENSA Pipeline System
Authors: Garci´a Hugo , Nieves Carlos , Colonia Juan Diego
Published: April 2011

Oil pipelines systems for hydrocarbons transportation are linear projects that can reach great lengths. For this reason, theirs paths may cross different geological formations, soil types, navigable or torrential waters; and they may face geotechnical and hydrological instability problems such as creeping slopes, geological faults, landslides, sudden river surges and differential settling which causes different relative movements between the soil and the pipeline. The OCENSA (Oleoducto Central S.A) 30″ and 36″ diameter system was built in 1997 to transport crude oil from the eastern foothills of the Andes to the Caribbean Coast along some 830 km of the Eastern Andes mountains range and the spurs of the central Andes mountains range of Colombia: it was a major challenge to secure the integrity of the pipeline in the face of natural events.
Anisotropy of the Stress-Strain Curves for Line Pipe Steels
Authors: Nagai Kensuke , Shinohara Yasuhiro , Sakamoto Shinya , Tsuru Eiji , Asahi Hitoshi , Hara Takuya
Published: April 2011

To suppress the appearance of Lu¨ders strain and to decrease yield to tensile strength ratio in the L-direction (longitudinal direction), as well as the C-direction (circumferential direction), have been more important for strain-based design. In this study, conventional UOE and ERW pipes were examined in terms of tensile properties in both directions. In the case of UOE pipes, yield point was clearly observed on the stress-strain curve in the C-direction. However, stress-strain curves in the L-direction showed the round-house type. This difference became prominent after heat treatment for the anti-corrosion. Namely, clear Lu¨ders strain appeared in the C-direction at a lower aging temperature compared with that in the L-direction. On the other hand, contrasting results were obtained in the case for ERW pipes. Thus far, it’s been thought that the difference between UOE and ERW pipe was caused by the direction of final strain during the pipe forming process. There are also differences in the occurrence of Lu¨ders strain between each grade. A stress-strain curve maintained the round-house type in X100 grade pipe after the heat treatment at 240°C for five minutes; however, X70 grade pipe showed the stress-strain curve in the L-direction with Lu¨ders strain after the heat treatment at the same temperature.
Development Project of an Automatic Sampling System for Part Time Unmanned Pipeline Terminals
Authors: Moreira Guilherme O. , de Almeida Ma´rcio M. G. , Ramos Ricardo R. , Potten Gary
Published: April 2011

The Sa˜o Paulo–Brasi´lia Pipeline was designed and constructed to be highly automated and is remotely operated by the National Pipeline Control Center in Rio de Janeiro. The terminals along the pipeline are largely unmanned nights and weekends. The PETROBRAS quality control standard establishes practices for tracking, sampling and analyzing product batches transported through the pipeline. A prototype of an automatic sampling system was designed to collect up to ten flow proportional and or instantaneous (“spot”) samples of different product batches transported through the pipeline for any given programmed schedule. This would eliminate the need for operators to be present at the terminals during weekends, holidays and night time to manually collect samples. This paper describes the successful implementation of this project from technical specification of the development of an Automatic Sampling System, the solutions proposed for its special features, the main characteristics of the Technical Cooperation Agreement (TCA) used to develop it and the systematic approach used for design, and factory / field testing phases.