bluuebunny/crossref_metadata_2025 huggingface dataset:
The Microboiling Processes of FC-72 in a Confined Space
Authors: Fernandez Anthony J. , Escobar-Vargas Sergio , Fabris Drazen , Gonzalez Jorge E. , Sharma Ratnesh , Bash Cullen
Published: July 2009

This paper is motivated by the need for efficient control of liquid sprays and presents an experimental effort to characterize the microboiling process of FC-72 in confined micro-heaters. The experimental set up consists of commercial Thermal Ink Jet (TIJ) heads used to boil degassed FC-72 inside a confined chamber with a transparent viewing window. The micro-boiling process is illuminated by a flash lamp and a CCD camera attached to a microscope captures images of the bubble’s growth. Image processing software provides precise quantitative information about the position and projected area of the bubble. The energy ranges applied to the microheater are 5.61μJ to 17.2μJ per pulse. Nucleation times were found to be in the range of 1.2 – 2.4 μs leading to a rapid growth followed by a small shrink from 4–5 μs. Maximum bubble sizes ranged from 1.2 – 2 times larger than the heater area. A faster nucleation time and longer bubble lifecycle are observed for FC-72 when compared to water which is attributed to the lower boiling point and latent heat of FC-72.
Statistical Model of Operational Parameter Influence on Thermal Contact Resistance in Bimetallic L-Type Finned Tubes
Authors: Carvajal-Mariscal Ignacio , Sanchez-Silva Florencio , Polupan Georgiy , Pysmennyy Yevgen
Published: July 2009

Statistical model development of operational parameter influence on Thermal Contact Resistance (TCR) in bimetallic L-type finned tubes is presented in this work. The Group Method of Data Handling (GMDH) scheme was utilized to develop a correlation that encompasses most important operational parameters including variation of temperature difference between hot inner flow and cooling air, influence of maximum operational temperature, and effect of repeated heating-cooling cycles. Using experimental data obtained on Cuprum-Aluminum L-type finned tubes and special calculations with the help of the developed model formulae, have permitted the estimating of degree of every parameter influence upon final function. It was found that maximum operational temperature has most influence on the TCR. Such results may be useful for a practical thermal design, and operation of heat exchangers based on bimetallic L-type finned tubes.
Simulations of Air and Water Ingress Transients for the Pebble Bed Modular Reactor (PBMR) by Means of the TINTE Code
Authors: Sikik Ugur Emre
Published: July 2009

In this study several air and water ingress scenarios for the PBMR [1] were simulated by means of the dynamic reactor code TINTE (TIme-dependent Neutronics and TEmperatures) [2]. The Power Conversion Unit (PCU) and other sub-systems cannot be modelled with the TINTE code and therefore air ingress rates were obtained from Computational Fluid Dynamics (CFD) analysis performed by utilizing the FLUENT code [3]. The use of the TINTE code was previously validated with simulations of the NACOK corrosion experiments [4], [5], [6]. The validations were performed at Forschungszentrum Juelich, however the results are not yet published. The rates of chemical reactions between graphite and gases like O2, CO2, H2O and H2 are negligible below 400°C. Air and water ingress into the PBMR core at high temperatures can result in corrosion of the PBMR fuel spheres and a possible increase in the fission product release rate. The air ingress scenarios included in this study are; a break in the core outlet pipe at the turbine inlet location, which results in air ingress from the outlet plenum, and a break in a pipe that is connected to the top of the Reactor Pressure Vessel (RPV), which results in air ingress from top of the core. For both transients it is assumed that a Depressurized Loss of Forced Cooling (DLOFC) event takes place prior to the air ingress. The DLOFC leads to high fuel and reflector temperatures that allow higher oxidation rates. The results show that the oxidation of graphite structures in the core is more severe in the case of the outlet pipe break transient. A break in the Core Conditioning System (CCS) heat exchanger circuit during a maintenance mode or following a reactor trip could result in water ingress of up to 1000 kg into the core (the primary system is depressurized at this stage). During the water ingress the CCS continuously cools down the core. Due to the low water ingress rate and lower fuel temperatures, the water ingress transient is not as severe as the air ingress transients.
Integrated Systems CFD Modelling Applied to Diffusion-Bonded Compact Heat Exchangers
Authors: Kruger Jan-Hendrik , le Grange Louis A. , Greyvenstein Gideon P.
Published: July 2009

Micro-channel heat exchangers consist of a number of plates, each containing fluid channels etched in the surface and diffusion bonded together to create a porous core of metal. The primary and secondary sides of the exchanger are formed by connecting the channels on alternating plates to the respective leader pipes. To analyze the thermal response of exchangers during operation, simulation software is used to create a network of numerical models representing the real-life thermal-hydraulics components. The Systems CFD approach uses one-dimensional empirical models for the fluid flow inside the channels and a three-dimensional model for the heat distribution inside the core. Spatial analysis of the geometry gives a connectivity stencil between the one- and three-dimensional models. This stencil implicitly links the equations of the models at matrix level in the numerical solver, with faster convergence in fewer iterations than when the models are coupled explicitly in different software applications. Results presented show the heat flux through an exchanger core and the fluid flow inside the channels.
Integration of Nuclear Energy Into Oil Sands Projects
Authors: Finan Ashley , Kadak Andrew C.
Published: July 2009

Energy security and greenhouse gas reductions are thought to be two of the most urgent priorities for sustaining and improving the human condition in the future. Few places pit the two goals so directly in opposition to one another as the Alberta oil sands. Here, Canadian natural gas is burned in massive quantities to extract oil from one of North America’s largest native sources of carbon-intensive heavy oil. This conflict need not continue, however; non-emitting nuclear energy can replace natural gas as a fuel source in an economical and more environmentally sound way. This would allow for the continued extraction of transportation fuels without greenhouse gas emissions, while freeing up the natural gas supply for hydrogen feedstock and other valuable applications. Bitumen production in Alberta has expanded dramatically in the past five years as the price of oil has risen to record levels. This paper explores the feasibility and economics of using nuclear energy to power future oil sands production and upgrading activities, and puts forth several nuclear energy application scenarios for providing steam and electricity to in-situ and surface mining operations. This review includes the Enhanced CANDU 6, the Advanced CANDU Reactor (ACR) and the Pebble Bed Modular Reactor (PBMR). Based on reasonable projections of available cost information, nuclear energy used for steam production is expected to be less expensive than steam produced by natural gas at current natural gas prices and under $7/MMBtu (CAD). For electricity production, nuclear becomes competitive with natural gas plants at natural gas prices of $10–13/MMBtu (CAD). Costs of constructing nuclear plants in Alberta are affected by higher local labor costs, which this paper took into account in making these estimates. Although more definitive analysis of construction costs and project economics will be required to confirm these findings, there appears to be sufficient merit in the potential economics to support further study. A single 500MWth PBMR reactor is able to supply high-pressure steam for a 40,000 to 60,000 bpd Steam Assisted Gravity Drainage (SAGD) plant, whereas the CANDU and ACR reactors are unable to produce sufficient steam pressures to be practical in that application. The CANDU, ACR and PBMR reactors have potential for supplying heat and electricity for surface mining operations. The primary environmental benefit of nuclear energy in this application is to reduce CO2 emissions by up to 3.1 million metric tons per year for each 100,000 barrel per day (bpd) bitumen production SAGD facility, or 2.0 million metric tons per year for the replacement of 700MWe of grid electricity with a nuclear power plant. Should carbon emissions be priced, the economic advantages of nuclear energy would be dramatically improved such that with a $50/ton CO2e at the releases expected for typical projects using natural gas, breakeven gas prices for nuclear drop to less than $3.50/MMBtu, well below the current natural gas price of $10/MMBtu for SADG steam production.
Development of a CFD Analysis Plan for the First VHTR Standard Problem
Authors: Johnson Richard W.
Published: July 2009

Data from a scaled model of a portion of the lower plenum of the helium-cooled very high temperature reactor (VHTR) are under consideration for acceptance as a computational fluid dynamics (CFD) validation data set or standard problem. A CFD analysis will help determine if the scaled model is a suitable geometry for validation data. The present article describes the development of an analysis plan for the CFD model. The plan examines the boundary conditions that should be used, the extent of the computational domain that should be included and which turbulence models need not be examined against the data. Calculations are made for a closely related 2D geometry to address these issues. It was found that a CFD model that includes only the inside of the scaled model in its computational domain is adequate for CFD calculations. The realizable k∼ε model was found not to be suitable for this problem because it did not predict vortex-shedding.
Statistical Maintenance Optimization Approach at Bruce Power
Authors: Doyle E. Kevin , Tuomi Vesa
Published: July 2009

The current reality of global competition and the deregulation of utilities necessitates the pursuit of all financial optimizers. At present, statistical modeling is not used in the conventional maintenance decisions of capital intensive industries such as nuclear, an industry that represents hundreds of billions of dollars of industrial infrastructure. Successful evaluations of Statistical Maintenance Techniques at Bruce Power have resulted in the decision to implement a plant wide program to help optimize the maintenance function. This paper contains a brief summary of some of these evaluations.
Simulation of TOSQAN 101 Containment Spray Test With Combined Eulerian CFD and Droplet-Tracking Modelling
Authors: Babic´ Miroslav , Kljenak Ivo , Leskovar Matjazˇ , Mavko Borut
Published: July 2009

The purposes of containment spray system operation during a severe accident in a light water reactor (LWR) nuclear power plant (NPP) are to depressurize the containment by steam condensation on spray droplets, to reduce the risk of hydrogen burning by mixing the containment atmosphere, and to collect radioactive aerosols from the containment atmosphere. While the depressurization may be predicted fairly well using lumped-parameter codes, the prediction of mixing and collection of aerosols requires a local description of transport phenomena. In the present work, modelling of sprays on local instantenous scale is presented and the Design of Experiment (DOE) method is used to assess the influence of boundary conditions on the simulation results. The TOSQAN 101 spray test, which was used for a benchmarking exercise within the EU Severe accident research network of excellence (SARNET), was simulated, and simulation results were compared to experimental data. The modelling approach is based on a Lagrangian description of the dispersed liquid phase (droplets), an Eulerian approach for the description of the continuous gas phase, and a two-way interaction between the phases. The simulations are performed using a combination of the computational fluid dynamics (CFD) code CFX4.4, which solves the gas transport equations, and of a newly proposed dedicated Lagrangian droplet-tracking code. The intent of the presented work is to assess the modeling of sprays and liquid on the wall in the presented approach with the emphasis on the heat and mass transfer between liquid and gas phase. The simulation-experiment comparison of available global and local variables demonstrates that the proposed approach is suitable for prediction of global variables evolution and of the non-homogenous structure of the atmosphere. The boundary condition steady-state sensitivity study is performed and shows that the global variables are mostly affected by the wall temperature boundary condition.
Loop Studies Addressing the Hydraulic Impact From the Presence of Part-Length Fuel Rods Within a BWR Fuel Element, Using Water and Air-Water Mixtures at Room Temperature and Low Pressure
Authors: Sadeghi Hamid , Blomstrand Jan , Urrutia Guillermo
Published: July 2009

There are a number of reactivity incidents which could possibly occur at low pressure in boiling water reactor (BWR) cores, and some of them may cause local boiling — entailing reactivity feed-back. Unfortunately, theoretical studies of events of this nature are somewhat hampered by the dearth of knowledge about the thermal-hydraulics involved. The research presented here addresses one particular aspect of this issue: how is BWR core thermal-hydraulics — at low pressure — affected in such fuel assemblies where some full-length rods have been replaced by part-length rods?
The VR Simulation for Spent Fuel Reprocessing
Authors: Zhu Bo , Yang Yanhua
Published: July 2009

The spent fuel disposal is a very important step during the recycling of nuclear fuel and the operation process is very complex and dangerous. With the fast development of nuclear power reactor in china, more and more spent fuel will occur and should be treated in the near future. For researching the spent fuel management and training the operators, we have been developing the virtual reality (VR) Simulation System for spent fuel reprocessing (VRSS) aimed at demonstrating and analyzing the treatment process. The VRSS is based the VR and visualization technology. Combined with the regulation of radiation protection, the integrated virtual operate environment is developed to enable user navigation the working place, and obtain target information “it can demonstrate the structure and component of equipment, it also can illustrate the disassembly craft transform principle and the operation way of extraction facility. It even can prompt the user how to operate when spent fuel handling accident occur.
Analyses of Free Span Oxide Layers on SG Tubes of NPP Temelin
Authors: Hojna A. , Hanus V. , Pisarik V. , Postler M. , Burda J. , Karnik D.
Published: July 2009

The differences in deposit layers on steam generator (SG) tubes of WWER NPP Temelin have been observed, namely in compactness and adhesiveness. The samples of the oxide layers have been taken from different SG during outage of the two units and analyzed. Results of the analyses are compared to previous results on deposit layers created during operation of SG model. The model simulates secondary side of SG tubes operation; the original feed water from the NPP Temelin has been used for tests. Deposit built up on tubes inside the model on the free surface is related to the real SG tube deposits and differences of the oxide layer morphologies are discussed.
Codes, Standards and Regulatory Topics for Nuclear Facilities
Authors: Wilde Taunia , Baker Shannan , Sandquist Gary M.
Published: July 2009

The design, construction, operation, maintenance, and decommissioning and decontamination of nuclear infrastructure particularly nuclear power plants licensed in the US by the US Nuclear Regulatory Commission (NRC) or operated by the US Department of Energy (DOE) or the US Department of Defense (DOD) must be executed under a rigorous and documented quality assurance program that provides adequate quality control and oversight. Those codes, standards, and orders regulate, document and prescribe the essentials for quality assurance (QA) and quality control (QC) that frequently impact nuclear facilities operated in the US are reviewed and compared.
Simple Analytical Models for Beams and Slabs Under Soft Impacts at Medium Speed
Authors: Rambach J.-M. , Tarallo F.
Published: July 2009

A simply supported reinforced concrete slender beam is modeled by 3 rigid consecutive elementary beams, the median beam being connected to the others by 2 viscous and elastoplastic spiral springs. The model can be assimilated as a non linear SDOF system convenient for the motion study of beams within flexural deformation domain, with displacements up to the height of the beam. The characteristics of the visco-elastoplastic springs are tuned so as be consistent with the beam motion before and after impact: the rigidity of the elastic domain of the springs is consistent with natural vibration frequencies which may be reduced after the impact due to subsequent damages. The motion of the beam during and after the impact is analyzed with such model: the values of the main mechanical characteristics (rigidity, plastic limit, viscous damping) may then be obtained. The impact tests performed by VTT (Finland) on one-way concrete slabs consolidate this approach and give consistent experimental values for the elastoplastic laws to be introduced in the model. With this experimental validation, the model may be used as a predictive tool for resistance and for displacements, as far as reinforced concrete beams and slabs are concerned. A thin reinforced concrete slab, simply supported along its 4 edges, is modeled by 4 to 5 rigid trapezoidal elementary slabs connected together by visco-elastoplastic spiral springs along the hinges. A non linear SDOF system is then developed to capture the behavior of such a slab within a flexural deformation domain, with displacements up to the slab thickness. The mechanism involving large shear deformations under the impact (“punching cone”) is taken into account by adding a second degree of freedom. The existing tests on reinforced concrete slabs submitted to medium velocity impacts found in literature may be used to consolidate this approach and to specify the values to be introduced in the model. The model will be used to analyze the forthcoming results (in terms of resistance and displacements) of VTT impact tests on simply supported reinforced concrete slabs. The behavior of civil works structures submitted to impacting missiles can nowadays be analyzed either with sophisticated FE calculation codes, or with analytical models. These analytical models may constitute simple but useful engineer’s tools for sensitivity analyses and for results checking of the necessary more sophisticated computation codes, in terms of resistance and in terms of displacement. They may be simply implemented on any spreadsheet software.
Convective Heat Transfer to CO2 at a Supercritical Pressure Flowing Vertically Upward in Tubes and an Annulus Channel
Authors: Bae Yoon-Yeong , Kim Hwan-Yeol , Kang Deog-Ji
Published: July 2009

Extensive experiments on heat transfer at a supercritical pressure to CO2 in tubes and annular channels have been performed. The geometries of the test sections include tubes of an internal diameter of 4.4 and 9 mm and an annular channel (8 × 10 mm). Based on the test results a set of correlations, which covers a deteriorated heat transfer regime as well as a normal heat transfer regime, was developed.
Analysis of Protected Accidental Transients in the EFIT Reactor With the RELAP5 Thermal-Hydraulic Code
Authors: Bandini Giacomino , Casamirra Maddalena , Castiglia Francesco , Giardina Mariarosa , Meloni Paride , Polidori Massimiliano
Published: July 2009

The European Facility for Industrial Transmutation (EFIT) is aimed at demonstrating the feasibility of transmutation process through the Accelerator Driven System (ADS) route on an industrial scale. The conceptual design of this reactor of about 400 MW thermal power is under development in the frame of the European EUROTRANS Integrated Project of the EURATOM Sixth Framework Program (FP6). EFIT is a pool-type reactor cooled by forced circulation of lead in the primary system where the heat is removed by steam generators installed inside the reactor vessel. The reactor power is sustained by a spallation neutron source supplied by a proton beam impinging on a lead target at the core centre. A safety-related Decay Heat Removal (DHR) system provided with four independent inherently safe loops is installed in the primary vessel to remove the decay heat in case of loss of secondary circuits heat removal capability. A quite detailed model of the EFIT reactor has been developed for the RELAP5 thermal-hydraulic code to be used in preliminary accidental transient analyses aimed at verifying the validity of the adopted solutions for the current reactor design with respect to the safety requirements, and confirm the inherent safety behavior of the reactor, such as decay heat removal in accidental conditions relying on natural circulation in the primary system. The accident analyses for the EFIT reactor include both protected and unprotected transients, on whether the reactor automatic trip, consisting in proton beam switch off, is actuated or not by the protection system. In this paper, the main results of the analyses of some protected transients with RELAP5 are presented. The analyzed transients concern the Protected Loss of Heat Sink (PLOHS), in which the DHR system plays a key role in bringing the reactor in safe conditions, and the Protected Loss of Flow (PLOF) transients with partial or total loss of forced circulation in the primary system.
Recent Advances in Nuclear-Based Hydrogen Production With the Thermochemical Copper-Chlorine Cycle
Authors: Naterer G. F. , Gabriel K. , Wang Z.
Published: July 2009

This paper presents a review of recent advances in nuclear-based hydrogen with the thermochemical copper-chlorine cycle. Growing attention has focused on thermochemical water decomposition as a promising alternative to steam-methane reforming as a sustainable future method of hydrogen production. Recent advances of specific processes within the Cu-Cl cycle will be presented, particularly for purposes of calculating the overall heat requirements of the cycle and preferred configurations of the oxygen cell, disposal of molten salt and the electrochemical process of copper electrowinning. Energy balances for each individual process will be formulated and numerical results will be obtained for the heat requirements of the chemical reactors.
Development of Full Scale Reactor Coolant Pump Thrust Bearing Test System and Qualification Process for Retrofit Thrust Bearing Oil Seal With Commercial Grade Components
Authors: Sinkhorn Jason , Mendez William
Published: July 2009

A fleet of reactor coolant pump thrust bearings were experiencing loss of oil inventory through a face rubbing mechanical oil seal. In a span of six months, Westinghouse developed a replacement seal which retrofit into the existing bearing, erected a full scale bearing test system, operated the prototype seal through various operating conditions utilizing Six Sigma Design of Experiments methodology, qualified the seal for sustained use in an operating reactor plant and supported the installation of the retrofit seals. The retrofit seal replaced a problematic face rubbing seal with a controlled leakage design utilizing a floating ring — a pressure reducing bushing free to translate in the X-Y plane. The prototype seal system was optimized through use of the Design of Experiments. Design optimization was aimed at reducing oil aeration to levels lower than those present with the original equipment, which when achieved, provided improved heat transfer from the bearing. The test system was constructed around a production thrust bearing, identical to those installed in the plant, which was modified to facilitate collection of a variety of process variables. In all, the system was capable of simultaneously sampling and storing data from 56 separate channels; while recording digital video from eight sources, from cameras both inside and outside of the bearing. All in-service operating parameters were duplicated by the test system, including: computer controlled variable vertical thrust load from zero to 90 tons, computer controlled variable radial thrust load and acceleration from standstill to operating speed in 16 seconds. Safe shutdown operating variables were monitored automatically by the system, in the event of a faulted condition the system automatically detected the fault and initiated a safe shutdown automatically. To date, all installed seal systems have performed as designed; allowing essentially no leakage at this location from the bearing reservoir. The test system continues to be used on development projects focused on improving other aspects of the bearing’s performance.
Heat-Affected Zone Hardness Limits for In-Service Welding
Authors: Bruce William A. , Etheridge Bradley C. , Carman Andrew
Published: July 2009

Welds made onto in-service pipelines are particularly susceptible to hydrogen cracking. During qualification of welding procedures, limits are often imposed on heat-affected zone hardness (e.g., 350 HV max.) as a way to avoid cracking. The hardness level below which hydrogen cracking does not occur is not a fixed value, but varies as a function of several parameters. The results of previous work resulted in the development of hardness evaluation criteria that can be used to quantify the trade-offs that can be made between HAZ hardness, hydrogen level, and the chemical composition of the materials being welded for welds made onto in-service pipelines. This paper describes a current project that is being sponsored in part by the US Department of Transportation – Pipeline and Hazardous Materials Safety Administration, which is focusing on the further development and validation of these criteria, particularly for modern microalloyed materials and material over a wide range of wall thicknesses. The use of these criteria will reduce the cost and increase the reliability of pipeline modifications and repairs.
A Study on Cold Region Pipeline Design Based on Full-Scale Experiment
Authors: Tanaka Toshiya , Haung Scott , Fukuda Masami , Bray Matthew T. , Akagawa Satoshi
Published: July 2009

One of the major technical challenges in constructing natural gas pipeline is how to cope with cold region pipeline engineering aspects caused by freezing and thawing of soil around the pipeline. A pipeline running through discontinuous permafrost is subject to the potential risk of an unacceptable deformation, which is caused by thaw settlement or frost heaving at the boundary of permafrost and non-permafrost. It is important for a design engineer to predict the behavior of soil-pipeline interaction and make an adequate assessment of safety of pipeline in such portion. Although extensive efforts have been made to document those aspects, relatively little research has been carried out to comprehensively study the behavior of pipeline in response to short- and long-term change of thermal and mechanical properties of permafrost. In order to understand the complex behavior of natural gas pipeline and surrounding soil in cold regions, a full-scale experimental gas pipeline was constructed near Fairbanks, Alaska and had been studied intensively. The research project was carried out from the year of 1999 to 2004 under the sponsorship of Japan Science and Technology. The changes of ground thermal regime, vertical movement of the pipeline and the induced bending stress in the pipes were studied. The research team including researchers from Japan and the U.S collected and analyzed the field measurements from the test site. In this paper, the major findings and lessons learned from the project will be presented together with the result of numerical simulations related to the experiment.
Steel Storage Tank Shell Settlement Assessment Based on Finite Element and API Standard 653 Analyses
Authors: Chebaro Mohamed R. , Yoosef-Ghodsi Nader , Yue Howard K.
Published: July 2009

API Standard 653 addresses issues related to the inspection, repair, alteration and reconstruction of steel storage tanks built according to API Standard 650 or API 12C to help maintain tank integrity. Although the standard covers three types of tank settlement, namely edge, bottom and shell, this paper focuses on the assessment of shell settlement. It also provides a comparison between an analytical model based on API Standard 653 and a finite element analysis (FEA) model that replicates field operating loading and settlement conditions of storage tanks. A basis for comparison between both models was established from the maximum allowable settlement and strain values. Several scenarios were generated using actual field data collected from steel storage tanks located in Alberta to illustrate the correlation between the two models. Specific information on the storage tanks under consideration cannot be disclosed for confidentiality reasons.
A FAD-Based Procedure for Defect Assessments of Welded Structures Including Effects of Weld Strength Mismatch: Micromechanics Approach and Application to Pipeline Girth Welds
Authors: Donato Gustavo H. B. , Ruggieri Claudio
Published: July 2009

ECA procedures of crack-like defects based upon the FAD philosophy have undergone extensive developments in the past decade to form the basis for industrial codes and guidelines for structural integrity assessments. However, the application of these procedures in welded structural components with mismatch in tensile properties between the weld and base metal remains a potential open issue. Weld strength mismatch may significantly alter the crack-tip driving forces, such as J and CTOD, thereby producing crack-tip stresses quite different than the fields that arise in corresponding homogeneous material. Weld strength mismatch also affects the plastic collapse load for the structural component which further complicates the interplay between fracture and plastic instability before gross yield section takes place. This work describes the development of a microme-chanics-based FAD methodology building upon a local fracture parameter, characterized by the Weibull stress (σw), to incorporate the effects of weld strength mismatch on crack-tip driving forces. As a further refinement, the study also addresses an exploratory application of a limit load analysis including effects of weld strength mismatch to correct the loading trajectory incorporated into the FAD procedure. Fracture testing of girth welds obtained from an API X80 pipeline steel provide the data needed to validate the proposed modified FAD procedure in failure predictions. Such an application serves as a prototype for a wide class of integrity assessment problems involving the effects of weld strength mismatch.
Effects of Soil Cohesiveness and Depth on Dynamic Ductile Fracture Speeds
Authors: Rudland D. , Shim D.-J. , Wilkowski G. M. , Kawaguchi S. , Hagiwara N. , Horsley D.
Published: July 2009

The ductile fracture resistance of newer line pipe steels is of concern for high grade/strength steels and higher-pressure pipeline designs. Although there have been several attempts to make improved ductile fracture arrest models, the model that is still used most frequently is the Battelle Two-Curve Method (TCM). This analysis incorporates the gas-decompression behavior with the fracture toughness of the pipe material to predict the minimum Charpy energy required for crack arrest. For this analysis, the influence of the backfill is lumped into one empirically developed “soil” coefficient which is not specific to soil type, density or strength. No attempt has been made to quantify the effects of soil depth, type, total density or strength on the fracture speeds of propagating cracks in line pipe steels. In this paper, results from small-scale and large-scale burst tests with well-controlled backfill conditions are presented and analyzed to determine the effects of soil depth and cohesiveness on the fracture speeds. Combining this data with the past full-scale burst data used in generating the original backfill coefficient provides additional insight into the effects of the soil properties on the fracture speeds and the arrest of running ductile fractures in line pipe materials.
Qualification of ILI Performance in Accordance With API 1163 and the Potential Impact for Management of Pipeline Integrity
Authors: Tomar Munendra S. , Fingerhut Martin , Yu Deli
Published: July 2009

Characterizing the performance of In Line Inspection (ILI) continues to be a subject of ongoing debate. Knowing the accuracy and reliability of ILI measurements is important for determining optimum integrity rehabilitation project scope, re-inspection interval and the risk associated with the pipeline section examined. The introduction of API 1163 (In-Line Inspection Systems Qualification Standard) is a positive step in defining the key metrics for qualification of ILI results. Qualifying these metrics requires verification measurements having accuracies an order of magnitude higher than in-line-inspection. LasersureSM provides a process which uses high resolution, high accuracy, in-the-ditch, Laser Profilometry measurements which satisfies these requirements and therefore is well suited for this purpose. This presentation will identify the components of the LasersureSM process and through example the potential impact of this process for management of pipeline integrity.
Inspection & Assessment of Damaged Subsea Pipelines: A Case Study
Authors: Espiner Richard , Kaye David , Goodfellow Graham , Hopkins Phil
Published: July 2009

The Central Area Transmission System (CATS) in the UK sector of the North Sea delivers natural gas through a 404 km pipeline from the CATS riser platform to the North East coast of England. During the summer of 2007 this 36 inch diameter natural gas pipeline was damaged by a vessel anchor. The anchor lifted the pipeline from under the seabed, dragged it across the seabed, bending the pipe and locally deforming it. This event resulted in a significant inspection, assessment and repair programme before the pipeline could safely return to operation. This paper describes the detailed structural assessment of the damaged pipeline and the inspection and repair operations. Following inspection of the pipeline by divers, the damage was assessed using the “Pipeline Defect Assessment Manual” (PDAM). The manual was prepared from research primarily for onshore pipelines: this paper discusses the strengths and weaknesses of PDAM and key differences in defect assessment for onshore and offshore pipelines. The paper highlights several very important lessons learnt from this incident, including: • the complex stresses developed in a pipeline that is pulled and moved by an anchor; • the need for damage assessment methods for pipe containing high compressive stresses and ‘locked-in’ stresses; • the safety aspects and complexity of inspecting a pressurised and damaged subsea pipeline. These lessons learnt are then translated into recommendations for the industry, and advice to other subsea pipeline operators.
Strain Capacity of X100 High-Strain Linepipe for Strain-Based Design Application
Authors: Igi Satoshi , Kondo Joe , Suzuki Nobuhisa , Zhou Joe , Duan Da-Ming
Published: July 2009

In recent years, several natural gas pipeline projects have been planned for permafrost regions. Pipelines laid in such areas are subjected to large plastic deformation as a result of ground movement due to repeated thawing and freezing of the frozen ground. Likewise, in pipeline design methods, research on application of strain-based design as an alternative to the conventional stress-based design method has begun. Much effort has been devoted to the application of strain-based design to high strength linepipe materials. In order to verify the applicability of high-strain X100 linepipe to long distance transmission, a large-scale X100 pipeline was constructed using linepipe with an OD of 42″ and wall thickness of 14.3mm. This paper presents the results of experiments and Finite Element Analysis (FEA) focusing on the strain capacity of high-strain X100 linepipes. The critical compressive strain of X100 high-strain linepipes is discussed based on the results of FEA taking into account geometric imperfections. The critical tensile strain for high-strain X100 pipelines is obtained based on a curved wide plate (CWP) tensile test using specimens taken from girth welded joints. Specifically, the effect of external coating treatment on the strain capacity of X100 high-strain linepipe is investigated. The strain capacity of the 42″ X100 pipeline is considered by comparing the tensile strain limit obtained from girth weld fracture and critical compressive strain which occurs in local buckling under pure bending deformation.
Data Mining Seismic Shothole Drillers’ Log Records: Regional Baseline Geoscience Information in Support of Pipeline Proposal Design, Assessment, and Development
Authors: Smith I. Rod
Published: July 2009

Assessment and development of pipeline projects in northern Canada, such as the proposed Mackenzie Valley gas pipeline (MGP), are hampered by a lack of baseline terrain geoscience information including drift thickness, sediment type, presence of massive ground ice, and the availability of granular aggregate resources. Clearly there is a need by Industry, Regulators, Aboriginal groups, and others, to understand the nature and character of near-surface earth materials, in order that pipeline proposals can be properly developed, evaluated, and when approved, proceed with the greatest degree of environmental sustainability and economic efficiency. While numerous field-based reports and surficial geology maps have been prepared for the MGP, there are long stretches along the proposed route for which little near-surface geoscience information is available. This is even more apt for areas outside the defined MGP corridor, where the likelihood of tie-in and gathering pipeline systems exist. Drillers’ logs, recorded during auger drilling of seismic shotholes, represent a virtually untapped resource of regional baseline geoscience information. The Geological Survey of Canada recently produced a digital archive of 76,000 shothole records from the Northwest Territories and Yukon, which had originally been collected on file cards in response to the 1970’s MGP proposal. Released in 2007 as a freely downloadable Open File report (#5465), the archive provides users with an Access database of drillers’ logs and derivative GIS maps in which shapefiles of drift isopach thickness, potential granular aggregate resources, geohazards, permafrost and ground ice occurrences, and muskeg thickness can be opened, viewed, and queried, or otherwise incorporated into GIS platforms of the user’s choice. Realizing the amount of additional archival shothole information held by Industry, and the great utility of bringing this forth in a public database and derivative GIS, a subsequent project has focused on capturing and integrating additional data. Receiving near-universal support by the Petroleum Industry, a Version 2 of the database and GIS is currently being assembled, and is scheduled for release in 2009 with some quarter million individual shothole drillers’ records. This presentation highlights the nature, character and distribution of shothole drillers’ logs in northern Canada. It also reviews the derived GIS layers, and how this baseline geoscience information can be beneficially utilized by the Pipeline and related infrastructure development industries, particularly as it may apply to focusing future field studies. It also serves as a key reference tool for those assessing pipeline development proposals.
Converting Moist Air Into Water and Power
Authors: Vidmar Robert J.
Published: July 2009

A method to process moist air into dry air and water results in a surplus of energy for the process. The sun evaporates water everywhere on earth and expends 2.26 MJ/kg (429.9 Btu/lbm) for each kg (2.204 lbm) of water evaporated. A mass of 1 kg (2.204 lbm) of water with a mixing ratio of 0.3% in dry air represents 2.26 MJ (199 Btu) of latent heat energy distributed in a volume of approximately 333 cubic meters (11,759 cubic feet). A system is described by which ambient water vapor is enriched, condensed with the release of latent heat in a heat-exchange boiler, which vaporizes a working fluid used in a Rankine-cycle turbine generator system. Water vapor enrichment is achieved with a vapor-separation barrier. Fans draw moist air through an air-intake system which brings the air into contact with a large surface-area vapor-separation barrier. The intake of a compressor imposes a vacuum on the extraction side of the barrier at a pressure that is lower than the ambient water-vapor pressure. This pressure difference drives water vapor across the barrier into the compressor. A two-stage compressor is used to maintain the low pressure and convey water vapor at high temperature and near atmospheric pressure to a heat-exchange boiler. Two processes occur in the heat-exchange boiler: 1) water vapor condenses and is pumped out of the boiler, and 2) heat is transferred to a working fluid that vaporizes. The vaporized working fluid drives a turbine in a Rankine cycle with condenser. Exhaust heat from the turbine is dissipated with a water-cooled condenser. An air-cooled rock-bed system is suggested as an alternative, when water cooling is not possible. Current advances in materials, the efficiency of turbomachinery, and the effectiveness of heat exchangers suggest that a system can be conceived that is completely fueled by moist air and produces water and excess shaft horsepower that can be converted into electricity. The analysis treats turbomachinery and heat exchangers as ideal components constrained by the Carnot and isentropic efficiencies. Pumps and fans are treated as components with state-of-the-art efficiency. System computations for an ideal 100% efficient system indicate that approximately 25% of the latent heat can be converted to electricity. For a system made with contemporary state-of-the art components a yield of a few percent is predicted. Principles of operation and engineering details are quantified.
Fossil Steam Turbine Upgrades/Modernizations: Case Studies of Recently Completed Projects and the Industry Challenges Moving Forward
Authors: Smiarowski Michael
Published: July 2009

Siemens Power Generation has recently completed a number of first time applications of Steam Turbine modernizations on its OEM fleet. This paper will discuss the R&D approach taken in developing these first-time solutions to help achieve and focus on case studies of completed projects that demonstrate the end result of this approach. Projects planned to be discussed are modernizations implemented in the last year (2007–2008) of a VHP/HP turbine steam path replacement, a full element HP/IP replacement, and applications on large fossil LP turbine replacements. Current industry challenges that will be discussed include resource constraints in engineering, material supply chain, and factory delivery slots that are escalating prices and increasing delivery times of replacement turbine equipment. Some of the actions the author’s company is taking to mitigate these issues, such as gaining earlier commitments, use of material indices, and others will be discussed to help utilities looking at undertaking a turbine modernization gain a better insight into vendor challenges.
Fully Reversed Electric Fatigue Behavior of a Piezoelectric Composite Actuator
Authors: Woo Sung-Choong , Goo Nam Seo
Published: July 2009

The aim of this study is to investigate fully reversed electric fatigue behavior of a piezoelectric composite actuator (PCA). For that purpose, fatigue tests with different loading conditions have been conducted and the performance degradation has been monitored. During a preset number of loading cycles, non-destructive acoustic emission (AE) tests were used for monitoring the damage evolution in real time. The displacement-cycle curves were obtained in fully reversed cyclic bending loading. The microstructures and fracture surfaces of PCA were examined to reveal their fatigue damage mechanism. The results indicated that the AE technique was applicable to fatigue damage assessment in the piezoelectric composite actuator. It was shown that the initial damage mechanism of PCAs under fully reversed electric cyclic loading originated from the transgranular fracture in the PZT ceramic layer; with increasing cycles, local intergranular cracking initiated and the either developed onto the surface of the PZT ceramic layer or propagated into the internal layer, which were some different depending on the drive frequencies and the lay-up sequence of the PCA.
Synthesis and Characterization of LDPE-Carbon Nanotube Composite Foams
Authors: Rizvi Reza , Naguib Hani
Published: July 2009

This study details the synthesis and characterization of composites and composite foams of low-density polyethylene (LDPE) and multi-walled carbon nanotubes (MWCNT). LDPE-MWCNT composites were prepared by melt blending the components in a twin screw compounder and their foams were produced by batch foaming using CO2 as the blowing agent. The composites were characterized for dispersion using SEM and image results indicate good dispersability of MWCNT in LDPE with the formation of a MWCNT network in the LDPE matrix. Thermal and rheological properties of the composites were characterized and results indicate that even a small amount (1 wt.%) of MWCNTs can significantly affect the crystallization kinetics and the rheological behavior. Batch foaming results of the composites depict MWCNTs as heterogeneous nucleation sites for gas bubbles as indicated by the increase in cell density of the composite foams when compared to LDPE foams.
Energy Harvesting With Piezoelectric Unimorph Circular Diaphragms
Authors: Mo Changki , Clark William W. , Radziemski Leon J.
Published: July 2009

This paper presents an experimental comparison of energy generating performance between piezoelectric harvesters for use in a pressure-loaded system. The energy harvesters in this study are simply-supported, partially covered piezoelectric unimorph circular diaphragms to capture and transfer biomechanical energy into electrical power for implantable medical devices. Experimental results indicate that both PMN-PT and PZT harvesters can generate useful power that might meet requirements for specific implants under the uniform cyclic pressure loading of 40mmHg blood pressure variation, but the PMN-PT harvester demonstrates over twice the power generating performance of the PZT harvester under the same pressure loading condition.