bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numerical Analysis of Shell-Side Flow Field Characteristics of Condenser in Nuclear Power Plant
Authors: Dai Shoubao , Xu Huiqiang , Zhan Tengteng , Zhang Dongyang 
Published: December 2022

Abstract
Integrated and modular design is an inevitable requirement for marine nuclear power plant to realize high power under the condition of limited cabin capacity. Heat exchange equipment is an important part of marine power system, occupying a large amount of space weight. The extensive development and application of multi-medium casing integrated condenser has a decisive influence on the improvement of comprehensive performance of marine such as high power and flexibility.
In this paper, according to the compact structure and operation characteristics of the condenser of nuclear power plant, the finite volume method is used to calculate the air, steam flow and condensation process. The model adopts continuous porous media to simplify the tube bundle structure, flow and heat transfer process. The influence of tube bundle and corresponding solid structure on steam flow and heat transfer process is characterized by defining the resistance coefficient of porous medium and heat transfer term.
The model developed in this paper is used to simulate the flow field on the shell side of a condenser sample, and the calculation results are compared with the experiment results, which verify the accuracy of the model. This model is used to simulate and analyze the characteristics of multi-media flow field on the shell side of the casing integrated condenser, which provides an effective means for the structural optimization design and operation of the integrated condenser.
Experimental Study of Droplets Collision and Bag Breaking in Rotating Gas Flow Field
Authors: Ouyang Shuo , Xiong Zhenqin , Zhao Jiyun , Kang Ruiqi , Li Zhen 
Published: December 2022

Abstract
In swirl-vane separators, the liquid phase is separated from the rotating gas flow under the action of centrifugal force. The droplets are carried by the rotating gas flow to the wall of the separator. In this paper, the phenomenon of a single droplet hitting on a stationary droplet on the wall in the rotating flow field is recorded by using a high-speed camera. Different types of droplet collisions appear as the inlet airflow velocity increases from 4 m/s to 4.8 m/s. Results show that the binary droplet impacts in the rotating flow field occur in asymmetric outcomes such as coalescence, finger spreading, finger breaking and splashing with the increase of the Weber number. The spiral characteristic of the rotating flow field leads to the asymmetry of the droplet collision. The bag breaking occurs in the rotating flow field. The number of droplets of bag breaking and breaking time are increased with Weber number increasing. This study provides basic characteristics for the impact of binary droplets in the rotating flow field and bag breaking, as well as improves the understanding of the separation efficiency mechanism of the gas-liquid separator.
Numerical Analysis on Heat Transfer Characteristics and Buoyancy Effects of Supercritical Pressure Water in Vertical Tube
Authors: Lou Yining , Zhang Zhen 
Published: December 2022

Abstract
Water is widely used in various nuclear power plants as coolant and moderator due to its good thermal conductivity and stability. However, when the pressure and temperature exceed its critical points, the physical properties of water change drastically, especially the specific heat capacity, which makes the heat transfer phenomenon near the critical point more complicated, even deteriorating. On the other hand, the curved geometry of the spiral pipe leads to a special secondary flow phenomenon in the fluid, which will intensify the heat and mass transfer and improve the heat transfer efficiency. At the same time, the flow will be more complicated in the joint influence of gravity, centrifugal force and Coriolis force. This paper studied the heat transfer characteristics of supercritical water in heated vertical tube by numerical simulation and found that changes of physical properties are the main reason for changes of heat transfer characteristics of supercritical water. And as the heat flux in the tube wall increases, heat transfer deterioration is more prone to occur around the pseudo-critical point. Then it verified the relationship between the criterion of buoyancy and heat transfer deterioration. Last, it explained the mechanism of heat transfer deterioration caused by buoyancy effect by calculating shear stress. In the future, works on the relationship between Bo* and shear stress are expected to carried out.
Effects of Power Oscillations on Natural Circulation Flow Instability With a Neutronic-Thermo-Hydraulic Loop
Authors: Chen Xianbing , Long Chengyi , Zhu Dongbao , Gao Puzhen , Kong Xiaming , Yao Lu 
Published: December 2022

Abstract
Nuclear power in a water-cooled reactor changes with reactivity under the influence of temperature and void fraction. Effects of power oscillations on natural circulation are experimentally investigated with a neutronic-thermo-hydraulic loop to better understand neutronic-thermo-hydraulic effects. Heating power can be precisely controlled by a DC power supply. Both stable natural circulation flow and flow instability experiments are conducted. Amplitude of flow oscillations increases with the increase of amplitude of power oscillations for the stable natural circulation flow. Period and amplitude of power oscillations are compared with those of flow oscillations. Period of flow oscillations corresponds with the period of power oscillations due to the relative balance between driving force and resistance. Amplitude and period of power oscillations are changed to obtain stability boundary by keeping other parameters constant. Experimental results indicated that small amplitude and short period power oscillations has little influence of the stability boundary. However, power oscillations cause the premature of flow instability when period and amplitude of power oscillations are further increased. The destabilizing effects of power oscillations on natural circulation flow depend on the period and amplitude. The stability region reduces with the increase of amplitude and period of power oscillation in this experimental loop.
Multiscale Thermal-Hydraulic Analysis of the ATHENA Core Simulator
Authors: Cioli Puviani Pietro , Di Piazza Ivan , Marinari Ranieri , Zanino Roberto , Tarantino Mariano 
Published: December 2022

Abstract
The Advanced Thermal Hydraulic Experiment for Nuclear Application (ATHENA) will play a fundamental role in the design, safety assessment and thermal-hydraulic (TH) characterization of the ALFRED reactor components. In ATHENA, full-scale systems and their mutual interactions will be tested in steady state and relevant transient conditions. The Core Simulator is the electrical heating system and aims to be representative of an ALFRED average fuel assembly (FA). CFD codes are gaining attention for the analysis of complex systems in pool-type reactors, since they are able to reproduce with high accuracy 3D TH phenomena. In this paper a multiscale approach based on porous media (PM) is proposed to reduce the computational cost of the Core Simulator CFD model. Firstly, the PM hydraulic behavior is characterized by means of CFD simulations on the infinite lattice domain. Then PM are applied in the system model in place of fuel assemblies (FAs). Three different approaches are investigated: (1) adopting a single porous domain for the entire FA ; (2) representing the FA with two porous domains; (3) adopting the so-called hybrid medium model. The results obtained with the PM models are validated against a detailed CFD simulation of the Core Simulator to evaluate the performance of the three approaches. Then, the best solution is applied on a model of the entire ATHENA Core Simulator integrated with the feeding region. The model is tested in simple transient conditions. The numerical experiment demonstrates the effectiveness of the multiscale approach in reducing the computational cost while maintaining high accuracy in representing the quantities of interest.
Effect of Crack Orientation on Toughness of Contemporary EW Pipe Seam Welds
Authors: Xu S. , Yang L. , Xue J. , Liang J. , Tyson W. R. 
Published: December 2022

Abstract
Toughness values of pipe steel and welds are key mechanical properties for material specification and integrity assurance. Toughness is influenced by crack size (deep vs. shallow), loading mode (bending vs. tension), crack orientation and sampled microstructure (notch location in weldments). To the best of the authors’ knowledge, no data exist in the open literature for crack orientation effects on Electric Welded (EW) welds. Charpy notch toughness and single-edge-notched bend (SE(B)) fracture toughness tests using surface-notched specimens of three modern (EW) pipe seam welds were performed at −20°C and −45°C, and the results are compared to those for through-thickness-notched (TTN) specimens.
Charpy results indicated that the tests were in lower-transition or lower-shelf regions. Charpy impact V-notch absorbed energies (CVNs) of EW welds displayed large scatter; the effect of crack orientation was small. The initiation J-integral values of SE(B) surface-notched specimens were higher than those of TTN specimens, although when brittle fracture initiation occurred the effect of orientation on toughness was negligible. Note that the specimen geometry likely affects the results; surfaced-notched specimens were B×B and through-thickness-notched specimens were B×2B, although they are all standard SE(B) specimens in ASTM E1820. A limited study of geometry effects on crack-tip stress was done in the present work by Finite Element Analysis (FEA). It was found that these geometries all have similar maximum crack-tip opening stresses at the same J value although the stress gradient through the ligament and hence the constraint parameter Q (measured at a distance 2J/σy from the crack tip) and the J-Q curves differ. Thus, differences in fracture toughness values for brittle fracture would be expected to be small because cleavage is stress controlled, although ductile fracture toughness may reflect the differences in J-Q curves. There was considerable scatter in both notch toughness and fracture toughness, and much of this may be attributed to slight variations in notch or crack location with respect to the weld bond line because the toughness can vary markedly across an EW weld. The variation in location is superimposed on the variation in toughness inherent in each weld microstructure.
The present data shows that the conventional use of TTN specimens is appropriate for EW weld toughness specification because toughness in this orientation is either equivalent to or lower than the toughness of surface-notched specimens (i.e. it is conservative).
Performance of Twelve Different Equations of State for Natural Gas and Hydrogen Blends
Authors: Botros Kamal K. , Jensen Larry 
Published: December 2022

Abstract
The aspiration for blending hydrogen (H2) into natural gas (NG) in gas transmission systems is high and is happening globally. However, the principal properties of the blended mixtures and their thermodynamic derivatives can significantly vary depending on the Equation of State (EOS) employed. There is a need to arrive at the best performing EOS for the prediction of the blended mixtures from low to high concentration of H2 in the blend with NG. Twelve different EOS were evaluated against measured data found in the open literature of pure H2, binary mixtures with alkanes and mixtures with NG. Three measured properties were found, namely density, speed of sound and isobaric heat capacity (Cp) in the range of pressures up to 50 MPa and temperatures in the range of −20°C to +80°C and H2 concentration up to 88%(mole). The total number of measured data points are 629 for pure H2 and 1788 for Binaries and NG mixtures with H2.
Performance of each EOS is based on the average of the absolute error (deviation%) between predicted vs. measured parameters. These were: density, which represents the principal performance of the EOS with respect the basic formulation of P, ρ and T, the speed of sound, which represents a thermodynamic derivative with respect to entropy, and isobaric heat capacity which represents a thermodynamic derivative with respect to enthalpy. All other thermodynamic derivatives can be related to these three parameters (e.g., J.T coefficient, isochoric heat capacity, enthalpy, internal energy,, compressibility factor and Helmholtz and Gibbs free energies, etc.). Transport properties predictions are based on other empirical and semi-empirical correlations that are independent of the EOS and hence were not considered. It was found that, for the most part and for pure H2, GERG2008 EOS performed best in predicting the above three principal parameters followed by AGA8. For Binary and NG mixtures with H2, again GERG2008 was found to be the best performing EOS for all ranges of P and T, while the second-best performer is BWRS in the range of 0.1–3 MPa and AGA8 in the range of 3–25 MPa, respectively.
Factors Affecting SMAW Pipeline Girth Weld Strength and Strain Concentration Under Tensile Loading
Authors: Willett Eric , Lehnhoff Greg 
Published: December 2022

Abstract
This paper presents the findings of a study to investigate the phenomena of girth weld strength undermatching and strain concentration in SMAW girth welds of API 5L X70 pipe, and to identify the significance of some key factors that may affect these phenomena including filler metal strength, heat input, and carbon equivalency of pipe base material. Test welds were subjected to a novel small-scale instrumented cross-weld tensile testing (ICWT) method employing multiple extensometers in different regions of the gage section. Hardness mapping of each weld cross-section was also performed.
This study highlights the importance of considering filler metal strength relative to base material strength when designing welded joints, as well as the importance of controlling welding heat input. It also points out potential issues with relying on failure location as an acceptance criterion in cross-weld tensile testing (CWTT) samples. The observations from this study may be useful in the development of strategies and practices for mitigating the risk of excessive weld strain concentration and premature girth weld failure under moderate tensile or bending loads typical of stress-based pipeline designs.
A New GIS-Based Method to Estimate Annual Probability of Pipeline Failure Resulting From Landslides Based on Actual Failure Locations
Authors: Varela Patricia , Cheng Sam , Sancio Rodolfo , Cook Doug , McKenzie-Johnson Alex , Koduru Smitha 
Published: December 2022

Abstract
Risk assessment and reliability models try to predict the probability of landslide-induced pipeline failures based on detailed, site-specific studies. Because these models are mainly designed to be used on a site-by-site basis, applying them over long pipelines is a challenge due to the challenges of collecting vast amounts of data for those long distances.
A new GIS-based method has been developed to produce an order of magnitude approach to estimating the annual probability of landslide-caused failures (POFs) of pipelines over entire transmission systems using historical data that can range from loss of containment, loss of serviceability, and significant deformations caused by landslides.
This new method uses high-resolution light detection and ranging (LiDAR) mapping to detect and delineate terrain anomalies interpreted to be the geomorphic response to ground deformations caused by landslides. The possible landslides are inventoried to record their activity, relative relationship with the pipeline, proximity to the centerline, length of intersection with a pipeline, and the angle of incidence between the perceived direction of movement of the potential landslide and the pipeline. This method also integrates regional landslide susceptibility maps depicting the relative likelihood of soil units to landslide occurrence along the pipeline corridor and its surrounding areas.
In the presented study case, the developed method is applied to an approximately 19,312-kilometer (12,000-mile) pipeline system located in the United States and Canada. The application of the model yielded results that significantly help the operator to prioritize and optimize the allocation of resources for landslide management. The model can be replicated over multiple pipeline systems and customized to the particular needs of the end-users.
Literature Review of Repair Technologies for Wrinkled Pipelines
Authors: Johnson Tyler , Mokry Curtis , Apps Chris , Parsibenehkohal Nima , Henderson Matthew 
Published: December 2022

Abstract
Wrinkles on a pipeline, whether produced intentionally by construction methods of vintage pipelines or unintentionally by bending loads from subsurface geotechnical movements, introduce significant stress concentration factors. However, common options for pipeline repair usually cannot be used given the protruding wrinkle geometry (e.g. steel sleeves), or are costly and can introduce additional safety concerns (e.g. pipe replacement). Numerous composite repair technologies have been developed that take the form of the underlying structure and, thus, may provide an alternative for this application. However, composite repairs have focused on restoring axial defects in pipelines (i.e. hoop reinforcement), while restoring the bending capacity of wrinkled pipe is less common. Therefore, this literature review consolidates the current state of knowledge regarding the effects of composite repairs on the bending load capacity of pipes.
The reviewed literature identified 14 studies (using finite element analysis, full-scale testing, or a combination of both) that investigated composite repairs on wrinkled pipe or under bending loads. Typically, for pipe with non-sharp flaws (e.g. corrosion or wrinkles), the bending capacity of the pipe with a sufficient repair is increased near or beyond that of pristine pipe. The latter case usually results in a new wrinkle forming outside of the repaired pipe section. Most repairs have also been shown to prevent significant plastic deformation of the base pipe beneath the repair. However, knowledge gaps are also identified by this review and present opportunities for future studies to further improve the performance of composite repairs for this application.
CSA EXP16: Human and Organizational Factors for Optimal Pipeline Performance
Authors: Bradley Claudine , Capper Sue 
Published: December 2022

Abstract
Human and Organizational Factors (HOF) as a discipline applies tools, theory, principles, data and methods to optimize human, organizational, and overall system performance. To date, there has been relatively little guidance available to pipeline operating companies regarding the integration of HOF within and across organizational management systems, pipeline protection programs, and operational activities. CSA Group Express Document EXP16 (EXP16) entitled Human and organizational factors for optimal pipeline performance is intended to address this deficiency. It builds upon a previously published express document, which was more limited in scope: CSA EXP248 Pipeline Human Factors.
EXP16 is intended to offer practical guidance regarding the management of Performance Influencing Factors (PIFs) and provide greater content dedicated to organizational factors such as leadership, governance, management system effectiveness, and safety culture.
EXP16 has been prepared and reviewed by the CSA Group’s Development Committee on Human and Organizational Factors for Optimal Pipeline Performance. The committee was comprised of representatives from pipeline companies, consulting firms, regulatory agencies, investigative bodies, and HOF subject matter experts from various technical fields (e.g., nuclear). The goal of the document was to marry the introduction of key concepts with practical guidance and best practices that a pipeline company may apply to support enhanced performance, including the prevention of harm to people, property, and the environment caused by a major hazard accident (e.g., unintended product release, spill, explosion, fire).
This paper will review the content and application of EXP16. It will discuss seven key HOF principles and introduce several relevant PIFs associated with People, Organization, and Task, Technology, and Workplace. The impact and management of PIFs throughout the pipeline life cycle will be explored.
This paper will also present the key concept of “the learning organization” and how this outcome may be facilitated through both the proactive and reactive application of HOFs.
A Quantitative Risk Assessment Framework for Natural Gas Storage Wells
Authors: Dessein Thomas , Ayton Brent , Fraser Alex , Smith Shawn , Shironishi Mari , Sera Travis 
Published: December 2022

Abstract
A quantitative framework for risk assessment of natural gas storage wells, including the wellhead and connected piping, has been developed to assess SoCalGas’s underground gas storage sites in California. The approach has been developed to meet and exceed the risk assessment requirements of API RP 1171 (incorporated by reference in U.S. regulation 49 CFR 192.12) and the recent changes to the California Code of Regulations. Further, several of the recommendations made in the recent PHMSA study, “Risk Assessment and Treatment of Wells” (2021), have been addressed and incorporated.
The framework uses a dynamic fault tree to aggregate the barrier failure rates from over 80 potential failure mechanisms to quantify the combined probability of an accidental release to the atmosphere and the resulting hazards. The modular architecture allows operators to use threat-specific models with differing levels of sophistication. Additionally, the framework accounts for the interplay between barriers to failure in a well, the benefits of continuous monitoring, and the effect that wellhead spacing, cement quality, and well-inflow performance have on the expected consequences.
Priority to develop quantitative models is given to the threats that potentially have high probability or high consequences and to threats with effective mitigation options, such as corrosion and external interference threats. For threats with very low consequences or likelihood of occurrence, simple models with conservative assumptions are typically sufficient because the contribution to overall risk is low. This process minimizes the overall analysis complexity and allows mitigations to be tailored to the higher-risk threats.
This paper describes example assessments to illustrate how the framework can quantify the benefits of integrity management activities, such as an erosion monitoring program, continuous pressure monitoring of the annuli, and adding protections to minimize risk from vehicle collisions.