bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of Prediction Tool for Flow-Accelerated Corrosion (1) Evaluation of Pipeline Layout Effect Considering Various Pipe Component Combinations
Authors: Yoneda Kimitoshi , Yuasa Tomohisa , Uchiyama Yuta , Morita Ryo 
Published: November 2023

Abstract
The pipeline layout effect on flow-accelerated corrosion (FAC), so-called “declining effect”, is evaluated considering various combinations of pipe components. Series of computational fluid dynamics (CFD) simulations are conducted to calculate the maximum mass transfer coefficient, the major hydraulic factor of FAC, in the downstream component affected by the flow turbulence due to upstream component by varying the distance between the components as the main parameter. Combinations of elbows, tees, and reducers are chosen for the evaluation according to the statistic counts of components in actual plant pipelines. As proposed in previous study, the declining effect is arranged in exponential declining curve in terms of the distance between components, qualitatively. However, it is found that the declining effect may differ depending on the pipe component combinations. Correlation equations for the declining curve are presented for the combinations of elbow-elbow, elbow-tee, tee-elbow and elbow-reducer, which showed evident declining behavior. It is also found that even when the distance is very short, the remaining portion of the upstream effect on the downstream component would be much less than 100 % and may improve the overprediction in proximate condition which was pointed out to be an issue in previous study.
Advancing the State-of-the-Art for Fretting Wear Testing
Authors: El Bouzidi Salim , Guerout Fabrice , Feenstra Paul , McLellan Anne , St. Pierre Brendan 
Published: November 2023

Abstract
High-temperature fretting wear tests have been conducted at CNL’s Chalk River Laboratories since the 1970s to study the wear characteristics of nuclear power plant components. The initial testing approach relied on an unbalanced motor excitation system, along with pre- and post-test characterization of the work rate. The approach was developed over subsequent decades to enable work rate monitoring during test runtime, through the incorporation of high-temperature dynamic force and displacement sensors into the harsh test environments (up to 12 MPa, 320°C). The approach has been used to predict the life of CANDU and light water reactor components subjected to in-service vibrations, for example in the case of fuel fretting and steam generator tube/support fretting.
In 2019, an effort was initiated to update the existing fretting wear testing capabilities to leverage advancements in data acquisition hardware, computational technology, and vibration instrumentation, to meet the evolving needs of the nuclear industry. This effort saw an overhaul of the test control and monitoring approach, enabling the excitation of the test specimens to be generated based on empirical excitation force spectra, as well as real-time monitoring and tallying of contact events throughout tests of extended duration (typically 500 hours). Alongside retrofitting the existing facilities, new capabilities are also being developed to enable fretting wear testing in advanced reactor conditions, such as testing in 700°C helium representative of high-temperature gas reactors, and testing in refreshed autoclave environments to enable more stringent chemistry control. An overview of the recently-upgraded fretting wear testing capabilities and those under development is provided.
Reheat Cracking in Welds of 1¼Cr-½Mo Steel Pressure Vessel During Fabrication
Authors: Suda Kazuki , Sakata Mikihiro , Miyashita Shigekazu , Takauchi Hideaki 
Published: November 2023

Abstract
1¼Cr–½Mo steel has been widely used in fluid catalytic cracking (FCC) reactors, continuous catalyst regeneration (CCR) reactors and desulfurization reactors, as these reactors operate at approximately 500 °C (932 °F). The first part of this paper presents a case history of reheat cracking in the weld metal of an FCC reactor made of 1¼Cr–½Mo steel during fabrication. The indication of cracking was first found in the weld metal by MT after postweld heat treatment at 691 °C (1,275 °F). Both flux cored arc welding (FCAW) and submerged arc welding (SAW) processes were employed to fabricate the reactor. However, the cracking was only found in the FCAW welds. Metallurgical investigation revealed that the cracking was intergranular, and chemical composition analysis showed that the cracked weld metal contained a high amount of boron. To evaluate the effect of boron on reheat cracking, a reheat cracking test using a C-ring type specimen was conducted. The test results showed that boron increased the susceptibility to reheat cracking of the weld metal. The last half of this paper is a review of the literature which focuses on the effects of boron on reheat cracking in 1¼Cr–½Mo steels. It was found that even 5–10 ppm of boron may significantly increase susceptibility to reheat cracking. The mechanism of how boron induces intergranular cracking was also discussed. Finally, this paper presents recommendations to reduce the risk of reheat cracking in 1¼Cr–½Mo steel weld metal.
Dynamic Stability of a Plate Supported by Air Pressure (Analysis of Two Degree-of-Freedom Coupled System of Translational and Rotational Motions)
Authors: Takeda Masakazu , Suda Takahiro , Sugawara Yoshiki , Watanabe Masahiro 
Published: November 2023

Abstract
This paper presents a stability analysis and exciting mechanism of coupled vibration of translation and rotation of a plate supported by air pressure. In stability analysis, the basic equation of fluid flow and the equation of motion of the plate are separated into the steady-state equation and the unsteady-state equation by the perturbation method. The unsteady-state equations are then Laplace transformed, and the steady-state terms obtained by solving the steady-state equations are substituted. The Laplace transformed equations are rearranged to obtain the characteristic equations for the vibration of the plate. The vibration characteristics and unstable condition of the self-excited vibration of the plate are calculated using the characteristic equations. The stability of the plate is affected by the air flow rate, the mass of the plate, the volume of chamber supplying air. we clarified those influences on the instability conditions of the self-excited vibration. Furthermore, the fluid force acting on the plate is separated into factors such as compressibility and viscosity. This is necessary for analyzing the effect of the work done by the fluid force derived from these factors on the dynamic stability of the system. The results reveal a critical factor for the occurrence of self-excited vibration; additionally, the detailed exciting mechanism of translational and rotational vibration is discussed.
Assessment of Gage Length Effects on Cylindrical Austenitic Stainless Steel Fatigue Specimens in Air and High-Temperature Water Environment
Authors: Baykal B. Aydin , Spätig Philippe , Seifert Hans-Peter 
Published: November 2023

Abstract
This paper addresses the specimen gage length on the fatigue behavior of 316L austenitic stainless steels when tested in air and light water reactor environment. In fatigue testing, the overall spread of the data tends to be high due to high natural random error and also unknown systematic errors arising from ambiguous or poorly constrained standards. Identifying and mitigating sources of systematic error can reduce the high spread in fatigue data and significantly increase the reliability of fatigue life approximations under a specific set of test conditions. In order to reduce sources of systematic error, we have explored the effect of the gage length of 316L stainless steel specimens in two different environments. For this purpose, a minimum of three low-cycle fatigue tests were performed for each set of conditions with 0.3% and 0.6% strain amplitude using gage lengths of 20, 27 and 34 mm. The effect of the high-temperature BWR environment results in a strong reduction of the fatigue life in comparison with tests carried out in air at room temperature. The effect is usually quantified in literature using the Fen factor defined as the ratio of the fatigue life in air at room temperature to the fatigue life in a light water reactor (LWR) environment. Fen factors were calculated for each set of conditions and specimen gage lengths using room temperature air tests as reference and compared with existing literature.
Numerical Prediction of Fracture Toughness of a Reactor Pressure Vessel Steel Based on Experiments Using Small Specimens
Authors: Metzler Timo , Gaganidze Ermile , Aktaa Jarir 
Published: November 2023

Abstract
Due to limited availability of irradiated material and safety concerns when testing large, irradiated specimens, a major effort is being made in nuclear materials research to establish small specimen testing techniques for determining the fracture resistance of reactor pressure vessel (RPV) steels. The ASTM E1921 standard is used extensively to estimate fracture toughness of ferritic steels in the ductile-to-brittle transition region. Because of the inherent low constraint of small specimens, many test results exceed the fracture toughness limit specified in the standard, resulting in wasted material. To avoid this problem, finite element analysis using the cohesive zone model is applied to predict the fracture toughness of standard-sized specimens based on small specimen test results. Those tests were carried out within the framework of the FRACTESUS project using miniaturized compact tension specimens. The parameters of the cohesive zone model are calibrated by means of a hybrid experimental-numerical approach. After identification of the parameters on small specimens, the simulation of a standard-sized geometry is performed, and the resulting fracture toughness is compared to the small specimen data.
Probabilistic Leak Before Break
Authors: Brigante Francesco , Pasti Fabio , De Haan-De Wilde F. H. E. 
Published: November 2023

Abstract
The Double Ended Guillotine Break (DEGB) is a pipe failure mode in nuclear power plant installations which is the postulated root cause of a Loss Of Coolant Accident (LOCA). Pipe whip restraints and jet impingement shield are safety systems that mitigate the effects of this postulated accident. The Leak Before Break (LBB) failure mode occurs when a small leak from a cracked pipe is detected prior to the DBEG failure. The application of this failure mode and the detection of cracked pipes would increase defense in depth and justify the removal from the plant of the pipe whip restraints and the jet impingement shield, decreasing costs and maintenance time. In this study a probabilistic assessment is performed with an in-house developed LBB software. The assessment models the complexity of the physical model and the diversity of the systems with stochastic input variables for the material properties and crack parameters. The developed deterministic code is based on the UK procedure for assessing the integrity of structures containing defects (R6). The Detectable Leak Before Break (DLBB) procedure is used, which is based on the Failure Assessment Diagram (FAD) Option 1 assessment procedure. The structural integrity assessment is then coupled with the Henry-Fauske two-phase critical flow model for the evaluation of the leakage rate. A sensitivity analysis is performed to reduce the number of probabilistic variables. The output from the assessment is the probability of defect detection prior to structural failure. The Second Order Reliability Method (SORM) is the probabilistic method used. The probabilistic results are then compared with the safety factors currently used for deterministic LBB assessments.
Seismic Dynamic Response Analysis of Liquid Storage Tank Under Uneven Foundation Settlement Based on Fluid-Structure Interaction
Authors: Huang Jiayi , Chen Zhiping , Jiao Peng 
Published: November 2023

Abstract
Large storage tanks are commonly used to store liquefied petroleum gas, liquefied natural gas, etc. In actual service process, the storage tank is not only vulnerable to foundation settlement, but also prone to structural damage caused by accidental loads such as earthquakes. This paper proposed a seismic dynamic response analysis method for storage tanks under uneven foundation settlement. Through the wet modal analysis, the self-vibration characteristics of the storage tank were obtained. Using a two-way fluid-solid coupling method, the structural response of the tank under combined action of settlement and seismic load was studied. The results showed that when the tank with uneven foundation settlement was subjected to seismic load, the maximum mises stress, maximum circumferential stress, and maximum axial compressive stress increased by 56.7%, 28.5%, and 30.8% respectively compared to the tank without settlement, and the maximum stress occurred at the location of the circumference angle deflection of about ± 25°, where was exactly the position that the maximum stress occurred under the action of uneven settlement alone. Under the combined action of seismic load and uneven settlement, the storage tank was in its elastic stage with no large deformation most of the time. The maximum deformation recovered from 8.21mm to 3.83mm at the end of the seismic load. These results can provide some theoretical reference for seismic design of storage tank and earthquake damage investigation.
Additive Manufacturing and Regulatory Testing of Canisters for Spent Nuclear Fuel Management
Authors: Martinez Oscar , Giuliano Dominic , Tang Wei , Nogradi Paul , Adeniyi Abiodun , Lowe Lance 
Published: November 2023

Abstract
The back end of the nuclear fuel cycle focuses on the interim storage, transportation, and final disposition of the spent nuclear fuel (SNF) from reactors. Commercial light-water nuclear power stations across the United States operate with fuel assemblies that are irradiated for up to 6 years (planned) in the reactor pressure vessel. After their planned irradiation, the fuel assemblies are moved to a spent fuel pool within the facility complex. After the SNF is removed from the fuel pool, it is typically inserted into a welded metal canister that can be transferred between overpacks for storage, transportation, and possibly disposal. Most dry storage systems used in industry today use dual-purpose canisters (DPCs), which designed for use in storage and transportation overpacks but are not specifically designed for disposal. Triple-purpose canisters, designed for disposal in addition to storage and transportation, have also been researched. Traditional manufacturing methods for spent fuel canisters involve fusion welding along the length or circumference of the canister, resulting in high-tensile residual stresses in the joint weld zone (WZ) and heat-affected zone (HAZ).
This paper documents work in which spent fuel canister designs were printed by wire arc additive manufacturing (AM) using the 316L SS welding wire to demonstrate (1) the feasibility of SNF canister fabrication using this advanced manufacturing method and (2) the dynamic response of the AM canister design when subjected to the federally mandated Normal Conditions of Transport (NCT) and Hypothetical Accident Conditions (HAC) physical tests for Type B packages. This paper focuses on the canister printing design and structural tests. The AM 3D-printed design, regulatory testing, and post-test evaluation of the canister tested to the 10 CFR 71.71 and 10 CFR 71.73 requirements are presented herein. One AM canister design was subjected to the penetration, free drop, and puncture test. Before and after the dynamic structural tests, the AM canister design was scanned with a handheld scanner to capture a 3D CAD geometry to compare to the 3D-printed canister design in the deformed shape. The scanned geometry was sectioned in areas with deformation, and the cross section profile was measured to determine accurate and repeated results of the deformed shape of the AM canister design.
Shaking Table Test on a Piping System Model for Developing High-Quality Simulation Model
Authors: Nakamura Izumi , Shibutani Tadahiro , Kuriyama Yukihisa , Kasai Naoya 
Published: November 2023

Abstract
A shaking table test on a piping system model was conducted to develop a reliable inelastic Finite Element Method (FEM) analysis model for a piping system. The purpose of this experiment was to obtain the data until failure, which can then be utilized to validate the numerical model. In this experiment, the test model was designed so that failure would occur at the tee pipe joint, because there are few data for failure behavior of tee pipe joint.
The experimental data until failure could be obtained successfully by the excitation tests performed by E-Defense. The result showed that fatigue failure at the tee pipe joint was the failure mode.
In addition to the excitation data, configuration data of the tee pipe and material data were also obtained. Based on these actual data, the pre-FEM analysis model was prepared prior to the excitation test. The analysis model could well predict the failure position qualitatively.
The Role of Internal vs External Hydrogen on Fracture Resistance of Austenitic Stainless Steels
Authors: Ronevich Joseph A. , Balch Dorian , San Marchi Chris 
Published: November 2023

Abstract
Austenitic stainless steels are used in high-pressure hydrogen containment infrastructure for their resistance to hydrogen embrittlement. Applications for the use of austenitic stainless steels include pressure vessels, tubing, piping, valves, fittings and other piping components. Despite their resistance to brittle behavior in the presence of hydrogen, austenitic stainless steels can exhibit degraded fracture performance. The mechanisms of hydrogen-assisted fracture, however, remain elusive, which has motivated continued research on these alloys. There are two principal approaches to evaluate the influence of gaseous hydrogen on mechanical properties: internal and external hydrogen, respectively. The austenite phase has high solubility and low diffusivity of hydrogen at room temperature, which enables introduction of hydrogen into the material through thermal precharging at elevated temperature and pressure; a condition referred to as internal hydrogen. H-precharged material can subsequently be tested in ambient conditions. Alternatively, mechanical testing can be performed while test coupons are immersed in gaseous hydrogen thereby evaluating the effects of external hydrogen on property degradation. The slow diffusivity of hydrogen in austenite at room temperature can often be a limiting factor in external hydrogen tests and may not properly characterize lower bound fracture behavior in components exposed to hydrogen for long time periods. In this study, the differences between internal and external hydrogen environments are evaluated in the context of fracture resistance measurements. Fracture testing was performed on two different forged austenitic stainless steel alloys (304L and XM-11) in three different environments: 1) non-charged and tested in gaseous hydrogen at pressure of 1,000 bar (external H2), 2) hydrogen precharged and tested in air (internal H), 3) hydrogen precharged and tested in 1,000 bar H2 (internal H + external H2). For all environments, elastic-plastic fracture measurements were conducted to establish J-R curves following the methods of ASTM E1820. Following fracture testing, fracture surfaces were examined to reveal predominant fracture mechanisms for the different conditions and to characterize differences (and similarities) in the macroscale fracture processes associated with these environmental conditions.
Design of a Lab-Scale Multi-Zone Autoclave for LDPE High-Pressure Polymerization Systems
Authors: Gockel Lena , Ständecke Laura , Schreiner Nicola , Busch Markus 
Published: November 2023

Abstract
Low-density polyethylene (LDPE) is produced industrially in high-pressure tubular or autoclave reactors at pressures up to 3000 bar. Autoclave reactors usually have a high height-to-diameter ratio and are divided into multiple reaction zones with additional feed points along the reactor axis. On the other hand, most laboratory reactors are stirred vessels with only one reaction zone and one feed stream. Consequently, the two types of reactors differ significantly in their residence time behavior, and typical temperature profiles of industrial autoclaves are difficult to establish at laboratory scale. In this work, a lab-scale multi-zone autoclave for high-pressure polymer synthesis is constructed. A division into three reaction zones is realized by a tailored stirrer design. Different stirrers are evaluated both experimentally and simulatively. The focus is on a rapid mixing of the feed and clean separation of the reaction zones. Experimentally, tracer experiments with ink in water are carried out. Computational Fluid Dynamics (CFD) is used to bridge the gap to high-pressure operating conditions.
Ultrasonic Phased Array Detection of Crack-Like Defects in Welds Based on Multi-Mode Total Focusing Method
Authors: Bu Yangguang , Fan Zhichao , Chen Xuedong , Cheng Jingwei , Chen Wei , Wang Zhe , Wang Haibin 
Published: November 2023

Abstract
As a critical structural component within pressure vessels, weld can be frequently found with harmful defects during service, such as microcracks with different orientations. Therefore, regular inspections of welds from pressure equipment are very important. Compared to traditional ultrasonic NDT, ultrasonic phased array total focusing method is a new postprocessing imaging method that is more accurate for defect localization. The inspection of defects in the weld often necessitates prior knowledge to scan multiple times using different inspection surfaces and angles to increase detection coverage, which is time-consuming and labor-intensive. In this study, a multi-mode ultrasonic phased array total focusing method (TFM) for crack-like defects with different orientation is proposed, and the multi-mode imaging method is applied to the inspection of butt welds and fillet welds to achieve effective and quantitative detection of defects in different orientations. In addition, according to the actual size of the detection object, the sound beam incident state and imaging parameters are calculated based on intelligent algorithms, and the optimum imaging view is selected. As a result, a multi-mode imaging method that can comprehensively cover the weld area is obtained. Experimental results show that the multi-view method delivers different sensitivity to different defect orientations, which can better suppress noise than single-view imaging, and improve the probability of detection for crack-like defect.