bluuebunny/crossref_metadata_2025_split huggingface dataset:
Statistical Approach to Developing a Performance Monitoring Program
Authors: Rudland David L. , Widrevitz Dan 
Published: November 2023

Abstract
Inservice inspection (ISI) of passive nuclear components can effectively ensure that aging-related degradation is managed and mitigated throughout the life of a nuclear reactor. However, the basis for the Code-required inspection interval, e.g., typically 10-years, is not clearly documented. Additionally, inspection programs for new and advanced reactors may not be compatible with the inspection methodology used by the current fleet light water reactors, and therefore other methods may be needed. Over the last several years, the U.S. Nuclear Regulatory Commission has approved plant-specific extensions to in-service inspection intervals with a basis that includes operational experience and risk-informed arguments. In some cases, requests have been made to extend this interval to the end of licensed life of the plant, resulting in possible inspection elimination. This paper describes some considerations for the performance monitoring needed to ensure that the analyses supporting inspection interval extensions remain valid throughout the operating life of the associated components. Further, special challenges associated with the development of performance monitoring strategies are discussed. While there may be many options in developing a robust performance monitoring program, this paper presents some initial thoughts on how statistical methods may be used to develop some aspects of a performance monitoring program that can be used in conjunction with detailed analyses to justify the extension of inservice inspection intervals, while continuing to ensure plant safety.
Evaluation of FMC/TFM Performance for Volumetric NDT to Field Piping Welding
Authors: Nakamura Shohei , Sakir Mohd Helmy , Rozikin Nuurul Akhyar , Saniman Muhammad Nur Farhan 
Published: November 2023

Abstract
Ultrasonics (UT) is a volumetric Nondestructive Examination (NDE) method widely used all over the world and across various industries and has seen rapid improvement. One of the latest UT techniques, Full Matrix Capture / Total Focusing Method (FMC/TFM), shows great potential for piping welding NDE. This study compared FMC/TFM with Phased Array UT (PAUT) and found that FMC/TFM is superior for piping welding NDE and has a wider application range than PAUT. Moreover, this study also investigated suitable equipment parameters for performing inspections more efficiently and precisely. As a result, probes with at least 32 elements should be used for optimal image resolution and flaw detection. When a probe with a small footprint [L23*W16*H20 (mm)] was used, it could be applied for both sides of transverse welds of piping larger than or equal to a nominal pipe size (NPS) of 8, even for pipe-to-elbow connections, since FMC/TFM requires a shorter offset distance from the probe to the weld toe than PAUT does. In conclusion, this study found that FMC/TFM has a great potential to be used instead of PAUT as a volumetric NDE technique for piping welding inspection.
Further Investigation of the API 579-1/ASME FFS-1 KPECL Stress Intensity Factors
Authors: Altstadt Steven 
Published: November 2023

Abstract
The API 579-1/ASME FFS-1 2021 Fitness-For-Service (API 579) stress intensity factor solution for a plate with an embedded crack, infinite length, through-wall fourth order polynomial stress distribution (KPECL) was further investigated. The new findings presented in this paper are built upon the findings and proposed API 579 updates presented in 2022. Current API 579 guidance is that the KPECL solution can be used as an acceptable approximation for a cylinder with an embedded crack, circumferential direction, 360 Degree, through-wall fourth order polynomial stress distribution (KCECCL) when the ratio of the internal radius (Ri) to wall thickness (t) is greater than or equal to five, Ri/t ≥ 5. API 579 also makes the same recommendation for the corresponding case of a cracked sphere geometry (KSECCL). As part of the investigation, KCECCL influence coefficient values and KSECCL influence coefficient values were calculated for Ri/t = 5 and are presented in this paper. A comparison of the new results to the previously reported KPECL influence coefficients are presented. For both curved geometries, it was determined that the KPECL influence coefficients proposed in 2022 are reasonable approximations for Ri/t ≥ 5, however a few scenarios were identified where this practice may under-predict the stress intensity factor by a few percent. The new influence coefficient values are recommended as options for fitness for service assessments that involve either the KCECCL scenario or the KSECCL scenario with Ri/t ≥ 5.
Age-Hardened Nickel-Base Alloys for Power Piping
Authors: deBarbadillo John 
Published: November 2023

Abstract
Age-hardened nickel-base alloys began to be seriously considered for power piping in the late 1990’s in the European Thermie project to develop materials technology for Advanced Ultra-supercritical (AUSC) coal-fired power boilers. It was recognized at that time that conventional ferritic and austenitic boiler tube would require unrealistically large wall thickness at the temperatures and pressures specified for AUSC. Only age hardened nickel-base alloys appeared to provide the required combination of creep strength, hot corrosion and oxidation resistance, and weldability. Over the next decade projects were initiated in many countries to characterize new and legacy alloys for this application. The results of this work were widely shared internationally and served as a material data basis for newer advanced energy technologies such as supercritical CO2, Gen 3 concentrating solar, and Gen 4 nuclear. Over the past decade full-scale component demonstrations and pilot plants designed for operation at or above 700°C have been constructed and operated in test mode. This paper summarizes achievements to date using primarily examples for UNS N07740 but with reference to published data on similar alloys. Specific challenges for future widespread use of these alloys are defined.
Simplified Method for Seismic Assessment of Buried Pipeline With Local Wall Thinning
Authors: Onuki Shoma , Mitsuya Masaki 
Published: November 2023

Abstract
This study proposed a seismic assessment formula for pipes with wall thinning subjected to cyclic axial loading assuming seismic motion. Cyclic loading experiments using pipes with wall thinning were conducted to study the deformation and failure behavior. Two deformation modes were observed: buckling and bending deformations at the point of wall thinning. In the buckling mode, the buckling deformation at wall thinning progressed in accordance with the number of cyclic loading; finally, plastic instability occurred due to elephant foot buckling at full pipe cross-section. In the bending mode, the bending deformation at wall thinning was repeated by cyclic loading. Subsequently, fatigue cracking initiated and penetrated the remaining pipe thickness at wall thinning. Based on the deformation behaviors at wall thinning during cyclic loading, simplified seismic assessment formula was proposed. The proposed formula can easily evaluate the seismic performance of the pipe with wall thinning against seismic motion. The formula was validated using finite element analysis for different wall thinning sizes and pipe properties. In addition, based on the proposed formula, the assessment curves were plotted for allowable size of the wall thinning against seismic motion. The formula can be used to formulate standards and assess the safety of pipes with wall thinning that are subjected to seismic motion.
Proposal of Revision of Upper Limit of Hydrostatic Test Pressure in KD-236 and KT-312.3 of ASME Section VIII Division 3
Authors: Terada Susumu 
Published: November 2023

Abstract
Regarding the upper limit of hydrostatic test pressure, KD-236 of Section VIII Division 3 prescribes that an elastic-plastic analysis using an elastic-perfectly plastic material model with the specified yield strength at test temperature shall be performed on a vessel. The reason why such material model shall be used for hydrostatic test criteria in KD-236 is to match the analysis to the criteria for the upper limit of the hydrostatic test pressure in KT-312. The upper limit of the hydrostatic test pressure for an open-end and closed-end cylindrical shell was based on general yielding using Gangling’s and Nadai’s equations with yield strength and design factor Kut for the upper limit of hydrostatic test pressure in KT-312. Especially for SA-372 Gr. E Class 70, the ratio of burst pressure to the upper limit of the hydrostatic test pressure becomes more than 1.5. There is a large amount of strain hardening which occurs in the deformation process of this material and the perfectly plastic limit makes it impossible to utilize the materials in a practical manner. The new hydrostatic test criteria for elastic-plastic analysis using an elastic-plastic stress-strain material model are proposed to reduce this conservativeness, instead of an elastic-perfectly plastic material model in current KD-236. The new load factor for the upper limit of the hydrostatic test should be 1.25 since the maximum equivalent plastic strain is less than 5 % and the shake-down on the inside surface is achieved by the subsequent design pressure. The revisions of KD-236 and KT-312 were proposed. The background of these revisions is described in this paper.
Assessment of the Need to Consider HAZ Properties as Part of RPV Integrity Management
Authors: Kirk Mark , Erickson Marjorie , Long Elliot J. 
Published: November 2023

Abstract
A heat-affected zone (HAZ) forms adjacent to any weld; it is the region of the base metal that has not melted but rather has had its properties affected by the heat of welding. The physical size of the HAZ depends on the welding heat input and section thickness; generally, reactor pressure vessel (RPV) structural welds have a HAZ that extends into the base metal by ≈3 mm. Due to the complex microstructures in the HAZ, presence of residual stresses, and potential for undetected and (therefore) unrepaired indications HAZ regions have long been identified as a potential Achilles heel of component structural integrity. Consequently, HAZ toughness properties have long been monitored as part of RPV surveillance and their consideration in structural integrity assessments has been required by ASME Code and regulations.
Considerable anecdotal evidence has accumulated over time suggesting that the toughness properties of the HAZ are, if anything, superior to that of the adjacent base metal and weld. As such, continued monitoring and assessment of these properties may no longer be needed to ensure the operating safety of RPVs. In this paper we provide a review of existing HAZ requirements in several countries and a comprehensive analysis of HAZ data in comparison with companion base and weld metal data. This analysis demonstrates that the HAZ material embrittles at a rate well modeled by existing predictive models for base metals, albeit with more uncertainty. This result suggests that in plants where the weld metal is more sensitive to the effects of embrittlement than the base metal (and, by association, the HAZ), the HAZ can never have the highest T41J value after embrittlement. For plants in which the base metal is more sensitive to the effects of embrittlement than the weld metal the only way for the HAZ transition temperature to exceed that of the base metal is via data scatter. Of the surveillance data examined the T41J of the HAZ exceeds that of the base metal less than 1% of the time.
Fracture and Fatigue Crack Growth Performance of a Vintage X60 Pipeline Material in Gaseous H2 and Comparison With Wet Sour Service
Authors: Bezensek Bostjan , Hopkin Sarah , Martin Tom , Guijt Wim 
Published: November 2023

Abstract
Fracture toughness and fatigue crack growth testing was performed on the parent and weld microstructures of a vintage offshore API 5L X60 grade pipeline material to assess the impact of various partial pressures of gaseous H2. Fracture toughness values were found to reduce compared to the in-air values as expected, and fatigue performance was consistent with published literature for ΔK above 5 MPa√m. At ΔK below 5 MPa√m the fatigue crack growth curve is higher than predicted, which is suspected to be driven by time dependent sustained cracking mechanism. This phenomenon appears to be a function of the applied pressure (i.e. the max stress intensity factor) and the microstructure. In comparison to the wet sour service the gaseous hydrogen appears less detrimental to the material performance at low partial pressure H2 (representative of a 10% blends) and becomes similar to the NACE Region 2/3 with low pH sour performance at higher partial pressures of H2.
Welding, Repair and Local Post Weld Heat Treatment Residual Stresses
Authors: Billon François , Tejc Josef , Krakovsky Andrej , Vanek Mojmir , Moreau François 
Published: November 2023

Abstract
The study presented deals with an industrial case and relates to the calculation of the residual stresses in a butt weld of two shells of large diameter, high thickness and great length constituting part of pressure equipment.
After completion of the weld, it can be repaired if unacceptable defects are detected and then stress relieved by a local heat treatment.
The objective of the study is therefore to calculate the residual stresses after completion of the weld, then the residual stresses after repair and finally the residual stresses after the local heat treatment.
The residual stresses at the different stages are carried out using finite element modeling of the assembled elements and by digital simulation of the production of the weld and its repairs by metal deposition in multiple passes.
The local stress-relieving post-treatment is carried out at an average temperature of 615°C in the weld and according to a well-defined thermal cycle.
The residual stresses at the end of the simulation are calculated by using the laws of behavior of the materials in plasticity and in creep and by taking account of the longitudinal thermal gradients generated by the locally heated zone.
The scientific calculation tool used is SYSWELD [1], dedicated specifically to welding and the total digital simulation is carried out continuously, successively welding, repair(s) and PWHT. Stress calculations are carried out with the viscoplastic laws of the materials involved and the metallurgical transformation laws for the deposited metal.
The expected results are the values and the distribution of the residual stresses at the end of the welding plus repairs simulations and PWHT to evaluate whether they must be considered further in the stress analyzes or not.
CFD Simulation of Gas-Liquid Non-Uniform Erosion in Connection Pipeline of Silicon Tetrachloride Hydrogenation Process
Authors: Shi Jiarui , Chen Sheng , He Meng , Liu Min , Zhu Liyun , Xie Guoshan , Wang Jiangyun 
Published: November 2023

Abstract
Modified Siemens is a main technology in polycrystalline silicon production unit. Their pipes often occur serious droplet particle erosion in the hydrogenation process that causes silicon tetrachloride reaction to trichlorosilane. Droplet particle erosion easily causes hazardous medium leakages, even leading to fire and explosion phenomena and economic losses. A droplet-particle erosion phenomenon happened in connecting pipe between the static mixer and the silicon tetrachloride evaporator of the polycrystalline silicon production unit. This work aimed to accurately analyze the erosion phenomenon position formation caused by simulation. The erosion phenomenon was predicted with the dense discrete particle model (DDPM), coupling into energy-minimization multi-scale (EMMS) drag model to improve the accuracy of non-uniform gas-liquid flow distribution. Comparison with simulation dates is conducted regarding the gas-droplet drag model, droplet wall specularity coefficient, atomized droplet size, and hydrogen volume fraction. The results indicated that the simulation approach with drag modified and suitable parameters selected has a good agreement with industrial phenomenon data. The different atomized droplet particle sizes directly affect the erosion location, the predicted position with 100μm droplet size is in accord with actual phenomena. The flow rate with the increase of hydrogen volume fraction also affects the erosion location and rate. In addition, the erosion phenomenon is due to poor atomization and a high gas-liquid flow rate.
Exploration of Design, Manufacture and Maintenance of Pressure Vessels in China Under Background of the Internet
Authors: Chen Xuedong , Fan Zhichao , Xu Shuangqing , Hu Jiushao , Zhu Jianxin 
Published: November 2023

Abstract
Pressure vessel is a kind of high-end equipment with a large quantity and wide applications, showing the potential hazard of leakage and explosion. In the past decade, the Chinese government has put forward clear requirements for the digitalization, networking and intelligentization of high-end equipment manufacturing under background of the Internet. Since the beginning of this century, Chinese scientific and technical workers have carried out engineering practice and exploration in the design, manufacturing and maintenance of pressure vessels based on life-cycle risk control in view of the prominent problems of high failure probability and many explosion accidents in China. The problems have been basically solved including the complex failure modes identification, inspection and monitoring, safety diagnosis and failure prevention under the extreme service environment and equipment size. The experience gained from in-service inspections and failure accidents analyses has been fed back to the early stage of pressure vessel design and manufacturing. The technical system of risk-based pressure vessel design, manufacturing and maintenance has been established. The standardization, softwareization and digitalization of the structural design, manufacturing process optimization and risk assessment of pressure vessels have been preliminarily realized, and good results have been achieved. However, in the face of the long-term safety service requirements of important pressure vessels in the development and utilization of new energy in the future, there are still problems such as unclear failure modes of some equipment, insufficient collaborative risk control of pressure vessels due to insufficient information and data interconnection in the optimization of material properties, manufacturing process, inspection, operation and maintenance. In this paper, it is proposed to develop an integrated cloud service platform in China for risk-based pressure vessel design, manufacturing and maintenance around 2025. A unified database architecture and risk influencing factors knowledge base will be established. The application problems of key technologies will be broken through such as cross-stage risk identification and control, cross-software multi-source heterogeneous data fusion, microservice architecture design, generative design, and digital twins in pressure vessels. The cloud service platform will integrate the services such as risk assessment, structural design, strength analysis, safety diagnosis, remaining life prediction, generative design, and digital twins, etc. It will provide support for the safe, green and intelligent development of high-end pressure vessels in the process industries.
Research and Application of a Dynamic Risk Management System for the Petrochemical Unit in Extended Service
Authors: Han Zhiyuan , Li Jun , Liu Juanbo , Xie Guoshan , Kang Haoyuan 
Published: November 2023

Abstract
A large number of pressure vessels and pipelines in China’s refining and chemical industry will soon enter the extended service period (more than 20 years). It is estimated that by 2025, the growth rate of pressure vessels in extended service will increase from the current 10 thousand units/year to 100 thousand units/year, thus the safety of these aging equipment is the focus of current attention. It is necessary to accurately evaluate and early warn the failure risk of these equipment, especially considering the complex influences, high uncertainty and suddenness of the failure in long-term service. On the other hand, the risk management methods of pressure vessels and pipelines are well-established based on API 571, API 581 and API 584. The commercial software is also developed for risk assessment and integrity management by some institutions and companies. However, at present, the risk assessment and control of equipment in refining and chemical industry are mainly based on the static data and static assessment methods, which have little correlations with the dynamic data from equipment operation and corrosion inspection. Based on the above requirements of corrosion management and risk control for the equipment in extended service, this study developed a dynamic risk management method and system, included the dynamic data interaction with Laboratory Information Management System (LIMS), Distributed Control System (DCS) and corrosion inspection systems, the damage identification diagnosis, the dynamic risk and residual life assessment, and the application of Integrity Operating Windows (IOWs). This paper also introduces the application of the system in crude distillation units as an example to explain the method in detail. The results show that the dynamic risk management system can effectively identify the real-time risks of aging equipment and give early warning to state parameters, which is important to avoid the failure of aging equipment.
Fretting Wear Prediction of an Energy-Based Model for Heat Transfer Tube in Steam Generators
Authors: Guo Kai , Wang Boyao , Zhang Hongsheng , Yu Meiqi , Tan Wei 
Published: November 2023

Abstract
The heat transfer tubes of steam generators can be vibrated by the fluid, which causes impact and sliding between tubes and the supports and leads to the fretting wear of tubes. Fretting wear is an unavoidable damage of heat exchanger tube bundles. In practical engineering, it is necessary to predict the wear of the heat exchanger tube, especially in steam generators. At present, the most widely-used fretting wear prediction model is the Archard model, which can not consider the effect of impact in wear process. In fact, the role of impact in wear can not be ignored. Based on an energy method, an impact-sliding prediction model is proposed. And a finite element calculation program is established, and the prediction results of the Archard model and the energy-based model method are calculated respectively. The results show that the prediction of impact sliding wear prediction model based on energy loss can adapt to more conditions, and is better than Archard model in the wear prediction of steam generator tube bundles. The model is promising in prediction of the fretting wear of the steam generator and ensure the safe operation of the equipment.