bluuebunny/crossref_metadata_2025 huggingface dataset:
Combining Acoustic Induced Vibration and Flow Induced Vibration
Authors: Izuchi Hisao , Swindell Rob , Mann Adin
Published: November 2022

During testing to support a program to improve acoustic induced vibration (AIV) assessments, it became clear that flow induced vibration (FIV) is excited at the same time; both mechanisms excite the shell flexural modes of the piping system, although their frequency characteristics are different but overlap. Typically, AIV and FIV are evaluated separately. However, review of some of the existing AIV assessment methods, particularly those that rely on empirical correlations with known failure cases, suggests that they effectively include an FIV element. In the case of a PSV tailpipe joining a subheader at a tee, the FIV is primarily present near the tee while AIV also present away from the tee. Therefore, combining the AIV and FIV assessments unwittingly into one assessment can result in significant conservatism away from the tee. Formulations for the FIV prediction and combining AIV and FIV into a pipe fatigue life assessment are presented. Data from a flare header test system is used to demonstrate the formulations and justify simplifications. The flare header test system consists of an NPS6x8 pressure relief valve, an NPS12 tailpipe with a tee connection to an NPS20 header.
Level 3 Fitness for Service Assessment of Dented Pipes With Diameter Less Than 6.25 Inch
Authors: Mostafa Khaled , Alian Ahmed
Published: November 2022

The aim of this paper is to investigate the parameters affecting the structural integrity for piping with dents anomalies. As per the requirements to part 12 of the API 579-1/ASME FFS-1, 2016 [1], level 1 and 2 fitness for service (FFS) assessment procedures can’t be used for dented pipe with diameter less than 6.25 inch. Such small size pipes can only be assessed using level 3 assessment procedure. The pipe was indented in the FEA model with a rigid indenter. The indented pipe was then evaluated under general collapse and local failure criteria under different loading combinations using the elastic plastic analysis approach. The pipe material is defined using a multi-linear isotropic hardening model as per Annex 3-D of ASME BPVC, sec. VIII, div. 2 [2]. The effect of nominal pipe size, pipe schedule, and dent’s radius of curvature and depth on the plastic strain, and strain ratio are studied. Following Taguchi design of experiments methodology [5], a partial factorial design was adopted to allow the investigation of multiple levels value for each parameter. This analysis uses a real-life dent profile which was measured using automatic ultrasound inspection (AUT) and fitted to a spherical profile. The significance of each parameter on the different measured responses is evaluated.
Fatigue Analysis of Nuclear Class-1 Small-Bore Piping Connections in CANDU Reactors
Authors: Rehman Sameer Abdul , Alian Ahmed , Abid Najmul
Published: November 2022

Class 1 nuclear piping systems, small-bore piping branch connections are susceptible to high thermal fatigue stresses, particularly in cases where harsh thermal transients are present. Calculating the Cumulative Usage Factor (CUF) using the procedure defined in the ASME Boiler and Pressure Vessel Code in Section III NB-3600 can limit the permissible cycle life (i.e., fatigue life) of the piping component. As per NB-3630(c), when a design does not satisfy the requirements of NB-3640 and NB-3650, a more detailed alternative analysis defined in NB-3200 can be used. This work compares the code requirements, analysis methodology, and results of a typical small bore branch connection connected to a piping header that is assessed against the requirements of NB-3600 and NB-3200. Piping is modeled using beam elements by utilizing PIPESTRESS piping analysis software for the NB-3600 based analysis. In comparison, a finite element model in Ansys Workbench is developed for the NB-3200 transient thermal and structural analysis. Representative pressure and thermal transients applicable to the heat transport system of a typical CANDU reactor are utilized in the analysis. The analysis results show that a significant drop in the Cumulative Usage Factor is achieved with the NB-3200 approach when compared with NB-3600.
An Assessment of the Significance of Design Factors in CUF-Based Fatigue Performance and Related Margins
Authors: Garud Yogendra
Published: November 2022

Fatigue assessment, including the development of a crack of engineering significance, is an integral and important part of design as well as life assessment/extension for long term operation of pressurized components. Additionally, in some cases, environmental effects on fatigue need to be taken into account. These areas are also part of several engineering Codes, such as the ASME B&PV Code, in which the related design margins and decision making are influenced by inherent material/physical variability, uncertainty in inputs, and modeling uncertainty. The code procedures are based on the use of a deterministically calculated measure — the cumulative usage factor (CUF) for a specified service envelope of load transients — to assess the component fatigue performance.

This paper presents the results of an assessment on the relative significance of key S–N adjustment factors (material variability, surface roughness, size, and load history) on the estimation of the CUF. The assessment is based on the recently proposed uncertainty quantification (UQ) and sensitivity analysis (SA) [PVP2017-65850], including the environmentally assisted fatigue. It takes into account the expected uncertainty in the key adjustment factors with sample limiting cases. The significance of these results is discussed in relation to their implications for design/analysis based on the CUF approach and the related fatigue margins.
Mechanical Properties and Metallurgical Examination Results for a Batch of Powder Metallurgy - Hot Isostatically Pressed Low Alloy Steel Grade 508 4N
Authors: Stewart David , Sulley John , Warner Ted , Wallace Phil , Jones Gary , Thatcher Dan
Published: November 2022

This paper presents the work conducted by Rolls-Royce to investigate the mechanical and metallurgical properties of a Low Alloy Steel (LAS) grade 508 alloy batch of material. The material was manufactured using the Powder Metallurgy – Hot Isostatic Pressing (PM-HIP) method. The LAS was an ASME 508 4N model alloy. Rolls-Royce has used PM-HIP extensively for the manufacture of nuclear grade components such as valves, piping and pump bowls, and is now investigating its use for the manufacture of LAS pressure vessels in order to provide an alternative sourcing route to forgings to reduce costs and manufacturing lead-times. A key part of this work is to assess whether mechanical properties can be achieved that meet the specification requirements and that are also comparable to the forged equivalent. In this regard, the toughness of the material is of particular interest, with it being extremely important for LAS pressure vessel applications. This paper reports, that for this particular batch of material, the Charpy toughness was significantly below the minimum room temperature specification requirement, but that the tensile properties were well above the minimum specification requirements for proof and ultimate tensile strength. The Charpy toughness at room temperature was only at 38% of the specification requirement, and only at 21% of forged equivalent material. The reason for the poor Charpy results is potentially attributed to prior austenite retention given the highly faceted nature of the fracture faces and the size of the facet faces. Oxides and other precipitates, such as nitrides, are not believed to have significantly contributed to the low Charpy values in this powder batch. This is because inclusion assessments against other powder HIP material, which had exhibited higher Charpy values but produced with higher oxygen content, did not show a significantly different variation in non-metallic inclusion count, and there was no clear evidence of prior particle boundaries being evident in the cross-sectional studies of the microstructure. Hence, it is hypothesised that increased prior austenite formation was due to the increased nitrogen levels in the gas atomised powder.
NeT Project Task Group 8 – An International Benchmark on Residual Stress Assessment for Welding Repair
Authors: Robin Vincent , Draup Jefri , Hendili Sofiane , Delmas Josselin , Xiong Qingrong , Smith Mike , Paget Alexandre
Published: November 2022

The mission of the European Network on Neutron Techniques Standardization for Structural Integrity (NeT) is to develop experimental and numerical techniques and standards for the reliable characterisation of residual stresses in structural welds. NeT was first established in 2002, and involves over 30 organisations from Europe and beyond. It operates on a “contribution in kind” basis from industrial, academic, and research facility partners. Each problem examined by the network is tackled by creating a dedicated Task Group (TG), which undertakes measurement and modelling studies and the interpretation of the results. NeT achieves this by conducting parallel measurement and prediction round robins on closely controlled and well characterized benchmark weldments. NeT TG8 follows on from the successful NeT TG1 and NeT TG4 benchmarks, which both examined welds in AISI 316L material and also NeT TG6 which examines an Alloy 600 plate containing a three pass “slot” weld made with Alloy 82 consumables. A new benchmark, NeT TG8, which examines an 18MnD5 (French nuclear code grade also named 18 MnNiMo 05) plate containing a five pass “slot” weld made with Alloy 52 consumables, has been organized to address welding repair issues. This paper describes the NeT TG8 benchmark as a whole, and presents preliminary materials characterization, residual stress measurement, and residual stress modelling results.
Development of the Technical Basis for the New Code Case “Performance and Qualification Criteria for Mitigation of Stress Corrosion Cracking by Surface Stress Improvement”
Authors: Mohr Nicholas , Tate Stephen , Albert Marc , Cho Sungwoo , Yi Won-Geun , Collin Jean , Burkardt Markus , Broussard John , Pyun Young Sik
Published: November 2022

Stress corrosion cracking (SCC) of nuclear power plant components is perhaps the most significant issue affecting nuclear power plant availability and plant lifetime management. Actions were taken within ASME Section III Task Group Weld Residual Stress to ensure mitigative actions, such as surface stress improvement (SSI), are taken when a construction repair is made on a surface that will be wetted and susceptible to SCC. The intent is to minimize the potential for SCC in operation by mitigating potentially susceptible areas during construction. However, no performance criteria specific to such construction repairs exist for pre-service SSI methods that mitigate SCC. Thus, TG-ASSIT is developing an alternate set of performance criteria that will be captured in a Section III Code Case. Additional testing was undertaken to support the development of this Code Case.

A number of organizations including DOOSAN and the Welding and Repair Technology Center (WRTC) and Advanced Nuclear Technology (ANT) programs of the Electric Power Research Institute (EPRI) jointly executed a three-year test program focused on evaluating the viability of novel-to-nuclear surface stress improvement techniques such as Ultrasonic Nanocrystal Surface Modification (UNSM) and Low Plasticity Burnishing (LPB) techniques. The program also included further demonstration of laser peening (LP) processes as a complement to the LP test data already captured by prior EPRI Materials Reliability Program (MRP) work (i.e., MRP-267 R2). This paper summarizes the results from the DOOSAN-WRTC-ANT test program and follow-on inspectability testing for UNSM and LPB that supports the SSI performance criteria for mitigation of SCC of ASME Section III components.
An Extended Process-Zone Modeling Framework for Overload Crack Initiation in Zr-2.5Nb Pressure Tubes
Authors: Xu Steven X. , Scarth Douglas A. , Cho David
Published: November 2022

Flaws found during in-service inspection of Zr-2.5Nb pressure tubes include fuel bundle scratches, debris fretting flaws, fuel bundle bearing pad fretting flaws and crevice corrosion flaws. These flaws are volumetric and blunt in nature. Crack initiation from these in-service flaws can be caused by the presence of hydrogen in operating pressure tubes and resultant formation of hydrided regions at the flaw tips during reactor heat-up and cool-down cycles.

There are two known hydride induced crack initiation mechanisms. One is delayed hydride cracking (DHC) that refers to the situations in which hydride formation and fracture occur at the same applied loads. The second crack initiation mechanism is known as overload crack initiation in a hydrided region. In this case, crack initiation occurs in the course of reactor transients when the applied stress acting on hydrided regions at flaw tips exceeds the stress at which these hydrided regions have been formed. The process-zone model was previously established to predict DHC initiation. There has been recent work to extend the process-zone model for predicting overload crack initiation in hydrided regions ahead of flaw tips. Efforts were made to identify appropriate modeling approaches for the two sequential and distinct physical stages of overload crack initiation: formation of hydrided regions with thermal cycles under constant load, and crack initiation from the pre-existing, fixed hydrided regions ahead of flaw tips under rising load (i.e. overload). The established process-zone methodology is used to model formation of hydrided regions at flaw tips with thermal cycles under constant load. A Weibull stress approach is proposed to predict fracture of the preexisting, flaw-tip hydrided regions during overload. This paper describes the extended process-zone modeling framework for overload crack initiation.
Piping Snubber Failure Experience and Mitigation
Authors: Saunders Kenneth L. , Onorato Michael
Published: November 2022

One of the typical characteristics of high temperature piping systems is that they are more flexible. This is due primarily to expansion stress limits which cause the piping designer to add additional elbows and to minimize axial or lateral stops. The resulting high flexibility and low frequency piping system is vulnerable to vibration loading which may result in excessive displacements, and hence, excessive stresses. As a result, designers often add mechanical or hydraulic snubbers to piping systems to mitigate potential vibration displacements. These snubbers work well for infrequent vibration loading such as that from an earthquake. However, operational vibrations have the potential to damage these snubbers and render them ineffective. One such piping system with these supports transfers high temperature crude oil from two furnaces to a large distillation column. The large vibration displacements caused one strut and most of the mechanical snubbers to fail from fatigue loading. There was a concern that the piping itself would eventually fail from fatigue loading and that there would be a loss of the pressure boundary. Our first task was to quantify the magnitude and the type of vibration loading in this piping system. With this information, we could confirm that the observed supports’ damage was caused by the operational vibrations. We next selected and installed viscodampers that are not prone to fail from operational vibration loading. Vibration measurements confirmed the significant vibration reduction after the new style snubbers were installed.
Reorganize Significance of Mt, Ms and Plastic Zone Size Against LMSD Under Plastic Collapse Regime
Authors: Ishizaki Yoichi , Yonekawa Futoshi
Published: November 2022

Due to the aging of facilities, Oil and Chemical industries in Japan has been longing for using API 579-1/ASME FFS-1 [1] Part 4 and Part 5 assessment over decades. However, most of equipment are subjected to Japanese High Pressure Gas Safety Law so our industry needed to pass through the discussion in a local committee. In the local committee, there was a conflict on the significance of Folias Factor, Mt, and surface correction factor, Ms. The conflict had been a stumbling block against the formal permission to use API 579-1/ASME FFS-1 Part 4 and Part 5 assessment technology.

In 2021, throughout the long term effort of cross industry task team led by authors supported by API579-1/ASME Joint Committee on Fitness-For-Service members, the conflict has been solved in the local committee. Effective from April 1st, 2022, Oil and Chemical industry in Japan got a formal approval from the government to use API 579-1/ASME FFS-1 Part 4 and Part 5 assessment for equipment subjected to High Pressure Gas Safety Law.

Authors noticed similar conflict on the significance of Folias Factor, Mt, and surface correction factor, Ms, is also found in societies outside of Japan occasionally. Those factors are sometimes referred as “bulging factor” that sounds like those are simple conversion factors between flat plate stress and cylinder stress. However, it is not a whole picture of the factor as discussed in this paper. Therefore, it would be beneficial for future improvement of Fitness-for-Service technology to share our outcomes on the correct significance of Mt and Ms including our Lr discussion on API579-1/ASME FFS-1 Part 9 Crack Like Flaw assessment taking this opportunity. In addition, authors studied the relative relationship between plastic zone length and distance to major stress discontinuity associated with the discussion. This might be beneficial to be shared for a future discussion too.

Through this paper, significance of Mt and Ms, including derivation of Ms reinforced by FEM analysis, will be discussed. Also, plastic zone size model that can be used for a future discussion on required Lmsd, distance to major stress discontinuity, will be introduced.
Managing Dissimilar Metal Welding in Hydrogen Rich and Low Temperature Petrochemical Applications
Authors: Dalal Mitul , Hosack Allie , Park Neil , Penso Jorge
Published: November 2022

Dissimilar metal welds (DSMW) have been used for extensive time in hydrogen rich and low temperature petrochemical applications. Frequently they are used when there is a temperature or corrosivity stream transition aiming to optimize initial project costs. Experience shows a mix of successful and failure applications. Industry standards have slowly adding guidance to prevent failures. The wide variety to DSMWs materials combinations and service conditions poses a significant challenge for standardization. Maximizing the lives of dissimilar metal weldments requires early involvement starting with the design and continuing with the fabrication, operation, and inspection phases. Although common goal is to avoid them, in practice there are situations when is no practical to elude them when constructing new units.

In this paper in additional to a literature review section, several real examples of ferritic-ferritic, austenitic-austenitic, and ferritic-austenitic dissimilar welds are described along with the steps involved as described above to prevent failures. Butt welds and weld overlays are covered, as well as some failures. Cases covered include dissimilar metals welds in steam methane reformers, hydroprocessing and olefin units at high and low temperatures. Examples of metallurgical characterization and fitness for service assessments are included. Also, a summary of industry code guidance for designing, fabrication and inspection are included.

The paper finally includes a summary of recent research activities in this field.
Leak Testing When Revising Operating, Upset, and Design Pressures in Pressure Piping
Authors: Seipp Trevor G. , Kudzhak Dina , Mckay Boyd
Published: November 2022

A pressure equipment operator initiated a program to achieve compliance with a jurisdiction’s requirements for Overpressure Risk Assessment updates. The program was also initiated to provide clarifications and improvements in the pressure piping documentation where overpressure allowances were inherent in the design of heritage piping and equipment. Most of these heritage piping systems were designed between 1975 to 1995.

During that period of time, it was a common industry practice to take advantage of the provision for variations per ASME B31.3 ¶302.2.4. As per this provision, it is acceptable for occasional, infrequent and short-in-duration upset events to exceed the design condition provided that all the requirements in ¶302.2.4 are met.

The Overpressure Risk Assessment review of a large number of existing piping OPPSD systems recognized higher operating cases and higher overpressure upset cases than those in the original documentation. In most cases, the main reason for this inconsistency between the original and the recently calculated values is due to changes in API 520 / API 521 upset cases. Additionally, operating history, since facility start-up, provides data that demonstrates that upset events have occasionally exceeded the original values which are currently presented in the LDT. Updates to the original LDT are necessary to properly capture the experienced upset events, operating cases and, in some cases, design conditions. For heritage (pre-2013) pressure piping (PP) systems that require updates of the design pressure, the traditional margin provided between the new design pressure and the original leak test pressure as required by ASME B31.3 ¶345.4.2 will not be fully available to support the required rerate.

The objective of this paper is to discuss whether another leak test, at a margin of 1.5 times new design pressure, would provide any additional value in terms of incremental safety. This is discussed in the context of pressure piping systems that have been in continuous successful service for between 25 and 43 years. The mechanical integrity of these systems is being ensured by monitoring and assessment activities that have been carried out within a comprehensive Pressure Equipment Integrity Program. The paper evaluates four different cases of the pressure piping systems that are in the scope of the program, discusses the purpose of leak testing in both construction and post-construction and lists potential risks associated with re-performing leak tests. The paper also provides recommendations for when a prior leak test is sufficient to demonstrate that a rerated piping system with a successful service history is suitable for the new service conditions.
Technical Justification to Extend Girth Weld Examination Intervals
Authors: Cohn Marvin J.
Published: November 2022

The American Society of Mechanical Engineers (ASME) Power Piping Code B31.1 discusses operation and maintenance piping system program requirements in Chapter VII. These program requirements for covered piping systems (CPS) operating in the creep range include the process of piping system walkdowns and the assessment of piping system integrity. For CPS operating in the creep range, this paper provides a methodology to justify extending examination intervals for girth welds subject to low stresses and high remaining useful lives (RULs) considering the observed field anomalies.

Piping system walkdowns frequently reveal piping support issues such as bottomed-out, topped-out, or broken spring hangers (Cohn, M.J., Gialdini, R.J., and Nye, O.B., 2021). These unintended field anomalies should be evaluated to determine the possible impact at the piping system girth welds.

The author’s strategy assumes that the unexamined girth welds have no significant fabrication defects, that future operation is similar to the past, that there are no future malfunctioning supports, and that there is no future significant off-design event. Evaluation of the first set of nondestructive examination (NDE) results will provide higher confidence in subsequent RUL estimates.

The assessment of the piping system integrity for malfunctioning supports includes calculating the highest ranked locations of consumed creep life and implementing applicable NDE at the selected high priority locations. The author’s strategy is to select locations with estimated RULs less than 20 years for NDE during the next scheduled outage. Locations with estimated RULs between 20 and 50 years are medium priority ranking and may be examined during the next scheduled outage, depending on the available resources. Locations with estimated RULs beyond 50 years can have much longer examination intervals.

The process of 1) comprehensive piping system walkdowns, 2) simulation as-found stress analyses to the observed field displacements, 3) NDE at the minimum remaining creep life locations, and 4) determining the next set of minimum creep life locations has been used to evaluate the current piping system integrity and provide additional confidence in safely operating the piping system until the next scheduled outage.

Several case studies are discussed to illustrate the piping system integrity evaluation process. This strategy typically identifies a few critical girth welds to be examined during the next scheduled outage and provides justification to extend examinations of girth welds with estimated remaining creep rupture lives beyond 50 years.
Additive Manufacturing of Monel K-500 via Directed Energy Deposition for Pressure Vessel Applications
Authors: Chen Ze , Wang Chengcheng , Kandukuri Sastry Yagnanna , Zhou Kun
Published: November 2022

Metal additive manufacturing has rapidly revolutionized the production processes across various industries. Laser-assisted powder-fed directed energy deposition (DED) has eminent advantages such as high deposition rate, capability for cladding and repairing valuable parts, and great potential for in-situ alloying, which are highly desirable attributes for pressure vessel applications. This study used DED to process Monel K-500, a nickel-based alloy approved by the American Society Of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code. Fully dense Monel K-500 parts were printed by DED with the tensile strength of ∼ 20% and elongation of ∼ 120% higher than their casted counterparts. Besides, the anisotropy of mechanical properties of DED fabricated Monel K-500 parts were investigated. This work provides a technical reference for industries to utilize DED to manufacture Monel K-500 parts with desirable performance for pressure vessel applications.
High Temperature Flaw Evaluation Code Case: Technical Basis and Examples
Authors: Brust Frederick , Sallaberry Cedric , Messner Mark
Published: November 2022

The Working Group on High Temperature Flaw Evaluation, which currently reports to both Section XI and Section III Division 5, has developed Code Case to address high temperature flaw evaluation. The evaluation procedures are based on accepted methods used by other Code bodies around the world. The Code Case integrates the creep rupture rules of Section III Division 5 and the fracture rules in Section XI which are enhanced to address high temperature crack growth. This Code Case will eventually reside in Section XI Division 2 within the Reliability and Integrity Management Program. The purpose of this procedure is to evaluate the growth of a single, characterized flaw for a defined evaluation period in a metallic component where the future thermomechanical loads are known or approximated. The procedure describes the growth of the flaw under periods of constant primary load. Crack growth is accumulated in discrete increments over a series of time increments Δt and continues until one of the following occurs: (i) The remaining ligament fails due to the interaction of net section yield or unsteady time independent crack growth, evaluated using a Failure Assessment Diagram (FAD) defined with Section XI rules. (ii) The remaining ligament fails due to creep rupture over a time less than the time increment Δt using Section III Division 5 rules. (iii) The crack exceeds the depth limits for specific components provided in the relevant Section XI appendix. (iv) The simulation time reaches the end of the evaluation period. Several application examples are provided.
Weld Residual Stress Modeling of and Fracture Assessment of Layered Pressure Vessels
Authors: Brust F. W.
Published: November 2022

NASA has hundreds of non-code layered pressure vessel (LPV) tanks that hold various gases at pressure. Many of the NASA tanks were fabricated in the 1950s and 1960s and are still in use. An agency wide effort is in progress to assess the fitness for continued service of these vessels. Layered tanks typically consist of an inner liner/shell (often about 12.5 mm thick) with different layers of thinner shells surrounding the inner liner each with thickness of about 6.25-mm. The layers serve as crack arrestors for crack growth through the thickness. Most tanks have between 4 and 20 layers. Cylindrical layers are welded longitudinally with staggering so that the weld heat affected zones do not overlap. The built-up shells are then circumferentially welded together or welded to a header to complete the tank construction. This paper presents results which consider weld residual stress and fracture assessment of some layered pressure vessels. This is part of the much larger probabilistic fitness for service evaluation of these tanks. All fabrication steps are modeled, and the high-level proof testing of the vessels has an important effect on the final WRS state. Because the tanks have low toughness the weld residual stress state has an important effect on the fitness for service of these tanks and are tabulated for use in the probabilistic code.
Design Modification Implementations for Mitigating the Reactor Inner Zone Inlet Header Temperature in CANDU Reactor Units
Authors: Tang Preston , Li Bing , Bhatia Akash , Cramer Leon
Published: November 2022

The Reactor Inner Zone Inlet Header (RIZIH) temperatures have raised more rapidly in the CANDU units in general, compared to the original aging predictions. This adverse trend is caused by a degradation mechanism that affecting heat exchange efficiency in certain areas of the process systems. The main contributor to the RIZIH temperature increase is the fouling in the preheaters and steam generator/boilers due to magnetite deposits on tube internal diameters. The RIZIH temperature rise had caused units de-rates to ensure the reactor safety and comply with the regulatory requirements. As reported in a previous PVP paper (PVP2017-65096), multiple design alternatives were considered and evaluated to address the adverse condition, the best design option with a piping modification by adding external feedwater bypass of high pressure heater was selected to improve RIZIH temperature control. Following the conceptual engineering, preliminary design and detail design, the engineering change was implemented in two CANDU reactor units between 2018 and 2019. This paper reports out the field physical implementations and discusses the effectiveness of the design change on mitigating the RIZIH temperature rise, it also presents the operational and financial benefits actualized through observations of the two implementing units.
Development Testing of High-Pressure Confinement Vessel for Proton Radiography of Explosively Driven Shock Physics Experiments
Authors: Cardon Devin , Spernjak Dusan , Fehlmann Kevin , Fister Matthew , Scarafiotti Jesse , Lakey Matthew , Biel Morgan , Marr-Lyon Mark , Mashburn Keith , Webber Kirk
Published: November 2022

The results of development testing of the Inner Pressure Confinement Vessel (IPCV) are presented here. The IPCV is part of a two-vessel confinement and containment system designed to support proton radiography of shock physics experiments at Los Alamos National Laboratory (LANL). The IPCV is explosively loaded and designed to confine the high-pressure detonation products, material fragments and any other hazardous materials created by explosively driving materials to extreme loading conditions. The IPCV is designed to meet the requirements of ASME Boiler and Pressure Vessel Code Section VIII, Division 3, Code case 2564. The unique and challenging design consideration for the IPCV is the proximity of the High Explosive (HE) charge to the radiographic imaging windows. The radiographic windows are fabricated from low-attenuating Beryllium which aids in obtaining high resolution radiographic images but is also brittle and susceptible to damage. Several rounds of developmental tests were conducted over the course of a few years.

The IPCV is designed to withstand a maximum HE charge size of 30g TNT equivalent. The main components of the IPCV are the Experimental Physics Package (EPP), fragment mitigation assembly, radiographic windows, and gas handling equipment. The radiographic windows are located only a few cm away from the EPP (which houses the HE) and are protected by the fragment mitigation assembly. The gas handling equipment allows for post-shot pressure monitoring and eventual venting of the vessel. The development tests were used to advise the design of the fragment mitigation strategy, develop testing processes and procedures, and collect data for comparison with the engineering models.
Technical Basis of the Code Case Providing Design Rules for the Use of Polyethylene Pipe for Class 3 ASME BPVC Section III, Division 1 Above Ground Piping Systems
Authors: Hebeisen Jason R. , Adams Timothy M.
Published: November 2022

ASME Boiler and Pressure Vessel Code, Section III, Mandatory Appendix XXVI provides rules for buried High Density Polyethylene (HDPE) Pipe for service water or cooling water piping systems. Section III has recently developed rules for above ground High Density Polyethylene (HDPE) piping systems in a Code Case (Code Case N886) that was published with the 2019 edition of the ASME Boiler and Pressure Vessel Code. This paper presents the technical basis of this above ground High Density Polyethylene (HDPE) piping Code Case. It provides the background on the development of the rules for above ground High Density Polyethylene (HDPE) piping systems. The authors completed extensive material testing over last 10 years to build the foundation of the Code Case rules. In addition, the historical background of the testing is given to provide the basis for the stress limits in the above ground case and the stress intensification factors. This paper will also explain the considerations for the selection of a dynamic load factor, the capacity of bolted flanged connections, and the considerations of buckling, which unlike buried pipe apply to above ground piping systems. A complete history and technical background for the basis of the above ground High Density Polyethylene (HDPE) code case rules will be presented in this paper.
Application of Leak-Before-Break to Small Diameter Piping Nozzles With Dissimilar Metal Butt Welds Susceptible to PWSCC Using xLPR
Authors: Cofie Nat , Dedhia Dilip , Dominguez Gary , Uddin Mo , Harrington Craig , Glunt Nate , Shim Do Jun
Published: November 2022

To address the dynamic effects of pipe break required by the General Design Criteria 4 (GDC-4), Appendix A of 10CFR50, deterministic leak-before-break (LBB) analysis (based on margins on leak rate and critical flaw size) as described in Standard Review Plan (SRP) 3.6.3 has been utilized by the nuclear industry. The LBB deterministic margins are generally met for large diameter piping (NPS 10 and greater) using a traditional LRD of 1.0 gpm. For smaller diameter piping, it is typically difficult to meet the required margins using LRD of 1.0 gpm necessitating a lower LRD. An alternate approach is to employ a probabilistic method to determine the probability of rupture and compare it to an appropriate probabilistic acceptance criterion. Recent release of the Extremely Low Probability of Rupture (xLPR) software has made the use of such a probabilistic approach possible.

In this paper, a feasibility study was performed using xLPR to investigate if low probability of rupture can be demonstrated for a typical small diameter piping nozzle with a dissimilar metal (DM) butt weld that is susceptible to primary water stress corrosion cracking (PWSCC). This study assumes a small surface crack and grows this crack to determine if rupture occurs by a through-wall crack or a surface crack. Several sensitivity studies were performed to investigate the effects of key input variables on the rupture probabilities.

The study has shown that it is feasible to justify low probability of rupture for small diameter DM welds susceptible to PWSCC. However, the WRS profile used in the evaluation has strong influence on the probability of rupture. The study has also shown the limitations in applying the deterministic LBB approach on a broader basis to small diameter DM welds in the presence of PWSCC, since rupture by surface cracks instead of through-wall cacks cannot be summarily dismissed and is a fundamental assumption in deterministic LBB with SRP 3.6.3.
Microtubule retrograde flow retains neuronal polarization in a fluctuating state
Authors: Schelski Max , Bradke Frank
Published: November 2022

In developing vertebrate neurons, a neurite is formed by more than a hundred microtubules. While individual microtubules are dynamic, the microtubule array has been regarded as stationary. Using live-cell imaging of neurons in culture or in brain slices, combined with photoconversion techniques and pharmacological manipulations, we uncovered that the microtubule array flows retrogradely within neurites to the soma. This flow drives cycles of microtubule density, a hallmark of the fluctuating state before axon formation, thereby inhibiting neurite growth. The motor protein dynein fuels this process. Shortly after axon formation, microtubule retrograde flow slows down in the axon, reducing microtubule density cycles and enabling axon extension. Thus, keeping neurites short is an active process. Microtubule retrograde flow is a previously unknown type of cytoskeletal dynamics, which changes the hitherto axon-centric view of neuronal polarization.
Secondary infections rejuvenate the intestinal CD103+tissue-resident memory T cell pool
Authors: von Hoesslin Madlaina , Kuhlmann Miriam , de Almeida Gustavo Pereira , Kanev Kristiyan , Wurmser Christine , Gerullis Ann-Katrin , Roelli Patrick , Berner Jacqueline , Zehn Dietmar
Published: November 2022

Resident T lymphocytes (TRM) protect tissues during pathogen reexposure. Although TRMphenotype and restricted migratory pattern are established, we have a limited understanding of their response kinetics, stability, and turnover during reinfections. Such characterizations have been restricted by the absence of in vivo fate-mapping systems. We generated two mouse models, one to stably mark CD103+T cells (a marker of TRMcells) and the other to specifically deplete CD103−T cells. Using these models, we observed that intestinal CD103+T cells became activated during viral or bacterial reinfection, remained organ-confined, and retained their original phenotype but failed to reexpand. Instead, the population was largely rejuvenated by CD103+T cells formed de novo during reinfections. This pattern remained unchanged upon deletion of antigen-specific circulating T cells, indicating that the lack of expansion was not due to competition with circulating subsets. Thus, although intestinal CD103+resident T cells survived long term without antigen, they lacked the ability of classical memory T cells to reexpand. This indicated that CD103+T cell populations could not autonomously maintain themselves. Instead, their numbers were sustained during reinfection via de novo formation from CD103−precursors. Moreover, in contrast to CD103-cells, which require antigen plus inflammation for their activation, CD103+TRMbecame fully activated follwing exposure to inflammation alone. Together, our data indicate that primary CD103+resident memory T cells lack secondary expansion potential and require CD103−precursors for their long-term maintenance.
Legal epidemiology of paediatric dog bite injuries
Authors: Patterson Kelli N , Beckmeyer Annamarie , Bourgeois Tran , Horvath Kyle Z , Pratt Amy L , Armour Lisa , Wang Ling , Minneci Peter C , Deans Katherine J , Thakkar Rajan K , Parasidis Efthimios
Published: November 2022

Background

Dog bite injuries cause over 100 000 paediatric emergency department visits annually. Our objective was to analyse associations between regional dog ownership laws and incidence of paediatric dog bites.

Methods

This observational study used an online search to locate local dog-related policies within Ohio cities. Data collected by Ohio Partners For Kids from 2011 through 2020 regarding claims for paediatric dog bite injuries were used to compare areas with and without located policies and the incidence of injury.

Results

Our cohort consisted of 6175 paediatric patients with dog bite injury encounters. A majority were white (79.1%), male (55.0%), 0–5 years old (39.2%) and did not require hospital admission (98.1%). Seventy-nine of 303 cities (26.1%) had city-specific policies related to dogs. Overall, the presence of dog-related policies was associated with lower incidence of dog bite injury claims (p=0.01). Specifically, metropolitan areas and the Central Ohio region had a significantly lower incidence when dog-related policies were present (324.85 per 100 000 children per year when present vs 398.56 when absent; p<0.05; 304.87 per 100 000 children per year when present vs 411.43 when absent; p<0.05).

Conclusions

The presence of city-specific dog-related policies is associated with lower incidence of paediatric dog bite injury claims, suggesting that local policy impacts this important public health issue. There are limited dog-related policies addressing dog bite prevention, with inconsistencies in breadth and depth. Creating consistent, practical requirements among policies with vigorous enforcement could ameliorate public health concerns from paediatric dog bite injuries.
Interpreting CAPWAP results for driven piles with corrections for setup and residual loads
Authors: Bartz James R. , Blatz James A.
Published: November 2022

Evaluation of pile capacity using dynamic testing and Case Pile Wave Analysis Program (CAPWAP) analysis has been shown to provide reasonable measurements of capacity and separates the shaft and tip resistance. It is a common method for verifying pile capacities; however, consideration of setup and presence of residual loads at the time of testing are necessary for interpreting the resistance distribution. A test pile program was conducted that included dynamic testing of piles at the end of initial driving and early restrikes to measure the rate of setup. The piles were instrumented to measure residual stresses. The shaft resistance and tip stiffness were interpreted from analyzing multiple blows and corrected for residual stresses. The results from CAPWAP were compared to measurements from static load tests. It was found that correcting CAPWAP results for residual loads resulted in better interpretation of the rate of setup and resistance distribution. Analyzing successive blows with CAPWAP provided an improved estimate of the tip load–movement curve by extrapolating the increase in tip capacity with penetration. The results demonstrate the importance of correcting CAPWAP results for residual stresses to gain a better understanding of the pile capacity, resistance distribution, and tip stiffness for design purposes.
Characterization and whole-genome sequencing of an extreme arsenic-tolerant Citrobacter freundii SRS1 strain isolated from Savar area in Bangladesh
Authors: Uddin Mohammed Jafar , Haque Farhana , Jabeen Ishrat , Shuvo Sabbir R.
Published: November 2022

Citrobacter freundii SRS1, gram-negative bacteria, were isolated from Savar, Bangladesh. The strain could tolerate up to 80 mmol L−1 sodium arsenite, 400 mmol L−1 sodium arsenate, 5 mmol L−1 manganese sulfate, 3 mmol L−1 lead nitrate, 2.5 mmol L−1 cobalt chloride, 2.5  mmol L−1 cadmium acetate, and 2.5 mmol L−1 chromium chloride. The whole-genome sequencing revealed that the genome size of C. freundii SRS1 is estimated to be 5.4 Mb long, and the G + C content is 51.7%. The genome of C. freundii SRS1 contains arsA, arsB, arsC, arsD, arsH, arsR, and acr3 genes for arsenic resistance; czcA, czcD, cbiN, and cbiM genes for cobalt resistance; chrA and chrB genes for chromium resistance; mntH, sitA, sitB, sitC, and sitD genes for manganese resistance; and zntA gene for lead and cadmium resistance. This novel acr3 gene has never previously been reported in any C. freundii strain except SRS1. A set of 130 completely sequenced strains of C. freundii was selected for phylogenomic analysis. The phylogenetic tree showed that the SRS1 strain is closely related to the C. freundii 62 strain. Further analyses of the genes involved in metal and metalloid resistance might facilitate identifying the mechanisms and pathways involved in high metal resistance in the C. freundii SRS1 strain.
Innovative and diverse soliton solutions of the dual core optical fiber nonlinear models via two competent techniques
Authors: Islam Md. Tarikul , Akter Mst. Armina , Gómez-Aguilar J. F. , Akbar Md. Ali , Pérez-Careta Eduardo
Published: November 2022

It becomes an interesting part for the researchers to analyze the dynamical behavior of soliton propagation in optical fibers for trans-oceanic and trans-continental distances. In this paper, we desire to retrieve distinct and innovative accurate wave solutions to the dual core optical fiber nonlinear equations by adopting the improved tanh method and the rational [Formula: see text]-expansion method. Consequently, a bundle of accurate wave solutions is achieved in diverse sense. The acquired solutions are made visible in the profiles of three-dimensional (3D), two-dimensional (2D) and contour shapes. The effects of the wave speed in soliton transmission are highlighted by plotting different 2D outlines in a single diagram for some obtained solutions. The employed techniques perform as before to unravel the suggested governing models for appropriate wave solutions and hence deserve to contribute in further research.
Simulation and Experimental Study on Surface Mechanical Attrition Treatment for Surface Roughness of 7075 Aluminum Alloys
Authors: Trung Pham Quang
Published: November 2022

This paper presents the effects of surface mechanical attrition treatment (SMAT) for the roughness of Aluminum specimens with three kinds of steel media that have different diameters (1.2[Formula: see text]mm, 1.5[Formula: see text]mm, and 2.4[Formula: see text]mm). First, experiments with SMAT for aluminum materials with a short time of 10[Formula: see text]s were performed, then a single-ball impact model was developed to find out the velocity of balls in the chamber. Next, a multi-ball model with the determined velocity was built. Finally, a comparison of the surface roughness was conducted between the experiment and simulation results. The results reveal that when the shot time and media size increase, the surface roughness value rises significantly in both experiment and simulation studies.