bluuebunny/crossref_metadata_2025_split huggingface dataset:
Establishing AMR Structural Integrity Codes and Standards for UK GDA (EASICS): Overview of Activities to Provide Guidance for the UK Generic Design Assessment Process for High Temperature Advanced Modular Reactors
Authors: Chevalier Marc , James Peter , Underwood Nicholas 
Published: October 2020

Abstract
The UK government has committed to achieving “net-zero” carbon emissions by 2050. Nuclear power is expected to play an important role in this undertaking. Therefore delivering new safe and cost efficient nuclear technologies is seen as essential by both the UK Government and industry. Included in these new nuclear technology are small modular Generation VI reactors, referred to as Advanced Modular Reactors (AMRs). It has previously been identified that there is currently no clear route to demonstrating the structural integrity of such high temperature reactors to the UK regulator, with known short falls in the available codes and standards.
Therefore EDF, Rolls-Royce and the National Nuclear Laboratory have collaborated to deliver the “Establishing AMR Structural Integrity Codes and Standards for UK GDA” (EASICS) project (part funded by the UK Government). This project looks to provide guidance on how existing design codes (such as RCC-MRx and ASME Section III Division 5) and assessment methodologies (such as R5 and R6) can be used to demonstrate the integrity of design within a UK regulatory framework. In addition, the project looks to make technological advancements in a number of key areas to address some known shortfalls in the available design codes and standards. These include 1) probabilistic design, 2) thin section defect tolerance and 3) creep-fatigue behaviour.
This paper provides a summary of the current findings and an overview of the planned activities regarding Codes and Standards aspects of the project. This includes a review of the challenges within a UK regulatory framework for high temperature plant, key differences between available high temperature design codes and assessment methodologies, operational experience of high temperature nuclear reactors and key shortfalls in the available codes and standards. It will finally provide a description of what the final EASICS guidance document will be expected to contain when delivered in 2021.
Comparison of Evolution Fatigue With Simplified Elastic Plastic Analysis, Plastic Analysis and a Fracture Mechanics Approach
Authors: Cedergren Joakim 
Published: October 2020

Abstract
Fatigue analyzes are performed to ensure that no damage leading to failure will occur in a component.
In ASME III NB-3222.4(e), a method is provided for analyzing a component’s resistance against cyclic loads. In ASME NB-3228.5 or alternatively NB-3653.6 (c) a simplified elastic-plastic method is given to take plasticity into account. According to NB-3228.4 (c), fatigue evaluation is allowed with plastic analysis where the stress amplitude is determined from the numerically maximum principal total strain range.
This report examines the fatigue life, using a continuum mechanics approach, of a pipe penetration that is subjected to a rapid cooling down followed by a slow heating up. Simplified elastic-plastic analysis and plastic analysis are performed. The analysis also takes into account the FEN-factor according to the method given NUREG/CR6909.
The fatigue life is also determined by a fracture mechanics approach using a R6 based fracture assessment and crack growth analysis.
The results show a large difference in fatigue life depending on the method used.
For the plastic analyzes it is of great importance to the result in which direction the evaluation is made. For the present case the maximum principal total strain range is obtained in the radial direction. The stresses in this direction are small. A crack tangentially to this direction lacks physical significance to a pipe geometry and cannot lead to failure. In this case it is recommended that evaluation is made for the strain range in the axial direction for pipe geometries instead of the maximum principal total strain range.
Comparison of Residual Stress Measurements on Single Bead-on-Plate Welds of a Martensitic Steel Using Neutron Diffraction
Authors: Alexandratos Spyridon A. , Wimpory Robert C. , Lee Tung-Lik , Mac Ardghail Padraig , Leen Sean B. , O’Dowd Noel P. 
Published: October 2020

Abstract
During the welding process, a material is subjected to thermal cycles with rapid heating and cooling rates resulting in residual stress in the weld and the base metal. These residual stress may affect the mechanical performance leading to premature failure of components. Therefore, it is critical to have a detailed knowledge of the residual stress distribution in the weld region as well as in the vicinity in order to predict the service life of components. Due to the high neutron penetration power, neutron diffraction is one of the most useful techniques for nondestructive evaluation of residual stress in welded regions within the bulk. In this paper, neutron diffraction was used to investigate the residual stress distribution within three single bead-on-plate welds of P91 martensitic steel. Residual stress measurements were performed at different neutron diffraction instruments and different methodology of stress determination was applied. Measurements were carried out at the diffractometers Engin-X (ISIS Neutron Source, Rutherford Appleton Laboratory), E3 (BER-II, Helmholtz-Zentrum Berlin) and SALSA (Institut Laue-Langevin). The results of the measurements presented here, were used to determine the variability of the three instruments and compare the effect of different welding parameters on residual stress. The residual stress measurements were also compared with the respective results of the Task Group 1 (TG1) of the European Network on Neutron Techniques standardization for structural integrity (NET).
Development of Valve Performance Qualification Methodology and Testing
Authors: Josodipuro Irawan 
Published: October 2020

Abstract
Valves play important roles in piping systems. In the oil and gas industry, for example, they are used to control flow rates in pipes, isolate flow, and provide over pressure protection of equipment. Given the role of valves in process industries, it is important that valve end-users feel confident that the valves they procure meet the design and qualification requirements in the specification. This paper presents a case study where there have been breakdowns in the qualification of valves being offered by valve suppliers to the industry that did not comply with industry standards which can adversely impact plant operations and personnel safety. The loss of valve supplier credibility is a concern that rarely occurs in mature economies but seem to be more prevalent in countries where design and testing standards are either relatively new or non-existent. To address this issue, the author presents a systematic approach that can be used to ensure that valves supplied to end-users in oil and gas industries in emerging countries meet the design requirements and standards they are required to meet. The process used to control the manufacturers begins with a qualification plan which each supplier has to establish for its product line. Following compliance with the qualification plan, a valve type criticality matrix is introduced to the manufacturers that classifies the criticality of each valve in the system and the associated testing program(s) that the manufacturers need to meet. The qualification program is conducted by the national oil and gas company and acknowledged by the country’s regulator. The recently established program has shown some merit and could be applied to all manufacturers in emerging countries to ensure consistency. The details of the qualification program used and how the process is evaluated are covered in the body of the paper together with examples of how the process has worked.
Effect of Friction Coefficients Regarding Bolt Self-Loosening
Authors: Shoji Yasumasa 
Published: October 2020

Abstract
As there have been many researches for bolt self-loosening and a lot of knowledge have been accumulated, the phenomena has been understood more and more clearly. On the other hand, it is quite difficult to achieve both non-self-loosening and easy bolting tasks. In practical situations, easy and stable bolting is more focused and torque control is employed for tension control in the fields. For the stable bolting, friction of the threads is reduced by lubrication. However, the effect of this friction reduction is not yet investigated in the aspect of self-loosening. In this paper, the effect of frictions between male and female threads and between nut and bearing surface is investigated by FEA simulations. This provides information how self-loosening can be controlled. In this paper, the motion of the fastened plate transverse to the bolt axis is considered. This motion is known as the easiest motion to make self-loosening in experience and also as shown so in the author’s previous researches. The friction seems to increase self-loosening and also decrease self-loosening at the same time. It seems that the friction on the bearing surface drives self-loosening and friction on the thread surfaces prevents it. In this paper, both the frictions are examined in the relative manner with the Finite Element Analyses.
Drop Tests Assessment of Internal Shock Absorbers for Packages Loaded With Encapsulations for Damaged Spent Nuclear Fuel
Authors: Müller Lars , Scheidemann R. , Schönfelder T. , Komann S. , Wille F. 
Published: October 2020

Abstract
Damaged spent nuclear fuel (DSNF) can be loaded in German dual-purpose casks (DPC) for transport and interim storage. Encapsulations are needed to guarantee a safe handling and a tight closure, separated from the package enclosure. These encapsulations shall be durable and leak-tight for a long storage period, because they are usually not accessible within periodical inspections of the DPC. Due to the general design of DPCs for standard fuel assemblies, specific requirements have to be considered for the design of encapsulations for DSNF to ensure the loading in existing package designs. Especially the primary lid system of a DPC is designed for maximum loads due to the internal impact of the content during drop test conditions. The main difference of encapsulations for damaged spent nuclear fuel is that they have usually a much higher stiffness than standard fuel assemblies. Therefore the design of an internal shock absorber, e.g. at the head of an encapsulation is required to reduce mechanical loads to the primary lid system during impacts.
BAM as part of the German competent authority system is responsible for the safety assessment of the mechanical and thermal package design, the release of radioactive material and the quality assurance of package manufacturing and operation. Concerning the mechanical design of the encapsulation BAM was involved in the comprehensive assessment procedure during the package design approval process. An internal shock absorber was developed by the package designer with numerical analyses and experimental drop tests. Experimental drop tests are needed to cover limiting parameters regarding, e.g. temperature and wall thickness of the shock absorbing element to enable a detailed specification of the whole load-deformation behavior of the encapsulation shock absorber.
The paper gives an overview of the assessment work by BAM and points out the main findings which are relevant for an acceptable design of internal shock absorbers. The physical drop tests were planned on the basis of pre-investigations of the applicant concerning shape, dimension and material properties. In advance of the final drop tests the possible internal impact behavior had to be analyzed and the setup of the test facility had to be validated. The planning, performance and evaluation of the final drop tests were witnessed and assessed by BAM. In conclusion it could be approved that the German encapsulation system for damaged spent nuclear fuel with shock absorbing components can be handled similar to standard fuel assemblies in existing package designs.
Fatigue Assessment of Dented Pipeline Specimens
Authors: Freire J. L. F. , Paiva V. E. L. , Gonzáles G. L. G. , Vieira R. D. , Diniz J. L. C. , Maneschy J. E. , d’Almeida A. L. F. S. 
Published: October 2020

Abstract
This paper reports results from an investigation program launched with the objective of assessing fatigue lives of actual pipeline specimens with dents. Nine pipeline 3m-length specimens were constructed with low carbon steel pipes API 5L Gr. B. The specimens had 323mm diameter and 6.35mm wall thickness. The specimens were loaded with hydrostatic internal pressure pulsating at a 1Hz rate. Six specimens had 15% deep longitudinal smooth dents (ratio between dent depth and outside specimen diameter) and three specimens had complex longitudinal 6% deep dent shapes. Nominal and hot spot stresses and strains were determined by experimental techniques (Fiber Optic Bragg Strain Gages - FBSG, and Digital Image Correlation - DIC) and by a numerical technique (Finite Elements - FE). The stresses and strain fields determined from nominal loading conditions or from experimental measurements and from the finite element analyses were combined with different fatigue assessment methods. The estimated lives were compared with the actual test results. The fatigue assessment methods encompassed those proposed by the Pipeline Defect Assessment Manual (PDAM) and by the API 579-1/ASME FFS-1 Level 2 methods described in parts 12 (Dents) and 14 (Fatigue). Most of the predicted lives exhibited high level of conservatism. A Level 3 method that employed experimentally and numerically determined hot-spot strains in conjunction with a fatigue strain-life equation proposed by Coffin-Manson predicted fatigue lives very close to the test results.
Challenging the Industry Practices of Temperature Distribution, SIF and its Effects on Piping Design
Authors: Bhende Gaurav , Jagdale Amit , Patel Jitendra 
Published: October 2020

Abstract
The piping, welding and its fittings contributes to around 25–35% of the total material [1] of any process plant. The quantity of the piping and fittings required in critical pipes (lines) is largely influenced by the flexibility requirements to comply with applicable codes. Since the pressure and weight driven stresses are primary in nature and taken care by the thickness & supports respectively. The Secondary stresses are mainly caused due to temperature and determines the route of the pipe. Unfortunately, there is no sufficient awareness amongst the Process engineers, who dictate the temperature, about the effect of temperature (listed in line list) on the plant cost. To make the situation worse, very often the pipe stress engineers follow thumb rules, conservative design basis while applying temperature to pipes without questioning process engineers the basis and without having experimental evidences which in turn ends up adding to the cost, labor and time of the plant. Another factor influencing the ‘flexibility need’ is ‘Stress Intensification Factor’ which, as well, incorrectly multiplied by conservative numbers, especially in case of 45° branch fittings. Even ‘Flange leakage analysis’ needs to be performed to ensure safety of the plant.
This paper challenges the mis-concepts in temperature distribution of a piping system by analyzing a real-life problem. Also, it provides the actual temperature measurements and compares it with theoretical values. At the end it provides a ‘Temperature de-rating factor, @(Taa)’ which can be used to derive actual expected temperature distribution. Further this paper provides a table to get the actual SIF of Tee and Fittings obtained by FEA. At the end it provides comparison between the results obtained by present industry practices against practical analysis and its effect on cost.
Estimating the contribution of tributary sand inputs to controlled flood deposits for sandbar restoration using elemental tracers, Colorado River, Grand Canyon National Park, Arizona
Authors: Chapman Katherine A. , Best Rebecca J. , Smith M. Elliot , Mueller Erich R. , Grams Paul E. , Parnell Roderic A. 
Published: October 2020

Abstract
Completion of Glen Canyon Dam in 1963 resulted in complete elimination of sediment delivery from the upstream Colorado River basin to Grand Canyon and nearly complete control of spring snowmelt floods responsible for creating channel and bar morphology. Management of the river ecosystem in Grand Canyon National Park now relies on dam-release floods to redistribute tributary-derived sediment accumulated on the channel bed to higher-elevation sandbars. Here, we used multivariate mixing analysis of sediment elemental compositions to evaluate the extent to which flood deposits derive from tributary-supplied sand compared to reworked, relict predam sediment. The concentrations of seven major and trace elements (Fe, Ca, K, Ti, Rb, Sr, and Zr) were measured in very fine–, fine-, and medium-grained sand from flood deposits using X-ray fluorescence and interpreted using a Bayesian mixing model to characterize the proportion of sand originating from the Paria River, the only major tributary within the study reach. Flood deposits from the 2013 and 2014 controlled floods contained 69% ± 16% and 84% ± 20% Paria River–derived material, respectively, with substantial variation among sites. Based on a sand mass balance, we calculated that under decreasing storage conditions since 1963, ∼77%–83% of the annual Paria River sand flux needs to be retained within the mass of active sand stored in Marble Canyon each year to reach the observed concentration of Paria River sand at sample locations. This finding suggests that the use of controlled floods may continue to be effective for sandbar maintenance, provided sand inputs from the Paria River do not decline.
Dilemma of crystalloid resuscitation in non-exsanguinating polytrauma: what is too much?
Authors: van Wessem Karlijn , Hietbrink Falco , Leenen Luke 
Published: October 2020

BackgroundAggressive crystalloid resuscitation increases morbidity and mortality in exsanguinating patients. Polytrauma patients with severe tissue injury and subsequent inflammatory response without major blood loss also need resuscitation. This study investigated crystalloid and blood product resuscitation in non-exsanguinating polytrauma patients and studied possible adverse outcomes.MethodsA 6.5-year prospective cohort study included consecutive trauma patients admitted to a Level 1 Trauma Center intensive care unit (ICU) who survived 48 hours. Demographics, physiologic and resuscitation parameters in first 24 hours, Denver Multiple Organ Failure scores, adult respiratory distress syndrome (ARDS) data and infectious complications were prospectively collected. Patients were divided in 5 L crystalloid volume subgroups (0–5, 5–10, 10–15 and >15 L) to make clinically relevant comparisons. Data are presented as median (IQR); p value <0.05 was considered significant.Results367 patients (70% men) were included with median age of 46 (28–61) years, median Injury Severity Score was 29 (22–35) and 95% sustained blunt injuries. 17% developed multiple organ dysfunction syndrome (MODS), 4% ARDS and 14% died. Increasing injury severity, acidosis and coagulopathy were associated with more crystalloid administration. Increasing crystalloid volumes were associated with more blood products, increased ventilator days, ICU length of stay, hospital length of stay, MODS, infectious complications and mortality rates. Urgent laparotomy was found to be the most important independent predictor for crystalloid resuscitation in multinominal regression analysis. Further, fresh frozen plasma (FFP)<8 hours was less likely to be administered in patients >5 L compared with the group 0–5 L. With increasing crystalloid volume, the adjusted odds of MODS, ARDS and infectious complications increased 3–4-fold, although not statistically significant. Mortality increased 6-fold in patients who received>15 L crystalloids (p=0.03).DiscussionPolytrauma patients received large amounts of crystalloids with few FFPs <24 hours. In patients with<10 L crystalloids,<24-hour mortality and MODS rates were not influenced by crystalloid resuscitation. Mortality increased 6-fold in patients who received >15 L crystalloids ≤24 hours. Efforts should be made to balance resuscitation with modest crystalloids and sufficient amount of FFPs.Level of evidenceLevel 3.Study typePopulation-based cohort study.
The impact of preconditioning exercise on the vascular response to an oral glucose challenge
Authors: Au Jason S. , Beaudry Kayleigh M. , Pancevski Kristian , Hughson Richard L. , Devries Michaela C. 
Published: October 2020

Exercise elicits direct benefits to insulin sensitivity but may also indirectly improve glucose uptake by hemodynamic conditioning of the vasculature. The purpose of this study was to examine the modifying effect of 3 different types of exercise on the vascular response to an oral glucose challenge. Twenty healthy adults (9 women, 11 men; aged 23 ± 3 years) completed a standard oral glucose tolerance test (OGTT) at rest, as well as 1.5 hours after moderate continuous cycling exercise (30 min; 65% peak oxygen consumption), high-intensity interval cycling exercise (10 × 1 min at 90% peak heart rate), and lower-load higher-repetition resistance exercise (25–35 repetitions/set, 3 sets). Brachial and superficial femoral artery blood flow, conductance, and oscillatory shear index were measured throughout the OGTT. Regardless of rested state or exercise preconditioning, the OGTT induced reductions in brachial artery blood flow and conductance (p < 0.001), and transient increases in brachial and superficial femoral artery oscillatory shear index and retrograde blood flow (p < 0.01). Continuous cycling and resistance exercise were followed with a small degree of protection against prolonged periods of oscillatory flow. Our findings imply transient peripheral vasoconstriction and decreased limb blood flow during a standard OGTT, for which prior exercise was unable to prevent in healthy adults. Novelty: We investigated the impact of continuous, interval, and resistance exercise on the hemodynamic response to an OGTT. Our findings suggest decreased upper-limb blood flow during an OGTT is not prevented by prior exercise in healthy adults.