bluuebunny/crossref_metadata_2025_split huggingface dataset:
VALIDATION OF THE WIMS/PANTHER EMBEDDED SUPERCELL METHOD
Authors: Bryce Paul , Hosking Glynn , Knight Martin , Lindley Ben , Powney David , Schneidesch Christophe , Slosse Nicolas , Taylor Tom 
Published: February 2021

The WIMS/PANTHER Embedded Supercell Method (ESM) provides a signiﬁcant improvement in prediction accuracy for radial power distributions for PWR reactors compared to the standard “two-step” approach, without the need for a signiﬁcant increase in computational resource. Recent papers at PHYSOR conferences have outlined the details of the method and demonstrated its operation, and the accuracy improvements possible, by means of benchmarking calculations.This paper applies the method to a 4-loop PWR in the U.K, and three PWRs (3-loop and 2-loop) in Belgium. Comparisons are made against measured data from the start-of-cycle physics testing performed for each cycle, and power-shape measurements collected during the cycle using a conventional “two-step” nodal reactor solution, and with the ESM. All results will be presented with the JEF2.2 nuclear data library, for ease of comparison between the methods and previously reported results, although the effects of more modern evaluations will be commented upon.The benchmark calculations referred to above studied a challenging MOX/UO2 benchmark core akin to an SMR. The four reactors studied here include conventional UO2 only core designs and cycles with UO2/MOX mixed cores. A variety of boron-and gadolinium-based burnable absorbers are also present. The data is used to show that the method both operates successfully for real reactor problems, and delivers improvements in the prediction accuracy of measured parameters.
USE OF THE SIMPLIFIED PN EQUATIONS AND TRANSPORT CORRECTIONS IN THE WIMS/PANTHER EMBEDDED SUPERCELL METHOD
Authors: Taylor Tom , Knight Martin , Bryce Paul 
Published: February 2021

The WIMS/PANTHER Embedded Supercell Method (ESM) provides a significant improvement in prediction accuracy in radial power distributions for pressurised water reactors compared to the standard “two-step” approach, without the need for a significant increase in computational resource.A companion paper presents validation of the ESM as previously presented, using PANTHER pin-by-pin diffusion to correct interface errors arising from the standard two-step approach. However, in principle any reference method can be used to solve the embedded supercells and correct the basic solution – this is a significant advantage of the ESM.A paper presented at PHYSOR 2016 demonstrated that use of diffusion theory introduces significant error relative to transport theory only in the high energy range, due to the discontinuous fission source when modelling the interface between two types of pincell.This paper investigates further improvement of the PANTHER solution through use of simplified PN in the fast energy groups. This solution method can be implemented without the need for any significant change to the calculation route and further improves agreement with a transport reference for a small computational cost.The remaining error in the solution is examined by derivation of an effective diffusion coefficient from a heterogeneous transport reference. This suggests a simple characterisation of the discrepancy, which can be easily corrected.Results are presented in comparison to WIMS for supercells and the KAIST benchmark. For the KAIST small core benchmark assembly power errors relative to a WIMS fine group transport reference are shown to be less than 0.5 %. Results are also presented in comparison to Monte Carlo for the Watts Bar benchmark.
VALIDATION OF WIMS11 FOR SMALL MODULAR REACTOR ANALYSIS
Authors: Smith Peter , Hosking Glynn , Tollit Brendan , Lindley Ben , Cox Andrew , Perry Ray , Ware Tim , Mason Robert , Stefanowska Magda 
Published: February 2021

The WIMS (Winfrith Improved Multigroup Scheme) reactor physics code is actively being developed for whole core modelling of a range of Small Modular Reactor types including the Pressurized Water Reactor (PWR), High Temperature Reactor (HTR), and Liquid Metal Cooled Fast reactor (LMFR). These developments include the capability for whole core multiphysics modelling with neutronics and thermal hydraulic feedback, as well as methods to determine the power deposition from neutron and gamma heating. Flux solutions are obtained using a wide variety of deterministic methods including diffusion theory, SP3, and full transport with the method of characteristics and Sn discrete ordinates methods, as well as multi-group Monte Carlo methods. The SP3 method allows both steady state and time dependent transient solutions by solving the time dependent SP3 equations. A wide variety of nuclear data libraries are available with WIMS including data from the JEF3.3, ENDF/B-VII.0 and CENDL3.1 nuclear data evaluations.
This paper presents validation of the latest version of the WIMS code, WIMS11, for PWR and HTR systems. Comparisons are made against physics data obtained from the OECD/NEA PWR Watts Bar multi-physics benchmark and the IAEA HTR-10 benchmark, as well as neutron and gamma heating experiments that took place on the NESSUS reactor at Winfrith in the United Kingdom. In each case, validation of WIMS has been obtained by comparison either against measured data, or results provided by other benchmark participants that have been obtained with alternative deterministic or Monte Carlo methods.
3D CORE CALCULATION BASED ON THE METHOD OF DYNAMIC HOMOGENIZATION
Authors: Galia Antonio , Zmijarevic Igor , Sanchez Richard 
Published: February 2021

The classical two-step calculation scheme has been extensively used to perform three-dimensional deterministic core calculations thanks to its fast results. On the other hand, direct 3D transport calculations and 2D/1D Fusion methods, mostly based on the method of characteristics, have recently been applied showing a prohibitive computational time for routine design purposes as well as in the context of multiphysics and core depletion calculations, due to current machine capabilities.
The Dynamic Homogenization method is here proposed as an alternative technique that may lie between the classical and the direct approaches in terms of precision and performance. In this work, the method is applied to the NEA ”PWR MOX/UO2 Core Benchmark” for a 3D configuration. Comparison of pin power relative errors and computational cost against the two-step and direct approaches are presented.
UTILIZING A REDUCED-ORDER MODEL AND PHYSICAL PROGRAMMING FOR PRELIMINARY REACTOR DESIGN OPTIMIZATION
Authors: Stewart Ryan , Palmer Todd S. 
Published: February 2021

Reactor core design is inherently a multi-objective problem which spans a large design space, and potentially larger objective space. This process relies on high-fidelity models to probe the design space, and sophisticated computer codes to calculate the important physics occurring in the reactor. In the past, the design space has been reduced by individuals with extensive knowledge of reactor core design; however, this approach is not always available. In this paper, we utilize a set of high-fidelity models to generate a reduced-order model, and couple this with a genetic algorithm to quickly and effectively optimize a preliminary design for a prototypical sodium fast reactor. We also examine augmenting the genetic algorithm with physical programming to generate the fitness function(s) that evaluates the degree to which a core has been optimized. Physical programming is used in two variations of multi-objective optimization and is compared with a traditional weighting scheme to examine the solutions present on the Pareto front.
Optimization on the reduced-order model produces a set of solutions on the Pareto front for a designer to examine. The uncertainty for the objective functions examined in the reduced-order model is less than 7% for the given designs, and improves as additional data points are employed. Utilizing a reduced-order model can significantly reduce the computation time and storage to perform preliminary optimization. Physical programming was shown to reduce the objective space when compared with a traditional weighting scheme. It also provides an intuitive and computationally efficient way to produce a Pareto front that meets the designer’s objectives.
DESIGN OF A CODE-AGNOSTIC DRIVER APPLICATION FOR HIGH-FIDELITY COUPLED NEUTRONICS AND THERMAL-HYDRAULIC SIMULATIONS
Authors: Romano Paul K. , Hamilton Steven P. , Rahaman Ronald O. , Novak April , Merzari Elia , Harper Sterling M. , Shriwise Patrick C. 
Published: February 2021

While the literature has numerous examples of Monte Carlo and computational fluid dynamics (CFD) coupling, most are hard-wired codes intended primarily for research rather than as standalone, general-purpose codes. In this work, we describe an open source application, ENRICO, that allows coupled neutronic and thermal-hydraulic simulations between multiple codes that can be chosen at runtime (as opposed to a coupling between two specific codes). In particular, we outline the class hierarchy in ENRICO and show how it enables a clean separation between the logic and data required for a coupled simulation (which is agnostic to the individual solvers used) from the logic/data required for individual physics solvers. ENRICO also allows coupling between high-order (and generally computationally expensive) solvers to low-order “surrogate” solvers; for example, Nek5000 can be swapped out with a subchannel solver.
ENRICO has been designed for use on distributed-memory computing environments. The transfer of solution fields between solvers is performed in memory rather than through file I/O.We describe the process topology among the different solvers and how it is leveraged to carry out solution transfers. We present results for a coupled simulation of a single light-water reactor fuel assembly using Monte Carlo neutron transport and CFD.
REVIEW ON THE NEUTRON SOURCE STRENGTH OF HEU METAL BURST REACTOR
Authors: Liu Xiaobo 
Published: February 2021

There were two similar series of burst waiting time experiments carried out on Godiva-II and Caliban respectively and analyzed for neutron initiation study, unfortunately both the strength of spontaneous fission neutron source given in the published papers are not consistent with the spontaneous fission data of U-235 and U-238.
In this paper, the discrepancies of spontaneous fission data of U-235 and U-238 from different references are reviewed and clarified and the correct strength of spontaneous fission neutron source for Godiva-II and Caliban are calculated respectively, then the multiplication equivalence method of arbitrary source is introduced and the equivalent fundamental-mode(EFM) co-efficiencies of spontaneous fission neutron source for Godiva-II and Caliban are calculated with MC software, lastly the strength of neutron source for these two HEU metal burst reactor in EFM are deduced. The EFM neutron strength of this two burst reactors are much less than proposed values used for burst waiting investigation in published papers respectively, and with the new data, the inconsistency of burst waiting time to the published results is presented and discussed.
DOSIMETRY MODELING AND EXPERIMENTAL VALIDATION FOR THE PETALE PROGRAM IN THE CROCUS REACTOR
Authors: Laureau A. , Lamirand V. , Gruel A. , Frajtag P. , Pautz A. 
Published: February 2021

The PETALE experimental program in the CROCUS reactor intends to provide integral measurements on reactivity worth and dosimetry measurement to constrain nuclear data relative to stainless steel heavy reflectors. The experimental setup consists in eight successive plates of pure iron, pure nickel, pure chromium, or nuclear-grade stainless steel set at the close periphery of the core. The plates are interleaved with up to nine dosimeters that consist of thin activation foils with different possible materials to be sensitive to different ranges of the neutron spectrum. A precise measurement with a good estimation of the uncertainties and correlations is required, especially when comparing reaction rates, e.g. transmission measurement and/or spectral indices.
The present work focuses on the validation of the dosimetry technics developed in preparation of this experimental program. Different aspects are discussed: monitors, efficiency calibration, self-absorption correction, self-shielding and nuclear data uncertainties. The different sources of uncertainties for the experiment-calculation comparisons are characterized, taking into account all the correlation between the different dosimeters. These correlations are a mandatory element for the aimed Bayesian assimilation in order to avoir overfitting when considering dosimeter providing a similar information.
EXPERIMENTAL VALIDATION OF NUCLEAR REACTION DATA FOR INVENTORY SIMULATIONS ON MOLYBDENUM
Authors: Gilbert M.R. , Packer L.W. , Stainer T. 
Published: February 2021

Molybdenum is being considered as a potential material for future nuclear fusion experiments and power plants. It has good thermo-mechanical properties and can be easily fabricated, making it attractive as an alternative first wall material to tungsten, which is the current leading candidate. Unfortunately, according to simulations, fusion-neutron irradiated Mo may become too activated during reactor operation to maintain the objective of fusion of avoiding the generation of long-term, higher-level radioactive waste.However, these simulated predictions rely heavily on having high-quality, accurate nuclear reaction data. For example, reliable simulations of the radiological response of isotopically-tailored Mo would be required by reactor designers and eventually nuclear regulators to assess if it is a viable low-activation fusion solution (in comparison to pure Mo). In recent years, UKAEA has developed benchmarks to test and validate the FISPACT-II inventory code and the input international nuclear data libraries against experimental measurements. This paper presents nuclear code prediction comparisons to new data acquired from γ-spectroscopy measurements of Mo irradiated in the ASP 14 MeV facility at AWE in the UK.Results demonstrate that FISPACT-II predictions for Mo are remarkably accurate; particularly for activity generated from the shorter-lived radionuclides explored by these laboratory experiments, such as91Mo and97Nb, etc., and their metastable isomeric states.
ALTERNATIVE METHOD OF NON-DESTRUCTIVE TESTING FOR NUCLEAR POWER PLANT
Authors: Surin V.I. , Alwaheba A.I. , Beketov V.G , Gazal Abu 
Published: February 2021

This study presents the results of electrophysical non-destructive testing of collectors welded joints to the body of steam generators PGV 1000Mof the reactor WWER-1000. The studied steam generators located in the Resource Сenter of National Research Nuclear University MEPhI at the site of reactors construction factory “Atommash” in Volgodonskcity-Russia. The primary loop collector was welded to the body of steam generators PGV 1000Mand the technical condition of welded joints was investigated by electrophysical non-destructive testing (EPhT). In steam generatorsmay appear corrosion and cracks due to corrosive environment and effect of stresses however,EPhTcan detect early stages of cracks.
The study highlights the theoretical part of electrophysical diagnostics and control method, using modern mathematical signals analysis, and issues related to the practical implementation of EPhT in the factory. The novel alternative method of non-destructive testing can be used in diagnostic oil and gas pipelines, elements of complex technical structures and industrial equipment. It can be used in many industries where it is necessary to process control of the entire structure or its individual parts under operating conditions.
Based on control results, potentiograms were constructed for various structural levels of the diagnostic signal. The results of controlled welded joints in steam generators showed their satisfactory condition.
DEVELOPMENT OF A MODELING APPROACH TO ESTIMATE RADIATION FROM A SPENT FUEL ROD QUIVER
Authors: Elter Zs. , Mishra V. , Grape S. , Branger E. , Jansson P. , Balkeståhl L. Pöder , Hedberg M. 
Published: February 2021

Before encapsulation of spent nuclear fuel in a geological repository, the fuels need to be verified for safeguards purposes. This requirement applies to all spent fuel assemblies, including those with properties or designs that are especially challenging to verify. One such example are quivers, a new type of containers used to hold damaged spent fuel rods. After placing damaged rods inside the quivers, they are sealed with a thick lid and the water is removed. The lid is thick enough to significantly reduce the amount of the gamma radiation penetrating through it, which can make safeguards verification from the top using gamma techniques difficult. Considering that the number of quivers at storage facilities is foreseen to increase in near future, studying the feasibility of verification is timely.
In this paper we make a feasibility study related to safeguards verification of quivers, aimed at investigating the gamma and neutron radiation field around a quiver designed by Westinghouse AB and filled with PWR fuel rods irradiated at the Swedish Ringhals site. A simplified geometry of the quiver and the detailed operational history of each rod are provided by Westinghouse and the reactor operator, respectively.
The nuclide inventory of the rods placed in the quiver and the emission source terms are calculated with ORIGEN-ARP. The radiation transport is modeled with the Serpent2 Monte Carlo code. The first objective is to assess the capability of the spent fuel attribute tester (SFAT) to verify the content for nuclear safeguards purposes. The results show that the thick quiver lid attenuates the gamma radiation, thereby making gamma radiation based verification from above the quiver difficult.
Effects of Isometric Biceps Exercise on Blood Pressure in Adults with Hypertension
Authors: Silva Paulo Henrique Medeiros , de Brito Leandro Campos , Cabral Ludmila Lucena Pereira , Farias-Junior Luiz Fernando , Browne Rodrigo Alberto Vieira , Vianna Lauro C. , Costa Eduardo Caldas 
Published: February 2021

AbstractWe investigated the acute effects of isometric biceps exercise on resting and ambulatory blood pressure in hypertensive adults. A total of 12 medicated hypertensive adults (aged 47±7 years; body mass index 27.2±2.7 kg/m2; resting blood pressure 123±12/74±6 mmHg) performed an isometric biceps exercise session (bilateral biceps exercise; 4×1 min at 30% of 1-RM, 2 min recovery) and a control session (without exercise) in a randomized order separated by a 7 to 10-day period. Resting blood pressure, heart rate, and heart rate variability indexes (SDNN, RMSSD, LF, HF, and LF/HF) were measured pre- and up to 30 min post-sessions. Next, ambulatory blood pressure was monitored during 22-hour post-sessions (awake and asleep periods). No significant changes were observed for resting blood pressure, heart rate, or heart rate variability indexes up to 30 min post-sessions (p>0.05). Furthermore, no significant differences were observed in average ambulatory blood pressure values in 22-hour (126±11/71±6 mmHg vs. 126±15/71±9 mmHg), awake (127±10/74±6 mmHg vs. 130±14/75±10 mmHg), and asleep (123±15/68±6 mmHg vs. 120±17/66±9 mmHg) periods between the control and isometric sessions, respectively (p>0.05). In conclusion, an isometric biceps exercise session does not elicit an acute antihypertensive effect in adults with hypertension, which suggests that its prescription to improve the acute BP control is limited.
Zervikofaziale Aktinomykose
Authors: Brosig Anja Maria , Hitzenbichler Florian , Ernst Benjamin , Köstler Josef , Bohr Christopher , Künzel Julian 
Published: February 2021

ZusammenfassungDie Aktinomykose ist eine durch grampositive, fakultativ anaerobe Bakterien verursachte Infektionskrankheit, die sich in den meisten Fällen im zervikofazialen Bereich manifestiert und oft einen dentogenen Fokus aufweist. Das klinische Bild reicht vom akuten Abszessgeschehen bis zu chronisch fistulierenden Gewebeprozessen. Eine frühzeitige Diagnose und ein angemessenes therapeutisches Vorgehen mit einer Kombination aus ausgedehnter antibiotischer Behandlung und ggf. chirurgischer Sanierung sind für einen günstigen Krankheitsverlauf entscheidend. In diesem Artikel werden 5 Fälle von Aktinomyzeteninfektionen dargestellt, welche die Vielfalt der klinischen Erscheinungsbilder, die Problematik auf dem Weg zur richtigen Diagnose und mögliche Therapieverläufe illustrieren sollen.
Belonging and exclusion: the dark side of regional identity in Germany
Authors: Hildebrandt Achim , Trüdinger Eva-Maria 
Published: February 2021

AbstractA collective regional identity is a favourable condition for the acceptance of majority decisions made at the regional level and for the delegation of competencies from the central to regional governments. Moreover, a regional identity can play an important role in times of global challenges. Regional attachment might generate a we-feeling and help individuals to cope better with a complex world. The same feeling, however, might also serve as a basis for exclusionary attitudes. In this article, we analyse regional identity at the Land level in Germany with data from the German General Social Survey. Our results show that regional identity is strong in both the eastern and western parts of the country, with people in the east, surprisingly, identifying with their respective Land slightly more than people in the west, even though the five eastern Länder were only established in 1990 after decades of centralist rule. Furthermore, the dark side of regional identity manifests itself only in eastern Germany, where a stronger regional identity tends to go hand in hand with a greater dislike of foreigners.
Non-culmination in two Bantu languages
Authors: Persohn Bastian 
Published: February 2021

AbstractThis paper describes an exploratory approach to two related aspectual phenomena, non-culminating accomplishments and non-culminating construals of implied-result verbs, in the Bantu languages Xhosa and Nyakyusa. While documented for a diverse array of languages, leading to the identification of some cross-linguistic commonalities and axes of variation, these phenomena have so far not been studied for any continental African language. Both Xhosa and Nyakyusa license non-culminating accomplishments but differ regarding the felicity of such construals with different sub-types of accomplishments in relation to event progress, a decisive factor being that Nyakyusa possesses verbal partitive morphology. Concerning the non-culmination of implied-result verbs, both languages show such readings and support prior cross-linguistic findings that zero change readings are more readily available with agentive subjects. The data further point to the potential role of causative morphology as a parameter of variation to be considered in further comparative research on these verbs.