Boron Transient Analysis by the GRS Coupled Code Systems QUABOX-CUBBOX/ATHLET and TORT-TD/ATHLET

2009 ◽  
Author(s):  
K. Velkov ◽  
A. Seubert ◽  
I. Pasichnyk ◽  
A. Pautz
Keyword(s):  
Transient Analysis ◽  
Transport Theory ◽  
State Of The Art ◽  
Diffusion Theory ◽  
Coarse Mesh ◽  
Code System ◽  
The Core ◽  
Simulation Results ◽  
The Impact ◽  
Transport Approach

The application of modern coupled thermal-hydraulic neutron-kinetic code systems is state of the art for performing safety analyses. In this paper, a radially asymmetric boron dilution transient in a PWR MOX/UO2 core is defined. The transient is analysed using the coupled code system QUABOX-CUBBOX/ATHLET which is based on fuel-assembly coarse mesh diffusion theory, and the results are compared to the solution obtained with the transport theory-based coupled code system TORT-TD/ATHLET with a pin-wise representation of the core. The aim of this study is to investigate the impact of the transport approach and the diffusion approximation on the simulation results.

scholarly journals A Combined Method for Predicting the Boron Deposited Mass and the CIPS Risk

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Shengzhe Li ◽  
Dongmei Yang ◽  
Tengfei Zhang ◽  
Xiaojing Liu
Keyword(s):  
Power Distribution ◽  
Neutron Cross Section ◽  
Local Power ◽  
Combined Method ◽  
Boron Compounds ◽  
The Core ◽  
Simulation Results ◽  
Deposit Model ◽  
Power Distribution Control ◽  
The Impact

CIPS is a shift in the axial power towards the bottom half of the core, also known as axial offset anomaly (AOA), which results from the deposited of corrosion products during an operation. The main reason of CIPS is the solute particles especially boron compounds concentrated inside the porous deposit. The impact of CIPS is that the axial power distribution control may be more difficult and the shutdown margin can be decreased simultaneously. Besides, it also requires estimated critical condition (ECC) calculations to account for the effects of AOA. In this article, thermal-hydraulic subchannel code and boron deposit model have been combined to analyze the CIPS risk. The neutronics codes deal with the generation of homogenized neutron cross section as well as the calculation of local power factor. A simple rod assembly is analyzed with this combined method and simulation results are presented. Simulation results provide the boron hideout amount inside crud deposits and power shapes. The obtained results clearly show the power shape suppression in regions where crud deposits exist, which is a clear indication of CIPS phenomenon. And the CIPS effects on CHF have also been investigated. Result shows a margin of DNBR decrease in the crud case.

Detection of Insulation Defects in Automated In-Process Testing of Electric Wire during its Extrusion

2019 ◽  
Vol 942 ◽  
pp. 141-150
Author(s):  
Alexander Goldshtein ◽  
Galina Vavilova ◽  
Alexander Rumkin ◽  
Oldrich Starý
Keyword(s):  
Numerical Simulation ◽  
Mathematical Simulation ◽  
Physical Model ◽  
The Core ◽  
Process Testing ◽  
Capacitive Method ◽  
Simulation Results ◽  
Local Defects ◽  
Air Cavities ◽  
The Impact

The paper describes the electro-capacitive method for monitoring wire capacitance, which is implemented using the CAP-10 device, employed for in-process testing of the single core electric wire capacitance. Focus is made on the operating principle of the CAP-10 device. The possibility of using the CAP-10 device for detecting local defects in wire insulation is proved. Insulation defects such as foreign inclusions in the form of copper shavings, air cavities inside insulation and those at the core–insulation boundary are modeled. The impact of the defect geometric parameters on the wire capacitance measured during in-process testing is investigated through numerical simulation. Mathematical simulation results are validated through the physical model using the CAP-10 device.

scholarly journals Assessment of the uncertainty of snowpack simulations based on variance decomposition

2015 ◽  
Vol 8 (3) ◽  
pp. 2807-2845 ◽  
Author(s):  
T. Sauter ◽  
F. Obleitner
Keyword(s):  
Measurement Errors ◽  
Surface Energy Balance ◽  
Global Sensitivity Analysis ◽  
State Of The Art ◽  
High Arctic ◽  
Limited Attention ◽  
Sensitivity Pattern ◽  
Simulation Results ◽  
The Impact ◽  
Different Sources

Abstract. State of the art numerical snow models essentially rely on observational data for initialization, forcing, parametrization and validation. Such data are available in increasing amount, but the inherent propagation of related uncertainties on the simulation results has received rather limited attention so far. Depending on their complexity, even small errors can have a profound effect on simulations, which dilutes our confidence in the results. This paper quantifies the fractional contributions of some archetypical measurement uncertainties on key simulation results in a high Arctic environment. The contribution of individual factors on the model variance, either alone or by interaction, is decomposed using Global Sensitivity Analysis. The work focuses on the temporal evolution of the fractional contribution of different sources on the model uncertainty, which provides a more detailed understanding of the model's sensitivity pattern. The decompositions demonstrate, that the impact of measurement errors on calculated snow depth and the surface energy balance components varies significantly throughout the year. Some factors show episodically strong impacts, although there overall mean contribution is low while others constantly affect the results. However, these results are not yet to be generalized imposing the need to further investigate the issue for e.g. other glaciological and meteorological settings.

IAEA CRP Benchmark of Kalinin VVER-1000 NPP: An Analysis Using EXCEL-TRIHEX-FA Code System

2008 ◽  
Author(s):  
Suhail Ahmad Khan ◽  
V. Jagannathan ◽  
R. P. Jain
Keyword(s):  
Power Distribution ◽  
Boron Concentration ◽  
Transport Theory ◽  
Fuel Cycle ◽  
Diffusion Theory ◽  
Nuclear Data ◽  
Core Level ◽  
Coolant Temperature ◽  
Code System ◽  
Density Values

Two units of VVER-1000Mwe reactors are in an advanced stage of construction at Kudankulam, Tamilnadu, India. With a view to assess the capability of analyzing the physics characteristics of VVER cores, the IAEA CRP benchmark problem of Kalinin VVER-1000 MWe NPP [1] is studied using the indigenous code system EXCEL-TRIHEX-FA [2,3]. The lattice burnup code EXCEL is based on a combination of 1-D multigroup transport theory and 2-D few group diffusion theory. Nuclear data in 172 group WIMS-D format based on JEFF-3.1 [4] has been used in the present analysis. The core level calculations are performed using the code TRIHEX-FA which solves the 3-D multigroup diffusion equation using the finite difference method with fine triangular meshes. Power dependent feedback models for xenon, Doppler, coolant temperature and density values have been incorporated in TRIHEX-FA. Keff for the critical soluble boron concentration, assembly power distribution and axial power distribution are calculated as a function of fuel cycle burnup. In the present paper, lattice level results are compared with the results of other participants reported in Ref. [1]. The results of core level calculations have been compared with the experimental data provided [1].

High-Speed, High-Frequency and Low-PDP, CNFET Full Adder Cells

2015 ◽  
Vol 24 (09) ◽  
pp. 1550130 ◽  
Author(s):  
Yavar Safaei Mehrabani ◽  
Mohammad Eshghi
Keyword(s):  
Monte Carlo ◽  
High Frequency ◽  
High Speed ◽  
Transient Analysis ◽  
State Of The Art ◽  
Process Variations ◽  
Full Adder ◽  
The Other ◽  
Simulation Results ◽  
Silicon Based

In this paper, three CNT-based full adder designs, called Design1, Design2 and Design3, are proposed. In these designs 12, 14 and 16 transistors are used, respectively. In all designs only 3-input NAND, Majority-not and NOR functions are used. First, a preliminary structure (Design1) is presented using 12 transistors. Then its weaknesses are tackled in two steps. In fact, in each step a new design is presented by adding two more transistors to its predecessor. Therefore two new structures called Design2 and Design3 are built in which Design3 is the most efficient one. To study the performance of Design3 versus other silicon-based and CNT-based 32-nm classical and state-of-the-art cells, comprehensive simulations with regard to various supplies, loads, operating frequencies, and temperatures are performed using Synopsys HSPICE tool. Simulation results confirm that the proposed cell is superior to the other cells. At last the robustness of Design3 against the diameter mismatches of CNTs which is one of the most important concerns of nanoelectronics is studied using Monte Carlo transient analysis. This simulation reveals that Design3 functions very well against manufacturing process variations.

Identifying influential spreaders based on diffusion K-truss decomposition

2018 ◽  
Vol 32 (22) ◽  
pp. 1850238 ◽  
Author(s):  
Li Yang ◽  
Yu-Rong Song ◽  
Guo-Ping Jiang ◽  
Ling-Ling Xia
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Network Structure ◽  
Decomposition Method ◽  
Spreading Behavior ◽  
The Core ◽  
Influential Nodes ◽  
Simulation Results ◽  
The Impact ◽  
Real Complex

Identifying the most influential spreaders is important in optimizing the network structure or disseminating information through networks. Recent study showed that the K-truss decomposition could filter out the nodes that performed a worse spreading behavior in the maximal K-shell subgraph. The spreaders belonging to the maximal K-truss subgraph show better performance compared to previously used importance criteria. However, the accuracy of the K-truss or the K-shell in determining node coreness is largely susceptible to core-like group. In this paper, we propose an improved diffusion K-truss decomposition method by considering both the diffusion and clustering of edges to eliminate the impact of core-like group on identifying influential nodes. To validate the effectiveness of the proposed method, we compare it with five typical methods by carrying out Monte–Carlo simulations over six real complex networks. Simulation results demonstrate that the proposed method can effectively disintegrate the core-like group and accurately identify the influential nodes.

Soziale Disziplinierung im flexiblen Kapitalismus

2004 ◽  
Vol 34 (136) ◽  
pp. 339-356
Author(s):  
Tobias Wölfle ◽  
Oliver Schöller
Keyword(s):  
Social Welfare ◽  
Second Step ◽  
Social Rights ◽  
Federal Law ◽  
Capitalist Development ◽  
The Core ◽  
The Past ◽  
The Impact ◽  
Municipal Level

Under the term “Hilfe zur Arbeit” (aid for work) the federal law of social welfare subsumes all kinds of labour disciplining instruments. First, the paper shows the historical connection of welfare and labour disciplining mechanisms in the context of different periods within capitalist development. In a second step, against the background of historical experiences, we will analyse the trends of “Hilfe zur Arbeit” during the past two decades. It will be shown that by the rise of unemployment, the impact of labour disciplining aspects of “Hilfe zur Arbeit” has increased both on the federal and on the municipal level. For this reason the leverage of the liberal paradigm would take place even in the core of social rights.

Citizen Deliberation Online

2019 ◽  
pp. 689-712
Author(s):  
Patrícia Rossini ◽  
Jennifer Stromer-Galley
Keyword(s):  
Political Engagement ◽  
Future Research ◽  
The Internet ◽  
Digital Platforms ◽  
The Core ◽  
Political Conversation ◽  
Political Talk ◽  
Citizen Deliberation ◽  
The Impact

Political conversation is at the heart of democratic societies, and it is an important precursor of political engagement. As society has become intertwined with the communication infrastructure of the Internet, we need to understand its uses and the implications of those uses for democracy. This chapter provides an overview of the core topics of scholarly concern around online citizen deliberation, focusing on three key areas of research: the standards of quality of communication and the normative stance on citizen deliberation online; the impact and importance of digital platforms in structuring political talk; and the differences between formal and informal political talk spaces. After providing a critical review of these three major areas of research, we outline directions for future research on online citizen deliberation.

scholarly journals Measuring Hydrometeors Using a Precipitation Microphysical Characteristics Sensor: Sampling Effect of Different Bin Sizes on Drop Size Distribution Parameters

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Xichuan Liu ◽  
Taichang Gao ◽  
Yuntao Hu ◽  
Xiaojian Shu
Keyword(s):  
Drop Size ◽  
Rain Rate ◽  
Monte Carlo Model ◽  
Rain Gauge ◽  
Sampling Schemes ◽  
Distribution Parameters ◽  
Optimum Sampling ◽  
Simulation Results ◽  
The Impact ◽  
Good Agreement

In order to improve the measurement of precipitation microphysical characteristics sensor (PMCS), the sampling process of raindrops by PMCS based on a particle-by-particle Monte-Carlo model was simulated to discuss the effect of different bin sizes on DSD measurement, and the optimum sampling bin sizes for PMCS were proposed based on the simulation results. The simulation results of five sampling schemes of bin sizes in four rain-rate categories show that the raw capture DSD has a significant fluctuation variation influenced by the capture probability, whereas the appropriate sampling bin size and width can reduce the impact of variation of raindrop number on DSD shape. A field measurement of a PMCS, an OTT PARSIVEL disdrometer, and a tipping bucket rain Gauge shows that the rain-rate and rainfall accumulations have good consistencies between PMCS, OTT, and Gauge; the DSD obtained by PMCS and OTT has a good agreement; the probability of N0, μ, and Λ shows that there is a good agreement between the Gamma parameters of PMCS and OTT; the fitted μ-Λ and Z-R relationship measured by PMCS is close to that measured by OTT, which validates the performance of PMCS on rain-rate, rainfall accumulation, and DSD related parameters.

scholarly journals Comparison of Industrial Quenching Oils

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 250
Author(s):  
Jiří Hájek ◽  
Zaneta Dlouha ◽  
Vojtěch Průcha
Keyword(s):  
State Of The Art ◽  
Cooling Capacity ◽  
Steel Grade ◽  
Cooling Curves ◽  
Cooling Process ◽  
Industrial Practice ◽  
Product Size ◽  
Cct Curve ◽  
Hardening Power ◽  
The Impact

This article is a response to the state of the art in monitoring the cooling capacity of quenching oils in industrial practice. Very often, a hardening shop requires a report with data on the cooling process for a particular quenching oil. However, the interpretation of the data can be rather difficult. The main goal of our work was to compare various criteria used for evaluating quenching oils. Those of which prove essential for operation in tempering plants would then be introduced into practice. Furthermore, the article describes monitoring the changes in the properties of a quenching oil used in a hardening shop, the effects of quenching oil temperature on its cooling capacity and the impact of the water content on certain cooling parameters of selected oils. Cooling curves were measured (including cooling rates and the time to reach relevant temperatures) according to ISO 9950. The hardening power of the oil and the area below the cooling rate curve as a function of temperature (amount of heat removed in the nose region of the Continuous cooling transformation - CCT curve) were calculated. V-values based on the work of Tamura, reflecting the steel type and its CCT curve, were calculated as well. All the data were compared against the hardness and microstructure on a section through a cylinder made of EN C35 steel cooled in the particular oil. Based on the results, criteria are recommended for assessing the suitability of a quenching oil for a specific steel grade and product size. The quenching oils used in the experiment were Houghto Quench C120, Paramo TK 22, Paramo TK 46, CS Noro MO 46 and Durixol W72.

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