Thermal-Hydraulic Simulations of Guard Containment in Depressurization Accidents of a Gas-Cooled Fast Reactor

2013 ◽  
Author(s):  
Zhanjie Xu ◽  
Thomas Jordan
Keyword(s):  
Fast Reactor ◽  
Nuclear Reactor ◽  
Source Term ◽  
Reference Value ◽  
Design Stage ◽  
Primary System ◽  
Simulation Results ◽  
Accident Scenarios ◽  
Design Pressure ◽  
The Eu

A gas-cooled fast reactor is designed as an advanced nuclear reactor in next generation in the EU. In depressurization accident scenarios, pressurization caused by a release of helium from the primary system with a higher pressure into the guard containment would endanger the integrity of the containment. In the design stage, the released source term is analyzed theoretically, and is applied as a boundary condition in the 3D CFD code simulation to the transient pressurization process. The simulation results supply a reference value about the design pressure of the containment.

scholarly journals An Intelligent Evaluation Method to Analyze the Competitiveness of Airlines

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Jun Zhao ◽  
Xumei Chen
Keyword(s):  
Neural Network ◽  
Prior Knowledge ◽  
Evaluation Method ◽  
Standard Sample ◽  
Reference Value ◽  
The Self ◽  
Index Data ◽  
Som Neural Network ◽  
Simulation Results ◽  
Self Organizing

An intelligent evaluation method is presented to analyze the competitiveness of airlines. From the perspective of safety, service, and normality, we establish the competitiveness indexes of traffic rights and the standard sample base. The self-organizing mapping (SOM) neural network is utilized to self-organize and self-learn the samples in the state of no supervision and prior knowledge. The training steps of high convergence speed and high clustering accuracy are determined based on the multistep setting. The typical airlines index data are utilized to verify the effect of the self-organizing mapping neural network on the airline competitiveness analysis. The simulation results show that the self-organizing mapping neural network can accurately and effectively classify and evaluate the competitiveness of airlines, and the results have important reference value for the allocation of traffic rights resources.

Numerical study of the flow over the modified simple frigate shape

2020 ◽  
pp. 095441002097775
Author(s):  
Tong Li ◽  
Yibin Wang ◽  
Ning Zhao
Keyword(s):  
Bluff Body ◽  
Recirculation Zone ◽  
Numerical Study ◽  
Reference Value ◽  
Flow Fields ◽  
Navier Stokes ◽  
Detached Eddy Simulation ◽  
Eddy Simulation ◽  
Delayed Detached Eddy Simulation ◽  
Simulation Results

The simple frigate shape (SFS) as defined by The Technical Co-operative Program (TTCP), is a simplified model of the frigate, which helps to investigate the basic flow fields of a frigate. In this paper, the flow fields of the different modified SFS models, consisting of a bluff body superstructure and the deck, were numerically studied. A parametric study was conducted by varying both the superstructure length L and width B to investigate the recirculation zone behind the hangar. The size and the position of the recirculation zones were compared between different models. The numerical simulation results show that the size and the location of the recirculation zone are significantly affected by the superstructure length and width. The results obtained by Reynolds-averaged Navier-Stokes method were also compared well with both the time averaged Improved Delayed Detached-Eddy Simulation results and the experimental data. In addition, by varying the model size and inflow velocity, various flow fields were numerically studied, which indicated that the changing of Reynolds number has tiny effect on the variation of the dimensionless size of the recirculation zone. The results in this study have certain reference value for the design of the frigate superstructure.

scholarly journals Temperature Dependence of Thermophysical Properties of Full-Scale Corium of Fast Energy Reactor

2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Mazhyn K. Skakov ◽  
Nurzhan Ye. Mukhamedov ◽  
Alexander D. Vurim ◽  
Ilya I. Deryavko
Keyword(s):  
Heat Capacity ◽  
Thermal Diffusivity ◽  
Fast Reactor ◽  
Thermophysical Properties ◽  
Heat Conductivity ◽  
Nuclear Reactor ◽  
Reactor Vessel ◽  
Full Scale ◽  
Temperature Fields ◽  
First Time

For the first time the paper determines thermophysical properties (specific heat capacity, thermal diffusivity, and heat conductivity) of the full-scale corium of the fast energy nuclear reactor within the temperature range from ~30°С to ~400°С. Obtained data are to be used in temperature fields calculations during modeling the processes of corium melt retention inside of the fast reactor vessel.

Research on Characteristics of Fluid Exciting Force of Reactor Internals

2021 ◽  
Author(s):  
Zhipeng Feng ◽  
Liwen Deng ◽  
Xuan Huang ◽  
Pingchuan Shen ◽  
Shuai Liu ◽  
...  
Keyword(s):  
Pressure Fluctuation ◽  
Nuclear Reactor ◽  
Wide Band ◽  
Exciting Force ◽  
Design Stage ◽  
Response Analysis ◽  
Flow Induced Vibration ◽  
Analysis And Evaluation ◽  
Safety And Reliability ◽  
Force Characteristics

Abstract Flow-induced vibration is an important issue related to the safety and reliability of nuclear reactor, which need to be analyzed and evaluated in the design stage. In order to obtain the input loads and key parameters used in the calculation of flow-induced vibration of reactor vessel internals (RVIs) that need to satisfy the engineering requirements. The typical RVIs are selected as the research object, and the fluid exciting force characteristics are studied based on the computational fluid dynamics methods. The results show that the fluid exciting force acting on the RVIs is a wide-band stochastic process. For upper internal, the largest pressure fluctuation occurs at the guide tubes and support columns located near the outlet. Therefore, it is necessary to pay more attention to these guide tubes and support columns in response analysis. As for core barrel, the root mean square value of the pressure fluctuation changes drastically at the inlet and outlet location. For lower internal, the lower flow field of RVIs is relatively disordered, and its pressure fluctuation possesses irregular characteristics. Each component of lower internal need to be considered in analysis and evaluation.

A Reformative Simulation Method of Motor Pole Core Vibration Characteristics

2013 ◽  
Vol 331 ◽  
pp. 118-123
Author(s):  
Tian Hui Ding ◽  
Yun Hua Chen ◽  
Lei Tian
Keyword(s):  
Reference Value ◽  
Simulation Method ◽  
Vibration Characteristics ◽  
New Method ◽  
Motor Design ◽  
Simulation Results ◽  
Vibration Performance

As to directing motor design, it is very important to make sure that the motor’s forecast of vibration performance has reference value. So, it must need motor’s parts vibration characteristics simulation results are so close to their characteristics. This paper puts forward a new simulation method of motor pole core vibration characteristics, this method includes setting anisotropy material attributes multipartite, getting attributes parameters values which are based on recommended fitting curves, modeling and equating windings, equating dipping lacquer and so on. Combining with experiments, the new method is validated its availability.

OPNET-Based Computer Simulation of MPLS VPN Security Solutions

2010 ◽  
Vol 40-41 ◽  
pp. 361-365
Author(s):  
Ya Qin Fan ◽  
Hao Fan ◽  
Chao Sun
Keyword(s):  
Computer Simulation ◽  
Information Disclosure ◽  
Reference Value ◽  
Simulation System ◽  
Simulation Software ◽  
Software Simulation ◽  
The Public ◽  
Backbone Network ◽  
Mpls Vpn ◽  
Simulation Results

This paper features of IPSec and MPLS technologies, proposes a suitable MPLS VPN security solutions. The program to solve the VPN using MPLS backbone network in the public transport there is a second layer of information can not automatically encrypt, or connect easily made because of errors due to the interruption of information disclosure and other issues. To verify the proposed security program, the actual MPLS VPN can be simplified, abstracestablishing a simulation system MPLS VPN, and using OPNET simulation software simulation, simulation results of VPN officers practical reference value.

Risk Evaluation at the Preliminary Design Stage of a High-Speed Craft

2004 ◽  
Vol 20 (03) ◽  
pp. 183-187
Author(s):  
Richard Birmingham ◽  
Jon McGregor ◽  
Severine Delautre ◽  
Jean-Claude Astrugue
Keyword(s):  
High Speed ◽  
Design Tool ◽  
Transport Infrastructure ◽  
Design Stage ◽  
Safety Issues ◽  
Research Areas ◽  
Marine Industry ◽  
Preliminary Design Stage ◽  
Eu Project ◽  
The Eu

Due to the congestion of the traditional transport infrastructure across Europe, the EU has developed the EU Common Transport Policy. This policy endorses the use of waterborne craft to ease onshore congestion. In addition to this there have been follow-up measures in the form of "short sea shipping" and lately the concept of "quality shipping" has surfaced to allay concerns arising from the standards of shipping. It is with this backdrop that an increase in demand for high-speed craft (HSC) has occurred. This in turn has created new concerns of how the safety of HSC can be assured when there is such a lack of historical data. To deal with these concerns, there has been a call for new design tools and methodologies to be developed that raise the profile of safety issues from the very beginning of the design process. It was with this in mind that funding was granted for an EU project called Safety at Speed (S@S), the details of which are described in the paper. S@S is made up of 15 partners spread throughout the EU. The partners come from all areas of the marine industry, including universities, designers/builders, class societies, and operators. The project has been split into six research areas. These are collision and grounding, motions, foundering, containment of damage and fire, integration, and case study. The paper is written from the perspective of the integration work package and describes in detail the driving "vision" behind the project. The perceived structure of the project is examined. The problems that the partners have had to overcome are laid out. These problems have led to an evolution of the interrelationships of work packages. The paper goes on to discuss the use of parameters and how their different forms can be incorporated into the design tool with reference to vast fluctuations in quality of input data. Finally, there is a discussion of how the output results from use of the tool, both for risk and cost, can most usefully be presented.

Public debt limit of the EU Member States and its impact on polish legal system – considerations in the context of public finance stability

2020 ◽  
Vol 18 (1) ◽  
pp. 239-255
Author(s):  
Wojciech Bożek
Keyword(s):  
Public Debt ◽  
Comparative Method ◽  
Reference Value ◽  
Case Law ◽  
Point Of View ◽  
Fiscal Rules ◽  
Eu Member States ◽  
Constitutional Tribunal ◽  
The Republic ◽  
The Eu

The author’s goal is to determine the consequences of implementing treaty solutions concerning public debt to the Polish Constitution and to define the differences between the methodology of counting public debt in the European Community and Polish legal order. The raised issues concern important problems from the substantive and practical point of view, therefore the study’s content is important for science and practice. The research methodology was based on the analysis of the EU and Poland’s normative solutions, opinions expressed in the international and national literature on the subject, and the case law of the Polish Constitutional Tribunal. The paper applies mostly the dogmatic-analytic and legal-comparative method with reference to available statistical data on Poland’s public debt. The study allowed the author to gain an understanding of the significance of fiscal rules implemented at the EU level to ensure stability. Article 216(5) of the Constitution of the Republic of Poland indicates that the treaty solutions regarding the reference value (public debt-to-GDP ratio) were reenacted. However, until this day, the EU and Poland’s debt measurement methods do not fully correspond. In order to counteract excessive debt incursion, a state is required to take not only efficient actions but also ones that are adequate and, to some extent, flexible. This is an expression of acceptance of the EU’s preventive assumptions. However, there is still no full correlation in the methodology of calculating public debt in the EU and the Republic of Poland.

scholarly journals Anti-Wiretap Spectrum-Sharing for Cooperative Cognitive Radio Communication Systems

Sensors ◽  
2019 ◽  
Vol 19 (19) ◽  
pp. 4142
Author(s):  
Peiyuan Si ◽  
Weidang Lu ◽  
Kecai Gu ◽  
Xin Liu ◽  
Bo Li ◽  
...  
Keyword(s):  
Cognitive Radio ◽  
Wireless Communication ◽  
Cooperative Communication ◽  
Communication Systems ◽  
Spectrum Sharing ◽  
Transmission Rate ◽  
Primary System ◽  
Radio Communication ◽  
Sharing Scheme ◽  
Simulation Results

As wireless communication technology keeps progressing, people’s requirements for wireless communication quality are getting higher and higher. Wireless communication brings convenience, but also causes some problems. On the one hand, the traditional static and fixed spectrum allocation strategy leads to high wastefulness of spectrum resources. The direction of improving the utility of spectrum resources by combining the advantages of cooperative communication and cognitive radio has attracted the attention of many scholars. On the other hand, security of communication is becoming an important issue because of the broadcasting nature and openness of wireless communication. Physical-layer security has been brought into focus due to the possibility of improving the security in wireless communication. In this paper, we propose an anti-wiretap spectrum-sharing scheme for cooperative cognitive radio communication systems which can secure the information transmission for the two transmission phases of the cooperative communication. We maximized the secondary system transmission rate by jointly optimizing power and bandwidth while ensuring the primary system achieves its secrecy transmission rate. Useful insights of the proposed anti-wiretap spectrum-sharing scheme are given in the simulation results. Moreover, several system parameters are shown to have a big impact for the simulation results.

Sign in / Sign up

Export Citation Format

Share Document