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Sample records for cask vsc system

  1. Inspection and Gamma-Ray Dose Rate Measurements of the Annulus of the VSC-17 Concrete Spent Nuclear Fuel Storage Cask

    Energy Technology Data Exchange (ETDEWEB)

    P. L. Winston

    2007-09-01

    The air cooling annulus of the Ventilated Storage Cask (VSC)-17 spent fuel storage cask was inspected using a Toshiba 7 mm (1/4”) CCD video camera. The dose rates observed in the annular space were measured to provide a reference for the activity to which the camera(s) being tested were being exposed. No gross degradation, pitting, or general corrosion was observed.

  2. Optimizing the performance of a VSC HVDC control system

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Mau Cuong; Rudion, Krzystof; Styczynski, Zbigniew Antoni [Magdeburg Univ. (Germany). Chair for Electric Power Networks and Renewable Energy Sources

    2011-07-01

    This paper deals with the optimization of the parameters in the various control loops of a voltage source converter based high voltage direct current (VSC HVDC) transmission system connected to a doubly fed induction generator (DFIG) based wind farm. These control loops include a number of proportional-integral (PI) controllers. The performance of VSC HVDC depends on the parameters of these PI controllers. In this paper, the control strategy of each converter of the VSC HVDC is first introduced to investigate a VSC HVDC transmission system that transfers DFIG wind power over a long distance. Secondly, the optimization process, based on the simplex method which is proposed in the literature, is applied with the initial values of the PI controller's parameters, which are obtained by studying the classical frequency response of the open-loop transfer function of the VSC HVDC. The objective is to simultaneously minimize the weighted sum of the integral of the time absolute-error products (ITAE) of the AC voltage, reactive power, DC voltage and inner current controllers of both VSC stations. The effectiveness of the optimized parameters is assessed in the field of requirements of the VSC HVDC control system as mentioned above during voltage down to zero to reduce the generated power from wind farm. (orig.)

  3. Stability of DC Voltage Droop Controllers in VSC HVDC Systems

    DEFF Research Database (Denmark)

    Thams, Florian; Suul, Jon Are; D’Arco, Salvatore;

    2015-01-01

    Future multi-terminal HVDC systems are expected to utilize dc voltage droop controllers and several control implementations have been proposed in literature. This paper first classifies possible dc droop implementations in a simple framework. Then, the small-signal stability of a VSC-based conver......Future multi-terminal HVDC systems are expected to utilize dc voltage droop controllers and several control implementations have been proposed in literature. This paper first classifies possible dc droop implementations in a simple framework. Then, the small-signal stability of a VSC...

  4. Control strategies for VSC-based HVDC transmission system

    DEFF Research Database (Denmark)

    Stan, Ana-Irina; Stroe, Daniel Ioan; Silva, Rodrigo Da

    2011-01-01

    the behavior of the developed VSC-based HVDC transmission system two study cases are carried out using MATLAB/Simulink. The results obtained from simulations show acceptable performances, of the proposed strategies, when changes in the reference parameters are considered. The active power flow between...

  5. VSC-HVDC系统启动控制%Startup Procedures for the VSC-HVDC System

    Institute of Scientific and Technical Information of China (English)

    张静; 徐政; 陈海荣

    2009-01-01

    In order to reduce the undesired impacts and damages on the VSC-HVDC system and the connected AC system during the startup and re-startup procedures, appropriate startup control strategy should be dedicatedly designed. Charging the DC capacitor voltage to the preset value quickly is the fundamental of the subsequent control strategy. In this paper, a two-stage self startup procedure is proposed for VSC-HVDC system consisting of two-level and diode-clamped three-level converters. During the first stage, the resistors are inserted to limit the current during the charging. If the DC voltage can not reach the preset value after predetermined time, the startup procedure switches to the second stage and the capacitors will be further charged with a DC voltage controller. The startup procedure completes till the DC link voltage reaches the preset value and then the converters are ready to change from the startup mode to the normal operating mode. In addition, a new control strategy is proposed for the startup of the passive network and the AC system suffered from black out. With the proposed control strategy, the inrush currents during the energization of the transformers and the overvoltage during the closure of the long overhead transmission lines can be suppressed. Simulation results verify the feasibility of the proposed startup procedures.%合适的启动方式对减缓VSC-HVDC系统启动及重新启动时对自身和电网的冲击非常重要.如何把直流电容器电压快速提升到设定值,是后续控制策略正确工作的基础.针对目前应用较广泛的两电平和二极管钳位型三电平换流器拓扑结构,提出了一种简单、适用于VSC-HVDC系统的两阶段自励启动方法.在启动第一阶段,串接限流电阻器对直流侧电路充电;若在设定的时间内电容器电压不能达到设定值,启动转入第二阶段,即换流站在直流电压控制器的作用下对电容器继续充电,直至达到预设值,从而为换

  6. Discrete-Time Nonlinear Control of VSC-HVDC System

    Directory of Open Access Journals (Sweden)

    TianTian Qian

    2015-01-01

    Full Text Available Because VSC-HVDC is a kind of strong nonlinear, coupling, and multi-input multioutput (MIMO system, its control problem is always attracting much attention from scholars. And a lot of papers have done research on its control strategy in the continuous-time domain. But the control system is implemented through the computer discrete sampling in practical engineering. It is necessary to study the mathematical model and control algorithm in the discrete-time domain. The discrete mathematical model based on output feedback linearization and discrete sliding mode control algorithm is proposed in this paper. And to ensure the effectiveness of the control system in the quasi sliding mode state, the fast output sampling method is used in the output feedback. The results from simulation experiment in MATLAB/SIMULINK prove that the proposed discrete control algorithm can make the VSC-HVDC system have good static, dynamic, and robust characteristics in discrete-time domain.

  7. Efficiency of VSC-HVDC System With Various Fuzzy Models

    Directory of Open Access Journals (Sweden)

    Mrs. Sonali R dasgupta,

    2011-05-01

    Full Text Available This paper suggests a Shrinking Span Membership function to be utilized in very fact changing system just like VSC- HVDC system. In this particular work Mamdani controller as well as the Takagi-Sugeno controller are compared with exact same input function(Shrinking Span Membership in simulation as well as on prototype hardware. Simulation result justify the. Takagi-Sugeno Controller gives better dynamic response then the Mamdani controller

  8. Assessment on the influence of resistive superconducting fault current limiter in VSC-HVDC system

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong-Geon; Khan, Umer Amir; Hwang, Jae-Sang; Seong, Jae-Kyu; Shin, Woo-Ju; Park, Byung-Bae; Lee, Bang-Wook, E-mail: bangwook@hanyang.ac.kr

    2014-09-15

    Highlights: • The role of SFCLs in VSC-HVDC systems was evaluated. • Simulation model based on Korea Jeju-Haenam HVDC power system was designed. • An effect and the feasible locations of resistive SFCLs were evaluated. • DC line-to-line, DC line-to-ground and 3 phase AC faults were imposed and analyzed. - Abstract: Due to fewer risk of commutation failures, harmonic occurrences and reactive power consumptions, Voltage Source Converter (VSC) based HVDC system is known as the optimum solution of HVDC power system for the future power grid. However, the absence of suitable fault protection devices for HVDC system hinders the efficient VSC-HVDC power grid design. In order to enhance the reliability of the VSC-HVDC power grid against the fault current problems, the application of resistive Superconducting Fault Current Limiters (SFCLs) could be considered. Also, SFCLs could be applied to the VSC-HVDC system with integrated AC Power Systems in order to enhance the transient response and the robustness of the system. In this paper, in order to evaluate the role of SFCLs in VSC-HVDC systems and to determine the suitable position of SFCLs in VSC-HVDC power systems integrated with AC power System, a simulation model based on Korea Jeju-Haenam HVDC power system was designed in Matlab Simulink/SimPowerSystems. This designed model was composed of VSC-HVDC system connected with an AC microgrid. Utilizing the designed VSC-HVDC systems, the feasible locations of resistive SFCLs were evaluated when DC line-to-line, DC line-to-ground and three phase AC faults were occurred. Consequently, it was found that the simulation model was effective to evaluate the positive effects of resistive SFCLs for the effective suppression of fault currents in VSC-HVDC systems as well as in integrated AC Systems. Finally, the optimum locations of SFCLs in VSC-HVDC transmission systems were suggested based on the simulation results.

  9. Assessment on the influence of resistive superconducting fault current limiter in VSC-HVDC system

    Science.gov (United States)

    Lee, Jong-Geon; Khan, Umer Amir; Hwang, Jae-Sang; Seong, Jae-Kyu; Shin, Woo-Ju; Park, Byung-Bae; Lee, Bang-Wook

    2014-09-01

    Due to fewer risk of commutation failures, harmonic occurrences and reactive power consumptions, Voltage Source Converter (VSC) based HVDC system is known as the optimum solution of HVDC power system for the future power grid. However, the absence of suitable fault protection devices for HVDC system hinders the efficient VSC-HVDC power grid design. In order to enhance the reliability of the VSC-HVDC power grid against the fault current problems, the application of resistive Superconducting Fault Current Limiters (SFCLs) could be considered. Also, SFCLs could be applied to the VSC-HVDC system with integrated AC Power Systems in order to enhance the transient response and the robustness of the system. In this paper, in order to evaluate the role of SFCLs in VSC-HVDC systems and to determine the suitable position of SFCLs in VSC-HVDC power systems integrated with AC power System, a simulation model based on Korea Jeju-Haenam HVDC power system was designed in Matlab Simulink/SimPowerSystems. This designed model was composed of VSC-HVDC system connected with an AC microgrid. Utilizing the designed VSC-HVDC systems, the feasible locations of resistive SFCLs were evaluated when DC line-to-line, DC line-to-ground and three phase AC faults were occurred. Consequently, it was found that the simulation model was effective to evaluate the positive effects of resistive SFCLs for the effective suppression of fault currents in VSC-HVDC systems as well as in integrated AC Systems. Finally, the optimum locations of SFCLs in VSC-HVDC transmission systems were suggested based on the simulation results.

  10. Contribution of VSC-HVDC to Frequency Regulation of Power Systems With Offshore Wind Generation

    DEFF Research Database (Denmark)

    Liu, Hongzhi; Chen, Zhe

    2015-01-01

    to the onshore system grid through voltage-source converter-based–high voltage direct current (VSC-HVdc) transmission systems. Due to the decoupling of VSC-HVdc and signal transmission delay, offshore wind farms may not be able to respond to the onshore grid frequency excursion in time and, consequently......, the stability and security of the power system will be put at risk, especially for those with high wind penetration. This paper proposes a coordinated control scheme to allow VSC-HVdc link to contribute to the system frequency regulation by adjusting its dc-link voltage. By means of this approach, the dc...... capacitors of VSC-HVdc are controlled to absorb or release energy so as to provide frequency support. To further enhance the system frequency response, the frequency support from VSC-HVdc is also finely coordinated with that from offshore wind farm according to the latency of offshore wind farm responding...

  11. Feasibility study for a transportation operations system cask maintenance facility

    Energy Technology Data Exchange (ETDEWEB)

    Rennich, M.J.; Medley, L.G.; Attaway, C.R.

    1991-01-01

    The US Department of Energy (DOE), Office of Civilian Radioactive Waste Management (OCRWM) is responsible for the development of a waste management program for the disposition of spent nuclear fuel (SNF) and high-level waste (HLW). The program will include a transportation system for moving the nuclear waste from the sources to a geologic repository for permanent disposal. Specially designed casks will be used to safely transport the waste. The cask systems must be operated within limits imposed by DOE, the Nuclear Regulatory Commission (NRC), and the Department of Transportation (DOT). A dedicated facility for inspecting, testing, and maintaining the cask systems was recommended by the General Accounting Office (in 1979) as the best means of assuring their operational effectiveness and safety, as well as regulatory compliance. In November of 1987, OCRWM requested a feasibility study be made of a Cask Maintenance Facility (CMF) that would perform the required functions. 46 refs., 16 figs., 13 tabs.

  12. Application of Multipoint DC Voltage Control in VSC-MTDC System

    Directory of Open Access Journals (Sweden)

    Yang Xi

    2013-01-01

    Full Text Available The voltage-source-converter- (VSC- based multiterminal VSC-HVDC power transmission system (VSC-MTDC is an ideal approach to connect wind farm with power grid. Analyzing the characteristics of doubly fed induction generators as well as the basic principle and the control strategy of VSC-MTDC, a multiterminal DC voltage control strategy suitable for wind farm connected with VSC-MTDC is proposed. By use of PSCAD/EMTDC, the proposed control strategy is simulated, and simulation results show that using the proposed control strategy the conversion between constant power control mode and constant DC voltage control mode can be automatically implemented; thus the DC voltage stability control and reliable power output of wind farm can be ensured after the fault-caused outage of converter station controlled by constant DC voltage and under other faults. The simulation result shows that the model can fulfill multiterminal power transmission and fast response control.

  13. Power control method on VSC-HVDC in a hybrid multi-infeed HVDC system

    DEFF Research Database (Denmark)

    Liu, Yan; Chen, Zhe

    2012-01-01

    Multi-infeed HVDC (MIDC) system connected with VSC-HVDC links and LCC-HVDC links is a new structure in modern power systems, which can be called hybrid multi-infeed HVDC (HMIDC) system. The paper presents the voltage stability analysis of a HMIDC system modeled from a possible future Danish power...... stability of the system with induction machine loads. The proposed power control method based on a VSC power circle makes fully use of the VSC-HVDC capacity to support system voltage during fault situations. Simulation model of the studied HMIDC system is built in PSCAD. Simulation studies under different...

  14. Geometric feasibility of flexible cask transportation system for ITER

    Energy Technology Data Exchange (ETDEWEB)

    Lima, P.; Ribeiro, M.I.; Aparicio, P. [Instituto Superior Tecnico-Instituto de Sistemas e Robotica, Lisboa (Portugal)

    1998-07-01

    One of the remote operations that has to be carried out in the International Thermonuclear Experimental Reactor (ITER) is the transportation of sealed casks between the various ports of the Tokamak Building (TB) and the Hot Cell Building (HCB). The casks may contain different in-vessel components (e.g. blanket modules, divertors) and are designed for a maximum load of about 80 ton. To improve the safety and flexibility of ITER Remote Handling (RH) transport vehicles, the cask is not motorized by itself, but instead, a motorized platform carrying the cask was proposed. This paper addresses the geometric feasibility of the flexible cask transportation system, taking into account the vehicle kinematics. The feasibility issues studied include planning smooth paths to increase safety, the discussion of building constraints by the evaluation of the vehicle spanned areas when following a planned path, and the analysis of the clearance required to remove the platform from underneath the cask at different possible failure locations. Simulation results are presented for the recommended trajectory, the spanned area and the rescue manoeuvres at critical locations along the path. (authors)

  15. Standard review plan for dry cask storage systems. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-01-01

    The Standard Review Plan (SRP) For Dry Cask Storage Systems provides guidance to the Nuclear Regulatory Commission staff in the Spent Fuel Project Office for performing safety reviews of dry cask storage systems. The SRP is intended to ensure the quality and uniformity of the staff reviews, present a basis for the review scope, and clarification of the regulatory requirements. Part 72, Subpart B generally specifies the information needed in a license application for the independent storage of spent nuclear fuel and high level radioactive waste. Regulatory Guide 3.61 {open_quotes}Standard Format and Content for a Topical Safety Analysis Report for a Spent Fuel Dry Storage Cask{close_quotes} contains an outline of the specific information required by the staff. The SRP is divided into 14 sections which reflect the standard application format. Regulatory requirements, staff positions, industry codes and standards, acceptance criteria, and other information are discussed.

  16. Coordinated Control Strategies of VSC-HVDC-Based Wind Power Systems for Low Voltage Ride Through

    Directory of Open Access Journals (Sweden)

    Xinyin Zhang

    2015-07-01

    Full Text Available The Voltage Source Converter-HVDC (VSC-HVDC system applied to wind power generation can solve large scale wind farm grid-connection and long distance transmission problems. However, the low voltage ride through (LVRT of the VSC-HVDC connected wind farm is a key technology issue that must be solved, and it is currently lacking an economic and effective solution. In this paper, a LVRT coordinated control strategy is proposed for the VSC-HVDC-based wind power system. In this strategy, the operation and control of VSC-HVDC and wind farm during the grid fault period is improved. The VSC-HVDC system not only provides reactive power support to the grid, but also effectively maintains the power balance and DC voltage stability by reducing wind-farm power output, without increasing the equipment investment. Correspondingly, to eliminate the influence on permanent magnet synchronous generator (PMSG-based wind turbine (WT systems, a hierarchical control strategy is designed. The speed and validity of the proposed LVRT coordinated control strategy and hierarchical control strategy were verified by MATLAB/Simulink simulations.

  17. Voltage Stability Bifurcation Analysis for AC/DC Systems with VSC-HVDC

    Directory of Open Access Journals (Sweden)

    Yanfang Wei

    2013-01-01

    Full Text Available A voltage stability bifurcation analysis approach for modeling AC/DC systems with VSC-HVDC is presented. The steady power model and control modes of VSC-HVDC are briefly presented firstly. Based on the steady model of VSC-HVDC, a new improved sequential iterative power flow algorithm is proposed. Then, by use of continuation power flow algorithm with the new sequential method, the voltage stability bifurcation of the system is discussed. The trace of the P-V curves and the computation of the saddle node bifurcation point of the system can be obtained. At last, the modified IEEE test systems are adopted to illustrate the effectiveness of the proposed method.

  18. Power system integration of VSC-HVDC connected offshore wind power plants

    DEFF Research Database (Denmark)

    Zeni, Lorenzo; Kjær, Philip Carne

    . The benefits of not prioritising active power during current-limited operation are demonstrated on a simple system and the possible implications on the control of a WPP potentially connected behind the HVDC converter are discussed. Active power balance control is the second service being analysed......This report presents an overview of challenges and solutions for the integration into the power system of offshore wind power plants (WPPs) connected to onshore grids through a voltage-source converter based high voltage direct current (VSC-HVDC) transmission system. Aspects that are touched upon...... are (i) principles for the control of offshore alternating current (AC) networks behind offshore VSC-HVDC converters, (ii) power system services that could be featured by VSC-HVDC connected WPPs and (iii) clustering of multiple WPPs to co-ordinately provide desired control actions. After a brief...

  19. A weight modification sequential method for VSC-MTDC power system state estimation

    Science.gov (United States)

    Yang, Xiaonan; Zhang, Hao; Li, Qiang; Guo, Ziming; Zhao, Kun; Li, Xinpeng; Han, Feng

    2017-06-01

    This paper presents an effective sequential approach based on weight modification for VSC-MTDC power system state estimation, called weight modification sequential method. The proposed approach simplifies the AC/DC system state estimation algorithm through modifying the weight of state quantity to keep the matrix dimension constant. The weight modification sequential method can also make the VSC-MTDC system state estimation calculation results more ccurate and increase the speed of calculation. The effectiveness of the proposed weight modification sequential method is demonstrated and validated in modified IEEE 14 bus system.

  20. A Review of Muti-Terminal VSC-HVDC System in Large Wind Farms%大型风电基地多端 VSC-HVDC系统综述

    Institute of Scientific and Technical Information of China (English)

    吴瀚俊; 刘海涛

    2014-01-01

    In recent years,the upgrowth of fully-controlled devices and pulse width modulation device PWM technology,has paved the way for the appearance and progression of VSC-HVDC technology.Multi-terminal VSC-HVDC technology can be applied to address such problems as island supply,distributed generation system connecting to large power grids,etc.This paper elucidates the principle of VSC-HVDC,and compares AC transmission and normal HVDC,aimed at highlighting the advantages of VSC-HVDC.The working mode of convertors,a key part of VSC-HVDC,is also briefly introduced.More importantly,this paper demonstrates topology and coordination control strategy of multi-terminal VSC-HVDC system in large-scale offshore wind farms,and predicts its future development trend.%随着近年来全控型器件的出现和发展以及脉宽调制( PWM)技术的日臻成熟,为VSC-HVDC技术的产生和发展创造了条件,而多端VSC-HVDC技术可以很好地解决孤岛供电、分布式发电系统接入大电网等问题。文章就VSC-HVDC原理进行阐述,通过对比交流输电和常规HVDC来突出VSC-HVDC的优点,并简单介绍了VSC-HVDC的关键部分也就是变流器的运行模式。文章重点论述大型风电基地多端VSC-HVDC系统的拓扑结构和协调控制策略,并对其未来发展趋势作出预测。

  1. Grid-connection of offshore wind farms using VSC-HVDC systems

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Xiaofan; Dessaint, Louis A. [Ecole de Technologie Superieure, Montreal, QC (Canada). Dept. of Electrical Engineering; Gagnon, Richard [Hydro-Quebec Research Institute, Montreal, QC (Canada)

    2011-07-01

    In this paper, the structure of variable speed PMSG-based offshore wind farms connected to the grid through VSC-HVDC link is presented. And the system models are developed. Also, the corresponding control strategy for this system is proposed. The control objective of the generator side VSC is to achieve the optimal wind power by adjusting the speed of permanent magnet synchronous generator, while the grid side VSC is to maintain DC voltage constant. Furthermore, a case study of 100MW offshore wind farm consisting of 50 individual 2MW PSMG-based wind turbines is developed in MATLAB/SimPowerSystems. Simulation results show the proposed scheme works well. (orig.)

  2. Real power regulation design for multi-terminal VSC-HVDC systems

    Science.gov (United States)

    Li, Guo-Jie; Ruan, Si-Ye; Lie, Tek

    2013-06-01

    A multi-terminal voltage-source-converter (VSC) based high voltage direct current (HVDC) system is concerned for its flexibility and reliability. In this study, a control strategy for multiple VSCs is proposed to auto-share the real power variation without changing control mode, which is based on "dc voltage droop" power regulation functions. With the proposed power regulation design, the multiple VSCs automatically share the real power change and the VSC-HVDC system is stable even under loss of any one converter while there is no overloading for any individual converter. Simulation results show that it is effective to balance real power for power disturbance and thus improves operation reliability for the multi-terminal VSC-HVDC system by the proposed control strategy.

  3. Stability analysis of multi-infeed HVDC system applying VSC-HVDC

    DEFF Research Database (Denmark)

    Liu, Yan; Chen, Zhe

    2010-01-01

    on this model is analyzed under steady state and different kinds of grid fault transient situations. Two main control methods applied on VSC-HVDC link in this dual infeed HVDC system are investigated, and comparative analysis of them under transient situation is presented. A simulation model is built in PSCAD....../EMTDC to verify the theoretical analysis. Simulation results indicate that this dual infeed HVDC system can realize higher stability than single infeed HVDC system. And different control strategies on a VSC-HVDC link may result in different influence on AC voltage and active power oscillation during transient...... situation....

  4. Design analysis report for the TN-WHC cask and transportation system

    Energy Technology Data Exchange (ETDEWEB)

    Brisbin, S.A., Fluor Daniel Hanford

    1997-02-13

    This document presents the evaluation of the Spent Nuclear Fuel Cask and Transportation System. The system design was developed by Transnuclear, Inc. and its team members NAC International, Nelson Manufacturing, Precision Components Corporation, and Numatec, Inc. The cask is designated the TN-WHC cask. This report describes the design features and presents preliminary analyses performed to size critical dimensions of the system while meeting the requirements of the performance specification.

  5. Analysis of VSC based FACTS stabilizers in damping power system oscillations : multi-machine power systems

    Energy Technology Data Exchange (ETDEWEB)

    Du, W. [Southeast Univ., Nanjing (China)]|[Bath Univ., Bath (United Kingdom); Wang, H.F. [Queen' s Univ. of Belfast, Belfast (United Kingdom); Dunn, R. [Bath Univ., Bath (United Kingdom)

    2008-07-01

    The Voltage Source Converter (VSC) for Flexible AC Transmission Systems (FACTS) devices can be equipped with a supplementary damping function to improve power system oscillation stability. This paper presented a general analytical method to study this type of VSC based FACTS stabilizers in damping power system oscillations. These converters include electronic devices such as the Static Synchronous Compensator (STATCOM), the Series Static Synchronous Compensator, (SSSC) and the Unified Power Flow Controller (UPFC). A proposed analysis was provided for the simple case of single-machine infinite-bus power systems. This paper also presented the extension of the proposed method to the more general case of multi-machine power systems. 10 refs., 5 figs.

  6. Impacts of large-scale offshore wind farm integration on power systems through VSC-HVDC

    DEFF Research Database (Denmark)

    Liu, Hongzhi; Chen, Zhe

    2013-01-01

    the impacts of integrating a large-scale offshore wind farm into the transmission system of a power grid through VSC-HVDC connection. The concerns are focused on steady-state voltage stability, dynamic voltage stability and transient angle stability. Simulation results based on an exemplary power system...

  7. Improved Power Flow Algorithm for VSC-HVDC System Based on High-Order Newton-Type Method

    Directory of Open Access Journals (Sweden)

    Yanfang Wei

    2013-01-01

    Full Text Available Voltage source converter (VSC based high-voltage direct-current (HVDC system is a new transmission technique, which has the most promising applications in the fields of power systems and power electronics. Considering the importance of power flow analysis of the VSC-HVDC system for its utilization and exploitation, the improved power flow algorithms for VSC-HVDC system based on third-order and sixth-order Newton-type method are presented. The steady power model of VSC-HVDC system is introduced firstly. Then the derivation solving formats of multivariable matrix for third-order and sixth-order Newton-type power flow method of VSC-HVDC system are given. The formats have the feature of third-order and sixth-order convergence based on Newton method. Further, based on the automatic differentiation technology and third-order Newton method, a new improved algorithm is given, which will help in improving the program development, computation efficiency, maintainability, and flexibility of the power flow. Simulations of AC/DC power systems in two-terminal, multi-terminal, and multi-infeed DC with VSC-HVDC are carried out for the modified IEEE bus systems, which show the effectiveness and practicality of the presented algorithms for VSC-HVDC system.

  8. Study of Power Flow Algorithm of AC/DC Distribution System including VSC-MTDC

    Directory of Open Access Journals (Sweden)

    Haifeng Liang

    2015-08-01

    Full Text Available In recent years, distributed generation and a large number of sensitive AC and DC loads have been connected to distribution networks, which introduce a series of challenges to distribution network operators (DNOs. In addition, the advantages of DC distribution networks, such as the energy conservation and emission reduction, mean that the voltage source converter based multi-terminal direct current (VSC-MTDC for AC/DC distribution systems demonstrates a great potential, hence drawing growing research interest. In this paper, considering losses of the reactor, the filter and the converter, a mathematical model of VSC-HVDC for the load flow analysis is derived. An AC/DC distribution network architecture has been built, based on which the differences in modified equations of the VSC-MTDC-based network under different control modes are analyzed. In addition, corresponding interface functions under five control modes are provided, and a back/forward iterative algorithm which is applied to power flow calculation of the AC/DC distribution system including VSC-MTDC is proposed. Finally, by calculating the power flow of the modified IEEE14 AC/DC distribution network, the efficiency and validity of the model and algorithm are evaluated. With various distributed generations connected to the network at appropriate locations, power flow results show that network losses and utilization of transmission networks are effectively reduced.

  9. A robotic system to conduct radiation and contamination surveys on nuclear waste transport casks

    Energy Technology Data Exchange (ETDEWEB)

    Harrigan, R.W.; Sanders, T.L.

    1990-06-01

    The feasibility of performing, numerous spent fuel cask operations using fully integrated robotic systems is under evaluation. Using existing technology, operational and descriptive software and hardware in the form of robotic end effectors are being designed in conjunction with interfacing cask components. A robotic radiation and contamination survey system has been developed and used on mock-up cask hardware to evaluate the impact of such fully automated operations on cask design features and productivity. Based on experience gained from the survey system, numerous health physics operations can be reliably performed with little human intervention using a fully automated system. Such operations can also significantly reduce time requirements for cask-receiving operations. 7 refs., 51 figs., 6 tabs.

  10. Integration of CCC-HVDC and VSC-HVDC Systems to Supply an Island Network

    Directory of Open Access Journals (Sweden)

    G.B. Gharehpetian

    2013-05-01

    Full Text Available Acombination of Capacitor Commutated Converter (CCC HVDC and voltage source converter (VSC HVDC is proposed to supply an island system without any local generation. The key point of this integration is the flat characteristic of dc voltage of CCC-HVDC, which provides the condition for VSC to connect to CCC dc link via a current regulator. The advantages of proposed combined in feeding system are requiring only one dc line and having better dynamic responses. The structure of the proposed in feeding system as well as its control system is shown in this study. The simulation results are presented to confirm the effectiveness of the proposed system. Two other schemes for in feeding the passive island systems are studied to demonstrate the advantages of the proposed system.

  11. Sliding Mode Control of Three Levels Back-To-Back VSC-HVDC System Using Space Vector Modulation

    Directory of Open Access Journals (Sweden)

    Bouafia Saber

    2014-03-01

    Full Text Available In this study, a sliding mode strategy proposed to control a three levels Back-to-Back High Voltage Direct Current (HVDC system based on the three-level voltage source converter (VSC. The voltage-balancing control of two split DC capacitors of the VSC-HVDC system is achieved using three-level space vector modulation with balancing strategy based on the effective use of the redundant switching states of the inverter voltage vectors. Finally, a complete simulation of the VSC-HVDC system validates the efficiency of the proposed strategy law. Compared to the conventional control, Sliding Mode Control scheme for the VSC-HVDC system shows the attractive advantages such as offering high tracking accuracy, fast dynamic response and good robustness.

  12. Transfer cask system design activities: status and plan

    Energy Technology Data Exchange (ETDEWEB)

    Locke, D., E-mail: darren.locke@f4e.europa.eu [Fusion for Energy Agency (F4E), Torres Diagonal Litoral B3, Josep Pla 2, 08019 Barcelona (Spain); Gutierrez, C. Gonzalez; Damiani, C.; Gracia, V. [Fusion for Energy Agency (F4E), Torres Diagonal Litoral B3, Josep Pla 2, 08019 Barcelona (Spain); Friconneau, J.-P.; Martins, J.-P.; Blight, J. [ITER Organisation, CS 90 046, 13067St. Paul Lez Durance Cedex (France)

    2011-10-15

    The ITER Cask and Plug Remote Handling System (CPRHS), a.k.a. Transfer Cask System, is a critical element of the ITER Remote Maintenance System (IRMS) devoted to transportation of components between the Tokamak building and Hot Cell. Due to the necessary confinement of contaminated components the CPRHS is defined as Safety Importance Class 1 (SIC-1) plus the mobile nature of the CPRHS brings with it a significant number of complex interfaces with other ITER sub-systems. With a total CPRHS fleet in excess of 20 units, including seven typologies, the management of design and procurement needs to be carefully planned and implemented to ensure compliance with ITER's requirements. Fusion for Energy (F4E) and its beneficiaries/contractors are currently working under ITER Task Agreements (ITAs) on the conceptual design of the CPRHS and, following the signing of the Procurement Arrangement (PA) in mid 2012, will take responsibility for the entire CPRHS fleet. F4E must, therefore, develop a robust strategy to meet the needs of both ITER machine assembly (for which a number of CPRHS units will be utilised) and the remote maintenance of ITER. Within this context this paper will present the status of the current CPRHS design activities, highlight some of the significant issues which will be faced during procurement and present the overall strategy which is being implemented by F4E in order to meet these challenging objectives.

  13. Damping torque analysis of VSC-based system utilizing power synchronization control

    Science.gov (United States)

    Fu, Q.; Du, W. J.; Zheng, K. Y.; Wang, H. F.

    2017-05-01

    Power synchronization control is a new control strategy of VSC-HVDC for connecting a weak power system. Different from the vector control method, this control method utilizes the internal synchronization mechanism in ac systems, in principle, similar to the operation of a synchronous machine. So that the parameters of controllers in power synchronization control will change the electromechanical oscillation modes and make an impact on the transient stability of power system. This paper present a mathematical model for small-signal stability analysis of VSC station used power synchronization control and analyse the impact of the dynamic interactions by calculating the contribution of the damping torque from the power synchronization control, besides, the parameters of controllers which correspond to damping torque and synchronous torque in the power synchronization control is defined respectively. At the end of the paper, an example power system is presented to demonstrate and validate the theoretical analysis and associated conclusions are made.

  14. A Hybrid LCC-VSC HVDC Transmission System Supplying a Passive Load

    Science.gov (United States)

    Kotb, Omar

    High Voltage Direct Current (HVDC) transmission systems continue to be an excellent asset in modern power systems, mainly for their ability to overcome the problems of AC transmission, such as the interconnection of asynchronous grids, stability of long transmission lines, and use of long cables for power transmission. In the past 20 years, Voltage Source Converter (VSC)-HVDC transmission systems were developed and installed in many projects, thereby adding more operational benefits to DC transmission option, such as high controllability, ability to supply weak networks, and reduced converter reactive power demand. Nevertheless, VSC-HVDC transmission suffers from the disadvantages of high losses and cost. In this research, a hybrid HVDC employing a Line Commutated Converter (LCC) as rectifier and a VSC as inverter is used to supply a passive network through a DC cable. The hybrid system is best suited for unidirectional power transmission scenarios, such as power transmission to islands and remote load centers, where the construction of new transmission lines is prohibitively expensive. Control modes for the rectifier and inverter are selected and implemented using Proportional Integral (PI) controllers. Special control schemes are developed for abnormal operating conditions such as starting at light load and recovering from AC network faults. The system performance under steady state and transient conditions is investigated by EMTP-RV simulations. The results show the feasibility of the hybrid system.

  15. A Solid-State Fault Current Limiting Device for VSC-HVDC Systems

    Science.gov (United States)

    Larruskain, D. Marene; Zamora, Inmaculada; Abarrategui, , Oihane; Iturregi, Araitz

    2013-08-01

    Faults in the DC circuit constitute one of the main limitations of voltage source converter VSC-HVDC systems, as the high fault currents can damage seriously the converters. In this article, a new design for a fault current limiter (FCL) is proposed, which is capable of limiting the fault current as well as interrupting it, isolating the DC grid. The operation of the proposed FCL is analysed and verified with the most usual faults that can occur in overhead lines.

  16. Droop Control Design of Multi-VSC Systems for Offshore Networks to Integrate Wind Energy

    Directory of Open Access Journals (Sweden)

    Muhammad Raza

    2016-10-01

    Full Text Available This research envisages the droop control design of multi voltage source converter systems for offshore networks to integrate wind power plant with the grids. An offshore AC network is formulated by connecting several nearby wind power plants together with AC cables. The net energy in the network is transferred to onshore using voltage source high voltage direct current (VSC-HVDC transmissionsystems. In the proposed configuration, an offshore network is energized by more than one VSC-HVDC system, hereby providing redundancy to continue operation in case of failure in one of the HVDC transmission lines. The power distribution between VSC-HVDC systems is done using a droop control scheme. Frequency droop is implemented to share active power, and voltage droop is implemented to share reactive power. Furthermore, a method of calculating droop gains according to the contribution factor of each converter is presented. The system has been analyzed to evaluate the voltage profile of the network affected by the droop control. Nonlinear dynamic simulation has been performed for the verification of the control principle.

  17. Documentation for initial testing and inspections of Beneficial Uses Shipping System (BUSS) Cask

    Energy Technology Data Exchange (ETDEWEB)

    Lundeen, J.E.

    1994-08-25

    The purpose of this report is to compile data generated during the initial tests and inspections of the Beneficial Uses Shipping System (BUSS) Cask. In addition, this report will verify that the testing criteria identified in section 8.1 of the BUSS Cask Safety Analysis Report for Packaging (SARP) was met. The BUSS Cask Model R-1 is a type B shipping container used for shipment of radioactive cesium-137 and strontium-90 capsules to Waste Encapsulation and Storage Facility (WESF). The BUSS Cask body and lid are each one-piece forgings fabricated from ASTM A473, Type 304 stainless steel. The primary purpose of the BUSS Cask is to provide shielding and confinement as well as impact, puncture, and thermal protection for the capsules under both normal and accident conditions. Chapter 8 of the BUSS Cask SARP requires several acceptance tests and inspections, each intended to evaluate the performance of different components of the BUSS Cask system, to be performed before its first use. The results of the tests and inspections required are included in this document.

  18. Short Circuit Ratio analysis of multi-infeed HVDC system with a VSC-HVDC link

    DEFF Research Database (Denmark)

    Liu, Yan; Chen, Zhe

    2011-01-01

    As an important indicator of system stability, Short Circuit Ratio (SCR) is commonly used in power system analysis. For systems include HVDC link connection, the Effective SCR (ESCR) is mostly applied to indicate the strength of HVDC infeed bus. The contribution of VSC-HVDC link to multi......-infeed HVDC system stability has been analyzed a lot but the study on ESCR of this kind of system is still insufficient. This paper presents a calculation method for ESCR of the hybrid multi infeed HVDC system based on a simple two-infeed HVDC system model. The equivalent circuit of this system under short...

  19. Performance analysis of a model-sized superconducting DC transmission system based VSC-HVDC transmission technologies using RTDS

    Science.gov (United States)

    Dinh, Minh-Chau; Ju, Chang-Hyeon; Kim, Sung-Kyu; Kim, Jin-Geun; Park, Minwon; Yu, In-Keun

    2012-08-01

    The combination of a high temperature superconducting DC power cable and a voltage source converter based HVDC (VSC-HVDC) creates a new option for transmitting power with multiple collection and distribution points for long distance and bulk power transmissions. It offers some greater advantages compared with HVAC or conventional HVDC transmission systems, and it is well suited for the grid integration of renewable energy sources in existing distribution or transmission systems. For this reason, a superconducting DC transmission system based HVDC transmission technologies is planned to be set up in the Jeju power system, Korea. Before applying this system to a real power system on Jeju Island, system analysis should be performed through a real time test. In this paper, a model-sized superconducting VSC-HVDC system, which consists of a small model-sized VSC-HVDC connected to a 2 m YBCO HTS DC model cable, is implemented. The authors have performed the real-time simulation method that incorporates the model-sized superconducting VSC-HVDC system into the simulated Jeju power system using Real Time Digital Simulator (RTDS). The performance analysis of the superconducting VSC-HVDC systems has been verified by the proposed test platform and the results were discussed in detail.

  20. SCANS (Shipping Cask ANalysis System) a microcomputer-based analysis system for shipping cask design review: User`s manual to Version 3a. Volume 1, Revision 2

    Energy Technology Data Exchange (ETDEWEB)

    Mok, G.C.; Thomas, G.R.; Gerhard, M.A.; Trummer, D.J.; Johnson, G.L. [Lawrence Livermore National Lab., CA (United States)

    1998-03-01

    SCANS (Shipping Cask ANalysis System) is a microcomputer-based system of computer programs and databases developed at the Lawrence Livermore National Laboratory (LLNL) for evaluating safety analysis reports on spent fuel shipping casks. SCANS is an easy-to-use system that calculates the global response to impact loads, pressure loads and thermal conditions, providing reviewers with an independent check on analyses submitted by licensees. SCANS is based on microcomputers compatible with the IBM-PC family of computers. The system is composed of a series of menus, input programs, cask analysis programs, and output display programs. All data is entered through fill-in-the-blank input screens that contain descriptive data requests. Analysis options are based on regulatory cases described in the Code of Federal Regulations 10 CFR 71 and Regulatory Guides published by the US Nuclear Regulatory Commission in 1977 and 1978.

  1. Operations manual for the Beneficial Uses Shipping System cask. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Bronowski, D.R.; Yoshimura, H.R.

    1993-04-01

    This document is the Operations Manual for the Beneficial Uses Shipping System (BUSS) cask. These operating instructions address requirements; for loading, shipping, and unloading, supplementing general operational information found in the BUSS Safety Analysis Report for Packaging (SARP), SAND 83-0698. Use of the BUSS cask is authorized by Department of Energy (DOE) and Nuclear Regulatory Commission (NRC) for the shipment of special form cesium chloride or strontium flouride capsules.

  2. CASKET: a computer code system for thermal and structural analyses of radioactive material transport and/or storage cask

    Energy Technology Data Exchange (ETDEWEB)

    Ikushima, Takeshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-05-01

    A computer code system CASKET (CASK thermal and structural analyses and Evaluation code system) for the thermal and structural analyses which are indispensable for radioactive material transport and/or storage cask designs has been developed. The CASKET is a simplified computer code system to perform parametric analyses on sensitivity evaluations in designing a cask and conducting its safety analysis. Main features of the CASKET are as follow: (1) it is capable to perform impact analysis of casks with shock absorbers, (2) it is capable to perform impact analysis of casks with fins. (3) puncture analysis of casks is capable, (4) rocking analysis of casks during seismic load is capable, (5) material property data library are provided for impact analysis of casks, (6) material property data library are provided for thermal analysis of casks, (7) fin energy absorption data library are provided for impact analysis of casks with fins are and (8) not only main frame computers (OS MSP) but also work stations (OS UNIX) and personal computers (OS Windows 3.1) are available. In the paper, brief illustrations of calculation methods are presented. Some calculation results are compared with experimental ones to confirm the computer programs are useful for thermal and structural analyses. (author)

  3. CASKET: a computer code system for thermal and structural analyses of radioactive material transport and/or storage cask

    Energy Technology Data Exchange (ETDEWEB)

    Ikushima, Takeshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-05-01

    A computer code system CASKET (CASK thermal and structural analyses and Evaluation code system) for the thermal and structural analyses which are indispensable for radioactive material transport and/or storage cask designs has been developed. The CASKET is a simplified computer code system to perform parametric analyses on sensitivity evaluations in designing a cask and conducting its safety analysis. Main features of the CASKET are as follow: (1) it is capable to perform impact analysis of casks with shock absorbers, (2) it is capable to perform impact analysis of casks with fins. (3) puncture analysis of casks is capable, (4) rocking analysis of casks during seismic load is capable, (5) material property data library are provided for impact analysis of casks, (6) material property data library are provided for thermal analysis of casks, (7) fin energy absorption data library are provided for impact analysis of casks with fins are and (8) not only main frame computers (OS MSP) but also work stations (OS UNIX) and personal computers (OS Windows 3.1) are available. In the paper, brief illustrations of calculation methods are presented. Some calculation results are compared with experimental ones to confirm the computer programs are useful for thermal and structural analyses. (author)

  4. A Flexible Power Control Method of VSC-HVDC Link for the Enhancement of Effective Short-Circuit Ratio in a Hybrid Multi-Infeed HVDC System

    DEFF Research Database (Denmark)

    Liu, Yan; Chen, Zhe

    2013-01-01

    With the emerging use of voltage source converter high voltage direct current (VSC-HVDC) links, the hybrid multi-infeed HVDC (HMIDC) system that includes the line commutated converter (LCC) HVDC and the VSC-HVDC links is becoming a promising power transmission structure in the modern power systems....... To evaluate the contribution of the VSC-HVDC link on the voltage stability of HMIDC system, this paper proposes an effective short circuit ratio (ESCR) calculation method. Through the calculation, the voltage support capability of the VSC-HVDC link can be quantitatively represented by the ESCR. Furthermore......, based on the calculation results, a flexible power control strategy for the VSC-HVDC link is developed to provide maximum reactive power support under grid faults. The theoretical analysis of the HMIDC system is based on the Danish transmission grid, evaluated through PSCAD simulations under different...

  5. Nonlinear Control of Back-to-Back VSC-HVDC System via Command-Filter Backstepping

    Directory of Open Access Journals (Sweden)

    Jie Huang

    2017-01-01

    Full Text Available This paper proposed a command-filtered backstepping controller to improve the dynamic performance of back-to-back voltage-source-converter high voltage direct current (BTB VSC-HVDC. First, the principle and model of BTB VSC-HVDC in abc and d-q frame are described. Then, backstepping method is applied to design a controller to maintain the voltage balance and realize coordinated control of active and reactive power. Meanwhile, command filter is introduced to deal with the problem of input saturation and explosion of complexity in conventional backstepping, and a filter compensation signal is designed to diminish the adverse effects caused by the command filter. Next, the stability and convergence of the whole system are proved via the Lyapunov theorem of asymptotic stability. Finally, simulation results are given to demonstrate that proposed controller has a better dynamic performance and stronger robustness compared to the traditional PID algorithm, which also proves the effectiveness and possibility of the designed controller.

  6. Review of Low Voltage Ride-Through Technology for VSC-HVDC Based Wind Power Generation Systems%基于VSC-HVDC的风电系统低电压穿越技术综述

    Institute of Scientific and Technical Information of China (English)

    章心因; 吴在军; 郝思鹏; 程桂林

    2013-01-01

      轻型高压直流输电系统(VSC-HVDC)是风电技术的重要发展方向。随着风电比重快速增加,电网对风电机组及其并网系统地低电压穿越(LVRT)能力提出了更高的要求。本文首先分析了电压跌落对VSC-HVDC系统和风电机组的影响,继而简要地总结了风电机组LVRT技术,然后对各种适合于VSC-HVDC风电系统的LVRT方案进行了分析评价,并重点讨论了该风电系统的LVRT协调控制技术。%Long-distance large-capacity wind farm connected to the grid by the VSC-HVDC transmission system will be an important trend of the wind power technology development. With the rapid increase in the proportion of wind power, the grid has a higher demand for the Low Voltage Ride-through(LVRT) ability of the wind turbine and its grid systems. The influence of voltage drop on the VSC-HVDC system and wind turbine is firstly analyzed. Meanwhile, the LVRT technology for the wind turbine is summarized briefly. Then, several types of LVRT solutions for the VSC-HVDC based wind power systems are analyzed and evaluated. In the end, the LVRT coordination control methods are mainly discussed.

  7. Simulation of offshore wind farm integrated into power grid using VSC HVDC system

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Hui; Nguyen, Mau Cuong; Rudion, Krzystof; Styczynski, Zbigniew Antoni [Magdeburg Univ. (Germany). Chair for Electric Power Networks and Renewable Energy Sources

    2011-07-01

    In this paper, the integration of an offshore wind farm into a power grid is studied based on the simulation of a developed test system including an aggregated DFIG wind farm model and VSC HVDC transmission system model. This paper concentrates on the transient stability and system performance with an applied controller for DFIG and HVDC converter stations. The results are obtained by simulation of the test system subjected to severe grid disturbance, e.g. three-phase short circuit fault at the point of common coupling (PCC). Furthermore, the conformity of the system performance with the current grid code, e.g. fault-ride through capability is investigated and confirmed from the simulation results. In addition, a DC-chopper circuit is modeled to protect the HVDC-link from the overvoltage without disconnection during grid faults. Different time delays of the DC-chopper are considered and simulated to investigate its influence on the system dynamics and performance. (orig.)

  8. Priority Control Strategy of VSC-MTDC System for Integrating Wind Power

    Directory of Open Access Journals (Sweden)

    Wen-ning Yan

    2015-01-01

    Full Text Available For the obvious advantages in integrating wind power, multiterminal HVDC transmission system (VSC-MTDC is widely used. The priority control strategy is proposed in this paper considering the penetration rate of wind power for the AC grid. The strategy aims to solve the problems of power allocation and DC voltage control of the DC system. The main advantage of this strategy is that the demands for wind power of different areas can be satisfied and a power reference for the wind power trade can also be provided when wind farms transmit active power to several AC grids through the DC network. The objective is that power is well distributed according to the output power of wind farm with the demand of AC system and satisfactory control performance of DC voltage is obtained.

  9. Fault ride-through and grid support of permanent magnet synchronous generator-based wind farms with HVAC and VSC-HVDC transmission systems

    DEFF Research Database (Denmark)

    Liu, Hongzhi; Chen, Zhe

    2012-01-01

    This paper describes fault ride-through and grid support of offshore wind farms based on permanent magnet synchronous generator (PMSG) wind turbines connected to the onshore AC network through two alternative transmission systems: high voltage AC (HVAC) or high voltage DC (HVDC) based on voltage...... source converters (VSC). The proposed configurations of the PMSG-based offshore wind farm and VSC-based HVDC are given as well as their control strategies under both steady state and fault state. The PMSG-based offshore wind farm is integrated into a test power transmission system via either HVAC or VSC-HVDC...

  10. ITER Transfer Cask System: Status of design, issues and future developments

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez, C. Gonzalez, E-mail: carmen.gonzalez@f4e.europa.e [Fusion for Energy, Torres Diagonal Litoral B3, Josep Pla 2, 08019 Barcelona (Spain); Damiani, C.; Irving, M. [Fusion for Energy, Torres Diagonal Litoral B3, Josep Pla 2, 08019 Barcelona (Spain); Friconneau, J.-P.; Tesini, A. [ITER Organization (IO), CS 90 046, 13067 St Paul Lez Durance Cedex (France); Ribeiro, I.; Vale, A. [Instituto Superior Tecnico (IST), ISR and IPFN, Av. Rovisco Pais 1, 1049-001 Lisboa (Portugal)

    2010-12-15

    The Remote Handling tasks scheduled during the ITER maintenance shutdown require transportation of in-vessel components from the Vacuum Vessel ports, at all levels of the Tokamak building, to the docking stations in the Hot Cell building. This transfer of radioactive, contaminated components represents a task of unprecedented complexity for a nuclear device like ITER. A Transfer Cask System (TCS) has been adopted as a reference solution. The TCS is a mobile, leak-tight unit, which can be divided into: (1) the cask itself, i.e., the container for the components to be transferred, able to avoid spread of contamination outside its envelope, equipped with in-cask handling devices; (2) the interface pallet that assists the docking operations of the cask and, underneath; (3) an Air Transfer System (ATS), i.e., a mobile platform floating on air-cushions with drive and steering wheels powered by electric motors and batteries on-board. The system will be remotely controlled, moving along previously defined paths. This paper focuses on the present status of the ATS design, the issues to be faced and the future developments foreseen.

  11. VSC-HVDC的交直流混合系统状态估计%State estimation of power system with VSC-HVDC

    Institute of Scientific and Technical Information of China (English)

    孙国强; 李育燕; 卫志农; 叶芳

    2010-01-01

    针对以电压源换流器(VSC)为基础的新一代高压直流输电(HVDC),对含VSC-HVDC的交直流混合系统进行静态状态估计.介绍了VSC-HVDC的稳态模型.通过确定交直流混合系统的量测函数、状态变量和雅可比矩阵,建立了含VSC-HVDC的交直流混合系统的状态估计模型;在基本加权最小二乘状态估计算法的基础上,提出了含VSC-HVDC的交直流混合状态估计同时迭代求解法:对经过修改的IEEE 14、IEEE30、IEEE 57节点系统算例进行仿真,从算法的估计误差、迭代次数和计算速度等方面验证了算法的有效性和实用性.

  12. Localization of cask and plug remote handling system in ITER using multiple video cameras

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, João, E-mail: jftferreira@ipfn.ist.utl.pt [Instituto de Plasmas e Fusão Nuclear - Laboratório Associado, Instituto Superior Técnico, Universidade Técnica de Lisboa, Av. Rovisco Pais 1, 1049-001 Lisboa (Portugal); Vale, Alberto [Instituto de Plasmas e Fusão Nuclear - Laboratório Associado, Instituto Superior Técnico, Universidade Técnica de Lisboa, Av. Rovisco Pais 1, 1049-001 Lisboa (Portugal); Ribeiro, Isabel [Laboratório de Robótica e Sistemas em Engenharia e Ciência - Laboratório Associado, Instituto Superior Técnico, Universidade Técnica de Lisboa, Av. Rovisco Pais 1, 1049-001 Lisboa (Portugal)

    2013-10-15

    Highlights: ► Localization of cask and plug remote handling system with video cameras and markers. ► Video cameras already installed on the building for remote operators. ► Fiducial markers glued or painted on cask and plug remote handling system. ► Augmented reality contents on the video streaming as an aid for remote operators. ► Integration with other localization systems for enhanced robustness and precision. -- Abstract: The cask and plug remote handling system (CPRHS) provides the means for the remote transfer of in-vessel components and remote handling equipment between the Hot Cell building and the Tokamak building in ITER. Different CPRHS typologies will be autonomously guided following predefined trajectories. Therefore, the localization of any CPRHS in operation must be continuously known in real time to provide the feedback for the control system and also for the human supervision. This paper proposes a localization system that uses the video streaming captured by the multiple cameras already installed in the ITER scenario to estimate with precision the position and the orientation of any CPRHS. In addition, an augmented reality system can be implemented using the same video streaming and the libraries for the localization system. The proposed localization system was tested in a mock-up scenario with a scale 1:25 of the divertor level of Tokamak building.

  13. Reprint of “Performance analysis of a model-sized superconducting DC transmission system based VSC-HVDC transmission technologies using RTDS”

    Science.gov (United States)

    Dinh, Minh-Chau; Ju, Chang-Hyeon; Kim, Sung-Kyu; Kim, Jin-Geun; Park, Minwon; Yu, In-Keun

    2013-01-01

    The combination of a high temperature superconducting DC power cable and a voltage source converter based HVDC (VSC-HVDC) creates a new option for transmitting power with multiple collection and distribution points for long distance and bulk power transmissions. It offers some greater advantages compared with HVAC or conventional HVDC transmission systems, and it is well suited for the grid integration of renewable energy sources in existing distribution or transmission systems. For this reason, a superconducting DC transmission system based HVDC transmission technologies is planned to be set up in the Jeju power system, Korea. Before applying this system to a real power system on Jeju Island, system analysis should be performed through a real time test. In this paper, a model-sized superconducting VSC-HVDC system, which consists of a small model-sized VSC-HVDC connected to a 2 m YBCO HTS DC model cable, is implemented. The authors have performed the real-time simulation method that incorporates the model-sized superconducting VSC-HVDC system into the simulated Jeju power system using Real Time Digital Simulator (RTDS). The performance analysis of the superconducting VSC-HVDC systems has been verified by the proposed test platform and the results were discussed in detail.

  14. Comparative study of superconducting fault current limiter both for LCC-HVDC and VSC-HVDC systems

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong-Geon; Khan, Umer Amir; Lim, Sung-Woo; Shin, Woo-ju; Seo, In-Jin; Lee, Bang-Wook, E-mail: bangwook@hanyang.ac.kr

    2015-11-15

    Highlights: • The role of SFCL in types of HVDC system was evaluated. • A simulation model based on Korea Jeju–Haenam HVDC power system was designed in Matlab/Simulink. • Utilizing the designed both HVDC power system models, the efficiency of DC-SFCL was relatively low, compared to AC-SFCL. • It was deduced that the AC-SFCL was more effective in LCC-HVDC system than VSC-HVDC system. - Abstract: High Voltage Direct Current (HVDC) system has been evaluated as the optimum solution for the renewable energy transmission and long-distance power grid connections. In spite of the various advantages of HVDC system, it still has been regarded as an unreliable system compared to AC system due to its vulnerable characteristics on the power system fault. Furthermore, unlike AC system, optimum protection and switching device has not been fully developed yet. Therefore, in order to enhance the reliability of the HVDC systems mitigation of power system fault and reliable fault current limiting and switching devices should be developed. In this paper, in order to mitigate HVDC fault, both for Line Commutated Converter HVDC (LCC-HVDC) and Voltage Source Converter HVDC (VSC-HVDC) system, an application of resistive superconducting fault current limiter which has been known as optimum solution to cope with the power system fault was considered. Firstly, simulation models for two types of LCC-HVDC and VSC-HVDC system which has point to point connection model were developed. From the designed model, fault current characteristics of faulty condition were analyzed. Second, application of SFCL on each types of HVDC system and comparative study of modified fault current characteristics were analyzed. Consequently, it was deduced that an application of AC-SFCL on LCC-HVDC system with point to point connection was desirable solution to mitigate the fault current stresses and to prevent commutation failure in HVDC electric power system interconnected with AC grid.

  15. Feasibility Study For Use Of Commercial Cask Vendor Dry Transfer Systems To Unload Used Fuel Assemblies In L-Area

    Energy Technology Data Exchange (ETDEWEB)

    Krementz, Dan; Rose, David; Dunsmuir, Mike

    2014-02-06

    The purpose of this study is to determine whether a commercial dry transfer system (DTS) could be used for loading or unloading used nuclear fuel (UNF) in L-Basin and to determine if a DTS pool adapter could be made for L-Basin Transfer Pit #2 that could accommodate a variety of DTS casks and fuel baskets or canisters up to 24” diameter.[1, 2] This study outlines the technical feasibility of accommodating different vendor dry transfer systems in the L-Basin Transfer Bay with a general work scope. It identifies equipment needing development, facility modifications, and describes the needed analyses and calculations. After reviewing the L-Basin Transfer Bay area layout and information on the only DTS system currently in use for the Nuclear Assurance Corporation Legal Weight Truck cask (NAC LWT), the authors conclude that use of a dry transfer cask is feasible. AREVA was contacted and acknowledged that they currently do not have a design for a dry transfer cask for their new Transnuclear Long Cask (TN-LC) cask. Nonetheless, this study accounted for a potential future DTS from AREVA to handle fuel baskets up to 18” in diameter. Due to the layout of the Transfer Bay, it was determined that a DTS cask pool adapter designed specifically for spanning Pit #2 and placed just north of the 70 Ton Cask lid lifting superstructure would be needed. The proposed pool adapter could be used to transition a fuel basket up to 24” in diameter and ~11 feet long from a dry transfer cask to the basin. The 18” and 24” applications of the pool adapter are pending vendor development of dry transfer casks that accommodate these diameters. Once a fuel basket has been lowered into Pit #2 through a pool adapter, a basket cart could be used to move the basket out from under the pool adapter for access by the 5 Ton Crane. The cost to install a dry transfer cask handling system in L-Area capable of handling multiple vendor provided transport and dry transfer casks and baskets with

  16. A generic inertia emulation controller for multi-terminal VSC-HVDC systems

    DEFF Research Database (Denmark)

    Zhu, Jiebei; Guerrero, Josep M.; Booth, Campbell;

    2013-01-01

    A generic Inertia Emulation Controller (INEC) for Multi-Terminal Voltage-source-converter based HVDC (VSC-MTDC) is proposed in this paper. The proposed INEC can be incorporated in any grid-side-voltage-source-converter (GVSC) station, allowing the MTDC terminal to contribute an inertial response...

  17. 基于负序电压补偿的VSC-HVDC系统的不平衡控制%Unbalanced control strategy based on negative voltage compensation for VSC-HVDC system

    Institute of Scientific and Technical Information of China (English)

    杨硕; 张卫星; 李德泉

    2012-01-01

    交流系统故障时VSC-HVDC系统的控制策略直接关系到系统的运行和安全性能,具有明显的工程应用价值.建立了交流系统不平衡故障时d-q同步旋转坐标系下系统换流器的正负序数学模型,设计了不平衡条件下的同步相位和正负序分量的实时检测系统.采用非线性系统反馈线性化理论,设计了系统的状态反馈线性化电流解耦控制器.在此基础上设计了负序电压补偿的不平衡控制系统,在有效抑制负序电流的同时,简化了控制系统结构.基于PSIM的数字仿真,验证了所设计的控制器具有良好的控制性能.%The control strategy for unbalanced VSC-HVDC system is directly related to its function and security, so it has a great importance for the engineering. The paper builds a positive and negative mathematical model of VSC in d-q synchronous reference frame, and designs a detecting system of synchronous phase and positive and negative component under unbalanced condition. By using nonlinear transformation and nonlinear system feedback linearization theory, the state-feedback linearization decoupling controller for VSC-HVDC system is established. Finally, the paper designs an unbalanced control strategy based on negative voltage compensation for VSC-HVDC. Besides restraining the negative current, it also simplifies the structure of the control system. The digital simulation based on PSIM proves the designed controller has good control performance.

  18. Comparative study of superconducting fault current limiter both for LCC-HVDC and VSC-HVDC systems

    Science.gov (United States)

    Lee, Jong-Geon; Khan, Umer Amir; Lim, Sung-Woo; Shin, Woo-ju; Seo, In-Jin; Lee, Bang-Wook

    2015-11-01

    High Voltage Direct Current (HVDC) system has been evaluated as the optimum solution for the renewable energy transmission and long-distance power grid connections. In spite of the various advantages of HVDC system, it still has been regarded as an unreliable system compared to AC system due to its vulnerable characteristics on the power system fault. Furthermore, unlike AC system, optimum protection and switching device has not been fully developed yet. Therefore, in order to enhance the reliability of the HVDC systems mitigation of power system fault and reliable fault current limiting and switching devices should be developed. In this paper, in order to mitigate HVDC fault, both for Line Commutated Converter HVDC (LCC-HVDC) and Voltage Source Converter HVDC (VSC-HVDC) system, an application of resistive superconducting fault current limiter which has been known as optimum solution to cope with the power system fault was considered. Firstly, simulation models for two types of LCC-HVDC and VSC-HVDC system which has point to point connection model were developed. From the designed model, fault current characteristics of faulty condition were analyzed. Second, application of SFCL on each types of HVDC system and comparative study of modified fault current characteristics were analyzed. Consequently, it was deduced that an application of AC-SFCL on LCC-HVDC system with point to point connection was desirable solution to mitigate the fault current stresses and to prevent commutation failure in HVDC electric power system interconnected with AC grid.

  19. Coordinated droop control for large-scale offshore wind farm grid-connected based on VSC-MTDC system%基于VSC-MTDC的大规模海上风电并网系统协调下垂控制方法

    Institute of Scientific and Technical Information of China (English)

    彭衍建; 李勇; 曹一家

    2016-01-01

    It is especially essential for large-scale offshore wind farm to improve the transmission power and efficiency of VSC-MTDC systems.A coordinated droop control method for the grid side's converters is proposed,and then,three typical control modes are made to realize the optimal transmission of the active power,which is generated from the large-scale wind farms.Thus,the transmission efficiency of VSC-MTDC can be improved effectively.A 4-terminal VSC-HVDC model is carry out in MATLAB/Simulink to prove the proposed three control modes respectively.The simulation results show that the proposed control modes can achieve the coordination distribution of the active power,stabilize the DC voltage and improve the operation stability of the VSC-MTDC system.%提升电压源型换流器的多端直流输电(VSC-MTDC)系统的传输功率和传输效率对于大规模风电并网而言至关重要.提出VSC-MTDC系统协调下垂控制方法,并制定3种典型的控制模式,从而实现风电场最优功率输送与VSC-MTDC系统效率的最大化.建立用于海上风电场并网的四端直流输电系统仿真模型,结果表明,所提协调下垂控制方法不仅能实现有功功率在VSC-MTDC系统中的最优分配,而且能稳定直流电压,增强VSC-MTDC系统的运行稳定性.

  20. Integral Plus Resonant Sliding Mode Direct Power Control for VSC-HVDC Systems under Unbalanced Grid Voltage Conditions

    Directory of Open Access Journals (Sweden)

    Weipeng Yang

    2017-10-01

    Full Text Available An integral plus resonant sliding mode direct power control (IRSMC DPC strategy for voltage source converter high voltage direct current (VSC-HVDC systems under unbalanced grid voltage conditions is proposed in this paper. Through detailed instantaneous power flow analysis, a generalized power compensation method, by which the ratio between the amplitude of active and reactive power ripples can be controlled continuously, is obtained. This enables the system to provide flexible power control, so that the desired performance of the system on both the ac and dc sides can be attained under different operating conditions. When the grid voltage is unbalanced, one or both of the active and reactive power terms contain ripples, oscillating at twice the grid frequency, to obtain non-distorted ac current. A power controller consisting of the proportional, integral and resonant control laws is designed using the sliding mode control approach, to achieve accurate power control objective. Simulation studies on a two-terminal VSC-HVDC system using MATLAB/SIMULINK (R2013b, Mathworks, Natick, MA, USA are conducted to verify the effectiveness of the IRSMC DPC strategy. The results show that this strategy ensures satisfactory performance of the system over a wide range of operating conditions.

  1. VSC-HVDC输电系统特点与应用%Characteristics and application of VSC-HVDC power transmission system

    Institute of Scientific and Technical Information of China (English)

    孟垂懿; 鲍洁秋; 武录

    2012-01-01

    随着半导体技术和新能源发电的发展,出现了基于VSC(Voltage Sourced Converters)技术的新型直流输电系统——轻型直流输电(HVDC Light),在介绍HvDC Light基本原理基础上,从结构和功能上与传统直流输电技术进行对比,阐述了HVDC Light的优点,并对其应用作了总结和展望.

  2. Enhanced Dynamic Voltage Stability Support by VSC-HVDC for Offshore Wind Applications using Trajectory Sensitivity Analysis

    DEFF Research Database (Denmark)

    Liu, Hongzhi; Chen, Zhe; Liu, Leo

    2013-01-01

    . In this paper, VSC-HVDC transmission system is used to integrate a large-scale wind power plant into the onshore power grid. For different voltage support strategies of VSC-HVDC, a trajectory sensitivity analysisbased approach is proposed to find the minimum onshore VSC capacity with which the VSC-HVDC can...

  3. Managing aging effects on dry cask storage systems for extended long-term storage and transportation of used fuel - rev. 0

    Energy Technology Data Exchange (ETDEWEB)

    Chopra, O.K.; Diercks, D.; Fabian, R.; Ma, D.; Shah, V.; Tam, S.W.; Liu, Y. (Decision and Information Sciences); ( EVS); ( NE)

    2012-07-06

    could affect the safe storage of the used fuel. The information contained in the license and CoC renewal applications will require NRC review to verify that the aging effects on the SSCs in DCSSs/ ISFSIs are adequately managed for the period of extended operation. To date, all of the ISFSIs located across the United States with more than 1,500 dry casks loaded with used fuel have initial license terms of 20 years; three ISFSIs (Surry, H.B. Robinson and Oconee) have received their renewed licenses for 20 years, and two other ISFSIs (Calvert Cliffs and Prairie Island) have applied for license renewal for 40 years. This report examines issues related to managing aging effects on the SSCs in DCSSs/ISFSIs for extended long-term storage and transportation of used fuels, following an approach similar to that of the Generic Aging Lessons Learned (GALL) report, NUREG-1801, for the aging management and license renewal of nuclear power plants. The report contains five chapters and an appendix on quality assurance for aging management programs for used-fuel dry storage systems. Chapter I of the report provides an overview of the ISFSI license renewal process based on 10 CFR 72 and the guidance provided in NUREG-1927. Chapter II contains definitions and terms for structures and components in DCSSs, materials, environments, aging effects, and aging mechanisms. Chapter III and Chapter IV contain generic TLAAs and AMPs, respectively, that have been developed for managing aging effects on the SSCs important to safety in the dry cask storage system designs described in Chapter V. The summary descriptions and tabulations of evaluations of AMPs and TLAAs for the SSCs that are important to safety in Chapter V include DCSS designs (i.e., NUHOMS{reg_sign}, HI-STORM 100, Transnuclear (TN) metal cask, NAC International S/T storage cask, ventilated storage cask (VSC-24), and the Westinghouse MC-10 metal dry storage cask) that have been and continue to be used by utilities across the country for

  4. Managing aging effects on dry cask storage systems for extended long-term storage and transportation of used fuel - rev. 0

    Energy Technology Data Exchange (ETDEWEB)

    Chopra, O.K.; Diercks, D.; Fabian, R.; Ma, D.; Shah, V.; Tam, S.W.; Liu, Y. (Decision and Information Sciences); ( EVS); ( NE)

    2012-07-06

    could affect the safe storage of the used fuel. The information contained in the license and CoC renewal applications will require NRC review to verify that the aging effects on the SSCs in DCSSs/ ISFSIs are adequately managed for the period of extended operation. To date, all of the ISFSIs located across the United States with more than 1,500 dry casks loaded with used fuel have initial license terms of 20 years; three ISFSIs (Surry, H.B. Robinson and Oconee) have received their renewed licenses for 20 years, and two other ISFSIs (Calvert Cliffs and Prairie Island) have applied for license renewal for 40 years. This report examines issues related to managing aging effects on the SSCs in DCSSs/ISFSIs for extended long-term storage and transportation of used fuels, following an approach similar to that of the Generic Aging Lessons Learned (GALL) report, NUREG-1801, for the aging management and license renewal of nuclear power plants. The report contains five chapters and an appendix on quality assurance for aging management programs for used-fuel dry storage systems. Chapter I of the report provides an overview of the ISFSI license renewal process based on 10 CFR 72 and the guidance provided in NUREG-1927. Chapter II contains definitions and terms for structures and components in DCSSs, materials, environments, aging effects, and aging mechanisms. Chapter III and Chapter IV contain generic TLAAs and AMPs, respectively, that have been developed for managing aging effects on the SSCs important to safety in the dry cask storage system designs described in Chapter V. The summary descriptions and tabulations of evaluations of AMPs and TLAAs for the SSCs that are important to safety in Chapter V include DCSS designs (i.e., NUHOMS{reg_sign}, HI-STORM 100, Transnuclear (TN) metal cask, NAC International S/T storage cask, ventilated storage cask (VSC-24), and the Westinghouse MC-10 metal dry storage cask) that have been and continue to be used by utilities across the country for

  5. VSC-HVDC输电系统的性能分析%Performance Analysis of Voltage Source Converter Based HVDC Transmission System

    Institute of Scientific and Technical Information of China (English)

    姜建国; 颜廷阁

    2012-01-01

    VSC-HVDC is a new type of power transmission technology developed based on traditional HVDC. Aiming at the features of VSC-HVDC system, e. g. , good controllability, compact modular design and easy to construct multi-terminal DC systems, etc, the working principle and dynamic performance are described. Meanwhile, dynamic performance analysis on the faults of 100 kV and 200 MV VSC-HVDC transmission systems is investigated. The simulation results by using Matlab/Simulink verify that the system possesses good performance and effective decoupling control under active and reactive power variations and fault conditions.%电压源型高压直流输电( VSC-HVDC)技术是在传统直流输电基础上发展起来的一种新型输电技术.针对VSC-HVDC系统具有良好的可控性、紧凑的模块化设计、容易构成多端直流系统等特点,阐述了其工作原理及动态性能.同时,探讨了100 kV、200 MVVSC-HVDC输电系统故障的动态性能分析,并采用Matlab/Simulink进行了仿真试验.试验结果证实了该系统在有功与无功变化以及在故障条件下具有性能良好和解耦控制有效的特性.

  6. La conception, la modelisation et la simulation du systeme VSC-HVDC offshore

    Science.gov (United States)

    Benhalima, Seghir

    Wind energy is recognized worldwide as a proven technology to meet the growing demands of green sustainable energy. To exploit this stochastic energy source and put together with the conventional energy sources without affecting the performance of existing electrical grids, several research projects have been achieved. In addition, at ocean level, wind energy has a great potential. It means that the production of this energy will increase in the world. The optimal extraction of this energy source needs to be connected to the grid via a voltage source converter which plays the role of interface. To minimise losses due to the transport of energy at very long distances, the technology called High Voltage Direct Current based on Voltage Source Converter (VSC-HVDC) is used. To achieve this goal, a new topology is designed with a new control algorithm based on control of power generated by the wind farm, the DC voltage regulation and the synchronization between wind farm and VSC-HVDC (based on NPC). The proposed topology and its control technique are validated using the "MATLAB/Simulink program". The results are promising, because the THD is less than 5% and the power factor is close to one.

  7. Behavior of spent fuel and cask components after extended periods of dry storage

    Energy Technology Data Exchange (ETDEWEB)

    Kenneally, R. [U.S. Nuclear Regulatory Commission, Rockville, MD (United States); Kessler, J. [Electric Power Research Inst., Palo Alto, CA (United States)

    2001-07-01

    The U.S. Nuclear Regulatory Commission (NRC) promulgated 10 CFR Part 72, Title 10, for the independent storage of spent nuclear fuel and high-level radioactive waste outside reactor spent fuel pools. Part 72 currently limits the license term for an independent spent fuel storage installation to 20 years from the date of issuance. Licenses may be renewed by the Commission at or before the expiration of the license term. Applications for renewal of a license should be filed at least two years prior to the expiration of the existing license. In preparation for possible license renewal, the NRC Office of Nuclear Material and Safeguards, Spent Fuel Project Office, is developing the technical basis for renewals of licenses and Certificates of Compliance for dry storage systems for spent nuclear fuel and high-level radioactive waste at independent spent fuel storage installation sites. An analysis of past performance of selected components of these systems is required as part of that technical basis. In the years 1980 through the early 1990, the Department of Energy (DOE) procured four prototype dry storage casks for testing at the Idaho National Engineering and Environmental Laboratory (INEEL): Castor-V/21, MC-10, TN-24P, and VSC-17. The primary purpose of the testing was to benchmark thermal and radiological codes and to determine the thermal and radiological characteristics of the casks. A series of examinations in 1999 and early 2000 to investigate the integrity of the Castor V/21 cask were undertaken. There is no evidence of significant degradation of the Castor V/21 cask systems important to safety from the time of initial loading of the cask in 1985 up to the time of testing in 1999. (author)

  8. Characteristics and Application of VSC-HVDC Transmission System%VSC-HVDC输电系统的特点与应用

    Institute of Scientific and Technical Information of China (English)

    唐博; 王鹏

    2014-01-01

    轻型直流输电系统是基于VSC技术的新型直流输电技术。介绍轻型直流输电基本原理,对比轻型直流输电技术与传统直流输电技术在结构和功能方面的区别,阐述轻型直流输电的优点,并对其应用进行总结和展望,以期为轻型直流输电技术在我国的应用和发展提供一定参考。%With the development of semiconductors and renewable generation, a new HVDC technology-HVDC Light based on VSC (Voltage Sourced Converters) arises. The principle of HVDC Light technology is presented in this paper and then a comparison of config-uration as well as function is made between HVDC Light and conventional HVDC, and the merits of HVDC Light are clarified. At last, the application of HVDC Light is summarized and prospected.

  9. Review of VSC HVDC Connection for Offshore Wind Power Integration

    DEFF Research Database (Denmark)

    Korompili, Asimenia; Wu, Qiuwei; Zhao, Haoran

    2016-01-01

    system is limited due to surplus charging current of the cables. The VSC HVDC transmission system has the ability to overcome the limitation and offers other advantages over the HVAC transmission system. This paper is to review the VSC HVDC transmission technology and its application for offshore wind...

  10. Voltage sensitivity based reactive power control on VSC-HVDC in a wind farm connected hybrid multi-infeed HVDC system

    DEFF Research Database (Denmark)

    Liu, Yan; Chen, Zhe

    2013-01-01

    With increasing application of both Line Commutated Converter based High Voltage Direct Current (LCC-HVDC) systems and Voltage Source Converter based HVDC (VSC-HVDC) links, a new type of system structure named Hybrid Multi-Infeed HVDC (HMIDC) system is formed in the modern power systems. This paper...... presents the operation and control method of the wind farm connected HMIDC system. The wind power fluctuation takes large influence to the system voltages. In order to reduce the voltage fluctuation of LCC-HVDC infeed bus caused by the wind power variation, a voltage sensitivity-based reactive power...... control method is proposed in the paper. According to the calculated sensitivity factors, a reactive power increment is added in the control loop of VSC-HVDC so as to regulate the voltage of the target bus. Dynamic simulations in PSCAD/EMTDC and MATLAB are presented to assess the performance...

  11. Droop Control Strategy for Wind Power Decentralized Integration Based on VSC-HVDC Systems%基于 VSC-HVDC 的风电分散并网下垂控制策略

    Institute of Scientific and Technical Information of China (English)

    田园园; 廖清芬; 刘涤尘; 彭思成; 邹宏亮

    2016-01-01

    With the large-scale development of offshore wind power,the voltage source converter based high voltage direct current(VSC-HVDC) transmission system has received extensive attention in recent years.By introducing the AC voltage droop control,a coordinated multi-terminal grid-connection control strategy for a wind farm AC-dispersed at the sending end based on VSC-HVDC systems is proposed.Based on the traditional control strategy for the flexible HVDC transmission system,the DC voltage control of inverters on the grid side is retained to guarantee system power balance,while AC voltage droop control rather than the original constant-power control is designed for the rectifier on the wind farm side to achieve the advantage of communication-free and reasonable dynamic allocation.Simulation analysis shows that the control strategy proposed is not only able to achieve flexible automatic tracking of rated active power,but also has certain tolerance of load fluctuation and the function of DC/AC fault isolation.And when it comes to power supply for multi-terminal distribution networks by a wind farm AC-dispersed at the sending end,quick power reversal can be achieved if the wind farm is cut out of the system to ensure power supply reliability.And the system is capable of realizing rational allocation of dynamic power automatically among them according to rated ratio,providing effective solutions for coordinated operation of wind farm”s decentralized integration into distribution networks.%海上风电的大规模开发使得柔性直流(VSC-HVDC)输电技术得到了越来越广泛的关注与应用。文中通过引入交流电压下垂控制,提出了基于 VSC-HVDC 的适应送端交流分散模式下的风电场多端并网的协调控制策略。在柔性直流输电传统控制策略的基础上,保留配电网侧逆变器的定直流电压控制,以保证系统功率平衡;而使风电场侧整流器采用交流电压下垂控制,以代替原有的恒功

  12. 78 FR 73379 - List of Approved Spent Fuel Storage Casks: HI-STORM 100 Cask System; Amendment No. 9

    Science.gov (United States)

    2013-12-06

    ... Federal and State Materials and Environmental Management Programs, U.S. Nuclear Regulatory Commission... February 19, 2014, unless significant adverse comments are received by January 6, 2014. If the direct final... and Management System (ADAMS): You may access publicly available documents online in the NRC Library...

  13. 78 FR 73456 - List of Approved Spent Fuel Storage Casks: HI-STORM 100 Cask System; Amendment No. 9

    Science.gov (United States)

    2013-12-06

    ... Federal and State Materials and Environmental Management Programs, U.S. Nuclear Regulatory Commission... editorial corrections. DATES: Submit comments by January 6, 2014. Comments received after this date will be...-0052. NRC's Agencywide Documents Access and Management System (ADAMS): You may access publicly...

  14. NRC approves spent-fuel cask for general use: Who needs Yucca Mountain?

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, J.

    1993-07-01

    The Nuclear Regulatory Commission (NRC) on April 7, 1993, added Pacific Sierra Nuclear Associates`s (PSNA`s) VSC-24 spent-fuel container to its list of approved storage casks. Unlike previously approved designs, however, the cask was made available for use by utilities without site-specific approval. The VSC-24 (ventilated storage cask) is a 130-ton, 16-foot high vertical storage container composed of a ventilated concrete cask (VCC) housing a steel multi-assembly sealed basket (MSB). A third component, a transfer cask (MTC), shields, supports, and protects the MSB during fuel loading and VCC loading operations. The VCC is a cylindrical reinforced-concrete cask 29 inches thick, with a 1.75-inch-thick A 36 steel liner. The cask contains eight vents-four on the top and four on the bottom-to provide for MSB (and fuel rod) cooling. Its concrete shell provides protection against shearing and penetration by tornado projectiles, protects the MSB in the event of a drop or tipover, and is designed to withstand internal temperatures of 350 degrees Farenheit. The VCC is closed with a bolted-down cover of 0.75-inch-thick A 36 steel. The MSB, which provides the primary boundary for 24 spent fuel rods, is a cylindrical steel shell with a thick shield plug and steel cover plates welded at each end. The shell and covers are constructed from SA 516 Grade 70 pressure vessel steel. Fuel is housed in a basket fabricated from SA 516 Grade 70 sheet steel. Penetrations in the MSB`s structural and shield lids allow for vacuum drying and backfilling with helium after fuel loading. Although its manufacturer claims a design life of 50 years, the NRC has licensed the VSC-24 cask for 20 years.

  15. Control Strategy of VSC-HVDC in Dual-infeed HVDC Systems%双馈入直流输电系统中VSC-HVDC的控制策略

    Institute of Scientific and Technical Information of China (English)

    赵成勇; 孙营; 李广凯

    2008-01-01

    针对多馈入直流输电(multi-infeed direct current,MIDC)系统的稳定性问题,提出将基于电压源换流器的高压直流输电(voltage source converter based HVDC,VSC-HVDC)引入到MIDC系统中,用以改善MIDC系统公共连接母线的电压特性.建立HVDC和VSC-HVDC双馈入系统的物理模型,导出相应的数学模型.并通过坐标变换得出VSC功率传输方程的直角坐标形式.采用多变量非线性控制的逆系统方法,设计VSC-HVDC系统的非线性控制器.PSCAD/EMTDC 环境下的仿真实验表明,所设计的VSC-HVDC非线性控制器不仅能有效改善VSC-HVDC的动态特性,而且在交流系统发生扰动时能有效稳定系统电压,减少HVDC逆变站发生换相失败的几率,提高HVDC系统的运行可靠性.

  16. Comparison of PI and PR current controllers applied on two-level VSC-HVDC transmission system

    DEFF Research Database (Denmark)

    Manoloiu, A.; Pereria, H.A.; Teodorescu, Remus;

    2015-01-01

    This paper analyzes differences between αβ and dq reference frames regarding the control of two-level VSC-HVDC current loop and dc-link voltage outer loop. In the first part, voltage feedforward effect is considered with PI and PR controllers. In the second part, the feedforward effect is removed...

  17. Developing a structural health monitoring system for nuclear dry cask storage canister

    Science.gov (United States)

    Sun, Xiaoyi; Lin, Bin; Bao, Jingjing; Giurgiutiu, Victor; Knight, Travis; Lam, Poh-Sang; Yu, Lingyu

    2015-03-01

    Interim storage of spent nuclear fuel from reactor sites has gained additional importance and urgency for resolving waste-management-related technical issues. In total, there are over 1482 dry cask storage system (DCSS) in use at US plants, storing 57,807 fuel assemblies. Nondestructive material condition monitoring is in urgent need and must be integrated into the fuel cycle to quantify the "state of health", and more importantly, to guarantee the safe operation of radioactive waste storage systems (RWSS) during their extended usage period. A state-of-the-art nuclear structural health monitoring (N-SHM) system based on in-situ sensing technologies that monitor material degradation and aging for nuclear spent fuel DCSS and similar structures is being developed. The N-SHM technology uses permanently installed low-profile piezoelectric wafer sensors to perform long-term health monitoring by strategically using a combined impedance (EMIS), acoustic emission (AE), and guided ultrasonic wave (GUW) approach, called "multimode sensing", which is conducted by the same network of installed sensors activated in a variety of ways. The system will detect AE events resulting from crack (case for study in this project) and evaluate the damage evolution; when significant AE is detected, the sensor network will switch to the GUW mode to perform damage localization, and quantification as well as probe "hot spots" that are prone to damage for material degradation evaluation using EMIS approach. The N-SHM is expected to eventually provide a systematic methodology for assessing and monitoring nuclear waste storage systems without incurring human radiation exposure.

  18. An Improvement VSC-HVDC Station in Thailand

    Directory of Open Access Journals (Sweden)

    Narin Watanakul

    2014-12-01

    Full Text Available The paper was to study design and improvement voltage source converter (VSC based HVDC long-distance transmission system around 110km between Thailand to Malaysia with rated 300MVA (±300 kV. This paper presents an application of an asynchronous back to back VSC-HVDC system, which uses multilevel converter a 7- level Diode-Clamped SPWM converters topology technique for the realization of HVDC system. The controller has been proposed by using PQ control and feedforward decoupled current control algorithm. The design and experimentally controllers of VSC in lab scaled test, MATLAB/Simulink program were performed VSC-HVDC transmission system, simulation in order to evaluate transient performance, can be controlled independently under two phase to ground faulted and three phases to ground faulted conditions. The system are used as a guideline for analysing and design of the data process control with the PQ-control HVDC system.

  19. Dicty_cDB: VSC602 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available ycdb.biol.tsukuba.ac.jp/CSM/VS/VSC6-A/VSC602Q.Seq.d/ Representative seq. ID VSC60...2E (Link to Original site) Representative DNA sequence >VSC602 (VSC602Q) /CSM/VS/VSC6-A/VSC602Q.Seq.d/ AGAAT

  20. Dicty_cDB: VSC895 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VS (Link to library) VSC895 (Link to dictyBase) - - - Contig-U15212-1 VSC895Z (Link... to Original site) - - VSC895Z 448 - - - - Show VSC895 Library VS (Link to library) Clone ID VSC895 (Link to...ycdb.biol.tsukuba.ac.jp/CSM/VS/VSC8-D/VSC895Q.Seq.d/ Representative seq. ID VSC89...5Z (Link to Original site) Representative DNA sequence >VSC895 (VSC895Q) /CSM/VS/VSC8-D/VSC895Q.Seq.d/ XXXXX...ppkc*sq r*s*gfkc*ktqdrsrssstcsttt*knlqstwsyqsihvftinc*ihph*s*kscpkts *rirpkeeicrh

  1. Dicty_cDB: VSC294 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VS (Link to library) VSC294 (Link to dictyBase) - - - Contig-U12817-1 VSC294Z (Link... to Original site) - - VSC294Z 550 - - - - Show VSC294 Library VS (Link to library) Clone ID VSC294 (Link to...ycdb.biol.tsukuba.ac.jp/CSM/VS/VSC2-D/VSC294Q.Seq.d/ Representative seq. ID VSC29...4Z (Link to Original site) Representative DNA sequence >VSC294 (VSC294Q) /CSM/VS/VSC2-D/VSC294Q.Seq.d/ XXXXX...pwtsiwtifpffilftncsrifft*i***sttys *iirr*iisiniywwk*ifycryckcrlviilklctii*cn*rtfpkyf*mvrfnqskri n*tsksinfrwf*kf*skftsc

  2. Dicty_cDB: VSC366 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VS (Link to library) VSC366 (Link to dictyBase) - - - Contig-U06228-1 VSC366Z (Link... to Original site) - - VSC366Z 575 - - - - Show VSC366 Library VS (Link to library) Clone ID VSC366 (Link to...ycdb.biol.tsukuba.ac.jp/CSM/VS/VSC3-C/VSC366Q.Seq.d/ Representative seq. ID VSC36...6Z (Link to Original site) Representative DNA sequence >VSC366 (VSC366Q) /CSM/VS/VSC3-C/VSC366Q.Seq.d/ XXXXX...LEILLH IPLLCEDKNIPYVFVSSKSELGRACDVSRPVVACAVTVDDKSQLKSQITNVKDSLDRLWI V*irfisciffiiqmctyihqnylnfnfffflkkkkkkki

  3. Dicty_cDB: VSC667 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VS (Link to library) VSC667 (Link to dictyBase) - - - Contig-U12705-1 VSC667Z (Link... to Original site) - - VSC667Z 587 - - - - Show VSC667 Library VS (Link to library) Clone ID VSC667 (Link to...ycdb.biol.tsukuba.ac.jp/CSM/VS/VSC6-C/VSC667Q.Seq.d/ Representative seq. ID VSC66...7Z (Link to Original site) Representative DNA sequence >VSC667 (VSC667Q) /CSM/VS/VSC6-C/VSC667Q.Seq.d/ XXXXX...TTWLTDARNLTNPNTVIM LIGNKKDLEGQRDVTYEEASAFAKQNGLIFVESSAKTGENVEEAFLRTAKLIFQSVQEGN VDLIPDGGITKNPPQTITDKPQDASKCSC

  4. Dicty_cDB: VSC206 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VS (Link to library) VSC206 (Link to dictyBase) - - - Contig-U16090-1 VSC206Z (Link... to Original site) - - VSC206Z 495 - - - - Show VSC206 Library VS (Link to library) Clone ID VSC206 (Link to...ycdb.biol.tsukuba.ac.jp/CSM/VS/VSC2-A/VSC206Q.Seq.d/ Representative seq. ID VSC20...6Z (Link to Original site) Representative DNA sequence >VSC206 (VSC206Q) /CSM/VS/VSC2-A/VSC206Q.Seq.d/ XXXXX...fssxp*tpqirchgrikeqt rlys*s*ssrfhgktspnfslqkwscqinpsrscfnqr*thpcw*tisqrsifprpc*ip kalrfsfnlpiswwssrsscp*ngqe

  5. Dicty_cDB: VSC345 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VS (Link to library) VSC345 (Link to dictyBase) - - - Contig-U14496-1 VSC345E (Link... to Original site) - - - - - - VSC345E 502 Show VSC345 Library VS (Link to library) Clone ID VSC345 (Link to...ycdb.biol.tsukuba.ac.jp/CSM/VS/VSC3-B/VSC345Q.Seq.d/ Representative seq. ID VSC34...5E (Link to Original site) Representative DNA sequence >VSC345 (VSC345Q) /CSM/VS/VSC3-B/VSC345Q.Seq.d/ ACCAG...vlvs*llkyfirinkyk*kk*lnlknik Frame C: qix*a*kikr*rlcrlrscw*tqkasrws**cwwshssqn*l*

  6. Dicty_cDB: VSC485 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VS (Link to library) VSC485 (Link to dictyBase) - - - Contig-U15450-1 VSC485Z (Link... to Original site) - - VSC485Z 672 - - - - Show VSC485 Library VS (Link to library) Clone ID VSC485 (Link to...ycdb.biol.tsukuba.ac.jp/CSM/VS/VSC4-D/VSC485Q.Seq.d/ Representative seq. ID VSC48...5Z (Link to Original site) Representative DNA sequence >VSC485 (VSC485Q) /CSM/VS/VSC4-D/VSC485Q.Seq.d/ XXXXX...QINPQNGTVGGTFTLSIAYTVTNTIATGQLAFNIIDPTGNAFGDAVLLVQQSPEQYTQ QFQFQATPSEQESFPNGLYTVQALVCEGSC

  7. Dry Cask Storage Characterization Project - Phase 1: CASTOR V/21 Cask Opening and Examination

    Energy Technology Data Exchange (ETDEWEB)

    Bare, Walter Claude; Ebner, Matthias Anthony; Torgerson, Laurence Dale

    2001-08-01

    This report documents visual examination and testing conducted in 1999 and early 2000 at the Idaho National Engineering and Environmental Laboratory (INEEL) on a Gesellschaft für Nuklear Service (GNS) CASTOR V/21 pressurized water reactor (PWR) spent fuel dry storage cask. The purpose of the examination and testing is to develop a technical basis for renewal of licenses and Certificates of Compliance for dry storage systems for spent nuclear fuel and high-level waste at independent spent fuel storage installation sites. The examination and testing was conducted to assess the condition of the cask internal and external surfaces, cask contents consisting of 21 Westinghouse PWR spent fuel assemblies from Dominion’s (formerly named Virginia Power) Surry Power Station and cask concrete storage pad. The assemblies have been continuously stored in the CASTOR cask since 1985. Cask exterior surface and selected fuel assembly temperatures, and cask surface gamma and neutron dose rates were measured. Cask external/internal surfaces, fuel basket components including accessible weldments, fuel assembly exteriors, and primary lid seals were visually examined. Selected fuel rods were removed from one fuel assembly, visually examined, and then shipped to Argonne National Laboratory for nondestructive, destructive, and mechanical examination. Cask interior crud samples and helium cover gas samples were collected and analyzed. The results of the examination and testing indicate the concrete storage pad, CASTOR V/21 cask, and cask contents exhibited sound structural and seal integrity and that long-term storage has not caused detectable degradation of the spent fuel cladding or the release of gaseous fission products between 1985 and 1999.

  8. Wind Farm Grid Integration Using VSC Based HVDC Transmission - An Overview

    DEFF Research Database (Denmark)

    Chaudhary, Sanjay Kumar; Teodorescu, Remus; Rodriguez, Pedro

    2008-01-01

    The paper gives an overview of HVAC and HVDC connection of wind farm to the grid, with an emphasis on Voltage Source Converter (VSC)-based HVDC for large wind farms requiring long distance cable connection. Flexible control capabilities of a VSC-based HVDC system enables smooth integration of wind...... farm into the power grid network while meeting the Grid Code Requirements (GCR). Operation of a wind farm with VSC-based HVDC connection is described....

  9. Grid connection of active stall wind farms using a VSC based DC transmission system

    DEFF Research Database (Denmark)

    Iov, Florin; Sorensen, Paul; Hansen, Anca-Daniela;

    2005-01-01

    are fulfilled. However, the traditional squirrel-cage generators based wind turbines/wind farms directly connected to the grid have less control capabilities. These wind turbines/farms cannot regulate their production and contribute to power system stability. A DC transmission system for connection...

  10. 76 FR 33121 - List of Approved Spent Fuel Storage Casks: HI-STORM Flood/Wind Addition

    Science.gov (United States)

    2011-06-08

    ... 3150-AI90 List of Approved Spent Fuel Storage Casks: HI-STORM Flood/Wind Addition AGENCY: Nuclear... the NRC's spent fuel storage regulations to add the Holtec HI-STORM Flood/Wind cask system to the... Holtec HI- STORM Flood/Wind cask system to the ``List of Approved Spent Fuel Storage Casks''...

  11. Power Delivery in Multiterminal VSC-HVDC Transmission System for Offshore Wind Power Applications

    DEFF Research Database (Denmark)

    Silva, Rodrigo Da; Teodorescu, Remus; Rodriguez, Pedro

    2010-01-01

    This paper deals with one of the challenges in the field of offshore wind power systems: power transmission among the wind farms and the land when there is more than one AC grid to be considered. This case is known in the literature as multiterminal connection. The proposed studies are going to p...

  12. Evaluation of impact limiter performance during end-on and slapdown drop tests of a one-third scale model storage/transport cask system

    Energy Technology Data Exchange (ETDEWEB)

    Yoshimura, H.R.; Bronowski, D.R.; Uncapher, W.L.; Attaway, S.W.; Bateman, V.I.; Carne, T.G.; Gregory, D.L. (Sandia National Labs., Albuquerque, NM (USA)); Huerta, M. (Southwest Engineering Associates, El Paso, TX (USA))

    1990-12-01

    This report describes drop testing of a one-third scale model shipping cask system. Two casks were designed and fabricated by Transnuclear, Inc., to ship spent fuel from the former Nuclear Fuel Services West Valley reprocessing facility in New York to the Idaho National Engineering Laboratory for a long-term spent fuel dry storage demonstration project. As part of the NRC's regulatory certification process, one-third scale model tests were performed to obtain experimental data on impact limiter performance during impact testing. The objectives of the testing program were to (1) obtain deceleration and displacement information for the cask and impact limiter system, (2) obtain dynamic force-displacement data for the impact limiters, (3) verify the integrity of the impact limiter retention system, and (4) examine the crush behavior of the limiters. Two 30-ft (9-m) drop tests were conducted on a mass model of the cask body and scaled balsa and redwood-filled impact limiters. This report describes the results of both tests in terms of measured decelerations, posttest deformation measurements, and the general structural response of the system. 3 refs., 32 figs.

  13. Dicty_cDB: VSC284 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VS (Link to library) VSC284 (Link to dictyBase) - - - Contig-U06415-1 VSC284E (Link... to Original site) - - - - - - VSC284E 357 Show VSC284 Library VS (Link to library) Clone ID VSC284 (Link to...ycdb.biol.tsukuba.ac.jp/CSM/VS/VSC2-D/VSC284Q.Seq.d/ Representative seq. ID VSC28...4E (Link to Original site) Representative DNA sequence >VSC284 (VSC284Q) /CSM/VS/VSC2-D/VSC284Q.Seq.d/ AGGAA...quences producing significant alignments: (bits) Value VSC284 (VSC284Q) /CSM/VS/VSC2-D/VSC284Q.Seq.d/ 192 2e

  14. Dicty_cDB: VSC288 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VS (Link to library) VSC288 (Link to dictyBase) - - - Contig-U14241-1 VSC288Z (Link... to Original site) - - VSC288Z 637 - - - - Show VSC288 Library VS (Link to library) Clone ID VSC288 (Link to...ycdb.biol.tsukuba.ac.jp/CSM/VS/VSC2-D/VSC288Q.Seq.d/ Representative seq. ID VSC28...8Z (Link to Original site) Representative DNA sequence >VSC288 (VSC288Q) /CSM/VS/VSC2-D/VSC288Q.Seq.d/ XXXXX...ing significant alignments: (bits) Value VSC288 (VSC288Q) /CSM/VS/VSC2-D/VSC288Q.Seq.d/ 367 e-100 VFG516 (VF

  15. Dicty_cDB: VSC231 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VS (Link to library) VSC231 (Link to dictyBase) - - - Contig-U12227-1 VSC231Z (Link... to Original site) - - VSC231Z 521 - - - - Show VSC231 Library VS (Link to library) Clone ID VSC231 (Link to...ycdb.biol.tsukuba.ac.jp/CSM/VS/VSC2-B/VSC231Q.Seq.d/ Representative seq. ID VSC23...1Z (Link to Original site) Representative DNA sequence >VSC231 (VSC231Q) /CSM/VS/VSC2-B/VSC231Q.Seq.d/ XXXXX... E Sequences producing significant alignments: (bits) Value VSC231 (VSC231Q) /CSM/VS/VSC2-B/VSC

  16. Dicty_cDB: VSC512 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VS (Link to library) VSC512 (Link to dictyBase) - - - Contig-U12183-1 VSC512Z (Link... to Original site) - - VSC512Z 298 - - - - Show VSC512 Library VS (Link to library) Clone ID VSC512 (Link to...ycdb.biol.tsukuba.ac.jp/CSM/VS/VSC5-A/VSC512Q.Seq.d/ Representative seq. ID VSC51...2Z (Link to Original site) Representative DNA sequence >VSC512 (VSC512Q) /CSM/VS/VSC5-A/VSC512Q.Seq.d/ XXXXX...roducing significant alignments: (bits) Value VSC512 (VSC512Q) /CSM/VS/VSC5-A/VSC512Q.Seq.d/ 355 2e-97 VSB88

  17. Control System interaction in the VSC-HVDC Grid Connected Offshore Wind Power Plant

    DEFF Research Database (Denmark)

    Glasdam, Jakob Bærholm; Kocewiak, Łukasz Hubert; Hjerrild, Jesper

    2015-01-01

    Conventional offshore wind power plants (OWPPs) are due to the combination of the extensive sub-marine cabling and possible low available short-circuit power at the point of common connection (PCC) susceptible to the harmonic instability phenomena. The instability is caused by the resonances...... in the electrical system which is generally located within the wind turbine generator (WTG) controller bandwidth. Some of the negative impact of the existence of harmonic instability include (but not limited to) accelerated component ageing due to increased thermal stresses and loss of power production before...

  18. 混合双馈入直流系统中VSC-HVDC对LCC-HVDC受端系统强度的影响%The Effects of VSC-HVDC on the System Strength of LCC-HVDC in Dual-infeed Hybrid HVDC System

    Institute of Scientific and Technical Information of China (English)

    倪晓军; 赵成勇; 郭春义; 刘羽超

    2015-01-01

    为了准确评估混合双馈入直流系统中电网换相换流器高压直流输电(line commutated converter based high voltage direct current,LCC-HVDC)子系统的受端系统强度,对LCC-HVDC 子系统的有效短路比进行研究。第一,基于牛顿最优潮流算法,分析混合双馈入直流系统中电压源换流器高压直流输电(voltage source converter based HVDC, VSC-HVDC)子系统采用不同的功率输送方向和控制方式时,对LCC-HVDC子系统的交流系统电压支撑强度的影响关系。第二,计算VSC-HVDC子系统的等效阻抗,提出能够有效评估混合双馈入系统中LCC-HVDC子系统有效短路比的等值有效短路比指标。利用该指标可将混合双馈入直流系统中LCC-HVDC子系统等效为受端交流系统电压支撑强度与之相同的单馈入直流输电系统。最后,基于 PSCAD/ EMTDC进行仿真分析,仿真结果证明了VSC-HVDC对LCC-HVDC 子系统影响关系的正确性以及等值有效短路比指标的有效性。%The effective short circuit ratio of line commutated converter based high voltage direct current (LCC-HVDC) sub-system in dual-infeed hybrid HVDC system was investigated to evaluate the system strength of LCC-HVDC. Firstly, the voltage support strength of AC system was analyzed when different power flow directions and different controled strategies were adopted in voltage source converter (VSC) based on optimal power flow by Newton approach. Secondly, the equivalent impedance of VSC-HVDC was calculated, and the effective short circuit ratio of the LCC-HVDC was quantified by a proposed “equivalent effective short circuit ratio” index. The LCC-HVDC in dual-infeed hybrid HVDC system could be equivalent to a single-infeed HVDC system which had the same voltage support strength by the index. Simulation results in PSCAD/EMTDC show that the analysis on the effects of VSC-HVDC to LCC-HVDC proved to be accurate and the “equivalent effective short circuit ratio” index is

  19. A Primal-Dual Interior Point Method-Based Algorithm Adopting Automatic Differentiation for Optimal Power Flow of AC/DC Power Grid Containing VSC-HVDC System%基于自动微分技术的VSC-HVDC内点法最优潮流

    Institute of Scientific and Technical Information of China (English)

    季聪; 卫志农; 汤涌; 孙国强; 韦延方; 孙永辉

    2012-01-01

    Based on steady state power flow model of voltage source converter-high voltage direct current (VSC-HVDC) power transmission system and combining with automatic differentiation (AD) technology, a primal-dual interior point method-based algorithm for optimal power flow (OPF) of AC/DC power grid was proposed. Using high efficient AD tool based on operator overloading the Jacobian and Hessian matrices were generated, thus the work load for derivation of differential expressions and code compiling could be reduced and the development efficiency of program could be improved. Simulation results of calculation examples showed that in the solution of OPF problem of AC/DC power grid containing VSC-HVDC power transmission system the high efficiency of traditional primal-dual interior point method could be kept and it possessed satisfied adaptability to the combination of different VSC control modes.%根据电压源换流器-高压直流输电(voltage source converter-high voltage direct current,VSC-HVDC)的稳态潮流模型,结合自动微分(automatic differentiation,AD)技术,提出一种基于原对偶内点法的交直流系统最优潮流算法.该算法利用高效的基于操作符重载的AD工具生成雅可比(Jacobian)矩阵和海森(Hessian)矩阵,减少了微分表达式推导和代码编写的工作量,提高了程序的开发效率.多个算例的仿真结果表明,该算法保持了传统原对偶内点法在解决含VSC-HVDC的交直流最优潮流问题上的高效性,且对VSC的不同控制方式组合均具有良好的适应性.

  20. Cask fleet operations study

    Energy Technology Data Exchange (ETDEWEB)

    1988-01-01

    The Nuclear Waste Policy Act of 1982 assigned to the Department of Energy's (DOE) Office of Civilian Waste Management the responsibility for disposing of high-level waste and spent fuel. A significant part of that responsibility involves transporting nuclear waste materials within the federal waste management system; that is, from the waste generator to the repository. The lead responsibility for transportation operations has been assigned to Oak Ridge Operations, with Oak Ridge National Laboratory (ORNL) providing technical support through the Transportation Operations Support Task Group. One of the ORNL support activities involves assessing what facilities, equipment and services are required to assure that an acceptable, cost-effective and safe transportation operations system can be designed, operated and maintained. This study reviews, surveys and assesses the experience of Nuclear Assurance Corporation (NAC) in operating a fleet of spent-fuel shipping casks to aid in developing the spent-fuel transportation system.

  1. Dicty_cDB: VSC521 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VS (Link to library) VSC521 (Link to dictyBase) - - - Contig-U15503-1 VSC521E (Link... to Original site) - - - - - - VSC521E 455 Show VSC521 Library VS (Link to library) Clone ID VSC521 (Link to...ycdb.biol.tsukuba.ac.jp/CSM/VS/VSC5-A/VSC521Q.Seq.d/ Representative seq. ID VSC52...1E (Link to Original site) Representative DNA sequence >VSC521 (VSC521Q) /CSM/VS/VSC5-A/VSC521Q.Seq.d/ CAAGA...ssisffffdikkkk Homology vs CSM-cDNA Score E Sequences producing significant alignments: (bits) Value VSC521 (VSC521Q) /CSM/VS/VSC

  2. Status update of the BWR cask simulator

    Energy Technology Data Exchange (ETDEWEB)

    Lindgren, Eric R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Durbin, Samuel G. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-09-01

    The performance of commercial nuclear spent fuel dry storage casks are typically evaluated through detailed numerical analysis of the system's thermal performance. These modeling efforts are performed by the vendor to demonstrate the performance and regulatory compliance and are independently verified by the Nuclear Regulatory Commission (NRC). Carefully measured data sets generated from testing of full sized casks or smaller cask analogs are widely recognized as vital for validating these models. Numerous studies have been previously conducted. Recent advances in dry storage cask designs have moved the storage location from above ground to below ground and significantly increased the maximum thermal load allowed in a cask in part by increasing the canister helium pressure. Previous cask performance validation testing did not capture these parameters. The purpose of the investigation described in this report is to produce a data set that can be used to test the validity of the assumptions associated with the calculations presently used to determine steady-state cladding temperatures in modern dry casks. These modern cask designs utilize elevated helium pressure in the sealed canister or are intended for subsurface storage. The BWR cask simulator (BCS) has been designed in detail for both the above ground and below ground venting configurations. The pressure vessel representing the canister has been designed, fabricated, and pressure tested for a maximum allowable pressure (MAWP) rating of 24 bar at 400 C. An existing electrically heated but otherwise prototypic BWR Incoloy-clad test assembly is being deployed inside of a representative storage basket and cylindrical pressure vessel that represents the canister. The symmetric single assembly geometry with well-controlled boundary conditions simplifies interpretation of results. Various configurations of outer concentric ducting will be used to mimic conditions for above and below ground storage configurations

  3. A cask fleet operations study

    Energy Technology Data Exchange (ETDEWEB)

    1988-03-01

    This document describes the cask fleet currently available to transport spent nuclear fuels. The report describes the proposed operational procedures for these casks and the vehicles intended to transport them. Included are techniques for loading the cask, lifting it onto the transport vehicle, preparing the invoices, and unloading the cask at the destination. The document concludes with a discussion on the maintenance and repair of the casks. (tem) 29 figs.

  4. VSC-HVDC的次同步阻尼特性研究%Study on sub-synchronous damping characteristic of VSC-HVDC

    Institute of Scientific and Technical Information of China (English)

    徐坤; 赵成勇; 高本锋

    2012-01-01

    目前针对基于电压源换流器(Voltage Source Converter)的高压直流输电技术(VSC-HVDC)的研究,主要集中在控制策略方面,而研究VSC-HVDC对相邻发电机组阻尼特性的影响较少.从VSC-HVDC的工作原理出发,阐述了VSC-HVDC的能够抑制次同步振荡的机理.采用基于时域实现的复转矩系数法-测试信号法,分析了机组作用系数、控制方式以及有功、无功功率水平对VSC-HVDC阻尼特性的影响.针对同一交流系统,对比分析了VSC-HVDC与传统的HVDC的阻尼特性的大小.研究结果表明,与传统HVDC相比,VSC-HVDC能够显著改善相邻发电机组的次同步阻尼特性.%The study on the HVDC based on voltage-source converter focuses mainly on the control strategy while less on the impact of electrical damping on the adjacent units by VSC-HVDC. The mechanism of VSC-HVDC on inhibiting sub-synchronous oscillation is analyzed theoretically in the respect of its operation principle. Then the complex torque coefficient method, namely the test signal method, which is realized by time domain simulation, is adopted to investigate the impact of the unit interaction factor, control mode, active power level and reactive power level on the electrical damping on the adjacent units. Finally, adopting the same system, the damping of VSC-HVDC and HVDC are compared using test signal method.

  5. Frequency control of grid-connection system based on VSC-HVDC for large-scale centralized wind farm%用于大规模集中式风电并网的VSC-HVDC频率控制方法

    Institute of Scientific and Technical Information of China (English)

    潘伟; 李勇; 曹一家; 辛建波

    2015-01-01

    针对大规模集中式风电并网过程中送端系统频率波动以及电能输送损耗严重等问题,提出一种基于电压源型换流器高压直流输电(VSC-HVDC)的大规模风电并网系统频率稳定控制方法.VSC送端换流器通过调节脉宽调制(PWM)移相角来控制交流侧电压相位大小,以达到控制线路有功功率传输的目的,从而保证风电并网系统有功功率的平衡及系统频率的稳定,同时通过调节PWM调制比来调节交流电压,使系统电压维持稳定;受端换流器控制直流侧电压的稳定,以保证VSC-HVDC系统的正常运行.通过在Power Factory Digsilent上进行仿真,验证了该控制策略能显著增强系统的频率稳定性.

  6. Fault Ride-Through Capability Enhancement of VSC HVDC connected Offshore Wind Power Plants

    DEFF Research Database (Denmark)

    Sharma, Ranjan; Wu, Qiuwei; Cha, Seung-Tae;

    2015-01-01

    This paper presents a feed forward direct current (DC) voltage control based fault ride-through (FRT) scheme for voltage source converter (VSC) high voltage DC (HVDC) connected offshore wind power plants (WPPs) in order to achieve active control of the WPP collector network AC voltage magnitude......, and to improve the FRT capability. During steady state operation, an open loop AC voltage control is implemented at the WPP side VSC of the HVDC system such that any possible control interactions between the WPP side VSC and the wind turbine VSC are minimized. Whereas during any grid faults, a dynamic AC voltage...... reference is applied based on both the DC voltage error and the AC active-current from the WPP collector system which ensures fast and robust FRT of the VSC HVDC connected offshore WPPs. Under unbalanced fault conditions in the host power system, the resulting oscillatory DC voltage is directly used...

  7. Dicty_cDB: VSC235 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VS (Link to library) VSC235 (Link to dictyBase) - G21287 DDB0189760 Contig-U16307-1 VSC...235Z (Link to Original site) - - VSC235Z 315 - - - - Show VSC235 Library VS (Link to library) Clone ID VSC...riginal site URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VS/VSC2-B/VSC235Q.Seq.d/ ...Representative seq. ID VSC235Z (Link to Original site) Representative DNA sequence >VSC235 (VSC235Q) /CSM/VS/VSC2-B/VSC...*vikilmifqmiyikilmvn*nhklkn Homology vs CSM-cDNA Score E Sequences producing significant alignments: (bits) Value VSC235 (VSC

  8. 77 FR 9591 - List of Approved Spent Fuel Storage Casks: HI-STORM 100, Revision 8

    Science.gov (United States)

    2012-02-17

    ... COMMISSION 10 CFR Part 72 RIN 3150-AJ05 List of Approved Spent Fuel Storage Casks: HI-STORM 100, Revision 8... the Holtec International HI-STORM 100 dry cask storage system listing within the ``List of Approved... other aspects of the HI-STORM 100 dry storage cask system. Because the NRC considers this...

  9. Negative sequence current control in wind power plants with VSC-HVDC connection

    DEFF Research Database (Denmark)

    Chaudhary, Sanjay; Teodorescu, Remus; Rodriguez, Pedro;

    2012-01-01

    Large offshore wind power plants may have multi-MW wind turbine generators (WTG) equipped with full-scale converters (FSC) and voltage source converter (VSC) based high voltaage direct-current (HVDC) transmission for grid connection. The power electronic converters in theWTG-FSC and the VSC-HVDC...... allow fast current control in the offshore grid. This paper presents a method of controlling the negative sequence current injection into the offshore grid from the VSC-HVDC as well as WTG-FSCs. This would minimize the power oscillations and hence reduce the dc voltage overshoots in the VSC-HVDC system...... sequence current control mitigates the power oscillations and therefore limits the dc voltage excursions in the VSC-HVDC system during the asymmetric faults....

  10. Coordinated frequency regulation by offshore wind farms and VSC-HVDC transmission

    DEFF Research Database (Denmark)

    Liu, Hongzhi; Chen, Zhe

    2014-01-01

    With the increasing wind penetration, large-scale offshore wind farms exert significant impact on power system security and operation, and thus are required to contribute to system frequency regulation. This paper develops a coordinated control strategy for offshore wind farms with voltage source...... converter-based HVDC (VSC-HVDC) transmission system to participate in power system frequency regulation. The strategy explores the frequency support capability of offshore wind farms and VSC-HVDC. By implementing the proposed coordinated control, the VSCHVDC link is able to provide quick virtual inertial...... are presented to demonstrate the frequency regulation capability of VSC-HVDC and validate the effectiveness of the proposed coordinated control strategy....

  11. Fault Ride-through Capability Enhancement of VSC-HVDC-connected Offshore Wind Power Plants

    Institute of Scientific and Technical Information of China (English)

    Ranjan SHARMA; Qiuwei WU; Seung Tae CHA; Kim Høj ENSEN; Tony Wederberg RASMUSSEN; Jacob ØSTERGAARD

    2015-01-01

    To achieve active control of the AC voltage magnitude of wind power plant(WPP) collector network and improve the fault ride-through (FRT) capability,an FRT scheme based on feed forward DC voltage control is presented for voltage source converter-high voltage direct current(VSC-HVDC) connected offshore WPPs.During steady state operation,an open loop AC voltage control is implemented at the WPP-side VSC of the HVDC system so that any possible control interactions between WPP-side VSC and VSC of wind turbine are minimized.Whereas during any grid fault,a dynamic AC voltage reference is made according to both the DC voltage error and AC active current from the WPP collector system,thus ensuring fast and robust FRT of the VSC-HVDC-connected offshore WPPs.Under the unbalanced fault condition in the host power system,the resulting oscillatory DC voltage is directly used in the VSC AC voltage controller at the WPP side so that the WPP collector system voltage also reflects the unbalance in the main grid.Time domain simulations are performed to verify the efficacy of the FRT scheme based on the proposed feed forward DC voltage control.Simulation results show satisfactory FRT responses of the VSC-HVDC-connected offshore WPP under balanced and unbalanced faults in the host power system,as is shown under a serious fault in the WPP collector network.

  12. Dicty_cDB: VSC819 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VS (Link to library) VSC819 (Link to dictyBase) - - - Contig-U16030-1 VSC819Z (Link... to Original site) - - VSC819Z 562 - - - - Show VSC819 Library VS (Link to library) Clone ID VSC819 (Link to...ycdb.biol.tsukuba.ac.jp/CSM/VS/VSC8-A/VSC819Q.Seq.d/ Representative seq. ID VSC81...9Z (Link to Original site) Representative DNA sequence >VSC819 (VSC819Q) /CSM/VS/VSC8-A/VSC819Q.Seq.d/ XXXXX...ifylpeq fnl*nri*k Translated Amino Acid sequence (All Frames) Frame A: ---nhkf*llsnvnrikrksrcqfrwsc

  13. Dicty_cDB: VSC728 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VS (Link to library) VSC728 (Link to dictyBase) - - - Contig-U08358-1 VSC728E (Link... to Original site) - - - - - - VSC728E 471 Show VSC728 Library VS (Link to library) Clone ID VSC728 (Link to...ycdb.biol.tsukuba.ac.jp/CSM/VS/VSC7-B/VSC728Q.Seq.d/ Representative seq. ID VSC72...8E (Link to Original site) Representative DNA sequence >VSC728 (VSC728Q) /CSM/VS/VSC7-B/VSC728Q.Seq.d/ TCATA...Amino Acid sequence (All Frames) Frame A: sy*rgkasm*enevkkgilyysnlfiiftflt*ivletkir*lfgss*ksc*kfldvvnr y**rs

  14. Grid-connection of large offshore windfarms utilizing VSC-HVDC: Modeling and grid impact

    DEFF Research Database (Denmark)

    Xue, Yijing; Akhmatov, Vladislav

    2009-01-01

    Utilization of Voltage Source Converter (VSC) – High Voltage Direct Current (HVDC) systems for grid-connection of large offshore windfarms becomes relevant as installed power capacities as well as distances to the connection points of the on-land transmission systems increase. At the same time......, the grid code requirements of the Transmission System Operators (TSO), including ancillary system services and Low-Voltage Fault-Ride-Through (LVFRT) capability of large offshore windfarms, become more demanding. This paper presents a general-level model of and a LVFRT solution for a VSC-HVDC system...... for grid-connection of large offshore windfarms. The VSC-HVDC model is implemented using a general approach of independent control of active and reactive power in normal operation situations. The on-land VSC inverter, which is also called a grid-side inverter, provides voltage support to the transmission...

  15. Power Flow Algorithms for Multi-Terminal VSC-HVDC With Droop Control

    OpenAIRE

    Wang, Wenyuan; Barnes, Mike

    2014-01-01

    This paper addresses the problem posed by complex, nonlinear controllers for power system load flows employing multi-terminal voltage source converter (VSC) HVDC systems. More realistic dc grid control strategies can thus be carefully considered in power flow analysis of ac/dc grids. Power flow methods for multi-terminal VSC-HVDC (MTDC) systems are analyzed for different types of dc voltage control techniques and the weaknesses of present methods are addressed. As distributed voltage control ...

  16. Basic Considerations for Dry Storage of Spent Nuclear Fuels and Revisited CFD Thermal Analysis on the Concrete Cask

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Jae Soo [ACT Co. Ltd., Daejeon (Korea, Republic of); Park, Younwon; Song, Sub Lee [BEES Inc., Daejeon (Korea, Republic of); Kim, Hyeun Min [KAIST, Daejeon (Korea, Republic of)

    2016-10-15

    The integrity of storage facility and also of the spent nuclear fuel itself is considered very important. Storage casks can be located in a designated area on a site or in a designated storage building. A number of different designs for dry storage have been developed and used in different countries. Dry storage system was classified into two categories by IAEA. One is container including cask and silo, the other one is vault. However, there is various way of categorization for dry storage system. Dry silo and cask are usually classified separately, so the dry storage system can be classified into three different types. Furthermore, dry cask storage can be categorized into two types based on the type of the materials, concrete cask and metal cask. In this paper, the design characteristics of dry storage cask are introduced and computational fluid dynamics (CFD) based thermal analysis for concrete cask is revisited. Basic principles for dry storage cask design were described. Based on that, thermal analysis of concrete dry cask was introduced from the study of H. M. Kim et al. From the CFD calculation, the temperature of concrete wall was maintained under the safety criteria. From this fundamental analysis, further investigations are expected. For example, thermal analysis on the metal cask, thermal analysis on horizontally laid spent nuclear fuel assemblies for transportation concerns, and investigations on better performance of natural air circulation in dry cask can be promising candidates.

  17. Power Hardware In The Loop Validation of Fault Ride Through of VSC HVDC Connected Offshore Wind Power Plants

    DEFF Research Database (Denmark)

    Sharma, Ranjan; Wu, Qiuwei; Cha, Seung-Tae;

    2014-01-01

    This paper presents the power hardware in the loop (PHIL) validation of a feed forward DC voltage control scheme for the fault ride through (FTR) of voltage source converter (VSC) high voltage DC (HVDC) connected offshore wind power plants (WPPs). In the proposed FRT scheme, the WPP collector...... network AC voltage is actively controlled by considering both the DC voltage error and the AC current from the WPP AC collector system which ensures fast and robust FRT of the VSC HVDC connected offshore WPPs. The PHIL tests were carried out in order to verify the efficacy of the proposed feed forward DC...... voltage control scheme for enhancing the FRT capability of the VSC HVDC connected WPPs. The PHIL test results have demonstrated the proper control coordination between the offshore WPP and the WPP side VSC and the efficient FRT of the VSC HVDC connected WPPs....

  18. 76 FR 2277 - List of Approved Spent Fuel Storage Casks: NUHOMS® HD System Revision 1

    Science.gov (United States)

    2011-01-13

    ... NUCLEAR FUEL, HIGH-LEVEL RADIOACTIVE WASTE, AND REACTOR- RELATED GREATER THAN CLASS C WASTE 1. The... the NUHOMS HD Horizontal Modular Storage System for Irradiated Nuclear Fuel. ] Docket Number: 72-1030... From the Federal Register Online via the Government Publishing Office NUCLEAR...

  19. 75 FR 25120 - List of Approved Spent Fuel Storage Casks: NUHOMS® HD System Revision 1

    Science.gov (United States)

    2010-05-07

    ... STORAGE OF SPENT NUCLEAR FUEL, HIGH-LEVEL RADIOACTIVE WASTE, AND REACTOR- RELATED GREATER THAN CLASS C... Safety Analysis Report for the NUHOMS HD Horizontal Modular Storage System for Irradiated Nuclear Fuel...; #0; #0;#0;Federal Register / Vol. 75, No. 88 / Friday, May 7, 2010 / Proposed Rules#0;#0; ]...

  20. Test Plan for the Boiling Water Reactor Dry Cask Simulator

    Energy Technology Data Exchange (ETDEWEB)

    Durbin, Samuel [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lindgren, Eric R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-11-01

    The thermal performance of commercial nuclear spent fuel dry storage casks are evaluated through detailed numerical analysis . These modeling efforts are completed by the vendor to demonstrate performance and regulatory compliance. The calculations are then independently verified by the Nuclear Regulatory Commission (NRC). Carefully measured data sets generated from testing of full sized casks or smaller cask analogs are widely recognized as vital for validating these models. Recent advances in dry storage cask designs have significantly increased the maximum thermal load allowed in a cask in part by increasing the efficiency of internal conduction pathways and by increasing the internal convection through greater canister helium pressure. These same vertical, canistered cask systems rely on ventilation between the canister and the overpack to convect heat away from the canister to the environment for both above and below-ground configurations. While several testing programs have been previously conducted, these earlier validation attempts did not capture the effects of elevated helium pressures or accurately portray the external convection of above-ground and below-ground canistered dry cask systems. The purpose of the investigation described in this report is to produce a data set that can be used to test the validity of the assumptions associated with the calculations presently used to determine steady-state cladding temperatures in modern vertical, canistered dry cask systems. The BWR cask simulator (BCS) has been designed in detail for both the above-ground and below-ground venting configurations. The pressure vessel representing the canister has been designed, fabricated, and pressure tested for a maximum allowable pressure (MAWP) rating of 24 bar at 400 deg C. An existing electrically heated but otherwise prototypic BWR Incoloy-clad test assembly is being deployed inside of a representative storage basket and cylindrical pressure vessel that represents the

  1. Modular VSC converter based HVDC power transmission from offshore wind power plant: Compared to the conventional HVAC system

    DEFF Research Database (Denmark)

    Sharma, Ranjan; Rasmussen, Tonny Wederberg; Jensen, Kim Høj;

    2010-01-01

    power transmission options with HVDC systems are under consideration. In this paper, a comparison between a conventional HVAC transmission system and a HVDC system equipped with modular voltage source converters is provided. The comparison is based on the total energy transmission capability...

  2. Inspection of Used Fuel Dry Storage Casks

    Energy Technology Data Exchange (ETDEWEB)

    Dennis C. Kunerth; Tim McJunkin; Mark McKay; Sasan Bakhtiari

    2012-09-01

    ABSTRACT The U.S. Nuclear Regulatory Commission (NRC) regulates the storage of used nuclear fuel, which is now and will be increasingly placed in dry storage systems. Since a final disposition pathway is not defined, the fuel is expected to be maintained in dry storage well beyond the time frame originally intended. Due to knowledge gaps regarding the viability of current dry storage systems for long term use, efforts are underway to acquire the technical knowledge and tools required to understand the issues and verify the integrity of the dry storage system components. This report summarizes the initial efforts performed by researchers at Idaho National Laboratory and Argonne National Laboratory to identify and evaluate approaches to in-situ inspection dry storage casks. This task is complicated by the design of the current storage systems that severely restrict access to the casks.

  3. Research on localization and alignment technology for transfer cask

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jingchuan, E-mail: jchwang@sjtu.edu.cn [Department of Automation, Shanghai Jiao Tong University, Shanghai (China); Key Laboratory of System Control and Information Processing, Ministry of Education of China, Shanghai (China); Yang, Ming; Chen, Weidong [Department of Automation, Shanghai Jiao Tong University, Shanghai (China); Key Laboratory of System Control and Information Processing, Ministry of Education of China, Shanghai (China)

    2015-10-15

    Highlights: • A method for the alignment between TB and HCB based on localizability is proposed. • A localization method based on the localizability estimation is proposed to realize the cask's localization accurately and ensures the transfer cask's accurate docking in the front of the window of Tokmak Building. • The experimental results show that the proposed algorithm works well in the indoor simulation environment. This system will be test in EAST of China. - Abstract: According to the long length characteristics of transfer cask compared to the environment space between Tokmak Building (TB) and HCB (Hot Cell Building), this paper proposes an autonomous localization and alignment method for the internal components transportation and replacement. A localization method based on the localizability estimation is used to realize the cask's localization and navigation accurately. Once the cask arrives at the front of the TB window, the position and attitude measurement system is used to detect the relative alignment error between the seal door of pallet and the window of TB real-time. The alignment between seal door and TB window could be realized based on this offset. The simulation experiment based on the real model is designed according to the real TB situation. The experiment results show that the proposed localization and alignment method can be used for transfer cask.

  4. Optimisation of VSC-HVDC Transmission for Wind Power Plants

    DEFF Research Database (Denmark)

    Silva, Rodrigo Da

    Connection of Wind Power Plants (WPP), typically oshore, using VSCHVDC transmission is an emerging solution with many benefits compared to the traditional AC solution, especially concerning the impact on control architecture of the wind farms and the grid. The VSC-HVDC solution is likely to meet...... more stringent grid codes than a conventional AC transmission connection. The purpose of this project is to analyse how HVDC solution, considering the voltage-source converter based technology, for grid connection of large wind power plants can be designed and optimised. By optimisation, the project...... the requirements established by the operators in the multiterminal VSC-HVDC transmission system. Moreover, the possibility in minimising the overall transmission losses can be a solution for small grids and the minimisation in the dispatch error is a new solution for power deliver maximisation. The second study...

  5. TRANSPORTATION CASK RECEIPT AND RETURN FACILITY WORKER DOSE ASSESSMENT

    Energy Technology Data Exchange (ETDEWEB)

    V. Arakali

    2005-02-24

    The purpose of this design calculation is to estimate radiation doses received by personnel working in the Transportation Cask Receipt and Return Facility (TCRRF) of the repository including the personnel at the security gate and cask staging areas. This calculation is required to support the preclosure safety analysis (PCSA) to ensure that the predicted doses are within the regulatory limits prescribed by the U.S. Nuclear Regulatory Commission (NRC). The Cask Receipt and Return Facility receives NRC licensed transportation casks loaded with spent nuclear fuel (SNF) and high-level radioactive waste (HLW). The TCRRF operation starts with the receipt, inspection, and survey of the casks at the security gate and the staging areas, and proceeds to the process facilities. The transportation casks arrive at the site via rail cars or trucks under the guidance of the national transportation system. This calculation was developed by the Environmental and Nuclear Engineering organization and is intended solely for the use of Design and Engineering in work regarding facility design. Environmental and Nuclear Engineering personnel should be consulted before using this calculation for purposes other than those stated herein or for use by individuals other than authorized personnel in the Environmental and Nuclear Engineering organization.

  6. 基于电压控制特性的电压源型多端直流/交流系统潮流求解%Power Flow Solving of VSC Multi-terminal DC/AC System Based on Voltage Control Characteristics

    Institute of Scientific and Technical Information of China (English)

    杨堤; 程浩忠; 姚良忠; 曾平良

    2016-01-01

    The voltage source converter based high voltage direct current (VSC-HVDC) transmission technology has good application prospects owing to its excellent controllability,voltage stability and good adaptability to power supply for load center,wind power accommodation,and power transmission among islands.The present research on power flow of VSC-HVDC system is mostly based on constant power control mode without considering the practical converter voltage control characteristics.In order to more accurately reflect the voltage control characteristics of VSC in the actual power grid,a voltage control model based on VSC is developed.As well,converter loss,AC filter,and converter capacity limit are considered in the power flow model.And a general power flow algorithm is proposed for power flow of the VSC based multi-terminal DC/AC system.Some cases with changed DC grid power injection,N -1 contingency and multi-terminal DC/AC system,are built and analyzed.The case analysis indicates that the power flow algorithm is able to reflect the voltage control ability of DC converters,while verifying the effectiveness,rationality and algorithm rapidity based on voltage control characteristics.%由于基于电压源型换流器的高压直流(VSC-HVDC)输电技术具有良好的可控性,对负荷中心供电、风电消纳、孤岛电力传输等适应能力强,电压稳定性好,因此具有良好的应用前景。当前对VSC-HVDC 系统主要基于定功率控制模式进行潮流计算,而很少考虑到实际的换流器电压控制能力。为了更加精确地反映实际电网中 VSC 的电压控制特性,文中建立了基于 VSC 的电压控制模型,考虑了换流器损耗、交流滤波器、换流器容量限制等的影响,并基于电压控制特性提出了 VSC多端直流/交流系统的通用潮流求解方法。对直流电网功率分布变化和 N -1故障以及多端直流/交流系统的潮流算例分析表明,所提的潮流算法能够反

  7. 77 FR 24585 - List of Approved Spent Fuel Storage Casks: HI-STORM 100, Revision 8

    Science.gov (United States)

    2012-04-25

    ... 3150-AJ05 List of Approved Spent Fuel Storage Casks: HI-STORM 100, Revision 8 AGENCY: Nuclear... amends the NRC's spent fuel storage regulations by revising the Holtec International HI-STORM 100 System... International HI-STORM 100 System listing within the ``List of Approved Spent Fuel Storage Casks'' to...

  8. LCC与VSC混联型多端高压直流输电系统运行特性的仿真研究%Simulation research on operation characteristics of hybrid multi-terminal HVDC system with LCC and VSC

    Institute of Scientific and Technical Information of China (English)

    雷霄; 王华伟; 曾南超; 闫朝; 谢国平; 李新年; 吴楠

    2013-01-01

    设计了由五个LCC换流站和一个VSC站组成的串并联混合型六端高压直流输电系统,该结构能发挥不同电压等级的LCC换流站以及VSC换流站的优势,扩展多端直流输电的应用范围.本文基于PSCAD/EMTDC平台建立该系统单极仿真模型,进行了稳态运行和暂态故障过程的相关研究,设计了直流功率协调控制器实现各换流站功率的协调控制,并提出了单换流站紧急停运的控制保护配合方法,仿真结果表明混联多端系统的可行性及控制保护策略的有效性.%A hybrid multi-terminal HVDC system consisting of five LCC converter stations and one VSC station is designed. This configuration can exploit the advantages both of LCC and VSC on different voltage levels to the full, and can extend the range of MTDC. A monopole model is built based on EMTDC/PSCAD, and the stable operation and transient faulty process of parallel multi-terminal HVDC system are studied. The DC power balance controller is worked out to achieve power cooperative control between converter stations. The control and protection coordinative sequences for emergency stop of one station is put forward, and simulation results prove the practicability of this configuration and the efficiency of the strategy.

  9. Electromechanical Transient Modeling and Simulation for Voltage Source Converter Based HVDC Power Transmission%VSC-HVDC机电暂态仿真建模及仿真

    Institute of Scientific and Technical Information of China (English)

    刘昇; 徐政; 唐庚; 华文; 薛英林

    2013-01-01

    Based on the fundamental frequency mathematical model of VSC-HVDC power transmission in d-q rotating dq rotary coordinate system, the electromechanical transient mathematical equations of VSC-HVDC power transmission are summarized, afterwards a electromechanical transient model for VSC-HVDC power transmission is achieved based on user-defined function of PSS/E and the achieved model is compared with the precise electromagnetic transient model for VSC-HVDC power transmission in PSCAD, and simulation results show that the steady state power flows from the two models are very similar and their dynamic characteristics are highly consistent each other, thus the effectiveness and accuracy of the achieved electromechanical transient model for VSC-HVDC power transmission are verified. Finally, using the achieved model the application of VSC-HVDC power transmission in actual large-scale multi-infeed HVDC power transmission system is researched, and research results show that using VSC-HVDC power transmission technology the commutation failure occurred in traditional HVDC power transmission system can be radically resolved.%  以VSC-HVDC在dq旋转坐标系下的基频数学模型为基础,总结了 VSC-HVDC 的机电暂态数学方程。之后基于 PSS/E 自定义模型功能实现了 VSC-HVDC 机电暂态模型,并将该模型和PSCAD中VSC-HVDC电磁暂态精确模型进行了对比,仿真结果表明两者的稳态潮流十分接近,动态特性具有很好的一致性,从而验证了VSC-HVDC机电暂态模型的有效性和准确性。最后基于该模型对VSC-HVDC 在实际大规模多直流馈入系统中的应用进行了研究,结果表明 VSC-HVDC 从根本上解决了传统直流输电的换相失败问题。

  10. Sodium-cooled LMFBR cask recommendations

    Energy Technology Data Exchange (ETDEWEB)

    1977-01-01

    In April of 1970 a design study to establish the parameters of a shipping cask for LMFBR Spent Fuel Assemblies from FFTF and the first demonstration plant was initiated. The basic criteria presented were that the cask should be limited to 75 tons, and that the cask should be compatible with the FFTF Fuel Assembly design and the first demonstration LMFBR Fuel Assembly design. Several features of the I-(182)-1 cask and their basis are described.

  11. Results for the Aboveground Configuration of the Boiling Water Reactor Dry Cask Simulator

    Energy Technology Data Exchange (ETDEWEB)

    Durbin, Samuel G. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lindgren, Eric R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-09-30

    The thermal performance of commercial nuclear spent fuel dry storage casks is evaluated through detailed numerical analysis. These modeling efforts are completed by the vendor to demonstrate performance and regulatory compliance. The calculations are then independently verified by the Nuclear Regulatory Commission (NRC). Carefully measured data sets generated from testing of full-sized casks or smaller cask analogs are widely recognized as vital for validating these models. Recent advances in dry storage cask designs have significantly increased the maximum thermal load allowed in a cask, in part by increasing the efficiency of internal conduction pathways, and also by increasing the internal convection through greater canister helium pressure. These same canistered cask systems rely on ventilation between the canister and the overpack to convect heat away from the canister to the environment for both above- and below-ground configurations. While several testing programs have been previously conducted, these earlier validation attempts did not capture the effects of elevated helium pressures or accurately portray the external convection of above-ground and below-ground canistered dry cask systems. The purpose of the current investigation was to produce data sets that can be used to test the validity of the assumptions associated with the calculations used to determine steady-state cladding temperatures in modern dry casks that utilize elevated helium pressure in the sealed canister in an above-ground configuration.

  12. VSC-HVDC for Enhancing the Power System Frequency and Voltage Stability in the Same Time%电压源换流器直流输电提高系统频率和电压稳定

    Institute of Scientific and Technical Information of China (English)

    郭丽

    2009-01-01

    将基于电压源换流器高压直流输电系统(VSC-HVDC)引入到交流系统中,建立了含有VSC-HVDC的电力系统的仿真模型,导出了相应的数学模型,利用VSC-HVDC能同时对有功功率和无功功率进行快速控制的特点来提高系统频率和电压稳定性.利用仿真软件进行了仿真,结果表明在负荷恢复时采用VSC-HVDC与发电机协调控制比传统调频调压方法更有利于提高电网的恢复速度和稳定性.

  13. Modelling and Simulation of VSC-HVDC Connection for Wind Power Plants

    DEFF Research Database (Denmark)

    Chaudhary, Sanjay Kumar; Teodorescu, Remus; Rodriguez, Pedro;

    2009-01-01

    This paper describes the modelling and simulation of offshore wind power plants (WPP) connected to the onshore power system grid by VSC based HVDC transmission. Offshore wind power plant is modelled with several wind turbine generators connected to two separate collector buses with their own plant...... step-up transformers. VSC's are modelled using ideal IGBT switches supplied by the gate pulses from their respective controllers. A sequence of operation has been simulated from the starting up of the VSC-HVDC transmission, energizing the offshore grid and subsequent synchronization of the individual...... wind turbines. Simulation of power ramping up and down as well as steady state operation has been demonstrated. As an additional case, the primary reserve control logic has been implemented and simulated in PSCAD model....

  14. Fault Current Contribution from VSC-based Wind Turbines to the Grid

    DEFF Research Database (Denmark)

    Iov, Florin; Valentini, Massimo; Akhmatov, V.

    2008-01-01

    current injections during the fault. In this paper an equivalent VSC-based wind turbine model for short-circuit calculations at steady-state conditions is developed and presented. The model is implemented in DigSILENT PowerFactory using the DPL-Programming Language. The developed wind turbine model...... Power. The wind turbine model is finally rescaled to obtain an aggregate wind farm model and used to perform short-circuit calculations in a realistic scenario; the Danish transmission system is considered and a large offshore wind farm with VSC-based wind turbines is included in the investigation....

  15. A novel protection method for VSC-HVDC transmission lines using single-end zero-mode current%利用零模电流的VSC-HVDC输电线路单端量保护原理研究

    Institute of Scientific and Technical Information of China (English)

    宋国兵; 冉孟兵; 靳幸福; 齐倩; 刘甜; 万青

    2014-01-01

    电压源换流器型直流输电(Voltage Source Converter HVDC,VSC-HVDC)控制系统复杂,故障承受能力差,研究适用于VSC-HVDC系统的高性能保护十分必要。分析了三相两电平VSC-HVDC系统的结构特性及VSC-HVDC系统的零模网络,并在此基础上提出了一种单端电气量保护。该方法仅需单端电流量,对直流线路一端正负极电流之和进行积分得到零模电流,根据零模电流的幅值大小可以判断出区内单极故障,适用于正负极对称运行的三相两电平 VSC-HVDC系统。算法简单可行,在时域进行,计算量小,对采样率要求低。利用PSCAD搭建VSC-HVDC系统进行仿真,仿真结果表明,该原理能够快速可靠地动作区内单极故障。%As the control system of Voltage Source Converter HVDC(VSC-HVDC) is very complex, its resistance to fault is poor. It’s necessary to do research on the protection of VSC-HVDC. This paper analyzes the structural characteristics and zero-mode network of VSC-HVDC, and proposes a single-end protection further. The proposed method needs only single-end zero-mode current which is obtained by integrating the sum of negative pole and positive pole currents. And the amplitude is used to distinguish internal single-pole-to-ground fault. The method applies to three-phase two-level VSC-HVDC system at positive and negative pole symmetrical operation status. The algorithm is very simple and implemented in time domain, needs fewer amount of computations, and its sampling frequency is lower. The PSCAD is used for fault simulation. Simulation results show that the proposed protection principle can find the internal single-pole-to-ground fault reliably and rapidly.

  16. An Interline DC Power Flow Controller Suitable for VSC-MTDC Systems%适用于多端柔性直流输电系统的直流潮流控制器

    Institute of Scientific and Technical Information of China (English)

    陈武; 朱旭; 姚良忠; 吴小刚; 蒋玮; 曹远志

    2015-01-01

    This paper focuses on the technology of direct current(DC) power flow control suitable for voltage source converter based multi-terminal high voltage DC(VSC-MTDC) systems.Based on an analysis of existing DC power flow controllers,a novel interline DC power flow controller (IDCPFC) is proposed for VSC-MTDC systems,which has the benefit of simpler circuit topology,fewer components and no external power supply needed.A three-terminal high voltage DC system including the IDCPFC is studied and its operation principle and characteristics are analyzed.Finally,steady state,dynamic state and fault condition simulations are performed with PSCAD/EMTDC to validate the feasibility of the proposed IDCPFC.The results show that the proposed IDCPFC can effectively realize DC power flow control. This work is supported by National Natural Science Foundation of China(No.5 1307024),Ph.D.Programs Foundation of Ministry of Education of China (No. 20120092120053), Fundamental Research Funds for the Central Universities (No.2242014R30018),Scientific Research Foundation for Returned Overseas Chinese Scholars,Ministry of Education of China,Jiangsu Province“Six Talent Peaks" Project(No.JNHB-01 5),and State Grid Corporation of China.%重点关注适用于多端柔性直流输电系统的直流潮流控制技术,在分析已有直流潮流控制技术基础上,文中提出了一种适用于多端柔性直流输电系统的线间直流潮流控制器,其具有结构简单、所需元器件少以及无需外部电源等优点。对一个包含该线间直流潮流控制器的三端环网式直流输电系统进行研究,分析了该控制器的工作原理及运行特性。在 PSCAD/EMTDC 中搭建了该系统的仿真模型,对其进行稳态、动态以及故障情况下的仿真验证。仿真结果表明,该线间直流潮流控制器在多种工况下都可以有效地实现直流潮流控制,并保持良好的稳定性。

  17. Frequency Regulation Strategies in Grid Integrated Offshore Wind Turbines via VSC-HVDC Technology: A Review

    Directory of Open Access Journals (Sweden)

    Jafar Jallad

    2017-08-01

    Full Text Available The inclusion of wind energy in a power system network is currently seeing a significant increase. However, this inclusion has resulted in degradation of the inertia response, which in turn seriously affects the stability of the power system’s frequency. This problem can be solved by using an active power reserve to stabilize the frequency within an allowable limit in the event of a sudden load increment or the loss of generators. Active power reserves can be utilized via three approaches: (1 de-loading method (pitching or over-speeding by a variable speed wind turbine (VSWT; (2 stored energy in the capacitors of voltage source converter-high voltage direct current (VSC-HVDC transmission; and (3 coordination of frequency regulation between the offshore wind farms and the VSC-HVDC transmission. This paper reviews the solutions that can be used to overcome problems related to the frequency stability of grid- integrated offshore wind turbines. It also details the permanent magnet synchronous generator (PMSG with full-scale back to back (B2B converters, its corresponding control strategies, and a typical VSC-HVDC system with an associated control system. The control methods, both on the levels of a wind turbine and the VSC-HVDC system that participate in a system’s primary frequency control and emulation inertia, are discussed.

  18. Computationally Efficient Transient Stability Modeling of multi-terminal VSC-HVDC

    DEFF Research Database (Denmark)

    van der Meer, Arjen A; Rueda-Torres, José; Silva, Filipe Miguel Faria da

    2016-01-01

    . The accuracy comparison is conducted by qualitative time-domain analysis taking the state-space model as a reference whereas the computational aspects are investigated by the respective execution times. The models are demonstrated on a three VSC terminal, two synchronous area system. It is shown...

  19. Thermoelectric Powered Wireless Sensors for Dry-Cask Storage

    Science.gov (United States)

    Carstens, Thomas Alan

    This study focuses on the development of self-powered wireless sensors. These sensors can be used to measure key parameters in extreme environments; e.g., temperature monitoring for spent nuclear fuel during dry-cask storage. This study has developed a design methodology for these self-powered monitoring systems. The main elements that constitute this work consist of selecting and testing a power source for the wireless sensor, determination of the attenuation of the wireless signal, and testing the wireless sensor circuitry in an extreme environment. OrigenArp determined the decay heat and gamma/neutron source strength of the spent fuel throughout the service life of the dry-cask. A first principles analysis modeled the temperatures inside the dry-cask. A finite-element heat transfer code calculated the temperature distribution of the thermoelectric and heat sink. The temperature distributions determine the power produced by the thermoelectric. It was experimentally verified that a thermoelectric generator (HZ-14) with a DC/DC converter (Linear Technology LTC3108EDE) can power a transceiver (EmbedRF) at condition which represent prototypical conditions throughout and beyond the service life of the dry-cask. The wireless sensor is required to broadcast with enough power to overcome the attenuation from the dry-cask. It will be important to minimize the attenuation of the signal in order to broadcast with a small transmission power. To investigate the signal transmission through the dry-cask, CST Microwave Studio was used to determine the scattering parameter S2,1 for a horizontal dry-cask. Important parameters that can influence the transmission of the signal are antenna orientation, antenna placement, and transmission frequency. The thermoelectric generator, DC/DC converter, and transceiver were exposed to 60Co gamma radiation (exposure rate170.3 Rad/min) at the University of Wisconsin Medical Radiation Research Center. The effects of gamma radiation on the

  20. COMPILATION OF DISPOSABLE SOLID WASTE CASK EVALUATIONS

    Energy Technology Data Exchange (ETDEWEB)

    THIELGES, J.R.; CHASTAIN, S.A.

    2007-06-21

    The Disposable Solid Waste Cask (DSWC) is a shielded cask capable of transporting, storing, and disposing of six non-fuel core components or approximately 27 cubic feet of radioactive solid waste. Five existing DSWCs are candidates for use in storing and disposing of non-fuel core components and radioactive solid waste from the Interim Examination and Maintenance Cell, ultimately shipping them to the 200 West Area disposal site for burial. A series of inspections, studies, analyses, and modifications were performed to ensure that these casks can be used to safely ship solid waste. These inspections, studies, analyses, and modifications are summarized and attached in this report. Visual inspection of the casks interiors provided information with respect to condition of the casks inner liners. Because water was allowed to enter the casks for varying lengths of time, condition of the cask liner pipe to bottom plate weld was of concern. Based on the visual inspection and a corrosion study, it was concluded that four of the five casks can be used from a corrosion standpoint. Only DSWC S/N-004 would need additional inspection and analysis to determine its usefulness. The five remaining DSWCs underwent some modification to prepare them for use. The existing cask lifting inserts were found to be corroded and deemed unusable. New lifting anchor bolts were installed to replace the existing anchors. Alternate lift lugs were fabricated for use with the new lifting anchor bolts. The cask tiedown frame was modified to facilitate adjustment of the cask tiedowns. As a result of the above mentioned inspections, studies, analysis, and modifications, four of the five existing casks can be used to store and transport waste from the Interim Examination and Maintenance Cell to the disposal site for burial. The fifth cask, DSWC S/N-004, would require further inspections before it could be used.

  1. Genetics Home Reference: CASK-related intellectual disability

    Science.gov (United States)

    ... Conditions CASK-related intellectual disability CASK-related intellectual disability Printable PDF Open All Close All Enable Javascript ... the expand/collapse boxes. Description CASK -related intellectual disability is a disorder of brain development that has ...

  2. Harmonic Analysis of VSC-HVDC%VSC-HVDC的谐波分析

    Institute of Scientific and Technical Information of China (English)

    胡弢

    2009-01-01

    基于电压源换流器的高压直流输电技术(VSC-HVDC)已经在电力系统中得到了应用.针对采用双闭环解耦控制的VSC-HVDC,对其谐渡产生机理进行了详细的理论分析和数学推导,并针对分析结果提出了变调制度的谐波抑制措施:通过Matlab/Simulink(建立了VSC-HVDC供电有源系统的仿真模型,仿真结果验证了理论分析的正确性和谐波抑制措施的有效性.

  3. Neuron-specific protein interactions of Drosophila CASK-b are revealed by mass spectrometry

    Directory of Open Access Journals (Sweden)

    Konark eMukherjee

    2014-06-01

    Full Text Available Modular scaffolding proteins are designed to have multiple interactors. CASK, a member of the membrane-associated guanylate kinase (MAGUK superfamily, has been shown to have roles in many tissues, including neurons and epithelia. It is likely that the set of proteins it interacts with is different in each of these diverse tissues. In this study we asked if within the Drosophila central nervous system, there were neuron-specific sets of CASK-interacting proteins. A YFP-tagged CASK transgene was expressed in genetically defined subsets of neurons in the Drosophila brain known to be important for CASK function, and proteins present in an anti-GFP immunoprecipitation were identified by mass spectrometry. Each subset of neurons had a distinct set of interacting proteins, suggesting that CASK participates in multiple protein networks and that these networks may be different in different neuronal circuits. One common set of proteins was associated with mitochondria, and we show here that endogenous CASK co-purifies with mitochondria. We also determined CASK posttranslational modifications for one cell type, supporting the idea that this technique can be used to assess cell- and circuit-specific protein modifications as well as protein interaction networks.

  4. Test Plan for Cask Identification Detector

    Energy Technology Data Exchange (ETDEWEB)

    Rauch, Eric Benton [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-09-29

    This document serves to outline the testing of a Used Fuel Cask Identification Detector (CID) currently being designed under the DOE-NE MPACT Campaign. A bench-scale prototype detector will be constructed and tested using surrogate neutron sources. The testing will serve to inform the design of the full detector that is to be used as a way of fingerprinting used fuel storage casks based on the neutron signature produced by the used fuel inside the cask.

  5. Radioactive fuel cask railcar humping study

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, L.T. (comp.)

    1978-01-01

    The response of two radioactive shipping casks due to railroad humping shocks was calculated using a spring-mass model. The two railcars for these casks had different coupling mechanisms and different tiedown arrangements. Humping tests had been performed on one of the railcars (ATMX-600) and the resulting shock spectra was used to adjust the spring-mass model to get matching results. One car (designed for cask shipment) was equipped with Freightmaster E-15 end of car coupler and had about /sup 1///sub 8/ in. free travel of the cask skid relative to the car. The other car (ATMX-600), equipped with Miner RF-333 draft gear, was designed for nuclear weapon shipment and adapted to nuclear waste shipment by fastening the casks to the floor. Both car frames were built by the same manufacturer and are very similar. The response of the casks was put in shock spectra format and a parametric study was performed with various cask weights. Additional studies were done on the effects of fastening the loose cask, and using the Freightmaster end of car coupler on the ATMX car. Half-sine response spectra were overlaid to include the natural frequency of the cask tiedown. The resulting shock amplitude was plotted against the cask weight for each car. The results show a constant acceleration level for all the weights on the car with hydraulic end-of-car coupler which results from constant force at that impact velocity. The cask acceleration can be reduced by fastening it to the car, rather than allowing it to move freely through some small space. This study also shows that the cask response can be optimized on railcars without hydraulic draft gear by adjusting the tiedown stiffness to keep the tiedown frequency different than car frequencies.

  6. Used Fuel Cask Identification through Neutron Profile

    Energy Technology Data Exchange (ETDEWEB)

    Rauch, Eric Benton [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-11-20

    Currently, most spent fuel is stored near reactors. An interim consolidated fuel storage facility would receive fuel from multiple sites and store it in casks on site for decades. For successful operation of such a facility there is need for a way to restore continuity of knowledge if lost as well as a method that will indicate state of fuel inside the cask. Used nuclear fuel is identifiable by its radiation emission, both gamma and neutron. Neutron emission from fission products, multiplication from remaining fissile material, and the unique distribution of both in each cask produce a unique neutron signature. If two signatures taken at different times do not match, either changes within the fuel content or misidentification of a cask occurred. It was found that identification of cask loadings works well through the profile of emitted neutrons in simulated real casks. Even casks with similar overall neutron emission or average counts around the circumference can be distinguished from each other by analyzing the profile. In conclusion, (1) identification of unaltered casks through neutron signature profile is viable; (2) collecting the profile provides insight to the condition and intactness of the fuel stored inside the cask; and (3) the signature profile is stable over time.

  7. Structural analysis of a metal spent-fuel storage cask in an aircraft crash for risk assessment

    Energy Technology Data Exchange (ETDEWEB)

    Almomani, Belal, E-mail: balmomani@kaist.ac.kr [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Lee, Sanghoon, E-mail: shlee1222@kmu.ac.kr [Department of Mechanical and Automotive Engineering, Keimyung University, Dalgubeol-daero 1095, Dalseo-gu, Daegu (Korea, Republic of); Kang, Hyun Gook, E-mail: hyungook@kaist.ac.kr [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)

    2016-11-15

    Highlights: • Several engine-applied loads with different locations of impact on the storage cask body were implemented. • Cask structural responses due to the influence of engine impact loadings were analyzed. • Leakage path areas from lid closure openings were numerically calculated. • Release fractions that depend on the generated seal opening areas and fuel damage ratios were estimated. - Abstract: Evaluations of the impact resistance of a dry storage cask under mechanical impact loadings resulting from a large commercial aircraft crash have become an important issue for designers and evaluators, in order to promote interim dry storage activities and to evaluate design safety margins. This study presents a method to evaluate the structural integrity of a generic metal cask subjected to various mechanical loading conditions, which represent aircraft engine impacts, on different locations of the cask body. Thirty representative impact conditions are analyzed to provide a comprehensive evaluation of cask damage response. The applied engine impact load–time functions were carefully re-derived by utilizing CRIEPI’s proposed curve through Riera’s approach for six impact velocities, and applied to five locations on a freestanding cask: lateral impacts on the lower half, center of gravity, and upper half of the cask body, corner impact on the lid closure, and vertical impact on the center of the lid closure. A nonlinear dynamic finite element analysis is performed to evaluate the dynamic response of the cask lid closure system and to calculate the lid gaps. The release fractions from the cask to the environment for each impact condition are preliminarily estimated by referring to a proposed methodology from literature. It is believed that this paper presents a systematic process to connect the mechanical analysis of a cask response at the moment of aircraft engine impact with its radiological consequence analysis.

  8. Seismic Performance of Dry Casks Storage for Long- Term Exposure

    Energy Technology Data Exchange (ETDEWEB)

    Ibarra, Luis [Univ. of Utah, Salt Lake City, UT (United States); Sanders, David [Univ. of Nevada, Reno, NV (United States); Yang, Haori [Oregon State Univ., Corvallis, OR (United States); Pantelides, Chris [Univ. of Utah, Salt Lake City, UT (United States)

    2016-12-30

    The main goal of this study is to evaluate the long-term seismic performance of freestanding and anchored Dry Storage Casks (DSCs) using experimental tests on a shaking table, as well as comprehensive numerical evaluations that include the cask-pad-soil system. The study focuses on the dynamic performance of vertical DSCs, which can be designed as free-standing structures resting on a reinforced concrete foundation pad, or casks anchored to a foundation pad. The spent nuclear fuel (SNF) at nuclear power plants (NPPs) is initially stored in fuel-storage pools to control the fuel temperature. After several years, the fuel assemblies are transferred to DSCs at sites contiguous to the plant, known as Interim Spent Fuel Storage Installations (ISFSIs). The regulations for these storage systems (10 CFR 72) ensure adequate passive heat removal and radiation shielding during normal operations, off-normal events, and accident scenarios. The integrity of the DSCs is important, even if the overpack does not breach, because eventually the spent fuel-rods need to be shipped either to a reprocessing plant or a repository. DSCs have been considered as a temporary storage solution, and usually are licensed for 20 years, although they can be relicensed for operating periods of up to 60 years. In recent years, DSCs have been reevaluated as a potential mid-term solution, in which the operating period may be extended for up to 300 years. At the same time, recent seismic events have underlined the significant risks DSCs are exposed. The consideration of DCSs for storing spent fuel for hundreds of years has created new challenges. In the case of seismic hazard, longer-term operating periods not only lead to larger horizontal accelerations, but also increase the relative effect of vertical accelerations that usually are disregarded for smaller seismic events. These larger seismic demands could lead to casks sliding and tipping over, impacting the concrete pad or adjacent casks. The casks

  9. Criticality Safety Analysis Of As-loaded Spent Nuclear Fuel Casks

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, Kaushik [ORNL; Scaglione, John M [ORNL

    2015-01-01

    The final safety analysis report (FSAR) or the safety analysis report (SAR) for a particular spent nuclear fuel (SNF) cask system documents models and calculations used to demonstrate that a system meets the regulatory requirements under all normal, off-normal, and accident conditions of spent fuel storage, and normal and accident conditions of transportation. FSAR/SAR calculations and approved content specifications are intended to be bounding in nature to certify cask systems for a variety of fuel characteristics with simplified SNF loading requirements. Therefore, in general, loaded cask systems possess excess and uncredited criticality margins (i.e., the difference between the licensing basis and the as-loaded calculations). This uncredited margin could be quantified by employing more detailed cask-specific evaluations that credit the actual as-loaded cask inventory, and taking into account full (actinide and fission product) burnup credit. This uncredited criticality margin could be potentially used to offset (1) uncertainties in the safety basis that needs to account for the effects of system aging during extended dry storage prior to transportation, and (2) increases in SNF system reactivity over a repository performance period (e.g., 10,000 years or more) as the system undergoes degradation and internal geometry changes. This paper summarizes an assessment of cask-specific, as-loaded criticality margins for SNF stored at eight reactor sites (215 loaded casks were analyzed) under fully flooded conditions to assess the margins available during transportation after extended storage. It is observed that the calculated keff margin varies from 0.05 to almost 0.3 Δkeff for the eight selected reactor sites, demonstrating that significant uncredited safety margins are present. In addition, this paper evaluates the sufficiency of this excess margin in applications involving direct disposal of currently loaded SNF casks.

  10. Criticality Safety Analysis Of As-loaded Spent Nuclear Fuel Casks

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, Kaushik [ORNL; Scaglione, John M [ORNL

    2015-01-01

    The final safety analysis report (FSAR) or the safety analysis report (SAR) for a particular spent nuclear fuel (SNF) cask system documents models and calculations used to demonstrate that a system meets the regulatory requirements under all normal, off-normal, and accident conditions of spent fuel storage, and normal and accident conditions of transportation. FSAR/SAR calculations and approved content specifications are intended to be bounding in nature to certify cask systems for a variety of fuel characteristics with simplified SNF loading requirements. Therefore, in general, loaded cask systems possess excess and uncredited criticality margins (i.e., the difference between the licensing basis and the as-loaded calculations). This uncredited margin could be quantified by employing more detailed cask-specific evaluations that credit the actual as-loaded cask inventory, and taking into account full (actinide and fission product) burnup credit. This uncredited criticality margin could be potentially used to offset (1) uncertainties in the safety basis that needs to account for the effects of system aging during extended dry storage prior to transportation, and (2) increases in SNF system reactivity over a repository performance period (e.g., 10,000 years or more) as the system undergoes degradation and internal geometry changes. This paper summarizes an assessment of cask-specific, as-loaded criticality margins for SNF stored at eight reactor sites (215 loaded casks were analyzed) under fully flooded conditions to assess the margins available during transportation after extended storage. It is observed that the calculated keff margin varies from 0.05 to almost 0.3 Δkeff for the eight selected reactor sites, demonstrating that significant uncredited safety margins are present. In addition, this paper evaluates the sufficiency of this excess margin in applications involving direct disposal of currently loaded SNF casks.

  11. Application of VSC-HVDC with Shunt Connected SMES for Compensation of Power Fluctuation

    Science.gov (United States)

    Linn, Zarchi; Kakigano, Hiroaki; Miura, Yushi; Ise, Toshifumi

    This paper describes the application of VSC-HVDC (High Voltage DC Transmission using Voltage Source Converter) with shunt connected SMES (Superconducting Magnetic Energy Storage) for compensation of power fluctuation caused by fluctuating power source such as photovoltaics and wind turbines. The objectives of this proposed system is to smooth out fluctuating power in one terminal side of HVDC in order to avoid causing power system instability and frequency deviation by absorbing or providing power according to the system requirement while another terminal side power is fluctuated. The shunt connected SMES charges and discharges the energy to and from the dc side and it compensates required power of fluctuation to obtain constant power flow in one terminal side of VSC-HVDC system. This system configuration has ability for power system stabilization in the case of power fluctuation from natural energy source. PSCAD/EMTDC simulation is used to evaluate the performance of applied system configuration and control method.

  12. Shielding Analysis of the 5320 Shipping Cask

    Energy Technology Data Exchange (ETDEWEB)

    Blanchard, A. [Westinghouse Savannah River Company, AIKEN, SC (United States); Nathan, S. [Westinghouse Safety Management Solutions, Aiken, SC (United States)

    1998-05-01

    The purpose of this work is to demonstrate that the 5320 shipping cask meets Federal regulations for maximum radiation dose rates when loaded with the intended plutonium oxide cargo. It should be emphasized that the 5320 is an existing cask, and therefore this work represents confirmatory analysis rather than design analysis.

  13. Evaluation of FSV-1 cask for the transport of LWR irradiated fuel assemblies

    Energy Technology Data Exchange (ETDEWEB)

    1980-05-01

    The Model FSV-1 spent fuel shipping cask was designed by General Atomic Company (GA) to service the Fort St. Vrain (FSV) nuclear generating station, a High Temperature Gas Reactor (HTGR) owned and operated by Public Service Company of Colorado (PSC). This report presents an evaluation of the suitability of the FSV-1 cask for the transport of irradiated Light Water Reactor (LWR) fuel assemblies from both Pressurized Water Reactors (PWR) and Boiling Water Reactors (BWR). The FSV-1 cask evaluation parameters covered a wide spectrum of LWR fuel assemblies, based on burnup in Megawatt Days/Metric Ton of Heavy Metal (MWD/MTHM) and years of decay since irradiation. The criteria for suitability included allowable radiation dose rates, cask surface and interior temperatures and the Gross Vehicle Weight (GVW) of the complete shipping system.

  14. Design review report FFTF interim storage cask

    Energy Technology Data Exchange (ETDEWEB)

    Scott, P.L.

    1995-01-03

    Final Design Review Report for the FFTF Interim Storage Cask. The Interim Storage Cask (ISC) will be used for long term above ground dry storage of FFTF irradiated fuel in Core Component Containers (CCC)s. The CCC has been designed and will house assemblies that have been sodium washed in the IEM Cell. The Solid Waste Cask (SWC) will transfer a full CCC from the IEM Cell to the RSB Cask Loading Station where the ISC will be located to receive it. Once the loaded ISC has been sealed at the RSB Cask Loading Station, it will be transferred by facility crane to the DSWC Transporter. After the ISC has been transferred to the Interim Storage Area (ISA), which is yet to be designed, a mobile crane will be used to place the ISC in its final storage location.

  15. Synthesis of a hybrid model of the VSC FACTS devices and HVDC technologies

    Science.gov (United States)

    Borovikov, Yu S.; Gusev, A. S.; Sulaymanov, A. O.; Ufa, R. A.

    2014-10-01

    The motivation of the presented research is based on the need for development of new methods and tools for adequate simulation of FACTS devices and HVDC systems as part of real electric power systems (EPS). The Research object: An alternative hybrid approach for synthesizing VSC-FACTS and -HVDC hybrid model is proposed. The results: the VSC- FACTS and -HVDC hybrid model is designed in accordance with the presented concepts of hybrid simulation. The developed model allows us to carry out adequate simulation in real time of all the processes in HVDC, FACTS devices and EPS as a whole without any decomposition and limitation on their duration, and also use the developed tool for effective solution of a design, operational and research tasks of EPS containing such devices.

  16. Performance of Four-Leg VSC based DSTATCOM using Single Phase P-Q Theory

    Science.gov (United States)

    Jampana, Bangarraju; Veramalla, Rajagopal; Askani, Jayalaxmi

    2016-06-01

    This paper presents single-phase P-Q theory for four-leg VSC based distributed static compensator (DSTATCOM) in the distribution system. The proposed DSTATCOM maintains unity power factor at source, zero voltage regulation, eliminates current harmonics, load balancing and neutral current compensation. The advantage of using four-leg VSC based DSTATCOM is to eliminate isolated/non-isolated transformer connection at point of common coupling (PCC) for neutral current compensation. The elimination of transformer connection at PCC with proposed topology will reduce cost of DSTATCOM. The single-phase P-Q theory control algorithm is used to extract fundamental component of active and reactive currents for generation of reference source currents which is based on indirect current control method. The proposed DSTATCOM is modelled and the results are validated with various consumer loads under unity power factor and zero voltage regulation modes in the MATLAB R2013a environment using simpower system toolbox.

  17. Performance of Four-Leg VSC based DSTATCOM using Single Phase P-Q Theory

    Science.gov (United States)

    Jampana, Bangarraju; Veramalla, Rajagopal; Askani, Jayalaxmi

    2017-02-01

    This paper presents single-phase P-Q theory for four-leg VSC based distributed static compensator (DSTATCOM) in the distribution system. The proposed DSTATCOM maintains unity power factor at source, zero voltage regulation, eliminates current harmonics, load balancing and neutral current compensation. The advantage of using four-leg VSC based DSTATCOM is to eliminate isolated/non-isolated transformer connection at point of common coupling (PCC) for neutral current compensation. The elimination of transformer connection at PCC with proposed topology will reduce cost of DSTATCOM. The single-phase P-Q theory control algorithm is used to extract fundamental component of active and reactive currents for generation of reference source currents which is based on indirect current control method. The proposed DSTATCOM is modelled and the results are validated with various consumer loads under unity power factor and zero voltage regulation modes in the MATLAB R2013a environment using simpower system toolbox.

  18. Steady-state model for simulating VSC based HVDC%VSC-HVDC的稳态模型仿真研究

    Institute of Scientific and Technical Information of China (English)

    张兴然; 王霞

    2007-01-01

    介绍了轻型直流输电(VSC-HVDC)技术的稳态运行特性,针对VSC-HVDC的稳态情况,设计了VSC-HVDC的控制策略,并基于PID控制原理设计了相应的控制器.仿真实验表明,该方法控制效果良好,对于故障情况能有很快的响应且稳定性良好.

  19. The System Commissioning of Nan’ao VSC-MTDC Demonstration Project%南澳多端柔性直流输电示范工程系统调试

    Institute of Scientific and Technical Information of China (English)

    魏伟; 许树楷; 李岩; 黎小林; 饶宏; 朱喆; 冯满盈; 陈俊

    2015-01-01

    南澳多端柔性直流输电示范工程的系统调试共完成了87个试验项目。功率阶跃试验显示,系统对换流器输出无功功率阶跃和有功功率阶跃的响应灵敏。功率反送试验、风电通过柔性直流并网试验和运行模式切换试验显示,南澳柔直工程能够适应各种工况运行。风电低电压穿越试验显示,该工程对交流电网故障具有较强的故障穿越能力。直流系统故障试验显示,故障后各站直流保护正确动作跳闸,控制保护功能正常。经调试检验,系统相关一、二次设备经调试检验总体符合设计要求,各项功能和性能指标满足工程设计规范要求。%A total of 87 test items has been completed in the system commissioning of Nan’ao VSC-MTDC Demonstration Project. The power step tests show that the system is sensitive to the reactive or active power step. The active power inversion test, wind power grid test and operation mode changeover test show that Nan’ao project can operate steady in all kinds of system conditions. The wind power LVRT test shows that the project has strong fault ride-through capability on AC grid failure. The DC system fault test shows that DC protections at each station have tripped correctly, their control and protection functions are proper. It is verified by the commissioning that the related primary equipment and secondary equipment can completely meet the design requirment, and the engineering functions and performance of the equipment are in agreement with the design specification.

  20. One-Terminal Fault Location for VSC-HVDC Transmission Lines Based on Principles of Parameter Identification%基于参数识别原理的VSC-HVDC输电线路单端故障定位

    Institute of Scientific and Technical Information of China (English)

    宋国兵; 李德坤; 褚旭; 饶菁; 蔡新雷

    2012-01-01

    为保障电压源换流器型直流输电(voltage source converter HVDC,VSC-HVDC)系统的可靠运行,提出一种基于参数识别原理的VSC-HVDC输电线路单端故障定位方法.由于VSC-HVDC输电线路两端并联大电容,识别故障距离的时候,在0模分量网络中可以把两端的换流站系统等效为电容,通过参数识别的原理列写出包含故障距离和过渡电阻2个未知参数的故障定位时域微分方程,通过最小二乘法优化求解该方程即可得到故障距离和过渡电阻,从而实现故障定位.PSCAD下的仿真结果表明,该方法能够实现VSC-HVDC输电线路的准确故障定位,最大测距误差不超过1%.该方法仅需要单端电气量就能实现准确故障定位,对采样频率的要求不高,理论上不受过渡电阻的影响,可以满足VSC-HVDC输电线路故障测距的要求.%To ensure reliable operation of voltage source converter HVDC (VSC-HVDC) transmission system, a one-terminal fault location method for VSC-HVDC transmission line is proposed. Because high-capacity capacitors are connected to both ends of VSC-HVDC transmission line, so during the fault location the converter station systems at both ends of VSC-HVDC transmission line can be equivalent to capacitors in the network of zero-mode component, and by means of the principle of parameter identification the differential equations in time-domain, which contains two unknown parameters of fault distance and transition resistance, can be listed, and solving this equation by least square optimization both fault distance and transition resistance can be attained, thus the fault location is implemented. The proposed method only needs single end electric quantities and is undemanding to sampling frequency, besides, theoretically this method is not affected by transition resistance, so it can meet the demand on fault location for VSC-HVDC transmission lines. Results of PSCAD simulation show that the proposed method can implement

  1. Cask Processing Enclosure Specification/Operation - 12231

    Energy Technology Data Exchange (ETDEWEB)

    Gentry, Ronald [Transuranic Waste Processing Center, Lenoir City TN, 37771 (United States)

    2012-07-01

    Following an evaluation of throughput rates in the Hot Cell at the Transuranic Waste Processing Center and considering the variability in the waste with respect to actual dose rates a new approach to processing transuranic waste was necessary. Compounding the issue was the remote equipment poor reliability and high down-time. After considering all the factors, the evaluation resulted in the design and construction of a new waste processing area for handling the concrete casks that predominately contain contact handled transuranic (TRU) waste. The area is called the Cask Processing Enclosure and essentially the Cask Processing Enclosure mimics the projects current process techniques used for processing Contact Handled -TRU waste in the existing Box Breakdown Area and Glovebox. The Cask Processing Enclosure approach was developed based on a review of the RH processing throughput rates in the Hot Cell. As the process was reviewed consideration was given to the variability in the waste with respect to actual dose rates and the lack of equipment reliability and high wear in the Hot Cell. Based on that review, a new contact handled processing area for handling the concrete casks is being constructed and startup is expected shortly following WM2012. The Cask Processing Enclosure essentially mimics the projects current process techniques used for processing Contact Handled waste in the existing Box Breakdown Area and Glovebox and the design takes into consideration six years of operational experience. (authors)

  2. 风电场向孤岛输电的VSC-HVDC Light的建模与仿真%Modelling and Simulation of VSC-HVDC Light for Electricity Transmission from Wind Farm to Solitary Island

    Institute of Scientific and Technical Information of China (English)

    谢海良; 王爱花; 赵君亮

    2014-01-01

    We introduced the operating principle and system of HVDC Light,which is based on the controlling of VSC. The simulation model of VSC-HVDC Light for electricity transmission from wind farm to solitary island by MATLAB is founded and simulated. The simulation result showed that system DC voltage value corresponds with the set value. The both ends of voltage value achieve coordination. Coordination control and self-banlancing transmission of active power are actualized. All quantities of states meet the theoretical value. The model accurately simulates the steady working condition of VSC-HVDC Light system,and offers the scientific basis for practical engineering.%介绍了以VSC控制为基础的HVDC Light的系统结构和工作原理,在MATLAB中创建了风电场向孤岛输电的VSC-HVDC Light系统仿真模型,并对其进行了稳态仿真研究。对仿真结果进行分析可知,系统直流电压基本稳定在给定的电压值,两端直流电压实现了协调配合,有功功率实现了协调控制和自动平衡传输,各状态量都符合理论值,模型准确模拟出了VSC-HVDC Light系统的稳态工作状况,为实际工程提供了科学的理论依据。

  3. Design and optimization of LCL-VSC grid-tied converter having short circuit fault current limiting ability

    Science.gov (United States)

    Liu, Mengqi; Liu, Haijun; Wang, Zhikai

    2017-01-01

    Traditional LCL grid-tied converters haven't the ability to limit the short-circuit fault current and only remove grid-connected converter using the breaker. However, the VSC converters become uncontrollable after the short circuit fault cutting off and the power switches may be damaged if the circuit breaker removes slowly. Compared to the filter function of the LCL passive components in traditional VSC converters, the novel LCL-VSC converter has the ability of limiting the short circuit fault current using the reasonable designed LCL parameters. In this paper the mathematical model of the LCL converter is established and the characteristics of the short circuit fault current generated by the ac side and dc side are analyzed. Thus one design and optimization scheme of the reasonable LCL passive parameter is proposed for the LCL-VSC converter having short circuit fault current limiting ability. In addition to ensuring the LCL passive components filtering the high-frequency harmonic, this scheme also considers the impedance characteristics to limit the fault current of AC and DC short circuit fault respectively flowing through the power switch no more than the maximum allowable operating current, in order to make the LCL converter working continuously. Finally, the 200kW simulation system is set up to prove the validity and feasibility of the theoretical analysis using the proposed design and optimization scheme.

  4. Current Compensation with Reduced Rating VSC and A ZIG – ZAG Transformer an A Three Phase Four-Wire Distribution System

    Directory of Open Access Journals (Sweden)

    P.Narasimhulu

    2014-09-01

    Full Text Available A reduced rating voltage-source converter with a zig-zag transformer as a distribution static compensator is proposed for power-quality improvement in the three-phase four-wire distribution system. The source voltages in the distribution systems are also experiencing power quality problems, such as harmonics, unbalance, flicker, sag, swell, etc. The distribution static compensator (DSTATCOM is proposed for compensating power quality problems in the current, and the dynamic voltage restorer (DVR is used for mitigating the power quality problems in the voltage. The zig-zag transformer is used for the neutral current compensation. Distribution systems are facing severe power-quality (PQ problems, such as poor voltage regulation, high reactive power and harmonics current burden, load unbalancing, excessive neutral current, etc. The zig-zag transformer is used for providing a path to the zero-sequence current. The DSTATCOM is used to improve the quality of power to the non linear loads. By using both zig-zag transformer and DSTATCOM in the distribution system the rating of the voltage source converter can be reduced. Hence it can be also called reduced rating device. The performance of the DSTATCOM is validated through extensive simulations using MATLAB software with its Simulink and power system block set toolboxes.

  5. Topology of Connecting Photovoltaic Power Station to Power Grid via VSC-HVDC and Its Control Strategy%光伏电站经VSC-HVDC并网拓扑及其控制策略

    Institute of Scientific and Technical Information of China (English)

    赵伟然; 李光辉; 何国庆; 石文辉; 徐青山

    2012-01-01

    In allusion to the mismatch between photovoltaic (PV) station and DC voltage class of voltage source converter-high voltage direct current (VSC-HVDC) system, a new topology of connecting PV station to power grid via VSC-HVDC and corresponding control strategy were proposed. The operational characteristics of PV station in the proposed grid-connecting scheme was researched and the control strategy for single PV generation unit and fault tolerant control strategy for the branch composed of cascade connected PV generation units were analyzed; to solve the problem that in the proposed topological structure the efficiency of cascade connected PV generation units was easy to be affected by unbalanced irradiance, an improved control strategy of voltage slope at DC side of voltage source converter (VSC) was put forward. The proposed control strategies were simulated under several typical irradiation conditions, and simulation results showed that the proposed control strategies were effective.%针对光伏发电与电压源换流器高压直流输电(voltage source converter-high voltage direct current,VSC-HVDC)系统直流电压等级不匹配问题,提出了一种新的光伏电站经VSC-HVDC并网拓扑和控制策略,研究了该并网方案中光伏电站的运行特性,分析了单个光伏发电单元的控制策略和串联光伏发电单元支路故障控制策略;针对该拓扑结构中串联光伏发电单元效率易受不均匀辐照度影响的问题,提出了改进的电压源换流器(voltage source converter,VSC)直流侧电压斜率控制策略.在几种典型辐射情况下进行仿真,结果验证了所提控制策略的有效性,表明该方案可解决VSC-HVDC技术应用于光伏发电并网所面临的电压等级匹配问题.

  6. Pengaruh Ritma Circadian Terhadap Produksi Volatile Sulfur Compounds (VSC Oral

    Directory of Open Access Journals (Sweden)

    Supriatno Supriatno

    2013-06-01

    of hydrogen sulfide (H2S, methyl mercaptan (CH3SH and dimethyl sulfide [(CH32S] gases. They are the main gases that cause halitosis. Circadian rhythm influenced the function of several organs of the human body including salivary secretion, hormone production, the body’s systems function, and activity of microorganisms. The purpose of this research is to examine the influence of circadian rhythm to oral VSC production measured by using a portable Oral Chroma. The research was carried-out by measuring the individual VSC gases in the morning, afternoon and evening at the integrated research laboratory, Faculty of Dentistry, UGM. Gases of H2S, CH3SH and (CH32S were tested by two-way ANOVA followed by Post-hoc LSD and Pearson correlation test with 95% significance level. The results showed the positive significant differences among the production of H2S, CH3SH and (CH32S with circadian time (p=0.000. Highly significant difference was also detected in amount of H2S and (CH32S gases in the morning, afternoon and evening (p=0.01 and p=0.00, as well as the amount of CH3SH gas in the afternoon and night (p=0.006, but not in amount of CH3SH gas in the morning (p=0.061. The highest production of H2S gas was known in the morning (mean 1.198 ng/10 ml, CH3SH gas was detected in the night (mean 0.099 ng/10 ml, and (CH32S gas was observed in the afternoon (mean 1.216 ng/10 ml. The strength of relationship among amount of three gases with circadian effects was r = 0.738. It is concluded that circadian rhythm markedly influences the production of oral VSCs. H2S and (CH32S gases production were significantly different among in the morning, afternoon and evening. However, amount of CH3SH gas production was significantly different only in the afternoon and the night. The highest gas production of H2S, CH3SH, and (CH32S was observed in the morning, in the night, and in the afternoon, respectively.

  7. Multiple-Angle Muon Radiography of a Dry Storage Cask

    Energy Technology Data Exchange (ETDEWEB)

    Durham, J. Matthew [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Guardincerri, Elena [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Morris, Christopher [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Poulson, Daniel Cris [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Bacon, Jeffrey Darnell [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Morley, Deborah Jean [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Plaud-Ramos, Kenie Omar [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-01-23

    A partially loaded dry storage cask was imaged using cosmic ray muons. Since the cask is large relative to the size of the muon tracking detectors, the instruments were placed at nine different positions around the cask to record data covering the entire fuel basket. We show that this technique can detect the removal of a single fuel assembly from the center of the cask.

  8. Cooling Performance Evaluation of the Hybrid Heat Pipe for Spent Nuclear Fuel Dry Storage Cask

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Yeong Shin; Bang, In Cheol [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    To evaluate the concept of the cooling device, 2-step CFD analysis was conducted for the cooling performance of hybrid heat pipe, which consists of single fuel assembly model and full scope dry cask model. As a passive cooling device of the metal cask for dry storage of spent nuclear fuel, hybrid heat pipe was applied to DPC developed in Korea. Hybrid heat pipe is the heat pipe containing neutron absorber can be used as a passive cooling in nuclear application with both decay heat removal and control the reactivity. In this study, 2-step CFD analysis was performed to find to evaluate the heat pipe-based passive cooling system for the application to the dry cask. Only spent fuel pool cannot satisfy the demands for high burnup fuel and large amount of spent fuel. Therefore, it is necessary to prepare supplement of the storage facilities. As one of the candidate of another type of storage, dry storage method have been preferred due to its good expansibility of storage capacity and easy long-term management. Dry storage uses the gas or air as coolant with passive cooling and neutron shielding materials was used instead of water in wet storage system. It is relatively safe and emits little radioactive waste for the storage. As short term actions for the limited storage capacity of spent fuel pool, it is considered to use dry interim/long term storage method to increase the capacity of spent nuclear fuel storage facilities. For 10-year cooled down spent fuel in the pool storage, fuel rod temperature inside metal cask is expected over 250 .deg. C in simulation. Although it satisfied the criteria that cladding temperature of the spent fuel should keep under 400 .deg. C during storage period, high temperature inside cask can accelerate the thermal degradation of the structural materials consisting metal cask and fuel assembly as well as limitation of the storage capacity of metal cask. In this paper, heat pipe-based cooling device for the dry storage cask was suggested for

  9. THERMAL EVALUATION OF ALTERNATE SHIPPING CASK FOR GTRI EXPERIMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Donna Post Guillen

    2014-06-01

    The Global Threat Reduction Initiative (GTRI) has many experiments yet to be irradiated in support of the High Performance Research Reactor fuels development program. Most of the experiments will be irradiated in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL), then later shipped to the Hot Fuel Examination Facility (HFEF) located at the Materials and Fuels Complex for post irradiation examination. To date, the General Electric (GE)-2000 cask has been used to transport GTRI experiments between these facilities. However, the availability of the GE-2000 cask to support future GTRI experiments is at risk. In addition, the internal cavity of the GE-2000 cask is too short to accommodate shipping the larger GTRI experiments. Therefore, an alternate shipping capability is being pursued. The Battelle Energy Alliance, LLC, Research Reactor (BRR) cask has been determined to be the best alternative to the GE-2000 cask. An evaluation of the thermal performance of the BRR cask is necessary before proceeding with fabrication of the newly designed cask hardware and the development of handling, shipping, and transport procedures. This paper presents the results of the thermal evaluation of the BRR cask loaded with a representative set of fueled and non-fueled experiments. When analyzed with identical payloads, experiment temperatures were found to be lower with the BRR cask than with the GE-2000 cask. From a thermal standpoint, the BRR cask was found to be a suitable alternate to the GE-2000 cask.

  10. Structural evaluation and analysis under normal conditions for spent fuel concrete storage cask

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Taechul; Baeg, Changyeal; Yoon, Sitae [Korea Radioactive waste Management Agency, Daejeon (Korea, Republic of); Jung, Insoo [Korea Nuclear Engineering and Service Co., Daejeon (Korea, Republic of)

    2014-05-15

    The purpose of this paper is the verification of stabilities of the structural elements that influence the safety of a concrete storage cask. The evaluation results were reviewed with respect to every design criterion, in terms of whether the results satisfy the criteria, provided by 10CFR 72 and NUREG-1536. The basic information on the design is partially explained in 2. Description of spent fuel storage system and the maintainability and assumptions included in the analysis were confirmed through detailed explanations of the acceptable standards, analysis model, and analysis method. ABAQUS 6.10, a widely used finite element analysis program, was used in the structural analysis. The storage cask shall maintain the sub-criticality, shielding, structural integrity, thermal capability and confinement in accordance with the requirements specified in US 10 CFR 72. The safety of storage cask is analyzed and it has been confirmed to meet the requirements of US 10 CFR 72. This paper summarizes the structural stability evaluation results of a concrete storage cask with respect to the design criteria. The evaluation results of this paper show that the maximum stress was below the allowable stress under every condition, and the concrete storage cask satisfied the design criteria.

  11. Documentation for fiscal year 1995 annual BUSS cask SARP testing and inspections

    Energy Technology Data Exchange (ETDEWEB)

    Saueressig, P.T.

    1994-11-08

    The purpose of this report is to compile the data generated during the Fiscal Year (FY) 1995 annual tests and inspections performed on the Beneficial Uses Shipping System (BUSS) cask. The BUSS Cask Model R-1 is a type B shipping container used for shipment of radioactive cesium-137 and strontium-90 capsules to Waste Encapsulation and Storage Facility (WESF). The primary purpose of the BUSS Cask is to provide shielding and confinement as well as impact, puncture, and thermal protection for the capsules under both normal and accident conditions. Section 8.2 ``Maintenance and Periodic Inspection Program`` of the BUSS Cask SARP requires that the following tests and inspections be performed on an annual basis: hydrostatic pressure test; helium leak test; dye penetrant test on the trunnions and life lugs; torque test on all permanent bolts; and impact limiter inspection and weight test. In addition to compiling the generated data, this report will verify that the testing criteria identified in section 8.2 of the BUSS Cask Safety Analysis Report for Packaging (SARP) was met.

  12. Activation analysis of dual-purpose metal cask after the end of design lifetime for decommission

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Man; Ku, Ji Young; Dho Ho Seog; Cho, Chun Hyung [Korea Radioactive Waste Agency, Daejeon (Korea, Republic of); Ko, Jae Hun [Korea Nuclear Engineering and Service Co., Daejeon (Korea, Republic of)

    2016-12-15

    The Korea Radioactive Waste Agency (KORAD) has developed a dual-purpose metal cask for the dry storage of spent nuclear fuel that has been generated by domestic light-water reactors. The metal cask was designed in compliance with international and domestic technology standards, and safety was the most important consideration in developing the design. It was designed to maintain its integrity for 50 years in terms of major safety factors. The metal cask ensures the minimization of waste generated by maintenance activities during the storage period as well as the safe management of the waste. An activation evaluation of the main body, which includes internal and external components of metal casks whose design lifetime has expired, provides quantitative data on their radioactive inventory. The radioactive inventory of the main body and the components of the metal cask were calculated by applying the MCNP5·ORIGEN-2 evaluation system and by considering each component's chemical composition, neutron flux distribution, and reaction rate, as well as the duration of neutron irradiation during the storage period. The evaluation results revealed that 10 years after the end of the cask's design life, {sup 60}Co had greater radioactivity than other nuclides among the metal materials. In the case of the neutron shield, nuclides that emit high-energy gamma rays such as {sup 28}Al and {sup 24}Na had greater radioactivity immediately after the design lifetime. However, their radioactivity level became negligible after six months due to their short half-life. The surface exposure dose rates of the canister and the main body of the metal cask from which the spent nuclear fuel had been removed with expiration of the design lifetime were determined to be at very low levels, and the radiation exposure doses to which radiation workers were subjected during the decommissioning process appeared to be at insignificant levels. The evaluations of this study strongly suggest that

  13. Small Signal Model for VSC-HVDC Connected DFIG-Based Offshore Wind Farms

    Directory of Open Access Journals (Sweden)

    Kai Liao

    2014-01-01

    Full Text Available Large-scale offshore wind farms are integrated with onshore ac grids through the voltage source converter based high voltage direct current (VSC-HVDC transmission system. The impact on the stability of the ac grids will be significant. The small signal model of a wind farm connected with voltage source converter based dc transmission system is studied in this paper. A suitable model for small signal stability analysis is presented. The control system of wind generator and the HVDC system has also been modeled in this model for small signal stability analysis. The impact of the control parameters on the network stability is investigated.

  14. TMI-2 (Three-Mile Island-Unit 2) rail cask and railcar maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Tyacke, M.J.; Ayers, A.L., Jr.; Ball, L.J.; Anselmo, A.A.

    1988-02-01

    This paper describes the NuPac 125-B cask system (i.e., cask and railcar), and the maintenance and inspection requirements for that system. The paper discusses the operations being done to satisfy those requirements and how, in some cases, it has been efficient for the operations to be more rigorous than the requirements. Finally, this paper discusses the experiences gained from those operations and how specific hardware and procedural enhancements have resulted in a reliable and continuous shipping campaign. 2 refs., 2 figs.

  15. Power Flow Algorithm of Multi-Terminal VSC-HVDC System Based on Nodal Current Relation%基于节点电流关系的多端柔性直流输电系统潮流计算

    Institute of Scientific and Technical Information of China (English)

    钱甜甜; 苗世洪

    2016-01-01

    多端柔性直流输电系统是近年来的研究热点,而关于其潮流计算的研究是系统稳定控制和故障分析的基础,迄今为止,已有很多文献对此做了研究,但从其使用的求解潮流的数学模型方面看,都是基于节点功率关系的。提出了一种基于节点电流关系的多端柔性直流网络潮流算法,且考虑了下垂控制方式,以6节点直流网络和11节点交直流混联网络为例,在 Matlab 中编制了相应的程序,并与现有文献中的基于节点功率关系的潮流算法做了对比。对比结果显示,在不同的网络运行方式下达到相同的预定计算精度时,均比基于节点功率关系的潮流算法迭代次数少,所用时间短且当节点电压初值发生一系列变化时,所提算法依然可以快速求解出收敛解,而基于节点功率关系的算法,对于电压初值变化很敏感,迭代次数随初值的变化而变化。算例结果表明,所提算法对含有多端柔性直流系统的网络潮流计算具有较好的快速性和计算精度。%Multi-terminal VSC-HVDC (voltage source converter-high voltage direct current) system is research hotspot in recent years. Its power flow calculation is basis of system stability control and fault analysis. Many references have performed researches on this topic. In term of mathematical model of power flow calculation, most references are based on nodal power relations. Power flow calculation model based on nodal current relation is proposed in this paper and voltage droop control is considered. A 6-node DC network and an 11-node AC-DC hybrid network are taken as examples and power flow calculation codes are compiled in MATLAB. Compared with power flow calculation results based on nodal power relation, the proposed method is easier to realize and needs less iterations in various operation modes with higher accuracy. When initial node voltage value changes, the proposed algorithm is

  16. A novel method to analyze damping effect of VSC based FACTS

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A novel method to analyze the damping effect of the VSC based FACTS(VBF) device is proposed,which is developed on the basis of the well-known equalarea criterion and small-disturbance analysis of power system oscillations.By use of the proposed method,two conclusions are obtained for study of the damping effect of the VBF.The research results clearly show the contribution of the VBF control to the damping of power system oscillations.Simulation results of an example power system are used to verify the effectiveness of the proposed method.

  17. Impact of Reactor Operating Parameters on Cask Reactivity in BWR Burnup Credit

    Energy Technology Data Exchange (ETDEWEB)

    Ilas, Germina [ORNL; Betzler, Benjamin R [ORNL; Ade, Brian J [ORNL

    2017-01-01

    This paper discusses the effect of reactor operating parameters used in fuel depletion calculations on spent fuel cask reactivity, with relevance for boiling-water reactor (BWR) burnup credit (BUC) applications. Assessments that used generic BWR fuel assembly and spent fuel cask configurations are presented. The considered operating parameters, which were independently varied in the depletion simulations for the assembly, included fuel temperature, bypass water density, specific power, and operating history. Different operating history scenarios were considered for the assembly depletion to determine the effect of relative power distribution during the irradiation cycles, as well as the downtime between cycles. Depletion, decay, and criticality simulations were performed using computer codes and associated nuclear data within the SCALE code system. Results quantifying the dependence of cask reactivity on the assembly depletion parameters are presented herein.

  18. Safety evaluation for packaging (onsite) SERF cask

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, W.S.

    1997-10-24

    This safety evaluation for packaging (SEP) documents the ability of the Special Environmental Radiometallurgy Facility (SERF) Cask to meet the requirements of WHC-CM-2-14, Hazardous Material Packaging and Shipping, for transfer of Type B quantities (up to highway route controlled quantities) of radioactive material within the 300 Area of the Hanford Site. This document shall be used to ensure that loading, tie down, transport, and unloading of the SERF Cask are performed in accordance with WHC-CM-2-14. This SEP is valid until October 1, 1999. After this date, an update or upgrade to this document is required.

  19. Safety Analysis of Dual Purpose Metal Cask Subjected to Impulsive Loads due to Aircraft Engine Crash

    Science.gov (United States)

    Shirai, Koji; Namba, Kosuke; Saegusa, Toshiari

    In Japan, the first Interim Storage Facility of spent nuclear fuel away from reactor site is being planned to start its commercial operation around 2010, in use of dual-purpose metal cask in the northern part of Main Japan Island. Business License Examination for safety design approval has started since March, 2007. To demonstrate the more scientific and rational performance of safety regulation activities on each phase for the first license procedure, CREPEI has executed demonstration tests with full scale casks, such as drop tests onto real targets without impact limiters(1) and seismic tests subjected to strong earthquake motions(2). Moreover, it is important to develop the knowledge for the inherent security of metal casks under extreme mechanical-impact conditions, especially for increasing interest since the terrorist attacks from 11th September 2001(3)-(6). This paper presents dynamic mechanical behavior of the metal cask lid closure system caused by direct aircraft engine crash and describes calculated results (especially, leak tightness based on relative dynamic displacements between metallic seals). Firstly, the local penetration damage of the interim storage facility building by a big passenger aircraft engine crash (diameter 2.7m, length 4.3m, weight 4.4ton, impact velocity 90m/s) has been examined. The reduced velocity is calculated by the local damage formula for concrete structure with its thickness of 70cm. The load vs. time function for this reduced velocity (60m/s) is estimated by the impact analysis using Finite Element code LS-DYNA with the full scale engine model onto a hypothetically rigid target. Secondly, as the most critical scenarios for the metal cask, two impact scenarios (horizontal impact hitting the cask and vertical impact onto the lid metallic seal system) are chosen. To consider the geometry of all bolts for two lids, the gasket reaction forces and the inner pressure of the cask cavity, the detailed three dimensional FEM models are

  20. Inertial Response of an Offshore Wind Power Plant with HVDC-VSC

    Energy Technology Data Exchange (ETDEWEB)

    Preciado, V.; Gevorgian, Vahan; Muljadi, Eduard; Madrigal, M.

    2017-01-05

    This paper analyzes the inertial response of an offshore wind power plant (WPP) to provide ancillary services to the power system grid. The WPP is connected to a high-voltage direct-current voltage source converter HVDC-VSC to deliver the power to the onshore substation. The wind turbine generator (WTG) used is a doubly-fed induction generator (Type 3 WTG). In this paper we analyze a control method for the WTGs in an offshore WPP to support the grid and contribute ancillary services to the power system network. Detailed time domain simulations will be conducted to show the transient behavior of the inertial response of an offshore WPP.

  1. The Feasibility of Cask "Fingerprinting" as a Spent-Fuel, Dry-Storage Cask Safeguards Technique

    Energy Technology Data Exchange (ETDEWEB)

    Ziock, K P; Vanier, P; Forman, L; Caffrey, G; Wharton, J; Lebrun, A

    2005-07-27

    This report documents a week-long measurement campaign conducted on six, dry-storage, spent-nuclear-fuel storage casks at the Idaho National Laboratory. A gamma-ray imager, a thermal-neutron imager and a germanium spectrometer were used to collect data on the casks. The campaign was conducted to examine the feasibility of using the cask radiation signatures as unique identifiers for individual casks as part of a safeguards regime. The results clearly show different morphologies for the various cask types although the signatures are deemed insufficient to uniquely identify individual casks of the same type. Based on results with the germanium spectrometer and differences between thermal neutron images and neutron-dose meters, this result is thought to be due to the limitations of the extant imagers used, rather than of the basic concept. Results indicate that measurements with improved imagers could contain significantly more information. Follow-on measurements with new imagers either currently available as laboratory prototypes or under development are recommended.

  2. CANISTER TRANSFER SYSTEM DESCRIPTION DOCUMENT

    Energy Technology Data Exchange (ETDEWEB)

    B. Gorpani

    2000-06-23

    The Canister Transfer System receives transportation casks containing large and small disposable canisters, unloads the canisters from the casks, stores the canisters as required, loads them into disposal containers (DCs), and prepares the empty casks for re-shipment. Cask unloading begins with cask inspection, sampling, and lid bolt removal operations. The cask lids are removed and the canisters are unloaded. Small canisters are loaded directly into a DC, or are stored until enough canisters are available to fill a DC. Large canisters are loaded directly into a DC. Transportation casks and related components are decontaminated as required, and empty casks are prepared for re-shipment. One independent, remotely operated canister transfer line is provided in the Waste Handling Building System. The canister transfer line consists of a Cask Transport System, Cask Preparation System, Canister Handling System, Disposal Container Transport System, an off-normal canister handling cell with a transfer tunnel connecting the two cells, and Control and Tracking System. The Canister Transfer System operating sequence begins with moving transportation casks to the cask preparation area with the Cask Transport System. The Cask Preparation System prepares the cask for unloading and consists of cask preparation manipulator, cask inspection and sampling equipment, and decontamination equipment. The Canister Handling System unloads the canister(s) and places them into a DC. Handling equipment consists of a bridge crane hoist, DC loading manipulator, lifting fixtures, and small canister staging racks. Once the cask has been unloaded, the Cask Preparation System decontaminates the cask exterior and returns it to the Carrier/Cask Handling System via the Cask Transport System. After the DC is fully loaded, the Disposal Container Transport System moves the DC to the Disposal Container Handling System for welding. To handle off-normal canisters, a separate off-normal canister handling

  3. Evaluation of capillary permeability and microcirculation in patients with chronic venous hypertension treated with venoruton by the vacuum suction chamber (VSC) device and laser-Doppler flowmetry.

    Science.gov (United States)

    Belcaro, G; D'Aulerio, A; Rulo, A; Candiani, C

    1988-01-01

    A new system to study capillary permeability, the VSC (vacuum suction chamber) device has been developed to evaluate the variations of capillary permeability in postphlebitic limbs. The VSC device produces by negative pressure [obtained in a plastic chamber applied to the skin at the perimalleolar region] a wheal which disappears in normals in less than one hour. In twelve patients with moderate [superficial] venous hypertension and in twelve patients with postphlebitic limbs the time of disappearance of the wheals was significantly longer in comparison with ten normal limbs. There was also a significantly increased time of disappearance of the wheals in postphlebitic legs in comparison with those with superficial incompetence. The validation of the VSC technique with venous occlusion plethysmography (VOP) showed that the increase of time of disappearance of the wheals is well correlated with the increase of capillary permeability demonstrated by VOP. After 2 weeks treatment with Venoruton (at the dosage of 1000 mg t.i.d.) the time of disappearance of the wheal was significantly reduced in both groups of patients (while it was unchanged in normals). Laser-Doppler parameters used together with the VSC device to evaluate the microcirculatory changes associated with an altered capillary permeability also showed a significant improvement of the laser-Doppler parameters after treatment. In conclusion there is evidence by the VSC device that capillary permeability [which is abnormally increased] in chronic venous hypertension is improved [decreased] after treatment for two weeks with Venoruton. This study demonstrated also the efficacy of the VSC device to study capillary permeability and the effects of drugs active on capillary permeability.

  4. Study on the key technologies of the Transfer Equipment Cask for Tokamak Equator Port Plug

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Buyun, E-mail: ayun@iim.ac.cn [Department of Automation, University of Science and Technology of China, Hefei, Anhui 230027 (China); Robot Sensors and Human-Machine Interaction Laboratory, Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Gao, Lifu [Department of Automation, University of Science and Technology of China, Hefei, Anhui 230027 (China); Robot Sensors and Human-Machine Interaction Laboratory, Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Cao, Huibin; Sun, Jian [Robot Sensors and Human-Machine Interaction Laboratory, Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Sun, Yuxiang; Song, Quanjun; Ma, Chengxue; Chang, Li; Shuang, Feng [Department of Automation, University of Science and Technology of China, Hefei, Anhui 230027 (China); Robot Sensors and Human-Machine Interaction Laboratory, Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei, Anhui 230031 (China)

    2014-12-15

    Highlights: • Design on Intelligent Air Transfer System (IATS) for Transfer Equipment Cask (TECA). • A rhombic-like parallel robot for docking with minimum misalignment. • Design on electro-hydraulic servo system of the TECA for Tokamak Equator Port Plug (TEPP) manipulation. • A control architecture with several algorithms and information acquired from sensors could be used by the TECA for Remote Handling (RH). - Abstract: The Transfer Equipment Cask (TECA) is a key solution for Remote Handling (RH) in Tokamak Equator Port Plug (TEPP) operations. From the perspectives of both engineering and technical designs of effective experiments on the TEPP, key technologies on these topics covering the TECA are required. According to conditions in ITER (International Thermonuclear Experimental Reactor) and features of the TEPP, this paper introduces the design of an Intelligent Air Transfer System (IATS) with an adaptive attitude and high precision positioning that transports a cask system of more than 30 tons from the Tokamak Building (TB) to the Hot Cell Building (HCB). Additionally, different actuators are discussed, and the hydraulic power drive is eventually selected and designed. A rhombic-like parallel robot is capable of being used for docking with minimum misalignment. Practical mechanisms of the cask system are presented for hostile environments. A control architecture with several algorithms and information acquired from sensors could be used by the TECA. These designs yield realistic and extended applications for the RH of ITER.

  5. 10 CFR 72.236 - Specific requirements for spent fuel storage cask approval and fabrication.

    Science.gov (United States)

    2010-01-01

    ... REQUIREMENTS FOR THE INDEPENDENT STORAGE OF SPENT NUCLEAR FUEL, HIGH-LEVEL RADIOACTIVE WASTE, AND REACTOR... storage cask must be designed to provide adequate heat removal capacity without active cooling systems. (g... ascertain that there are no cracks, pinholes, uncontrolled voids, or other defects that could...

  6. Transportation cask decontamination and maintenance at the potential Yucca Mountain repository; Yucca Mountain Site characterization project

    Energy Technology Data Exchange (ETDEWEB)

    Hartman, D.J.; Miller, D.D. [Bechtel National, Inc., San Francisco, CA (United States); Hill, R.R. [Sandia National Labs., Albuquerque, NM (United States)

    1992-04-01

    This study investigates spent fuel cask handling experience at existing nuclear facilities to determine appropriate cask decontamination and maintenance operations at the potential Yucca Mountain repository. These operations are categorized as either routine or nonroutine. Routine cask decontamination and maintenance tasks are performed in the cask preparation area at the repository. Casks are taken offline to a separate cask maintenance area for major nonroutine tasks. The study develops conceptual designs of the cask preparation area and cask maintenance area. The functions, layouts, and major features of these areas are also described.

  7. High Burnup Dry Storage Cask Research and Development Project, Final Test Plan

    Energy Technology Data Exchange (ETDEWEB)

    None

    2014-02-27

    EPRI is leading a project team to develop and implement the first five years of a Test Plan to collect data from a SNF dry storage system containing high burnup fuel.12 The Test Plan defined in this document outlines the data to be collected, and the storage system design, procedures, and licensing necessary to implement the Test Plan.13 The main goals of the proposed test are to provide confirmatory data14 for models, future SNF dry storage cask design, and to support license renewals and new licenses for ISFSIs. To provide data that is most relevant to high burnup fuel in dry storage, the design of the test storage system must mimic real conditions that high burnup SNF experiences during all stages of dry storage: loading, cask drying, inert gas backfilling, and transfer to the ISFSI for multi-year storage.15 Along with other optional modeling, SETs, and SSTs, the data collected in this Test Plan can be used to evaluate the integrity of dry storage systems and the high burnup fuel contained therein over many decades. It should be noted that the Test Plan described in this document discusses essential activities that go beyond the first five years of Test Plan implementation.16 The first five years of the Test Plan include activities up through loading the cask, initiating the data collection, and beginning the long-term storage period at the ISFSI. The Test Plan encompasses the overall project that includes activities that may not be completed until 15 or more years from now, including continued data collection, shipment of the Research Project Cask to a Fuel Examination Facility, opening the cask at the Fuel Examination Facility, and examining the high burnup fuel after the initial storage period.

  8. Dynamic Response Analysis of Storage Cask Lid Structure Subjected to Lateral Impact Load of Aircraft Engine Crash

    Energy Technology Data Exchange (ETDEWEB)

    Almomania, Belal; Kang, Hyun Gook [KAIST, Daejeon (Korea, Republic of); Lee, Sanghoon [Keimyung Univ., Daegu (Korea, Republic of)

    2015-10-15

    Several numerical methods and tests have been carried out to measure the capability of storage cask to withstand extreme impact loads. Testing methods are often constrained by cost, and difficulty in preparation for several impact conditions with different applied loads, and areas of impact. Instead, analytic method is an acceptable process that can easily apply different impact conditions for the evaluation of cask integrity. The aircraft engine impact is considered as one of the most critical impact accidents on the storage cask that significantly affects onto the lid closure system and may cause a considerable release of radioactive materials. This paper presents a method for evaluating the dynamic responses of one upper metal cask lid closure without impact limiters subjected to lateral impact of an aircraft engine with respect to variation of the impact velocity. An assessment method to predict damage response due to the lateral engine impact onto metal storage cask has been studied by using computer code LS-DYNA. The dynamic behavior of the lid movements was successfully calculated by utilizing a simplified finite element cask model, which showed a good agreement with the previous research. The simulation analyses results showed that no significant plastic deformation for bolts, lid, and the cask body. In this study, the lid opening and sliding displacements are considered as the major factors in initiating the leakage path. This analysis may be useful for evaluating the instantaneous leakage rates in a connection with the sliding and opening displacements between the lid and the flange to ensure that the radiological consequences caused by an aircraft engine crash accident during the storage phase are within the permissible level.

  9. Improved Adaptive Droop Control Design for Optimal Power Sharing in VSC-MTDC Integrating Wind Farms

    Directory of Open Access Journals (Sweden)

    Xiaohong Ran

    2015-07-01

    Full Text Available With the advance of insulated gate bipolar transistor (IGBT converters, Multi-Terminal DC (MTDC based on the voltage-source converter (VSC has developed rapidly in renewable and electric power systems. To reduce the copper loss of large capacity and long distance DC transmission line, an improved droop control design based on optimal power sharing in VSC-MTDC integrating offshore wind farm is proposed. The proposed approach provided a calculation method for power-voltage droop coefficients under two different scenarios either considering local load or not. The available headroom of each converter station was considered as a converter outage, to participate in the power adjustment according to their ability. A four-terminal MTDC model system including two large scale wind farms was set up in PSCAD/EMTDC. Then, the proposed control strategy was verified through simulation under the various conditions, including wind speed variation, rectifier outage and inverter outage, and a three-phase short-circuit of the converter.

  10. MCO loading and cask loadout technical manual

    Energy Technology Data Exchange (ETDEWEB)

    PRAGA, A.N.

    1998-10-01

    A compilation of the technical basis for loading a multi-canister overpack (MCO) with spent nuclear fuel and then placing the MCO into a cask for shipment to the Cold Vacuum Drying Facility. The technical basis includes a description of the process, process technology that forms the basis for loading alternatives, process control considerations, safety considerations, equipment description, and a brief facility structure description.

  11. Impact Analyses and Tests of Metal Cask Considering Aircraft Engine Crash - 12308

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sanghoon; Choi, Woo-Seok; Kim, Ki-Young; Jeon, Je-Eon; Seo, Ki-Seog [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-07-01

    The structural integrity of a dual purpose metal cask currently under development by the Korea Radioactive Waste Management Cooperation (KRMC) is evaluated through analyses and tests under a high-speed missile impact considering the targeted aircraft crash conditions. The impact conditions were carefully chosen through a survey on accident cases and recommendations from the literature. The missile impact velocity was set at 150 m/s, and two impact orientations were considered. A simplified missile simulating a commercial aircraft engine is designed from an impact load history curve provided in the literature. In the analyses, the focus is on the evaluation of the containment boundary integrity of the metal cask. The analyses results are compared with the results of tests using a 1/3 scale model. The results show very good agreements, and the procedure and methodology adopted in the structural analyses are validated. While the integrity of the cask is maintained in one evaluation where the missile impacts the top side of the free standing cask, the containment boundary is breached in another case in which the missile impacts the center of the cask lid in a perpendicular orientation. A safety assessment using a numerical simulation of an aircraft engine crash into spent nuclear fuel storage systems is performed. A commercially available explicit finite element code is utilized for the dynamic simulation, and the strain rate effect is included in the modeling of the materials used in the target system and missile. The simulation results show very good agreement with the test results. It is noted that this is the first test considering an aircraft crash in Korea. (authors)

  12. Structural dimensioning of dual purpose cask prototype; Dimensionamento estrutural de prototipo de casco de duplo proposito

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Luiz Leite da; Mourao, Rogerio Pimenta; Lopes, Claudio Cunha [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil)]. E-mail: silvall@cdtn.br; mouraor@cdtn.br; ccl@cdtn.br

    2005-07-01

    The structural dimensioning of a Type B(U) dual purpose cask prototype is part of the scope of work of the Brazilian institute CDTN in the IAEA regional project involving Latin American countries which operate research reactors (Argentina, Brazil, Chile, Mexico and Peru). In order to meet the dimensional and operational characteristics of the reactor facilities in these countries, a maximum weight of 10.000 kgf and a maximum dimension of 1 m in at least one direction were set for the cask. With these design restrictions, the cask's payload is either 21 MTR or 78 TRIGA fuel elements. The cask's most important components are main body, primary and secondary lids, basket and impact limiters. The main body has a sandwich-like wall with internal and external layers made of AISI 304 stainless steel with lead in-between. The lead provides biological shielding. The primary lid is similarly layered, but in the axial direction. It is provided with a double system of metallic rings and has ports for pressurization, sampling and containment verification. The secondary lid has the main function of protecting the primary lid against mechanical impacts. The basket structure is basically a tube array reinforced by bottom plate, feet and spacers. Square tubes are used for MTR elements and circular tubes for TRIGA elements. Finally, the impact limiters are structures made of an external stainless steel thin covering and a filling made of the wood composite OSB - Oriented Strand Board. The prototype is provided with bottom and top impact limiters, which are attached to each other by means of four threaded rods. The limiters are not rigidly attached to the cask body. A half scale cask model was designed to be submitted to a testing program. As its volume scales down to 1:8, the model weight is 1,250 kgf. This paper presents the methodology for the preliminary structural dimensioning of the critical parameters of the cask prototype. Both normal conditions of operation and

  13. Synthesis of Microporous Materials and Their VSC Adsorption Properties

    Science.gov (United States)

    Yokogawa, Y.; Morikawa, H.; Sakanishi, M.; Utaka, H.; Nakamura, A.; Kishida, I.

    2011-10-01

    Oral malodor is caused by volatile sulfur compounds (VSC) such as hydrogen sulfide (H2S), methyl mercaptan and dimethyl sulfide produced in mouth. VSC induces permeability of mucous membrane and oral malodor formation. Thus, the adsorbent which highly adsorbs VSC should be useful for health in mouth and may prevent teeth from decaying. The microporous material, hydrotalcite, was synthesized by a wet method, and the H2S adsorption was studied. The samples, identified by powder X-ray diffraction method, were put into glass flask filled with H2S gas. The initial concentration of H2S was 30 ppm. The change in concentrations of H2S was measured at rt, and the amount of H2S absorbed on the hydrotalcite for 24 h was 300 micro L/g. The samples were taken out from the above glass flask and put into a pyrolysis plant attached to gas chromatography-mass spectrometry to determine the amount of H2S desorbed from samples. Only 3 % of H2S was desorbed when heated at 500 °C. H2S in water was also found to adsorb into hydrotalcite, which was confirmed by the headspace gas chromatography with flame photometric detector. The hydrotalcite material should be expected to be an adsorbent material, useful for health in mouth.

  14. Thermo-mechanical finite element analyses of bolted cask lid structures

    Energy Technology Data Exchange (ETDEWEB)

    Wieser, G.; Qiao Linan; Eberle, A.; Voelzke, H. [Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin (Germany)

    2004-07-01

    The analysis of complex bolted cask lid structures under mechanical or thermal accident conditions is important for the evaluation of cask integrity and leak-tightness in package design assessment according to the Transport Regulations or in aircraft crash scenarios. In this context BAM is developing methods based on Finite Elements to calculate the effects of mechanical impacts onto the bolted lid structures as well as effects caused by severe fire scenarios. I n case of fire it might be not enough to perform only a thermal heat transfer analysis. The complex cask design in connection with a severe hypothetical time-temperature-curve representing an accident fire scenario will create a strong transient heating up of the cask body and its lid system. This causes relative displacements between the seals and its counterparts that can be analyzed by a so-called thermo-mechanical calculation. Although it is currently not possible to correlate leakage rates with results from deformation analyses directly an appropriate Finite Element model of the considered type of metallic lid seal has been developed. For the present it is possible to estimate the behaviour of the seal based on the calculated relative displacements at its seating and the behaviour of the lid bolts under the impact load or the temperature field respectively. Except of the lid bolts the geometry of the cask and the mechanical loading is axial-symmetric which simplifies the analysis considerably and a two-dimensional Finite Element model with substitute lid bolts may be used. The substitute bolts are modelled as one-dimensional truss or beam elements. An advanced two-dimensional bolt submodel represents the bolts with plane stress continuum elements. This paper discusses the influence of different bolt modelling on the relative displacements at the seating of the seals. Besides this, the influence of bolt modelling, thermal properties and detail in geometry of the two-dimensional Finite Element models on

  15. COBRA-SFS modifications and cask model optimization

    Energy Technology Data Exchange (ETDEWEB)

    Rector, D.R.; Michener, T.E.

    1989-01-01

    Spent-fuel storage systems are complex systems and developing a computational model for one can be a difficult task. The COBRA-SFS computer code provides many capabilities for modeling the details of these systems, but these capabilities can also allow users to specify a more complex model than necessary. This report provides important guidance to users that dramatically reduces the size of the model while maintaining the accuracy of the calculation. A series of model optimization studies was performed, based on the TN-24P spent-fuel storage cask, to determine the optimal model geometry. Expanded modeling capabilities of the code are also described. These include adding fluid shear stress terms and a detailed plenum model. The mathematical models for each code modification are described, along with the associated verification results. 22 refs., 107 figs., 7 tabs.

  16. Shielding calculations with SCALE/MAVRIC and comparison with measurements for the TN85 cask with vitrified high level radioactive waste

    Science.gov (United States)

    Thiele, Holger; Börst, Frank-Michael

    2017-09-01

    A series of dose rate/spectra measurements in the German interim storage facility Gorleben was carried out at a TN85 cask in April 2009. This type of cask is used for the transport and interim storage of vitrified high level radioactive waste (HAW) from reprocessing. The aim of this work is to assess the shielding component MAVRIC of the SCALE code system with these measurements for the use in the German Bundesamt für Kerntechnische Entsorgungssicherheit (BfE).

  17. Safety analysis report for packaging: the ORNL loop transport cask

    Energy Technology Data Exchange (ETDEWEB)

    Evans, J.H.; Chipley, K.K.; Nelms, H.A.; Crowley, W.K.; Just, R.A.

    1977-11-01

    An evaluation of the ORNL loop transport cask demonstrating its compliance with the regulations governing the transportation of radioactive and fissile materials is presented. A previous review of the cask is updated to demonstrate compliance with current regulations, to present current procedures, and to reflect the more recent technology.

  18. Breeder Spent Fuel Handling Program multipurpose cask design basis document

    Energy Technology Data Exchange (ETDEWEB)

    Duckett, A.J.; Sorenson, K.B.

    1985-09-01

    The Breeder Spent Fuel Handling (BSFH) Program multipurpose cask Design Basis Document defines the performance requirements essential to the development of a legal weight truck cask to transport FFTF spent fuel from reactor to a reprocessing facility and the resultant High Level Waste (HLW) to a repository. 1 ref.

  19. VSC-HVDC-based Network Modeling and its Simulation%VSC-HVDC并网稳态建模及仿真研究

    Institute of Scientific and Technical Information of China (English)

    詹昕; 王凯; 刘春梅

    2011-01-01

    介绍VSC-HVDC的基本原理及其并网的运行机理,分析换流器两侧的功率关系,建立VSC-HVDC系统并网的数学模型,利用灵敏度法则进行解耦分析,从而确定控制器的内部控制关系.建立VSC-HVDC的仿真模型,加入控制策略,仿真分析验证了加入控制策略能够提高系统的稳定性.

  20. What drives Greek consumer preferences for cask wine?

    DEFF Research Database (Denmark)

    Chrysochou, Polymeros; Corsi, A. M.; Krystallis Krontalis, Athanasios

    2012-01-01

    to structure, the Greek cask wine market was found to consist of four distinct segments that were labelled as connoisseurs, convenience seekers, experienced and risk averse. These segments showed differences in relation to their past experience and in the importance given to intrinsic (quality, taste, origin......Purpose – Cask wine (bag-in-box, soft pack) has not received considerable attention in wine marketing research, but interest among winemakers and consumers has been increasing steadily. However, little is known about what drives consumer preferences for cask wine and, furthermore, what the profile...... of the cask wine consumer is. This study aims at filling this gap. Design/methodology/approach – Based on a web-based survey, the best-worst scaling (BWS) method was applied to measure the importance of attributes that Greek consumers assign when choosing cask wine. Then, a latent class clustering analysis...

  1. Study on VSC HVDC Modeling and Control Strategies for Wind Power Integration

    DEFF Research Database (Denmark)

    Korompili, Asimenia; Wu, Qiuwei

    in their applications. The main focus is given in the HVDC transmission systems, since they do not exhibit these disadvantages, whereas they additionally present beneficial attributes. This is the reason for which the applications of HVDC systems have been increased in the latest years. A brief description of different...... application cases is provided in the introduction of this report, while the rest chapters deal with the use of the HVDC technology for the grid connection of offshore wind farms. The main structure of the HVDC system is analysed, by describing the role and operation of its main components. Especially...... is performed, regarding power losses, costs, equipment aspects and control capabilities. It is concluded that the VSC-HVDC system exhibits the most advantageous features for the grid connection of offshore wind farms. In addition, various topologies of the HVDC converter stations are analysed. Furthermore...

  2. MEASUREMENT METHOD AND PHYSICAL MODEL OF VSC CONDUCTIVITY AND ITS APPLICATIONS IN CONDUCTING POLYMERS

    Institute of Scientific and Technical Information of China (English)

    WAN Meixiang

    1989-01-01

    Method of VSC (Voltage Shorted Compaction ) can be used to determine the intrinsic temperature dependence of conductivity of polycrystalline compaction .The experimental conditions and technical key for preparation of VSC device and its physical model as well as its applications in conducting polymers are discussed in detail.

  3. Conceptual design of the Clinch River Breeder Reactor spent-fuel shipping cask

    Energy Technology Data Exchange (ETDEWEB)

    Pope, R B; Diggs, J M [eds.

    1982-04-01

    Details of a baseline conceptual design of a spent fuel shipping cask for the Clinch River Breeder Reactor (CRBR) are presented including an assessment of shielding, structural, thermal, fabrication and cask/plant interfacing problems. A basis for continued cask development and for new technological development is established. Alternates to the baseline design are briefly presented. Estimates of development schedules, cask utilization and cost schedules, and of personnel dose commitments during CRBR in-plant handling of the cask are also presented.

  4. Grid Integration of Offshore Wind Farms via VSC-HVDC – Dynamic Stability Study

    DEFF Research Database (Denmark)

    Liu, Hongzhi

    -HVDC transmission are addressed. The main objectives have been to study the dynamic interactions between offshore wind farms and interconnected power systems, pinpoint the impact on the electrical grid while integrating large-scale offshore wind farms via VSC-HVDC link and propose potential solutions to improve......, may not be able to respond to the onshore grid frequency excursion in time. Consequently, the stability and security of power system will be put at risk, especially for those with high wind penetration. A coordinated frequency control scheme is developed not only to reduce the responding latency...... fluctuation mitigation. A new converter rating evaluation approach as well as a new power management strategy is proposed to enable the BESS to enhance the system frequency response on the basis of wind power fluctuation mitigation....

  5. Cost and Benefit Analysis of VSC-HVDC Schemes for Offshore Wind Power Transmission

    Institute of Scientific and Technical Information of China (English)

    Sheng WANG; Chunmei FENG; An WEN; Jun LIANG

    2013-01-01

    Due to low load factors of wind power generation,it is possible to reduce transmission capacity to minimize the cost of transmission system construction.Two VSC-HVDC schemes for offshore wind farm,called the point to point (PTP) and DC mesh connections are compared in terms of the utilization of transmission system and its cost.A Weibull distribution is used for estimating offshore wind power generation,besides,the cross correlation between wind farms is considered.The wind energy curtailment is analyzed using the capacity output possibility table (COPT).The system power losses,costs of transmission investment and wind energy curtailment are also computed.A statistic model for the wind generation and transmission is built and simulated in MATLAB to validate the study.It is concluded that a DC mesh transmission can reduce the energy curtailment and power losses.Further benefit is achievable as the wind cross correlation between wind farms decreases.

  6. Signatures of Extended Storage of Used Nuclear Fuel in Casks

    Energy Technology Data Exchange (ETDEWEB)

    Rauch, Eric Benton [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-09-28

    As the amount of used nuclear fuel continues to grow, more and more used nuclear fuel will be transferred to storage casks. A consolidated storage facility is currently in the planning stages for storing these casks, where at least 10,000 MTHM of fuel will be stored. This site will have potentially thousands of casks once it is operational. A facility this large presents new safeguards and nuclear material accounting concerns. A new signature based on the distribution of neutron sources and multiplication within casks was part of the Department of Energy Office of Nuclear Energy’s Material Protection, Account and Control Technologies (MPACT) campaign. Under this project we looked at fingerprinting each casks neutron signature. Each cask has a unique set of fuel, with a unique spread of initial enrichment, burnup, cooling time, and power history. The unique set of fuel creates a unique signature of neutron intensity based on the arrangement of the assemblies. The unique arrangement of neutron sources and multiplication produces a reliable and unique identification of the cask that has been shown to be relatively constant over long time periods. The work presented here could be used to restore from a loss of continuity of knowledge at the storage site. This presentation will show the steps used to simulate and form this signature from the start of the effort through its conclusion in September 2016.

  7. Signatures of Extended Storage of Used Nuclear Fuel in Casks

    Energy Technology Data Exchange (ETDEWEB)

    Rauch, Eric Benton [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-09-28

    As the amount of used nuclear fuel continues to grow, more and more used nuclear fuel will be transferred to storage casks. A consolidated storage facility is currently in the planning stages for storing these casks, where at least 10,000 MTHM of fuel will be stored. This site will have potentially thousands of casks once it is operational. A facility this large presents new safeguards and nuclear material accounting concerns. A new signature based on the distribution of neutron sources and multiplication within casks was part of the Department of Energy Office of Nuclear Energy’s Material Protection, Account and Control Technologies (MPACT) campaign. Under this project we looked at fingerprinting each cask's neutron signature. Each cask has a unique set of fuel, with a unique spread of initial enrichment, burnup, cooling time, and power history. The unique set of fuel creates a unique signature of neutron intensity based on the arrangement of the assemblies. The unique arrangement of neutron sources and multiplication produces a reliable and unique identification of the cask that has been shown to be relatively constant over long time periods. The work presented here could be used to restore from a loss of continuity of knowledge at the storage site. This presentation will show the steps used to simulate and form this signature from the start of the effort through its conclusion in September 2016.

  8. Safety aspects of long-term dry interim storage of type-B spent fuel and HLW transport casks

    Energy Technology Data Exchange (ETDEWEB)

    Wolff, D.; Probst, U.; Voelzke, H.; Droste, B.; Roedel, R. [Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin (Germany)

    2004-07-01

    Based on the German decision to minimise transports of spent fuel casks between nuclear power plants, reprocessing plants and central storage facilities several on-site storage facilities have been licensed till the end of 2003. Because of the large amount of type-B transport casks which are going to be used for long-term interim storage the question of time limited type-B license maintenance during the storage period of up to 40 years has been discussed under different aspects. This paper describes present technical aspects of the discussion. A main aspect of transport cask qualification for interim storage is the long-term behaviour of the metallic seal lid system. Concerning this results from current experimental long-term tests with metallic ''Helicoflex''-seals in which pool water is enclosed are presented. The test series has been performed by the Federal Institute for Materials Research and Testing (BAM) on behalf of the Federal Office for Radiation Protection (BfS) since 2001. Finally, the paper presents a German concept for an authorities' and technical experts' exchange of experience, know-how and state of the art referring to cask dispatch in nuclear facilities. BAM has taken over a central role in this so-called ''co-ordinating institution for cask dispatching information'' (''KOBAF'') which contains an online data base and a technical working group meeting twice a year. The goal is to keep comparable technical standards for all nuclear sites and storage facilities which are going to load and dispatch casks of the same or similar types under the responsibility of different German state governments for the next decades.

  9. Viability of Existing INL Facilities for Dry Storage Cask Handling

    Energy Technology Data Exchange (ETDEWEB)

    Randy Bohachek; Charles Park; Bruce Wallace; Phil Winston; Steve Marschman

    2013-04-01

    This report evaluates existing capabilities at the INL to determine if a practical and cost effective method could be developed for opening and handling full-sized dry storage casks. The Idaho Nuclear Technology and Engineering Center (INTEC) CPP-603, Irradiated Spent Fuel Storage Facility, provides the infrastructure to support handling and examining casks and their contents. Based on a reasonable set of assumptions, it is possible to receive, open, inspect, remove samples, close, and reseal large bolted-lid dry storage casks at the INL. The capability can also be used to open and inspect casks that were last examined at the TAN Hot Shop over ten years ago. The Castor V/21 and REA-2023 casks can provide additional confirmatory information regarding the extended performance of low-burnup (<45 GWD/MTU) used nuclear fuel. Once a dry storage cask is opened inside CPP-603, used fuel retrieved from the cask can be packaged in a shipping cask, and sent to a laboratory for testing. Testing at the INL’s Materials and Fuels Complex (MFC) can occur starting with shipment of samples from CPP-603 over an on-site road, avoiding the need to use public highways. This reduces cost and reduces the risk to the public. The full suite of characterization methods needed to establish the condition of the fuel exists and MFC. Many other testing capabilities also exist at MFC, but when those capabilities are not adequate, samples can be prepared and shipped to other laboratories for testing. This report discusses how the casks would be handled, what work needs to be done to ready the facilities/capabilities, and what the work will cost.

  10. Viability of Existing INL Facilities for Dry Storage Cask Handling

    Energy Technology Data Exchange (ETDEWEB)

    Bohachek, Randy; Wallace, Bruce; Winston, Phil; Marschman, Steve

    2013-04-30

    This report evaluates existing capabilities at the INL to determine if a practical and cost effective method could be developed for opening and handling full-sized dry storage casks. The Idaho Nuclear Technology and Engineering Center (INTEC) CPP-603, Irradiated Spent Fuel Storage Facility, provides the infrastructure to support handling and examining casks and their contents. Based on a reasonable set of assumptions, it is possible to receive, open, inspect, remove samples, close, and reseal large bolted-lid dry storage casks at the INL. The capability can also be used to open and inspect casks that were last examined at the TAN Hot Shop over ten years ago. The Castor V/21 and REA-2023 casks can provide additional confirmatory information regarding the extended performance of low-burnup (<45 GWD/MTU) used nuclear fuel. Once a dry storage cask is opened inside CPP-603, used fuel retrieved from the cask can be packaged in a shipping cask, and sent to a laboratory for testing. Testing at the INL’s Materials and Fuels Complex (MFC) can occur starting with shipment of samples from CPP-603 over an on-site road, avoiding the need to use public highways. This reduces cost and reduces the risk to the public. The full suite of characterization methods needed to establish the condition of the fuel exists and MFC. Many other testing capabilities also exist at MFC, but when those capabilities are not adequate, samples can be prepared and shipped to other laboratories for testing. This report discusses how the casks would be handled, what work needs to be done to ready the facilities/capabilities, and what the work will cost.

  11. Nuclear cask testing films misleading and misused

    Energy Technology Data Exchange (ETDEWEB)

    Audin, L. (Audin (Lindsay), Ossining, NY (United States))

    1991-10-01

    In 1977 and 1978, Sandia National Laboratories, located in Albuquerque, New Mexico, and operated for the US Department of Energy (DOE), filmed a series of crash and fire tests performed on three casks designed to transport irradiated nuclear fuel assemblies. While the tests were performed to assess the applicability of scale and computer modeling techniques to actual accidents, films of them were quickly pressed into service by the DOE and nuclear utilities as proof'' to the public of the safety of the casks. In the public debate over the safety of irradiated nuclear fuel transportation, the films have served as the mainstay for the nuclear industry. Although the scripts of all the films were reviewed by USDOE officials before production, they contain numerous misleading concepts and images, and omit significant facts. The shorter versions eliminated qualifying statements contained in the longer version, and created false impressions. This paper discusses factors which cast doubt on the veracity of the films and the results of the tests.

  12. Nuclear cask testing films misleading and misused

    Energy Technology Data Exchange (ETDEWEB)

    Audin, L. [Audin (Lindsay), Ossining, NY (United States)

    1991-10-01

    In 1977 and 1978, Sandia National Laboratories, located in Albuquerque, New Mexico, and operated for the US Department of Energy (DOE), filmed a series of crash and fire tests performed on three casks designed to transport irradiated nuclear fuel assemblies. While the tests were performed to assess the applicability of scale and computer modeling techniques to actual accidents, films of them were quickly pressed into service by the DOE and nuclear utilities as ``proof`` to the public of the safety of the casks. In the public debate over the safety of irradiated nuclear fuel transportation, the films have served as the mainstay for the nuclear industry. Although the scripts of all the films were reviewed by USDOE officials before production, they contain numerous misleading concepts and images, and omit significant facts. The shorter versions eliminated qualifying statements contained in the longer version, and created false impressions. This paper discusses factors which cast doubt on the veracity of the films and the results of the tests.

  13. Nondestructive evaluation of LWR spent fuel shipping casks

    Energy Technology Data Exchange (ETDEWEB)

    Ballard, D.W.

    1978-02-01

    An analysis of nondestructve testing (NDT) methods currently being used to evaluate the integrity of Light Water Reactor (LWR) spent fuel shipping casks is presented. An assessment of anticipated NDT needs related to breeder reactor cask requirements is included. Specific R and D approaches to probable NDT problem areas such as the evaluation of austenitic stainless steel weldments are outlined. A comprehensive bibliography of current NDT methods for cask evaluation in the USA, Great Britain, Japan and West Germany was compiled for this study.

  14. Transients in VSC-HVDC connected offshore wind power plant

    DEFF Research Database (Denmark)

    El-Khatib, Walid Ziad; Schwartzberg, D.; Arana Aristi, I.;

    2015-01-01

    The focus of this paper is transient phenomena in VSC-HVDC connected offshore wind power plants (WPPs). With the help of a case study modelled in PSCAD simulation software, energisation events are analysed in the time domain. A comparison with more well-known results obtained at energisation of AC...... connected WPPs indicates that significant differences arise as the energy involved in the switching event increases, due to the presence of the HVDC converter control. The influence of the offshore HVDC converter control gain in the most critical cases is assessed empirically and explained qualitatively....

  15. Control and Protection of Wind Power Plants with VSC-HVDC Connection

    DEFF Research Database (Denmark)

    Chaudhary, Sanjay

    Wind power plants are the fastest growing source of renewable energy. The European Union expects to generate 230 GW wind power, in which the offshore wind power is expected to contribute 40 GW. Offshore wind power plants have better wind velocity profile leading to a higher energy yield. Europe has...... a huge potential of offshore wind energy, which is a green and sustainable resource. All these have led to the development of offshore wind power plants. However, overall cost of the offshore installation, operation, and maintenance are higher than those of the onshore wind power plants. Therefore...... oscillations, and hence, lower dc voltage overshoots in the VSC-HVDC system. On the protection side, the coordination of over-current relays has been analysed in the new environment. A simple yet reliable scheme utilizing the well-known over-current relay characteristics has been presented for the detection...

  16. Nonlinear Ultrasonic Diagnosis and Prognosis of ASR Damage in Dry Cask Storage

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Jianmin [Northwestern Univ., Evanston, IL (United States); Bazant, Zdenek [Northwestern Univ., Evanston, IL (United States); Jacobs, Laurence [Georgia Inst. of Technology, Atlanta, GA (United States); Guimaraes, Maria [Electrical Power Research Institute, Palo Alto, CA (United States)

    2015-11-30

    Alkali-silica reaction (ASR) is a deleterious chemical process that may occur in cement-based materials such as mortars and concretes, where the hydroxyl ions in the highly alkaline pore solution attack the siloxane groups in the siliceous minerals in the aggregates. The reaction produces a cross-linked alkali-silica gel. The ASR gel swells in the presence of water. Expansion of the gel results in cracking when the swelling-induced stress exceeds the fracture toughness of the concrete. As the ASR continues, cracks may grow and eventually coalesce, which results in reduced service life and a decrease safety of concrete structures. Since concrete is widely used as a critical structural component in dry cask storage of used nuclear fuels, ASR damage poses a significant threat to the sustainability of long term dry cask storage systems. Therefore, techniques for effectively detecting, managing and mitigating ASR damage are needed. Currently, there are no nondestructive methods to accurately detect ASR damage in existing concrete structures. The only current way of accurately assessing ASR damage is to drill a core from an existing structure, and conduct microscopy on this drilled cylindrical core. Clearly, such a practice is not applicable to dry cask storage systems. To meet these needs, this research is aimed at developing (1) a suite of nonlinear ultrasonic quantitative nondestructive evaluation (QNDE) techniques to characterize ASR damage, and (2) a physics-based model for ASR damage evolution using the QNDE data. Outcomes of this research will provide a nondestructive diagnostic tool to evaluate the extent of the ASR damage, and a prognostic tool to estimate the future reliability and safety of the concrete structures in dry cask storage systems

  17. Fault Current Limitation and Analysis of Current Limiting Characteristic for Multi-terminal VSC-HVDC DC Lines%多端VSC-HVDC直流线路故障限流及限流特性分析

    Institute of Scientific and Technical Information of China (English)

    刘剑; 邰能灵; 范春菊; 郑晓冬; 唐跃中

    2016-01-01

    基于电压源型换流器(voltage source converters,VSC)的多端柔性直流系统中直流线路的故障电流上升速度快、电流峰值大。然而具有大容量、快切断能力的高压直流断路器正在研制中。结合目前直流断路器开断容量水平,该文提出通过在直流线路两端串入限流电路的方法来限制故障电流的峰值和电流的上升速度率,并给出相关参数的理论计算方法。对该电路的限流特性进行分析与对比,结果表明,该限流电路能有效抑制故障电流,降低了对直流断路器开断容量和开断速度的要求。在该限流电路的基础上,提出一种多端VSC-HVDC 直流线路故障处理方案。仿真分析表明,该故障处理方案能够有效抑制直流线路故障电流以及 IGBT 并联二极管电流,故障切除后非故障系统能保持正常运行,可以有效地增强多端VSC-HVDC系统对直流线路故障的处理能力。%The fault current of DC line in multi-terminal HVDC system based on voltage source converters (VSC) increases quickly with large peak, while the DC circuit breaker with large capacity and fast breaking speed is still under development. Combined with the capacity level of DC circuit breaker breaking, a current limiting circuit was proposed to limit the peak and rising rate of fault current by connecting it to DC line ends. Theoretical calculation method for the circuit parameters was also given. The analysis results about the circuit and the comparison with other methods show that the proposed circuit is able to limit the fault current effectively and reduce the requirement for DC breaker capacity and speed. Based on the circuit, a fault-handling scheme for DC lines in multi-terminal VSC-HVDC was proposed. The simulation results show that the proposed scheme is capable of limiting fault current of DC lines and parallel diodes effectively, and non-fault system can maintain normal operation after fault

  18. Experience with certifying borated stainless steel as a shipping cask basket material

    Energy Technology Data Exchange (ETDEWEB)

    Abbott, D.G. (EG and G Idaho, Inc., Idaho Falls, ID (USA)); Nickell, R.E. (Applied Science and Technology, Inc., Poway, CA (USA))

    1990-01-01

    The original cask designs for a cask demonstration project featured fuel baskets constructed of borated stainless steel (bss) as a structural material. The project is intended to demonstrate casks that can be used for both shipping and storing spent nuclear fuel assemblies. The baskets were intended to maintain the fuel assemblies in a subcritical array for both normal and accident conditions. The Nuclear Regulatory Commission, however, judged bss to be unacceptable as a structural material. The cask designs were subsequently modified. The knowledge gained during this cask demonstration project may be applicable to development of bss as a basket material in future cask design. 6 refs., 2 figs., 2 tabs.

  19. Experience with certifying borated stainless steel as a shipping cask basket material

    Energy Technology Data Exchange (ETDEWEB)

    Abbott, D.G. [Idaho National Engineering Lab., Idaho Falls, ID (United States); Nickell, R.E. [Applied Science and Technology, Poway, CA (United States)

    1990-10-01

    This paper discusses the original cask designs for a cask demonstration project that has featured fuel baskets constructed of borated stainless steel (bss) as a structural material. The project is intended to demonstrate casks that can be used for both shipping and storing spent nuclear fuel assemblies. The baskets were intended to maintain the fuel assemblies in a subcritical array for both normal and accident conditions. The Nuclear Regulatory Commission, judged bss to be unacceptable as a structural material. The cask designs were subsequently modified. The knowledge gained during this cask demonstration project may be applicable to development of bss as a basket material in future cask design.

  20. ASSEMBLY TRANSFER SYSTEM DESCRIPTION DOCUMENT

    Energy Technology Data Exchange (ETDEWEB)

    B. Gorpani

    2000-06-26

    The Assembly Transfer System (ATS) receives, cools, and opens rail and truck transportation casks from the Carrier/Cask Handling System (CCHS). The system unloads transportation casks consisting of bare Spent Nuclear Fuel (SNF) assemblies, single element canisters, and Dual Purpose Canisters (DPCs). For casks containing DPCs, the system opens the DPCs and unloads the SNF. The system stages the assemblies, transfer assemblies to and from fuel-blending inventory pools, loads them into Disposal Containers (DCs), temporarily seals and inerts the DC, decontaminates the DC and transfers it to the Disposal Container Handling System. The system also prepares empty casks and DPCs for off-site shipment. Two identical Assembly Transfer System lines are provided in the Waste Handling Building (WHB). Each line operates independently to handle the waste transfer throughput and to support maintenance operations. Each system line primarily consists of wet and dry handling areas. The wet handling area includes a cask transport system, cask and DPC preparation system, and a wet assembly handling system. The basket transport system forms the transition between the wet and dry handling areas. The dry handling area includes the dry assembly handling system, assembly drying system, DC preparation system, and DC transport system. Both the wet and dry handling areas are controlled by the control and tracking system. The system operating sequence begins with moving transportation casks to the cask preparation area. The cask preparation operations consist of cask cavity gas sampling, cask venting, cask cool-down, outer lid removal, and inner shield plug lifting fixture attachment. Casks containing bare SNF (no DPC) are filled with water and placed in the cask unloading pool. The inner shield plugs are removed underwater. For casks containing a DPC, the cask lid(s) is removed, and the DPC is penetrated, sampled, vented, and cooled. A DPC lifting fixture is attached and the cask is placed

  1. Thermal analysis of a storage cask for 24 spent PWR fuel assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J.C.; Bang, K.S.; Seo, K.S.; Kim, H.D. [Korea Atomic Energy Research Inst., Daejeon (Korea); Choi, B.I.; Lee, H.Y.; Song, M.J. [Korea Hydro and Nuclear Power Co., Ltd., Daejeon (Korea)

    2004-07-01

    The purpose of this paper is to perform a thermal analysis of a spent fuel storage cask in order to predict the maximum concrete and fuel cladding temperatures. Thermal analyses have been carried out for a storage cask under normal and off-normal conditions. The environmental temperature is assumed to be 27 {open_square} under the normal condition. The off-normal condition has an environmental temperature of 40 {open_square}. An additional off-normal condition is considered as a partial blockage of the air inlet ducts. Four of the eight inlet ducts are assumed to be completely blocked. The storage cask is designed to store 24 PWR spent fuel assemblies with a burn-up of 55,000 MWD/MTU and a cooling time of 7 years. The decay heat load from the 24 PWR assemblies is 25.2 kW. Thermal analyses of ventilation system have been carried out for the determination of the optimum duct size and shape. The finite volume computational fluid dynamics code FLUENT was used for the thermal analysis. In the results of the analysis, the maximum temperatures of the fuel rod and concrete overpack were lower than the allowable values under the normal condition and off-normal conditions.

  2. Probabilistic Risk Assessment of Cask Drop Accident during On-site Spent Nuclear Fuel Transportation

    Energy Technology Data Exchange (ETDEWEB)

    Ham, Jae Hyun; Christian, Robby; Momani, Belal Al; Kang, Hyun Gook [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    There are two ways to transfer the SNF from a site to other site, one is land transportation and the other is maritime transportation. Maritime transportation might be used because this way uses more safe route which is far from populated area. The whole transportation process can be divided in two parts: transferring the SNF between SNP and wharf in-Nuclear Power Plant (NPP) site by truck, and transferring the SNF from the wharf to the other wharf by ship. In this research, on-site SNF transportation between SNP and wharf was considered. Two kinds of single accident can occur during this type of SNF transportation, impact and fire, caused by internal events and external events. In this research, PRA of cask drop accident during onsite SNF transportation was done, risk to a person (mSv/person) from a case with specific conditions was calculated. In every 11 FEM simulation drop cases, FDR is 1 even the fuel assemblies are located inside of the cask. It is a quite larger value for all cases than the results with similar drop condition from the reports which covers the PRA on cask storage system. Because different from previous reports, subsequent impact was considered. Like in figure 8, accelerations which are used to calculate the FDR has extremely higher values in subsequent impact than the first impact for all SNF assemblies.

  3. Alternate approaches to verifying the structural adequacy of the Defense High Level Waste Shipping Cask

    Energy Technology Data Exchange (ETDEWEB)

    Zimmer, A.; Koploy, M.

    1991-12-01

    In the early 1980s, the US Department of Energy/Defense Programs (DOE/DP) initiated a project to develop a safe and efficient transportation system for defense high level waste (DHLW). A long-standing objective of the DHLW transportation project is to develop a truck cask that represents the leading edge of cask technology as well as one that fully complies with all applicable DOE, Nuclear Regulatory Commission (NRC), and Department of Transportation (DOT) regulations. General Atomics (GA) designed the DHLW Truck Shipping Cask using state-of-the-art analytical techniques verified by model testing performed by Sandia National Laboratories (SNL). The analytical techniques include two approaches, inelastic analysis and elastic analysis. This topical report presents the results of the two analytical approaches and the model testing results. The purpose of this work is to show that there are two viable analytical alternatives to verify the structural adequacy of a Type B package and to obtain an NRC license. It addition, this data will help to support the future acceptance by the NRC of inelastic analysis as a tool in packaging design and licensing.

  4. SHIELDING ANALYSIS OF DUAL PURPOSE CASKS FOR SPENT NUCLEAR FUEL UNDER NORMAL STORAGE CONDITIONS

    Directory of Open Access Journals (Sweden)

    JAE-HUN KO

    2014-08-01

    The design of the cask is based on the safety requirements for normal storage conditions under 10 CFR Part 72. A radiation shielding analysis of the metal storage cask optimized for loading 21 design basis fuels was performed for two cases; one for a single cask and the other for a 2×10 cask array. For the single cask, dose rates at the external surface of the metal cask, 1m and 2m away from the cask surface, were evaluated. For the 2×10 cask array, dose rates at the center point of the array and at the center of the casks’ height were evaluated. The results of the shielding analysis for the single cask show that dose rates were considerably higher at the lower side (from the bottom of the cask to the bottom of the neutron shielding of the cask, at over 2mSv/hr at the external surface of the cask. However, this is not considered to be a significant issue since additional shielding will be installed at the storage facility. The shielding analysis results for the 2×10 cask array showed exponential decrease with distance off the sources. The controlled area boundary was calculated to be approximately 280m from the array, with a dose rate of 25mrem/yr. Actual dose rates within the controlled area boundary will be lower than 25mrem/yr, due to the decay of radioactivity of spent fuel in storage.

  5. 基于禁忌搜索优化算法的高压大容量柔性直流输电子模块电容电压平衡算法%A Capacitor Voltage Balancing Control Strategy for High-voltage Large-capacity VSC-HVDC Systems Based on Tabu Search Hard Optimization Algorithm

    Institute of Scientific and Technical Information of China (English)

    姜喜瑞; 贺之渊; 汤广福; 谢敏华; 刘栋

    2013-01-01

    This paper is written on the valve base control strategy specifically for high-voltage large-capacity modular multi-level converter (MMC) and on the sub-module capacitor voltage balance control strategy using tabu search optimization algorithm. In the context of high-voltage large-capacity VSC-HVDC transmission system, the paper analyzes MMC topology and related valve base control technique. The criteria for sub-module capacitor voltage balance algorithm are brought forward; the switching principle of sub-module pulse distribution is given in-depth study. Based on a distributed system structure, a novel sub-module voltage balance model using tabu search optimization algorithm is presented applicable to VSC-HVDC valve base control technique. In order to set up the objective function and constraints, establish the state decision optimization model, and formulate the optimization algorithm process, this model considers various factors, such as sub-module switch- on/off, energy fluctuations, and key parameters quintuple information tree. Simulation test and off-line test were carried out on the dynamic simulation platform employing PSCAD/EMTDC software. The test results showed that this approach was as good as nearest level approximation in terms of functionality and performance reliability, thus providing theoretical support and engineering basis.%  针对高压大容量模块化多电平换流器(modular multilevel converter,MMC)的阀基控制技术策略,研究基于禁忌搜索优化算法的子模块电容电压平衡控制策略。以高压大容量柔性直流输电系统为应用背景,对MMC技术及其阀基控制技术进行分析研究,通过对MMC技术子模块电压平衡策略的研究,提出了子模块电容电压平衡算法的评判指标,并对子模块脉冲分配投切机理进行了深入的分析研究;在分布式系统架构基础上,提出了一种新颖的适用于高压大容量柔性直流输电系统阀基控制技

  6. 基于VSC-HVDC提高系统电压稳定性研究

    Institute of Scientific and Technical Information of China (English)

    郭贺宏; 杜欣慧

    2006-01-01

    针对无功功率投切的过程中引起系统的电压不稳定问题,提出将基于电压源换流器的高压直流输电系统(VSC-HVDC)能够起到STATCOM的作用,稳定交流母线电压。建立了交流系统和VSC-HVDC系统的物理模型,在PSCAD/EMTDC环境下的仿真,比较交流系统与具有VSC-HVDC的交流系统下在投切相同无功负荷时,实验表明VSC-HVDC从而避免了出现无功功率大幅度不平衡情况,提高系统的电压稳定性。

  7. Preliminary design report: Babcock and Wilcox BR-100 100-ton rail/barge spent fuel shipping cask

    Energy Technology Data Exchange (ETDEWEB)

    None

    1990-02-01

    The purpose of this document is to provide information on burnup credit as applied to the preliminary design of the BR-100 shipping cask. There is a brief description of the preliminary basket design and the features used to maintain a critically safe system. Following the basket description is a discussion of various criticality analyses used to evaluate burnup credit. The results from these analyses are then reviewed in the perspective of fuel burnups expected to be shipped to either the final repository or a Monitored Retrievable Storage (MRS) facility. The hurdles to employing burnup credit in the certification of any cask are then outlines and reviewed. the last section gives conclusions reached as to burnup credit for the BR-100 cask, based on our analyses and experience. All information in this study refers to the cask configured to transport PWR fuel. Boiling Water Reactor (BWR) fuel satisfies the criticality requirements so that burnup credit is not needed. All calculations generated in the preparation of this report were based upon the preliminary design which will be optimized during the final design. 8 refs., 19 figs., 16 tabs.

  8. Multi-frequency proportional-resonant (MFPR) current controller for PWM VSC under unbalanced supply conditions

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This letter presents a multi-frequency proportional-resonant (MFPR) current controller developed for PWM voltage source converter (VSC) under the unbalanced supply voltage conditions. The delta operator is used in place of the shift operator for the implementation of MFPR by using a low-cost fixed-point DSP. The experimental results with an alternative control strategy validated the feasibility of the proposed MFPR current controller for the PWM VSC during voltage unbalance.

  9. 空间矢量脉宽调制在离散VSC-HVDC中的应用%Space Vector Pulse Width Modulation Applied in Discrete VSC-HVDC

    Institute of Scientific and Technical Information of China (English)

    张楠

    2014-01-01

    在仿真软件PSCAD/EMTDC中,利用Fortran语言创建空间矢量脉宽调制(SVPWM)功能模块,实现SVPWM在VSC-HVDC离散控制策略中的应用.为验证所提方案的可行性,在仿真软件中建立了向无源网络供电的VSC-HVDC离散控制策略数字仿真模型,并进行了仿真.仿真结果表明,所提SVPWM方案能够有效地改善VSC-HVDC控制系统的性能.

  10. 77 FR 64834 - Computational Fluid Dynamics Best Practice Guidelines for Dry Cask Applications

    Science.gov (United States)

    2012-10-23

    ...The U.S. Nuclear Regulatory Commission (NRC or the Commission) is requesting public comments on draft NUREG-2152, ``Computational Fluid Dynamics Best Practice Guidelines for Dry Cask Applications.'' The draft NUREG-2152 report provides best practice guidelines for undertaking simulations used to evaluate the thermal response of dry casks. Dry cask applications include transfer, transport, and......

  11. Safety Assessment of a Metal Cask under Aircraft Engine Crash

    Directory of Open Access Journals (Sweden)

    Sanghoon Lee

    2016-04-01

    Full Text Available The structural integrity of a dual-purpose metal cask currently under development by the Korea Radioactive Waste Agency (KORAD was evaluated, through numerical simulations and a model test, under high-speed missile impact reflecting targeted aircraft crash conditions. The impact conditions were carefully chosen through a survey on accident cases and recommendations from literature. In the impact scenario, a missile flying horizontally hits the top side of the cask, which is freestanding on a concrete pad, with a velocity of 150 m/s. A simplified missile simulating a commercial aircraft engine was designed from an impact load–time function available in literature. In the analyses, the dynamic behavior of the metal cask and the integrity of the containment boundary were assessed. The simulation results were compared with the test results for a 1:3 scale model. Although the dynamic behavior of the cask in the model test did not match exactly with the prediction from the numerical simulation, other structural responses, such as the acceleration and strain history during the impact, showed very good agreement. Moreover, the containment function of the cask survived the missile impact as expected from the numerical simulation. Thus, the procedure and methodology adopted in the structural numerical analyses were successfully validated.

  12. Safety assessment of a metal cask under aircraft engine crash

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Hoon [Dept. of Mechanical and Automotive Engineering, Keimyung University, Daegu (Korea, Republic of); Choi, Woo Seok; Seo, Ki Seog [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-04-15

    The structural integrity of a dual-purpose metal cask currently under development by the Korea Radioactive Waste Agency (KORAD) was evaluated, through numerical simulations and a model test, under high-speed missile impact reflecting targeted aircraft crash conditions. The impact conditions were carefully chosen through a survey on accident cases and recommendations from literature. In the impact scenario, a missile flying horizontally hits the top side of the cask, which is free standing on a concrete pad, with a velocity of 150 m/s. A simplified missile simulating a commercial aircraft engine was designed from an impact load-time function available in literature. In the analyses, the dynamic behavior of the metal cask and the integrity of the containment boundary were assessed. The simulation results were compared with the test results for a 1:3 scale model. Although the dynamic behavior of the cask in the model test did not match exactly with the prediction from the numerical simulation, other structural responses, such as the acceleration and strain history during the impact, showed very good agreement. Moreover, the containment function of the cask survived the missile impact as expected from the numerical simulation. Thus, the procedure and methodology adopted in the structural numerical analyses were successfully validated.

  13. Application of an Improved PSO-based PID Neural Network Controller for VSC-HVDC%基于改进粒子群算法的PIDNN控制器在VSC-HVDC中的应用

    Institute of Scientific and Technical Information of China (English)

    李爽; 王志新; 王国强

    2013-01-01

    An improved niche chaotic particle swarm optimization (INCPSO) method for voltage source converter based high-voltage direct-current (VSC-HVDC) system was presented. It emerges the good features of niche and chaotic mutation evolutionary algorithms for searching the global best parameters of proportional-integral-derivative neural-network (PIDNN). With the introduction of restricted competition selection (RCS) method into the niche mechanism, the global exploration ability of PSO is enhanced. Simultaneously, the precise local exploitation performance can be well achieved by using the chaotic mutation algorithm with tent-mapping functions. The INCPSO can solve the premature phenomenon and local convergence problem of traditional PSO, and give a balance point between the exploration and exploitation capability. The detail steps of parameters optimizing for PIDNN controller in VSC-HVDC system was presented, and a numerical example was carried out to validate the feasibility and effectiveness of INCPSO. Simulation results show that the INCPSO search capability is more accurate, effective and robust. The INCPSO based PIDNN controller provides a feasible control scheme in the offshore wind farm VSC-HVDC system.%针对海上风电场并网柔性直流输电(voltage source converter based high-voltage direct-current,VSC-HVDC)系统比例-积分-微分神经网络(PID neural network,PIDNN)控制器参数寻优过程中存在的问题,提出一种基于限制竞争小生境混沌变异的改进粒子群算法(improved niche· chaotic particle swarm optimization,INCPSO).该算法中小生境技术引入限制竞争淘汰机制,使其具有良好的全局寻优能力(探索),配合改进的帐篷映射混沌变异算法,可获得局部精细遍历性能(发现).在解决粒子群算法早熟收敛和搜索精度低等问题的同时,最大程度地平衡了粒子群算法在解空间内的探索和发现能力.给出了VSC-HVDC系统中PIDNN控制器参数寻优INCPSO算法

  14. Vestibule and Cask Preparation Mechanical Handling Calculation

    Energy Technology Data Exchange (ETDEWEB)

    N. Ambre

    2004-05-26

    The scope of this document is to develop the size, operational envelopes, and major requirements of the equipment to be used in the vestibule, cask preparation area, and the crane maintenance area of the Fuel Handling Facility. This calculation is intended to support the License Application (LA) submittal of December 2004, in accordance with the directive given by DOE correspondence received on the 27th of January 2004 entitled: ''Authorization for Bechtel SAIC Company L.L.C. to Include a Bare Fuel Handling Facility and Increased Aging Capacity in the License Application, Contract Number DE-AC28-01R W12101'' (Ref. 167124). This correspondence was appended by further correspondence received on the 19th of February 2004 entitled: ''Technical Direction to Bechtel SAIC Company L.L. C. for Surface Facility Improvements, Contract Number DE-AC28-01R W12101; TDL No. 04-024'' (Ref. 16875 1). These documents give the authorization for a Fuel Handling Facility to be included in the baseline. The limitations of this preliminary calculation lie within the assumptions of section 5 , as this calculation is part of an evolutionary design process.

  15. Contract Report for Usage Inspection of KN-12 Transport Cask

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J. C.; Seo, K. S.; Bang, K. S.; Cho, I. J.; Kim, D. H.; Min, D. K

    2007-03-15

    The usage inspection of the KN-12 spent nuclear fuel transport package was performed to receive the license for reuse. According to the Korea Atomic Energy Act, all type B transport package should receive and pass the usage inspection every five years. The KN-12 transport cask was designed to transport twelve spent PWR fuel assemblies under wet and dry conditions. The cask was developed and licensed in 2002 in accordance with the Korea and the IAEA's safe transport regulations. The areas of usage inspection include: visual inspection, nondestructive weld inspection, load test, maximum operating pressure test, leakage test, shielding test, thermal test, external surface contamination test. In the results of the usage inspection, the damage or defect could not found out and the performance of the cask was maintained according to the requirements of the regulation. Therefore, the usage inspection was successfully performed to acquire the license for the reuse.

  16. Evaluation of Effect of Fuel Assembly Loading Patterns on Thermal and Shielding Performance of a Spent Fuel Storage/Transportation Cask

    Energy Technology Data Exchange (ETDEWEB)

    Cuta, Judith M.; Jenquin, Urban P.; McKinnon, Mikal A.

    2001-11-20

    The licensing of spent fuel storage casks is generally based on conservative analyses that assume a storage system being uniformly loaded with design basis fuel. The design basis fuel typically assumes a maximum assembly enrichment, maximum burn up, and minimum cooling time. These conditions set the maximum decay heat loads and radioactive source terms for the design. Recognizing that reactor spent fuel pools hold spent fuel with an array of initial enrichments, burners, and cooling times, this study was performed to evaluate the effect of load pattern on peak cladding temperature and cask surface dose rate. Based on the analysis, the authors concluded that load patterns could be used to reduce peak cladding temperatures in a cask without adversely impacting the surface dose rates.

  17. Benchmarking Data for the Proposed Signature of Used Fuel Casks

    Energy Technology Data Exchange (ETDEWEB)

    Rauch, Eric Benton [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-09-23

    A set of benchmarking measurements to test facets of the proposed extended storage signature was conducted on May 17, 2016. The measurements were designed to test the overall concept of how the proposed signature can be used to identify a used fuel cask based only on the distribution of neutron sources within the cask. To simulate the distribution, 4 Cf-252 sources were chosen and arranged on a 3x3 grid in 3 different patterns and raw neutron totals counts were taken at 6 locations around the grid. This is a very simplified test of the typical geometry studied previously in simulation with simulated used nuclear fuel.

  18. Safety analysis report for medical radioisotope transport cask

    Energy Technology Data Exchange (ETDEWEB)

    Seo, K. S.; Ku, J. H.; Lee, J. C. [Korea Atomic Energy Research Institute, Taejon (Korea)

    1999-10-01

    KAERI has been producing radioisotopes for medical and industrial use and supplying them to radioisotope-using hospitals and industries. RI transport cask of A type package has been developed to transport medical radioisotopes from the HANARO to the hospitals. The safety analyses were performed under normal transport conditions in accordance with standards of transport regulations. As a results, it should be verified that the cask maintains the shielding and structural integrities under prescribed condition by the regulations. 8 refs., 20 figs., 7 tabs. (Author)

  19. ACCIDENTAL DROP OF A CARBON STEEL/LEAD SHIPPING CASK AT LOW TEMPERATURES

    Energy Technology Data Exchange (ETDEWEB)

    B. D. Hawkes; K. R. Durstine

    2007-07-01

    A shielded cask is used to transport radioactive materials between facilities. The cask was fabricated with an outer and inner shell of hot rolled low carbon steel. Lead was poured in the annular space between the shells to provide radiation shielding. Carbon steel is known to be susceptible to lowtemperature brittle fracture under impact loading. This paper will present the analysis results representing postulated transportation accidents during on-site transfers of the cask. The accident scenarios were based on a series of cask drops onto a rigid surface from a height of 6 ft assuming brittle failure of the cask shell at subzero temperatures. Finite element models of the cask and its contents were solved and post processed using ABAQUS software. Each model was examined for failure to contain radioactive materials and/or significant loss of radiation shielding. Results of these analyses show that the body of the cask exhibits considerable ruggedness and will remain largely intact after the impact. There will be deformation of the main cask body with localized brittle failure of the cask outer shell and components and but no complete penetration of the cask shielding. The cask payload outer waste can will experience some permanent plastic deformation in each drop, but will not be deformed to the point where it will rupture, thus maintaining confinement of the can contents.

  20. Cosmic ray muon computed tomography of spent nuclear fuel in dry storage casks

    CERN Document Server

    Poulson, D; Guardincerri, E; Morris, C L; Bacon, J D; Plaud-Ramos, K; Morley, D; Hecht, A

    2016-01-01

    Radiography with cosmic ray muon scattering has proven to be a successful method of imaging nuclear material through heavy shielding. Of particular interest is monitoring dry storage casks for diversion of plutonium contained in spent reactor fuel. Using muon tracking detectors that surround a cylindrical cask, cosmic ray muon scattering can be simultaneously measured from all azimuthal angles, giving complete tomographic coverage of the cask interior. This paper describes the first application of filtered back projection algorithms, typically used in medical imaging, to cosmic ray muon imaging. The specific application to monitoring spent nuclear fuel in dry storage casks is investigated via GEANT4 simulations. With a cylindrical muon tracking detector surrounding a typical spent fuel cask, the cask contents can be confirmed with high confidence in less than two days exposure. Similar results can be obtained by moving a smaller detector to view the cask from multiple angles.

  1. Analysis, scale modeling, and full-scale test of a railcar and spent-nuclear-fuel shipping cask in a high-velocity impact against a rigid barrier

    Energy Technology Data Exchange (ETDEWEB)

    Huerta, M.

    1981-06-01

    This report describes the mathematical analysis, the physical scale modeling, and a full-scale crash test of a railcar spent-nuclear-fuel shipping system. The mathematical analysis utilized a lumped-parameter model to predict the structural response of the railcar and the shipping cask. The physical scale modeling analysis consisted of two crash tests that used 1/8-scale models to assess railcar and shipping cask damage. The full-scale crash test, conducted with retired railcar equipment, was carefully monitored with onboard instrumentation and high-speed photography. Results of the mathematical and scale modeling analyses are compared with the full-scale test. 29 figures.

  2. A Study on the Black Start Capability of VSC-HVDC Using Soft-Starting Mode%采用软启动方式的VSC-HVDC黑启动能力研究

    Institute of Scientific and Technical Information of China (English)

    周明霞; 刘宗歧; 李胜; 张建华; 李银辉

    2009-01-01

    合理的黑启动方案对于快速可靠地恢复供电至关重要.分析了VSC-HVDC作为黑启动电源的优势.通过PSCAD/EMTDC软件验证了VSC-HVDC软启动主要电力设备的能力.仿真过程中记录的波形显示了VSC-HVDC良好的电压、频率特性.对VSC-HVDC黑肩动控制到正常潮流控制的转换过程也做了仿真研究.仿真结果表明,当采用软启动方式时,VSC-HVDC是一种理想的黑启动电源.

  3. Cooperative control of VSC-HVDC connected offshore wind farm with Low-Voltage Ride-Through capability

    DEFF Research Database (Denmark)

    Liu, Yan; Wang, Xiongfei; Chen, Zhe

    2012-01-01

    The Low-Voltage Ride-Through (LVRT) has become an important grid requirement for offshore wind farms connecting with Voltage Source Converter based High Voltage Direct Current (VSC-HVDC) links. In this paper, a cooperative control strategy with LVRT ability is proposed for a VSC-HVDC connected va...

  4. A design report for DFDF radioactive waste storage cask

    Energy Technology Data Exchange (ETDEWEB)

    Lee, H. H.; Kim, J. H.; Park, J. J.; Yang, M. S.; Lee, J. C.; Seo, K. S

    2004-01-01

    The fabrication of DUPIC fuel powder, pellet and fuel rod has been conducted since the early 2000 at DFDF hot cell, together with their fabrication characterization experiment. The equipment that were used in the experiment, if necessary, have to be disassembled to be transported to the storage facility according to the appropriate management procedures. Therefore, specially designed dedicated storage cask is needed for the waste of large volume such as contaminated equipment and disassembled parts from the equipment. The storage cask, 'A' type transportation cask, has a cylindrical shape and consists of body and lid. It also has a dual cell structure. The cells are made of stainless steel and the lead is molded into the space between cells as a gamma radiation protector. The storage cask is 1,145mm high and weighs 3.5 ton. Its inner and outer diameter are 1,080mm and 1,210mm, respectively. It is designed to maintain at 0.3kg/cm{sup 2} to prevent possible leakage during the storage.

  5. THERMAL MODELING ANALYSIS OF SRS 70 TON CASK

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.; Jordan, J.; Hensel, S.

    2011-03-08

    The primary objective of this work was to perform the thermal calculations to evaluate the Material Test Reactor (MTR) fuel assembly temperatures inside the SRS 70-Ton Cask loaded with various bundle powers. MTR fuel consists of HFBR, MURR, MIT, and NIST. The MURR fuel was used to develop a bounding case since it is the fuel with the highest heat load. The results will be provided for technical input for the SRS 70 Ton Cask Onsite Safety Assessment. The calculation results show that for the SRS 70 ton dry cask with 2750 watts total heat source with a maximum bundle heat of 670 watts and 9 bundles of MURR bounding fuel, the highest fuel assembly temperatures are below about 263 C. Maximum top surface temperature of the plastic cover is about 112 C, much lower than its melting temperature 260 C. For 12 bundles of MURR bounding fuel with 2750 watts total heat and a maximum fuel bundle of 482 watts, the highest fuel assembly temperatures are bounded by the 9 bundle case. The component temperatures of the cask were calculated by a three-dimensional computational fluid dynamics approach. The modeling calculations were performed by considering daily-averaged solar heat flux.

  6. Accidental Drop of a Carbon Steel/Lead Shipping Cask (HFEF 14) at Low Temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Brian D. Hawkes; Michael E. Nitzel

    2007-08-01

    A shielded cask is used to transport radioactive materials between facilities at the Idaho National Laboratory. The cask was fabricated with an outer and inner shell of A36 carbon steel with lead poured in the annular space between the shells to provide radiation shielding. Carbon steel is known to be susceptible to low-temperature brittle fracture under impact loading. This paper will present the analysis results representing postulated transportation accidents during on-site transfers of the cask at subzero temperatures. The accident scenarios were based on a series of cask drops onto a rigid surface from a height of 1.83m (6 ft.) Finite element models of the cask and its contents were solved and post processed using the ABAQUS software. Each model was examined for failure to contain radioactive materials and/or significant loss of radiation shielding. Results of these analyses show that the body of the cask exhibits considerable ruggedness and will remain largely intact after the impact. There will be deformation of the main cask body with localized brittle failure of the cask outer shell and door structure. The cask payload outer waste can remains in the cask but will experience some permanent plastic deformation in each drop. It will not be deformed to the point where it will rupture, thus maintaining confinement of the can contents.

  7. Design of casks: incorporating operational feedback from maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Bimet, F.; Hartenstein, M. [COGEMA Logistics, Saint Quentin (France)

    2004-07-01

    Casks are designed to conform to regulations and to client specifications. Essential areas such as easy operation, low costs of maintenance, low operation and maintenance doses, limited waste, are not explicitly covered. Notwithstanding, COGEMA LOGISTICS uses all feedback available, so that casks are designed to be easy, safe and economical to operate and maintain. Maintenance is an activity where you do spot items that old-time designers could have made better, and things that users should not have done. Thanks to quality assurance, there are a number of data available, waiting to be collected and exploited; they have to be identified, located, retrieved, and analysed. Using information such as wear, damage, use of spare parts, access problems helps to make casks ever better. It leads to more efficient concepts, and to upgrades on existing designs; it also allows to integrate environmental considerations, inter alia in the choice of materials and in maintenance methods. It is necessary for the designer to interact with the users, the cask owners, the maintenance providers, in order to gather all relevant information and events. This is made easier when all these actors are ''under one roof'', or have very close ties. This paper presents COGEMA LOGISTICS methods for collecting and analysing all these experiences waiting to be used. It explains our process for analysing data, preparing yearly reports that are made available to our designers. It describes how each new design is subject to a maintainability study, using this feedback, so that the cask safety is always assured, that radiological doses are kept to a minimum, and that operating and maintenance costs will remain as low as possible.

  8. VSC-HVDC运行机理及直流调制技术研究

    Institute of Scientific and Technical Information of China (English)

    於海

    2010-01-01

    VSC-HVDC是利用自换相电压源换流器VSC进行直流输电的技术,其通过控制VSC输出电压的幅值和相位就可以分别控制有功功率和无功功率,是近年来来出现的一种新型输电技术,现就VSC-HVDC运行机理及直流调制技术进行了分析研究.

  9. VSC-HVDC运行机理及直流调制技术研究

    Institute of Scientific and Technical Information of China (English)

    於海

    2010-01-01

    VSC-HVDC是利用自换相电压源换流器VSC进行直流输电的技术,其通过控制VSC输出电压的幅值和相位就可以分别控制有功功率和无功功率,是近年来来出现的一种新型输电技术,现就VSC-HVDC运行机理及直流调制技术进行了分析研究。

  10. A Comparative analysis of three level VSC based multi-pulse STATCOM

    Directory of Open Access Journals (Sweden)

    Smruti Ranjan Barik

    2014-07-01

    Full Text Available This paper presents a comparative analysis among different models of three level NPC (Neutral point clamped VSC (Voltage source converter based STATCOMs. Here separate models of 12- pulse, 24-pulse, 36-pulse, 48-pulse VSC based STATCOMs are configured in MATLAB environment. These individual models are synthesized using appropriate number of three level converters which are switched at fundamental frequency and their gate pulse pattern are properly phase shifted to get desired number of pulses. The simulation results of each individual model are analyzed in three different modes: inductive, capacitive and floating mode. Harmonic content of the proposed higher pulse models are limited as per IEEE 519 standards.

  11. Developing a voltage-stability-constrained security assessment system part II : Structure and function design and technology used

    OpenAIRE

    Ni, YX; Wu, FF; Shi, LB; Zhou, HF; Tam, PTC; Chang, NC; Su, JF; Du, ZB

    2005-01-01

    This is the second part in a two-part paper on the development of a voltage stability constrained security assessment system (VSC-SAS). In this part, overall VSC-SAS structure and function design and technology used will be presented. The system is expected to be used in both on-line and off-line modes. In on-line mode, on-line SCADA/EMS data will be used for VSC-SAS use; while in off-line mode (usually day-ahead calculation), historical data can be used for VSC-SAS. Both results (i.e. system...

  12. Survivability Tests on a Nuclear Waste Cask in Simulated Railroad Accident Fires.

    Science.gov (United States)

    1983-06-01

    Test Number 1 42 11. The Wind Direction as a Function of Time During the HNPF Cask Thermal Test Number 1...43 12. The Wind Speed as a Function of Time During the HNPF Cask Thermal Test Number 1 .......................................... 44 13. The Ambient...60 27. A View of the HNPF Cask Taken During Torch Thermal Test Number 2 62 28. The Wind Direction as a

  13. Conceptual design of fuel transfer cask for Reactor TRIGA PUSPATI (RTP)

    Science.gov (United States)

    Muhamad, Shalina Sheik; Hamzah, Mohd Arif Arif B.

    2014-02-01

    Spent fuel transfer cask is used to transfer a spent fuel from the reactor tank to the spent fuel storage or for spent fuel inspection. Typically, the cask made from steel cylinders that are either welded or bolted closed. The cylinder is enclosed with additional steel, concrete, or other material to provide radiation shielding and containment of the spent fuel. This paper will discuss the Conceptual Design of fuel transfer cask for Reactor TRIGA Puspati (RTP).

  14. Phenotypic and molecular insights into CASK-related disorders in males

    OpenAIRE

    Moog, U.; T Bierhals; Brand, K.; Bautsch, J.; Biskup, S.; Brune, T.; J. Denecke; Die-Smulders, C E M de; Evers, C.; Hempel, M.; Henneke, M; Yntema, H.G.; Menten, B.; Pietz, J.; Pfundt, R.P.

    2015-01-01

    Background Heterozygous loss-of-function mutations in the X-linked CASK gene cause progressive microcephaly with pontine and cerebellar hypoplasia (MICPCH) and severe intellectual disability (ID) in females. Different CASK mutations have also been reported in males. The associated phenotypes range from nonsyndromic ID to Ohtahara syndrome with cerebellar hypoplasia. However, the phenotypic spectrum in males has not been systematically evaluated to date. Methods We identified a CASK alteration...

  15. STABILITY EVALUATION OF METAL CASK ATTACHED TO A TRANSFER PALLET DURING LONG-PERIOD SEISMIC MOTIONS

    Science.gov (United States)

    Kawaguchi, Shohei; Shirai, Koji; Kanazawa, Kenji

    Rocking behavior of unfixed body is affected by center of mass, material coefficient of restitution and so on. 2/5 scale metal cask model considering these parameter was used for seismic test to evaluate stability of grounding metal cask attached to a transfer pallet under the influence of long-period earthquake motion. The newest knowledge from seismic test indicates seismic motion with high velocity over 100 kine not always cause the raise of response velocity of metal cask because of energy consumption by cask sliding and impact deformation of concrete. And new estimation method (called "Window energy spectrum method") of earthquake response spectrum gives suitable evaluation of response energy.

  16. Safety analysis report for packaging: the ORNL in-pile capsule shipping cask

    Energy Technology Data Exchange (ETDEWEB)

    Evans, J.H.; Chipley, K.K.; Haynie, C.B.; Crowley, W.K.; Just, R.A.

    1977-11-01

    The ORNL in-pile capsule shipping cask is used to transport irradiated experimental capsules and spent fuel elements. The cask was analytically evaluated to determine its compliance with the applicable regulations governing containers in which radioactive materials are transported. Computational procedures were used to determine the structural integrity and thermal behavior of the cask relative to the general standards for normal conditions of transport and the standards for the hypothetical accident conditions. The results of the evaluation show that the cask is in compliance with the applicable regulations.

  17. Breeder Spent Fuel Handling (BSFH) cask study for FY83. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Diggs, J M

    1985-01-01

    This report documents a study conducted to investigate the applicability of existing LWR casks to shipment of long-cooled LMFBR fuel from the Clinch River Breeder Reactor Plant (CRBRP) to the Breeder Reprocessing Engineering Test (BRET) Facility. This study considered a base case of physical constraints of plants and casks, handling capabilities of plants, through-put requirements, shielding requirements due to transportation regulation, and heat transfer capabilities of the cask designs. Each cask design was measured relative to the base case. 15 references, 4 figures, 6 tables.

  18. improvement of power system quality using vsc-based hvdc ...

    African Journals Online (AJOL)

    HOD

    -frame selected such that the quadrature component will result in the ratio between the ..... needed. Figure 8 (a) and (b) shows the analysis of the Voltage waveform and FFT wave spectrum, the ... (MMC) on electromagnetic transient simulation.

  19. Interaction of Droop Control Structures and its Inherent Effect on the Power Transfer Limits in Multi-terminal VSC-HVDC

    DEFF Research Database (Denmark)

    Thams, Florian; Eriksson, Robert; Molinas, M.

    2016-01-01

    Future multi-terminal HVDC systems are expected to utilize dc voltage droop controllers and several control structures have been proposed in literature. This paper proposes a methodology to analyse the impact of various types of droop control structures using small-signal stability analysis...... to disturbances for all the implementations. A case study analyzing a three terminal HVDC VSC-based grid with eight different kinds of droop control schemes points out that three control structures outperform the remaining ones. Additionally, a multi-vendor case is considered where the most beneficial...

  20. Control and operation of wind turbine converters during faults in an offshore wind power plant grid with VSC-HVDC connection

    DEFF Research Database (Denmark)

    Chaudhary, Sanjay; Teodorescu, Remus; Rodriguez, Pedro

    2011-01-01

    ). Current limit control enables the GSC to sustain the fault currents during short circuits in the offshore wind collector system grid. However, power transmission is affected, and the fault has to be isolated. It can be resynchronized after the fault has been cleared and the breaker reclosed. Healthy WTG......Voltage source converter (VSC) based high voltage dc (HVDC) transmission is an attractive technique for large offshore wind power plants, especially when long cable transmission is required for connection to the onshore grid. New multi-MW wind turbines are likely to be equipped with full scale...

  1. Modelling and Simulation of VSC-HVDC Connection for Offshore Wind Power Plants

    DEFF Research Database (Denmark)

    Chaudhary, Sanjay Kumar; Teodorescu, Remus; Rodriguez, Pedro

    2010-01-01

    Several large offshore wind power plants (WPP) are planned in the seas around Europe. VSC-HVDC is a suitable means of integrating such large and distant offshore WPP which need long submarine cable transmission to the onshore grid. Recent trend is to use large wind turbine generators with full...

  2. 交流系统故障时 VSC-HVDC 的保护策略研究

    Institute of Scientific and Technical Information of China (English)

    王帅

    2015-01-01

    本文分析了交流系统电压平衡时 VSC-HVDC 系统的控制策略,阐述了柔性直流输电系统的控制,SC-HVDC 系统的控制策略,内环电流控制器设计,VSC-HVDC 系统仿真与分析,指出交流系统故障时VSC-HVDC 系统的控制策略。

  3. Bonner sphere neutron spectrometry at spent fuel casks

    CERN Document Server

    Rimpler, A

    2002-01-01

    For transport and interim storage of spent fuel elements from power reactors and vitrified highly active waste (HAW) from reprocessing, various types of casks are used. The radiation exposure of the personnel during transportation and storage of these casks is caused by mixed photon-neutron fields and, frequently, the neutron dose is predominant. In operational radiation protection, survey meters and even personal dosemeters with imperfect energy dependence of the dose-equivalent response are used, i.e. the fluence response of the devices does not match the fluence-to-dose equivalent conversion function. In order to achieve more accurate dosimetric information and to investigate the performance of dosemeters, spectrometric investigations of the neutron fields are necessary. Therefore, fluence spectra and dose rates were measured by means of a simple portable Bonner multisphere spectrometer (BSS). The paper describes briefly the experimental set-up and evaluation procedure. Measured spectra for different locat...

  4. A criticality analysis of the GBC-32 dry storage cask with Hanbit nuclear power plant unit 3 fuel assemblies from the viewpoint of burnup credit

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Hyung Ju; Kim, Do Yeon; Park, Kwang Heon; Hong, Ser Gi [Dept. of Nuclear Engineering, Kyung Hee University, Seoul (Korea, Republic of)

    2016-06-15

    Nuclear criticality safety analyses (NCSAs) considering burnup credit were performed for the GBC-32 cask. The used nuclear fuel assemblies (UNFAs) discharged from Hanbit Nuclear Power Plant Unit 3 Cycle 6 were loaded into the cask. Their axial burnup distributions and average discharge burnups were evaluated using the DeCART and Multi-purpose Analyzer for Static and Transient Effects of Reactors (MASTER) codes, and NCSAs were performed using SCALE 6.1/STandardized Analysis of Reactivity for Burnup Credit using SCALE (STARBUCS) and Monte Carlo N-Particle transport code, version 6 (MCNP 6). The axial burnup distributions were determined for 20 UNFAs with various initial enrichments and burnups, which were applied to the criticality analysis for the cask system. The UNFAs for 20- and 30-year cooling times were assumed to be stored in the cask. The criticality analyses indicated that keff values for UNFAs with nonuniform axial burnup distributions were larger than those with a uniform distribution, that is, the end effects were positive but much smaller than those with the reference distribution. The axial burnup distributions for 20 UNFAs had shapes that were more symmetrical with a less steep gradient in the upper region than the reference ones of the United States Department of Energy. These differences in the axial burnup distributions resulted in a significant reduction in end effects compared with the reference.

  5. Safety evaluation for packaging (onsite) disposable solid waste cask

    Energy Technology Data Exchange (ETDEWEB)

    Flanagan, B.D., Westinghouse Hanford

    1996-12-20

    This safety evaluation for packaging (SEP) evaluates and documents the ability of the Disposable Solid Waste Cask (DSWC) to meet the packaging requirements of HNF-CM-2-14, Hazardous Material Packaging and Shipping, for the onsite transfer of special form, highway route controlled quantity, Type B fissile radioactive material. This SEP evaluates five shipments of DSWCs used for the transport and storage of Fast Flux Test Facility unirradiated fuel to the Plutonium Finishing Plant Protected Area.

  6. Performance of bolted closure joint elastomers under cask aging conditions

    Energy Technology Data Exchange (ETDEWEB)

    Verst, C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Sindelar, R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Skidmore, E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Daugherty, W. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-07-23

    The bolted closure joint of a bare spent fuel cask is susceptible to age-related degradation and potential loss of confinement function under long-term storage conditions. Elastomeric seals, a component of the joint typically used to facilitate leak testing of the primary seal that includes the metallic seal and bolting, is susceptible to degradation over time by several mechanisms, principally via thermo-oxidation, stress-relaxation, and radiolytic degradation under time and temperature condition. Irradiation and thermal exposure testing and evaluation of an ethylene-propylene diene monomer (EPDM) elastomeric seal material similar to that used in the CASTOR® V/21 cask for a matrix of temperature and radiation exposure conditions relevant to the cask extended storage conditions, and development of semiempirical predictive models for loss of sealing force is in progress. A special insert was developed to allow Compressive Stress Relaxation (CSR) measurements before and after the irradiation and/or thermal exposure without unloading the elastomer. A condition of the loss of sealing force for the onset of leakage was suggested. The experimentation and modeling being performed could enable acquisition of extensive coupled aging data as well as an estimation of the timeframe when loss of sealing function under aging (temperature/radiation) conditions may occur.

  7. 背靠背VSC-HVDC的多目标优化布点%Multi-Objective Optimal Allocation of Back-to-BackVSC-HVDC

    Institute of Scientific and Technical Information of China (English)

    关玉衡; 汪隆君; 王钢

    2016-01-01

    电网间的电气联系日趋紧密,多个500 kV变电站短路电流接近或超过断路器遮断容量,严重威胁电网安全。采用背靠背电压源换流器型高压直流输电(voltage source convertor-based high voltage direct current,VSC-HVDC)技术限制短路电流的方案获得业界的关注和认同。在分析VSC-HVDC 降低短路电流原理的基础上,建立以短路电流降低综合效果和投资经济性最优为目标的VSC-HVDC多目标优化布点模型,并采用快速非支配排序遗传算法求解;通过多端口网络等值模型约简可行解空间,以提高个体适应度评估速度;基于模糊选择策略获得最优折中分期建设方案。以2015年夏大运行方式的广东电网为算例,验证表明:1)短路电流降低综合效果指标能有效反映限流措施效果和作用范围;2)多端口网络等值能大幅提高算法求解效率;3)综合限流效果与配置点短路电流大小无直接关系。%Electrical connection between power grids becomes increasingly closer. Short-circuit currents of several 500kVsubstations approach or exceed breaking capability of circuit breakers, seriously threatening safe operation of power grid. Scheme of back-to-back voltage source convertor-based HVDC (VSC-HVDC) technology for short-circuit current limiting attracts more and more attention and gets recognition from power industry. Based on analyzing principle of using VSC-HVDC to reduce short-circuit current, multi-objective optimal allocation model of VSC-HVDC is established with objectives of optimizing comprehensive effects of reducing short-circuit current and investment economy. Non-dominated sorting genetic algorithm-II is employed to solve the proposed model. In order to improve speed of individual fitness evaluation, feasible solution space is reduced with multi-port network equivalent model. Fuzzy selection strategy is used to obtain optimal compromised phased construction scheme

  8. Characteristics and fabrication of cermet spent nuclear fuel casks: ceramic particles embedded in steel

    Energy Technology Data Exchange (ETDEWEB)

    Forsberg, C.W.; Swaney, P.M.; Tiegs, T.N. [Oak Ridge National Lab., Oak Ridge, TN (United States)

    2004-07-01

    Cermets are being investigated as an advanced material of construction for casks that can be used for storage, transport, or disposal of spent nuclear fuel (SNF). Cermets, which consist of ceramic particles embedded in steel, are a method to incorporate brittle ceramics with highly desirable properties into a strong ductile metal matrix with a high thermal conductivity, thus combining the best properties of both materials. Traditional applications of cermets include tank armor, vault armor, drill bits, and nuclear test-reactor fuel. Cermets with different ceramics (DUO{sub 2}, Al{sub 2}O{sub 3}, Gd{sub 2}O{sub 3}, etc.) are being investigated for the manufacture of SNF casks. Cermet casks offer four potential benefits: greater capacity (more SNF assemblies) for the same gross weight cask, greater capacity (more SNF assemblies) for the same external dimensions, improved resistance to assault, and superior repository performance. These benefits are achieved by varying the composition, volume fraction, and particulate size of the ceramic particles in the cermet with position in the cask body. Addition of depleted uranium dioxide (DUO{sub 2}) to the cermet increases shielding density, improves shielding effectiveness, and increases cask capacity for a given cask weight or size. Addition of low-density aluminium oxide (Al{sub 2}O{sub 3}) to the outer top and bottom sections of the cermet cask, where the radiation levels are lower, can lower cask weight without compromising shielding. The use of Al2O3 and other oxides, in appropriate locations, can increase resistance to assault. Repository performance may be improved by compositional control of the cask body to (1) create a local geochemical environment that slows the long-term degradation of the SNF and (2) enables the use of DUO{sub 2} for longterm criticality control. While the benefits of using cermets follow directly from their known properties, the primary challenge is to develop low-cost methods to fabricate

  9. Power-Hardware-In-the-Loop (PHIL) Test of VSC-based HVDC connection for Offshore Wind Power Plants (WPPs)

    DEFF Research Database (Denmark)

    Sharma, Ranjan; Cha, Seung-Tae; Wu, Qiuwei;

    2011-01-01

    This paper presents a power-hardware-in-the-loop (PHIL) test for an offshore wind power plant (WPP) interconnected to the onshore grid by a VSC-based HVDC connection. The intention of the PHIL test is to verify the control coordination between the plant side converter of the HVDC connection...... the successful control coordination between the WPP and the plant side VSC converter of the HVDC connection of the WPP....

  10. Transporte de energía eléctrica en corriente contínua. Enlaces HVDC-VSC

    OpenAIRE

    Monterrubio Díez, Mario

    2013-01-01

    El proyecto fin de carrera se plantea como un estudio de la tecnología HVDC-VSC, por su carácter novedoso y reciente implantación en los sistemas de transporte de electricidad. Con este trabajo se pretende dar a conocer de modo general la tecnología HVDC y de manera particular la variante HVDC-VSC.

  11. Phenotypic and molecular insights into CASK-related disorders in males

    NARCIS (Netherlands)

    Moog, U.; Bierhals, T.; Brand, K.; Bautsch, J.; Biskup, S.; Brune, T.; Denecke, J.; Die-Smulders, C.E.M. de; Evers, C.; Hempel, M.; Henneke, M.; Yntema, H.G.; Menten, B.; Pietz, J.; Pfundt, R.P.; Schmidtke, J.; Steinemann, D.; Stumpel, C.T.; Maldergem, L. Van; Kutsche, K.

    2015-01-01

    BACKGROUND: Heterozygous loss-of-function mutations in the X-linked CASK gene cause progressive microcephaly with pontine and cerebellar hypoplasia (MICPCH) and severe intellectual disability (ID) in females. Different CASK mutations have also been reported in males. The associated phenotypes range

  12. 78 FR 8050 - Spent Fuel Cask Certificate of Compliance Format and Content

    Science.gov (United States)

    2013-02-05

    ... designers, major architect/engineering firms, and other organizations and entities involved in the nuclear... NRC-certified dry storage cask designs.'' III. The Petition In its petition (ADAMS Accession No... encompass the evaluation of the site-specific parameters versus the cask design bases information''...

  13. Phenotypic and molecular insights into CASK-related disorders in males

    NARCIS (Netherlands)

    Moog, U.; Bierhals, T.; Brand, K.; Bautsch, J.; Biskup, S.; Brune, T.; Denecke, J.; Die-Smulders, C.E.M. de; Evers, C.; Hempel, M.; Henneke, M.; Yntema, H.G.; Menten, B.; Pietz, J.; Pfundt, R.P.; Schmidtke, J.; Steinemann, D.; Stumpel, C.T.; Maldergem, L. Van; Kutsche, K.

    2015-01-01

    BACKGROUND: Heterozygous loss-of-function mutations in the X-linked CASK gene cause progressive microcephaly with pontine and cerebellar hypoplasia (MICPCH) and severe intellectual disability (ID) in females. Different CASK mutations have also been reported in males. The associated phenotypes range

  14. Regulation of dopamine release by CASK-β modulates locomotor initiation in Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Justin eSlawson

    2014-11-01

    Full Text Available CASK is an evolutionarily conserved scaffolding protein that has roles in many cell types. In Drosophila, loss of the entire CASK gene or just the CASK-β transcript causes a complex set of adult locomotor defects. In this study, we show that the motor initiation component of this phenotype is due to loss of CASK-β in dopaminergic neurons and can be specifically rescued by expression of CASK-β within this subset of neurons. Functional imaging demonstrates that mutation of CASK-β disrupts coupling of neuronal activity to vesicle fusion. Consistent with this, locomotor initiation can be rescued by artificially driving activity in dopaminergic neurons. The molecular mechanism underlying this role of CASK-β in dopaminergic neurons involves interaction with Hsc70-4, a molecular chaperone previously shown to regulate calcium-dependent vesicle fusion. These data suggest that there is a novel CASK-β-dependent regulatory complex in dopaminergic neurons that serves to link activity and neurotransmitter release.

  15. Examination of fault ride-through methods for off-shore wind farms connected to the grid through VSC-based HVDC transmission

    Energy Technology Data Exchange (ETDEWEB)

    Karaagac, U.; Mahseredjian, J.; Saad, H. [Ecole Polytechnique de Montreal, QC (Canada); Jensen, S.; Cai, L. [REpower Systems AG, Hamburg (Germany)

    2012-07-01

    The fault ride-through (FRT) performance of offshore wind farms (OWFs) is a challenging task when the OWF is connected to the onshore ac grid through a voltage source converter (VSC) based HVDC transmission system. The injected power from the OWF cannot be reduced by the offshore VSC during onshore ac faults and this causes a fast increase in the dc network voltage. Without any special FRT method, the dc network voltage may increase up to intolerable levels and cause operation of dc overvoltage protection. This paper compares various FRT methods based on fast reduction of power generation in OWFs. In addition, this paper proposes an improved FRT method based on controlled voltage drop for output power reduction in OWFs. The proposed improvement reduces mechanical stress on the wind turbine (WT) drive train, and electrical stress on the insulated gate bipolar transistors (IGBTs) of the HVDC and doubly-fed induction generator (DFIG) converters. Practical onshore ac fault scenarios are simulated for an OWF composed of DFIG type WTs and connected to a practical ac grid through a point-to-point modular multilevel converter (MMC) based HVDC system. (orig.)

  16. 基于VSC-HVDC的黑启动线路工频过电压抑制策略分析

    Institute of Scientific and Technical Information of China (English)

    赵廷刚; 苏旭辉; 陈伟; 龙伟

    2012-01-01

    对黑启动过程中,VSC-HVDC带空载长线路所引起的工频过电压问题进行了研究.通过对工频过电压以及VSC-HVDC模型的理论分析,提出了基于VSC-HVDC抑制工频过电压的控制策略,并采用PSCAD对传统启动方式和基于VSC-HVDC的黑启动方式进行仿真,仿真结果验证了该控制策略的正确性.

  17. Active and reactive power flow regulation for a grid connected vsc based on fuzzy controllers

    Directory of Open Access Journals (Sweden)

    Nelson Díaz Aldana

    2013-01-01

    bajo diferentes niveles de transferencia de potencia. Este artículo, presenta el análisis, diseño y resultados de la implementación de controladores difusos para la regulación del flujo de potencia activa y reactiva de un VSC conectado a red. Además, se muestra la dependencia de la respuesta transitoria y de estado estacionario con la forma de las funciones de pertenencia del controlador difuso cuando este se aplica a diferentes niveles de transferencia de potencia. El desempeño de los controladores se verifica mediante simulación y mediante implementación física en un prototipo construido de un VSC.

  18. Detailed Equivalent VSC-HVDC Modelling for Time Domain Harmonic Stability Studies in Wind Power Plants

    DEFF Research Database (Denmark)

    Glasdam, Jakob Bærholm; Bak, Claus Leth; Kocewiak, Lukasz Hubert;

    2017-01-01

    This paper presents a detailed equivalent modelling approach of the modular multi-level cascaded converter (MMCC) voltage source converter high voltage direct current (VSC-HVDC) in electromagnetic transient programs (EMTPs). The presented MMCC model will be evaluated based on comparison with the ......This paper presents a detailed equivalent modelling approach of the modular multi-level cascaded converter (MMCC) voltage source converter high voltage direct current (VSC-HVDC) in electromagnetic transient programs (EMTPs). The presented MMCC model will be evaluated based on comparison...... generators in service, as this is known to influence the harmonic stability in OWPPs. The paper demonstrates the necessity of the inclusion of a detailed equivalent model of the HVDC converter for harmonic stability studies in the time domain. By implementation of active filtering in the converters...

  19. Dynamic modelling of VSC-HVDC for connection of offshore wind farms

    DEFF Research Database (Denmark)

    Rios, Bardo; Garcia-Valle, Rodrigo

    2011-01-01

    A VSC-HVDC (Voltage Source Converter – High Voltage Direct Current) dynamic model with a set of control strategies is developed in DIgSILENT Power-Factory with the objective of analyzing the converter’s operating capability for grid support during grid faults. The investigation is carried out based...... on a 165 MW offshore wind farm with induction generators and a Low Voltage Ride-Through solution of the offshore wind turbines and Static Voltage Compensator units in the point of connection with a grid represented by a reduced four-generator power grid model. VSC-HVDC promises to be a reliable alternative...... solution for interconnection with off-shore wind farms as they become larger, with a higher installed power capacity, increased number of wind turbines, and geographically situated at larger distances from suitable connection points in the transmission grids....

  20. Dynamics of voltage source converter in a grid connected solar photovoltaic system

    DEFF Research Database (Denmark)

    Haribabu, Divyanagalakshmi; Vangari, Adithya; Sakamuri, Jayachandra N.

    2015-01-01

    This paper emphasises the modelling and control of a voltage source converter (VSC) for three phase grid connected PV system. The transfer functions for inner current control and outer DC link voltage control for VSC are derived. The controllers for VSC are designed based on PI and K factor contr...... conditions. The effectiveness of the proposed controller is illustrated by evaluating the response of PV system for power system voltage sag and swell conditions as well as grid faults.......This paper emphasises the modelling and control of a voltage source converter (VSC) for three phase grid connected PV system. The transfer functions for inner current control and outer DC link voltage control for VSC are derived. The controllers for VSC are designed based on PI and K factor control...... methods and the performance of VSC using both the methods are presented with the simulations performed using PSCAD/EMTDC. The design of LC filter to meet the specified THD requirement for grid connected VSC is presented and the corresponding harmonic analysis is performed for different solar radiation...

  1. Reuse inspection refort of the spent fuel cask

    Energy Technology Data Exchange (ETDEWEB)

    Park, S. W.; Seo, K. S.; Ku, J. H.; Lee, J. C.; Bang, K. S.; Min, D. K. [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2000-04-01

    This is the contract result report performed by KAERI under the contract with KPS for the reuse inspection of the KSC-4 No. 2 cask to receive the license for the reuse of next 5 years. According to the revision of the atomic regulations, all type B package should receive and pass the reuse inspection for every 5 years. This report contains the summary of the reuse inspection project, the details of the inspection methods and evaluation criteria, the documents which submitted to the KINS and the license approved by the KINS. 1 tabs. (Author)

  2. Safety analysis report for packaging (onsite) multicanister overpack cask

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, W.S.

    1997-07-14

    This safety analysis report for packaging (SARP) documents the safety of shipments of irradiated fuel elements in the MUlticanister Overpack (MCO) and MCO Cask for a highway route controlled quantity, Type B fissile package. This SARP evaluates the package during transfers of (1) water-filled MCOs from the K Basins to the Cold Vacuum Drying Facility (CVDF) and (2) sealed and cold vacuum dried MCOs from the CVDF in the 100 K Area to the Canister Storage Building in the 200 East Area.

  3. 南澳多端柔性直流输电示范工程仿真和测试%Simulation and Test of Nan’ao VSC-MTDC Demonstration Project

    Institute of Scientific and Technical Information of China (English)

    冯满盈; 李岩; 许树楷; 饶宏; 黎小林; 朱喆; 魏伟; 陈名

    2015-01-01

    南澳多端柔性直流输电示范工程(简称南澳柔直工程)是世界上第一个VSC-MTDC工程。对该工程柔直换流器满载运行时谐波和损耗水平进行测试,结果表明柔直换流器产生谐波电流小,对交流电网电压畸变率基本无影响,换流器损耗在额定功率的1%左右。对换流器的有功和无功阶跃、风电场通过纯直流系统并网、系统功率反转和三端功率升降进行了仿真研究,结果表明南澳柔直工程构成了灵活可控的三端直流输电网络,能将南澳岛风电场的风电接入电网并保持自身和相关电网稳定运行。%Nan’ao VSC-MTDC Demonstration Project is the first VSC-MTDC project in the world. The harmonic and loss have been tested when the converters were of full load, the results show that the harmonic current generated by the VSC converters is so small that it is almost of no distortion in AC voltage, and the converter loss is about 1% of rated capacity. Simulations of the active and reactive power step, grid integration of wind farm by a pure DC system, power inversion of the system, and power up and down of the three terminals are carried out. The results show that Nan’ao VSC-MTDC project results in a HVDC system with three terminals, which can integrate the wind power of the wind farms at Nan’ao island into the power grid and keep itself and the related grid in stable operation.

  4. Implications of the Baltimore Rail Tunnel Fire for Full-Scale Testing of Shipping Casks

    Energy Technology Data Exchange (ETDEWEB)

    Halstead, R. J.; Dilger, F.

    2003-02-25

    The U.S. Nuclear Regulatory Commission (NRC) does not currently require full-scale physical testing of shipping casks as part of its certification process. Stakeholders have long urged NRC to require full-scale testing as part of certification. NRC is currently preparing a full-scale casktesting proposal as part of the Package Performance Study (PPS) that grew out of the NRC reexamination of the Modal Study. The State of Nevada and Clark County remain committed to the position that demonstration testing would not be an acceptable substitute for a combination of full-scale testing, scale-model tests, and computer simulation of each new cask design prior to certification. Based on previous analyses of cask testing issues, and on preliminary findings regarding the July 2001 Baltimore rail tunnel fire, the authors recommend that NRC prioritize extra-regulatory thermal testing of a large rail cask and the GA-4 truck cask under the PPS. The specific fire conditions and other aspects of the full-scale extra-regulatory tests recommended for the PPS are yet to be determined. NRC, in consultation with stakeholders, must consider past real-world accidents and computer simulations to establish temperature failure thresholds for cask containment and fuel cladding. The cost of extra-regulatory thermal testing is yet to be determined. The minimum cost for regulatory thermal testing of a legal-weight truck cask would likely be $3.3-3.8 million.

  5. 并联电容器对VSC-HVDC供电无源网络的影响%The Impact of Shunt Reactors on Passive Electronical Networks with VSC-HVDC Power Supply

    Institute of Scientific and Technical Information of China (English)

    乔丽; 程佳音

    2009-01-01

    当负荷超过基于电压源换流器的高压直流输电(VSC-HVDC)系统的调节能力时,其不能满足负荷的需求.基于VSC-HVDC的稳态物理模型,设计了其供电无源网络时的控制系统.分析了在逆变侧母线投入并联电容器时对VSC-HVDC系统调节能力和输送功率的影响,提出了由VSC-HVDC和电容器组成的"可变电容器"的理念.PSCAC/EMTDC仿真结果证明了所设计控制系统的有效性.同时证明了并联电容器可以改善VSC-HVDC供电无源网络时的调节特性和输送功率能力;且当负荷增加时,"可变电容器"对无功功率的调节具有速度快,冲击小的特点.

  6. Study of VSC-HVDC Controller to Mitigate Voltage Fluctuation Caused by Wind Farm Integration%VSC-HVDC控制器抑制风电场电压波动的研究

    Institute of Scientific and Technical Information of China (English)

    魏晓光; 汤广福; 魏晓云; 迟永宁

    2007-01-01

    风电潮流的波动会引起并网系统公共连接点(PCC)电压的波动.在基于电压源换流器的高压直流输电(VSC-HVDC)交直流混合风电场并网系统中,控制VSC-HVDC送端站注入到PCC点的无功功率可以抑制电压波动.本文讨论了VSC-HVDC的无功功率控制器和定电压控制器抑制电压波动的原理.基于电磁暂态软件PSCAD/EMTDC建立了并网风电场模型、VSC-HVDC模型及控制系统模型.仿真结果表明VSC-HVDC采用定电压控制器的并网系统能更好的抑制电压波动,采用无功功率控制器的系统具有较好的风电场并网性能.

  7. Contamination transfers during fuel transport cask loading. A concrete situation

    Energy Technology Data Exchange (ETDEWEB)

    Fournel, B.; Turchet, J.P.; Faure, S.; Allinei, P.G. [DEN/DED Centre d' Etudes de Cadarache, 13 - Saint Paul lez Durance (France); Briquet, L. [EDF GENV, 93 - Saint Denis (France); Baubet, D. [SGS Qualitest Industrie, 30 - Pont Saint Esprit (France)

    2002-07-01

    In 1998, a number of contamination cases detected during fuel shipments have been pointed out by the french nuclear safety authority. Wagon and casks external surfaces were partly contaminated upon arrival in Valognes railway terminal. Since then, measures taken by nuclear power plants operators in France and abroad solved the problem. In Germany, a report analyzing the situation in depth has been published in which correctives actions have been listed. In France, EDF launched a large cleanliness program (projet proprete radiologique) in order to better understand contamination transfers mechanisms during power plants exploitation and to list remediation actions to avoid further problems. In this context, CEA Department for Wastes Studies at Cadarache (CEA/DEN/DED) was in charge of a study about contamination transfers during fuel elements loading operations. It was decided to lead experiments for a concrete case. The loading of a transport cask at Tricastin-PWR-1 was followed in november 2000 and different analysis comprising water analysis and smear tests analysis were carried out and are detailed in this paper. Results are discussed and qualitatively compared to those obtained in Philippsburg-BWR, Germany for a similar set of tests. (authors)

  8. Material specification and quality control program for ductile iron spent fuel casks

    Energy Technology Data Exchange (ETDEWEB)

    Rehmer, B.; Frenz, H.; Weidlich, S.; Kuehn, H.D.

    1995-12-31

    In the process of testing spent fuel casks, BAM is gaining a lot of relevant data regarding the quality level of Ductile Cast Iron (DCI). This paper discusses the basic parameters governing the material behavior of ferritic and ferritic-pearlitic DCI and reviews the development of cask quality over the last years. The effect of microstructure and sample size on the fracture toughness of DCI is discussed. The results of a test program show the prominent effect of pearlite content and graphite nodule structure in the mechanical and fracture toughness characteristics of DCI. This observation is important for quality assurance programs for shipping and storage casks of radioactive materials.

  9. Modelisation et simulation d'une liaison HVDC de type VSC-MMC

    Science.gov (United States)

    Saad, Hani Aziz

    High-voltage direct current transmission systems (HVDC) are rapidly expanding in the world. Two main factors are responsible for this expansion. The first is related to the difficulty of building new overhead lines to ensure the development of high-voltage AC grids, which makes the usage of underground cables more common. However, the use of such cables is limited in length to a few tens of km because of the capacitive current generated by the cable itself. Beyond this length limit, the solution is usually to transmit in DC. The second factor is related to the development of offshore wind power plants that require connecting powers of several hundred of MW to the mainland grid by cables whose lengths can reach several hundreds of km and consequently require HVDC transmission system. Several HVDC projects are currently planned and developed by the French transmission system operator RTE. One of such projects is the INELFE interconnection project, with a capacity of 2,000 MW, between France and Spain. This thesis has been funded by RTE, in order to model and simulate in off-line and real time modes, modern HVDC interconnections. The delivered simulation means are used to examine targeted HVDC system performances and risks of abnormal interactions with surrounding power systems. The particularity of the INELFE HVDC system is the usage of a dedicated control system that will largely determine the dynamic behaviour of the system for both large disturbances (faults on the network) and small perturbations (power step changes). Various VSC topologies, including the conventional two-level, multi-level diode-clamped and floating capacitor multi-level converters, have been proposed and reported in the literature. However, due to the complexity of controls and practical limitations, the VSC-HVDC system installations have been limited to the two-level and three-level diode-clamped converters. Recently, the development of modular technology called MMC (Modular Multilevel

  10. Linealización de sistemas VSC-HVDC para el diseño de un controlador PI vectorial

    Directory of Open Access Journals (Sweden)

    Nelson Díaz Aldana

    2014-01-01

    Full Text Available Los sistemas VSC-HVDC son muy utilizados para la transmisión de energía en redes de interconexión eléctrica. Uno de los principales problemas que poseen estos sistemas es la complejidad de su modelo matemático, lo que conlleva grandes dificultades para el diseño de controladores que permitan la regulación de parámetros como la tensión DC de transmisión, así como la potencia activa y reactiva del sistema VSC-HVDC. En este artículo se presenta la linealización de un sistema VSC-HVDC y el posterior diseño de un controlador lineal PI vectorial a partir del modelo linealizado. Adicionalmente, se proponen dos estrategias para la validación de este tipo de controladores, la primera consiste en un único controlador PI para regular los estados del sistema para cada VSC, la segunda consiste en el diseño de controladores PI vectoriales independientes para la regulación de cada estado del VSC.

  11. Phase-domain power flows in the rectangular co-ordinates frame of reference including VSC-based FACTS controllers

    Energy Technology Data Exchange (ETDEWEB)

    Angeles-Camacho, C. [Universidad Nacional Autonoma de Mexico, Instituto de Ingenieria, Edif. Bernardo Quintana, Circuito Exterior Ciudad Universitaria, 04510 Mexico, D.F. (Mexico); Acha, E. [Electronics and Electrical Engineering, The University of Glasgow (United Kingdom)

    2008-03-15

    This paper presents a method for systematic modelling of VSC-based FACTS controllers within three-phase power flows in rectangular co-ordinates. Among the FACTS controllers modelled are the STATCOM, SSSC, UPFC and HVDC-VSC. The approach taken is to represent the fundamental frequency operation of each power converter as a three-phase voltage source behind a leakage reactance, where one or two of them may be connected in either series or parallel depending on the FACTS controller being modelled. Active and reactive power flow equations are developed for each voltage source circuit together with constraint equations to account for co-ordinated operation of two converters, such as in modelling of UPFC and HVDC-VSC. The power flow equations representing the VSC-based FACTS controllers are combined with the nodal power equations of the power network for a combined iterative solution using a Newton-Raphson three-phase power flow algorithm in rectangular co-ordinates enabling robust and efficient solutions of three-phase power networks with any number and kind of VSC-based controllers. (author)

  12. Enhanced control of DFIG-used back-to-back PWM VSC under unbalanced grid voltage conditions

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This paper presents a unified positive- and negative-sequence dual-dq dynamic model of wind-turbine driven doublyfed induction generator (DFIG) under unbalanced grid voltage conditions. Strategies for enhanced control and operation of a DFIG-used back-to-back (BTB) PWM voltage source converter (VSC) are proposed. The modified control design for the grid-side converter in the stationary αβ frames diminishes the amplitude of DC-link voltage ripples of twice the grid frequency, and the two proposed control targets for the rotor-side converter are alternatively achieved, which, as a result, improve the fault-ride through (FRT) capability of the DFIG based wind power generation systems during unbalanced network supply. A complete unbalanced control scheme with both grid- and rotor-side converters included is designed. Finally, simulation was carried out on a 1.5 MW wind-turbine driven DFIG system and the validity of the developed unified model and the feasibility of the proposed control strategies are all confirmed by the simulated results.

  13. Packaging design criteria for the MCO cask

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, W.S.

    1997-01-30

    Approximately 2,100 metric tons of unprocessed, irradiated nuclear fuel elements are presently stored in the K Basins. To permit cleanup of the K Basins and fuel conditioning, the fuel will be transported from the K Basins to a Canister Storage Building in the 200 East Area. The purpose of this packaging design criteria is to provide criteria for the design, fabrication, and use of a packaging system to transport the large quantities of irradiated nuclear fuel elements positioned within Multiple Canister Overpacks.

  14. Packaging design criteria for the MCO cask

    Energy Technology Data Exchange (ETDEWEB)

    Clements, M.D.

    1996-01-01

    Approximately 2,100 metric tons of unprocessed, irradiated nuclear fuel elements are presently stored in the K Basins. To permit cleanup of the K Basins and fuel conditioning, the fuel will be transported from the K Basins to a Canister Storage Building in the 200 East Area. The purpose of this packaging design criteria is to provide criteria for the design, fabrication, and use of a packaging system to transport the large quantities of irradiated nuclear fuel elements positioned within Multiple Canister Overpacks.

  15. Packaging design criteria for the MCO cask

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, W.S.

    1996-09-11

    Approximately 2,100 metric tons of unprocessed, irradiated nuclear fuel elements are presently stored in the K Basins. To permit cleanup of the K Basins and fuel conditioning, the fuel will be transported from the K Basins to a Canister Storage Building in the 200 East Area. The purpose of this packaging design criteria is to provide criteria for the design,fabrication, and use of a packaging system to transport the large quantities of irradiated nuclear fuel elements positioned within Multiple Canister Overpacks.

  16. Tandem SAM Domain Structure of Human Caskin1: A Presynaptic, Self-Assembling Scaffold for CASK

    Energy Technology Data Exchange (ETDEWEB)

    Stafford, Ryan L.; Hinde, Elizabeth; Knight, Mary Jane; Pennella, Mario A.; Ear, Jason; Digman, Michelle A.; Gratton, Enrico; Bowie, James U. (UCI); (UCLA)

    2012-02-07

    The synaptic scaffolding proteins CASK and Caskin1 are part of the fibrous mesh of proteins that organize the active zones of neural synapses. CASK binds to a region of Caskin1 called the CASK interaction domain (CID). Adjacent to the CID, Caskin1 contains two tandem sterile a motif (SAM) domains. Many SAM domains form polymers so they are good candidates for forming the fibrous structures seen in the active zone. We show here that the SAM domains of Caskin1 form a new type of SAM helical polymer. The Caskin1 polymer interface exhibits a remarkable segregation of charged residues, resulting in a high sensitivity to ionic strength in vitro. The Caskin1 polymers can be decorated with CASK proteins, illustrating how these proteins may work together to organize the cytomatrix in active zones.

  17. A method for determining the spent-fuel contribution to transport cask containment requirements

    Energy Technology Data Exchange (ETDEWEB)

    Sanders, T.L.; Seager, K.D. [Sandia National Labs., Albuquerque, NM (United States); Rashid, Y.R.; Barrett, P.R. [ANATECH Research Corp., La Jolla, CA (United States); Malinauskas, A.P. [Oak Ridge National Lab., TN (United States); Einziger, R.E. [Pacific Northwest Lab., Richland, WA (United States); Jordan, H. [EG and G Rocky Flats, Inc., Golden, CO (United States). Rocky Flats Plant; Duffey, T.A.; Sutherland, S.H. [APTEK, Inc., Colorado Springs, CO (United States); Reardon, P.C. [GRAM, Inc., Albuquerque, NM (United States)

    1992-11-01

    This report examines containment requirements for spent-fuel transport containers that are transported under normal and hypothetical accident conditions. A methodology is described that estimates the probability of rod failure and the quantity of radioactive material released from breached rods. This methodology characterizes the dynamic environment of the cask and its contents and deterministically models the peak stresses that are induced in spent-fuel cladding by the mechanical and thermal dynamic environments. The peak stresses are evaluated in relation to probabilistic failure criteria for generated or preexisting ductile tearing and material fractures at cracks partially through the wall in fuel rods. Activity concentrations in the cask cavity are predicted from estimates of the fraction of gases, volatiles, and fuel fines that are released when the rod cladding is breached. Containment requirements based on the source term are calculated in terms of maximum permissible volumetric leak rates from the cask. Calculations are included for representative cask designs.

  18. Packaging Design Criteria for the MCO Cask

    Energy Technology Data Exchange (ETDEWEB)

    FLANAGAN, B.D.

    2000-08-01

    Approximately 2,100 metric tons of unprocessed, irradiated, nuclear fuel elements are presently stored in the K Basins (including approximately 700 additional elements from the Plutonium-Uranium Extraction Plant, N Reactor, and 327 Laboratory). To permit cleanup of the K Basins and fuel conditioning, the fuel will be transported from the 100 K Area to a Canister Storage Building (CSB) in the 200 East Area. The purpose of this packaging design criteria is to provide criteria for the design, fabrication, and use of a packaging system to transport the large quantities of irradiated nuclear fuel elements positioned within Multi-canister Overpacks. Concurrent with the K Basin cleanup, 72 Shippingport Pressurized Water Reactor Core 2 fuel assemblies will be transported from T Plant to the CSB to provide space at T Plant for K Basin sludge canisters.

  19. Packaging design criteria for the MCO cask

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, W.S.

    1996-04-29

    Approximately 2,100 metric tons of unprocessed, irradiated nuclear fuel elements are presently stored in the K Basins (including possibly 700 additional elements from PUREX, N Reactor, and 327 Laboratory). The basin water, particularly in the K East Basin, contains significant quantities of dissolved nuclear isotopes and radioactive fuel corrosion particles. To permit cleanup of the K Basins and fuel conditioning, the fuel will be transported from the 100 K Area to a Canister Storage Building (CSB) in the 200 East area. In order to initiate K Basin cleanup on schedule, the two-year fuel-shipping campaign must begin by December 1997. The purpose of this packaging design criteria is to provide criteria for the design, fabrication, and use of a packaging system to transport the large quantities of irradiated nuclear fuel elements positioned within Multiple Canister Overpacks.

  20. Effect of embedded voltage source converter on power system oscillation damping

    Institute of Scientific and Technical Information of China (English)

    R; DUNN

    2010-01-01

    This paper presents the damping torque analysis of power system oscillation stability as affected by the dynamic and control functions of an embedded voltage source converter(VSC).The objective of the study is to explain why and how the dynamic and basic control functions of the embedded VSC,ac and dc voltage regulation,provide damping to power system oscillations.The most important conclusion obtained in the paper is that both the dynamics and the dc voltage control of the VSC contribute a variable damping torque,which can be positive or negative,at different levels of system load conditions.More positive damping torque can be provided by the VSC at a heavier load condition.There exists a point of system load condition where the VSC provides no damping torque to power system oscillation hence dose not impose any influence on power system oscillation stability.The VSC studied in the paper can be the power-electronics-based interface of various FACTS(flexible ac transmission systems) devices,energy storage systems and renewable power generation units,although the focus of the discussion presented in this paper is the effect of the dynamics and basic control functions of the VSC themselves on power system oscillation damping.To demonstrate the analytical conclusions obtained in the paper,results of eigenvalue computation and nonlinear simulation of an example power system with STATCOM(static synchronous compensator) are given.

  1. Evaluation of computer programs used for structural analyses of impact response of spent fuel shipping casks

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, B A; Gwinn, K W

    1984-05-01

    This report presents the results of a study of impact analyses of a generic spent-fuel cask. The study compares the use and results of three different finite element computer codes. Seven different cask-like model analyses are considered. The models encompass both linear and nonlinear geometric and material behavior. On the basis of the analyses results, this report recommends what parameters are useful in the comparison of different structural finite element computer programs. 5 references, 36 figures, 11 tables.

  2. Nondestructive Examination Guidance for Dry Storage Casks

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Ryan M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Suffield, Sarah R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hirt, Evelyn H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Suter, Jonathan D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lareau, John P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Zhuge, Jing Wei [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Qiao, Hong [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Moran, Traci L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Ramuhalli, Pradeep [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-09-30

    In this report, an assessment of NDE methods is performed for components of NUHOMS 80 and 102 dry storage system components in an effort to assist NRC staff with review of license renewal applications. The report considers concrete components associated with the horizontal storage modules (HSMs) as well as metal components in the HSMs. In addition, the report considers the dry shielded canister (DSC). Scope is limited to NDE methods that are considered most likely to be proposed by licensees. The document, ACI 349.3R, Evaluation of Existing Nuclear Safety-Related Concrete Structures, is used as the basis for the majority of the NDE methods summarized for inspecting HSM concrete components. Two other documents, ACI 228.2R, Nondestructive Test Methods for Evaluation of Concrete in Structures, and ORNL/TM-2007/191, Inspection of Nuclear Power Plant Structure-Overview of Methods and Related Application, supplement the list with additional technologies that are considered applicable. For the canister, the ASME B&PV Code is used as the basis for NDE methods considered, along with currently funded efforts through industry (Electric Power Research Institute [EPRI]) and the U.S. Department of Energy (DOE) to develop inspection technologies for canisters. The report provides a description of HSM and DSC components with a focus on those aspects of design considered relevant to inspection. This is followed by a brief description of other concrete structural components such as bridge decks, dams, and reactor containment structures in an effort to facilitate comparison between these structures and HSM concrete components and infer which NDE methods may work best for certain HSM concrete components based on experience with these other structures. Brief overviews of the NDE methods are provided with a focus on issues and influencing factors that may impact implementation or performance. An analysis is performed to determine which NDE methods are most applicable to specific

  3. Estimation of terrorist attack resistibility of dual-purpose cask TP-117 with DU (depleted uranium) gamma shield

    Energy Technology Data Exchange (ETDEWEB)

    Alekseev, O.G.; Matveev, V.Z.; Morenko, A.I.; Il' kaev, R.I.; Shapovalov, V.I. [Russian Federal Nuclear Center - All-Russian Research Inst. of Experimental Physics, Sarov (Russian Federation)

    2004-07-01

    Report is devoted to numerical research of dual-purpose unified cask (used for SFA transportation and storage) resistance to terrorist attacks. High resistance of dual-purpose unified cask has been achieved due to the unique design-technological solutions and implementation of depleted uranium in cask construction. In suggested variant of construction depleted uranium fulfils functions of shielding and constructional material. It is used both in metallic and cermet form (basing on steel and depleted uranium dioxide). Implementation of depleted uranium in cask construction allows maximal load in existing overall dimensions of the cask. At the same time: 1) all safety requirements (IAEA) are met, 2) dual-purpose cask with SFA has high resistance to terrorist attacks.

  4. 基于VSC-HVDC的风电场侧换流站控制策略研究

    Institute of Scientific and Technical Information of China (English)

    陈怀顺

    2011-01-01

    研究了风电场联网用VSC-HVDC的风电场侧换流站定交流电压矢量控制策略原理,基于MATLAB/Simulink建立了基于VSC-HVDC的风电场联网系统,在定交流电压矢量控制下进行了仿真,仿真结果表明,采用定交流电压控制器的并网系统能更好地抑制电压波动,适合风电场联网。

  5. Second Order Cone Programming (SOCP) Relaxation Based Optimal Power Flow with Hybrid VSC-HVDC Transmission and Active Distribution Networks

    DEFF Research Database (Denmark)

    Ding, Tao; Li, Cheng; Yang, Yongheng

    2017-01-01

    The detailed topology of renewable resource bases may have the impact on the optimal power flow of the VSC-HVDC transmission network. To address this issue, this paper develops an optimal power flow with the hybrid VSC-HVDC transmission and active distribution networks to optimally schedule...... the generation output and voltage regulation of both networks, which leads to a non-convex programming model. Furthermore, the non-convex power flow equations are based on the Second Order Cone Programming (SOCP) relaxation approach. Thus, the proposed model can be relaxed to a SOCP that can be tractably solved...

  6. Feasibility of Raising the Maximum Conductor Temperature to 90℃ of DC XLPE Cables with Rated Voltages up to 320 kV for VSC System%柔性直流输电系统用直流交联聚乙烯绝缘电缆导体最高温度提高到90℃的可行性

    Institute of Scientific and Technical Information of China (English)

    应启良

    2014-01-01

    以实际直流交联聚乙烯(DC XLPE)电缆工程设计示例,表明将柔性直流输电(VSC)系统用DC XLPE电缆的导体的最高运行温度提高到90℃,其技术经济效果显著.按DC XLPE电缆抑制空间电荷要求,阐明DCXLPE电缆绝缘的直流恒定电流电场中空间电荷密度与绝缘温度梯度和XLPE绝缘的体积电阻率的温度系数成正比而与导体最高温度不直接相关.通过合理的DC XLPE电缆工程设计和正确选用DC XLPE电缆,可以在提高DC XLPE电缆传输功率和减小绝缘温差抑制空间电荷方面取得优化结果.320 kV及以下XLPE电缆在导体最高温度90℃下运行,绝缘损耗远低于导体损耗,DC XLPE电缆发生热不稳定的可能性很低.对VSC系统用DC XLPE电缆导体运行温度提高到90℃的可行性表示肯定的意见,对实现目标提出具体的措施建议.

  7. 基于VSC-HVDC的风力发电并网技术

    Institute of Scientific and Technical Information of China (English)

    叶丽雅; 王璐; 佟晶晶

    2012-01-01

    随着电力电子技术的发展,电压源换流器型直流输电(Vsc—HVDC)并嘲技术具有独立控制有功和无功、控制方式灵活等优点,为风电场并刚提供了可能。本文详细的介绍了VSC-HVDC的基本工作原理和技术优势,讨论了VSC—IVDC在大规模风电场并网中的广阔前景。

  8. VSC-HVDC输电系统特点与应用

    Institute of Scientific and Technical Information of China (English)

    孟垂懿; 蔡志远; 马少华; 王文贵

    2011-01-01

    随着半导体技术和新能源发电的发展,出现了基于VSC(Voltage Sourced Converters)技术的新型直流输电系统——轻型直流输电(HVDC Light),本文在介绍HVDC Light基本原理的基础上,从结构和功能上和传统直流输电技术进行对比,阐述了HVDC Light的优点,并对其应用作了总结和展望.

  9. Impact of modeling Choices on Inventory and In-Cask Criticality Calculations for Forsmark 3 BWR Spent Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Gonzalez, Jesus S. [Univ. Politecnica de Madrid (Spain); Ade, Brian J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bowman, Stephen M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gauld, Ian C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ilas, Germina [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Marshall, William BJ J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-01-01

    Simulation of boiling water reactor (BWR) fuel depletion poses a challenge for nuclide inventory validation and nuclear criticality safety analyses. This challenge is due to the complex operating conditions and assembly design heterogeneities that characterize these nuclear systems. Fuel depletion simulations and in-cask criticality calculations are affected by (1) completeness of design information, (2) variability of operating conditions needed for modeling purposes, and (3) possible modeling choices. These effects must be identified, quantified, and ranked according to their significance. This paper presents an investigation of BWR fuel depletion using a complete set of actual design specifications and detailed operational data available for five operating cycles of the Swedish BWR Forsmark 3 reactor. The data includes detailed axial profiles of power, burnup, and void fraction in a very fine temporal mesh for a GE14 (10×10) fuel assembly. The specifications of this case can be used to assess the impacts of different modeling choices on inventory prediction and in-cask criticality, specifically regarding the key parameters that drive inventory and reactivity throughout fuel burnup. This study focused on the effects of the fidelity with which power history and void fraction distributions are modeled. The corresponding sensitivity of the reactivity in storage configurations is assessed, and the impacts of modeling choices on decay heat and inventory are addressed.

  10. Liprin-α2 promotes the presynaptic recruitment and turnover of RIM1/CASK to facilitate synaptic transmission.

    Science.gov (United States)

    Spangler, Samantha A; Schmitz, Sabine K; Kevenaar, Josta T; de Graaff, Esther; de Wit, Heidi; Demmers, Jeroen; Toonen, Ruud F; Hoogenraad, Casper C

    2013-06-10

    The presynaptic active zone mediates synaptic vesicle exocytosis, and modulation of its molecular composition is important for many types of synaptic plasticity. Here, we identify synaptic scaffold protein liprin-α2 as a key organizer in this process. We show that liprin-α2 levels were regulated by synaptic activity and the ubiquitin-proteasome system. Furthermore, liprin-α2 organized presynaptic ultrastructure and controlled synaptic output by regulating synaptic vesicle pool size. The presence of liprin-α2 at presynaptic sites did not depend on other active zone scaffolding proteins but was critical for recruitment of several components of the release machinery, including RIM1 and CASK. Fluorescence recovery after photobleaching showed that depletion of liprin-α2 resulted in reduced turnover of RIM1 and CASK at presynaptic terminals, suggesting that liprin-α2 promotes dynamic scaffolding for molecular complexes that facilitate synaptic vesicle release. Therefore, liprin-α2 plays an important role in maintaining active zone dynamics to modulate synaptic efficacy in response to changes in network activity.

  11. Based on PSCAD/EMTDC Fault Simulation of VSC-HVDC Line%基于PSCAD/EMTDC的VSC-HVDC直流输电线路的故障仿真

    Institute of Scientific and Technical Information of China (English)

    余志豪; 许傲然; 谷采连; 王刚; 赵毅

    2016-01-01

    目前,对VSC-HVDC的直流故障研究不够全面,在故障情况下不能快速可靠地判别故障类型,更无法准确测算出故障距离,难以满足系统瞬时稳定性能的要求.为此,以PSCAD/EMTDC为仿真分析平台,建立电压源换流器型直流输电系统(voltage sourceconverter HVDC,VSC-HVDC).针对VSC-HVDC直流输电系统可能出现的故障进行设置与仿真,分析直流输电线路的故障特点,并训练神经网络对故障类型进行分类.仿真结果与理论分析一致,表明所建立的模型符合实际,为更好地研究VSC-HVDC的保护与故障测距提供了正确的理论分析平台.

  12. New variable structure control for MIMO nonlinear system based on I/O linearization

    Institute of Scientific and Technical Information of China (English)

    许春山; 孙兴进; 曹广益

    2004-01-01

    A novel variable structure control (VSC) with new rapid-smooth reaching law (RSRL) and new rapid-convergent sliding mode (FCSM) is proposed, which is based on analysis of normal VSC system. When it is used for an MIMO nonlinear system, we combine the method of Input/Output linearizing (I/O L) with VSC. After analyzing the robustness of the MIMO nonlinear system, we use this novel controller for Precision One Robot position control system. Simulation provides a quite satisfactory performance with uncertainties and external disturbances.

  13. Acoustic emission detection with fiber optical sensors for dry cask storage health monitoring

    Science.gov (United States)

    Lin, Bin; Bao, Jingjing; Yu, Lingyu; Giurgiutiu, Victor

    2016-04-01

    The increasing number, size, and complexity of nuclear facilities deployed worldwide are increasing the need to maintain readiness and develop innovative sensing materials to monitor important to safety structures (ITS). In the past two decades, an extensive sensor technology development has been used for structural health monitoring (SHM). Technologies for the diagnosis and prognosis of a nuclear system, such as dry cask storage system (DCSS), can improve verification of the health of the structure that can eventually reduce the likelihood of inadvertently failure of a component. Fiber optical sensors have emerged as one of the major SHM technologies developed particularly for temperature and strain measurements. This paper presents the development of optical equipment that is suitable for ultrasonic guided wave detection for active SHM in the MHz range. An experimental study of using fiber Bragg grating (FBG) as acoustic emission (AE) sensors was performed on steel blocks. FBG have the advantage of being durable, lightweight, and easily embeddable into composite structures as well as being immune to electromagnetic interference and optically multiplexed. The temperature effect on the FBG sensors was also studied. A multi-channel FBG system was developed and compared with piezoelectric based AE system. The paper ends with conclusions and suggestions for further work.

  14. Converter Structure-Based Power Loss and Static Thermal Modeling of The Press-Pack IGBT Three-Level ANPC VSC Applied to Multi-MW Wind Turbines

    DEFF Research Database (Denmark)

    Senturk, Osman Selcuk; Helle, Lars; Munk-Nielsen, Stig

    2011-01-01

    MW wind turbine to a MV grid. The switching power loss models are built using the experimental switching power loss data acquired via the double-pulse tests conducted on a full-scale 3L-ANPC-VSC prototype. The converter static thermal model is developed based on the double-sided water-cooled press......-pack switches. Via a single-phase test setup with two full-scale 3L-ANPC-VSC legs, the developed power loss and thermal models are validated experimentally. Employing the validated models, the 3L-ANPC-VSC's thermal performance is demonstrated on simulation for a 6 MW wind turbine grid interface. Hence...

  15. HVDC System Stability – Analysis, Monitoring and Control in Wide Area Power Systems

    OpenAIRE

    Kuehn, Walter; Vanfretti, Luigi; Fischer, W.

    2014-01-01

    To a great extent future electric power systems will use HVDC technologies, based on either current sourced or voltage sourced converters (CSC, resp. VSC). Both technologies have their merits and range of applications being connected to technical capabilities, costs and operational properties and performance. Voltage stability is an important issue in classical CSC-based HVDC systems, while voltage stability and angle stability (both transmission angle and rotor angle) are of concern in VSC-H...

  16. VARIABLE STRUCTURE CONTROL APPLIED IN ELECTRO-HYDRAULIC SERVO SYSTEM WITH ANN

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The variable structure control (VSC) theory is applied to the electro-hydraulic servo system here. The VSC control law is achieved using Lyapunov method and pole placement. To eliminate the chattering phenomena, a saturation function is adopted. The proposed VSC approach is fairly robust to load disturbance and system parameter variation. Since the distortion including phase lag and amplitude attenuation occurs in the system sinusoid response, the amplitude and phase control (APC)algorithm, based on Adaline neural network and using LMS algorithm, is developed for distortion cancellation. The APC controller is simple and can on-line adjust, thus it gives accurate tracking.

  17. Conceptual Design Report Cask Loadout Sys and Cask Drop Redesign for the Immersion Pail Support Structure and Operator Interface Platform at 105 K West

    Energy Technology Data Exchange (ETDEWEB)

    LANGEVIN, A.S.

    1999-07-12

    This conceptual design report documents the redesign of the IPSS and the OIP in the 105 KW Basin south loadout pit due to a postulated cask drop accident, as part of Project A.5/A.6, Canister Transfer Facility Modifications. Project A.5/A.6 involves facility modifications needed to transfer fuel from the basin into the cask-MCO. The function of the IPSS is to suspend, guide, and position the immersion pail. The immersion pail protects the cask-MCO from contamination by basin water and acts as a lifting device for the cask-MCO. The OIP provides operator access to the south loadout pit. Previous analyses studied the effects of a cask-MCO drop on the south loadout pit concrete structure and on the IPSS. The most recent analysis considered the resulting loads at the pit slab/wall joint (Kanjilal, 1999). This area had not been modeled previously, and the analysis results indicate that the demand capacity exceeds the allowable at the slab/wall joint. The energy induced on the south loadout pit must be limited such that the safety class function of the basin is maintained. The solution presented in this CDR redesigns the IPSS and the OIP to include impact-absorbing features that will reduce the induced energy. The impact absorbing features of the new design include: Impact-absorbing material at the IPSS base and at the upper portion of the IPSS legs. A sleeve which provides a hydraulic means of absorbing energy. Designing the OIP to act as an impact absorber. The existing IPSS structure in 105 KW will be removed. This conceptual design considers only loads resulting from drops directly over the IPSS and south loadout pit area. Drops in other areas of the basin are not considered, and will be covered as part of a future revision to this CDR.

  18. Robust controller for synchronous generator with local load via VSC

    Energy Technology Data Exchange (ETDEWEB)

    Cabrera-Vazquez, J. [Universidad de Guadalajara, Centro Universitario de Ciencias Exactas e Ingenierias, Departamento de Electronica, Av. Revolucion No. 1500, Modulo ' ' O' ' , Apdo. Postal 44840, Guadalajara Jalisco (Mexico); Loukianov, Alexander G.; Canedo, Jose M. [Centro de Investigacion y de Estudios Avanzados del IPN, Apdo. Postal 31-438, Plaza La Luna, C. P. 44550, Guadalajara, Jalisco (Mexico); Utkin, Vadim I. [Department of Electrical Engineering, The Ohio-State University, Columbus, OH 43210-1272 (United States)

    2007-05-15

    The objective of this paper is to design a nonlinear observer-based excitation controller for power system comprising a single synchronous generator connected to an infinite bus with local load. The controller proposed is based on the using first singular perturbation systems concepts and then Sliding Mode Control technique combining with Block Control Principle. To reduce ''chattering'' a nonlinear observer with estimation of the mechanical torque and rotor fluxes is designed. This combined approach enables to compensate the inherent nonlinearities of the generator and to reject external disturbances. (author)

  19. A Structural Analytic Evaluation of a Connote Pad In a Spent Fuel Dry Storage Cask

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Hak; Seo, Ki Seog; Lee, Ju Chan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lee, Yeon Do; Cho, Chun Hyung; Lee, Dae Ki [Nuclear Environment Technology Institute, Daejeon (Korea, Republic of)

    2006-06-15

    A spent fuel storage cask is required to prove the safety of a canister under a hypothetical accidental drop condition. A hypothetical accidental drop condition means that a canister is assumed to be a lee drop on to a pad of the storage cask during loading it into a storage cask. A pad of the storage cask absorbs shock to maintain the structural integrities of a canister under a hypothetical accidental drop condition. In this paper a finite element analysis for various pad structures was carried out to improve the structural integrity of a canister under a hypothetical accidental drop condition. A pad of a storage cask was designed a steel structure with concrete. The 1/4 height of a pad was modified with a structure composed of a steel and a polyurethane foam as a impact limiter. The effect of a shape of a steel structure was studied. The effects of the thickness of a steel structure and the density of a polyurethane foam was also studied.

  20. Safety analysis report vitrified high level waste type B shipping cask

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-03-01

    This Safety Analysis Report describes the design, analyses, and principle features of the Vitrified High Level Waste (VHLW) Cask. In preparing this report a detailed evaluation of the design has been performed to ensure that all safety, licensing, and operational goals for the cask and its associated Department of Energy program can be met. The functions of this report are: (1) to fully document that all functional and regulatory requirements of 10CFR71 can be met by the package; and (2) to document the design and analyses of the cask for review by the Nuclear Regulatory Commission. The VHLW Cask is the reusable shipping package designed by GNSI under Department of Energy contract DE-AC04-89AL53-689 for transportation of Vitrified High Level Waste, and to meet the requirements for certification under 10CFR71 for a Type B(U) package. The VHLW cask has been designed as packaging for transport of canisters of Vitrified High Level Waste solidified at Department of Energy facilities.

  1. Study of minimum-weight highway transporters for spent nuclear fuel casks: Technical report

    Energy Technology Data Exchange (ETDEWEB)

    Hoess, J.A.; Drago, V.J.

    1989-05-01

    There are federal and state limits on the maximum tractor-trailer- payload combination and individual axle loads permissible on US highways. These can generally be considered as two sets, i.e., legal-weight and overweight limits. The number of individual shipments required will decrease as the capacity of the spent nuclear fuel cask increases. Thus, there is an incentive for identifying readily available minimum-weight tractors and trailers capable of safely and reliably transporting as large a cask as possible without exceeding the legal gross combination weight (GCW) of 80,000 lb or selected overweight GCW limit of 110,000 lb. This study identifies options for commercially available heavy-duty on-highway tractors and trailers for transporting proposed future loaded spent nuclear fuel casks. Loaded cask weights of 56,000 and 80,000 lb were selected as reference design points for the legal-weight and overweight transporters, respectively. The technical data on tractor and trailer characteristics obtained indicate that it is possible to develop a tractor-trailer combination, tailored for spent nuclear fuel transportation service, utilizing existing technology and commercially available components, capable of safely and reliably transporting 56,000 and 80,000-lb spent nuclear fuel casks without exceeding GCWs of 80,000 and 10,000 lb, respectively. 4 figs., 14 tabs.

  2. Analysis of dose consequences arising from the release of spent nuclear fuel from dry storage casks.

    Energy Technology Data Exchange (ETDEWEB)

    Durbin, Samuel G.; Morrow, Charles.

    2013-01-01

    The resulting dose consequences from releases of spent nuclear fuel (SNF) residing in a dry storage casks are examined parametrically. The dose consequences are characterized by developing dose versus distance curves using simplified bounding assumptions. The dispersion calculations are performed using the MELCOR Accident Consequence Code System (MACCS2) code. Constant weather and generic system parameters were chosen to ensure that the results in this report are comparable with each other and to determine the relative impact on dose of each variable. Actual analyses of site releases would need to accommodate local weather and geographic data. These calculations assume a range of fuel burnups, release fractions (RFs), three exposure scenarios (2 hrs and evacuate, 2 hrs and shelter, and 24 hrs exposure), two meteorological conditions (D-4 and F-2), and three release heights (ground level 1 meter (m), 10 m, and 100 m). This information was developed to support a policy paper being developed by U.S. Nuclear Regulatory Commission (NRC) staff on an independent spent fuel storage installation (ISFSI) and monitored retrievable storage installation (MRS) security rulemaking.

  3. Study and full-scale test of a high-velocity grade-crossing simulated accident of a locomotive and a nuclear-spent-fuel shipping cask

    Energy Technology Data Exchange (ETDEWEB)

    Huerta, M.; Yoshimura, H.R.

    1983-02-01

    This report described structural analyses of a high-speed impact between a locomotive and a tractor-trailer system carrying a nuclear-spent-fuel shipping cask. The analyses included both mathematical and physical scale-modeling of the system. The report then describes the full-scale test conducted as part of the program. The system response is described in detail, and a comparison is made between the analyses and the actual hardware response as observed in the full-scale test. 34 figures.

  4. Evaluation of Impact Resistance of Concrete Overpack of Storage Cask

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sanghoon; Kim, Ki-Young; Jeon, Je-Eon; Seo, Ki-Seog [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    The concrete overpack of the cask provides radiation shielding as well as physical protection for inner canister against external mechanical shock. When the overpack undergoes a severe missile impact which might be caused by tornado or aircraft crash, it should sustain minimal level of structural integrity so that the radiation shielding and the retrievability of canister are maintained. Empirical formulas have been developed for the evaluation of concrete damage but those formulas can be used only for local damage evaluation and not for global damage evaluation. In this research, a series of numerical simulations and tests have been performed to evaluate the damage of two types of concrete overpack segment models under high speed missile impact. It is shown that appropriate modeling of material failure is crucial in this kind of analyses and finding the correct failure parameters may not be straightforward. When comparing the simulation results with the test results, it is shown that neither setting, case 1 and 2 provides results with consistent agreement with test results. That is, case 1 setting is more close to reality in Type 1 model analysis, but for Type 2, case 2 setting provides more close results to the reality. In both the case, not enough deformation is predicted by simulation compared to the tests. Weak failure and eroding criteria give larger penetration depth with insufficient overall damage due to energy loss with element erosion.

  5. A methodology for estimating the residual contamination contribution to the source term in a spent-fuel transport cask

    Energy Technology Data Exchange (ETDEWEB)

    Sanders, T.L. (Sandia National Labs., Albuquerque, NM (United States)); Jordan, H. (EG and G Rocky Flats, Inc., Golden, CO (United States). Rocky Flats Plant); Pasupathi, V. (Battelle, Columbus, OH (United States)); Mings, W.J. (USDOE Idaho Field Office, Idaho Falls, ID (United States)); Reardon, P.C. (GRAM, Inc., Albuquerque, NM (United States))

    1991-09-01

    This report describes the ranges of the residual contamination that may build up in spent-fuel transport casks. These contamination ranges are calculated based on data taken from published reports and from previously unpublished data supplied by cask transporters. The data involve dose rate measurements, interior smear surveys, and analyses of water flushed out of cask cavities during decontamination operations. A methodology has been developed to estimate the effect of residual contamination on spent-fuel cask containment requirements. Factors in estimating the maximum permissible leak rates include the form of the residual contamination; possible release modes; internal gas-borne depletion; and the temperature, pressure, and vibration characteristics of the cask during transport under normal and accident conditions. 12 refs., 9 figs., 4 tabs.

  6. Structural design of concrete storage pads for spent-fuel casks

    Energy Technology Data Exchange (ETDEWEB)

    Rashid, Y.R.; Nickell, R.E.; James, R.J. (ANATECH Research Corp., San Diego, CA (United States))

    1993-04-01

    The loading experienced by spent fuel dry storage casks and storage pads due to potential drop or tip-over accidents is evaluated using state-of-the-art concrete structural analysis methodology. The purpose of this analysis is to provide simple design charts and formulas so that design adequacy of storage pads and dry storage casks can be demonstrated. The analysis covers a wide range of slab-design parameters, e.g., reinforcement ratio, slab thickness, concrete compressive strength, and sub-base soil compaction, as well as variations in drop orientation and drop height. The results are presented in the form of curves, giving the force on the cask as a function of storage pad hardness for various drop heights. In addition, force-displacement curves, deformed shapes, crack patterns, stresses and strains are given for various slab-design conditions and drop events. The utility of the results in design are illustrated through examples.

  7. Development of Aircraft Impact Scenario on a Concrete Cask in Interim Storage Facility

    Energy Technology Data Exchange (ETDEWEB)

    Momani, Belal Al; Yoo, Min; Kang, Hyun Gook [KAIST, Daejeon (Korea, Republic of)

    2015-05-15

    This paper provides a method for determining the failure criteria in global and local damage responses for the concrete cask under extreme mechanical impact condition. IAEA safety guide No. SSG-15 mentions the hypothetical initiating events of SNF storage. Among the external initiating events, the aircraft strike on a storage cask is considered one of the dominant contributions to the risk during storage phase. Although the probability of aircraft crash on ISF is extremely small, it is important to develop the accident scenario caused by an intentional malicious acts launched towards the storage facility in terms to improve inherent security. Thus, the probabilistic approach to develop aircraft impact scenarios on a storage cask is needed.

  8. Shielding calculation and criticality safety analysis of spent fuel transportation cask in research reactors.

    Science.gov (United States)

    Mohammadi, A; Hassanzadeh, M; Gharib, M

    2016-02-01

    In this study, shielding calculation and criticality safety analysis were carried out for general material testing reactor (MTR) research reactors interim storage and relevant transportation cask. During these processes, three major terms were considered: source term, shielding, and criticality calculations. The Monte Carlo transport code MCNP5 was used for shielding calculation and criticality safety analysis and ORIGEN2.1 code for source term calculation. According to the results obtained, a cylindrical cask with body, top, and bottom thicknesses of 18, 13, and 13 cm, respectively, was accepted as the dual-purpose cask. Furthermore, it is shown that the total dose rates are below the normal transport criteria that meet the standards specified.

  9. Ageing of a neutron shielding used in transport/storage casks

    Energy Technology Data Exchange (ETDEWEB)

    Nizeyiman, Fidele; Alami, Aatif; Issard, Herve; Bellenger, Veronique [TN International, 1 rue des herons, Montigny le Bretonneux, 78054 Saint Quentin en Yvelines (France); Laboratoire PIMM, Arts and Metiers ParisTech, 151 Bd de l' Hopital, 75013 Paris (France)

    2012-07-11

    In radioactive materials transport/storage casks, a mineral-filled vinylester composite is used for neutron shielding which relies on its hydrogen and boron atoms content. During cask service life, this composite is mainly subjected to three types of ageing: hydrothermal ageing, thermal oxidation and neutron irradiation. The aim of this study is to investigate the effect of hydrothermal ageing on the properties and chemical composition of this polymer composite. At high temperature (120 Degree-Sign C and 140 Degree-Sign C), the main consequence is the strong decrease of mechanical properties induced by the filler/matrix debonding.

  10. Seismic and cask drop excitation evaluation of the tower shielding reactor

    Energy Technology Data Exchange (ETDEWEB)

    Harris, S.P.; Stover, R.L.; Johnson, J.J.; Sumodobila, B.N. (EQE, Inc., San Francisco, CA (USA); Oak Ridge National Lab., TN (USA); EQE, Inc., San Francisco, CA (USA))

    1989-01-01

    During the current shutdown of the Tower Shielding Reactor II (TSR-II), analyses were performed to determine the effect of nearby cask drops on the structural and mechanical integrity of the reactor. This evaluation was then extended to include the effects of earthquakes. Several analytic models were developed to simulate the effects of earthquake and cask drop excitation. A coupled soil-structure model was developed. As a result of the analyses, several hardware modifications and enhancements were implemented to ensure reactor integrity during future operations. 6 figs.

  11. A structural analysis on the KN-12 spent nuclear fuel transport casks

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dew Hey [Korea Institute of Nuclear Safety, Taejon (Korea, Republic of); Lee, Young Shin; Ryu, Chung Hyun; Kim, Hyun Su; Lee, Jae Hyung; Na, Jae Yun [Chungnam National Univ., Taejon (Korea, Republic of)

    2001-08-15

    In this study, safety of the spent nuclear fuel cask KN-12 which is developed in 2000 is evaluated for hypothetical accidents conditions such as free drop, puncture, fire accident and water immersion. Finite element code ABAQUS/Explicit is used to compare with safety analysis report of the GNB in which analysis is performed with LS-DYNA3D for hypothetical accident conditions. Through this study, the safety of KN-12 is evaluated by comprehensive structural analysis. The capability and technological advancement of Korean community on the analysis and structural assessment of the cask will be improved. Also people's anxiety about radioactive dangers will be eliminated.

  12. Variable Structure Control for Unmatched MIMO Nonlinear System with Its Application to MCFC Stacks

    Institute of Scientific and Technical Information of China (English)

    Xu Chunshan(许春山); Sun Xingjin; Cao Guangyi; Zhu Xinjian

    2004-01-01

    A new Variable Structure Control (VSC) with Rapid-Smooth Reaching Law (RSRL) and Rapid-Convergent Sliding Mode (FCSM) is proposed, which is based on normal VSC system. When it is used to unmatched MIMO nonlinear system, the authors combine the method of Input/Output Linearizing (I/O L) with VSC: they use the I/O L method to solve the "Unmatched" problem and use the new VSC to get good result of control. After analyzing the robustness of the MIMO nonlinear system, they use this novel controller to the temperature and gas pressure control system of Molten Carbonate Fuel Cell (MCFC) Stacks. Simulation provides quite satisfactory performance with unmatched uncertainties and external disturbances. Its future actual application is practical.

  13. Simulation of the dynamic response of radioactive material shipping package-railcar systems during coupling operations

    Energy Technology Data Exchange (ETDEWEB)

    Fields, S.R.

    1983-10-01

    The basic equations of the computer model CARDS (Cask-Railcar Dynamic Simulator), developed for the US Nuclear Regulatory Commission to simulate the dynamic behavior of radioactive material shipping package - railcar systems, are presented. A companion model, CARRS (Cask Railcar Response Spectrum Generator), that generates system response as frequency response spectra is also presented in terms of its basic equations. 1 reference, 18 figures.

  14. Simulation of the dynamic response of radioactive material shipping package - railcar systems during coupling operations

    Energy Technology Data Exchange (ETDEWEB)

    Fields, S.R.

    1981-12-01

    The basic equations of the computer model CARDS (Cask-Railcar Dynamic Simulator), developed for the U.S. Nuclear Regulatory Commission to simulate the dynamic behavior of radioactive material shipping package - railcar systems, are presented. A companion model, CARRS (Casks Railcar Response Spectrum Generator), that generates system response as frequency response spectra is also presented in terms of its basic equations.

  15. Calcium/calmodulin-dependent serine protein kinase (CASK), a protein implicated in mental retardation and autism-spectrum disorders, interacts with T-Brain-1 (TBR1) to control extinction of associative memory in male mice

    Science.gov (United States)

    Huang, Tzyy-Nan; Hsueh, Yi-Ping

    2017-01-01

    Background Human genetic studies have indicated that mutations in calcium/calmodulin-dependent serine protein kinase (CASK) result in X-linked mental retardation and autism-spectrum disorders. We aimed to establish a mouse model to study how Cask regulates mental ability. Methods Because Cask encodes a multidomain scaffold protein, a possible strategy to dissect how CASK regulates mental ability and cognition is to disrupt specific protein–protein interactions of CASK in vivo and then investigate the impact of individual specific protein interactions. Previous in vitro analyses indicated that a rat CASK T724A mutation reduces the interaction between CASK and T-brain-1 (TBR1) in transfected COS cells. Because TBR1 is critical for glutamate receptor, ionotropic, N-methyl-d-aspartate receptor subunit 2B (Grin2b) expression and is a causative gene for autism and intellectual disability, we then generated CASK T740A (corresponding to rat CASK T724A) mutant mice using a gene-targeting approach. Immunoblotting, coimmunoprecipitation, histological methods and behavioural assays (including home cage, open field, auditory and contextual fear conditioning and conditioned taste aversion) were applied to investigate expression of CASK and its related proteins, the protein–protein interactions of CASK, and anatomic and behavioural features of CASK T740A mice. Results The CASK T740A mutation attenuated the interaction between CASK and TBR1 in the brain. However, CASK T740A mice were generally healthy, without obvious defects in brain morphology. The most dramatic defect among the mutant mice was in extinction of associative memory, though acquisition was normal. Limitations The functions of other CASK protein interactions cannot be addressed using CASK T740A mice. Conclusion Disruption of the CASK and TBR1 interaction impairs extinction, suggesting the involvement of CASK in cognitive flexibility. PMID:28234597

  16. VSC-HVDC Technology Suitable for Bulk Power Overhead Line Transmission%大容量架空线柔性直流输电关键技术及前景展望

    Institute of Scientific and Technical Information of China (English)

    徐政; 薛英林; 张哲任

    2014-01-01

    To make the voltage source converter based high voltage direct current (VSC-HVDC) system extend to long distance bulk power overhead line transmission is the inherent requirement of energy source distribution in China and future trend of power grid development. However, the challenges associated with the state-of-the-art VSC-HVDC system mainly include: a) difficulty to handle dc fault, b) less transmission capacity compared with the traditional HVDC systems, and c) difficulty to select grounding point. For the first challenge, this paper analyzes vulnerability of the existing topologies against dc faults, focusing on an overview of the topologies with dc fault ride-through capability. According to the characteristics of dc fault processing, these topologies can be divided into three basic types. Furthermore, advantages and defects of these typical topologies are discussed. For the second and third challenges, to achieve a high voltage and power level, a bipolar VSC-HVDC topology with assembly converter is proposed. In this topology, each pole consists of several basic converter units (BCU) in series or in parallel; between the positive pole and the negative pole is the neutral bus which is connected to the ground electrode. Furthermore, the advantages and shortcomings of the possible grounding modes are summarized. At last, according to the unidirectional energy flow characteristics of China, two basic VSC-HVDC structures are analyzed.%柔性直流输电技术(voltage source converter based high voltage direct current,VSC-HVDC)应用于远距离大容量架空线输电是实现我国能源资源优化配置的客观要求,也是电网技术发展的未来趋势。目前柔性直流输电技术扩展到架空线输电场合所面临的关键问题有:直流线路故障难以快速清除、输送容量难以与传统直流输电相媲拟、主接线方式和接地方式选择原则还没有定论等。针对问题1,分析现有工程所采用的拓扑结构

  17. 一种柔性直流输电系统PID-ANFIS优化控制方法%A control method of PID-ANFIS controller for VSC-HVDC

    Institute of Scientific and Technical Information of China (English)

    杨天; 霍琳琳

    2015-01-01

    Due to the PI control system for VSC-HVDC has problems of parameters difficult to set, too many control users, and so on, a novel controller composed of PID function and multiple-output ANFIS (PID-ANFIS) is presented, which is made up of neural network, two order fuzzy control and PID control. A treble cooperative PSO (TCPSO) is also presented to optimize PID-ANFIS controller’s neural parameters. TCPSO is forged by harmonizing the grouping cooperation, the dimension-reduced cooperation and memory cooperation, which is able to improve the precision of optimizing neural networks. This paper provides the process of PID-ANFIS parameters training by TCPSO. Then, the TCPSO based PID-ANFIS controller performs the function of direct power control. The simulation results show that the controller presented has significant advantages of faster speed, smaller overshoot and better robustness by comparing to PI and it is a viable choice for VSC-HVDC control system.%针对柔性直流输电系统(Voltage Source Converter based High-Voltage Direct-Current, VSC-HVDC)双闭环控制中PI控制存在参数整定困难及控制器数量过多等问题,提出一种具有PID功能的自适应神经元模糊推理系统(Adaptive Neuro-Fuzzy Inference System with PID function, PID-ANFIS)控制器用于该系统控制。其中,PID-ANFIS控制器兼有神经网络控制、二阶模糊控制及PID功能;同时提出的基于三重合作粒子群算法(Treble Cooperative Particle Swarm Optimization, TCPSO)用于优化该控制器中神经网络参数。TCPSO采用由降维合作、分组合作与记忆合作组成的三重合作策略,极大程度上提升了神经网络参数优化的精度。深入研究了TCPSO优化PID-ANFIS控制器参数的步骤。基于TCPSO优化的PID-ANFIS控制器能够实现VSC-HVDC系统的直接功率控制效果。仿真结果表明该控制器具有控制速度快、超调量小、抗干扰能力强等优点,是VSC-HVDC控制系统的一个可行方案。

  18. 77 FR 9515 - List of Approved Spent Fuel Storage Casks: HI-STORM 100, Revision 8

    Science.gov (United States)

    2012-02-17

    ... RIN 3150-AJ05 List of Approved Spent Fuel Storage Casks: HI-STORM 100, Revision 8 AGENCY: Nuclear... Commission) is amending its spent fuel storage regulations by revising the Holtec International HI-STORM 100... and safety will be adequately protected. This direct final rule revises the HI-STORM 100 listing in...

  19. A Stylistic Analysis on Edgar Allan Poe's The Cask of Amontillado

    Institute of Scientific and Technical Information of China (English)

    杨赛菲

    2016-01-01

    The Cask of Amontillado is one of Poe's best-known horror short stories. Based on Stylistics, this paper attempts to analyze this story from the aspects of themes, characterization, point of view, syntactic and lexical features, to reveal Poe's excellent skills and the artistic charm.

  20. The Applicability of Traditional Protection Methods to Lines Emanating from VSC-HVDC Interconnectors and a Novel Protection Principle

    Directory of Open Access Journals (Sweden)

    Shimin Xue

    2016-05-01

    Full Text Available Voltage source converter (VSC-based high voltage direct current (VSC-HVDC interconnectors can realize accurate and fast control of power transmission among AC networks, and provide emergency power support for AC networks. VSC-HVDC interconnectors bring exclusive fault characteristics to AC networks, thus influencing the performance of traditional protections. Since fault characteristics are related to the control schemes of interconnectors, a fault ride-through (FRT strategy which is applicable to the interconnector operating characteristic of working in four quadrants and capable of eliminating negative-sequence currents under unbalanced fault conditions is proposed first. Then, the additional terms of measured impedances of distance relays caused by fault resistances are derived using a symmetrical component method. Theoretical analysis shows the output currents of interconnectors are controllable after faults, which may cause malfunctions in distance protections installed on lines emanating from interconnectors under the effect of fault resistances. Pilot protection is also inapplicable to lines emanating from interconnectors. Furthermore, a novel pilot protection principle based on the ratio between phase currents and the ratio between negative-sequence currents flowing through both sides is proposed for lines emanating from the interconnectors whose control scheme aims at eliminating negative-sequence currents. The validity of theoretical analysis and the protection principle is verified by PSCAD/EMTDC simulations.

  1. Thermal modeling of a vertical dry storage cask for used nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jie, E-mail: jieli@anl.gov; Liu, Yung Y., E-mail: yyliu@anl.gov

    2016-05-15

    Graphical abstract: - Highlights: • Thermal performance of a 3-D vertical dry cask under various conditions has been numerically studied by using ANSYS/FLUENT code. • The simulation was validated by comparing the results against data obtained from the temperature measurements of a commercial cask. • The results indicated that the basket with higher thermal conductivity dissipates decay heat out of the cask more efficiently than that with a lower thermal conductivity (aluminum composite vs. stainless steel). A heavier cooling gas is also helpful to enhance heat transfer via enhanced natural convection (N{sub 2} vs. He). • Coolant release from the fuel canister results in temperature change of the canister external surfaces. The simulation shows that such a change is large enough and detectable, which can provide a mechanism for leak detection by continuously monitoring this temperature change at the top center of the canister surface. • Partial blockage of the cask air inlets affects the temperature profiles marginally for both the fuel canister and those components inside. In contrast, fully blocked air inlets will lead to remarkable increases of the component temperatures. - Abstract: Thermal modeling of temperature profiles of dry casks has been identified as a high-priority item in a U.S. Department of Energy gap analysis. In this work, a three-dimensional model of a vertical dry cask has been constructed for computer simulation by using the ANSYS/FLUENT code. The vertical storage cask contains a welded canister for 32 Pressurized Water Reactor (PWR) used-fuel assemblies with a total decay heat load of 34 kW. To simplify thermal calculations, an effective thermal conductivity model for a 17 × 17 PWR used (or spent)-fuel assembly was developed and used in the simulation of thermal performance. The effects of canister fill gas (helium or nitrogen), internal pressure (1–6 atm), and basket material (stainless steel or aluminum alloy) were studied to

  2. Metal cask RT-5000 for the dry storage and transportation of spent nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Vorobyov, A.I.; Kazeev, V.G.; Krayev, V.S.; Shcherbina, A.N.; Churikov, Y.I. [All-Russian Research Inst. of Technical Physics, Snezhinsk (Russian Federation)

    2003-05-01

    Presentation of new-type cask, developed at RFNC-VNIITF, is in the article. The prototype model of the shipping cask was subjected to tests imitating normal shipment conditions (free fall, pressing, and impact) and to tests imitating emergency situation during shipment (a drop from the 9-m height onto a pin is replaced by acceleration of the shipping cask at a guide rail of the rocket-catapult installation (RCI), a 1-m drop onto a pin, heat tests a 30-minutes fire at the temperature of for 8500 C, submergence to the depth of 15 and 200 meters). After each test the hermeticity preservation is examined. Parallel with the real testing, a mathematical simulation of physical processes induced by the corresponding tests was conducted at the RFNC-VNIITF. The required parameters obtained from the tests are used to calibrate the calculation methods. As a result it has been possible to obtain a good agreement between the results of calculations and experiments; this will allow the mathematic simulation to be used wider. The advantage of the RT-5000 metal cask in comparison with metal-concrete analogs are as follows: SFA are placed into the RT-5000 entirely without cutting into two bunches of fuel elements; the expensive hot doom is not required for automatic cutting the SFA and for loading the bunches of fuel elements into intermediate cases; the possibility remains to transport the RT-5000 without reloading SFA after 50-year storage, although this is a problem for the metal-concrete casks.

  3. PRELIMINARY REPORT: EFFECTS OF IRRADIATION AND THERMAL EXPOSURE ON ELASTOMERIC SEALS FOR CASK TRANSPORTATION AND STORAGE

    Energy Technology Data Exchange (ETDEWEB)

    Verst, C.; Skidmore, E.; Daugherty, W.

    2014-05-30

    A testing and analysis approach to predict the sealing behavior of elastomeric seal materials in dry storage casks and evaluate their ability to maintain a seal under thermal and radiation exposure conditions of extended storage and beyond was developed, and initial tests have been conducted. The initial tests evaluate the aging response of EPDM elastomer O-ring seals. The thermal and radiation exposure conditions of the CASTOR® V/21 casks were selected for testing as this cask design is of interest due to its widespread use, and close proximity of the seals to the fuel compared to other cask designs leading to a relatively high temperature and dose under storage conditions. A novel test fixture was developed to enable compression stress relaxation measurements for the seal material at the thermal and radiation exposure conditions. A loss of compression stress of 90% is suggested as the threshold at which sealing ability of an elastomeric seal would be lost. Previous studies have shown this value to be conservative to actual leakage failure for most aging conditions. These initial results indicate that the seal would be expected to retain sealing ability throughout extended storage at the cask design conditions, though longer exposure times are needed to validate this assumption. The high constant dose rate used in the testing is not prototypic of the decreasingly low dose rate that would occur under extended storage. The primary degradation mechanism of oxidation of polymeric compounds is highly dependent on temperature and time of exposure, and with radiation expected to exacerbate the oxidation.

  4. Second Annual Maintenance, Inspection, and Test Report for PAS-1 Cask Certification for Shipping Payload B

    Energy Technology Data Exchange (ETDEWEB)

    KELLY, D.J.

    2000-10-09

    The Nuclear Packaging, Inc. (NuPac), PAS-1 cask is required to undergo annual maintenance and inspections to retain certification in accordance with U.S. Department of Energy (DOE) Certificate of Compliance USA/9184B(U) (Appendix A). The packaging configuration being tested and maintained is the NuPac PAS-1 cask for Payload B. The intent of the maintenance and inspections is to ensure the packaging remains in unimpaired physical condition. Two casks, serial numbers 2162-026 and 2162-027, were maintained, inspected, and tested at the 306E Development, Fabrication, and Test Laboratory, located at the Hanford Site's 300 Area. Waste Management Federal Services, Inc. (WMFS), a subsidiary of GTS Duratek, was in charge of the maintenance and testing. Cogema Engineering Corporation (Cogema) directed the operations in the test facility. The maintenance, testing, and inspections were conducted successfully with both PAS-1 casks. The work conducted on the overpacks included weighing, gasket replacement, and plastic pipe plug and foam inspections. The work conducted on the secondary containment vessel (SCV) consisted of visual inspection of the vessel and threaded parts (i.e., fasteners), visual inspection of sealing surfaces, replacement of O-ring seals, and a helium leak test. The work conducted on the primary containment vessel (PCV) consisted of visual inspection of the vessel and threaded parts (i.e., fasteners), visual inspection of sealing surfaces, replacement of O-ring seals, dimensional inspection of the vessel bottom, a helium leak test, and dye penetrant inspection of the welds. The vermiculite material used in the cask rack assembly was replaced.

  5. Human machine interface to manually drive rhombic like vehicles such as transport casks in ITER

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Pedro; Vale, Alberto [Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Universidade de Lisboa, Av. Rovisco Pais 1, 1049-001 Lisboa (Portugal); Ventura, Rodrigo [Institute for Systems and Robotics, Instituto Superior Tecnico, Universidade de Lisboa, Av. Rovisco Pais 1, 1049-001 Lisboa (Portugal)

    2015-07-01

    The Cask and Plug Remote Handling System (CPRHS) and the respective Cask Transfer System (CTS) are designed to transport activated components between the reactor and the hot cell buildings of ITER during maintenance operations. In nominal operation, the CPRHS/CTS shall operate autonomously under human supervision. However, in some unexpected situations, the automatic mode must be overridden and the vehicle must be remotely guided by a human operator due to the harsh conditions of the environment. The CPRHS/CTS is a rhombic-like vehicle with two independent steerable and drivable wheels along its longitudinal axis, giving it omni-directional capabilities. During manual guidance, the human operator has to deal with four degrees of freedom, namely the orientations and speeds of two wheels. This work proposes a Human Machine Interface (HMI) to manage the degrees of freedom and to remotely guide the CPRHS/CTS in ITER taking the most advantages of rhombic like capabilities. Previous work was done to drive each wheel independently, i.e., control the orientation and speed of each wheel independently. The results have shown that the proposed solution is inefficient. The attention of the human operator becomes focused in a single wheel. In addition, the proposed solution cannot assure that the commands accomplish the physical constrains of the vehicle, resulting in slippage or even in clashes. This work proposes a solution that consists in the control of the vehicle looking at the position of its center of mass and its heading in the world frame. The solution is implemented using a rotational disk to control the vehicle heading and a common analogue joystick to control the vector speed of the center of the mass of the vehicle. The number of degrees of freedom reduces to three, i.e., two angles (vehicle heading and the orientation of the vector speed) and a scalar (the magnitude of the speed vector). This is possible using a kinematic model based on the vehicle Instantaneous

  6. Releasable activity and maximum permissible leakage rate within a transport cask of Tehran Research Reactor fuel samples

    Directory of Open Access Journals (Sweden)

    Rezaeian Mahdi

    2015-01-01

    Full Text Available Containment of a transport cask during both normal and accident conditions is important to the health and safety of the public and of the operators. Based on IAEA regulations, releasable activity and maximum permissible volumetric leakage rate within the cask containing fuel samples of Tehran Research Reactor enclosed in an irradiated capsule are calculated. The contributions to the total activity from the four sources of gas, volatile, fines, and corrosion products are treated separately. These calculations are necessary to identify an appropriate leak test that must be performed on the cask and the results can be utilized as the source term for dose evaluation in the safety assessment of the cask.

  7. Safety assessment technology on the free drop impact and puncture analysis of the cask for radioactive material transport

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dew Hey [Korea Institute of Nuclear Safety, Taejon (Korea, Republic of); Lee, Young Shin; Ryu, Chung Hyun; Kim, Hyun Su; Lee, Ho Chul; Hong, Song Jin; Choi, Young Jin; Lee, Jae Hyung; Na, Jae Yun [Chungnam National Univ., Taejon (Korea, Republic of)

    2001-03-15

    In this study, the regulatory condition and analysis condition is analyzed for the free drop and puncture impact analysis to develop the safety assessment technology. Impact analysis is performed with finite element method which is one of the many analysis methods of the shipping cask. LS-DYNA3D and ABAQUS is suitable for the free drop and the puncture impact analysis of the shipping cask. For the analysis model, the KSC-4 that is the shipping cask to transport spent nuclear fuel is investigated. The results of both LS-DYNA3D and ABAQUS is completely corresponded. And The integrity of the shipping cask is verified. Using this study, the reliable safety assessment technology is supplied to the staff. The efficient and reliable regulatory tasks is performed using the standard safety assessment technology.

  8. Study on controlling of VSC- HVDC based on advanced phase locked loop technique%基于改进锁相环的柔性直流输电系统控制研究

    Institute of Scientific and Technical Information of China (English)

    郑连清; 池俊锋; 陈杰

    2011-01-01

    Under AC power system frequency excursion and harmonics produced by switching devices, detecting synchronous phase and instantaneous symmetrical components quickly and accurately is an important part of the control and protection system of voltage source converter based high-voltage direct current transmission ( VSC - HVDC). Combined with the conception of SPLL and the VSC - HVD system, which can make the independence decoupling of the active power and the reactive power, devising a new system for three-phase phase-locked loop, with double-phase discriminators. According to eliminate the double frequency, reducing the system's main error, and at same time, making PI regulator has better frequency response characteristics and better frequency locking ability. It is verified by PSCAD that dynamic response of the system can be improved and locking frequency range of phase can be extended.%针对系统频率波动、开关器件动作产生大量的谐波等问题,快速、准确地提供同步相位,是基于电压源型换流器的高压直流输电系统实现控制和保护的关键问题.通过引进软件锁相环概念(SPLL),并结合VSC-HVDC系统能瞬间实现有功、无功解耦的特点,设计了双鉴相器的三相锁相系统.通过消除二倍频,抑制了引起误差的主要因素,同时使PI调节器具有更好的频率锁定和响应特性.通过PSCAD对改进前后系统的在消除谐波、提高系统整体性能,以及电网频率一定范围内突变时系统的响应特性等方面进行比较,实现了对原理的验证.

  9. Evaluating the feasibility of new surveillance concept for Dry Storage System through CFD methodology

    Energy Technology Data Exchange (ETDEWEB)

    Tseng, Y.S., E-mail: yungshintseng@gmail.com [Nuclear Science and Technology Development Center, National Tsing Hua University, 101, Sec. 2, Kuang-Fu Rd., Hsingchu 30013, 325, Taiwan, ROC (China); Lin, C.H., E-mail: gp6ej3@gmail.com [Center for Energy and Environmental Research, National Tsing Hua University, 101, Sec. 2, Kuang-Fu Rd., Hsingchu 30013, 325, Taiwan, ROC (China); Shih, C., E-mail: ckshih@ess.nthu.edu.tw [Institute of Nuclear Engineering and Science, National Tsing Hua University, 101, Sec. 2, Kuang-Fu Rd., Hsingchu 30013, 325, Taiwan, ROC (China); Wang, J.R., E-mail: jongrongwang@gmail.com [Institute of Nuclear Engineering and Science, National Tsing Hua University, 101, Sec. 2, Kuang-Fu Rd., Hsingchu 30013, 325, Taiwan, ROC (China)

    2016-08-01

    Highlights: • Thermal hydraulic behavior of a 3-D dry cask under several off-normal conditions has been numerically investigated by ANSYS/FLUENT. • The simulation methodology was fully validated by comparing the measured results of VSC-17. • The results indicated that many design bases accidents can be early detected by the purposed surveillance method. • A simply determine rule has been developed for future application for dry storage ​monitoring. - Abstract: Since the Dry Storage System (DSS) has passed into a widespread middle-term storage method for Spent Nuclear Fuels (SNFs), the situation monitoring technology for a DSS should be further improved to ensure the reliability of DSS during storing time. However, a passive cooling mechanism with a full-sealed storage requirement causes that the internal situation cannot be directly monitored by thermocouples inserted into the DSS. In this study, a new surveillance method, therefore, has been proposed to overcome this problem. It can predict the DSS situation through measuring the temperature profile at the Transportable Storage Canister (TSC). A validated CFD methodology has been utilized to confirm the method through simulating the thermal characteristics of the ChinShan DSS (CSDSS). The major factors, such as the thermal loading, accident situation and flaw caused by penetrated hole probably, have been considered in this present work. The result shows that the above-mentioned issues would obviously affect the temperature profile on the TSC and can be identified via detecting the temperature profile difference on of TSC. These results confirm that the indirectly surveillance method has enough capability to replace the original monitored method and provide more system information of DSS vendor for middle-term storage.

  10. VSC—HVDC在风电场并网系统中的应用研究%A survey of VSC - HVDC for wind farm interconnection

    Institute of Scientific and Technical Information of China (English)

    肖小兵; 周杰娜; 袁旭峰; 姚刚; 何肖蒙

    2012-01-01

    介绍风力发电并网对电网产生的影响,分析说明VSC—HVDC的工作原理和技术特点,并对风电场联网VSC—HVDC控制器设计进行阐述,列举VSC~HVDC的应用场合,并且举例介绍国外采用VSC—HVDC在风电并网中的应用。%The impact of the wind farm interconnection is described, then the working principle and the technical characteristics of VSC - HVDC are analyzed and explained, and then the design of the wind farm interconnection with VSC - HVDC controller is described, finally a list of application in VSC - HVDC controll on wind farm intergration is listed together with illustrated examples.

  11. Study of the temperature distribution on welded thin plates of duplex steel to be used for the external clad of a cask for transportation of radiopharmaceuticals products

    Energy Technology Data Exchange (ETDEWEB)

    Betini, Evandro G.; Ceoni, Francisco C.; Mucsi, Cristiano S.; Politano, Rodolfo; Rossi, Jesualdo L., E-mail: egbetini@ipen.br, E-mail: fceoni@hotmail.com, E-mail: csmucsi@ipen.br, E-mail: politano@ipen.br, E-mail: jelrossi@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Orlando, Marcos T.D., E-mail: mtdorlando@gmail.com [Universidade Federal do Espirito Santo (CCE/DFIS/UFES), Vitoria, ES (Brazil). Centro de Ciencias Exatas. Departamento de Fisica

    2015-07-01

    The clad material for a proprietary transport device for radiopharmaceutical products is the main focus of the present work. The production of {sup 99}Mo-{sup 99m}Tc transport cask requires a receptacle or cask where the UNS S32304 duplex steel sheet has shown that it meets high demands as the required mechanical strength and the spread of impact or shock waves mitigation. This work reports the experimental efforts in recording the thermal distribution on autogenous thin plates of UNS S32304 steel during welding. The UNS S32304 duplex steel is the most probable candidate for the external clad of the containment package for the transport of radioactive substances so it is highly relevant the understanding of all its physical parameters and its behavior under the thermal cycle imposed by a welding process. For the welding of the UNS S32304 autogenous plates the GTAW (gas tungsten arc welding) process was used with a pure argon arc protection atmosphere in order to simulate a butt joint weld on a thin duplex steel plate without filler metal. The thermal cycles were recorded by means of K-type thermocouples embedded by electrical spot welding near the weld region and connected to a multi-channel data acquisition system. The obtained results validate the reliability of the experimental apparatus for the future complete analysis of the welding experiment and further comparison to numerical analysis. (author)

  12. Genes similar to the Vibrio parahaemolyticus virulence-related genes tdh, tlh, and vscC2 occur in other vibrionaceae species isolated from a pristine estuary.

    Science.gov (United States)

    Klein, Savannah L; Gutierrez West, Casandra K; Mejia, Diana M; Lovell, Charles R

    2014-01-01

    Detection of the human pathogen Vibrio parahaemolyticus often relies on molecular biological analysis of species-specific virulence factor genes. These genes have been employed in determinations of V. parahaemolyticus population numbers and the prevalence of pathogenic V. parahaemolyticus strains. Strains of the Vibrionaceae species Photobacterium damselae, Vibrio diabolicus, Vibrio harveyi, and Vibrio natriegens, as well as strains similar to Vibrio tubiashii, were isolated from a pristine salt marsh estuary. These strains were examined for the V. parahaemolyticus hemolysin genes tdh, trh, and tlh and for the V. parahaemolyticus type III secretion system 2α gene vscC2 using established PCR primers and protocols. Virulence-related genes occurred at high frequencies in non-V. parahaemolyticus Vibrionaceae species. V. diabolicus was of particular interest, as several strains were recovered, and the large majority (>83%) contained virulence-related genes. It is clear that detection of these genes does not ensure correct identification of virulent V. parahaemolyticus. Further, the occurrence of V. parahaemolyticus-like virulence factors in other vibrios potentially complicates tracking of outbreaks of V. parahaemolyticus infections.

  13. Safety evaluation for packaging (onsite) plutonium recycle test reactor graphite cask

    Energy Technology Data Exchange (ETDEWEB)

    Romano, T.

    1997-09-29

    This safety evaluation for packaging (SEP) provides the evaluation necessary to demonstrate that the Plutonium Recycle Test Reactor (PRTR) Graphite Cask meets the requirements of WHC-CM-2-14, Hazardous Material Packaging and Shipping, for transfer of Type B, fissile, non-highway route controlled quantities of radioactive material within the 300 Area of the Hanford Site. The scope of this SEP includes risk, shieldling, criticality, and.tiedown analyses to demonstrate that onsite transportation safety requirements are satisfied. This SEP also establishes operational and maintenance guidelines to ensure that transport of the PRTR Graphite Cask is performed safely in accordance with WHC-CM-2-14. This SEP is valid until October 1, 1999. After this date, an update or upgrade to this document is required.

  14. Advantages of dry hardened cask storage over wet storage for spent nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Romanato, Luiz Sergio, E-mail: romanato@ctmsp.mar.mil.b [Centro Tecnologico da Marinha em Sao Paulo (CTMSP), Sao Paulo, SP (Brazil). Dept. da Qualidade

    2011-07-01

    Pools are generally used to store and maintain spent nuclear fuel assemblies for cooling, after removed from reactors. After three to five years stored in the pools, spent fuel can be reprocessed or sent to a final disposition in a geological repository and handled as radioactive waste or sent to another site waiting for future solution. Spent fuel can be stored in dry or wet installations, depending on the method adopted by the nuclear plant. If this storage were exclusively wet, at the installation decommissioning in the future, another solution for storage will need to be found. Today, after a preliminary cooling, the spent fuel assemblies can be removed from the pool and sent to dry hardened storage installations. This kind of storage does not need complex radiation monitoring and it is safer than wet storage. Brazil has two nuclear reactors in operation, a third reactor is under construction and they use wet spent fuel storage . Dry hardened casks use metal or both metal and concrete for radiation shielding and they are safe, especially during an earthquake. An earthquake struck Japan on March 11, 2011 damaging Fukushima Daiichi nuclear power plant. The occurrence of earthquakes in Brazil is very small but dry casks can resist to other events, including terrorist acts, better than pools. This paper shows the advantages of dry hardened cask storage in comparison with the wet storage (water pools) for spent nuclear fuel. (author)

  15. Quivers For Special Fuel Rods-Disposal Of Special Fuel Rods In CASTOR V Casks

    Energy Technology Data Exchange (ETDEWEB)

    Bannani, Amin; Cebula, Wojciech; Buchmuller, Olga; Huggenberg, Roland [GNS, Essen (Germany); Helmut Kuhl [WTI, Julich (Germany)

    2015-05-15

    While GNS casks of the CASTOR family are a suitable means to transfer fuel assemblies (FA) from the NPP to an interim dry storage site, Germanys phase-out of nuclear energy has triggered the demand for an additional solution to dispose of special fuel rods (SFR), normally remaining in the fuel pond until the final shutdown of the NPP. SFR are fuel rods that had to be removed from fuel assemblies mainly due to their special condition, e. g. damages in the cladding of the fuel rods which may have occurred during reactor operations. SFR are usually stored in the spent fuel pond after they are removed from the FA. The quiver for special fuel rods features a robust yet simple design, with a high mechanical stability, a reliable leak-tightness and large safety margins for future requirements on safety analysis. The quiver for special fuel rods can be easily adapted to a large variety of different damaged fuel rods and tailored to the specific need of the customer. The quiver for special fuel rods is adaptable e.g. in length and diameter for use in other types of transport and storage casks and is applicable in other countries as well. The overall concept presented here is a first of its kind solution for the disposal of SFRs via Castor V-casks. This provides an important precondition in achieving the status 'free from nuclear fuel' of the shut down German NPPs.

  16. Alternative Splicing of a Novel Inducible Exon Diversifies the CASK Guanylate Kinase Domain

    Directory of Open Access Journals (Sweden)

    Jill A. Dembowski

    2012-01-01

    Full Text Available Alternative pre-mRNA splicing has a major impact on cellular functions and development with the potential to fine-tune cellular localization, posttranslational modification, interaction properties, and expression levels of cognate proteins. The plasticity of regulation sets the stage for cells to adjust the relative levels of spliced mRNA isoforms in response to stress or stimulation. As part of an exon profiling analysis of mouse cortical neurons stimulated with high KCl to induce membrane depolarization, we detected a previously unrecognized exon (E24a of the CASK gene, which encodes for a conserved peptide insertion in the guanylate kinase interaction domain. Comparative sequence analysis shows that E24a appeared selectively in mammalian CASK genes as part of a >3,000 base pair intron insertion. We demonstrate that a combination of a naturally defective 5 splice site and negative regulation by several splicing factors, including SC35 (SRSF2 and ASF/SF2 (SRSF1, drives E24a skipping in most cell types. However, this negative regulation is countered with an observed increase in E24a inclusion after neuronal stimulation and NMDA receptor signaling. Taken together, E24a is typically a skipped exon, which awakens during neuronal stimulation with the potential to diversify the protein interaction properties of the CASK polypeptide.

  17. A comparison of spent fuel shipping cask response to 10 CFR 71 normal conditions and realistic hot day extremes

    Energy Technology Data Exchange (ETDEWEB)

    Manson, S.J.; Gianoulakis, S.E. [Sandia National Labs., Albuquerque, NM (United States). Transportation Systems Development Dept.

    1994-04-01

    An examination of the effect of a realistic (though conservative) hot day environment on the thermal transient behavior of spent fuel shipping casks is made. These results are compared to those that develop under the prescribed normal thermal condition of 10 CFR 71. Of specific concern are the characteristics of propagating thermal waves, which are set up by diurnal variations of temperature and insolation in the outdoor environment. In order to arrive at a realistic approximation of these variations on a conservative hot day, actual temperature and insolation measurements have been obtained from the National Climatic Data Center (NCDC) for representatively hot and high heat flux days. Thus, the use of authentic meteorological data ensures the realistic approach sought. Further supporting the desired realism of the modeling effort is the use of realistic cask configurations in which multiple laminations of structural, shielding, and other materials are expected to attenuate the propagating thermal waves. The completed analysis revealed that the majority of wall temperatures, for a wide variety of spent fuel shipping cask configurations, fall well below those predicted by enforcement of the regulatory environmental conditions of 10 CFR 71. It was found that maximum temperatures at the cask surface occasionally lie above temperatures predicted under the prescribed regulatory conditions. However, the temperature differences are small enough that the normal conservative assumptions that are made in the course of typical cask evaluations should correct for any potential violations. The analysis demonstrates that diurnal temperature variations that penetrate the cask wall all have maxima substantially less than the corresponding regulatory solutions. Therefore it is certain that vital cask components and the spent fuel itself will not exceed the temperatures calculated by use of the conditions of 10 CFR 71.

  18. REVIEW OF FAST FLUX TEST FACILITY (FFTF) FUEL EXPERIMENTS FOR STORAGE IN INTERIM STORAGE CASKS (ISC)

    Energy Technology Data Exchange (ETDEWEB)

    CHASTAIN, S.A.

    2005-10-24

    Appendix H, Section H.3.3.10.11 of the Final Safety Analysis Report (FSAR), provides the limits to be observed for fueled components authorized for storage in the Fast Flux Test Facility (FFTF) spent fuel storage system. Currently, the authorization basis allows standard driver fuel assemblies (DFA), as described in the FSAR Chapter 17, Section 17.5.3.1, to be stored provided decay power per assembly is {le} 250 watts, post-irradiation time is four years minimum, average assembly burn-up is 150,000 MWD/MTHM maximum and the pre-irradiation enrichment is 29.3% maximum (per H.3.3.10.11). In addition, driver evaluation (DE), core characterizer assemblies (CCA), and run-to-cladding-breach (RTCB) assemblies are included based on their similarities to a standard DFA. Ident-69 pin containers with fuel pins from these DFAs can also be stored. Section H.3.3.10.11 states that fuel types outside the specification criteria above will be addressed on a case-by-case basis. There are many different types of fuel and blanket experiments that were irradiated in the FFTF which now require offload to the spent fuel storage system. Two reviews were completed for a portion of these special type fuel components to determine if placement into the Core Component Container (CCC)/Interim Storage Cask (ISC) would require any special considerations or changes to the authorization basis. Project mission priorities coupled with availability of resources and analysts prevented these evaluations from being completed as a single effort. Areas of review have included radiological accident release consequences, radiological shielding adequacy, criticality safety, thermal limits, confinement, and stress. The results of these reviews are available in WHC-SD-FF-RPT-005, Rev. 0 and 1, ''Review of FFTF Fuel Experiments for Storage at ISA'', (Reference I), which subsequently allowed a large portion of these components to be included in the authorization basis (Table H.3.3-21). The

  19. Discussion of Available Methods to Support Reviews of Spent Fuel Storage Installation Cask Drop Evaluations

    Energy Technology Data Exchange (ETDEWEB)

    Witte, M.

    2000-03-28

    Applicants seeking a Certificate of Compliance for an Independent Spent Fuel Storage Installation (ISFSI) cask must evaluate the consequences of a handling accident resulting in a drop or tip-over of the cask onto a concrete storage pad. As a result, analytical modeling approaches that might be used to evaluate the impact of cylindrical containers onto concrete pads are needed. One such approach, described and benchmarked in NUREG/CR-6608,{sup 1} consists of a dynamic finite element analysis using a concrete material model available in DYNA3D{sup 2} and in LS-DYNA,{sup 3} together with a method for post-processing the analysis results to calculate the deceleration of a solid steel billet when subjected to a drop or tip-over onto a concrete storage pad. The analysis approach described in NUREG/CR-6608 gives a good correlation of analysis and test results. The material model used for the concrete in the analyses in NUREG/CR-6608 is, however, somewhat troublesome to use, requiring a number of material constants which are difficult to obtain. Because of this a simpler approach, which adequately evaluates the impact of cylindrical containers onto concrete pads, is sought. Since finite element modeling of metals, and in particular carbon and stainless steel, is routinely and accurately accomplished with a number of finite element codes, the current task involves a literature search for and a discussion of available concrete models used in finite element codes. The goal is to find a balance between a concrete material model with a limited number of required material parameters which are readily obtainable, and a more complex model which is capable of accurately representing the complex behavior of the concrete storage pad under impact conditions. The purpose of this effort is to find the simplest possible way to analytically represent the storage cask deceleration during a cask tip-over or a cask drop onto a concrete storage pad. This report is divided into three sections

  20. Behaviour of neutron moderator materials at high temperatures in CASTOR {sup registered} -casks: qualification and assessment

    Energy Technology Data Exchange (ETDEWEB)

    Krietsch, T.; Wolff, D. [Federal Inst. for Materials Research and Testing (BAM), Berlin (Germany); Knopp, U. [Gesellschaft fuer Nuklear-Behaelter mbH (GNB), Essen (Germany); Brocke, H.D. [TUeV Rheinland Group, Berlin (Germany)

    2004-07-01

    The Federal Institute for Materials Research and Testing (BAM) is the responsible German authority for the assessment of mechanical and thermal designs of transport and storage casks for radioactive materials. BAM checks up the proofs of the applicants in their safety reports and assesses the conformity to the Regulations for the Safe Transport of Radioactive Material. One applicant is the Gesellschaft fuer Nuklear-Behaelter mbH (GNB) with a new generation of transport and storage casks of CASTOR {sup registered} -design. GNB typically uses ultra high molecular weight Polyethylene (UHMW-PE) for the moderation of free neutrons. Rods made of UHMW-PE are positioned in axial bore holes in the wall of the cask and plates of UHMW-PE are in free spaces between primary and secondary lid and between the bottom of the cask and an outer plate (Figure 1). Because of the heat generated by the radioactive inventory and because of a strained spring at the bottom of every bore hole, UHMW-PE is subjected to permanent thermal and mechanical loads as well as loads from gamma and neutron radiation. UHMW-PE has been used under routine- and normal conditions of transport for maximum temperatures up to 130 C. For new generations of CASTOR registered -design maximum temperatures will be increased up to 160 C. That means a permanent use of UHMW-PE at temperatures within and above the melting region of the crystallites. In this paper, some results of special investigations for the proofs of usability of UHMW-PE at temperatures up to 160 C under real conditions of transport and storage in CASTOR registered -casks are given. For that, investigations on temperature dependent expansion behaviour under laboratory conditions as well as in large scale experiments, especially in the case of multiple heating and cooling, were done. Besides, geometrical creep strength for long-term loading by temperatures and pressures with regard to the chemical and physical stability properties of UHMW-PE above the

  1. 柔性直流输电线路故障处理与保护技术评述%Comments on Fault Handling and Protection Technology for VSC-HVDC Transmission Lines

    Institute of Scientific and Technical Information of China (English)

    刘剑; 邰能灵; 范春菊; 黄文焘

    2015-01-01

    由于柔性直流输电系统调节方式和自身结构的特殊性,直流线路的故障电流具有上升速度快、峰值大的特点,极易损坏换流器件和设备绝缘,且柔性直流系统无法通过调节触发角实现故障自清除。因此,对直流线路故障处理和保护提出了更高要求。对于柔性直流线路故障,不仅需要快速且可靠的线路保护对故障进行识别,也需要相应的处理措施和手段对故障后的电流进行有效限制,以减少故障冲击电流对换流器件、直流线路自身以及系统的损害。基于柔性直流输电线路的故障特征,从直流线路故障电流抑制、减少故障影响、线路保护原理等方面,系统地介绍了国内、国外柔性直流输电线路故障处理与保护技术的现状和发展。重点分析了几种辅助电路、新型换流器拓扑和直流输电结构,以及直流断路器在处理直流线路故障方面的性能。探讨了目前柔性直流输电线路故障处理和保护亟须解决的关键问题以及未来进一步的研究方向。%Owing to the specific mode of regulation and structure of the voltage source converter-high voltage direct current (VSC-HVDC) transmission system,the DC line fault current is characterized by high increasing speed and great peak value. This is extremely susceptible to destruction of converter devices and damage to insulation of equipment.VSC-HVDC system cannot realize fault self-clearing by adjusting the firing angle.Therefore,higher requirements are made on protection and fault handling of DC transmission lines.For DC line faults,not only is reliable and fast protection needed for fault identification,but also corresponding control measures and circuit should be taken to limit the fault current and reduce the damage of the current to converter devices,the DC line itself and system.Based on the fault characteristics of VSC-HVDC transmission lines,the state of the art of DC line

  2. 大型海上风电场并网VSC-HVDC变流器关键技术%Key Technologies of Large Offshore Wind Farm VSC-HVDC Converters for Grid Integration

    Institute of Scientific and Technical Information of China (English)

    王志新; 吴杰; 徐烈; 王国强

    2013-01-01

    In recent years, offshore wind energy has been developing rapidly because of many advantages, e.g. not taking up land resources, high utilization rate and so on. By 2011, the global total installed capacity of offshore wind power was 4 954 MW, with 241.3 MW in China. And the planning capacity in China would be 5 GW by 2015 and 30 GW by 2020. Large-scale development and utilization of offshore wind farms increase the requirements for converters of VSC direct current transmission, such as converter topology and control method, and their applications to offshore wind farms. Key technologies of large offshore wind farm VSC-HVDC converter involve detailed multilevel converter topology, modulation, voltage balancing strategies and offshore wind farm modeling techniques etc. These can provide theoretical foundation for the grid integration of large offshore wind farms, and there is academic significance and practical value for improving the utilization and large-scale development of offshore wind power.%  近年来,海上风电因具有不占用陆上土地资源、风能利用率高等诸多优势,得到了迅速发展。截至2011年底,全球已建成80个海上风电场,累计装机容量达到4954 MW。其中,我国2011年海上风电累计总装机为241.3 MW。此外,我国还规划到2015年和2020年,我国海上风电总装机将分别累计达到5和30 GW。随着海上风电的规模化开发与利用量的巨大增长,海上风电场并网柔性直流输电系统(voltage source converter based high-voltage direct current , VSC-HVDC)的应用也为业界所关注,并对海上风电柔性直流输电变流器提出了更高的要求。大型海上风电场并网VSC-HVDC 的关键技术主要涉及变流器拓扑结构和控制方法,以及在海上风电场中的应用等,例如海上风电柔性直流输电变流器的多电平拓扑结构、调制方法、均压控制策略以及海上风电场建模等关键技术。分析、总

  3. In vitro CPC retention and VSC adsorption by IPM oil droplets: possible mechanisms of action of a two phase mouthwash.

    Science.gov (United States)

    Sterer, N; Slutzky, H; Kohavi, D; Matalon, S

    2013-09-01

    Two phase oil-water mouthwash has been previously shown to efficiently bind oral microorganisms, relying on their cell surface hydrophobicity. The aim of the present in vitro study was to test the cetylpyridinium chloride (CPC) retention and volatile sulfide compounds (VSCs) adsorption abilities of the oil droplets created by mixing of a two phase oil-water solution. VSC adsorption was assayed using a salivary incubation assay and garlic powder solutions, and demonstrated using microscopic sulfide assay. CPC retention was assayed by kinetic and endpoint measurement of Streptococcus salivarius outgrowth using microplate (ELISA) reader. Results showed that the isopropyl myristate (IPM) oil droplets in the two phase solutions were able to adsorb 68-80% of VSCs. CPC at a concentration of 0.05% was most affectively retained by the oil droplets showing a significantly increase in residual antibacterial activity against Streptococcus salivarius. These results taken together, suggests that VSC adsorption and CPC retention by IPM oil droplets may be two additional mechanisms in the activity of the two phase mouthwash formulation.

  4. CASK interacts with PMCA4b and JAM-A on the mouse sperm flagellum to regulate Ca2+ homeostasis and motility.

    Science.gov (United States)

    Aravindan, Rolands G; Fomin, Victor P; Naik, Ulhas P; Modelski, Mark J; Naik, Meghna U; Galileo, Deni S; Duncan, Randall L; Martin-Deleon, Patricia A

    2012-08-01

    Deletion of the highly conserved gene for the major Ca(2+) efflux pump, Plasma membrane calcium/calmodulin-dependent ATPase 4b (Pmca4b), in the mouse leads to loss of progressive and hyperactivated sperm motility and infertility. Here we first demonstrate that compared to wild-type (WT), Junctional adhesion molecule-A (Jam-A) null sperm, previously shown to have motility defects and an abnormal mitochondrial phenotype reminiscent of that seen in Pmca4b nulls, exhibit reduced (P JAM-A on the proximal principal piece, acts as a common interacting partner of both. Importantly, CASK binds alternatively and non-synergistically with each of these molecules via its single PDZ (PDS-95/Dlg/ZO-1) domain to either inhibit or promote efflux. In the absence of CASK-JAM-A interaction in Jam-A null sperm, CASK-PMCA4b interaction is increased, resulting in inhibition of PMCA4b's enzymatic activity, consequent Ca(2+) accumulation, and a ∼6-fold over-expression of constitutively ATP-utilizing CASK, compared to WT. Thus, CASK negatively regulates PMCA4b by directly binding to it and JAM-A positively regulates it indirectly through CASK. The decreased motility is likely due to the collateral net deficit in ATP observed in nulls. Our data indicate that Ca(2+) homeostasis in sperm is maintained by the relative ratios of CASK-PMCA4b and CASK-JAM-A interactions.

  5. Analysis of Corrosion Residues Collected from the Aluminum Basket Rails of the High-Burnup Demonstration Cask.

    Energy Technology Data Exchange (ETDEWEB)

    Bryan, Charles R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-03-01

    On September, 2015, an inspection was performed on the TN-32B cask that will be used for the high-burnup demonstration project. During the survey, wooden cribbing that had been placed within the cask eleven years earlier to prevent shifting of the basket during transport was removed, revealing two areas of residue on the aluminum basket rails, where they had contacted the cribbing. The residue appeared to be a corrosion product, and concerns were raised that similar attack could exist at more difficult-to-inspect locations in the canister. Accordingly, when the canister was reopened, samples of the residue were collected for analysis. This report presents the results of that assessment, which determined that the corrosion was due to the presence of the cribbing. The corrosion was associated with fungal material, and fungal activity likely contributed to an aggressive chemical environment. Once the cask has been cleaned, there will be no risk of further corrosion.

  6. Interaction of cosmic ray muons with spent nuclear fuel dry casks and determination of lower detection limit

    Science.gov (United States)

    Chatzidakis, S.; Choi, C. K.; Tsoukalas, L. H.

    2016-08-01

    The potential non-proliferation monitoring of spent nuclear fuel sealed in dry casks interacting continuously with the naturally generated cosmic ray muons is investigated. Treatments on the muon RMS scattering angle by Moliere, Rossi-Greisen, Highland and, Lynch-Dahl were analyzed and compared with simplified Monte Carlo simulations. The Lynch-Dahl expression has the lowest error and appears to be appropriate when performing conceptual calculations for high-Z, thick targets such as dry casks. The GEANT4 Monte Carlo code was used to simulate dry casks with various fuel loadings and scattering variance estimates for each case were obtained. The scattering variance estimation was shown to be unbiased and using Chebyshev's inequality, it was found that 106 muons will provide estimates of the scattering variances that are within 1% of the true value at a 99% confidence level. These estimates were used as reference values to calculate scattering distributions and evaluate the asymptotic behavior for small variations on fuel loading. It is shown that the scattering distributions between a fully loaded dry cask and one with a fuel assembly missing initially overlap significantly but their distance eventually increases with increasing number of muons. One missing fuel assembly can be distinguished from a fully loaded cask with a small overlapping between the distributions which is the case of 100,000 muons. This indicates that the removal of a standard fuel assembly can be identified using muons providing that enough muons are collected. A Bayesian algorithm was developed to classify dry casks and provide a decision rule that minimizes the risk of making an incorrect decision. The algorithm performance was evaluated and the lower detection limit was determined.

  7. Identification and glycerol-induced correction of misfolding mutations in the X-linked mental retardation gene CASK.

    Directory of Open Access Journals (Sweden)

    Leslie E W LaConte

    Full Text Available The overwhelming amount of available genomic sequence variation information demands a streamlined approach to examine known pathogenic mutations of any given protein. Here we seek to outline a strategy to easily classify pathogenic missense mutations that cause protein misfolding and are thus good candidates for chaperone-based therapeutic strategies, using previously identified mutations in the gene CASK. We applied a battery of bioinformatics algorithms designed to predict potential impact on protein structure to five pathogenic missense mutations in the protein CASK that have been shown to underlie pathologies ranging from X-linked mental retardation to autism spectrum disorder. A successful classification of the mutations as damaging was not consistently achieved despite the known pathogenicity. In addition to the bioinformatics analyses, we performed molecular modeling and phylogenetic comparisons. Finally, we developed a simple high-throughput imaging assay to measure the misfolding propensity of the CASK mutants in situ. Our data suggests that a phylogenetic analysis may be a robust method for predicting structurally damaging mutations in CASK. Mutations in two evolutionarily invariant residues (Y728C and W919R exhibited a strong propensity to misfold and form visible aggregates in the cytosolic milieu. The remaining mutations (R28L, Y268H, and P396S showed no evidence of aggregation and maintained their interactions with known CASK binding partners liprin-α3 Mint-1, and Veli, indicating an intact structure. Intriguingly, the protein aggregation caused by the Y728C and W919R mutations was reversed by treating the cells with a chemical chaperone (glycerol, providing a possible therapeutic strategy for treating structural mutations in CASK in the future.

  8. A novel interaction between FRMD7 and CASK: evidence for a causal role in idiopathic infantile nystagmus.

    Science.gov (United States)

    Watkins, Rachel J; Patil, Rajashree; Goult, Benjamin T; Thomas, Mervyn G; Gottlob, Irene; Shackleton, Sue

    2013-05-15

    Idiopathic infantile nystagmus (IIN) is a genetically heterogeneous disorder of eye movement that can be caused by mutations in the FRMD7 gene that encodes a FERM domain protein. FRMD7 is expressed in the brain and knock-down studies suggest it plays a role in neurite extension through modulation of the actin cytoskeleton, yet little is known about its precise molecular function and the effects of IIN mutations. Here, we studied four IIN-associated missense mutants and found them to have diverse effects on FRMD7 expression and cytoplasmic localization. The C271Y mutant accumulates in the nucleus, possibly due to disruption of a nuclear export sequence located downstream of the FERM-adjacent domain. While overexpression of wild-type FRMD7 promotes neurite outgrowth, mutants reduce this effect to differing degrees and the nuclear localizing C271Y mutant acts in a dominant-negative manner to inhibit neurite formation. To gain insight into FRMD7 molecular function, we used an IP-MS approach and identified the multi-domain plasma membrane scaffolding protein, CASK, as a FRMD7 interactor. Importantly, CASK promotes FRMD7 co-localization at the plasma membrane, where it enhances CASK-induced neurite length, whereas IIN-associated FRMD7 mutations impair all of these features. Mutations in CASK cause X-linked mental retardation. Patients with C-terminal CASK mutations also present with nystagmus and, strikingly, we show that these mutations specifically disrupt interaction with FRMD7. Together, our data strongly support a model whereby CASK recruits FRMD7 to the plasma membrane to promote neurite outgrowth during development of the oculomotor neural network and that defects in this interaction result in nystagmus.

  9. Criticality Analysis of Assembly Misload in a PWR Burnup Credit Cask

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, J. C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2008-01-31

    The Interim Staff Guidance on bumup credit (ISG-8) for spent fuel in storage and transportation casks, issued by the Nuclear Regulatory Commission's Spent Fuel Project Office, recommends a bumup measurement for each assembly to confirm the reactor record and compliance with the assembly bumup value used for loading acceptance. This recommendation is intended to prevent unauthorized loading (misloading) of assemblies due to inaccuracies in reactor burnup records and/or improper assembly identification, thereby ensuring that the appropriate subcritical margin is maintained. This report presents a computational criticality safety analysis of the consequences of misloading fuel assemblies in a highcapacity cask that relies on burnup credit for criticality safety. The purpose of this report is to provide a quantitative understanding of the effects of fuel misloading events on safety margins. A wide variety of fuel-misloading configurations are investigated and results are provided for informational purposes. This report does not address the likelihood of occurrence for any of the misload configurations considered. For representative, qualified bumup-enrichment combinations, with and without fission products included, misloading two assemblies that are underburned by 75% results in an increase in keff of 0.025-0.045, while misloading four assemblies that are underburned by 50% also results in an increase in keff of 0.025-0.045. For the cask and conditions considered, a reduction in bumup of 20% in all assemblies results in an increase in kff of less than 0.035. Misloading a single fresh assembly with 3, 4, or 5 wt% 235U enrichment results in an increase in keffof--0.02, 0.04, or 0.06, respectively. The report concludes with a summary of these and other important findings, as well as a discussion of relevant issues that should be considered when assessing the appropriate role of burnup measurements.

  10. Conceptual design of a high-integrity impact limiter for use in shipment of dual-purpose spent-fuel casks

    Energy Technology Data Exchange (ETDEWEB)

    Nickell, R.E. (Applied Science and Technology, Inc., Poway, CA (United States)); Haelsig, R.T.; Hansen, L.J. (Hansen Haelsig Associates, Bellevue, Washington (USA))

    1991-09-01

    A conceptual design for a high-integrity impact limiting system to protect dry metallic spent fuel storage casks during rail transport is proposed. The system is intended to limit the deceleration of the cask during severe rail accidents through three layers of energy-absorbing polyurethane foam material. The crush strengths of the foam is chosen such that the lowest crush strength foam forms the most exterior layer, with the crush strengths increasingly progressively in the two inner layers. The design basis for the external layer of foam is the hypothetical 30-foot free drop impact event prescribed in 10 CFR 71, with a peak steady deceleration limit of about 75 g. The two interior layers absorb up to five times the impact energy of the 30-foot free drop while limiting the decelerations to first 125 g and then to 175 g. The former is felt to be a nominal fuel rod failure threshold, while the latter is at or near the failure level for bolted closure assemblies. These deceleration targets, if met, provide a means for substantially reducing the risk of radioactive material transport. The conceptual design incorporates features for maintaining the integrity of the impact limiter attachment system during severe accidents and enhancing heat dissipation through the impact limiter for short-cooled fuel, through the use of radial aluminum fins. An alternative impact-limiting material -- aluminum honeycomb -- is included in the economic assessment. Both the polyurethane foam and aluminum honeycomb designs appear to meet a cost target of $1.0M, with the polyurethane foam limiter cost estimated at somewhat less than $400K and the aluminum honeycomb cost at somewhat less than $700K. 28 refs., 17 figs., 5 tabs.

  11. Recommendations on Fuel Parameters for Standard Technical Specifications for Spent Fuel Storage Casks

    Energy Technology Data Exchange (ETDEWEB)

    Bowman, S.M.

    2001-03-08

    The U.S. Nuclear Regulatory Commission (NRC) is currently reviewing the technical specifications for spent fuel storage casks in an effort to develop standard technical specifications (STS) that define the allowable spent nuclear fuel (SNF) contents. One of the objectives of the review is to minimize the level of detail in the STS that define the acceptable fuel types. To support this initiative, this study has been performed to identify potential fuel specification parameters needed for criticality safety and radiation shielding analysis and rank their importance relative to a potential compromise of the margin of safety.

  12. Increase in fault ride through capability of direct drive permanent magnet based wind farm using VSC-HVDC

    Science.gov (United States)

    Maleki, Hesamaldin; Ramachandaramurthy, V. K.; Lak, Moein

    2013-06-01

    Burning of fossil fuels and green house gasses causes global warming. This has led to governments to explore the use of green energies instead of fossil fuels. The availability of wind has made wind technology a viable alternative for generating electrical power. Hence, many parts of the world, especially Europe are experiencing a growth in wind farms. However, by increasing the number of wind farms connected to the grid, power quality and voltage stability of grid becomes a matter of concern. In this paper, VSC-HVDC control strategy which enables the wind farm to ride-through faults and regulate voltage for fault types is proposed. The results show that the wind turbine output voltage fulfills the E.ON grid code requirements, when subjected to three phase to ground fault. Hence, continues operation of the wind farm is achieved.

  13. IMPACT ANALYSES AND TESTS OF CONCRETE OVERPACKS OF SPENT NUCLEAR FUEL STORAGE CASKS

    Directory of Open Access Journals (Sweden)

    SANGHOON LEE

    2014-02-01

    Full Text Available A concrete cask is an option for spent nuclear fuel interim storage. A concrete cask usually consists of a metallic canister which confines the spent nuclear fuel assemblies and a concrete overpack. When the overpack undergoes a missile impact, which might be caused by a tornado or an aircraft crash, it should sustain an acceptable level of structural integrity so that its radiation shielding capability and the retrievability of the canister are maintained. A missile impact against a concrete overpack produces two damage modes, local damage and global damage. In conventional approaches [1], those two damage modes are decoupled and evaluated separately. The local damage of concrete is usually evaluated by empirical formulas, while the global damage is evaluated by finite element analysis. However, this decoupled approach may lead to a very conservative estimation of both damages. In this research, finite element analysis with material failure models and element erosion is applied to the evaluation of local and global damage of concrete overpacks under high speed missile impacts. Two types of concrete overpacks with different configurations are considered. The numerical simulation results are compared with test results, and it is shown that the finite element analysis predicts both local and global damage qualitatively well, but the quantitative accuracy of the results are highly dependent on the fine-tuning of material and failure parameters.

  14. IMPACLIB: a material property data library for impact analysis of radioactive material transport casks

    Energy Technology Data Exchange (ETDEWEB)

    Ikushima, Takeshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-12-01

    The paper describes the structural data library and graphical program for impact and stress analyses of radioactive material transport casks. Four kinds of material data, structure steels, stainless steels, leads and woods are compiled. These materials are main structural elements of casks. Structural data such as, coefficient of thermal expansion, modulus of longitudinal elasticity, modulus of transverse elasticity, Poisson`s ratio and stress-strain relationship have been tabulated. Main features of IMPACLIB are as follows: (1) data have been tabulated against temperature or strain rate, (2) thirteen kinds of polynominal fitting for stress-strain curve are available, (3) it is capable of graphical representations for structural data and (4) the IMPACLIB is able to be used on not only main frame computers but also work stations (OS UNIX) and personal computers (OS Windows 3.1). In the paper, brief illustration of data library is presented in the first section. The second section presents descriptions of structural data. The third section provides a user`s guide for computer program and input data for the IMPACLIB. (author)

  15. 78 FR 67348 - Invitation for Public Comment on Draft Test Plan for the High Burnup Dry Storage Cask Research...

    Science.gov (United States)

    2013-11-12

    ...: U.S. Department of Energy, C/O Melissa Bates, 1955 Freemont Ave., MS 1235, Idaho Falls, ID 83415..., 1955 Fremont Ave., Attn: Melissa Bates, Idaho Falls, ID, between 8 a.m. and 3:30 p.m. MT, Monday.... Melissa Bates, Contracting Officers Representative, High Burnup Dry Storage Cask Research and...

  16. Experience with the transport and storage casks CASTOR (registered) MTR 2 for spent nuclear fuel assemblies from research reactors

    Energy Technology Data Exchange (ETDEWEB)

    Jack, Allen; Rettenbacher, Katharina; Skrzyppek, Juergen [GNS Gesellschaft fuer Nuklear-Service mbH, Essen (Germany)

    2011-07-01

    The CASTOR (registered) MTR 2 cask was designed and manufactured by the company GNS during the 1990's for the transport and interim storage of spent nuclear fuel assemblies from various types of research reactors. Casks of this type have been used at the VKTA Research Centre in Rossendorf near Dresden, Germany as well as at the European Commission's Joint Research Centre at Petten and at the HOR reactor at Delft in the Netherlands. A total of 24 units have been used for the functions of transport and storage with various spent fuel types (VVER, HFR-HEU, and HOR-HEU) for more than ten years now. This type of packaging for radioactive material is a member of the CASTOR (registered) family of spent nuclear fuel casks used worldwide. Over 1000 units are loaded and in storage in Europe, Asia, Africa and North America. This paper presents the experience from the use of the casks for transport and storage in the past, as well as the prospects for the future. (author)

  17. Safety evaluation for packaging for the transport of K Basin sludge samples in the PAS-1 cask

    Energy Technology Data Exchange (ETDEWEB)

    SMITH, R.J.

    1998-11-17

    This safety evaluation for packaging authorizes the shipment of up to two 4-L sludge samples to and from the 325 Lab or 222-S Lab for characterization. The safety of this shipment is based on the current U.S. Department of Energy Certification of Compliance (CoC) for the PAS-1 cask, USA/9184/B(U) (DOE).

  18. A Quantitative Evaluation Method on Interaction Analysis of Hybrid Multi-infeed HVDC System%混合多馈入直流输电系统相互作用关系的定量评估方法

    Institute of Scientific and Technical Information of China (English)

    郭春义; 倪晓军; 赵成勇

    2016-01-01

    Apparent increase in short circuit ratio (AISCR) is an index to quantitatively evaluate the impact of voltage source converter based high voltage direct current (VSC-HVDC) on line commutated converter based high voltage direct current (LCC-HVDC) in hybrid mutli-infeed HVDC system. Based on the AISCR index, the impact of VSC-HVDC on LCC-HVDC was further studied considering different power flow direction of VSC-HVDC link. Then, the transient performances of LCC-HVDC, such as transient over-voltage, commutation failure immunity and fault recovery performances, were investigated in PSCAD/EMTDC software, when VSC operates as rectifier or inverter. Considering the electric distance between VSC-HVDC and LCC-HVDC, the trend of AISCR was calculated with varying distance. Finally, the coupling effects of AC system and VSC-HVDC on AISCR of LCC-HVDC were decoupled, and the AISCR impacted by VSC-HVDC only, without the impact of AC system, was obtained. The conclusions got could provide valuable theoretical guide for capacity and feed-in location selection of VSC-HVDC in hybrid multi-infeed HVDC system.%视在短路比增加量(apparent increase in short circuit ratio,AISCR)是一种定量评估混合多馈入系统中电压源换流器型高压直流输电(voltage source converter based high voltage direct current,VSC-HVDC)对电网换相换流器高压直流输电(line commutated converter based high voltage direct current,LCC-HVDC)运行特性影响关系的指标,该文基于AISCR指标,定量评估混合双馈入系统中当VSC-HVDC潮流方向不同时对LCC-HVDC运行特性的影响,在此基础上基于PSCAD/EMTDC对比分析VSC分别作为整流运行和逆变运行时LCC-HVDC的暂态过电压、换相失败抵御能力、故障恢复等暂态运行特性。研究当 VSC-HVDC 与LCC-HVDC之间存在电气距离的情况下AISCR随着电气距离的变化趋势;最后将交流系统与 VSC-HVDC 对LCC-HVDC 视在短路比增加量的耦合作用进行了

  19. Effect of a single brushing with two Zn-containing toothpastes on VSC in morning breath: a 12 h, randomized, double-blind, cross-over clinical study.

    Science.gov (United States)

    Young, A; Jonski, G

    2011-12-01

    This randomized, double-blind, 12 h clinical study tested the effect of a single brushing with two Zn-containing toothpastes on volatile sulfur compound (VSC) levels in morning breath. The following toothpastes were each tested by all 28 participants: A-Zn toothpaste, B--experimental toothpaste (Zn citrate + PVM/MA copolymer) and C--control toothpaste without Zn. The evening prior to test days participants brushed their teeth for 2 min with 1 g toothpaste. 12 h later and prior to eating or performing oral hygiene, morning breath levels of VSC (H(2)S, CH(3)SH) were analysed by gas chromatography. Subjects then rinsed for 30 s with 5 ml cysteine and breath samples were analysed for H(2)S (H(2)S(cys)). Median VSC (area under the curve) values were compared for A, B and C and the effects of A and B on VSC were compared with C. Toothpaste B was more effective than both toothpastes A and C in reducing H(2)S, CH(3)SH and H(2)S(cys) (p toothpaste C, toothpastes A and B reduced H(2)S by 35% and 68%, respectively (p = 0.003), and CH(3)SH by 12% and 47%, respectively (p = 0.002). Toothpaste B reduced H(2)S(cys) by 48% compared with toothpaste C (p = 0.001). It is suggested that the superior effect of the experimental toothpaste was most likely due to a higher Zn concentration combined with longer retention of Zn due to the PVM/MA copolymer.

  20. Probabilistic Multi-Hazard Assessment of Dry Cask Structures

    Energy Technology Data Exchange (ETDEWEB)

    Bencturk, Bora [Univ. of Houston, TX (United States); Padgett, Jamie [Rice Univ., Houston, TX (United States); Uddin, Rizwan [Univ. of Illinois, Urbana-Champaign, IL (United States).

    2017-01-10

    systems the concrete shall not only provide shielding but insures stability of the upright canister, facilitates anchoring, allows ventilation, and provides physical protection against theft, severe weather and natural (seismic) as well as man-made events (blast incidences). Given the need to remain functional for 40 years or even longer in case of interim storage, the concrete outerpack and the internal canister components need to be evaluated with regard to their long-term ability to perform their intended design functions. Just as evidenced by deteriorating concrete bridges, there are reported visible degradation mechanisms of dry storage systems especially when high corrosive environments are considered in maritime locations. The degradation of reinforced concrete is caused by multiple physical and chemical mechanisms, which may be summarized under the heading of environmental aging. The underlying hygro-thermal transport processes are accelerated by irradiation effects, hence creep and shrinkage need to include the effect of chloride penetration, alkali aggregate reaction as well as corrosion of the reinforcing steel. In light of the above, the two main objectives of this project are to (1) develop a probabilistic multi-hazard assessment framework, and (2) through experimental and numerical research perform a comprehensive assessment under combined earthquake loads and aging induced deterioration, which will also provide data for the development and validation of the probabilistic framework.

  1. Coordinated system services from offshore wind power plants connected through HVDC networks

    DEFF Research Database (Denmark)

    Zeni, Lorenzo; Glasdam, Jakob; Hesselbæk, Bo;

    2014-01-01

    This paper presents an overview of power system services in networks involving multiple onshore power systems, a voltage sourced converter (VSC) based high voltage direct current (HVDC) offshore network and an offshore wind power plant (OWPP). A comprehensive list of services regarding onshore...... to their implementation. For example, new findings on onshore AC voltage control are reported, that help the characterisation of potential AC voltage control that a VSC-HVDC station may offer to an onshore AC grid. The HVDC system behind the VSC-HVDC station may connect, through other converters, to another AC power...... system, or an OWPP, or both. Moreover, the implementation of power oscillation damping (POD) and HVDC voltage control into an OWPP controller is proposed, discussing the main challenges related to their efficient design. Dynamic control challenges are assessed, in particular in relation to the inherent...

  2. Effect of a dual-purpose cask payload increment of spent fuel assemblies from VVER 1000 Bushehr Nuclear Power Plant on basket criticality.

    Science.gov (United States)

    Rezaeian, M; Kamali, J

    2017-01-01

    Dual-purpose casks can be utilized for dry interim storage and transportation of the highly radioactive spent fuel assemblies (SFAs) of Bushehr Nuclear Power Plant (NPP). Criticality safety analysis was carried out using the MCNP code for the cask containing 12, 18, or 19 SFAs. The basket materials of borated stainless steel and Boral (Al-B4C) were investigated, and the minimum required receptacle pitch of the basket was determined. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Method and system for a gas tube switch-based voltage source high voltage direct current transmission system

    Energy Technology Data Exchange (ETDEWEB)

    She, Xu; Chokhawala, Rahul Shantilal; Zhou, Rui; Zhang, Di; Sommerer, Timothy John; Bray, James William

    2016-12-13

    A voltage source converter based high-voltage direct-current (HVDC) transmission system includes a voltage source converter (VSC)-based power converter channel. The VSC-based power converter channel includes an AC-DC converter and a DC-AC inverter electrically coupled to the AC-DC converter. The AC-DC converter and a DC-AC inverter include at least one gas tube switching device coupled in electrical anti-parallel with a respective gas tube diode. The VSC-based power converter channel includes a commutating circuit communicatively coupled to one or more of the at least one gas tube switching devices. The commutating circuit is configured to "switch on" a respective one of the one or more gas tube switching devices during a first portion of an operational cycle and "switch off" the respective one of the one or more gas tube switching devices during a second portion of the operational cycle.

  4. Full-scale prototyping of the Hitachi dual-purpose metal cask and verification of its heat transfer characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Kumagai, N.; Ishida, N.; Ootsuka, M.; Kamoshida, M.; Hiranuma, T.; Doumori, S.; Hoshikawa, T.; Shimizu, M.; Kashiwakura, J.; Hayashi, M. [Hitachi, Ltd., Hitachi (Japan)

    2004-07-01

    Hitachi has been developing dual-purpose metal casks for transport and storage of spent nuclear fuels. The Hitachi cask, HDP69B can store 69 BWR fuel assemblies. The cask features are as follows. 1) The fuel basket is assembled mainly with plates of borated stainless steel. The plates are not welded, but cross-inserted into each other like the dividers in an egg carton. Since the borated stainless steel has relatively low heat conductivity, aluminum alloy plates are inserted along with some stainless steel plates to enhance heat removal ability. 2) Cured resin blocks are fitted into the inner shell of the cask for neutron shielding of the cask body. The resin blocks are surrounded by an aluminum casing which transfers heat of stored fuel from the inner shell to the outer shell of the cask. The block type shield structure eliminates the need for welding the heat transfer fins to the inner and outer shells. The weldless structures of the HDP69B lead to its enhanced manufacturability, but they complicate the heat transfer characteristics because there are gaps between such components as the aluminum casing and inner/outer shells. We carried out full-scale prototyping of the HDP69B and ran a heat transfer test using the prototype. The purposes of the heat transfer test were to check the heat removal ability of the HDP69B and to verify the safety analysis model for heat removal. Results of the heat transfer test and optimized analysis model for heat transfer characteristics of the HDP69B are the focus of this paper. The heat transfer test is summarized as follows. Sixty nine heaters simulating the shape and heat power of spent fuel assemblies were inserted into the fuel basket. After replacing the inner atmosphere with 0.1 MPa of helium, the heat transfer test was started. About 7 days were required to equilibrate the temperature distribution. The temperature at the center of the basket was 194 C. The results confirmed the HDP69B had sufficient heat removal ability. The

  5. Grid Integration of Single Stage Solar PV System using Three-level Voltage Source Converter

    Science.gov (United States)

    Hussain, Ikhlaq; Kandpal, Maulik; Singh, Bhim

    2016-08-01

    This paper presents a single stage solar PV (photovoltaic) grid integrated power generating system using a three level voltage source converter (VSC) operating at low switching frequency of 900 Hz with robust synchronizing phase locked loop (RS-PLL) based control algorithm. To track the maximum power from solar PV array, an incremental conductance algorithm is used and this maximum power is fed to the grid via three-level VSC. The use of single stage system with three level VSC offers the advantage of low switching losses and the operation at high voltages and high power which results in enhancement of power quality in the proposed system. Simulated results validate the design and control algorithm under steady state and dynamic conditions.

  6. LOAD-CHECK, program supported optimization of the fuel element disposal in cask CASTOR {sup registered} V casks; LOAD-CHECK, programmunterstuetzte Optimierung der Brennelemententsorgung in CASTOR {sup registered} V-Behaeltern

    Energy Technology Data Exchange (ETDEWEB)

    Amian, D.; Braun, A. [WTI Wissenschaftlich-Technische Ingenieurberatung GmbH, Juelich (Germany); Graf, R.; Hoffmann, V. [GNS Gesellschaft fuer Nuklear-Service mbH, Essen (Germany)

    2010-05-15

    LOAD-CHECK is an interactive program module for the systematic and strategic spent fuel disposal planning. Using physical fuel element data the loading scenarios for the routine operation and the post-closure operation phase can be simulated for free selectable time periods. The basis for the loading license application are the available spent fuel casks according to the regulations of the interim storage facility. LOAD-CHECK allows the optimization of the loading campaigns with respect to the time schedule and the number of casks including the planning of optimized disposal of special spent fuel (MOX fuel elements or high-burnup fuel elements). Possibilities for a reduced post-closure operating phase of nuclear power plants might be the consequence.

  7. Experimental assessment on the thermal effects of the neutron shielding and heat-transfer fin of dual purpose casks on open pool fire

    Energy Technology Data Exchange (ETDEWEB)

    Bang, Kyoung-Sik, E-mail: nksbang@kaeri.re.kr; Yu, Seung-Hwan; Lee, Ju-Chan; Seo, Ki-Seog; Choi, Woo-Seok

    2016-08-01

    Highlights: • An open pool fire test was performed to estimate not only the combustion effect of the neutron shielding but also the effect of the heat transfer fin of the dual purpose cask. • The heat transfer to the inside of the dual purpose cask was reduced, when the neutron shielding burns. • The surface temperatures are lower in the present of the heat transfer fins. • If inflammable material is used as the components of the cask, evaluating thermal integrity using the thermal test would be desirable. - Abstract: Dual purpose casks are used for storage and transport of spent nuclear fuel assemblies. They must therefore satisfy the requirements prescribed in the Korea Nuclear Safety Security Commission Act 2014-50, the IAEA Safety Standard Series No. SSR-6, and US 10 CFR Part 71. These regulatory guidelines classify the dual purpose cask as a Type B package and state that a Type B package must be able to withstand a temperature of 800 °C for a period of 30 min. NS-4-FR is used as neutron shielding of the dual purpose cask. Heat transfer fins are embedded to enhance heat transfer from the cask body to the outer-shell because the thermal conductivity of NS-4-FR is not good. However, accurately simulating not only the combustion effect of the neutron shielding but also the effect of the heat transfer fin in the thermal analysis is not easy. Therefore, an open pool fire test was conducted using a one-sixth slice of a real cask to estimate these effects at a temperature of 800 °C for a period of 30 min. The temperature at the central portion of the neutron shielding was lower when the neutron shielding in contact with the outer cask burned because the neutron shielding absorbed the surrounding latent heat as the neutron shielding burned. Therefore, the heat transfer to the inside of the dual purpose cask was reduced. The surface temperature was lower when a heat transfer fin was installed because the high heat generated by the flame was transferred to the

  8. Dry spent fuel storage with the MACSTOR system

    Energy Technology Data Exchange (ETDEWEB)

    Pare, F. [Atomic Energy of Canada Ltd., Montreal, PQ (Canada). CANDU Operations

    1996-10-01

    Atomic Energy of Canada Limited (AECL), and Transnuclear Inc. (TNI) began in 1989 the development of the concrete spent fuel storage system, called MACSTOR (Modular Air-Cooled Canister STORage) for use with LWR spent fuel assemblies. It is a hybrid system which combines the operational economies of metal cask technology with the capital economies of concrete technology. The MACSTOR Module is a monolithic, shielded concrete vault structure that can accommodate up to 20 spent fuel canisters. Each canister typically holds up to 21 PWR or 44 BWR spent fuel assemblies with a nominal fuel burn up rate of 40,000 MWD/MTU and a 7 year minimum cooling period. The structure is passively cooled by natural convection through an array of inlet and outlet gratings and galleries serving a central plenum where the (vertically) stored canisters are located. The canisters are continuously monitored by means of a pressure monitoring system developed by TNI. Thus, the utility can be assured of both positive cooling of the fuel and verification of the integrity of the fuel confinement boundary. The structure is seismically designed and is capable of withstanding site design basis accident events. The MACSTOR system includes the storage module(s), an overhead gantry system for cask handling, a transfer cask for moving fuel from wet to dry storage and a cask transporter. The canister and transfer cask designs are based on Transnuclear transport cask designs and proven hot cell transfer cask technology, adapted to requirements for on-site spent fuel storage. The MACSTOR system can economically address a wide range of storage capacity requirements. The modular concept allows for flexibility in determining each module`s capacity. Starting with 8 canisters, the capacity can be increased by increments of 4 up to 20 canisters. The MACSTOR system is also flexible in accommodating the various spent fuel types from such reactors as VVER-440, VVER-1000 and RBMK 1500. (J.P.N.)

  9. Predictive Current Method Control for Novel HVDC under Three Phase Voltage Unbalanced Condition%预测电流法控制三相电压不平衡下VSC-HVDC

    Institute of Scientific and Technical Information of China (English)

    孙栩; 朱艺颖

    2010-01-01

    VSC-HVDC由于连接模式非常灵活和多样,特别是有可能接入低压配电网,其将面临诸如三相不平衡等问题,而三相不平衡问题将影响整个系统的正常运行.双电流闭环控制法虽然可以解决此问题,但是比较复杂.笔者提出利用预测电流法控制VSC-HVDC的理论方法.最终的仿真结果表明,预测电流法能够保证VSC-HVDC在三相电压不平衡情况下仍然保持良好的性能.

  10. Electro-thermal Modeling for Junction Temperature Cycling-Based Lifetime Prediction of a Press-Pack IGBT 3L-NPC-VSC Applied to Large Wind Turbines

    DEFF Research Database (Denmark)

    Senturk, Osman Selcuk; Munk-Nielsen, Stig; Teodorescu, Remus;

    2011-01-01

    reliability is investigated regarding IGBT lifetime based on junction temperature cycling for the grid-side press-pack IGBT 3L-NPC-VSC, which is a state-of-the art high reliability solution. In order to acquire IGBT junction temperatures for given wind power profiles and to use them in IGBT lifetime...... prediction, the converter electro-thermal model including electrical, power loss, and dynamical thermal models is developed with the main focus on the thermal modeling regarding converter topology, switch technology, and physical structure. Moreover, these models are simplified for their practical...

  11. Advanced fault ride-through control of DFIG based wind turbines including grid connection via VSC-HVDC

    Energy Technology Data Exchange (ETDEWEB)

    Feltes, Christian

    2012-07-01

    With the growing renewable energy share in the power generation mix it becomes inevitable that also these new generation technologies participate on the provision of grid services to guarantee stable operation of the grid, especially when one considers the decreasing number of conventional power plants in operation as a result of the expansion of wind based generation plants. These so-called ancillary services include frequency / active power control, voltage / reactive power control and fault ride-through (FRT) with fast voltage control and are stipulated in modern grid codes. In the context of this thesis advanced control algorithms have been developed for wind turbines based on doubly-fed induction generator (DFIG) to allow safe FRT during symmetrical and unsymmetrical faults. This covers the control for conventional AC grid connection as well as for the connection through voltage source converter (VSC) based high voltage direct current transmission (HVDC). Currently, the DFIG is the most used generator technology in modem wind turbines, since it combines a relatively simple slip-ring induction machine with a frequency converter rated to only approx. 30% of the total power. This makes the DFIG a cost-effective concept, which offers a variable speed range and a high degree of flexibility in control. However, due to the direct coupling of the generator stator circuit to the grid, grid faults are a special challenge for the frequency converter, its protection circuits and control algorithms. As base for the detailed evaluation of the impact of grid faults to the DFIG, this thesis contains the analytical derivation of the DFIG short circuit currents under consideration of frequency converter control. The DFIG concept presented in this thesis makes use of a DC chopper in the frequency converter, which allows safe FRT with grid voltage support through both converter sides. The developed control contains a new algorithm for a clear separation and control of positive

  12. The application of fracture mechanics to the safety assessment of transport casks for radioactive materials

    Energy Technology Data Exchange (ETDEWEB)

    Zencker, U.; Mueller, K.; Droste, B.; Roedel, R.; Voelzke, H. [Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin (Germany)

    2004-07-01

    BAM is the German responsible authority for the mechanical and thermal design safety assessment of packages for the transport of radioactive materials. The assessment has to cover the brittle fracture safety proof of package components made of potentially brittle materials. This paper gives a survey of the regulatory and technical requirements for such an assessment according to BAM's new ''Guidelines for the Application of Ductile Cast Iron for Transport and Storage Casks for Radioactive Materials''. Based on these guidelines higher stresses than before can become permissible, but it is necessary to put more effort into the safety assessment procedure. The fundamentals of such a proof with the help of the methods of fracture mechanics are presented. The recommended procedure takes into account the guidelines of the IAEA Advisory Material which are based on the prevention of crack initiation. Examples of BAM's research and safety assessment practices are given. Recommendations for further developments towards package designs with higher acceptable stress levels will be concluded.

  13. Spent fuel criticality and compositions evaluation for long-term disposal in a generic cask

    Energy Technology Data Exchange (ETDEWEB)

    Velasquez, C.E.; Sousa, R.V.; Fortini, A.; Pereira, C., E-mail: claubia@nuclear.ufmg.br; Costa, A.L.; Silva, C.A.M. da; Veloso, M.A.F.; Oliveira, A.H. de; Carvalho, F.R. de

    2014-08-15

    The Nuclear Energy Agency (NEA) Expert Group on Burn-up Credit Criticality Safety published a Benchmark with results obtained from simulations with some nuclear codes for a PWR-UO{sub 2} nuclear fuel disposed of in a cask. The same situations were simulated at the Departamento de Engenharia Nuclear/Universidade Federal de Minas Gerais (DEN/UFMG) with the SCALE 6.0 (KENOVI/ORIGENS), MCNPX 2.6.0/CINDER and Monteburns (MCNP5/ORIGEN2.1). Combinations of codes and nuclear data are slightly different from those used by the organizations who participate of the Benchmark. For k{sub eff} time evolution, the results are very similar to the values obtained by the benchmark participants. For decay time evolution, the results obtained for several nuclides presented the expected behavior. Nevertheless, differences in the composition increase during the time specially using the Monteburns code. These differences may be attributed to the libraries and methodology for choosing libraries to decay calculation and the number of days to a year considered to calculations.

  14. Large deformation inelastic analysis of impact for shipping casks. [DYNA3D Code

    Energy Technology Data Exchange (ETDEWEB)

    Charman, C.M.; Grenier, R.M. (General Atomic Co., San Diego, CA (USA)); Nickell, R.E. (Applied Science and Technology, Poway, CA (USA))

    1982-09-01

    This paper describes the use of two- and three-dimensional nonlinear finite element computer programs to design a radioative material transportation cask to withstand a drop of 30 feet onto an unyielding surface. Because of recent advancement in the area of non-linear finite element code development, the use of such codes for an iterative design process is becoming practicable. The paper begins with a section dealing with a two-dimensional side drop analysis and is followed by a discussion of the general capabilities of DYNA3D and a brief discussion of the implementation of the code on a computational mainframe unlike any for which the developer had intended. Then, a section on three-dimensional models of center-of-gravity over a corner impact follows, which introduces design features such as bolted closures, internal impact limiter, seals and shear rings. Figs. showing the deformed model grids are included. Stress and strain results are given in the subsequent section. Finally, we interpret these results in terms of possible rules being developed by the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code committees.

  15. THERMLIB: a material property data library for thermal analysis of radioactive material transport casks

    Energy Technology Data Exchange (ETDEWEB)

    Ikushima, Takeshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-03-01

    The paper describes an heat conduction data library and graphical program for analysis of radioactive material transport casks. More than 1000 of material data are compiled in the data library which was produced by Lawrence Livermore Laboratory. Thermal data such as, density, thermal conductivity, specific heat, phase-change or solid-state, transition temperature and latent heat have been tabulated. Using this data library, a data library processing program THERMLIB for thermal analysis has been developed. Main features of THERMLIB are as follows: (1) data have been tabulated against temperature, (2) more than 1000 material data are available, (3) it is capable of graphical representations for thermal data and (4) not only main frame computer but also work stations (OS UNIX) and personal computer (OS Windows) are available for use of THERMLIB. In the paper, brief illustration of data library is presented in the first section. The second section presents descriptions of structural data. The third section provides an user`s guide for computer program and input data for THERMLIB. (author)

  16. Estimates of durability of TMI-2 core debris canisters and cask liners

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, A.B. Jr.; Lund, A.L.; Pednekar, S.P.

    1994-04-01

    Core debris from the Three Mile Island-2 (TMI-2) reactor is currently stored in stainless steel canisters. The need to maintain the integrity of the TMI-2 core debris containers through the period of extended storage and possibly into disposal prompted this assessment. In the assessment, corrosion-induced degradation was estimated for two materials: type 304L stainless steel (SS) canisters that contain the core debris, and type 1020 carbon steel (CS) liners in the concrete casks planned for containing the canisters from 2000 AD until the TMI-2 core debris is placed in a repository. Three environments were considered: air-saturated water (with 2 ppM Cl{sup {minus}}) at 20{degree}C, and air at 20{degree}C with two relative humidities (RHs), 10 and 40%. Corrosion mechanisms assessed included general corrosion (failure criterion: 50% loss of wall thickness) and localized attack (failure criterion: through-wall pinhole penetration). Estimation of carbon steel corrosion after 50 y also was requested.

  17. Study of casks shielded with heavy metal to transport highly radioactive substances; Estudo de embalados com blindagem em metal pesado para transporte de substancias altamente radioativas

    Energy Technology Data Exchange (ETDEWEB)

    Lucchesi, R.F.; Hara, D.H.S.; Martinez, L.G.; Mucsi, C.S.; Rossi, J.L., E-mail: rflguimaraes@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2014-07-01

    Nowadays, Brazil relies on casks produced abroad for transportation in its territory of substances that are sources of high radioactivity, especially the Mo-99. The product of the radioactive decay of the Mo-99 is the Tc-99m, which is used in nuclear medicine for administration to humans in the form of injectable radioactive drugs for the image diagnosis of numerous pathologies. This paper aims to study the existing casks in order to propose materials for the construction of the core part as shielding against gamma radiation. To this purpose, the existing literature on the subject was studied, as well as evaluation of existing and available casks. The study was focused on the core of which is made of heavy metals, especially depleted uranium for shielding the emitted radiation. (author)

  18. Calculative activation analysis of the transport rack for CASTOR {sup registered} casks; Berechnung der Aktivierung eines Transportgestells fuer CASTOR {sup registered} -Behaelter

    Energy Technology Data Exchange (ETDEWEB)

    Tittelbach, S. [Wissenschaftlich-Technische Ingenieurberatung GmbH (WTI), Juelich (Germany); Biedermann, R. [GNS Gesellschaft fuer Nuklear-Service mbH, Essen (Germany); Schmidt-Wohlfarth, Y.; Louia, A. [EnBW Kernkraft GmbH, Philippsburg (Germany)

    2011-07-01

    The transport rack for the internal transport of loaded CASTOR {sup registered} casks before the storage in the intermediate storage facility at the site of the NPP Philippsburg is exposed to neutron irradiation from the cask inventory. Using the Monte Carlo code MCNP the activation rates of the transport rack materials are calculated for typical storage times of the casks in the rack. The long-term activation was also calculated for the continuous use of the transport rack over 10 years. Further topics were the dose rate in the near surrounding of the transport rack after long-term activation and finally the disposability of rack components according to the legal regulations. The maximum contact dose rate was calculated to be below 1 micro Sv/h after 10 years of application. The transport rack can be disposed with large safety margins to the radiation protection limits.

  19. CAPSIZE: A personal computer program and cross-section library for determining the shielding requirements, size, and capacity of shipping casks subject to various proposed objectives

    Energy Technology Data Exchange (ETDEWEB)

    Bucholz, J.A.

    1987-05-01

    A new interactive program called CAPSIZE has been written for the IBM-PC to rapidly determine the likely impact that proposed design objectives might have on the size and capacity of spent fuel shipping casks designed to meet those objectives. Given the burnup of the spent fuel, its cooling time, the thickness of the internal basket walls, the desired external dose rate, and the nominal weight limit of the loaded cask, the CAPSIZE program will determine the maximum number of PWR fuel assemblies that may be shipped in a lead-, steel-, or uranium-shielded cask meeting those objectives. The necessary neutron and gamma shield thicknesses are determined by the program in such a way as to meet the specified external dose rate while simultaneously minimizing the overall weight of the loaded cask. The one-group cross-section library used in the CAPSIZE program has been distilled from the intermediate results of several hundred 1-D multigroaup discrete ordinates calculations for different types of casks. Neutron and gamma source terms, as well as the decay heat terms, are based on ORIGEN-S analyses of PWR fuel assemblies having exposures of 10, 20, 30, 40, 50, and 60 gigawatt days per metric tonne of initial heavy metal (GWD/MTIHM). In each case, values have been tabulated at 17 different decay times between 120 days and 25 years. Other features of the CAPSIZE program include a steady-state heat transfer calculation which will minimize the size and weight of external cooling fins, if and when such fins are required. Comparisons with previously reported results show that the CAPSIZE program can generally estimate the necessary neutron and gamma shield thicknesses to within 0.16 in. and 0.08 in., respectively. The corresponding cask weights have generally been found to be within 1000 lbs of previously reported results. 13 refs., 20 figs., 54 tabs.

  20. Shielding Research of Cobalt Adjuster Rod Transport Cask%钴调节棒转运容器屏蔽研究

    Institute of Scientific and Technical Information of China (English)

    王炳衡; 薛娜; 毛亚蔚

    2013-01-01

    Dose rates at the surface of adjuster rod transport cask were calculated with MCNP code and MCAM code.The calculation results were compared with national standard to estimate shielding design of the cask.To meet the requirement of the standard,original design of the cask was updated through the calculation of these codes.To reduce the radiation level,temporary shielding for the gap (between shielding door and main cask) was applied and 5 cm shielding layer of depleted uranium was applied to the side shield instead of 5 cm lead layer.According to the results,new shielding design of transport cask can meet the national standard.The measuring results show that the design of the cask is reasonable and reliable.%采用MCAM程序与MCNP程序模拟计算钴调节棒转运容器的表面剂量率,并以此来判断容器的屏蔽设计是否满足标准要求.通过程序系统估算,在容器初始设计模型的基础上将5 cm铅层替换为5cm贫铀防护层,并提出了在容器下部屏蔽门缝隙处增加临时屏蔽装置以降低该处的辐射水平.经过优化设计后,钴调节棒转运容器能够满足国家相应的屏蔽标准要求.现场操作时的实测结果也进一步验证了容器屏蔽设计的合理性和可靠性.

  1. Control and operation of multi-terminal VSC-DC networks

    OpenAIRE

    Gavriluţă, Cătălin

    2015-01-01

    For the past century, ac networks have been established as the standard technology for electrical power transmission system s. However, the de technology has not disappeared completely from this picture. The capability of de systems to transmit higher power over longer distances, the possibility of interconnecting asynchronous networks, and their high efficiency has maintained the interest of both industry and academia. Historically, systems based on dc-generators and mercury valves were used...

  2. Creation of a Geant4 Muon Tomography Package for Imaging of Nuclear Fuel in Dry Cask Storage

    Energy Technology Data Exchange (ETDEWEB)

    Tsoukalas, Lefteri H. [Purdue Univ., West Lafayette, IN (United States)

    2016-03-01

    This is the final report of the NEUP project “Creation of a Geant4 Muon Tomography Package for Imaging of Nuclear Fuel in Dry Cask Storage”, DE-NE0000695. The project started on December 1, 2013 and this report covers the period December 1, 2013 through November 30, 2015. The project was successfully completed and this report provides an overview of the main achievements, results and findings throughout the duration of the project. Additional details can be found in the main body of this report and on the individual Quarterly Reports and associated Deliverables of the project, uploaded in PICS-NE.

  3. Alternatives for Primary Frequency Control Contribution from Wind Power Plants Connected to VSC-HVDC Intertie

    DEFF Research Database (Denmark)

    Laukhamar, Andreas Grøsvik; Zeni, Lorenzo; Sørensen, Poul Ejnar

    how a large offshore wind power plant (OWPP) with high voltage direct current (HVDC) intertie connection to two asynchronous onshore AC power systems can be part of the solution in providing short-term mutual active power balancing. The primary frequency control is investigated for four different...... in a sharing of the primary reserves and rolling inertia between the two onshore AC power systems connected to the HVDC intertie, whilst also exploiting the OWPP in the primary frequency control scheme....

  4. Evaluation of half-bridge modular multilevel converter model for VSC-HVDC transient stability studies

    DEFF Research Database (Denmark)

    Irnawan, Roni; Silva, Filipe Miguel Faria da; Bak, Claus Leth

    2017-01-01

    is described. This RMS model is then simplified by neglecting the inner/current controller. Both detailed and simplified RMS models are then validated against an accurate electromagnetic (EMT) transient model in a point-to-point (PtP) transmission system with different AC network strength, power directions...

  5. 新型双馈入直流输电系统供电无源网络的运行特性研究%Operation Characteristic Research on Novel Double-Infeed HVDC System Supplying Passive Network

    Institute of Scientific and Technical Information of China (English)

    郭春义; 赵成勇; 王晶

    2012-01-01

    A novel double-infeed HVDC system, combining a conventional high voltage direct current transmission (HVDC) and voltage-source converter based HVDC (VSC-HVDC), is proposed in this paper for supplying an entirely passive AC network. The detailed model for starting HVDC using VSC-HVDC is provided and control strategies of the whole system are designed. Aiming to validate the steady state and dynamic performance of the double-infeed HVDC system, the process of starting HVDC using VSC-HVDC and the dynamic performance of double-infeed HVDC when three-phase to ground fault occurring at HVDC inverter side are investigated. PSCAD/EMTDC Simulation results show that, the proposed double-Infeed HVDC system can supply power to passive network and it also has favorable dynamic and fault-restoration performance.%提出由传统高压直流输电系统(HVDC)和电压源换流器高压直流输电系统(VSC-HVDC)组成的新型双馈入直流输电系统(Double-InfeedHVDC)向无源网络输送电能。建立了利用VSC-HVDC启动HVDC的详细模型,并设计了Double-InfeedHVDC的控制系统。为了研究该双馈入直流输电系统的稳态和暂态性能,分别针对VSC-HVDC启动HVDC的特性和HVDC逆变侧发生三相短路故障时的特性进行了研究。PSCAD/EMTDC下的仿真结果表明,Double-InfeedHVDC系统可以为无源网络供电,同时具有良好的动态和故障恢复性能。

  6. 改进的DFIG与VSC-HVDC协调控制改善风电场低电压穿越能力%Improvement of low voltage ride through capability of wind farm using coordinated control of the improved DFIG and VSC-HVDC

    Institute of Scientific and Technical Information of China (English)

    边晓燕; 王本利; 陈建平; 杨立宁

    2016-01-01

    VSC-HVDC并网风电系统在风电场侧故障时,风电机组出口母线电压过低,极易引起风力机脱网.而双馈风力发电机(DFIG)传统的Crowbar技术在故障时将转子侧变流器(RSC)短接,使发电机定子侧失去了为电网提供无功的能力,风力机的低电压穿越能力较低.提出一种改进的DFIG模型,加入了主动式DC-Chopper,与传统的Crowbar相配合,降低Crowbar动作的概率,使得DFIG转子侧变流器可以控制定子侧在故障时期继续提供无功功率.并利用此改进的DFIG与VSC-HVDC协调控制,改善风电场侧母线电压水平.通过算例仿真表明,在严重故障时采用改进式DFIG的Crowbar仍未动作.从而大大降低Crowbar动作的概率,双馈风电机组RSC故障期间可以继续投入运行并为电网提供无功支持.完成故障期间DFIG两侧变流器与VSC-HVDC风电场侧变流器(WFVSC)之间的无功协调,使风电场具有更好的低电压穿越能力(Low Voltage Ride Though,LVRT).

  7. The Study on Hybrid Multi-Infeed HVDC System Connecting with Offshore Wind Farm

    DEFF Research Database (Denmark)

    Liu, Yan

    , a cooperative control of the VSC-HVDC system and a variable speed Squirrel Cage Induction Generator (SCIG)-based offshore wind farm is proposed. In the approach, an active power-frequency droop control is developed to achieve an autonomous reduction of the generated active powers from wind turbines, which thus...

  8. Effects of T-type Channel on Natural Convection Flows in Airflow-Path of Concrete Storage Cask

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Gyeong Uk; Kim, Hyoung Jin; Cho, Chun Hyung [KORAD, Daejeon (Korea, Republic of)

    2016-05-15

    The natural convection flows occurring in airflow-path are not simple due to complex flow-path configurations such as horizontal ducts, bent tube and annular flow-path. In addition, 16 T type channels acting as the shroud are attached vertically and 16 channel supporting the canister are attached horizontally on the inner surface of over-pack. The existence and nonexistence of T type channels have influences on the flow fields in airflow- path. The concrete storage cask has to satisfy the requirements to secure the thermal integrity under the normal, off-normal, and accident conditions. The present work is aiming at investigating the effects of T type channels on the flows in airflow-path under the normal conditions using the FLUENT 16.1 code. In order to focus on the flows in airflow-path, fuel regions in the canister are regarded as a single cylinder with heat sources and other components are fully modeled. This study investigated the flow fields in airflow-path of concrete storage cask, numerically. It was found that excepting for the fuel regions, maximum temperatures on other components were evaluated below allowable values. The location of maximum velocities depended on support channels, T type channels and flow area. The flows through air inlets developed along annular flow- path with forming the hot plumes. According to the existence and nonexistence of T type channel, the plume behavior showed the different flow patterns.

  9. Power Oscillation Damping from VSC-HVDC Connected Offshore Wind Power Plants

    DEFF Research Database (Denmark)

    Zeni, Lorenzo; Eriksson, Robert; Goumalatsos, Spyridon

    2016-01-01

    The implementation of power oscillation damping service on offshore wind power plants connected to onshore grids by voltage-source-converter-based high voltage direct current transmission is discussed. Novel design guidelines for damping controllers on voltage-source converters and wind power plant...... regarding real wind power plants are discussed: 1) robustness against control/communication delays; 2) limitations due to mechanical resonances in wind turbine generators; 3) actual capability of wind power plants to provide damping without curtailing production; and 4) power-ramp rate limiters....... controllers are derived, using phasor diagrams and a test network model and are then verified on a generic power system model. The effect of voltage regulators is analyzed, which is important for selecting the most robust damping strategy. Furthermore, other often disregarded practical implementation aspects...

  10. Storage, transportation and disposal system for used nuclear fuel assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Scaglione, John M.; Wagner, John C.

    2017-07-11

    An integrated storage, transportation and disposal system for used fuel assemblies is provided. The system includes a plurality of sealed canisters and a cask sized to receive the sealed canisters in side by side relationship. The plurality of sealed canisters include an internal basket structure to receive a plurality of used fuel assemblies. The internal basket structure includes a plurality of radiation-absorbing panels and a plurality of hemispherical ribs generally perpendicular to the canister sidewall. The sealed canisters are received within the cask for storage and transportation and are removed from the cask for disposal at a designated repository. The system of the present invention allows the handling of sealed canisters separately or collectively, while allowing storage and transportation of high burnup fuel and damaged fuel to the designated repository.

  11. Storage, transportation and disposal system for used nuclear fuel assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Scaglione, John M.; Wagner, John C.

    2017-01-10

    An integrated storage, transportation and disposal system for used fuel assemblies is provided. The system includes a plurality of sealed canisters and a cask sized to receive the sealed canisters in side by side relationship. The plurality of sealed canisters include an internal basket structure to receive a plurality of used fuel assemblies. The internal basket structure includes a plurality of radiation-absorbing panels and a plurality of hemispherical ribs generally perpendicular to the canister sidewall. The sealed canisters are received within the cask for storage and transportation and are removed from the cask for disposal at a designated repository. The system of the present invention allows the handling of sealed canisters separately or collectively, while allowing storage and transportation of high burnup fuel and damaged fuel to the designated repository.

  12. Spectrum of pontocerebellar hypoplasia in 13 girls and boys with CASK mutations: confirmation of a recognizable phenotype and first description of a male mosaic patient

    Directory of Open Access Journals (Sweden)

    Burglen Lydie

    2012-03-01

    Full Text Available Abstract Background Pontocerebellar hypoplasia (PCH is a heterogeneous group of diseases characterized by lack of development and/or early neurodegeneration of cerebellum and brainstem. According to clinical features, seven subtypes of PCH have been described, PCH type 2 related to TSEN54 mutations being the most frequent. PCH is most often autosomal recessive though de novo anomalies in the X-linked gene CASK have recently been identified in patients, mostly females, presenting with intellectual disability, microcephaly and PCH (MICPCH. Methods Fourteen patients (12 females and two males; aged 16 months-14 years presenting with PCH at neuroimaging and with clinical characteristics unsuggestive of PCH1 or PCH2 were included. The CASK gene screening was performed using Array-CGH and sequencing. Clinical and neuroradiological features were collected. Results We observed a high frequency of patients with a CASK mutation (13/14. Ten patients (8 girls and 2 boys had intragenic mutations and three female patients had a Xp11.4 submicroscopic deletion including the CASK gene. All were de novo mutations. Phenotype was variable in severity but highly similar among the 11 girls and was characterized by psychomotor retardation, severe intellectual disability, progressive microcephaly, dystonia, mild dysmorphism, and scoliosis. Other signs were frequently associated, such as growth retardation, ophthalmologic anomalies (glaucoma, megalocornea and optic atrophy, deafness and epilepsy. As expected in an X-linked disease manifesting mainly in females, the boy hemizygous for a splice mutation had a very severe phenotype with nearly no development and refractory epilepsy. We described a mild phenotype in a boy with a mosaic truncating mutation. We found some degree of correlation between severity of the vermis hypoplasia and clinical phenotype. Conclusion This study describes a new series of PCH female patients with CASK inactivating mutations and confirms that

  13. An Optimal Control Strategy for DC Bus Voltage Regulation in Photovoltaic System with Battery Energy Storage

    Directory of Open Access Journals (Sweden)

    Muhamad Zalani Daud

    2014-01-01

    Full Text Available This paper presents an evaluation of an optimal DC bus voltage regulation strategy for grid-connected photovoltaic (PV system with battery energy storage (BES. The BES is connected to the PV system DC bus using a DC/DC buck-boost converter. The converter facilitates the BES power charge/discharge to compensate for the DC bus voltage deviation during severe disturbance conditions. In this way, the regulation of DC bus voltage of the PV/BES system can be enhanced as compared to the conventional regulation that is solely based on the voltage-sourced converter (VSC. For the grid side VSC (G-VSC, two control methods, namely, the voltage-mode and current-mode controls, are applied. For control parameter optimization, the simplex optimization technique is applied for the G-VSC voltage- and current-mode controls, including the BES DC/DC buck-boost converter controllers. A new set of optimized parameters are obtained for each of the power converters for comparison purposes. The PSCAD/EMTDC-based simulation case studies are presented to evaluate the performance of the proposed optimized control scheme in comparison to the conventional methods.

  14. An optimal control strategy for DC bus voltage regulation in photovoltaic system with battery energy storage.

    Science.gov (United States)

    Daud, Muhamad Zalani; Mohamed, Azah; Hannan, M A

    2014-01-01

    This paper presents an evaluation of an optimal DC bus voltage regulation strategy for grid-connected photovoltaic (PV) system with battery energy storage (BES). The BES is connected to the PV system DC bus using a DC/DC buck-boost converter. The converter facilitates the BES power charge/discharge to compensate for the DC bus voltage deviation during severe disturbance conditions. In this way, the regulation of DC bus voltage of the PV/BES system can be enhanced as compared to the conventional regulation that is solely based on the voltage-sourced converter (VSC). For the grid side VSC (G-VSC), two control methods, namely, the voltage-mode and current-mode controls, are applied. For control parameter optimization, the simplex optimization technique is applied for the G-VSC voltage- and current-mode controls, including the BES DC/DC buck-boost converter controllers. A new set of optimized parameters are obtained for each of the power converters for comparison purposes. The PSCAD/EMTDC-based simulation case studies are presented to evaluate the performance of the proposed optimized control scheme in comparison to the conventional methods.

  15. Commercial radioactive waste management system feasibility with the universal canister concept. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Morissette, R.P.; Schneringer, P.E.; Lane, R.K.; Moore, R.L.; Young, K.A.

    1986-01-01

    A Program Research and Development Announcement (PRDA) was initiated by DOE to solicit from industry new and novel ideas for improvements in the nuclear waste management system. GA Technologies Inc. was contracted to study a system utilizing a universal canister which could be loaded at the reactor and used throughout the waste management system. The proposed canister was developed with the objective of meeting the mission requirements with maximum flexibility and at minimum cost. Canister criteria were selected from a thorough analysis of the spent fuel inventory, and canister concepts were evaluated along with the shipping and storage casks to determine the maximum payload. Engineering analyses were performed on various cask/canister combinations. One important criterion was the interchangeability of the canisters between truck and rail cask systems. A canister was selected which could hold three PWR intact fuel elements or up to eight consolidated PWR fuel elements. One canister could be shipped in an overweight truck cask or six in a rail cask. Economic analysis showed a cost savings of the reference system under consideration at that time.

  16. 75 FR 24786 - List of Approved Spent Fuel Storage Casks: NUHOMS® HD System Revision 1

    Science.gov (United States)

    2010-05-06

    ... include pressurized water reactor fuel assemblies with control components, reduce the minimum initial..., for the dry storage of spent nuclear fuel at civilian nuclear power reactor sites, with the objective... sites of civilian nuclear power reactors without, to the maximum extent practicable, the need...

  17. 76 FR 2243 - List of Approved Spent Fuel Storage Casks: NUHOMS ® HD System Revision 1

    Science.gov (United States)

    2011-01-13

    ... Federal Regulations is sold by the Superintendent of Documents. #0;Prices of new books are listed in the... Combustion Engineering 16x16 class fuel assemblies as authorized contents; reduce the minimum off-normal... Engineering 16x16 class fuel assemblies as authorized contents; reduce the minimum off-normal...

  18. Comparison of cask and drywell storage concepts for a monitored retrievable storage/interim storage system

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, D.E.

    1982-12-01

    The Department of Energy, through its Richland Operations Office is evaluating the feasibility, timing, and cost of providing a federal capability for storing the spent fuel, high-level wastes, and transuranic wastes that DOE may be obligated by law to manage until permanent waste disposal facilities are available. Three concepts utilizing a monitored retrievable storage/interim storage (MRS/IS) facility have been developed and analyzed. The first concept, co-location with a reprocessing plant, has been developed by staff of Allied General Nuclear Services. the second concept, a stand-alone facility, has been developed by staff of the General Atomic Company. The third concept, co-location with a deep geologic repository, has been developed by the Pacific Northwest Laboratory with the assistance of the Westinghouse Hanford Company and Kaiser Engineers. The objectives of this study are: to develop preconceptual designs for MRS/IS facilities: to examine various issues such as transportation of wastes, licensing of the facilities, and environmental concerns associated with operation of such facilities; and to estimate the life-cycle costs of the facilities when operated in response to a set of scenarios that define the quantities and types of waste requiring storage in specific time periods, generally spanning the years 1989 to 2037. Three scenarios are examined to develop estimates of life-cycle costs for the MRS/IS facilities. In the first scenario, the reprocessing plant is placed in service in 1989 and HLW canisters are stored until a repository is opened in the year 1998. Additional reprocessing plants and repositories are placed in service at intervals as needed to meet the demand. In the second scenario, the reprocessing plants are delayed in starting operations by 10 years, but the repositories open on schedule. In the third scenario, the repositories are delayed 10 years, but the reprocessing plants open on schedule.

  19. 76 FR 70374 - List of Approved Spent Fuel Storage Casks: MAGNASTOR® System, Revision 2

    Science.gov (United States)

    2011-11-14

    ... ID NRC- 2011-0008. Address questions about NRC dockets to Carol Gallagher, telephone: (301) 492-3668, email: Carol.Gallagher@nrc.gov . Mail comments to: Secretary, U.S. Nuclear Regulatory Commission..., 2011. For the Nuclear Regulatory Commission. Michael F. Weber, Acting Executive Director for...

  20. 78 FR 16601 - List of Approved Spent Fuel Storage Casks: MAGNASTOR® System

    Science.gov (United States)

    2013-03-18

    ... National Technology Transfer and Advancement Act of 1995 (Pub. L. 104-113) requires that Federal agencies... spent fuel storage regulations by revising the NAC International, Inc. (NAC) Modular Advanced Generation... explains why the rule would be inappropriate, including challenges to the rule's underlying premise...

  1. 78 FR 37927 - List of Approved Spent Fuel Storage Casks: MAGNASTOR® System

    Science.gov (United States)

    2013-06-25

    ... Federal Regulations is sold by the Superintendent of Documents. #0;Prices of new books are listed in the... revises authorized contents to include: pressurized water reactor (PWR) damaged fuel contained in damaged.... Tanious, Office of Federal and State Materials and Environmental Management Programs, U.S....

  2. Evaluation of sulcular sulphide level monitoring using a portable sensor system.

    Science.gov (United States)

    Gleissner, C; Springborn, I; Willershausen, B

    2002-11-25

    Volatile sulphur compounds (VSC) such as hydrogen sulphide and methyl mercaptan are toxic bacterial metabolites considered to contribute to the progression of periodontitis. However, the quantitative determination of sulcular VSC concentration requires costly time-consuming laboratory methods limiting its evaluation in large clinical trials. Recently, a portable monitor with a sulphide microsensor has been developed to measure sulcular VSC levels (SU). This cross-sectional study evaluated 1) the clinical usage of the sulphide sensor system, 2) the reproducibility of SU-measurements, 3) the distribution of SU-values in periodontal health and disease and 4) the relationship between SU and clinical parameters documenting periodontal disease severity. The specificity, the measuring range and the reproducibility of the sensor system were tested with reference solutions in vitro. 10 probands with healthy gingiva, 23 patients with gingivitis and 30 patients with chronic periodontitis were examined recording periodontal parameters (clinical attachment loss, CAL, probing depth, PD, bleeding on probing intensity BI, plaque and gingival index PI, GI) and sulcular sulphide level (SU) measured by the portable monitor as a digital score ranging from 0.0 (data. The portable sulphide monitor is a reliable method for the chairside determination of sulcular sulphide level in periodontal disease and in spite of its limitations a valuable supplementation of traditional clinical examination methods. It offers the possibility of relating in vitro results on the toxicity of VSC to clinical findings and might provide new insight into the impact of sulcular sulphide on the pathophysiology of periodontitis.

  3. Radiological characterization of container materials after interim storage using the example of CASTOR {sup registered} casks; Radiologische Charakterisierung von Behaelterwerkstoffen nach der Zwischenlagerung am Beispiel von CASTOR {sup registered} -Behaeltern

    Energy Technology Data Exchange (ETDEWEB)

    Rother, W. [WTI Wissenschaftlich-Technische Ingenieurberatung GmbH, Juelich (Germany); Graf, R.; Winterhagen, D. [GNS Gesellschaft fuer Nuklear-Service mbH, Essen (Germany)

    2012-11-01

    During interim storage the spent fuel casks or the casks for high-level waste (HAW) coquilles are exposed to neutron irradiation from their inventory that induces activation of the pannier the container body and its components. The presented contribution is an exemplary calculation of mean radial and axial reaction rates for components of HAW coquille or PWR fuel element loaded casks of the type CASTOR {sup registered} HAW28M and CASTOR {sup registered} V/19. The results of the Monte Carlo calculations include statistical uncertainties dependent on several parameters. Using the typical assumption that the casks will be unloaded after 40 years of interim storage the specific activities of significant reaction products are radiological assessed for further 60 years. An unrestricted release according paragraph 29 StrlSchV is discussed.

  4. Research on Shielding of High-capacity Cobalt Source Transport Cask%大容量钴源运输容器屏蔽研究

    Institute of Scientific and Technical Information of China (English)

    薛娜; 王炳衡; 毛亚蔚

    2015-01-01

    大容量钴源运输容器为运输工业用钴源而设计的专用设备。由于内容物放射性活度水平很高、衰变热很大,仅有少数国家具有设计能力,在国内的研制尚属首次。在对钴源运输容器的屏蔽设计研制过程中,突破之前的屏蔽设计技术束缚,采用MCAM程序与MCNP程序模拟计算钴源运输容器外的剂量率水平,并在设计过程中及时发现容器存在的设计缺陷,从而进行了设计改进,保证了容器满足国家标准要求的各项设计措施。目前这些设计措施已通过相关的试验验证。结果表明:针对大容量60 Co运输容器的关键技术制定的设计措施合理有效,充分保证了容器在经受国家标准中规定的正常运输条件和运输中事故条件下各项试验后容器屏蔽性能的完整性,确保钴源运输的安全。%High‐capacity cobalt source transport casks are used to transport 60 Co indus‐trial irradiators .The radioactive contents have special features of high‐activity and high residual heat ,so only a few countries have design capacity .This is the first design pro‐ject for the self‐reliant design of high‐capacity cobalt source transport casks .This paper was devoted to key technology in shielding design of these casks .The MCAM code and MCNP code were used for the calculation of the dose rate level outside the cask and the design improvement was applied in the cask to meet the requirements in national stand‐ard .A series of test proved the casks have ability to transport high‐activity sealed sources safely .Calculation results in design are in well concordance with survey results . It demonstrates the rationality and reliability of the methods used in this shielding design .The patent for the design of high‐capacity cobalt source transport casks was obtained .Through the design for cobalt source transport casks ,a good foundation is laid for the self‐reliant design of spent fuel

  5. A methodology to quantify the release of spent nuclear fuel from dry casks during security-related scenarios.

    Energy Technology Data Exchange (ETDEWEB)

    Durbin, Samuel G.; Luna, Robert Earl

    2013-11-01

    Assessing the risk to the public and the environment from a release of radioactive material produced by accidental or purposeful forces/environments is an important aspect of the regulatory process in many facets of the nuclear industry. In particular, the transport and storage of radioactive materials is of particular concern to the public, especially with regard to potential sabotage acts that might be undertaken by terror groups to cause injuries, panic, and/or economic consequences to a nation. For many such postulated attacks, no breach in the robust cask or storage module containment is expected to occur. However, there exists evidence that some hypothetical attack modes can penetrate and cause a release of radioactive material. This report is intended as an unclassified overview of the methodology for release estimation as well as a guide to useful resource data from unclassified sources and relevant analysis methods for the estimation process.

  6. Actinide-only and full burn-up credit in criticality assessment of RBMK-1500 spent nuclear fuel storage cask using axial burn-up profile

    Energy Technology Data Exchange (ETDEWEB)

    Barkauskas, V., E-mail: vytenis.barkauskas@ftmc.lt; Plukiene, R., E-mail: rita.plukiene@ftmc.lt; Plukis, A., E-mail: arturas.plukis@ftmc.lt

    2016-10-15

    Highlights: • RBMK-1500 fuel burn-up impact on k{sub eff} in the SNF cask was calculated using SCALE 6.1. • Positive end effect was noticed at certain burn-up for the RBMK-1500 spent nuclear fuel. • The non-uniform uranium depletion is responsible for the end effect in RBMK-1500 SNF. • k{sub eff} in the SNF cask does not exceed a value of 0.95 which is set in the safety requirements. - Abstract: Safe long-term storage of spent nuclear fuel (SNF) is one of the main issues in the field of nuclear safety. Burn-up credit application in criticality analysis of SNF reduces conservatism of usually used fresh fuel assumption and implies a positive economic impact for the SNF storage. Criticality calculations of spent nuclear fuel in the CONSTOR® RBMK-1500/M2 cask were performed using pre-generated ORIGEN-ARP spent nuclear fuel composition libraries, and the results of the RBMK-1500 burn-up credit impact on the effective neutron multiplication factor (k{sub eff}) have been obtained and are presented in the paper. SCALE 6.1 code package with the STARBUCKS burn-up credit evaluation tool was used for modeling. Pre-generated ARP (Automatic Rapid Processing) crosssection libraries based on ENDF/B-VII cross section library were used for fast burn-up inventory modeling. Different conditions in the SNF cask were modeled: 2.0% and 2.8% initial enrichment fuel of various burn-up and water density inside cavities of the SNF cask. The fuel composition for the criticality analysis was chosen taking into account main actinides and most important fission products used in burn-up calculations. A significant positive end effect is noticed from 15 GWd/tU burn-up for 2.8% enrichment fuel and from 9 GWd/tU for 2.0% enrichment fuel applying the actinide-only approach. The obtained results may be applied in further evaluations of the RBMK type reactor SNF storage as well as help to optimize the SNF storage volume inside the CONSTOR® RBMK-1500/M2 cask without compromising criticality

  7. Robust sliding mode control for uncertain discrete time systems

    Institute of Scientific and Technical Information of China (English)

    QU Shaocheng; WANG Yongji

    2003-01-01

    A novel variable structure control (VSC) strategy with a dynamic disturbance compensator based on the reaching law for a class of uncertain discrete systems is presented. The robust stability to disturbance and the system dynamics in the vicinity of the switching plane are studied. A measure of the uncertain parameters and external disturbance is obtained through delaying every sampling time. Theoretical analysis and experimental simulation results demonstrate that the dynamic performance and robustness of the closed-loop system are improved effectively.

  8. The evaluation for the usability of the Varian Standard Couch modelingusing Treatment Planning System

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yong Mo; Song, Yong Min; Kim, Jin Man; Choi, Ji Min; Choi, Byeung Gi [Dept. of Radiation Oncology, Samsung Medical Center, Seoul (Korea, Republic of)

    2016-06-15

    When a radiation treatment, there is an attenuation by Carbon Fiber Couch. In this study, we tried to evaluate the usability of the Varian Standard Couch(VSC) by modeling with Treatment Planning System (TPS) VSC was scanned by CBCT(Cone Beam Computed Tomography) of the Linac(Clinac IX, VARIAN, USA), following the three conditions of VSC, Side Rail OutGrid(SROG), Side Rail InGrid(SRIG), Side Rail In OutSpine Down Bar(SRIOS). After scan, the data was transferred to TPS and modeled by contouring Side Rail, Side Bar Upper, Side Bar Lower, Spine Down Bar automatically. We scanned the Cheese Phantom(Middelton, USA) using Computed Tomography(Light Speed RT 16, GE, USA) and transfer the data to TPS, and apply VSC modeled previously with TPS to it. Dose was measured at the isocenter of Ion Chamber(A1SL, Standard imaging, USA) in Cheese Phantom using 4 and 10 MV radiation for every 5° gantry angle in a different filed size(3 X 3 cm{sup 2},10 X 10cm{sup 2}) without any change of MU(=100), and then we compared the calculated dose and measured dose. Also we included dose at the 127° in SRIG to compare the attenuation by Side Bar Upper. Results : The density of VSC by CBCT in TPS was 0.9g/cm{sup 3}, and in the case of Spine Down Bar, it was 0.7g/cm{sup 3}. The radiation was attenuated by 17.49%, 16.49%, 8.54%, and 7.59% at the Side Rail, Side Bar Upper, Side Bar Lower, and Spine Down Bar. For the accuracy of modeling, calculated dose and measured dose were compared. The average error was 1.13% and the maximum error was 1.98% at the 170° beam crossing the Spine Down Bar. To evaluate the usability for the VSC modeled by TPS, the maximum error was 1.98% as a result of compassion between calculated dose and measured dose. We found out that VSC modeling helped expect the dose, so we think that it will be helpful for the more accurate treatment.

  9. Robust nonlinear variable selective control for networked systems

    Science.gov (United States)

    Rahmani, Behrooz

    2016-10-01

    This paper is concerned with the networked control of a class of uncertain nonlinear systems. In this way, Takagi-Sugeno (T-S) fuzzy modelling is used to extend the previously proposed variable selective control (VSC) methodology to nonlinear systems. This extension is based upon the decomposition of the nonlinear system to a set of fuzzy-blended locally linearised subsystems and further application of the VSC methodology to each subsystem. To increase the applicability of the T-S approach for uncertain nonlinear networked control systems, this study considers the asynchronous premise variables in the plant and the controller, and then introduces a robust stability analysis and control synthesis. The resulting optimal switching-fuzzy controller provides a minimum guaranteed cost on an H2 performance index. Simulation studies on three nonlinear benchmark problems demonstrate the effectiveness of the proposed method.

  10. Analysis and Performance Comparison of Different Power Conditioning Systems for SMES-Based Energy Systems in Wind Turbines

    Directory of Open Access Journals (Sweden)

    Francisco J. Rodríguez

    2013-03-01

    Full Text Available Suitability of energy systems based on Superconducting Magnetic Energy Storage (SMES has been widely tested in the field of wind energy, being able to supply power in cases such as low wind speeds or voltage dips, and to store energy when there are surpluses. This article analyzes and compares the performance of three SMES-based systems that differ in the topology of power converter: a two-level Voltage Source Converter (VSC, a three-level VSC and a two-level Current Source Converter (CSC. Their performance has been improved by means of an appropriate modulation strategy. To obtain a high reliability and accuracy, a co-simulation between MATLAB/Simulink® (running the control system and PSIM® (running the power system has been executed.

  11. Summary of the technical review of the safety analysis reports for packaging (SARP) for the transnuclear transport/storage casks: TN-BRP and TN-REG

    Energy Technology Data Exchange (ETDEWEB)

    1986-07-01

    The Safety Analysis Reports for Packaging for two spent fuel shipping casks were technically reviewed by the Oak Ridge National Laboratory. The casks were designed by Transnuclear, Inc., for shipment of 85 Big Rock Point boiling water reactor fuel elements and 40 R.E. Ginna pressurized water reactor fuel elements from West Valley, New York, to Idaho Falls, Idaho. The intent of the review was to ensure compliance of the casks with the requirements the applicable Federal Regulations contained in 10 CFR Pt. 71 and allow issuance of Department of Energy Certificates of Compliance for transport by the Department of Energy Idaho Operations Office. The review was performed by a team of Oak Ridge National Laboratory staff assembled for their expertise in criticality analysis, shielding, metallurgy, nondestructive testing, thermal analysis, structural analysis, and containment. This report describes the review processes, the findings in each technical area, and the overall conclusion that a Certificate of Compliance could be issued for the proposed single shipment under the specified conditions and constraints.

  12. CORROSION OF ALUMINUM CLAD SPENT NUCLEAR FUEL IN THE 70 TON CASK DURING TRANSFER FROM L AREA TO H-CANYON

    Energy Technology Data Exchange (ETDEWEB)

    Mickalonis, J.

    2014-06-01

    Aluminum-clad spent nuclear fuel will be transported for processing in the 70-ton nuclear fuel element cask from L Basin to H-canyon. During transport these fuels would be expected to experience high temperature aqueous corrosion from the residual L Basin water that will be present in the cask. Cladding corrosion losses during transport were calculated for material test reactor (MTR) and high flux isotope reactors (HFIR) fuels using literature and site information on aqueous corrosion at a range of time/temperature conditions. Calculations of the cladding corrosion loss were based on Arrhenius relationships developed for aluminum alloys typical of cladding material with the primary assumption that an adherent passive film does not form to retard the initial corrosion rate. For MTR fuels a cladding thickness loss of 33 % was found after 1 year in the cask with a maximum temperature of 260 {degrees}C. HFIR fuels showed a thickness loss of only 6% after 1 year at a maximum temperature of 180 {degrees}C. These losses are not expected to impact the overall confinement function of the aluminum cladding.

  13. Corrosion of aluminum clad spent nuclear fuel in the 70 ton cask during transfer from L area to H-canyon

    Energy Technology Data Exchange (ETDEWEB)

    Mickalonis, J. I. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-08-01

    Aluminum-clad spent nuclear fuel will be transported for processing in the 70-ton nuclear fuel element cask from L Basin to H-canyon. During transport these fuels would be expected to experience high temperature aqueous corrosion from the residual L Basin water that will be present in the cask. Cladding corrosion losses during transport were calculated for material test reactor (MTR) and high flux isotope reactors (HFIR) fuels using literature and site information on aqueous corrosion at a range of time/temperature conditions. Calculations of the cladding corrosion loss were based on Arrhenius relationships developed for aluminum alloys typical of cladding material with the primary assumption that an adherent passive film does not form to retard the initial corrosion rate. For MTR fuels a cladding thickness loss of 33% was found after 1 year in the cask with a maximum temperature of 263 °C. HFIR fuels showed a thickness loss of only 6% after 1 year at a maximum temperature of 180 °C. These losses are not expected to impact the overall confinement function of the aluminum cladding.

  14. Corrosion of aluminum clad spent nuclear fuel in the 70 ton cask during transfer from L area to H-canyon

    Energy Technology Data Exchange (ETDEWEB)

    Mickalonis, J. I. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-08-31

    Aluminum-clad spent nuclear fuel will be transported for processing in the 70-ton nuclear fuel element cask from L Basin to H-canyon. During transport these fuels would be expected to experience high temperature aqueous corrosion from the residual L Basin water that will be present in the cask. Cladding corrosion losses during transport were calculated for material test reactor (MTR) and high flux isotope reactors (HFIR) fuels using literature and site information on aqueous corrosion at a range of time/temperature conditions. Calculations of the cladding corrosion loss were based on Arrhenius relationships developed for aluminum alloys typical of cladding material with the primary assumption that an adherent passive film does not form to retard the initial corrosion rate. For MTR fuels a cladding thickness loss of 33 % was found after 1 year in the cask with a maximum temperature of 263 °C. HFIR fuels showed a thickness loss of only 6% after 1 year at a maximum temperature of 180 °C. These losses are not expected to impact the overall confinement function of the aluminum cladding.

  15. Preliminary assessment of radiological doses in alternative waste management systems without an MRS facility

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, K.J.; Pelto, P.J.; Daling, P.M.; Lavender, J.C.; Fecht, B.A.

    1986-06-01

    This report presents generic analyses of radiological dose impacts of nine hypothetical changes in the operation of a waste management system without a monitored retrievable storage (MRS) facility. The waste management activities examined in this study include those for handling commercial spent fuel at nuclear power reactors and at the surface facilities of a deep geologic repository, and the transportation of spent fuel by rail and truck between the reactors and the repository. In the reference study system, the radiological doses to the public and to the occupational workers are low, about 170 person-rem/1000 metric ton of uranium (MTU) handled with 70% of the fuel transported by rail and 30% by truck. The radiological doses to the public are almost entirely from transportation, whereas the doses to the occupational workers are highest at the reactors and the repository. Operating alternatives examined included using larger transportation casks, marshaling rail cars into multicar dedicated trains, consolidating spent fuel at the reactors, and wet or dry transfer options of spent fuel from dry storage casks. The largest contribution to radiological doses per unit of spent fuel for both the public and occupational workers would result from use of truck transportation casks, which are smaller than rail casks. Thus, reducing the number of shipments by increasing cask sizes and capacities (which also would reduce the number of casks to be handled at the terminals) would reduce the radiological doses in all cases. Consolidating spent fuel at the reactors would reduce the radiological doses to the public but would increase the doses to the occupational workers at the reactors.

  16. A Vector Switching Method of Multiphase Chopper in Superconducting Magnetic Energy Storage Systems%超导磁储能系统用多相斩波器矢量切换控制方法

    Institute of Scientific and Technical Information of China (English)

    施啸寒; 王少荣; 左文平

    2013-01-01

    在高功率超导磁储能装置(superconducting magnetic energy storage,SMES)中,电压源型功率调节系统首先利用多相斩波器将超导磁体电流转化成稳定的直流电压,再利用后级电压源型变流器(voltage source converter,VSC)与交流%In the high power superconducting magnetic energy storage (SMES) device, the voltage source converter (VSC) based power conditioning system (PCS) first converts the current of the superconducting magnetic to a stable DC voltage with the help of a multiphase chopper, and then utilizes a VSC to communicate power with the AC system. However, in the situation when the power communication between SMES and the grid changes too fast, a multiphase chopper with traditional current-self-shared PI controller has some problems such as the DC voltage deviation and transient current unbalance. The DC voltage deviation will further exert adverse effects on the control accuracy and speed of the succeeding VSC. To overcome these problems, this paper deduces the switching-function model of the multiphase chopper, and proposes a vector-switching-based control method using the deduced model. This method utilizes the hysteresis to switch the control vector to realize the DC voltage control, at the same time utilizes the redundant switch combinations of a control vector to realize the current sharing. Simulation shows that the proposed method can eliminate the DC voltage deviation when the power communication suddenly changing, and thus, provides a favorable condition for the fast and accurate control of the VSC. Besides, the proposed method can also realize current-sharing of the multiphase chopper in most of the situations, and therefore ensure the long-term operation of the system reliably.

  17. Harmonics in Offshore Wind Power Plants Employing Power Electronic Devices in the Transmission System

    DEFF Research Database (Denmark)

    Glasdam, Jakob Bærholm

    of wind power. The onshore as well as offshore wind power plants (OWPPs) therefore have to meet the same stringent requirement as the conventional power plants. This can be accommodated by employment of flexible alternating current transmission system (FACTS) devices, such as the static compensator...... gives rise to a number of challenges to the wind power industry with regard to construction, installation as well as transmission of the generated energy. The STATCOM and the voltage-sourced converter high-voltage direct current (VSC-HVDC) are attractive solutions for grid connection of remotely located...... OWPPs. The new system configuration requires in-depth knowledge of all relevant technical aspects, including e.g. the involved control systems performance and robustness for all possible operating conditions. The transmission system operator might impose new control requirements when the VSC...

  18. SCALE/MAVRIC calculation of dose rates measured for a gamma radiation source in a thick-walled transport and storage cask of ductile cast iron with lead inserts

    Science.gov (United States)

    Baumgarten, Werner; Thiele, Holger; Ruprecht, Benjamin; Phlippen, Peter-W.; Schlömer, Luc

    2017-09-01

    Dose rate calculations are important for judging the shielding performance of transport casks for radioactive material. Therefore it is important to have reliable calculation tools. We report on measured and calculated dose rates near a thick-walled transport and storage cask of ductile cast iron with lead inserts and a Co-60 source inside. In a series of experiments the thickness of the inserts was varied, and measured dose rates near the cask were compared with SCALE/MAVRIC 6.1.3 and SCALE/MAVRIC 6.2 calculation results. Deviations from the measurements were found to be higher for increased lead thicknesses. Furthermore, it is shown how the shielding material density, air scattering and accounting for the floor influence the quality of the calculation.

  19. Transient Voltage Stability Analysis and Improvement of A Network with different HVDC Systems

    DEFF Research Database (Denmark)

    Liu, Yan; Chen, Zhe

    2011-01-01

    the theoretical analysis and the improved control method, real time simulation model of a hybrid multi-infeed HVDC system based on western Danish power system is established in RTDS™. Simulation results show that the enhanced transient voltage stability can be achieved.......This paper presents transient voltage stability analysis of an AC system with multi-infeed HVDC links including a traditional LCC HVDC link and a VSC HVDC link. It is found that the voltage supporting capability of the VSC-HVDC link is significantly influenced by the tie-line distance between...... the two links and the size of loads. In order to improve the transient voltage stability, a voltage adjusting method is proposed in this paper. A voltage increment component has been introduced into the outer voltage control loop under emergency situation caused by severe grid faults. In order to verify...

  20. Determination of uncertainties in the calculation of dose rates at transport and storage casks; Unsicherheiten bei der Berechnung von Dosisleistungen an Transport- und Lagerbehaeltern

    Energy Technology Data Exchange (ETDEWEB)

    Schloemer, Luc Laurent Alexander

    2014-12-17

    The compliance with the dose rate limits for transport and storage casks (TLB) for spent nuclear fuel from pressurised water reactors can be proved by calculation. This includes the determination of the radioactive sources and the shielding-capability of the cask. In this thesis the entire computational chain, which extends from the determination of the source terms to the final Monte-Carlo-transport-calculation is analysed and the arising uncertainties are quantified not only by benchmarks but also by variational calculi. The background of these analyses is that the comparison with measured dose rates at different TLBs shows an overestimation by the values calculated. Regarding the studies performed, the overestimation can be mainly explained by the detector characteristics for the measurement of the neutron dose rate and additionally in case of the gamma dose rates by the energy group structure, which the calculation is based on. It turns out that the consideration of the uncertainties occurring along the computational chain can lead to even greater overestimation. Concerning the dose rate calculation at cask loadings with spent uranium fuel assemblies an uncertainty of (({sup +21}{sub -28}) ±2) % (rel.) for the total gamma dose rate and of ({sup +28±23}{sub -55±4}) % (rel.) for the total neutron dose rate are estimated. For mixed-loadings with spent uranium and MOX fuel assemblies an uncertainty of ({sup +24±3}{sub -27±2}) % (rel.) for the total gamma dose rate and of ({sup +28±23}{sub -55±4}) % (rel.) for the total neutron dose rate are quantified. The results show that the computational chain has not to be modified, because the calculations performed lead to conservative dose rate predictions, even if high uncertainties at neutron dose rate measurements arise. Thus at first the uncertainties of the neutron dose rate measurement have to be decreased to enable a reduction of the overestimation of the calculated dose rate afterwards. In the present thesis

  1. CONTINUOUS ROBUST TRACKING CONTROLLERS FOR A CLASS OF UNCERTAIN NONLINEAR DYNAMICAL SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    胡剑波; 苏宏业; 柯挺; 褚健; 陈新海

    2001-01-01

    Robust tracking controller for a class of uncertain nonlinear dynamical systems, which are linearizable by input-output feedback with matching uncertainties, was investigated. In this study, uniform ultimate bound or uniformly asymptotic stability of tracking errors were obtained by different choice of the control gain. A simulation to determine the effectiveness of the proposed approach showed that the control performance was better than that of VSC (Variable Structure Control).

  2. Control of VSC-HVDC in offshore AC islands with wind power plants: Comparison of two alternatives

    DEFF Research Database (Denmark)

    Zeni, Lorenzo; Hesselbæk, Bo; Sørensen, Poul Ejnar;

    2015-01-01

    The subject of this paper is the control of offshore AC collection and export networks behind a voltage source converter based high voltage direct current transmission system. The inertia-less nature of such grids makes the control of voltages and power flows potentially more flexible, but at the...

  3. An Approach to Polynomial NARX/NARMAX Systems Identification in a Closed-loop with Variable Structure Control

    Institute of Scientific and Technical Information of China (English)

    O. M. Mohamed Vall; R. M'hiri

    2008-01-01

    Many physical processes have nonlinear behavior which can be well represented by a polynomial NARX or NARMAX model. The identification of such models has been widely explored in literature. The majority of these approaches are for the open-loop identification. However, for reasons such as safety and production restrictions, open-loop identification cannot always be done. In such cases, closed-loop identification is necessary. This paper presents a two-step approach to closed-loop identification of the polynomial NARX/NARMAX systems with variable structure control (VSC). First, a genetic algorithm (GA) is used to maximize the similarity of VSC signal to white noise by tuning the switching function parameters. Second, the system is simulated again and its parameters are estimated by an algorithm of the least square (LS) family. Finally, simulation examples are given to show the validity of the proposed approach.

  4. 10 CFR 72.214 - List of approved spent fuel storage casks.

    Science.gov (United States)

    2010-01-01

    ... 72.214 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR THE INDEPENDENT STORAGE OF SPENT NUCLEAR FUEL, HIGH-LEVEL RADIOACTIVE WASTE, AND REACTOR-RELATED GREATER THAN CLASS C... Standardized NUHOMS® Horizontal Modular Storage System for Irradiated Nuclear Fuel. Docket Number:...

  5. 10 CFR 72.240 - Conditions for spent fuel storage cask reapproval.

    Science.gov (United States)

    2010-01-01

    ... Section 72.240 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR THE INDEPENDENT STORAGE OF SPENT NUCLEAR FUEL, HIGH-LEVEL RADIOACTIVE WASTE, AND REACTOR-RELATED GREATER THAN CLASS C... adversely affected structures, systems, and components important to safety....

  6. An Assessment of Converter Modelling Needs for Offshore Wind Power Plants Connected via VSC-HVDC Networks

    DEFF Research Database (Denmark)

    Glasdam, Jakob; Zeni, Lorenzo; Hjerrild, Jesper

    2013-01-01

    Modular multilevel cascaded converter (MMCC) based high voltage direct current (HVDC) transmission is technically superior to other technologies, especially in case of connection of offshore wind power plants (OWPPs). Modelling challenges are faced by OWPP developers, who are not acquainted...... with detailed information regarding the internal behaviour of such complex devices. This paper presents an investigation of the modelling requirements of the MMCC HVDC system, based on comparison between simulation results using a detailed HVDC representation in PSCAD/EMTDC and two less detailed models realised...

  7. 76 FR 12825 - List of Approved Spent Fuel Storage Casks: NUHOMS® HD System Revision 1; Confirmation of...

    Science.gov (United States)

    2011-03-09

    ... Federal Regulations is sold by the Superintendent of Documents. #0;Prices of new books are listed in the...; add definitions for Fuel Class and Reconstituted Fuel Assembly; add Combustion Engineering 16x16...

  8. Modelling of pool fire environments using experimental results of a two-hour test of a railcar/cask system

    Energy Technology Data Exchange (ETDEWEB)

    Hamann, J.E.; Klein, D.E.; Pope, R.B.; Yoshimura, H.R.

    1980-01-01

    It was demonstrated that time and spatial variations in the local source temperatures, the radiant shielding of intervening structure and the effects of wind can significantly affect the amount of heat input to a large package in a simulated accidental fire. The pool fire provided a significantly non-uniform heat source to the package. Despite these effects, however, the amount of heat input to the package was generally equivalent to that which would be received from a regulatory 800/sup 0/C uniform thermal source. 7 firegures.

  9. GY-20和GY-40型大容量钴-60运输容器关键技术研究%Key Technology Studies of GY-20 and GY-40 High-Capacity Cobalt-60 Transport Casks

    Institute of Scientific and Technical Information of China (English)

    刘慧芳; 张鑫

    2012-01-01

    GY -20和GY- 40型大容量钴-60运输容器是为运输工业用钴-60成品源和钴-60棒束而设计的专用设备.由于内容物放射性活度水平高、衰变热大,仅有加拿大、英国、俄罗斯等少数国家具有设计能力.本文综合考虑容器结构、热工、力学、屏蔽等方面的要求,对容器设计和制造过程中的关键技术以及解决方案进行了分析研究.试验验证结果表明,容器的结构设计、包铅边界设计准则的确定和制造过程的质量控制措施合理、有效,能保证容器在各种工况下的屏蔽完整性,容器具有安全运输大容量钴-60源项的能力,其设计满足相关标准和规范要求,可为其他B型货包的设计提供参考.%GY-20 and GY-40 high-capacity cobalt-60 transport,casks are used to transport cobalt-60 industrial irradiators and cobalt-60 bundles. The radioactive contents have special features of high-activity and high residual heat, so only a few countries such as Canada, England and Russia have design capacity. The key technologies and corresponding solutions were studied for the design and manufacture of the cask taking into account the structural, thermal, mechanics and shield requests. A series of tests prove that the cask structure design, design criteria for lead coating structure and quality control measurements are reasonable and effective, and the cask shield integrity can be ensured for all conditions. The casks have ability to transport high-activity sealed sources safely, and the design of cask satisfies the requirement of design code and standard. It can provide reference for other B type package.

  10. Bias estimates used in lieu of validation of fission products and minor actinides in MCNP Keff calculations for PWR burnup credit casks

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Don [ORNL; Marshall, William BJ J [ORNL; Wagner, John C [ORNL; Bowen, Douglas G [ORNL

    2015-09-01

    The U.S. Nuclear Regulatory Commission (NRC) Division of Spent Fuel Storage and Transportation recently issued Interim Staff Guidance (ISG) 8, Revision 3. This ISG provides guidance for burnup credit (BUC) analyses supporting transport and storage of PWR pressurized water reactor (PWR) fuel in casks. Revision 3 includes guidance for addressing validation of criticality (keff) calculations crediting the presence of a limited set of fission products and minor actinides (FP&MA). Based on previous work documented in NUREG/CR-7109, recommendation 4 of ISG-8, Rev. 3, includes a recommendation to use 1.5 or 3% of the FP&MA worth to conservatively cover the bias due to the specified FP&MAs. This bias is supplementary to the bias and bias uncertainty resulting from validation of keff calculations for the major actinides in SNF and does not address extension to actinides and fission products beyond those identified herein. The work described in this report involves comparison of FP&MA worths calculated using SCALE and MCNP with ENDF/B-V, -VI, and -VII based nuclear data and supports use of the 1.5% FP&MA worth bias when either SCALE or MCNP codes are used for criticality calculations, provided the other conditions of the recommendation 4 are met. The method used in this report may also be applied to demonstrate the applicability of the 1.5% FP&MA worth bias to other codes using ENDF/B V, VI or VII based nuclear data. The method involves use of the applicant s computational method to generate FP&MA worths for a reference SNF cask model using specified spent fuel compositions. The applicant s FP&MA worths are then compared to reference values provided in this report. The applicants FP&MA worths should not exceed the reference results by more than 1.5% of the reference FP&MA worths.

  11. Investigation of the behaviour of impact limiting devices of transport casks for radioactive materials in the package approval and risk analysis; Untersuchung des Verhaltens stossdaempfender Bauteile von Transportbehaeltern fuer radioaktive Stoffe in Bauartpruefung und Risikoanalyse

    Energy Technology Data Exchange (ETDEWEB)

    Neumann, Martin

    2009-08-20

    Transport casks for radioactive materials with a Type-B package certificate have to ensure that even under severe accident scenarios the radioactive content remains safely enclosed, in an undercritical arrangement and that ionising radiation is sufficiently shielded. The impact limiter absorbs in an accident scenario the major part of the impact energy and reduces the maximum force applied on the cask body. Therefore the simulation of the behaviour of impact limiting devices of transport casks for nuclear material is of great interest for the design assessment in the package approval as well as for risk analysis in the field of transport of radioactive materials. The behaviour of the impact limiter is influenced by a number of parameters like impact limiter construction, material properties and loading conditions. Uncertainties exist for the application of simplified numerical tools for calculations of impact limiting devices. Uncertainities exist when applying simplified numerical tools. A model describing the compression of wood in axial direction of wood under large deformations for simulation with complex numerical procedures like dynamic Finite Element Methods has not been developed yet. Therefore this thesis concentrates on deriving a physical model for the behaviour of wood and analysing the applicability of different modeling techniques. A model describing the compression of wood in axial direction under large deformations was developed on the basis of an analysis of impact limiter of prototypes of casks for radioactive materials after a 9-m-drop-test and impact tests with wooden specimens. The model describes the softening, which wood under large deformation exhibits, as a function of the lateral strain constraint. The larger the lateral strain restriction, the more energy wood can absorb. The energy absorption capacity of impact limiter depends therefore on the ability of the outer steel sheet structure to prevent wood from evading from the main

  12. Static compensators (STATCOMs) in power systems

    CERN Document Server

    Shahnia, Farhad; Ghosh, Arindam

    2014-01-01

    A static compensator (STATCOM), also known as static synchronous compensator, is a member of the flexible alternating current transmission system (FACTS) devices. It is a power-electronics based regulating device which is composed of a voltage source converter (VSC) and is shunt-connected to alternating current electricity transmission and distribution networks. The voltage source is created from a DC capacitor and the STATCOM can exchange reactive power with the network. It can also supply some active power to the network, if a DC source of power is connected across the capacitor. A STATCOM

  13. Advanced solutions in power systems HVDC, facts, and artificial intelligence

    CERN Document Server

    Liu, Chen-Ching; Edris, Abdel-Aty

    2016-01-01

    Provides insight on both classical means and new trends in the application of power electronic and artificial intelligence techniques in power system operation and control This book presents advanced solutions for power system controllability improvement, transmission capability enhancement and operation planning. The book is organized into three parts. The first part describes the CSC-HVDC and VSC-HVDC technologies, the second part presents the FACTS devices, and the third part refers to the artificial intelligence techniques. All technologies and tools approached in this book are essential for power system development to comply with the smart grid requirements.

  14. Systems and methods for harvesting and storing materials produced in a nuclear reactor

    Energy Technology Data Exchange (ETDEWEB)

    Heinold, Mark R.; Dayal, Yogeshwar; Brittingham, Martin W.

    2016-04-05

    Systems produce desired isotopes through irradiation in nuclear reactor instrumentation tubes and deposit the same in a robust facility for immediate shipping, handling, and/or consumption. Irradiation targets are inserted and removed through inaccessible areas without plant shutdown and placed in the harvesting facility, such as a plurality of sealable and shipping-safe casks and/or canisters. Systems may connect various structures in a sealed manner to avoid release of dangerous or unwanted matter throughout the nuclear plant, and/or systems may also automatically decontaminate materials to be released. Useable casks or canisters can include plural barriers for containment that are temporarily and selectively removable with specially-configured paths inserted therein. Penetrations in the facilities may limit waste or pneumatic gas escape and allow the same to be removed from the systems without over-pressurization or leakage. Methods include processing irradiation targets through such systems and securely delivering them in such harvesting facilities.

  15. Coordinated Fast Primary Frequency Control from Offshore Wind Power Plants in MTDC System

    DEFF Research Database (Denmark)

    Sakamuri, Jayachandra N.; Hansen, Anca Daniela; Cutululis, Nicolaos Antonio

    2016-01-01

    In this paper, coordinated fast primary frequency control (FPFC) from offshore wind power plants (OWPPs) integrated to surrounding onshore AC power system through a three terminal VSC HVDC system is presented. The onshore AC grid frequency variations are emulated at offshore AC grid through...... and the dynamics of wind turbine are also discussed. The corresponding impact of OWPPs active power output variation at different wind speeds on the power system frequency control and DC grid voltage is also presented. The results show that the proposed coordinated fast primary frequency control from OWPPs...... improves the power system frequency while relieving the stress on the other AC grid participating in frequency control....

  16. Decree no. 2001-1199 of the 10 december 2001 publishing the resolution MSC. 88 (71) notifying adoption of the international compilation of safety rules for the spent nuclear fuels, plutonium and high level radioactive wastes transport in casks on ships (compilation INF) (annexes), adopted at London the 27 may 1999; Decret no. 2001-1199 du 10 decembre 2001 portant publication de la resolution MSC.88 (71) portant adoption du recueil international de regles de securite pour le transport de combustible nucleaire irradie, de plutonium et de dechets hautement radioactifs en colis a bord de navires (recueil INF) (ensemble une annexe), adoptee a Londres le 27 mai 1999

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    This legislative text concerns the safety rules of spent nuclear fuels, plutonium and high level radioactive wastes transport, in casks on ships. Rules, fire prevention, temperature control of casks, electric supply, radioprotection, management and emergency plans are detailed. (A.L.B.)

  17. Statement of work for the immobilized high-level waste transportation system, Project W-464

    Energy Technology Data Exchange (ETDEWEB)

    Mouette, P.

    1998-06-24

    The objective of this Statement of Work (SOW) is to present the scope, the deliverables, the organization, the technical and schedule expectations for the development of a Package Design Criteria (PDC), cost and schedule estimate for the acquisition of a transportation system for the Immobilized High-Level Waste (IHLW). This transportation system which includes the truck, the trailer, and a shielded cask will be used for on-site transportation of the IHLW canisters from the private vendor vitrification facility to the Hanford Site interim storage facility, i.e., vaults 2 and 3 of the Canister Storage Building (CSB). This Statement of Work asks Waste Management Federal Services, Inc., Northwest Operations, to provide Project W-464 with a Design Criteria Document, plus a life-cycle schedule and cost estimate for the acquisition of a transportation system (shielded cask, truck, trailer) for IHLW on-site transportation.

  18. Loading 076 assemblies in two IV-04 transport casks for transport to the U.S. Savannah River Site (SC); Trasferimento di 72 elementi irraggiati MTR dalla piscina dell`impianto EUREX a due contenitori IU-04 per il trasporto al Savannah River Site-Department of Energy (USA)

    Energy Technology Data Exchange (ETDEWEB)

    Gili, Michele [ENEA, Centro Ricerche Saluggia, Vercelli (Italy). Dipt. Energia

    1997-09-01

    The National Agency for New Technologies and the Environments has signed with the US Department of Energy a contract for the transfer of 150 irradiated MTR fuel assemblies stored in the EUREX plant pool at The National Agency for New Technologies and the Environments Research Centre of Saluggia. The first scheduled transport has been made in february 1997 and has involved the successful loading of 76 assemblies in two IU-04 (Pegase) transport casks. The loaded casks have been shipped to the U.S. Savannah River Site (SC).

  19. Dry Transfer Systems for Used Nuclear Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Brett W. Carlsen; Michaele BradyRaap

    2012-05-01

    The potential need for a dry transfer system (DTS) to enable retrieval of used nuclear fuel (UNF) for inspection or repackaging will increase as the duration and quantity of fuel in dry storage increases. This report explores the uses for a DTS, identifies associated general functional requirements, and reviews existing and proposed systems that currently perform dry fuel transfers. The focus of this paper is on the need for a DTS to enable transfer of bare fuel assemblies. Dry transfer systems for UNF canisters are currently available and in use for transferring loaded canisters between the drying station and storage and transportation casks.

  20. Fast Protection Scheme for Overhead Transmission Lines of VSC-based HVDC Grid%柔性直流电网架空线路快速保护方案

    Institute of Scientific and Technical Information of China (English)

    王艳婷; 张保会; 范新凯

    2016-01-01

    The voltage source converter(VSC)-based high voltage direct current(HVDC)grid technology is an effective means for large-scale integration of clean energy.The fast DC line protection technology is one of the main challenges to HVDC grids. Based on the Zhangbei HVDC grid project,this paper proposes a fast protection scheme for overhead transmission lines of bipolar VSC-based HVDC grids equipped with DC circuit breakers.The protection is based on local measurements featuring fast response speed.The voltage gradient is used to detect faults rapidly,and the voltage derivative criterion is adopted to identify the protection zone in which the fault occurs thanks to the smoothing effect of the fault current limiter.And the faulty pole is identified according to the different propagation characteristics between the line mode and zero mode voltage,ensuring the selectivity of the protection as well as high reliability.The Zhangbei HVDC grid model is built in PSCAD/EMTDC and the performance of the proposed protection scheme is verified by simulation results of various fault conditions,as well as different operation modes of the HVDC grids.%基于柔性直流输电的直流电网技术,是大规模清洁能源接入电网的有效手段,直流电网快速线路保护是其面临的重要技术挑战之一。以国内计划建设的张北直流电网工程为背景,提出了一套适用于全网配置直流断路器、采用架空线输电的对称双极直流电网线路快速保护方案。保护仅利用单端信息进行故障判别,且保护数据窗短,满足速动性的要求;保护采用电压梯度快速检测故障,利用限流电抗器对故障电压信号的平滑作用实现故障区间的判别,并根据零模与一模电压传播特性的差异判定故障极,实现保护的选择性与高可靠性。结合直流电网的PSCAD模型,验证了所提出方案在不同故障情况下的保护性能,并分析了保护对运行方式改变的适应性。

  1. Wide-band Model of Critical Equipment in VSC-HVDC Converter Stations%柔性直流换流站关键设备宽频模型

    Institute of Scientific and Technical Information of China (English)

    孙海峰; 刘晓倩

    2016-01-01

    为研究柔性直流换流阀正常运行时产生的电磁骚扰的传播规律及其对换流站内的二次设备和周围的无线电台站的影响,基于黑箱理论,以点对点阻抗模型(NIF)为基础,利用网络分析仪测量了三相设备在外部端子不同的连接方式下的端口阻抗,根据测量的端口阻抗参数与NIF模型中虚拟阻抗的关系得到三相设备的宽频模型(频带范围100 kHz~ 50 MHz).以华北电力大学新能源实验室VSC-HVDC换流系统为实验平台,对换流站内的三相设备变压器、EMI滤波器、换相电抗器进行建模.将建立的模型根据实际系统互相连接,模拟了整个交流系统对高频信号的衰减特性,为换流站的电磁干扰预测和电磁兼容提供可靠依据,并通过实验测量与仿真结果对比证明了本文方法和模型的有效性.

  2. OPF-Based Optimal Location of Two Systems Two Terminal HVDC to Power System Optimal Operation

    Directory of Open Access Journals (Sweden)

    Mehdi Abolfazli

    2013-04-01

    Full Text Available In this paper a suitable mathematical model of the two terminal HVDC system is provided for optimal power flow (OPF and optimal location based on OPF such power injection model. The ability of voltage source converter (VSC-based HVDC to independently control active and reactive power is well represented by the model. The model is used to develop an OPF-based optimal location algorithm of two systems two terminal HVDC to minimize the total fuel cost and active power losses as objective function. The optimization framework is modeled as non-linear programming (NLP and solved by Matlab and GAMS softwares. The proposed algorithm is implemented on the IEEE 14- and 30-bus test systems. The simulation results show ability of two systems two terminal HVDC in improving the power system operation. Furthermore, two systems two terminal HVDC is compared by PST and OUPFC in the power system operation from economical and technical aspects.

  3. Investigation of the behaviour of impact limiting devices of transport casks for radioactive materials in the package approval and risk analysis; Untersuchung des Verhaltens stossdaempfender Bauteile von Transportbehaeltern fuer radioaktive Stoffe in Bauartpruefung und Risikoanalyse

    Energy Technology Data Exchange (ETDEWEB)

    Neumann, Martin

    2009-08-20

    Transport casks for radioactive materials with a Type-B package certificate have to ensure that even under severe accident scenarios the radioactive content remains safely enclosed, in an undercritical arrangement and that ionising radiation is sufficiently shielded. The impact limiter absorbs in an accident scenario the major part of the impact energy and reduces the maximum force applied on the cask body. Therefore the simulation of the behaviour of impact limiting devices of transport casks for nuclear material is of great interest for the design assessment in the package approval as well as for risk analysis in the field of transport of radioactive materials. The behaviour of the impact limiter is influenced by a number of parameters like impact limiter construction, material properties and loading conditions. Uncertainties exist for the application of simplified numerical tools for calculations of impact limiting devices. Uncertainities exist when applying simplified numerical tools. A model describing the compression of wood in axial direction of wood under large deformations for simulation with complex numerical procedures like dynamic Finite Element Methods has not been developed yet. Therefore this thesis concentrates on deriving a physical model for the behaviour of wood and analysing the applicability of different modeling techniques. A model describing the compression of wood in axial direction under large deformations was developed on the basis of an analysis of impact limiter of prototypes of casks for radioactive materials after a 9-m-drop-test and impact tests with wooden specimens. The model describes the softening, which wood under large deformation exhibits, as a function of the lateral strain constraint. The larger the lateral strain restriction, the more energy wood can absorb. The energy absorption capacity of impact limiter depends therefore on the ability of the outer steel sheet structure to prevent wood from evading from the main

  4. A novel power control strategy of Modular Multi-level Converter in HVDC-AC hybrid transmission systems for passive networks

    DEFF Research Database (Denmark)

    Hu, Zhenda; Wu, Rui; Yang, Xiaodong;

    2014-01-01

    With the development of High Voltage DC Transmission (HVDC) technology, there will be more and more HVDC-AC hybrid transmission system in the world. A basic challenge in HVDC-AC hybrid transmission systems is to optimize the power sharing between DC and AC lines, which become more severe when...... supplying power for passive networks, as the surplus power can only flow back to power grids through the AC lines. To deal with this issue, it demands not only accurate system capability design but also flexible power control strategy of power converters in VSC-HVDC. This paper proposes a novel power...

  5. Hard- and software of real time simulation tools of Electric Power System for adequate modeling power semiconductors in voltage source convertor based HVDC and FACTS

    Directory of Open Access Journals (Sweden)

    Ufa Ruslan A.

    2014-01-01

    Full Text Available The motivation of the presented research is based on the needs for development of new methods and tools for adequate simulation of Flexible Alternating Current Transmission System (FACTS devices and High Voltage Direct Current Transmission (HVDC system as part of real electric power systems (EPS. For that, a hybrid approach for advanced simulation of the FACTS and HVDC based on Voltage Source is proposed. The presented simulation results of the developed hybrid model of VSC confirm the achievement of the desired properties of the model and the effectiveness of the proposed solutions.

  6. Sensitivity analysis of parameters important to nuclear criticality safety of Castor X/28F spent nuclear fuel cask

    Energy Technology Data Exchange (ETDEWEB)

    Leotlela, Mosebetsi J. [Witwatersrand Univ., Johannesburg (South Africa). School of Physics; Koeberg Operating Unit, Johannesburg (South Africa). Regulations and Licensing; Malgas, Isaac [Koeberg Nuclear Power Station, Duinefontein (South Africa). Nuclear Engineering Analysis; Taviv, Eugene [ASARA consultants (PTY) LTD, Johannesburg (South Africa)

    2015-11-15

    In nuclear criticality safety analysis it is essential to ascertain how various components of the nuclear system will perform under certain conditions they may be subjected to, particularly if the components of the system are likely to be affected by environmental factors such as temperature, radiation or material composition. It is therefore prudent that a sensitivity analysis is performed to determine and quantify the response of the output to variation in any of the input parameters. In a fissile system, the output parameter of importance is the k{sub eff}. Therefore, in attempting to prevent reactivity-induced accidents, it is important for the criticality safety analyst to have a quantified degree of response for the neutron multiplication factor to perturbation in a given input parameter. This article will present the results of the perturbation of the parameters that are important to nuclear criticality safety analysis and their respective correlation equations for deriving the sensitivity coefficients.

  7. Simulative Study into the Development of a Hybrid HVDC System Through a Comparative Research with HVAC: a Futuristic Approach

    Directory of Open Access Journals (Sweden)

    R. S. Narayan

    2017-06-01

    Full Text Available High Voltage Direct Current Transmission (HVDC is considered a better solution for bulk long distance transmissions. The increased use of HVDC is a result of its advantages over the HVAC systems and especially of its fault stability nature. A better solution is proposed by using a Voltage Source Controlled–HVDC as one of the infeed for the Multi-Infeed HVDC (MIDC or MI-HVDC systems. The main advantage with the VSC converter is its flexible power control which enhances the stability of the MIDC systems. In this paper, the behavior of an HVDC system is compared with that of an HVAC during faults. A Hybrid HVDC system that includes a LCC as a rectifier unit and a VSC converter as the inverter is being proposed. It is considered suitable for MIDC systems and particularly for supplying a weak AC system. The performance of the system during steady state and transient conditions for all the proposed topologies including HVDC, HVAC and Hybrid HVDC are studied in MATLAB/SIMULINK. All of the proposed control strategies are evaluated via a series of simulation case studies.

  8. Design, Control, and Modeling of a New Voltage Source Converter for HVDC System

    Science.gov (United States)

    Mohan, Madhan; Singh, Bhim; Ketan Panigrahi, Bijaya

    2013-05-01

    Abstract: A New Voltage Source Converter (VSC) based on neutral clamped three-level circuit is proposed for High Voltage DC (HVDC) system. The proposed VSC is designed in a multipulse configuration. The converter is operated by Fundamental Frequency Switching (FFS). A new control method is developed for achieving all the necessary control aspects of HVDC system such as independent real and reactive power control, bidirectional real and reactive power control. The basic of the control method is varying the pulse width and by keeping the dc link voltage constant. The steady state and dynamic performances of HVDC system interconnecting two different frequencies network are demonstrated for active and reactive power control. Total number of transformers used in this system are reduced to half in comparison with the two-level VSCs for both active and reactive power control. The performance of the HVDC system is improved in terms of reduced harmonics level even at fundamental frequency switching. The harmonic performance of the designed converter is also studied for different value of the dead angle (β), and the optimized range of the dead angle is achieved for varying reactive power requirement. Simulation results are presented for the designed three level multipulse voltage source converters with the proposed control algorithm.

  9. Perfil físico-químico de aguardente durante envelhecimento em tonéis de carvalho Chemical profile of aguardente - Brazilian sugar cane alcoholic drink - aged in oak casks

    Directory of Open Access Journals (Sweden)

    Mariana Branco de Miranda

    2008-12-01

    Full Text Available Avaliou-se por um período de 390 dias o perfil da composição química da aguardente sob envelhecimento em tonéis de carvalho de 20 L. O envelhecimento da aguardente em tonéis de madeira melhora a qualidade sensorial do destilado. As aguardentes envelhecidas foram analisadas aos 0, 76, 147, 228, 314 e 390 dias de armazenamento quanto às concentrações de etanol, acidez volátil, ésteres, aldeídos, furfural, álcoois superiores (n-propílico, isobutílico e isoamílicos, metanol, cobre, extrato seco, taninos e cor. Após os 390 dias de armazenamento, a aguardente apresentou maiores concentrações de acidez volátil, ésteres, aldeídos, furfural, álcoois superiores, congêneres, extrato seco e tanino. Sua coloração tornou-se amarelada. As concentrações de etanol e de metanol não se alteraram, e o teor de cobre apresentou ligeiro declínio. O envelhecimento da aguardente por 390 dias em tonéis de carvalho alterou a sua composição química, porém ela se manteve dentro de todos os padrões de qualidade estabelecidos pela legislação nacional em vigor.The chemical composition of aguardente - Brazilian sugar cane alcoholic drink - under aging during in 20 L oak casks was evaluated for 390 days. Aging sugar cane aguardente in wood casks improves the sensorial quality of the distillate. The concentrations of ethanol, volatile acidity, esters, aldehydes, furfural, higher alcohols (n-propylic, isobutylic and isoamylics, methanol, copper, dry extract, tannins, and color of the aged sugar cane aguardente were analysed at 0, 76, 147, 228, 314, and 390 days of storage. After 390 days of aging the sugar cane aguardente presented higher concentrations of volatile acidity, esters, aldehydes, furfural, higher alcohols, congeners, dry extract, and tannin. Its color became golden. The concentrations of ethanol and methanol did not change and the copper content decreased slightly. The aging of the sugar cane aguardente in oak casks for 390 days

  10. Study of a brazilian cask and its installation for PWR spent nuclear fuel dry storage; Estudo de um casco nacional e sua instalacao para armazenagem seca de combustivel nuclear queimado gerado em reatores PWR

    Energy Technology Data Exchange (ETDEWEB)

    Romanato, Luiz Sergio

    2009-07-01

    Spent nuclear fuel (SNF) is removed from the nuclear reactor after the depletion on efficiency in generating energy. After the withdrawal from the reactor core, the SNF is temporarily stored in pools at the same site of the reactor. At this time, the generated heat and the short and medium lived radioactive elements decay to levels that allow removing SNF from the pool and sending it to temporary dry storage. In that phase, the fuel needs to be safely and efficiently stored, and then, it can be retrieved in a future, or can be disposed as radioactive waste. The amount of spent fuel increases annually and, in the next years, will still increase more, because of the construction of new nuclear plants. Today, the number of new facilities back up to levels of the 1970's, since it is greater than the amount of decommissioning in old installations. As no final decision on the back-end of the nuclear fuel cycle is foreseen in the near future in Brazil, either to recover the SNF or to consider it as radioactive waste, this material has to be isolated in some type of storage model existing around the world. In the present study it is shown that dry SNF storage is the best option. A national cask model for SNF as well these casks storage installation are proposed. It is a multidisciplinary study in which the engineering conceptual task was developed and may be applied to national SNF removed from the Brazilian power reactors, to be safely stored for a long time until the Brazilian authorities will decide about the site for final disposal. (author)

  11. Develop an piezoelectric sensing based on SHM system for nuclear dry storage system

    Science.gov (United States)

    Ma, Linlin; Lin, Bin; Sun, Xiaoyi; Howden, Stephen; Yu, Lingyu

    2016-04-01

    In US, there are over 1482 dry cask storage system (DCSS) in use storing 57,807 fuel assemblies. Monitoring is necessary to determine and predict the degradation state of the systems and structures. Therefore, nondestructive monitoring is in urgent need and must be integrated into the fuel cycle to quantify the "state of health" for the safe operation of nuclear power plants (NPP) and radioactive waste storage systems (RWSS). Innovative approaches are desired to evaluate the degradation and damage of used fuel containers under extended storage. Structural health monitoring (SHM) is an emerging technology that uses in-situ sensory system to perform rapid nondestructive detection of structural damage as well as long-term integrity monitoring. It has been extensively studied in aerospace engineering over the past two decades. This paper presents the development of a SHM and damage detection methodology based on piezoelectric sensors technologies for steel canisters in nuclear dry cask storage system. Durability and survivability of piezoelectric sensors under temperature influence are first investigated in this work by evaluating sensor capacitance and electromechanical admittance. Toward damage detection, the PES are configured in pitch catch setup to transmit and receive guided waves in plate-like structures. When the inspected structure has damage such as a surface defect, the incident guided waves will be reflected or scattered resulting in changes in the wave measurements. Sparse array algorithm is developed and implemented using multiple sensors to image the structure. The sparse array algorithm is also evaluated at elevated temperature.

  12. SNF AGING SYSTEM DESCRIPTION DOCUMENT

    Energy Technology Data Exchange (ETDEWEB)

    L.L. Swanson

    2005-04-06

    The purpose of this system description document (SDD) is to establish requirements that drive the design of the spent nuclear fuel (SNF) aging system and associated bases, which will allow the design effort to proceed. This SDD will be revised at strategic points as the design matures. This SDD identifies the requirements and describes the system design, as it currently exists, with emphasis on attributes of the design provided to meet the requirements. This SDD is an engineering tool for design control; accordingly, the primary audience and users are design engineers. This SDD is part of an iterative design process. It leads the design process with regard to the flow down of upper tier requirements onto the system. Knowledge of these requirements is essential in performing the design process. The SDD follows the design with regard to the description of the system. The description provided in the SDD reflects the current results of the design process. Throughout this SDD, the term aging cask applies to vertical site-specific casks and to horizontal aging modules. The term overpack is a vertical site-specific cask that contains a dual-purpose canister (DPC) or a disposable canister. Functional and operational requirements applicable to this system were obtained from ''Project Functional and Operational Requirements'' (F&OR) (Curry 2004 [DIRS 170557]). Other requirements that support the design process were taken from documents such as ''Project Design Criteria Document'' (PDC) (BSC 2004 [DES 171599]), ''Site Fire Hazards Analyses'' (BSC 2005 [DIRS 172174]), and ''Nuclear Safety Design Bases for License Application'' (BSC 2005 [DIRS 171512]). The documents address requirements in the ''Project Requirements Document'' (PRD) (Canori and Leitner 2003 [DIRS 166275]). This SDD includes several appendices. Appendix A is a Glossary; Appendix B is a list of key system charts

  13. Conception of transport cask with advanced safety, aimed at transportation and storage of spent nuclear fuel of power reactors, which meets the requirements of IAEA in terms of safety and increased stability during beyond-design-basis accidents and acts of terrorism

    Energy Technology Data Exchange (ETDEWEB)

    Il' kaev, R.I.; Matveev, V.Z.; Morenko, A.I.; Shapovalov, V.I. [Russian Federal Nuclear Center - All-Russian Research Inst. of Experimental Physics, Sarov (Russian Federation); Semenov, A.G.; Sergeyev, V.M.; Orlov, V.K. [All-Russian Research Inst. of Inorganic Materials, Moscow (Russian Federation); Shatalov, V.V.; Gotovchikov, V.T.; Seredenko, V.A. [All-Russian Research Inst. of Applied Chemistry, Moscow (Russian Federation); Haire, Jonathan M.; Forsberg, C.W. [Oak Ridge National Lab., Oak Ridge (United States)

    2004-07-01

    The report is devoted to the problem of creation of a new generation of multi-purpose universal transport cask with advanced safety, aimed at transportation and storage of spent nuclear fuel (SNF) of power reactors, which meets all requirements of IAEA in terms of safety and increased stability during beyond-design-basis accidents and acts of terrorism. Meeting all IAEA requirements in terms of safety both in normal operation conditions and accidents, as well as increased stability of transport cask (TC) with SNF under the conditions of beyond-design-basis accidents and acts of terrorism has been achieved in the design of multi-purpose universal TC due to the use of DU (depleted uranium) in it. At that, it is suggested to use DU in TC, which acts as effective gamma shield and constructional material in the form of both metallic depleted uranium and metal-ceramic mixture (cermet), based on stainless or carbon steel and DU dioxide. The metal in the cermet is chosen to optimize cask performance. The use of DU in the design of multi-purpose universal TC enables getting maximum load of the container for spent nuclear fuel when meeting IAEA requirements in terms of safety and providing increased stability of the container with SNF under conditions of beyond-design-basis accident and acts of terrorism.

  14. Investigation of novel spent fuel verification system for safeguard application

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Haneol; Yim, Man-Sung [KAIST, Daejeon (Korea, Republic of)

    2016-10-15

    Radioactive waste, especially spent fuel, is generated from the operation of nuclear power plants. The final stage of radioactive waste management is disposal which isolates radioactive waste from the accessible environment and allows it to decay. The safety, security, and safeguard of a spent fuel repository have to be evaluated before its operation. Many researchers have evaluated the safety of a repository. These researchers calculated dose to public after the repository is closed depending on their scenario. Because most spent fuel repositories are non-retrievable, research on security or safeguards of spent fuel repositories have to be performed. Design based security or safeguard have to be developed for future repository designs. This study summarizes the requirements of future spent fuel repositories especially safeguards, and suggests a novel system which meets the safeguard requirements. Applying safeguards to a spent fuel repository is becoming increasingly important. The future requirements for a spent fuel repository are suggested by several expert groups, such as ASTOR in IAEA. The requirements emphasizes surveillance and verification. The surveillance and verification of spent fuel is currently accomplished by using the Cerenkov radiation detector while spent fuel is being stored in a fuel pool. This research investigated an advanced spent fuel verification system using a system which converts spent fuel radiation into electricity. The system generates electricity while it is conveyed from a transportation cask to a disposal cask. The electricity conversion system was verified in a lab scale experiment using an 8.51GBq Cs-137 gamma source.

  15. The Knee Clinical Assessment Study – CAS(K. A prospective study of knee pain and knee osteoarthritis in the general population: baseline recruitment and retention at 18 months

    Directory of Open Access Journals (Sweden)

    Duncan Rachel

    2006-03-01

    Full Text Available Abstract Background Selective non-participation at baseline (due to non-response and non-consent and loss to follow-up are important concerns for longitudinal observational research. We investigated these matters in the context of baseline recruitment and retention at 18 months of participants for a prospective observational cohort study of knee pain and knee osteoarthritis in the general population. Methods Participants were recruited to the Knee Clinical Assessment Study – CAS(K – by a multi-stage process involving response to two postal questionnaires, consent to further contact and medical record review (optional, and attendance at a research clinic. Follow-up at 18-months was by postal questionnaire. The characteristics of responders/consenters were described for each stage in the recruitment process to identify patterns of selective non-participation and loss to follow-up. The external validity of findings from the clinic attenders was tested by comparing the distribution of WOMAC scores and the association between physical function and obesity with the same parameters measured directly in the target population as whole. Results 3106 adults aged 50 years and over reporting knee pain in the previous 12 months were identified from the first baseline questionnaire. Of these, 819 consented to further contact, responded to the second questionnaire, and attended the research clinics. 776 were successfully followed up at 18 months. There was evidence of selective non-participation during recruitment (aged 80 years and over, lower socioeconomic group, currently in employment, experiencing anxiety or depression, brief episode of knee pain within the previous year. This did not cause significant bias in either the distribution of WOMAC scores or the association between physical function and obesity. Conclusion Despite recruiting a minority of the target population to the research clinics and some evidence of selective non-participation, this

  16. Study on the Control Strategy of the Offshore Wind Energy Flexible Direct Current Transmission Using VSC-HVDC%采用VSC-HVDC的海上风电场柔性直流输电系统控制策略研究

    Institute of Scientific and Technical Information of China (English)

    蒋辰晖; 王志新; 吴定国

    2012-01-01

    Taking the three phase two-level voltage source current converter widely used in the actual offshore wind power transmission project as the research objective, this paper establishes a two—phase rotating dq system mathematical model in the two-phase rotating dq system by the coordinate transformation of the main converter circuit topology; and for the control system, uses the PI control method with a dual closed loop, and uses the current decoupling control to achieve the constant active/reactive power control which improves the system's dynamic performance and anti-jamming capability; and uses the space vector PWM modulation (which reduces the switching loss and harmonic content) for converting the current. The final matlab/Simulink simulation results and the 3.5 kW test show that the program has good control effects with voltage and current waveform stable, harmonic content low and response speedy. It is suitable for the offshore wind farm with the HVDC-Flexible system.%以实际应用于海上风电输电工程中的三相两电平电压源换流器为研究对象,通过对换流器主电路拓扑结构进行坐标变换,建立了便于解析的两相旋转dq坐标系下的数学模型;换流器控制系统采用了双闭环PI控制方法,并引入电流解耦控制,实现了一侧定有功、一侧定直流电压控制,提高了系统的动态性能和抗干扰能力;采用了SVPWM调制方式进行调制,有效地降低了谐波含量和开关损耗;采用Matlab/Simulink仿真,并搭建了3.5 kW试验验证平台.结果表明该方案控制效果良好,电压、电流波形稳定、谐波含量少且响应速度较快.因此,适用于海上风电场柔性直流输电系统.

  17. Generic inertia emulation controller for multi-terminal voltage-source-converter high voltage direct current systems

    DEFF Research Database (Denmark)

    Zhu, Jiebei; Guerrero, Josep M.; Hung, William;

    2014-01-01

    within a safe and pre-defined range. A theoretical treatment of the INEC algorithm and its implementation and integration within a conventional VSC control system are presented, and the impact on the total DC capacitance required within the MTDC network to ensure that DC voltages vary within...... an acceptable range are discussed. The proposed INEC scheme is validated using a Matlab/Simulink model under various changes in demand and in response to AC network faults. The model incorporates a multi-machine AC power system connected to a MTDC transmission system with multiple converter-interfaced nodes....... The effectiveness of the INEC in damping post-fault oscillations and in enhancing AC system frequency stability is also investigated. The system is shown to perform well and is attractive for providing a stable MTDC system that is capable of providing valuable support to the connected AC systems....

  18. Baseline Design Compliance Matrix for the Rotary Mode Core Sampling System

    Energy Technology Data Exchange (ETDEWEB)

    LECHELT, J.A.

    2000-10-17

    The purpose of the design compliance matrix (DCM) is to provide a single-source document of all design requirements associated with the fifteen subsystems that make up the rotary mode core sampling (RMCS) system. It is intended to be the baseline requirement document for the RMCS system and to be used in governing all future design and design verification activities associated with it. This document is the DCM for the RMCS system used on Hanford single-shell radioactive waste storage tanks. This includes the Exhauster System, Rotary Mode Core Sample Trucks, Universal Sampling System, Diesel Generator System, Distribution Trailer, X-Ray Cart System, Breathing Air Compressor, Nitrogen Supply Trailer, Casks and Cask Truck, Service Trailer, Core Sampling Riser Equipment, Core Sampling Support Trucks, Foot Clamp, Ramps and Platforms and Purged Camera System. Excluded items are tools such as light plants and light stands. Other items such as the breather inlet filter are covered by a different design baseline. In this case, the inlet breather filter is covered by the Tank Farms Design Compliance Matrix.

  19. Matlab Based Human & Hardware-in-Loop Simulation for the Study on Vehicle Stability Control

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This paper described an effective method to implement human & hardware in the loop simulation (HHILS), which is based on MATLAB system and can be used to study human driving actions in the abrupt situation and vehicle stability control(VSC). A hybrid control algorithm, which makes full use of the advantages of robust control and fuzzy logic, was adopted in VSC system. The results of HHILS show that HHILS' application on the vehicle handling and VSC resarch is feasible. These results also confirm that the handling performance of the vehicle with VSC is improved obviously compared to the vehicle without VSC.

  20. A study on the control of a hybrid MTDC system supplying a passive network

    DEFF Research Database (Denmark)

    Kotb, Omar; Ghandhari, Mehrdad; Eriksson, Robert

    2014-01-01

    A hybrid Multi-Terminal DC (MTDC) system can combine the benefits of both Line Commutated Converter (LCC) and Voltage Source Converter (VSC) technologies in the form of reduced losses and flexibility to connect to weak and passive grids. In this paper, an analysis of control strategies used...... in a hybrid MTDC system is presented. A case study of a four terminal hybrid MTDC system supplying a passive AC network was considered for simulation study. A control scheme based on voltage margin was developed to cope with the condition of main DC voltage controlling station tripping. Two various control...... scenarios for controlling the VSCs connected to the passive network were presented and compared. The system performance was studied through EMTP-RV simulations under different disturbances. The results show the ability of selected converter control modes and proposed control schemes to operate the hybrid...

  1. Retrievable surface storage facility conceptual system design description

    Energy Technology Data Exchange (ETDEWEB)

    1977-03-01

    The studies evaluated several potentially attractive methods for processing and retrievably storing high-level radioactive waste after delivery to the Federal repository. These studies indicated that several systems could be engineered to safely store the waste, but that the simplest and most attractive concept from a technical standpoint would be to store the waste in a sealed stainless steel canister enclosed in a 2 in. thick carbon steel cask which in turn would be inserted into a reinforced concrete gamma-neutron shield, which would also provide the necessary air-cooling through an air annulus between the cask and the shield. This concept best satisfies the requirements for safety, long-term exposure to natural phenomena, low capital and operating costs, retrievability, amenability to incremental development, and acceptably small environmental impact. This document assumes that the reference site would be on ERDA's Hanford reservation. This document is a Conceptual System Design Description of the facilities which could satisfy all of the functional requirements within the established basic design criteria. The Retrievable Surface Storage Facility (RSSF) is planned with the capacity to process and store the waste received in either a calcine or glass/ceramic form. The RSSF planning is based on a modular development program in which the modular increments are constructed at rates matching projected waste receipts.

  2. The Application of Auto-Disturbance Rejection Control Optimized by Least Squares Support Vector Machines Method and Time-Frequency Representation in Voltage Source Converter-High Voltage Direct Current System.

    Directory of Open Access Journals (Sweden)

    Ying-Pei Liu

    Full Text Available In order to improve the performance of voltage source converter-high voltage direct current (VSC-HVDC system, we propose an improved auto-disturbance rejection control (ADRC method based on least squares support vector machines (LSSVM in the rectifier side. Firstly, we deduce the high frequency transient mathematical model of VSC-HVDC system. Then we investigate the ADRC and LSSVM principles. We ignore the tracking differentiator in the ADRC controller aiming to improve the system dynamic response speed. On this basis, we derive the mathematical model of ADRC controller optimized by LSSVM for direct current voltage loop. Finally we carry out simulations to verify the feasibility and effectiveness of our proposed control method. In addition, we employ the time-frequency representation methods, i.e., Wigner-Ville distribution (WVD and adaptive optimal kernel (AOK time-frequency representation, to demonstrate our proposed method performs better than the traditional method from the perspective of energy distribution in time and frequency plane.

  3. The Application of Auto-Disturbance Rejection Control Optimized by Least Squares Support Vector Machines Method and Time-Frequency Representation in Voltage Source Converter-High Voltage Direct Current System.

    Science.gov (United States)

    Liu, Ying-Pei; Liang, Hai-Ping; Gao, Zhong-Ke

    2015-01-01

    In order to improve the performance of voltage source converter-high voltage direct current (VSC-HVDC) system, we propose an improved auto-disturbance rejection control (ADRC) method based on least squares support vector machines (LSSVM) in the rectifier side. Firstly, we deduce the high frequency transient mathematical model of VSC-HVDC system. Then we investigate the ADRC and LSSVM principles. We ignore the tracking differentiator in the ADRC controller aiming to improve the system dynamic response speed. On this basis, we derive the mathematical model of ADRC controller optimized by LSSVM for direct current voltage loop. Finally we carry out simulations to verify the feasibility and effectiveness of our proposed control method. In addition, we employ the time-frequency representation methods, i.e., Wigner-Ville distribution (WVD) and adaptive optimal kernel (AOK) time-frequency representation, to demonstrate our proposed method performs better than the traditional method from the perspective of energy distribution in time and frequency plane.

  4. Super-capacitor based energy storage system for improved load frequency control

    Energy Technology Data Exchange (ETDEWEB)

    Mufti, Mairaj ud din; Lone, Shameem Ahmad; Iqbal, Shiekh Javed; Ahmad, Muzzafar; Ismail, Mudasir [Electrical Engineering Department, National Institute of Technology, Hazratbal, Srinagar 190006, Jammu and Kashmir (India)

    2009-01-15

    A fuzzy-logic controlled super-capacitor bank (SCB) for improved load frequency control (LFC) of an interconnected power system is proposed, in this paper. The super-capacitor bank in each control area is interfaced with the area control bus through a power conversion system (PCS) comprising of a voltage source converter (VSC) and a buck-boost chopper. The fuzzy controller for SCB is designed in such a way that the effects of load disturbances are rejected on a continuous basis. Necessary models are developed and control and implementation aspects are presented in a detailed manner. Time domain simulations are carried out to demonstrate the effectiveness of the proposed scheme. The performance of the resulting power system under realistic situation is investigated by including the effects of generation rate constraint (GRC) and governor dead band (DB) in the simulation studies. (author)

  5. A Categorization of Converter Station Controllers Within Multi-terminal DC Transmission Systems

    DEFF Research Database (Denmark)

    Irnawan, Roni; Silva, Filipe Miguel Faria da; Bak, Claus Leth;

    2016-01-01

    As more and more VSC-HVDC links are planned and commissioned, interconnection of neighboring links or connection to an existing link becomes a feasible step towards secure and reliable multi-terminal DC (MTDC) transmission systems. Multi-vendor MTDC (MV-MTDC) operation is anticipated as an impact...... of this gradual DC grids development. In order to achieve certain operation conditions, DC grid controller needs to send specific control settings to individual converter station controls. One of the challenges in MV-MTDC transmission systems occurs in coordination of converters since different types...... of controller might exist in the same system. It is therefore important to identify the parameters required by the converter station controllers to ensure a smooth coordination. In this paper, different converter station controllers available in the literatures are categorized. Challenges of converter station...

  6. Power Quality Improvement Using Hybrid Power Flow Controller in Power System

    Directory of Open Access Journals (Sweden)

    Manidhar Thula ,

    2014-01-01

    Full Text Available This paper discusses the applicability of Hybrid Power Flow Controller (HPFC as an alternative to Unified Power Flow Controller (UPFC for improvement of power system performance. UPFC is a flexible AC transmission system (FACTS device containing two switching converters, one in series and one in shunt. To configure the HPFC, one of the switching converters of the UPFC is replaced by thyristor controlled variable impedances, thus reducing the cost. In this paper, the HPFC has been configured by multilevel Voltage Source Converter (VSC used for the shunt compensation branches and a thyristor controlled variable impedance used for series compensation. It is shown that with suitable control the HPFC can inject a voltage of required magnitude in series with the line at any desired angle, just like UPFC. This helps in providing compensation equivalent to UPFC and improving the steady state stability limits of the power system.

  7. Real time implementation and control validation of the wind energy conversion system

    Science.gov (United States)

    Sattar, Adnan

    The purpose of the thesis is to analyze dynamic and transient characteristics of wind energy conversion systems including the stability issues in real time environment using the Real Time Digital Simulator (RTDS). There are different power system simulation tools available in the market. Real time digital simulator (RTDS) is one of the powerful tools among those. RTDS simulator has a Graphical User Interface called RSCAD which contains detail component model library for both power system and control relevant analysis. The hardware is based upon the digital signal processors mounted in the racks. RTDS simulator has the advantage of interfacing the real world signals from the external devices, hence used to test the protection and control system equipments. Dynamic and transient characteristics of the fixed and variable speed wind turbine generating systems (WTGSs) are analyzed, in this thesis. Static Synchronous Compensator (STATCOM) as a flexible ac transmission system (FACTS) device is used to enhance the fault ride through (FRT) capability of the fixed speed wind farm. Two level voltage source converter based STATCOM is modeled in both VSC small time-step and VSC large time-step of RTDS. The simulation results of the RTDS model system are compared with the off-line EMTP software i.e. PSCAD/EMTDC. A new operational scheme for a MW class grid-connected variable speed wind turbine driven permanent magnet synchronous generator (VSWT-PMSG) is developed. VSWT-PMSG uses fully controlled frequency converters for the grid interfacing and thus have the ability to control the real and reactive powers simultaneously. Frequency converters are modeled in the VSC small time-step of the RTDS and three phase realistic grid is adopted with RSCAD simulation through the use of optical analogue digital converter (OADC) card of the RTDS. Steady state and LVRT characteristics are carried out to validate the proposed operational scheme. Simulation results show good agreement with real

  8. Extended calculations of OECD/NEA phase II-C burnup credit criticality benchmark problem for PWR spent fuel transport cask by using MCNP-4B2 code and JENDL-3.2 library

    Energy Technology Data Exchange (ETDEWEB)

    Kuroishi, Takeshi; Hoang, Anh Tuan; Nomura, Yasushi; Okuno, Hiroshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2003-03-01

    The reactivity effect of the asymmetry of axial burnup profile in burnup credit criticality safety is studied for a realistic PWR spent fuel transport cask proposed in the current OECD/NEA Phase II-C benchmark problem. The axial burnup profiles are simulated in 21 material zones based on in-core flux measurements varying from strong asymmetry to more or less no asymmetry. Criticality calculations in a 3-D model have been performed using the continuous energy Monte Carlo code MCNP-4B2 and the nuclear data library JENDL-3.2. Calculation conditions are determined with consideration of the axial fission source convergence. Calculations are carried out not only for cases proposed in the benchmark but also for additional cases assuming symmetric burnup profile. The actinide-only approach supposed for first domestic introduction of burnup credit into criticality evaluation is also considered in addition to the actinide plus fission product approach adopted in the benchmark. The calculated results show that k{sub eff} and the end effect increase almost linearly with increasing burnup axial offset that is defined as one of typical parameters showing the intensity of axial burnup asymmetry. The end effect is more sensitive to the asymmetry of burnup profile for the higher burnup. For an axially distributed burnup, the axial fission source distribution becomes strongly asymmetric as its peak shifts toward the top end of the fuel's active zone where the local burnup is less than that of the bottom end. The peak of fission source distribution becomes higher with the increase of either the asymmetry of burnup profile or the assembly-averaged burnup. The conservatism of the assumption of uniform axial burnup based on the actinide-only approach is estimated quantitatively in comparison with the k{sub eff} result calculated with experiment-based strongest asymmetric axial burnup profile with the actinide plus fission product approach. (author)

  9. Extended calculations of OECD/NEA phase II-C burnup credit criticality benchmark problem for PWR spent fuel transport cask by using MCNP-4B2 code and JENDL-3.2 library

    Energy Technology Data Exchange (ETDEWEB)

    Kuroishi, Takeshi; Hoang, Anh Tuan; Nomura, Yasushi; Okuno, Hiroshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2003-03-01

    The reactivity effect of the asymmetry of axial burnup profile in burnup credit criticality safety is studied for a realistic PWR spent fuel transport cask proposed in the current OECD/NEA Phase II-C benchmark problem. The axial burnup profiles are simulated in 21 material zones based on in-core flux measurements varying from strong asymmetry to more or less no asymmetry. Criticality calculations in a 3-D model have been performed using the continuous energy Monte Carlo code MCNP-4B2 and the nuclear data library JENDL-3.2. Calculation conditions are determined with consideration of the axial fission source convergence. Calculations are carried out not only for cases proposed in the benchmark but also for additional cases assuming symmetric burnup profile. The actinide-only approach supposed for first domestic introduction of burnup credit into criticality evaluation is also considered in addition to the actinide plus fission product approach adopted in the benchmark. The calculated results show that k{sub eff} and the end effect increase almost linearly with increasing burnup axial offset that is defined as one of typical parameters showing the intensity of axial burnup asymmetry. The end effect is more sensitive to the asymmetry of burnup profile for the higher burnup. For an axially distributed burnup, the axial fission source distribution becomes strongly asymmetric as its peak shifts toward the top end of the fuel's active zone where the local burnup is less than that of the bottom end. The peak of fission source distribution becomes higher with the increase of either the asymmetry of burnup profile or the assembly-averaged burnup. The conservatism of the assumption of uniform axial burnup based on the actinide-only approach is estimated quantitatively in comparison with the k{sub eff} result calculated with experiment-based strongest asymmetric axial burnup profile with the actinide plus fission product approach. (author)

  10. Coordinated system services from offshore wind power plants connected through HVDC networks

    DEFF Research Database (Denmark)

    Zeni, L.; Glasdam, Jakob Bærholm; Hesselbæk, B.

    2014-01-01

    This paper presents an overview of power system services in networks involving multiple onshore power systems, a voltage sourced converter (VSC) based high voltage direct current (HVDC) offshore network and an offshore wind power plant (OWPP). A comprehensive list of services regarding onshore...... control and communication delays of OWPPs, and their influence on the successful delivery of the targeted services. Furthermore, it is shown that as an HVDC network increases in size from the point-to-point, the handling of onshore short circuits calls for the proper combination of DC chopper(s) and fast...... as well as offshore network operation – both AC and DC – will be discussed from a state of the art perspective. Among them, the most interesting have been selected and will be treated in more detail and the main contribution of this paper will be to shed light on the most relevant aspects related...

  11. Charter for Systems Engineer Working Group

    Science.gov (United States)

    Suffredini, Michael T.; Grissom, Larry

    2015-01-01

    This charter establishes the International Space Station Program (ISSP) Mobile Servicing System (MSS) Systems Engineering Working Group (SEWG). The MSS SEWG is established to provide a mechanism for Systems Engineering for the end-to-end MSS function. The MSS end-to-end function includes the Space Station Remote Manipulator System (SSRMS), the Mobile Remote Servicer (MRS) Base System (MBS), Robotic Work Station (RWS), Special Purpose Dexterous Manipulator (SPDM), Video Signal Converters (VSC), and Operations Control Software (OCS), the Mobile Transporter (MT), and by interfaces between and among these elements, and United States On-Orbit Segment (USOS) distributed systems, and other International Space Station Elements and Payloads, (including the Power Data Grapple Fixtures (PDGFs), MSS Capture Attach System (MCAS) and the Mobile Transporter Capture Latch (MTCL)). This end-to-end function will be supported by the ISS and MSS ground segment facilities. This charter defines the scope and limits of the program authority and document control that is delegated to the SEWG and it also identifies the panel core membership and specific operating policies.

  12. The Fusion of Horror and Aesthetics:Gothic Narration in The Cask of Amontillado%恐怖与美学的融合:《阿芒提拉多酒桶》的哥特式叙事

    Institute of Scientific and Technical Information of China (English)

    孙峰

    2014-01-01

    As an important way of narration, Gothic style is vividly and incisively applied in many of Edgar Allan Poe’s short stories, showing quite a lot of horrible and scary scenes for the readers. While reaching to an extreme, the horror may turn to its opposite side and presents the story with a strange beauty of literature, which is bestowed with unconventional aesthetic characteristics. As one of Edgar Allan Poe’s masterpieces, the short story The Cask of Amontillado deals with the theme of revenge and death. It contains only a few characters and its plot is not too complex. However, the story has a rich atmosphere of horror, which conveys exactly the Gothic style and achieves an unusual artistic effect.%作为一种重要的叙事方式,哥特手法在爱伦·坡的众多短篇小说中得到了淋漓尽致的运用,为读者展现了一幕幕令人惊悚恐惧的场景。这种恐怖达到一个极致,便向它的相反面转化,使作为载体的故事情节呈现了一种异样的文学之美,从而被赋予了反传统的美学艺术特征。短篇小说《阿芒提拉多酒桶》作为爱伦·坡的短篇代表作之一,以复仇和死亡为主题,人物不多,情节也不太复杂,但却有着浓郁的恐怖气氛,恰到好处地传达出这种创作特征,实现了异乎寻常的艺术效果。

  13. Design of a high-level waste repository system for the United States

    Energy Technology Data Exchange (ETDEWEB)

    Baeza, J.L.; Boerigter, S.T.; Broadbent, G.E.; Cabello, E.D.; Duran, V.B.; Hollaway, W.R.; Karlberg, R.P.; Siegel, M.J.; Simonson, S.A.

    1988-05-12

    This report presents a conceptual design for a High Level Waste disposal system for fuel discharged by US commercial power reactors, using the Yucca Mountain repository site recently designated by federal legislation. Principal features of the resulting conceptual design include use of unit trains for periodic removal of old spent fuel from at-reactor storage facilities, buffer storage at the repository site using dual purpose transportation/storage casks, repackaging of the spent fuel from the dual purpose transportation/storage casks directly into special-alloy disposal canisters as intact fuel assemblies, without rod consolidation, emplacement into a repository of modular design, use of excavation techniques that minimize disturbance, both mechanical and chemical, to the geologic environment, a unit rail mounted vehicle for both the transportation and emplacement of the canister from the surface facilities to the underground repository, and a cost-effectiveness computer model of Yucca Mountain and an independent cost evaluation by members of the design team. 31 refs., 58 figs., 15 tabs.

  14. Aspectos da composição química e aceitação sensorial da aguardente de cana-de-açúcar envelhecida em tonéis de diferentes madeiras Aspects of the chemical composition and sensorial acceptance of sugar cane spirit aged in casks of different types of woods

    Directory of Open Access Journals (Sweden)

    André Ricardo Alcarde

    2010-05-01

    sugar cane spirit aged for 3 years in casks of different types of wood (peanut wood, araruva or striped wood, red cabreuva, oak, cherrywood, Brazilian gold wood, purple tabebuia, cariniana legalis, and pear tree. The simple alcoholic distillate which originated the sugar cane spirit was produced at the Distillery of ESALQ/USP. After aging, the sugar cane spirits were analyzed in terms of ethanol concentrations o, volatile acidity, furfural, aldehydes, esters, higher alcohols, methanol, copper, total phenolic compounds, color, and sensorial acceptance. Regardless the type of wood the casks were made of, the aged sugar cane spirits became darker and presented higher concentrations of volatile acidity, furfural, esters, higher alcohols, congeners, and total phenolic compounds than the simple alcoholic distillate. On the other hand, the aged sugar cane spirits presented lower concentrations of aldehydes, methanol, and copper than the simple alcoholic distillate. The statistical analysis, considering the global physicochemical composition of the sugar cane spirits aged in the casks made of different types of wood, showed similarities among the sugar cane spirits aged in the casks of peanut wood, araruva or striped wood, and cariniana legalis. It also indicates similarities among the sugar cane spirits aged in the casks of red cabreuva and pear tree and among the sugar cane spirits aged in the casks of oak, cherrywood, Brazilian gold wood, and purple tabebuia. The sugar cane spirits aged in the casks of the different types of wood were in accordance with the composition and quality standards established by the Brazilian laws. The sugar cane spirit aged in oak presented the best sensorial acceptance. Among the Brazilian woods, purple tabebuia, peanut wood, red cabreuva, cherrywood and pear tree were those that produced sugar cane spirits with better sensorial qualities.

  15. Heat Removal Performance in accordance with the Location of the Half-blockage of the Inlet Openings of Concrete Storage Cask

    Energy Technology Data Exchange (ETDEWEB)

    Bang, K. S.; Yu, S. H.; Lee, J. C.; Lee, S. H. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    The heat transfer rate to the ambient atmosphere by convective air through a passive heat removal system under off-normal conditions reached 87.4 %. Therefore, the half-blockage of the inlet openings has a relatively small effect on the maximum temperature and temperature distributions. A temperature difference in accordance with the location of the half-blockage of the inlet openings was not found. Therefore, the influence of the direction of the half-blockage of the inlet openings reaching the heat removal performance was estimated to be minimal.

  16. Finite-element-method-based assessment on the dropping accident of an high temperature gas cooled reactor fuel cask%基于有限元方法的高温气冷堆燃料贮存罐跌落事故评价

    Institute of Scientific and Technical Information of China (English)

    聂君锋; 张海泉; 李红克; 王鑫; 张征明

    2013-01-01

    通过将燃料元件等效为流体,本文采用耦合Eulerian-Lagrangian(CEL)方法研究了高温气冷堆燃料元件贮存罐的跌落事故.该方法能够描述燃料元件在跌落过程中的流动性和惯性效应,以及燃料元件对贮存罐所产生的侧向液动压力.与等效质量法进行了对比,结果表明:在跌落冲击过程中,等效质量法计算得到的冲击力更大、跌落接触时间更短,而CEL方法则能体现罐体的径向膨胀.因此,CEL方法能够模拟燃料元件的惯性效应以及流动效应,而等效质量法则能充分考虑冲击力的作用,结构设计中可以结合2种方法的计算结果,给出更为合理的设计方案.%Accidental dropping of an HTGR (high temperature gas cooled reactor) fuel cask was analyzed using the Euler-Lagrange (CEL) method with the fuel element modeled as the fluid.The method can describe the flow and inertial effects of the fuel elements during the fall and the lateral fluid dynamic pressure generated by the fuel element on the fuel cask.The results give a larger impact force than the equivalent mass method with a shorter drop time.The CEL method can also predict the radial expansion of the cask.Therefore,the CEL method is able to simulate the inertial effects and the liquidity effects of the fuel element,while the equivalent mass method analyzes only the impact.The results of the two methods can be combined in the structural design to give a more reasonable design.

  17. Evolution of the MACSTOR{trademark} dry spent fuel storage system

    Energy Technology Data Exchange (ETDEWEB)

    Pare, F.E.; Joubert, W.M. [Atomic Energy of Canada Ltd., Montreal, Quebec (Canada)

    1995-12-31

    The MACSTOR{trademark} (Modular Air-Cooled Canister Storage) system was developed by Atomic Energy of Canada Limited (AECL) for the interim storage of spent fuel discharged by light water reactors. It is a hybrid system which combines the operational economies of metal cask technology with the capital economies of concrete technology. The system includes all the necessary equipment to transfer spent fuel from a storage pool to an independent interim dry spent fuel storage site. After presenting a description of the system and a brief history of its development, the paper addresses its thermal performance and modeling for various design configurations. Finally, a brief summary of the experience being gained during the implementation of a MACSTOR{trademark} system modified for CANDU spent fuel at the Gentilly-2 NPP in Quebec is presented. It includes progress made in licensing activities and in public hearings pertinent to the initiation of the project.

  18. Investigation of Hybrid Bipolar HVDC System Performances%混合双极高压直流输电系统的特性研究

    Institute of Scientific and Technical Information of China (English)

    郭春义; 赵成勇; Allan Montanari; Aniruddha M. Gole; 肖湘宁

    2012-01-01

    为了充分发挥电网换相换流器高压直流输电系统 (line commutated converter based high voltage direct current,LCC—HVDC)和电压源换流器高压直流输电系统(voltagesourceconverterbasedHVDC,VSC.HVDC)的优势,针对~种新型的混合双极高压直流输电系统(hybridbipolarbasedhighvoltagedirectcurrent,HB—HVDC)进行了研究,该系统的正极是传统的12脉动LCC.HVDC系统,而负极是VSC—HVDC系统。建立了由LCC正极和VSC负极组成的混合双极高压直流输电系统的模型,推导了其在稳态时的数学模型,并设计了正负极之间的协调控制策略。在PSCAD/EMTDC环境下对HB—HVDC系统的稳态和暂态运行特性进行了研究分析。最后对HB—HVDC系统和闭锁负极VSC—HVDC后LCC—HVDC系统的运行特性进行了对比研究。结果表明:HB-HVDC系统可以更好地调节交流母线电压,减少LCC极换相失败的可能性,并且具有快速的故障恢复能力;同时也证明所设计的协调控制策略可以有效地改善HB—HVDC系统的稳态和动态特性。%A new hybrid bipolar high voltage direct current system (HB-HVDC) was investigated to synthetically utilize the advantages of line commutated converter based HVDC (LCC-HVDC) and voltage source converter based HVDC (VSC-HVDC). The positive pole was a conventional 12-pulse LCC-HVDC system and the negative pole was a VSC-HVDC system. The model of HB-HVDC was developed, and its steady-state mathematical model was deduced. Then the coordinated control strategy between positive pole LCC-HVDC and negative pole VSC-HVDC was designed. The operation performances of HB-HVDC system in steady and transient state were studied. Finally, the performances of the HB-HVDC system were compared with an identical LCC- HVDC with VSC-HVDC blocked. The results show that HB- HVDC system has a better regulation for AC busbar voltage, makes the LCC-HVDC less susceptible to commutation

  19. 系统性红斑狼疮中内皮细胞相关自身抗原的鉴定%Identification of autoantigens associated with systemic lupus erythematosus from endothelial cells

    Institute of Scientific and Technical Information of China (English)

    曹毅; 吴乔; 牟芝蓉

    2012-01-01

    We aimed to identify new potential autoantigens associated with systemic lupus erythematosus (SLE) in human umbilical vein endothelial cells (HUVEC). Serum samples were collected from 27 SLE patients and 24 health donors. And IgG from serum was captured by Protein G Beads. Then the beads were washed and incubated with HUVEC lysate. The proteins which reacted with IgG-Beads were separated by immobilized pH gradient two -dimensional (2 -D) gel electrophoresis, and the unique protein spots in SLE patients group were identified by LC -MS -MS. We identified several proteins including known SLE autoantigen GAPDH, in which calcium/calmodulin-dependent serine protein kinase (CASK) was the first find to be involved in SLE. Furthermore, we also found that CASK antibody expression in SLE was significantly higher than that in health donor. From all the results, we presumed that CASK in HUVEC may be a new potential autoantigen in SLE. Systemic lupus erythematosus; Human umbilical vein endothelial cells; Calcium/calmodulin-%目的 在内皮细胞中筛选与系统性红斑狼疮(systemic lupus erythematosus,SLE)疾病相关的自身抗原.方法 用免疫沉淀法以SLE病人血清中自身抗体捕获人脐带内皮细胞(human umbilical vein endothelial cell,HUVEC)相关抗原,并用双向电泳法分离免疫沉淀产物,然后用LC-MS-MS串联质谱鉴定与SLE病人血清反应的蛋白点.最后用Western blot法验证部分鉴定蛋白.结果 相对于正常人血清对照,SLE病人血清捕获了多个内皮细胞相关蛋白,质谱鉴定结果 显示:通过免疫沉淀与双向电泳结合的方法 成功鉴定了包括GAPDH等已知SLE自身抗原在内的一系列蛋白,其中钙/钙调蛋白依赖性丝氨酸蛋白激酶(calcium/calmodulin-dependent serine protein kinase,CASK)为新发现SLE候选自身抗原.并以重组人CASK蛋白证实SLE病人血清中CASK抗体水平显著高于正常人对照.结论 内皮细胞蛋白CASK可能作为一个新的SLE相关自身抗原.

  20. Report on task assignment No. 3 for the Waste Package Project; Parts A & B, ASME pressure vessel codes review for waste package application; Part C, Library search for reliability/failure rates data on low temperature low pressure piping, containers, and casks with long design lives

    Energy Technology Data Exchange (ETDEWEB)

    Trabia, M.B.; Kiley, M.; Cardle, J.; Joseph, M.

    1991-07-01

    The Waste Package Project Research Team, at UNLV, has four general required tasks. Task one is the management, quality assurance, and overview of the research that is performed under the cooperative agreement. Task two is the structural analysis of spent fuel and high level waste. Task three is an American Society of Mechanical Engineers (ASME) Pressure Vessel Code review for waste package application. Finally, task four is waste package labeling. This report includes preliminary information about task three (ASME Pressure Vessel Code review for Waste package Application). The first objective is to compile a list of the ASME Pressure Vessel Code that can be applied to waste package containers design and manufacturing processes. The second objective is to explore the use of these applicable codes to the preliminary waste package container designs. The final objective is to perform a library search for reliability and/or failure rates data on low pressure, low temperature, containers and casks with long design lives.