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Sample records for auxiliary feedwater system

  1. Auxiliary feedwater system aging study

    International Nuclear Information System (INIS)

    Kueck, J.D.

    1993-07-01

    This report documents the results of a Phase I follow-on study of the Auxiliary Feedwater (AFW) System that has been conducted for the US Regulatory Commission's Nuclear Plant Aging research Program. The Phase I study found a number of significant AFW System functions that are not being adequately tested by conventional test methods and some that are actually being degraded by conventional testing. Thus, it was decided that this follow-on study would focus on these testing omissions nd equipment degradation. The deficiencies in current monitoring and operating practice are categorized and evaluated. Areas of component degradation caused by current practice are discussed. Recommendations are made for improved diagnostic methods and test procedures

  2. System Study: Auxiliary Feedwater 1998–2013

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, John Alton [Idaho National Lab. (INL), Idaho Falls, ID (United States). Risk Assessment and Management Services Dept.

    2014-12-31

    This report presents an unreliability evaluation of the auxiliary feedwater (AFW) system at 69 U.S. commercial nuclear power plants. Demand, run hours, and failure data from fiscal year 1998 through 2013 for selected components were obtained from the Institute of Nuclear Power Operations (INPO) Consolidated Events Database (ICES). The unreliability results are trended for the most recent 10-year period, while yearly estimates for system unreliability are provided for the entire active period. No statistically significant increasing or decreasing trends were identified in the AFW results.

  3. System Study: Auxiliary Feedwater 1998-2014

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, John Alton [Idaho National Lab. (INL), Idaho Falls, ID (United States). Risk Assessment and Management Services Dept.

    2015-12-01

    This report presents an unreliability evaluation of the auxiliary feedwater (AFW) system at 69 U.S. commercial nuclear power plants. Demand, run hours, and failure data from fiscal year 1998 through 2014 for selected components were obtained from the Institute of Nuclear Power Operations (INPO) Consolidated Events Database (ICES). The unreliability results are trended for the most recent 10 year period, while yearly estimates for system unreliability are provided for the entire active period. No statistically significant increasing or decreasing trends were identified in the AFW results.

  4. Operating experiences and degradation detection for auxiliary feedwater systems

    International Nuclear Information System (INIS)

    Casada, D.; Farmer, W.S.

    1992-01-01

    A study of Pressurized Water Reactor Auxiliary Feedwater (AFW) Systems has been conducted by Oak Ridge National Laboratory (ORNL) under the auspices of the Nuclear Regulatory Commission's Nuclear Plant Aging Research Program. The results of the study are documented in NUREG/CR-5404, Vol. 1, Auxiliary Feedwater System Aging Study. The study reviewed historical failure experience and current monitoring practices for the AFW System. This paper provides an overview of the study approach and results

  5. Aging assessment of PWR [Pressurized Water Reactor] Auxiliary Feedwater Systems

    International Nuclear Information System (INIS)

    Casada, D.A.

    1988-01-01

    In support of the Nuclear Regulatory Commission's Nuclear Plant Aging Research (NPAR) Program, Oak Ridge National Laboratory is conducting a review of Pressurized Water Reactor Auxiliary Feedwater Systems. Two of the objectives of the NPAR Program are to identify failure modes and causes and identify methods to detect and track degradation. In Phase I of the Auxiliary Feedwater System study, a detailed review of system design and operating and surveillance practices at a reference plant is being conducted to determine failure modes and to provide an indication of the ability of current monitoring methods to detect system degradation. The extent to which current practices are contributing to aging and service wear related degradation is also being assessed. This paper provides a description of the study approach, examples of results, and some interim observations and conclusions. 1 fig., 1 tab

  6. Simulation of a passive auxiliary feedwater system with TRACE5

    Energy Technology Data Exchange (ETDEWEB)

    Lorduy, María; Gallardo, Sergio; Verdú, Gumersindo, E-mail: maloral@upv.es, E-mail: sergalbe@iqn.upv.es, E-mail: gverdu@iqn.upv.es [Instituto Universitario de Seguridad Industrial, Radiofísica y Medioambiental (ISIRYM), València (Spain)

    2017-07-01

    The study of the nuclear power plant accidents occurred in recent decades, as well as the probabilistic risk assessment carried out for this type of facility, present human error as one of the main contingency factors. For this reason, the design and development of generation III, III+ and IV reactors, which include inherent and passive safety systems, have been promoted. In this work, a TRACE5 model of ATLAS (Advanced Thermal- Hydraulic Test Loop for Accident Simulation) is used to reproduce an accidental scenario consisting in a prolonged Station BlackOut (SBO). In particular, the A1.2 test of the OECD-ATLAS project is analyzed, whose purpose is to study the primary system cooling by means of the water supply to one of the steam generators from a Passive Auxiliary Feedwater System (PAFS). This safety feature prevents the loss of secondary system inventory by means of the steam condensation and its recirculation. Thus, the conservation of a heat sink allows the natural circulation flow rate until restoring stable conditions. For the reproduction of the test, an ATLAS model has been adapted to the experiment conditions, and a PAFS has been incorporated. >From the simulation test results, the main thermal-hydraulic variables (pressure, flow rates, collapsed water level and temperature) are analyzed in the different circuits, contrasting them with experimental data series. As a conclusion, the work shows the TRACE5 code capability to correctly simulate the behavior of a passive feedwater system. (author)

  7. Seismic qualification of PWR plant auxiliary feedwater systems

    International Nuclear Information System (INIS)

    Lu, S.C.; Tsai, N.C.

    1983-08-01

    The NRC Standard Review Plan specifies that the auxiliary feedwater (AFW) system of a pressurized water reactor (PWR) is a safeguard system that functions in the event of a Safe Shutdown Earthquake (SSE) to remove the decay heat via the steam generator. Only recently licensed PWR plants have an AFW system designed to the current Standard Review Plan specifications. The NRC devised the Multiplant Action Plan C-14 in order to make a survey of the seismic capability of the AFW systems of operating PWR plants. The purpose of this survey is to enable the NRC to make decisions regarding the need of requiring the licensees to upgrade the AFW systems to an SSE level of seismic capability. To implement the first phase of the C-14 plan, the NRC issued a Generic Letter (GL) 81-14 to all operating PWR licensees requesting information on the seismic capability of their AFW systems. This report summarizes Lawrence Livermore National Laboratory's efforts to assist the NRC in evaluating the status of seismic qualification of the AFW systems in 40 PWR plants, by reviewing the licensees' responses to GL 81-14

  8. Operation of the main feedwater system turbopump following plant trip with total failure of the auxiliary feedwater system

    International Nuclear Information System (INIS)

    Lucas Alvaro, A.M. de; Rosa Martinez, B. de la; Alcaide, F.; Toledano Camara, C.

    1993-01-01

    The Auxiliary Feedwater System (AF) is a safeguard system which has been designed to supply feedwater to the steam generators, cool the primary system and remove decay heat from the reactor when the main feedwater pumps fail due to loss of power or any other reason. Thus, when plant trip occurs, the AF system pumps start up automatically, allowing removal of decay heat from the reactor. However, even though this system (2 motor-driven pumps and 1 turbopump) is highly reliable, injection of water to the steam generators must be ensured when it fails completely. To do this, if plant trip has not been caused by loss of off site power or failure of the Main Feedwater System (FW) turbopumps, one of these turbopumps can be used to achieve removal of decay heat. Since a large amount of steam is consumed by these turbopumps, an analysis has been performed to determine whether one of these pumps can be used and what actions are necessary to inject water into the steam generators. Results show that, for the case in question, a FW turbopump can be used to remove decay heat from the reactor. (author)

  9. Resolution of concerns in auxiliary feedwater piping

    International Nuclear Information System (INIS)

    Bain, R.A.; Testa, M.F.

    1994-01-01

    Auxiliary feedwater piping systems at pressurized water reactor (PWR) nuclear power plants have experienced unanticipated operating conditions during plant operation. These unanticipated conditions have included plant events involving backleakage through check valves, temperatures in portions of the auxiliary feedwater piping system that exceed design conditions, and the occurrence of unanticipated severe fluid transients. The impact of these events has had an adverse effect at some nuclear stations on plant operation, installed plant components and hardware, and design basis calculations. Beaver Valley Unit 2, a three loop pressurized water reactor nuclear plant, has observed anomalies with the auxiliary feedwater system since the unit went operational in 1987. The consequences of these anomalies and plant events have been addressed and resolved for Beaver Valley Unit 2 by performing engineering and construction activities. These activities included pipe stress, pipe support and pipe rupture analysis, the monitoring of auxiliary feedwater system temperature and pressure, and the modification to plant piping, supports, valves, structures and operating procedures

  10. Common-cause failure analysis of McGuire Unit 2 auxiliary feedwater system

    International Nuclear Information System (INIS)

    Rasmuson, D.M.; Shepherd, J.C.; Fowler, R.D.; Summitt, R.L.; Logan, B.W.

    1982-01-01

    A powerful method for qualitative common cause failure analysis (CCFA) of nuclear power plant systems was developed by EG and G Idaho at the Idaho National Engineering Laboratory. As a cooperative project to demonstrate and evaluate the usefulness of the method, the Duke Power Company agreed to allow a CCFA of the auxiliary feedwater system (AFWS) in their McGuire Nuclear Station Unit 2. The results of the CCFA are the subject of this discussion

  11. A reliability centered maintenance model applied to the auxiliary feedwater system of a nuclear power plant

    International Nuclear Information System (INIS)

    Araujo, Jefferson Borges

    1998-01-01

    The main objective of maintenance in a nuclear power plant is to assure that structures, systems and components will perform their design functions with reliability and availability in order to obtain a safety and economic electric power generation. Reliability Centered Maintenance (RCM) is a method of systematic review to develop or optimize Preventive Maintenance Programs. This study presents the objectives, concepts, organization and methods used in the development of RCM application to nuclear power plants. Some examples of this application are included, considering the Auxiliary Feedwater System of a generic two loops PWR nuclear power plant of Westinghouse design. (author)

  12. Probabilistic analysis of reactor safety - The auxiliary feedwater system of Angra I

    International Nuclear Information System (INIS)

    Oliveira, L.C.R. da L.C. de.

    1981-09-01

    The unavailability of the auxiliary feedwater system (AFWS) of Angra-1, was calculated. The fault tree analysis technique was used, considering two diferent types of contribution to system unavailability: The one due to hard-ware failure and the contribution due to test and maintenance which was separately analysed. The COMBO-and SAMPLE computer codes were used. The results have shown that the AFWS of Angra-1 contains enough redundancy to guarantee a safe operation under the conditions analysed, best values having been obtained for the unavailability of AFWS of Angra 1 with those codes than with the WASH-1400. (E.G.) [pt

  13. Steady state flow evaluations for passive auxiliary feedwater system of APR

    International Nuclear Information System (INIS)

    Park, Jongha; Kim, Jaeyul; Seong, Hoje; Kang, Kyoungho

    2012-01-01

    This paper briefly introduces a methodology to evaluate steady state flow of APR+ Passive Auxiliary Feedwater System (PAFS). The PAFS is being developed as a safety grade passive system to completely replace the existing active Auxiliary Feedwater System (AFWS). Natural circulation cooling can be generally classified into the single-phase, two-phase, and boiling-condensation modes. The PAF is designed to be operated in a boiling-condensation natural circulation mode. The steady-state flow rate should be equal to the steady-state boiling/condensation rate determined by the steady-state energy and momentum balances in the PAFS. The determined steady-state flow rate can be used in the design optimization for the natural circulation loop of the PAFS through the steady-state momentum balance. Since the retarding force, which is to be balanced by the driving force in the natural circulation system design depends on the reliable evaluation of the success of a natural circulation system design depends on the reliable evaluation of the pressure loss coefficients. In PAFS, the core decay heat is released by natural circulation flow between the S G secondary side and the Passive Condensation Heat Exchanger (PCHX) that is immersed in the Passive Condensation Cooling Tank (PCCT). The PCCT is located on the top of Auxiliary building The driving force is determined by the difference between the S/G (heat Source) secondary water level and condensation liquid (heat sink) level. It will overcome retarding force at flowrate in the system, which is determined by vaporization and condensation of the steam which is generated at the S/G by the latent heat in system. In this study, the theoretical method to estimate the steady state flow rate in boiling-condensation natural circulation system is developed and compared with test results

  14. Integral effect test and code analysis on the cooling performance of the PAFS (passive auxiliary feedwater system) during an FLB (feedwater line break) accident

    International Nuclear Information System (INIS)

    Bae, Byoung-Uhn; Kim, Seok; Park, Yu-Sun; Kang, Kyoung-Ho

    2014-01-01

    Highlights: • This study focuses on the experimental validation of the operational performance of the PAFS (passive auxiliary feedwater system). • A transient simulation of the FLB (feedwater line break) in the integral effect test facility, ATLAS-PAFS, was performed to investigate thermal hydraulic behavior during the PAFS actuation. • The test result confirmed that the APR+ has the capability of coping with the FLB scenario by adopting the PAFS and proper set-points for its operation. • The experimental result was utilized to evaluate the prediction capability of a thermal hydraulic system analysis code, MARS-KS. - Abstract: APR+ (Advanced Power Reactor Plus), which is a GEN-III+ nuclear power plant developed in Korea, adopts PAFS (passive auxiliary feedwater system) as an advanced safety feature. The PAFS can completely replace an active auxiliary feedwater system by cooling down the secondary side of steam generators with a natural convection mechanism. This study focuses on experimental and analytical investigation for cooling and operational performance of the PAFS during an FLB (feedwater line break) transient with an integral effect test facility, ATLAS-PAFS. To realistically simulate the FLB accident of the APR+, the three-level scaling methodology was taken into account to design the test facility and determine the test condition. From the test result, the PAFS was actuated to successfully cool down the decay heat of the reactor core by the condensation heat transfer at the PCHX (passive condensation heat exchanger), and thus it could be confirmed that the APR+ has the capability of coping with a FLB scenario by adopting the PAFS and proper set-points for its operation. This integral effect test data were used to evaluate the prediction capability of a thermal hydraulic system analysis code, MARS-KS. The code analysis result proved that it could reasonably predict the FLB transient including the actuation of the PAFS and the natural convection

  15. ASSESSMENT OF CONDENSATION HEAT TRANSFER MODEL TO EVALUATE PERFORMANCE OF THE PASSIVE AUXILIARY FEEDWATER SYSTEM

    Directory of Open Access Journals (Sweden)

    YUN-JE CHO

    2013-11-01

    Full Text Available As passive safety features for nuclear power plants receive increasing attention, various studies have been conducted to develop safety systems for 3rd-generation (GEN-III nuclear power plants that are driven by passive systems. The Passive Auxiliary Feedwater System (PAFS is one of several passive safety systems being designed for the Advanced Power Reactor Plus (APR+, and extensive studies are being conducted to complete its design and to verify its feasibility. Because the PAFS removes decay heat from the reactor core under transient and accident conditions, it is necessary to evaluate the heat removal capability of the PAFS under hypothetical accident conditions. The heat removal capability of the PAFS is strongly dependent on the heat transfer at the condensate tube in Passive Condensation Heat Exchanger (PCHX. To evaluate the model of heat transfer coefficient for condensation, the Multi-dimensional Analysis of Reactor Safety (MARS code is used to simulate the experimental results from PAFS Condensing Heat Removal Assessment Loop (PASCAL. The Shah model, a default model for condensation heat transfer coefficient in the MARS code, under-predicts the experimental data from the PASCAL. To improve the calculation result, The Thome model and the new version of the Shah model are implemented and compared with the experimental data.

  16. Auxiliary feedwater system risk-based inspection guide for the South Texas Project nuclear power plant

    International Nuclear Information System (INIS)

    Bumgardner, J.D.; Nickolaus, J.R.; Moffitt, N.E.; Gore, B.F.; Vo, T.V.

    1993-12-01

    In a study sponsored by the US Nuclear Regulatory Commission (NRC), Pacific Northwest Laboratory has developed and applied a methodology for deriving plant-specific risk-based inspection guidance for the auxiliary feedwater (AFW) system at pressurized water reactors that have not undergone probabilistic risk assessment (PRA). This methodology uses existing PRA results and plant operating experience information. Existing PRA-based inspection guidance information recently developed for the NRC for various plants was used to identify generic component failure modes. This information was then combined with plant-specific and industry-wide component information and failure data to identify failure modes and failure mechanisms for the AFW system at the selected plants. South Texas Project was selected as a plant for study. The product of this effort is a prioritized listing of AFW failures which have occurred at the plant and at other PWRs. This listing is intended for use by the NRC inspectors in preparation of inspection plans addressing AFW risk important components at the South Texas Project plant

  17. Auxiliary feedwater system risk-based inspection guide for the McGuire nuclear power plant

    International Nuclear Information System (INIS)

    Bumgardner, J.D.; Lloyd, R.C.; Moffitt, N.E.; Gore, B.F.; Vo, T.V.

    1994-05-01

    In a study sponsored by the US Nuclear Regulatory Commission (NRC), Pacific Northwest Laboratory has developed and applied a methodology for deriving plant-specific risk-based inspection guidance for the auxiliary feedwater (AFW) system at pressurized water reactors that have not undergone probabilistic risk assessment (PRA). This methodology uses existing PRA results and plant operating experience information. Existing PRA-based inspection guidance information recently developed for the NRC for various plants was used to identify generic component failure modes. This information was then combined with plant-specific and industry-wide component information and failure data to identify failure modes and failure mechanisms for the AFW system at the selected plants. McGuire was selected as one of a series of plants for study. The product of this effort is a prioritized listing of AFW failures which have occurred at the plant and at other PWRs. This listing is intended for use by NRC inspectors in the preparation of inspection plans addressing AFW risk-important components at the McGuire plant

  18. Auxiliary feedwater system risk-based inspection guide for the Point Beach nuclear power plant

    International Nuclear Information System (INIS)

    Lloyd, R.C.; Moffitt, N.E.; Gore, B.F.; Vo, T.V.; Vehec, T.A.

    1993-02-01

    In a study sponsored by the US Nuclear Regulatory Commission (NRC), Pacific Northwest Laboratory has developed and applied a methodology for deriving plant-specific risk-based inspection guidance for the auxiliary feedwater (AFW) system at pressurized water reactors that have not undergone probabilistic risk assessment (PRA). This methodology uses existing PRA results and plant operating experience information. Existing PRA-based inspection guidance information recently developed for the NRC for various plants was used to identify generic component failure modes. This information was then combined with plant-specific and industry-wide component information and failure data to identify failure modes and failure mechanisms for the AFW system at the selected plants. Point Beach was selected as one of a series of plants for study. The product of this effort is a prioritized listing of AFW failures which have occurred at the plant and at other PWRS. This listing is intended for use by NRC inspectors in the preparation of inspection plans addressing AFW risk-important components at the Point Beach plant

  19. Auxiliary feedwater system risk-based inspection guide for the H. B. Robinson nuclear power plant

    International Nuclear Information System (INIS)

    Moffitt, N.E.; Lloyd, R.C.; Gore, B.F.; Vo, T.V.; Garner, L.W.

    1993-08-01

    In a study sponsored by the US Nuclear Regulatory Commission (NRC), Pacific Northwest Laboratory has developed and applied a methodology for deriving plant-specific risk-based inspection guidance for the auxiliary feedwater (AFW) system at pressurized water reactors that have not undergone probabilistic risk assessment (PRA). This methodology uses existing PRA results and plant operating experience information. Existing PRA-based inspection guidance information recently developed for the NRC for various plants was used to identify generic component failure modes. This information was then combined with plant-specific and industry-wide component information and failure data to identify failure modes and failure mechanisms for the AFW system at the selected plants. H. B. Robinson was selected as one of a series of plants for study. The product of this effort is a prioritized listing of AFW failures which have occurred at the plant and at other PWRs. This listing is intended for use by NRC inspectors in the preparation of inspection plans addressing AFW risk-important components at the H. B. Robinson plant

  20. Auxiliary feedwater system risk-based inspection guide for the Byron and Braidwood nuclear power plants

    International Nuclear Information System (INIS)

    Moffitt, N.E.; Gore, B.F.; Vo, T.V.

    1991-07-01

    In a study sponsored by the US Nuclear Regulatory Commission (NRC), Pacific Northwest Laboratory has developed and applied a methodology for deriving plant-specific risk-based inspection guidance for the auxiliary feedwater (AFW) system at pressurized water reactors that have not undergone probabilistic risk assessment (PRA). This methodology uses existing PRA results and plant operating experience information. Existing PRA-based inspection guidance information recently developed for the NRC for various plants was used to identify generic component failure modes. This information was then combined with plant-specific and industry-wide component information and failure data to identify failure modes and failure mechanisms for the AFW system at the selected plants. Byron and Braidwood were selected for the fourth study in this program. The produce of this effort is a prioritized listing of AFW failures which have occurred at the plants and at other PWRs. This listing is intended for use by NRC inspectors in the preparation of inspection plans addressing AFW risk-important components at the Byron/Braidwood plants. 23 refs., 1 fig., 1 tab

  1. Reliability study of the auxiliary feed-water system of a pressurized water reactor by faults tree and Bayesian Network

    Energy Technology Data Exchange (ETDEWEB)

    Lava, Deise Diana; Borges, Diogo da Silva; Guimarães, Antonio Cesar Ferreira; Moreira, Maria de Lourdes, E-mail: deise_dy@hotmail.com, E-mail: diogosb@outlook.com, E-mail: tony@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2017-07-01

    This paper aims to present a study of the reliability of the Auxiliary Feed-water System (AFWS) through the methods of Fault Tree and Bayesian Network. Therefore, the paper consists of a literature review of the history of nuclear energy and the methodologies used. The AFWS is responsible for providing water system to cool the secondary circuit of nuclear reactors of the PWR type when normal feeding water system failure. How this system operates only when the primary system fails, it is expected that the AFWS failure probability is very low. The AFWS failure probability is divided into two cases: the first is the probability of failure in the first eight hours of operation and the second is the probability of failure after eight hours of operation, considering that the system has not failed within the first eight hours. The calculation of the probability of failure of the second case was made through the use of Fault Tree and Bayesian Network, that it was constructed from the Fault Tree. The results of the failure probability obtained were very close, on the order of 10{sup -3}. (author)

  2. The analysis of the functional role of man and machine in the control of a notional auxiliary feedwater system

    International Nuclear Information System (INIS)

    Cacciabue, P.C.; Codazzi, A.; Decortis, F.

    1991-01-01

    We will describe here the simulation of a moderately complex plant, i.e. the Auxiliary Feedwater System (AFWS) of a nuclear power plant, which has been developed for interacting with a cognitive model of operator in a simulation framework of man-machine system studies as well as with an external operator for verifying and validating the hypotheses of the theoretical model by experimental studies. In order to develop such simulation, which must be very flexible for satisfying the needs of interaction with an operator as well as with a cognitive model, a number of special conditions have been respected: the model of functional behaviour of the system has been extended to include the logic of control mechanisms, i.e. components, indicators and actuators; the control tasks for a number of sequences has been developed; the robustness of physical model has been tested in whole possible configuration of the plant; and finally, the interface of the simulation with the model for dynamic failures of components has also been granted. In this paper, these aspects of the deterministic model of the AFWS will be firstly presented in detail. Then, the interface of the plant simulation with an external user or with the cognitive model of the operator will be described focusing on the analysis of the control task. Finally, we will attempt to integrate our approach in an overall framework of taxonomy for studying human actions in complex work context

  3. Auxiliary feedwater system risk-based inspection guide for the Beaver Valley, Units 1 and 2 nuclear power plants

    International Nuclear Information System (INIS)

    Lloyd, R.C.; Vehec, T.A.; Moffitt, N.E.; Gore, B.F.; Vo, T.V.; Rossbach, L.W.; Sena, P.P. III

    1993-02-01

    In a study sponsored by the US Nuclear Regulatory Commission (NRC), Pacific Northwest Laboratory has developed and applied a methodology for deriving plant-specific risk-based inspection guidance for the auxiliary feedwater (AFW) system at pressurized water reactors that have not undergone probabilistic risk assessment (PRA). This methodology uses existing PRA results and plant operating experience information. Existing PRA-based inspection guidance information recently developed for the NRC for various plants was used to identify generic component failure modes. This information was then combined with plant-specific and industry-wide component information and failure data to identify failure modes and failure mechanisms for the AFW system at the selected plants. Beaver Valley Units 1 and 2 were selected as two of a series of plants for study. The product of this effort is a prioritized listing of AFW failures which have occurred at the plant and at other PWRs. This listing is intended for use by NRC inspectors in the preparation of inspection plans addressing AFW risk-important components at Beaver Valley Units 1 and 2

  4. Parallel island genetic algorithm applied to a nuclear power plant auxiliary feedwater system surveillance tests policy optimization

    International Nuclear Information System (INIS)

    Pereira, Claudio M.N.A.; Lapa, Celso M.F.

    2003-01-01

    In this work, we focus the application of an Island Genetic Algorithm (IGA), a coarse-grained parallel genetic algorithm (PGA) model, to a Nuclear Power Plant (NPP) Auxiliary Feedwater System (AFWS) surveillance tests policy optimization. Here, the main objective is to outline, by means of comparisons, the advantages of the IGA over the simple (non-parallel) genetic algorithm (GA), which has been successfully applied in the solution of such kind of problem. The goal of the optimization is to maximize the system's average availability for a given period of time, considering realistic features such as: i) aging effects on standby components during the tests; ii) revealing failures in the tests implies on corrective maintenance, increasing outage times; iii) components have distinct test parameters (outage time, aging factors, etc.) and iv) tests are not necessarily periodic. In our experiments, which were made in a cluster comprised by 8 1-GHz personal computers, we could clearly observe gains not only in the computational time, which reduced linearly with the number of computers, but in the optimization outcome

  5. Aging assessment of auxiliary feedwater pumps

    International Nuclear Information System (INIS)

    Greenstreet, W.L.

    1987-01-01

    ORNL is conducting aging assessments of auxiliary feedwater pumps to provide recommendations for monitoring and assessing the severity of time-dependent degradation as well as to recommend maintenance and replacement practices. Cornerstones of these activities are the identification of failure modes and causes and ranking of causes. Failure modes and causes of interest are those due to aging and service wear. Design details, functional requirements, and operating experience data were used to identify failure modes and causes and to rank the latter. Based on this input, potentially useful inspection, surveillance, and condition monitoring methods that are currently available for use or in the developmental stage were examined and recommendations made. The methods selected are listed and discussed in terms of use and information to be obtained. Relationships between inspection, surveillance, and monitoring and maintenance practices entered prominently into maintenance recommendations. These recommendations, therefore, embrace predictive as well as corrective and preventative maintenance practices. The recommendations are described, inspection details are discussed, and periodic inspection and maintenance interval guidelines are given. Surveillance testing at low-flow conditions is also discussed. It is shown that this type of testing can lead to accelerated aging

  6. Auxiliary feedwater system risk-based inspection guide for the Diablo Canyon Unit 1 Nuclear Power Plant

    International Nuclear Information System (INIS)

    Gore, B.F.; Vo, T.V.; Harrison, D.G.

    1990-08-01

    This document presents a compilation of auxiliary feedwater (AFW) system failure information which has been screened for risk significance in terms of failure frequency and degradation of system performance. It is a risk-prioritized listing of failure events and their causes that are significant enough to warrant consideration in inspection planning at Diablo Canyon. This information is presented to provide inspectors with increased resources for inspection planning at Diablo Canyon. The risk importance of various component failure modes was identified by analysis of the results of probabilistic risk assessments (PRAs) for many pressurized water reactors (PWRs). However, the component failure categories identified in PRAs are rather broad, because the failure data used in the PRAs is an aggregate of many individual failures having a variety of root causes. In order to help inspectors to focus on specific aspects of component operation, maintenance and design which might cause these failures, an extensive review of component failure information was performed to identify and rank the root causes of these component failures. Both Diablo Canyon and industry-wide failure information was analyzed. Failure causes were sorted on the basis of frequency of occurrence and seriousness of consequence, and categorized as common cause failures, human errors, design problems, or component failures. This information permits an inspector to concentrate on components important to the prevention of core damage. Other components which perform essential functions, but which are not included because of high reliability or redundancy, must also be addressed to ensure that degradation does not increase their failure probabilities, and hence their risk importances. 23 refs., 1 fig., 1 tab

  7. Aging and low-flow degradation of auxiliary feedwater pumps

    International Nuclear Information System (INIS)

    Adams, M.L.

    1991-01-01

    This paper documents the results of research done under the auspices of the Nuclear Regulatory Commission Nuclear Plant Aging Research Program. It examines the degradation imparted to safety Auxiliary Feedwater System pumps at nuclear plants due to the low flow operation. The Auxiliary Feedwater (AFW) System is normally a stand-by system. As such it is operated most often in the test mode. Since few plants are equipped with full flow test loops, most testing is accomplished at minimum flow conditions in pump by-pass lines. It is the vibration and hydraulic forces generated at low flow conditions that have been shown to be the major causes of AFW pump aging and degradation. The wear can be manifested in a number of ways, such as impeller or diffuser breakage, thrust bearing and/or balance device failure due to excessive loading, cavitation damage on such stage impellers, increase seal leakage or failure, sear injection piping failure, shaft or coupling breakage, and rotating element seizure

  8. Feedwater control system

    International Nuclear Information System (INIS)

    Cook, B.M.

    1982-01-01

    Excessive swing of the feedwater in nuclear reactor power supply apparatus on the occurrence of a transient is suppressed by injecting an anticipatory compensating signal (δWsub(fw)) into the control for the feedwater. Typical overshoot occurs on removal of a large part of the load, the steam flow is reduced so that the conventional control system reduces the flow of feedwater. At the same time there is a reduction of feedwater level in the steam generator because of the collapse of the bubbles under increased steam pressure. By the time the control responds to the drop in level, the apparatus has begun to stabilize so that there is overshoot. The anticipatory signal is derived from the boiling power (BP) which is a function of the nuclear power (Qsub(N)) developed, the enthalpy of saturated water (hsub(s)) and the enthalpy of the feedwater injected into the steam generator (hsub(fw)). From the boiling power (BP) and the increment in steam pressure resulting from the transient an anticipatory increment of feedwater flow is derived. This increment is added to the other parameters controlling the feedwater. (author)

  9. Study of the reliability of the Auxiliary Feedwater System of a LWR nuclear power plant through the Fault Tree and Bayesian Network

    International Nuclear Information System (INIS)

    Lava, Deise Diana

    2016-01-01

    This paper aims to present a study of the reliability of the Auxiliary Feedwater System (AFWS) through the methods of Fault Tree and Bayesian Network. Therefore, the paper consists of a literature review of the history of nuclear energy and the methodologies used. The AFWS is responsible for providing water system to cool the secondary circuit of nuclear reactors of the PWR type when normal feeding water system failure. How this system operates only when the primary system fails, it is expected that the AFWS failure probability is very low. The AFWS failure probability is divided into two cases: the first is the probability of failure in the first eight hours of operation and the second is the probability of failure after eight hours of operation, considering that the system has not failed within the first eight hours. The calculation of the probability of failure of the second case was made through the use of Fault Tree and Bayesian Network, that it was constructed from the Fault Tree. The results of the failure probability obtained were very close, on the order of 10 -3 . (author)

  10. A reliability centered maintenance model applied to the auxiliary feedwater system of a nuclear power plant; Um modelo de manutencao centrada em confiabilidade aplicada ao sistema de agua de alimentacaco auxiliar de uma usina nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Jefferson Borges

    1998-01-15

    The main objective of maintenance in a nuclear power plant is to assure that structures, systems and components will perform their design functions with reliability and availability in order to obtain a safety and economic electric power generation. Reliability Centered Maintenance (RCM) is a method of systematic review to develop or optimize Preventive Maintenance Programs. This study presents the objectives, concepts, organization and methods used in the development of RCM application to nuclear power plants. Some examples of this application are included, considering the Auxiliary Feedwater System of a generic two loops PWR nuclear power plant of Westinghouse design. (author)

  11. A decision theoretic approach to an accident sequence: when feedwater and auxiliary feedwater fail in a nuclear power plant

    International Nuclear Information System (INIS)

    Svenson, Ola

    1998-01-01

    This study applies a decision theoretic perspective on a severe accident management sequence in a processing industry. The sequence contains loss of feedwater and auxiliary feedwater in a boiling water nuclear reactor (BWR), which necessitates manual depressurization of the reactor pressure vessel to enable low pressure cooling of the core. The sequence is fast and is a major contributor to core damage in probabilistic risk analyses (PRAs) of this kind of plant. The management of the sequence also includes important, difficult and fast human decision making. The decision theoretic perspective, which is applied to a Swedish ABB-type reactor, stresses the roles played by uncertainties about plant state, consequences of different actions and goals during the management of a severe accident sequence. Based on a theoretical analysis and empirical simulator data the human error probabilities in the PRA for the plant are considered to be too small. Recommendations for how to improve safety are given and they include full automation of the sequence, improved operator training, and/or actions to assist the operators' decision making through reduction of uncertainties, for example, concerning water/steam level for sufficient cooling, time remaining before insufficient cooling level in the tank is reached and organizational cost-benefit evaluations of the events following a false alarm depressurization as well as the events following a successful depressurization at different points in time. Finally, it is pointed out that the approach exemplified in this study is applicable to any accident scenario which includes difficult human decision making with conflicting goals, uncertain information and with very serious consequences

  12. Simulation of main steam and feedwater system of full scope simulator for Qinshan 300 MW Nuclear Power Unit

    International Nuclear Information System (INIS)

    Zhao Xiaoyu

    1996-01-01

    The simulation of main steam and feedwater system is the most important and maximal part in secondary circuit model, including all of main steam and feedwater's thermal-hydraulic properties, except heat-exchange of secondary side of steam generator. It simulates main steam header, steam power in each stage of turbine, moisture separator-reheater, deaerator, condenser, high pressure and low pressure heater, auxiliary feedwater and main steam bypass in full scope

  13. Aging and service wear of auxiliary feedwater pumps for PWR nuclear power plants

    International Nuclear Information System (INIS)

    Greenstreet, W.L.

    1989-01-01

    This paper describes investigations on auxiliary feedwater pumps being done under the Nuclear Plant Aging Research (NPAR) Program. Objectives of these studies are: to identify and evaluate practical, cost-effective methods for detecting, monitoring, and assessing the severity of time-dependent degradation (aging and service wear); recommend inspection and maintenance practices; establish acceptance criteria; and help facilitate use of the results. Emphasis is given to identifying and assessing methods for detecting failure in the incipient stage and to developing degradation trends to allow timely maintenance, repair or replacement actions. 3 refs

  14. Feedwater temperature control methods and systems

    Science.gov (United States)

    Moen, Stephan Craig; Noonan, Jack Patrick; Saha, Pradip

    2014-04-22

    A system for controlling the power level of a natural circulation boiling water nuclear reactor (NCBWR) is disclosed. The system, in accordance with an example embodiment of the present invention, may include a controller configured to control a power output level of the NCBWR by controlling a heating subsystem to adjust a temperature of feedwater flowing into an annulus of the NCBWR. The heating subsystem may include a steam diversion line configured to receive steam generated by a core of the NCBWR and a steam bypass valve configured to receive commands from the controller to control a flow of the steam in the steam diversion line, wherein the steam received by the steam diversion line has not passed through a turbine. Additional embodiments of the invention may include a feedwater bypass valve for controlling an amount of flow of the feedwater through a heater bypass line to the annulus.

  15. Condensate and feedwater systems, pumps, and water chemistry. Volume seven

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    Subject matter includes condensate and feedwater systems (general features of condensate and feedwater systems, condenser hotwell level control, condensate flow, feedwater flow), pumps (principles of fluid flow, types of pumps, centrifugal pumps, positive displacement pumps, jet pumps, pump operating characteristics) and water chemistry (water chemistry fundamentals, corrosion, scaling, radiochemistry, water chemistry control processes, water pretreatment, PWR water chemistry, BWR water chemistry, condenser circulating water chemistry

  16. Development of 2-loop feedwater control system

    International Nuclear Information System (INIS)

    Omori, Takashi; Watanabe, Takao; Hirose, Masao.

    1981-01-01

    A 2-loop feedwater control system has been developed for automatic transfer control of the reactor feed pumps (RFP's) in BWR plants. This system consists of a master level controller and sub-loop flow controllers for each of the RFP's. Control characteristics of the 2-loop control system were investigated using a dynamic analysis code for the condensate feedwater system. Although the RFP system has a hydraulic coupling effect, the flow control loops become stable by setting adequate controller gains in the sub-loop flow controllers. The control characteristics in the major loop were modified in their initial response to level setpoint change by using a lead/lag compensator. Moreover, reactor core cooling was protected sufficiently during the transient in a trip of a turbine driven RFP. From simulation results of the transfer controls from the motor driven RFP to turbine driven RFP, it was ascertained that the 2-loop control system has such advantages as shorter completion time and superior controllability against ON-OFF action of a RFP recirculation valve during transfer control. (author)

  17. CAREM-25. Auxiliary systems

    International Nuclear Information System (INIS)

    Acosta, Eduardo; Amaya, Daniel; Carlevaris, Rodolfo; Patrignani, A.; Ramilo, L.; Santecchia, A.; Vindrola, C.

    2000-01-01

    CAREM is an innovative PWR reactor whose prototype will be of small power generation capacity (100MWt, about 25MWe).CAREM design is based on light water integrated reactor with slightly enriched uranium.In this work, a summary of the functions and most relevant design characteristics of main auxiliary systems associated to the chain of heat removal and physicochemical - radiological treatment of the cooling fluids of the CAREM-25 prototype is presented.Even though these auxiliary systems of the reactor are not safety system, they fulfill functions related with the nuclear safety at different operative modes of the reactor

  18. CAREM-25. Auxiliary systems

    International Nuclear Information System (INIS)

    Acosta, Eduardo; Amaya, Daniel; Carlevaris, Rodolfo; Patrignani, Alberto; Santecchia, Alberto; Vindrola, Carlos; Ramilo, Lucia B.

    2000-01-01

    CAREM is an innovative PWR reactor whose prototype will be of small power generation capacity (100 M Wt, about 25 M We). CAREM design is based on light water integrated reactor with slightly enriched uranium. In this work, a summary of the functions and most relevant design characteristics of main auxiliary systems associated to the chain of heat removal and physicochemical - radiological treatment of the cooling fluids of the CAREM-25 prototype is presented. Even though these auxiliary systems of the reactor are not safety system, they fulfill functions related with the nuclear safety at different operative modes of the reactor. (author)

  19. Operation auxiliary system (SAO)

    International Nuclear Information System (INIS)

    Lolich, J.; Santome, D.; Drexler, J.

    1990-01-01

    This work presents an auxiliary system for nuclear power plants operation (SAO). The development purpose consisted in a computing supervision system to be installed at different sites of a reactor, mainly in the control room. The inclusion of this system to a nuclear power plant minimizes the possibility of human error for the facility operation. (Author) [es

  20. Study of the reliability of the Auxiliary Feedwater System of a LWR nuclear power plant through the Fault Tree and Bayesian Network; Estudo de confiabilidade do Sistema Auxiliar de Agua de Alimentacao de uma central nuclear a agua leve por arvore de falhas e rede Bayesiana

    Energy Technology Data Exchange (ETDEWEB)

    Lava, Deise Diana

    2016-10-01

    This paper aims to present a study of the reliability of the Auxiliary Feedwater System (AFWS) through the methods of Fault Tree and Bayesian Network. Therefore, the paper consists of a literature review of the history of nuclear energy and the methodologies used. The AFWS is responsible for providing water system to cool the secondary circuit of nuclear reactors of the PWR type when normal feeding water system failure. How this system operates only when the primary system fails, it is expected that the AFWS failure probability is very low. The AFWS failure probability is divided into two cases: the first is the probability of failure in the first eight hours of operation and the second is the probability of failure after eight hours of operation, considering that the system has not failed within the first eight hours. The calculation of the probability of failure of the second case was made through the use of Fault Tree and Bayesian Network, that it was constructed from the Fault Tree. The results of the failure probability obtained were very close, on the order of 10{sup -3}. (author)

  1. Aging and service wear of auxiliary feedwater pumps for PWR nuclear power plants. Volume 1. Operating experience and failure identification

    Energy Technology Data Exchange (ETDEWEB)

    Adams, M.L.; Makay, E.

    1986-07-01

    This report was produced under the Detection of Defects and Degradation Monitoring element of the Nuclear Plant Aging Research Program. Typical auxiliary feedwater pump (AUXFP) configurations are described in terms of configuration details, materials of construction, operating requirements, and modes of operation. AUXFP failure modes and causes due to aging and service wear are identified and explained, and measurable parameters (including functional indicators) for potential use in assessing operational readiness, establishing degradation trends, and detecting incipient failures are given. A series of measures to correct present deficiencies in surveillance, monitoring, and in-service testing practices is discussed. The main body of the report is supplemented by a number of relevant appendixes; in particular, a major appendix is included on engineering and design information useful to assess AUXFP operational readiness. 17 figs., 17 tabs.

  2. Expert system for nuclear power plant feedwater system diagnosis

    International Nuclear Information System (INIS)

    Meguro, R.; Kinoshita, Y.; Sato, T.; Yokota, Y.; Yokota, M.

    1987-01-01

    The Expert System for Nuclear Power Plant Feedwater System Diagnosis has been developed to assist maintenance engineers in nuclear power plants. This system adopts the latest process computer TOSBAC G8050 and the expert system developing tool TDES2, and has a large scale knowledge base which consists of the expert knowledge and experience of engineers in many fields. The man-machine system, which has been developed exclusively for diagnosis, improves the man-machine interface and realizes the graphic displays of diagnostic process and path, stores diagnostic results and searches past reference

  3. Intersection auxiliary signal system

    Science.gov (United States)

    Zhang, Jian

    1995-12-01

    Many intersection accidents are related to drivers' inappropriate responses to an amber signal light, due to their misjudgment on the traffic situation and/or their aggressive behavior. To reduce intersection accidents of this nature, this paper proposes the Intersection Auxiliary Signal System (IAS). IAS can be installed at selected intersections, where information regarding signal phasing, intersection geometry and speed limit is transmitted from an ultrasonic/infra-red transmitter. An on-vehicle device receivers and processes the information, the provides the driver with explicit suggestions on the correct action to take (continue to pass or decelerate to stop), or warnings against on-going incorrect actions. IAS is expected to be more effective in suburban intersections, which are usually characterized by greater dimension, longer amber phases, and higher vehicle speeds. Both the intersection transmitters and the on-vehicle processors are expected to have simple structures and low costs. Simulation results show that IAS has a significant effect on reducing red signal violation, especially when there is no significant dilemma zones.

  4. Loss of main and auxiliary feedwater event at the Davis-Besse Plant on June 9, 1985

    Energy Technology Data Exchange (ETDEWEB)

    None

    1985-07-01

    On June 9, 1985, Toledo Edison Company's Davis-Besse Nuclear Power Plant, located in Ottawa County, Ohio, experienced a partial loss of feedwater while the plant was operating at 90% power. Following a reactor trip, a loss of all feedwater occurred. The event involved a number of equipment malfunctions and extensive operator actions, including operator actions outside the control room. Several operator errors also occurred during the event. This report documents the findings of an NRC Team sent to Davis-Besse by the NRC Executive Director for Operations in conformance with the staff-proposed Incident Investigation Program.

  5. Loss of main and auxiliary feedwater event at the Davis-Besse Plant on June 9, 1985

    International Nuclear Information System (INIS)

    1985-07-01

    On June 9, 1985, Toledo Edison Company's Davis-Besse Nuclear Power Plant, located in Ottawa County, Ohio, experienced a partial loss of feedwater while the plant was operating at 90% power. Following a reactor trip, a loss of all feedwater occurred. The event involved a number of equipment malfunctions and extensive operator actions, including operator actions outside the control room. Several operator errors also occurred during the event. This report documents the findings of an NRC Team sent to Davis-Besse by the NRC Executive Director for Operations in conformance with the staff-proposed Incident Investigation Program

  6. Loss of Normal Feedwater analyses for Krsko Full Scope Simulator verification

    International Nuclear Information System (INIS)

    Parzer, I.; Prosek, A.; Hrvatin, S.

    2000-01-01

    The purpose of these analyses was to perform calculations of a Loss of Normal (Main) Feedwater transient for Krsko NPP. The results of calculations were used for the verification of reactor coolant system thermal-hydraulic response predicted by Krsko Full Scope Simulator. To perform the thermal-hydraulic analyses, the RELAP5/MOD2 computer code and the NPP Krsko input card deck were used. In the presented paper two scenarios have been analyzed. Both of them started with a loss of normal feedwater event. Thus, a reduction or an interruption of the heat removal by the secondary system occurred. The first scenario assumed that auxiliary feedwater was available during the transient, while in the second scenario both normal and auxiliary feedwater were unavailable. The results showed that with auxiliary feedwater pumps unavailable additional operator actions would be needed to prevent overheating of the core. (author)

  7. Water hammer calculation and analysis in main feedwater system of PWR nuclear power plants

    International Nuclear Information System (INIS)

    Wang Xin; Han Weishi

    2010-01-01

    The main feedwater system of a nuclear power plant is an important part in ensuring the cooling of the steam generator. Moreover, it is the main pipe section where water hammers frequently occur. Studying the regular patterns of water hammers to the main feedwater system is significant to the stable operation of the system. The paper focuses on the study of water hammers through Flowmaster's transient calculating function to establish a mathematical model with boundary conditions such as a feedwater pump, control valves, etc.; calculation of the water hammers pressure when feedwater pumps and control valves shut down; exporting the instantaneous change in solution of pressure. Combined with engineering practical examples, the conclusions verify the viability of calculating the water hammers pressure through Flowmaster's transient function, increasing the periods of closure of control valves and feedwater pumps control water hammers effectively, changing the intervals of closing signals to feedwater pumps and control valves to relieve hydraulic impact. This could be a guideline for practical engineering design and system optimization. (authors)

  8. Radiant vessel auxiliary cooling system

    Science.gov (United States)

    Germer, John H.

    1987-01-01

    In a modular liquid-metal pool breeder reactor, a radiant vessel auxiliary cooling system is disclosed for removing the residual heat resulting from the shutdown of a reactor by a completely passive heat transfer system. A shell surrounds the reactor and containment vessel, separated from the containment vessel by an air passage. Natural circulation of air is provided by air vents at the lower and upper ends of the shell. Longitudinal, radial and inwardly extending fins extend from the shell into the air passage. The fins are heated by radiation from the containment vessel and convect the heat to the circulating air. Residual heat from the primary reactor vessel is transmitted from the reactor vessel through an inert gas plenum to a guard or containment vessel designed to contain any leaking coolant. The containment vessel is conventional and is surrounded by the shell.

  9. Mobile polishing system of feedwater at start-up feedback from the implementation and future prospects

    International Nuclear Information System (INIS)

    Faure, Celine; Eade, Kevin; Fontan, Guillaume

    2012-09-01

    offered increased operational flexibility. Its use is limited to the start-up of a unit up to the point where the chemical criteria are met for the changeover from auxiliary feedwater to final feedwater and, at most, up to 20% Pn. In 2006, the will to optimise the discharge during start-up in order to increase the availability of the waste tanks, and to reduce the quantity of metallic oxides in the SGs at the start-up following the appearance of the clogging of SGs broached-hole tube support plates, lead EDF to recreate identical SMEs for the rest of the fleet. Using the SME at the start-up is beneficial for safety, availability, lifespan and discharge reduction. This paper develops the context and technical choices which lead EDF to implement the SME; it goes on to present the design of the treatment system, as well as the implementation feedback of its use on a number of plants. (authors)

  10. Design enhancement in BWR feedwater control system: Experience feedback from Kuosheng NPP

    International Nuclear Information System (INIS)

    Chen, C. C.

    2006-01-01

    Though feedwater control system is used only for normal operation of the plant, it belongs to the category cited by SRP chapter 7.7 that has the potential to affect the performance of critical safety functions. Kousheng has been commercial operation for more than 20 years. Because of equipment aging problem and difficulties in getting spare parts, feedwater control system needs upgrade. Unit II feedwater control system was upgraded to modern digital control system in EOC-17 and Unit I was upgraded in EOC-18. Before the implementation of the project, Taipower has accumulated various experiences from previous digital control system retrofits in Chin-Shan, Kousheng and Maanshan NPP. A task force lead by author is formed to assist Kousheng. This paper shares the experience of Kousheng retrofit project. (authors)

  11. Influence of feedwater and blowdown systems on the mineral distribution in WWER steam generators

    International Nuclear Information System (INIS)

    Pappx, L.

    1994-01-01

    After modification of Dukovany NPP steam generator feedwater system, the increased concentration of minerals was measured in the cold leg of modified steam generator. Some modifications were performed on operating WWER 1000 steam generators with aim to optimize the water chemistry in the collectors area. Since the distribution of minerals can substantially affect on corrosion processes in steam generators, VITKOVICE, as a producer of WWER steam generators, has focused this attention on the optimizing of these systems. To predict the mineral distribution on the secondary side of steam generators for considered feedwater/blowdown systems, the simple model of flow distribution in the secondary side of SG was developed. (Author)

  12. Influence of feedwater and blowdown systems on the mineral distribution in WWER steam generators

    International Nuclear Information System (INIS)

    Papp, L.

    1995-01-01

    After modification of Dukovany NPP steam generator (SG) feedwater system, the increased concentration of minerals was measured in the cold leg of modified SG. Some modifications were performed on operating WWER 1000 steam generators with aim to optimize the water chemistry in the collectors area. Since the distribution of minerals can substantially affect on corrosion processes in steam generators, VITKOVICE, as a producer of WWER steam generators has focused the attention to the optimizing of these systems. To predict the mineral distribution on the secondary side of steam generators for considered feedwater/blowdown systems, the simple model of the flow distribution in the secondary side of SG was developed

  13. Influence of feedwater and blowdown systems on the mineral distribution in WWER steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Papp, L. [Inst. of Material Engineering, Ostrava (Switzerland)

    1995-12-31

    After modification of Dukovany NPP steam generator (SG) feedwater system, the increased concentration of minerals was measured in the cold leg of modified SG. Some modifications were performed on operating WWER 1000 steam generators with aim to optimize the water chemistry in the collectors area. Since the distribution of minerals can substantially affect on corrosion processes in steam generators, VITKOVICE, as a producer of WWER steam generators has focused the attention to the optimizing of these systems. To predict the mineral distribution on the secondary side of steam generators for considered feedwater/blowdown systems, the simple model of the flow distribution in the secondary side of SG was developed.

  14. 77 FR 55877 - Initial Test Program of Condensate and Feedwater Systems for Light-Water Reactors

    Science.gov (United States)

    2012-09-11

    ... Systems for Light-Water Reactors AGENCY: Nuclear Regulatory Commission. ACTION: Regulatory guide; issuance... Systems for Boiling Water Reactor Power Plants.'' This regulatory guide is being revised to: (1) Expand... for the condensate and feedwater systems in all types of light water reactor facilities; and (2) to...

  15. 77 FR 15812 - Initial Test Program of Condensate and Feedwater Systems for Light-Water Reactors

    Science.gov (United States)

    2012-03-16

    ... Systems for Light-Water Reactors AGENCY: Nuclear Regulatory Commission. ACTION: Draft regulatory guide... Feedwater Systems for Light- Water Reactors.'' DG-1265 is proposed revision 2 of Regulatory Guide 1.68.1... Plants,'' dated January 1977. This regulatory guide is being revised to: (1) expand the scope of the...

  16. Implementation of a digital feedwater control system at Dresden Nuclear Power Plant, Units 2 and 3: Final report

    International Nuclear Information System (INIS)

    Zapotocky, A.; Popovic, J.R.; Fournier, R.D.

    1988-12-01

    This report describes the Digital Feedwater Control System Implementation at the Dresden 2 or 3 Units of the BWR Nuclear Power Plant owned by the Commonwealth Edison Company. The digital system has been operational in Unit 3 since August 1986, and in Unit 2 since April 1987. The Bailey Control's Network 90 based digital control system replaced the obsolete GE/MAC 5000 analog control system in the reactor feedwater control loop as a ''like-for-like'' replacement. Operational experience from the Digital Feedwater Control installations has been good and the system demonstrated better performance than the old analog systems. 14 refs., 15 figs., 17 tabs

  17. Using risk-informed asset management for feedwater system preventative maintenance optimization

    International Nuclear Information System (INIS)

    Kee, Ernest; Sun, Alice; Richards, Andrew; Grantom, Rick; Liming, James; Salter, James

    2004-01-01

    The initial development of a South Texas Project Nuclear Operating Company process for supporting preventative maintenance optimization by applying the Balance-Of-Plant model and Risk-Informed Asset Management alpha-level software applications is presented. Preventative maintenance activities are evaluated in the South Texas Project Risk-Informed Asset Management software while the plant maintains or improves upon high levels of nuclear safety. In the Balance-Of-Plant availability application, the level of detail in the feedwater system is enhanced to support plant decision-making at the component failure mode and human error mode level of indenture by elaborating on the current model at the super-component level of indenture. The enhanced model and modeling techniques are presented. Results of case studies in feedwater system preventative maintenance optimization sing plant-specific data are also presented. (author)

  18. 30 CFR 57.8529 - Auxiliary fan systems

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Auxiliary fan systems 57.8529 Section 57.8529 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Underground Only § 57.8529 Auxiliary fan systems When auxiliary fan systems are used, such systems shall...

  19. Implementation of an advanced digital feedwater control system at the Prairie Island nuclear generating station

    International Nuclear Information System (INIS)

    Paris, R.E.; Gaydos, K.A.; Hill, J.O.; Whitson, S.G.; Wirkkala, R.

    1990-05-01

    EPRI Project RP2126-4 was a cooperative effort between TVA, EPRI, and Westinghouse which resulted in the demonstration of a prototype of a full range, fully automatic feedwater control system, using fault tolerant digital technology, at the TVA Sequoyah simulator site. That prototype system also included advanced signal validation algorithms and an advanced man-machine interface that used CRT-based soft-control technology. The Westinghouse Advanced Digital Feedwater Control System (ADFCS) upgrade, which contains elements that were part of that prototype system, has since been installed at Northern States Power's Prairie Island Unit 2. This upgrade was very successful due to the use of an advanced control system design and the execution of a well coordinated joint effort between the utility and the supplier. The project experience is documented in this report to help utilities evaluate the technical implications of such a project. The design basis of the Prairie Island ADFCS signal validation for input signal failure fault tolerance is outlined first. Features of the industry-proven system control algorithms are then described. Pre-shipment hardware-in-loop and factory acceptance testing of the Prairie Island system are summarized. Post-shipment site testing, including preoperational and plant startup testing, is also summarized. Plant data from the initial system startup is included. The installation of the Prairie Island ADFCS is described, including both the feedwater control instrumentation and the control board interface. Modification of the plant simulator and operator and I ampersand C personnel training are also discussed. 6 refs., 14 figs., 3 tabs

  20. Boiler feedwater quality improvement by replacing conventional pre-treatment with advanced membrane systems

    Energy Technology Data Exchange (ETDEWEB)

    Doll, Bernhard [Process Systems Pall GmbH, Dreieich (Germany). Marketing; Venkatadri, Ramraj [Pall Corporation, Port Washington, NY (United States). Global Marketing Energy

    2013-09-01

    Two case studies in different application fields highlight significant economical and operational improvements that were achieved by replacing conventional water treatment technologies by highly-sophisticated membrane systems. The first case study deals with boiler feedwater in a power plant, focusing on the challenges faced as well as the direct and indirect benefits gained by the new system within a utility station. The second case study deals with the conventional water treatment scheme for groundwater from 13 wells at a major oil sands facility. Operational performance as well as the cost improvements gained in both cases will be presented. (orig.)

  1. Heat exchanger with auxiliary cooling system

    Science.gov (United States)

    Coleman, John H.

    1980-01-01

    A heat exchanger with an auxiliary cooling system capable of cooling a nuclear reactor should the normal cooling mechanism become inoperable. A cooling coil is disposed around vertical heat transfer tubes that carry secondary coolant therethrough and is located in a downward flow of primary coolant that passes in heat transfer relationship with both the cooling coil and the vertical heat transfer tubes. A third coolant is pumped through the cooling coil which absorbs heat from the primary coolant which increases the downward flow of the primary coolant thereby increasing the natural circulation of the primary coolant through the nuclear reactor.

  2. LOX/hydrocarbon auxiliary propulsion system study

    Science.gov (United States)

    Orton, G. F.; Mark, T. D.; Weber, D. D.

    1982-01-01

    Liquid oxygen (LOX)/hydrocarbon propulsion concepts for a "second generation' orbiter auxiliary propulsion system was evaluated. The most attractive fuel and system design approach identified, and the technology advancements that are needed to provide high confidence for a subsequent system development were determined. The fuel candidates were ethanol, methane, propane, and ammonia. Even though ammonia is not a hydrocarbon, it was included for evaluation because it is clean burning and has a good technology base. The major system design options were pump versus pressure feed, cryogenic versus ambient temperature RCS propellant feed, and the degree of OMS-RCS integration. Ethanol was determined to be the best fuel candidate. It is an earth-storable fuel with a vapor pressure slightly higher than monomethyl hydrazine. A pump-fed OMS was recommended because of its high specific impulse, enabling greater velocity change and greater payload capability than a pressure fed system.

  3. Modernization of the feedwater heaters control level of the Almaraz I Nuclear Power Plant by OVATION system

    International Nuclear Information System (INIS)

    Madronal Rodriguez, E.; Cabrero Munoz, J. E.

    2010-01-01

    As a result of the process of technological renovation of the heaters system and the power increase project, Almaraz Nuclear Power Plant has made several design changes in the feedwater heaters system. Within these changes, the old heaters control loops are replaced because the new power will increase the heaters drainage caudal. This modernization is carried out using the OVATION control system.

  4. Auxiliary reactor for a hydrocarbon reforming system

    Science.gov (United States)

    Clawson, Lawrence G.; Dorson, Matthew H.; Mitchell, William L.; Nowicki, Brian J.; Bentley, Jeffrey M.; Davis, Robert; Rumsey, Jennifer W.

    2006-01-17

    An auxiliary reactor for use with a reformer reactor having at least one reaction zone, and including a burner for burning fuel and creating a heated auxiliary reactor gas stream, and heat exchanger for transferring heat from auxiliary reactor gas stream and heat transfer medium, preferably two-phase water, to reformer reaction zone. Auxiliary reactor may include first cylindrical wall defining a chamber for burning fuel and creating a heated auxiliary reactor gas stream, the chamber having an inlet end, an outlet end, a second cylindrical wall surrounding first wall and a second annular chamber there between. The reactor being configured so heated auxiliary reactor gas flows out the outlet end and into and through second annular chamber and conduit which is disposed in second annular chamber, the conduit adapted to carry heat transfer medium and being connectable to reformer reaction zone for additional heat exchange.

  5. Feedwater control method and device therefor

    International Nuclear Information System (INIS)

    Nakahara, Mitsugu; Ichikawa, Yoshiaki; Ishii, Yoshikazu; Suzuki, Katsuyuki; Tanikawa, Naoshi; Mizuki, Fumio.

    1997-01-01

    The present invention provides a method of and a device for easily changing the constitution of feedwater systems without causing change in the water level of a reactor even when a plurality of feedwater systems have imbalance points. Namely, a feedwater control device comprises at least two feedwater systems capable of feeding water to tanks independently respectively and a controller capable of controlling water level in the tanks by controlling these feedwater systems. There is disposed a means for outputting gradually increasing driving signals to other feedwater systems, when the water level controller automatically controls one of the feedwater systems. There is also disposed a means for switching from automatic control for one of the feedwater systems to automatic control for the other feedwater system by a water level controller when the other feedwater system is in a stable operation region. As a result, entire feedwater flow rate is not temporarily changed and the water level in the tanks can be maintained constant. (N.H.)

  6. Reactor feedwater facility

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, Tadashi; Kinoshita, Shoichiro; Akatsu, Jun-ichi

    1996-04-30

    In a reactor feedwater facility in which one stand-by system and at least three ordinary systems are disposed in parallel, each of the feedwater pumps is driven by an electromotor, and has substantially the same capacity. At least two systems among the ordinary systems have a pump rotation number variable means. Since the volume of each of the feedwater pump of each system is determined substantially equal, standardization is enabled to facilitate the production. While the number of electromotors is increased, since they are driven by electromotors, turbines, steam pipelines and valves for driving feed water pumps can be eliminated. Therefore, the feedwater pumps can be disposed to a region of low radiation dose being separated from a main turbine and a main condensator, to improve the degree of freedom in view of the installation. In addition, accessibility to equipments during operation is improved to improve the maintenance of feed water facilities. The number of parts for equipments can be reduced compared with that in a turbine-driving system thereby capable of reducing the operation amount for the maintenance and inspection. (N.H.)

  7. Energy consumption of auxiliary systems of electric cars

    Directory of Open Access Journals (Sweden)

    Evtimov Ivan

    2017-01-01

    Full Text Available The paper analyzes the power demand of the auxiliary systems of electric cars. On the basis of existing electric cars an analysis of energy consumption of different auxiliary systems is done. As a result possibilities for rational use of these systems have been proposed, which can increase the mileage per one charge of the battery.

  8. Controlling method for impurity concentration in the feedwater system of a BWR type reactor

    International Nuclear Information System (INIS)

    Yamazaki, Kenji

    1987-01-01

    Purpose: To decrease ionic radioactive deposition and reduce the exposure dose upon inspection in the recycling system of a nuclear reactor. Method: Fe concentration is analyzed based on the crud concentration measured by a turbidimeter and the concentration is calculated. Further, Ni density is analyzed by an ion crossed meter and the density is calculated. From the calculated values, the density between Fe density and Ni density, i.e., Fe/Ni is calculated. If the calculated value for Fe/Ni is lower than a setting value (Fe/Ni = 2), an open signal is outputted for an iron injection valve disposed at the midway of a pipeway connected from a tank containing suspended iron oxide or iron hydroxide to a feedwater pipe. Then, the opening degree of the iron injection valve is adjusted based on the deviation value between the setting value (Fe/Ni = 2) and the calculated value for Fe/Ni. (Yoshino, Y.)

  9. Feedwater heater

    International Nuclear Information System (INIS)

    Murata, Shigeto; Minato, Akihiko; Yokomizo, Osamu; Masuhara, Yasuhiro.

    1991-01-01

    The present invention concerns a feedwater heater for a BWR type reactor. A cylinder is fit into the lower portion of a drain inlet pipe, to which drain water inflows from a turbine, and a disk is disposed to the lower end of the cylinder vertically to the axis of the cylinder, to constitute a drain water dispersing mechanism. Drain water inflown from the drain inlet pipe is fallen in the cylinder and collides against the disk. The collided drain water is splashed horizontally by its kinetic energy to reach the heat transfer pipe and conducts heat exchange. In this case, the drain water is converted into fine droplets by the collision against the disk and scattered in a wide range in the heater. As a result, sensible heat in the drain water can be transferred to feedwater effectively. Then, even the heat energy of the drain water can be utilized effectively for heat exchange, to improve the heat exchange efficiency. (I.N.)

  10. Satellite auxiliary-propulsion selection techniques. Addendum: A survey of auxiliary electric propulsion systems

    Science.gov (United States)

    Holcomb, L. B.

    1971-01-01

    A review of electric thrusters for satellite auxiliary propulsion was conducted at JPL during the past year. Comparisons of the various thrusters for attitude propulsion and east-west and north-south stationkeeping were made based upon performance, mass, power, and demonstrated life. Reliability and cost are also discussed. The method of electrical acceleration of propellant served to divide the thruster systems into two groups: electrostatic and electromagnetic. Ion and colloid thrusters fall within the electrostatically accelerated group while MPD and pulsed plasma thrusters comprise the electromagnetically accelerated group. The survey was confined to research in the United States with accent on flight and flight prototype systems.

  11. Probabilistic cloning with supplementary information contained in the quantum states of two auxiliary systems

    International Nuclear Information System (INIS)

    Li, Lvjun; Qiu, Daowen

    2007-01-01

    In probabilistic cloning with two auxiliary systems, we consider and compare three different protocols for the success probabilities of cloning. We show that, in certain circumstances, it may increase the success probability to add an auxiliary system to the probabilistic cloning machine having one auxiliary system, but we always can find another cloning machine with one auxiliary system having the same success probability as that with two auxiliary systems

  12. Development of KALIMER auxiliary sodium and cover gas management system

    International Nuclear Information System (INIS)

    Kwon, Sang Woon; Hwang, Sung Tae

    1996-11-01

    The objectives of this report are to develop and to describe the auxiliary liquid metal and cover gas management systems of KALIMER. the system includes following system: (1) Auxiliary liquid metal system (2) Inert gas receiving and processing system (3) Impurity monitoring and analysis system. Auxiliary liquid metal and cover gas management system of KALIMER was developed. Functions of each systems and design basis were describes. The auxiliary liquid metal system receives, transfers, and purifies all sodium used in the plant. The system furnishes the required sodium quantity at the pressure, temperature, flow rate, and purity specified by the interfacing system. The intermediated sodium processing subsystem (ISPS) provides continuous purification of IHTS sodium, as well as performs the initial fill operation for both the IHTS and reactor vessel. The primary sodium processing subsystem provides purification (cold trapping) for sodium used in the reactor vessel. The inert gas receiving and processing (IGRP) system provides liquefied and ambient gas storage, delivers inert gases of specified composition and purity at regulated flow rates and pressures to points of usage throughout the KALIMER, and accepts the contaminated gases through its vacuum facilities for storage and transfer to the gas radwaste system. Three gases are used in the KALIMER: helium, argon, and nitrogen. 11 tabs., 12 figs. (Author)

  13. Modeling and simulation of the feedwater system, associated controller and interface with the user for the SUN-RAH nucleo electric plants university student simulator

    International Nuclear Information System (INIS)

    Sanchez B, A.

    2003-01-01

    The simulation process of the component systems of the feedwater of a nucleo electric plant is presented, using several models of reduced order that represent the diverse elements that compose the systems like: the heaters of feedwater, the condenser, the feedwater pump, etc. The integration of the same ones in one simulative structure, and the development of a platform that to give the appearance of to be executed in continuous time, it is the objective of the feedwater simulator, as well as of the SUN-RAH simulator, of which is part. The simulator uses models of reduced order that respond to the observed behavior of a nuclear plant of BWR type. Likewise, it is presented a model of a flow controller of feedwater that will be the one in charge of regulating the demand of the system according to the characteristics and criticize restrictions of safety and controllability, assigned according to those wanted parameters of performance of this system inside the nucleo electric plant. The integration of these models, the adaptation of the variables and parameters, are presented in a way that the integration with the other ones models of the remaining systems of the plant (reactor, steam lines, turbine, etc.), be direct and coherent with the principles of thermodynamic cycles relative to this type of generation plants. The design of those graphic interfaces and the environment where the simulator works its are part of those developments of this work. The reaches and objectives of the simulator complement the description of the simulator. (Author)

  14. Study by the disco method of critical components of a P.W.R. normal feedwater system

    International Nuclear Information System (INIS)

    Duchemin, B.; Villeneuve, M.J. de; Vallette, F.; Bruna, J.G.

    1983-03-01

    The DISCO (Determination of Importance Sensitivity of COmponents) method objectif is to rank the components of a system in order to obtain the most important ones versus availability. This method uses the fault tree description of the system and the cut set technique. It ranks the components by ordering the importances attributed to each one. The DISCO method was applied to the study of the 900 MWe P.W.R. normal feedwater system with insufficient flow in steam generator. In order to take account of operating experience several data banks were used and the results compared. This study allowed to determine the most critical component (the turbo-pumps) and to propose and quantify modifications of the system in order to improve its availability

  15. Application of the RCM (Reliability Centered Maintenance) approach to the optimization of emergency feedwater pump system maintenance

    International Nuclear Information System (INIS)

    Adamec, P.; Stvan, F.

    2001-12-01

    The major steps of the RCM analysis for the emergency feedwater pump system at the Dukovany NPP were as follows: Familiarization with the Dukovany maintenance process and strategy; Collection of information regarding data and information availability; system selection for the RCM study; implementation and use of suitable software; consulting the staff; FFA (Functional Failure Analysis) and FMEA (Failure Mode and Effect Analysis); Assessment of current periodical maintenance; and recommendations from the RCM analysis. The following Annexes are appended: A - Technological layouts; B - List of components; C - Information on functions; D - Critical components; E - FMEA; F - Consulting the staff (notes); G - Failure data (from RCM Workstation); H - Current periodical maintenance tasks; I - Selection of periodical maintenance tasks. (P.A.)

  16. Trend and pattern analysis of failures of main feedwater system components in United States commercial nuclear power plants

    International Nuclear Information System (INIS)

    Gentillon, C.D.; Meachum, T.R.; Brady, B.M.

    1987-01-01

    The goal of the trend and pattern analysis of MFW (main feedwater) component failure data is to identify component attributes that are associated with relatively high incidences of failure. Manufacturer, valve type, and pump rotational speed are examples of component attributes under study; in addition, the pattern of failures among NPP units is studied. A series of statistical methods is applied to identify trends and patterns in failures and trends in occurrences in time with regard to these component attributes or variables. This process is followed by an engineering evaluation of the statistical results. In the remainder of this paper, the characteristics of the NPRDS that facilitate its use in reliability and risk studies are highlighted, the analysis methods are briefly described, and the lessons learned thus far for improving MFW system availability and reliability are summarized (orig./GL)

  17. LQG/LTR [linear quadratic Gaussian with loop transfer recovery] robust control system design for a low-pressure feedwater heater train

    International Nuclear Information System (INIS)

    Murphy, G.V.; Bailey, J.M.

    1990-01-01

    This paper uses the linear quadratic Gaussian with loop transfer recovery (LQG/LTR) control system design method to obtain a level control system for a low-pressure feedwater heater train. The control system performance and stability robustness are evaluated for a given set of system design specifications. The tools for analysis are the return ratio, return difference, and inverse return difference singular-valve plots for a loop break at the plant output. 3 refs., 7 figs., 2 tabs

  18. Assembly auxiliary system for narrow cabins of spacecraft

    Science.gov (United States)

    Liu, Yi; Li, Shiqi; Wang, Junfeng

    2015-09-01

    Due to the narrow space and complex structure of spacecraft cabin, the existing asssembly systems can not well suit for the assembly process of cabin products. This paper aims to introduce an assembly auxiliary system for cabin products. A hierarchical-classification method is proposed to re-adjust the initial assembly relationship of cabin into a new hierarchical structure for efficient assembly planning. An improved ant colony algorithm based on three assembly principles is established for searching a optimizational assembly sequence of cabin parts. A mixed reality assembly environment is constructed with enhanced information to promote interaction efficiency of assembly training and guidance. Based on the machine vision technology, the inspection of left redundant objects and measurement of parts distance in inner cabin are efficiently performed. The proposed system has been applied to the assembly work of a spacecraft cabin with 107 parts, which includes cabin assembly planning, assembly training and assembly quality inspection. The application result indicates that the proposed system can be an effective assistant tool to cabin assembly works and provide an intuitive and real assembly experience for workers. This paper presents an assembly auxiliary system for spacecraft cabin products, which can provide technical support to the spacecraft cabin assembly industry.

  19. A Smart Soft Sensor Predicting Feedwater Flow Rate

    International Nuclear Information System (INIS)

    Yang, Heon Young; Na, Man Gyun

    2009-01-01

    Since we evaluate thermal nuclear reactor power with secondary system calorimetric calculations based on feedwater flow rate measurements, we need to measure the feedwater flow rate accurately. The Venturi flow meters that are being used to measure the feedwater flow rate in most pressurized water reactors (PWRs) measure the flow rate by developing a differential pressure across a physical flow restriction. The differential pressure is then multiplied by a calibration factor that depends on various flow conditions in order to calculate the feedwater flow rate. The calibration factor is determined by the feedwater temperature and pressure. However, Venturi meters cause a buildup of corrosion products near the orifice of the meter. This fouling increases the measured pressure drop across the meter, thereby causing an overestimation of the feedwater flow rate

  20. STARTER-GENERATOR SYSTEM FOR AUXILIARY POWER UNIT

    Directory of Open Access Journals (Sweden)

    A. V. Levin

    2017-01-01

    Full Text Available The article presents a starter-generator system for an auxiliary power unit of an aircraft. A feature of the presented system is the use of a synchronous generator with excitation from permanent magnets and a semiconductor converter. The main problem of the system is the generation of electric energy of an aircraft on the basis of a synchronous generator with excitation from permanent magnets is the absence of the possibility of regulating the voltage and frequency of electrical energy, in this connection, a semiconductor converter that ensures the conversion of generated electric energy with significant mass-dimensions characteristics.The article proposes an approach to designing a starter-generator system with a parallel connection of a synchronous generator with excitation from permanent magnets and a semiconductor converter. This approach makes it possible to significantly reduce the part of the electrical energy that needs to be converted, as a consequence, the semiconductor converter has significantly smaller mass-and-batch characteristics.In the article the modes of generation of electric energy and the starter mode of operation of the starter-generator system are considered in detail, the circuit realization of the semiconductor converter is shown. A scheme for replacing one phase of the system for generating electric energy and calculating electric parameters is presented.The possibility of creating a highly efficient starter-generator system based on a synchronous generator with excitation from permanent magnets and a semiconductor converter for an auxiliary power plant of aircrafts is shown. Structural and basic schemes for constructing a system for generating electrical energy are proposed. The approach to the choice of rational circuit solutions is substantiated, basic estimates of the electrical parameters of the system are obtained. The possibility of achieving a specific mass of a semiconductor converter for synchronous

  1. Auxiliary lift propulsion system with oversized front fan

    Energy Technology Data Exchange (ETDEWEB)

    Castells, O.T.; Johnson, J.E.; Rundell, D.J.

    1980-09-16

    A propulsion system for use primarily in V/STOL aircraft is provided with a variable cycle, double bypass gas turbofan engine and a remote augmenter to produce auxiliary lift. The fan is oversized in air-pumping capability with respect to the cruise flight requirements of the remainder of the engine and a variable area, low pressure turbine is capable of supplying varying amounts of rotational energy to the oversized fan, thereby modulating its speed and pumping capability. During powered lift flight, the variable cycle engine is operated in the single bypass mode with the oversized fan at its maximum pumping capability. In this mode, substantially all of the bypass flow is routed as an auxiliary airstream to the remote augmenter where it is mixed with fuel, burned and exhausted through a vectorable nozzle to produce thrust for lifting. Additional lift is generated by the high energy products of combustion of the variable cycle engine which are further energized in an afterburner and exhausted through a thrust vectorable nozzle at the rear of the engine.

  2. Integrated hydrogen/oxygen technology applied to auxiliary propulsion systems

    Science.gov (United States)

    Gerhardt, David L.

    1990-01-01

    The purpose of the Integrated Hydrogen/Oxygen Technology (IHOT) study was to determine if the vehicle/mission needs and technology of the 1990's support development of an all cryogenic H2/O2 system. In order to accomplish this, IHOT adopted the approach of designing Integrated Auxiliary Propulsion Systems (IAPS) for a representative manned vehicle; the advanced manned launch system. The primary objectives were to develop IAPS concepts which appeared to offer viable alternatives to state-of-the-art (i.e., hypergolic, or earth-storable) APS approaches. The IHOT study resulted in the definition of three APS concepts; two cryogenic IAPS, and a third concept utilizing hypergolic propellants.

  3. Improvements of feedwater controller for the super fast reactor

    International Nuclear Information System (INIS)

    Ishiwatari, Yuki; Peng, Changhong; Ikejiri, Satoshi; Oka, Yoshiaki

    2010-01-01

    The main steam temperature of SCWRs sensitively changes with the power-to-flow ratio. In this article, the feedwater controller of the Super FR (fast-spectrum SCWR) is modified from that of the Super LWR (thermal-spectrum SCWR) for suppressing the variation of the main steam temperature. A plant system analysis code SPRAT-F is used. One of three feedback terms is added to the original feedwater controller that took only the deviation of the main steam temperature into consideration. In the feedwater controller (A), the deviation of the power-to-flow ratio is considered. In the feedwater controller (B), the deviation of the power is considered. In the feedwater controller (C), the time derivative of the power is considered. All the modified feedwater controllers keep the variation of the main steam temperature within 2degC, which has been achieved in recent supercritical coal-fired power plants, against typical load change. In order to further confirm the performance of the modified feedwater controllers, five typical perturbations are analyzed. All the feedwater controllers including the original one stably control the Super FR against all the perturbations without a significant oscillation or offset. Among them, the feedwater controller (B) gives a smaller or at least not larger variation of the main steam temperature compared with the original one at all the perturbations, while the feedwater controllers (A) and (C) give a larger variation in particular cases. From these results, it is concluded that the original feedwater controller is successfully improved as the feedwater controller (B). (author)

  4. Performance evaluation of solar aided feedwater heating of coal-fired power generation (SAFHCPG) system under different operating conditions

    International Nuclear Information System (INIS)

    Hong-juan, Hou; Zhen-yue, Yu; Yong-ping, Yang; Si, Chen; Na, Luo; Junjie, Wu

    2013-01-01

    Highlights: • The performance of a SAFHCPG system at design point is analyzed. • The solar radiation intensity and the electrical load demand on the grid side are considered in the annual performance analysis. • The optimum aperture area of the solar field has been discussed based on the annual performance. - Abstract: Integrating solar energy with a coal-fired power plant or other power systems has been proved to be an efficient way to utilize solar energy for power generation. Solar aided feedwater heating of a coal-fired power generation (SAFHCPG) system, which is mainly discussed in this paper, is chosen as an option for its easy operation and flexible control nature. The performance of a SAFHCPG system at design point is analyzed under various load conditions in the paper. As the results show in Table 4, the lower load of coal-fired unit that solar aid, the lower solar-to-electric efficiency will be. For a SAFHCPG system, its performance is influenced by the solar radiation intensity and the electrical load demand on the grid side. The correlation between the annual performance of a SAFHCPG plant and the two key factors is discussed and then the optimal aperture area of solar field is derived. The result shows that, for the case studied the optimal aperture area of solar field and the lowest LEC (Levelized Electricity Costs) are: 115395 m 2 and 0.472 ¥/kW h in a typical year; 138945 m 2 and 1.010 ¥/kW h in an extremely low radiation year; 91845 m 2 and 0.426 ¥/kW h in an extremely high radiation year respectively

  5. Evaluation of Transmission Grid Voltage Impact on the Operation of Power Units’ Auxiliary Systems

    Directory of Open Access Journals (Sweden)

    Józef Paska

    2015-12-01

    Full Text Available This paper presents the low voltage impact on the operation of critical auxiliaries of selected generation units in the national power system. Time limits are determined for the operation of these auxiliaries at low voltage in the power system and the acceptable reduced voltages in their secondary circuits at which the generation unit is capable of interoperation with the system. Upgrades of auxiliary systems are proposed which would enable interoperation of the unit and the system at significantly reduced system voltages.

  6. Application of fuzzy logic control system for reactor feed-water control

    International Nuclear Information System (INIS)

    Iijima, T.; Nakajima, Y.

    1994-01-01

    The successful actual application of a fuzzy logic control system to the a nuclear Fugen nuclear power reactor is described. Fugen is a heavy-water moderated, light-water cooled reactor. The introduction of fuzzy logic control system has enabled operators to control the steam drum water level more effectively in comparison to a conventional proportional-integral (PI) control system

  7. Auxiliary System Load Schemes in Large Thermal and Nuclear Power Plants

    International Nuclear Information System (INIS)

    Kuzle, I.; Bosnjak, D.; Pandzic, H.

    2010-01-01

    Uninterrupted auxiliary system power supply in large power plants is a key factor for normal operation, transient states, start-ups and shutdowns and particularly during fault conditions. Therefore, there are many challenges in designing the main electrical system as well as the auxiliary systems power supply. Depending upon the type of fuel used and the environmental control system required, a thermal power plant may consume as much as 10% of its total generation for auxiliary power, while a nuclear power plant may require only 4 - 6% auxiliaries. In general, the larger the power generating plant, the higher the voltage selected for the AC auxiliary electric system. Most stations in the 75 to 500 MW range utilize 4,2 kV as the base auxiliary system voltage. Large generating stations 500 - 1000 MW and more use voltage levels of 6,9 kV and more. Some single dedicated loads such as electric driven boiler feed pumps are supplied ba a 13,8 kV bus. While designing the auxiliary electric system, the following areas must be considered: motor starting requirements, voltage regulation requirements, short-circuit duty requirements, economic considerations, reliability and alternate sources. Auxiliary power supply can't be completely generalized and each situation should be studied on its own merits to determine the optimal solution. Naturally, nuclear power plants have more reliability requirements and safety design criteria. Main coolant-pump power supply and continuity of service to other vital loads deserve special attention. This paper presents an overview of some up-to-date power plant auxiliary load system concepts. The main types of auxiliary loads are described and the electric diagrams of the modern auxiliary system supply concepts are given. Various alternative sources of auxiliary electrical supply are considered, the advantages and disadvantages of these are compared and proposals are made for high voltage distribution systems around the thermal and nuclear plant

  8. Reactor feedwater pump control device

    International Nuclear Information System (INIS)

    Nishiyama, Hiroyuki.

    1990-01-01

    An amount of feedwater necessary for ensuring reactor inventory after scram is ensured automatically based on the reactor output before scram of a BWR type reactor. That is, if scram should occur, a feedwater flow rate just before the scram is stored by reactor output signals. Further, the amount of feedwater required after the scram is determined based on the output of the memory. The reactor power after the scram based on a feedwater flow rate and a main steam flow rate is inputted to an integrator, to calculate and output the amount of the feedwater flow rate (1) injected after the scram for the inventory. A coast down flowrate (2) in a case of pump trip is forecast by the output signals. Automatic trip is outputted to all turbine driving feedwater pumps when the sum of (1) and (2) exceeds a necessary and sufficient amount of feedwater required for ensuring inventory. For motor driving feedwater pumps, only a portion, for example, one of the pumps is automatically started while other pumps are stopped their operation, only in this case, to prevent excess water feeding. (I.S.)

  9. Modernization of the feedwater heaters control level of the Almaraz I Nuclear Power Plant by OVATION system; Modernizacion del control de nivel de los calentadores de agua de alimentacion de C.N. Almaraz I mediante el sistema OVATION

    Energy Technology Data Exchange (ETDEWEB)

    Madronal Rodriguez, E.; Cabrero Munoz, J. E.

    2010-07-01

    As a result of the process of technological renovation of the heaters system and the power increase project, Almaraz Nuclear Power Plant has made several design changes in the feedwater heaters system. Within these changes, the old heaters control loops are replaced because the new power will increase the heaters drainage caudal. This modernization is carried out using the OVATION control system.

  10. Disturbance in the power system caused by auxiliary DC installation failure of switchyard

    Energy Technology Data Exchange (ETDEWEB)

    Mesic, M. [HEP Transmission System Operator, Zagreb (Croatia); Tesnjak, S.; Skok, S. [Zagreb Univ. (Croatia). Faculty of Electrical Engineering and Computing

    2008-07-01

    Auxiliary direct current (DC) installation failures can lead to outages in power plants and compromise the security of power systems. In this study, a simplified stationary model was used to simulate an auxiliary DC installation in a switchyard. The aim of the study was to evaluate new International Electrotechnical Commission (IEC) standards for auxiliary DC installation dimensioning and analysis. Criteria included the dimensioning and selection of batteries; the calculation of conductor heating; voltage drop calculations; conductor squares in relation to permanent currents; and the evaluation of protection elements. The new standards were compared with the previous auxiliary system installation methodology. Results of the study suggested that the new standard has introduced significant improvements in short circuit current calculation. Laboratory tests for the measurement of short circuits showed that the active network has less of an impact on the auxiliary system than previous measuring methods. Alterations to the IEC standard will be required as a result of limitations to the short circuit current and new rectifier technology. Results of the study will be used to develop a new model and scheme for dimensioning and analyzing auxiliary DC installations. 9 refs., 4 tabs., 5 figs.

  11. Regulatory analysis for the resolution of Generic Issue 125.II.7 ''Reevaluate Provision to Automatically Isolate Feedwater from Steam Generator During a Line Break''

    International Nuclear Information System (INIS)

    Basdekas, D.L.

    1988-09-01

    Generic Issue 125.II.7 addresses the concern related to the automatic isolation of auxiliary feedwater (AFW) to a steam generator with a broken steam or feedwater line. This regulatory analysis provides a quantitative assessment of the costs and benefits associated with the removal of the AFW automatic isolation and concludes that no new regulatory requirements are warranted. 21 refs., 7 tabs

  12. An effect of downcomer feedwater fraction on steam generator performance with an axial flow economizer

    International Nuclear Information System (INIS)

    Jung, Byung Ryul; Park, Hu Shin; Chung, Duk Muk; Baik, Se Jin

    2000-01-01

    The effects of feedwater flow fraction introduced into the downcomer region have been evaluated in terms of steam generator performance based on the same steam generator thermal output for the Korea Standard Nuclear Power Plant (KSNP) steam generator. The KSNP steam generator design has an integral axial flow economizer which is designed such that most of the feedwater is introduced through the economizer region and only a portion of feedwater through the downcomer region. The feedwater flow introduced into the downcomer region is not normally controlled during the power operation. However, the actual feedwater fraction into the downcomer region may differ from the design flow depending on the as-built system and component characteristics. Investigated in this paper were the downcomer feedwater flow effects on the steam pressure, circulation ratio, internal void fraction and velocity distribution in the tube bundle region at the steady state operation using SAFE and ATHOS3 codes. The results show that the steam pressure increases and the resultant total feedwater flow increases with reducing the downcomer feedwater flow fraction for the same steam generator thermal output. The slight off-design condition of downcomer feedwater flow fraction renders no significant effect on the steam generator performance such as circulation ratios, steam qualities, void fractions and internal velocity distributions. The evaluation shows that the slight off-design downcomer feedwater flow fraction deviation up to ± 5% is acceptable for the steam generator performance

  13. Aiming of Kirkpatrick-Baez microscope based on auxiliary optical system

    International Nuclear Information System (INIS)

    Huang Shengling; Mu Baozhong; Yi Shengzhen; Wang Xin; Wang Zhanshan; Ding Yongkun; Miao Wenyong; Dong Jianjun

    2009-01-01

    An auxiliary optical system has been designed, which can provide precise positioning for aiming Kirkpatrick-Baez (KB) microscope object location. An 8 keV X-ray imaging system by KB microscope with periodic multilayer films has been designed. The field of view and depth of field in the resolution of 5 μm are got, and then the corresponding point and depth of field in diagnostic experiments are calculated. Based on the object-image relations and precision of the KB microscope, an auxiliary visible light imaging system is designed and X-ray imaging experiments are performed, which can achieve equivalent aiming between the visible imaging system and the KB microscope. The results show that ±20 μm vertical axis plane and ±300 μm axial accuracy are achieved through the auxiliary optical path, which can meet the object point positioning requirements of the KB microscope. (authors)

  14. Technical feasibility study of a low-cost hybrid PAC-UF system for wastewater reclamation and reuse: a focus on feedwater production for low-pressure boilers.

    Science.gov (United States)

    Amosa, Mutiu Kolade; Jami, Mohammed Saedi; Alkhatib, Ma'an Fahmi R; Majozi, Thokozani

    2016-11-01

    This study has applied the concept of the hybrid PAC-UF process in the treatment of the final effluent of the palm oil industry for reuse as feedwater for low-pressure boilers. In a bench-scale set-up, a low-cost empty fruit bunch-based powdered activated carbon (PAC) was employed for upstream adsorption of biotreated palm oil mill effluent (BPOME) with the process conditions: 60 g/L dose of PAC, 68 min of mixing time and 200 rpm of mixing speed, to reduce the feedwater strength, alleviate probable fouling of the membranes and thus improve the process flux (productivity). Three polyethersulfone ultrafiltration membranes of molecular weight cut-off (MWCO) of 1, 5 and 10 kDa were investigated in a cross-flow filtration mode, and under constant transmembrane pressures of 40, 80, and 120 kPa. The permeate qualities of the hybrid processes were evaluated, and it was found that the integrated process with the 1 kDa MWCO UF membrane yielded the best water quality that falls within the US EPA reuse standard for boiler-feed and cooling water. It was also observed that the permeate quality is fit for extended reuse as process water in the cement, petroleum and coal industries. In addition, the hybrid system's operation consumed 37.13 Wh m -3 of energy at the highest applied pressure of 120 kPa, which is far lesser than the typical energy requirement range (0.8-1.0 kWh m -3 ) for such wastewater reclamation.

  15. Smart Soft-Sensing for the Feedwater Flowrate at PWRs Using a GMDH Algorithm

    Science.gov (United States)

    Lim, Dong Hyuk; Lee, Sung Han; Na, Man Gyun

    2010-02-01

    The thermal reactor power in pressurized water reactors (PWRs) is typically assessed using secondary system calorimetric calculations based on accurate measurements of the feedwater flowrate. Therefore, precise measurements of the feedwater flowrate are essential. In most PWRs, Venturi meters are used to measure the feedwater flowrate. However, the fouling phenomena of the Venturi meter deteriorate the accuracy of the existing hardware sensors. Consequently, it is essential to resolve the inaccurate measurements of the feedwater flowrate. In this study, in order to estimate the feedwater flowrate online with high precision, a smart soft sensing model for monitoring the feedwater flowrate was developed using a group method of data handling (GMDH) algorithm combined with a sequential probability ratio test (SPRT). The uncertainty of the GMDH model was also analyzed. The proposed sensing and monitoring algorithm was verified using the acquired real plant data from Yonggwang Nuclear Power Plant Unit 3.

  16. Computer determination of event maps with application to auxiliary supply systems

    International Nuclear Information System (INIS)

    Wredenberg, L.; Billinton, R.

    1975-01-01

    A method of evaluating the reliability of sequential operations in systems containing standby and alternate supply facilities is presented. The method is based upon the use of a digital computer for automatic development of event maps. The technique is illustrated by application to a nuclear power plant auxiliary supply system. (author)

  17. Multireference Density Functional Theory with Generalized Auxiliary Systems for Ground and Excited States.

    Science.gov (United States)

    Chen, Zehua; Zhang, Du; Jin, Ye; Yang, Yang; Su, Neil Qiang; Yang, Weitao

    2017-09-21

    To describe static correlation, we develop a new approach to density functional theory (DFT), which uses a generalized auxiliary system that is of a different symmetry, such as particle number or spin, from that of the physical system. The total energy of the physical system consists of two parts: the energy of the auxiliary system, which is determined with a chosen density functional approximation (DFA), and the excitation energy from an approximate linear response theory that restores the symmetry to that of the physical system, thus rigorously leading to a multideterminant description of the physical system. The electron density of the physical system is different from that of the auxiliary system and is uniquely determined from the functional derivative of the total energy with respect to the external potential. Our energy functional is thus an implicit functional of the physical system density, but an explicit functional of the auxiliary system density. We show that the total energy minimum and stationary states, describing the ground and excited states of the physical system, can be obtained by a self-consistent optimization with respect to the explicit variable, the generalized Kohn-Sham noninteracting density matrix. We have developed the generalized optimized effective potential method for the self-consistent optimization. Among options of the auxiliary system and the associated linear response theory, reformulated versions of the particle-particle random phase approximation (pp-RPA) and the spin-flip time-dependent density functional theory (SF-TDDFT) are selected for illustration of principle. Numerical results show that our multireference DFT successfully describes static correlation in bond dissociation and double bond rotation.

  18. Progress in the integration of the ITER plant systems in auxiliary buildings

    International Nuclear Information System (INIS)

    Kotamäki, M.; Cordier, J.-J.; Kuehn, I.; Perrin, J.-L.; Sweeney, S.; Villedary, B.

    2016-01-01

    Highlights: • Usage of 3D CAD model in ITER configuration management presented. • 3D CAD models efficient in configuration and interface management. • Costly and schedule delaying changes avoided with proper interface management. • ITER buildings construction progressing. - Abstract: The ITER Tokamak machine is located in the center of Tokamak complex buildings consisting of Tokamak, Diagnostic, and Tritium buildings. Around the Tokamak complex there are over 30 auxiliary buildings housing various plant systems serving the Tokamak machine either directly or indirectly. The layout and space allocation of each auxiliary building and plant systems housed by the building are represented in the so-called Configuration Management Models (CMM). These are light 3D CAD models that define the required space envelope and the physical interfaces between the systems and the buildings and in-between the systems. The paper describes the CMM and interface management processes of the ITER auxiliary buildings and plant systems, and discusses the preparations for the plant installation phase. In addition, the current baseline configuration of the ITER plant systems in auxiliary buildings is described together with the recent developments in the configuration of different systems, as well as the current status of the construction of the buildings.

  19. Secondary systems of PWR and BWR

    International Nuclear Information System (INIS)

    Schindler, N.

    1981-01-01

    The secondary systems of a nuclear power plant comprises the steam, condensate and feedwater cycle, the steam plant auxiliary or ancillary systems and the cooling water systems. The presentation gives a general review about the main systems which show a high similarity of PWR and BWR plants. (orig./RW)

  20. “Wheelchair slow transit” system-based elderly auxiliary travel mode

    Directory of Open Access Journals (Sweden)

    Yan Lin

    2015-09-01

    Full Text Available Based on research of the current situation and analysis result of a case study in the Nanjing region, this paper proposes a “wheelchair slow transit”(WST system-based elderly auxiliary travel mode. The system involves three fundamental composition frames, namely, support, transit components, and connection components. Each component is designed as an armrest, ground track, or vertical type to respond to actual demands. Thus, this system may be adaptable to diverse conditions. Taking Xiangpuying community as a case study, the author examined the application of the WST auxiliary mode in particular communities. The WST system helps to increase the accessibility of existing public areas, creates a safe community traffic environment, improves municipal facilities, and strengthens universal design. The study intends to provide a reference to obtain a complete aged care design and to build a comfortable and livable aged care community environment.

  1. Pressurized water-reactor feedwater piping response to water hammer

    International Nuclear Information System (INIS)

    Arthur, D.

    1978-03-01

    The nuclear power industry is interested in steam-generator water hammer because it has damaged the piping and components at pressurized water reactors (PWRs). Water hammer arises when rapid steam condensation in the steam-generator feedwater inlet of a PWR causes depressurization, water-slug acceleration, and slug impact at the nearest pipe elbow. The resulting pressure pulse causes the pipe system to shake, sometimes violently. The objective of this study is to evaluate the potential structural effects of steam-generator water hammer on feedwater piping. This was accomplished by finite-element computation of the response of two sections of a typical feedwater pipe system to four representative water-hammer pulses. All four pulses produced high shear and bending stresses in both sections of pipe. Maximum calculated pipe stresses varied because the sections had different characteristics and were sensitive to boundary-condition modeling

  2. Comparative LCA of methanol-fuelled SOFCs as auxiliary power systems on-board ships

    International Nuclear Information System (INIS)

    Strazza, C.; Del Borghi, A.; Costamagna, P.; Traverso, A.; Santin, M.

    2010-01-01

    Fuel cells own the potential for significant environmental improvements both in terms of air quality and climate protection. Through the use of renewable primary energies, local pollutant and greenhouse gas emissions can be significantly minimized over the full life cycle of the electricity generation process, so that marine industry accounts renewable energy as its future energy source. The aim of this paper is to evaluate the use of methanol in Solid Oxide Fuel Cells (SOFC), as auxiliary power systems for commercial vessels, through Life Cycle Assessment (LCA). The LCA methodology allows the assessment of the potential environmental impact along the whole life cycle of the process. The unit considered is a 20 kWel fuel cell system. In a first part of the study different fuel options have been compared (methanol, bio-methanol, natural gas, hydrogen from cracking, electrolysis and reforming), then the operation of the cell fed with methanol has been compared with the traditional auxiliary power system, i.e. a diesel engine. The environmental benefits of the use of fuel cells have been assessed considering different impact categories. The results of the analysis show that fuel production phase has a strong influence on the life cycle impacts and highlight that feeding with bio-methanol represents a highly attractive solution from a life cycle point of view. The comparison with the conventional auxiliary power system shows extremely lower impacts for SOFCs.

  3. Feedwater control device for reactor pressure vessels

    International Nuclear Information System (INIS)

    Oonuma, Takeshi.

    1982-01-01

    Purpose: To prevent the generation of thermal stresses at the junction between a clean-up water pipe and a feedwater pipe. Constitution: Hot water containing impurities in a pressure vessel is caused to flow by a recycling pump through a heat exchanger, a cooler and a clean-up desalter and again by way of the heat exchanger into the feedwater pipe at the junction with the clean-up water pipe, where it is mixed with the feedwater passed by way of a feedwater heater and supplied to the pressure vessel. The feedwater temperature for the feedwater pipe and the set temperature for the clean-up water are compared with each other by using temperature sensors disposed to the feedwater pipe between the junction and the feedwater heater at the upstream of the junction. If the temperature difference is increased, for instance, upon transient state where the operation of the feedwater heater is not yet stabilized, the recycling pump is controlled to stop the supply of the clean-up water to the junction while flowing only the feedwater. This makes the temperature distribution uniform and prevents the generation of the thermal stresses at the junction, by which reactor safety can be improved. (Moriyama, K.)

  4. Apparatus and methods for supplying auxiliary steam in a combined cycle system

    Science.gov (United States)

    Gorman, William G.; Carberg, William George; Jones, Charles Michael

    2002-01-01

    To provide auxiliary steam, a low pressure valve is opened in a combined cycle system to divert low pressure steam from the heat recovery steam generator to a header for supplying steam to a second combined cycle's steam turbine seals, sparging devices and cooling steam for the steam turbine if the steam turbine and gas turbine lie on a common shaft with the generator. Cooling steam is supplied the gas turbine in the combined cycle system from the high pressure steam turbine. Spent gas turbine cooling steam may augment the low pressure steam supplied to the header by opening a high pressure valve whereby high and low pressure steam flows are combined. An attemperator is used to reduce the temperature of the combined steam in response to auxiliary steam flows above a predetermined flow and a steam header temperature above a predetermined temperature. The auxiliary steam may be used to start additional combined cycle units or to provide a host unit with steam turbine cooling and sealing steam during full-speed no-load operation after a load rejection.

  5. Energic, Exergic, Exergo‐economic investigation and optimization of auxiliary cooling system (ACS equipped with compression refrigerating system (CRS

    Directory of Open Access Journals (Sweden)

    Omid Karimi Sadaghiyani

    2017-09-01

    Full Text Available Heller main cooling tower as air-cooled heat exchanger is used in the combined cycle power plants (CCPP to reduce the temperature of condenser. In extreme summer heat, the efficiency of the cooling tower is reduced and it lessens performance of Steam Turbine Generation (STG unit of Combined Cycle Power Plant (CCPP. Thus, the auxiliary cooling system (ACS is equipped with compression refrigerating system (CRS. This auxiliary system is linked with the Heller main cooling tower and improves the performance of power plant. In other words, this auxiliary system increases the generated power of STG unit of CCPP by decreasing the temperature of returning water from cooling tower Therefore, in the first step, the mentioned auxiliary cooling system (ACS as a heat exchanger and compression refrigerating system (CRS have been designed via ASPEN HTFS and EES code respectively. In order to validate their results, these two systems have been built and theirs experimentally obtained data have been compared with ASPEN and EES results. There are good agreements between results. After that, exergic and exergo-economic analysis of designed systems have been carried out. Finally, the compression refrigerating system (CRS has been optimized via Genetic Algorithm (GA. Increasing in exergy efficiency (ε from 14.23% up to 36.12% and decreasing the total cost rate (ĊSystem from 378.2 ($/h to 308.2 ($/h are as results of multi-objective optimization.

  6. The integrated design of the ITER magnets and their auxiliary systems

    International Nuclear Information System (INIS)

    Huget, M.

    1999-01-01

    The magnet system design for the International Thermonuclear Experimental Reactor (ITER) has reached a high degree of integration to meet performance and operation requirements, including reliability and maintainability, in a cost effective manner. This paper identifies the requirements of long inductive burn time, large number of tokamak pulses, operational flexibility for the poloidal field (PF) system, magnet reliability and the cost constraints as the main design drivers. Key features of the magnet system which stem from these design drivers are described, together with interfaces and integration aspects of certain auxiliary systems. (author)

  7. Replacement of the feedwater pipe system in reactor building outside containment at the nuclear power plant Philippsburg; Austausch der Speisewasserleitung im Reaktorgebaeude ausserhalb SHB im Kernkraftwerk Philippsburg I

    Energy Technology Data Exchange (ETDEWEB)

    Kessler, A. [Energie-Versorgung Schwaben AG, Stuttgart (Germany); Labes, M. [Siemens AG Unternehmensbereich KWU, Offenbach am Main (Germany); Schwenk, B. [Kernkraftwerk Philippsburg GmbH (Germany)

    1998-11-01

    After full replacement of the feedwater pipe system during the inspection period in 1997, combined with a modern materials, manufacturing and analysis concept, the entire pipe system of the water/steam cycle in the reactor building of KKP 1 now consists of high-toughness materials. The safety level of the entire plant has been increased by leaving aside postulation of F2 breaks in the reactor building and providing for protection against 0.1 leaks. Based on fluid-dynamic calculations for the cases of pump failure and pipe break, as well as pipe system calculations in 5 extensive calculation cycles, about 130 documents were filed for inspection and approval (excluding preliminary test documents on restraints). Points of main interest for safety analysis in this context were the optimised closing performance of the 3rd check valves and the integrity of the nozzle region at the RPV. (oirg./CB) [Deutsch] Durch den Restaustausch der Speisewasserleitungen in der Revision 1997, verbunden mit einem modernen Werkstoff-, Fertigungs- und Nachweiskonzept, sind im Reaktorgebaeude von KKP 1 in den Hauptleitungen des Wasser-Dampf-Kreislaufes nur noch hochzaehe Werkstoffe eingesetzt. Durch den Verzicht auf das Postulat von 2F-Bruechen im Reaktorgebaeude und durch die Auslegung gegen 0,1F-Lecks wird das Sicherheitsniveau der Anlage insgesamt gesteigert. Ausgehend von fluiddynamischen Berechnungen fuer Pumpenausfall und Rohrbruch sowie Rohrsystem-Berechnungen in 5 umfangreichen Berechnungskreisen wurden fuer die Genehmigung und Begutachtung ca. 130 Unterlagen (ohne Halterungs-Vorpruefunterlagen) eingereicht und vom Gutachter geprueft. Schwerpunkte der Nachweisfuehrung waren die Optimierung des Schliessverhaltens der 3. Rueckschlagarmaturen sowie der Integritaetsnachweis des RDB-Anschlusses. (orig./MM)

  8. Improved 3-dimensional image processing technology for remote handling auxiliary system

    International Nuclear Information System (INIS)

    Tomizuka, Chiaki; Jinza, Keisuke; Takahashi, Hiroshi

    2008-01-01

    In the radioactive environment of a nuclear facility, access to the work environment is restricted and therefore handling operations are performed using remote controlled devices. Fuji Electric has developed a remote-controlled auxiliary system that utilizes shape recognition technology to identify and visualize the location and orientation of target objects to be handled. By watching the operation screen of this system, an operator can easily control a manipulator or other handling apparatus. This paper presents an overview and describes details of the development of the system. (author)

  9. Analysis of a postulated pipe rupture and subsequent check valve slam of a PWR feedwater line

    International Nuclear Information System (INIS)

    Chang, K.C.; Adams, T.M.

    1983-01-01

    System designs criteria employed in the design of pressurized water reactors (PWR) requires that, for a postulated instantaneous guillotine rupture anywhere in the steam generator feedwater system, no more than one steam generator can be allowed to blowdown. Feedwater systems in many PWR's consist of pipe lines running from the feedwater pumps into a common feedwater header then branching into each steam generator from the header. The feedwater piping to each steam generator contains swing check valves to prevent reverse flow from the steam generator. This activation of some or all of these check valves significantly complicates the system structural analysis in that not only the blowdown forces resulting from the postulated pipe rupture, but also the water hammer loads resulting from closure of the check valve at high reverse flow velocities must be considered. The loads resulting from system blowdown and check valve closure are axial in nature. Peak loads ranging from 130000 lbs. to 180000 lbs. are not uncommon and are layout dependent. The analysis and design to withstand this transient loading deviates from the usual feedwater line design in that supports are required along the piping axis in the direction normal to the usual seismic supports. A brief and general discussion of the methods employed in the generation of the thermal-hydraulic loadings is presented. However, the discussion emphasizes the piping and piping support structural design and analysis method and approaches used in evaluating a selected portion of such a feedwater system. (orig./RW)

  10. High voltage bus and auxiliary heater control system for an electric or hybrid vehicle

    Science.gov (United States)

    Murty, Balarama Vempaty

    2000-01-01

    A control system for an electric or hybrid electric vehicle includes a vehicle system controller and a control circuit having an electric immersion heater. The heater is electrically connected to the vehicle's high voltage bus and is thermally coupled to a coolant loop containing a heater core for the vehicle's climate control system. The system controller responds to cabin heat requests from the climate control system by generating a pulse width modulated signal that is used by the control circuit to operate the heater at a duty cycle appropriate for the amount of cabin heating requested. The control system also uses the heater to dissipate excess energy produced by an auxiliary power unit and to provide electric braking when regenerative braking is not desirable and manual braking is not necessary. The control system further utilizes the heater to provide a safe discharge of a bank of energy storage capacitors following disconnection of the battery or one of the high voltage connectors used to transmit high voltage operating power to the various vehicle systems. The control circuit includes a high voltage clamping circuit that monitors the voltage on the bus and operates the heater to clamp down the bus voltage when it exceeds a pre-selected maximum voltage. The control system can also be used to phase in operation of the heater when the bus voltage exceeds a lower threshold voltage and can be used to phase out the auxiliary power unit charging and regenerative braking when the battery becomes fully charged.

  11. Feedwater heat condition assessment - An NDE perspective

    International Nuclear Information System (INIS)

    Krzywosz, K.J.

    1995-01-01

    An integral part of the feedwater heater condition assessment program consists of an inspection program performed on a periodic basis to help extend the availability of feedwater heaters. If applied effectively, NDE can extend the life of feedwater heaters by eliminating insurance plugs, minimizing tube leaks, assisting where necessary with design modifications and improved water chemistry, and repairing defective tubes for safety and remedial reasons. By performing inspection on a periodic basis, more realistic, up-to-date heater conditions can be obtained for a planned and timely heater replacements. This paper presents essential components of an effective NDE program to better prepare and assist utilities with reliable feedwater heater inspections

  12. Auxiliary buildings

    International Nuclear Information System (INIS)

    Lakner, I.; Lestyan, E.

    1979-01-01

    The nuclear power station represents a complicated and a particular industrial project. Consequently, the design of the auxiliary buildings serving the power station (offices, kitchen, refreshment room, workshops, depots, water treatment plant building, boiler houses, etc.) requires more attention than usual. This chapter gives a short survey of the auxiliary buildings already completed and discusses the problems of their design, location and structure. (author)

  13. Modeling and simulation of the feedwater system, associated controller and interface with the user for the SUN-RAH nucleo electric plants university student simulator; Modelado y simulacion del sistema de agua de alimentacion, controlador asociado e interfaz con el usuario para el simulador universitario de nucleoelectricas SUN-RAH

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez B, A. [Laboratorio de Analisis de Ingenieria de Reactores Nucleares, DEPFI Campus Morelos, en IMTA Jiutepec, Morelos (Mexico)]. e-mail: alitet@eresmas.com

    2003-07-01

    The simulation process of the component systems of the feedwater of a nucleo electric plant is presented, using several models of reduced order that represent the diverse elements that compose the systems like: the heaters of feedwater, the condenser, the feedwater pump, etc. The integration of the same ones in one simulative structure, and the development of a platform that to give the appearance of to be executed in continuous time, it is the objective of the feedwater simulator, as well as of the SUN-RAH simulator, of which is part. The simulator uses models of reduced order that respond to the observed behavior of a nuclear plant of BWR type. Likewise, it is presented a model of a flow controller of feedwater that will be the one in charge of regulating the demand of the system according to the characteristics and criticize restrictions of safety and controllability, assigned according to those wanted parameters of performance of this system inside the nucleo electric plant. The integration of these models, the adaptation of the variables and parameters, are presented in a way that the integration with the other ones models of the remaining systems of the plant (reactor, steam lines, turbine, etc.), be direct and coherent with the principles of thermodynamic cycles relative to this type of generation plants. The design of those graphic interfaces and the environment where the simulator works its are part of those developments of this work. The reaches and objectives of the simulator complement the description of the simulator. (Author)

  14. A data acquisition and storage system for the ion auxiliary propulsion system cyclic thruster test

    Science.gov (United States)

    Hamley, John A.

    1989-01-01

    A nine-track tape drive interfaced to a standard personal computer was used to transport data from a remote test site to the NASA Lewis mainframe computer for analysis. The Cyclic Ground Test of the Ion Auxiliary Propulsion System (IAPS), which successfully achieved its goal of 2557 cycles and 7057 hr of thrusting beam on time generated several megabytes of test data over many months of continuous testing. A flight-like controller and power supply were used to control the thruster and acquire data. Thruster data was converted to RS232 format and transmitted to a personal computer, which stored the raw digital data on the nine-track tape. The tape format was such that with minor modifications, mainframe flight data analysis software could be used to analyze the Cyclic Ground Test data. The personal computer also converted the digital data to engineering units and displayed real time thruster parameters. Hardcopy data was printed at a rate dependent on thruster operating conditions. The tape drive provided a convenient means to transport the data to the mainframe for analysis, and avoided a development effort for new data analysis software for the Cyclic test. This paper describes the data system, interfacing and software requirements.

  15. Computer-generated direct perception displays for supporting PWR feedwater system start-up and fault management: a proof-of-principle in design

    International Nuclear Information System (INIS)

    Reising, D.V.C.; Jones, B.G.; Shaheen, S.; Moray, N.; Sanderson, P.M.; Rasmussen, J.

    1998-01-01

    difficult problems which have not yet been investigated in extending the proposed approach to fault management. In the present research Rasmussen et al's framework was used for designing computer-generated graphical displays that support pressurized water reactor (PWR) start-up. Specifically, a suite of displays was developed to support a PWR's feedwater (FW) system start-up as a proof-of-principle. The suite of displays demonstrate the theoretical design approach and are not meant to represent a fully implementable interface for FW system control. (author)

  16. Research of Tai-chi-chuan auxiliary training system based on Kinect

    Directory of Open Access Journals (Sweden)

    Zhihong XUE

    2017-04-01

    Full Text Available In order to promote the scientific standardization of Tai-chi-chuan teaching and training, a Tai-chi-chuan auxiliary training system based on Kinect motion capture technology and extraction of the angle feature and speed feature is proposed and designed. The dynamic time planning algorithm (DTW sampling corresponding frame is applied to replace the traditional method of sampling the key frame. The auxiliary training system consists of learning module, action acquisition module and action scoring module. Learning module with stan-dard action teaching video, to meet the requirements of students learning; action acquisition module uses Microsoft developed Kinect equipment to realize data acquisition of the spatial coordinates of the human skeleton in Tai-chi-chuan action, and through filtered noise reduction and the occlusion point data processing the skeleton data is saved. The scoring module constructs the test sequence based on the 16 angle features of eight key joint nodes and the instantaneous velocity characteristics of 20 joint nodes. By comparing with the standard sequence in real time, the original scoring rules is used to achieve the scoring function, which provides students with intuitive and reliable training recommendations, so as to improve the efficiency of learning. By increasing the number of sensors, further designing and optimizing data fusion and filtering algorithm, combining with Microsoft’s Kinect2.0 version, the system can also be applied to medical rehabilitation, physical training analysis and evaluation, virtual reality and human-computer interaction, etc.

  17. The mitigation of flow-accelerated corrosion in the feedwater systems of nuclear reactors - the influence of dissolved oxygen under different operating conditions

    International Nuclear Information System (INIS)

    Lister, D.; Feicht, A.; Fujiwara, K.; Khatibi, M.; Liu, L.; Ohira, T.; Uchida, S.

    2010-01-01

    In order to improve our understanding of the flow-accelerated corrosion (FAC) of carbon steel piping in feedwater systems, a collaborative research program between Japan and Canada has investigated the combined effects of system operating parameters. A major objective was to optimize techniques for minimizing degradation; accordingly, we report here the influence of dissolved oxygen on FAC rate under a range of conditions as examined in the laboratory with a high-temperature water loop. Most of the experiments were done at 140°C in neutral water, in ammoniated water at pH 25°C 9.2 and in ammoniated water at pH 25°C 9.2 with 100 ppb hydrazine. Several flow rates were imposed and two grades of carbon steel were employed for test probes: one containing 0.019% chromium and the other containing 0.001% chromium. Probes were designed to monitor continuously both FAC (by an electrical resistance technique) and electrochemical corrosion potential, ECP (relative to a Ag/AgCl reference electrode). During a typical experiment, probes of different diameter were installed in series. Downstream of the 'resistance probes' to measure FAC, removable probes for detailed surface examination by techniques such as laser-Raman microscopy, scanning-electron microscopy and energy-dispersive x-ray analysis were also installed. In neutral water, FAC rates reached ~6 mm/a and were apparently controlled by mass transfer, which led to a numerical correlation with fluid shear stress at the tube wall. The steel with the lower chromium content had a greater FAC rate by a factor of about 2.4. An oxygen concentration of almost 40 ppb was required to stifle FAC. In ammoniated water, FAC rates were relatively low and correlations depending on mass transfer were dubious. Hydrazine reduced the FAC rate, possibly because it affected the pH locally at the metal surface. It also increased the stifling oxygen concentration at pH 25°C 9.2 to ~3 ppb. At pH 25°C 10, FAC could not be detected

  18. Auxiliary Sensor-Based Borehole Transient Electromagnetic System for the Nondestructive Inspection of Multipipe Strings

    Directory of Open Access Journals (Sweden)

    Bo Dang

    2017-08-01

    Full Text Available Transient electromagnetic (TEM techniques are widely used in the field of geophysical prospecting. In borehole detection, the nondestructive inspection (NDI of a metal pipe can be performed efficiently using the properties of eddy currents. However, with increasing concern for safety in oil and gas production, more than one string of pipe is used to protect wellbores, which complicates data interpretation. In this paper, an auxiliary sensor-based borehole TEM system for the NDI of multipipe strings is presented. On the basis of the characteristics of the borehole TEM model, we investigate the principle behind the NDI of multipipe strings using multiple time slices of induced electromotive force (EMF in a single sensor. The results show that the detection performance of NDI is strongly influenced by eddy-current diffusion in the longitudinal direction. To solve this problem, we used time slices of the induced EMF in both the main and auxiliary sensors. The performance of the proposed system was verified by applying it to an oil well with a production casing and liner. Moreover, field experiments were conducted, and the results demonstrate the effectiveness of the proposed method.

  19. Methodology for testing a system for remote monitoring and control on auxiliary machines in electric vehicles

    Directory of Open Access Journals (Sweden)

    Dimitrov Vasil

    2017-01-01

    Full Text Available A laboratory system for remote monitoring and control of an asynchronous motor controlled by a soft starter and contemporary measuring and control devices has been developed and built. This laboratory system is used for research and in teaching. A study of the principles of operation, setting up and examination of intelligent energy meters, soft starters and PLC has been made as knowledge of the relevant software products is necessary. This is of great importance because systems for remote monitoring and control of energy consumption, efficiency and proper operation of the controlled objects are very often used in different spheres of industry, in building automation, transport, electricity distribution network, etc. Their implementation in electric vehicles for remote monitoring and control on auxiliary machines is also possible and very useful. In this paper, a methodology of tests is developed and some experiments are presented. Thus, an experimental verification of the developed methodology is made.

  20. 49 CFR 230.57 - Injectors and feedwater pumps.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Injectors and feedwater pumps. 230.57 Section 230... Appurtenances Injectors, Feedwater Pumps, and Flue Plugs § 230.57 Injectors and feedwater pumps. (a) Water.... Injectors and feedwater pumps must be kept in good condition, free from scale, and must be tested at the...

  1. An auxiliary frequency tracking system for general purpose lock-in amplifiers

    Science.gov (United States)

    Xie, Kai; Chen, Liuhao; Huang, Anfeng; Zhao, Kai; Zhang, Hanlu

    2018-04-01

    Lock-in amplifiers (LIAs) are designed to measure weak signals submerged by noise. This is achieved with a signal modulator to avoid low-frequency noise and a narrow-band filter to suppress out-of-band noise. In asynchronous measurement, even a slight frequency deviation between the modulator and the reference may lead to measurement error because the filter’s passband is not flat. Because many commercial LIAs are unable to track frequency deviations, in this paper we propose an auxiliary frequency tracking system. We analyze the measurement error caused by the frequency deviation and propose both a tracking method and an auto-tracking system. This approach requires only three basic parameters, which can be obtained from any general purpose LIA via its communications interface, to calculate the frequency deviation from the phase difference. The proposed auxiliary tracking system is designed as a peripheral connected to the LIA’s serial port, removing the need for an additional power supply. The test results verified the effectiveness of the proposed system; the modified commercial LIA (model SR-850) was able to track the frequency deviation and continuous drift. For step frequency deviations, a steady tracking error of less than 0.001% was achieved within three adjustments, and the worst tracking accuracy was still better than 0.1% for a continuous frequency drift. The tracking system can be used to expand the application scope of commercial LIAs, especially for remote measurements in which the modulation clock and the local reference are separated.

  2. Fuel handling machine and auxiliary systems for a fuel handling cell

    International Nuclear Information System (INIS)

    Suikki, M.

    2013-10-01

    This working report is an update for as well as a supplement to an earlier fuel handling machine design (Kukkola and Roennqvist 2006). A focus in the earlier design proposal was primarily on the selection of a mechanical structure and operating principle for the fuel handling machine. This report introduces not only a fuel handling machine design but also auxiliary fuel handling cell equipment and its operation. An objective of the design work was to verify the operating principles of and space allocations for fuel handling cell equipment. The fuel handling machine is a remote controlled apparatus capable of handling intensely radiating fuel assemblies in the fuel handling cell of an encapsulation plant. The fuel handling cell is air tight space radiation-shielded with massive concrete walls. The fuel handling machine is based on a bridge crane capable of traveling in the handling cell along wall tracks. The bridge crane has its carriage provided with a carousel type turntable having mounted thereon both fixed and telescopic masts. The fixed mast has a gripper movable on linear guides for the transfer of fuel assemblies. The telescopic mast has a manipulator arm capable of maneuvering equipment present in the fuel handling cell, as well as conducting necessary maintenance and cleaning operations or rectifying possible fault conditions. The auxiliary fuel handling cell systems consist of several subsystems. The subsystems include a service manipulator, a tool carrier for manipulators, a material hatch, assisting winches, a vacuum cleaner, as well as a hose reel. With the exception of the vacuum cleaner, the devices included in the fuel handling cell's auxiliary system are only used when the actual encapsulation process is not ongoing. The malfunctions of mechanisms or actuators responsible for the motion actions of a fuel handling machine preclude in a worst case scenario the bringing of the fuel handling cell and related systems to a condition appropriate for

  3. Precision improvement of frequency-modulated continuous-wave laser ranging system with two auxiliary interferometers

    Science.gov (United States)

    Shi, Guang; Wang, Wen; Zhang, Fumin

    2018-03-01

    The measurement precision of frequency-modulated continuous-wave (FMCW) laser distance measurement should be proportional to the scanning range of the tunable laser. However, the commercial external cavity diode laser (ECDL) is not an ideal tunable laser source in practical applications. Due to the unavoidable mode hopping and scanning nonlinearity of the ECDL, the measurement precision of FMCW laser distance measurements can be substantially affected. Therefore, an FMCW laser ranging system with two auxiliary interferometers is proposed in this paper. Moreover, to eliminate the effects of ECDL, the frequency-sampling method and mode hopping influence suppression method are employed. Compared with a fringe counting interferometer, this FMCW laser ranging system has a measuring error of ± 20 μm at the distance of 5.8 m.

  4. Simulation of the behaviour of a servo actuated check valve upon rupture of the feedwater pipe

    International Nuclear Information System (INIS)

    Lucas, A.M. de; Perezagua, R.L.; Rosa, B. de la; Sanz, J.

    1995-01-01

    The steam generator replacement programme at Almaraz NPP, provides for the installation of a replacement damped non-return valve for the feedwater system. the function of this valve is to protect the steam generator in the event of a rupture in the feedwater pipe. Sudden closure of the check valve, against the flow and following rupture of the feedwater pipe, causes overpressure in the valve which is transmitted to the steam generator nozzle. It is therefore necessary to know this when designing the internal systems of the steam generator. Using the RELAP5/MODE3 code, it has been possible to simulate the dynamic behaviour of a check valve upon rupture of a feedwater pipe postulated outside the containment. The calculation model has been applied to different types of check valve. (Author)

  5. Condition assessment of closed feedwater heaters

    International Nuclear Information System (INIS)

    Bell, R.J.

    1995-01-01

    Feedwater heaters are often forgotten in condition assessments plans. While they have no moving parts, these components have a significant impact on plant performance equivalent availability. Condition assessment of feedwater heaters includes not only an analysis of the tubing, which because of its thin wall nature is the primary objective of analysis, but other failure causes, such as tube joint leaks, an adverse condition which can and often does occur. For these reasons a comprehensive condition assessment program should be employed. This paper will identify the three level approach suggested by EPRI and many of the testing methods used to assess feedwater heater condition

  6. Design, Testing and Modeling of the Direct Reactor Auxiliary Cooling System for AHTRs

    International Nuclear Information System (INIS)

    Lv, Quiping; Sun, Xiaodong; Chtistensen, Richard; Blue, Thomas; Yoder, Graydon; Wilson, Dane

    2015-01-01

    The principal objective of this research is to test and model the heat transfer performance and reliability of the Direct Reactor Auxiliary Cooling System (DRACS) for AHTRs. In addition, component testing of fluidic diodes is to be performed to examine the performance and viability of several existing fluidic diode designs. An extensive database related to the thermal performance of the heat exchangers involved will be obtained, which will be used to benchmark a computer code for the DRACS design and to evaluate and improve, if needed, existing heat transfer models of interest. The database will also be valuable for assessing the viability of the DRACS concept and benchmarking any related computer codes in the future. The experience of making a liquid fluoride salt test facility available, with lessons learned, will greatly benefit the development of the Fluoride Salt-cooled High-temperature Reactor (FHR) and eventually the AHTR programs.

  7. Research of grounding capacitive current of neutral non-grounding auxiliary system in nuclear power plants

    International Nuclear Information System (INIS)

    Yang Shan; Liu Li; Huang Xiaojing

    2014-01-01

    In the domestic and abroad standards, the grounding capacitive current limitation in the non-grounding electric auxiliary system is less than 10 A. Limiting capacitive current in the standard aims to speed up the arc extinguishing to reduce the duration of arc over-voltage, but not to prevent the arc producing, The arc over-voltage harm is related to the multiple, frequency and duration of the over-voltage. When the insulation vulnerabilities appear in the equipment, the arc over-voltage may result in insulation vulnerabilities of the electrical equipment breakdown, which leads to multiple, short-circuit accidents. The cable connector, accessory and electromotor winding are all insulation vulnerabilities. Setting the arc suppression coil which can counteract the grounding capacitive current makes the arc vanish quickly. Using the casting bus which remarkably reduces the ground capacitance of the electric transmission line makes the equipment safer. (authors)

  8. Design, Testing and Modeling of the Direct Reactor Auxiliary Cooling System for AHTRs

    Energy Technology Data Exchange (ETDEWEB)

    Lv, Quiping [The Ohio State Univ., Columbus, OH (United States); Sun, Xiaodong [The Ohio State Univ., Columbus, OH (United States); Chtistensen, Richard [The Ohio State Univ., Columbus, OH (United States); Blue, Thomas [The Ohio State Univ., Columbus, OH (United States); Yoder, Graydon [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wilson, Dane [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-05-08

    The principal objective of this research is to test and model the heat transfer performance and reliability of the Direct Reactor Auxiliary Cooling System (DRACS) for AHTRs. In addition, component testing of fluidic diodes is to be performed to examine the performance and viability of several existing fluidic diode designs. An extensive database related to the thermal performance of the heat exchangers involved will be obtained, which will be used to benchmark a computer code for the DRACS design and to evaluate and improve, if needed, existing heat transfer models of interest. The database will also be valuable for assessing the viability of the DRACS concept and benchmarking any related computer codes in the future. The experience of making a liquid fluoride salt test facility available, with lessons learned, will greatly benefit the development of the Fluoride Salt-cooled High-temperature Reactor (FHR) and eventually the AHTR programs.

  9. Feedwater heaters functional analysis at Embalse NGS

    International Nuclear Information System (INIS)

    Lolis, R.R.

    1992-01-01

    This study is concerned with the analysis or feedwater heaters, to detect actual failure or a bad trend beyond acceptable operating limits. When these situations are identified, preventive or corrective maintenance must be done. 2 tabs., 14 figs

  10. Boiler feedwater treatment using reverse osmosis at Suncor OSG

    International Nuclear Information System (INIS)

    Brown, T.

    1997-01-01

    The installation of a new 1000 cu m/hr reverse osmosis water treatment system for boiler feedwater at a Suncor plant was discussed. The selection process began in 1993 when Suncor identified a need to increase its boiler feedwater capacity. The company reviewed many options available to increase the treated water capacity. These included: contracting the supply of treated water, adding additional capacity, replacing the entire plant, reverse osmosis, and demineralization. The eventual decision was to build a new 1000 cu m/hr reverse osmosis water treatment plant with the following key components: a Degremont Infilco Ultra Pulsator Clarifier and a Glegg Water Conditioning multimedia filter, Amberpack softeners and reverse osmosis arrays. The reverse osmosis plant was environmentally favourable over an equivalent demineralization plant. A technical comparison was provided between demineralization and reverse osmosis. The system has proven to be successful and economical in meeting the plants needs. 5 figs

  11. Space shuttle auxiliary propulsion system design study. Phase C report: Oxygen-hydrogen RCS/OMS integration study

    Science.gov (United States)

    Bruns, A. E.; Regnier, W. W.

    1972-01-01

    A comparison of the concepts of auxiliary propulsion systems proposed for the space shuttle vehicle is discussed. An evaluation of the potential of integration between the reaction control system and the orbit maneuvering system was conducted. Numerous methods of implementing the various levels of integration were evaluated. Preferred methods were selected and design points were developed for two fully integrated systems, one partially integrated system, and one separate system.

  12. Detection of global and local parameter variations using nonlinear feedback auxiliary signals and system augmentation

    Science.gov (United States)

    D'Souza, Kiran; Epureanu, Bogdan I.

    2010-06-01

    Recently, system augmentation has been combined with nonlinear feedback auxiliary signals to provide sensitivity enhancement in both linear and nonlinear systems. Augmented systems are higher dimensional linear systems that follow trajectories of a nonlinear system one at a time. These augmented systems are subject to a specialized augmented forcing which enforces the augmented system to exactly reproduce the trajectory of the nonlinear system when projected onto the lower dimensional (physical) system. Augmented systems have additional benefits outside of handling nonlinear systems, which makes them more desirable than regular linear systems for sensitivity enhancing control. One of the key advantages of augmented systems is the complete control over the augmented degrees of freedom, and the additional sensor-type knowledge from the augmented variables. These sensing and actuation features are very useful when only few physical actuators and sensors can be placed. Such restrictions are common in most applications, and they severely limit the usefulness of traditional linear sensitivity enhancing feedback approaches. Another benefit of the augmentation is that the control exerted on the augmented degrees of freedom does not require any physical energy, rather it is just signal processing. In this work, these benefits are refined to improve the robustness of detection using sensitivity enhancement. Also, the benefits of system augmentation are explored by using few actuators and sensors. An optimization algorithm is employed not only to maximize the sensitivity of resonant frequencies to added mass at particular locations, but also to detect uniform changes in mass and stiffness. In addition to increased sensitivity for both global and local parameter changes, a study of increasing the sensitivity of local changes, while decreasing the sensitivity of global changes is conducted. Additionally, a methodology is presented to accurately extract augmented frequencies

  13. Space shuttle auxiliary propulsion system design study. Phase C and E report: Storable propellants, RCS/OMS/APU integration study

    Science.gov (United States)

    Anglim, D. D.; Bruns, A. E.; Perryman, D. C.; Wieland, D. L.

    1972-01-01

    Auxiliary propulsion concepts for application to the space shuttle are compared. Both monopropellant and bipropellant earth storable reaction control systems were evaluated. The fundamental concepts evaluated were: (1) monopropellant and bipropellant systems installed integrally within the vehicle, (2) fuel systems installed modularly in nose and wing tip pods, and (3) fuel systems installed modularly in nose and fuselage pods. Numerous design variations within these three concepts were evaluated. The system design analysis and methods for implementing each of the concepts are reported.

  14. Liquid oxygen/liquid hydrogen boost/vane pump for the advanced orbit transfer vehicles auxiliary propulsion system

    Science.gov (United States)

    Gluzek, F.; Mokadam, R. G.; To, I. H.; Stanitz, J. D.; Wollschlager, J.

    1979-01-01

    A rotating, positive displacement vane pump with an integral boost stage was designed to pump saturated liquid oxygen and liquid hydrogen for auxiliary propulsion system of orbit transfer vehicle. This unit is designed to ingest 10% vapor by volume, contamination free liquid oxygen and liquid hydrogen. The final pump configuration and the predicted performance are included.

  15. Auxiliary mine ventilation manual

    International Nuclear Information System (INIS)

    Workplace Safety North

    2010-01-01

    An adequate ventilation system is needed for air quality and handling in a mine and is comprised of many different pieces of equipment for removing contaminated air and supplying fresh air and thereby provide a satisfactory working environment. This manual highlights auxiliary ventilation systems made up of small fans, ducts, tubes, air movers, deflectors and additional air flow controls which distribute fresh air delivered by the primary system to all areas. A review of auxiliary ventilation is provided. Design, operation and management issues are discussed and guidelines are furnished. This manual is limited to underground hard rock operations and does not address directly other, specific auxiliary systems, either in underground coal mines or uranium mines.

  16. Feedwater flow measurements: challenges, current solutions, and 'soft' developments

    International Nuclear Information System (INIS)

    Ruan, D.; Roverso, D.; Fantoni, P.F.; Sanabrias, J.I.; Carrasco, J.A.; Fernandez, L.

    2002-07-01

    This report presents an early progress of a feasibility study of a computational intelligence approach to the enhancement of the accuracy of feedwater flow measurements in the framework of an ongoing cooperation between Tecnatom s.a. in Madrid and the OECD Halden Reactor Project (HRP) in Halden. The aim of this research project is to contribute to the development and validation of a flow sensor in a nuclear power plant (NPP). The basic idea is to combine the use of applied computational intelligence approaches (noise analysis, neural networks, fuzzy systems, wavelets etc.) with existing traditional flow measurements, and in particular with cross correlation flow meter concepts. In this report, Section 2 outlines relevant aspects of thermal power calculations on electrical power plants. Section 3 reviews from the available literature possible approaches and solutions for feedwater flow measurement, including ultrasonic flow meters, cross-correlation flow meters, and 'Virtural' flow meters with artificial neural networks. Section 4 reports typical experimental measurements at the Tecnatom's facility. Section 5 presents an integration approach and preliminary experimental tests. Section 6 discusses the role of soft computing techniques in the context of feedwater flow measurements related nuclear fields, and Section 7 highlights the future research direction. (Author)

  17. Enhancing VHTR Passive Safety and Economy with Thermal Radiation Based Direct Reactor Auxiliary Cooling System

    Energy Technology Data Exchange (ETDEWEB)

    Haihua Zhao; Hongbin Zhang; Ling Zou; Xiaodong Sun

    2012-06-01

    One of the most important requirements for Gen. IV Very High Temperature Reactor (VHTR) is passive safety. Currently all the gas cooled version of VHTR designs use Reactor Vessel Auxiliary Cooling System (RVACS) for passive decay heat removal. The decay heat first is transferred to the core barrel by conduction and radiation, and then to the reactor vessel by thermal radiation and convection; finally the decay heat is transferred to natural circulated air or water systems. RVACS can be characterized as a surface based decay heat removal system. The RVACS is especially suitable for smaller power reactors since small systems have relatively larger surface area to volume ratio. However, RVACS limits the maximum achievable power level for modular VHTRs due to the mismatch between the reactor power (proportional to volume) and decay heat removal capability (proportional to surface area). When the relative decay heat removal capability decreases, the peak fuel temperature increases, even close to the design limit. Annular core designs with inner graphite reflector can mitigate this effect; therefore can further increase the reactor power. Another way to increase the reactor power is to increase power density. However, the reactor power is also limited by the decay heat removal capability. Besides the safety considerations, VHTRs also need to be economical in order to compete with other reactor concepts and other types of energy sources. The limit of decay heat removal capability set by using RVACS has affected the economy of VHTRs. A potential alternative solution is to use a volume-based passive decay heat removal system, called Direct Reactor Auxiliary Cooling Systems (DRACS), to remove or mitigate the limitation on decay heat removal capability. DRACS composes of natural circulation loops with two sets of heat exchangers, one on the reactor side and another on the environment side. For the reactor side, cooling pipes will be inserted into holes made in the outer or

  18. A New Online Secondary Path Modeling Method with An Auxiliary Noise Power Scheduling Strategy for Narrowband Active Noise Control Systems

    Directory of Open Access Journals (Sweden)

    Chao Sun

    2017-11-01

    Full Text Available In recent years, the online secondary path modeling (SPM method with an auxiliary noise power scheduling strategy has been crucial for active noise control (ANC systems and has also become a popular research topic. However, most scheduling strategies have been designed for broadband active noise control (BANC, and these ideas may not be directly applied to narrowband active noise control (NANC systems due to the difference in structure between BANC and NANC systems. In this paper, a new online SPM method with auxiliary noise power scheduling is proposed. Here, the controlled system is adapted using the filtered-x weighted accumulated least mean square (FXWALMS algorithm proposed by the authors. Moreover, the auxiliary noise power is scheduled based on the convergence status of the forgetting factor to accurately track the change in the NANC system. As a result, the proposed method not only achieves good modeling accuracy and fast convergence but also considerably increases noise attenuation. Extensive simulations are conducted to prove the superior performance of the proposed method in various scenarios.

  19. Thermal-hydraulic analysis for changing feedwater check valve leakage rate testing methodology

    Energy Technology Data Exchange (ETDEWEB)

    Fuller, R.; Harrell, J.

    1996-12-01

    The current design and testing requirements for the feedwater check valves (FWCVs) at the Grand Gulf Nuclear Station are established from original licensing requirements that necessitate extremely restrictive air testing with tight allowable leakage limits. As a direct result of these requirements, the original high endurance hard seats in the FWCVs were modified with elastomeric seals to provide a sealing surface capable of meeting the stringent air leakage limits. However, due to the relatively short functional life of the elastomeric seals compared to the hard seats, the overall reliability of the sealing function actually decreased. This degraded performance was exhibited by frequent seal failures and subsequent valve repairs. The original requirements were based on limited analysis and the belief that all of the high energy feedwater vaporized during the LOCA blowdown. These phenomena would have resulted in completely voided feedwater lines and thus a steam environment within the feedwater leak pathway. To challenge these criteria, a comprehensive design basis accident analysis was developed using the RELAP5/MOD3.1 thermal-hydraulic code. Realistic assumptions were used to more accurately model the post-accident fluid conditions within the feedwater system. The results of this analysis demonstrated that no leak path exists through the feedwater lines during the reactor blowdown phase and that sufficient subcooled water remains in various portions of the feedwater piping to form liquid water loop seals that effectively isolate this leak path. These results provided the bases for changing the leak testing requirements of the FWCVs from air to water. The analysis results also established more accurate allowable leakage limits, determined the real effective margins associated with the FWCV safety functions, and led to design changes that improved the overall functional performance of the valves.

  20. Performance evaluation of a state-of-the-art solar air-heating system with auxiliary heat pump

    Science.gov (United States)

    1980-01-01

    The system in Solar House 2 consists of 57.9 sq. m. of Solaron Series 300 Collectors, 10.3 cu. m. of pebble bed storage, domestic water preheating capability and a Carrier air-to-air heat pump as an auxiliary heater. Although the control subsystem was specially constructed to facilitate experimental changes and data reduction, the balance of the solar system was assembled with off-the-shelf components. Since all components of the system are commercially available the system is considered to be a state of the art solar air-heating system. The system design is one that is recommended for residential and small office buildings.

  1. Multi-unit shutdown due to boiler feedwater chemical excursion

    International Nuclear Information System (INIS)

    Diebel, M.E.

    1991-01-01

    Ontario Hydro's Bruce Nuclear Generating Station 'B' consists of four 935 W CANDU units located on the east shore of Lake Huron in the province of Ontario, Canada. On July 25 and 26, 1989 three of the four operating units were shutdown due to boiler feedwater chemical excursions initiated by a process upset in the Water Treatment Plant that provides demineralized make-up water to all four units. The chemicals that escaped from an ion exchange vessel during a routine regeneration very quickly spread through the condensate make-up system and into the boiler feedwater systems. This resulted in boiler sulfate levels exceeding shutdown limits. A total of 260 GWH of electrical generation was unexpectedly made unavailable to the grid at a time of peak seasonal demand. This event exposed several unforeseen deficiencies and vulnerabilities in the automatic demineralized water make-up quality protection scheme, system designs, operating procedures and the ability of operating personnel to recognize and appropriately respond to such an event. The combination of these factors contributed towards turning a minor system upset into a major multi-unit shutdown. This paper provides the details of the actual event initiation in the Water Treatment Plant and describes the sequence of events that led to the eventual shutdown of three units and near shutdown of the fourth. The design inadequacies, procedural deficiencies and operating personnel responses and difficulties are described. The process of recovering from this event, the flushing out of system piping, boilers and the feedwater train is covered as well as our experiences with setting up supplemental demineralized water supplies including trucking in water and the use of rental trailer mounted demineralizing systems. System design, procedural and operational changes that have been made and that are still being worked on in response to this event are described. The latest evidence of the effect of this event on boiler tube

  2. PS auxiliary magnet

    CERN Multimedia

    CERN PhotoLab

    1974-01-01

    Units of the PS auxiliary magnet system. The picture shows how the new dipoles, used for vertical and horizontal high-energy beam manipulation, are split for installation and removal so that it is not necessary to break the accelerator vacuum. On the right, adjacent to the sector valve and the windings of the main magnet, is an octupole of the set.

  3. A simplified approach to feedwater train modeling

    International Nuclear Information System (INIS)

    Ollat, X.; Smoak, R.A.

    1990-01-01

    This paper presents a method to simplify feedwater train models for power plants. A simple set of algebraic equations, based on mass and energy balances, is developed to replace complex representations of the components under certain assumptions. The method was tested and used to model the low pressure heaters of the Sequoyah Nuclear Plant in a larger simulation

  4. Coordination Control of SMR-Based NSSS Modules Integrated by Feedwater Distribution

    Science.gov (United States)

    Dong, Zhe; Song, Maoxuan; Huang, Xiaojin; Zhang, Zuoyi; Wu, Zongxin

    2016-10-01

    Due to its strong safety feature, the small modular reactor whose electric output is no more than 300MWe has been seen as a promising trend in nuclear engineering. By adopting multi-modular scheme, i.e. the superheated steam flows produced by multiple SMR-based nuclear heating system (NSSS) modules are combined to drive a common thermal load, the strong safety feature of a SMR can be applied to large-scale nuclear plants. To improve the economic competitiveness, it is meaningful to integrate multiple NSSS modules by the scheme of feedwater distribution, i.e. sharing a common pump and distributing feedwater by adjusting the opening of regulating valve of each module. The module coordination control of multiple SMR-based NSSS modules coupled by feedwater distribution is essentially the flowrate-pressure control of the common secondary-loop fluid flow network (FFN). In this paper, the nonlinear differential-algebraic model for the FFNs with a single feedwater pump is first given. A novel distributed adaptive flowrate-pressure control is proposed, which is then applied to realize the module coordination. Numerical simulation results in the case of coordination control of two MHTGR-based NSSS modules integrated by feedwater distribution scheme show the feasibility as well as the satisfactory transient performance of this newly-built coordination control law.

  5. Mechanical (turbines and auxiliary equipment)

    CERN Document Server

    Sherry, A; Cruddace, AE

    2013-01-01

    Modern Power Station Practice, Volume 3: Mechanical (Turbines and Auxiliary Equipment) focuses on the development of turbines and auxiliary equipment used in power stations in Great Britain. Topics covered include thermodynamics and steam turbine theory; turbine auxiliary systems such as lubrication systems, feed water heating systems, and the condenser and cooling water plants. Miscellaneous station services, and pipework in power plants are also described. This book is comprised of five chapters and begins with an overview of thermodynamics and steam turbine theory, paying particular attenti

  6. CADRIGS--computer aided design reliability interactive graphics system

    International Nuclear Information System (INIS)

    Kwik, R.J.; Polizzi, L.M.; Sticco, S.; Gerrard, P.B.; Yeater, M.L.; Hockenbury, R.W.; Phillips, M.A.

    1982-01-01

    An integrated reliability analysis program combining graphic representation of fault trees, automated data base loadings and reference, and automated construction of reliability code input files was developed. The functional specifications for CADRIGS, the computer aided design reliability interactive graphics system, are presented. Previously developed fault tree segments used in auxiliary feedwater system safety analysis were constructed on CADRIGS and, when combined, yielded results identical to those resulting from manual input to the same reliability codes

  7. Test facility for auxiliary cooling system (ACS) of fast breeder reactor for Power Reactor and Nuclear Fuel Development Corporation (PNC)

    International Nuclear Information System (INIS)

    1983-01-01

    In preparation of constructing ''Monju'', a prototype fast breeder reactor, PNC has been pushing forward its research and development projects and the ACS was constructed under these projects. The auxiliary cooling system is an important engineered safety feature, and is used for safe removal of heat from the reactor at the shutdown. The ACS serves as a means of testing and assessing the auxiliary cooling system for the ''Monju'' and is designed and manufactured to have one fifth capacity of the Monju. The air heat exchanger and the ACS system was designed to withstand higher temperature range of the conventional design code (MITI-501), and finned tubes were applied for effective heat removal. Preheating system was designed to heat up the whole system over 200 0 C within 20 hours to prevent sodium from freezing. Basic performance of ACS was verified satisfactorily by a series of performance tests, such as start up test, flow rate measurement and preheating test before delivery. The experience from designing and construction of ACS and data obtained by these tests will be very instructive for designing and construction of the ''Monju''. (author)

  8. Design and setting up of a system for remote monitoring and control on auxiliary machines in electric vehicles

    Directory of Open Access Journals (Sweden)

    Dimitrov Vasil

    2017-01-01

    Full Text Available Systems for remote monitoring and control of the proper operation, energy consumption, and efficiency of the controlled objects are very often used in different spheres of industry, in the electricity distribution network, etc. Various types of intelligent energy meters, PLCs and other control devices are involved in such systems. Proper operation of the auxiliary machines in electric vehicles is of great importance and implementation of a system for their remote monitoring and control is useful and ensures reliability and increased efficiency. A system has been designed and built using contemporary devices. An asynchronous motor is controlled by a soft starter and opportunities for remote monitoring (by an intelligent energy meter and control (by a PLC and Touch panel have been provided. Soft starters are widely used in industry for control on asynchronous drives when speed regulation is not a mandatory requirement. They are cheaper than inverters and frequency converters and allow for temporal reduction of the torque and current surge during start-up, as well as smooth deceleration. Therefore they can also be used in electric vehicles to control auxiliary machines (pumps, fans, air coolers, compressors, etc.. The present paper presents a methodology for their design and setting up.

  9. Comparative Study of Electric Energy Storages and Thermal Energy Auxiliaries for Improving Wind Power Integration in the Cogeneration System

    Directory of Open Access Journals (Sweden)

    Yanjuan Yu

    2018-01-01

    Full Text Available In regards to the cogeneration system in Northern China, mainly supported by combined heat and power (CHP plants, it usually offers limited operation flexibility due to the joint production of electric and thermal power. For that large-scale wind farms included in the cogeneration system, a large amount of wind energy may have to be wasted. To solve this issue, the utilization of the electric energy storages and the thermal energy auxiliaries are recommended, including pumped hydro storage (PHS, compressed air energy storage (CAES, hydrogen-based energy storage (HES, heat storage (HS, electric boilers (EB, and heat pumps (HP. This paper proposes a general evaluation method to compare the performance of these six different approaches for promoting wind power integration. In consideration of saving coal consumption, reducing CO2 emissions, and increasing investment cost, the comprehensive benefit is defined as the evaluation index. Specifically, a wind-thermal conflicting expression (WTCE is put forward to simplify the formulation of the comprehensive benefit. Further, according to the cogeneration system of the West Inner Mongolia (WIM power grid, a test system is modelled to perform the comparison of the six different approaches. The results show that introducing the electric energy storages and the thermal energy auxiliaries can both contribute to facilitating wind power integration, and the HP can provide the best comprehensive benefit.

  10. VGB conference 'Chemistry in the power plant 1984' - VGB feedwater conditioning conference

    International Nuclear Information System (INIS)

    1984-01-01

    The conference bears various aspects of feedwater conditioning for power plant cooling systems and steam generators as well as on the analytical assessment of water quality and its translation into operational method approaches. 5 out of the total 14 papers were entered separately in the database. (RB) [de

  11. Operational challenges to feedwater/steam generator water level control

    International Nuclear Information System (INIS)

    Thomas, V.M.; Whaley, S.D.; Federico, P.A.

    2012-01-01

    Feedwater control and turbine control have historically been at the top of the list of contributors to unplanned outages and forced curtailments in the nuclear industry, and they remain so according to recent industry data. Much has been done and is available by way of measures to improve this area and, in spite of much progress, opportunities remain to extend implementation. Toward this end, this paper aims to focus upon feedwater control and provide background on associated characteristics and attributes as a context for identifying the issues which are key challenges that lie at the root of this concern. Primary groupings of these issues will be discussed in order to better define their nature and to establish a basis for a presentation of the range of solutions which have been implemented and remain available to address them. The need for a systems engineering approach, and the role of I&C and field-mounted equipment to application of these solutions will be discussed. (author)

  12. Operational challenges to feedwater/steam generator water level control

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, V.M.; Whaley, S.D.; Federico, P.A. [Westinghouse Electric Company, Cranberry Township, Pennsylvania (United States)

    2012-07-01

    Feedwater control and turbine control have historically been at the top of the list of contributors to unplanned outages and forced curtailments in the nuclear industry, and they remain so according to recent industry data. Much has been done and is available by way of measures to improve this area and, in spite of much progress, opportunities remain to extend implementation. Toward this end, this paper aims to focus upon feedwater control and provide background on associated characteristics and attributes as a context for identifying the issues which are key challenges that lie at the root of this concern. Primary groupings of these issues will be discussed in order to better define their nature and to establish a basis for a presentation of the range of solutions which have been implemented and remain available to address them. The need for a systems engineering approach, and the role of I&C and field-mounted equipment to application of these solutions will be discussed. (author)

  13. Derivation of the mass factors for decommissioning cost estimation of low contaminated auxiliary systems

    International Nuclear Information System (INIS)

    Poskas, G.

    2015-01-01

    Ignalina NPP was operating two RBMK-1500 reactors. Unit 1 was closed at the end of 2004, and Unit 2 - at the end of 2009. Now they are under decommissioning. Decommissioning has been started from the reactor's periphery, with dismantling of non-contaminated and low contaminated equipment and installations. This paper discusses a methodology for derivation of mass factors for preliminary decommissioning costing at NPP when the number of inventory items is significant, and separate consideration of each inventory item is impossible or impractical for preliminary decommissioning plan, especially when the level of radioactive contamination is very low. The methodology is based on detailed data analysis of building V1 taking into account period and inventory based activities, investment and consumables and other decommissioning approach- related properties for building average mass factors. The methodology can be used for cost estimation of preliminary decommissioning planning of NPP auxiliary buildings with mostly very low level contamination. (authors)

  14. Method for measuring feedwater flow rate using ultrasonic technique in PWR power plant

    International Nuclear Information System (INIS)

    Ozaki, Yoshihiko; Oda, Minoru; Tanaka, Mitsuo

    1988-01-01

    At present, differential pressure type flowmeters are widely used in feedwater systems of PWR plants. In these flowmeters, however, scales gradually deposit at the nozzle throat during the plant operation, causing the apparent flow rate to increase and consequently becoming a serious problem for efficient plant operations. Therefore, a new type of ultrasonic flowmeter (USFM) having good stability and free of the above phenomenon has been developed. A method to compensate for the effect of dependency of sound velocity on water temperature and pressure corresponding to PWR feedwater conditions was contrived. The validity of the method was confirmed in an experiment for investigating the sound velocity dependency in practice. The performance of the USFM was also examined using a water loop in various flow conditions with satisfactory results. After the basic studies, finally, the USFM was tested in an actual PWR feedwater system for almost 3 yr. The USFM met all the required characteristics for PWR feedwater systems, those being linearity, accuracy and stability. (author)

  15. Computation of Ground-State Properties in Molecular Systems: Back-Propagation with Auxiliary-Field Quantum Monte Carlo.

    Science.gov (United States)

    Motta, Mario; Zhang, Shiwei

    2017-11-14

    We address the computation of ground-state properties of chemical systems and realistic materials within the auxiliary-field quantum Monte Carlo method. The phase constraint to control the Fermion phase problem requires the random walks in Slater determinant space to be open-ended with branching. This in turn makes it necessary to use back-propagation (BP) to compute averages and correlation functions of operators that do not commute with the Hamiltonian. Several BP schemes are investigated, and their optimization with respect to the phaseless constraint is considered. We propose a modified BP method for the computation of observables in electronic systems, discuss its numerical stability and computational complexity, and assess its performance by computing ground-state properties in several molecular systems, including small organic molecules.

  16. Collector feedwater supply and stability of the power distribution in a pressurized-water reactor

    International Nuclear Information System (INIS)

    Budnikov, V.I.; Kosolapov, S.V.; Kramerov, A.Ya.

    1980-01-01

    It is necessary to determine how the collector feedwater supply affects the disposition of the stability limits and the instability period for the power distribution in such a reactor. The main reason for the fluctuations in feedwater flow rate were shown by additional calculations with the general power regulator switched out to be due to instability on the fundamental in the neutron distribution. The power-level fluctuations are due to oscillation of the feed valve in the level regulator, and consequently to oscillations in the feedwater flow rate. If collector feed is to be employed, it is desirable to improve the response of the pressure control system for the separator drum, because under certain emergency conditions there will be a considerable fall in pressure in the separator drum. The deviation from saturation for the water in the separator drum tube is less in the second method than it is in the first, so the cavitation margin in the principal pumps may be reduced somewhat. Calculations show that this reduction will not occur if the time constant of the turbine synchronizer is about 10 sec. Also, the dynamic characteristics of the nuclear power station in these modes of feedwater supply are appreciably influenced by the parameters of the pressure-control system and the water-level control for the separator drum

  17. Control of feedwater composition of BWR power plant

    International Nuclear Information System (INIS)

    Sturla, P.; D'Anna, A.; Borgese, D.

    1983-01-01

    Corrosion behaviour of fuel element cladding, cycle structural materials and dose rate increase are relevant to physico-chemical characteristics of process coolants and to adopted operational conditions. A careful control of cycle chemistry, during loading and shutdown periods, is necessary to verify material choices, the polishing system and chemistry specifications. For this purpose ENEL carried out some preliminary experimental tests employing continuous control system and samples for specific analytical determinations. The cycle points checked during about two months were: main condensate; condensate after polishing system; outlet of low pressure heathers; final feedwater; inlet and outlet of clean-up system; drains to condenser. The physico-chemical analysis were related to corrosion product levels (Cu, Fe, Ni, Co) and water chemistry (pH, conductivity, dissolved oxygen etc.). The preliminary results allow to express some considerations about sampling procedures, detection limits and reliability of analytical employed methods. The acquisition data time and some morphological oxide pictures are also showed. (author)

  18. 46 CFR 58.01-35 - Main propulsion auxiliary machinery.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Main propulsion auxiliary machinery. 58.01-35 Section 58.01-35 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MAIN AND AUXILIARY MACHINERY AND RELATED SYSTEMS General Requirements § 58.01-35 Main propulsion auxiliary machinery. Auxiliary machinery vital to the main...

  19. Coordinated application of electrical auxiliaries equipment

    Energy Technology Data Exchange (ETDEWEB)

    Appiarius, J.C.; Krug, R.O.

    1977-01-01

    As the power requirements of auxiliaries continue to increase, both in total and as a percentage of generating unit capacity, coordinated application of auxiliaries system components demands more sophisticated approaches to system design. Among the techniques developed to assist system designers is a method which separates the auxiliaries system into modules for conceptual design, with analyses which consider design criteria, equipment capability, and expected operating constraints. This and other techniques, intended to optimize application of metalclad switchgear and auxiliaries transformers, can provide the designer with tools for proper selection and application of equipment which can contribute significantly to overall system performance.

  20. Dispersant application: (1) during steam generator wet layup for removal of existing deposits, and (2) during the long-path recirculation cleanup process of the condensate/feedwater system to reduce startup corrosion product transport to the steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Fruzzetti, K. [Electric Power Research Inst., Palo Alto, California (United States); Anderson, C.; Marks, C.; Kreider, M. [Dominion Engineering, Inc., Reston, Virginia (United States); Walton, B. [Exelon Corp., TMI Nuclear Generating Station, Middleton, Pennsylvania (United States); Reecher, W. [Exelon Corp., Byron Nuclear Generating Station, Byron, Illinois (United States); Morey, D. [Exelon Corp., Warrenville, Illinois (United States)

    2010-07-01

    management operations (e.g., sludge lancing, chemical cleaning, etc.). In 2009 EPRI worked with Exelon Corporation to develop and implement a plan for a trial dispersant application during the SG wet layup at Three Mile Island Unit 1 (TMI-1). Because the SGs were scheduled for replacement during the Fall 2009 outage, this trial represented a unique opportunity to evaluate the efficacy of a dispersant wet layup application with minimal risk to the SGs. This paper discusses the technical bases supporting the addition of dispersant during wet layup at TMI-1 and the results of the Fall 2009 trial application. Additional applications, under EPRI sponsorship, have either just taken place (Doel 3 in Summer 2010) or are planned (Braidwood 1 in Fall 2010). It is anticipated that addition of a dispersant during the long-path recirculation cleanup process will more readily clean up transportable corrosion products from the system and increase their retention time in solution, thereby increasing the amount of iron removed from the condensate and feedwater systems prior to initiation of flow to the SGs. Evaluations preparing for applications of this type include: Reviews of the procedure and general characteristics of the long-path recirculation cleanup process at three plants: Byron Unit 1, Millstone Unit 2 and Three Mile Island (TMI) Unit 1; A laboratory test program to assess dispersant efficacy under the conditions present during the long-path recirculation cleanup process. A number of different dispersant chemicals, including the polyacrylic acid (PAA) used in online applications, were investigated; Generic and plant-specific evaluations (for the above three units) of the compatibility of PAA with the secondary system components anticipated to be wetted during the long-path recirculation cleanup process. Based on the results of this study, inputs concerning the recommended dispersant chemical, concentration, application schedule, and cleanup criteria were generated to aid interested

  1. Auxiliary propulsion

    Science.gov (United States)

    Rosenberg, S. D.

    1984-02-01

    When man is put in the loop, almost anything can happen. Caution must be exercised in permitting life cycle costs analysis to control technology investment. One of the ways of reducing cost is to stay with the old tried and true technology. However, when requirements of a permanent space station are considered (15-year life, the issues associated with health monitoring, maintenance, and repair), the conclusion is that very little, if anything, is really state of the art. Before investing in old technologies to make them comply with the requirements of a permanent space station, the question of whether or not it is worth putting the money there as opposed to advancing the state of the art should be considered. Program managers and system designers must not make the mistake of selecting old technologies in the belief that they are state of the art.

  2. Integrated experimental test program on waterhammer pressure pulses and associated structural responses within a feedwater sparger

    Energy Technology Data Exchange (ETDEWEB)

    Nurkkala, P.; Hoikkanen, J. [Imatran Voima Oy, Vantaa (Finland)

    1997-12-31

    This paper describes the methods and systems as utilized in an integrated experimental thermohydraulic/mechanics analysis test program on waterhammer pressure pulses within a revised feedwater sparger of a Loviisa generation VVER-440-type reactor. This program was carried out in two stages: (1) measurements with a strictly limited set of operating parameters at Loviisa NPP, and (2) measurements with the full set of operating parameters on a test article simulating the revised feedwater sparger. The experiments at Loviisa NPS served as an invaluable source of information on the nature of waterhammer pressure pulses and structural responses. These tests thus helped to set the objectives and formulate the concept for series of tests on a test article to study the water hammer phenomena. The heavily instrumented full size test article of a steam generator feedwater sparger was placed within a pressure vessel simulating the steam generator. The feedwater sparger was subjected to the full range of operating parameters which were to result in waterhammer pressure pulse trains of various magnitudes and duration. Two different designs of revised feedwater sparger were investigated (i.e. `grounded` and `with goose neck`). The following objects were to be met within this program: (1) establish the thermohydraulic parameters that facilitate the occurrence of water hammer pressure pulses, (2) provide a database for further analysis of the pressure pulse phenomena, (3) establish location and severity of these water hammer pressure pulses, (4) establish the structural response due to these pressure pulses, (5) provide input data for structural integrity analysis. (orig.). 3 refs.

  3. 'Better feedwater quality through heat exchange equipment renovation'

    International Nuclear Information System (INIS)

    Pouzenc, C.

    2002-01-01

    In a fossil-fired or nuclear steam power plant, the water secondary circuit is a critical part of its thermodynamic cycle, as it achieves conditioning, pressurizing and heating of the condensate to match the conditions required at the steam generator inlet. Furthermore, the power plant electrical output and efficiency depend on availability and performances of each component of this secondary circuit from the condenser to the steam generator. Erosion and corrosion phenomena are at the origin of most significant failures in these components and related interconnecting systems. Feedwater chemistry is, together with the selection of materials and optimization of fluid velocities, one of the key levers to protect, as efficiently as possible, the components of the water secondary. (authors)

  4. Model predictive control-based dynamic coordinate strategy for hydraulic hub-motor auxiliary system of a heavy commercial vehicle

    Science.gov (United States)

    Zeng, Xiaohua; Li, Guanghan; Yin, Guodong; Song, Dafeng; Li, Sheng; Yang, Nannan

    2018-02-01

    Equipping a hydraulic hub-motor auxiliary system (HHMAS), which mainly consists of a hydraulic variable pump, a hydraulic hub-motor, a hydraulic valve block and hydraulic accumulators, with part-time all-wheel-drive functions improves the power performance and fuel economy of heavy commercial vehicles. The coordinated control problem that occurs when HHMAS operates in the auxiliary drive mode is addressed in this paper; the solution to this problem is the key to the maximization of HHMAS. To achieve a reasonable distribution of the engine power between mechanical and hydraulic paths, a nonlinear control scheme based on model predictive control (MPC) is investigated. First, a nonlinear model of HHMAS with vehicle dynamics and tire slip characteristics is built, and a controller-design-oriented model is simplified. Then, a steady-state feedforward + dynamic MPC feedback controller (FMPC) is designed to calculate the control input sequence of engine torque and hydraulic variable pump displacement. Finally, the controller is tested in the MATLAB/Simulink and AMESim co-simulation platform and the hardware-in-the-loop experiment platform, and its performance is compared with that of the existing proportional-integral-derivative controller and the feedforward controller under the same conditions. Simulation results show that the designed FMPC has the best performance, and control performance can be guaranteed in a real-time environment. Compared with the tracking control error of the feedforward controller, that of the designed FMPC is decreased by 85% and the traction efficiency performance is improved by 23% under a low-friction-surface condition. Moreover, under common road conditions for heavy commercial vehicles, the traction force can increase up to 13.4-15.6%.

  5. Start-up of a power unit of a thermal power plant auxiliary system with supply from a hydropower plant

    Directory of Open Access Journals (Sweden)

    Zbigniew Lubośny

    2013-09-01

    Full Text Available This article discusses the issues related to a power unit of a thermal power plant start-up with the use of a hydropower plant. Hydropower plant can supply and will enable start-up of auxiliary equipment in a power unit of a thermal power plant. Due to high capacity of auxiliary drives, startup of auxiliaries in a thermal power plant after blackout (and boiler shutdown is not possible from emergency energy sources in the power plant. In such a case an external electricity source with high capacity is required.

  6. The VieB auxiliary protein negatively regulates the VieSA signal transduction system in Vibrio cholerae.

    Science.gov (United States)

    Mitchell, Stephanie L; Ismail, Ayman M; Kenrick, Sophia A; Camilli, Andrew

    2015-03-04

    Vibrio cholerae is a facultative pathogen that lives in the aquatic environment and the human host. The ability of V. cholerae to monitor environmental changes as it transitions between these diverse environments is vital to its pathogenic lifestyle. One way V. cholerae senses changing external stimuli is through the three-component signal transduction system, VieSAB, which is encoded by the vieSAB operon. The VieSAB system plays a role in the inverse regulation of biofilm and virulence genes by controlling the concentration of the secondary messenger, cyclic-di-GMP. While the sensor kinase, VieS, and the response regulator, VieA, behave similar to typical two-component phosphorelay systems, the role of the auxiliary protein, VieB, is unclear. Here we show that VieB binds to VieS and inhibits its autophosphorylation and phosphotransfer activity thus preventing phosphorylation of VieA. Additionally, we show that phosphorylation of the highly conserved Asp residue in the receiver domain of VieB regulates the inhibitory activity of VieB. Taken together, these data point to an inhibitory role of VieB on the VieSA phosphorelay, allowing for additional control over the signal output. Insight into the function and regulatory mechanism of the VieSAB system improves our understanding of how V. cholerae controls gene expression as it transitions between the aquatic environment and human host.

  7. Lower Snake River Little Goose and Lower Granite Locks and Dams: Adult Fishway Systems Emergency Auxiliary Water Supply

    National Research Council Canada - National Science Library

    Wielick, Rolf

    2000-01-01

    ... to address the Biological Opinion requirement. This Emergency Auxiliary Water Supply, Phase II - Technical Report continues to evaluate the Phase I report alternatives for the Little Goose and Lower Granite Lock and Dams at a greater...

  8. Development of the user interface for visualization of the auxiliary systems of the TRIGA Mark III nuclear reactor

    International Nuclear Information System (INIS)

    Merced D, J. E.

    2016-01-01

    The Instituto Nacional de Investigaciones Nucleares (ININ) has a nuclear research reactor type swimming pool with movable core cooled and moderate with light water. The nominal maximum power of the reactor is 1 MW in steady-state operation and can be pulsed at a maximum power of 2,000 MW for approximately 10 milliseconds. This reactor is mainly used to study the effects of radiation on various materials and substances. In 2001 the new control console of the nuclear reactor was installed which was based on two digital computers, one computer controls the bar management mechanisms and the other the systems to the reactor operator. In 2004, the control computer was replaced and the software was updated. Within the modernization and/or updating of the TRIGA Mark III reactor of ININ, is intended (theme of this work) to develop the user interface for the visualization of the auxiliary systems, through a Man-Machine Interface module for the renewal process of the control console. The man-machine interface system to be developed will have communication with the programmable logic controllers that will be constantly monitored and controlled to obtain real-time variables of the reactor behavior. (Author)

  9. Participation of Empresarios Agrupados in engineering of the Tokamak systems and auxiliary buildings

    International Nuclear Information System (INIS)

    Fernandez del Palacio, V.

    2013-01-01

    The Architect Engineering works comprise approximately the design of 32 buildings and structures, some of them very simple and others extremely complex. 32 buildings include nuclear buildings, as the Toyama, tritium, or the building of emergency diesel and buildings conventional and the building of the site services. Systems including those related to systems within a building they reach conventional, while interfaces with process systems are countless. Grouped entrepreneurs led the design of the mechanical (PBS65) systems and Electric (PBS43) actively participating in the design of systems of fire proofing of buildings and site. During the development of engineering accident of Fukushima works directly affect in the design of the systems.

  10. Sensitivity of energy and exergy performances of heating and cooling systems to auxiliary components

    DEFF Research Database (Denmark)

    Kazanci, Ongun Berk; Shukuya, Masanori; Olesen, Bjarne W.

    2017-01-01

    Heating and cooling systems in buildings consist of three main subsystems: heating/cooling plant, distribution system, and indoor terminal unit. The choice of indoor terminal unit determines the characteristics of the distribution system and the heating and cooling plants that can be used....... Different forms of energy (electricity and heat) are used in heating and cooling systems, and therefore, a holistic approach to system design and analysis is needed. In particular, distribution systems use electricity as a direct input to pumps and fans, and to other components. Therefore, exergy concept...... should be used in design and analysis of the whole heating and cooling systems, in addition to the energy analysis. In this study, water-based (floor heating and cooling, and radiator heating) and air-based (air heating and cooling) heating and cooling systems were compared in terms of their energy use...

  11. Modifications done in the IPR-R1 reactor and their auxiliary systems

    International Nuclear Information System (INIS)

    Maretti Junior, F.; Amorim, V.A. de; Coura, J.G.

    1986-01-01

    The improvements done in the IPR-R1 reactor for adequateness of operation conditions and increase of irradiation sample capability. The cooling systems, reactor pool, system of control rods were substituted. The optimization of transfer pneumatic system was done. (M.C.K.) [pt

  12. Optimal Scheduling of a Battery Energy Storage System with Electric Vehicles’ Auxiliary for a Distribution Network with Renewable Energy Integration

    Directory of Open Access Journals (Sweden)

    Yuqing Yang

    2015-09-01

    Full Text Available With global conventional energy depletion, as well as environmental pollution, utilizing renewable energy for power supply is the only way for human beings to survive. Currently, distributed generation incorporated into a distribution network has become the new trend, with the advantages of controllability, flexibility and tremendous potential. However, the fluctuation of distributed energy resources (DERs is still the main concern for accurate deployment. Thus, a battery energy storage system (BESS has to be involved to mitigate the bad effects of DERs’ integration. In this paper, optimal scheduling strategies for BESS operation have been proposed, to assist with consuming the renewable energy, reduce the active power loss, alleviate the voltage fluctuation and minimize the electricity cost. Besides, the electric vehicles (EVs considered as the auxiliary technique are also introduced to attenuate the DERs’ influence. Moreover, both day-ahead and real-time operation scheduling strategies were presented under the consideration with the constraints of BESS and the EVs’ operation, and the optimization was tackled by a fuzzy mathematical method and an improved particle swarm optimization (IPSO algorithm. Furthermore, the test system for the proposed strategies is a real distribution network with renewable energy integration. After simulation, the proposed scheduling strategies have been verified to be extremely effective for the enhancement of the distribution network characteristics.

  13. Auxiliary verbs in Dinka

    DEFF Research Database (Denmark)

    Andersen, Torben

    2007-01-01

    Dinka, a Western Nilotic language, has a class of auxiliary verbs which is remarkable in the following four respects: (i) It is unusually large, comprising some 20 members; (ii) it is grammatically homogeneous in terms of both morphology and syntax; (iii) most of the auxiliary verbs correspond...... to adverbs in languages like English, while the rest are tense-aspect markers; and (iv) it is possible to combine several auxiliary verbs in a single clause. For some of the auxiliary verbs there are extant full verbs from which they have evolved. To some extent, therefore, it is possible to observe what...

  14. Integrated TRAC/MELPROG analysis of core damage from a severe feedwater transient in the Oconee-1 PWR

    International Nuclear Information System (INIS)

    Henninger, R.J.; Boyack, B.E.

    1986-01-01

    A postulated complete loss-of-feedwater event in the Oconee-1 pressurized water reactor has been analyzed. With an initial version of the lonked TRAC and MELPROG codes, we have modeled the loss-of-feedwater event from initiation to the time of complete disruption of the core, which was calculated to occur by 6800 s. The highest structure temperatures otuside the vessel are on the flow path from the vessel to the pressurizer relief valve. Temperatures in excess of 1200 K could result in failure and depressurization of the primary system before vessel failure

  15. Solutions of system of P1 equations without use of auxiliary differential equations coupled

    International Nuclear Information System (INIS)

    Martinez, Aquilino Senra; Silva, Fernando Carvalho da; Cardoso, Carlos Eduardo Santos

    2000-01-01

    The system of P1 equations is composed by two equations coupled itself one for the neutron flux and other for the current. Usually this system is solved by definitions of two integrals parameters, which are named slowing down densities of the flux and the current. Hence, the system P1 can be change from integral to only two differential equations. However, there are two new differentials equations that may be solved with the initial system. The present work analyzes this procedure and studies a method, which solve the P1 equations directly, without definitions of slowing down densities. (author)

  16. Planned flight test of a mercury ion auxiliary propulsion system. Part 2: Integration with host spacecraft

    Science.gov (United States)

    Knight, R. M.

    1978-01-01

    The objectives of the flight test and a description on how those objectives are in support of an overall program goal of attaining user application were described. The approach to accomplishment was presented as it applies to integrating the propulsion system with the host spacecraft. A number of known interface design considerations which affect the propulsion system and the spacecraft were discussed. Analogies were drawn comparing the relationship of the organizations involved with this flight test with those anticipated for future operational missions. The paper also expanded upon objectives, system description, mission operations, and measurement of plume effects.

  17. Feedwater temperature control device in nuclear power plants

    International Nuclear Information System (INIS)

    Nakamoto, Masashi.

    1985-01-01

    Purpose: To automatically and optimally control the temperature of feedwater supplied to the nuclear reactor of a nuclear power plant regardless the load on a steam turbine. Constitution: A pressure switch is disposed for detecting the turbine extract pressure within an extract pipeway leading to the feedwater heater and heating steams are supplied by selectively switching the control valve disposed to the pipeway for introducing the turbine extract or main steams to the feedwater heater by the signal from the pressure switch. Since the temperature at the exit of the feedwater heater is determined by the pressure inside of the respective equipments, the pressure inside the extract pipe is detected by the pressure switch, and the control valve is put to close and open based on the value to thereby control the entrance of steams to the feedwater heater. As a result, the temperature of the feedwater supplied to the nuclear reactor can be set and controlled automatically within a region where the steam is generated stably in the nuclear reactor. (Kamimura, M.)

  18. Plant data comparisons for Comanche Peak 1/2 main feedwater pump trip transient

    Energy Technology Data Exchange (ETDEWEB)

    Boatwright, W.J.; Choe, W.G; Hiltbrand, D.W. [TU Electric, Dallas, TX (United States)] [and others

    1995-09-01

    A RETRAN-02 MOD5 model of Comanche Peak Steam Electric Station was developed by TU Electric for the purpose of performing core reload safety analyses. In order to qualify this model, comparisons against plant transient data from a partial loss of main feedwater flow were performed. These comparisons demonstrated that good representations of the plant response could be obtained with RETRAN-02 and the user-developed models of the primary-to-secondary heat transfer and plant control systems.

  19. BIOFEAT: Biodiesel fuel processor for a vehicle fuel cell auxiliary power unit. Study of the feed system

    Science.gov (United States)

    Sgroi, M.; Bollito, G.; Saracco, G.; Specchia, S.

    An integrated auxiliary power unit (APU) based on a 10 kW e integrated biodiesel fuel processor has been designed and is being developed. Auto-thermal reforming (ATR) and thermal cracking (TC) were considered for converting the fuel into a hydrogen-rich gas suitable for PEM fuel cells. The fuel processor includes also a gas clean-up system that will reduce the carbon monoxide in the primary processor exit gas to below 10 ppm via a new heat-integrated CO clean-up unit, based on the assembly of catalytic heat exchange plates, so as to meet the operational requirements of a PEMFC stack. This article is devoted to the study and selection of the proper feed strategy for the primary fuel processor. Different pre-treatment and feed alternatives (e.g. based on nozzles or simple coils) were devised and tested for the ATR processors, which turned out to be the preferred primary processing route. A nozzle-based strategy was finally selected along with special recommendations about the constituent materials and the operating procedures to be adopted to avoid coking and nozzle corrosion as well as to allow a wide turn down ratio.

  20. Ultrasonographic scoring system: an auxiliary to differential diagnosis of gastric pathologies.

    Science.gov (United States)

    Boyacioğlu, S; Dolar, E; Acar, Y; Dalay, R; Temuçin, G

    1993-02-01

    In a prospective clinical study, 64 patients with gastric pathologies (27 malignant and 37 benign) were examined ultrasonographically. Gastric wall layer changes, gastric wall thickness, lesion length, and protrusion into the lumen were evaluated. A scoring system was defined based on the distribution of these parameters and the score of each patient was calculated retrospectively. Six of the malignant cases had scores in the benign range and 3 of the benign cases had scores in the malignant range. Sensitivity of this scoring system in terms of detecting malignancy was 78% and specificity 92%. The positive predictive value was 88%, the negative predictive value was 85%, and overall diagnostic accuracy was 86%. This scoring system was considered to be a useful aid in the differential diagnosis of gastric pathologies.

  1. Loss-of-normal-feedwater sensitivity studies for AP600 behavior characterization

    International Nuclear Information System (INIS)

    Saiu, G.

    1996-01-01

    Activity concerning the development of a RELAP5/MOD3 model to simulate the Westinghouse Electric Corporation AP600 is summarized. The aim is to gain initial insight into the capability of RELAP5 to simulate the behavior of AP600 safety features. A-loss-of-normal-feedwater event is studied. Of the transients that must be investigated, this transient has been chosen to be one of the most relevant because the response of the AP600 to a loss-of-normal-feedwater event differs significantly from that of current pressurized water reactors in the extensive use of passive safety features peculiar to the AP600. Also, strong interactions among the AP600 safety systems, which should be further analyzed to permit full optimization of the system actuation logic and operation, are shown. Finally, a loss of normal feedwater without reactor scram, performed to investigate short-term plant behavior, shows that the pressure peak is affected by critical discharge flow coefficients applied to the pressurizer safety valves, while a relatively small reduction of the pressure peak is observed when both heat exchangers of the passive heat removal system are operating as opposed to the case in which only one is available. The data used for this study are derived from the Standard Safety Analysis Report configuration of the Westinghouse AP600 as of 1992

  2. Auxiliary control system of the safety parameters for IPR-R1 reactor

    International Nuclear Information System (INIS)

    Coura, J.G.

    1986-01-01

    This paper deals with the description for the control of three cooling water parameters (conductivity, temperature and the maximum and minimum water levels) as well as the percent power fraction of the nuclear research reactor IPR-R1. In order to keep the reactor in good operation conditions, one permanent and accurate control of the cooling water is needed. The double monitoring of a fourth parameter, part of the original design, the percent power fraction, is obtained through the control of the uncompensated ion chamber current and aims to avoid the operation of the reactor without running the cooling system. (Author) [pt

  3. Support on water chemistry and processes for nuclear power plant auxiliary systems

    Energy Technology Data Exchange (ETDEWEB)

    Chocron, M.; Becquart, E.; La Gamma, A.M.; Schoenbrod, B. [Unidad de Actividad Quimica, Gcia. Centro Atomico Constituyentes, Comision Nacional de Energia, Buenos Aires (Argentina); Allemandi, W.; Fernandez, A.N.; Ovando, L. [Central Nuclear Embalse, Nucleoelectrica Argentina S.A. (Argentina)

    2002-07-01

    In particular PHWRs have a system devoted to the purification and upgrading of the collected heavy water leaks. The purification train is fed with different degradation ratios (D{sub 2}O/H{sub 2}O), activities and impurities. The water is distilled in a packed bed column filled with a mesh type packing. The mesh wire is made of a bronze substrate covered by copper oxides whose current composition has been determined by Moessbauer spectroscopy. With the purpose of minimizing the column stack corrosion, the water is pre-treated in a train consisting of an activated charcoal bed-strong cationic-anionic resin and a final polishing mixed bed resin. Ionic chemicals like acetic acid (whose provenance is suspected to come from the air treatment/D{sub 2}O recovery system where the regeneration is performed at high temperature) are detected by the conductivity and ion chromatography when they concentrate at the column bottom. Traces of oils are retained by the charcoal bed but some compounds extracted by the aqueous phase are suspected to be responsible for the resins fouling or precursors of potentially aggressive agents inside the distillation column. Those species have been detected and identified by gaseous chromatography-mass spectrometry (GC-MS). In the present work, the identification, evaluation of alternatives for the retention and results compared to the original products present in the water upgrading purification train have been summarized. (authors)

  4. Definition of an auxiliary processor dedicated to real-time operating system kernels

    Science.gov (United States)

    Halang, Wolfgang A.

    1988-01-01

    In order to increase the efficiency of process control data processing, it is necessary to enhance the productivity of real time high level languages and to automate the task administration, because presently 60 percent or more of the applications are still programmed in assembly languages. This may be achieved by migrating apt functions for the support of process control oriented languages into the hardware, i.e., by new architectures. Whereas numerous high level languages have already been defined or realized, there are no investigations yet on hardware assisted implementation of real time features. The requirements to be fulfilled by languages and operating systems in hard real time environment are summarized. A comparison of the most prominent languages, viz. Ada, HAL/S, LTR, Pearl, as well as the real time extensions of FORTRAN and PL/1, reveals how existing languages meet these demands and which features still need to be incorporated to enable the development of reliable software with predictable program behavior, thus making it possible to carry out a technical safety approval. Accordingly, Pearl proved to be the closest match to the mentioned requirements.

  5. Evaluation of the performance of the systems cooling auxiliary of the Almaraz NPP turbine building; Evaluacion del rendimiento de los sistemas de refrigeracion auxiliar del edificio de turbinas de CNA

    Energy Technology Data Exchange (ETDEWEB)

    Vilar Carmona, G.

    2011-07-01

    After the successive performance improvements, to evacuate the thermal loads, and maintain acceptable temperatures throughout the year, added an auxiliary cooling system of the building of turbine, TCA system, composed of 5 shot forced by unit cooling towers.

  6. Equipment reliability and life cycle optimization of a nuclear plant feedwater heater

    International Nuclear Information System (INIS)

    Thomas, Daniel; Coakley, Michael; Catapano, Michael; Svensson, Eric

    2006-01-01

    Many papers published over the last 25 years have strongly emphasized the need for an ongoing program of inspection and testing with subsequent failure cause analysis of feedwater heaters. Plants must be run more competitively; therefore, Utilities must lower operation and maintenance costs, while optimizing overall plant efficiency and capacity factor. One recognized area that needs to be addressed in accomplishing this goal is the heat cycle. This paper specifically deals with the feedwater heating system. Utility engineers must monitor feedwater heater performance in order to recognize degradation, identify and mitigate failure mechanisms, and prevent in-service failures thereby optimizing availability. Periodic tube plugging without complete analysis of the degraded/failed areas resolves the immediate need for return to service; however, heater life will not be optimized. This paper illustrates a complete life cycle management inspection, testing, and maintenance program implemented at Peach Bottom Atomic Power Station (PBAPS). Concerns that tubes may have been too conservatively plugged due to insufficient data and lack of root cause analysis, justified a program that included: - Removal of previously installed plugs; - Video-probe inspection of failed areas; - Extraction of tube samples for further analysis; - Eddy current testing of selected tubes; - Evaluation of the condition of 'insurance' plugged tubes for return to service; - Hydrostatic testing of selected individual tubes; - Final repair plan based on the results of the above program. This paper concludes that no single method of inspection or testing should solely be relied upon in establishing: - The extent of actual degraded conditions; - The mechanism(s) of failure; - The details of repair to be implemented. Evaluating all data affords the best chance in arresting problems and optimizing feedwater heater life. Problem heaters should be continuously monitored and inspected over time until the facts

  7. Equipment reliability and life cycle optimization of a nuclear plant feedwater heater

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Daniel; Coakley, Michael [Exelon/Peach Bottom Atomic Power Station, 200 Exelon Way, Kennett Square, PA 19348 (United States); Catapano, Michael; Svensson, Eric [Powerfect, Inc. 9 Great Meadow Lane, East Hanover, N. J. 07936 (United States)

    2006-07-01

    Many papers published over the last 25 years have strongly emphasized the need for an ongoing program of inspection and testing with subsequent failure cause analysis of feedwater heaters. Plants must be run more competitively; therefore, Utilities must lower operation and maintenance costs, while optimizing overall plant efficiency and capacity factor. One recognized area that needs to be addressed in accomplishing this goal is the heat cycle. This paper specifically deals with the feedwater heating system. Utility engineers must monitor feedwater heater performance in order to recognize degradation, identify and mitigate failure mechanisms, and prevent in-service failures thereby optimizing availability. Periodic tube plugging without complete analysis of the degraded/failed areas resolves the immediate need for return to service; however, heater life will not be optimized. This paper illustrates a complete life cycle management inspection, testing, and maintenance program implemented at Peach Bottom Atomic Power Station (PBAPS). Concerns that tubes may have been too conservatively plugged due to insufficient data and lack of root cause analysis, justified a program that included: - Removal of previously installed plugs; - Video-probe inspection of failed areas; - Extraction of tube samples for further analysis; - Eddy current testing of selected tubes; - Evaluation of the condition of 'insurance' plugged tubes for return to service; - Hydrostatic testing of selected individual tubes; - Final repair plan based on the results of the above program. This paper concludes that no single method of inspection or testing should solely be relied upon in establishing: - The extent of actual degraded conditions; - The mechanism(s) of failure; - The details of repair to be implemented. Evaluating all data affords the best chance in arresting problems and optimizing feedwater heater life. Problem heaters should be continuously monitored and inspected over time until

  8. Monitoring the performance of Aux. Feedwater Pump using Smart Sensing Model

    International Nuclear Information System (INIS)

    No, Young Gyu; Seong, Poong Hyun

    2015-01-01

    Many artificial intelligence (AI) techniques equipped with learning systems have recently been proposed to monitor sensors and components in NPPs. Therefore, the objective of this study is the development of an integrity evaluation method for safety critical components such as Aux. feedwater pump, high pressure safety injection (HPSI) pump, etc. using smart sensing models based on AI techniques. In this work, the smart sensing model is developed at first to predict the performance of Aux. feedwater pump by estimating flowrate using group method of data handing (GMDH) method. If the performance prediction is achieved by this feasibility study, the smart sensing model will be applied to development of the integrity evaluation method for safety critical components. Also, the proposed algorithm for the performance prediction is verified by comparison with the simulation data of the MARS code for station blackout (SBO) events. In this study, the smart sensing model for the prediction performance of Aux. feedwater pump has been developed. In order to develop the smart sensing model, the GMDH algorithm is employed. The GMDH algorithm is the way to find a function that can well express a dependent variable from independent variables. This method uses a data structure similar to that of multiple regression models. The proposed GMDH model can accurately predict the performance of Aux

  9. A moving image system for cardiovascular nuclear medicine. A dedicated auxiliary device for the total capacity imaging system for multiple plane dynamic colour display

    International Nuclear Information System (INIS)

    Iio, M.; Toyama, H.; Murata, H.; Takaoka, S.

    1981-01-01

    The recent device of the authors, the dedicated multiplane dynamic colour image display system for nuclear medicine, is discussed. This new device is a hardware-based auxiliary moving image system (AMIS) attached to the total capacity image processing system of the authors' department. The major purpose of this study is to develop the dedicated device so that cardiovascular nuclear medicine and other dynamic studies will include the ability to assess the real time delicate processing of the colour selection, edge detection, phased analysis, etc. The auxiliary system consists of the interface for image transferring, four IC refresh memories of 64x64 matrix with 10 bit count depth, a digital 20-in colour TV monitor, a control keyboard and a control panel with potentiometers. This system has five major functions for colour display: (1) A microcomputer board can select any one of 40 different colour tables preset in the colour transformation RAM. This key also provides edge detection at a certain level of the count by leaving the optional colour and setting the rest of the levels at 0 (black); (2) The arithmetic processing circuit performs the operation of the fundamental rules, permitting arithmetic processes of the two images; (3) The colour level control circuit is operated independently by four potentiometers for four refresh image memories, so that the gain and offset of the colour level can be manually and visually controlled to the satisfaction of the operator; (4) The simultaneous CRT display of the maximum four images with or without cinematic motion is possible; (5) The real time movie interval is also adjustable by hardware, and certain frames can be freezed with overlapping of the dynamic frames. Since this system of AMIS is linked with the whole capacity image processing system of the CPU size of 128kW, etc., clinical applications are not limited to cardiovascular nuclear medicine. (author)

  10. Nuclear plant power up-rate study: feedwater heater evaluations

    International Nuclear Information System (INIS)

    Svensson, Eric; Catapano, Michael; Coakley, Michael; Thomas, Dan

    2014-01-01

    Given today's nuclear industry business climate, it has become common for Utility companies to consider increasing unit capacities through turbine replacement and power up-rates. An integral part of the studies conducted by many towards this end, involve the generation of a set of turbine cycle heat balances with predicted performance parameters for the up-rated condition. Once these tentative operating values are established, it becomes necessary to evaluate the suitability of the existing components within each system to ensure they are capable of continued safe and reliable operation. The ultimate cost for the up-rate, including the cost for any major required modifications or significant replacements is weighed against increased revenue generated from the up-rate over time. Exelon's Peach Bottom Atomic Power Station (PBAPS) is currently planning for an Extended Power up-rate (EPU) for both units. To ensure the existing Feedwater Heaters (FWH) could maintain the operating and transient response margins at the EPU condition, an engineering study was conducted. Powerfect Inc. in conjunction with SPX Heat Transfer LLC were contracted to provide engineering services to analyze the design, thermal performance, reliability and operating conditions at projected EPU conditions. Specifically, to address the following with regard to the station's Feedwater Heaters (FWHs): 1. Evaluate Drain Cooler (DC) Velocities - including zone inlet velocity, cross and window velocities and outlet velocities. 2. Evaluate Drain Cooler Zone Pressure Drop for effect on drain cooler margins to flashing. 3. Evaluate differential pressure allowable across the pass partition plate. 4. Evaluate Drain Cooler Tube Vibration Potential. 5. Perform detailed steam dome velocity calculations. The goal of the study was to identify the most susceptible areas within the heaters for problems and potential failures when operating at the higher duty of the EPU condition for the remaining life

  11. 46 CFR 52.01-115 - Feedwater supply (modifies PG-61).

    Science.gov (United States)

    2010-10-01

    ... BOILERS General Requirements § 52.01-115 Feedwater supply (modifies PG-61). Boiler feedwater supply must meet the requirements of PG-61 of section I of the ASME Boiler and Pressure Vessel Code (incorporated...

  12. Data report of ROSA/LSTF experiment TR-LF-07. Loss-of-feedwater transient with primary feed-and-bleed operation

    International Nuclear Information System (INIS)

    Takeda, Takeshi

    2016-07-01

    An experiment TR-LF-07 was conducted on June 23, 1992 using the Large Scale Test Facility (LSTF) in the Rig of Safety Assessment-IV (ROSA-IV) Program. The ROSA/LSTF experiment TR-LF-07 simulated a loss-of-feedwater transient in a pressurized water reactor (PWR) under assumptions of primary feed-and-bleed operation and total failure of auxiliary feedwater system. A safety injection (SI) signal was generated when steam generator (SG) secondary-side collapsed liquid level decreased to 3 m. Primary depressurization was initiated by fully opening a power-operated relief valve (PORV) of pressurizer (PZR) 30 min after the SI signal. High pressure injection (HPI) system was started in loop with PZR 12 s after the SI signal, while it was initiated in loop without PZR when the primary pressure decreased to 10.7 MPa. The primary and SG secondary pressures were kept almost constant because of cycle opening of the PZR PORV and SG relief valves. The PZR liquid level began to drop steeply following the PORV full opening, which caused liquid level formation at the hot leg. The PZR and hot leg liquid levels recovered due to the HPI actuation in both loops. The primary pressure became lower than the SG secondary pressure, which resulted in the actuation of accumulator (ACC) system in both loops. The PZR and hot legs became full of liquid again after the ACC actuation. The primary feed-and-bleed operation by use of the PORV, HPI and ACC systems was effective to core cooling because of no core uncovery. The experiment was terminated when the continuous core cooling was confirmed due to the successive coolant injection from the HPI system even after the ACC termination. The obtained data would be useful to study operator actions and procedures in the PWR multiple fault events which behaviors in the PZR affect. This report summarizes the test procedures, conditions and major observation in the ROSA/LSTF experiment TR-LF-07. (author)

  13. Auxiliary Deep Generative Models

    DEFF Research Database (Denmark)

    Maaløe, Lars; Sønderby, Casper Kaae; Sønderby, Søren Kaae

    2016-01-01

    Deep generative models parameterized by neural networks have recently achieved state-of-the-art performance in unsupervised and semi-supervised learning. We extend deep generative models with auxiliary variables which improves the variational approximation. The auxiliary variables leave...... faster with better results. We show state-of-the-art performance within semi-supervised learning on MNIST (0.96%), SVHN (16.61%) and NORB (9.40%) datasets....

  14. Commonality Study of the Pressure-Volume-Temperature Based Propellant Gaging Software Modules for the Auxiliary Power Unit, Reaction Control System, and Orbital Maneuvering System

    Science.gov (United States)

    Duhon, D. D.

    1975-01-01

    Computer storage requirements can be reduced if areas of commonality exist in two or more programs placed in the same computer and identical code can be used by more than one program. The pressure-volume-temperature (P-V-T) relationship for the propellant tank pressurant agent is utilized as the basis for either a primary of a backup propellant gaging program for the auxiliary power unit (APU), the reaction control system (RCS), and the orbital maneuvering system (OMS). These three propellant gaging programs were investigated. It was revealed that a very limited degree of software commonality exits among them. An examination of this common software indicated that only the computation of the helium compressibility factor in an external function subprogram accessible to both the RCS and OMS propellant gaging programs appears to offer a savings in computer storage requirements.

  15. Ultrasonic pattern recognition study of feedwater nozzle inner radius indication

    International Nuclear Information System (INIS)

    Yoneyama, H.; Takama, S.; Kishigami, M.; Sasahara, T.; Ando, H.

    1983-01-01

    A study was made to distinguish defects on feed-water nozzle inner radius from noise echo caused by stainless steel cladding by using ultrasonic pattern recognition method with frequency analysis technique. Experiment has been successfully performed on flat clad plates and nozzle mock-up containing fatigue cracks and the following results which shows the high capability of frequency analysis technique are obtained

  16. Auxiliary resonant DC tank converter

    Science.gov (United States)

    Peng, Fang Z.

    2000-01-01

    An auxiliary resonant dc tank (ARDCT) converter is provided for achieving soft-switching in a power converter. An ARDCT circuit is coupled directly across a dc bus to the inverter to generate a resonant dc bus voltage, including upper and lower resonant capacitors connected in series as a resonant leg, first and second dc tank capacitors connected in series as a tank leg, and an auxiliary resonant circuit comprising a series combination of a resonant inductor and a pair of auxiliary switching devices. The ARDCT circuit further includes first clamping means for holding the resonant dc bus voltage to the dc tank voltage of the tank leg, and second clamping means for clamping the resonant dc bus voltage to zero during a resonant period. The ARDCT circuit resonantly brings the dc bus voltage to zero in order to provide a zero-voltage switching opportunity for the inverter, then quickly rebounds the dc bus voltage back to the dc tank voltage after the inverter changes state. The auxiliary switching devices are turned on and off under zero-current conditions. The ARDCT circuit only absorbs ripples of the inverter dc bus current, thus having less current stress. In addition, since the ARDCT circuit is coupled in parallel with the dc power supply and the inverter for merely assisting soft-switching of the inverter without participating in real dc power transmission and power conversion, malfunction and failure of the tank circuit will not affect the functional operation of the inverter; thus a highly reliable converter system is expected.

  17. Removal of Iron Oxide Scale from Feed-water in Thermal Power Plant by Using Magnetic Separation

    Science.gov (United States)

    Nakanishi, Motohiro; Shibatani, Saori; Mishima, Fumihito; Akiyama, Yoko; Nishijima, Shigehiro

    2017-09-01

    One of the factors of deterioration in thermal power generation efficiency is adhesion of the scale to inner wall in feed-water system. Though thermal power plants have employed All Volatile Treatment (AVT) or Oxygen Treatment (OT) to prevent scale formation, these treatments cannot prevent it completely. In order to remove iron oxide scale, we proposed magnetic separation system using solenoidal superconducting magnet. Magnetic separation efficiency is influenced by component and morphology of scale which changes their property depending on the type of water treatment and temperature. In this study, we estimated component and morphology of iron oxide scale at each equipment in the feed-water system by analyzing simulated scale generated in the pressure vessel at 320 K to 550 K. Based on the results, we considered installation sites of the magnetic separation system.

  18. Application of a Long Term Asset Management Strategy for HP Feedwater Heaters

    International Nuclear Information System (INIS)

    Won, Se Youl; Yun, Eun Sub; Park, Young Sheop

    2008-01-01

    As the commercial operating year of nuclear power plants is increased, it becomes imperative to develop integrated cost-effective asset management and to improve plans for degraded Structures, Systems, and Components (SSCs) in terms of safety and economical consideration. A long-term asset management (LTAM) strategy can improve the condition of nuclear plants, maximize their value, and optimize their operational life by maintaining their safety. This paper presents an optimized LTAM plan for HP feedwater heaters at a specific nuclear power plant

  19. Methodology for carrying out energy diagnosis in auxiliaries systems in thermal electrical central stations; Metodologia para realizar un diagnostico energetico en sistemas auxiliares de centrales termoelectricas

    Energy Technology Data Exchange (ETDEWEB)

    Nebradt Garcia, Jesus [Comision Federal de Electricidad (CFE), Mexico, D. F. (Mexico); Rojas Hidalgo, Ismael; Huante Perez, Liborio [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1998-12-31

    One of the potential areas for energy saving in Central Electric Power Plants are the auxiliaries system, so as to based in a preliminary energy diagnosis and considering that energy saving measures would be taken, going from the instrumentation, operational changes in equipment, as well as in using velocity variators in motors, it turns out to be that the energy consumption of auxiliaries at 75% load in a 150 MW thermal power plant varies from 3% to 4% and for the case of a 350 MW power plant the energy consumption of the auxiliaries represents 2 to 3.5%. Nowadays this consumption are above 6%. Considering that the country has 40 units with capacities varying from 150 to 350 MW, the economical and the fuel saving would be substantial. This paper will present a summary of the methodology to be used to carry out this type of projects. [Espanol] Una de las areas potenciales de ahorro de energia en centrales termoelectricas son los sistemas auxiliares, de tal manera que basados en un diagnostico energetico preliminar y considerando que se aplicarian las medidas de ahorro de energia que van desde la instrumentacion, cambios operativos en equipos, asi como el uso de variadores de velocidad en motores, se tienen que los consumos de auxiliares para un 75% de carga en una central termoelectrica de 150 MW varian desde un 3% hasta un 4% y para el caso de una central termoelectrica de 350 MW, el consumo de auxiliares representa del 2 al 3.5%. Hoy en dia dichos consumos estan por encima del 6%. Si consideramos que el pais cuenta con 40 unidades que varian desde 150 MW hasta 350 MW, entonces los ahorros economicos y de combustible serian impactantes. La presente ponencia mostrara un resumen de la metodologia a emplear para la realizacion de este tipo de proyectos.

  20. Application of neural networks to validation of feedwater flow rate in a nuclear power plant

    International Nuclear Information System (INIS)

    Khadem, M.; Ipakchi, A.; Alexandro, F.J.; Colley, R.W.

    1993-01-01

    Feedwater flow rate measurement in nuclear power plants requires periodic calibration. This is due to the fact that the venturi surface condition of the feedwater flow rate sensor changes because of a chemical reaction between the surface coating material and the feedwater. Fouling of the venturi surface, due to this chemical reaction and the deposits of foreign materials, has been observed shortly after a clean venturi is put in operation. A fouled venturi causes an incorrect measurement of feedwater flow rate, which in turn results in an inaccurate calculation of the generated power. This paper presents two methods for verifying incipient and continuing fouling of the venturi of the feedwater flow rate sensors. Both methods are based on the use of a set of dissimilar process variables dynamically related to the feedwater flow rate variable. The first method uses a neural network to generate estimates of the feedwater flow rate readings. Agreement, within a given tolerance, of the feedwater flow rate instrument reading, and the corresponding neural network output establishes that the feedwater flow rate instrument is operating properly. The second method is similar to the first method except that the neural network predicts the core power which is calculated from measurements on the primary loop, rather than the feedwater flow rates. This core power is referred to the primary core power in this paper. A comparison of the power calculated from the feedwater flow measurements in the secondary loop, with the calculated and neural network predicted primary core power provides information from which it can be determined whether fouling is beginning to occur. The two methods were tested using data from the feedwater flow meters in the two feedwater flow loops of the TMI-1 nuclear power plant

  1. Numerical simulation of a 374 tons/h water-tube steam boiler following a feedwater line break

    International Nuclear Information System (INIS)

    Deghal Cheridi, Amina Lyria; Chaker, Abla; Loubar, Ahcène

    2016-01-01

    Highlights: • We simulate the behavior of a steam boiler during feed-water line break accident. • To perform accident analysis of the steam boiler, Relap5/Mod3.2 system code is used. • A Relap5 model of the boiler is developed and qualified at the steady state level. • A good agreement between Relap5 results and available experimental data. • The Relap5 model predicts well the main transient features of the boiler. - Abstract: To ensure the operational safety of an industrial water-tube steam boiler it is very important to assess various accident scenarios in real plant working conditions. One of the most challenging scenarios is the loss of feedwater to the steam boiler. In this paper, a simulation of the behavior of an industrial water-tube radiant steam boiler during feedwater line break accident is discussed. The simulation is carried out using the RELAP5 system code. The steam boiler is installed in an Algerian natural gas liquefaction complex. The simulation shows the capabilities of RELAP5 system code in predicting the behavior of the steam boiler at both steady state and transient working conditions. From another side, the behavior of the steam boiler following the accident shows how the control system can successfully mitigate the effects and consequences of such accident and how the evaporator tubes can undergo a severe damage due to an uncontrolled increase of the wall temperature in case of failure of this system.

  2. Electric power plant technology. Generators, transformers, auxiliary installations, protective systems. Lecture notes. 5. rev. ed.; Elektrische Kraftwerkstechnik. Generatoren, Transformatoren, Eigenbedarfsanlagen, Schutzeinrichtungen. Vorlesungsskript

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, Ulrich

    2009-07-01

    The lecture series on electric power plant engineering was initiated in 1969 by Prof. Helmut Schaefer, founder of the then department of power economy and power plant engineering. The lecture series was continuously updated in its contents and didactic approach, e.g. by integrating innovative power generation concepts like micro cogeneration plants and fuel cell systems. The focus is on the fundamentals and function of generators, main transformers, auxiliary installations and protective systems in power plant. Apart from the electrotechnical aspects, also aspects of mechanical engineering are gone into. Also discussed are energy conversion concepts fo renewable power generation plants like wind turbines and PV systems. This is the 5th, completely revised edition. It addresses primarily attendants of the lectures but may also serve as a textbook and reference manual for interested experts.

  3. Pressure waves transient occurred in the steam generators feedwater lines of the Atucha-1 Nuclear Power Plant

    International Nuclear Information System (INIS)

    Balino, J.L.; Carrica, P.M.; Larreteguy, A.E.

    1993-01-01

    The pressure transient occurred at Atucha I Nuclear Power Plant in March 1990 is simulated. The transient was due to the fast closure of a flow control valve at the steam generators feedwater lines. The system was modelled, including the actuation of the relief valves. The minimum closure time for no actuation of the relief valves and the evolution of the velocity and piezo metric head for different cases were calculated. (author)

  4. Changes in feedwater organic matter concentrations based on intake type and pretreatment processes at SWRO facilities, Red Sea, Saudi Arabia

    KAUST Repository

    Dehwah, Abdullah

    2015-03-01

    Transparent exopolymer particles (TEP), natural organic matter, and bacterial concentrations in feedwater are important factors that can lead to membrane biofouling in seawater reverse osmosis (SWRO) systems. Two methods for controlling these concentrations in the feedwater prior to pretreatment have been suggested; use of subsurface intake systems or placement of the intake at a greater depth in the sea. These proposed solutions were tested at two SWRO facilities located along the Red Sea of Saudi Arabia. A shallow well intake system was very effective in reducing the algae and bacterial concentrations and somewhat effective in reducing TEP concentrations. An intake placed at a depth of 9. m below the surface was found to have limited impact on improving water quality compared to a surface intake. The algae and bacteria concentration in the feedwater (deep) was lower compared to the surface seawater, but the overall TEP concentration was higher. Bacteria and TEP measurements made in the pretreatment process train in the plant and after the cartridge filters suggest that regrowth of bacteria is occurring within the cartridge filters.

  5. Assessment of RELAP5/MOD2 against a main feedwater turbopump trip transient in the Vandellos II Nuclear Power Plant

    International Nuclear Information System (INIS)

    Llopis, C.; Casals, A.; Perez, J.; Mendizabal, R.

    1993-12-01

    The Consejo de Seguridad Nuclear (CSN) and the Asociacion Nuclear Vandellos (ANV) have developed a model of Vandellos II Nuclear Power Plant. The ANV collaboration consisted in the supply of design and actual data, the cooperation in the simulation of the control systems and other model components, as well as in the results analysis. The obtained model has been assessed against the following transients occurred in plant: A trip from the 100% power level (CSN); a load rejection from 100% to 50% (CSN); a load rejection from 75% to 65% (ANV); and, a feedwater turbopump trip (ANV). This copy is a report of the feedwater turbopump trip transient simulation. This transient actually occurred in the plant on June 19, 1989

  6. Replacement of the condenser necked feedwater heaters for nuclear power plant

    International Nuclear Information System (INIS)

    Shimada, A.; Yamaguchi, H.; Kimura, M.; Ooshima, Y.; Nakashima, Y.; Ogawa, K.; Akiba, T.; Hoshi, T.

    2008-01-01

    In Fukushima Daiichi Nuclear Power Station Unit 2, the feedwater heaters, which were placed in the condenser neck, were replaced in 2006. Many feedwater heaters had been replaced in BWR plants, but, only a few condenser necked heaters were replaced. As the necked heaters were large-scale and placed in the condenser, various technical problems should be solved for replacing. This report shows some solutions applied in the condenser necked feedwater heater replacement. (author)

  7. Chemistry control approach of pre commissioning and power operation of primary and auxiliary system of KGS-3 and 4 and trouble shooting made

    International Nuclear Information System (INIS)

    Bennet Raj, N.; Sahu, B.S.; Kumar, Vineet; Valluri, J.

    2008-01-01

    KGS (Kaiga Generating Station) 3 and 4 is a 220 MWe pressurized heavy water reactor (PHWR) using heavy water (D 2 O) as moderator and primary heat coolant and the secondary system is light water which is used to make the steam for generating the power. The chemistry control approach made for the successful commissioning and subsequent power operation of the unit is discussed here. The chemistry control is of two parts first part covers the pre commissioning chemistry control and the second part covers the commissioning chemistry control. During commissioning all systems were preserved by proper chemistry control and regular recirculation of system to avoid stagnancy. The major pre commissioning and commissioning chemistry control are depicted below: Pre commissioning chemistry control of primary heat transport (PHT) system and auxiliaries; Pre commissioning chemistry control of moderator system; Primary heat transport system hot conditioning with light water; Commissioning chemistry control of End Shield System (ESC) and Calandria Vault Cooling (CVC) system; Heavy water addition and its chemistry control in moderator system; and Heavy water addition and its chemistry control in PHT system. During power operation dew point in annular gas monitoring system (AGMS) of KGS unit 3 was maintaining in higher side under recirculation. The increase of dew point could be due to ingress of heavy water or light water. A new device was developed to collect condensate and the chemistry of the condensate was checked. The result indicated the ingress of light water. (author)

  8. Considerations for surviving the loss of a main feedwater pump at full power

    International Nuclear Information System (INIS)

    Gaydos, K.A.; Calvo, R.; Conroy, P.W.; Klein, C.M.; Mellers, J.E.

    1990-01-01

    Today's economics dictate that nuclear power operational costs be contained by addressing frequently-occurring trips that might be minimized or avoided via specific upgrades. Much recent attention has focused on the significant percentage of plant trips related to feedwater flow regulation; however, another frequent feedwater-related trip stems from the loss of a single main feedwater pump while operating at high power levels, causing a plant trip on low steam generator water-level. This paper summarizes the results of several plant-specific studies that evaluate a unit's capabilities to consistently survive the loss of a main feedwater pump from full power, and outlines a methodology for analyzing this capability

  9. Evolution of carbon steel corrosion in feedwater conditions reproduce by the Fortrand loop

    International Nuclear Information System (INIS)

    Delaunay, Sophie; Bescond, Aurelien; Mansour, Carine; Bretelle, Jean-Luc

    2012-09-01

    Fouling and tubes support plate blockage of steam generators (SG) are major problems in the secondary circuit of pressurized water reactor (PWR) plants. Corrosion products (CP) responsible of these phenomena are mainly constituted of magnetite. Limit the amount of these CP, generated in the feedwater system and transported to SG, constitutes one way to limit fouling and blockage of SGs. This work requires the understanding of CP behaviour in the feedwater system conditions. A specific experimental circulating water loop, FORTRAND, was built at EDF to follow the formation, the transport and the deposition of iron oxides in representative conditions of the secondary circuit feedwater system. The test section operating at high temperature (up to 250 deg. C) is made in carbon steel and includes three removable segments while all the other parts of the loop are made in stainless steel. First results confirm the formation of iron oxides on carbon steel and stainless steel surface in the conditions of PWR secondary circuits. The surface characterizations show that magnetite is the corrosion product formed on carbon steel and stainless steel at 220 deg. C and goethite is formed at room temperature on stainless steel. The aim of the most recent tests performed in FORTRAND loop was to follow the evolution of corrosion in the feedwater conditions. Tests were performed in one-phase flow conditions at 150 L.h -1 with a linear velocity of 0.82 m/s at 220 deg. C in morpholine/ammonia/hydrazine medium, at pH 25C equal to 9.2. To conduct this study, a removable segment constituted by ten tubes was added to the loop. Several tests were performed to follow the deposit thickness, the iron lost in solution and the oxide morphology with time from two to nine hundred sixty hours. Chemical conditions were controlled and the reproducibility of the results was confirmed by the observation of three tubes at each test. SEM pictures present kinetics with three steps: after the first hours the

  10. Auxiliary power unit for moving a vehicle

    Science.gov (United States)

    Akasam, Sivaprasad [Peoria, IL; Johnson, Kris W [Peoria, IL; Johnson, Matthew D [Peoria, IL; Slone, Larry M [Washington, IL; Welter, James Milton [Chillicothe, IL

    2009-02-03

    A power system is provided having at least one traction device and a primary power source configured to power the at least one traction device. In addition, the power system includes an auxiliary power source also configured to power the at least one traction device.

  11. Effect of Modifications to Induction System on Altitude Performance of V-1710-93 Engine III : Use of Parabolic Rotating Guide Vanes and NACA Designed Auxiliary-stage Inlet Elbow and Interstage Duct

    Science.gov (United States)

    Standahar, Ray M; Mccarty, James S

    1947-01-01

    Bench runs of a modified V-1710-93 engine equipped with a two-stage supercharger, interstage carburetor, aftercooler assembly, and backfire screens have been made at a simulated altitude of 29,000 feet to determine the effect of several induction-system modifications on the engine and supercharger performance. The standard guide vanes on the auxiliary- and engine-stage superchargers were replaced by rotating guide vanes with a parabolic blade profile. The auxiliary-stage inlet elbow and interstage duct were replaced with new units of NACA design. These modifications were made one at a time and data were obtained after each change to determine the effect of each modification. All runs were made at a constant engine speed of 3000 rpm at a simulated altitude of 29,000 feet and all changes in engine power were made by varying the speed of the auxiliary-stage supercharger.

  12. On-line validation of feedwater flow rate in nuclear power plants using neural networks

    International Nuclear Information System (INIS)

    Khadem, M.; Ipakchi, A.; Alexandro, F.J.; Colley, R.W.

    1994-01-01

    On-line calibration of feedwater flow rate measurement in nuclear power plants provides a continuous realistic value of feedwater flow rate. It also reduces the manpower required for periodic calibration needed due to the fouling and defouling of the venturi meter surface condition. This paper presents a method for on-line validation of feedwater flow rate in nuclear power plants. The method is an improvement of the previously developed method which is based on the use of a set of process variables dynamically related to the feedwater flow rate. The online measurements of this set of variables are used as inputs to a neural network to obtain an estimate of the feedwater flow rate reading. The difference between the on-line feedwater flow rate reading, and the neural network estimate establishes whether there is a need to apply a correction factor to the feedwater flow rate measurement for calculation of the actual reactor power. The method was applied to the feedwater flow meters in the two feedwater flow loops of the TMI-1 nuclear power plant. The venturi meters used for flow measurements are susceptible to frequent fouling that degrades their measurement accuracy. The fouling effects can cause an inaccuracy of up to 3% relative error in feedwater flow rate reading. A neural network, whose inputs were the readings of a set of reference instruments, was designed to predict both feedwater flow rates simultaneously. A multi-layer feedforward neural network employing the backpropagation algorithm was used. A number of neural network training tests were performed to obtain an optimum filtering technique of the input/output data of the neural networks. The result of the selection of the filtering technique was confirmed by numerous Fast Fourier Transform (FFT) tests. Training and testing were done on data from TMI-1 nuclear power plant. The results show that the neural network can predict the correct flow rates with an absolute relative error of less than 2%

  13. Cutting feedwater oxygen concentrations by catalysis

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

    Designed to reduce oxygen concentrations in water storage and makeup systems from fully aerated conditions of 8000ppb to 10ppb in a single pass, the Westinghouse catalytic oxygen removal system (CORS) is a proven alternative to other methods of deoxygenation. (author)

  14. Fuzzy Logic Approach to Diagnosis of Feedwater Heater Performance Degradation

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Yeon Kwan; Kim, Hyeon Min; Heo, Gyun Young [Kyung Hee University, Yongin (Korea, Republic of); Sang, Seok Yoon [Engineering and Technical Center, Korea Hydro, Daejeon (Korea, Republic of)

    2014-08-15

    Since failure in, damage to, and performance degradation of power generation components in operation under harsh environment of high pressure and high temperature may cause both economic and human loss at power plants, highly reliable operation and control of these components are necessary. Therefore, a systematic method of diagnosing the condition of these components in its early stages is required. There have been many researches related to the diagnosis of these components, but our group developed an approach using a regression model and diagnosis table, specializing in diagnosis relating to thermal efficiency degradation of power plant. However, there was a difficulty in applying the method using the regression model to power plants with different operating conditions because the model was sensitive to value. In case of the method that uses diagnosis table, it was difficult to find the level at which each performance degradation factor had an effect on the components. Therefore, fuzzy logic was introduced in order to diagnose performance degradation using both qualitative and quantitative results obtained from the components' operation data. The model makes performance degradation assessment using various performance degradation variables according to the input rule constructed based on fuzzy logic. The purpose of the model is to help the operator diagnose performance degradation of components of power plants. This paper makes an analysis of power plant feedwater heater by using fuzzy logic. Feedwater heater is one of the core components that regulate life-cycle of a power plant. Performance degradation has a direct effect on power generation efficiency. It is not easy to observe performance degradation of feedwater heater. However, on the other hand, troubles such as tube leakage may bring simultaneous damage to the tube bundle and therefore it is the object of concern in economic aspect. This study explains the process of diagnosing and verifying typical

  15. Inferential smart sensing for feedwater flowrate in PWRs

    International Nuclear Information System (INIS)

    Na, M. G.; Hwang, I. J.; Lee, Y. J.

    2006-01-01

    The feedwater flowrate that is measured by Venturi flow meters in most pressurized water reactors can be over-measured because of the fouling phenomena that make corrosion products accumulate in the Venturi meters. Therefore, in this work, two kinds of methods, a support vector regression method and a fuzzy modeling method, combined with a sequential probability ratio test, are used in order to accurately estimate online the feedwater flowrate, and also to monitor the status of the existing hardware sensors. Also, the data for training the support vector machines and the fuzzy model are selected by using a subtractive clustering scheme to use informative data from among all acquired data. The proposed inferential sensing and monitoring algorithm is verified by using the acquired real plant data of Yonggwang Nuclear Power Plant Unit 3. In the simulations, it was known that the root mean squared error and the relative maximum error are so small and the proposed method early detects the degradation of an existing hardware sensor. (authors)

  16. Inferential smart sensing for feedwater flowrate in PWRs

    Energy Technology Data Exchange (ETDEWEB)

    Na, M. G.; Hwang, I. J. [Nuclear Eng. Dept., Chosun Univ., 375 Seosuk-dong, Dong-gu, Gwangju 501-759 (Korea, Republic of); Lee, Y. J. [Nuclear and Energy Eng. Dept., Cheju National Univ., 1 Ara-il-dong, Jeju-do 690-756 (Korea, Republic of)

    2006-07-01

    The feedwater flowrate that is measured by Venturi flow meters in most pressurized water reactors can be over-measured because of the fouling phenomena that make corrosion products accumulate in the Venturi meters. Therefore, in this work, two kinds of methods, a support vector regression method and a fuzzy modeling method, combined with a sequential probability ratio test, are used in order to accurately estimate online the feedwater flowrate, and also to monitor the status of the existing hardware sensors. Also, the data for training the support vector machines and the fuzzy model are selected by using a subtractive clustering scheme to use informative data from among all acquired data. The proposed inferential sensing and monitoring algorithm is verified by using the acquired real plant data of Yonggwang Nuclear Power Plant Unit 3. In the simulations, it was known that the root mean squared error and the relative maximum error are so small and the proposed method early detects the degradation of an existing hardware sensor. (authors)

  17. Qualitative accident analysis on loss of normal feedwater for AP1000

    International Nuclear Information System (INIS)

    Li Yankai; Lin Meng; Hou Dong; Li Meilin; Yang Yanhua

    2012-01-01

    For the analysis of loss of normal feedwater accident for AP1000, a thermalhydraulic model was built based on a two-fluid best estimate code, RELAP5. A control system model was built based on Matlab/Simulink code. As the main data for modeling was from AP1000 Design Control Document (AP1000 DCD), which was inadequate and not accurate enough, the accident analysis was qualitative. The calculation results, overall consistent with the same accident in DCD, show that the RELAP5 code has the ability to calculate the natural circulation. PRHRS and CMT are able to remove the core residual heat, decay heat timely and efficiently during the accident to guarantee the safety of the core. In the calculation model, the capability of PRHRS is stronger, which makes the coolant temperature quickly reduced to a lower level, leading to an earlier actuation of CMT, followed by different responses of the plant. (authors)

  18. Heat exchanger inventory cost optimization for power cycles with one feedwater heater

    International Nuclear Information System (INIS)

    Qureshi, Bilal Ahmed; Antar, Mohamed A.; Zubair, Syed M.

    2014-01-01

    Highlights: • Cost optimization of heat exchanger inventory in power cycles is investigated. • Analysis for an endoreversible power cycle with an open feedwater heater is shown. • Different constraints on the power cycle are investigated. • The constant heat addition scenario resulted in the lowest value of the cost function. - Abstract: Cost optimization of heat exchanger inventory in power cycles with one open feedwater heater is undertaken. In this regard, thermoeconomic analysis for an endoreversible power cycle with an open feedwater heater is shown. The scenarios of constant heat rejection and addition rates, power as well as rate of heat transfer in the open feedwater heater are studied. All cost functions displayed minima with respect to the high-side absolute temperature ratio (θ 1 ). In this case, the effect of the Carnot temperature ratio (Φ 1 ), absolute temperature ratio (ξ) and the phase-change absolute temperature ratio for the feedwater heater (Φ 2 ) are qualitatively the same. Furthermore, the constant heat addition scenario resulted in the lowest value of the cost function. For variation of all cost functions, the smaller the value of the phase-change absolute temperature ratio for the feedwater heater (Φ 2 ), lower the cost at the minima. As feedwater heater to hot end unit cost ratio decreases, the minimum total conductance required increases

  19. Decommissioning of the ASTRA research reactor - dismantling the auxiliary systems and clearance and reuse of the buildings

    International Nuclear Information System (INIS)

    Meyer, F.; Steger, F.; Steininger, R.

    2008-01-01

    The paper presents work performed in the last phase of the decommissioning of the ASTRA research reactor at the Austrian Research Centers Seibersdorf. Dismantling the pump room installations and the ventilation system, as well as the clearance of the buildings is described. Some conclusions and summary data regarding the time table, material management, and the cost of the entire project are also presented. (author)

  20. Decommissioning of the ASTRA research reactor: Dismantling the auxiliary systems and clearance and reuse of the buildings

    Directory of Open Access Journals (Sweden)

    Meyer Franz

    2008-01-01

    Full Text Available The paper presents work performed in the last phase of the decommissioning of the ASTRA research reactor at the Austrian Research Centers Seibersdorf. Dismantling the pump room installations and the ventilation system, as well as the clearance of the buildings is described. Some conclusions and summary data regarding the timetable, material management, and the cost of the entire project are also presented.

  1. Cox17 Protein Is an Auxiliary Factor Involved in the Control of the Mitochondrial Contact Site and Cristae Organizing System*

    OpenAIRE

    Chojnacka, Magdalena; Gornicka, Agnieszka; Oeljeklaus, Silke; Warscheid, Bettina; Chacinska, Agnieszka

    2015-01-01

    The mitochondrial contact site and cristae organizing system (MICOS) is a recently discovered protein complex that is crucial for establishing and maintaining the proper inner membrane architecture and contacts with the outer membrane of mitochondria. The ways in which the MICOS complex is assembled and its integrity is regulated remain elusive. Here, we report a direct link between Cox17, a protein involved in the assembly of cytochrome c oxidase, and the MICOS complex. Cox17 interacts with ...

  2. Infrared Camera Characterization of Bi-Propellant Reaction Control Engines during Auxiliary Propulsion Systems Tests at NASA's White Sands Test Facility in Las Cruces, New Mexico

    Science.gov (United States)

    Holleman, Elizabeth; Sharp, David; Sheller, Richard; Styron, Jason

    2007-01-01

    This paper describes the application of a FUR Systems A40M infrared (IR) digital camera for thermal monitoring of a Liquid Oxygen (LOX) and Ethanol bi-propellant Reaction Control Engine (RCE) during Auxiliary Propulsion System (APS) testing at the National Aeronautics & Space Administration's (NASA) White Sands Test Facility (WSTF) near Las Cruces, New Mexico. Typically, NASA has relied mostly on the use of ThermoCouples (TC) for this type of thermal monitoring due to the variability of constraints required to accurately map rapidly changing temperatures from ambient to glowing hot chamber material. Obtaining accurate real-time temperatures in the JR spectrum is made even more elusive by the changing emissivity of the chamber material as it begins to glow. The parameters evaluated prior to APS testing included: (1) remote operation of the A40M camera using fiber optic Firewire signal sender and receiver units; (2) operation of the camera inside a Pelco explosion proof enclosure with a germanium window; (3) remote analog signal display for real-time monitoring; (4) remote digital data acquisition of the A40M's sensor information using FUR's ThermaCAM Researcher Pro 2.8 software; and (5) overall reliability of the system. An initial characterization report was prepared after the A40M characterization tests at Marshall Space Flight Center (MSFC) to document controlled heat source comparisons to calibrated TCs. Summary IR digital data recorded from WSTF's APS testing is included within this document along with findings, lessons learned, and recommendations for further usage as a monitoring tool for the development of rocket engines.

  3. Replacement of electrical protection of generation (main generator, main transformer and auxiliary transformers) and new associated monitoring system

    International Nuclear Information System (INIS)

    Archilla, J.

    2013-01-01

    The replacement of the electrical protection of generation is a technological quantum leap, since moving from an analog system (known by) (all, intuitive and visual) to a digital (integrates the hardware on a single computer, much more powerful and programmable). The keys to overcoming the challenge are know to manage the technological leap, the operational limitations of plant (keep operating the)preferred sources of energy) and make a good design (including a review independent of the configuration of the relays, taking into account the experience (operational available).

  4. Leak Detection of High Pressure Feedwater Heater Using Empirical Models

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Song Kyu; Kim, Eun Kee [Korea Power Engineering Company, Daejeon (Korea, Republic of); Heo, Gyun Young [Kyung Hee University, Yongin (Korea, Republic of); An, Sang Ha [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2009-10-15

    Even small leak from tube side or pass partition within the high pressure feedwater heater (HPFWH) causes a significant deficiency in its performance. Plant operation under the HPFWH leak condition for long time will result in cost increase. Tube side leak within HPFWH can produce the high velocity jet of water and it can cause neighboring tube failures. However, most of plants are being operated without any information for internal leaks of HPFWH, even though it is prone to be damaged under high temperature and high pressure operating conditions. Leaks from tubes and/or pass partition of HPFWH occurred in many nuclear power plants, for example, Mihama PS-2, Takahama PS-2 and Point Beach Nuclear Plant Unit 1. If the internal leaks of HPFWH are monitored, the cost can be reduced by inexpensive repairs relative to loss in performance and moreover plant shutdown as well as further tube damages can be prevented.

  5. 46 CFR 182.620 - Auxiliary means of steering.

    Science.gov (United States)

    2010-10-01

    ... TONS) MACHINERY INSTALLATION Steering Systems § 182.620 Auxiliary means of steering. (a) Except as... personnel hazards during normal or heavy weather operation. (b) A suitable hand tiller may be acceptable as...

  6. Cox17 Protein Is an Auxiliary Factor Involved in the Control of the Mitochondrial Contact Site and Cristae Organizing System.

    Science.gov (United States)

    Chojnacka, Magdalena; Gornicka, Agnieszka; Oeljeklaus, Silke; Warscheid, Bettina; Chacinska, Agnieszka

    2015-06-12

    The mitochondrial contact site and cristae organizing system (MICOS) is a recently discovered protein complex that is crucial for establishing and maintaining the proper inner membrane architecture and contacts with the outer membrane of mitochondria. The ways in which the MICOS complex is assembled and its integrity is regulated remain elusive. Here, we report a direct link between Cox17, a protein involved in the assembly of cytochrome c oxidase, and the MICOS complex. Cox17 interacts with Mic60, thereby modulating MICOS complex integrity. This interaction does not involve Sco1, a partner of Cox17 in transferring copper ions to cytochrome c oxidase. However, the Cox17-MICOS interaction is regulated by copper ions. We propose that Cox17 is a newly identified factor involved in maintaining the architecture of the MICOS complex. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  7. Cox17 Protein Is an Auxiliary Factor Involved in the Control of the Mitochondrial Contact Site and Cristae Organizing System*

    Science.gov (United States)

    Chojnacka, Magdalena; Gornicka, Agnieszka; Oeljeklaus, Silke; Warscheid, Bettina; Chacinska, Agnieszka

    2015-01-01

    The mitochondrial contact site and cristae organizing system (MICOS) is a recently discovered protein complex that is crucial for establishing and maintaining the proper inner membrane architecture and contacts with the outer membrane of mitochondria. The ways in which the MICOS complex is assembled and its integrity is regulated remain elusive. Here, we report a direct link between Cox17, a protein involved in the assembly of cytochrome c oxidase, and the MICOS complex. Cox17 interacts with Mic60, thereby modulating MICOS complex integrity. This interaction does not involve Sco1, a partner of Cox17 in transferring copper ions to cytochrome c oxidase. However, the Cox17-MICOS interaction is regulated by copper ions. We propose that Cox17 is a newly identified factor involved in maintaining the architecture of the MICOS complex. PMID:25918166

  8. Hybrid mesons with auxiliary fields

    International Nuclear Information System (INIS)

    Buisseret, F.; Mathieu, V.

    2006-01-01

    Hybrid mesons are exotic mesons in which the color field is not in the ground state. Their understanding deserves interest from a theoretical point of view, because it is intimately related to nonperturbative aspects of QCD. Moreover, it seems that some recently detected particles, such as the π 1 (1600) and the Y(4260), are serious hybrid candidates. In this work, we investigate the description of such exotic hadrons by applying the auxiliary fields technique (also known as the einbein field method) to the widely used spinless Salpeter Hamiltonian with appropriate linear confinement. Instead of the usual numerical resolution, this technique allows to find simplified analytical mass spectra and wave functions of the Hamiltonian, which still lead to reliable qualitative predictions. We analyse and compare two different descriptions of hybrid mesons, namely a two-body q system with an excited flux tube, or a three-body qg system. We also compute the masses of the 1 -+ hybrids. Our results are shown to be in satisfactory agreement with lattice QCD and other effective models. (orig.)

  9. Active mass damper system for high-rise buildings using neural oscillator and position controller: sinusoidally varying desired displacement of auxiliary mass intended for reduction of maximum control force

    Science.gov (United States)

    Iba, D.; Hongu, J.; Sasaki, T.; Shima, S.; Nakamura, M.; Moriwaki, I.

    2017-04-01

    Reducing vibration of high-rise structures under earthquake load has been the subject of considerable efforts in Japan. Relevant researches about vibration energy dissipation devices for buildings have been undertaken. An active mass damper is one of the well-known vibration control devices. Despite the accumulation of much knowledge of control design methods for the system, application of the devices to high-rise structures under earthquake load is challenging, because the active mass dampers have one serious disadvantage about stroke limitation of the auxiliary mass. In this study, we have proposed a new control system, which had a neural oscillator and position controller, to solve this problem. The objective of this paper is to improve the vibration control performance of the proposed active mass damper system. The previous method generated rectangular waves as the desired displacement, whose amplitude is varied in accordance with the vibration responses of a structure excited by earthquakes. Furthermore, the gains of the position controller, which derives the auxiliary mass to the desired displacement, have been designed in consideration of response reduction of the structure. However, the generated rectangular desired displacement was not adequate to reduce the maximum acceleration responses of the structure, because the driving force for the auxiliary mass generates excessive amounts of acceleration as the direction of the desired displacement is switched. Thus, this paper proposes a new method, which generates sinusoidal varying desired displacement for the auxiliary mass of the active mass damper system to reduce the acceleration response of structures. The results of numerical simulation showed that the proposed method in this work was effective for improving the control performance.

  10. 46 CFR 52.25-3 - Feedwater heaters (modifies PFH-1).

    Science.gov (United States)

    2010-10-01

    ... BOILERS Other Boiler Types § 52.25-3 Feedwater heaters (modifies PFH-1). In addition to the requirements in PFH-1 of section I of the ASME Boiler and Pressure Vessel Code (incorporated by reference; see 46...

  11. Study of thermohydraulic characteristics of upgraded feedwater collector in PGV-440 steam generator

    Energy Technology Data Exchange (ETDEWEB)

    Tarankov, G.A.; Trunov, N.B.; Titov, V.F. [OKB Gidropress (Russian Federation); Urbansky, V.V. [Rovno NPP (Ukraine); Lenkei, I.; Notarosh, M. [Paks NPP (Hungary)

    1995-12-31

    Reconstruction of feedwater distribution collector was performed at unit 1 of Rowno NPP. Main results of measurements of temperatures in water volume, reparation characteristics and impurities distribution are presented. Analysis of tests results and design criteria is given. (orig.).

  12. Digital controller for feedwater and recirculation flow control of BWR plant

    International Nuclear Information System (INIS)

    Sato, Takao; Ito, Tetsuo; Omori, Takashi; Iida, Hiroshi; Yanai, Katsuya.

    1980-01-01

    In nuclear power plants, it is required to operate the plants on load-following basis as the proportion of nuclear power plants in whole power supply network has been increasing. For this purpose, the requirements of more reliable, more automated plants and of the flexibility of operation are becoming serious. To respond to such demands, digital controllers are inevitable because analog controllers are limited in their controllability. It is also required to devise more intelligent systems such as those enabling strengthened diagnostic functions or sophisticated predictive control. On such background, duplicated redundant digital control system has been developed, using two control microcomputers and uniting the conventional feed-water control system and recirculation flow control system. The report discribes on the design concept for this digital controller, the hardware and software of the control system and the confirmation of the performance by simulation. The verifying test for the control performance, the simulation test for recirculation pump abnormality, the test for predictive control and the test on the response characteristics of recirculation system were carried out. The digital controller attained the MTBF 10 times as much, and the down time ratio 1/5 as small as those of the analog control systems. (Wakatsuki, Y.)

  13. Hydraulic turbines and auxiliary equipment

    Energy Technology Data Exchange (ETDEWEB)

    Luo Gaorong [Organization of the United Nations, Beijing (China). International Centre of Small Hydroelectric Power Plants

    1995-07-01

    This document presents a general overview on hydraulic turbines and auxiliary equipment, emphasizing the turbine classification, in accordance with the different types of turbines, standard turbine series in China, turbine selection based on the basic data required for the preliminary design, general hill model curves, chart of turbine series and the arrangement of application for hydraulic turbines, hydraulic turbine testing, and speed regulating device.

  14. Aspectual auxiliary verbs in Xitsonga

    African Journals Online (AJOL)

    Kate H

    Let him always come' e. á vá hátl-é vá yá étlélà. OPT 3PL quickly-OPT 3PL go sleep. 'Let them quickly go to bed'. 3.4 Negative markers. Negation is marked on AA verbs. The auxiliary verb hatla 'quickly' is negated in three tenses.

  15. Economizer water-wall damages initiated by feedwater impurities

    Directory of Open Access Journals (Sweden)

    Vidojković Sonja M.

    2014-01-01

    Full Text Available The main causes of efficiency loss in thermal power plants are boiler tube failures that diminish unit reliability and availability, and raise the cost of the electric energy. For that reason, regular examination of boiler tubes is indispensable measure for prevention future malfunctions of power units. Microscopic examination of economizer inner wall microstructure, analysis of chemical composition of deposit using x-ray diffraction (XRD and scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS has been performed in a subcritical power plant. Stress corrosion cracking, pitting corrosion, destroyed protective magnetite layer, presence of magnetite and hematite in deposit and corrosive impurities within the cracks were indicated the effect of inadequate quality of feedwater that can not entirely ensure reliable operation of the boiler. It may be stated that maintenance of present boiler does not provide its reliable operation. Extensive chemical control of water/steam cycle was recommended. [Projekat Ministartsva nauke Republike Srbije, br. III 43009 i br. III 45012

  16. Ultrasonic meters in the feedwater flow to recover thermal power in the reactor of nuclear power plant of Laguna Verde U1 and U2

    International Nuclear Information System (INIS)

    Tijerina S, F.

    2008-01-01

    The engineers in nuclear power plants BWRs and PWRs based on the development of the ultrasonic technology for the measurement of the mass, volumetric flow, density and temperature in fluids, have applied this technology in two primary targets approved by the NRC: the use for the recovery of thermal power in the reactor and/or to be able to realize an increase of thermal power licensed in a 2% (MUR) by 1OCFR50 Appendix K. The present article mentions the current problem in the measurement of the feedwater flow with Venturi meters, which affects that the thermal balance of reactor BWRs or PWRs this underestimated. One in broad strokes describes the application of the ultrasonic technology for the ultrasonic measurement in the flow of the feedwater system of the reactor and power to recover thermal power of the reactor. One is to the methodology developed in CFE for a calibration of the temperature transmitters of RTD's and the methodology for a calibration of the venturi flow transmitters using ultrasonic measurement. Are show the measurements in the feedwater of reactor of the temperature with RTD's and ultrasonic measurement, as well as the flow with the venturi and the ultrasonic measurement operating the reactor to the 100% of nominal thermal power, before and after the calibration of the temperature transmitters and flow. Finally, is a plan to be able to realize a recovery of thermal power of the reactor, showing as carrying out their estimations. As a result of the application of ultrasonic technology in the feedwater of reactor BWR-5 in Laguna Verde, in the Unit 1 cycle 13 it was recover an equivalent energy to a thermal power of 25 MWt in the reactor and an exit electrical power of 6 M We in the turbogenerator. Also in the Unit 2 cycle 10 it was recover an equivalent energy to a thermal power of 40 MWt in the reactor and an exit electrical power of 16 M We in the turbogenerator. (Author)

  17. Hydrogen/oxygen auxiliary propulsion technology

    Science.gov (United States)

    Reed, Brian D.; Schneider, Steven J.

    1991-01-01

    This paper provides a survey of hydogen/oxygen (H/O) auxiliary propulsion system (APS) concepts and low thrust H/O rocket technology. A review of H/O APS studies performed for the Space Shuttle, Space Tug, Space Station Freedom, and Advanced Manned Launch System programs is given. The survey also includes a review of low thrust H/O rocket technology programs, covering liquid H/O and gaseous H/O thrusters, ranging from 6600 N to 440 mN thrust. Ignition concepts for H/O thrusters and high-temperature, oxidation-resistant chamber materials are also reviewed.

  18. Decontamination of the reactor pressure vessel and further internals and auxiliary systems in the German boiling water reactor Isar-1; Dekontamination des RDB inkl. der Einbauten wie Dampftrockner und Wasserabscheider sowie der angeschlossenen Hilfssysteme im deutschen Siedewasserreaktor ISAR 1

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Michael; Sempere Belda, Luis; Basu, Ashim; Topf, Christian [AREVA GmbH, Erlangen (Germany). Abt. Chemistry Services; Erbacher, Thomas; Hiermer, Thomas; Schnurr, Bernhard; Appeldorn, Thomas van [E.ON Kernkraft GmbH, Kernkraftwerk ISAR, Essenbach (Germany). Abt. Maschinentechnik; Volkmann, Christian [ESG Engineering Services GmbH, Greifswald (Germany)

    2015-12-15

    The German nuclear power plant ISAR 1 (KKI 1), a 878 MWe boiling water reactor of KWU design, was shut down on March 17{sup th}, 2011. With the objective to minimize the plants activity inventory accompanied by the reduction of contact dose rates of systems and components the project 'decontamination of the RPV incl. steam dryer and water separator and the connected auxiliary systems' was implemented in the first quarter of 2015. One major focus within the project was the specific in-situ decontamination of the steam dryer.

  19. 33 CFR 5.47 - Auxiliary ensign.

    Science.gov (United States)

    2010-07-01

    ... matching blue Coast Guard Auxiliary emblem is centered. The white slash shall be at a 70 degree angle, rising away from the hoist. (c) The Auxiliary emblem consists of a disk with the shield of the Coat of...

  20. Influence of reactor vessel nodalization in the coupled code analysis of Asymmetric Main Feedwater Isolation

    International Nuclear Information System (INIS)

    Bencik, V.; Feretic, D.; Grgic, D.

    2001-01-01

    Asymmetric Main Feedwater Isolation (AMFWI) transient in one Steam Generator (SG) for NPP Krsko using RELAP5 standalone code and coupled code RELAP5- QUABOX/CUBBOX (R5QC) was analyzed. In the RELAP5 standalone calculation, a point kinetics model was used, while in the coupled code a three-dimensional (3D) neutronics model of QUABOX with different RELAP5 nodalization schemes of reactor vessel was used. Both code versions use best-estimate thermal-hydraulic system code for all components in the plant and include realistic description of plant protection and control systems. Two different types of calculations were performed: with and without automatic control rod system available. The AMFWI transient causes the great asymmetry of the transferred heat in the SGs and subsequently the asymmetry of the power produced across the core due to different reactivity feedback resulting from the thermal-hydraulic channels assigned to different loops. The work presented in the paper is a part of validation of the 3D coupled code R5QC in the analysis of asymmetric transients.(author)

  1. 45 CFR 707.10 - Auxiliary aids.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Auxiliary aids. 707.10 Section 707.10 Public Welfare Regulations Relating to Public Welfare (Continued) COMMISSION ON CIVIL RIGHTS ENFORCEMENT OF... § 707.10 Auxiliary aids. (a) The Agency shall furnish appropriate auxiliary aids where necessary to...

  2. 7 CFR 15b.37 - Auxiliary aids.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Auxiliary aids. 15b.37 Section 15b.37 Agriculture... ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Other Aid, Benefits, or Services § 15b.37 Auxiliary aids... appropriate auxiliary aids to persons with impaired sensory, manual, or speaking skills, where necessary to...

  3. 78 FR 27321 - Revision of Auxiliary Regulations

    Science.gov (United States)

    2013-05-10

    ...--Auxiliary emblem: We propose to revise this section. Provisions of the existing Sec. 5.41 would be... existing Sec. 5.47(c) describing the Auxiliary emblem and explain the use of the emblem as identification...), and 5.36(c). Added language to describe the Auxiliary emblem and discuss when it can be worn and used...

  4. A study on the relief of shell wall thinning of high pressure feedwater heater

    International Nuclear Information System (INIS)

    Kim, Hyung Joon; Park, Sang Hoon; Seo, Hyuk Ki; Kim, Kyung Hoon; Hwang, Kyung Mo

    2008-01-01

    Feedwater heaters of many nuclear power plants have recently experienced severe wall thinning damage, which will increase as operating time progresses. Several nuclear power plants in Korea have experienced wall thinning damage in the area around the impingement baffle-installed downstream of the high pressure turbine extraction stream line- inside number 5A and 5B feedwater heaters. At that point, the extracted steam from the high pressure turbine is two phase fluid at high temperature, high pressure, and high speed. Since it flows in reverse direction after impinging the impingement baffle, the shell wall of the number 5 high pressure feedwater heater may be affected by flow-accelerated corrosion. This paper describes operation of experience and numerical analysis composed similar condition with real high pressure feedwater heater. This study applied squared, curved and new type impingement baffle plates to feedwater heater same as previous study. In addition, it shows difference of pressure distribution and value between single phase and two phase based on experience and numerical analysis

  5. Heat exchanger in which the feedwater is injected into the upper part by a feed pipe open downing

    International Nuclear Information System (INIS)

    Poussin, C.

    1994-01-01

    The feedwater is injected into the upper part of the annular space formed between the exterior casing and the tube bundle envelope of the steam generator. The feedwater is injected via a feed pipe with an inversed T-piece and which opens into an overflowing channel open down. 10 figs

  6. Soft-Sensing for the Feedwater Flowrate at PWRs Using a GMDH Algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Su; Lee, Sung Han; Na, Man Gyun [Chosun University, Gwangju (Korea, Republic of); Lim, Dong Hyuk [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2009-10-15

    Currently, Venturi flow meters are being used to measure the feedwater flowrate in most pressurized water reactors (PWRs). These meters can induce measurement drift owing to corrosion product buildup near the meter orifice through long-term operation. Fouling of the Venturi meter decreases the accuracy of the existing hardware sensors. These requirements result in nuclear power plants operating at lower-than-planned power levels. Therefore, considerable research has been focused on resolving the inaccurate measurement issue of the feedwater flowrate. This study employed the Group Method of Data Handling (GMDH) which is one of the data driven models, such as Artificial Neural Networks (ANNs), to increase the thermal efficiency by accurately estimating online the feedwater flowrate. The GMDH method was trained using the informative data selected through a subtractive clustering (SC) scheme. In addition, the uncertainty of the GMDH algorithm was analyzed using a statistical uncertainty method.

  7. Welding overlay analysis of dissimilar metal weld cracking of feedwater nozzle

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, Y.L., E-mail: YLTsai@itri.org.t [National Chiao Tung University, Mechanical Engineering Department, 1001 TaHsueh Road, HsinChu, Taiwan 30010 (China); Industrial Technology Research Institute (ITRI), 195 Chung Hsing Rd., Sec.4 Chu Tung, HsinChu, Taiwan 310 (China); Wang, Li. H. [Industrial Technology Research Institute (ITRI), 195 Chung Hsing Rd., Sec.4 Chu Tung, HsinChu, Taiwan 310 (China); Fan, T.W. [Industrial Technology Research Institute (ITRI), 195 Chung Hsing Rd., Sec.4 Chu Tung, HsinChu, Taiwan 310 (China); Chung Hua University, Department of Civil Engineering and Engineering Informatics, 707, Sec.2, WuFu Rd., HsinChu, Taiwan 300 (China); Ranganath, Sam [Industrial Technology Research Institute (ITRI), 195 Chung Hsing Rd., Sec.4 Chu Tung, HsinChu, Taiwan 310 (China); Wang, C.K. [Taiwan Power Company (TPC), No.242, Sec. 3, Roosevelt Rd., Zhongzheng District, Taipei City 100, Taiwan (China); Chou, C.P. [National Chiao Tung University, Mechanical Engineering Department, 1001 TaHsueh Road, HsinChu, Taiwan 30010 (China)

    2010-01-15

    Inspection of the weld between the feedwater nozzle and the safe end at one Taiwan BWR showed axial indications in the Alloy 182 weld. The indication was sufficiently deep that continued operation could not be justified considering the crack growth for one cycle. A weld overlay was decided to implement for restoring the structural margin. This study reviews the cracking cases of feedwater nozzle welds in other nuclear plants, and reports the lesson learned in the engineering project of this weld overlay repair. The overlay design, the FCG calculation and the stress analysis by FEM are presented to confirm that the Code Case structural margins are met. The evaluations of the effect of weld shrinkage on the attached feedwater piping are also included. A number of challenges encountered in the engineering and analysis period are proposed for future study.

  8. Acoustic resonances in the steam and feedwater lines at the Dukovany NPP, unit 1

    International Nuclear Information System (INIS)

    Krupa, V.; Pecinka, L.

    1995-04-01

    The steam and feedwater line integrity and reliability programme for the loops of the Dukovany 1 reactor unit beyond the hermetic zone required calculation of the probability of their damage during normal operation and during a shock event such as a pressure wave propagation due to collapse of a steam or air bubble at the highest lying site of the feedwater piping (i. e. before the inlet to the main steam header) or to the closure of the quick-acting valve of the turbine, etc. For this purpose, the steam and feedwater eigenfrequencies were calculated for the segments from the steam generator to the turbine quick-acting valve or to the second high-pressure heater. The simple waveguide variants as well as the inclusion of the steam generator or main steam header as resonators were considered. The electromechanical analogy was employed for the calculation. (P.A.). 7 tabs., 8 figs., 6 refs

  9. History of Sandia National Laboratories` auxiliary closure mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Weydert, J.C. [Sandia National Labs., Albuquerque, NM (United States); Ponder, G.M. [Geo-Centers, Inc., Albuquerque, NM (United States)

    1993-12-01

    An essential component of a horizontal, underground nuclear test setup at the Nevada Test Site is the auxiliary closure system. The massive gates that slam shut immediately after a device has been detonated allow the prompt radiation to pass, but block debris and hot gases from continuing down the tunnel. Thus, the gates protect experiments located in the horizontal line-of-sight steel pipe. Sandia National Laboratories has been the major designer and developer of these closure systems. This report records the history of SNL`s participation in and contributions to the technology of auxiliary closure systems used in horizontal tunnel tests in the underground test program.

  10. Feedwater transient and small break loss of coolant accident analyses for the Bellefonte Nuclear Plant

    Energy Technology Data Exchange (ETDEWEB)

    Bayless, P D; Dobbe, C A; Chambers, R

    1987-03-01

    Specific sequences that may lead to core damage were analyzed for the Bellefonte nuclear plant as part of the US Nuclear Regulatory Commission's Severe Accident Sequence Analysis Program. The RELAP5, SCDAP, and SCDAP/RELAP5 computer codes were used in the analyses. The two main initiating events investigated were a loss of all feedwater to the steam generators and a small cold leg break loss of coolant accident. The transients of primary interest within these categories were the TMLB' and S/sub 2/D sequences. Variations on systems availability were also investigated. Possible operator actions that could prevent or delay core damage were identified, and two were investigated for a small break transient. All of the transients were analyzed until either core damage began or long-term decay heat removal was established. The analyses showed that for the sequences considered the injection flow from one high-pressure injection pump was necessary and sufficient to prevent core damage in the absence of operator actions. Operator actions were able to prevent core damage in the S/sub 2/D sequence; no operator actions were available to prevent core damage in the TMLB' sequence.

  11. Audit calculation of the limiting CESSAR feedwater-line-break transient with RELAP5/MOD1

    International Nuclear Information System (INIS)

    Chung, K.S.; Kennedy, M.F.; Guttmann, J.

    1983-01-01

    Argonne National Laboratory (ANL) performed a series of audit calculations of the limiting FLB transient presented in Appendix 15B to the CESSAR FSAR, supported by a limited number of additional calculations to investigate the sensitivity of the results (in terms of peak primary reactor system pressure) to break area and reactor trip time. The latter calculations were performed to quantify potential benefits in crediting reactor tip on low steam generator downcomer water level, which occurs earlier than the trip shown in the limiting FSAR transient, which tripped on high pressurizer pressure. These calculations were performed to verify the break spectrum results presented by C-E and to insure that C-E did indeed analyze the limiting transient. All of the ANL calculations were performed with RELAP5/MOD1 (cycle 18) using an input deck developed at ANL from CESSAR plant data provided by C-E. In this paper we compare the results and provide insight into the generic behavior of a Feedwater Line Break transient

  12. Inteligent control system for a CANDU 600 type reactor process

    International Nuclear Information System (INIS)

    Venescu, B.; Zevedei, D.; Jurian, M.; Venescu, R.

    2013-01-01

    The present paper is set on presenting a highly intelligent configuration, capable of controlling, without the need of the human factor, a complete nuclear power plant type of system, giving it the status of an autonomous system. The urge for such a controlling system is justified by the amount of drawbacks that appear in real life as disadvantages, loses and sometimes even inefficiency in the current controlling and comanding systems of the nuclear reactors. The application stands in the comand sent from the auxiliary feedwater flow control valves to the steam generators. As an environment fit for development I chose Matlab Simulink to simulate the behaviour of the process and the adjusted system. Comparing the results obtained after the fuzzy regulation with those obtained after the classical regulation, we can demonstrate the necessity of implementing artificial intelligence techniques in nuclear power plants and we can agree to the advantages of being able to control everything automatically. (authors)

  13. Refined analysis of effects on the LOFT containment building resulting from main steam and feedwater breaks

    Energy Technology Data Exchange (ETDEWEB)

    Mosby, W.R.

    1979-01-16

    Dynamic one-degree-of-freedom analyses of main steam breaks 8/10B and 8/11 and feedwater break 9/40 were performed using refined jet-plus-reaction force-time functions. Feedwater breaks 10/8B and 10/11 were analyzed statically using a refined maximum jet-plus-reaction force and assuming a dynamic load factor of 2. None of the breaks were found to stress the containment shell in excess of the ASME Boiler and Pressure Vessel Code allowables.

  14. Thermal-hydraulics of PGV-4 water volume during damage of the feedwater collector nozzles

    Energy Technology Data Exchange (ETDEWEB)

    Logvinov, S.A.; Titov, V.F. [OKB Gidropress (Russian Federation); Notaros, U.; Lenkei, I. [NPP Paks (Hungary)

    1995-12-31

    A number of VVER-440 plants has experienced the distributing nozzles of feedwater collector being damaged due to corrosion-erosion wearing. Such phenomenon could result in feedwater redistribution within the SG inventory with undesirable consequences. The collector with damaged nozzles has to be replaced but a certain time is needed for the preparatory works. The main objective of the investigation conducted is to assess if the safe operation of SG is possible before collector replacement. It was shown that the nozzle damage as observed did not result in the dangerous disturbances of thermobydraulics as compared with the conditions existing at the initial period of operation. (orig.).

  15. Auxiliary equipment cooling circuit in nuclear reactors

    International Nuclear Information System (INIS)

    Yanagisawa, Ko.

    1986-01-01

    Purpose: To prevent the propagation of bacterias that transform NO 2 into NO 3 in auxiliary equipment coolants using corrosion inhibitors of nitrite type in BWR type reactors. Method: In auxiliary equipments coolant systems, water quality is controlled by using purified water as supplement water and nitrite such as Na 2 NO 2 as the corrosion inhibitors. However, in the circumstance where dissolved oxygen is present, bacteria propagate to oxidize NO 2 into NO 3 . Thus, NO 2 at 200 ppm is reduced to 20 ppm. In view of the above, a surge tank supplied from water supplement line is connected in series and a deaeration device is disposed thereto. Since the presence of dissolved oxygen causes the bacteria to propagate it is desired that the dissolved oxygen density in the supplement water is less than 5 ppm. Deaeration and pressure reduction in the surge tank can remove the dissolved oxygen, prevent NO 3 increase and also prevent stress corrosion cracks in the system pipeways. (Horiuchi, T.)

  16. Reactor auxiliary cooling facility and coolant supplying method therefor

    Energy Technology Data Exchange (ETDEWEB)

    Ando, Koji; Kinoshita, Shoichiro

    1996-06-07

    A reactor auxiliary cooling facility of the present invention comprises a coolant recycling line for recycling coolants by way of a reactor auxiliary coolant pump and a cooling load, a gravitational surge tank for supplying coolants to the coolant recycling line and a supplemental water supplying line for supplying a supply the supplemental water to the tank. Then, a pressurization-type supply water surge tank is disposed for operating the coolant recycling line upon performing an initial system performance test in parallel with the gravitational surge tank. With such a constitution, the period of time required from the start of the installation of reactor auxiliary cooling facilities to the completion of the system performance test can be shortened at a reduced cost without enlarging the scale of the facility. (T.M.)

  17. Reactor auxiliary cooling facility and coolant supplying method therefor

    International Nuclear Information System (INIS)

    Ando, Koji; Kinoshita, Shoichiro.

    1996-01-01

    A reactor auxiliary cooling facility of the present invention comprises a coolant recycling line for recycling coolants by way of a reactor auxiliary coolant pump and a cooling load, a gravitational surge tank for supplying coolants to the coolant recycling line and a supplemental water supplying line for supplying a supply the supplemental water to the tank. Then, a pressurization-type supply water surge tank is disposed for operating the coolant recycling line upon performing an initial system performance test in parallel with the gravitational surge tank. With such a constitution, the period of time required from the start of the installation of reactor auxiliary cooling facilities to the completion of the system performance test can be shortened at a reduced cost without enlarging the scale of the facility. (T.M.)

  18. Diagnosis of Feedwater Heater Performance Degradation using Fuzzy Approach

    International Nuclear Information System (INIS)

    Kim, Hyeonmin; Kang, Yeon Kwan; Heo, Gyunyoung; Song, Seok Yoon

    2014-01-01

    It is inevitable to avoid degradation of component, which operates continuously for long time in harsh environment. Since this degradation causes economical loss and human loss, it is important to monitor and diagnose the degradation of component. The diagnosis requires a well-systematic method for timely decision. Before this article, the methods using regression model and diagnosis table have been proposed to perform the diagnosis study for thermal efficiency in Nuclear Power Plants (NPPs). Since the regression model was numerically less-stable under changes of operating variables, it was difficult to provide good results in operating plants. Contrary to this, the diagnosis table was hard to use due to ambiguous points and to detect how it affects degradation. In order to cover the issues of previous researches, we proposed fuzzy approaches and applied it to diagnose Feedwater Heater (FWH) degradation to check the feasibility. The degradation of FWHs is not easy to be observed, while trouble such as tube leakage may bring simultaneous damage to the tube bundle. This study explains the steps of diagnosing typical failure modes of FWHs. In order to cover the technical issues of previous researches, we adopted fuzzy logic to suggest a diagnosis algorithm for the degradation of FHWs and performed feasibility study. In this paper, total 7 modes of FWH degradation modes are considered, which are High Drain Level, Low Shell Pressure, Tube Pressure Increase, Tube Fouling, Pass Partition Plate Leakage, Tube Leakage, Abnormal venting. From the literature survey and simulation, diagnosis table for FWH is made. We apply fuzzy logic based on diagnosis table. Authors verify fuzzy diagnosis for FWH degradation synthesized the random input sets from made diagnosis table. Comparing previous researches, suggested method more-stable under changes of operating variables, than regression model. On the contrary, the problem which ambiguous points and detect how it affects degradation

  19. Hovercraft auxiliary power units (APUs)

    Energy Technology Data Exchange (ETDEWEB)

    Russell, B.J.

    1983-08-01

    Auxiliary power units (APU) manufactured by British firms for use in hovercraft are characterized. Both diesel and gas-turbine APUs are found to be well suited to the demands of this application. The design features, dimensions, performance data, and installation requirements are discussed for the SS 90, SS 923, DA-1, BA-1, HM 5, and Gevaudan 9 APUs, as well as the TRS 18 gas-turbine smoke generator. The progress made in improving the fuel efficiency of gas turbines and reducing the weight of diesel engines is considered significant.

  20. Unavailability modeling and analysis of redundant safety systems

    Energy Technology Data Exchange (ETDEWEB)

    Vaurio, J.K.; Sciaudone, D.

    1979-10-01

    Analytical expressions have been developed to estimate the average unavailability of an m-out-of-n (m/n, 1 less than or equal to m less than or equal to n less than or equal to 4) standby safety system of a nuclear power plant. The expressions take into account contributions made by testing, repair, equipment failure, human error, and different testing schemes. A computer code, ICARUS, has been written to incorporate these analytical equations. The code is capable of calculating the average unavailability, optimum test interval, and relative contributions of testing, repair, and random failures for any of three testing schemes. After verification of the methodology and coding in ICARUS, a typical auxiliary feedwater system of a nuclear power plant was analyzed. The results show that the failure modes associated with testing and true demands contribute considerably to the unavailability and that diesel generators are the most critical components contributing to the overall unavailability of the system.

  1. Calculation of the limiting CESSAR Feedwater Line-Break and Steam Line-Break transients

    International Nuclear Information System (INIS)

    Peeler, G.B.; Kennedy, M.F.; Caraher, D.L.; Guttmann, J.; Chung, K.S.

    1983-01-01

    Argonne National Laboratory (ANL), under contract to the Nuclear Regulatory Commission, performed audit calculations of the limiting Feedwater Line Break (FLB) and Steam Line Break (SLB) transients presented in the CESSAR FSAR. The results of the FLB and SLB calculations are discussed

  2. Auxiliary bearing design considerations for gas cooled reactors

    International Nuclear Information System (INIS)

    Penfield, S.R. Jr.; Rodwell, E.

    2001-01-01

    The need to avoid contamination of the primary system, along with other perceived advantages, has led to the selection of electromagnetic bearings (EMBs) in most ongoing commercial-scale gas cooled reactor (GCR) designs. However, one implication of magnetic bearings is the requirement to provide backup support to mitigate the effects of failures or overload conditions. The demands on these auxiliary or 'catcher' bearings have been substantially escalated by the recent development of direct Brayton cycle GCR concepts. Conversely, there has been only limited directed research in the area of auxiliary bearings, particularly for vertically oriented turbomachines. This paper explores the current state-of-the-art for auxiliary bearings and the implications for current GCR designs. (author)

  3. Impact of the operation of non-displaced feedwater heaters on the performance of Solar Aided Power Generation plants

    International Nuclear Information System (INIS)

    Qin, Jiyun; Hu, Eric; Nathan, Graham J.

    2017-01-01

    Highlights: • Impact of non-displaced feedwater heater on plant’s performance has been evaluated. • Two operation strategies for non-displaced feedwater heater has been proposed. • Constant temperature strategy is generally better. • Constant mass flow rate strategy is suit for rich solar thermal input. - Abstract: Solar Aided Power Generation is a technology in which low grade solar thermal energy is used to displace the high grade heat of the extraction steam in a regenerative Rankine cycle power plant for feedwater preheating purpose. The displaced extraction steam can then expand further in the steam turbine to generate power. In such a power plant, using the (concentrated) solar thermal energy to displace the extraction steam to high pressure/temperature feedwater heaters (i.e. displaced feedwater heaters) is the most popular arrangement. Namely the extraction steam to low pressure/temperature feedwater heaters (i.e. non-displaced feedwater heaters) is not displaced by the solar thermal energy. In a Solar Aided Power Generation plants, when solar radiation/input changes, the extraction steam to the displaced feedwater heaters requires to be adjusted according to the solar radiation. However, for the extraction steams to the non-displaced feedwater heaters, it can be either adjusted accordingly following so-called constant temperature strategy or unadjusted i.e. following so-called constant mass flow rate strategy, when solar radiation/input changes. The previous studies overlooked the operation of non-displaced feedwater heaters, which has also impact on the whole plant’s performance. This paper aims to understand/reveal the impact of the two different operation strategies for non-displaced feedwater heaters on the plant’s performance. In this paper, a 300 MW Rankine cycle power plant, in which the extraction steam to high pressure/temperature feedwater heaters is displaced by the solar thermal energy, is used as study case for this purpose. It

  4. 47 CFR 74.6 - Licensing of broadcast auxiliary and low power auxiliary stations.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Licensing of broadcast auxiliary and low power auxiliary stations. 74.6 Section 74.6 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES EXPERIMENTAL RADIO, AUXILIARY, SPECIAL BROADCAST AND OTHER PROGRAM DISTRIBUTIONAL SERVICES General; Rules Applicable to Al...

  5. A multivariate statistical study on a diversified data gathering system for nuclear power plants

    International Nuclear Information System (INIS)

    Samanta, P.K.; Teichmann, T.; Levine, M.M.; Kato, W.Y.

    1989-02-01

    In this report, multivariate statistical methods are presented and applied to demonstrate their use in analyzing nuclear power plant operational data. For analyses of nuclear power plant events, approaches are presented for detecting malfunctions and degradations within the course of the event. At the system level, approaches are investigated as a means of diagnosis of system level performance. This involves the detection of deviations from normal performance of the system. The input data analyzed are the measurable physical parameters, such as steam generator level, pressurizer water level, auxiliary feedwater flow, etc. The study provides the methodology and illustrative examples based on data gathered from simulation of nuclear power plant transients and computer simulation of a plant system performance (due to lack of easily accessible operational data). Such an approach, once fully developed, can be used to explore statistically the detection of failure trends and patterns and prevention of conditions with serious safety implications. 33 refs., 18 figs., 9 tabs

  6. Aspectual auxiliary verbs in Xitsonga

    Directory of Open Access Journals (Sweden)

    Seunghun J Lee

    2016-01-01

    Full Text Available In Xitsonga, certain Aspectual Auxiliary verbs (AA verbs appear with double subject agreement. While these AA verbs have been reported in the description of Xitsonga (Baumbach 1987: 250-252, a systematic morphosyntactic study of these constructions has not been undertaken. This study aims to fill this gap. An AA verb is marked with tense, aspect, mood, negation and relative clause markers and may occur in wh-questions. The lexical verb following the AA verb may be the target of verbal extensions (applicative and reciprocal, reflexive, causative and passive markers. [Please click on "Supplementary files" in the ARTICLE TOOLS sidebar on the right for the accompanying sound files.

  7. 46 CFR 63.25-1 - Small automatic auxiliary boilers.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Small automatic auxiliary boilers. 63.25-1 Section 63.25... AUXILIARY BOILERS Requirements for Specific Types of Automatic Auxiliary Boilers § 63.25-1 Small automatic auxiliary boilers. Small automatic auxiliary boilers defined as having heat-input ratings of 400,000 Btu/hr...

  8. Lecture 1. on auxiliary heating in 'Breakeven Tokamaks'

    International Nuclear Information System (INIS)

    Sheffield, John

    1978-01-01

    We may identify two main areas where auxiliary heating may be used in breakeven Tokamak reactors. (1) In the start up phase of a Tokamak reactor, having a thermal energy distribution, auxiliary heating is required to bridge the gap between the ohmic state where the temperature will probably be approximately 1 keV, and the ignited condition where T>5 keV. (2) In two component and three component systems, auxiliary power is required to maintain a non-thermal ion distribution. I will follow a similar line to that taken in the above papers and will assess the auxiliary heating requirements of a 'Breakeven Tokamak' producing approximately 500 MW of thermal power, using the D-T cycle. I will consider two and three component systems insofar as they may be used during the start up phase, but not as reactor systems in their own right. In the first lecture I will not discuss details of the heating methods. Symbols and units are given in the Appendix

  9. 47 CFR 73.1675 - Auxiliary antennas.

    Science.gov (United States)

    2010-10-01

    ... Class A TV licensees may request a decrease from the authorized facility's ERP in the license application. An FM, TV or Class A TV licensee may also increase the ERP of the auxiliary facility in a license... licensed main facility as an auxiliary facility with an ERP less than or equal to the ERP specified on the...

  10. Orthodontic springs and auxiliary appliances: assessment of magnetic field interactions associated with 1.5 T and 3 T magnetic resonance systems

    International Nuclear Information System (INIS)

    Kemper, J.; Priest, A.N.; Adam, G.; Schulze, D.; Kahl-Nieke, B.; Klocke, A.

    2007-01-01

    The objective of this paper is to evaluate magnetic field interactions at 1.5 and 3 T for 20 orthodontic devices used for fixed orthodontic therapy. Twenty springs and auxiliary parts made from varying ferromagnetic alloys were tested for magnetic field interactions in the static magnetic field at 1.5 and 3 T. Magnetic translational force F z (in millinewtons) was evaluated by determining the deflection angle β [American Society for Testing and Materials (ASTM standard test method)]. Magnetic-field-induced rotational force F rot was qualitatively determined using a five-point scale. β was found to be >45 in 13(15) devices at 1.5(3) T and translational force F z exceeded gravitational force F g on the particular object [F z 10.17-261.4 mN (10.72-566.4 mN) at 1.5(3) T]. F z was found to be up to 24.1(47.5)-fold higher than F g at 1.5(3) T. Corresponding to this, F rot on the objects was shown to be high at both field strengths (≥ +3). Three objects (at 1.5 T) and one object (at 3 T) showed deflection angles rot was found to be ≥ +3 at both field strengths. For the remaining objects, β was below 45 and torque measurements ranged from 0 to +2. Of 20 objects investigated for magnetic field interactions at 1.5(3) T, 13(15) were unsafe in magnetic resonance (MR), based on the ASTM criteria of F z . The implications of these results for orthodontic patients undergoing MRI are discussed. (orig.)

  11. Power-feedwater temperature operating domain for Sbwr applying Monte Carlo simulation

    International Nuclear Information System (INIS)

    Aguilar M, L. A.; Quezada G, S.; Espinosa M, E. G.; Vazquez R, A.; Varela H, J. R.; Cazares R, R. I.; Espinosa P, G.

    2014-10-01

    In this work the analyses of the feedwater temperature effects on reactor power in a simplified boiling water reactor (Sbwr) applying a methodology based on Monte Carlo simulation is presented. The Monte Carlo methodology was applied systematically to establish operating domain, due that the Sbwr are not yet in operation, the analysis of the nuclear and thermal-hydraulic processes must rely on numerical modeling, with the purpose of developing or confirming the design basis and qualifying the existing or new computer codes to enable reliable analyses. The results show that the reactor power is inversely proportional to the temperature of the feedwater, reactor power changes at 8% when the feed water temperature changes in 8%. (Author)

  12. Power-feedwater temperature operating domain for Sbwr applying Monte Carlo simulation

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar M, L. A.; Quezada G, S.; Espinosa M, E. G.; Vazquez R, A.; Varela H, J. R.; Cazares R, R. I.; Espinosa P, G., E-mail: sequega@gmail.com [Universidad Autonoma Metropolitana, Unidad Iztapalapa, San Rafael Atlixco No. 186, Col. Vicentina, 09340 Mexico D. F. (Mexico)

    2014-10-15

    In this work the analyses of the feedwater temperature effects on reactor power in a simplified boiling water reactor (Sbwr) applying a methodology based on Monte Carlo simulation is presented. The Monte Carlo methodology was applied systematically to establish operating domain, due that the Sbwr are not yet in operation, the analysis of the nuclear and thermal-hydraulic processes must rely on numerical modeling, with the purpose of developing or confirming the design basis and qualifying the existing or new computer codes to enable reliable analyses. The results show that the reactor power is inversely proportional to the temperature of the feedwater, reactor power changes at 8% when the feed water temperature changes in 8%. (Author)

  13. Developing the optimum boiler water and feedwater treatment for fossil plants

    Energy Technology Data Exchange (ETDEWEB)

    Dooley, B. [Electric Power Research Inst., Palo Alto, California (United States)

    1996-12-01

    Over the last two years a new set of cycle chemistry guidelines has been developed for each of the treatments used in fossil plants. These revisions have been based on research conducted over the last ten years, much at the international collaborative level. By careful selection and optimization of the boiler water and feedwater treatments, it will be possible to accrue large financial, maintenance, availability and performance improvements. (au) 14 refs.

  14. Qualitative and Quantitative Analysis of Organic Impurities in Feedwater of a Heat-Recovery Steam Generator

    Science.gov (United States)

    Chichirov, A. A.; Chichirova, N. D.; Filimonova, A. A.; Gafiatullina, A. A.

    2018-03-01

    In recent years, combined-cycle units with heat-recovery steam generators have been constructed and commissioned extensively in the European part of Russia. By the example of the Kazan Cogeneration Power Station no. 3 (TETs-3), an affiliate of JSC TGK-16, the specific problems for most power stations with combined-cycle power units that stem from an elevated content of organic impurities in the feedwater of the heat-recovery steam generator (HRSG) are examined. The HRSG is fed with highly demineralized water in which the content of organic carbon is also standardized. It is assumed that the demineralized water coming from the chemical water treatment department of TETs-3 will be used. Natural water from the Volga River is treated to produce demineralized water. The results of a preliminary analysis of the feedwater demonstrate that certain quality indices, principally, the total organic carbon, are above the standard values. Hence, a comprehensive investigation of the feedwater for organic impurities was performed, which included determination of their structure using IR and UV spectroscopy techniques, potentiometric measurements, and element analysis; determination of physical and chemical properties of organic impurities; and prediction of their behavior in the HRSG. The estimation of the total organic carbon revealed that it exceeded the standard values in all sources of water comprising the feedwater for the HRSG. The extracted impurities were humic substances, namely, a mixture of humic and fulvic acids in a 20 : 80 ratio, respectively. In addition, an analysis was performed of water samples taken at all intermediate stages of water treatment to study the behavior of organic substances in different water treatment processes. An analysis of removal of the humus substances in sections of the water treatment plant yielded the concentration of organic substances on the HRSG condensate. This was from 100 to 150 μg/dm3. Organic impurities in boiler water can induce

  15. A soft-sensing model for feedwater flow rate using fuzzy support vector regression

    Energy Technology Data Exchange (ETDEWEB)

    Na, Man Gyun; Yang, Heon Young; Lim, Dong Hyuk [Chosun University, Gwangju (Korea, Republic of)

    2008-02-15

    Most pressurized water reactors use Venturi flow meters to measure the feedwater flow rate. However, fouling phenomena, which allow corrosion products to accumulate and increase the differential pressure across the Venturi flow meter, can result in an overestimation of the flow rate. In this study, a soft-sensing model based on fuzzy support vector regression was developed to enable accurate on-line prediction of the feedwater flow rate. The available data was divided into two groups by fuzzy c-means clustering in order to reduce the training time. The data for training the soft-sensing model was selected from each data group with the aid of a subtractive clustering scheme because informative data increases the learning effect. The proposed soft-sensing model was confirmed with the real plant data of Yonggwang Nuclear Power Plant Unit 3. The root mean square error and relative maximum error of the model were quite small. Hence, this model can be used to validate and monitor existing hardware feedwater flow meters.

  16. Interim status report on the revision of ASME PTC 12.1 -- closed feedwater heaters

    International Nuclear Information System (INIS)

    Stellern, J.L.; Hoobler, J.V.; Milton, J.W.; Welch, T.; Kona, C.; Thompson, H.N.; Tsou, J.L.

    1993-01-01

    The ASME Performance Test Code (PTC) 12.1-1978 for the performance testing of feedwater heaters is being revised extensively and updated. The committee anticipates that the final draft of the proposed Code will be ready for industry review in 1993. This Code revision will greatly enhance the usefulness and cost effectiveness of feedwater heater performance testing. This paper has been prepared to report on the progress of the committee and to disseminate information on the nature of the revision. Included in this paper are some of the notable changes intended for the Code. The most extensive change is the calculation method, which is described in step-by-step detail. An approach is also described for using ultrasonic flow techniques to test individual or split-string feedwater heaters, when flow nozzles are not available. Additionally some educational information on the use and limitations of ultrasonic measurement instrumentation is included. Discussion is also included on the required uncertainty analysis. 3 refs., 2 figs., 2 tabs

  17. Analysis of ultrasound propagation in high-temperature nuclear reactor feedwater to investigate a clamp-on ultrasonic pulse doppler flowmeter

    International Nuclear Information System (INIS)

    Tezuka, Kenichi; Mori, Michitsugu; Wada, Sanehiro; Aritomi, Masanori; Kikura, Hiroshige; Sakai, Yukihiro

    2008-01-01

    The flow rate of nuclear reactor feedwater is an important factor in the operation of a nuclear power reactor. Venturi nozzles are widely used to measure the flow rate. Other types of flowmeters have been proposed to improve measurement accuracy and permit the flow rate and reactor power to be increased. The ultrasonic pulse Doppler system is expected to be a candidate method because it can measure the flow profile across the pipe cross section, which changes with time. For accurate estimation of the flow velocity, the incidence angle of ultrasound entering the fluid should be estimated using Snell's law. However, evaluation of the ultrasound propagation is not straightforward, especially for a high-temperature pipe with a clamp-on ultrasonic Doppler flowmeter. The ultrasound beam path may differ from what is expected from Snell's law due to the temperature gradient in the wedge and variation in the acoustic impedance between interfaces. Recently, simulation code for ultrasound propagation has come into use in the nuclear field for nondestructive testing. This article analyzes and discusses ultrasound propagation, using 3D-FEM simulation code plus the Kirchhoff method, as it relates to flow profile measurement in nuclear reactor feedwater with the ultrasonic pulse Doppler system. (author)

  18. Development of the user interface for visualization of the auxiliary systems of the TRIGA Mark III nuclear reactor; Desarrollo de la interface de usuario para la visualizacion de los sistemas auxiliares del reactor nuclear Triga Mark III

    Energy Technology Data Exchange (ETDEWEB)

    Merced D, J. E.

    2016-07-01

    The Instituto Nacional de Investigaciones Nucleares (ININ) has a nuclear research reactor type swimming pool with movable core cooled and moderate with light water. The nominal maximum power of the reactor is 1 MW in steady-state operation and can be pulsed at a maximum power of 2,000 MW for approximately 10 milliseconds. This reactor is mainly used to study the effects of radiation on various materials and substances. In 2001 the new control console of the nuclear reactor was installed which was based on two digital computers, one computer controls the bar management mechanisms and the other the systems to the reactor operator. In 2004, the control computer was replaced and the software was updated. Within the modernization and/or updating of the TRIGA Mark III reactor of ININ, is intended (theme of this work) to develop the user interface for the visualization of the auxiliary systems, through a Man-Machine Interface module for the renewal process of the control console. The man-machine interface system to be developed will have communication with the programmable logic controllers that will be constantly monitored and controlled to obtain real-time variables of the reactor behavior. (Author)

  19. Feedwater line break accident analysis for SMART in the view point of minimum departure from nucleate boiling ratio

    Energy Technology Data Exchange (ETDEWEB)

    Kim Soo Hyoung; Bae, Kyoo Hwan; Chung, Young Jong; Kim, Keung Koo [KAERI, Daejeon (Korea, Republic of)

    2012-10-15

    KAERI and KEPCO consortium had performed standard design of SMART(System integrated Modular Advanced ReacTor) from 2009 to 2011 and obtained standard design approval in July 2012. To confirm the safety of SMART design, all of the safety related design basis events were analyzed. A feedwater line break (FLB) is a postulated accident and is a limiting accident for a decrease in the heat removal by the secondary system in the view point of the peak RCS pressure. It is well known that departure from nucleate boiling ratio (DNBR) increases with the increase of the system pressure for conventional nuclear power plants. But SMART has comparatively lower RCS flow rate, and there is a possibility to show different DNBR behavior depending on the system pressure. To confirm that SMART is safe in case of FLB accident, the Korean nuclear regulatory body required to perform the safety analysis in the view point of minimum DNBR (MDNBR) during the licensing review process for standard design approval (SDA) of SMART design. In this paper, the safety analysis results of the FLB accident for SMART in the view point of MDNBR is described.

  20. Participation of Empresarios Agrupados in engineering of the Tokamak systems and auxiliary buildings; Participacion de Empresarios Agrupados en la Ingenieria de los sistemas de tokamak y edificios auxiliares

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez del Palacio, V.

    2013-07-01

    The Architect Engineering works comprise approximately the design of 32 buildings and structures, some of them very simple and others extremely complex. 32 buildings include nuclear buildings, as the Toyama, tritium, or the building of emergency diesel and buildings conventional and the building of the site services. Systems including those related to systems within a building they reach conventional, while interfaces with process systems are countless. Grouped entrepreneurs led the design of the mechanical (PBS65) systems and Electric (PBS43) actively participating in the design of systems of fire proofing of buildings and site. During the development of engineering accident of Fukushima works directly affect in the design of the systems.

  1. 30 CFR 75.331 - Auxiliary fans and tubing.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Auxiliary fans and tubing. 75.331 Section 75... HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.331 Auxiliary fans and tubing. (a) When auxiliary fans and tubing are used for face ventilation, each auxiliary fan shall be— (1...

  2. Auxiliary Density Matrix Methods for Hartree-Fock Exchange Calculations.

    Science.gov (United States)

    Guidon, Manuel; Hutter, Jürg; VandeVondele, Joost

    2010-08-10

    The calculation of Hartree-Fock exchange (HFX) is computationally demanding for large systems described with high-quality basis sets. In this work, we show that excellent performance and good accuracy can nevertheless be obtained if an auxiliary density matrix is employed for the HFX calculation. Several schemes to derive an auxiliary density matrix from a high-quality density matrix are discussed. Key to the accuracy of the auxiliary density matrix methods (ADMM) is the use of a correction based on standard generalized gradient approximations for HFX. ADMM integrates seamlessly in existing HFX codes and, in particular, can be employed in linear scaling implementations. Demonstrating the performance of the method, the effect of HFX on the structure of liquid water is investigated in detail using Born-Oppenheimer molecular dynamics simulations (300 ps) of a system of 64 molecules. Representative for large systems are calculations on a solvated protein (Rubredoxin), for which ADMM outperforms the corresponding standard HFX implementation by approximately a factor 20.

  3. Hydrothermal carbonization (HTC) of wheat straw: influence of feedwater pH prepared by acetic acid and potassium hydroxide.

    Science.gov (United States)

    Reza, M Toufiq; Rottler, Erwin; Herklotz, Laureen; Wirth, Benjamin

    2015-04-01

    In this study, influence of feedwater pH (2-12) was studied for hydrothermal carbonization (HTC) of wheat straw at 200 and 260°C. Acetic acid and KOH were used as acidic and basic medium, respectively. Hydrochars were characterized by elemental and fiber analyses, SEM, surface area, pore volume and size, and ATR-FTIR, while HTC process liquids were analyzed by HPLC and GC. Both hydrochar and HTC process liquid qualities vary with feedwater pH. At acidic pH, cellulose and elemental carbon increase in hydrochar, while hemicellulose and pseudo-lignin decrease. Hydrochars produced at pH 2 feedwater has 2.7 times larger surface area than that produced at pH 12. It also has the largest pore volume (1.1 × 10(-1) ml g(-1)) and pore size (20.2 nm). Organic acids were increasing, while sugars were decreasing in case of basic feedwater, however, phenolic compounds were present only at 260°C and their concentrations were increasing in basic feedwater. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. LOFT/LP-FW-1, Loss of Fluid Test, PWR Response to Loss-of-Feedwater Transient

    International Nuclear Information System (INIS)

    1989-01-01

    1 - Description of test facility: The LOFT Integral Test Facility is a scale model of a LPWR. The intent of the facility is to model the nuclear, thermal-hydraulic phenomena which would take place in a LPWR during a LOCA. The general philosophy in scaling coolant volumes and flow areas in LOFT was to use the ratio of the LOFT core [50 MW(t)] to a typical LPWR core [3000 MW(t)]. For some components, this factor is not applied; however, it is used as extensively as practical. In general, components used in LOFT are similar in design to those of a LPWR. Because of scaling and component design, the LOFT LOCA is expected to closely model a LPWR LOCA. 2 - Description of test: The first OECD LOFT experiment was conducted on February 20, 1983. It was designed to evaluate the generic PWR system response during a complete loss-of-feedwater transient. The objective of the experiment was to investigate the performance of primary 'feed and bleed' using a 'bleed' from the PORV and 'feed' from the HPIS to provide decay heat removal and system pressure reduction while maintaining the primary coolant inventory. 3 - Experimental limitations or shortcomings: Short core and steam generator, excessive core bypass, other scaling compromises, and lack of adequate measurements in certain areas

  5. Device for detecting the water leak within a feedwater nozzle in water cooled reactors

    International Nuclear Information System (INIS)

    Hattori, Tsunekazu.

    1984-01-01

    Purpose: To enable exact recognition and detection for the state of water leak. Constitution: The detection device comprises a thermocouple disposed to the outer surface of a feedwater nozzle, a distortion meter for detecting the change in the outer diameter of a nozzle and an acoustic emission generator disposed to the inside of the nozzle for generating a signal upon temperature change. These sensors previously monitor the states during normal operation, and thus detect the change in each of the states upon occurrence of water leakage to issue an alarm. (Kamimura, M.)

  6. Feed-water heaters alternative design comparison; Comparacion de disenos alternativos de calentadores

    Energy Technology Data Exchange (ETDEWEB)

    Torres Toledano, Gerardo [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1988-12-31

    A procedure is presented for the alternative design comparison of feed water heaters, based in the failure records of damaged tubes during operation. The procedure is used for cases in which non-continuous or random inspections are made to the feed-water heaters. [Espanol] Se presenta un procedimiento para comparar disenos alternativos de calentadores, basandose en los registros de fallas de los tubos rotos acumuladas durante su operacion. El procedimiento se emplea para casos en los que se realizan inspecciones a los calentadores no continuas, ya sea periodicas o al azar.

  7. Solids filtration of high-temperature feedwater in a PWR secondary circuit: Final report

    International Nuclear Information System (INIS)

    Siegwarth, D.P.; Friedman, K.A.; Chakravorti, R.K.; Alibutod, L.J.

    1988-11-01

    Pressurized water reactor steam generators and turbines have experienced a variety of corrosion problems as a result of ionic, corrosion product and oxidizing species transport to the steam generators. Installation of high temperature filters on final feedwater, high pressure drains and moisture separator drains to reduce corrosion product ingress to the steam generators of a 1160 MWe design basis plant are specified and evaluated. Cost estimates for installing electromagnetic filters, and added operating and maintenance costs are given. 18 refs., 12 figs., 9 tabs

  8. Power-feedwater enthalpy operating domain for SBWR applying Monte Carlo simulation

    International Nuclear Information System (INIS)

    Quezada-Garcia, S.; Espinosa-Martinez, E.-G.; Vazquez-Rodriguez, A.; Varela-Ham, J.R.; Espinosa-Paredes, G.

    2014-01-01

    In this work the analyses of the feedwater enthalpy effects on reactor power in a simplified boiling water reactor (SBWR) applying a methodology based on Monte Carlo's simulation (MCS), is presented. The MCS methodology was applied systematically to establish operating domain, due that the SBWR are not yet in operation, the analysis of the nuclear and thermalhydraulic processes must rely on numerical modeling, with the purpose of developing or confirming the design basis and qualifying the existing or new computer codes to enable reliable analyses. (author)

  9. Life cycle management, design review, and condition assessment of feedwater heaters

    International Nuclear Information System (INIS)

    Gammage, D.; Idvorian, N.

    2012-01-01

    OPEX from both the Nuclear and Fossil Power Generation Industries shows that Feedwater Heaters (FWHs) are subject to several degradation mechanisms and that this degradation commonly leads to replacement of these vessels in order to ensure reliable, efficient operation of the plants. Loss of feedwater heating will impact plant thermal performance. In response to inspection results showing on-going degradation as well as other factors, B&W Canada completed a project in conjunction with a US PWR utility to review the design, condition, and Life Cycle Management of their FWHs. This project involved a multi-disciplinary approach in order to consider all aspects of the FWHs in order to provide insight into the Life Cycle Management Plan (LCMP) so that the FWHs can be operated reliably into the future and so that adequate inspections can be conducted in order to produce a detailed condition assessment. The utility was interested in evaluating their FWH LCMP to determine if it was adequate in its requirements to enable reliable, leak-free operation of their FWH equipment. As inputs to this evaluation, it was required that B&W Canada evaluate both confirmed and plausible degradation mechanisms. They also required that the thermal hydraulic and functional design be evaluated for their particular FWHs. It was important to also incorporate industry OPEX in order to provide proper trending information for tube plugging. Out of this evaluation there were several findings and recommendations that could be used to update the utilities’ LCMP as it was apparent that the current version may not be truly reflective of the current condition of the equipment or of current industry OPEX of such FWHs. Several recommendations came from this evaluation, the most significant were: • Performing thermal/hydraulic, FIV (flow-induced vibration), and tube/shell interaction calculations to determine how the FWHs operate and how their performance can change over time as a function of tube

  10. Remote visual testing (RVT) for the diagnostic inspection of feedwater heaters

    International Nuclear Information System (INIS)

    Nugent, M.J.; Pellegrino, B.A.

    1991-01-01

    In this paper the benefits and limitations of Non-Destructive Testing (NDT) on feedwater heaters will be briefly reviewed. All Remote Visual Testing (RVT) devices including borescopes, fiberscopes, videoborescopes and Closed Circuit Television (CCTV) cameras will be discussed along with currently accepted formats for documentation. The benefits of a comprehensive in-place inspection involving Remote Visual Testing will be discussed in relationship to its diagnostic capabilities. The results of eight post-service heater inspections will be discussed along with the root cause of failure of seven unique failure mechanisms. These inspections, including FWH access, RVT tool and data analysis, will be detailed

  11. Computation within the auxiliary field approach

    CERN Document Server

    Baeurle, S A

    2003-01-01

    Recently, the classical auxiliary field methodology has been developed as a new simulation technique for performing calculations within the framework of classical statistical mechanics. Since the approach suffers from a sign problem, a judicious choice of the sampling algorithm, allowing a fast statistical convergence and an efficient generation of field configurations, is of fundamental importance for a successful simulation. In this paper we focus on the computational aspects of this simulation methodology. We introduce two different types of algorithms, the single-move auxiliary field Metropolis Monte Carlo algorithm and two new classes of force-based algorithms, which enable multiple-move propagation. In addition, to further optimize the sampling, we describe a preconditioning scheme, which permits to treat each field degree of freedom individually with regard to the evolution through the auxiliary field configuration space. Finally, we demonstrate the validity and assess the competitiveness of these algo...

  12. Builtin vs. auxiliary detection of extrapolation risk.

    Energy Technology Data Exchange (ETDEWEB)

    Munson, Miles Arthur; Kegelmeyer, W. Philip,

    2013-02-01

    A key assumption in supervised machine learning is that future data will be similar to historical data. This assumption is often false in real world applications, and as a result, prediction models often return predictions that are extrapolations. We compare four approaches to estimating extrapolation risk for machine learning predictions. Two builtin methods use information available from the classification model to decide if the model would be extrapolating for an input data point. The other two build auxiliary models to supplement the classification model and explicitly model extrapolation risk. Experiments with synthetic and real data sets show that the auxiliary models are more reliable risk detectors. To best safeguard against extrapolating predictions, however, we recommend combining builtin and auxiliary diagnostics.

  13. CIT burn control using auxiliary power modulation

    International Nuclear Information System (INIS)

    Chaniotakis, E.A.; Freidberg, J.P.; Cohn, D.R.

    1989-01-01

    It is predicted that ignited tokamaks such as CIT will experience a thermal instability. In this work a zero dimensional transport model is used as a means of examining this thermal instability. In order to solve the problems associated with the uncertainty in predicting the behavior of an ignited tokamak plasma, auxiliary power may be used for mapping the tokamak operating space, both in the low temperature stable regime and in the high temperature unstable regime. Auxiliary power modulation as a means of burn control is the most reliable method, especially during the initial stages of CIT operation. By modulating the auxiliary power stable thermal equilibria can be created at relatively high values of Q (∼65). 20 refs., 28 figs

  14. Preliminary Results of a New Auxiliary Mechatronic Near-Field Radar System to 3D Mammography for Early Detection of Breast Cancer

    Directory of Open Access Journals (Sweden)

    Ashkan Ghanbarzadeh Dagheyan

    2018-01-01

    Full Text Available Accurate and early detection of breast cancer is of high importance, as it is directly associated with the patients’ overall well-being during treatment and their chances of survival. Uncertainties in current breast imaging methods can potentially cause two main problems: (1 missing newly formed or small tumors; and (2 false alarms, which could be a source of stress for patients. A recent study at the Massachusetts General Hospital (MGH indicates that using Digital Breast Tomosynthesis (DBT can reduce the number of false alarms, when compared to conventional mammography. Despite the image quality enhancement DBT provides, the accurate detection of cancerous masses is still limited by low radiological contrast (about 1% between the fibro-glandular tissue and affected tissue at X-ray frequencies. In a lower frequency region, at microwave frequencies, the contrast is comparatively higher (about 10% between the aforementioned tissues; yet, microwave imaging suffers from low spatial resolution. This work reviews conventional X-ray breast imaging and describes the preliminary results of a novel near-field radar imaging mechatronic system (NRIMS that can be fused with the DBT, in a co-registered fashion, to combine the advantages of both modalities. The NRIMS consists of two antipodal Vivaldi antennas, an XY positioner, and an ethanol container, all of which are particularly designed based on the DBT physical specifications. In this paper, the independent performance of the NRIMS is assessed by (1 imaging a bearing ball immersed in sunflower oil and (2 computing the heat Specific Absorption Rate (SAR due to the electromagnetic power transmitted into the breast. The preliminary results demonstrate that the system is capable of generating images of the ball. Furthermore, the SAR results show that the system complies with the standards set for human trials. As a result, a configuration based on this design might be suitable for use in realistic clinical

  15. Generating Selected Color using RGB, Auxiliary Lights, and Simplex Search

    Directory of Open Access Journals (Sweden)

    Kim HyungTae

    2015-01-01

    Full Text Available A mixed light source generates various colors, with the potential to adjust intensities of multiple LEDs, which makes it possible to generate arbitrary colors. Currently, PCs and OSs provide color selection windows that can obtain the RGB or HSL color coordinates of a user’s selection. Mixed light sources are usually composed of LEDs in the primary colors, with LEDs in auxiliary colors such as white and yellow used in a few cases. When using auxiliary color LEDs, the number of LED inputs, the dimming levels, is larger than the number of elements in the color coordinate, which causes an under-determined problem. This study proposed how to determine the dimming levels of LEDs based on the selected color. Commercial LEDs have di_erent optical power values and impure color coordinates, even if they are RGB. Hence, the characteristics of the LEDs were described using a linear model derived from the tri-stimulus values (an XYZ color coordinate model and dimming levels. Color mixing models were derived for the arbitrary number of auxiliary color LEDs. The under-determined problem was solved using a simplex search method without an inverse matrix operation. The proposed method can be applied to a machine vision system and an RGBW light mixer for semiconductor inspection. The dimming levels, obtained using the proposed method were better than derived using other methods.

  16. Heat transfer equipment performance diagnosis of auxiliary systems in electric power stations; Diagnostico de comportamiento de equipo de transferencia de calor de sistemas auxiliares de centrales termoelectricas

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz Esparza Gutierrez, Rogelio [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1990-12-31

    In this article the methodology followed to diagnose the performance of the equipment where heat is transferred from the feed water, condensate and circulation water systems in fossil power plants (FPP). The data collection is made with the unit in normal operation, using local instrumentation without taking the equipment out of service for its installation. The equipment diagnosis is made through the analysis of the collected data in actual operation and the design data; for this purpose a thermal balance of the interested systems is performed to obtain all the conditions an operation data. Later on the performance indicative parameters (PIP) of actual operation and design are calculated and compared one against the other. Such a comparison reveals the performance deterioration and the possible equipment faults. The data obtained and the supplementary information are stored in a data base whose objective is that Comision Federal de Electricidad has on hand a prompt access to them in order to control the performance, compare them among similar units and power stations, and inclusively verify possible recurrent causes of low availability in the referred systems. [Espanol] En este articulo se presenta la metodologia seguida para diagnosticar el comportamiento de equipos en los que se transfiere calor de los sistemas de agua de alimentacion, condensado y circulacion de las centrales termoelectricas (CTE). La toma de datos se realiza con la unidad en operacion normal, utilizando instrumentacion local sin necesidad de sacar de servicio a los equipos para su instalacion, ya que se ocupan los mismos puntos para instrumentos con que cuentan por diseno. El diagnostico de los equipos se realiza mediante el analisis de los datos recopilados, tanto de operacion real como de diseno; para ello, se efectua un balance termico de los sistemas de interes para obtener todas las condiciones y los datos de operacion. Posteriormente, se calculan los parametros indicativos de

  17. Analysis of the Pactel loss-of-feedwater experiments

    International Nuclear Information System (INIS)

    Korteniemi, V.; Virtanen, E.; Haapalehto, T.; Kouhia, J.

    1995-01-01

    The western thermal-hydraulic system codes, like RELAP5 and CATHARE2, are developed and validated to model the phenomena in the vertical steam generators. The differences between vertical and horizontal steam generators are so significant that the calculational models developed for the vertical steam generators are not directly applicable for the horizontal steam generators. The PACTEL loss of feed water experiments have been performed to study the overall behaviour of the horizontal steam generators and especially to produce experimental data for code assessment. In this paper the results from APROS, CATHARE2 and RELAP5 calculations of a series of experiments are presented

  18. Analysis of the Pactel loss-of-feedwater experiments

    Energy Technology Data Exchange (ETDEWEB)

    Korteniemi, V.; Virtanen, E.; Haapalehto, T. [Lappeenranta Univ. of Technology (Finland); Kouhia, J. [VTT Energy, Espoo (Finland). Nuclear Energy

    1995-12-31

    The western thermal-hydraulic system codes, like RELAP5 and CATHARE2, are developed and validated to model the phenomena in the vertical steam generators. The differences between vertical and horizontal steam generators are so significant that the calculational models developed for the vertical steam generators are not directly applicable for the horizontal steam generators. The PACTEL loss of feed water experiments have been performed to study the overall behaviour of the horizontal steam generators and especially to produce experimental data for code assessment. In this paper the results from APROS, CATHARE2 and RELAP5 calculations of a series of experiments are presented. 6 refs.

  19. New energy conversion processes and neglected auxiliary systems - a treasure trove for energy service providers; Neue Techniken und vernachlaessigte Nebenanlagen - eine Fundgrube fuer Energiedienstleister

    Energy Technology Data Exchange (ETDEWEB)

    Jochem, E.

    1998-12-31

    The paper shows that apart from the risks, the deregulation of the energy sector also offered new chances, which recently materialized in three emerging independent trends, initiating innovative approaches for energy conversion and applications and demand for new knowledge-based, near-production energy services as a new field for engineers: Providers of energy efficiency-related technology widen their capabilities by adding the new business segment of energy service marketing. Industrial energy users more strongly consider outsourcing of energy conversion systems and the relevant contracting schemes as an option for reducing energy costs. Public enterprise as energy users started following this trend, all the more as insufficient financial resources do not permit them to reinvest. The paper discusses the conversion processes which currently open up promising chances for energy service producers. (orig./CB) [Deutsch] Neben Gefahren, die inhaerentes Merkmal der Liberalisierung sind, zeichnen sich drei unabhaengige Entwicklungen ab, die innovative Initiativen in der Energiewandlung und -nutzung staerken und wissensintensive produktionsnahe Dienstleistungen als zentrale Aufgabe fuer den Ingenieur initieren: - Die Energieeffizienz-Technologieanbieter nehmen die Energiedienstleistungen in ihre Angebotspalette auf. - Die betrieblichen Energieanwender beginnen zunehmend, ueber das Outsourcing energiewandelnder Anlagen Energiekosten zu senken. - Die oeffentliche Hand als Energieanwender beginnt aehnlich zu denken, zumal sie infolge der hohen Verschuldung unzureichende finanzielle Mittel fuer Reinvestitionen hat. Hierueber sei kurz berichtet, bevor auf die Techniken eingegangen wird, die sich besonders aus heutiger Sicht fuer Energiedienstleister eignen. (orig./RHM)

  20. Simulation of loss of feedwater transient of MASLWR test facility by MARS-KS code

    Energy Technology Data Exchange (ETDEWEB)

    Park, Juyeop [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2013-05-15

    MASLWR test facility is a mock-up of a passive integral type reactor equipped with helical coil steam generator. Since SMART reactor which is being current developed domestically also adopts helical coil steam generator, KINS has joined this ICSP to evaluate performance of domestic regulatory audit thermal-hydraulic code (MARS-KS code) in various respects including wall-to-fluid heat transfer model modification implemented in the code by independent international experiment database. In the ICSP, two types of transient experiments have been focused and they are loss of feedwater transient with subsequent ADS operation and long term cooling (SP-2) and normal operating conditions at different power levels (SP-3). In the present study, KINS simulation results by the MARS-KS code (KS-002 version) for the SP-2 experiment are presented in detail and conclusions on MARS-KS code performance drawn through this simulation is described. Performance of the MARS-KS code is evaluated through the simulation of the loss of feedwater transient of the MASLWR test facility. Steady state run shows helical coil specific heat transfer models implemented in the code is reasonable. However, through the transient run, it is also found that three-dimensional effect within the HPC and axial conduction effect through the HTP are not well reproduced by the code.

  1. Evaluation method for two-phase flow and heat transfer in a feed-water heater

    International Nuclear Information System (INIS)

    Takamori, Kazuhide; Minato, Akihiko

    1993-01-01

    A multidimensional analysis code for two-phase flow using a two-fluid model was improved by taking into consideration the condensation heat transfer, film thickness, and film velocity, in order to develop an evaluation method for two-phase flow and heat transfer in a feed-water heater. The following results were obtained by a two-dimensional analysis of a feed-water heater for a power plant. (1) In the model, the film flowed downward in laminar flow due to gravity, with droplet entrainment and deposition. For evaluation of the film thickness, Fujii's equation was used in order to account for forced convection of steam flow. (2) Based on the former experimental data, the droplet deposition coefficient and droplet entrainment rate of liquid film were determined. When the ratio at which the liquid film directly flowed from an upper heat transfer tube to a lower heat transfer tube was 0.7, the calculated total heat transfer rate agreed with the measured value of 130 MW. (3) At the upper region of a heat transfer tube bundle where film thickness was thin, and at the outer region of a heat transfer tube bundle where steam velocity was high, the heat transfer rate was large. (author)

  2. Condensation heat transfer of a feed-water heater and improvement of its performance

    International Nuclear Information System (INIS)

    Takamori, Kazuhide; Murase, Michio; Baba, Yoshikazu; Aihara, Tsuyoshi

    1995-01-01

    In this study, a condensation heat transfer model, coupled with a three-dimensional two-phase flow analysis, was developed. In the heat transfer model, the liquid film flow rate on the heat transfer tubes was calculated by a mass balance equation and the liquid film thickness was calculated from the liquid film flow rate using Nusselt's laminar flow model and Fujii's equation for the steam velocity effect. The model was verified by condensation heat transfer experiments. In the experiments, 112 horizontal, staggered tubes with an outer diameter of 16mm and length of 0.55m were used. The calculated over-all heat transfer coefficients agreed with the data within ±5% under the inlet quality conditions of 13-100%. Based on a three-dimensional two-phase flow analysis, an improved feed-water heater with support plates, which have flow holes between the upper and lower tube bundles, was designed. The total heat exchange capacity of the improved feed-water heater increased about 6%. (author)

  3. Loss Model and Efficiency Analysis of Tram Auxiliary Converter Based on a SiC Device

    Directory of Open Access Journals (Sweden)

    Hao Liu

    2017-12-01

    Full Text Available Currently, the auxiliary converter in the auxiliary power supply system of a modern tram adopts Si IGBT as its switching device and with the 1700 V/225 A SiC MOSFET module commercially available from Cree, an auxiliary converter using all SiC devices is now possible. A SiC auxiliary converter prototype is developed during this study. The author(s derive the loss calculation formula of the SiC auxiliary converter according to the system topology and principle and each part loss in this system can be calculated based on the device datasheet. Then, the static and dynamic characteristics of the SiC MOSFET module used in the system are tested, which aids in fully understanding the performance of the SiC devices and provides data support for the establishment of the PLECS loss simulation model. Additionally, according to the actual circuit parameters, the PLECS loss simulation model is set up. This simulation model can simulate the actual operating conditions of the auxiliary converter system and calculate the loss of each switching device. Finally, the loss of the SiC auxiliary converter prototype is measured and through comparison it is found that the loss calculation theory and PLECS loss simulation model is valuable. Furthermore, the thermal images of the system can prove the conclusion about loss distribution to some extent. Moreover, these two methods have the advantages of less variables and fast calculation for high power applications. The loss models may aid in optimizing the switching frequency and improving the efficiency of the system.

  4. Curricular Guidelines for Dental Auxiliary Radiology.

    Science.gov (United States)

    Journal of Dental Education, 1981

    1981-01-01

    AADS curricular guidelines suggest objectives for these areas of dental auxiliary radiology: physical principles of X-radiation in dentistry, related radiobiological concepts, principles of radiologic health, radiographic technique, x-ray films and intensifying screens, factors contributing to film quality, darkroom, and normal variations in…

  5. Monitoring process variability using auxiliary information

    NARCIS (Netherlands)

    Riaz, M.

    2008-01-01

    In this study a Shewhart type control chart namely V (r) chart is proposed for improved monitoring of process variability (targeting large shifts) of a quality characteristic of interest Y. The proposed control chart is based on regression type estimator of variance using a single auxiliary variable

  6. EDF (Electricite de France) feedback shot-peening on feedwater plants working to 360 0 C: prediction correlation and follow-up of thermal stresses relaxation

    International Nuclear Information System (INIS)

    Gauchet, J.P.

    1995-01-01

    This study predicts life duration of shot-peening effect and finally to allow the plant operator to prepare routine stopping, considering the following four steps have been: the shot-peening parameters must been carefully chosen and implementation must be reliable and perfectly reproducible; the residual stresses and cold working state checked by X-ray diffraction; the EDF feedback on different steam-water system components working at around-300 0 C and repaired by shot-peening, like feed heater water boxes, water tanks and vessels, steam pipes; a program, carried out on a feedwater tank repaired by welding and hot-peening and working at 360 0 C, on the correlation between expected and effective results. (author). 7 refs., 3 figs., 1 tab

  7. Computer Simulation of Auxiliary Power Systems.

    Science.gov (United States)

    1980-03-01

    EFFICIENCY (1.0) ETAM - MECHANICAL EFFICIENCY (1.0) * HV - MAIN COMBUSTOR FUEL HEATING VALUE AT T4 FOR JP-4 (Optional. If omitted, it is calculated by...2559.67, DPT=0.O, M-2, N=2, WrF4DS=0., ETAHPC-.746, HPACC=g*5, PRLPT=9.418, HPDS=200., IV-18400., ITITLE=1, DPIN=.04, ETAM =. 98, ETAHPT=.8, PRHPT-1 .5...OPT, cP’E, OPINV DO-, HPACC, HODS, S LCSL, HCSL, 2 PCBLC, TI., ETAM $ IMcENSION ANUM (2), AWORO (?), 3W1’RO (?), TITLE REAL LCSL DATA AWORD / 3rlATI

  8. Design and scope of impact of auxiliary lanes : technical report.

    Science.gov (United States)

    2014-06-01

    For decades, Texas Department of Transportation districts have constructed auxiliary lanes to support interchange : ramp operations and to resolve congestion proximate to freeway entrance and exit ramps. While auxiliary lanes are : built throughout T...

  9. Diesel reforming for SOFC auxiliary power units

    Energy Technology Data Exchange (ETDEWEB)

    Borup, R. L. (Rodney L.); Parkinson, W. J. (William Jerry),; Inbody, M. A. (Michael A.); Tafoya, J. I. (Jose I.); Guidry, D. R. (Dennis Ray)

    2004-01-01

    The use of a solid-oxide fuel cell (SOFC) to provide auxiliary power for heavy duty trucks can increase fuel efficiency and reduce emissions by reducing engine idling time. The logical fuel of choice for a truck SOFC APU is diesel fuel, as diesel is the fuel of choice for these vehicles. SOFC's that directly oxidize hydrocarbon fuels have lower power densities than do SOFC's that operate from hydrocarbon reformate, and since the SOFC is a costly component, maximizing the fuel cell power density provides benefits in reducing the overall APU system cost. Thus current SOFC APU systems require the reformation of higher hydrocarbons for the most efficient and cost effect fuel cell system. The objective of this research is to develop the technology to enable diesel reforming for SOFC truck APU applications. Diesel fuel can be reformed into a H{sub 2} and CO-rich fuel feed stream for a SOFC by autothermal reforming (ATR), a combination of catalytic partial oxidation (CPOx), and steam reforming (SR). The typical autothermal reformer is an adiabatic, heterogeneous catalytic reactor and the challenges in its design, operation and durability on diesel fuel are manifold. These challenges begin with the vaporization and mixing of diesel fuel with air and steam where fuel pyrolysis can occur and improper mixing leads to hot and cold spots, which contribute to carbon formation and incomplete fuel conversion. The exotherm of the partial oxidation reaction can generate temperatures in excess of 800 C, a temperature at which catalysts rapidly sinter, thus reducing their lifetime. The temperature rise can be reduced by the steam reforming endotherm, but this requires the addition of water along with proper design to balance the kinetic rates. Carbon formation during operation and startup can lead to catalyst deactivation and fouling of downstream components, thus reducing durability of the fuel processor. Water addition helps to reduce carbon formation, but a key issue is

  10. The English Primary Auxiliary Verbs: A Linguistic Theoretical Exercise

    African Journals Online (AJOL)

    Nekky Umera

    words, because the English primary auxiliary verbs are so important in our communication, speakers must consider the various ways thus type of auxiliary verbs can be grammatically used in sentences. Traditional Grammar Approach to the Use of English Auxiliaries. Greenbaum (1988) defines grammar as a general theory ...

  11. 14 CFR 25.445 - Auxiliary aerodynamic surfaces.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Auxiliary aerodynamic surfaces. 25.445... § 25.445 Auxiliary aerodynamic surfaces. (a) When significant, the aerodynamic influence between auxiliary aerodynamic surfaces, such as outboard fins and winglets, and their supporting aerodynamic...

  12. Modified Darboux transformations with foreign auxiliary equations

    International Nuclear Information System (INIS)

    Schulze-Halberg, Axel

    2011-01-01

    We construct a new type of first-order Darboux transformations for the stationary Schroedinger equation. In contrast to the conventional case, our Darboux transformations support arbitrary (foreign) auxiliary equations. We show that among other applications, our formalism can be used to systematically construct Darboux transformations for Schroedinger equations with energy-dependent potentials, including a recent result (Lin et al., 2007) as a special case. -- Highlights: → We generalize the Darboux transformation for the Schroedinger equation. → By admitting arbitrary auxiliary functions, we provide a new tool for generating solutions. → As a special case we recover a recent result on energy-dependent potentials. → We extend the latter result to very general energy-dependence.

  13. Ferroresonance Phenomenon in Power Plant Auxiliary Grids

    Directory of Open Access Journals (Sweden)

    Maciej Łosiński

    2015-03-01

    Full Text Available The paper discusses the problem of the ferroresonance phenomenon occurring in a medium voltage grid with an ungrounded neutral point of the supply transformer. Results of a study of ferroresonance in the auxiliary grid at Żarnowiec Pumped Storage Power Plant are presented. Analysis of the study results has led to the development and implementation of an effective method of preventing the adverse ferroresonance phenomenon.

  14. Thermal stratification in steam generator feedwater line. Life assessment from real transients

    International Nuclear Information System (INIS)

    Morilhat, P.

    1989-01-01

    Thermal stratification in the vicinity of steam generator feedwater nozzle at low flow rates has led to the surveillance of two specially instrumented PWR units during a complete fuel cycle. This paper is an overview of the tests performed. The analysis of the operating conditions of these units shows their representativness with the characteristics of the other plants and identifies the main phases responsible for stratified states. A simplified model for computing axial stresses is carried out. Computed stresses are compared with the values given by extensometric gauges. The fatigue usage factor is calculated from transients actually occurred on these units and the share of damage due to each type of event is assessed

  15. Considerations on the question of applying ion exchange or reverse osmosis methods in boiler feedwater processing

    International Nuclear Information System (INIS)

    Marquardt, K.; Dengler, H.

    1976-01-01

    This consideration is to show that the method of reverse osmosis presents in many cases an interesting and economical alternative to part and total desolination plants using ion exchangers. The essential advantages of the reverse osmosis are a higher degree of automization, no additional salting of the removed waste water, small constructional volume of the plant as well as favourable operational costs with increasing salt content of the crude water to be processed. As there is a relatively high salt breakthrough compared to the ion exchange method, the future tendency in boiler feedwater processing will be more towards a combination of methods of reverse osmosis and post-purification through continuous ion exchange methods. (orig./LH) [de

  16. Threshold concentration of easily assimilable organic carton in feedwater for biofouling of spiral-wound membranes.

    Science.gov (United States)

    Hijnen, W A M; Biraud, D; Cornelissen, E R; van der Kooij, D

    2009-07-01

    One of the major impediments in the application of spiral-wound membranes in water treatment or desalination is clogging of the feed channel by biofouling which is induced by nutrients in the feedwater. Organic carbon is, under most conditions, limiting the microbial growth. The objective of this study is to assess the relationship between the concentration of an easily assimilable organic compound such as acetate in the feedwater and the pressure drop increase in the feed channel. For this purpose the membrane fouling simulator (MFS) was used as a model for the feed channel of a spiral-wound membrane. This MFS unit was supplied with drinking water enriched with acetate at concentrations ranging from 1 to 1000 microg C x L(-1). The pressure drop (PD) in the feed channel increased at all tested concentrations but not with the blank. The PD increase could be described by a first order process based on theoretical considerations concerning biofilm formation rate and porosity decline. The relationship between the first order fouling rate constant R(f) and the acetate concentration is described with a saturation function corresponding with the growth kinetics of bacteria. Under the applied conditions the maximum R(f) (0.555 d(-1)) was reached at 25 microg acetate-C x L(-1) and the half saturation constant k(f) was estimated at 15 microg acetate-C x L(-1). This value is higher than k(s) values for suspended bacteria grown on acetate, which is attributed to substrate limited growth conditions in the biofilm. The threshold concentration for biofouling of the feed channel is about 1 microg acetate-C x L(-1).

  17. Solar combisystems with forecast control to increase the solar fraction and lower the auxiliary energy cost

    DEFF Research Database (Denmark)

    Perers, Bengt; Furbo, Simon; Fan, Jianhua

    2011-01-01

    Solar Combi systems still need quite a lot of auxiliary energy especially in small systems without seasonal storage possibilities. The control of the auxiliary energy input both in time and power is important to utilize as much as possible of the solar energy available from the collectors and also...... energy sources. It can be either direct electric heating elements or a heat pump upgrading ambient energy in the air, ground, solar collector or waste heat from the house. The paper describes system modeling and simulation results. Advanced laboratory experiments are also starting now with three...

  18. VLTI auxiliary telescopes: a full object-oriented approach

    Science.gov (United States)

    Chiozzi, Gianluca; Duhoux, Philippe; Karban, Robert

    2000-06-01

    The Very Large Telescope (VLT) Telescope Control Software (TCS) is a portable system. It is now in use or will be used in a whole family of ESO telescopes VLT Unit Telescopes, VLTI Auxiliary Telescopes, NTT, La Silla 3.6, VLT Survey Telescope and Astronomical Site Monitors in Paranal and La Silla). Although it has been developed making extensive usage of Object Oriented (OO) methodologies, the overall development process chosen at the beginning of the project used traditional methods. In order to warranty a longer lifetime to the system (improving documentation and maintainability) and to prepare for future projects, we have introduced a full OO process. We have taken as a basis the United Software Development Process with the Unified Modeling Language (UML) and we have adapted the process to our specific needs. This paper describes how the process has been applied to the VLTI Auxiliary Telescopes Control Software (ATCS). The ATCS is based on the portable VLT TCS, but some subsystems are new or have specific characteristics. The complete process has been applied to the new subsystems, while reused code has been integrated in the UML models. We have used the ATCS on one side to tune the process and train the team members and on the other side to provide a UML and WWW based documentation for the portable VLT TCS.

  19. Design and operation of the LAMPF Auxiliary Controller. High-speed remote processing on the CAMAC dataway

    International Nuclear Information System (INIS)

    Machen, D.R.

    1979-02-01

    A CAMAC Auxiliary Controller has been developed to further the concepts of distributed processing in both process control and experiment data-acquisition systems. The Auxiliary Controller is built around a commercially available 16-bit microcomputer and a high-speed bit-sliced microprocessor capable of instruction execution times of 140 ns. The modular nature of the controller allows the user to tailor the controller capabilities to the system problem, while maintaining the interface techniques of the CAMAC Standard

  20. Terminal Sliding Mode Control with Unidirectional Auxiliary Surfaces for Hypersonic Vehicles Based on Adaptive Disturbance Observer

    Directory of Open Access Journals (Sweden)

    Naibao He

    2015-01-01

    Full Text Available A novel flight control scheme is proposed using the terminal sliding mode technique, unidirectional auxiliary surfaces and the disturbance observer model. These proposed dynamic attitude control systems can improve control performance of hypersonic vehicles despite uncertainties and external disturbances. The terminal attractor is employed to improve the convergence rate associated with the critical damping characteristics problem noted in short-period motions of hypersonic vehicles. The proposed robust attitude control scheme uses a dynamic terminal sliding mode with unidirectional auxiliary surfaces. The nonlinear disturbance observer is designed to estimate system uncertainties and external disturbances. The output of the disturbance observer aids the robust adaptive control scheme and improves robust attitude control performance. Finally, simulation results are presented to illustrate the effectiveness of the proposed terminal sliding mode with unidirectional auxiliary surfaces.

  1. Importance of continuous monitoring and control of auxiliary power consumption in thermal power plants

    Directory of Open Access Journals (Sweden)

    Nikolić Aleksandar

    2017-01-01

    Full Text Available The paper presents the conceptual solution on the basis of which a system for continuous monitoring and control of auxiliary power consumption is defined in the four most important thermal power plants within the Electric Power Industry of Serbia (TENT A and B, TE Kostolac A and B. A unique system of measuring of auxiliary power consumption at the level of EPS is established in order to perform the appropriate measurement in the following phases, whose data would be archived for the purpose of further analyzes of energy balances. The results of these measurements should be used to define the concrete measures for auxiliary power consumption reduction in power plants, which, in addition to improving energy efficiency, would directly affect the cost reduction.

  2. Design and Experiment of Auxiliary Bearing for Helium Blower of HTR-PM

    International Nuclear Information System (INIS)

    Yang Guojun; Shi Zhengang; Liu Xingnan; Zhao Jingjing

    2014-01-01

    The helium blower is the important equipment for HTR-PM. Active magnetic bearing (AMB) instead of mechanical bearing is selected to support the rotor of the helium blower. However, one implication of AMB is the requirement to provide the auxiliary bearing to mitigate the effects of failures or overload conditions. The auxiliary bearing is used to support the rotor when the AMB fails to work. It must support the dropping rotor and bear the great impact force and friction heat. The design of the auxiliary bearing is one of the challenging problems in the whole system. It is very important for the helium blower with AMB of HTR-PM to make success. The rotor’s length of helium blower of HTR-PM is about 3.3 m, its weight is about 4000 kg and the rotating speed is 4000 r/min. The axial load is 4500kg, and the radial load is 1950kg. The angular contact ball bearing was selected as the auxiliary bearing. The test rig has been finished. It is difficult to analyze the falling course of the rotor. The preliminary analysis of the dropping rotor was done in the special condition. The impact force of auxiliary bearing was computed for the axial and radial load. And the dropping test of the blower rotor for HTR-10 will be introduced also in this paper. Results offer the important theoretical base for the protector design of the helium blower with AMB for HTR-PM. (author)

  3. Auxiliary Linear Problem, Difference Fay Identities and Dispersionless Limit of Pfaff-Toda Hierarchy

    Directory of Open Access Journals (Sweden)

    Kanehisa Takasaki

    2009-12-01

    Full Text Available Recently the study of Fay-type identities revealed some new features of the DKP hierarchy (also known as ''the coupled KP hierarchy'' and ''the Pfaff lattice''. Those results are now extended to a Toda version of the DKP hierarchy (tentatively called ''the Pfaff-Toda hierarchy''. Firstly, an auxiliary linear problem of this hierarchy is constructed. Unlike the case of the DKP hierarchy, building blocks of the auxiliary linear problem are difference operators. A set of evolution equations for dressing operators of the wave functions are also obtained. Secondly, a system of Fay-like identities (difference Fay identities are derived. They give a generating functional expression of auxiliary linear equations. Thirdly, these difference Fay identities have well defined dispersionless limit (dispersionless Hirota equations. As in the case of the DKP hierarchy, an elliptic curve is hidden in these dispersionless Hirota equations. This curve is a kind of spectral curve, whose defining equation is identified with the characteristic equation of a subset of all auxiliary linear equations. The other auxiliary linear equations are related to quasi-classical deformations of this elliptic spectral curve.

  4. Simulation of the fault transitory of the feedwater controller in a Boiling water reactor with the Ramona-3B code

    International Nuclear Information System (INIS)

    Hernandez M, J.L.; Ortiz V, J.

    2005-01-01

    The obtained results when carrying out the simulation of the fault transitory of the feedwater controller (FCAA) with the Ramona-3B code, happened in the Unit 2 of the Laguna Verde power plant (CNLV), in September of the year 2000 are presented. The transitory originates as consequence of the controller's fault of speed of a turbo pump of feedwater. The work includes a short description of the event, the suppositions considered for the simulation and the obtained results. Also, a discussion of the impact of the transitory event is presented on aspects of reactor safety. Although the carried out simulation is limited by the capacities of the code and for the lack of available information, it was found that even in a conservative situation, the power was incremented only in 12% above the nominal value, while that the thermal limit determined by the minimum reason of the critical power, MCPR, always stayed above the limit values of operation and safety. (Author)

  5. Review of industry efforts to manage pressurized water reactor feedwater nozzle, piping, and feedring cracking and wall thinning

    Energy Technology Data Exchange (ETDEWEB)

    Shah, V.N.; Ware, A.G.; Porter, A.M.

    1997-03-01

    This report presents a review of nuclear industry efforts to manage thermal fatigue, flow-accelerated corrosion, and water hammer damage to pressurized water reactor (PWR) feedwater nozzles, piping, and feedrings. The review includes an evaluation of design modifications, operating procedure changes, augmented inspection and monitoring programs, and mitigation, repair and replacement activities. Four actions were taken: (a) review of field experience to identify trends of operating events, (b) review of technical literature, (c) visits to PWR plants and a PWR vendor, and (d) solicitation of information from 8 other countries. Assessment of field experience is that licensees have apparently taken sufficient action to minimize feedwater nozzle cracking caused by thermal fatigue and wall thinning of J-tubes and feedwater piping. Specific industry actions to minimize the wall-thinning in feedrings and thermal sleeves were not found, but visual inspection and necessary repairs are being performed. Assessment of field experience indicates that licensees have taken sufficient action to minimize steam generator water hammer in both top-feed and preheat steam generators. Industry efforts to minimize multiple check valve failures that have allowed backflow of steam from a steam generator and have played a major role in several steam generator water hammer events were not evaluated. A major finding of this review is that analysis, inspection, monitoring, mitigation, and replacement techniques have been developed for managing thermal fatigue and flow-accelerated corrosion damage to feedwater nozzles, piping, and feedrings. Adequate training and appropriate applications of these techniques would ensure effective management of this damage.

  6. Evaluation of auxiliary tempering pump effectiveness at Chalk Point Steam Electric Station

    Energy Technology Data Exchange (ETDEWEB)

    Wendling, L.C.; Holland, A.F.

    1989-08-01

    The effectiveness of auxiliary tempering pump operation at Chalk Point Steam Electric Station (SES) at reducing plant-induced mortality of aquatic biota was evaluated. Several Representative Important Species (RIS) and dominant benthic and zooplankton species were used in the evaluation as indicators of overall system-wide responses. Expected mortality with and without auxiliary pump operation was estimated using thermal tolerance data available from the scientific literature for blue crabs, white perch, striped bass, spot, Macoma balthica and Acartia tonsa. The evaluation led to the conclusion that the operation of auxiliary tempering pumps at Chalk Point SES increases plant-induced mortality of spot, white perch, striped bass, and zooplankton. Operation of the tempering pumps may reduce blue crab mortality slightly under certain circumstances, and Macoma balthica mortality is probably largely unaffected by their operation.

  7. Effects of Auxiliary-Source Connection in Multichip Power Module

    DEFF Research Database (Denmark)

    Li, Helong; Munk-Nielsen, Stig; Wang, Xiongfei

    2017-01-01

    the power loop and the gate loop like how the Kelvin-source connection does, owing to their involvement in the loop of the power source current. Three effects of the auxiliary-source connections are then analyzed, which are 1) the common source stray inductance reduction, 2) the transient drain-source......Auxiliary-source bond wires and connections are widely used in power modules with paralleled MOSFETs or IGBTs. This paper investigates the operation mechanism of the auxiliary-source connections in multichip power modules. It reveals that the auxiliary-source connections cannot fully decouple...

  8. ECOSIM - Applied to a study on the thermo-hydraulic behaviour of feedwater heaters

    International Nuclear Information System (INIS)

    Huelamo Martinez, E.; Casado Flores, E.; Bosch Aparicio, F.

    1998-01-01

    In order to carry out a behaviour study on the secondary circuit of a nuclear power plant operating at a load level higher than originally planned, it is essential to know if the cycle heaters are valid from the thermo-dynamic point of view. This paper describes the models which were used for the study of certain heaters; these models were validated by checking that they faithfully reproduced the behaviour of the equipment (TTD and DCA) in areas where data from the manufacturer was available. The behaviour of said equipment was later obtained in the foreseen operating range. The calculations necessary for these studies were carried out by building ECOSIM models, taking into account that the behaviour of the feedwater heaters depends both on the entry conditions of the extraction steam and also on the remaining mass and energy inputs. For this reason the actual plant layout was taken into consideration, as it was different from the original design. This paper describes the starting hypothesis, the correlations used, the results obtained, an analysis of said results, and a comparison with the manufacturer's data where available. (Author)

  9. The choice of terminal temperature difference for closed feedwater heaters in a steam power cycle

    International Nuclear Information System (INIS)

    D'Errico, P.A.; Andreone, C.F.

    1989-01-01

    Terminal temperature difference (TTD) and the drains cooler approach (DCA), the thermal performance parameters for closed feedwater heaters, (CFWH) in steam power cycles, frequently are selected on the basis of economics. In the design study process, optimal heater performance is determined by analyzing the trends in overall cycle performance economics as they vary with heater TTD and DCA. TTD and DCA are selected to provide the lowest evaluated cost, taking into account unit performance cost and the investment costs associated with the heaters as these performance parameters are varied. Practical constraints such as an overall heater length, tube side velocities, desuperheating (DSH) zone wet wall, etc, must be considered as well. An exception occurs when this procedure is applied to the TTD of the highest pressure heater in the cycle. When calculating overall cycle performance, the heat rate is found to improve with improved (lower) TTD results in greater investment costs, the evaluation for the highest extraction pressure CFWH may be contrary to those obtained for similar calculations on other heaters. This paper discusses guidelines for calculating heater performance parameters and specifically addresses the practical aspects of choosing the TTD's for CFWH in a steam power cycle

  10. GEOTHERMAL / SOLAR HYBRID DESIGNS: USE OF GEOTHERMAL ENERGY FOR CSP FEEDWATER HEATING

    Energy Technology Data Exchange (ETDEWEB)

    Craig Turchi; Guangdong Zhu; Michael Wagner; Tom Williams; Dan Wendt

    2014-10-01

    This paper examines a hybrid geothermal / solar thermal plant design that uses geothermal energy to provide feedwater heating in a conventional steam-Rankine power cycle deployed by a concentrating solar power (CSP) plant. The geothermal energy represents slightly over 10% of the total thermal input to the hybrid plant. The geothermal energy allows power output from the hybrid plant to increase by about 8% relative to a stand-alone CSP plant with the same solar-thermal input. Geothermal energy is converted to electricity at an efficiency of 1.7 to 2.5 times greater than would occur in a stand-alone, binary-cycle geothermal plant using the same geothermal resource. While the design exhibits a clear advantage during hybrid plant operation, the annual advantage of the hybrid versus two stand-alone power plants depends on the total annual operating hours of the hybrid plant. The annual results in this draft paper are preliminary, and further results are expected prior to submission of a final paper.

  11. Auxiliary VHF transmitter to aid recovery of solar Argos/GPS PTTs

    Science.gov (United States)

    Christopher P. Hansen; Mark A. Rumble; R. Scott Gamo; Joshua J. Millspaugh

    2014-01-01

    While conducting greater sage-grouse (Centrocercus urophasianus) research, we found that solar-powered global positioning systems platform transmitter terminals (GPS PTTs) can be lost if the solar panel does not receive adequate sunlight. Thus, we developed 5-g (mortality sensor included; Prototype A) and 9.8-g (no mortality sensor; Prototype B) auxiliary very high...

  12. The auxiliary elliptic-like equation and the exp-function method

    Indian Academy of Sciences (India)

    exact solutions of the nonlinear evolution equations are derived with the aid of auxiliary elliptic-like equation. As examples, the RKL models, the high-order nonlinear Schrödinger equation, the Hamilton amplitude equation, the generalized Hirota–Satsuma coupled KdV system and the generalized ZK–BBM equation are ...

  13. Stability and Confinement Properties of Auxiliary Heated NSTX Discharges

    Energy Technology Data Exchange (ETDEWEB)

    J.E. Menard; R.E.Bell; C. Bourdelle; D.S. Darrow; E.D. Fredrickson; D.A. Gates; L.R. Grisham; S.M. Kaye; B.P. LeBlanc; R. Maingi; S.S. Medley; D. Mueller; F. Paoletti; S.A. Sabbagh; D. Stutman; D.W. Swain; J.R. Wilson; M.G. Bell; J.M. Bialek; C.E.Bush; J.C. Hosea; D.W. Johnson; R. Kaita; H.W. Kugel; R.J. Maqueda; M. Ono; Y-K.M. Peng; C.H. Skinner; V.A. Soukhanovskii; E.J. Synakowski; G. Taylor; G.A. Wurden; and S.J. Zweben

    2001-07-05

    The National Spherical Torus Experiment (NSTX) is a spherical tokamak with nominal plasma major radius R(subscript ''0'') = 0.85 m, minor radius a = 0.66 m, and aspect ratio A > 1.28. Typical discharge parameters are plasma current I (subscript ''p'') = 0.7-1.4 MA, toroidal magnetic field B(subscript ''t0'') = 0.25-0.45 Tesla at major radius R(subscript ''0''), elongation = 1.7-2.2, triangularity 0.3-0.5, line-average electron density = 2-5 x 10(superscript ''19'') m(superscript ''-3''), electron temperature T(subscript ''e'')(0) = 0.5-1.5 keV, and ion temperature T(subscript ''i'')(0) = 0.5-2 keV. The NSTX auxiliary heating systems can routinely deliver 4.5 MW of 80-keV deuterium neutral beams and 3 MW of 30-MHz high-harmonic fast-wave power. Kinetic profile diagnostics presently include a 10-channel, 30-Hz multipulse Thomson scattering system (MPTS), a 17-channel charge-exchange recombination spectroscopy (CHERS) system, a 48-chord ultra-soft X-ray (USXR) array, and a 15-chord bolometry array. Initial experiments utilizing auxiliary heating on NSTX have focused on MHD stability limits, confinement trends, studying H-mode characteristics, and performing initial power balance calculations.

  14. ASCERTAINMENT OF ELECTRIC-SUPPLY SCHEMES RELIABILITY FOR THE ATOMIC POWER PLANT AUXILIARIES

    Directory of Open Access Journals (Sweden)

    A. L. Starzhinskij

    2015-01-01

    Full Text Available The paper completes ascertainment of electrical-supply scheme reliability for the auxiliaries of a nuclear power plant. Thereat the author considers the system behavior during the block normal operation, carrying out current maintenance, and capital repairs in combination with initiating events. The initiating events for reactors include complete blackout, i.e. the loss of outside power supply (normal and reserve; emergency switching one of the working turbogenerators; momentary dumping the normal rating to the level of auxiliaries with seating the cutout valve of one turbo-generator. The combination of any initiating event with the repairing mode in case of one of the system elements failure should not lead to blackout occurrence of more than one system of the reliable power supply. This requirement rests content with the help of the reliable power supply system self-dependence (electrical and functional and the emergency power-supply operational autonomy (diesel generator and accumulator batteries.The reliability indicators of the power supply system for the nuclear power plant auxiliaries are the conditional probabilities of conjoined blackout of one, two, and three sections of the reliable power supply conditional upon an initiating event emerging and the blackout of one, two, and three reliable power-supply sections under the normal operational mode. Furthermore, they also are the blackout periodicity of one and conjointly two, three, and four sections of normal operation under the block normal operational mode. It is established that the blackout of one bus section of normal operation and one section of reliable power-supply system of the auxiliaries that does not lead to complete blackout of the plant auxiliaries may occur once in three years. The probability of simultaneous power failure of two or three normal-operation sections and of two reliable power-supply sections during the power plant service life is unlikely.

  15. Development of the APR+ Auxiliary Building General Arrangement (GA)

    International Nuclear Information System (INIS)

    Moon, Hyung Keun; Park, Young Sheop; Kang, Yong Chul

    2011-01-01

    The general arrangement (GA) drawing of a nuclear power plant is the most basic drawing which contains all of the plant equipment, systems, and rooms. Therefore, it should be issued at an early design stage to provide the contours of the overall plant structure. This type of drawing is typically used widely throughout the design stages. The development project of APR+ (Advanced Power Reactor+), as a succeeding model of the APR1400 (Advanced Power Reactor 1400) design, has its own GA that encompasses all of its power buildings. This was developed starting in October of 2009. Among several of the buildings in this design, the Auxiliary Building (AB) is one of the most important buildings to produce electricity, and to protect against undesirable radiation emissions. This paper focuses on the design characteristics of the general arrangement of the AB

  16. Auxiliary fields in the geometrical relativistic particle dynamics

    International Nuclear Information System (INIS)

    Amador, A; Bagatella, N; Rojas, E; Cordero, R

    2008-01-01

    We describe how to construct the dynamics of relativistic particles, following either timelike or null curves, by means of an auxiliary variables method instead of the standard theory of deformations for curves. There are interesting physical particle models governed by actions that involve higher order derivatives of the embedding functions of the worldline. We point out that the mechanical content of such models can be extracted wisely from a lower order action, which can be performed by implementing in the action a finite number of constraints that involve the geometrical relationship structures inherent to a curve and by using a covariant formalism. We emphasize our approach for null curves. For such systems, the natural time parameter is a pseudo-arclength whose properties resemble those of the standard proper time. We illustrate the formalism by applying it to some models for relativistic particles

  17. Auxiliary fields in the geometrical relativistic particle dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Amador, A; Bagatella, N; Rojas, E [Departamento de Fisica, Facultad de Fisica e Inteligencia Artificial, Universidad Veracruzana, 91000 Xalapa, Veracruz (Mexico); Cordero, R [Departamento de Fisica, Escuela Superior de Fisica y Matematicas del I.P.N, Edificio 9, 07738 Mexico D.F (Mexico)], E-mail: aramador@gmail.com, E-mail: nbagatella@uv.mx, E-mail: cordero@esfm.ipn.mx, E-mail: efrojas@uv.mx

    2008-03-21

    We describe how to construct the dynamics of relativistic particles, following either timelike or null curves, by means of an auxiliary variables method instead of the standard theory of deformations for curves. There are interesting physical particle models governed by actions that involve higher order derivatives of the embedding functions of the worldline. We point out that the mechanical content of such models can be extracted wisely from a lower order action, which can be performed by implementing in the action a finite number of constraints that involve the geometrical relationship structures inherent to a curve and by using a covariant formalism. We emphasize our approach for null curves. For such systems, the natural time parameter is a pseudo-arclength whose properties resemble those of the standard proper time. We illustrate the formalism by applying it to some models for relativistic particles.

  18. 75 FR 57200 - National Poultry Improvement Plan and Auxiliary Provisions

    Science.gov (United States)

    2010-09-20

    ... 147 [Docket No. APHIS-2009-0031] RIN 0579-AD21 National Poultry Improvement Plan and Auxiliary... proposing to amend the National Poultry Improvement Plan (the Plan) and its auxiliary provisions by... Coordinator, Poultry Improvement Staff, National Poultry Improvement Plan, Veterinary Services, APHIS, USDA...

  19. 76 FR 15791 - National Poultry Improvement Plan and Auxiliary Provisions

    Science.gov (United States)

    2011-03-22

    ... [Docket No. APHIS-2009-0031] RIN 0579-AD21 National Poultry Improvement Plan and Auxiliary Provisions... the National Poultry Improvement Plan (the Plan) and its auxiliary provisions by providing new or... National Poultry Improvement Plan (NPIP, also referred to below as ``the Plan'') is a cooperative Federal...

  20. 14 CFR 25.1142 - Auxiliary power unit controls.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Auxiliary power unit controls. 25.1142... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Powerplant Controls and Accessories § 25.1142 Auxiliary power unit controls. Means must be provided on the flight deck for starting...

  1. 14 CFR 23.1142 - Auxiliary power unit controls.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Auxiliary power unit controls. 23.1142... Powerplant Controls and Accessories § 23.1142 Auxiliary power unit controls. Means must be provided on the... power unit. [Doc. No. 26344, 58 FR 18974, Apr. 9, 1993] ...

  2. 14 CFR 29.1142 - Auxiliary power unit controls.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Auxiliary power unit controls. 29.1142... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Powerplant Controls and Accessories § 29.1142 Auxiliary power unit controls. Means must be provided on the flight deck for starting...

  3. The English Primary Auxiliary Verbs: A Linguistic Theoretical Exercise

    African Journals Online (AJOL)

    themselves. This paper aims at carrying out linguistic theoretical exercise as regards the use of the English primary auxiliary verbs. The paper also aims at exposing the rate at which speakers of English Language misuse the. English primary auxiliary verbs. The traditional grammar alongside structural grammar was used to ...

  4. Dedicated auxiliary power units for Hybrid Electric Vehicles

    NARCIS (Netherlands)

    Mourad, S.; Weijer, C.J.T. van de

    1998-01-01

    The use of a dedicated auxiliary power unit is essential to utilize the potential that hybrid vehicles offer for efficient and ultra-clean transportation. An example of a hybrid project at the TNO Road-Vehicles Research Institute shows the development and the results of a dedicated auxiliary power

  5. 47 CFR 80.290 - Auxiliary receiving antenna.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Auxiliary receiving antenna. 80.290 Section 80... antenna. An auxiliary receiving antenna must be provided when necessary to avoid unauthorized interruption or reduced efficiency of the required watch because the normal receiving antenna is not available...

  6. ON THE CATEGORY STATUS OF AUXILIARIES AND THE ...

    African Journals Online (AJOL)

    Seem requires a [+ stativeJ verb in its complement. However, this set of auxiliaries cannot occur in the complement of a verb like force, requiring a [- stativeJ verb in its comPlement.18). Ross explains the above data by assuming that this set of auxiliaries has the features. [: ~ux. J. The major premiss of the relevant argument ...

  7. Elimination of the auxiliary fields in the antifield formalism

    International Nuclear Information System (INIS)

    Henneaux, M.

    1990-01-01

    The problem of the elimination of the auxiliary fields in the path integral quantization of gauge theories is investigated in the context of the antifield formalism. It is shown that gauge fixing fermions can be found such that: (i) the auxiliary fields remain auxiliary after gauge fixing; and (ii) the gauge fixed actions obtained by eliminating the auxiliary fields before or after writing down the path integral coincide. The contribution of the auxiliary fields to the integration measure is also discussed. These results are applied (i) to the problem of the equivalence between the lagrangian and hamiltonian path integral formulations; and (ii) to the problem of the elimination of the second class constraints in the hamiltonian formalism. (orig.)

  8. Effects of auxiliary source connections in multichip power module

    DEFF Research Database (Denmark)

    Li, Helong; Munk-Nielsen, Stig; Beczkowski, Szymon

    2016-01-01

    totally decouple the power loop and the gate loop like how the Kelvin source connection does, because they are still in the loop of power source current. Three effects of the auxiliary source connection are investigated and analyzed: common source stray inductance reduction, transient drain-source current......Auxiliary source bond wires and connections are widely used to in the power module with paralleled MOSFETs or IGBTs. This paper investigates the working mechanism and the effects of the auxiliary source connections in multichip power modules. It reveals that the auxiliary source connections cannot...... imbalance mitigation and influence on the steady state bond wire current distribution. Simulation and experimental results validate the working mechanism analysis and the effects of the auxiliary source connections....

  9. LOX/hydrocarbon auxiliary propulsion for the Space Shuttle Orbiter

    Science.gov (United States)

    Orton, G. F.; Mark, T. D.

    1982-01-01

    The completed phases of a study evaluating LOX/hydrocarbon auxiliary propulsion system concepts for a second generation Space Shuttle Orbital Maneuvering Subsystem (OMS) and Reaction Control Subsystem (RCS) are presented. The results of the preliminary system evaluation phase are summarized, and efforts regarding the in-depth system evaluation phase are described. Ethanol and methane are considered to be the best fuel candidates as both are non-coking, non-corrosive, and offer high performance capability. Ethanol affords the highest dV and total impulse capability because of its high density-specific impulse product, while methane affords the lowest system wet weight when the system is sized for a fixed dV or total impulse requirement. The LOX/ethanol system allows the use of a simple non-insulated RCS feed system, and is the most attractive LOX/hydrocarbon OMS-RCS. Its operational costs would be substantially less than the current N2O4/MMH system.

  10. Condensate feeding system

    International Nuclear Information System (INIS)

    Iwami, Hiroshi.

    1981-01-01

    Purpose: To control the dissolved oxygen concentration in water of a condensate feeding system to a desired level. Constitution: Coolant is fed to a nuclear reactor through a route from the steam exit of the reactor and by way of turbine, turbine condensator, condensate pump, condensate desalinator, feedwater heater and feed pump. Steam extraction lines are branched from the turbines, and pipeways are further branched from the steam extraction lines for feeding steam by way of extraction steam injection valves to steam-water mixers disposed on the upstream of the feedwater heater. On the downstream of the feedwater heater, is provided a dissolved oxygen concentration meter, the indication value of which controls the opening degree of the steam injection valves which, in turn, controls the opening degree of the steam feed valves for the feedwater heater to adjust the amount for the injection steams. Accordingly, the dissolved oxygen concentration in the water of the condensate feeding system can be controlled by the inclusion of steams with high dissolved oxygen concentration into the feedwater system from the turbine steam extraction lines by way of the mixers. (Furukawa, Y.)

  11. Report of the Bulletins and Orders Task Force. Volume II. Appendices

    International Nuclear Information System (INIS)

    1980-01-01

    Appendices include: Office of Inspection and Enforcement bulletins; NRR status report on feedwater transients in BWR plants; orders on Babcock and Wilcox Company plants; letters lifting orders; letters issuing auxiliary feedwater system requirements; letter to licensees of all operating reactors, dated October 30, 1979 concerning short-term lessons learned requirements; and letters approving guidelines for preparation of small-break LOCA operating procedures

  12. TRAC-PF1 analysis of LOFT steam-generator feedwater transient test L9-1

    International Nuclear Information System (INIS)

    Meier, J.K.

    1983-01-01

    The Transient Reactor Analysis Code (TRAC-PF1) calculations were compared to test data from Loss-of-Fluid Test (LOFT) L9-1, which was a loss-of-feedwater transient. This paper includes descriptions of the test and the TRAC input and compares the TRAC-calculated results with the test data. We conclude that the code predicted the experiment well, given the uncertainties in the boundary conditions. The analysis indicates the need to model all the flow paths and heat structures, and to improve the TRAC wall condensation heat-transfer model

  13. Response of the C-E owners group to the loss-of-feedwater event at the Davis-Besse plant

    International Nuclear Information System (INIS)

    Cogburn, T.H.; Pfeifer, J.W.; Sibiga, D.L.

    1987-01-01

    As a result of the Davis-Besse loss of all feedwater event, C-E owners group (CEOG) agreed at its September, 1985 meeting to form a review group for the purpose of evaluating the event with respect to its impact on plants with a C-E nuclear steam supply system (NSSS). Objectives of the review group included review of the Davis-Besse event, determining generic concerns applicable to CEOG plants and development of an action plan to address these concerns. The review documents the inherent design differences between CEOG plants and the Davis-Besse plant. These differences are such that a similar LOF event at a CEOG plant would have a significantly different and improved safety margin relative to that which existed during the Davis-Besse event. Although the impact of this type of event on CEOG plants would be less adverse, the review of the event did identify a number of generic issues for CEOG plants. an action plan was created to address each of the applicable generic issues

  14. National Ignition Facility subsystem design requirements target area auxiliary subsystem SSDR 1.8.6

    International Nuclear Information System (INIS)

    Reitz, T.

    1996-01-01

    This Subsystem Design Requirement (SSDR) establishes the performance, design, development, and test requirements for the Target Area Auxiliary Subsystems (WBS 1.8.6), which is part of the NIF Target Experimental System (WBS 1.8). This document responds directly to the requirements detailed in NIF Target Experimental System SDR 003 document. Key elements of the Target Area Auxiliary Subsystems include: WBS 1.8.6.1 Local Utility Services; WBS 1.8.6.2 Cable Trays; WBS 1.8.6.3 Personnel, Safety, and Occupational Access; WBS 1.8.6.4 Assembly, Installation, and Maintenance Equipment; WBS 1.8.6.4.1 Target Chamber Service System; WBS 1.8.6.4.2 Target Bay Service Systems

  15. Modeling and stability analysis for the upper atmosphere research satellite auxiliary array switch component

    Science.gov (United States)

    Wolfgang, R.; Natarajan, T.; Day, J.

    1987-01-01

    A feedback control system, called an auxiliary array switch, was designed to connect or disconnect auxiliary solar panel segments from a spacecraft electrical bus to meet fluctuating demand for power. A simulation of the control system was used to carry out a number of design and analysis tasks that could not economically be performed with a breadboard of the hardware. These tasks included: (1) the diagnosis of a stability problem, (2) identification of parameters to which the performance of the control system was particularly sensitive, (3) verification that the response of the control system to anticipated fluctuations in the electrical load of the spacecraft was satisfactory, and (4) specification of limitations on the frequency and amplitude of the load fluctuations.

  16. Low speed performance of a supersonic axisymmetric mixed compression inlet with auxiliary inlets. [Lewis 9x15-ft anechoic wind tunnel tests

    Science.gov (United States)

    Wasserbauer, J. F.; Cubbison, R. W.; Trefny, C. J.

    1983-01-01

    The aerodynamic performance of a representative supersonic cruise inlet was investigated using a fan simulator coupled to the inlet to provide characteristic noise signatures and to pump the inlet flow. Data were obtained at Mach numbers from 0 to 0.2 for the inlet equipped with an auxiliary inlet system that provided 20 to 40 percent of the fan flow. Results show that inlet performance improved when the inlet bleed systems were sealed; when the freestream Mach number was increased; and when the auxiliary inlets were opened. The inlet flow could not be choked by either centerbody translation or by increasing the fan speed when the 40 percent auxiliary inlet was incorporated.

  17. Recirculating flow-rate control system in an atomic power plant

    International Nuclear Information System (INIS)

    Shida, Toichi; Nakamura, Hideo; Hirose, Masao; Tohei, Kazushige.

    1975-01-01

    Object: To control recirculating flow-rate when feedwater temperature is lowered to minimize possibility of a fast-neutron flux scram, thereby maintaining soundness of fuel. Structure: An atomic power plant comprising a reactor, a recirculating flow-rate control means for controlling a power of said reactor, and a feedwater system for supplying water to said reactor, said plant further including a water temperature detector for detecting temperature of water in said feedwater system, first means for presuming the water temperature in the feedwater system corresponding to the power of the atomic power plant, and second means for obtaining a deviation between the output of said first means and the output of said water temperature detector to impact said output to the recirculating flow-rate control device, whereby preventing fluctuation in the power of the reactor due to fluctuation in water temperature. (Kamimura, M.)

  18. Parallel Auxiliary Space AMG Solver for $H(div)$ Problems

    Energy Technology Data Exchange (ETDEWEB)

    Kolev, Tzanio V. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Vassilevski, Panayot S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2012-12-18

    We present a family of scalable preconditioners for matrices arising in the discretization of $H(div)$ problems using the lowest order Raviart--Thomas finite elements. Our approach belongs to the class of “auxiliary space''--based methods and requires only the finite element stiffness matrix plus some minimal additional discretization information about the topology and orientation of mesh entities. Also, we provide a detailed algebraic description of the theory, parallel implementation, and different variants of this parallel auxiliary space divergence solver (ADS) and discuss its relations to the Hiptmair--Xu (HX) auxiliary space decomposition of $H(div)$ [SIAM J. Numer. Anal., 45 (2007), pp. 2483--2509] and to the auxiliary space Maxwell solver AMS [J. Comput. Math., 27 (2009), pp. 604--623]. Finally, an extensive set of numerical experiments demonstrates the robustness and scalability of our implementation on large-scale $H(div)$ problems with large jumps in the material coefficients.

  19. New set of auxiliary fields for supergravity theories

    International Nuclear Information System (INIS)

    Oliveira Rivelles, V. de.

    1983-02-01

    A brief introduction on supersymmetry is given. The problems with the obtainment of the auxiliary fields in supergravity theories are discussed, after a short presentation of the supersymmetry algebra representations. (L.C.) [pt

  20. Results of an aging-related failure survey of light water safety systems and components

    International Nuclear Information System (INIS)

    Meale, B.M.; Satterwhite, D.G.; MacDonald, P.E.

    1988-01-01

    The collection and evaluation of operating experience data are necessary in determining the effects of aging on the safety of operating nuclear plants. This paper presents the final results of a two-year research effort evaluating aging impacts on components in light water reactor systems. This research was performed as a part of the Nuclear Plant Aging Research program, sponsored by the US Nuclear Regulatory Commission. Two unique types of data analyses were performed. In the first, an aging-survey study, aging-related failure data for fifteen light water reactor systems were obtained from the Nuclear Plant Reliability Data System (NPRDS). These included safety, support, and power conversion systems. A computerized sort of these records classified each record into one of five generic categories, based on the utility's choice of the failure's NPRDS cause category. Systems and components within the systems that were most affected by aging were identified. In the second analysis, information on aging-related reported causes of failures was evaluated for component failures reported to NPRDS for auxiliary feedwater, high pressure injection, service water, and Class 1E electrical power distribution systems. 3 refs., 13 figs., 4 tabs

  1. Auxiliary device for the assembly of cruciform BWR control rods

    International Nuclear Information System (INIS)

    Lippert, H.J.

    1980-01-01

    The mounting auxiliary equipment has got a frame of the size of a core cell that can be put on the core grid. Diagonally arranged link bodies serve to center the cross-shaped control rod. The mounting auxiliary equipment consists of a single piece and therefore facilitates manipulation for which a diagonal handle is provided at the upper end. It may be swung aside. (RW) [de

  2. Auxiliary device for the assembly of cruciform BWR control rods

    International Nuclear Information System (INIS)

    Lippert, H.J.

    1982-01-01

    The mounting auxiliary equipment has got a frame of the size of a core cell that can be put on the core grid. Diagonally arranged link bodies serve to center the cross-shaped control rod. The mounting auxiliary equipment consists of a single piece and therefore facilitates manipulation for which a diagonal handle is provided at the upper end. It may be swung aside. (orig./HP)

  3. Study of check valve slamming in a BWR feedwater system following a postulated pipe break

    International Nuclear Information System (INIS)

    Safwat, H.H.; Arastu, A.H.; Norman, A.

    1985-01-01

    This study deals with a swing check valve slamming due to a break at relatively short distance from the valve. Under this situation, substantial flashing occurs near the valve and the result of the study are subject to what is believed to be a conservative simplifying assumption, i.e., the hydrodynamic moment acting on the valve during the transient is represented by resultant moment due to the pressure differential across the valve. It is believed that vapor voids forming at the valve would actually reduce the disk impact velocities in comparison to those predicted under this simplifying assumption. A technique used to represent a double-ended break through hypothetical valves may have some influence on the results particularly for long break opening times. The study has yielded good insight to help understand the complex problem. The study has focused on some parameters and the reader may raise questions on the effects of other parameters. Nevertheless, the present study underlines the complexity facing analysts dealing with this transient using analytical methods. Though some experimental data are available, the authors believe that an experimental study (recognizing the complexity of the experimental setup and instrumentation), would be quite useful. It can provide answers to questions facing analysts dealing with this problem and thus avoid unnecessary conservatisms due to uncertainties in input data

  4. Environmental impact assessment of the incineration of municipal solid waste with auxiliary coal in China

    DEFF Research Database (Denmark)

    Zhao, Yan; Xing, Wei; Lu, Wenjing

    2012-01-01

    The environmental impacts of waste incineration with auxiliary coal were investigated using the life-cycle-based software, EASEWASTE, based on the municipal solid waste (MSW) management system in Shuozhou City. In the current system, MSW is collected, transported, and incinerated with 250kg of co...... political reduction targets. Results indicate that heavy metal and acidic gas emissions should be given more attention in waste incineration. This study provides scientific support for the management of MSW systems dominated by incineration with auxiliary coal in China.......The environmental impacts of waste incineration with auxiliary coal were investigated using the life-cycle-based software, EASEWASTE, based on the municipal solid waste (MSW) management system in Shuozhou City. In the current system, MSW is collected, transported, and incinerated with 250kg of coal...... per ton of waste. Based on observed environmental impacts of incineration, fossil CO2 and heavy metals were primary contributors to global warming and ecotoxicity in soil, respectively. Compared with incinerators using excess coal, incineration with adequate coal presents significant benefits...

  5. INFLUENCE OF FEEDING ELECTRIC ENERGY QUALITY ON HEATING OF THE AUXILIARY MA-CHINES OF AC ELECTRIC ROLLING STOCK

    Directory of Open Access Journals (Sweden)

    O. YU. Baliichuk

    2014-04-01

    Full Text Available Purpose. The article aims to study the problem of increase the reliability of auxiliary machines for AC electric trains during operation in real conditions. Methodology. The peculiarity of system construction of auxiliary machines for AC electric rolling stock is the use of asynchronous motors for general industrial purpose. An engineering method of influence determination on the feeding voltage asymmetry and its deviation from the nominal value on heating of auxiliary machines insulation was proposed. Findings. It is found out that in case when the auxiliary machines of AC electric trains work under asymmetry factor of the voltage 10% or more and feeding voltage deviation from the nominal order 0.6 relative unit then it is possible the overheat of their isolation, even if it has class H. Originality. For the first time the issue of the total insulation heating under such boundary parameters combinations of energy quality, when each of them contributes to the heating insulation increase as compared to the nominal regime of the "rotating phase splitter−auxiliary machinery" system was illuminated. Practical value. Conducted research allow us to establish the boundary parameter values of feeding energy quality (asymmetry factor, feeding voltage deviations from the nominal value, at which additional isolation overheating of this class under the effect of specified factors will not exceed the agreed value.

  6. VLTI First Fringes with Two Auxiliary Telescopes at Paranal

    Science.gov (United States)

    2005-03-01

    [Preview - JPEG: 537 x 400 pix - 31k] [Normal - JPEG: 1074 x 800 pix - 555k] [HiRes - JPEG: 3000 x 2235 pix - 6.0M] ESO PR Photo 07d/05 ESO PR Photo 07d/05 [Preview - JPEG: 400 x 550 pix - 60k] [Normal - JPEG: 800 x 1099 pix - 946k] [HiRes - JPEG: 2414 x 3316 pix - 11.0M] Captions: ESO PR Photo 07b/05 shows VLTI Auxiliary Telescopes 1 and 2 (AT1 and AT2) in the early evening light, with the spherical domes opened and ready for observations. In ESO PR Photo 07c/05, the same scene is repeated later in the evening, with three of the large telescope enclosures in the background. This photo and ESO PR Photo 07c/05 which is a time-exposure with AT1 and AT2 under the beautiful night sky with the southern Milky Way band were obtained by ESO staff member Frédéric Gomté. However, most of the time the large telescopes are used for other research purposes. They are therefore only available for interferometric observations during a limited number of nights every year. Thus, in order to exploit the VLTI each night and to achieve the full potential of this unique setup, some other (smaller), dedicated telescopes were included into the overall VLT concept. These telescopes, known as the VLTI Auxiliary Telescopes (ATs), are mounted on tracks and can be placed at precisely defined "parking" observing positions on the observatory platform. From these positions, their light beams are fed into the same common focal point via a complex system of reflecting mirrors mounted in an underground system of tunnels. The Auxiliary Telescopes are real technological jewels. They are placed in ultra-compact enclosures, complete with all necessary electronics, an air conditioning system and cooling liquid for thermal control, compressed air for enclosure seals, a hydraulic plant for opening the dome shells, etc. Each AT is also fitted with a transporter that lifts the telescope and relocates it from one station to another. It moves around with its own housing on the top of Paranal, almost like a snail

  7. Adaptation of computer code ALMOD 3.4 for safety analyses of Westighouse type NPPs and calculation of main feedwater loss

    International Nuclear Information System (INIS)

    Kordis, I.; Jerele, A.; Brajak, F.

    1986-01-01

    The paper presents theoretical foundations of ALMOD 3.4 code and modification done in order to adjust the model to westinghouse type NPP. test cases for verification of added modules functioning were done and loss of main feedwater (FW) transient at nominal power was analysed. (author)

  8. Comparison of collective Thomson scattering signals due to fast ions in ITER scenarios with fusion and auxiliary heating

    DEFF Research Database (Denmark)

    Salewski, Mirko; Asunta, O.; Eriksson, L.-G.

    2009-01-01

    functions of fast ions generated by NBI and ICRH are calculated for a steady-state ITER burning plasma equilibrium with the ASCOT and PION codes, respectively. The parameters for the auxiliary heating systems correspond to the design currently foreseen for ITER. The geometry of the CTS system for ITER...

  9. A comparative simulation of feed and bleed operation during the total loss of feedwater event by RELAP5/MOD3 and CEFLASH-4AS/REM computer codes

    International Nuclear Information System (INIS)

    Kwon, Y.M.; Ro, T.S.; Song, J.H.

    1995-01-01

    The Ulchin 3 and 4 nuclear power plants, which are two-loop 2,825 MW(thermal) pressurized water reactors designed by the Korea Atomic Energy Research Institute, adopted a safety depressurization system (SDS) to mitigate the beyond-design-basis event of a total loss of feedwater (TLOFW). A comparative simulation by the CEFLASH-4AS/REM and RELAP5/MOD3 computer codes for the TLOFW event without operator recovery and the TLOFW event with feed and bleed (F and B) operation is performed for Ulchin 3 and 4. In the analyses, the SDS bleed paths are modeled by orifices located on the top of the pressurizer, where the analytical area of the bleed path is based on the Ulchin 3 and 4 SDS design flow capacity. An additional case, where the SDS piping and valves are modeled explicitly, is considered for the RELAP5 analysis. The predictions by the CEFLASH-4AS/REM of the transient two-phase system behavior show good qualitative and quantitative agreement with those by the RELAP5 simulation. The RELAP5 case with explicit piping results in less repressurization and lower reactor coolant system pressure than that of the case without explicit SDS modeling. However, the two cases of RELAP5 analyses result in essentially the same transient scenarios for TLOFW with F and B operation. The results of the simulation demonstrate the validity of the Ulchin 3 and 4 design approach, which employs CEFLASH-4AS/REM computer code and SDS bleed paths modeled by orifices located on the top of the pressurizer. The results also indicate that the decay heat removal and core inventory makeup function can be successfully accomplished by F and B operation by using the SDS for Ulchin 3 and 4

  10. Development of the integrated system reliability analysis code MODULE

    International Nuclear Information System (INIS)

    Han, S.H.; Yoo, K.J.; Kim, T.W.

    1987-01-01

    The major components in a system reliability analysis are the determination of cut sets, importance measure, and uncertainty analysis. Various computer codes have been used for these purposes. For example, SETS and FTAP are used to determine cut sets; Importance for importance calculations; and Sample, CONINT, and MOCUP for uncertainty analysis. There have been problems when the codes run each other and the input and output are not linked, which could result in errors when preparing input for each code. The code MODULE was developed to carry out the above calculations simultaneously without linking input and outputs to other codes. MODULE can also prepare input for SETS for the case of a large fault tree that cannot be handled by MODULE. The flow diagram of the MODULE code is shown. To verify the MODULE code, two examples are selected and the results and computation times are compared with those of SETS, FTAP, CONINT, and MOCUP on both Cyber 170-875 and IBM PC/AT. Two examples are fault trees of the auxiliary feedwater system (AFWS) of Korea Nuclear Units (KNU)-1 and -2, which have 54 gates and 115 events, 39 gates and 92 events, respectively. The MODULE code has the advantage that it can calculate the cut sets, importances, and uncertainties in a single run with little increase in computing time over other codes and that it can be used in personal computers

  11. Reliability of supply of switchgear for auxiliary low voltage in substations extra high voltage to high voltage

    Directory of Open Access Journals (Sweden)

    Perić Dragoslav M.

    2015-01-01

    Full Text Available Switchgear for auxiliary low voltage in substations (SS of extra high voltages (EHV to high voltage (HV - SS EHV/HV kV/kV is of special interest for the functioning of these important SS, as it provides a supply for system of protection and other vital functions of SS. The article addresses several characteristic examples involving MV lines with varying degrees of independence of their supply, and the possible application of direct transformation EHV/LV through special voltage transformers. Auxiliary sources such as inverters and diesel generators, which have limited power and expensive energy, are also used for the supply of switchgear for auxiliary low voltage. Corresponding reliability indices are calculated for all examples including mean expected annual engagement of diesel generators. The applicability of certain solutions of switchgear for auxiliary low voltage SS EHV/HV, taking into account their reliability, feasibility and cost-effectiveness is analyzed too. In particular, the analysis of applications of direct transformation EHV/LV for supply of switchgear for auxiliary low voltage, for both new and existing SS EHV/HV.

  12. Technical specification action requirements for AFW system failures: Method development and application to four PWR plants

    International Nuclear Information System (INIS)

    Mankamo, T.; Kim, I.S.; Yang, Ji Wu; Samanta, P.K.

    1996-01-01

    Failures in the auxiliary feedwater (AFW) system of pressurized water reactors (PWRs) are considered to involve substantial risk whether a decision is made to either continue power operation while repair is being done, or to shut down the plant to undertake repairs. Technical specification action requirements usually require immediate plant shutdown in the case of multiple failures in the system (in some cases, immediate repair of one train is required when all AFW trains fail). This paper presents a probabilistic risk assessment-based method to quantitatively evaluate and compare both the risks of continued power operation and of shutting the plant down, given known failures in the system. The method is applied to the AFW system for four different PWRs. Results show that the risk of continued power operation and plant shutdown both are substantial, but the latter is larger than the former over the usual repair time. This was proven for four plants with different designs: two operating Westinghouse plants, one operating Asea-Brown Boveri Combustion Engineering Plant, and one of evolutionary design. The method can be used to analyze individual plant design and to improve AFW action requirements using risk-informed evaluations

  13. Vehicle Integrated Photovoltaics for Compression Ignition Vehicles: An Experimental Investigation of Solar Alkaline Water Electrolysis for Improving Diesel Combustion and a Solar Charging System for Reducing Auxiliary Engine Loads

    Science.gov (United States)

    Negroni, Garry Inocentes

    Vehicle-integrated photovoltaic electricity can be applied towards aspiration of hydrogen-oxygen-steam gas produced through alkaline electrolysis and reductions in auxiliary alternator load for reducing hydrocarbon emissions in low nitrogen oxide indirect-injection compression-ignition engines. Aspiration of 0.516 ± 0.007 liters-per-minute of gas produced through alkaline electrolysis of potassium-hydroxide 2wt.% improves full-load performance; however, part-load performance decreases due to auto-ignition of aspirated gas prior to top-dead center. Alternator load reductions offer improved part-load and full-load performance with practical limitations resulting from accessory electrical loads. In an additive approach, solar electrolysis can electrochemically convert solar photovoltaic electricity into a gas comprised of stoichiometric hydrogen and oxygen gas. Aspiration of this hydrogen-oxygen gas enhances combustion properties decreasing emissions and increased combustion efficiency in light-duty diesel vehicles. The 316L stainless steel (SS) electrolyser plates are arranged with two anodes and three cathodes space with four bipolar plates delineating four stacks in parallel with five cells per stack. The electrolyser was tested using potassium hydroxide 2 wt.% and hydronium 3wt.% at measured voltage and current inputs. The flow rate output from the reservoir cell was measured in parallel with the V and I inputs producing a regression model correlating current input to flow rate. KOH 2 wt.% produced 0.005 LPM/W, while H9O44 3 wt.% produced less at 0.00126 LPM/W. In a subtractive approach, solar energy can be used to charge a larger energy storage device, as is with plug-in electric vehicles, in order to alleviate the engine of the mechanical load placed upon it by the vehicles electrical accessories through the alternator. Solar electrolysis can improve part-load emissions and full-load performance. The average solar-to-battery efficiency based on the OEM rated

  14. Electrospinning of aligned fibers with adjustable orientation using auxiliary electrodes

    International Nuclear Information System (INIS)

    Arras, Matthias M L; Grasl, Christian; Schima, Heinrich; Bergmeister, Helga

    2012-01-01

    A conventional electrospinning setup was upgraded by two turnable plate-like auxiliary high-voltage electrodes that allowed aligned fiber deposition in adjustable directions. Fiber morphology was analyzed by scanning electron microscopy and attenuated total reflection Fourier transform infrared spectroscopy (FTIR-ATR). The auxiliary electric field constrained the jet bending instability and the fiber deposition became controllable. At target speeds of 0.9 m s −1 90% of the fibers had aligned within 2°, whereas the angular spread was 70° without the use of auxiliary electrodes. It was even possible to orient fibers perpendicular to the rotational direction of the target. The fiber diameter became smaller and its distribution narrower, while according to the FTIR-ATR measurement the molecular orientation of the polymer was unaltered. This study comprehensively documents the feasibility of directed fiber deposition and offers an easy upgrade to existing electrospinning setups. (paper)

  15. Dental auxiliaries versus community health workers: similarities and contrasts

    Directory of Open Access Journals (Sweden)

    Simone De Melo Costa

    Full Text Available INTRODUCTION: The dental auxiliaries and the community health workers (CHWs are practitioners that represent an important part in the Family Health Policy in Brazil and have several tasks. OBJECTIVE: To analyze the attributes of the dental auxiliaries and of the CHWs, regarding the application of their services and their education/training, to identify the similarities and contrasts between these health care practitioners. METHODOLOGY: Quantitative and census method data collection performed on the context of the Education Program for Health Workers - PET‑Saúde, 2010‑2012. The data collection method was a semi-structured questionnaire. The analysis has a level of significance of p0.05. CONCLUSION: Similarities and contrasts were identified between these health care workers. The dental auxiliaries, despite being mostly issued to specific assignments on a clinical environment, are able to shift their praxis by taking actions on a family and community context once integrated to a family health team.

  16. What Modals Are: Modal Verbs, Modal Words, and Auxiliary Modals

    Directory of Open Access Journals (Sweden)

    Fazira A. Kakzhanova

    2013-01-01

    Full Text Available The modals are a complicated grammatical phenomenon. As of today, the status of modals is still not precisely defined in the linguistics literature, and they are described under different names: modal verbs, modal words, auxiliary modals, or defective verbs. Modals express the result of the conversion of thought processes (deep structure about the realization of actions into surface structure. As articles determine the status of nouns as indefinite or definite things, modals determine the relation of a person to actions or the quality of an action as realizable or unrealizable. Modals cannot truly be ‘modal verbs’, because they lack the morphological characteristics of verbs (aspect, voice, mood, and tense, and the term ‘defective verb’ is flawed for the same reason. Furthermore, they cannot be ‘auxiliary modals’, because they don’t neutralize their main meanings when they become auxiliary. Thus, I propose to refer to these elements only as modals or modal words.

  17. Sampling designs dependent on sample parameters of auxiliary variables

    CERN Document Server

    Wywiał, Janusz L

    2015-01-01

    The book offers a valuable resource for students and statisticians whose work involves survey sampling. An estimation of the population parameters in finite and fixed populations assisted by auxiliary variables is considered. New sampling designs dependent on moments or quantiles of auxiliary variables are presented on the background of the classical methods. Accuracies of the estimators based on original sampling design are compared with classical estimation procedures. Specific conditional sampling designs are applied to problems of small area estimation as well as to estimation of quantiles of variables under study. .

  18. Vanishing auxiliary variables in PPS sampling - with applications in microscopy

    DEFF Research Database (Denmark)

    Andersen, Ina Trolle; Hahn, Ute; Jensen, Eva B. Vedel

    Recently, non-uniform sampling has been suggested in microscopy to increase efficiency. More precisely, sampling proportional to size (PPS) has been introduced where the probability of sampling a unit in the population is proportional to the value of an auxiliary variable. Unfortunately, vanishing...... auxiliary variables are a common phenomenon in microscopy and, accordingly, part of the population is not accessible, using PPS sampling. We propose a modification of the design, for which an optimal solution can be found, using a model assisted approach. The optimal design has independent interest...

  19. Analysis and Measurement of NOx Emissions in Port Auxiliary Vessels

    Directory of Open Access Journals (Sweden)

    German de Melo Rodriguez

    2013-09-01

    Full Text Available This paper is made NOx pollution emitted by port auxiliary vessels, specifically by harbour tugs, due to its unique operating characteristics of operation, require a large propulsion power changes discontinuously, also possess some peculiar technical characteristics, large tonnage and high propulsive power, that differentiate them from other auxiliary vessels of the port. Taking into account all the above features, there are no studies of the NOx emission engines caused by different working regimes of power because engine manufacturers have not measured these emissions across the range of operating power, but usually we only report the pollution produced by its engines to a maximum continuous power.

  20. Modulatory mechanisms and multiple functions of somatodendritic A-type K+ channel auxiliary subunits

    Directory of Open Access Journals (Sweden)

    Henry Hungtao Jerng

    2014-03-01

    Full Text Available Auxiliary subunits are non-conducting, modulatory components of the multi-protein ion channel complexes that underlie normal neuronal signaling. They interact with the pore-forming α-subunits to modulate surface distribution, ion conductance, and channel gating properties. For the somatodendritic subthreshold A-type potassium (ISA channel based on Kv4 α-subunits, two types of auxiliary subunits have been extensively studied: Kv channel-interacting proteins (KChIPs and dipeptidyl peptidase-like proteins (DPLPs. KChIPs are cytoplasmic calcium-binding proteins that interact with intracellular portions of the Kv4 subunits, whereas DPLPs are type II transmembrane proteins that associate with the Kv4 channel core. Both KChIPs and DPLPs genes contain multiple start sites that are used by various neuronal populations to drive the differential expression of functionally distinct N-terminal variants. In turn, these N-terminal variants generate tremendous functional diversity across the nervous system. Here, we focus our review on (1 the molecular mechanism underlying the unique properties of different N-terminal variants, (2 the shaping of native ISA properties by the concerted actions of KChIPs and DPLP variants, and (3 the surprising ways that KChIPs and DPLPs coordinate the activity of multiple channels to fine-tune neuronal excitability. Unlocking the unique contributions of different auxiliary subunit N-terminal variants may provide an important opportunity to develop novel targeted therapeutics to treat numerous neurological disorders.

  1. The SOL-2/Neto auxiliary protein modulates the function of AMPA-subtype ionotropic glutamate receptors.

    Science.gov (United States)

    Wang, Rui; Mellem, Jerry E; Jensen, Michael; Brockie, Penelope J; Walker, Craig S; Hoerndli, Frédéric J; Hauth, Linda; Madsen, David M; Maricq, Andres V

    2012-09-06

    The neurotransmitter glutamate mediates excitatory synaptic transmission by gating ionotropic glutamate receptors (iGluRs). AMPA receptors (AMPARs), a subtype of iGluR, are strongly implicated in synaptic plasticity, learning, and memory. We previously discovered two classes of AMPAR auxiliary proteins in C. elegans that modify receptor kinetics and thus change synaptic transmission. Here, we have identified another auxiliary protein, SOL-2, a CUB-domain protein that associates with both the related auxiliary subunit SOL-1 and with the GLR-1 AMPAR. In sol-2 mutants, behaviors dependent on glutamatergic transmission are disrupted, GLR-1-mediated currents are diminished, and GLR-1 desensitization and pharmacology are modified. Remarkably, a secreted variant of SOL-1 delivered in trans can rescue sol-1 mutants, and this rescue depends on in cis expression of SOL-2. Finally, we demonstrate that SOL-1 and SOL-2 have an ongoing role in the adult nervous system to control AMPAR-mediated currents. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. Solutions of system of P1 equations without use of auxiliary differential equations coupled; Solucoes do sistema de equacoes P1 sem o uso de equacoes diferenciais auxiliares acopladas

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Aquilino Senra; Silva, Fernando Carvalho da; Cardoso, Carlos Eduardo Santos [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear

    2000-07-01

    The system of P1 equations is composed by two equations coupled itself one for the neutron flux and other for the current. Usually this system is solved by definitions of two integrals parameters, which are named slowing down densities of the flux and the current. Hence, the system P1 can be change from integral to only two differential equations. However, there are two new differentials equations that may be solved with the initial system. The present work analyzes this procedure and studies a method, which solve the P1 equations directly, without definitions of slowing down densities. (author)

  3. 76 FR 22295 - National Poultry Improvement Plan and Auxiliary Provisions

    Science.gov (United States)

    2011-04-21

    ... DEPARTMENT OF AGRICULTURE Animal and Plant Health Inspection 9 CFR Part 145 [Docket No. APHIS-2009-0031] RIN 0579-AD21 National Poultry Improvement Plan and Auxiliary Provisions Correction In rule document 2011-6539 appearing on pages 15791-15798 in the issue of Tuesday, March 22, 2011, make the...

  4. An analysis of the auxiliary structure of basic Nigerian pidgin ...

    African Journals Online (AJOL)

    The existence of pidgin as a language should not depend on “social” recognition or “social” approval. The basis for ... Premised on the foregoing, this study strives to illustratively analyse the auxiliary structure of basic Nigerian pidgin sentences since the issue of basic word order is one of the universals of human language.

  5. On the computation of molecular auxiliary functions An and Bn

    Indian Academy of Sciences (India)

    Comment: “On the computation of molecular auxiliary functions An and Bn”. FRANK E HARRIS. Department of Physics, University of Utah, Salt Lake City, UT 84112, USA. Quantum Theory Project, University of Florida, P.O. Box 118435, Gainesville, FL 32611, USA. Email: harris@qtp.ufl.edu. Abstract. Guseinov, Mamedov ...

  6. Auxiliary services for petrochemistry. Cogeneration, thermocompression, steam distribution networks

    International Nuclear Information System (INIS)

    Vergerio, G.; Bruzzi, V.

    1999-01-01

    The article gives some guidelines for the choice of the most suitable energy vectors distributed in petrochemical plants and refineries for auxiliary services and for processes (mainly distillation). Conclusions are summed up in a diagram showing the most suitable heat sources and sinks for the various temperature ranges [it

  7. Dental auxiliaries for dental care traditionally provided by dentists.

    Science.gov (United States)

    Dyer, Tom A; Brocklehurst, Paul; Glenny, Anne-Marie; Davies, Linda; Tickle, Martin; Issac, Ansy; Robinson, Peter G

    2014-08-20

    Poor or inequitable access to oral health care is commonly reported in high-, middle- and low-income countries. Although the severity of these problems varies, a lack of supply of dentists and their uneven distribution are important factors. Delegating care to dental auxiliaries could ease this problem, extend services to where they are unavailable and liberate time for dentists to do more complex work. Before such an approach can be advocated, it is important to know the relative effectiveness of dental auxiliaries and dentists. To assess the effectiveness, costs and cost effectiveness of dental auxiliaries in providing care traditionally provided by dentists. We searched the following electronic databases from their inception dates up to November 2013: the Cochrane Effective Practice and Organisation of Care (EPOC) Group's Specialised Register; Cochrane Oral Health Group's Specialised Register; the Cochrane Central Register of Controlled Trials (Issue 11, 2013); MEDLINE; EMBASE; CINAHL; Cochrane Database of Systematic Reviews; Database of Abstracts of Reviews of Effectiveness; five other databases and two trial registries. We also undertook a grey literature search and searched the reference list of included studies and contacted authors of relevant papers. We included randomised controlled trials (RCTs), non-randomised controlled clinical trials (NRCTs), interrupted time series (ITSs) and controlled before and after studies (CBAs) evaluating the effectiveness of dental auxiliaries compared with dentists in undertaking clinical tasks traditionally performed by a dentist. Three review authors independently applied eligibility criteria, extracted data and assessed the risk of bias of each included study and two review authors assessed the quality of the evidence from the included studies, according to The Cochrane Collaboration's procedures. Since meta-analysis was not possible, we gave a narrative description of the results. We identified five studies (one cluster

  8. On the computation of molecular auxiliary functions An and Bn

    Indian Academy of Sciences (India)

    Department of Physics, Faculty of Arts and Sciences, Onsekiz Mart University, C¸ anakkale, Turkey. Email: guseinov@cheerful.com. Abstract. The Comment 'on the computation of auxiliary functions An(p) and Bn(pt)' (F E Harris,. Pramana – J. Phys. 61, C779 (2003)) is analysed in the arbitrary range of parameters n p and pt.

  9. 49 CFR 229.125 - Headlights and auxiliary lights.

    Science.gov (United States)

    2010-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Cabs and... compromise the integrity of the car body or be otherwise impractical. Auxiliary lights on such MU locomotives... flashing feature may be activated automatically, but shall be capable of manual activation and deactivation...

  10. Improving Semi-Supervised Learning with Auxiliary Deep Generative Models

    DEFF Research Database (Denmark)

    Maaløe, Lars; Sønderby, Casper Kaae; Sønderby, Søren Kaae

    expressive for semi-supervised learning. By utilizing the stochasticity of the auxiliary variable we demonstrate how to train discriminative classifiers resulting in state-of-the-art performance within semi-supervised learning exemplified by an 0.96% error on MNIST using 100 labeled data points. Furthermore...

  11. Ultrasonic meters in the feedwater flow to recover thermal power in the reactor of nuclear power plant of Laguna Verde U1 and U2; Medidores ultrasonicos en el flujo de agua de alimentacion para recuperar potencia termica en el reactor de la Central Nuclear Laguna Verde U1 and U2

    Energy Technology Data Exchange (ETDEWEB)

    Tijerina S, F. [CFE, Central Laguna Verde, Km. 42.5 Carretera Cardel-Nautla, Veracruz (Mexico)]. e-mail: francisco.tijerina@cfe.gob.mx

    2008-07-01

    The engineers in nuclear power plants BWRs and PWRs based on the development of the ultrasonic technology for the measurement of the mass, volumetric flow, density and temperature in fluids, have applied this technology in two primary targets approved by the NRC: the use for the recovery of thermal power in the reactor and/or to be able to realize an increase of thermal power licensed in a 2% (MUR) by 1OCFR50 Appendix K. The present article mentions the current problem in the measurement of the feedwater flow with Venturi meters, which affects that the thermal balance of reactor BWRs or PWRs this underestimated. One in broad strokes describes the application of the ultrasonic technology for the ultrasonic measurement in the flow of the feedwater system of the reactor and power to recover thermal power of the reactor. One is to the methodology developed in CFE for a calibration of the temperature transmitters of RTD's and the methodology for a calibration of the venturi flow transmitters using ultrasonic measurement. Are show the measurements in the feedwater of reactor of the temperature with RTD's and ultrasonic measurement, as well as the flow with the venturi and the ultrasonic measurement operating the reactor to the 100% of nominal thermal power, before and after the calibration of the temperature transmitters and flow. Finally, is a plan to be able to realize a recovery of thermal power of the reactor, showing as carrying out their estimations. As a result of the application of ultrasonic technology in the feedwater of reactor BWR-5 in Laguna Verde, in the Unit 1 cycle 13 it was recover an equivalent energy to a thermal power of 25 MWt in the reactor and an exit electrical power of 6 M We in the turbogenerator. Also in the Unit 2 cycle 10 it was recover an equivalent energy to a thermal power of 40 MWt in the reactor and an exit electrical power of 16 M We in the turbogenerator. (Author)

  12. Engineering the CernVM-Filesystem as a High Bandwidth Distributed Filesystem for Auxiliary Physics Data

    Energy Technology Data Exchange (ETDEWEB)

    Dykstra, D. [Fermilab; Bockelman, B. [Nebraska U.; Blomer, J. [CERN; Herner, K. [Fermilab; Levshina, T. [Fermilab; Slyz, M. [Fermilab

    2015-12-23

    A common use pattern in the computing models of particle physics experiments is running many distributed applications that read from a shared set of data files. We refer to this data is auxiliary data, to distinguish it from (a) event data from the detector (which tends to be different for every job), and (b) conditions data about the detector (which tends to be the same for each job in a batch of jobs). Relatively speaking, conditions data also tends to be relatively small per job where both event data and auxiliary data are larger per job. Unlike event data, auxiliary data comes from a limited working set of shared files. Since there is spatial locality of the auxiliary data access, the use case appears to be identical to that of the CernVM- Filesystem (CVMFS). However, we show that distributing auxiliary data through CVMFS causes the existing CVMFS infrastructure to perform poorly. We utilize a CVMFS client feature called 'alien cache' to cache data on existing local high-bandwidth data servers that were engineered for storing event data. This cache is shared between the worker nodes at a site and replaces caching CVMFS files on both the worker node local disks and on the site's local squids. We have tested this alien cache with the dCache NFSv4.1 interface, Lustre, and the Hadoop Distributed File System (HDFS) FUSE interface, and measured performance. In addition, we use high-bandwidth data servers at central sites to perform the CVMFS Stratum 1 function instead of the low-bandwidth web servers deployed for the CVMFS software distribution function. We have tested this using the dCache HTTP interface. As a result, we have a design for an end-to-end high-bandwidth distributed caching read-only filesystem, using existing client software already widely deployed to grid worker nodes and existing file servers already widely installed at grid sites. Files are published in a central place and are soon available on demand throughout the grid and cached

  13. Approaching the Hartree-Fock Limit through the Complementary Auxiliary Basis Set Singles Correction and Auxiliary Basis Sets.

    Science.gov (United States)

    Shaw, Robert A; Hill, J Grant

    2017-04-11

    Auxiliary basis sets for use in the resolution of the identity (RI) approximation in explicitly correlated methods are presented for the elements H-Ar. These extend the cc-pVnZ-F12/OptRI (n = D-Q) auxiliary basis sets of Peterson and co-workers by the addition of a small number of s- and p-functions, optimized so as to yield the greatest complementary auxiliary basis set (CABS) singles correction to the Hartree-Fock energy. The new sets, denoted OptRI+, also lead to a reduction in errors due to the RI approximation and hence an improvement in correlation energies. The atomization energies and heats of formation for a test set of small molecules, and spectroscopic constants for 27 diatomics, calculated at the CCSD(T)-F12b level, are shown to have improved error distributions for the new auxiliary basis sets with negligible additional effort. The OptRI+ sets retain all of the desirable properties of the original OptRI, including the production of smooth potential energy surfaces, while maintaining a compact nature.

  14. An Analytical Method of Auxiliary Sources Solution for Plane Wave Scattering by Impedance Cylinders

    DEFF Research Database (Denmark)

    Larsen, Niels Vesterdal; Breinbjerg, Olav

    2004-01-01

    Analytical Method of Auxiliary Sources solutions for plane wave scattering by circular impedance cylinders are derived by transformation of the exact eigenfunction series solutions employing the Hankel function wave transformation. The analytical Method of Auxiliary Sources solution thus obtained...

  15. Levitated Duct Fan (LDF) Aircraft Auxiliary Generator

    Science.gov (United States)

    Eichenberg, Dennis J.; Emerson, Dawn C.; Gallo, Christopher A.; Thompson, William K.

    2011-01-01

    This generator concept includes a novel stator and rotor architecture made from composite material with blades attached to the outer rotating shell of a ducted fan drum rotor, a non-contact support system between the stator and rotor using magnetic fields to provide levitation, and an integrated electromagnetic generation system. The magnetic suspension between the rotor and the stator suspends and supports the rotor within the stator housing using permanent magnets attached to the outer circumference of the drum rotor and passive levitation coils in the stator shell. The magnets are arranged in a Halbach array configuration.

  16. Feedwater flowrate estimation based on the two-step de-noising using the wavelet analysis and an autoassociative neural network

    International Nuclear Information System (INIS)

    Heo, Gyun Young; Choi, Seong Soo; Chang, Soon Heung

    1999-01-01

    This paper proposes an improved signal processing strategy for accurate feedwater flowrate estimation in nuclear power plants. It is generally known that ∼ 2% thermal power errors occur due to fouling phenomena in feedwater flowmeters. In the strategy proposed, the noises included in feedwater flowrate signal are classified into rapidly varying noises and gradually varying noises according to the characteristics in a frequency domain. The estimation precision is enhanced by introducing a low pass filter with the wavelet analysis against rapidly varying noises, and an autoassociative neural network which takes charge of the correction of only gradually varying noises. The modified multivariate stratification sampling using the concept of time stratification and MAXIMIN criteria is developed to overcome the shortcoming of a general random sampling. In addition the multi-stage robust training method is developed to increase the quality and reliability of training signals. Some validations using the simulated data from a micro-simulator were carried out. In the validation tests, the proposed methodology removed both rapidly varying noises and gradually varying noises respectively in each de-noising step, and 5.54 % root mean square errors of initial noisy signals were decreased to 0.674% after denoising. These results indicate that it is possible to estimate the reactor thermal power more elaborately by adopting this strategy. (author). 16 refs., 6 figs., 2 tabs

  17. 47 CFR 74.601 - Classes of TV broadcast auxiliary stations.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Classes of TV broadcast auxiliary stations. 74... Television Broadcast Auxiliary Stations § 74.601 Classes of TV broadcast auxiliary stations. (a) TV pickup stations. A land mobile station used for the transmission of TV program material and related communications...

  18. 30 CFR 57.22209 - Auxiliary fans (I-C mines).

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Auxiliary fans (I-C mines). 57.22209 Section 57... Standards for Methane in Metal and Nonmetal Mines Ventilation § 57.22209 Auxiliary fans (I-C mines). Electric auxiliary fans shall be approved by MSHA under the applicable requirements of 30 CFR part 18...

  19. 30 CFR 57.8534 - Shutdown or failure of auxiliary fans.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Shutdown or failure of auxiliary fans. 57.8534... Ventilation Underground Only § 57.8534 Shutdown or failure of auxiliary fans. (a) Auxiliary fans installed and... fan maintenance or fan adjustments where air quality is maintained in compliance with the applicable...

  20. The Bantu-Romance-Greek connection revisited: Processing constraints in auxiliary and clitic placement from a cross-linguistic perspective

    Directory of Open Access Journals (Sweden)

    Stergios Chatzikyriakidis

    2017-02-01

    Full Text Available This paper explores a connection between Romance and Greek on the one hand, and Bantu on the other. More specifically, we look at auxiliary placement in Rangi and clitic placement in Tobler Mussafia languages, with a special emphasis on Cypriot Greek, and argue that a common explanation for their distribution can be found once a move into a dynamic framework is made. Rangi exhibits an unusual word order alternation in auxiliary constructions under which the position of the auxiliary appears to be sensitive to an element appearing at the left periphery of the clause. A similar sensitivity to a left-peripheral element can be seen to regulate clitic placement in Cypriot Greek (and generally in the so-called Tobler Mussafia clitic languages. The paper presents a parsing-oriented account of these two phenomena in the Dynamic Syntax framework, arguing that the similarities in syntactic distribution are the result of the encoding in the lexicon of processing strategies that were potentially pragmatic preferences in earlier stages of the respective languages. The account thus leans on the role played by the lexical entries for auxiliary and clitic forms, as well as the assumption that underspecification is inherent in the process of establishing meaning in context. The account is further supplemented by possible pathways of diachronic change that could have given rise to the systems found in present day varieties.

  1. Environmental impact assessment of the incineration of municipal solid waste with auxiliary coal in China.

    Science.gov (United States)

    Zhao, Yan; Xing, Wei; Lu, Wenjing; Zhang, Xu; Christensen, Thomas H

    2012-10-01

    The environmental impacts of waste incineration with auxiliary coal were investigated using the life-cycle-based software, EASEWASTE, based on the municipal solid waste (MSW) management system in Shuozhou City. In the current system, MSW is collected, transported, and incinerated with 250 kg of coal per ton of waste. Based on observed environmental impacts of incineration, fossil CO(2) and heavy metals were primary contributors to global warming and ecotoxicity in soil, respectively. Compared with incinerators using excess coal, incineration with adequate coal presents significant benefits in mitigating global warming, whereas incineration with a mass of coal can avoid more impacts to acidification, photochemical ozone and nutrient enrichment because of increased electricity substitution and reduced emission from coal power plants. The "Emission standard of air pollutants for thermal power plants (GB13223-2011)" implemented in 2012 introduced stricter policies on controlling SO(2) and NO(x) emissions from coal power plants. Thus, increased use of auxiliary coal during incineration yields fewer avoided impacts on acidification and nutrient enrichment. When two-thirds of ash is source-separated and landfilled, the incineration of rest-waste presents better results on global warming, acidification, nutrient enrichment, and even ecotoxicity in soil. This process is considered a promising solution for MSW management in Shuozhou City. Weighted normalized environmental impacts were assessed based on Chinese political reduction targets. Results indicate that heavy metal and acidic gas emissions should be given more attention in waste incineration. This study provides scientific support for the management of MSW systems dominated by incineration with auxiliary coal in China. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Replacement of electrical protection of generation (main generator, main transformer and auxiliary transformers) and new associated monitoring system; Sustitucion de portecciones electricas de generacion (genrador principal, transformador principal y transformadores auxiliares) y nuevo sistema de supervision asociado

    Energy Technology Data Exchange (ETDEWEB)

    Archilla, J.

    2013-07-01

    The replacement of the electrical protection of generation is a technological quantum leap, since moving from an analog system (known by) (all, intuitive and visual) to a digital (integrates the hardware on a single computer, much more powerful and programmable). The keys to overcoming the challenge are know to manage the technological leap, the operational limitations of plant (keep operating the)preferred sources of energy) and make a good design (including a review independent of the configuration of the relays, taking into account the experience (operational available).

  3. Auxiliary plasma heating and fueling models for use in particle simulation codes

    International Nuclear Information System (INIS)

    Procassini, R.J.; Cohen, B.I.

    1989-01-01

    Computational models of a radiofrequency (RF) heating system and neutral-beam injector are presented. These physics packages, when incorporated into a particle simulation code allow one to simulate the auxiliary heating and fueling of fusion plasmas. The RF-heating package is based upon a quasilinear diffusion equation which describes the slow evolution of the heated particle distribution. The neutral-beam injector package models the charge exchange and impact ionization processes which transfer energy and particles from the beam to the background plasma. Particle simulations of an RF-heated and a neutral-beam-heated simple-mirror plasma are presented. 8 refs., 5 figs

  4. An Analytical Method of Auxiliary Sources Solution for Plane Wave Scattering by Impedance Cylinders - A Reference Solution for the Numerical Method of Auxiliary Sources

    DEFF Research Database (Denmark)

    Larsen, Niels Vesterdal; Breinbjerg, Olav

    2004-01-01

    To facilitate the validation of the numerical Method of Auxiliary Sources an analytical Method of Auxiliary Sources solution is derived in this paper. The Analytical solution is valid for transverse magnetic, and electric, plane wave scattering by circular impedance Cylinders, and it is derived...... of the numerical Method of Auxiliary Sources for a range of scattering configurations....... with their singularities at different positions away from the origin. The transformation necessitates a truncation of the wave transformation but the inaccuracy introduced hereby is shown to be negligible. The analytical Method of Auxiliary Sources solution is employed as a reference to investigate the accuracy...

  5. Contracted auxiliary Gaussian basis integral and derivative evaluation

    Science.gov (United States)

    Giese, Timothy J.; York, Darrin M.

    2008-02-01

    The rapid evaluation of two-center Coulomb and overlap integrals between contracted auxiliary solid harmonic Gaussian functions is examined. Integral expressions are derived from the application of Hobson's theorem and Dunlap's product and differentiation rules of the spherical tensor gradient operator. It is shown that inclusion of the primitive normalization constants greatly simplifies the calculation of contracted functions corresponding to a Gaussian multipole expansion of a diffuse charge density. Derivative expressions are presented and it is shown that chain rules are avoided by expressing the derivatives as a linear combination of auxiliary integrals involving no more than five terms. Calculation of integrals and derivatives requires the contraction of a single vector corresponding to the monopolar result and its scalar derivatives. Implementation of the method is discussed and comparison is made with a Cartesian Gaussian-based method. The current method is superior for the evaluation of both integrals and derivatives using either primitive or contracted functions.

  6. Investigation of surface oxide morphology in SG feedwater pipes and study of its influence on flow accelerated corrosion rate

    International Nuclear Information System (INIS)

    Qiu, G.; Alos-Ramos, O.; Monchecourt, D.; Mansour, C.; Delaunay, S.; Trevin, S.

    2015-01-01

    Flow accelerated corrosion (FAC) affects carbon steel components in the secondary circuits of PWR plants. The mandatory use of the prediction tool BRT-CICERO in all its PWR plants enables EDF to perform efficient inspections programs and minimize the number of leaks in the secondary circuits. Due to the operating conditions, SG feedwater flow regulation (ARE) circuits can be affected by FAC phenomenon. Thickness loss has been reported by several plants during the last 10 years, although significant damage by FAC remains very rare. This paper describes the surface features observed on an ARE straight tube that has orange peel pattern with thickness loss on the one half of its inner surface and a thick fouling layer without much thickness loss on the other. An analysis of the oxide porosity and structure by SEM investigation has been carried out. The origin of fouling layer and its behavior in the ARE circuits environment (oxide solubility, flow stability/turbulence) have been discussed. Finally by comparing with the classic FAC models, an attempt of correlation between the presence of the fouling layer and the lower corrosion rate is proposed. (authors)

  7. Optimization of the pumping ring in a mechanical seal with an integrated cooler for feed-water pumps

    International Nuclear Information System (INIS)

    Buchdahl, D.; Martin, R.; Gueret, G.; Blanc, M.

    1994-07-01

    To simplify maintenance, E.D.F. along with its collaborators undertook the study of mechanical seal with integrated cooler used in feed-water pumps in the nuclear power plants. The cooler, integrated to the pump acts as a thermal barrier as well as a cooler of the mechanical seal. The water circulation in the cooler is assumed by an integrated pumping ring in the rotary part of the mechanical seal, with a matching screw thread in the pumping case. This assembly of mechanical seal/integrated cooler is tested in a test loop at the EDF/DER Laboratory. All working conditions are similar to that at site. Tests with different configurations of the rotor/stator profiles are performed, i.e.; different lengths and types of threading. Hydraulic performances and the global thermal balance of this assembly are studied. Our basic aim during these tests is to optimize the hydraulic performance of the pumping ring so as to best cool the mechanical seal faces. The different results obtained and the conclusions drawn during these tests are presented. (authors). 7 figs., 3 refs

  8. Sandia Laboratories technical capabilities: auxiliary capabilities

    International Nuclear Information System (INIS)

    1978-09-01

    The primary responsibility of the environmental health function is the evaluation and control of hazardous materials and conditions. The evaluation and control of toxic materials, nonionizing radiation such as laser beams and microwaves, and ionizing radiation such as from radiation machines and radioactive sources, are examples of the activities of environmental health programs. A chemical laboratory is operated for the analysis of toxic and radioactive substances and for the bioassay program to provide an index of internal exposure of personnel to toxic and radioactive materials. Instrumentation support and development is provided for environmental health activities. A dosimetry program is maintained to measure personnel exposure to external ionizing radiation. A radiation counting laboratory is maintained. Reentry safety control and effluent documentation support are provided for underground nuclear tests at the Nevada Test Site. A radiation training program is provided for laboratory personnel which covers all areas of radiation protection, from working with radioactive materials to radiation-producing machines. The information science activity functions within the framework of Sandia Laboratories' technical libraries. Information science is oriented toward the efficient dissemination of information to technical and administrative personnel. Computerized systems are used to collect, process and circulate books, reports, and other literature. Current-awareness, reference, translation, and literature-search services are also provided

  9. A study on effective system depressurization during a PWR vessel bottom break LOCA with HPI failure and gas inflow prevention. ROSA-V/LSTF test SB-PV-05

    International Nuclear Information System (INIS)

    Suzuki, Mitsuhiro; Takeda, Takeshi; Asaka, Hideaki; Nakamura, Hideo

    2006-11-01

    A small break loss-of-coolant accident (SBLOCA) experiment was conducted at the Large Scale Test Facility (LSTF) of ROSA-V program to study effects of accident management (AM) measures on core cooling, which are important in case of total failure of high pressure injection (HPI) system during an SBLOCA at a pressurized water reactor (PWR). The LSTF is a full-height and 1/48 volume-scaled facility simulating a 4-loop Westinghouse-type PWR (3423 MWt). The experiment, SB-PV-05, simulated a PWR vessel bottom SBLOCA with a rupture of nine instrument tubes, which is equivalent to 0.18% cold leg break. It is clarified that AM actions with steam generator (SG) depressurization to achieve a primary loop cooling rate at -55 K/h and auxiliary feedwater supply for 30 minutes are effective to avoid core uncovery by actuating the low pressure injection (LPI) system. It is also shown through the comparison with the previous experiment of SB-PV-03 that prevention of non-condensable gas inflow from the accumulator injection system (AIS) is very important to actuate the LPI to achieve adequate core cooling. This report presents experiment results of SB-PV-05 in detail and shows the effects of gas inflow prevention on core cooling through the estimation of primary coolant mass and energy balance in the primary system. (author)

  10. Elimination of the low feedwater flow reactor trip via implementation of the median signal selector (MSS)

    Energy Technology Data Exchange (ETDEWEB)

    Valle, J.L.

    2015-07-01

    Common instrument channels are often used in both the Reactor Protection System and the Reactor Control System for those process parameters for which measurement is required in both the protection and control system designs. This practice allows the NSSS to be controlled from the same measurements with which it is protected. (See figure 1) Control and protection system interaction addresses any mechanism causing failure of a single system component of channel, or removal from service of any single protection system component or channel which is common to both the control and protection systems. The mechanism may be a physical interaction such as electrical faults originating in the control system and propagating to the protection system (there by bringing about an attendant failure within the protection system), or a functional interaction where the action of a control system is coupled to the ability of the protection system to provide adequate core protection consistent with the requirements of IEEE 279-1971. Is the intent of this requirement that if a failure mechanism which is common to the control and protection system were to occur, the protection system would continue to satisfy all reliability, redundancy, and independence requirements. Thus, to prevent control and protection system interaction, protection systems are in general, designed with regard for the requirements of physical, electrical and functional independence of the control system (Author)

  11. Bayesian Analysis of Geostatistical Models With an Auxiliary Lattice

    KAUST Repository

    Park, Jincheol

    2012-04-01

    The Gaussian geostatistical model has been widely used for modeling spatial data. However, this model suffers from a severe difficulty in computation: it requires users to invert a large covariance matrix. This is infeasible when the number of observations is large. In this article, we propose an auxiliary lattice-based approach for tackling this difficulty. By introducing an auxiliary lattice to the space of observations and defining a Gaussian Markov random field on the auxiliary lattice, our model completely avoids the requirement of matrix inversion. It is remarkable that the computational complexity of our method is only O(n), where n is the number of observations. Hence, our method can be applied to very large datasets with reasonable computational (CPU) times. The numerical results indicate that our model can approximate Gaussian random fields very well in terms of predictions, even for those with long correlation lengths. For real data examples, our model can generally outperform conventional Gaussian random field models in both prediction errors and CPU times. Supplemental materials for the article are available online. © 2012 American Statistical Association, Institute of Mathematical Statistics, and Interface Foundation of North America.

  12. Enhanced Deposition Uniformity via an Auxiliary Electrode in Massive Electrospinning.

    Science.gov (United States)

    Wu, Dezhi; Xiao, Zhiming; Deng, Lei; Sun, Yu; Tan, Qiulin; Dong, Linxi; Huang, Shaohua; Zhu, Rui; Liu, Yifang; Zheng, Wanxi; Zhao, Yang; Wang, Lingyun; Sun, Daoheng

    2016-07-22

    Uniform deposition of nanofibers in the massive electrospinning process is critical in the industrial applications of nanofibers. Tip-Induced Electrospinning (TIE) is a cost-effective large-scale nanofiber-manufacturing method, but it has poor deposition uniformity. An auxiliary conductive electrode connected to the emitting electrode was introduced to improve the deposition uniformity of the nanofibers. The effects of the auxiliary electrode shape, the tilted angles and the position of the boat-like electrode on the electric field distribution, the diameter of the nanofibers, the jet control and the deposition uniformity were explored by using finite element analysis of the electric field and experiments. Experiments showed that the boat-like electrode at 20 mm above the reservoir bottom with a 5° tilted angle helped to decrease the relative deposition error of nanofibers in the greatest extent to about 5.66%, indicating such an auxiliary electrode is a good candidate method to greatly improve the deposition uniformity of nanofibers in massive electrospinning.

  13. Auxiliary extended reach system for master-slave manipulator

    International Nuclear Information System (INIS)

    Haaker, L.W.; Jelatis, D.G.

    1981-01-01

    A remote control master-slave manipulator for performing work on the opposite side of a barrier wall, is described. The manipulator consists of a rotatable horizontal support adapted to extend through the wall and two longitudinally extensible arms, a master and a slave, pivotally connected one at each end of the support, the slave arm being of a doubly telescopic nature. (U.K.)

  14. An Analytical Method of Auxiliary Sources Solution for Plane Wave Scattering by Impedance Cylinders - A Reference Solution for the Numerical Method of Auxiliary Sources

    DEFF Research Database (Denmark)

    Larsen, Niels Vesterdal; Breinbjerg, Olav

    2004-01-01

    To facilitate the validation of the numerical Method of Auxiliary Sources an analytical Method of Auxiliary Sources solution is derived in this paper. The Analytical solution is valid for transverse magnetic, and electric, plane wave scattering by circular impedance Cylinders, and it is derived b...

  15. A diesel fuel processor for fuel-cell-based auxiliary power unit applications

    Science.gov (United States)

    Samsun, Remzi Can; Krekel, Daniel; Pasel, Joachim; Prawitz, Matthias; Peters, Ralf; Stolten, Detlef

    2017-07-01

    Producing a hydrogen-rich gas from diesel fuel enables the efficient generation of electricity in a fuel-cell-based auxiliary power unit. In recent years, significant progress has been achieved in diesel reforming. One issue encountered is the stable operation of water-gas shift reactors with real reformates. A new fuel processor is developed using a commercial shift catalyst. The system is operated using optimized start-up and shut-down strategies. Experiments with diesel and kerosene fuels show slight performance drops in the shift reactor during continuous operation for 100 h. CO concentrations much lower than the target value are achieved during system operation in auxiliary power unit mode at partial loads of up to 60%. The regeneration leads to full recovery of the shift activity. Finally, a new operation strategy is developed whereby the gas hourly space velocity of the shift stages is re-designed. This strategy is validated using different diesel and kerosene fuels, showing a maximum CO concentration of 1.5% at the fuel processor outlet under extreme conditions, which can be tolerated by a high-temperature PEFC. The proposed operation strategy solves the issue of strong performance drop in the shift reactor and makes this technology available for reducing emissions in the transportation sector.

  16. Diesel Fueled SOFC for Class 7/Class 8 On-Highway Truck Auxiliary Power

    Energy Technology Data Exchange (ETDEWEB)

    Vesely, Charles John-Paul [Cummins Power Generation; Fuchs, Benjamin S. [Cummins Power Generation; Booten, Chuck W. [Protonex Technology, LLC

    2010-03-31

    The following report documents the progress of the Cummins Power Generation (CPG) Diesel Fueled SOFC for Class 7/Class 8 On-Highway Truck Auxiliary Power (SOFC APU) development and final testing under the U.S. Department of Energy (DOE) Energy Efficiency and Renewable Energy (EERE) contract DE-FC36-04GO14318. This report overviews and summarizes CPG and partner development leading to successful demonstration of the SOFC APU objectives and significant progress towards SOFC commercialization. Significant SOFC APU Milestones: Demonstrated: Operation meeting SOFC APU requirements on commercial Ultra Low Sulfur Diesel (ULSD) fuel. SOFC systems operating on dry CPOX reformate. Successful start-up and shut-down of SOFC APU system without inert gas purge. Developed: Low cost balance of plant concepts and compatible systems designs. Identified low cost, high volume components for balance of plant systems. Demonstrated efficient SOFC output power conditioning. Demonstrated SOFC control strategies and tuning methods.

  17. Analysis of Nigerian dentists' opinion and consequences on expanded function dental auxiliaries.

    Science.gov (United States)

    Umanah, A U; Azodo, C

    2015-06-01

    To examine Nigerian dentists' opinion on expanded function dental auxiliaries. This cross-sectional study of Nigerian dentists attending a dental conference was conducting in 2012 using self-administered questionnaire. The data were analyzed using Statistical Package for the Social Sciences version 16.0. P opinion towards expanded duty dental auxiliaries. The mean scores on consequences, of expanded function dental auxiliaries ranked redundancy of dentist as highest. Males and non-specialist significantly reported expanded function dental auxiliaries would lead to redundancy of dentists. Practitioners working in other hospitals other than teaching hospital significantly reported that appropriate legislation are necessary before expansion of duties of the dental auxiliaries can be done. The dentists with favorable opinion significantly reported that expanded duty dental auxiliaries would not cause redundancy of dentist and the task are not too difficult for dental auxiliaries with necessary training but will increase service delivery and efficiency, increase job satisfaction, lead to dental auxiliary specialization with legislation. Data from this study revealed overall unfavorable opinion of Nigerian dentists on the expanded duty dental auxiliaries. However, those with favorable opinion were significantly supportive of expanded function dental auxiliaries. This information would serve as a useful tool for Nigerian oral healthcare policy formulators.

  18. Sampling general N-body interactions with auxiliary fields

    Science.gov (United States)

    Körber, C.; Berkowitz, E.; Luu, T.

    2017-09-01

    We present a general auxiliary field transformation which generates effective interactions containing all possible N-body contact terms. The strength of the induced terms can analytically be described in terms of general coefficients associated with the transformation and thus are controllable. This transformation provides a novel way for sampling 3- and 4-body (and higher) contact interactions non-perturbatively in lattice quantum Monte Carlo simulations. As a proof of principle, we show that our method reproduces the exact solution for a two-site quantum mechanical problem.

  19. Helicene-like chiral auxiliaries in asymmetric catalysis.

    Science.gov (United States)

    Aillard, P; Voituriez, A; Marinetti, A

    2014-11-07

    This literature overview demonstrates that helically chiral ligands and organocatalysts have been largely neglected so far. However, a few recent studies on helical pyridine, the corresponding ammonium salts and N-oxides have highlighted the significant potential of these compounds as organocatalysts for Michael type additions, aldehyde propargylations, epoxide openings, and others. In addition, helicenes displaying a fused phosphole ring at the end of their polyaromatic structures, have been used as ligands in enantioselective gold promoted cycloisomerization reactions, giving both excellent catalytic activity and high enantiomeric excesses. These recent results are expected to stimulate further research on the catalytic applications of helically chiral auxiliaries in the next few years.

  20. A deterministic global optimization using smooth diagonal auxiliary functions

    Science.gov (United States)

    Sergeyev, Yaroslav D.; Kvasov, Dmitri E.

    2015-04-01

    In many practical decision-making problems it happens that functions involved in optimization process are black-box with unknown analytical representations and hard to evaluate. In this paper, a global optimization problem is considered where both the goal function f (x) and its gradient f‧ (x) are black-box functions. It is supposed that f‧ (x) satisfies the Lipschitz condition over the search hyperinterval with an unknown Lipschitz constant K. A new deterministic 'Divide-the-Best' algorithm based on efficient diagonal partitions and smooth auxiliary functions is proposed in its basic version, its convergence conditions are studied and numerical experiments executed on eight hundred test functions are presented.

  1. Sandia Laboratories technical capabilities. Auxiliary capabilities: environmental health information science

    International Nuclear Information System (INIS)

    1975-09-01

    Sandia Laboratories is an engineering laboratory in which research, development, testing, and evaluation capabilities are integrated by program management for the generation of advanced designs. In fulfilling its primary responsibility to ERDA, Sandia Laboratories has acquired extensive research and development capabilities. The purpose of this series of documents is to catalog the many technical capabilities of the Laboratories. After the listing of capabilities, supporting information is provided in the form of highlights, which show applications. This document deals with auxiliary capabilities, in particular, environmental health and information science. (11 figures, 1 table) (RWR)

  2. Phonetic physical feature formula for identification of radiation auxiliary workers and security applications

    International Nuclear Information System (INIS)

    Srivastava, D.N.; Srivastava, M.K.; Kher, R.K.

    1997-08-01

    This report gives a review of human physical features with the aim of evolving a simple and practical formula which can be used to identify radiation auxiliary workers even if they do not reveal their radiation work history either due to ignorance or intentionally. To have the formula short, the phonetic number system of radix 128 has been employed. The formula finally arrived at consists of three phonetic digits representing 17 features and age in blocks of 8 years. There are four main advantages of this formula. The first is binary division which has more surety and better accuracy. The second is expert redundancy, that is expert examination is not required. Third is very large number of categories (128K=131072). And the fourth is nearly equal probabilities of all categories which make the number of people in each category very few and that simplifies the search. Hence by the scan of a few records, it is easily possible to ascertain whether a person is a new entrant or an old timer. Its application ensures better monitoring of the radiation exposure of auxiliary workers. This formula can also be used by police department and investigating agencies to classify the records of suspected persons for the ease of their identification when they give misleading information

  3. Differential modulations of KCNQ1 by auxiliary proteins KCNE1 and KCNE2.

    Science.gov (United States)

    Li, Pan; Liu, Haowen; Lai, Chaohua; Sun, Peibei; Zeng, Wenping; Wu, Fangming; Zhang, Longhua; Wang, Sheng; Tian, Changlin; Ding, Jiuping

    2014-05-15

    KCNQ1 channels play vital roles in cardiovascular, gastric and other systems. The conductance and dynamics of KCNQ1 could be modulated by different single transmembrane helical auxiliary proteins (such as KCNE1, KCNE2 and others). In this study, detail KCNQ1 function modulations by different regions of KCNE1 or KCNE2 were examined using combinational methods of electrophysiology, immunofluorescence, solution NMR and related backbone flexibility analysis. In the presence of KCNE2 N-terminus, decreased surface expression and consequent low activities of KCNQ1 were observed. The transmembrane domains (TMDs) of KCNE1 and KCNE2 were illustrated to associate with the KCNQ1 channel in different modes: Ile64 in KCNE2-TMD interacting with Phe340 and Phe275 in KCNQ1, while two pairs of interacting residues (Phe340-Thr58 and Ala244-Tyr65) in the KCNQ1/KCNE1 complex. The KCNE1 C-terminus could modulate gating property of KCNQ1, whereas KCNE2 C-terminus had only minimal influences on KCNQ1. All of the results demonstrated different KCNQ1 function modulations by different regions of the two auxiliary proteins.

  4. Part-load operation of the boiler feedwater pumps for the new French PWR 1400 MW nuclear plants - a challenge for the designer

    International Nuclear Information System (INIS)

    Martin, R.; Canavelis, R.; Guilloiseau, P.

    1988-01-01

    The Boiler feedwater pumps in Electricite de France Power Stations have to work reliably for all flow rates between 33% and 134% of the flow corresponding to the best efficiency point (Q BEP ). Under transient conditions associated with load changing these limits increase to 33% to 147% Q BEP . Due to the high specific power of these pumps, the operating conditions heavily influence the hydraulic and mechanical dimensioning. This paper presents some particular aspects of their design and test results obtained on a pump model as well as on a full scale prototype concerning suction performance, head capacity curve stability, pressure pulsations and structural excitations. (author)

  5. Fixed energy potentials through an auxiliary inverse eigenvalue problem

    International Nuclear Information System (INIS)

    Pálmai, Tamás; Apagyi, Barnabás

    2012-01-01

    An inverse scattering method based on an auxiliary inverse Sturm–Liouville problem recently proposed by Horváth and Apagyi (2008 Mod. Phys. Lett. B 22 2137) is examined in various aspects and developed further to (re)construct spherically symmetric fixed energy potentials of compact support realized in the three-dimensional Schrödinger equation. The method is generalized to obtain a family of inverse procedures characterized by two parameters originating, respectively, from the Liouville transformation and the solution of the inverse Sturm–Liouville problem. Both parameters affect the bound states arising in the auxiliary inverse spectral problem and one of them enables us to reduce their number which is assessed by a simple method. Various solution techniques of the underlying moment problem are proposed including the exact Cauchy matrix inversion method, usage of spurious bound state and assessment of the number of bound states. Examples include (re)productions of potentials from phase shifts known theoretically or derived from scattering experiments. (paper)

  6. On the Auxiliary Status of Dare in Old English

    Directory of Open Access Journals (Sweden)

    Tomaszewska Magdalena

    2014-12-01

    Full Text Available OE *durran ‘dare’ belongs to a group of the so-called preterite-present verbs which developed weak past tense forms replacing the originally strong forms throughout the paradigm. The present study hypothesizes that the potential sources of this development are related to the decay of the subjunctive mood in Old English. Further, this corpus-based study analyses the status of DARE in Old English, with the findings showing that the verb displayed both lexical and auxiliary verb characteristics. These results are juxtaposed and compared with the verb's developments in Middle English. The databases examined are the corpus of The Dictionary of Old English in Electronic Form (A-G and the Innsbruck Computer Archive of Machine-Readable English Texts. In both cases, a search of potential forms was performed on all the files of the corpora, the raw results were then analysed in order to eliminate irrelevant instances (adjectives, nouns, foreign words, etc.. The relevant forms were examined with the aim to check the properties of DARE as a lexical and an auxiliary verb, and compare the findings with Molencki’s (2002, 2005 observations.

  7. Analysis of water hammer phenomena - Application to deaerator-feedwater pump node

    International Nuclear Information System (INIS)

    Bigu, Melania; Tenescu, Mircea; Nita, Iulian Pavel

    2008-01-01

    The hydraulic hammer adverse effects are extensively presented in the literature available to those who operate and design installations in which this phenomenon occurs. There are specialized computational programs which evaluate diverse technical aspects which occur in this phenomenon. One must be noticed that not all the technical characteristics and not all effective operating modes which are treated in this paper are covered by existing computational programs. Moreover, even specialized developers of such programs recommend insistently that computational results offered by specialized programs to be verified by specialized technologists with experience in alternative theoretical computations in order to avoid any misinterpretation of results obtained by computational codes. After selective exposures of theoretical fundamentals of the problem there are presented a computational calculation obtained using the specialized calculation code PIPENET (Sunrise System Limited, Cambridge, Great Britain). The PIPENET calculation is compared with a standard computational calculation using theoretical correlations. An evaluation of the differences between those two computational methods is made in order to reveal the capabilities of the computational codes in solving the hydraulic hammering problems. In the first stage we obtained the elastic characteristics of the pipe where the phenomena of hydraulic hammering takes place. There are derivative descriptions of differential equations which describe the physical phenomena. In the second part we carried out a complete system analysis of water hammer effect due to a faulty closing of the four level control valves in steam generators. We compared the highest attended pressure with design pressure of the system. We observed that the design pressure is not overpassed. The analysis concluded that pumps' head protection is a very important parameter against overpressure in the feed water system. (authors)

  8. Energy confinement scaling in tokamaks: some implications of recent experiments with ohmic and strong auxiliary heating

    International Nuclear Information System (INIS)

    Goldston, R.J.

    1984-02-01

    Recent results from confinement scaling experiments on tokamaks with ohmic and strong auxiliary heating are reviewed. An attempt is made to draw these results together into a low-density ohmic confinement scaling law, and a scaling law for confinement with auxiliary heating. The auxiliary heating confinement law may also serve to explain the saturation in tau/sub E/ vs anti n/sub e/ observed in some ohmic heating density scaling experiments

  9. The relationship among the solutions of two auxiliary ordinary differential equations

    International Nuclear Information System (INIS)

    Liu Xiaoping; Liu Chunping

    2009-01-01

    In a recent article [Phys. Lett. A 356 (2006) 124], Sirendaoreji extended their auxiliary equation method by introducing a new auxiliary ordinary differential equation (NAODE) and its 14 solutions. Then the author studied some nonlinear evolution equations (NLEEs) and got more exact travelling wave solutions. In this paper, we will show that the 14 solutions of the NAODE are actually the same as the solutions obtained by original auxiliary equation method, and they are only different in the form.

  10. A fuzzy logic controller for feedwater regulation in pressurized water reactors

    International Nuclear Information System (INIS)

    Eryuerek, E.E.; Upadhyaya, B.R.; Alguindigue, I.E.

    1994-01-01

    Fuzzy control refers to the application of fuzzy logic theory to control systems. In this paper fuzzy controllers for steam generator water level control and pump speed control are presented, and their performance in the presence of perturbations is discussed. In order to test the robustness of the controllers, their performance is compared with the performance of model based adaptive controllers and traditional PID controllers. The control actions calculated by the fuzzy controllers is have the characteristic of quick and smooth control compared to the others

  11. Standard review plan for the review of safety analysis reports for nuclear power plants

    International Nuclear Information System (INIS)

    1984-04-01

    Revised information is presented concerning the stress analysis of engineered safety systems; control rod drive systems; reactor core isolation coding system; residual heat removal system; emergency core cooling system; station service water system; reactor auxiliary coding water systems; main steam supply system; and condensate and feedwater system

  12. An experimental study of solar desalination using free jets and an auxiliary hot air stream

    Science.gov (United States)

    Eid, Eldesouki I.; Khalaf-Allah, Reda A.; Dahab, Mohamed A.

    2018-04-01

    An experimental study for a solar desalination system based on jet-humidification with an auxiliary perpendicular hot air stream was carried out at Suez city, Egypt 29.9668°N, 32.5498°E. The tests were done from May to October 2016. The effects of nozzles situations and nozzle diameter with and without hot air stream on fresh water productivity were monitored. The results show that; the lateral and downward jets from narrow nozzles have more productivities than other situations. The hot air stream has to be adapted at a certain flow rate to get high values of productivity. The system productivity is (5.6 L/m 2 ), the estimated cost is (0.030063 / L) and the efficiency is 32.8%.

  13. Development of a solid oxide fuel cell (SOFC) automotive auxiliary power unit (APU) fueled by gasoline

    International Nuclear Information System (INIS)

    DeMinco, C.; Mukerjee, S.; Grieve, J.; Faville, M.; Noetzel, J.; Perry, M.; Horvath, A.; Prediger, D.; Pastula, M.; Boersma, R.; Ghosh, D.

    2000-01-01

    This paper describes the design and the development progress of a 3 to 5 auxiliary power unit (APU) based on a gasoline fueled solid oxide fuel cell (SOFC). This fuel cell was supplied reformate gas (reactant) by a partial oxidation (POx) catalytic reformer utilizing liquid gasoline and designed by Delphi Automotive Systems. This reformate gas consists mainly of hydrogen, carbon monoxide and nitrogen and was fed directly in to the SOFC stack without any additional fuel reformer processing. The SOFC stack was developed by Global Thermoelectric and operates around 700 o C. This automotive APU produces power to support future 42 volt vehicle electrical architectures and loads. The balance of the APU, designed by Delphi Automotive Systems, employs a packaging and insulation design to facilitate installation and operation on-board automobiles. (author)

  14. Suppression/reducing method for total organic carbon in feedwater/condensate

    International Nuclear Information System (INIS)

    Maeda, Katsuharu.

    1993-01-01

    The present invention suppresses/reduces the concentration of the total organic carbon before the startup of a reactor, to decrease (TOC) which is brought into the reactor upon startup of the operation and suppress/moderate degradation of water quality of reactor water. That is, in-service period of a condensate desalting tower is shortened, to avoid concentration increase of TOC in feed water/condensate which is leached out from the condensate desalting tower. The condensate desalting towers are put to in-service for the entire towers after increasing the vacuum degree of the condensator, to suppress leaching of TOC from the condensate desalting tower. Further, upon startup of a nuclear power plant, when the condensate desalting tower is put to in-service, condensate filters of the entire towers are previously back-washed and regenerated to remove TOC efficiently. By these procedures, TOC brought from a water supply system upon startup of the plant is thermally decomposed or radiolyzed in the reactor, thereby enabling to suppress/avoid worsening of water quality of reactor water caused by generated ion impurities. (I.S.)

  15. Application of SMA technology to auxiliary functions in appliances

    Science.gov (United States)

    Johnson, Bart; Brei, Diann E.; Patera, John

    2002-07-01

    Traditionally smart material actuation has been reserved for high technology industries such as space and aerospace; however, as the field matures more and more instances are found in low-cost, high production areas. This paper describes one such instance - the application of shape memory alloys to auxiliary functions in appliances. This investigation focused on lid locks for washing machines because it is representative of several other applications found in appliances including valves, dispensers, locks, brakes, etc. Several competing concepts for SMA actuated lid locks are discussed including simple analytical design models and experimental characterization of proof-of-concept prototypes. A comparison of these designs based on performance (force, response times), energy (power requirements) and economic metrics is given. From this study, a final concept was developed based upon the best attributes of the different concepts. The resulting proof-of-concept prototype demonstrated improved performance over the current state with a potential for cost reduction.

  16. Stripping of organic compounds from wastewater as an auxiliary fuel of regenerative thermal oxidizer.

    Science.gov (United States)

    Chang, Meng-Wen; Chern, Jia-Ming

    2009-08-15

    Organic solvents with different volatilities are widely used in various processes and generate air and water pollution problems. In the cleaning processes of electronics industries, most volatile organic compounds (VOCs) are vented to air pollution control devices while most non-volatile organic solvents dissolve in the cleaning water and become the major sources of COD in wastewater. Discharging a high-COD wastewater stream to wastewater treatment facility often disturbs the treatment performance. A pretreatment of the high-COD wastewater is therefore highly desirable. This study used a packed-bed stripping tower in combination with a regenerative thermal oxidizer to remove the COD in the wastewater from a printed circuit board manufacturing process and to utilize the stripped organic compounds as the auxiliary fuel of the RTO. The experimental results showed that up to 45% of the COD could be removed and 66% of the RTO fuel could be saved by the combined treatment system.

  17. Integration of thermoelectrics and photovoltaics as auxiliary power sources in mobile computing applications

    Science.gov (United States)

    Muhtaroglu, Ali; Yokochi, Alex; von Jouanne, Annette

    The inclusion of renewable technologies as auxiliary power sources in mobile computing platforms can lead to improved performance such as the extension of battery life. This paper presents sustainable power management characteristics and performance enhancement opportunities in mobile computing systems resulting from the integration of thermoelectric generators and photovoltaic units. Thermoelectric generators are employed for scavenging waste heat from processors or other significant components in the computer's chipset while the integration of photovoltaic units is demonstrated for generating power from environmental illumination. A scalable and flexible power architecture is also verified to effectively integrate these renewable energy sources. This paper confirms that battery life extension can be achieved through the appropriate integration of renewable sources such as thermoelectric and photovoltaic devices.

  18. 76 FR 65935 - National Poultry Improvement Plan and Auxiliary Provisions; Correction

    Science.gov (United States)

    2011-10-25

    .... APHIS-2009-0031] RIN 0579-AD21 National Poultry Improvement Plan and Auxiliary Provisions; Correction... Poultry Improvement Plan (the Plan) and its auxiliary provisions by providing new or modified sampling and testing procedures for Plan participants and participating flocks. We also amended the regulations in 9...

  19. Dummy auxiliaries in child and adult second language acquisition of Dutch

    NARCIS (Netherlands)

    Blom, W.B.T.; de Korte, S.

    2011-01-01

    In previous research it has been observed that second language (L2) learners of Dutch and German use analytic verbs in contexts where the target language requires synthetic verbs. These analytic verbs consist of a semantically empty auxiliary (dummy auxiliary) that selects a lexical infinitive. In

  20. Modal Auxiliaries and Their Semantic Functions Used by Advanced EFL Learners

    Science.gov (United States)

    Torabiardakani, Najmeh; Khojasteh, Laleh; Shokrpour, Nasrin

    2015-01-01

    Since modal auxiliary verbs have been proved to be one of the most troublesome grammatical structures in English, the researchers of this study decided to do an analysis on the ways in which advanced EFL Iranian students use modal auxiliaries focusing specially on nine modals' semantic functions. Consequently, was conducted based on the following…

  1. 30 CFR 18.22 - Boring-type machines equipped for auxiliary face ventilation.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Boring-type machines equipped for auxiliary... AND ACCESSORIES Construction and Design Requirements § 18.22 Boring-type machines equipped for auxiliary face ventilation. Each boring-type continuous-mining machine that is submitted for approval shall...

  2. 14 CFR 33.96 - Engine tests in auxiliary power unit (APU) mode.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Engine tests in auxiliary power unit (APU... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.96 Engine tests in auxiliary power unit (APU) mode. If the engine is designed with a propeller brake which...

  3. Auxiliary Armed Forces and Innovations in Security Governance in Mozambique’s Civil War

    NARCIS (Netherlands)

    Jentzsch, C.

    2017-01-01

    Who rules during the civil war? This article argues that the concept of armed group governance must be expanded to include auxiliary armed forces linked to rebels or the government. Comparing the organization of rebel and government auxiliaries, the article demonstrates that security governance

  4. 77 FR 11421 - Airworthiness Directives; Pratt & Whitney Canada, Auxiliary Power Units

    Science.gov (United States)

    2012-02-27

    ... Canada, Auxiliary Power Units AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of... serial numbers of Pratt & Whitney Canada (P&WC) PW901A auxiliary power units (APUs) approved under... address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. Fax: 202-493-2251...

  5. Goal programming for cyclical auxiliary police scheduling at UiTM Cawangan Perlis

    Science.gov (United States)

    Mustapar, Wasilatul Effah; Nasir, Diana Sirmayunie Mohd; Nor, Nor Azriani Mohamad; Abas, Sharifah Fhahriyah Syed

    2017-11-01

    Constructing a good and fair schedule for shift workers poses a great challenge as it requires a lot of time and effort. In this study, goal programming has been applied on scheduling to achieve the hard and soft constraints for a cyclical schedule that would ease the head of auxiliary police at building new schedules. To accomplish this goal, shift types were assigned in order to provide a fair schedule that takes into account the auxiliary police's policies and preferences. The model was run using Lingo software. Three out of four goals set for the study were achieved. In addition, the results considered an equal allocation for every auxiliary police, namely 70% for total duty and 30% for the day. Furthermore, the schedule was able to cyclically generate another 10 sets schedule. More importantly, the model has provided unbiased scheduling of auxiliary policies which led to high satisfaction in auxiliary police management.

  6. Assessing Landscape-Scale Soil Moisture Distribution Using Auxiliary Sensing Technologies and Multivariate Geostatistics

    Science.gov (United States)

    Landrum, C.; Castrignanò, A.; Mueller, T.; Zourarakis, D.; Zhu, J.

    2013-12-01

    It is important to assess soil moisture to develop strategies to better manage its availability and use. At the landscape scale, soil moisture distribution derives from an integration of hydrologic, pedologic and geomorphic processes that cause soil moisture variability (SMV) to be time, space, and scale-dependent. Traditional methods to assess SMV at this scale are often costly, labor intensive, and invasive, which can lead to inadequate sampling density and spatial coverage. Fusing traditional sampling techniques with georeferenced auxiliary sensing technologies, such as geoelectric sensing and LiDAR, provide an alternative approach. Because geoelectric and LiDAR measurements are sensitive to soil properties and terrain features that affect soil moisture variation, they are often employed as auxiliary measures to support less dense direct sampling. Georeferenced proximal sensing acquires rapid, real-time, high resolution data over large spatial extents that is enriched with spatial, temporal and scale-dependent information. Data fusion becomes important when proximal sensing is used in tandem with more sparse direct sampling. Multicollocated factorial cokriging (MFC) is one technique of multivariate geostatistics to fuse multiple data sources collected at different sampling scales to study the spatial characteristics of environmental properties. With MFC sparse soil observations are supported by more densely sampled auxiliary attributes to produce more consistent spatial descriptions of scale-dependent parameters affecting SMV. This study uses high resolution geoelectric and LiDAR data as auxiliary measures to support direct soil sampling (n=127) over a 40 hectare Central Kentucky (USA) landscape. Shallow and deep apparent electrical resistivity (ERa) were measured using a Veris 3100 in tandem with soil moisture sampling on three separate dates with ascending soil moisture contents ranging from plant wilting point to field capacity. Terrain features were produced

  7. Synergistic Effect Evaluation of Main and Auxiliary Industry of Power Grid Based on the Information Fusion Technology from the Perspective of Sustainable Development of Enterprises

    Directory of Open Access Journals (Sweden)

    Xiaomin Xu

    2018-02-01

    Full Text Available With the development of the diversified economic union, the power grid enterprises’ auxiliary industries are continuing to grow and develop faster. However, in the process of development, power grid enterprises are still faced with the problem of low efficiency of the management of main and auxiliary and resource allocation and utilization. Thus, the synergistic development evaluation for power grid enterprises’ main and auxiliary industries has a strong practical significance. It can help the managers to find the short board of each industry and search for the exploration direction for improvement to promote the sustainable development of the main and auxiliary industries comprehensively. It can also provide the reference for improving the management level of power grid enterprises. Information fusion technology, as a process of information processing for decision making, can make use of multi-source information synergistically to get a more objective and more essential understanding of the same thing or the same goal. It has been applied to many fields in a mature way. Based on the characteristics of each industry, this paper constructs a synergistic effect evaluation index system of the main and auxiliary industries from the aspects of management foundation, resource integration, operational efficiency and effectiveness. The variable precision fuzzy rough set (VPFRS is introduced to screen the index system, eliminate redundant indexes, retain key indexes and improve the efficiency and accuracy of evaluation effectively. Meanwhile, based on the characteristic of dealing with the imprecise problem of the vague set, this paper establishes the evaluation model based on information fusion technology of the variable precision fuzzy rough set and vague set (VPFRS-Vague. In order to verify the validity of the model, five typical companies belonging to power grid enterprises are selected as examples for analysis to prove the validity and

  8. A magnetorheological clutch for efficient automotive auxiliary device actuation

    Directory of Open Access Journals (Sweden)

    F. Bucchi

    2013-01-01

    Full Text Available In this paper the results of a project funded by Regione Toscana aimed at reducing the power absorption of auxiliary devices in vehicles are presented. In particular the design, testing and application of a magnetorheological clutch (MR is proposed, aimed at disengaging the vacuum pump, which draws in air from the power-brake booster chamber, in order to reduce the device power absorption. Several clutch preliminary studies done to choose the clutch geometry and the magnetic field supply are illustrated. The final choice consisted in an MR clutch with permanent magnet, which satisfied size, torque and fail-safe specifications. The clutch characteristics, in terms of torque versus slip, were obtained experimentally for three different clutch prototypes on an ad-hoc developed test bench.As result of a preliminary simulation, a comparison between the power absorption of a current production vacuum pump, an innovative vacuum pump and both vacuum pumps coupled with the MR clutch is presented. The New European Driving Cycle is considered for simulating the vacuum pump operation both in urban and highway driving. Results show that the use of the innovative vacuum pump reduces the device consumption of about 35%, whereas the use of MR clutch coupled with the innovative vacuum pump reduces it up to about 44% in urban driving and 50% in highway driving.

  9. Neutral particle diagnostics for ohmically and auxiliary heated tokamaks

    International Nuclear Information System (INIS)

    Wagner, F.

    1982-01-01

    Protons and hydrogen atoms in a plasma undergo charge-exchange collisions which give rise to an energetic charge-exchange flux emerging from the plasma. The intensity and energy distribution of the charge-exchange flux is measured separately for hydrogen or deuterium. Besides discussing the basic principles and the experimental techniques, this report concentrates on plasma characteristics accessible to neutral particle diagnostics. From the energy distribution of the charge exchange flux, the ion energy distribution can be inferred. In the case of a thermal plasma the measurement of the ion temperature profile allows the analysis of the ion energy transport, and with auxiliary heating the ion heating efficiency can be estimated. From the absolute intensity of the charge-exchange flux the hydrogen atom density can be determined; strong toroidal variation, with sharp increases at limiter and gas input valve, is observed. The atom flux which leaves the plasma hits the wall and forms one branch of plasma wall interaction which can be investigated by measuring the backscattering of neutrals from the wall and by analyzing the wall sputtering due to charge-exchange atoms. Neutral particle diagnostics carried out in the divertor chamber of a divertor tokamak reveal strong plasma wall interaction at the neutralizer plate

  10. Auxiliary antenna-assisted interference mitigation for radio astronomy arrays

    Science.gov (United States)

    Jeffs, B. D.; Li, L.; Warnick, K. F.

    2005-02-01

    Interferometric image synthesis in radio astronomy is plagued by signal corruption from man-made sources. The very weak signals of interest can be overwhelmed by such interference. Recent work has proposed using array signal processing techniques of adaptive beamforming, adaptive filtering, and subspace projection to remove interference prior to image synthesis. In some practical scenarios, we have found poor cancellation performance when using such methods. Because signal-of-interest levels in radio astronomy (RA) are usually well below the noise, even interference to noise ratios (INR) less than unity can affect signal estimation. At these low INRs, it is difficult to estimate interference parameters or statistics with sufficient accuracy for high-performance adaptive cancellation or subspace projection. By adding a few (one to three) low-gain (relative to the primary telescope dishes) "auxiliary" antennas to an array, it is possible to overcome this problem. This paper will show that using such antennas (e.g. commercial-grade 3-m dishes) with an existing array can significantly improve interference rejection. New extensions to subspace projection spatial filtering methods are presented, along with analytical and simulated results for performance comparison.

  11. Self-patching firmware program. [Method of branching to auxiliary program without hardware or software modification

    Energy Technology Data Exchange (ETDEWEB)

    Stanchi, L.

    1976-12-01

    A method of branching to an auxiliary program without any hardware or software modification at the time the auxiliary program will be written is described. Suitable statements in the main program are already prepared to accept a future program that will be written in machine language. The main program is stored as firmware in PROM memory, while the auxiliary program is loaded into RAM memory. The method is described for the Intel 8080 microprocessor, but can be generalized for any microprocessor or minicomputer that uses ROMs or PROMs. 1 figure, 2 tables.

  12. Kinetics of low temperature polyester dyeing with high molecular weight disperse dyes by solvent microemulsion and agrosourced auxiliaries

    OpenAIRE

    Radei, Shahram; Carrión-Fité, Francisco Javier; Ardanuy Raso, Mònica; Canal Arias, José Ma

    2018-01-01

    This work focused on the evaluation of the kinetics of dyeing polyester fabrics with high molecular weight disperse dyes, at low temperature by solvent microemulsion. This study also compared the effect of two non-toxic agro-sourced auxiliaries (o-vanillin and coumarin) using a non-toxic organic solvent. A dyeing bath consisting of a micro-emulsion system involving a small proportion of n-butyl acetate was used, and the kinetics of dyeing were analysed at four temperatures (83, 90, 95 and 100...

  13. Kinetics of Low Temperature Polyester Dyeing with High Molecular Weight Disperse Dyes by Solvent Microemulsion and AgroSourced Auxiliaries

    OpenAIRE

    Shahram Radei; F. Javier Carrión-Fité; Mònica Ardanuy; José María Canal

    2018-01-01

    This work focused on the evaluation of the kinetics of dyeing polyester fabrics with high molecular weight disperse dyes, at low temperature by solvent microemulsion. This study also compared the effect of two non-toxic agro-sourced auxiliaries (o-vanillin and coumarin) using a non-toxic organic solvent. A dyeing bath consisting of a micro-emulsion system involving a small proportion of n-butyl acetate was used, and the kinetics of dyeing were analysed at four temperatures (83, 90, 95 and 100...

  14. Digital control system of a steam generator water level by LQG optimal method

    International Nuclear Information System (INIS)

    Lee, Yoon Joon

    1993-01-01

    A digital control system for the steam generator water level control is developed using LQG optimal design method. To describe the more realistic situaton, a feedwater valve actuator is assumed to be of the first order lagger and is included in the overall control system. By composing the digital control circuit in such a way that the overall control system consists of two sub-systems of feedwater station and feedback loop digital controller, the design procedure is divided into two independent steps. The feedwater station system is described in the error dynamics of an ordinary regulator system. The optimal gains are obtained by LQ method which imposes the constraints of the feedwater valve motion as well as on the output deviations. Developed also is a Kalman observer on account of the flow measurement uncertainty at low power. Then a digital controller on the feedback loop is designed so that the system maintains the same stability margins for all power ranges. The simulation results show thst the optimal digital system has a good control characteristics despite the adverse dynamics of a steam generator at low power. (Author)

  15. Applications of Human Performance Models to System Design: Defense Research Series. Volume 2

    Science.gov (United States)

    1989-01-01

    Island near-accident was that the reserve feedwater supply system pipe had been blocked off by maintenance personnel who forgot to reinstall the system...Research Est. BIB FOT&E USAF Queens Road, Middlesex Det 1 49th Test Squadron Teddington UK Dyess AFB TX 79607 USA Hazeltine, Alice Kaiura, Richard Martin

  16. Improved Aqueous Solubility and Antihypercholesterolemic Activity of Ezetimibe on Formulating with Hydroxypropyl-β-Cyclodextrin and Hydrophilic Auxiliary Substances.

    Science.gov (United States)

    Srivalli, Kale Mohana Raghava; Mishra, Brahmeshwar

    2016-04-01

    The purpose of this study was to improve the aqueous solubility, dissolution, and pharmacodynamic properties of a BCS class II drug, ezetimibe (Eze) by preparing ternary cyclodextrin complex systems. We investigated the potential synergistic effect of two novel hydrophilic auxiliary substances, D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) and L-ascorbic acid-2-glucoside (AA2G) on hydroxypropyl-β-cyclodextrin (HPBCD) solubilization of poorly water-soluble hypocholesterolemic drug, Eze. In solution state, the binary and ternary systems were analyzed by phase solubility studies and Job's plot. The solid complexes prepared by freeze-drying were characterized by Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), powder X-ray diffraction (XRD), nuclear magnetic resonance (NMR), and scanning electron microscopy (SEM). The log P values, aqueous solubility, dissolution, and antihypercholesterolemic activity of all systems were studied. The analytical techniques confirmed the formation of inclusion complexes in the binary and ternary systems. HPBCD complexation significantly (p solubility, dissolution, and hypocholesterolemic properties of Eze, and the addition of ternary component produced further significant improvement (p solubility, dissolution, and antihypercholesterolemic activity due to the addition of TPGS or AA2G may be attributed to enhanced wetting, dispersibility, and complete amorphization. The use of TPGS or AA2G as ternary hydrophilic auxiliary substances improved the HPBCD solubilization and antihypercholesterolemic activity of Eze.

  17. LOFT integral test system final safety analysis report

    International Nuclear Information System (INIS)

    1974-03-01

    Safety analyses are presented for the following LOFT Reactor systems: engineering safety features; support buildings and facilities; instrumentation and controls; electrical systems; and auxiliary systems. (JWR)

  18. Wigner Transport Simulation of Resonant Tunneling Diodes with Auxiliary Quantum Wells

    Science.gov (United States)

    Lee, Joon-Ho; Shin, Mincheol; Byun, Seok-Joo; Kim, Wangki

    2018-03-01

    Resonant-tunneling diodes (RTDs) with auxiliary quantum wells ( e.g., emitter prewell, subwell, and collector postwell) are studied using a Wigner transport equation (WTE) discretized by a thirdorder upwind differential scheme. A flat-band potential profile is used for the WTE simulation. Our calculations revealed functions of the auxiliary wells as follows: The prewell increases the current density ( J) and the peak voltage ( V p ) while decreasing the peak-to-valley current ratio (PVCR), and the postwell decreases J while increasing the PVCR. The subwell affects J and PVCR, but its main effect is to decrease V p . When multiple auxiliary wells are used, each auxiliary well contributes independently to the transport without producing side effects.

  19. Analysis of Heat Transfers inside Counterflow Plate Heat Exchanger Augmented by an Auxiliary Fluid Flow

    Science.gov (United States)

    Khaled, A.-R. A.

    2014-01-01

    Enhancement of heat transfers in counterflow plate heat exchanger due to presence of an intermediate auxiliary fluid flow is investigated. The intermediate auxiliary channel is supported by transverse conducting pins. The momentum and energy equations for the primary fluids are solved numerically and validated against a derived approximate analytical solution. A parametric study including the effect of the various plate heat exchanger, and auxiliary channel dimensionless parameters is conducted. Different enhancement performance indicators are computed. The various trends of parameters that can better enhance heat transfer rates above those for the conventional plate heat exchanger are identified. Large enhancement factors are obtained under fully developed flow conditions. The maximum enhancement factors can be increased by above 8.0- and 5.0-fold for the step and exponential distributions of the pins, respectively. Finally, counterflow plate heat exchangers with auxiliary fluid flows are recommended over the typical ones if these flows can be provided with the least cost. PMID:24719572

  20. 14 CFR 23.1549 - Powerplant and auxiliary power unit instruments.

    Science.gov (United States)

    2010-01-01

    ... radial or a red line; (b) Each normal operating range must be marked with a green arc or green line, not... marked with a yellow arc or a yellow line; and (d) Each engine, auxiliary power unit, or propeller range...

  1. 14 CFR 25.1549 - Powerplant and auxiliary power unit instruments.

    Science.gov (United States)

    2010-01-01

    ...) Each normal operating range must be marked with a green arc or green line, not extending beyond the... or a yellow line; and (d) Each engine, auxiliary power unit, or propeller speed range that is...

  2. Ocean Surface Topography Mission (OSTM) /Jason-2: Auxiliary Files (NODC Accession 0044983)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This accession contains the data descriptions for the OSTM/Jason-2 Auxiliary data files, which is served through the NOAA/NESDIS Comprehensive Large Array-data...

  3. Derived Requirements for Double Shell Tank (DST) High Level Waste (HLW) Auxiliary Solids Mobilization

    Energy Technology Data Exchange (ETDEWEB)

    TEDESCHI, A.R.

    2000-02-28

    The potential need for auxiliary double-shell tank waste mixing and solids mobilization requires an evaluation of optional technologies. This document formalizes those operating and design requirements needed for further engineering evaluations.

  4. Analysis of heat transfers inside counterflow plate heat exchanger augmented by an auxiliary fluid flow.

    Science.gov (United States)

    Khaled, A-R A

    2014-01-01

    Enhancement of heat transfers in counterflow plate heat exchanger due to presence of an intermediate auxiliary fluid flow is investigated. The intermediate auxiliary channel is supported by transverse conducting pins. The momentum and energy equations for the primary fluids are solved numerically and validated against a derived approximate analytical solution. A parametric study including the effect of the various plate heat exchanger, and auxiliary channel dimensionless parameters is conducted. Different enhancement performance indicators are computed. The various trends of parameters that can better enhance heat transfer rates above those for the conventional plate heat exchanger are identified. Large enhancement factors are obtained under fully developed flow conditions. The maximum enhancement factors can be increased by above 8.0- and 5.0-fold for the step and exponential distributions of the pins, respectively. Finally, counterflow plate heat exchangers with auxiliary fluid flows are recommended over the typical ones if these flows can be provided with the least cost.

  5. Precision control of high temperature furnaces using an auxiliary power supply and charged particle current flow

    Science.gov (United States)

    Pollock, G.G.

    1997-01-28

    Two power supplies are combined to control a furnace. A main power supply heats the furnace in the traditional manner, while the power from the auxiliary supply is introduced as a current flow through charged particles existing due to ionized gas or thermionic emission. The main power supply provides the bulk heating power and the auxiliary supply provides a precise and fast power source such that the precision of the total power delivered to the furnace is improved. 5 figs.

  6. Precision control of high temperature furnaces using an auxiliary power supply and charged practice current flow

    Science.gov (United States)

    Pollock, George G.

    1997-01-01

    Two power supplies are combined to control a furnace. A main power supply heats the furnace in the traditional manner, while the power from the auxiliary supply is introduced as a current flow through charged particles existing due to ionized gas or thermionic emission. The main power supply provides the bulk heating power and the auxiliary supply provides a precise and fast power source such that the precision of the total power delivered to the furnace is improved.

  7. A study on ship automatic berthing with assistance of auxiliary devices

    Directory of Open Access Journals (Sweden)

    Van Luong Tran

    2012-09-01

    Full Text Available The recent researches on the automatic berthing control problems have used various kinds of tools as a control method such as expert system, fuzzy logic controllers and artificial neural network (ANN. Among them, ANN has proved to be one of the most effective and attractive options. In a marine context, the berthing maneuver is a complicated procedure in which both human experience and intensive control operations are involved. Nowadays, in most cases of berthing operation, auxiliary devices are used to make the schedule safer and faster but none of above researches has taken into account. In this study, ANN is applied to design the controllers for automatic ship berthing using assistant devices such as bow thruster and tug. Using back-propagation algorithm, we trained ANN with set of teaching data to get a minimal error between output values and desired values of four control outputs including rudder, propeller revolution, bow thruster and tug. Then, computer simulations of automatic berthing were carried out to verify the effecttiveness of the system. The results of the simulations showed good performance for the proposed berthing control system.

  8. Preliminary safety analysis report for the Auxiliary Hot Cell Facility, Sandia National Laboratories, Albuquerque, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    OSCAR,DEBBY S.; WALKER,SHARON ANN; HUNTER,REGINA LEE; WALKER,CHERYL A.

    1999-12-01

    The Auxiliary Hot Cell Facility (AHCF) at Sandia National Laboratories, New Mexico (SNL/NM) will be a Hazard Category 3 nuclear facility used to characterize, treat, and repackage radioactive and mixed material and waste for reuse, recycling, or ultimate disposal. A significant upgrade to a previous facility, the Temporary Hot Cell, will be implemented to perform this mission. The following major features will be added: a permanent shield wall; eight floor silos; new roof portals in the hot-cell roof; an upgraded ventilation system; and upgraded hot-cell jib crane; and video cameras to record operations and facilitate remote-handled operations. No safety-class systems, structures, and components will be present in the AHCF. There will be five safety-significant SSCs: hot cell structure, permanent shield wall, shield plugs, ventilation system, and HEPA filters. The type and quantity of radionuclides that could be located in the AHCF are defined primarily by SNL/NM's legacy materials, which include radioactive, transuranic, and mixed waste. The risk to the public or the environment presented by the AHCF is minor due to the inventory limitations of the Hazard Category 3 classification. Potential doses at the exclusion boundary are well below the evaluation guidelines of 25 rem. Potential for worker exposure is limited by the passive design features incorporated in the AHCF and by SNL's radiation protection program. There is no potential for exposure of the public to chemical hazards above the Emergency Response Protection Guidelines Level 2.

  9. Preliminary safety analysis report for the Auxiliary Hot Cell Facility, Sandia National Laboratories, Albuquerque, New Mexico

    International Nuclear Information System (INIS)

    OSCAR, DEBBY S.; WALKER, SHARON ANN; HUNTER, REGINA LEE; WALKER, CHERYL A.

    1999-01-01

    The Auxiliary Hot Cell Facility (AHCF) at Sandia National Laboratories, New Mexico (SNL/NM) will be a Hazard Category 3 nuclear facility used to characterize, treat, and repackage radioactive and mixed material and waste for reuse, recycling, or ultimate disposal. A significant upgrade to a previous facility, the Temporary Hot Cell, will be implemented to perform this mission. The following major features will be added: a permanent shield wall; eight floor silos; new roof portals in the hot-cell roof; an upgraded ventilation system; and upgraded hot-cell jib crane; and video cameras to record operations and facilitate remote-handled operations. No safety-class systems, structures, and components will be present in the AHCF. There will be five safety-significant SSCs: hot cell structure, permanent shield wall, shield plugs, ventilation system, and HEPA filters. The type and quantity of radionuclides that could be located in the AHCF are defined primarily by SNL/NM's legacy materials, which include radioactive, transuranic, and mixed waste. The risk to the public or the environment presented by the AHCF is minor due to the inventory limitations of the Hazard Category 3 classification. Potential doses at the exclusion boundary are well below the evaluation guidelines of 25 rem. Potential for worker exposure is limited by the passive design features incorporated in the AHCF and by SNL's radiation protection program. There is no potential for exposure of the public to chemical hazards above the Emergency Response Protection Guidelines Level 2

  10. Application of flow network models of SINDA/FLUINT{sup TM} to a nuclear power plant system thermal hydraulic code

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Ji Bum [Institute for Advanced Engineering, Yongin (Korea, Republic of); Park, Jong Woon [Korea Electric Power Research Institute, Taejon (Korea, Republic of)

    1998-12-31

    In order to enhance the dynamic and interactive simulation capability of a system thermal hydraulic code for nuclear power plant, applicability of flow network models in SINDA/FLUINT{sup TM} has been tested by modeling feedwater system and coupling to DSNP which is one of a system thermal hydraulic simulation code for a pressurized heavy water reactor. The feedwater system is selected since it is one of the most important balance of plant systems with a potential to greatly affect the behavior of nuclear steam supply system. The flow network model of this feedwater system consists of condenser, condensate pumps, low and high pressure heaters, deaerator, feedwater pumps, and control valves. This complicated flow network is modeled and coupled to DSNP and it is tested for several normal and abnormal transient conditions such turbine load maneuvering, turbine trip, and loss of class IV power. The results show reasonable behavior of the coupled code and also gives a good dynamic and interactive simulation capabilities for the several mild transient conditions. It has been found that coupling system thermal hydraulic code with a flow network code is a proper way of upgrading simulation capability of DSNP to mature nuclear plant analyzer (NPA). 5 refs., 10 figs. (Author)

  11. A review of high-temperature polymer electrolyte membrane fuel-cell (HT-PEMFC)-based auxiliary power units for diesel-powered road vehicles

    Science.gov (United States)

    Liu, Yongfeng; Lehnert, Werner; Janßen, Holger; Samsun, Remzi Can; Stolten, Detlef

    2016-04-01

    This paper presents an extensive review of research on the development of auxiliary power units with enhanced reformate tolerance for high temperature polymer electrolyte membrane fuel cells (HT-PEMFCs). Developments in diesel reforming for fuel cells as auxiliary power units (APUs), single fuel cells and stacks and systems are outlined in detail and key findings are presented. Summaries of HT-PEMFC APU applications and start-up times for HT-PEMFC systems are then given. A summary of cooling HT-PEMFC stacks using a classic schematic diagram of a 24-cell HT-PEMFC stack, with a cooling plate for every third cell, is also presented as part of a stack analysis. Finally, a summary of CO tolerances for fuel cells is given, along with the effects of different CO volume fractions on polarization curves, the fraction of CO coverage, hydrogen coverage, anode overpotential and cell potential.

  12. Simulation of engine auxiliary drive V-belt slip motion. Part 1. Development of belt slip model; Engine hoki V belt slip kyodo no simulation. 1. Belt slip model no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Kurisu, T. [Mazda Motor Corp., Hiroshima (Japan)

    1997-10-01

    V-belts are widely used for driving auxiliary components of an engine. Inadequet design of such belt system sometimes results in troubles such as belt squeak, side rubber separation and/or bottom rubber crack. However, there has been no design tools which can predict belt slip quantitatively. The author developed a motion simulation program of Auxiliary Drive V-Belt System considering belt slip. The program showed good prediction accuracy for belt slip motion. This paper describes the simulation model. 1 ref., 12 figs.

  13. Exergo-Ecological Assessment Of Auxiliary Fuel Injection Into Blast-Furnace

    Directory of Open Access Journals (Sweden)

    Stanek W.

    2015-06-01

    Full Text Available Metallurgy represents complex technological chain supplied with different kinds of primary resources. Iron metallurgy based on blast-furnace process, dominates in world steel production. Metallurgical coke is the basic fuel in this case. Its production is connected with several environmental disadvantageous impacts. One of them is the extended production chain from primary energy to final energy. The reduction of coke consumption in the process can be achieved e.g. by injection of auxiliary fuels or increasing the thermal parameters in the process. In present injection of pulverised coal dominates while recirculation of top-gas seems to be future technology. However, the latter one requires the CO2 removal that additionally extended the production chain. The evaluation of resources management in complex energy-technological systems required application of advanced method based on thermodynamics. In the paper the system exergo-ecological assessment of pulverised coal injection into blast-furnace and top-gas recirculation has been applied. As a comparative criterion the thermo-ecological cost has been proposed.

  14. Solid Oxide Fuel Cell Development for Auxiliary Power in Heavy Duty Vehicle Applications

    Energy Technology Data Exchange (ETDEWEB)

    Daniel T. Hennessy

    2010-06-15

    Changing economic and environmental needs of the trucking industry is driving the use of auxiliary power unit (APU) technology for over the road haul trucks. The trucking industry in the United States remains the key to the economy of the nation and one of the major changes affecting the trucking industry is the reduction of engine idling. Delphi Automotive Systems, LLC (Delphi) teamed with heavy-duty truck Original Equipment Manufacturers (OEMs) PACCAR Incorporated (PACCAR), and Volvo Trucks North America (VTNA) to define system level requirements and develop an SOFC based APU. The project defines system level requirements, and subsequently designs and implements an optimized system architecture using an SOFC APU to demonstrate and validate that the APU will meet system level goals. The primary focus is on APUs in the range of 3-5 kW for truck idling reduction. Fuels utilized were derived from low-sulfur diesel fuel. Key areas of study and development included sulfur remediation with reformer operation; stack sensitivity testing; testing of catalyst carbon plugging and combustion start plugging; system pre-combustion; and overall system and electrical integration. This development, once fully implemented and commercialized, has the potential to significantly reduce the fuel idling Class 7/8 trucks consume. In addition, the significant amounts of NOx, CO2 and PM that are produced under these engine idling conditions will be virtually eliminated, inclusive of the noise pollution. The environmental impact will be significant with the added benefit of fuel savings and payback for the vehicle operators / owners.

  15. Role stress among auxiliary nurses midwives in Gujarat, India.

    Science.gov (United States)

    Purohit, Bhaskar; Vasava, Paul

    2017-01-23

    Understanding Role Stress is important as health service providers, especially nurses experience high levels of Role Stress which is linked to burnout, poor quality of care and high turnover. The current study explicates the concept of Role Stress and assesses the Role Stress experienced by the Auxiliary Nurse Midwives (ANMs) working with rural government health centres from Gujarat, India. The study included 84 ANMs working with government health centres from one district in India. A structured instrument with established reliability and validity was used to measure 10 dimensions of Role Stress namely: Inter-role distance, role stagnation, role expectation conflict, role erosion: role overload, role isolation, personal inadequacy, self-role distance, role ambiguity and resource inadequacy. The study instrument was based on 5 point Likert rating scale that contained 50 unidirectional negative statements, 5 for each dimension. Kolmogorov-Smirnov and Shapiro-Wilk test were carried out to assess if the data were normally distributed. Cronbach's alpha test was carried out to assess reliability of the instrument. The study data was analyzed using descriptive statistics mainly using mean scores with higher scores indicating higher Role Stress and vice versa. The data was analyzed using SPSS version 19. Kolmogorov-Smirnov and Shapiro-Wilk test indicated that the data were normally distributed. Cronbach's alpha test indicated values of 0.852 suggesting high reliability of the tool. The highest Role Stress among ANMs was experienced for resource inadequacy. Role overload, role stagnation and inter-role distance were among the other important role stressors for ANMs. The study results suggests that ANMs frequently feel that: they do not have adequate amount of resources, facilities and financial support from the high levels authorities; people have too many expectations from their roles and as result they are overloaded with work and have very limited opportunities for

  16. Design, construction and test run of a two-tonne capacity solar rice dryer with rice-husk-fired auxiliary heater

    International Nuclear Information System (INIS)

    Iloeje, O.C.; Ekechukwu, O.V.; Ezeike, G.O.I.

    1993-09-01

    The design and construction details of a two-tonne per batch capacity natural-circulation solar rice dryer and the highlights of the design of its rice-husk-fired auxiliary heating system which is still under construction are presented. The dryer measures approximately 17.7m long by 9.8m wide by 6m high. Preliminary results of a test run on the solar dryer section only is reported. (author). 5 refs, 3 figs

  17. A battery-fuel cell hybrid auxiliary power unit for trucks: Analysis of direct and indirect hybrid configurations

    International Nuclear Information System (INIS)

    Samsun, Remzi Can; Krupp, Carsten; Baltzer, Sidney; Gnörich, Bruno; Peters, Ralf; Stolten, Detlef

    2016-01-01

    Highlights: • A battery-fuel cell hybrid auxiliary power unit for heavy duty vehicles is reported. • Comparison of direct and indirect hybrids using representative load profiles. • Evaluation based on validated fuel cell system and battery models. • Indirect hybrid with constant fuel cell load yields 29.3% hybrid system efficiency. • Fuel cell should be pre-heated using waste heat from the diesel engine during drive. - Abstract: The idling operation of engines in heavy duty vehicles to cover electricity demand during layovers entails significant fuel consumption and corresponding emissions. Indeed, this mode of operation is highly inefficient and a noteworthy contributor to the transportation sector’s aggregate carbon dioxide emissions. Here, a potential solution to this wasteful practice is outlined in the form of a hybrid battery-fuel cell system for application as an auxiliary power unit for trucks. Drawing on experimentally-validated fuel cell and battery models, several possible hybrid concepts are evaluated and direct and indirect hybrid configurations analyzed using a representative load profile. The results indicate that a direct hybrid configuration is only applicable if the load demand profile does not deviate strongly from the assumed profile. Operation of an indirect hybrid with a constant fuel cell load yields the greatest hybrid system efficiency, at 29.3%, while battery size could be reduced by 87% if the fuel cell is operated at the highest dynamics. Maximum efficiency in truck applications can be achieved by pre-heating the system prior to operation using exhaust heat from the motor, which increased system efficiency from 25.3% to 28.1%, including start-up. These findings confirm that hybrid systems could offer enormous fuel savings and constitute a sizeable step on the path toward energy-efficient and environmentally-friendly heavy duty vehicles that does not necessitate a fuel switch.

  18. Research on dynamics and experiments about auxiliary bearings for the helium circulator of the 10 MW high temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Zhao, Yulan; Yang, Guojun; Liu, Xingnan; Shi, Zhengang; Zhao, Lei

    2016-01-01

    Highlights: • The research in this paper is based on the AMB helium circulator of HTR-10. • The dynamic rotor performance is analyzed by processing experimental data. • The mechanical bearing without lubrication can be applied in the HTR-10 system. - Abstract: The 10 MW high-temperature gas-cooled reactor (HTR-10) was constructed by the Institute of Nuclear and New Energy Technology (INET) of Tsinghua University. The auxiliary bearing is utilized in this system to meet particular requirements for the reactor. The main role of the auxiliary bearing is to constrain rotor displacements and also to support the rotor when the rotor drops down, which is caused by the active magnetic bearing (AMB) failure. The auxiliary bearing needs to endure huge impact, rapid angular acceleration and thermal shock. On the one hand, complex geometrical constructions and forces applied on the system bring difficulties and restrictions to establish an appropriate model to reveal the actual dynamic process. On the other hand, large volumes of data obtained from experiments show velocities and displacements of the rotor during the rotor drop process and then can indicate the actual dynamic interactions to a great extent. The research in this paper is based on the test rig of the AMB helium circulator of HTR-10. This paper aims to analyze the dynamic performance and contact forces of the rotor by processing experimental data. A measurement to estimate forces developed due to impacts of the rotor and the auxiliary bearings is presented. It is of great significance and provides certain foundation to elaborate the rotor drop process for the AMB helium circulator of HTR-10.

  19. Preparation and photoluminescence enhancement in terbium(III ternary complexes with β-diketone and monodentate auxiliary ligands

    Directory of Open Access Journals (Sweden)

    Devender Singh

    2016-12-01

    Full Text Available A series of new solid ternary complexes of terbium(III ion based on β-diketone ligand acetylacetone (acac and monodentate auxiliary ligands (aqua/urea/triphenylphosphineoxide/pyridine-N-oxide had been prepared. The structural characterizations of synthesized ternary compounds were studied by means of elemental analysis, infrared (IR, and proton nuclear magnetic resonance (NMR spectral techniques. The optical characteristics were investigated with absorption as well as photoluminescence spectroscopy. Thermal behavior of compounds was examined by TGA/DTA analysis and all metal complexes were found to have good thermal stability. The luminescence decay time of complexes were also calculated by monitoring at emission wavelength corresponding to 5D4 → 7F5 transition. A comparative inspection of the luminescent behavior of prepared ternary compounds was performed in order to determine the function of auxiliary ligands in the enhancement of luminescence intensity produced by central terbium(III ion. The color coordinates values suggested that compounds showed bright green emission in visible region in electromagnetic spectrum. Complexes producing green light could play a significant role in the fabrication of efficient light conversion molecular devices for display purposes and lightning systems.

  20. Hijacking of the Ubiquitin/Proteasome Pathway by the HIV Auxiliary Proteins

    Directory of Open Access Journals (Sweden)

    Tanja Seissler

    2017-10-01

    Full Text Available The ubiquitin-proteasome system (UPS ensures regulation of the protein pool in the cell by ubiquitination of proteins followed by their degradation by the proteasome. It plays a central role in the cell under normal physiological conditions as well as during viral infections. On the one hand, the UPS can be used by the cell to degrade viral proteins, thereby restricting the viral infection. On the other hand, it can also be subverted by the virus to its own advantage, notably to induce degradation of cellular restriction factors. This makes the UPS a central player in viral restriction and counter-restriction. In this respect, the human immunodeficiency viruses (HIV-1 and 2 represent excellent examples. Indeed, many steps of the HIV life cycle are restricted by cellular proteins, some of which are themselves components of the UPS. However, HIV itself hijacks the UPS to mediate defense against several cellular restriction factors. For example, the HIV auxiliary proteins Vif, Vpx and Vpu counteract specific restriction factors by the recruitment of cellular UPS components. In this review, we describe the interplay between HIV and the UPS to illustrate its role in the restriction of viral infections and its hijacking by viral proteins for counter-restriction.

  1. Analysis of Buoyancy Module Auxiliary Installation Technology Based on Numerical Simulation

    Science.gov (United States)

    Xu, Songsen; Jiao, Chunshuo; Ning, Meng; Dong, Sheng

    2018-04-01

    To reduce the requirement for lifting capacity and decrease the hoist cable force during the descending and laying process of a subsea production system (SPS), a buoyancy module auxiliary installation technology was proposed by loading buoyancy modules on the SPS to reduce the lifting weight. Two models are established, namely, the SPS lowering-down model and the buoyancy module floating-up model. The main study results are the following: 1) When the buoyancy module enters the water under wave condition, the amplitude of tension fluctuation is twice that when SPS enters water; 2) Under current condition, the displacement of SPS becomes three times larger because of the existence of the buoyancy module; 3) After being released, the velocity of the buoyancy module increases to a large speed rapidly and then reaches a balancing speed gradually. The buoyancy module floats up at a balancing speed and rushes out from the water at a pop-up distance; 4) In deep water, the floating-up velocity of the buoyancy module is related to its mass density and shape, and it is not related to water depth; 5) A drag parachute can reduce floating-up velocity and pop-up distance effectively. Good agreement was found between the simulation and experiment results.

  2. Characterization of an aerosol sample from the auxiliary building of the Three Mile Island reactor.

    Science.gov (United States)

    Kanapilly, G M; Stanley, J A; Newton, G J; Wong, B A; DeNee, P B

    1983-11-01

    Analyses for radioisotopic composition and dissolution characteristics were performed on an aerosol filter sample collected for a week by an air sampler located in the auxiliary building of the Three Mile Island nuclear reactor. The major radioisotopes found on the filter were 89Sr, 90Sr, 134Cs and 137Cs. Greater than 90% of both 89-90Sr and 134-137Cs dissolved within 48 hr in an in vitro test system. Scanning electron microscopic analyses showed the presence of respirable size particles as well as larger particles ranging up to 10 micron in diameter. The major matrix components were Fe, Ca, S, Mg, Al and Si. Although the radionuclides were present in a heterogeneous matrix, they were in a soluble form. This information enables a better evaluation of bioassay data and predictions of dose distribution resulting from an inhalation exposure to this aerosol. Further, the combination of techniques used in this study may be applicable to the characterization of other aerosols of unknown composition.

  3. Efficient Estimation of the Cox Model With Auxiliary Subgroup Survival Information.

    Science.gov (United States)

    Huang, Chiung-Yu; Qin, Jing; Tsai, Huei-Ting

    2016-01-01

    With the rapidly increasing availability of data in the public domain, combining information from different sources to infer about associations or differences of interest has become an emerging challenge to researchers. This paper presents a novel approach to improve efficiency in estimating the survival time distribution by synthesizing information from the individual-level data with t -year survival probabilities from external sources such as disease registries. While disease registries provide accurate and reliable overall survival statistics for the disease population, critical pieces of information that influence both choice of treatment and clinical outcomes usually are not available in the registry database. To combine with the published information, we propose to summarize the external survival information via a system of nonlinear population moments and estimate the survival time model using empirical likelihood methods. The proposed approach is more flexible than the conventional meta-analysis in the sense that it can automatically combine survival information for different subgroups and the information may be derived from different studies. Moreover, an extended estimator that allows for a different baseline risk in the aggregate data is also studied. Empirical likelihood ratio tests are proposed to examine whether the auxiliary survival information is consistent with the individual-level data. Simulation studies show that the proposed estimators yield a substantial gain in efficiency over the conventional partial likelihood approach. Two sets of data analysis are conducted to illustrate the methods and theory.

  4. Efficient KDM-CCA Secure Public-Key Encryption via Auxiliary-Input Authenticated Encryption

    Directory of Open Access Journals (Sweden)

    Shuai Han

    2017-01-01

    Full Text Available KDM[F]-CCA security of public-key encryption (PKE ensures the privacy of key-dependent messages f(sk which are closely related to the secret key sk, where f∈F, even if the adversary is allowed to make decryption queries. In this paper, we study the design of KDM-CCA secure PKE. To this end, we develop a new primitive named Auxiliary-Input Authenticated Encryption (AIAE. For AIAE, we introduce two related-key attack (RKA security notions, including IND-RKA and weak-INT-RKA. We present a generic construction of AIAE from tag-based hash proof system (HPS and one-time secure authenticated encryption (AE and give an instantiation of AIAE under the Decisional Diffie-Hellman (DDH assumption. Using AIAE as an essential building block, we give two constructions of efficient KDM-CCA secure PKE based on the DDH and the Decisional Composite Residuosity (DCR assumptions. Specifically, (i our first PKE construction is the first one achieving KDM[Faff]-CCA security for the set of affine functions and compactness of ciphertexts simultaneously. (ii Our second PKE construction is the first one achieving KDM[Fpolyd]-CCA security for the set of polynomial functions and almost compactness of ciphertexts simultaneously. Our PKE constructions are very efficient; in particular, they are pairing-free and NIZK-free.

  5. Summary of energy and particle confinement in pellet-fuelled auxiliary-heated discharges on JET

    International Nuclear Information System (INIS)

    Milora, S.L.; Baylor, L.R.; Bartlett, D.V.

    1989-01-01

    A transient improvement in plasma performance and central confinement has been observed in auxiliary heated JET limiter plasmas associated with a peaking of the plasma density profile and strong centralized heating. Suitable target plasmas for ICRF and NBI heating experiments are created by deuterium pellet injection with a multi pellet injector system developed jointly by ORNL and JETZ . Two types of discharge conditions have been observed. In the first (type A), the density profiles decay gradually during the first 1.3s of the heating pulse while maintaining an elevated density core plasma inside r/a < 0.6 superimposed on a flat density pedestal. During this phase the central electron and ion temperatures increase rapidly (up to 12 keV and 10 keV respectively in the best discharges). This results in an increase in the central plasma pressure by approximately a factor of three (β(0) 5%) above gas fuelled discharges and gives rise to sharply increased pressure gradients in the plasma. An abrupt collapse of the central electron and ion temperatures terminates the enhanced phase at 1.3 s and leads eventually to a 20% decrease in plasma stored energy. While these discharges are predicted to be stable to kink modes, they approach the first stability boundary for ballooning modes in the region of steepest pressure gradient. The pressure and q profiles inferred from transport analysis are also close to those for which intermediate-n mode instability is predicted. (author) 11 refs., 4 figs

  6. Establishment of data base files of thermodynamic data developed by OECD/NEA. Pt. 2. Thermodynamic data of Tc, U, Np, Pu and Am with auxiliary species

    International Nuclear Information System (INIS)

    Yoshida, Yasushi; Shibata, Masahiro

    2005-03-01

    Thermodynamic data base for compounds and complexes of actinides and fission products with auxiliary species specialized in modeling requirements for safety assessment of radioactive waste disposal systems are being developed by NEA TDB project of OECD/NEA. In this project, relevant data bases for compounds and complexes of U, Am, Tc, Np and Pu with auxiliary species were updated and published in 2003. JNC established the data base files available for geochemical calculation codes using these updated data. The procedure for establishment and contents of data base files are described in this report. These data base files were prepared as the formats of major geochemical codes PHREEQE, PHREEQC, EQ3/6 and Geochemist's workbench. Additionally modification for data in the thermodynamic data base files which had been already published by JNC was also done. This procedure and revised data bases are shown in the appendix of this report. (author)

  7. Total synthesis of cytochrome b562 by native chemical ligation using a removable auxiliary

    Science.gov (United States)

    Low, Donald W.; Hill, Michael G.; Carrasco, Michael R.; Kent, Stephen B. H.; Botti, Paolo

    2001-01-01

    We have completed the total chemical synthesis of cytochrome b562 and an axial ligand analogue, [SeMet7]cyt b562, by thioester-mediated chemical ligation of unprotected peptide segments. A novel auxiliary-mediated native chemical ligation that enables peptide ligation to be applied to protein sequences lacking cysteine was used. A cleavable thiol-containing auxiliary group, 1-phenyl-2-mercaptoethyl, was added to the α-amino group of one peptide segment to facilitate amide bond-forming ligation. The amine-linked 1-phenyl-2-mercaptoethyl auxiliary was stable to anhydrous hydrogen fluoride used to cleave and deprotect peptides after solid-phase peptide synthesis. Following native chemical ligation with a thioester-containing segment, the auxiliary group was cleanly removed from the newly formed amide bond by treatment with anhydrous hydrogen fluoride, yielding a full-length unmodified polypeptide product. The resulting polypeptide was reconstituted with heme and folded to form the functional protein molecule. Synthetic wild-type cyt b562 exhibited spectroscopic and electrochemical properties identical to the recombinant protein, whereas the engineered [SeMet7]cyt b562 analogue protein was spectroscopically and functionally distinct, with a reduction potential shifted by ≈45 mV. The use of the 1-phenyl-2-mercaptoethyl removable auxiliary reported here will greatly expand the applicability of total protein synthesis by native chemical ligation of unprotected peptide segments. PMID:11390992

  8. Awareness of biomedical waste management among dental professionals and auxiliary staff in Amritsar, India.

    Science.gov (United States)

    Narang, Ramandeep S; Manchanda, Adesh; Singh, Simarpreet; Verma, Nitin; Padda, Sarfaraz

    2012-12-01

    The aim of this study was to determine awareness of biomedical waste (BMW) management policies and practices among dental professionals and auxiliary staff in a dental hospital/clinics in Amritsar, India, to inform the development of future policies for effective implementation of BMW rules. The study involved 160 staff members at the Amritsar hospital/clinics (80 dentists and 80 auxiliary staff) to whom a questionnaire was distributed regarding policies, practices and awareness relating to BMW. The questionnaire was first piloted. Completed questionnaires were returned anonymously. The resulting data were statistically tested using the chi-square test for differences between the dentists and auxiliary staff. In respect of BMW management policies, there was a highly significant difference in the responses of the dentists, whose answers suggested far greater knowledge than that of the auxiliaries (Pmanagement practices, the dentists were significantly more aware (Pwaste collection in the hospital and the disposal of various items into different colour-coded bags. As for employee education/awareness, there was a significant difference (Pmanagement among dental auxiliary staff in the dental hospital/clinics in Amritsar and a lack of awareness of some aspects among dentists who work in the hospital/clinics. The results provide the hospital authorities with data upon which they can develop a strategy for improving BMW management.

  9. Decision making by auxiliary nurses to assess postpartum bleeding in a Dominican Republic maternity ward.

    Science.gov (United States)

    Foster, Jennifer; Regueira, Yadira; Heath, AnneMarie

    2006-01-01

    To understand the process of decision making by auxiliary nurses regarding postpartum bleeding among women in the Dominican Republic. An ethnographic qualitative design of semistructured interviews and participant observation. Twenty four auxiliary nurses on a maternity unit of a referral hospital in the Dominican Republic. Auxiliary nurses use specific criteria and logic to decide if postpartum maternal bleeding is excessive. However, systematic postpartum assessments are not routinely conducted on every woman. A decision tree that traces how auxiliary nurses evaluate postpartum bleeding indicates that they have knowledge of contemporary obstetric nursing care, but the organization of care delivery is not structured for them to apply it routinely. A collaboration of U.S. midwives and Dominican nurses will build on the assets of the auxiliary nurses. Rather than focusing the content of educational conferences on current knowledge of labor and delivery, an important next step is modeling woman- and family-centered care. The U.S. midwives and Dominican nurses are committed to finding empowering and effective ways to improve maternity care.

  10. Environmental practices of the auxiliary companies to the Spanish automobile industry

    Science.gov (United States)

    González-Torre, Pilar L.; González, Beatriz A.; Gupta, Surendra M.

    2005-11-01

    The automobile manufacturing industry plays a very important role in a country's economy. The importance of automobile manufacturing industry lies in its sheer size and complexity in terms of the direct and indirect influence it commands across many other industries. While millions of people are employed in the automobile manufacturing industry, it is estimated that more than two and half times that number are employed in the auxiliary companies that supply parts to the automobile manufacturing companies. The auxiliary companies represent a group of businesses of various sizes, types, and geographical locations, producing a vast variety of products ranging from the very simple to the extremely intricate. In this study, the current environmental practices of management in the core Spanish auxiliary companies that do business with the automobile manufacturing industry (and thus form a large part of the automobile manufacturing industry's supply chain) are investigated. We show that while automobile manufacturing companies are under scrutiny to become more and more environmentally friendly, not only at their manufacturing stage but also at their products' useful and EOL stages, there appears to be no such burden on the auxiliary companies. Our conclusion is based on an elaborate survey conducted during the fall of 2004 of Spanish auxiliary companies with questions about the characteristics, environmental practices and reverse logistics related activities carried out by the companies.

  11. Evaluation of Flood Level under Main Feedwater Line Break Accident using GOTHIC Computer Code and Analytical Calculation by ANSI 56.11

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Keon Yeop; Park, Jae Won; Jeon, Woo Jae [FNC Technology Co., Yongin (Korea, Republic of)

    2016-10-15

    The design basis internal flooding is caused by postulated pipe ruptures or component failures. The flooding can cause failure of safety-related equipment and affect the integrity of the structure. Though large diameter pipe rupture is significant in flooding analysis, split breaks should also be considered with consideration of a spectrum of pipe break size and power level. The pipe rupture analysis should be based on the most severe single active failure. For enveloping spectrum of pipe break condition, flood relief paths are necessary and passive flood protection without operating action, basically, shall be applied. In this study, the evaluation of flood level in case of Main Feedwater Line Break (MFLB) was performed by using GOTHIC computer program and hand calculation. The flooding analyses were performed by hand calculation and GOTHIC analysis for an assumed MFLB condition. The calculated flood levels were 0.823m and 0.691m for hand calculation and GOTHIC analysis, respectively. In comparison to the GOTHIC analysis, hand calculation showed conservative results. However, in actual flood protection design, margin for uncertainty shall be considered, in order to reflect the outflow reducing effect due to vortex and intake of air.

  12. Evaluation of Flood Level under Main Feedwater Line Break Accident using GOTHIC Computer Code and Analytical Calculation by ANSI 56.11

    International Nuclear Information System (INIS)

    Kim, Keon Yeop; Park, Jae Won; Jeon, Woo Jae

    2016-01-01

    The design basis internal flooding is caused by postulated pipe ruptures or component failures. The flooding can cause failure of safety-related equipment and affect the integrity of the structure. Though large diameter pipe rupture is significant in flooding analysis, split breaks should also be considered with consideration of a spectrum of pipe break size and power level. The pipe rupture analysis should be based on the most severe single active failure. For enveloping spectrum of pipe break condition, flood relief paths are necessary and passive flood protection without operating action, basically, shall be applied. In this study, the evaluation of flood level in case of Main Feedwater Line Break (MFLB) was performed by using GOTHIC computer program and hand calculation. The flooding analyses were performed by hand calculation and GOTHIC analysis for an assumed MFLB condition. The calculated flood levels were 0.823m and 0.691m for hand calculation and GOTHIC analysis, respectively. In comparison to the GOTHIC analysis, hand calculation showed conservative results. However, in actual flood protection design, margin for uncertainty shall be considered, in order to reflect the outflow reducing effect due to vortex and intake of air

  13. 30 CFR 57.22208 - Auxiliary fans (I-A, II-A, III, and V-A mines).

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Auxiliary fans (I-A, II-A, III, and V-A mines... fans (I-A, II-A, III, and V-A mines). (a) Auxiliary fans, except fans used in shops and other areas... applicable requirements of 30 CFR part 18, and be operated so that recirculation is minimized. Auxiliary fans...

  14. 10 CFR Appendix E to Part 50 - Emergency Planning and Preparedness for Production and Utilization Facilities

    Science.gov (United States)

    2010-01-01

    ..., licensees would have the opportunity to consider accident management strategies, supervised instruction... pressures, main feedwater flows, and auxiliary and emergency feedwater flows; (3) Safety injection: High- and low-pressure safety injection flows, safety injection flows (Westinghouse), and borated water...

  15. Treatment for chronic daily headache by using auxiliary and alternative methods

    Directory of Open Access Journals (Sweden)

    V. A. Golovacheva

    2015-01-01

    Full Text Available Chronic daily headache (CDH is one of the top 10 causes of adult disability and one of the 5 most common causes of female disability. To treat patients with CDH is one of the most difficult tasks in neurological practice. Difficulties in managing patients with CHD are associated with the high prevalence of comorbid mental disorders, analgesic abuse, pain syndromes at another site, and misconceptions of a patient about his/her disease. A combination of drug and non-drug therapies is the mainstay of the current approach to treating patients with CDH. Standard, alternative, and auxiliary therapies are identified. The paper describes different types of current auxiliary and alternative therapy used in the world’s leading headache centers and clinics. It describes experience with cerebrolysin used as auxiliary and alternative pharmacotherapies for CDH.

  16. On adjustment for auxiliary covariates in additive hazard models for the analysis of randomized experiments

    DEFF Research Database (Denmark)

    Vansteelandt, S.; Martinussen, Torben; Tchetgen, E. J Tchetgen

    2014-01-01

    We consider additive hazard models (Aalen, 1989) for the effect of a randomized treatment on a survival outcome, adjusting for auxiliary baseline covariates. We demonstrate that the Aalen least-squares estimator of the treatment effect parameter is asymptotically unbiased, even when the hazard...... that, in view of its robustness against model misspecification, Aalen least-squares estimation is attractive for evaluating treatment effects on a survival outcome in randomized experiments, and the primary reasons to consider baseline covariate adjustment in such settings could be interest in subgroup......'s dependence on time or on the auxiliary covariates is misspecified, and even away from the null hypothesis of no treatment effect. We furthermore show that adjustment for auxiliary baseline covariates does not change the asymptotic variance of the estimator of the effect of a randomized treatment. We conclude...

  17. Estimation Method for Turn-off Collector Voltage of IGBTs Using Emitter-auxiliary Inductor

    DEFF Research Database (Denmark)

    Luo, Haoze; Iannuzzo, Francesco; Blaabjerg, Frede

    2016-01-01

    This paper presents a method for estimating the instantaneous turn-off collector voltage of high-power IGBT modules. Because of the parasitic inductors in circuit, the fast turn-off collector current usually leads to a voltage overshoot on IGBT modules during the turn-off transition. In terms...... of high-voltage and high-power IGBT module, there exists an emitter-auxiliary inductor between the power emitter and Kelvin emitter. The same variable dic/dt during turn-off transition will also induce a measurable voltage veE across the emitter-auxiliary inductor LeE. As a result, the hazardous turn......-off peak collector voltage can be reflected by the induced νeE in the case of fixed commutation loop inductors and emitter auxiliary inductor. Finally, a double pulse test platform is used to validate the effectiveness of estimation method. The estimation curves of turn-off collector voltage...

  18. The use of auxiliary devices during irrigation to increase the cleaning ability of a chelating agent

    Directory of Open Access Journals (Sweden)

    Marina Carvalho Prado

    2017-05-01

    Full Text Available Objectives This study investigated the cleaning ability of ultrasonically activated irrigation (UAI and a novel activation system with reciprocating motion (EC, EasyClean, Easy Equipamentos Odontológicos when used with a relatively new chelating agent (QMix, Dentsply. In addition, the effect of QMix solution when used for a shorter (1 minute and a longer application time (3 minutes was investigated. Materials and Methods Fifty permanent human teeth were prepared with K3 rotary system and 6% sodium hypochlorite. Samples were randomly assigned to five groups (n = 10 according to the final irrigation protocol: G1, negative control (distilled water; G2, positive control (QMix 1 minute; G3, QMix 1 minute/UAI; G4, QMix 1 minute/EC; G5, QMix 3 minutes. Subsequently the teeth were prepared and three photomicrographs were obtained in each root third of root walls, by scanning electron microscopy. Two blinded and pre-calibrated examiners evaluated the images using a four-category scoring system. Data were statistically analyzed using Kruskal-Wallis and Dunn tests (p < 0.05. Results There were differences among groups (p < 0.05. UAI showed better cleaning ability than EC (p < 0.05. There were improvements when QMix was used with auxiliary devices in comparison with conventional irrigation (p < 0.05. Conventional irrigation for 3 minutes presented significantly better results than its use for 1 minute (p < 0.05. Conclusions QMix should be used for 1 minute when it is used with UAI, since this final irrigation protocol showed the best performance and also allowed clinical optimization of this procedure.

  19. The sensitivity of auxiliary examinations in different stages of sporadic Creutzfeldt-Jakob disease

    Directory of Open Access Journals (Sweden)

    Jiao-jiao JIANG

    2017-06-01

    Full Text Available Objective To analyze the sensitivity of auxiliary examinations in different periods of sporadic Creutzfeldt-Jakob disease (sCJD. Methods The clinical data of 53 sCJD patients were retrospectively analyzed including the different stages of skull diffusion-weighted magnetic resonance imaging (DWI, 24-hour ambulatory electroencephalogram (EEG, 18F-FDG PET/CT (PET-CT and cerebrospinal fluid 14-3-3 protein. When calculating the sensitivity of an auxiliary examination, the diagnostic criteria were defined by combining the specific clinical manifestations with two or more positive results of other auxiliary examinations. Results There were 24, 53 and 22 sCJD patients, respectively, met the criterion of early (E, middle (M and later (L stage of disease (some patients fit 2 or 3 stages. The sensitivity of DWI (E: 58.3%, M: 85.4%, L: 94.7%, EEG (E: 45.8%, M: 62.7%, L: 77.8%, 14-3-3 protein in cerebrospinal fluid (E: 11.1%, M: 52.9% and PET-CT (E: 80%, M: 100% increased gradually with disease progression. The sensitivity of PET-CT was higher than the other auxiliary examinations for E and M stages; no PET-CT was conducted in L stage. High signal regions mainly distributed in the cortex in E and M stages, but in L stage, no significant difference was found on the distribution of high signal regions between cortex and basal ganglia. Conclusions The sensitivities of the auxiliary examinations were different for sCJD patients in different stages. Reexaminations in different periods may improve the sensitivity for sCJD diagnosis. The sensitivity of PET-CT was high, and the combination of PET-CT and other auxiliary examinations may play a key role in the diagnosis of sCJD. DOI: 10.11855/j.issn.0577-7402.2017.05.15

  20. A new auxiliary equation and exact travelling wave solutions of nonlinear equations

    International Nuclear Information System (INIS)

    Sirendaoreji

    2006-01-01

    A new auxiliary ordinary differential equation and its solutions are used for constructing exact travelling wave solutions of nonlinear partial differential equations in a unified way. The main idea of this method is to take full advantage of the auxiliary equation which has more new exact solutions. More new exact travelling wave solutions are obtained for the quadratic nonlinear Klein-Gordon equation, the combined KdV and mKdV equation, the sine-Gordon equation and the Whitham-Broer-Kaup equations