Analysis on Single Point Vulnerabilities of Plant Control System

International Nuclear Information System (INIS)

Chi, Moon Goo; Lee, Eun Chan; Bae, Yeon Kyoung

2011-01-01

The Plant Control System (PCS) is a system that controls pumps, valves, dampers, etc. in nuclear power plants with an OPR-1000 design. When there is a failure or spurious actuation of the critical components in the PCS, it can result in unexpected plant trips or transients. From this viewpoint, single point vulnerabilities are evaluated in detail using failure mode effect analyses (FMEA) and fault tree analyses (FTA). This evaluation demonstrates that the PCS has many vulnerable components and the analysis results are provided for OPR-1000 plants for reliability improvements that can reduce their vulnerabilities

Analysis on Single Point Vulnerabilities of Plant Control System

Energy Technology Data Exchange (ETDEWEB)

Chi, Moon Goo; Lee, Eun Chan; Bae, Yeon Kyoung [Korea Hydro and Nuclear Power Co., Daejeon (Korea, Republic of)

2011-08-15

The Plant Control System (PCS) is a system that controls pumps, valves, dampers, etc. in nuclear power plants with an OPR-1000 design. When there is a failure or spurious actuation of the critical components in the PCS, it can result in unexpected plant trips or transients. From this viewpoint, single point vulnerabilities are evaluated in detail using failure mode effect analyses (FMEA) and fault tree analyses (FTA). This evaluation demonstrates that the PCS has many vulnerable components and the analysis results are provided for OPR-1000 plants for reliability improvements that can reduce their vulnerabilities.

Distributed and hierarchical control techniques for large-scale power plant systems

International Nuclear Information System (INIS)

Raju, G.V.S.; Kisner, R.A.

1985-08-01

In large-scale systems, integrated and coordinated control functions are required to maximize plant availability, to allow maneuverability through various power levels, and to meet externally imposed regulatory limitations. Nuclear power plants are large-scale systems. Prime subsystems are those that contribute directly to the behavior of the plant's ultimate output. The prime subsystems in a nuclear power plant include reactor, primary and intermediate heat transport, steam generator, turbine generator, and feedwater system. This paper describes and discusses the continuous-variable control system developed to supervise prime plant subsystems for optimal control and coordination

Control room habitability in Spanish Nuclear Power Plants

International Nuclear Information System (INIS)

Mediavilla, F.; Sierra, J. J.

2007-01-01

Since the NRC published in 2003 the Generic Letter 2003-01 Control room Habitability and the Regulatory guide 1.197 Demonstrating Control Room Envelope Integrity at Nuclear Power Reactors, where it is emphasized the importance of verifying the control room habitability by means of alternative methods, Spanish Nuclear Power Plants are undertaking the different necessary activities to fulfill the requirements of the regulatory commission. This paper describes the main mechanisms included in NEI 99-03 Nuclear Energy Institute publication Control room Habitability Assessment guidance, to demonstrate and maintain Control room Habitability. In addition, in this article it Ds shown the theoretical principle of the test used to quantify air in-leakage in a control room envelope by using tracer gas techniques. The necessary activities to perform the initial in leakage testing are also put forward. Since 2006 Tecnatom, S. A. has performed the baseline testing in four Spanish Units, all of them with successful results. The rest of the Plants are scheduled to perform the tests during the second half of this year. Finally, this document summarises the more important aspects to be taken into account in the development of control room Habitability Programs, which are expected to ensure the integral maintenance of the Control room Envelope during the life a plant. (Author)

Development of model reference adaptive control theory for electric power plant control applications

Energy Technology Data Exchange (ETDEWEB)

Mabius, L.E.

1982-09-15

The scope of this effort includes the theoretical development of a multi-input, multi-output (MIMO) Model Reference Control (MRC) algorithm, (i.e., model following control law), Model Reference Adaptive Control (MRAC) algorithm and the formulation of a nonlinear model of a typical electric power plant. Previous single-input, single-output MRAC algorithm designs have been generalized to MIMO MRAC designs using the MIMO MRC algorithm. This MRC algorithm, which has been developed using Command Generator Tracker methodologies, represents the steady state behavior (in the adaptive sense) of the MRAC algorithm. The MRC algorithm is a fundamental component in the MRAC design and stability analysis. An enhanced MRC algorithm, which has been developed for systems with more controls than regulated outputs, alleviates the MRC stability constraint of stable plant transmission zeroes. The nonlinear power plant model is based on the Cromby model with the addition of a governor valve management algorithm, turbine dynamics and turbine interactions with extraction flows. An application of the MRC algorithm to a linearization of this model demonstrates its applicability to power plant systems. In particular, the generated power changes at 7% per minute while throttle pressure and temperature, reheat temperature and drum level are held constant with a reasonable level of control. The enhanced algorithm reduces significantly control fluctuations without modifying the output response.

Distributed Low-Complexity Controller for Wind Power Plant in Derated Operation

DEFF Research Database (Denmark)

Biegel, Benjamin; Madjidian, Daria; Spudic, Vedrana

2013-01-01

We consider a wind power plant of megawatt wind turbines operating in derated mode. When operating in this mode, the wind power plant controller is free to distribute power set-points to the individual turbines, as long as the total power demand is met. In this work, we design a controller...... that exploits this freedom to reduce the fatigue on the turbines in the wind power plant. We show that the controller can be designed in a decentralized manner, such that each wind turbine is equipped with a local low-complexity controller relying only on few measurements and little communication. As a basis...... for the controller design, a linear wind turbine model is constructed and verified in an operational wind power plant of megawatt turbines. Due to limitations of the wind power plant available for tests, it is not possible to implement the developed controller; instead the final distributed controller is evaluated...

Wind Plant Power Optimization and Control under Uncertainty

Science.gov (United States)

Jha, Pankaj; Ulker, Demet; Hutchings, Kyle; Oxley, Gregory

2017-11-01

The development of optimized cooperative wind plant control involves the coordinated operation of individual turbines co-located within a wind plant to improve the overall power production. This is typically achieved by manipulating the trajectory and intensity of wake interactions between nearby turbines, thereby reducing wake losses. However, there are various types of uncertainties involved, such as turbulent inflow and microscale and turbine model input parameters. In a recent NREL-Envision collaboration, a controller that performs wake steering was designed and implemented for the Longyuan Rudong offshore wind plant in Jiangsu, China. The Rudong site contains 25 Envision EN136-4 MW turbines, of which a subset was selected for the field test campaign consisting of the front two rows for the northeasterly wind direction. In the first row, a turbine was selected as the reference turbine, providing comparison power data, while another was selected as the controlled turbine. This controlled turbine wakes three different turbines in the second row depending on the wind direction. A yaw misalignment strategy was designed using Envision's GWCFD, a multi-fidelity plant-scale CFD tool based on SOWFA with a generalized actuator disc (GAD) turbine model, which, in turn, was used to tune NREL's FLORIS model used for wake steering and yaw control optimization. The presentation will account for some associated uncertainties, such as those in atmospheric turbulence and wake profile.

Monitor and control device in a nuclear power plant

International Nuclear Information System (INIS)

Neda, Toshikatsu.

1980-01-01

Purpose: To facilitate and ensure monitor and control, as well as improve the operation efficiency and save man power, by render the operation automatic utilizing a process computer and centralizing the monitor and control functions. Constitution: All of the operations from the start up to stop in a nuclear power plant are conducted by way of a monitor and control board. The process data for the nuclear power plant are read into the process computer and displayed on a CRT display. Controls are carried out respectively for the control rod on a control rod panel, for the feedwater rate on a feedwater control panel, for the recycling flow rate on a recycling control panel and for the turbine generator on a turbine control panel. When the operation is conducted by an automatic console, operation signals from the console are imputted into the process computer and the state of the power plant is monitored and automatic operation is carried out based on the operation signals and from signals from each of the panels. (Moriyama, K.)

Efectividad del ajuste oclusal en pacientes de alta de ortodoncia Effectiveness of occlusal adjustment in patients with orthodontic discharge

Directory of Open Access Journals (Sweden)

Amitis Ruiseco Palomares

2006-12-01

Full Text Available El tratamiento ortodóncico tiene como objetivo llegar a un punto óptimo oclusal, estético y funcional. Con frecuencia son introducidas interferencias que a largo plazo pueden provocar disturbios del sistema estomatognático; una técnica de ajuste oclusal puede ser útil para estabilizar la función y garantizar la salud de este. Se seleccionó una muestra constituida por 14 pacientes con más de 6 meses de alta ortodóncica, diagnosticados con interferencias oclusales en una investigación previa. A cada uno de ellos se les realizó un ajuste oclusal por tallado selectivo, y pasados 6 meses, se procedió a la evaluación de la oclusión para la detección de posibles interferencias, analizándolas durante los diferentes movimientos mandibulares, tanto en las áreas de trabajo como de no trabajo, así como por grupos dentarios. Para ello se les realizó el análisis funcional de la oclusión en boca, completándose el estudio con el montaje de los modelos en el articulador semiajustable Dentatus ARL mediante el uso del arco facial. El estudio reveló que a la mayoría de los pacientes se les reestableció una oclusión funcional, lo que demuestra la efectividad del tratamiento, que el mayor porcentaje de interferencias después del ajuste fueron en el área de no trabajo y durante los movimientos de lateralidad, además de que el grupo molar fue el de mayor cantidad de interferencias, tanto antes como después del tratamiento oclusal.The orthodontic treatment is aimed at reaching an occlusal, aesthetic, and functional optimal point. The frequently introduced interferences may cause disorders of the stomathognatic system, and an occlusal adjustment technique may be useful to stabilize the function and to gurantee its health. A sample of 14 patients with more than 6 months of orthodontic discharge that were diagnosed occlusal interferences in a previous research was selected. Each of them underwent occlusal adjustment by selective grinding, and

Solar field control for desalination plants

Energy Technology Data Exchange (ETDEWEB)

Roca, Lidia [Convenio Universidad de Almeria, Plataforma Solar de Almeria, Ctra. Senes s/n, 04200 Tabernas, Almeria (Spain); Berenguel, Manuel [Universidad de Almeria, Dpto. Lenguajes y Computacion, Ctra. Sacramento s/n, 04120 Almeria (Spain); Yebra, Luis; Alarcon-Padilla, Diego C. [CIEMAT, Plataforma Solar de Almeria, Ctra. Senes s/n, 04200 Tabernas, Almeria (Spain)

2008-09-15

This paper presents the development and application of a feedback linearization control strategy for a solar collector field supplying process heat to a multi-effect seawater distillation plant. Since one objective is to use as much as possible the solar resource, control techniques can be used to produce the maximum heat process in the solar field. The main purpose of the controller presented in this paper is to manipulate the water flow rate to maintain an outlet-inlet temperature gradient in the collectors, thereby ensuring continuous process heating, or in other words, continuous production of fresh water in spite of disturbances. The dynamic behaviour of this solar field was approximated by a simplified lumped-parameters nonlinear model based on differential equations, validated with real data and used in the feedback linearization control design. Experimental results in the seawater desalination plant at the Plataforma Solar de Almeria (Spain) show good agreement of the model and real data despite the approximations included. Moreover, by using feedback linearization control it is possible to track a constant gradient temperature reference in the solar field with good results. (author)

Plant response-based sensing for control starategies in sustainable greenhouse production

International Nuclear Information System (INIS)

Kacira, M.; Sase, S.; Okushima, L.; Ling, P.P.

2005-01-01

The effect of environmental variability is one of the major concerns in experimental design for both research in plant systems and greenhouse plant production. Microclimates surrounding plants are not usually uniform. Therefore, many samples and sensors are required to obtain a true representation of the plant population. A plant monitoring system capable of reducing the required number of samples by reducing environmental variability would be more advantageous. To better understand plant-environment interaction, it is essential to study plants, microclimate surrounding the plants and the growth media. To achieve this, the monitoring system must be equipped with proper instrumentation. To achieve proper management practices and sustainable greenhouse production, it is essential first to understand plants and their interactions with their surroundings and then establish plant response-based sensing and control strategies for greenhouse processes. Therefore, an effort was conducted to review and discuss current sensing and control strategies in greenhouse research and plant production and provide recommendations on plant response-based sensing and control strategies for sustainable greenhouse production

Control oriented concentrating solar power (CSP) plant model and its applications

Science.gov (United States)

Luo, Qi

Solar receivers in concentrating solar thermal power plants (CSP) undergo over 10,000 start-ups and shutdowns, and over 25,000 rapid rate of change in temperature on receivers due to cloud transients resulting in performance degradation and material fatigue in their expected lifetime of over 30 years. The research proposes to develop a three-level controller that uses multi-input-multi-output (MIMO) control technology to minimize the effect of these disturbances, improve plant performance, and extend plant life. The controller can be readily installed on any vendor supplied state-of-the-art control hardware. We propose a three-level controller architecture using multi-input-multi-output (MIMO) control for CSP plants that can be implemented on existing plants to improve performance, reliability, and extend the life of the plant. This architecture optimizes the performance on multiple time scalesreactive level (regulation to temperature set points), tactical level (adaptation of temperature set points), and strategic level (trading off fatigue life due to thermal cycling and current production). This controller unique to CSP plants operating at temperatures greater than 550 °C, will make CSPs competitive with conventional power plants and contribute significantly towards the Sunshot goal of 0.06/kWh(e), while responding with agility to both market dynamics and changes in solar irradiance such as due to passing clouds. Moreover, our development of control software with performance guarantees will avoid early stage failures and permit smooth grid integration of the CSP power plants. The proposed controller can be implemented with existing control hardware infrastructure with little or no additional equipment. In the thesis, we demonstrate a dynamics model of CSP, of which different components are modelled with different time scales. We also show a real time control strategy of CSP control oriented model in steady state. Furthermore, we shown different controllers

Reactive power control with CHP plants - A demonstration

DEFF Research Database (Denmark)

Nyeng, Preben; Østergaard, Jacob; Andersen, Claus A.

2010-01-01

power rating of 7.3 MW on two synchronous generators. A closed-loop control is implemented, that remote controls the CHP plant to achieve a certain reactive power flow in a near-by substation. The solution communicates with the grid operator’s existing SCADA system to obtain measurements from...... lines to underground cables has changed the reactive power balance, and third, the TSO has introduced restrictions in the allowed exchange of reactive power between the transmission system and distribution grids (known as the Mvar-arrangement). The demonstration includes a CHP plant with an electric......In this project the potential for ancillary services provision by distributed energy resources is investigated. Specifically, the provision of reactive power control by combined heat and power plants is examined, and the application of the new standard for DER communication systems, IEC 61850...

Environmental radioactive contamination and its control for nuclear power plants

International Nuclear Information System (INIS)

Shi Zhongqi; Qu Jingyuan; Cui Yongli

1998-01-01

The environmental radioactive releases and exposure to human being due to operation of nuclear power plants in the world and in China, environmental contamination and consequences caused by severe nuclear power plant accidents in the history, control of the radioactive contamination in China, and some nuclear laws on the radioactive contamination control established by international organizations and USA etc. are described according to literature investigation and research. Some problems and comments in radioactive contamination control for nuclear power plants in China are presented. Therefore, perfecting laws and regulations and enhancing surveillances on the contamination control are recommended

Voltage Control in Wind Power Plants with Doubly Fed Generators

DEFF Research Database (Denmark)

Garcia, Jorge Martinez

In this work, the process of designing a wind power plant composed of; doubly fed induction generators, a static compensator unit, mechanically switched capacitors and on-load tap changer, for voltage control is shown. The selected control structure is based on a decentralized system, since...... supplied by the doubly fed induction generator wind turbines is overcome by installing a reactive power compensator, i.e. a static compensator unit, which is coordinated with the plant control by a specific dispatcher. This dispatcher is set according to the result of the wind power plant load flow....... To release the operation of the converters during steady-state disturbances, mechanically switched capacitors are installed in the wind power plant, which due to their characteristics, they are appropriate for permanent disturbances compensation. The mechanically switched capacitors are controlled to allow...

A Plant Control Technology Using Reinforcement Learning Method with Automatic Reward Adjustment

Science.gov (United States)

Eguchi, Toru; Sekiai, Takaaki; Yamada, Akihiro; Shimizu, Satoru; Fukai, Masayuki

A control technology using Reinforcement Learning (RL) and Radial Basis Function (RBF) Network has been developed to reduce environmental load substances exhausted from power and industrial plants. This technology consists of the statistic model using RBF Network, which estimates characteristics of plants with respect to environmental load substances, and RL agent, which learns the control logic for the plants using the statistic model. In this technology, it is necessary to design an appropriate reward function given to the agent immediately according to operation conditions and control goals to control plants flexibly. Therefore, we propose an automatic reward adjusting method of RL for plant control. This method adjusts the reward function automatically using information of the statistic model obtained in its learning process. In the simulations, it is confirmed that the proposed method can adjust the reward function adaptively for several test functions, and executes robust control toward the thermal power plant considering the change of operation conditions and control goals.

Transient behaviour and control of the ACACIA plant

International Nuclear Information System (INIS)

Kikstra, J.F.; Heek, A.I. van; Verkooijen, A.H.M.

2001-01-01

This article deals with dynamic modelling and control of the ACACIA plant. A one-dimensional flow model describing the helium flow and the two-phase water flow is used through the whole plant, with different source terms in different pieces of equipment. A stage-by-stage model is produced for the radial compressor and axial turbine. Other models include the recuperator, water/helium heat exchangers, a natural convection evaporator, valves, etc. The models have been checked by comparison of the transient behavior with several other models, e.g. produced in RELAP. The dynamic behavior of this plant is analysed and a control structure is designed. First the requirements and options for a control system design are investigated. A number of possible control valve positions in the flowsheet are tested with transients in order to make an argued choice. The model is subsequently used to determine the optimal working conditions for different heat and power demands, these are used as set-points for the control system. Then the interaction between manipulated and controlled variables is mapped and based on this information a choice for coupling them in decentralised feedback control loops is made. This control structure is then tuned and tested. It can be concluded that both heat and power demand can be followed with acceptable performance over a wide range. (author)

Optimization control of LNG regasification plant using Model Predictive Control

Science.gov (United States)

Wahid, A.; Adicandra, F. F.

2018-03-01

Optimization of liquified natural gas (LNG) regasification plant is important to minimize costs, especially operational costs. Therefore, it is important to choose optimum LNG regasification plant design and maintaining the optimum operating conditions through the implementation of model predictive control (MPC). Optimal tuning parameter for MPC such as P (prediction horizon), M (control of the horizon) and T (sampling time) are achieved by using fine-tuning method. The optimal criterion for design is the minimum amount of energy used and for control is integral of square error (ISE). As a result, the optimum design is scheme 2 which is developed by Devold with an energy savings of 40%. To maintain the optimum conditions, required MPC with P, M and T as follows: tank storage pressure: 90, 2, 1; product pressure: 95, 2, 1; temperature vaporizer: 65, 2, 2; and temperature heater: 35, 6, 5, with ISE value at set point tracking respectively 0.99, 1792.78, 34.89 and 7.54, or improvement of control performance respectively 4.6%, 63.5%, 3.1% and 58.2% compared to PI controller performance. The energy savings that MPC controllers can make when there is a disturbance in temperature rise 1°C of sea water is 0.02 MW.

Aspects regarding computer control of 15 N separation plant

International Nuclear Information System (INIS)

Kaucsar, M.; Cosma, V.; Axente, D.; Baldea, A.; Bendea, H.; Bunea, V

2001-01-01

In order to improve the efficiency of a separation plant the whole process must be automatically controlled. The plant has a single output - the isotopic product. This output is characterized by a complex function, which involves qualitative or/and quantitative properties of the product. There are two important inputs into the system, namely: the amount of the substances and compounds which supply the plant and the electric power consumption. Our first aim is to reduce the input/output ratio of the separation plant. On the other hand, by applying this automatic control system we can reduce the operating personnel also. The isotopic product is sampled and analyzed using a dedicated mass spectrometer. An overall closed loop through the separation plant including this mass spectrometer could be very efficient, but the theoretical analysis is too complex and it is very difficult to realize it in practice. Therefore, multiple local control loops are preferred to apply for each product correlated parameter. Between these parameters there are complex interdependencies, governed by differential equations. The computer is equipped with standard input/output hardware, but in order to use it in the complex feedback loops, extra input/output hardware must be added, namely, dedicated input/output module cards. Depending on the operating principle of the detectors and actuators the signals involved in the whole system are analog and digital. The majority of the sensors and transducers generates analog signals and only a few of them have digital output. The last case is typical for transducers specialized mainly for detecting the level of a parameter. Actuators also need analog or digital control signals, corresponding to their operating principles. The computer control of isotopic plant has a great advantage of being very flexible in implementing adequate control software with operator friendly interfacing routines. (authors)

Benchmarking of Control Strategies for Wastewater Treatment Plants

DEFF Research Database (Denmark)

Wastewater treatment plants are large non-linear systems subject to large perturbations in wastewater flow rate, load and composition. Nevertheless these plants have to be operated continuously, meeting stricter and stricter regulations. Many control strategies have been proposed in the literature...

Recent experience in water chemistry control at PWR plants

International Nuclear Information System (INIS)

Makino, Ichiro

2000-01-01

At present, 23 units of PWRs are under operation in all of Japan, among which 11 units are operated by the Kansai Electric Power Co., Inc. (KEP). Plant availability in KEP's PWRs has been improved for the past several years, through their successive stable operation. Recently, a focus is given not only to maintenance of plant integrity, but also to preventive maintenance and water chemistry control. Various measures have been carried out to enhance exposure reduction of the primary water chemistry control in the Japanese PWRs. As a result, environmental dose equivalent rate is decreasing. A secondary system is now under excellent condition because of application of diversified measures for prevention of the SG tube corrosion. At present, the water chemistry control measures which take into account of efficient chemistry control and plant aging deterioration prevention, are being examined to use for both primary and secondary systems in Japanese PWRs, to further enhance their plant integrity and availability. And, some of them are currently being actually applied. (G.K.)

Automated systems for control of technological processes at nuclear power plants and their use in putting the plant into operation

International Nuclear Information System (INIS)

Majtan, L.

1987-01-01

The systems of testing and control of technological processes in WWER-440 units in nuclear power plants which have so far been constructed in Czechoslovakia have been based on the conceptual principles and hardware used in the USSR. For the Mochovce nuclear power plant an automated process control system is to be introduced which proceeds from experiences gained with new Czechoslovak conventional power plants with 200 MW units. The control system consists of two levels: unit control and the control of the whole power plant the unit control consists of the DERIS-900 decentralized control system and the SM 1804 microcomputer and SM 1420 minicomputer based information and control system. A data processing system based on the SM 52/11.M1 minicomputer system will be used for power plant start-up and commissioning. (Z.M.). 2 figs., 4 refs

A minimum attention control center for nuclear power plants

International Nuclear Information System (INIS)

Meijer, C.H.

1986-01-01

Control Centers for Nuclear Power Plants have characteristically been designed for maximum attention by the operating staffs of these plants. Consequently, the monitoring, control and diagnostics oriented cognitive activities by these staffs, were mostly ''data-driven'' in nature. This paper addresses a control center concept, under development by Combustion Engineering, that promotes a more ''information-driven'' cognitive interaction process between the operator and the plant. The more ''intelligent'' and therefore less attentive nature of such interactive process utilizes computer implemented cognitive engineered algorithms. The underlying structure of these algorithms is based upon the Critical Function/Success Path monitoring principle. The paper highlights a typical implementation of the minimum attention concept for the handling of unfamiliar safety related events. (author)

Model Predictive Control of Integrated Gasification Combined Cycle Power Plants

Energy Technology Data Exchange (ETDEWEB)

B. Wayne Bequette; Priyadarshi Mahapatra

2010-08-31

The primary project objectives were to understand how the process design of an integrated gasification combined cycle (IGCC) power plant affects the dynamic operability and controllability of the process. Steady-state and dynamic simulation models were developed to predict the process behavior during typical transients that occur in plant operation. Advanced control strategies were developed to improve the ability of the process to follow changes in the power load demand, and to improve performance during transitions between power levels. Another objective of the proposed work was to educate graduate and undergraduate students in the application of process systems and control to coal technology. Educational materials were developed for use in engineering courses to further broaden this exposure to many students. ASPENTECH software was used to perform steady-state and dynamic simulations of an IGCC power plant. Linear systems analysis techniques were used to assess the steady-state and dynamic operability of the power plant under various plant operating conditions. Model predictive control (MPC) strategies were developed to improve the dynamic operation of the power plants. MATLAB and SIMULINK software were used for systems analysis and control system design, and the SIMULINK functionality in ASPEN DYNAMICS was used to test the control strategies on the simulated process. Project funds were used to support a Ph.D. student to receive education and training in coal technology and the application of modeling and simulation techniques.

Fuzzy control applied to nuclear power plant pressurizer system

International Nuclear Information System (INIS)

Oliveira, Mauro V.; Almeida, Jose C.S.

2011-01-01

In a pressurized water reactor (PWR) nuclear power plants (NPPs) the pressure control in the primary loop is very important for keeping the reactor in a safety condition and improve the generation process efficiency. The main component responsible for this task is the pressurizer. The pressurizer pressure control system (PPCS) utilizes heaters and spray valves to maintain the pressure within an operating band during steady state conditions, and limits the pressure changes, during transient conditions. Relief and safety valves provide overpressure protection for the reactor coolant system (RCS) to ensure system integrity. Various protective reactor trips are generated if the system parameters exceed safe bounds. Historically, a proportional-integral derivative (PID) controller is used in PWRs to keep the pressure in the set point, during those operation conditions. The purpose of this study has two main goals: first is to develop a pressurizer model based on artificial neural networks (ANNs); second is to develop a fuzzy controller for the PWR pressurizer pressure, and compare its performance with the P controller. Data from a simulator PWR plant was used to test the ANN and the controllers as well. The reference simulator is a Westinghouse 3-loop PWR plant with a total thermal output of 2785 MWth. The simulation results show that the pressurizer ANN model response are in reasonable agreement with the simulated power plant, and the fuzzy controller built in this study has better performance compared to the P controller. (author)

Fuzzy control applied to nuclear power plant pressurizer system

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Mauro V.; Almeida, Jose C.S., E-mail: mvitor@ien.gov.b, E-mail: jcsa@ien.gov.b [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

2011-07-01

In a pressurized water reactor (PWR) nuclear power plants (NPPs) the pressure control in the primary loop is very important for keeping the reactor in a safety condition and improve the generation process efficiency. The main component responsible for this task is the pressurizer. The pressurizer pressure control system (PPCS) utilizes heaters and spray valves to maintain the pressure within an operating band during steady state conditions, and limits the pressure changes, during transient conditions. Relief and safety valves provide overpressure protection for the reactor coolant system (RCS) to ensure system integrity. Various protective reactor trips are generated if the system parameters exceed safe bounds. Historically, a proportional-integral derivative (PID) controller is used in PWRs to keep the pressure in the set point, during those operation conditions. The purpose of this study has two main goals: first is to develop a pressurizer model based on artificial neural networks (ANNs); second is to develop a fuzzy controller for the PWR pressurizer pressure, and compare its performance with the P controller. Data from a simulator PWR plant was used to test the ANN and the controllers as well. The reference simulator is a Westinghouse 3-loop PWR plant with a total thermal output of 2785 MWth. The simulation results show that the pressurizer ANN model response are in reasonable agreement with the simulated power plant, and the fuzzy controller built in this study has better performance compared to the P controller. (author)

Position control of a floating nuclear power plant

International Nuclear Information System (INIS)

Motohashi, K.; Hamamoto, T.; Sasaki, R.; Kojima, M.

1993-01-01

In spite of the increasing demand of electricity in Japan, the sites of nuclear power plants suitable for conventional seismic regulations become severely limited. Under these circumstances, several types of advanced siting technology have been developed. Among them, floating power plants have a great advantage of seismic isolation that leads to the seismic design standardization and factory fabrication. The feasibility studies or preliminary designs of floating power plants enclosed by breakwaters in the shallow sea have been carried out last two decades in U.S. and Japan. On the other hand, there are few investigations on the dynamic behavior of floating power plants in the deep sea. The offshore floating nuclear power plants have an additional advantage in that large breakwaters are not required, although the safety checking is inevitable against wind-induced waves. The tension-leg platforms which have been constructed for oil drilling in the deep sea seem to be a promising offshore siting technology of nuclear power plants. The tension-leg mooring system can considerably restrain the heave and pitch of a floating power plant because of significant stiffness in the vertical direction. Different from seismic effects, wind-induced waves may be predicted in advance by making use of ocean weather forecasts using artificial satellites. According to the wave prediction, the position of the floating plant may be controlled by adjusting the water content in ballast tanks and the length of tension-legs before the expected load arrives. The position control system can reduce the wave force acting on the plant and to avoid the unfavorable response behavior of the plant. In this study a semi-submerged circular cylinder with tension-legs is considered as a mathematical model. The configuration of circular cylinder is effective because the dynamic behavior does not depend on incident wave directions. It is also unique in that it can obtain the closed-form solution of

Development of Plant Control Diagnosis Technology and Increasing Its Applications

Science.gov (United States)

Kugemoto, Hidekazu; Yoshimura, Satoshi; Hashizume, Satoru; Kageyama, Takashi; Yamamoto, Toru

A plant control diagnosis technology was developed to improve the performance of plant-wide control and maintain high productivity of plants. The control performance diagnosis system containing this technology picks out the poor performance loop, analyzes the cause, and outputs the result on the Web page. Meanwhile, the PID tuning tool is used to tune extracted loops from the control performance diagnosis system. It has an advantage of tuning safely without process changes. These systems are powerful tools to do Kaizen (continuous improvement efforts) step by step, coordinating with the operator. This paper describes a practical technique regarding the diagnosis system and its industrial applications.

The operational benefits of integrated PC control of gamma irradiation plants

International Nuclear Information System (INIS)

Comben, M.; Stephens, P.

1998-01-01

Compared with the traditional PLC control systems used on many gamma irradiation plants, the semi-intelligent decision making capabilities of a fully integrated PC control system can bring many benefits to the plant operator. The authors will describe how plant operation is fully automatic with the PC control providing all the input-output data required to run the plant efficiently and safely. Detailed product tracking, with live on-screen data, can be incorporated to give both plant operator and product manufacturer complete confidence in the irradiation process. Advanced features such as on-line diagnostics and mechanical part failure prediction are also described. Also available is automated dosimetry, reducing the opportunity for human error, whilst at the same time saving on staff costs and providing highly professional dose validation reports and comprehensive routine dosimetry documentation. The benefits of PURIDEC's PC control system are not only available with its new plants. The system can be supplied as an upgrade to plants of all ages and design giving the current operator all the benefits described in the paper

Utility of low-order linear nuclear-power-plant models in plant diagnostics and control

International Nuclear Information System (INIS)

Tylee, J.L.

1981-01-01

A low-order, linear model of a pressurized water reactor (PWR) plant is described and evaluated. The model consists of 23 linear, first-order difference equations and simulates all subsystems of both the primary and secondary sides of the plant. Comparisons between the calculated model response and available test data show the model to be an adequate representation of the actual plant dynamics. Suggested use for the model in an on-line digital plant diagnostics and control system are presented

Aquatic plant control research

Energy Technology Data Exchange (ETDEWEB)

Pryfogle, P.A.; Rinehart, B.N. [Idaho National Engineering Lab., Idaho Falls, ID (United States); Ghio, E.G. [Pacific Gas & Electric Company, San Francisco, CA (United States). Hydro Generation Engineering

1997-05-01

The Northwest region of the United States contains extensive canal systems that transport water for hydropower generation. Nuisance plants, including algae, that grow in these systems reduce their hydraulic capacity through water displacement and increased surface friction. Most control methods are applied in an ad hoc fashion. The goal of this work is to develop cost-effective, environmentally sound, long-term management strategies to prevent and control nuisance algal growth. This paper reports on a multi-year study, performed in collaboration with the Pacific Gas & Electric Company, to investigate algal growth in their canal systems, and to evaluate various control methodologies. Three types of controls, including mechanical, biological and chemical treatment, were selected for testing and evaluation. As part of this study, water quality data were collected and algal communities were sampled from numerous stations throughout the distribution system at regular intervals. This study resulted in a more comprehensive understanding of conditions leading to the development of nuisance algal growth, a better informed selection of treatment plans, and improved evaluation of the effectiveness for the control strategies selected for testing.

An Evolutionary Robotics Approach to the Control of Plant Growth and Motion: Modeling Plants and Crossing the Reality Gap

DEFF Research Database (Denmark)

Wahby, Mostafa; Hofstadler, Daniel Nicolas; Heinrich, Mary Katherine

2016-01-01

The self-organizing bio-hybrid collaboration of robots and natural plants allows for a variety of interesting applications. As an example we investigate how robots can be used to control the growth and motion of a natural plant, using LEDs to provide stimuli. We follow an evolutionary robotics...... approach where task performance is determined by monitoring the plant's reaction. First, we do initial plant experiments with simple, predetermined controllers. Then we use image sampling data as a model of the dynamics of the plant tip xy position. Second, we use this approach to evolve robot controllers...

Comparison of two voltage control strategies for a wind power plant

DEFF Research Database (Denmark)

Martinez, Jorge; Kjær, Philip C.; Rodriguez, Pedro

2011-01-01

plants. This paper addresses the analysis of two different voltage control strategies for a wind power plant, i.e. decentralized and centralized voltage control schemes. The analysis has been performed using the equivalent and simplified transfer functions of the system. Using this representation......Larger percentages of wind power penetration translate to more demanding requirements from grid codes. Recently, voltage support at the point of connection has been introduced by several grid codes from around the world, thus, making it important to analyze this control when applied to wind power......, it is possible to investigate the influence of the plant control gain, short circuit ratio, and time delays on the system stability, as well as the fulfillment of the design requirements. The implemented plant voltage control is based on a slope voltage controller, which calculates the references to be sent...

Recent control and instrumentation systems for BWR nuclear power plant

International Nuclear Information System (INIS)

Fujii, Hiroaki; Higashikawa, Yuichi; Sato, Hideyuki

1990-01-01

For the needs of the more stable operation of nuclear power stations, the upgrading of the measurement and control system for BWRs has been promoted by positively introducing remarkably advancing electronic technology. Further, it is aimed at to construct the synthetic digitized measurement and control system for nuclear power stations to heighten the operation reliability in ABWRs. As the first step of the development in the synthetic digitization, the monitoring and control system for radioactive waste treatment was put in practical use for No.5 plant of Kashiwazaki, Kariwa Nuclear Power Station, Tokyo Electric Power Co., Inc. Hitachi Ltd. has promoted the development and the application to actual plants of the measurement and control system for BWRs, in which digital control technology, optical information transmission technology and the operation-supporting technology using a computer were utilized. Hereafter, it is intended to expand the application of digital measurement and control aiming at improving the reliability, operation performance and maintainability. The nuclear power plant control complex with advanced man-machine interface-90 (NUCAMM-90) was developed, and its application to actual plants is planned. (K.I.)

Backfitting of the nuclear plant V1 power control system

International Nuclear Information System (INIS)

Karpeta, C.; Rubek, J.; Stirsky, P.

1985-01-01

The paper deals with some aspects of implementation of modifications into the Czechoslovak nuclear plant V1 control system as called for on the basis of experience gained during the first period of the plant operation. Brief description of the plant power control system and its main functions is given. Some deficiencies in the system performance during abnormal conditions are outlined and measures taken to overcome them are presented. (author)

Reactor instrumentation and control in nuclear power plants in Germany

International Nuclear Information System (INIS)

Aleite, W.

1993-01-01

The pertinent legislation, guidelines and standards of importance for nuclear power plant construction as well as the relevant committees in Germany are covered. The impact of international developments on the German regulatory scene is mentioned. A series of 15 data sheets on reactor control, followed by 5 data sheets on instrumentation and control in nuclear power plants, which were drawn up for German plants, are compared and commented in some detail. Digitalization of instrumentation and control systems continues apace. To illustrate the results that can be achieved with a digitalized information system, a picture series that documents a plant test of behavior on simulated steam generator tube rupture is elaborately commented. An outlook on backfitting and upgrading applications concludes this paper. (orig.) [de

Applications of modern control systems in nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Wilhelm, H [Brown, Boveri und Cie A.G., Mannheim (Germany, F.R.). Abt. GK/TE

1980-10-01

A new generation of automation and control systems are currently becoming commercially available in the power plant market which, because of their incorporation of microprocessors and bus data transmission systems, represent a major step forward in innovation. The application of these systems meets today's requirements and solutions, for the number of measurements to be performed has increased five or sixfold in the past few years, and the number of drive systems to be controlled has doubled or even tripled. Requirements to be met by process management systems have become vastly more complicated: peak load operation, short startup times, improved communication, and rising safety and reliability requirements, especially in nuclear power plants. Control concepts have been developed for the area relevant to reactor safety and for the whole of the plant, which make full use of the possibilities offered by plant systems. More stringent demands must be met especially in the areas of handling, communication, testing capability, improved function, and flexibility and modular design in the safety sector.

New technology for BWR power plant control and instrumentation

International Nuclear Information System (INIS)

Takano, Yoshiyuki; Nakamura, Makoto; Murata, Fumio.

1992-01-01

Nuclear power plants are facing strong demands for higher reliability and cost-performance in their control and instrumentation systems. To meet these needs, Hitachi is developing advanced control and instrumentation technology by rationalizing the conventional technology in that field. The rationalization is done through the utilization of reliable digital technology and optical transmission technology, and others, which are now commonly used in computer applications. The goal of the development work is to ensure safe, stable operation of the plant facilities and to secure harmony between man and machine. To alleviate the burdens of the operators, the latest electronic devices are being employed to create an advanced man-machine interface, and to promote automatic operation of the plant based upon the automatic operation of individual systems. In addition, the control and instrumentation system, including the safety system, incorporates more and more digital components in order to further enhance the reliability and maintainability of the plant. (author)

Implementation considerations for digital control systems in power plants: Final report

International Nuclear Information System (INIS)

Shah, S.C.; Lehman, L.L.; Sarchet, M.M.

1988-09-01

Conversion of nuclear power plants fron analog to digital control systems will require careful design, testing, and integration of the control algorithms, the software which implements the algorithms, the digital instrumentation, the digital communications network, and analog/digital device interfaces. Digital control systems are more flexible than their analog counterparts, and therefore greater attention must be paid by the customer to all stages of the control system design process. This flexibility also provides the framework for development of significant safety and reliability are inherant aspects of the chosen design processes. Digital control algorithms are capable of improving their performance by on-line self-tuning of the control parameters. It is therefore incumbant on system designers to choose self-tuning algorithms for power plant control. Implementation of these algorithms in software required a careful software design and development process to minimize errors in interpretation of the engineering design and prevent the inclusion of programming errors during software production. Digital control system and communications software must exhibit sufficient ''fault tolerance'' to maintain some level of safe plant operation or execute a safe plant shutdown in the event of both hard equipment failures and the appearance of software design faults. A number of standardized digital communications protocols are available to designers of digital control systems. These standardized digital communications protocols provide reliable fault tolerant communication between all digital elements of the plant control system and can be implemented redundantly to further enhance power plant operational safety. 5 refs., 11 figs., 1 tab

Digital control in nuclear power plants

International Nuclear Information System (INIS)

Bouzon, B.

1984-01-01

This document presents the latest automatic control structures used in the programmable control systems of 13.00 MW nuclear power plants constructed by Electricite de France. The impact of this technological innovation goes beyond a straightforward design modification; in addition to the new range of processes made possible, it permits far-reaching changes in the working method employed at the design office and in the field. (author)

Chapter 8. Controlling plant competition

Science.gov (United States)

Stephen B. Monsen

2004-01-01

Generally, range or wildlife habitat improvement projects seek to achieve desirable plants through the elimination or replacement of undesirable species or both. Control measures are thus designed to: (1) reduce the competitive effects of existing species (Evans and Young 1987a,b; Robertson and Pearse 1945), (2) allow the establishment of seeded species (Harper and...

50 CFR 35.7 - Control of wildfires, insects, pest plants, and disease.

Science.gov (United States)

2010-10-01

... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Control of wildfires, insects, pest plants... MANAGEMENT General Rules § 35.7 Control of wildfires, insects, pest plants, and disease. To the extent necessary, the Director shall prescribe measures to control wildfires, insects, pest plants, and disease to...

Nuclear techniques in plant pathology 1. Plant disease control and physiology of parasitism

International Nuclear Information System (INIS)

Menten, J.O.M.; Ando, A.; Tulmann Neto, A.

1986-01-01

Nuclear techniques are advantageously used in several areas of plant pathology. Among them are: induction of mutation for disease resistance, studies with pesticides, disease control through pathogen inactivation, induction of variability and stimulation in pathogens and natural enemies, studies of microorganism physiology and diseased plant physiology, effect of gamma radiation on pesticides, technology of pesticides application, etc. (Author) [pt

Rapid Control Prototyping Plataform for Didactic Plant Motor DC

Directory of Open Access Journals (Sweden)

Cristian Bazán-Orobio

2013-06-01

Full Text Available In this paper a design, implementation and validation of a Rapid Control Prototype platform for a plant based on a DC motor is proposed. This low-cost prototype provides of an electronic card (with a motor DC and sensors manipulated by PC with free software tools using Linux, Scilab / Scicos and RTAI-Lab. This RCP System allows developing speed -position control trainings by using different types of PID industrial controllers with anti – wind up and bump less transfer schemes. We develop a speed control application structured in four steps: identification, controller design, simulation and real time control, where there are pedagogical advantages of a platform that not only allows simulation but also real-time control of a plant.

A modeling and control approach to advanced nuclear power plants with gas turbines

International Nuclear Information System (INIS)

Ablay, Günyaz

2013-01-01

Highlights: • Load frequency control strategies in nuclear plants are researched. • Nuclear reactor-centered control system may not be suitable for load control. • Local unit controllers improve stability and overall time constant. • Coolant loops in nuclear plants should be controlled locally. - Abstract: Advanced nuclear power plants are currently being proposed with a number of various designs. However, there is a lack of modeling and control strategies to deal with load following operations. This research investigates a possible modeling approach and load following control strategy for gas turbine nuclear power plants in order to provide an assessment way to the concept designs. A load frequency control strategy and average temperature control mechanism are studied to get load following nuclear power plants. The suitability of the control strategies and concept designs are assessed through linear stability analysis methods. Numerical results are presented on an advanced molten salt reactor concept as an example nuclear power plant system to demonstrate the validity and effectiveness of the proposed modeling and load following control strategies

Fuel oil heating process and viscosity control system based on PI controllers; Proceso de calentamiento de combustoleo y sistema de control de viscosidad en base a controladores PI

Energy Technology Data Exchange (ETDEWEB)

Delgadillo Valencia, Miguel Angel; Dominguez Molina, Beatriz Adriana [Gerencia de Control e Instrumentacionn Instituto de Investigaciones Eletricas, Cuernavaca, Morelos (Mexico)]. E-mail: madv@iie.org.mx; ingbty@hotmail.com

2010-11-15

This job presents a mathematical development for evaluating the fuel oil viscosity from direct pressure drop measurement data in a piece of tube, the density of the oil and the oil flow at the main heater input of a conventional power plant. A group of curves obtained from different type of oils are presented in equation form which are used to interpolate the actual oil and to extend it to evaluate the corresponding temperature for the goal viscosity. This temperature is used as temperature setpoint for the proposed viscosity control system. A conventional plant main heater model is developed in order to carry out simulation tests for the viscosity control. Simulation tests are done in the Simulink of Matlab platform and graphs of runs are presented. [Spanish] Este trabajo presenta un desarrollo matematico para la evaluacion de la viscosidad del combustoleo a partir de datos de medicion directa de caida de presion en un tramo de tuberia, de la densidad y del flujo de combustible a la entrada del calentador principal de una central termoelectrica convencional. A traves de datos de diferentes tipos de combustible se presentaron un conjunto de curvas, representadas por ecuaciones, mediante las cuales se interpola la curva correspondiente al combustible actual y se proyecta para evaluar la temperatura correspondiente a la viscosidad objetivo; esta temperatura objetivo se utiliza despues como senal de punto de ajuste para el control de la viscosidad del combustible en un sistema de control propuesto. Para la realizacion de pruebas del control de viscosidad, se plantea el desarrollo del modelo del calentador principal de la central termoelectrica. Las corridas de simulacion se realizan en la plataforma de Simulink de Matlab y se presentan las graficas de dichas corridas.

Man-machine considerations in nuclear power plant control room design

International Nuclear Information System (INIS)

Tennant, D.V.

1987-01-01

Although human factors is a subject that has been around for a number of years, this area of design has only recently become known to the power industry. As power plants have grown in size and complexity, the instrumentation required to control and monitor plant processes has increased tremendously. This has been especially true in nuclear power facilities. Although operators are better trained and qualified, very little consideration has been devoted to man-machine interface and the limitations of human operators. This paper explores the historic aspects and design philosophy associated with nuclear plant control rooms. Current problems and solutions are explored along with the components of a control room review. Finally, a survey of future advances in control room design are offered. This paper is concerned with instrumentation, controls, and displays

Creencias y ajuste psicológico de la persona que acompaña al drogodependiente y creencias de éste durante el tratamiento

OpenAIRE

José Miguel Martínez González; Humberto Manuel Trujillo Mendoza

2005-01-01

El objetivo de esta investigación fue estudiar si las creencias relacionadas con la vivencia del acompañamiento de un familiar en el tratamiento de un drogodependiente, y las del mismo paciente, varían en función de aspectos como el tiempo de abstinencia, el tiempo dedicado al tratamiento, la presencia de patología dual en el drogodependiente, la gravedad de ajuste psicológico del acompañante, los años de evolución de la drogodependencia y el tiempo transcurrido desde que se co...

Distributed Control Systems in New Nuclear Power Plants

International Nuclear Information System (INIS)

Doerfler, Joseph

2008-01-01

With the growing demand for energy many countries have expressed interest in constructing new plants over the next 15 to 20 years. These expectations have presented a challenge to the nuclear industry to provide a high volume of construction. A key strategy to meet this challenge is developing an advanced nuclear power plant design that allows for a modular construction, a high level of standardization, passive safety features, reduced number of components, and a short bid-to-build time. In addition, the implementation of the plant control system has evolved as new technologies emerge to support these goals. The purpose of this paper is to discuss the ways that the distributed control and information systems in the new generation of nuclear power plants will differ from those currently in service. The new designs provide opportunities to improve overall performance through the use of bus technology, a video display driven Human System Interface, enhanced diagnostics and improved maintenance features. However, the new technologies must fully address requirements for cyber security and high reliability. This paper will give an overview of new technology, improvements, as well as emerging issues in new plant design. (authors)

Distributed Control Systems in New Nuclear Power Plants

Energy Technology Data Exchange (ETDEWEB)

Doerfler, Joseph [Westinghouse Electric Company, 4350 Northern Pike, Monroeville, PA 15146 (United States)

2008-07-01

With the growing demand for energy many countries have expressed interest in constructing new plants over the next 15 to 20 years. These expectations have presented a challenge to the nuclear industry to provide a high volume of construction. A key strategy to meet this challenge is developing an advanced nuclear power plant design that allows for a modular construction, a high level of standardization, passive safety features, reduced number of components, and a short bid-to-build time. In addition, the implementation of the plant control system has evolved as new technologies emerge to support these goals. The purpose of this paper is to discuss the ways that the distributed control and information systems in the new generation of nuclear power plants will differ from those currently in service. The new designs provide opportunities to improve overall performance through the use of bus technology, a video display driven Human System Interface, enhanced diagnostics and improved maintenance features. However, the new technologies must fully address requirements for cyber security and high reliability. This paper will give an overview of new technology, improvements, as well as emerging issues in new plant design. (authors)

Ajuste oclusal na Ortodontia: por que, quando e como? Occlusal adjustment in Orthodontics: why, when and how?

Directory of Open Access Journals (Sweden)

Roberto Carlos Bodart Brandão

2008-06-01

Full Text Available INTRODUÇÃO: o conhecimento sobre oclusão dentária deve ser considerado condição fundamental para a prática de uma Ortodontia de qualidade. O diagnóstico feito sem a manipulação do paciente em Relação Cêntrica pode levar à surpresa desagradável de se planejar o tratamento de uma má oclusão e se deparar com outra, depois dos primeiros arcos de nivelamento. Ao usar arcos retangulares, é importante a checagem dos contatos oclusais para se definir o tipo de movimento dentário necessário para o alcance do equilíbrio oclusal e, principalmente, verificar se este movimento é exeqüível. Durante o tratamento ortodôntico, devido à complexidade das superfícies oclusais, o ajuste oclusal por desgaste deve ser realizado para viabilizar movimentos dentários verticais, reduzindo o tempo de tratamento. Interferências oclusais são responsáveis tanto por efeitos adversos na biomecânica, quanto por aplicação de forças excessivas, que podem causar reabsorções radiculares. Após a Ortodontia, o ajuste oclusal é um dos determinantes da estabilização dentária, devendo-se obter, para cada dente posterior, contatos oclusais "A" e "B", ou "B" e "C" no sentido vestibulolingual, além dos contatos de "parada" e "equilíbrio" no sentido mesiodistal. Os dentes anteriores passam a funcionar em movimentos mandibulares, desocluindo de imediato os dentes posteriores, o que é denominado de guia anterior, visando equilíbrio muscular e proteção do sistema estomatognático. O desgaste seletivo não deve ser utilizado como substituto da movimentação ortodôntica. OBJETIVO: apresentar os princípios relacionados ao ajuste oclusal em Ortodontia.INTRODUCTION: The knowledge of dental occlusion should be considered the basic foundation to an excellent orthodontic practice. The patient’s diagnose without the centric relation assessment can take the orthodontist to an unpleasant surprises. The use of rectangular archwires requires occlusal

Development of Rotational Smart Lighting Control System for Plant Factory

OpenAIRE

Won-Sub Lee; Sung-Gaun Kim

2012-01-01

Rotational Smart Lighting Control System can supply the quantity of lighting which is required to run plants by rotating few LED and Fluorescent instead of that are used in the existing plant factories.The initial installation of the existing plants factory is expensive, so in order to solve the problem with smart lighting control system was developed. The beam required intensity for the growth of crops, Photosynthetic Photon Flux Density(PPFD)is calculated; and the numbe...

Modifier le cadre participatif pour résoudre un problème client : exemples d’ajustement opéré par les professionnels dans les interactions en centre d’appels

Directory of Open Access Journals (Sweden)

Colón De Carvajal Isabel

2012-07-01

Full Text Available Si, dans les interactions de service en centre d’appels, la conversation principale est celle engagée entre l’appelant et l’appelé, une multitude d’autres interactions caractérise le travail des opérateurs. Cet article présente une étude linguistique sur les interactions entre les opérateurs du centre d’appels LocBike, qui propose l’accès à des vélos en libre service dans une grande ville française, et les clients, qui empruntent ces vélos et appellent le centre en cas de problèmes. Ces interactions ont la particularité d’être menées autour d’objets technologiques, afin d’interagir avec le client et traiter son dossier. L’accès à cet environnement d’interactions téléphoniques médiées par ordinateur permet d’analyser la résolution du problème client du point de vue de l’opérateur, et d’observer que ce travail se réalise parfois en collaboration avec son collègue co-présent dans son environnement immédiat. Les professionnels opèrent alors des ajustements par rapport au dispositif de communication, ou s’ajustent eux-mêmes à ce dispositif, pendant l’interaction principale avec le client, ce qui tend à modifier le cadre participatif. L’objectif de notre travail est d’analyser les pratiques des professionnels lors de modifications du cadre participatif, et ce, dans le but de résoudre un problème client. A travers des exemples de collaboration, nous étudierons les formes d’ajustement que les professionnels mettent en place par rapport au dispositif de communication, modifiant ainsi temporairement le cadre participatif.

A coordinated MIMO control design for a power plant using improved sliding mode controller.

Science.gov (United States)

Ataei, Mohammad; Hooshmand, Rahmat-Allah; Samani, Siavash Golmohammadi

2014-03-01

For the participation of the steam power plants in regulating the network frequency, boilers and turbines should be co-ordinately controlled in addition to the base load productions. Lack of coordinated control over boiler-turbine may lead to instability; oscillation in producing power and boiler parameters; reduction in the reliability of the unit; and inflicting thermodynamic tension on devices. This paper proposes a boiler-turbine coordinated multivariable control system based on improved sliding mode controller (ISMC). The system controls two main boiler-turbine parameters i.e., the turbine revolution and superheated steam pressure of the boiler output. For this purpose, a comprehensive model of the system including complete and exact description of the subsystems is extracted. The parameters of this model are determined according to our case study that is the 320MW unit of Islam-Abad power plant in Isfahan/Iran. The ISMC method is simulated on the power plant and its performance is compared with the related real PI (proportional-integral) controllers which have been used in this unit. The simulation results show the capability of the proposed controller system in controlling local network frequency and superheated steam pressure in the presence of load variations and disturbances of boiler. © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

Development of assessment methodology for plant configuration control

Energy Technology Data Exchange (ETDEWEB)

Chung, Chang Hyun; You, Young Woo; Kim, Yoon Ik; Yang, Hui Chang; Huh, Byeong Gill; Lee, Dong Won; Ahn, Gwan Won [Seoul National Univ., Seoul (Korea, Republic of)

2001-03-15

The purpose of this study IS the development of effective and overall assessment methodology which reflects the characteristics of plants for the surveillance, maintenance, repair and operation of nuclear power plants. In this study, recent researches are surveyed and concept definition, procedures, current PSA methodologies, implementation of various models are evaluated. Through this survey, systematic assessment methodology is suggested. Configuration control assessment methodology suggested in this study for the purpose of the development of configuration control methodology reflecting the characteristics of Korean NPPs, can be utilized as the supplement of current PSA methodologies.

From control switches to integrated process control systems. 60 years of power plant control technology; Vom Steuerquittierschalter zum integrierten Prozessleitsystem. 60 Jahre Kraftwerksleittechnik

Energy Technology Data Exchange (ETDEWEB)

Pagel, Peter [ABB AG, Mannheim (Germany). Marketing

2009-07-01

Power plant control has always been based on the process requirements and on the need to reduce the process cost. Modern power plant control systems also take account of the need for emission reduction. They have developed into integrated navigation platforms with functional confectioning of workstations, focusing on the aspects of functionality, efficiency, ergonomics, plant availability and life cycle cost. The contribution outlines important developments of power plant control technology during the past few decades. (orig.)

Expert System Control of Plant Growth in an Enclosed Space

Science.gov (United States)

May, George; Lanoue, Mark; Bathel, Matthew; Ryan, Robert E.

2008-01-01

The Expert System is an enclosed, controlled environment for growing plants, which incorporates a computerized, knowledge-based software program that is designed to capture the knowledge, experience, and problem-solving skills of one or more human experts in a particular discipline. The Expert System is trained to analyze crop/plant status, to monitor the condition of the plants and the environment, and to adjust operational parameters to optimize the plant-growth process. This system is intended to provide a way to remotely control plant growth with little or no human intervention. More specifically, the term control implies an autonomous method for detecting plant states such as health (biomass) or stress and then for recommending and implementing cultivation and/or remediation to optimize plant growth and to minimize consumption of energy and nutrients. Because of difficulties associated with delivering energy and nutrients remotely, a key feature of this Expert System is its ability to minimize this effort and to achieve optimum growth while taking into account the diverse range of environmental considerations that exist in an enclosed environment. The plant-growth environment for the Expert System could be made from a variety of structures, including a greenhouse, an underground cavern, or another enclosed chamber. Imaging equipment positioned within or around the chamber provides spatially distributed crop/plant-growth information. Sensors mounted in the chamber provide data and information pertaining to environmental conditions that could affect plant development. Lamps in the growth environment structure supply illumination, and other additional equipment in the chamber supplies essential nutrients and chemicals.

Process control and monitoring system: Thermal Power Plant Gacko

International Nuclear Information System (INIS)

Jeremovic, Dragan; Skoko, Maksim; Gjokanovic, Zdravko

2004-01-01

DCS Ovation system, manufactured by Westinghouse, USA, is described in this paper. Emphasize on concept of realization and basic characteristic in Thermal Power Plant Gacko is given in this paper. The most important, noticed by now, comparative effects and performances of new monitoring and control system according to classical monitoring and control system of 300 MW units Thermal Power Plant Gacko in Gacko, are given in the conclusion. (Author)

Health-aware Model Predictive Control of Pasteurization Plant

Science.gov (United States)

Karimi Pour, Fatemeh; Puig, Vicenç; Ocampo-Martinez, Carlos

2017-01-01

In order to optimize the trade-off between components life and energy consumption, the integration of a system health management and control modules is required. This paper proposes the integration of model predictive control (MPC) with a fatigue estimation approach that minimizes the damage of the components of a pasteurization plant. The fatigue estimation is assessed with the rainflow counting algorithm. Using data from this algorithm, a simplified model that characterizes the health of the system is developed and integrated with MPC. The MPC controller objective is modified by adding an extra criterion that takes into account the accumulated damage. But, a steady-state offset is created by adding this extra criterion. Finally, by including an integral action in the MPC controller, the steady-state error for regulation purpose is eliminated. The proposed control scheme is validated in simulation using a simulator of a utility-scale pasteurization plant.

Applications of modern control systems in nuclear power plants

International Nuclear Information System (INIS)

Wilhelm, H.

1980-01-01

A new generation of automation and control systems are currently becoming commercially available in the power plant market which, because of their incorporation of microprocessors and bus data transmission systems, represent a major step forward in innovation. The application of these systems meets today's requirements and solutions, for the number of measurements to be performed has increased five or sixfold in the past few years, and the number of drive systems to be controlled has doubled or even tripled. Requirements to be met by process management systems have become vastly more complicated: peak load operation, short startup times, improved communication, and rising safety and reliability requirements, especially in nuclear power plants. Control concepts have been developed for the area relevant to reactor safety and for the whole of the plant, which make full use of the possibilities offered by plant systems. More stringent demands must be met especially in the areas of handling, communication, testing capability, improved function, and flexibility and modular design in the safety sector. (orig.) [de

Results from an in-plant demonstration of intelligent control

International Nuclear Information System (INIS)

Edwards, R.M.; Garcia, H.E.; Messick, N.

1993-01-01

A learning systems-based reconfigurable controller was demonstrated on the deaerating feedwater heater at the Experimental Breeder Reactor II (EBR-II) on April 1, 1993. Failures of the normal pressure regulating process were introduced by reducing the steam flow to the heater by as much as 10%. The controller maintained pressure in the heater at acceptable levels for several minutes, whereas operator intervention would have otherwise been required within a few seconds. This experiment demonstrates the potential of advanced control techniques for improving safety, reliability, and performance of power plant operations as well as the utility of EBR-II as an experimental power plant controls facility

Autonomous Control of Nuclear Power Plants

Energy Technology Data Exchange (ETDEWEB)

Basher, H.

2003-10-20

A nuclear reactor is a complex system that requires highly sophisticated controllers to ensure that desired performance and safety can be achieved and maintained during its operations. Higher-demanding operational requirements such as reliability, lower environmental impacts, and improved performance under adverse conditions in nuclear power plants, coupled with the complexity and uncertainty of the models, necessitate the use of an increased level of autonomy in the control methods. In the opinion of many researchers, the tasks involved during nuclear reactor design and operation (e.g., design optimization, transient diagnosis, and core reload optimization) involve important human cognition and decisions that may be more easily achieved with intelligent methods such as expert systems, fuzzy logic, neural networks, and genetic algorithms. Many experts in the field of control systems share the idea that a higher degree of autonomy in control of complex systems such as nuclear plants is more easily achievable through the integration of conventional control systems and the intelligent components. Researchers have investigated the feasibility of the integration of fuzzy logic, neural networks, genetic algorithms, and expert systems with the conventional control methods to achieve higher degrees of autonomy in different aspects of reactor operations such as reactor startup, shutdown in emergency situations, fault detection and diagnosis, nuclear reactor alarm processing and diagnosis, and reactor load-following operations, to name a few. With the advancement of new technologies and computing power, it is feasible to automate most of the nuclear reactor control and operation, which will result in increased safety and economical benefits. This study surveys current status, practices, and recent advances made towards developing autonomous control systems for nuclear reactors.

Autonomous Control of Nuclear Power Plants

International Nuclear Information System (INIS)

Basher, H.

2003-01-01

A nuclear reactor is a complex system that requires highly sophisticated controllers to ensure that desired performance and safety can be achieved and maintained during its operations. Higher-demanding operational requirements such as reliability, lower environmental impacts, and improved performance under adverse conditions in nuclear power plants, coupled with the complexity and uncertainty of the models, necessitate the use of an increased level of autonomy in the control methods. In the opinion of many researchers, the tasks involved during nuclear reactor design and operation (e.g., design optimization, transient diagnosis, and core reload optimization) involve important human cognition and decisions that may be more easily achieved with intelligent methods such as expert systems, fuzzy logic, neural networks, and genetic algorithms. Many experts in the field of control systems share the idea that a higher degree of autonomy in control of complex systems such as nuclear plants is more easily achievable through the integration of conventional control systems and the intelligent components. Researchers have investigated the feasibility of the integration of fuzzy logic, neural networks, genetic algorithms, and expert systems with the conventional control methods to achieve higher degrees of autonomy in different aspects of reactor operations such as reactor startup, shutdown in emergency situations, fault detection and diagnosis, nuclear reactor alarm processing and diagnosis, and reactor load-following operations, to name a few. With the advancement of new technologies and computing power, it is feasible to automate most of the nuclear reactor control and operation, which will result in increased safety and economical benefits. This study surveys current status, practices, and recent advances made towards developing autonomous control systems for nuclear reactors

Improvement on main control room for Japanese PWR plants

International Nuclear Information System (INIS)

Matsumiya, Masayuki

1996-01-01

The main control room which is the information center of nuclear power plant has been continuously improved utilizing the state of the art ergonomics, a high performance computer, computer graphic technologies, etc. For the latest Japanese Pressurized Water Reactor (PWR) plant, the CRT monitoring system is applied as the major information source for facilitating operators' plant monitoring tasks. For an operating plant, enhancement of monitoring and logging functions has been made adopting a high performance computer

Using H∞ to design robust POD controllers for wind power plants

DEFF Research Database (Denmark)

Mehmedalic, Jasmin; Knüppel, Thyge; Østergaard, Jacob

2012-01-01

Large wind power plants (WPPs) can help to improve small signal stability by increasing the damping of electromechanical modes of oscillation. This can be done by adding a power system oscillation damping (POD) controller to the wind power plants, similar to power system stabilizer (PSS......) controllers on conventional generation. Here two different design methods are evaluated for their suitability in producing a robust power system oscillation damping controller for wind power plants with full-load converter wind turbine generators (WTGs). Controllers are designed using classic PSS design and H......∞ methods and the designed controllers evaluated on both performance and robustness. It is found that the choice of control signal has a large influence on the robustness of the controllers, and the best performance and robustness is found when the converter active power command is used as control signal...

Development of Automatic Control of Bayer Plant Digestion

Science.gov (United States)

Riffaud, J. P.

Supervisory computer control has been achieved in Alcan's Bayer Plants at Arvida, Quebec, Canada. The purpose of the automatic control system is to stabilize and consequently increase, the alumina/caustic ratio within the digester train and in the blow-off liquor. Measurements of the electrical conductivity of the liquor are obtained from electrodeless conductivity meters. These signals, along with several others are scanned by the computer and converted to engineering units, using specific relationships which are updated periodically for calibration purposes. On regular time intervals, values of ratio are compared to target values and adjustments are made to the bauxite flow entering the digesters. Dead time compensation included in the control algorithm enables a faster rate for corrections. Modification of production rate is achieved through careful timing of various flow changes. Calibration of the conductivity meters is achieved by sampling at intervals the liquor flowing through them, and analysing it with a thermometric titrator. Calibration of the thermometric titrator is done at intervals with a standard solution. Calculations for both calibrations are performed by computer from data entered by the analyst. The computer was used for on-line data collection, modelling of the digester system, calculation of disturbances and simulation of control strategies before implementing the most successful strategy in the Plant. Control of ratio has been improved by the integrated system, resulting in increased Plant productivity.

Roles of programmable logic controllers in fuel reprocessing plants

International Nuclear Information System (INIS)

Mishra, Hrishikesh; Balakrishnan, V.P.; Pandya, G.J.

1999-01-01

Fuel charging facility is another application of Programmable Logic Controllers (PLC) in fuel reprocessing plants, that involves automatic operation of fuel cask dolly, charging motor, pneumatic doors, clutches, clamps, stepper motors and rod pushers in a pre-determined sequence. Block diagram of ACF system is given for underlining the scope of control and interlocks requirements involved for automation of the fuel charging system has been provided for the purpose at KARP Plant, Kalpakkam

An adaptive control application in a large thermal combined power plant

International Nuclear Information System (INIS)

Kocaarslan, Ilhan; Cam, Ertugrul

2007-01-01

In this paper, an adaptive controller was applied to a 765 MW large thermal power plant to decrease operating costs, increase quality of generated electricity and satisfy environmental concerns. Since power plants may present several operating problems such as disturbances and severe effects at operating points, design of their controllers needs to be carried out adequately. For these reasons, first, a reduced mathematical model was developed under Computer Aided Analysis and Design Package for Control (CADACS), so that the results of the experimental model have briefly been discussed. Second, conventional PID and adaptive controllers were designed and implemented under the real-time environment of the CADACS software. Additionally, the design of the adaptive model-reference and conventional PID controllers used in the power plant for real-time control were theoretically presented. All processes were realized in real-time. Due to safety restrictions, a direct connection to the sensors and actuators of the plant was not allowed. Instead a coupling to the control system was realized. This offers, in addition, the usage of the supervisory functions of an industrial process computer system. Application of the controllers indicated that the proposed adaptive controller has better performances for rise and settling times of electrical power, and enthalpy outputs than the conventional PID controller does

Plant parasite control and soil fauna diversity.

Science.gov (United States)

Lavelle, Patrick; Blouin, Manuel; Boyer, Johnny; Cadet, Patrice; Laffray, Daniel; Pham-Thi, Anh-Thu; Reversat, Georges; Settle, William; Zuily, Yasmine

2004-07-01

The use of pesticides to control plant parasites and diseases has generated serious problems of public health and environmental quality, leading to the promotion of alternative Integrated Pest Management strategies that tend to rely more on natural processes and the active participation of farmers as observers and experimenters in their own fields. We present three case studies that point at different options provided by locally available populations of soil organisms, the maintenance of diverse populations of pests or increased resistance of plants to pest attacks by their interactions with earthworms and other useful soil organisms. These examples demonstrate the diversity of options offered by the non-planned agro-ecosystem diversity in pest control and the need to identify management options that maintain this biodiversity.

Plant control impact on IFR power plant passive safety response

International Nuclear Information System (INIS)

Vilim, R.B.

1993-01-01

A method is described for optimizing the closed-loop plant control strategy with respect to safety margins sustained in the unprotected upset response of a liquid metal reactor. The optimization is performed subject to the normal requirements for reactor startup, load change and compensation for reactivity changes over the cycle. The method provides a formal approach to the process of exploiting the innate self-regulating property of a metal fueled reactor to make it less dependent on operator action and less vulnerable to automatic control system fault and/or operator error

Pollution control in oil, gas and chemical plants

CERN Document Server

Bahadori, Alireza

2014-01-01

This unique book covers the fundamental requirements for air, soil, noise and water pollution control in oil and gas refineries, chemical plants, oil terminals, petrochemical plants, and related facilities. Coverage includes design and operational considerations relevant to critical systems such as monitoring of water pollution control, equipment, and engineering techniques as well as engineering/technological methods related to soil, noise and air pollution control. This book also: ·         Covers a diverse list of pollution control strategies important to practitioners, ranging from waste water gathering systems and oil/suspended solids removal to chemical flocculation units, biological treatment, and sludge handling and treatment ·         Provides numerous step-by-step tutorials that orient both entry level and veteran engineers to the essentials of pollution control methods in petroleum and chemical industries ·         Includes a comprehensive glossary providing readers with...

Mercury controls for coal-fired power plants - status and challenges

Energy Technology Data Exchange (ETDEWEB)

Offen, G.; Shick, N.; Chang, R.; Chu, P.; Dene, C.; Rhudy, R. [EPRI, Palo Alto (US)

2005-05-01

Although the US Environmental Protection Agency has issued its mercury rule, setting limits for emissions from new power plants and placing an eventual cap on emissions from all plants, mercury control technologies offering sustainable performance and known applicability, impact, and cost are still in the future. Co-operative funding for long-term, full-scale tests of technologies in advanced stages of development, and support for emerging ones, promises to close the gap. The goal is to learn how to tailor control technologies to flue gas environments at individual power plants. In this paper the authors describe the current performance of mercury control technologies and outline the research needed to demonstrate their easiness for commercial deployment. 4 figs.

Control room systems design for nuclear power plants

International Nuclear Information System (INIS)

1995-07-01

This publication provides a resource for those who are involved in researching, managing, conceptualizing, designing, manufacturing or backfitting power plant control room systems. It will also be useful to those responsible for performing reviews or evaluations of the design and facilities associated with existing power plant control room systems. The ultimate worth of the publication, however, will depend upon how well it can support its users. Readers are invited to provide comments and observations to the IAEA, Division of Nuclear Power. If appropriate, the report will subsequently be re-issued, taking such feedback into account. Refs, figs and tabs

Control room systems design for nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-07-01

This publication provides a resource for those who are involved in researching, managing, conceptualizing, designing, manufacturing or backfitting power plant control room systems. It will also be useful to those responsible for performing reviews or evaluations of the design and facilities associated with existing power plant control room systems. The ultimate worth of the publication, however, will depend upon how well it can support its users. Readers are invited to provide comments and observations to the IAEA, Division of Nuclear Power. If appropriate, the report will subsequently be re-issued, taking such feedback into account. Refs, figs and tabs.

Advanced control room design for nuclear power plants

International Nuclear Information System (INIS)

Scarola, K.

1987-01-01

The power industry has seen a continuous growth of size and complexity of nuclear power plants. Accompanying these changes have been extensive regulatory requirements resulting in significant construction, operation and maintenance costs. In response to related concerns raised by industry members, Combustion Engineering developed the NUPLEX 80 Advanced Control Room. The goal of NUPLEX 80 TM is to: reduce design and construction costs; increase plant safety and availability through improvements in the man-machine interface; and reduce maintenance costs. This paper provides an overview of the NUPLEX 80 Advanced Control Room and explains how the stated goals are achieved. (author)

Material control and accountancy at EDF PWR plants

International Nuclear Information System (INIS)

de Cormis, F.

1991-01-01

The paper describes the comprehensive system which is developed and implemented at Electricite de France to provide a single reliable nuclear material control and accounting system for all nuclear plants. This software aims at several objectives among which are: the control and the accountancy of nuclear material at the plant, the optimization of the consistency of data by minimizing the possibility of transcription errors, the fulfillment of the statutory requirements by automatic transfer of reports to national and international safeguards authorities, the servicing of other EDF users of nuclear material data for technical or commercial purposes

Optimal control of a waste water cleaning plant

Directory of Open Access Journals (Sweden)

Ellina V. Grigorieva

2010-09-01

Full Text Available In this work, a model of a waste water treatment plant is investigated. The model is described by a nonlinear system of two differential equations with one bounded control. An optimal control problem of minimizing concentration of the polluted water at the terminal time T is stated and solved analytically with the use of the Pontryagin Maximum Principle. Dependence of the optimal solution on the initial conditions is established. Computer simulations of a model of an industrial waste water treatment plant show the advantage of using our optimal strategy. Possible applications are discussed.

Outside-in control -Does plant cell wall integrity regulate cell cycle progression?

Science.gov (United States)

Gigli-Bisceglia, Nora; Hamann, Thorsten

2018-04-13

During recent years it has become accepted that plant cell walls are not inert objects surrounding all plant cells but are instead highly dynamic, plastic structures. They are involved in a large number of cell biological processes and contribute actively to plant growth, development and interaction with environment. Therefore, it is not surprising that cellular processes can control plant cell wall integrity while, simultaneously, cell wall integrity can influence cellular processes. In yeast and animal cells such a bi-directional relationship also exists between the yeast/animal extra-cellular matrices and the cell cycle. In yeast, the cell wall integrity maintenance mechanism and a dedicated plasmamembrane integrity checkpoint are mediating this relationship. Recent research has yielded insights into the mechanism controlling plant cell wall metabolism during cytokinesis. However, knowledge regarding putative regulatory pathways controlling adaptive modifications in plant cell cycle activity in response to changes in the state of the plant cell wall are not yet identified. In this review, we summarize similarities and differences in regulatory mechanisms coordinating extra cellular matrices and cell cycle activity in animal and yeast cells, discuss the available evidence supporting the existence of such a mechanism in plants and suggest that the plant cell wall integrity maintenance mechanism might also control cell cycle activity in plant cells. This article is protected by copyright. All rights reserved.

Distributed computer control systems in future nuclear power plants

International Nuclear Information System (INIS)

Yan, G.; L'Archeveque, J.V.R.; Watkins, L.M.

1978-09-01

Good operating experience with computer control in CANDU reactors over the last decade justifies a broadening of the role of digital electronic and computer related technologies in future plants. Functions of electronic systems in the total plant context are reappraised to help evolve an appropriate match between technology and future applications. The systems research, development and demonstration program at CRNL is described, focusing on the projects pertinent to the real-time data acquisition and process control requirements. (author)

Modelo experimental de bandagem ajustável do tronco pulmonar para preparo rápido do ventrículo

Directory of Open Access Journals (Sweden)

DIAS Carlos A.

2000-01-01

Full Text Available OBJETIVO: Um dispositivo de bandagem do tronco pulmonar (TP com ajuste percutâneo foi desenvolvido com o objetivo de induzir a hipertrofia rápida do ventrículo subpulmonar. MATERIAL E MÉTODOS: Consiste de um manguito de silicone insuflável percutaneamente, através de um botão de silicone auto-selante. Os corações de 7 cabritos jovens (peso médio: 8,7 kg foram submetidos à sobrecarga sistólica imposta pelo dispositivo e avaliados sob os aspectos hemodinâmicos, ecocardiográficos e morfológicos. Foram extraídas biópsias basais do miocárdio do ventrículo direito (VD para análise microscópica (perímetro e área do miócito. O dispositivo foi implantado no TP. As pressões do VD, TP e aorta foram monitorizadas. Após convalescença, foi iniciado o protocolo de insuflação do dispositivo de bandagem do TP. Foi injetada água destilada no botão auto-selante (via percutânea, até que a pressão sistólica do VD atingisse 70% da pressão sistólica do VE. As avaliações ecocardiográfica e hemodinâmica foram realizadas a cada 24 horas. A sobrecarga sistólica do VD foi mantida por um período de 96 horas, com insuflações progressivas no limite máximo tolerado, a cada 24 horas. Após esse período, os animais foram sacrificados para análise morfológica dos corações. Outros 9 cabritos (peso médio: 7,7 kg foram utilizados como grupo controle, para análise do peso do VD. RESULTADOS: Após 96 horas de sobrecarga sistólica do VD, foi observado um aumento do gradiente sistólico VD/TP de 10,1±4,3 mmHg para 60,0±11,0 mmHg e da pressão sistólica no VD de 22,4±4,1 mmHg para 71,0±10,0 mmHg (p<0,0001. O ecocardiograma revelou aumento da espessura muscular do VD, de 4,4±0,5 mm para 7,3±1,7 mm (p=0,001. Quando comparado ao grupo controle, houve um ganho de peso de 74% do VD submetido à sobrecarga sistólica (p<0,0001. À microscopia óptica, foi observado aumento de 27% no perímetro e de 69% na área dos miócitos (p=0

Augmenting Plant Immune Responses and Biological Control by Microbial Determinants

Directory of Open Access Journals (Sweden)

Sang Moo Lee

2015-09-01

Full Text Available Plant have developed sophisticated defence mechanisms against microbial pathogens. The recent accumulated information allow us to understand the nature of plant immune responses followed by recognition of microbial factors/determinants through cutting-edge genomics and multi-omics techniques. However, the practical approaches to sustain plant health using enhancement of plant immunity is yet to be fully appreciated. Here, we overviewed the general concept and representative examples on the plant immunity. The fungal, bacterial, and viral determinants that was previously reported as the triggers of plant immune responses are introduced and described as the potential protocol of biological control. Specifically, the role of chitin, glucan, lipopolysaccharides/extracellular polysaccharides, microbe/pathogen-associated molecular pattern, antibiotics, mimic-phytohormones, N-acyl homoserine lactone, harpin, vitamins, and volatile organic compounds are considered. We hope that this review stimulates scientific community and farmers to broaden their knowledge on the microbial determinant-based biological control and to apply the technology on the integrated pest management program.

Wind Power Plant Control Optimisation with Incorporation of Wind Turbines and STATCOMs

DEFF Research Database (Denmark)

Petersen, Lennart; Kryezi, Fitim; Iov, Florin

2015-01-01

This paper addresses a detailed design and tuning of a wind power plant slope voltage control with reactive power contribution of wind turbines and STATCOMS. First, small-signal models of a single wind turbine and the whole wind power plant are developed, being appropriate for voltage control...... assessment. An exemplary wind power plant located in the United Kingdom and the corresponding grid code requirements are used as a base case. The final design and tuning process of the voltage controller results in a guidance, proposed for this particular control architecture. It provides qualitative...... outcomes regarding the impact of system delays, grid conditions and various operating conditions of the wind power plant, with and without incorporation of STATCOMS....

Time scaling internal state predictive control of a solar plant

Energy Technology Data Exchange (ETDEWEB)

Silva, R.N. [DEE-FCT/UNL, Caparica (Portugal); Rato, L.M. [INESC-ID/University, Evora (Portugal); Lemos, J.M. [INESC-ID/IST, Lisboa (Portugal)

2003-12-01

The control of a distributed collector solar field is addressed in this work, exploiting the plant's transport characteristic. The plant is modeled by a hyperbolic type partial differential equation (PDE) where the transport speed is the manipulated flow, i.e. the controller output. The model has an external distributed source, which is the solar radiation captured along the collector, approximated to depend only of time. From the solution of the PDE, a linear discrete state space model is obtained by using time-scaling and the redefinition of the control input. This method allows overcoming the dependency of the time constants with the operating point. A model-based predictive adaptive controller is derived with the internal temperature distribution estimated with a state observer. Experimental results at the solar power plant are presented, illustrating the advantages of the approach under consideration. (author)

Nuclear power plant control and instrumentation 1993. Working material

International Nuclear Information System (INIS)

1994-01-01

The regular meeting of the International Working Group on Nuclear Power Plant Control and Instrumentation (IWG-NPPCI) was organized in order to summarize operating experience of nuclear power plant control systems, gain a general overview of activities in development of modern control systems and receive recommendations on the further directions and particular measures within the Agency's programme. The meeting was held at the Merlin-Gerin Headquarters in Paris and was attended by twenty one national delegates and observers from 17 countries. The present volume contains: (1) report on the meeting of the IWG-NPPCI, Paris, 21-22 October 1993, (2) report by the scientific secretary on the major activities of IAEA during 1991-1993 in the NPPCI area, and (3) reports of the national representatives to the International Working Group on NPPCI. The papers and discussions with practical experience and described actual problems encountered. Emphasis was placed on the technical, industrial and economic aspects of the introduction of modern control systems and on the improvement of plant availability and safety. Refs, figs and tabs

Agricultural Plant Pest Control. Manual 93.

Science.gov (United States)

Missouri Univ., Columbia. Agricultural Experiment Station.

This training manual provides information needed to meet the minimum EPA standards for certification as a commercial applicator of pesticides for the agricultural plant pest control category. The text discusses the insect pests including caterpillars, beetles, and soil inhabiting insects; diseases and nematodes; and weeds. Consideration is given…

Probabilistic safety assessment- a tool for configuration control of nuclear power plants

International Nuclear Information System (INIS)

Vijaya, A.K.; Guptan, Rajee; Mohan, Nalini; Ghadge, S.G.; Bajaj, S.S.

2006-01-01

A comprehensive configuration control programme implies a sophisticated set of risk related measures to manage and control concurrent unavailabilities of components, the possibility of functional alternative components, the outage times of the unavailable components and the frequency of critical configurations. These measures are implemented through operational and maintenance activities such as maintenance and test scheduling and scheduling of operational realignments. An appropriate risk based configuration control programme would enable plant personnel to maintain the risk level of the nuclear power plant within an acceptable range during all the operational regimes. Use of plant specific PSA to support configuration control makes it risk based. The PSA can help to identify the measures needed according to the situation to reduce risk to acceptable level. The main benefit of establishing a risk based configuration control programme is the reduction of risk peaks and the control of cumulative or average risk. It helps to ensure that as far as possible, the plant does not enter the critical, high risk situations and other risk significant configurations are avoided A plant specific PSA along with a 'Risk Monitor' can be used as an efficient tool for Configuration Control. (author)

Calcium constrains plant control over forest ecosystem nitrogen cycling.

Science.gov (United States)

Groffman, Peter M; Fisk, Melany C

2011-11-01

Forest ecosystem nitrogen (N) cycling is a critical controller of the ability of forests to prevent the movement of reactive N to receiving waters and the atmosphere and to sequester elevated levels of atmospheric carbon dioxide (CO2). Here we show that calcium (Ca) constrains the ability of northern hardwood forest trees to control the availability and loss of nitrogen. We evaluated soil N-cycling response to Ca additions in the presence and absence of plants and observed that when plants were present, Ca additions "tightened" the ecosystem N cycle, with decreases in inorganic N levels, potential net N mineralization rates, microbial biomass N content, and denitrification potential. In the absence of plants, Ca additions induced marked increases in nitrification (the key process controlling ecosystem N losses) and inorganic N levels. The observed "tightening" of the N cycle when Ca was added in the presence of plants suggests that the capacity of forests to absorb elevated levels of atmospheric N and CO2 is fundamentally constrained by base cations, which have been depleted in many areas of the globe by acid rain and forest harvesting.

Optimizing the roles of man and computer in nuclear power plant control

International Nuclear Information System (INIS)

Colley, R.W.; Seeman, S.E.

1983-10-01

We are presently participating in a program to optimize the functional man-machine interface for Liquid Metal-Cooled Fast Breeder Reactors. The overall objective of this program is to enhance operational safety; that is, to accommodate plant incidents through optimal integration of man and machine in performing the functions required to safely control a plant during both normal and off-normal conditions. Purpose of this talk is to describe an approach to determine the optimal roles of man and computer in the control of nuclear power plants. Purpose of this session was to get together people that are working in the areas of understanding of how operators control plants, and working on developing new aids for these operators. We were asked to explain how our modeling and approach we're taking will lead us to an optimization of the roles of the man and the computer in the control of nuclear power plants. Our emphasis was to be on the functions required for plant control, and how the attributes of the human operator and the attributes of the computer can be optimally used to enhance operational safety in performing these functions

Balancing the roles of humans and machines in power plant control

International Nuclear Information System (INIS)

Lipsett, J.J.

1989-05-01

A number of factors are leading to a re-examination of the balance between the roles of the operators and the machine in controlling nuclear power plants. Some of these factors are: the advent of new and advanced computer technologies; increased plant complexity, placing heavy workloads and stress on the control room operator; and increasing concerns about the role of human reliability in industrial mishaps. In light of the changing control aspects, we examine the meaning of automation, we discuss a proposed model of the control process, the concept of control within a few defined reactor states, a decision-making sequence; and we identify some possible problem areas in implementing new control technologies. Significant benefits should come from the new control methods and these opportunities should be exploited as soon as prudence allows, taking great care that the safety of the plants is improved

Changes in control room at Swedish nuclear power plants

International Nuclear Information System (INIS)

Kecklund, Lena

2005-09-01

The Swedish nuclear power plants were commissioned during a period between 1972 and 1985 and the instrumentation and control equipment are basically from that period. For several years there have been plans made for changes in all the nuclear power plants and to a certain extent the changes in control equipment and monitoring rooms have also been implemented. The object of this project was to make a comprehensive review of the changes in control room design implemented in the Swedish nuclear power plants and to describe how the MTO- (Man-Technology-Organisation) and (Man-Machine-Interface) -issues have been integrated in the process. The survey is intended to give an overall picture of the changes in control room design and man-machine-interface made in the Swedish control rooms, in order to get a deeper knowledge of the change management process and its results as well as of the management of MTO-issues in these projects. The units included in this survey are: Oskarhamn reactor 2 and 3; Ringhals reactor 2, 3 and 4; Forsmark reactor 1, 2 and 3. The Oskarshamn 1 unit has not been included in this report as it has recently undergone an extensive modernisation program as well as a detailed inspection by the SKI (Swedish Nuclear Power Inspectorate). At Ringhals 2 the modernisation work is carried out at present and the unit is also subjected to extensive inspection activities carried out by SKI and is therefore not part of this survey. This report also includes a short description of relevant standards and requirements. Then follows a presentation of the results of the plant survey, presented as case studies for three companies OKG, Ringhals and FKA. Control room changes are summarized as well as the results on specific MTO issues which has been surveyed. In all the power companies there is a joint way of working with projects concerning plant modifications. This process is described for each company separately. In the concluding of the report the strengths and

A metamorphic controller for plant control system design

Directory of Open Access Journals (Sweden)

Tomasz Klopot

2016-07-01

Full Text Available One of the major problems in the design of industrial control systems is the selection and parameterization of the control algorithm. In practice, the most common solution is the PI (proportional-integral controller, which is simple to implement, but is not always the best control strategy. The use of more advanced controllers may result in a better efficiency of the control system. However, the implementation of advanced control algorithms is more time-consuming and requires specialized knowledge from control engineers. To overcome these problems and to support control engineers at the controller design stage, the paper describes a tool, i.e., a metamorphic controller with extended functionality, for selection and implementation of the most suitable control algorithm. In comparison to existing solutions, the main advantage of the metamorphic controller is its possibility of changing the control algorithm. In turn, the candidate algorithms can be tested through simulations and the total time needed to perform all simulations can be less than a few minutes, which is less than or comparable to the design time in the concurrent design approach. Moreover, the use of well-known tuning procedures, makes the system easy to understand and operate even by inexperienced control engineers. The application was implemented in the real industrial programmable logic controller (PLC and tested with linear and nonlinear virtual plants. The obtained simulation results confirm that the change of the control algorithm allows the control objectives to be achieved at lower costs and in less time.

Medicinal plants used to control internal and external parasites in goats

Directory of Open Access Journals (Sweden)

Marcia Sanhokwe

2016-04-01

Full Text Available The use of medicinal plants plays a major role in the primary health care of animals in South Africa. A survey was conducted to document medicinal plants used to control parasites in goats in Kwezi and Ntambethemba villages in the Eastern Cape Province, South Africa. Information from 50 farmers and 3 herbalists was obtained through the use of a structured questionnaire, and a snowball sampling technique was used to identify key informants. The obtained data were analysed using PROC FREQ of SAS (2003, and fidelity level values were determined to estimate the healing potential of the mentioned plants. The survey revealed nine plant species belonging to eight families that were used to control parasites in goats. Asphodelaceae (22.22% was the most frequently used plant family. Leaves were the most used plant parts, constituting 60.38%. They were prepared either as infusions or decoctions of single plants or in mixtures. Aloe ferox, Acokanthera oppositifolia and Elephantorrhiza elephantina were the plants having the highest fidelity level for their use to control parasites, each scoring 100%, followed by Albuca setosa (83.33%. The study revealed low knowledge about ethnoveterinary medicine in the study area. It also revealed that information on ethno-veterinary medicine in this area is mostly confined to older people and there is danger that this knowledge can be lost before being passed on to other generations. Therefore, there is an urgent need to document information on these plant species so that the future generation can benefit. Further investigation should be carried out to validate the efficacy and safety of the above-mentioned plants so as to provide cheap alternative ways of controlling parasites. Keywords: ailments; ethno-veterinary practices; small ruminant; traditional medicine

Tritium control in reprocessing plants

International Nuclear Information System (INIS)

Goumondy, J.P.; Miquel, P.

1977-01-01

There is a danger that the T which is formed in water reactors will prove detrimental to the environment over the next few years, and studies have been undertaken to develop techniques to contain and process it where possible. In order to retain T, which is present largely in the fuel and on the possible to adapt for use in the conventional design of reprocessing plant. In this process T is maintained in the form of an aqueous solution in the high-active area of the plant. Control is achieved by restricting as far as possible the ingress of non-tritiated water into this area, and by setting up a tritiated water barrier at the first U and Pu extraction stage, stripping the tritium-containing solvent at that point with ordinary water. In this way the T can be extracted in a small volume of water with a view to intermediate storage, disposal at sea additional processing to remove the T from the water. Experiments carried out so far have demonstrated the effectiveness of the T barrier and have shown what equipment would be required for the application of the process in new reprocessing plants. (orig.) [de

Design of control rooms and ergonomics in power plants

International Nuclear Information System (INIS)

Herbst, L.; Hinz, W.

1981-01-01

Modern power plant control rooms are characterized by automation of protection and control functions, subdivision according to functions, computer-aided information processing, and ergonomic design. Automation relieves the personnel of stress. Subdivision according to functions permits optimized procedures. Computer-aided information processing results in variable information output tailored to the actual needs. Ergonomic design assures qualified man-machine interaction. Of course, these characteristics will vary between power plants in dependence of unit power, mode of operation, and safety and availability requirements. (orig.) [de

Reliable control system for nuclear power plant

International Nuclear Information System (INIS)

Okamoto, Tetsuo; Miyazaki, Shiro

1980-01-01

The System 1100 for nuclear power plants is the measuring and control system which utilizes the features of the System 1100 for electric power market in addition to the results of nuclear instrumentation with EBS-ZN series, and it has the following features. The maintenance and inspection in operation are easy. The construction of control loops is made flexibly by the combination of modules. The construction of multi-variable control system using mainly feed forward control is easy. Such functions as the automatic switching of control modes can be included. The switching of manual and automatic operations is easy, and if some trouble occurred in a module, the manual operation can be made. The aseismatic ability is improved by rigid structure cubicles. Nonflammable materials are used for wires, multi-core cables, paints and printed boards. The anti-noise characteristics are improved, and the reliability is high. The policy of developing the System 1100 for nuclear power plants, the type approval tests on modules and units and the type approval test on the system are described. The items of the system type approval test were standard performance test, earthquake test, noise isolation test, temperature and humidity test, and drift test. The aseismatic cubicle showed good endurance in its vibration test. (Kako, I.)

Tangible interfaces for virtual nuclear power plant control desk

Energy Technology Data Exchange (ETDEWEB)

Aghina, Mauricio Alves C.; Mol, Antonio Carlos A.; Jorge, Carlos Alexandre F.; Lapa, Celso M.F. [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Nomiya, Diogo [Engenharia Eletrica (UFRJ), Universidade Federal do Rio de Janeiro, RJ (Brazil); Cunha, Gerson G.; Landau, Luiz [Programa de Engenharia Civil (PEC/COPPE/UFRJ), Universidade Federal do Rio de Janeiro, RJ (Brazil)

2011-07-01

Due to the high safety requirements for nuclear power plant operation, control desks must be designed in such a way operators can take all the procedures safely, with a good overview of all variable indicators and easy access to actuator controls. Also, operators must see alarms indication in a way they can easily identify any abnormal conditions and bring the NPP back to normal operation. The ergonomics and human factors fields have helped evaluations to improve the design of nuclear power plant control systems. Lately, the use of virtual control desks have helped even more such evaluations, by integrating in one platform both nuclear power plant dynamics simulator with a high visual fidelity control desk proto typing. Operators can interact with these virtual control desks in a similar way as with real ones. Such a virtual control desk has been under development at Instituto de Engenharia Nuclear, IEN/CNEN. This paper reports the latest improvements, with the use of more interaction modes, to turn operation a friendlier task. An automatic speech recognition interface has been implemented as a self-contained system, by accessing directly MS Windows Application Interface, and with online neural network training for spoken commend recognition. Thus, operators can switch among different desk views. Besides this, head tracking interfaces have been integrated with the virtual control desk, to move within desk views according to users head movements. Both marker and markerless-based head tracking interfaces have been implemented. Results are shown and commented. (author)

Tangible interfaces for virtual nuclear power plant control desk

International Nuclear Information System (INIS)

Aghina, Mauricio Alves C.; Mol, Antonio Carlos A.; Jorge, Carlos Alexandre F.; Lapa, Celso M.F.; Nomiya, Diogo; Cunha, Gerson G.; Landau, Luiz

2011-01-01

Due to the high safety requirements for nuclear power plant operation, control desks must be designed in such a way operators can take all the procedures safely, with a good overview of all variable indicators and easy access to actuator controls. Also, operators must see alarms indication in a way they can easily identify any abnormal conditions and bring the NPP back to normal operation. The ergonomics and human factors fields have helped evaluations to improve the design of nuclear power plant control systems. Lately, the use of virtual control desks have helped even more such evaluations, by integrating in one platform both nuclear power plant dynamics simulator with a high visual fidelity control desk proto typing. Operators can interact with these virtual control desks in a similar way as with real ones. Such a virtual control desk has been under development at Instituto de Engenharia Nuclear, IEN/CNEN. This paper reports the latest improvements, with the use of more interaction modes, to turn operation a friendlier task. An automatic speech recognition interface has been implemented as a self-contained system, by accessing directly MS Windows Application Interface, and with online neural network training for spoken commend recognition. Thus, operators can switch among different desk views. Besides this, head tracking interfaces have been integrated with the virtual control desk, to move within desk views according to users head movements. Both marker and markerless-based head tracking interfaces have been implemented. Results are shown and commented. (author)

The advanced main control console for next japanese PWR plants

International Nuclear Information System (INIS)

Tsuchiya, A.; Ito, K.; Yokoyama, M.

2001-01-01

The purpose of the improvement of main control room designing in a nuclear power plant is to reduce operators' workload and potential human errors by offering a better working environment where operators can maximize their abilities. In order to satisfy such requirements, the design of main control board applied to Japanese Pressurized Water Reactor (PWR) type nuclear power plant has been continuously modified and improved. the Japanese Pressurized Water Reactor (PWR) Utilities (Electric Power Companies) and Mitsubishi Group have developed an advanced main control board (console) reflecting on the study of human factors, as well as using a state of the art electronics technology. In this report, we would like to introduce the configuration and features of the Advanced Main Control Console for the practical application to the next generation PWR type nuclear power plants including TOMARI No.3 Unit of Hokkaido Electric Power Co., Inc. (author)

Quality control during construction of power plants

International Nuclear Information System (INIS)

Hartstern, R.F.

1982-01-01

This paper traces the background and examines the necessity for a program to control quality during the construction phase of a power plant. It also attempts to point out considerations for making these programs cost effective

Cascade plant control by timer method

International Nuclear Information System (INIS)

Kiguchi, Takashi; Inoue, Kotaro; Kawai, Toshio; Senoo, Makoto.

1970-01-01

The present invention relates to a method of controlling uranium flow rate through a cascaded centrifuge plant for the purpose of enriching uranium 235. Such a cascade includes multiple gas separation stage each of which consists of a plurality of centrifuges. The product gas usually includes a large amount of He gas, and a cold trap is used to eliminate the He from UF 6 . The cold trap is operated periodically in such a way that the mixed gas of He and UF 6 is cooled to solidify only UF 6 and then warmed to obtain UF 6 by gasification. In order to operate the plant continuously, parallel multiple cold traps are operated alternatively. The operating conditions in such a complex cascade system are difficult to alter by conventional control methods. The present invention provides a rapid method of controlling the system when a certain percentage of the centrifuges in one stage malfunction. The control system consists of timers which are provided one for each cold trap to control the operational period of the trap. For example, if 20% of the centrifuges in a particular stage malfunction, the timer period of the cold traps attached to the normally operating centrifuge within the stage is maintained, and the period of all the other centrifuges are changed to 10/8 times that of the initial value. In this way the flow volume through all centrifuges except that in the particular stage is reduced to 80% of the initial value and the operation of the system can be continued with reduced efficiency. (Masui, R.)

A Business Case for Nuclear Plant Control Room Modernization

International Nuclear Information System (INIS)

Thomas, Ken; Lawrie, Sean; Niedermuller, Josef M.

2016-01-01

This paper presents a generic business case for implementation of technology that supports Control Room Modernization (CRM). The analysis presented in two forms; 1) a standalone technology upgrade, and 2) a technology upgrade that is built upon and incremental to a prior business case created for Mobile Work Packages (MWP). The business case contends that advanced communication and networking and analytical technologies will allow NPP to conduct control room operations with improved focus by reducing human factors and redundant manpower, and therefore operate with fewer errors. While some labor savings can be harvested in terms of overtime, the majority of savings are demonstrated as reduced time to take the plant off line and bring back on line in support of outages. The benefits are quantified to a rough order of magnitude that provides directional guidance to NPPs that are interested in developing a similar business case. This business case focuses on modernization of the operator control room and does not consider a complete overhaul and modernization of a plants instrument and control systems. While operators may be considering such an investment at their plants, the sizable capital investment required is not likely supported by a cost/benefit analysis alone. More likely, it is driven by obsolescence and reliability issues, and requires consideration of mechanical condition of plant systems, capital depreciation, financing, relicensing and overall viability of the plant asset over a 20-year horizon in a competitive market. Prior studies [REF] have indicated that such a modernization of plant I&C systems, alone or as part of a larger modernization effort, can yield very significant reductions in O&M costs. However, the depth of research and analysis required to develop a meaningful business case for a plant modernization effort is well beyond the scope of this study. While CRM as considered in this study can be easily integrated as part of grander plant

A Business Case for Nuclear Plant Control Room Modernization

Energy Technology Data Exchange (ETDEWEB)

Thomas, Ken [Idaho National Lab. (INL), Idaho Falls, ID (United States); Lawrie, Sean [Idaho National Lab. (INL), Idaho Falls, ID (United States); Niedermuller, Josef M. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2016-06-01

This paper presents a generic business case for implementation of technology that supports Control Room Modernization (CRM). The analysis presented in two forms; 1) a standalone technology upgrade, and 2) a technology upgrade that is built upon and incremental to a prior business case created for Mobile Work Packages (MWP). The business case contends that advanced communication and networking and analytical technologies will allow NPP to conduct control room operations with improved focus by reducing human factors and redundant manpower, and therefore operate with fewer errors. While some labor savings can be harvested in terms of overtime, the majority of savings are demonstrated as reduced time to take the plant off line and bring back on line in support of outages. The benefits are quantified to a rough order of magnitude that provides directional guidance to NPPs that are interested in developing a similar business case. This business case focuses on modernization of the operator control room and does not consider a complete overhaul and modernization of a plants instrument and control systems. While operators may be considering such an investment at their plants, the sizable capital investment required is not likely supported by a cost/benefit analysis alone. More likely, it is driven by obsolescence and reliability issues, and requires consideration of mechanical condition of plant systems, capital depreciation, financing, relicensing and overall viability of the plant asset over a 20-year horizon in a competitive market. Prior studies [REF] have indicated that such a modernization of plant I&C systems, alone or as part of a larger modernization effort, can yield very significant reductions in O&M costs. However, the depth of research and analysis required to develop a meaningful business case for a plant modernization effort is well beyond the scope of this study. While CRM as considered in this study can be easily integrated as part of grander plant

A discrete control model of PLANT

Science.gov (United States)

Mitchell, C. M.

1985-01-01

A model of the PLANT system using the discrete control modeling techniques developed by Miller is described. Discrete control models attempt to represent in a mathematical form how a human operator might decompose a complex system into simpler parts and how the control actions and system configuration are coordinated so that acceptable overall system performance is achieved. Basic questions include knowledge representation, information flow, and decision making in complex systems. The structure of the model is a general hierarchical/heterarchical scheme which structurally accounts for coordination and dynamic focus of attention. Mathematically, the discrete control model is defined in terms of a network of finite state systems. Specifically, the discrete control model accounts for how specific control actions are selected from information about the controlled system, the environment, and the context of the situation. The objective is to provide a plausible and empirically testable accounting and, if possible, explanation of control behavior.

Spectral composition of light and growing of plants in controlled environments

Energy Technology Data Exchange (ETDEWEB)

Tikhomirov, A.A. [Institute of Biophysics, Krasnoyarsk (Russian Federation)

1994-12-31

The curve of the action spectrum of photosynthesis is examined under the controlled influence of light that involves av 3-5 minutes irradiation with one specific spectral flux. Different curves were obtained for spectral affectivity of green leaf photosynthesis when plants have had long duration adaptation to lamps of different spectral composition and PAR intensity. The author suggests that the illumination of plants in natural conditions does not have to be copied for growing plants in controlled environments.

Choosing Actuators for Automatic Control Systems of Thermal Power Plants

Energy Technology Data Exchange (ETDEWEB)

Gorbunov, A. I., E-mail: gor@tornado.nsk.ru [JSC “Tornado Modular Systems” (Russian Federation); Serdyukov, O. V. [Siberian Branch of the Russian Academy of Sciences, Institute of Automation and Electrometry (Russian Federation)

2015-03-15

Two types of actuators for automatic control systems of thermal power plants are analyzed: (i) pulse-controlled actuator and (ii) analog-controlled actuator with positioning function. The actuators are compared in terms of control circuit, control accuracy, reliability, and cost.

Control and automation technology in United States nuclear power plants

International Nuclear Information System (INIS)

Sun, B.K.H.

1997-01-01

The need to use computers for nuclear power plant design, engineering, operation and maintenance has been growing since the inception of commercial nuclear power electricity generation in the 1960s. The needs have intensified in recent years as the demands of safety and reliability, as well as economic competition, have become stronger. The rapid advance of computer hardware and software technology in the last two decades has greatly enlarged the potential of computer applications to plant instrumentation and control of future plants, as well as those needed for operation of existing plants. The traditional role of computers for mathematical calculations and data manipulation has been expanded to automate plant control functions and to enhance human performance and productivity. The major goals of using computers for instrumentation and control of nuclear power plants are (1) to improve safety; (2) to reduce challenges to the power plant; (3) to reduce the cost of operations and maintenance; (4) to enhance power production, and (5) to increase productivity of people. Many functions in nuclear power plants are achieved by a combination of human action and automation. Increasingly, computer-based systems are used to support operations and maintenance personnel in the performance of their tasks. There are many benefits which can accrue from the use of computers but it is important to ensure that the design and implementation of the support system and the human task places the human in the correct role in relation to the machine; that is, in a management position, with the computer serving the human. In addition, consideration must be given to computer system integrity, software validation and verification, consequences of error, etc., to ensure its reliability for nuclear power plant applications. (author). 31 refs

Control and automation technology in United States nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Sun, B K.H. [Sunutech, Inc., Los Altos, CA (United States)

1997-07-01

The need to use computers for nuclear power plant design, engineering, operation and maintenance has been growing since the inception of commercial nuclear power electricity generation in the 1960s. The needs have intensified in recent years as the demands of safety and reliability, as well as economic competition, have become stronger. The rapid advance of computer hardware and software technology in the last two decades has greatly enlarged the potential of computer applications to plant instrumentation and control of future plants, as well as those needed for operation of existing plants. The traditional role of computers for mathematical calculations and data manipulation has been expanded to automate plant control functions and to enhance human performance and productivity. The major goals of using computers for instrumentation and control of nuclear power plants are (1) to improve safety; (2) to reduce challenges to the power plant; (3) to reduce the cost of operations and maintenance; (4) to enhance power production, and (5) to increase productivity of people. Many functions in nuclear power plants are achieved by a combination of human action and automation. Increasingly, computer-based systems are used to support operations and maintenance personnel in the performance of their tasks. There are many benefits which can accrue from the use of computers but it is important to ensure that the design and implementation of the support system and the human task places the human in the correct role in relation to the machine; that is, in a management position, with the computer serving the human. In addition, consideration must be given to computer system integrity, software validation and verification, consequences of error, etc., to ensure its reliability for nuclear power plant applications. (author). 31 refs.

Development of high-reliability control system for nuclear power plants

International Nuclear Information System (INIS)

Asami, K.; Yanai, K.; Hirose, H.; Ito, T.

1983-01-01

In Japan, many nuclear power generating plants are in operation and under construction. There is a general awareness of the problems in connection with nuclear power generation and strong emphasis is put on achieving highly reliable operation of nuclear power plants. Hitachi has developed a new high-reliability control system. NURECS-3000 (NUclear Power Plant High-REliability Control System), which is applied to the main control systems, such as the reactor feedwater control system, the reactor recirculation control system and the main turbine control system. The NURECS-3000 system was designed taking into account the fact that there will be failures, but the aim is for the system to continue to function correctly; it is therefore a fault-tolerant system. It has redundant components which can be completely isolated from each other in order to prevent fault propagation. The system has a hierarchical configuration, with a main controller, consisting of a triplex microcomputer system, and sub-loop controllers. Special care was taken to ensure the independence of these subsystems. Since most of the redundant system failures are caused by common-mode failures and the reliability of redundant systems depends on the reliability of the common-mode parts, the aim was to minimize these parts. (author)

Control of Listeria monocytogenes in food production plants

Directory of Open Access Journals (Sweden)

Dimitrijević Mirjana

2008-01-01

Full Text Available L. monocytogenes has been established in different plants for the production of food, including dairy plants, abattoirs, plants for the processing of fish, as well as those for the production of ready-to-eat (RTE food and this fact is being considered as the primary mechanism of food contamination with this bacteria. There is also the factor of numerous and diverse contaminated production equipment, because it has certain parts that are inaccessible for the necessary cleaning and disinfection. The temperature, position, as well as the material of the work surface are also linked to the contamination of plants with this bacteria. Investigations carried out so far have helped toward the better understanding of the manner and time of contamination of food items in the course of the production process, but there are still unresolved problems, including most certainly the biggest one - the adherence of bacteria and the creation of a biofilm, when the bacteria is in that condition more resistant to so-called stress factors which are usually used in the food industry for the purpose of decontamination of the surfaces with which foods come into contact. The control of L. monocytogenes in food production plants is possible primarily by using an integrated programme, compatible with the systems Hazard Analysis Critical Control Point (HACCP and Good Hygiene Practice (GHP, necessary in the production of food that is safe for the consumer. Essentially, the control measures that can contribute to reducing the incidence of findings of L.monocytogenes in the finished product, as well as the reducing of the level of contamination with this bacteria are linked, on the one hand, with hygiene procedures in the production process, and, on the other, with the applied technological procedures.

Possibilities of avoidance and control of bacterial plant diseases when using pathogen-tested (certified) or - treated planting material

NARCIS (Netherlands)

Janse, J.; Wenneker, M.

2002-01-01

Testing of planting material for freedom from phytopathogenic bacteria is an important, although not exclusive, method for control of bacterial diseases of plants. Ideally, pathogen-free or pathogen-/disease-resistant planting material is desirable, but this situation is not always possible on a

Control system upgrades support better plant economics

International Nuclear Information System (INIS)

De Grosbois, J.; Hepburn, A.; Storey, H.; Basso, R.; Kumar, V.

2002-01-01

This paper (second in the series, see [1]) provides insight on how nuclear plants can achieve better efficiencies and reduced operations and maintenance (O and M) costs through focused control system upgrades. An understanding of this relationship is necessary to properly assess the economics of plant refurbishment decisions. Traditional economic feasibility assessment methods such as benefit cost analysis (BCA), internal rate of return (IRR), benefit cost ratios (B/C), or payback analysis are often performed without full consideration of project alternatives, quantified benefits, and life cycle costing. Consideration must be given to not only capital cost and project risk, but also to the potential economic benefits of new technology and added functionality offered by plant upgrades. Recent experience shows that if upgrades are focused on priority objectives, and are effectively implemented, they can deliver significant payback over the life of the plant, sometimes orders of magnitude higher than their initial capital cost. The following discussion explores some of the key issues and rationale behind upgrade decisions and their impact on improved plant efficiency and reduced O and M costs. A subsequent paper will explain how the justification for these improvements can be captured in an economic analysis and feasibility study to support strategic decision-making in a plant refurbishment context. (author)

Design of a Load Following Controller for APR+ Nuclear Plants

International Nuclear Information System (INIS)

Lee, Sim Won; Kim, Jae Hwan; Kim, Dong Su; Na, Man Gyun; Yu, Keuk Jong

2011-01-01

The load-following operation of an APR+ nuclear plants is required to restrain the adjustment of boric acid concentration and to efficiently control the control rods for the flexibility of the operation. Especially, axial flux distribution disproportion that is usually caused by load-following operation in a reactor core induces xenon oscillation because the absorption cross-section of xenon is extremely large and its effects in a reactor are delayed by the iodine precursor. Rapid and smooth power maneuvering has its benefits in view of the economical and safe operation of reactors, so it is required that the controller is efficiently designed. Therefore, the load-following operation of an APR+ nuclear plants needs the ultimate automatic control and the advanced control method that satisfies the conditions such as the flexibility, safety and convenience. A model predictive control (MPC) method is applied to design an automatic load-following controller for the integrated thermal power level and axial shape index (ASI) control for an APR+ nuclear plants. Some tracking controllers use only the current tracking command. On the other hand, since MPC considers future commands in addition to the current tracking command, the MPC can achieve better tracking performance. Therefore, the MPC has been applied very much to the control of industrial process systems. The basic concept of the MPC is to solve an optimization problem for generating finite future control inputs at current time and to implement as the current control input only the first control input among the solutions of the finite time steps. At the next time step, the second control input is not implemented and the procedure to solve the optimization problem is then repeated. The power level and the ASI are controlled by the regulating control banks and part-strength control banks together with the automatic adjustment of boric acid concentration. The 3-dimensional MASTER code, which models the APR+ nuclear

Design of a Load Following Controller for APR+ Nuclear Plants

Energy Technology Data Exchange (ETDEWEB)

Lee, Sim Won; Kim, Jae Hwan; Kim, Dong Su; Na, Man Gyun [Chosun University, Gwnagju (Korea, Republic of); Yu, Keuk Jong [Korea Hydro and Nuclear Power Co., Daejeon (Korea, Republic of)

2011-08-15

The load-following operation of an APR+ nuclear plants is required to restrain the adjustment of boric acid concentration and to efficiently control the control rods for the flexibility of the operation. Especially, axial flux distribution disproportion that is usually caused by load-following operation in a reactor core induces xenon oscillation because the absorption cross-section of xenon is extremely large and its effects in a reactor are delayed by the iodine precursor. Rapid and smooth power maneuvering has its benefits in view of the economical and safe operation of reactors, so it is required that the controller is efficiently designed. Therefore, the load-following operation of an APR+ nuclear plants needs the ultimate automatic control and the advanced control method that satisfies the conditions such as the flexibility, safety and convenience. A model predictive control (MPC) method is applied to design an automatic load-following controller for the integrated thermal power level and axial shape index (ASI) control for an APR+ nuclear plants. Some tracking controllers use only the current tracking command. On the other hand, since MPC considers future commands in addition to the current tracking command, the MPC can achieve better tracking performance. Therefore, the MPC has been applied very much to the control of industrial process systems. The basic concept of the MPC is to solve an optimization problem for generating finite future control inputs at current time and to implement as the current control input only the first control input among the solutions of the finite time steps. At the next time step, the second control input is not implemented and the procedure to solve the optimization problem is then repeated. The power level and the ASI are controlled by the regulating control banks and part-strength control banks together with the automatic adjustment of boric acid concentration. The 3-dimensional MASTER code, which models the APR+ nuclear

Simulation research on multivariable fuzzy model predictive control of nuclear power plant

International Nuclear Information System (INIS)

Su Jie

2012-01-01

To improve the dynamic control capabilities of the nuclear power plant, the algorithm of the multivariable nonlinear predictive control based on the fuzzy model was applied in the main parameters control of the nuclear power plant, including control structure and the design of controller in the base of expounding the math model of the turbine and the once-through steam generator. The simulation results show that the respond of the change of the gas turbine speed and the steam pressure under the algorithm of multivariable fuzzy model predictive control is faster than that under the PID control algorithm, and the output value of the gas turbine speed and the steam pressure under the PID control algorithm is 3%-5% more than that under the algorithm of multi-variable fuzzy model predictive control. So it shows that the algorithm of multi-variable fuzzy model predictive control can control the output of the main parameters of the nuclear power plant well and get better control effect. (author)

Combined cycle plant controls retrofit case history

International Nuclear Information System (INIS)

Tenney, D.; Pieszchala, T.

1991-01-01

The Comanche Power Station, Public Service of Oklahoma's combined cycle generating facility, underwent a controls and operator panel retrofit at the end of 1988. The plant consists of two gas turbines, two heat recovery boilers and a steam turbine along with three generators. This paper examines the extent to which the original goals and specifications were met. Costs, operating principles and modifications since the original installation are discussed. Operating procedures are compared with the original system. The future of the plant is discussed and the impact on the power system grid is analyzed

Aplicación de dos pruebas estadísticas de bondad de ajuste en muestras complejas: un caso práctico en el campo forestal

OpenAIRE

Quintero-Méndez, María A.; Durán-Núñez, Mariano J.

2008-01-01

En esta investigación se comparan dos pruebas de bondad de ajuste en términos de su error tipo I: ji-cuadrada de Pearson y Rao-Scott con corrección de segundo orden, aplicadas a datos recolectados mediante técnicas de muestreo que no cumplen los supuestos de independencia e igual probabilidad de inclusión de las observaciones, llamadas muestras complejas. Ambas pruebas se usaron para ajustar categorías diamétricas en una plantación de gmelina (Gmelina arborea), aplicando muestreo sistemático ...

How to design electrical systems with central control capability for industrial plants

Energy Technology Data Exchange (ETDEWEB)

Cigolini, S.; Galati, G.; Lionetto, P.F.; Stiz, M. (Siemens, Milan (Italy) Centro Elettrotecnico Sperimentale Italiano, Milan (Italy))

1991-12-01

The modern centralized control system, incorporating microprocessors, constitutes an extremely efficacious instrument for the management of an industrial plant's electrical system and provides the performance, reliability, flexibility and safety features required by today's technologically advanced plant processes. The use of intelligent centralized control systems, capable of autonomous operation and dialoguing with industrial plant electrical systems, simplifies the design of the overall plant. This paper reviews the main design criteria for the automated systems and gives examples of some suitable commercially available intelligent systems.

Long-term preventive maintenance of instrumentation control equipment for PWR plants

International Nuclear Information System (INIS)

Sugitani, S.; Nanba, M.

2006-01-01

Since the PWR plants in Japan have been operated more than 30 years, main instrumentation control equipment of analog systems has been renewed to digital control systems. Renewal works had to be done in short period within periodical inspection term and for several facilities. The Mitsubishi LTD group had been provided with these market needs by its digital control system (MELTAC-NplusR 3) applicable to main instrumentation control equipment for primary and secondary systems and had already finished the renewal for practical plants. (T. Tanaka)

Identification and Control of Nutrient Removing Processes in Wastewater Treatment Plants

DEFF Research Database (Denmark)

Nielsen, Marinus K.; Madsen, Henrik; Carstensen, Niels Jacob

1994-01-01

the possibility of using statistical methods for identifying dynamical models for the biological processes. These models can then be used for simulating various control strategies and the parameters of the controllers can be found by off-line optimization. Simulation studies have shown that considerable savings......Today the use of on-line control for wastewater treatment plants is very low. A main reason is the lack of quality of the data, and the fact that more sophisticated control strategies must be based on a model of the dynamics of the biological processes. This paper discusses the historical reasons...... for the limited use of modern control strategies for wastewater treatment plants. Today, however, on-line nutrient sensors are more reliable. In the present context the use of on-line monitored values of ammonia, nitrate and phosphate from a full scale plant are used as the background for discussing...

Advanced digital computers, controls, and automation technologies for power plants: Proceedings

International Nuclear Information System (INIS)

Bhatt, S.C.

1992-08-01

This document is a compilation of the papers that were presented at an EPRI workshop on Advances in Computers, Controls, and Automation Technologies for Power Plants. The workshop, sponsored by EPRI's Nuclear Power Division, took place February 1992. It was attended by 157 representatives from electric utilities, equipment manufacturers, engineering consulting organizations, universities, national laboratories, government agencies and international utilities. More than 40% of the attendees were from utilities representing the majority group. There were 30% attendees from equipment manufacturers and the engineering consulting organizations. The participants from government agencies, universities, and national laboratories were about 10% each. The workshop included a keynote address, 35 technical papers, and vendor's equipment demonstrations. The technical papers described the state-of-the-art in the areas of recent utility digital upgrades such as digital feedwater controllers, steam generator level controllers, integrated plant computer systems, computer aided diagnostics, automated testing and surveillance and other applications. A group of technical papers presented the ongoing B ampersand W PWR integrated plant control system prototype developments with the triple redundant advanced digital control system. Several international papers from France, Japan and U.K. presented their programs on advance power plant design and applications. Significant advances in the control and automation technologies such as adaptive controls, self-tuning methods, neural networks and expert systems were presented by developers, universities, and national laboratories. Individual papers are indexed separately

Informatization of items quality control for NI in nuclear power plant

International Nuclear Information System (INIS)

Zhang Jiankui; Zang Baiqi

2010-01-01

Design ideas, implementation methods and some key techniques for item quality control of NI in nuclear power plant are illustrated in this article according to item quality management mode. The item quality control method can improve the quality of NI, ensure the safety and lower the construction and operation cost of nuclear power plant. (authors)

Reply to Miglietta et al.: Maximal transpiration controlled by plants

NARCIS (Netherlands)

Boer, H.J. de; Lammertsma, E.I.; Wagner-Cremer, F.; Dilcher, D.L.; Wassen, M.J.; Dekker, S.C.

2011-01-01

We thank Miglietta et al. for their interest in our study. Their first and main point arises from the idea that plant transpiration (T) is driven by atmospheric demand, giving plants limited control over the water they lose...

Nuclear reactor plants and control systems therefor

International Nuclear Information System (INIS)

de Boer, G.A.; de Hex, M.

1976-01-01

A nuclear reactor plant is described comprising at least two hydraulically separated but thermally interconnected heat conveying circuits, of which one is the reactor circuit filled with a non-water medium and the other one is the water-steam-circuit equipped with a steam generator, a feed water conduit controlled by a valve and a steam turbine, and a control system mainly influenced by the pressure drop caused in said feed water conduit and its control valve and having a value of at least 10 bars at full load

Control and automation technology in United States nuclear power plants

International Nuclear Information System (INIS)

Sun, B.K.H.

1995-01-01

The need to use computers for nuclear power plant design, engineering, operation and maintenance has been growing since the inception of commercial nuclear power electricity generation in the 1960s. The needs have intensified in recent years as the demands of safety and reliability, as well as economic competition, have become stronger. The rapid advanced of computer hardware and software technology in the last two decades has greatly enlarged the potential of computer applications to plant instrumentation and control of future plants, as well as those needed for operation of existing plants. The traditional role of computers for mathematical calculations and data manipulation has been expanded to automate plant control functions and to enhance human performance and productivity. The major goals of using computers for instrumentation and control of nuclear power plants are: (1) to improve safety; (2) to reduce challenges to capital investments; (3) to reduce the cost of operations and maintenance; (4) to enhance power production; and (5) to increase productivity of people. Many functions in nuclear power plants are achieved by a combination of human action and automation. Increasingly, computer-based systems are used to support operations and maintenance personnel in the performance of their tasks. There are many benefits which can accrue from the use of computers but it is important to ensure that the design and implementation of the support system, and the human task places the human in the correct role in the relation to the machine; that is, in a management position, with the computer serving the human. In addition, consideration must be given to computer system integrity, software validation and verification, consequences of error, etc., to ensure its reliability for nuclear power plant applications. (author). 31 refs

Demonstration of a Porous Tube Hydroponic System to Control Plant Moisture and Growth

Science.gov (United States)

Dreschel, T. W.; Hall, C. R.; Foster, T. E.

2003-01-01

Accurate remote detection of plant health indicators such as moisture, plant pigment concentrations, photosynthetic flux, and other biochemicals in canopies is a major goal in plant research. Influencing factors include complex interactions between wavelength dependent absorbing and scattering features from backgrounds as well as canopy biochemical and biophysical constituents. Accurately controlling these factors in outdoor field studies is difficult. Early testing of a porous tube plant culture system has indicated that plant biomass production, biomass partitioning, and leaf moisture of plants can be controlled by precisely managing the root water potential. Managing nutrient solution chemistry can also control plant pigments, biochemical concentrations, plant biomass production, and photosynthetic rates. A test bed was developed which utilized the porous tube technology with the intent of evaluating remote sensing systems, spectral analyses procedures, gas-exchange, and fluorescence measurements for their ability to detect small differences in plant water status. Spectral analysis was able to detect small differences in the mean leaf water content between the treatments. However these small differences were not detectable in the gas-exchange or fluorescence measurements.

B-Plant Canyon Ventilation Control System Description; FINAL

International Nuclear Information System (INIS)

MCDANIEL, K.S.

1999-01-01

Project W-059 installed a new B Plant Canyon Ventilation System. Monitoring and control of the system is implemented by the Canyon Ventilation Control System (CVCS). This document describes the CVCS system components which include a Programmable Logic Controller (PLC) coupled with an Operator Interface Unit (OIU) and application software. This document also includes an Alarm Index specifying the setpoints and technical basis for system analog and digital alarms

Control room modernization at Finnish nuclear power plants - Two projects compared

International Nuclear Information System (INIS)

Laarni, J.; Norros, L.

2006-01-01

The modernization of automation systems and human-machine interfaces is a current issue at both of the two nuclear power plants (i.e., Fortum's Loviisa plant and TVO's Olkiluoto plant) in Finland. Since the plants have been launched in the 1970's or 1980's, technology is in part old-fashioned and needs to be renewed. At Olkiluoto upgrades of the turbine operator systems have already been conducted; at Loviisa the first phase of the modernization project has just started. Basically, there is a question of the complete digitalization of the information streams at the two plants, and transition from a conventional hard-wired or hybrid control room to a screen-based one. The new human-machine interfaces will comprise new technology, such as PC workstations, soft control, touch screens and large-screen overall displays. The modernization of human-system interfaces is carried out in a stepwise manner at both plants. At both plants the main driver has not been the need to renew the user interfaces of the control room, but the need to upgrade the automation systems. In part because of this, there is a lack of a systematic top-down approach in which different aspects of human factors (HF) engineering are considered in relationship to higher level goals. Our aim here is to give an overview description of the control room modernization projects at the two plants and provide a preliminary evaluation of their progress to date. The projects are also compared, for example, in terms of duration, scope and phasing, and who is responsible for the realization of the project. In addition, we also compare experiences from the Finnish projects to experiences from similar projects abroad. The main part of the data used in this study is based on designers' and project members' interviews. (authors)

Assessment of control rooms of nuclear power plants

International Nuclear Information System (INIS)

Norros, L.; Ranta, J.; Wahlstroem, B.

1983-05-01

To identify and correct the lacks in control rooms of operating power plants and plants under construction an extensive program has been started in the USA. In Finland as in other countries using nuclear power, the development in the USA particularly with regard to the requirements imposed on nuclear power plants is carefully followed. The changes in these requirements are sooner or later also reflected in the guidelines given by the Finnish authorities. It is therefore important to be able to form a notion of how the new requirements apply to Finnish conditions. Especially it is important to review the latest assessment guidelines for control room implementation (NUREG-0700). Thus we can avoid possible over hasty conclusions. The aim of the analysis of the method and experiments presented in NUREG 0700 report was to create a basis for assessment of the suitability of the method for Finnish control room implementation. The task group has made a general methodical analysis of the method, and partly tried it in assessment of the TVO2 control room. It is obvious that direct conclusions from the American situation are misleading. It can be considered unfeasible to follow the American requirements as such, because they can lead to unwanted results. If the review is limited to control room details, the NRC program (checklist) can be considered successful. It can also be used during planning to observation of small discrepancies. However, we can question the applicability of some requirements. It is, though, more essential that the control room entity has neither in this nor in several other programs been reached or standardized. In spite of the difficulties we should try to reach this most important goal. (author)

Development of a visual control and display system for the SMART plant analyzer

International Nuclear Information System (INIS)

Kang, Han Ok; Yoon, Ju Hyeon; Seo, Jae Kwang; Lee, Doo Jeong

2000-01-01

A Visual Control and Display System (VCDS) for the SMART plant analyzer has been developed using the MMS simulation tools. The SAMRT plant analyzer consists of the VCDS and the MMS SMART model. The MMS SMART model is a numerical simulation model for the SMART plant and is composed of the MMS real-time modules and control blocks. It covers the whole plant including primary, secondary and auxiliary systems. The developed VCDS is Graphical User Interfaces (GUI) that is running in a synchronized way with the SMART model. The VCDS consists of the MMS Simulation tools and seven control and display screens. The VCDS provides easy means for the control and display of the SMART model status. The VCDS allows users to display and change a specified list of model variables and transient scenarios interactively through the MMS simulation tools. The control and display screens are developed with Visual Basic 6.0 and MMI32 ActiveX controls and it can be executed in several TCP/IP networked computers simultaneously. The developed VCDS can be utilized for the engineering simulation of the SMART plant operation, and for control logic and operational procedure developments

A framework for selecting suitable control technologies for nuclear power plant systems

International Nuclear Information System (INIS)

Kisner, R.A.

1992-01-01

New concepts continue to emerge for controlling systems, subsystems, and components and for monitoring parameters, characteristics, and vital signs in nuclear power plants. The steady stream of new control theories and the evolving state of control software exacerbates the difficulty of selecting the most appropriate control technology for nuclear power plant systems. As plant control room operators increase their reliance on computerized systems, the integration of monitoring, diagnostic, and control functions into a uniform and understandable environment becomes imperative. A systematic framework for comparing and evaluating the overall usefulness of control techniques is needed. This paper describes nine factors that may be used to evaluate alternative control concepts. These factors relate to a control system's potential effectiveness within the context of the overall environment, including both human and machine components. Although not an in-depth study, this paper serves to outline an evaluation framework based on several measures of utility. 32 refs

Improvement of environmental aspects of thermal power plant operation by advanced control concepts

Directory of Open Access Journals (Sweden)

Mikulandrić Robert

2012-01-01

Full Text Available The necessity of the reduction of greenhouse gas emissions, as formulated in the Kyoto Protocol, imposes the need for improving environmental aspects of existing thermal power plants operation. Improvements can be reached either by efficiency increment or by implementation of emission reduction measures. Investments in refurbishment of existing plant components or in plant upgrading by flue gas desulphurization, by primary and secondary measures of nitrogen oxides reduction, or by biomass co-firing, are usually accompanied by modernisation of thermal power plant instrumentation and control system including sensors, equipment diagnostics and advanced controls. Impact of advanced control solutions implementation depends on technical characteristics and status of existing instrumentation and control systems as well as on design characteristics and actual conditions of installed plant components. Evaluation of adequacy of implementation of advanced control concepts is especially important in Western Balkan region where thermal power plants portfolio is rather diversified in terms of size, type and commissioning year and where generally poor maintenance and lack of investments in power generation sector resulted in high greenhouse gases emissions and low efficiency of plants in operation. This paper is intended to present possibilities of implementation of advanced control concepts, and particularly those based on artificial intelligence, in selected thermal power plants in order to increase plant efficiency and to lower pollutants emissions and to comply with environmental quality standards prescribed in large combustion plant directive. [Acknowledgements. This paper has been created within WBalkICT - Supporting Common RTD actions in WBCs for developing Low Cost and Low Risk ICT based solutions for TPPs Energy Efficiency increasing, SEE-ERA.NET plus project in cooperation among partners from IPA SA - Romania, University of Zagreb - Croatia and Vinca

Proceedings of the Tripartite Seminar on Nuclear Material Accounting and Control at Radiochemical Plants

International Nuclear Information System (INIS)

1999-01-01

The problems of creation and operation of nuclear materials (NM) control and accounting systems and their components at radiochemical plants were discussed in seminar during November 2-6 of 1998. There were 63 Russian and 25 foreign participants in seminar. The seminar programme includes following sessions and articles: the aspects of State NM control and accountancy; NM control and accounting in radiochemical plants and at separate stages of reprocessing of spent nuclear fuel and irradiated fuel elements of commercial reactors; NM control and accountancy in storage facilities of radiochemical plants; NM control and accounting computerization, material balance assessment, preparation of reports; qualitative and quantitative measurements in NM control and accounting at radiochemical plants destructive analysis techniques [ru

The System 80+ Standard Plant design control document. Volume 18

International Nuclear Information System (INIS)

1997-01-01

This Design Control Document (DCD) is a repository of information comprising the System 80+trademark Standard Plant Design. The DCD also provides that design-related information to be incorporated by reference in the design certification rule for the System 80+ Standard Plant Design. Applicants for a combined license pursuant to 10 CFR 52 must ensure that the final Design Certification Rule and the associated Statements of Consideration are used when making all licensing decisions relevant to the System 80+ Standard Plant Design. The Design Control Document contains the DCD introduction, The Certified Design Material (CDM) [i.e., ''Tier 1''] and the Approved Design Material (ADM) [i.e., ''Tier 2''] for the System 80+ Standard Plant Design. The CDM includes the following sections: (1) Introductory material; (2) Certified Design Material for System 80+ systems and structures; (3) Certified Design Material for non-system-based aspects of the System 80+ Certified design; (4) Interface requirements; and (5) Site parameters. The ADM, to the extent applicable for the System 80+ Standard Plant Design, includes: (1) the information required for the final safety analysis report under 20 CFR 50.34; (2) other relevant information required by 10 CFR 52.47; and (3) emergency operations guidelines. This volume contains the following technical specifications of section 16 (Technical Specifications) of the ADM Design and Analysis: TS 3.3 Instrumentation; TS 3.4 Reactor Coolant System; TS 3.5 Emergency Core Cooling System; TS 3.6 Containment Systems; TS 3.7 Plant Systems; TS 3.8 Electrical Power Systems; TS 3.9 Refueling Operations; TS 4.0 Design Features; TS 5.0 Administrative Controls. Appendix 16 A Tech Spec Bases is also included. It contains the following: TS B2.0 Safety Limits Bases; TS B3.0 LCO Applicability Bases; TS B3.1 Reactivity Control Bases; TS B3.2 Power Distribution Bases

Modernization of instrumentation and control in nuclear power plants. Report prepared within the framework of the International Working Group on Nuclear Power Plant Control and Instrumentation

International Nuclear Information System (INIS)

1998-05-01

The scope of the modernization activities described in this report includes the modernization of equipment in operating plants and partially built plants. It covers the full range of types of instrumentation and control (I and C) systems including protection, safety, control and information systems. It is applicable for a plant throughout its life. The report includes appropriate consideration of the increasingly international nature of the I and C systems supply industry and takes advantage of the activities and lessons learned in the different national approaches to develop general guidance and recommendations. An Annex includes 10 country reports which were separately indexed

Control room, emergency control system and local control panels in nuclear power plants

International Nuclear Information System (INIS)

1988-01-01

The requirements on planning and construction of control boards including ergonomic-technical designing are specified in this rule. The specifications put the requirements on the design of place, process and environment of work, which are mentioned in the sections 90 and 91 of the labor-management relations act, into more concrete terms for the safety-relevant control panels as work places in a nuclear power station. The work places at control panels are not considered as video workstations in the sense of the 'Safety Rules for Video Workstations in the Office Sector' published by the General Association of the Industrial Trade Associations. The requirements are based on the operation and information technology realized at present in control panels of stationary nuclear power plants. (orig./HP) [de

Parasitic plants in agriculture: Chemical ecology of germination and host-plant location as targets for sustainable control: A review

Science.gov (United States)

Justin B. Runyon; John F. Tooker; Mark C. Mescher; Consuelo M. De Moraes

2009-01-01

Parasitic plants are among the most problematic pests of agricultural crops worldwide. Effective means of control are generally lacking, in part because of the close physiological connection between the established parasite and host plant hindering efficient control using traditional methods. Seed germination and host location are critical early-growth stages that...

Malaysian Preparation for Nuclear Power Plant Instrumentation and Control System

International Nuclear Information System (INIS)

Mohd Idris Taib; Nurfarhana Ayuni Joha; Kamarudin Sulaiman; Izhar Abu Hussin

2011-01-01

Instrumentation and Control System is required in Nuclear Power Plant for their safe and effective operation. The system is combination and integrated from detectors, actuators, analog system as well as digital system. Current design of system definitely follows of electronic as well as computer technology, with strictly follow regulation and guideline from local regulator as well as International Atomic Energy Agency. Commercial Off-The-Shelf products are extensively used with specific nucleonic instrumentation. Malaysian experiences depend on Reactor TRIGA PUSPATI Instrumentation and Control, Power Plant Instrumentation and Control as well as Process Control System. However Malaysians have capabilities to upgrade themself from Electronics, Computers, Electrical and Mechanical based. Proposal is presented for Malaysian preparation. (author)

Angra nuclear plant - environmental control program; Usina Nuclear de Angra: programa de controle ambiental

Energy Technology Data Exchange (ETDEWEB)

Kircher, E; Cruz, E.S. da [FURNAS, Rio de Janeiro, RJ (Brazil)

1990-12-31

The pre-operational studies, that were elaborated before the beginning of Angra I Power Plant operation, are described in particular the environmental radiological safety area till the fuel loading in the core reactor. Several aspects are included, as socio-economic survey, seismological analysis, Meteorological Program, marine biology, water cooling system, exposure measures of natural radiation, marine sediments characterization in the effluent dispersion area and Environmental Radiological Monitoring Program. The main environmental programs developed for the operational phase of the Angra I Plant are also presented, citing some considerations about the Meteorological Program, Marine Biology Control Program, Temperature and Chlorine Control in Piraquara de Fora Bay, Radiological Environmental Monitoring Program, Sanitary Effluent Control Program and Radiological Emergency Program. (C.G.C.). 2 refs.

Epigenetic control of effectors in plant pathogens

Directory of Open Access Journals (Sweden)

Mark eGijzen

2014-11-01

Full Text Available Plant pathogens display impressive versatility in adapting to host immune systems. Pathogen effector proteins facilitate disease but can become avirulence (Avr factors when the host acquires discrete recognition capabilities that trigger immunity. The mechanisms that lead to changes to pathogen Avr factors that enable escape from host immunity are diverse, and include epigenetic switches that allow for reuse or recycling of effectors. This perspective outlines possibilities of how epigenetic control of Avr effector gene expression may have arisen and persisted in plant pathogens, and how it presents special problems for diagnosis and detection of specific pathogen strains or pathotypes.

Fuzzy logic control for improved pressurizer systems in nuclear power plants

International Nuclear Information System (INIS)

Brown, Chris; Gabbar, Hossam A.

2014-01-01

Highlights: • Improved performance of the pressurizer system in a CANDU nuclear power plant (NPP). • Inventory control for the pressurizer system in NPP. • Compare fuzzy logic with PID in pressurizer system in NPP. • Develop a fuzzy controller to regulate the pressurizer inventory control. • Compare control performance with current proportional controller used at NPP. - Abstract: The pressurizer system in a CANDU nuclear power plant is responsible for maintaining the pressure of the primary heat transport system to ensure the plant is operated within its safe operating envelope. The inventory control for the pressurizer system use a combination of level sensors, feed valves and bleed valves to ensure that there is adequate room in the pressurizer to accommodate any swell or shrinkage in the PHT system. The Darlington Nuclear Generating Station (DNGS) in Ontario, Canada currently uses a proportional controller for the bleed and feed valves to regulate the pressurizer inventory control which can result in large coolant level overshoot along with excessive settling times. The purpose of this paper is to develop a fuzzy controller to regulate the pressurizer inventory control and compare its performance to the current proportional controller used at DNGS. The simulation of the pressurizer inventory control system shows the fuzzy controller performs better than the proportional controller in terms of settling time and overshoot

BIOLOGICAL CONTROL OF WEEDS BY MEANS OF PLANT PATHOGENS

OpenAIRE

Marija Ravlić; Renata Baličević

2014-01-01

Biological control is the use of live beneficial organisms and products of their metabolism in the pests control. Plant pathogens can be used for weed control in three different ways: as classical, conservation and augmentative (inoculative and inundated) biological control. Inundated biological control involves the use of bioherbicides (mycoherbicides) or artificial breeding of pathogens and application in specific stages of crops and weeds. Biological control of weeds can be used where chem...

Model-based reasoning and the control of process plants

International Nuclear Information System (INIS)

Vaelisuo, Heikki

1993-02-01

In addition to feedback control, safe and economic operation of industrial process plants requires discrete-event type logic control like for example automatic control sequences, interlocks, etc. A lot of complex routine reasoning is involved in the design and verification and validation (VandV) of such automatics. Similar reasoning tasks are encountered during plant operation in action planning and fault diagnosis. The low-level part of the required problem solving is so straightforward that it could be accomplished by a computer if only there were plant models which allow versatile mechanised reasoning. Such plant models and corresponding inference algorithms are the main subject of this report. Deep knowledge and qualitative modelling play an essential role in this work. Deep knowledge refers to mechanised reasoning based on the first principles of the phenomena in the problem domain. Qualitative modelling refers to knowledge representation formalism and related reasoning methods which allow solving problems on an abstraction level higher than for example traditional simulation and optimisation. Prolog is a commonly used platform for artificial intelligence (Al) applications. Constraint logic languages like CLP(R) and Prolog-III extend the scope of logic programming to numeric problem solving. In addition they allow a programming style which often reduces the computational complexity significantly. An approach to model-based reasoning implemented in constraint logic programming language CLP(R) is presented. The approach is based on some of the principles of QSIM, an algorithm for qualitative simulation. It is discussed how model-based reasoning can be applied in the design and VandV of plant automatics and in action planning during plant operation. A prototype tool called ISIR is discussed and some initial results obtained during the development of the tool are presented. The results presented originate from preliminary test results of the prototype obtained

Performance assessment of non-self-regulating controllers in a cogeneration power plant

International Nuclear Information System (INIS)

Howard, Rachelle; Cooper, Douglas J.

2009-01-01

This work details a novel method for assessing the performance of a PI (proportional-integral) feedback controller when the process displays non-self-regulating dynamic behavior. By applying an intuitive process control-based pattern recognition method to the autocorrelation function of the process measurement signal, the controller's disturbance rejection performance can automatically be categorized. Stochastic data collected over days or weeks is analyzed to compute an index descriptive of current controller performance. If the control response has drifted from a user-defined target value, the analysis further provides a guide for tuning adjustments to restore desired performance. Significant aspects of this approach are that no plant disruption or process knowledge is required for evaluation. Classic examples of non-self-regulating behavior include certain liquid level control loops and pressure control loops which are prevalent in cogeneration power plants. In this work, we detail how the performance assessment method was used to improve performance of such controllers in the University of Connecticut's power plant.

Père ou pair? Décalages et ajustements co-énonciatifs

Directory of Open Access Journals (Sweden)

Christiane Préneron

2010-12-01

Full Text Available

L’objet de notre analyse dialogique et co-énonciative concerne la forme prise par la relation entre un père et son fi ls au cours d’échanges verbaux. Dans cette dimension relationnelle, nous avons cherché plus particulièrement à éclairer le statut d’énonciateur que chacun octroie à lui-même et à l’autre. Les images qu’un père et un fi ls ont l’un de l’autre et les places qu’ils occupent dans le dialogue sont en partie déterminées par leur statut de père et d’enfant. Ces places ne confi gurent pas un mode relationnel homogène. Au contraire, cet extrait de corpus est frappant par la grande diversité d’attitudes adoptées par le père avec son enfant: tour à tour il lui donne des ordres, des permissions, le réconforte, joue avec lui, lui propose des défi s ou rivalise avec lui. Daniel peut entrer dans le jeu proposé par son père ou s’y opposer, se laisser guider ou refuser, mais aussi être à l’initiative par des demandes ou des jeux. C’est cette diversité que nous tentons de mettre au jour, sachant que certaines séquences se caractérisent plus particulièrement par des décalages entre les interlocuteurs, alors que d’autres conduisent à des ajustements. Si la diversité qui caractérise cet extrait ne saurait être étendue comme caractérisant toute interaction père/enfant, l’analyse qui en est faite peut servir de repère pour l’étude de nouvelles interactions parent/enfant.

Técnica de suturas ajustables: Resultados Technique of adjustable sutures: Results

Directory of Open Access Journals (Sweden)

Lourdes R. Hernández Santos

2001-06-01

Full Text Available Se realizó un estudio sensorial y motor preoperatorio y posoperatorio a 84 pacientes que acudieron a la consulta de Visión Binocular con el diagnóstico de estrabismo horizontal a partir de los 13 años de edad. El método estadístico utilizado fue "t" o Chi cuadrado. Nos trazamos como objetivo determinar los resultados posoperatorios de la cirugía de estrabismo realizada con la técnica de suturas ajustables, que fueron los siguientes: el 61 % de los pacientes con exotropía y el 71,4 % con el diagnóstico de exotropía se encontraban en ortotropía a los 6 meses de la intervención. El 71,4 % de los pacientes con esotropía y el 83,3 % con el diagnóstico de esotropía se encontraban en ortotropía al año de la intervención. Esta técnica quirúrgica permite la modificación de la desviación en el posoperatorio inmediato.A preoperative and postoperative sensorial and motor study was conducted among 84 patients who received attention at the consultation room of Binocular Vision with the diagnosis of horizontal strabismus from the age of 13 years old on. The statistical method used was "t" or chi square test. Our objective was to determine the postoperative results of the strabismus surgery performed by the technique of adjustable sutures. The results were as follows: 61 % of the patients with exotropia and 71.4 % with the diagnosis of exotropia were in orthotropia 6 months after the operation. 71.4 % of the patients with exotropia and 83.3 % with the diagnosis of exotropia were in orthotropia a year after the operation. This surgical technique allows the modification of the deviation in the immediate postoperative.

Process control of an HTGR fuel reprocessing cold pilot plant

International Nuclear Information System (INIS)

Rode, J.S.

1976-10-01

Development of engineering-scale systems for a large-scale HTGR fuel reprocessing demonstration facility is currently underway in a cold pilot plant. These systems include two fluidized-bed burners, which remove the graphite (carbon) matrix from the crushed HTGR fuel by high temperature (900 0 C) oxidation. The burners are controlled by a digital process controller with an all analog input/output interface which has been in use since March, 1976. The advantages of such a control system to a pilot plant operation can be summarized as follows: (1) Control loop functions and configurations can be changed easily; (2) control constants, alarm limits, output limits, and scaling constants can be changed easily; (3) calculation of data and/or interface with a computerized information retrieval system during operation are available; (4) diagnosis of process control problems is facilitated; and (5) control panel/room space is saved

Optimal sampling period of the digital control system for the nuclear power plant steam generator water level control

International Nuclear Information System (INIS)

Hur, Woo Sung; Seong, Poong Hyun

1995-01-01

A great effort has been made to improve the nuclear plant control system by use of digital technologies and a long term schedule for the control system upgrade has been prepared with an aim to implementation in the next generation nuclear plants. In case of digital control system, it is important to decide the sampling period for analysis and design of the system, because the performance and the stability of a digital control system depend on the value of the sampling period of the digital control system. There is, however, currently no systematic method used universally for determining the sampling period of the digital control system. Generally, a traditional way to select the sampling frequency is to use 20 to 30 times the bandwidth of the analog control system which has the same system configuration and parameters as the digital one. In this paper, a new method to select the sampling period is suggested which takes into account of the performance as well as the stability of the digital control system. By use of the Irving's model steam generator, the optimal sampling period of an assumptive digital control system for steam generator level control is estimated and is actually verified in the digital control simulation system for Kori-2 nuclear power plant steam generator level control. Consequently, we conclude the optimal sampling period of the digital control system for Kori-2 nuclear power plant steam generator level control is 1 second for all power ranges. 7 figs., 3 tabs., 8 refs. (Author)

Digital Full-Scope Simulation of a Conventional Nuclear Power Plant Control Room, Phase 2: Installation of a Reconfigurable Simulator to Support Nuclear Plant Sustainability

Energy Technology Data Exchange (ETDEWEB)

Ronald L. Boring; Vivek Agarwal; Kirk Fitzgerald; Jacques Hugo; Bruce Hallbert

2013-03-01

The U.S. Department of Energy’s Light Water Reactor Sustainability program has developed a control room simulator in support of control room modernization at nuclear power plants in the U.S. This report highlights the recent completion of this reconfigurable, full-scale, full-scope control room simulator buildout at the Idaho National Laboratory. The simulator is fully reconfigurable, meaning it supports multiple plant models developed by different simulator vendors. The simulator is full-scale, using glasstop virtual panels to display the analog control boards found at current plants. The present installation features 15 glasstop panels, uniquely achieving a complete control room representation. The simulator is also full-scope, meaning it uses the same plant models used for training simulators at actual plants. Unlike in the plant training simulators, the deployment on glasstop panels allows a high degree of customization of the panels, allowing the simulator to be used for research on the design of new digital control systems for control room modernization. This report includes separate sections discussing the glasstop panels, their layout to mimic control rooms at actual plants, technical details on creating a multi-plant and multi-vendor reconfigurable simulator, and current efforts to support control room modernization at U.S. utilities. The glasstop simulator provides an ideal testbed for prototyping and validating new control room concepts. Equally importantly, it is helping create a standardized and vetted human factors engineering process that can be used across the nuclear industry to ensure control room upgrades maintain and even improve current reliability and safety.

Experience feedback of computerized controlled nuclear power plants

International Nuclear Information System (INIS)

Poizat, F.

2004-01-01

The N4 step of French PWR-type nuclear power plants is characterized by an instrumentation and control system entirely computerized (operation procedures including normal and accidental operation). Four power plants of this type (Chooz and Civaux sites) of 1450 MWe each were connected to the power grid between August 1996 and December 1999. The achievement of this program make it possible and necessary to carry out an experience feedback about the development, successes and difficulties encountered in order to draw out some lessons for future realizations. This is the aim of this article: 1 - usefulness and difficulties of such an experience feedback: evolution of instrumentation and control systems, necessary cautions; 2 - a successful computerized control: checking of systems operation, advantages, expectations; 3 - efficiency of computerized systems: demonstration of operation safety, profitability; 4 - conclusions and interrogations: system approach instead of 'micro-software' approach, commercial or 'made to measure' products, contract agreement with a supplier, when and how upgrading. (J.S.)

El ajuste entre la estrategia competitiva y la estrategia de innovación tecnológica: Su implicación en el resultado de la empresa

OpenAIRE

González Moreno, Ángela

2011-01-01

A pesar de la importancia de la innovación tecnológica en la obtención de la ventaja competitiva, las relaciones entre la estrategia competitiva y la estrategia de innovación no han sido tratadas en profundidad. Esta tesis pone de manifiesto la necesidad del buen acoplamiento entre estos dos tipos de estrategia, proporcionando evidencia empírica acerca de como el ajuste entre ambas repercute positivamente en el resultado. El análisis aplicado a empresas del sector industrial de la electrón...

Two-loop feed water control system in BWR plants

International Nuclear Information System (INIS)

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

1982-01-01

In the process of the start-up and shutdown of BWR plants, the operation of changing over feed pumps corresponding to plant output is performed. Therefore, it is necessary to develop the automatic changeover system for feed pumps, which minimizes the variation of water level in reactors and is easy to operate. The three-element control system with the water level in reactors, the flow rate of main steam and the flow rate of feed water as the input is mainly applied, but long time is required for the changeover of feed pumps. The two-loop feed control system can control simultaneously two pumps being changed over, therefore it is suitable to the automatic changeover control system for feed pumps. Also it is excellent for the control of the recirculating valves of feed pumps. The control characteristics of the two-loop feed water control system against the external disturbance which causes the variation of water level in reactors were examined. The results of analysis by simulation are reported. The features of the two-loop feed water control system, the method of simulation and the evaluation of the two-loop feed water control system are described. Its connection with a digital feed water recirculation control system is expected. (Kako, I.)

Trichoderma-plant-pathogen interactions: advances in genetics of biological control.

Science.gov (United States)

Mukherjee, Mala; Mukherjee, Prasun K; Horwitz, Benjamin A; Zachow, Christin; Berg, Gabriele; Zeilinger, Susanne

2012-12-01

Trichoderma spp. are widely used in agriculture as biofungicides. Induction of plant defense and mycoparasitism (killing of one fungus by another) are considered to be the most important mechanisms of Trichoderma-mediated biological control. Understanding these mechanisms at the molecular level would help in developing strains with superior biocontrol properties. In this article, we review our current understanding of the genetics of interactions of Trichoderma with plants and plant pathogens.

Safety and security analysis for distributed control system in nuclear power plants

International Nuclear Information System (INIS)

Lu Zhigang; Liu Baoxu

2011-01-01

The Digital Distributed Control System (DCS) is the core that manages all monitoring and operation tasks in a Nuclear Power Plant (NPP). So, Digital Distributed Control System in Nuclear Power Plant has strict requirements for control and automation device safety and security due to many factors. In this article, factors of safety are analyzed firstly, while placing top priority on reliability, quality of supply and stability have also been carefully considered. In particular, advanced digital and electronic technologies are adopted to maintain sufficient reliability and supervisory capabilities in nuclear power plants. Then, security of networking and information technology have been remarked, several design methodologies considering the security characteristics are suggested. Methods and technologies of this article are being used in testing and evaluation for a real implement of a nuclear power plant in China. (author)

Hazard Identification, Risk Assessment and Risk Control (HIRARC Accidents at Power Plant

Directory of Open Access Journals (Sweden)

Ahmad Asmalia Che

2016-01-01

Full Text Available Power plant had a reputation of being one of the most hazardous workplace environments. Workers in the power plant face many safety risks due to the nature of the job. Although power plants are safer nowadays since the industry has urged the employer to improve their employees’ safety, the employees still stumble upon many hazards thus accidents at workplace. The aim of the present study is to investigate work related accidents at power plants based on HIRARC (Hazard Identification, Risk Assessment and Risk Control process. The data were collected at two coal-fired power plant located in Malaysia. The finding of the study identified hazards and assess risk relate to accidents occurred at the power plants. The finding of the study suggested the possible control measures and corrective actions to reduce or eliminate the risk that can be used by power plant in preventing accidents from occurred

Considerations concerning the ergonomics of power plant control rooms

International Nuclear Information System (INIS)

Herbst, L.; Hinz, W.

1981-01-01

Modern control rooms for the monitoring and control of large power plants have a high degree of automation. However, it is the responsibility of the control room personnel to ensure optimum process control during all operational states. The proper ergonomic design of a control room is one of the prerequisites to ensure that the operators are able to perceive the often large flow of current information and, after processing, to respond properly. (orig.) [de

Modernization of instrumentation and control in nuclear power plants. Report prepared within the framework of the International Working Group on Nuclear Power Plant Control and Instrumentation

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-05-01

The scope of the modernization activities described in this report includes the modernization of equipment in operating plants and partially built plants. It covers the full range of types of instrumentation and control (I and C) systems including protection, safety, control and information systems. It is applicable for a plant throughout its life. The report includes appropriate consideration of the increasingly international nature of the I and C systems supply industry and takes advantage of the activities and lessons learned in the different national approaches to develop general guidance and recommendations. An Annex includes 10 country reports which were separately indexed Refs, figs, tabs

Adaptive control theory of concentration in the uranium enrichment plant

International Nuclear Information System (INIS)

Sugitsue, Noritake; Miyagawa, Hiroshi; Yokoyama, Kaoru; Nakakura, Hiroyuki

1999-01-01

This paper presents the new adaptive control of concentration in the uranium enrichment plant. The purpose of this control system is average concentration control in production tram. As a result the accuracy and practical use of this control system have already been confirmed by the operation of the uranium enrichment demonstration plant. Three elements of technology are required to this method. The first is the measurement of the concentration using product flow quantity change. This technology shall be called 'Qp difference to Xp transform method'. The second is the relationship between temperature change and flow quantity using G.M.D.H. (Groupe Method of Data Handling) and the third is the estimation of temperature change using AR (Auto-regressive) model. (author)

Plant-wide Control Strategy for Improving Produced Water Treatment

DEFF Research Database (Denmark)

Yang, Zhenyu; Pedersen, Simon; Løhndorf, Petar Durdevic

2016-01-01

This work focuses on investigation and development of an innovative Produced Water Treatment (PWT) technology for offshore oil & gas production by employing the model-based plant-wide control strategy. The key contributions lie in two folds: (i) the advanced anti-slug analysis and control...

Computer functions in overall plant control of candu generating stations

International Nuclear Information System (INIS)

Chou, Q.B.; Stokes, H.W.

1976-01-01

System Planning Specifications form the basic requirements for the performance of the plant including its response to abnormal situations. The rules for the computer control programs are devised from these, taking into account limitations imposed by the reactor, heat transport and turbine-generator systems. The paper outlines these specifications and the limitations imposed by the major items of plant equipment. It describes the functions of each of the main programs, their interactions and the control modes used in the existing Ontario Hydro's nuclear station or proposed for future stations. Some simulation results showing the performance of the overall unit control system and plans for future studies are discussed. (orig.) [de

Control rooms and man-machine interface in nuclear power plants

International Nuclear Information System (INIS)

1990-08-01

The importance of man-machine interface for ensuring safe and reliable operation of nuclear power plants has always been recognized. Since the early 1970's, the concepts of operator support and human factors have been increasingly used to better define the role of control rooms. In the late 1970's, the lessons learned from experience considerably accelerated the development of recommendations and regulatory requirements governing the resources and data available to operators in nuclear power plant control rooms, and specified the expertise required to assist them in case of need. This document summarizes the steps which have been taken and are being planned around the world to improve the man-machine interface for safe and economic power generation. It intends to present to the reader useful examples on some selected control room design and man-machine interface practices for operation and surveillance of nuclear power plants. 53 refs, 94 figs, 27 tabs

Internal transport control in pot plant production

NARCIS (Netherlands)

Annevelink, E.

1999-01-01

Drawing up internal transport schedules in pot plant production is a very complex task. Scheduling internal transport at the operational level and providing control on a day-to-day or even hour-to-hour basis in particular requires a new approach. A hierarchical planning approach based on

The role of plant-microbiome interactions in weed establishment and control.

Science.gov (United States)

Trognitz, Friederike; Hackl, Evelyn; Widhalm, Siegrid; Sessitsch, Angela

2016-10-01

The soil microbiome plays an important role in the establishment of weeds and invasive plants. They associate with microorganisms supporting their growth and health. Weed management strategies, like tillage and herbicide treatments, to control weeds generally alter soil structure going alongside with changes in the microbial community. Once a weed population establishes in the field, the plants build up a close relationship with the available microorganisms. Seeds or vegetative organs overwinter in soil and select early in the season their own microbiome before crop plants start to vegetate. Weed and crop plants compete for light, nutrition and water, but may differently interact with soil microorganisms. The development of new sequencing technologies for analyzing soil microbiomes has opened up the possibility for in depth analysis of the interaction between 'undesired' plants and crop plants under different management systems. These findings will help us to understand the functions of microorganisms involved in crop productivity and plant health, weed establishment and weed prevention. Exploitation of the knowledge offers the possibility to search for new biocontrol methods against weeds based on soil and plant-associated microorganisms. This review discusses the recent advances in understanding the functions of microbial communities for weed/invasive plant establishment and shows new ways to use plant-associated microorganisms to control weeds and invasive plants in different land management systems. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Design of an automatic control system of a district heating nuclear plant

International Nuclear Information System (INIS)

Zebiri, Abderrahim.

1980-06-01

This paper presents the synthesis of the control system of a nuclear/oil fuelled district heating plant. Operating criteria take into account the economical background of the problem. Nuclear reactor control loops were specially conceived, due to the specific perturbations to which is submitted a district heating plant [fr

The System 80+ Standard Plant design control document. Volume 11

International Nuclear Information System (INIS)

1997-01-01

This Design Control Document (DCD) is a repository of information comprising the System 80+trademark Standard Plant Design. The DCD also provides that design-related information to be incorporated by reference in the design certification rule for the System 80+ Standard Plant Design. Applicants for a combined license pursuant to 10 CFR 52 must ensure that the final Design Certification Rule and the associated Statements of Consideration are used when making all licensing decisions relevant to the System 80+ Standard Plant Design. The Design Control Document contains the DCD introduction, The Certified Design Material (CDM) [i.e., ''Tier 1''] and the Approved Design Material (ADM) [i.e., ''Tier 2''] for the System 80+ Standard Plant Design. The CDM includes the following sections: (1) Introductory material; (2) Certified Design Material for System 80+ systems and structures; (3) Certified Design Material for non-system-based aspects of the System 80+ Certified design; (4) Interface requirements; and (5) Site parameters. The ADM, to the extent applicable for the System 80+ Standard Plant Design, includes: (1) the information required for the final safety analysis report under 20 CFR 50.34; (2) other relevant information required by 10 CFR 52.47; and (3) emergency operations guidelines. This volume covers parts 6 and 7 and appendix 7A for section 7 (Instrumentation and Control) of the ADM Design and Analysis. The topics covered by these are: other systems required for safety; control systems not required by safety; and CMF evaluation of limiting faults. Parts 1--3 of section 8 (Electric Power) of the ADM are also included in this volume. Topics covered by these parts are: introduction; offsite power system; and onsite power system

Planting pattern and weed control method influence on yield production of corn (Zea mays L.)

Science.gov (United States)

Purba, E.; Nasution, D. P.

2018-02-01

Field experiment was carried out to evaluate the influence of planting patterns and weed control methods on the growth and yield of corn. The effect of the planting pattern and weed control method was studied in a split plot design. The main plots were that of planting pattern single row (25cm x 60cm), double row (25cm x 25cm x 60cm) and triangle row ( 25cm x 25cm x 25cm). Subplot was that of weed control method consisted five methods namely weed free throughout the growing season, hand weeding, sprayed with glyphosate, sprayed with paraquat, and no weeding.. Result showed that both planting pattern and weed control method did not affect the growth of corn. However, planting pattern and weed control method significantly affected yield production. Yield resulted from double row and triangle planting pattern was 14% and 41% higher, consecutively, than that of single row pattern. The triangle planting pattern combined with any weed control method produced the highest yield production of corn.

A systematic methodology for controller tuning in wastewater treatment plants

DEFF Research Database (Denmark)

Mauricio Iglesias, Miguel; Jørgensen, S.B.; Sin, G.

2012-01-01

Wastewater treatment plants are typically subject to continuous disturbances caused by influent variations which exhibits diurnal patterns as well as stochastic changes due to rain and storm water events. In order to achieve an efficient operation, the control system of the plant should be able t...

A Controlled Environment System For Measuring Plant-Atmosphere Gas Exchange

Science.gov (United States)

James M. Brown

1975-01-01

Describes an inexpensive, efficient system for measuring plant-atmosphere gas exchange. Designed to measure transpiration from potted tree seedlings, it is readily adaptable for measuring other gas exchanges or gas exchange by plant parts. Light level, air and root temperature can be precisely controlled at minimum cost.

Regulatory control of nuclear power plants

International Nuclear Information System (INIS)

2002-01-01

The purpose of this book is to support IAEA training courses and workshops in the field of regulatory control of nuclear power plants as well as to support the regulatory bodies of Member States in their own training activities. The target group is the professional staff members of nuclear safety regulatory bodies supervising nuclear power plants and having duties and responsibilities in the following regulatory fields: regulatory framework; regulatory organization; regulatory guidance; licensing and licensing documents; assessment of safety; and regulatory inspection and enforcement. Important topics such as regulatory competence and quality of regulatory work as well as emergency preparedness and public communication are also covered. The book also presents the key issues of nuclear safety such as 'defence-in-depth' and safety culture and explains how these should be taken into account in regulatory work, e.g. during safety assessment and regulatory inspection. The book also reflects how nuclear safety has been developed during the years on the basis of operating experience feedback and results of safety research by giving topical examples. The examples cover development of operating procedures and accident management to cope with complicated incidents and severe accidents to stress the importance of regulatory role in nuclear safety research. The main target group is new staff members of regulatory bodies, but the book also offers good examples for more experienced inspectors to be used as comparison and discussion basis in internal workshops organized by the regulatory bodies for refreshing and continuing training. The book was originally compiled on the basis of presentations provided during the two regulatory control training courses in 1997 and 1998. The textbook was reviewed at the beginning of the years 2000 and 2002 by IAEA staff members and consistency with the latest revisions of safety standards have been ensured. The textbook was completed in the

Automated control system for the Temelin nuclear power plant

International Nuclear Information System (INIS)

Labik, V.

1990-01-01

Instrumentation of the automated control system of the Temelin nuclear power plant in the section of the main production unit and of the major auxiliary equipment is described, the results of testing are reported, and the present status of design activities is assessed. The suitability of application of Czechoslovak automation facilities to the instrumentation of the automated control system of the power plant was confirmed by the Soviet designer and supplier based on favorable results of polygonal testing. Capacity problems in the development of the designs and user software are alleviated by extensive cooperation. It is envisaged that all tasks will be fulfilled as planned. (P.A.). 1 fig., 5 refs

78 FR 38739 - Special Nuclear Material Control and Accounting Systems for Nuclear Power Plants

Science.gov (United States)

2013-06-27

... Systems for Nuclear Power Plants AGENCY: Nuclear Regulatory Commission. ACTION: Regulatory guide; issuance... Guide (RG) 5.29, ``Special Nuclear Material Control and Accounting Systems for Nuclear Power Plants... material control and accounting. This guide applies to all nuclear power plants. ADDRESSES: Please refer to...

Strategy for improving instrumentation and control in operating nuclear power plants

International Nuclear Information System (INIS)

Abad Bassols, L.; Nino Perote, R.

1996-01-01

There are three basic reasons why nuclear power plants need to systematically upgrade their instrumentation and control equipment: Obsolete instrumentation and lack spares Little capacity of flexibility for extension Possibility of attaining better systems integration and improving systems-operations interface This article shows how to approach these issues using the following strategies: Use of distributed control systems and PLCs for control, signalling, command, communications, etc, in both nuclear and conventional applications Upgrading of process instrumentation equipment, sensors, transmitters, etc Upgrading of alarm-signalling systems In each group of equipment items consideration should be given to: Aspects regarding manufacturers-suppliers Effects on design, adaptation and documentation of operating plants Effects on the training and handling skills of operation and maintenance staff Strategy for incorporating the new system into the Plant with minimum impact on operation (Author)

Controlled procurement for nuclear power plants

International Nuclear Information System (INIS)

MacFarlane, I.S.

1985-01-01

A method is presented for establishing a controlled materials management system that facilitates materials procurement at nuclear power plants. This method is based on the determination of informational data requirements, appropriate input and approvals, and extent of administrative controls. Implementation of the techniques described herein will ensure that the accuracy of important procurement information is not compromised by unauthorized initial input or changes and/or failure to maintain the information. Needed material can thus be ordered through the materials management system with a high degree of confidence that the correct items are ordered, with minimal internal lead time and minimum delays during the receiving process

NPAR approach to controlling aging in nuclear power plants

International Nuclear Information System (INIS)

Christensen, J.A.

1990-01-01

Aging degradation in nuclear power plants must be controlled to prevent safety margins from declining below limits provided in plant design bases. The NPAR Program and other aging-related programs conducted under the auspices of the Nuclear Regulatory Commission (NRC) Office of Research are developing needed technical guidance for control of aging. Results from these programs, together with relevant information developed by industry and elsewhere, are implemented through various ongoing NRC and industry programs and initiatives as well as by means of conventional regulatory instruments. The aging control process central to these efforts consists of three key elements: (1) selection of components, systems, and structures (CSS) in which aging must be controlled, (2) understanding of the mechanisms and rates of degradation in these CSS, and (3) managing degradation through effective surveillance and maintenance. These elements are addressed in Good Practices Guidance that integrates information developed under NPAR and other studies of aging into a systems-oriented format that tracks directly with the safety analysis reports

Control of the technological processes at ''Azovstal'' plant using radioisotope devices

Energy Technology Data Exchange (ETDEWEB)

Nosochenko, O V; Overchenko, Z V; Karpov, O I; Deryabina, G N

1980-05-01

Considered is the state of radioisotope control of the technological process at 'Azovstal' plant which has permitted to increase the quality of metal and of metal production. With the help of radioisotope densimeter PR-1024 carried out is the control of the density of the lime solution used for hearth spraying at pig iron casting. A system of automatic correction of skip coke supply according to indications of moisture gauges ''Neutron 3-1'' is implemented at blast furnaces. A radioisotope thickness gauge of hot rolling is positioned on the section of finishing stand of thick-sheet plant, its operation is based on the ..gamma.. radiation weakening in dependence on sheet thickness. The introduction of thickness gauges in the automatized system of rolling control is planned. A radioisotope device ''Paza 2'' for measuring of continuous ingot skin thickness is tested successively at the plant. Gamma-relay devices are used to control the level of loose materials in bunkers. Noted is the prospects of using radioisotopic means of control and automatization of technological processes in ferrous matallurgy.

Methodology for risk-based configuration control of nuclear power plant operation

International Nuclear Information System (INIS)

Valle, Antonio Torres; Oliva, Jose de Jesus Rivero

2012-01-01

The hazardous configurations control in Nuclear Power Plants is an application of a previous Probabilistic Safety Analysis (PSA). A more complete option would be the risk monitoring for the online detection of these configurations but expert personnel would be required to deal with the complexities of PSA and risk monitor. The paper presents a simpler but effective approach: a method of configuration control, based on dependencies matrixes. The algorithm is included in a computer code called SECURE A-Z. The configuration control is carried out in a qualitative way, without previous PSA results and not using a Risk Monitor. The simplicity of the method warrants its application to facilities where these tools have not been developed, allowing the detection of hazardous configurations during operation and increasing plant safety. This configuration control system was implemented in the Embalse Nuclear Power Plant in Argentina. The paper shows the application of the algorithm to the analysis of a simplified safety system. (author)

Is micro-CHP price controllable under price signal controlled Virtual Power Plants?

DEFF Research Database (Denmark)

You, Shi; Træholt, Chresten; Poulsen, Bjarne

2011-01-01

As micro-combined heat and power (micro-CHP) systems move towards mass deployment together with other kinds of distributed energy resources (DER), an increasing emphasis has been placed on how to coordinate such a large diversified DER portfolio in an efficient way by the Virtual Power Plant (VPP...... for three different micro-CHP systems to investigate the feasibility of being controlled by price. Such analysis is relevant for both controller designs for micro-CHP systems and VPP related operations. The results indicate that controlling the micro-CHP systems by price is feasible but could result...

Development of nuclear power plant online monitoring system using statistical quality control

International Nuclear Information System (INIS)

An, Sang Ha

2006-02-01

Statistical Quality Control techniques have been applied to many aspects of industrial engineering. An application to nuclear power plant maintenance and control is also presented that can greatly improve plant safety. As a demonstration of such an approach, a specific system is analyzed: the reactor coolant pumps (RCP) and the fouling resistance of heat exchanger. This research uses Shewart X-bar, R charts, Cumulative Sum charts (CUSUM), and Sequential Probability Ratio Test (SPRT) to analyze the process for the state of statistical control. And we made Control Chart Analyzer (CCA) to support these analyses that can make a decision of error in process. The analysis shows that statistical process control methods can be applied as an early warning system capable of identifying significant equipment problems well in advance of traditional control room alarm indicators. Such a system would provide operators with enough time to respond to possible emergency situations and thus improve plant safety and reliability

On fuzzy control of water desalination plants

Energy Technology Data Exchange (ETDEWEB)

Titli, A. [Centre National de la Recherche Scientifique (CNRS), 31 - Toulouse (France); Jamshidi, M. [New Mexico Univ., Albuquerque, NM (United States); Olafsson, F. [Institute of Technology, Norway (Norway)

1995-12-31

In this report we have chosen a sub-system of an MSF water desalination plant, the brine heater, for analysis, synthesis, and simulation. This system has been modelled and implemented on computer. A fuzzy logic controller (FLC) for the top brine temperature control loop has been designed and implemented on the computer. The performance of the proposed FLC is compared with three other conventional control strategies: PID, cascade and disturbance rejection control. One major concern on FLC`s has been the lack of stability criteria. An up to-date survey of stability of fuzzy control systems is given. We have shown stability of the proposed FLC using the Sinusoidal Input Describing Functions (SIDF) method. The potential applications of fuzzy controllers for complex and large-scale systems through hierarchy of rule sets and hybridization with conventional approaches are also investigated. (authors)

On fuzzy control of water desalination plants

Energy Technology Data Exchange (ETDEWEB)

Titli, A [Centre National de la Recherche Scientifique (CNRS), 31 - Toulouse (France); Jamshidi, M [New Mexico Univ., Albuquerque, NM (United States); Olafsson, F [Institute of Technology, Norway (Norway)

1996-12-31

In this report we have chosen a sub-system of an MSF water desalination plant, the brine heater, for analysis, synthesis, and simulation. This system has been modelled and implemented on computer. A fuzzy logic controller (FLC) for the top brine temperature control loop has been designed and implemented on the computer. The performance of the proposed FLC is compared with three other conventional control strategies: PID, cascade and disturbance rejection control. One major concern on FLC`s has been the lack of stability criteria. An up to-date survey of stability of fuzzy control systems is given. We have shown stability of the proposed FLC using the Sinusoidal Input Describing Functions (SIDF) method. The potential applications of fuzzy controllers for complex and large-scale systems through hierarchy of rule sets and hybridization with conventional approaches are also investigated. (authors)

The Feasibility of Noise Control in a Soft Drink Plant

Directory of Open Access Journals (Sweden)

Fouladi Dehaghi

2016-03-01

Full Text Available Background “Noise” can be defined as any unwanted sound. Soft drink plants, which produce the raw materials used in most carbonated beverage factories, are sources of noise. Objectives This study investigated the noise pollution present in a soft drink CO2 gas injection plant, in order to present noise control measures. Materials and Methods The instructions specified by the canadian center for occupational health and safety (CCOHS were followed during the noise study, and a sound level meter, CEL.450 calibrated with CEL-110.2 based on ISO-9612 methods, was used to record the sound pressure level (SPL at each grid point. SPL was determined in weighting scales A and C. and a noise survey map of equivalent SPLs was drawn for each part. Each part of the floor area of the soft drink factory where SPL exceeded 85 dBA was identified from the noise survey map to determine the causes of high levels of noise. In order to reduce noise level in each part, the absorption coefficient, transmission loss, and noise reduction rate were calculated in the proposed control area. Results According to the study results, noise levels in a CO2 plant’s house and control room ranged from 88 to 102 dB and 79 to 82 dB (A, respectively. In order to reduce the amount of emitted noise in the CO2 plant house and control room, a noise control plan was implemented in each part of the facility; it was met with effective results. Conclusions The findings of this investigation have clearly revealed that plant workers are at risk of developing noise-induced hearing loss. However, after the implementation of a noise control plan in each part of the facility, the noise dose received by workers has significantly decreased. The need to implement a noise conservation program was established.

Voltage Control Support and Coordination between Renewable Generation Plants in MV Distribution Systems

DEFF Research Database (Denmark)

Petersen, Lennart; Iov, Florin; Hansen, Anca Daniela

2016-01-01

This paper focusses on voltage control support and coordination between renewable generation plants in medium voltage distribution systems. An exemplary benchmark grid in Denmark, including a number of flexible ReGen plants providing voltage control functionality, is used as a base case. First......, voltage sensitivity analysis is performed to quantify node voltage variations due to injections of reactive power for given operational points of the network. The results are then used to develop an adaptive voltage droop control method, where various droop settings are allocated to each ReGen plant...... according to the sensitivity indices of corresponding node voltages and the location of respective ReGen plants in the distribution system. Case studies are performed in time-domain to analyze the impact of voltage fluctuations due to active power variations of ReGen plants in order to verify...

A Calculation of hydrodynamic noise of control valve on instrumentation and control system using smart plant

International Nuclear Information System (INIS)

Demon Handoyo; Djoko H Nugroho

2012-01-01

It has been calculated characteristics of the control valve Instrumentation and Control Systems using Smart Plant software. This calculation is done in order to control the valve that will be installed as part of the instrumentation and control systems to provide the performance according to the design. The characteristics that have been calculated are Reynolds number factors which are related to the flow regime in the valve. Critical pressure factor, Valve Hydrodynamic cavitation and noise index. In this paper the discussion will be limited to matters relating to Hydrodynamic noise generation process using model of the instrumentation and control system in the plant design in yellow cake PIPKPP activities in 2012. The results of the calculation of the noise on the valves design are in the range between 9.58~70.1 dBA. (author)

Model-based Fuel Flow Control for Fossil-fired Power Plants

DEFF Research Database (Denmark)

Niemczyk, Piotr

2010-01-01

-fired power plants represent the largest reserve of such controllable power sources in several countries. However, their production take-up rates are limited, mainly due to poor fuel flow control. The thesis presents analysis of difficulties and potential improvements in the control of the coal grinding...

Introducing Model Predictive Control for Improving Power Plant Portfolio Performance

DEFF Research Database (Denmark)

Edlund, Kristian Skjoldborg; Bendtsen, Jan Dimon; Børresen, Simon

2008-01-01

This paper introduces a model predictive control (MPC) approach for construction of a controller for balancing the power generation against consumption in a power system. The objective of the controller is to coordinate a portfolio consisting of multiple power plant units in the effort to perform...

Genetic and epigenetic control of plant heat responses

Directory of Open Access Journals (Sweden)

Junzhong eLiu

2015-04-01

Full Text Available Plants have evolved sophisticated genetic and epigenetic regulatory systems to respond quickly to unfavorable environmental conditions such as heat, cold, drought, and pathogen infections. In particular, heat greatly affects plant growth and development, immunity and circadian rhythm, and poses a serious threat to the global food supply. According to temperatures exposing, heat can be usually classified as warm ambient temperature (about 22-27℃, high temperature (27-30℃ and extremely high temperature (37-42℃, also known as heat stress for the model plant Arabidopsis thaliana. The genetic mechanisms of plant responses to heat have been well studied, mainly focusing on elevated ambient temperature-mediated morphological acclimation and acceleration of flowering, modulation of plant immunity and circadian clock by high temperatures, and thermotolerance to heat stress. Recently, great progress has been achieved on epigenetic regulation of heat responses, including DNA methylation, histone modifications, histone variants, ATP-dependent chromatin remodeling, histone chaperones, small RNAs, long non-coding RNAs and other undefined epigenetic mechanisms. These epigenetic modifications regulate the expression of heat-responsive genes and function to prevent heat-related damage. This review focuses on recent progresses regarding the genetic and epigenetic control of heat responses in plants, and pays more attention to the role of the major epigenetic mechanisms in plant heat responses. Further research perspectives are also discussed.

Concept and design of a fully computerized control room for future nuclear power plant

International Nuclear Information System (INIS)

Hinz, W.; Kollmannsberger, J.

1991-01-01

The development of digital process control equipment and of safety engineering equipment together with the CRT - based information visualization systems is advanced to a state allowing process control of nuclear power plant to be done by these equipments. The systems have been tested in the control room of the fossil-fuel Staudinger reactor station, unit 5, and the computer-assisted PRISCA process information system has been tested in the Konvoi-type nuclear reactor series. These tests serve as a basis for further process control system development by Siemens KWU, to be used in their future nuclear power plants. The advantages of digital process control and CRT-based information display are intended to be used for further optimization of the man-machine interface in nuclear power plant. One important aspect is to give the control room personnel complete insight into the operational processes of the entire plant, and to establish for detail recognition for process monitoring a very close mental link between operators and the system processes. In addition, the control room operator has to be given appropriate means and tools for process monitoring and control, fulfilling the requirements of guaranteeing the plant's availability and safety. These requirements put very high demands on the process monitoring and control equipment. (orig.) [de

DO INCENTIVO À CRIMINALIZAÇÃO: OS TERMOS DE AJUSTE DE CONDUTA NA ORIZICULTURA EM SANTA CATARINA - BRASIL

Directory of Open Access Journals (Sweden)

Alfredo Celso Fantini

2014-03-01

Full Text Available Em Santa Catarina os Termos de Ajuste de Conduta (TACs vêm ganhando espaço como estratégia para garantir, na zona rural, a recuperação de áreas de preservação permanente, principalmente as matas ciliares. No caso dos plantadores de arroz a situação é, no mínimo, discutível: agricultores antes incentivados pelo Estado a usarem para a produção toda a área de várzea, até o limite dos rios, são obrigados agora a recuperarem a vegetação ciliar “que nunca deveria ter sido suprimida”. Ignorando a complexidade da questão, o Ministério Público adotou o comando e controle para resolver “o problema”. Passados três anos, quase nada aconteceu na prática. Neste artigo, usamos uma abordagem sistêmica para compreender a situação-problema e apontar encaminhamentos para a sua melhoria. Em um estudo de caso realizado em Jacinto Machado-SC, foram utilizados métodos qualitativos e quantitativos (análise documental, entrevistas, inventários e oficinas e principalmente a Soft System Methodology (SSM. Os resultados revelaram que a mata ciliar é só mais um elemento de um complexo sistema de interesses, onde fatores sociais, culturais, ambientais e econômicos interagem dinamicamente. Apontam, também, a necessidade de uma aproximação entre os interessados na situação-problema para tornar possível uma acomodação entre as diferentes visões de mundo dos envolvidos

Intelligent distributed control for nuclear power plants

International Nuclear Information System (INIS)

Klevans, E.H.

1991-01-01

In September of 1989 work began on the DOE University Program grant DE-FG07-89ER12889. The grant provides support for a three year project to develop and demonstrate Intelligent Distributed Control (IDC) for Nuclear Power Plants. The body of this First Annual Technical Progress report summarizes the first year tasks while the appendices provide detailed information presented at conference meetings. One major addendum report, authored by M.A. Schultz, describes the ultimate goals and projected structure of an automatic distributed control system for EBR-2. The remaining tasks of the project develop specific implementations of various components required to demonstrate the intelligent distributed control concept

Regulatory control of maintenance activities in Argentine nuclear power plants

International Nuclear Information System (INIS)

Calvo, J.C.; Caruso, G.

2000-01-01

The main maintenance objective is to assure that the safety features of structures, components and systems of nuclear power plants are kept as designed. Therefore, there is a direct relationship between safety and maintenance. Owing to the above mentioned, maintenance activities are considered a relevant regulatory issue for the Argentine Nuclear Regulatory Authority (ARN). This paper describes the regulatory control to maintenance activities of Argentine nuclear power plants. It also addresses essential elements for maintenance control, routine inspections, special inspections during planned outages, audits and license conditions and requirements. (author)

Designing the controllability of a HVAC-plant by dynamic simulation

Energy Technology Data Exchange (ETDEWEB)

Novakovic, V; Grindal, A

1994-05-01

This paper was presented at CLIMA 2000 - The international conference on energy and environmental matters in built environment, London, 1.-3. November 1993. Nowadays, HVAC engineers can use dynamic simulation programs in their everyday work. Such tools provide the ability to analyze different system configurations and to check the obtained states even before the building and plant are constructed. To encourage its wider use, the authors present in this paper the experiences obtained with the simulation program HVAC-DYNAMICS. The program was used to simulate the retrofitting of a heat recovery wheel to a conventional ventilation plant with a hot water heating coil. The effects of different design parameters on the controllability of the plant were investigated. Interestingly, some commonly recommended ``clever`` configurations can lead to unexpected control scenarios. 4 refs., 3 figs., 2 tabs.

Quality control of three main materials for civil construction of nuclear power plant

International Nuclear Information System (INIS)

Wang Feng

2011-01-01

The construction and operation of nuclear power plant is a systematic engineering. To ensure quality and safety of nuclear power plants, each work from design to operation can have certain impact on the quality and safety of the project. The quality of each related work shall be controlled. Starting from the quality control over raw materials for the civil construction of nuclear power plant, this article mainly analyzes how to control the quality and manage the three main materials of steel, concrete and modular parts in the civil construction. (author)

Plant management in natural areas: balancing chemical, mechanical, and cultural control methods

Science.gov (United States)

Steven Manning; James. Miller

2011-01-01

After determining the best course of action for control of an invasive plant population, it is important to understand the variety of methods available to the integrated pest management professional. A variety of methods are now widely used in managing invasive plants in natural areas, including chemical, mechanical, and cultural control methods. Once the preferred...

The System 80+ Standard Plant design control document. Volume 20

International Nuclear Information System (INIS)

1997-01-01

This Design Control Document (DCD) is a repository of information comprising the System 80+trademark Standard Plant Design. The DCD also provides that design-related information to be incorporated by reference in the design certification rule for the System 80+ Standard Plant Design. Applicants for a combined license pursuant to 10 CFR 52 must ensure that the final Design Certification Rule and the associated Statements of Consideration are used when making all licensing decisions relevant to the System 80+ Standard Plant Design. The Design Control Document contains the DCD introduction, The Certified Design Material (CDM) [i.e., ''Tier 1''] and the Approved Design Material (ADM) [i.e., ''Tier 2''] for the System 80+ Standard Plant Design. The CDM includes the following sections: (1) Introductory material; (2) Certified Design Material for System 80+ systems and structures; (3) Certified Design Material for non-system-based aspects of the System 80+ Certified design; (4) Interface requirements; and (5) Site parameters. The ADM, to the extent applicable for the System 80+ Standard Plant Design, includes: (1) the information required for the final safety analysis report under 20 CFR 50.34; (2) other relevant information required by 10 CFR 52.47; and (3) emergency operations guidelines. This volume contains 2 technical specifications bases as part of Appendix 16 A Tech Spec Bases. They are TS B3.8 Electrical Power Technical Systems Bases and TS B3.9 Refueling Operations Bases. All 3 parts of section 17 (QA) and all 10 parts of section 18 (Human Factors) of the ADM Design and Analysis are contained in this volume. Topics covered in section 17 are: design phase QA; operations phase QA; and design phase reliability assurance. Topics covered by section 18 are: design team organization; design goals; design process; functional task analysis; control room configuration; information presentation; control and monitoring; verification and validation; and review documents

Application of process computers and colour CRT displays in the plant control room of a BWR

International Nuclear Information System (INIS)

Itoh, M.; Hayakawa, H.; Kawahara, H.; Neda, T.; Wakabayashi, Y.

1983-01-01

The recent application of a CRT display system in an 1100-MW(e) BWR plant control room and the design features of a new control room whose installation is planned for the next generation are discussed. As reactor unit capacity and the need for plant safety and reliability continue to increase, instrumentation and control equipment is growing in number and complexity. In consequence, control and supervision of plant operations require improvement. Thus, because of recent progress in the field of process computers and display equipment (colour CRTs), efficient improvements of the control room are under way in the Japanese BWR plant. In the recently constructed BWR plant (1100 MW(e)), five CRTs on the bench board and two process computers were additionally installed in the control room during the construction stage to improve plant control and supervisory functions by implementing the lessons learned from the Three Mile Island incident. The major functions of the new computers and display systems are to show integrated graphic displays of the plant status, to monitor the standby condition of the safety system, to show the condition of the integrated alarm system, etc. In practice, in the actual plant, this newly installed system performs well. On the basis of the experience gained in these activities, a new computerized control and monitoring system is now being designed for subsequent domestic BWR plants. This advanced system will incorporate not only the functions already mentioned, but also a surveillance guide system and plant automation. For future plants, a diagnostic system and an instructional system that can analyse a disturbance and give operational guidance to the plant operator are being developed in a government-sponsored programme. (author)

Nuclear Power Plant Control and Instrumentation in Pakistan

International Nuclear Information System (INIS)

Iqleem, J.; Hashmi, J.A.; Siddiqui, Z.H.

1990-01-01

Nuclear reactors generate 15% of the world's supply electric power. The substantial growth in world energy demand is inevitably continuing throughout the next century. Nuclear power which has already paid more than enough for itself and its development, will provide increasing share of electricity production both in the developed and developing countries. For Pakistan with limited natural resources such as oil, gas, and fully tapped hydel power, nuclear power is the only viable option. However, things are not simple for developing countries which embark on nuclear power program. A technical infrastructure should be established as it has been shown by the experience of Control and Instrumentation of the Karachi Nuclear Power Plant. The national report describes the program of Pakistan Atomic Energy Commission in (NPP) Computers, Control and Instrumentation for design, construction, operation, and maintenance of nuclear power plants. (author)

Water chemistry control of PWR nuclear power plant

International Nuclear Information System (INIS)

Hino, Yuichi; Makino, Ichiro; Yamauchi, Sumio; Fukuda, Fumihito.

1992-01-01

In PWR power plants, the primary system taking heat out of nuclear reactors and the secondary system generating steam and driving turbines are completely separated by steam generators, accordingly, by mutually independent water treatment, both systems are to be maintained in the optimal conditions. Namely, primary system is the closed water circulation circuit of simple liquid phase though under high temperature, high pressure condition, therefore, water shows the stable physical and chemical properties, and the minute water treatment for restraining the corrosion of structural materials and reducing radioactivity can be done. Secondary system is similar to the condensate and feedwater system of thermal power plants, and is the circuit for liquid-vapor two-phase transformation, but due to the local concentration of impurities by evaporation, the strict requirement is set for secondary water quality. However, secondary system can be treated in the state without radioactivity, and this is a great merit. The outline, basic concept and execution of primary water quality control, and the outline, concept, control criteria, facilities and execution of secondary water quality control are reported. (K.I.)

Self-control system in storage unit of PV plants

Energy Technology Data Exchange (ETDEWEB)

Al-Shaban, Saad; Mohmoud, Ali [Hadhramout Univ. of Science and Technology, Faculty of Engineering, Mukalla (Yemen)

2000-04-01

A new system for self-controlling of storage batteries being charged by PV plants has been developed. This provides enhanced system reliability, lower system cost, and simpler operation for the user. In this system, the only requirement is to design and select PV panels so that their voltage-sensitive region (on the I-V curve) coincides with that required for a simpler remote PV plant and for long periods. (Author)

Nuclear power plant control room operators' performance research

International Nuclear Information System (INIS)

Gray, L.H.; Haas, P.M.

1984-01-01

A research program is being conducted to provide information on the performance of nuclear power plant control room operators when responding to abnormal/emergency events in the plants and in full-scope training simulators. The initial impetus for this program was the need for data to assess proposed design criteria for the choice of manual versus automatic action for accomplishing safety-related functions during design basis accidents. The program also included studies of training simulator capabilities, of procedures and data for specifying and verifying simulator performance, and of methods and applications of task analysis

Information integration in control rooms and technical offices in nuclear power plants. Report prepared within the framework of the International Working Group on Nuclear Power Plant Control and Instrumentation

International Nuclear Information System (INIS)

2001-11-01

The majority of the nuclear power plants in the world were designed 25 to 45 years ago. The information, instrumentation, safety, and control systems in these plant designs were based on analog, relay, and primitive digital technology. Computers that were available when most of the nuclear power plants were built were unsophisticated compared with those currently available. These less powerful machines with limited computational capabilities and memory were used to collect and store information. The main means for obtaining information from the plant were analog meters and strip chart recorders. In many cases these pieces of data had to be integrated and correlated with other data manually, in order to be usable. Procedures and plant information resided on paper only and were frequently hard to find and access in a timely manner. This report provides guidance to help with the integration of information in order to enhance the usability and usefulness of the information. It can also be used to help avoid the pitfalls that can occur when implementing new systems with respect to the information they need and produce. This reports philosophy is based on three important issues that allow the convenient structuring of the problem and to keep all of its important features. The first issue is the process of information systems integration and use. This is achieved by long term planning and the creation of the plant infrastructure plan. The second is to take care of the end users' needs in relation to their abilities. This is realized through analyses of user needs. Third is the design of the human-system interface (HSI), for example to distinguish between types of information for use in the plant control room and in technical offices. The development of this report was initiated by the IAEA International Working Group on Nuclear Power Plant Control and Instrumentation (IWG-NPPCI). It is a logical follow-up to IAEA-TECDOC-1016, Modernization of Instrumentation and Control

Design and simplification of Adaptive Neuro-Fuzzy Inference Controllers for power plants

Energy Technology Data Exchange (ETDEWEB)

Alturki, F.A.; Abdennour, A. [King Saud University, Riyadh (Saudi Arabia). Electrical Engineering Dept.

1999-10-01

This article presents the design of an Adaptive Neuro-Fuzzy Inference Controller (ANFIC) for a 160 MW power plant. The space of operating conditions of the plant is partitioned into five regions. For each of the regions, an optimal controller is designed to meet a set of design objectives. The resulting five linear controllers are used to train the ANFIC. To enhance the applicability of the control system, a new algorithm that reduces the fuzzy rules to the most essential ones is also presented. This algorithm offers substantial savings in computation time while maintaining the performance and robustness of the original controller. (author)

Power control device of an atomic power plant

International Nuclear Information System (INIS)

Ootsuka, Shiro; Ito, Takero.

1980-01-01

Purpose: To improve the power controllability of an atomic power plant by improving the controllability, response and stability of the recirculation flow rate. Constitution: The power control device comprises a power detector of the reactor, which detects and operates the reactor power from the thermal power, neutron flux or the process quantity controlling the same, and a deviation detector which seeks deviation between the power signal of the power detector and the power set value of the reactor or power station. By use of the power control device constituted in this manner, the core flow rate is regulated by the power signal of the deviation detector thereby to control the power. (Aizawa, K.)

Chlorination for biofouling control in power plant cooling water system - a review

International Nuclear Information System (INIS)

Satpathy, K.K.; Ruth Nithila, S.D.

2008-01-01

Fresh water is becoming a rare commodity day by day and thus power plant authorities are turning into sea to make use of the copious amount of seawater available at an economical rate for condenser cooling. Unfortunately, biofouling; the growth and colonization of marine organisms affect the smooth operation of power plant cooling water systems. This is more so, if the plant is located in tropical climate having clean environment, which enhances the variety and density of organisms. Thus, biofouling needs to be controlled for efficient operation of the power plant. Biocide used for biofouling control is decided based on three major criteria viz: it should be economically, operationally and environmentally acceptable to the power plant authorities. Chlorine among others stands out on the top and meets all the above requirements in spite of a few shortcomings. Therefore it is no wonder that still chlorine rules the roost and chlorination remains the most common method of biofouling control in power plant cooling water system all over the world. Although, it is easier said than done, a good amount of R and D work is essential before a precise chlorination regime is put into pragmatic use. This paper discusses in details the chemistry of chlorination such as chlorine demand, chlorine decay, break point chlorination, speciation of chlorine residual and role of temperature and ammonia on chlorination in biofouling control. Moreover, targeted and pulse chlorination are also discussed briefly. (author)

Progress in XRCS-Survey plant instrumentation and control design for ITER

International Nuclear Information System (INIS)

Varshney, Sanjeev; Jha, Shivakant; Simrock, Stefan; Barnsley, Robin; Martin, Vincent; Mishra, Sapna; Patil, Prabhakant; Patel, Shreyas; Kumar, Vinay

2016-01-01

Highlights: • An identification of the major process functions system compliant to Plant Control Design Handbook (PCDH) has been made for XRCS-Survey plant I&C. • I&C Functional Breakdown Structure (FBS) and Operation Procedure (OP) have been drafted using Enterprise architect (EA). • I&C architecture, interface with ITER networks and Plants, configuration of cubicles are discussed towards nine design review deliverables. - Abstract: A real time, plasma impurity survey system based on X-ray Crystal Spectroscopy (XRCS) has been designed for ITER and will be made available in the set of first plasma diagnostics for measuring impurity ion concentrations and their in-flux. For the purpose of developing a component level design of XRCS-Survey plant I&C system that is compliant to the rules and guidelines defined in the Plant Control Design Handbook (PCDH), firstly an identification of the major process functions has been made. The preliminary plant I&C Functional Breakdown Structure (FBS) and Operation Procedure (OP) have been drafted using a system engineering tool, Enterprise Architect (EA). Conceptual I&C architecture, interface with the ITER networks and other Plants have been discussed along with the basic configuration of I&C cubicles aiming towards nine I&C deliverables for the design review.

Progress in XRCS-Survey plant instrumentation and control design for ITER

Energy Technology Data Exchange (ETDEWEB)

Varshney, Sanjeev, E-mail: sanjeev.varshney@iter-india.org [ITER-India, Institute for Plasma Research, Bhat, Gandhinagar, 382 428 (India); Jha, Shivakant [ITER-India, Institute for Plasma Research, Bhat, Gandhinagar, 382 428 (India); Simrock, Stefan; Barnsley, Robin; Martin, Vincent [ITER-Organization, Route de Vinon sur Verdon, CS 90 046, 13067 St. Paul-Lez-Durance, Cedex (France); Mishra, Sapna [ITER-India, Institute for Plasma Research, Bhat, Gandhinagar, 382 428 (India); Patil, Prabhakant [ITER-Organization, Route de Vinon sur Verdon, CS 90 046, 13067 St. Paul-Lez-Durance, Cedex (France); Patel, Shreyas; Kumar, Vinay [ITER-India, Institute for Plasma Research, Bhat, Gandhinagar, 382 428 (India)

2016-11-15

Highlights: • An identification of the major process functions system compliant to Plant Control Design Handbook (PCDH) has been made for XRCS-Survey plant I&C. • I&C Functional Breakdown Structure (FBS) and Operation Procedure (OP) have been drafted using Enterprise architect (EA). • I&C architecture, interface with ITER networks and Plants, configuration of cubicles are discussed towards nine design review deliverables. - Abstract: A real time, plasma impurity survey system based on X-ray Crystal Spectroscopy (XRCS) has been designed for ITER and will be made available in the set of first plasma diagnostics for measuring impurity ion concentrations and their in-flux. For the purpose of developing a component level design of XRCS-Survey plant I&C system that is compliant to the rules and guidelines defined in the Plant Control Design Handbook (PCDH), firstly an identification of the major process functions has been made. The preliminary plant I&C Functional Breakdown Structure (FBS) and Operation Procedure (OP) have been drafted using a system engineering tool, Enterprise Architect (EA). Conceptual I&C architecture, interface with the ITER networks and other Plants have been discussed along with the basic configuration of I&C cubicles aiming towards nine I&C deliverables for the design review.

Voltage Control Support and Coordination between Renewable Generation Plants in MV Distribution Systems

DEFF Research Database (Denmark)

Petersen, Lennart; Iov, Florin; Hansen, Anca Daniela

2016-01-01

This paper focusses on voltage control support and coordination between renewable generation plants in medium voltage distribution systems. An exemplary benchmark grid in Denmark, including a number of flexible ReGen plants providing voltage control functionality, is used as a base case. First...

GUIDANCE FOR NUCLEAR POWER PLANT CONTROL ROOM AND HUMAN-SYSTEM INTERFACE MODERNIZATION

International Nuclear Information System (INIS)

Naser, J.; Morris, G.

2004-01-01

Several nuclear power plants in the United States are starting instrumentation and control (I and C) modernization programs using digital equipment to address obsolescence issues and the need to improve plant performance while maintaining high levels of safety. As an integral part of the I and C modernization program at a nuclear power plant, the control room and other human-system interfaces (HSIs) are also being modernized. To support safe and effective operation, it is critical to plan, design, implement, train for, operate, and maintain the control room and HSI changes to take advantage of human cognitive processing abilities. A project, jointly funded by the Electric Power Research Institute (EPRI) and the United States Department of Energy (DOE) under the Nuclear Energy Plant Optimization (NEPO) Program, is developing guidance for specifying and designing control rooms, remote shut-down panels, HSIs etc. The guidance is intended for application by utilities and suppliers of control room and HSI modernization. The guidance will facilitate specification, design, implementation, operations, maintenance, training, and licensing activities. This guidance will be used to reduce the likelihood of human errors and licensing risk, to gain maximum benefit of implemented technology, and to increase performance. The guidance is of five types. The first is planning guidance to help a utility develop its plant-specific control room operating concepts, its plant-specific endpoint vision for the control room, its migration path to achieve that endpoint vision, and its regulatory, licensing, and human factors program plans. The second is process guidance for general HSI design and integration, human factors engineering analyses, verification and validation, in-service monitoring processes, etc. The third is detailed human factors engineering guidance for control room and HSI technical areas. The fourth is guidance for licensing. The fifth is guidance for special topics

Nuclear power plant control and instrumentation activities in Argentina during 1989-1991

International Nuclear Information System (INIS)

Lorenzetti, J.R.

1992-01-01

A brief resume of the activities in the different areas of control and instrumentation is included. As there was a delay in the construction of the new power plant most of the effort were dedicated to the plants that they are in operation. It has been added instrumentation to have better information in the control room and to check new variables of the plant according with the experience learned from the operation. It was dedicated special strength in the areas of training simulators and in service inspection. (author)

The Remotely Controlled Robot System for Nuclear Power Plants

International Nuclear Information System (INIS)

Koh, Kwangill; Lee, Gwangnam; Lim, Kyeyoung

1993-01-01

The problem of radioactivity has been our major concern. So, it makes the needs of remotely controlled robot system necessary for maintenance and repair services. Up to now, several foreign companies have been contracted for the maintenance of the steam generators of nuclear power plants in Korea, to acquire its own capability of maintaining the steam generators of it impossible for Korea to acquire its own capability of maintaining the steam generators. In case of emergency, it is difficult to take appropriate steps on its own. In order to resolve the above problems, it seems inevitable to develop the robot system for the inspection and repair of steam generator. This project intends to acquire domestic capabilities of maintaining steam generators, so that this advanced skills could be applied to the related areas. As a result, it will save immense money in the future. the purposes of development of the remotely controlled robot system are : to perform the desired tasks at the polluted area without requiring entry of personnel. to closely inspect the steam generator U-tubes at high speed. to inspect the steam generator intelligently and efficiently under the extreme circumstances where radioactivity problem is very severe. to use for the repair of steam generator tube. Considering from the social and technical standpoint, we can say that the development of the remotely controlled robot system for nuclear power plants resulted in great achievements. From the social standpoint, it should be recognized that domestic robot for nuclear power plant was successfully developed and operator was protected against radioactivity. Also, we advanced our skills in the area of mechanical and control system design for an articulated robot. Using the robot controller in hierarchical structure, it was possible to control the robot remotely. In addition, resolver feedback typed A C servo drive was proven to be sturdy in hazardous environment. Now we are confident that our robot will

The System 80+ Standard Plant design control document. Volume 1

International Nuclear Information System (INIS)

1997-01-01

This Design Control Document (DCD) is a repository of information comprising the System 80+trademark Standard Plant Design. The DCD also provides that design-related information to be incorporated by reference in the design certification rule for the System 80+ Standard Plant Design. Applicants for a combined license pursuant to 10 CFR 52 must ensure that the final Design Certification Rule and the associated Statements of Consideration are used when making all licensing decisions relevant to the System 80+ Standard Plant Design. The Design Control Document contains the DCD introduction, The Certified Design Material (CDM) [i.e., ''Tier 1''] and the Approved Design Material (ADM) [i.e., ''Tier 2''] for the System 80+ Standard Plant Design. The CDM includes the following sections: (1) Introductory material; (2) Certified Design Material for System 80+ systems and structures; (3) Certified Design Material for non-system-based aspects of the System 80+ Certified design; (4) Interface requirements; and (5) Site parameters. The ADM, to the extent applicable for the System 80+ Standard Plant Design, includes: (1) the information required for the final safety analysis report under 20 CFR 50.34; (2) other relevant information required by 10 CFR 52.47; and (3) emergency operations guidelines. This volume covers the DCD introduction and contains sections 1 and parts 1--7 of section 2 of the CDM. Parts 1--7 included the following: (2.1) Design of SSC; (2.2) Reactor; (2.3) RCS and connected systems; (2.4) Engineered Safety Features; (2.5) Instrumentation and Control; (2.6) Electric Power; and (2.7) Auxiliary Systems

Series de días hábiles en Colombia: una aplicación al ajuste del crecimiento industrial

Directory of Open Access Journals (Sweden)

Álvaro Montenegro García

2014-06-01

Full Text Available Si bien muchos economistas son conscientes del efecto de los días hábiles sobre la medición de la producción, aún es frecuente encontrar que estas cifras se analizan sin el correspondiente ajuste. En general, el número de días hábiles en un mes cambia de un año a otro, lo cual es cierto para todos los meses, no solo para los que contienen la Semana Santa. Este trabajo recopila la serie de días hábiles mensuales tomando en cuenta los festivos actuales y anteriores a la Ley Emiliani, y la utiliza para ajustar la serie de producción manufacturera del DANE. Para algunos meses, la diferencia entre la cifra de crecimiento industrial reportada por el DANE y la cifra ajustada por días hábiles puede acercarse a los 12 puntos porcentuales, en cualquier dirección

Control system for high-temperature slagging incinerator plant

International Nuclear Information System (INIS)

Matsuzaki, Yuji

1986-01-01

Low-level radioactive wastes generated in the nuclear generating plants are increasing year by year and to dispose them safely constitutes a big problem for the society. A few years ago, as the means of reducing them to as little volume as possible by incinerating and fusing the wastes, a high-temperature slagging incinerating method was developed, and this method is highly assessed. JGC Corp. has introduced that system technology and in order to prove the capacity of disposal and salubrity of the plant, and have constructed a full-sized pilot plant, then obtained the operational record and performance as they had planned. This report introduces the general processing of the wastes from their incineration and fusion as well as process control technology characteristic to high-temperature slagging incinerator furnaces and sensor technology. (author)

A novel technology for control of variable speed pumped storage power plant

Institute of Scientific and Technical Information of China (English)

Seyed Mohammad Hassan Hosseini; Mohammad Reza Semsar

2016-01-01

Variable speed pumped storage machines are used extensively in wind power plant and pumped storage power plant. This paper presents direct torque and flux control (DTFC) of a variable speed pumped storage power plant (VSPSP). By this method both torque and flux have been applied to control the VSPSP. The comparison between VSPSP’s control strategies is studied. At the first, a wind turbine with the capacity 2.2 kW and DTFC control strategies simulated then a 250 MW VSPSP is simulated with all of its parts (including electrical, mechanical, hydraulic and its control system) by MATLAB software. In all of simulations, both converters including two-level voltage source converter (2LVSC) and three-level voltage source converter (3LVSC) are applied. The results of applying 2LVSC and 3LVSC are the rapid dynamic responses with better efficiency, reducing the total harmonic distortion (THD) and ripple of rotor torque and flux.

Resultados de tres años de ensayo en el ajuste de la tecnología de “Tree Row Volume” (TRV para el control de mancha negra en naranja Valencia

Directory of Open Access Journals (Sweden)

HABERLE, T.J.

2011-08-01

Full Text Available Actualmente, los consumidores de fruta son altamente exigentes tanto en la calidad externa como interna de la fruta. En el aspecto externo, exigen ausencia de daños causados por plagas y/o enfermedades con énfasis en aquellas consideradas cuarentenarias como es Mancha Negra (MN causada por el hongo Guignardia citricarpa Kiely. Con respecto a los aspectos internos, se considera que debe tener alta calidad organoléptica y, sobre todo, tener mínimos residuos de plaguicidas. Para contribuir con ambos objetivos, se están realizando desde hace varios años tratamientos para optimizar la dosis de fungicidas y volúmenes aplicados a lotes con frutas con destino de exportación. A tal efecto se han realizado ensayos por tres años para el ajuste del volumen de caldo a aplicar por hectárea en función del tamaño de los árboles aplicando la fórmula del TRV (“Tree Row Volume” en un lote de naranja Valencia (Citrus sinensis L. Osb. con alta incidencia de (MN. Los ensayos consistieron en la utilización de picos inyectores de aire ID instalados en turbinas de alto volumen con el fin de reducir el volumen total de caldo de modo similar al logrado con la tecnología de bajo volumen. Los resultadosobtenidos en diferentes campañas con picos ID en tratamientos reducidos al 50% en volumen ejercieron un muy buen control de la enfermedad sin diferencias significativas con respecto a los tratamientos de alto volumen convencionales. Esta estrategia permite optimizar la utilización de equipos existentes con el beneficiodel ahorro de agua, insumos y, además, sustentable con el ambiente.

A Robust Multivariable Feedforward/Feedback Controller Design for Integrated Power Control of Boiling Water Reactor Power Plants

International Nuclear Information System (INIS)

Shyu, S.-S.; Edwards, Robert M.

2002-01-01

In this paper, a methodology for synthesizing a robust multivariable feedforward/feedback control (FF/FBC) strategy is proposed for an integrated control of turbine power, throttle pressure, and reactor water level in a nuclear power plant. In the proposed method, the FBC is synthesized by the robust control approach. The feedforward control, which is generated via nonlinear programming, is added to the robust FBC system to further improve the control performance. The plant uncertainties, including unmodeled dynamics, linearization, and model reduction, are characterized and estimated. The comparisons of simulation responses based on a nonlinear reactor model demonstrate the achievement of the proposed controller with specified performance and endurance under uncertainty. It is also important to note that all input variables are manipulated in an orchestrated manner in response to a single output's setpoint change

DSC: software tool for simulation-based design of control strategies applied to wastewater treatment plants.

Science.gov (United States)

Ruano, M V; Ribes, J; Seco, A; Ferrer, J

2011-01-01

This paper presents a computer tool called DSC (Simulation based Controllers Design) that enables an easy design of control systems and strategies applied to wastewater treatment plants. Although the control systems are developed and evaluated by simulation, this tool aims to facilitate the direct implementation of the designed control system to the PC of the full-scale WWTP (wastewater treatment plants). The designed control system can be programmed in a dedicated control application and can be connected to either the simulation software or the SCADA of the plant. To this end, the developed DSC incorporates an OPC server (OLE for process control) which facilitates an open-standard communication protocol for different industrial process applications. The potential capabilities of the DSC tool are illustrated through the example of a full-scale application. An aeration control system applied to a nutrient removing WWTP was designed, tuned and evaluated with the DSC tool before its implementation in the full scale plant. The control parameters obtained by simulation were suitable for the full scale plant with only few modifications to improve the control performance. With the DSC tool, the control systems performance can be easily evaluated by simulation. Once developed and tuned by simulation, the control systems can be directly applied to the full-scale WWTP.

Recent digital control and protection retrofits in power plants

International Nuclear Information System (INIS)

Fournier, R.D.; Hammer, M.; Smith, J.E.

1987-01-01

Digital computers are now being retrofitted to all types of power plants, replacing analog equipment and solving problems such as equipment obsolescence and low reliability. Three diverse examples of retrofits are presented in this paper, representing trends in man/machine interface design at an oil-fired plant, protection system in pressurized heavy-water reactors, and control systems in light water reactors (LWRs). The examples have been chosen to illustrate diverse reasons for the retrofits and the benefits derived. The cases presented report retrofits at Northern States Power's Monticello boiling water reactor, New Brunswick Electric Power Commission's (NBEPC's) Point Lepreau Nuclear Generating Station, and finally NBEPC's oil-fired plant at Courtney Bay

Configuration control during plant outages. A review of operating experience

Energy Technology Data Exchange (ETDEWEB)

Peinador Veira, Miguel; El Kanbi, Semir [European Commission Joint Research Centre, Petten (Netherlands). Inst. for Energy and Transport; Stephan, Jean-Luc [Institut de Radioprotection et de Surete Nucleaire (IRSN), Fontenay-aux-Roses (France); Martens, Johannes [Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) gGmbH, Koeln (Germany)

2015-03-15

After the occurrence of several significant events in nuclear power plants during shut-down modes of operation in the eighties, and from the results of probabilistic safety assessments completed in the nineties, it was clear that risk from low power and shutdown operational modes could not be neglected and had to be addressed by appropriate safety programs. A comprehensive review of operating experience from the last ten years has been conducted by the Joint Research Centre with the objective of deriving lessons learned and recommendations useful for nuclear regulatory bodies and utilities alike. This paper is focused on one particular challenge that any nuclear plant faces whenever it plans its next outage period: how to manage the configuration of all systems under a complex environment involving numerous concurrent activities, and how to make sure that systems are returned to their valid configuration before the plant resumes power operation. This study highlights the importance of conveying accurate but synthesized information on the status of the plant to the operators in the main control room. Many of the lessons learned are related to the alarm display in the control room and to the use of check lists to control the status of systems. Members of the industry and safety authorities may now use these recommendations and lessons learned to feed their own operating experience feedback programs, and check their applicability for specific sites.

Evolved Control of Natural Plants: Crossing the Reality Gap for User-Defined Steering of Growth and Motion

DEFF Research Database (Denmark)

Hofstadler, Daniel Nicolas; Wahby, Mostafa; Heinrich, Mary Katherine

2017-01-01

Mixing societies of natural and artificial systems can provide interesting and potentially fruitful research targets. Here we mix robotic setups and natural plants in order to steer the motion behavior of plants while growing. The robotic setup uses a camera to observe the plant and uses a pair...... of light sources to trigger phototropic response, steering the plant to user-defined targets. An evolutionary robotic approach is used to design a controller for the setup. Initially, preliminary experiments are performed with a simple predetermined controller and a growing bean plant. The plant behavior......-evolved controller in the real setup controlling a natural bean plant. The results demonstrate a successful crossing of the reality gap in the setup. The success of the approach allows for future extensions to more complex tasks including control of the shape of plants and pattern formation in multiple plant setups....

Studies on improvements in the control methods of boiling water reactor plant

International Nuclear Information System (INIS)

Mankin, Shuichi

1982-08-01

In order to improve the performance of regulation and load following control of boiling water reactor plant, optimal control theory is applied and new types of control method are developed. Case-α controller is first formulated on the basis of the optimal linear regulator theory applied to the linealized model of the system; it is then modified by adding a integration-type action in a feed back loop and by the use of variable gain and reference for adapting to the power level requested. Case-#betta# controller consists of a hierarchical control scheme which has classical P.I. type sub-loop controllers at the first level and a linear optimal regulator at the second level. The controller is designed on the basis of the optimal regulator theory applied to the multivariate autoregressive system model which is obtained from the identification experiments, where the system model is determined with the conventional sub-loop controllers included. The results of the simulation experiments show these control methods proposed have performed fairly well and will be useful for the improvement of the performance of nuclear power plant control. In addition, it is suggested that these control methods will be also attractive for the control of other production plants because these were developed in the attempt to solve the problems deviated from so called 'The gap between the optimal contro theory and actual systems.' (author)

Radiosterilization process control in plants using electron accelerators

International Nuclear Information System (INIS)

Stuglik, Z.

1997-01-01

Electron beam parameters deciding the irradiation dose in radiosterilization plants should be continuously controlled during the process. Dosimetric procedure suitable to irradiated material and dose range should be chosen. The practical advice and directions in this subject have been done. 7 refs

Total quality control: the deming management philosophy applied to nuclear power plants

International Nuclear Information System (INIS)

Heising, C.D.; Wetherell, D.L.; Melhem, S.A.; Sato, M.

1987-01-01

In recent years, a call has come for the development of inherently safe nuclear reactor systems that cannot have large-scale accidents. In the search for the perfect inherently safe reactor system, some are calling for the institution of computerized automated control of reactors eliminating most human operators from the control room. A different approach to the problem of the control of inherently safe reactors is that both future and present nuclear power plants need to institute total quality control (TQC) to plant operations and management. The Deming management philosophy of TQC has been implemented in a wide range of industries - particularly in Japan and the US. Specific attention is given, however, to TQC implementation in the electric power industry as applied to nuclear plants. The Kansai Electric Power Company and Florida Power and Light Company have recently implemented TQC. Statistical quality control methods have been applied to monitor and control reactor variables (for example, to the steam generator water level important to start-up operations of pressurized water reactors)

Joint excitation and reactive power control in thermal power plant

Directory of Open Access Journals (Sweden)

Dragosavac Jasna

2013-01-01

Full Text Available The coordinated voltage and reactive power controller, designed for the thermal power plant, is presented in the paper. A brief explanation of the need for such device is given and justification for commissioning of such equipment is outlined. After short description of the theoretical background of the proposed control design, the achieved features of the commissioned equipment are fully given. Achieved performances are illustrated by recorded reactive power and bus voltage responses after commissioning of the described equipment into the largest thermal power plant in Serbia. As it can be seen in presented records, all design targets are met.

HTGR power plant hot reheat steam pressure control system

International Nuclear Information System (INIS)

Braytenbah, A.S.; Jaegtnes, K.O.

1975-01-01

A control system for a high temperature gas cooled reactor (HTGR) power plant is disclosed wherein such plant includes a plurality of steam generators. Dual turbine-generators are connected to the common steam headers, a high pressure element of each turbine receiving steam from the main steam header, and an intermediate-low pressure element of each turbine receiving steam from the hot reheat header. Associated with each high pressure element is a bypass line connected between the main steam header and a cold reheat header, which is commonly connected to the high pressure element exhausts. A control system governs the flow of steam through the first and second bypass lines to provide for a desired minimum steam flow through the steam generator reheater sections at times when the total steam flow through the turbines is less than such minimum, and to regulate the hot reheat header steam pressure to improve control of the auxiliary steam turbines and thereby improve control of the reactor coolant gas flow, particularly following a turbine trip. (U.S.)

Avaliação de marcapasso unicameral de ajuste automático de freqüência de pulso mediado por movimentação corporal

OpenAIRE

Brofman,Paulo R; Loures,Danton R. da Rocha; Rossi,Paulo R. F; Ardito,Roberto V; Greco,Osvaldo T; Braile,Domingo M; Sant'Anna,João R; Lucchese,Fernando A; Kalil,Renato A. K; Eloy,Ricardo; Barros,Rubens T; Andrade,José Carlos S; Pesarini,Aldo; Gauch,Paulo R. A

1987-01-01

Quarenta e oito pacientes com marcapasso unicameral de ajuste automático de freqüência de pulso mediado por movimentação corporal (AAI-R/VVI-R) foram avaliados através da eletrocardiografia dinâmica, para correlacionar a atividade física com a variação da freqüência de estímulos e teste ergométrico em esteira (pareados e randomizados em modo AAI/VVI e modo AAI-R/VVI-R), para quantificar a capacidade de realizar esforço físico, um mês após o implante do gerador de pulso Activitrax 8400. A idad...

Control and decision strategies in wastewater treatment plants for operation improvement

CERN Document Server

Santín, Ignacio; Vilanova, Ramón

2017-01-01

This book examines the operation of biological wastewater treatment plants (WWTPs), with a focus on maintaining effluent water quality while keeping operational costs within constrained limits. It includes control operation and decision schemes and is based on the use of benchmarking scenarios that yield easily reproducible results that readers can implement for their own solutions. The final criterion is the effect of the applied control strategy on plant performance – specifically, improving effluent quality, reducing costs and avoiding violations of established effluent limits. The evaluation of the different control strategies is achieved with the help of two Benchmark Simulation Models (BSM1, BSM2). Given the complexity of the biological and biochemical processes involved and the major fluctuations in the influent flow rate, controlling WWTPs poses a serious challenge. Further, the importance of control goal formulation and control structure design in relation to WWTP process control is widely recogniz...

How to improve plant efficiency through leading plant monitoring and control system technology-Almaraz NPP Samo

International Nuclear Information System (INIS)

Garcia Rodriguez, A.; Schwee, S.M.

1994-01-01

The nuclear industry is currently faced with an intense pressure to reduce the cost of electric production. To achieve these cost reductions, utilities are changing the way they have traditionally operated. They are embracing innovative processes and systems to fundamentally change the way they have operated and maintained their plants. Plant monitoring and control technology has been instrumental in affecting these rapid and proactive changes. Our challenge is to use these new technologies in ways that improve plant reliability while lowering operation and maintenance costs. What must we do to increase operational time, improve safety and reliability while reducing all costs including fixed as well as labor? We will discuss an overall plant monitoring system vision that will allow these changes in operational practices. (Author)

Cirurgia de estrabismo ajustável no peroperatório com anestesia tópica em pacientes com orbitopatia de Graves Intraoperative adjustable strabismus surgery under drop anesthesia in patients with Graves' orbitopathy

Directory of Open Access Journals (Sweden)

Patrícia Grativol Costa

2008-06-01

Full Text Available OBJETIVO: Descrever as características clínicas pré-operatórias dos pacientes com estrabismo secundário à orbitopatia de Graves e os resultados da cirurgia com anestesia tópica e sutura ajustável. MÉTODOS: Estudo retrospectivo realizado no Hospital das Clínicas da Universidade de São Paulo. Foram pesquisados os prontuários de todos os pacientes atendidos no ambulatório de estrabismo no período de março de 1994 a maio de 2004. Destes, foram separados aqueles com estrabismo associado à orbitopatia de Graves submetidos à cirurgia ajustável com anestesia tópica. As características clínicas pré-operatórias e os resultados cirúrgicos foram levantados a partir desta análise. RESULTADOS: Foram incluídos 13 pacientes. O tipo de desvio mais freqüentemente encontrado foi esotropia com hipotropia. Em 9 pacientes modificou-se o retrocesso programado no pré-operatório. Três casos necessitaram de uma segunda cirurgia. Após 6 meses de seguimento, 8 dos 13 pacientes estavam ortotrópicos ou com foria pequena e com algum grau de estereopsia. CONCLUSÃO: Neste estudo observou-se que 62% (8/13 dos pacientes apresentavam hipotropia com esotropia, provavelmente por causa do comprometimento associado do reto inferior e reto medial. Nove dos 13 pacientes necessitaram de ajuste no peroperatório e apenas 3 foram reoperados, indicando a importância da técnica ajustável para melhor alinhamento ocular no pós-operatório, possibilitando obter resultados mais satisfatórios.PURPOSE: To report the clinical features of strabismus associated with Graves' orbitopathy, and the results of surgery with adjustable suture under drop anesthesia. METHODS: The charts of 13 patients who had surgical treatment for strabismus related to Graves' orbitopathy at Hospital das Clínicas of University of São Paulo were retrospectively reviewed. Ocular motility, sensorial examination and the follow-up after strabismus correction were studied. RESULTS

Adaptive Neural Network Algorithm for Power Control in Nuclear Power Plants

International Nuclear Information System (INIS)

Husam Fayiz, Al Masri

2017-01-01

The aim of this paper is to design, test and evaluate a prototype of an adaptive neural network algorithm for the power controlling system of a nuclear power plant. The task of power control in nuclear reactors is one of the fundamental tasks in this field. Therefore, researches are constantly conducted to ameliorate the power reactor control process. Currently, in the Department of Automation in the National Research Nuclear University (NRNU) MEPhI, numerous studies are utilizing various methodologies of artificial intelligence (expert systems, neural networks, fuzzy systems and genetic algorithms) to enhance the performance, safety, efficiency and reliability of nuclear power plants. In particular, a study of an adaptive artificial intelligent power regulator in the control systems of nuclear power reactors is being undertaken to enhance performance and to minimize the output error of the Automatic Power Controller (APC) on the grounds of a multifunctional computer analyzer (simulator) of the Water-Water Energetic Reactor known as Vodo-Vodyanoi Energetichesky Reaktor (VVER) in Russian. In this paper, a block diagram of an adaptive reactor power controller was built on the basis of an intelligent control algorithm. When implementing intelligent neural network principles, it is possible to improve the quality and dynamic of any control system in accordance with the principles of adaptive control. It is common knowledge that an adaptive control system permits adjusting the controller’s parameters according to the transitions in the characteristics of the control object or external disturbances. In this project, it is demonstrated that the propitious options for an automatic power controller in nuclear power plants is a control system constructed on intelligent neural network algorithms. (paper)

Validation and implementation of model based control strategies at an industrial wastewater treatment plant.

Science.gov (United States)

Demey, D; Vanderhaegen, B; Vanhooren, H; Liessens, J; Van Eyck, L; Hopkins, L; Vanrolleghem, P A

2001-01-01

In this paper, the practical implementation and validation of advanced control strategies, designed using model based techniques, at an industrial wastewater treatment plant is demonstrated. The plant under study is treating the wastewater of a large pharmaceutical production facility. The process characteristics of the wastewater treatment were quantified by means of tracer tests, intensive measurement campaigns and the use of on-line sensors. In parallel, a dynamical model of the complete wastewater plant was developed according to the specific kinetic characteristics of the sludge and the highly varying composition of the industrial wastewater. Based on real-time data and dynamic models, control strategies for the equalisation system, the polymer dosing and phosphorus addition were established. The control strategies are being integrated in the existing SCADA system combining traditional PLC technology with robust PC based control calculations. The use of intelligent control in wastewater treatment offers a wide spectrum of possibilities to upgrade existing plants, to increase the capacity of the plant and to eliminate peaks. This can result in a more stable and secure overall performance and, finally, in cost savings. The use of on-line sensors has a potential not only for monitoring concentrations, but also for manipulating flows and concentrations. This way the performance of the plant can be secured.

The plant cytoskeleton controls regulatory volume increase.

Science.gov (United States)

Liu, Qiong; Qiao, Fei; Ismail, Ahmed; Chang, Xiaoli; Nick, Peter

2013-09-01

The ability to adjust cell volume is required for the adaptation to osmotic stress. Plant protoplasts can swell within seconds in response to hypoosmotic shock suggesting that membrane material is released from internal stores. Since the stability of plant membranes depends on submembraneous actin, we asked, whether this regulatory volume control depends on the cytoskeleton. As system we used two cell lines from grapevine which differ in their osmotic tolerance and observed that the cytoskeleton responded differently in these two cell lines. To quantify the ability for regulatory volume control, we used hydraulic conductivity (Lp) as readout and demonstrated a role of the cytoskeleton in protoplast swelling. Chelation of calcium, inhibition of calcium channels, or manipulation of membrane fluidity, did not significantly alter Lp, whereas direct manipulation of the cytoskeleton via specific chemical reagents, or indirectly, through the bacterial elicitor Harpin or activation of phospholipase D, was effective. By optochemical engineering of actin using a caged form of the phytohormone auxin we can break the symmetry of actin organisation resulting in a localised deformation of cell shape indicative of a locally increased Lp. We interpret our findings in terms of a model, where the submembraneous cytoskeleton controls the release of intracellular membrane stores during regulatory volume change. Copyright © 2013 Elsevier B.V. All rights reserved.

Aquatic Plant Control Research Program. Volume A-00-1

National Research Council Canada - National Science Library

Kirk, James

2000-01-01

... at the Waterways Experiment Station. It is principally intended to be a forum whereby information pertaining to and resulting from the Corps of Engineers' nationwide Aquatic Plant Control Research Program (APCRP...

Method for fault diagnosis of digital control systems in nuclear power plant

International Nuclear Information System (INIS)

Suzuki, Satoshi; Nagaoka, Yukio; Ohga, Yukiharu; Ito, Tetsuo

1990-01-01

This paper presents a method for localizing faulty components of control systems by replaceable parts such as print boards and cables, in a large scale plant like a nuclear power plant. Most of today's control systems form a distributed configuration including many digital controllers interconnected by data communication networks. Usually, to localize the faulty components in nuclear plant control systems, suspected faulty components are narrowed down by executing manual tests to examine whether the objects are normal or abnormal based on design documents and personnel know-how, besides the uses of self-diagnosis functions built into the control systems. In the present method, procedures of various tests including the know-how and checking of self-diagnosis functions are provided as knowledge of tests. The tests to be executed is determined by considering failure probabilities of objects, and easiness and effectiveness of testing. Then, the suspects are narrowed down sequentially based on the test result. In checking feasibility of this diagnosis method for a simulated control system, intended faults are satisfactorily localized. This method is confirmed to be practicable for diagnosis of large scale digital control systems. (author)

Instrumentation and control systems for CANDU-PHW nuclear power plants

International Nuclear Information System (INIS)

Lepp, R.M.; Watkins, L.M.

1982-02-01

The instrumentation and control of CANDU nuclear power plants takes advantage of modern electronics technology in the extensive computerization of important control and man-machine functions. A description of these functions as well as those of the four Special Safety Systems is provided

Study of two control rods of a district heating nuclear plant

International Nuclear Information System (INIS)

Martinez, J.M.

1979-01-01

This paper broaches the study of the control rods to ensure a convenient working during load following of the nuclear reactor THERMOS. The mathematical model is descriptive of the whole of the nuclear plant (point model for the core and the heat balances). Two power control are studied. The first, like PWR, is a program for the mean temperature of primary water. The second takes into account the structure of the plant and is described by a schedule of powers [fr

The System 80+ Standard Plant design control document. Volume 10

International Nuclear Information System (INIS)

1997-01-01

This Design Control Document (DCD) is a repository of information comprising the System 80+trademark Standard Plant Design. The DCD also provides that design-related information to be incorporated by reference in the design certification rule for the System 80+ Standard Plant Design. Applicants for a combined license pursuant to 10 CFR 52 must ensure that the final Design Certification Rule and the associated Statements of Consideration are used when making all licensing decisions relevant to the System 80+ Standard Plant Design. The Design Control Document contains the DCD introduction, The Certified Design Material (CDM) [i.e., ''Tier 1''] and the Approved Design Material (ADM) [i.e., ''Tier 2''] for the System 80+ Standard Plant Design. The CDM includes the following sections: (1) Introductory material; (2) Certified Design Material for System 80+ systems and structures; (3) Certified Design Material for non-system-based aspects of the System 80+ Certified design; (4) Interface requirements; and (5) Site parameters. The ADM, to the extent applicable for the System 80+ Standard Plant Design, includes: (1) the information required for the final safety analysis report under 20 CFR 50.34; (2) other relevant information required by 10 CFR 52.47; and (3) emergency operations guidelines. This volume contains Appendices 6A, 6B, and 6C for section 6 (Engineered Safety Features) of the ADM Design and Analysis. Also, parts 1--5 of section 7 (Instrumentation and Control) of the ADM Design and Analysis are covered. The following information is covered in these parts: introduction; reactor protection system; ESF actuation system; system required for safe shutdown; and safety-related display instrumentation

In vivo assessment of plant extracts for control of plant diseases: A sesquiterpene ketolactone isolated from Curcuma zedoaria suppresses wheat leaf rust.

Science.gov (United States)

Han, Jae Woo; Shim, Sang Hee; Jang, Kyoung Soo; Choi, Yong Ho; Dang, Quang Le; Kim, Hun; Choi, Gyung Ja

2018-02-01

As an alternative to synthetic pesticides, natural materials such as plant extracts and microbes have been considered to control plant diseases. In this study, methanol extracts of 120 plants were explored for in vivo antifungal activity against Rhizoctonia solani, Botrytis cinerea, Phytophthora infestans, Puccinia triticina, and Blumeria graminis f. sp. hordei. Of the 120 plant extracts, eight plant extracts exhibited a disease control efficacy of more than 90% against at least one of five plant diseases. In particular, a methanol extract of Curcuma zedoaria rhizomes exhibited strong activity against wheat leaf rust caused by P. triticina. When the C. zedoaria methanol extracts were partitioned with various solvents, the layers of n-hexane, methylene chloride, and ethyl acetate showed disease control values of 100, 80, and 43%, respectively, against wheat leaf rust. From the C. zedoaria rhizome extracts, an antifungal substance was isolated and identified as a sesquiterpene ketolactone based on the mass and nuclear magnetic resonance spectral data. The active compound controlled the development of rice sheath blight, wheat leaf rust, and tomato late blight. Considering the in vivo antifungal activities of the sesquiterpene ketolactone and the C. zedoaria extracts, these results suggest that C. zedoaria can be used as a potent fungicide in organic agriculture.

Near-term improvements for nuclear power plant control room annunciator systems

International Nuclear Information System (INIS)

Rankin, W.L.; Duvernoy, E.G.; Ames, K.R.; Morgenstern, M.H.; Eckenrode, R.J.