WorldWideScience

Sample records for generator water level

  1. Method for steam generator water level measurement

    International Nuclear Information System (INIS)

    Srinivasan, J.S.

    1991-01-01

    This paper describes a nuclear power plant, a method of controlling the steam generator water level, wherein the steam generator has an upper level tap corresponding to an upper level, a lower level, a riser positioned between the lower and upper taps, and level sensor means for indicating water level between a first range limit and a second range limit, the sensor means being connected to at least the lower tap. It comprises: calculating a measure of velocity head at about the lower level tap; calculating a measure of full water level as the upper level less the measure of velocity head; calibrating the level sensor means to provide an output at the first limit corresponding to an input thereto representative of the measure of full level; calculating a high level setpoint equal to the level of the riser less a bias amount which is a function of the position of the riser relative to the span between the taps; and controlling the water level when the sensor means indicates that the high level setpoint has been reached

  2. Water level control for a nuclear steam generator

    International Nuclear Information System (INIS)

    Wen Tan

    2011-01-01

    Research highlights: → A water level control system for a nuclear steam generator (SG) is proposed. → The parameters of the control system are directly related to those of the plant model thus scheduling is easy to implement in practice. → The proposed gain-scheduled controller can achieve good performance at both low and high power levels. - Abstract: A water level control system for a nuclear steam generator (SG) is proposed. The control system consists of a feedback controller and a feedforward controller. The feedback controller is of first order, the feedforward controller is of second order, and parameters of the two controllers are directly related to the parameters of plant model thus scheduling is easy to implement in practice. Robustness and performance of the feedback and the feedforward controllers are analyzed in details and tuning of the two parameters of the controllers are discussed. Comparisons among a single robust controller, a multi-model controller and a gain-scheduled controller are studied. It is shown that the proposed gain-scheduled controller can achieve good performance at both low and high power levels.

  3. A Receding Horizon Controller for the Steam Generator Water Level

    International Nuclear Information System (INIS)

    Na, Man Gyun; Lee, Yoon Joon

    2003-01-01

    In this work, the receding horizon control method was used to control the water level of nuclear steam generators and applied to two linear models and also a nonlinear model of steam generators. A receding horizon control method is to solve an optimization problem for finite future steps at current time and to implement the first optimal control input as the current control input. The procedure is then repeated at each subsequent instant. The dynamics of steam generators is very different according to power levels. The receding horizon controller is designed by using a reduced linear steam generator model fixed over a certain power range and applied to a Westinghouse-type (U-tube recirculating type) nuclear steam generator. The proposed controller designed at a fixed power level shows good performance for any other power level within this power range. The steam generator shows actually nonlinear characteristics. Therefore, the proposed algorithm is implemented for a nonlinear model of the nuclear steam generator to verify its real performance and also shows good responses

  4. Identification and simulation for steam generator water level based on Kalman Filter

    International Nuclear Information System (INIS)

    Deng Chen; Zhang Qinshun

    2008-01-01

    In order to effectively control the water level of the steam generator (SG), this paper has set about the state-observer theory in modern control and put forward a method to detect the 'false water level' based on Kalman Filter. Kalman Filter is a efficient tool to estimate state-variable by measured value including noise. For heavy measurement noise of steam flow, constructing a 'false water level' observer by Kalman Filter could availably obtain state variable of 'false water level'. The simulation computing for the dynamics characteristic of nuclear SG water level process under several typically running power was implemented by employing the simulation model. The result shows that the simulation model accurately identifies the 'false water level' produced in the reverse thermal-dynamic effects of nuclear SG water level process. The simulation model can realize the precise analysis of dynamics characteristic for the nuclear SG water level process. It can provide a kind of new ideas for the 'false water level' detecting of SG. (authors)

  5. Support vector regression model based predictive control of water level of U-tube steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Kavaklioglu, Kadir, E-mail: kadir.kavaklioglu@pau.edu.tr

    2014-10-15

    Highlights: • Water level of U-tube steam generators was controlled in a model predictive fashion. • Models for steam generator water level were built using support vector regression. • Cost function minimization for future optimal controls was performed by using the steepest descent method. • The results indicated the feasibility of the proposed method. - Abstract: A predictive control algorithm using support vector regression based models was proposed for controlling the water level of U-tube steam generators of pressurized water reactors. Steam generator data were obtained using a transfer function model of U-tube steam generators. Support vector regression based models were built using a time series type model structure for five different operating powers. Feedwater flow controls were calculated by minimizing a cost function that includes the level error, the feedwater change and the mismatch between feedwater and steam flow rates. Proposed algorithm was applied for a scenario consisting of a level setpoint change and a steam flow disturbance. The results showed that steam generator level can be controlled at all powers effectively by the proposed method.

  6. Digitization and simulation realization of full range control system for steam generator water level

    International Nuclear Information System (INIS)

    Qian Hong; Ye Jianhua; Qian Fei; Li Chao

    2010-01-01

    In this paper, a full range digital control system for the steam generator water level is designed by a control scheme of single element control and three-element cascade feed-forward control, and the method to use the software module configuration is proposed to realize the water level control strategy. This control strategy is then applied in the operation of the nuclear power simulation machine. The simulation result curves indicate that the steam generator water level maintains constant at the stable operation condition, and when the load changes, the water level changes but finally maintains the constant. (authors)

  7. Estimation of bias shifts in a steam-generator water-level controller

    International Nuclear Information System (INIS)

    Tylee, J.L.

    1983-01-01

    A method for detecting and estimating the value of sudden bias shifts in a U-tube steam-generator water-level controller is described and evaluated. Generalized likelihood ratios (GLR) are used to perform both the bias detection and bias estimation. Simulation results using a seventh-order, linear, discrete steam-generator model demonstrate the capabilities of the GLR detection/estimation approach

  8. Units 3 and 4 steam generators new water level control system

    International Nuclear Information System (INIS)

    Dragoev, D.; Genov, St.

    2001-01-01

    The Steam Generator Water Level Control System is one of the most important for the normal operation systems, related to the safety and reliability of the units. The main upgrading objective for the SG level and SGWLC System modernization is to assure an automatic maintaining of the SG level within acceptable limits (below protections and interlocks) from 0% to 100% of the power in normal operation conditions and in case of transients followed by disturbances in the SG controlled parameters - level, steam flow, feedwater flow and/or pressure/temperature. To achieve this objective, the computerized controllers of new SG water level control system follows current computer control technology and is implemented together with replacement of the feedwater control valves and the needed I and C equipment. (author)

  9. Fuzzy logic control of steam generator water level in pressurized water reactors

    International Nuclear Information System (INIS)

    Kuan, C.C.; Lin, C.; Hsu, C.C.

    1992-01-01

    In this paper a fuzzy logic controller is applied to control the steam generator water level in a pressurized water reactor. The method does not require a detailed mathematical mode of the object to be controlled. The design is based on a set of linguistic rules that were adopted from the human operator's experience. After off-line fuzzy computation, the controller is a lookup table, and thus, real-time control is achieved. Shrink-and-swell phenomena are considered in the linguistic rules, and the simulation results show that their effect is dramatically reduced. The performance of the control system can also be improved by changing the input and output scaling factors, which is convenient for on-line tuning

  10. Preliminary Study of Steam Generator Water Level Tracking by Three Different Methods Using RELAP5/MOD3

    Energy Technology Data Exchange (ETDEWEB)

    Park, Ki Moon; Lee, Jeong Ik [KAIST, Daejeon (Korea, Republic of)

    2016-10-15

    It has been identified in the previous works that the tracking of a steam generator (SG) water level is important. However, three different parameters can be used as an indicator of the SG water level. These parameters are: (1) SG downcomer collapsed water level, (2) water mass inventory and (3) pressure differential between upper and low tap of SG. Instead the SG water level is calculated by either SG downcomer collapsed water level or water mass inventory. However, the pressure differential measurement is the most widely used method for estimating the SG water level in the experiment as well as in the industry In this paper, therefore, three events are analyzed to perform sensitivity study of the SG water level calculation with RELAP5/MOD3 and evaluate SG level difference by three parameters. In this paper, three events are analyzed using the system analysis code (RELAP5/MOD3) to check for the consistency among the downcomer collapsed water level, mass inventory and the pressure differential measurement methods. This is to identify the sensitivity of the nuclear power plant accident response when one of the above three parameters is selected as the representative parameter of the steam generator water level. It is confirmed that mass inventory method is not affected by shrinking and swelling effect and the reactor trip time is significantly different among three parameters during TLOFW. In addition, level recovery rate is different when LOMF occurs. Thus, the SG level sensitivity of SG water level tracking method using three parameters has to be further studied not only for the steady-state operation but also for understanding the nuclear power plant response under various transient scenarios.

  11. Fuzzy logic controller architecture for water level control in nuclear power plant steam generator using ANFIS training method

    International Nuclear Information System (INIS)

    Vosoughi, Naser; Ekrami, AmirHasan; Naseri, Zahra

    2003-01-01

    Since suitable control of water level can greatly enhance the operation of a power station, a fuzzy logic controller is applied to control the steam generator water level in a pressurized water reactor. The method does not require a detailed mathematical model of the object to be controlled. It is shown that two inputs, a single output and the least number of rules (9 rules) are considered for a controller, and the ANFIS training method is employed to model functions in a controlled system. By using ANFIS training method, initial membership functions will be trained and appropriate functions are generated to control water level inside the steam generator while using the stated rules. The proposed architecture can construct an input-output mapping based on both human knowledge (in the from of fuzzy if - then rules) and stipulated input-output data. This fuzzy logic controller is applied to the steam generator level control by computer simulations. The simulation results confirm the excellent performance of this control architecture in compare with a well-turned PID controller. (author)

  12. Reactor water level control device

    International Nuclear Information System (INIS)

    Hiramatsu, Yohei.

    1980-01-01

    Purpose: To increase the rapid response of the waterlevel control converting a reactor water level signal into a non-linear type, when the water level is near to a set value, to stabilize the water level reducting correlatively the reactor water level variation signal to stabilize greatly from the set value, and increasing the variation signal. Constitution: A main vapor flow quality transmitter detects the vapor flow generated in a reactor and introduced into a turbine. A feed water flow transmitter detects the quantity of a feed water flow from the turbine to the reactor, this detected value is sent to an addition operating apparatus. On the other hand, the power signal of the reactor water level transmitter is sent to the addition operating apparatus through a non-linear water level signal converter. The addition operation apparatus generates a signal for requesting the feed water flow quantity from both signals. Upon this occasion, the reactor water level signal converter makes small the reactor water level variation when the reactor level is close the set value, and when the water level deviates greatly from the set value, the reactor water level variation is made large thereby to improve the rapid response of the reactor coater level control. (Yoshino, Y.)

  13. MPC-based auto-tuned PID controller for the steam generator water level

    International Nuclear Information System (INIS)

    Na, Man Gyun

    2001-01-01

    In this work, proportional-integral-derivative (PID) control gains are automatically tuned by using a model predictive control (MPC) method. The MPC has received much attention as a powerful tool for the control of industrial process systems. An MPC-based PID controller can be derived from the second order linear model of a process. The steam generator is usually described by the well-known 4 th order linear model which consists of the mass capacity, reverse dynamics and mechanical oscillations terms. But the important terms in this linear model are the mass capacity and reverse dynamics terms, both of which can be described by a 2 nd order linear system. The proposed auto-tuned PID controller was applied to a linear model of steam generators. The parameters of a linear model for steam generators are very different according to the power levels. The proposed controller showed good performance for the water level deviation and sudden steam flow disturbances that are typical in the existing power plants by changing only the input-weighting factor according to the power level

  14. Suppression device for the reactor water level lowering

    International Nuclear Information System (INIS)

    Kasuga, Hajime; Kasuga, Hiroshi.

    1984-01-01

    Purpose: To suppress the lowering in the reactor water level so as to avoid unnecessary actuation of ECCS upon generation of transient changes which forecasts the lowering of the reactor water level in a BWR type reactor. Constitution: There are provided a water level suppression signal generator for generating a water level suppression signal upon generation of a transient change signal which forecasts the water level lowering in a nuclear reactor and a recycling flow rate controller that applies a recycling flow rate control signal to a recycling pump drive motor by the water level lowering suppression signal. The velocity of the recycling pump is controlled by a reactor scram signal by way of the water level lowering suppresion signal generator and a recycling flow rate controller. Then, the recycling reactor core flow rate is decreased and the void amount in the reactor is transiently increased where the water level tends to increase. Accordingly, the water level lowering by the scram is moderated by the increasing tendency of the water level. (Ikeda, J.)

  15. Identification and robust water level control of horizontal steam generators using quantitative feedback theory

    International Nuclear Information System (INIS)

    Safarzadeh, O.; Khaki-Sedigh, A.; Shirani, A.S.

    2011-01-01

    Highlights: → A robust water level controller for steam generators (SGs) is designed based on the Quantitative Feedback Theory. → To design the controller, fairly accurate linear models are identified for the SG. → The designed controller is verified using a developed novel global locally linear neuro-fuzzy model of the SG. → Both of the linear and nonlinear models are based on the SG mathematical thermal-hydraulic model developed using the simulation computer code. → The proposed method is easy to apply and guarantees desired closed loop performance. - Abstract: In this paper, a robust water level control system for the horizontal steam generator (SG) using the quantitative feedback theory (QFT) method is presented. To design a robust QFT controller for the nonlinear uncertain SG, control oriented linear models are identified. Then, the nonlinear system is modeled as an uncertain linear time invariant (LTI) system. The robust designed controller is applied to the nonlinear plant model. This nonlinear model is based on a locally linear neuro-fuzzy (LLNF) model. This model is trained using the locally linear model tree (LOLIMOT) algorithm. Finally, simulation results are employed to show the effectiveness of the designed QFT level controller. It is shown that it will ensure the entire designer's water level closed loop specifications.

  16. Identification and robust water level control of horizontal steam generators using quantitative feedback theory

    Energy Technology Data Exchange (ETDEWEB)

    Safarzadeh, O., E-mail: O_Safarzadeh@sbu.ac.ir [Shahid Beheshti University, P.O. Box: 19839-63113, Tehran (Iran, Islamic Republic of); Khaki-Sedigh, A. [K. N. Toosi University of Technology, Tehran (Iran, Islamic Republic of); Shirani, A.S. [Shahid Beheshti University, P.O. Box: 19839-63113, Tehran (Iran, Islamic Republic of)

    2011-09-15

    Highlights: {yields} A robust water level controller for steam generators (SGs) is designed based on the Quantitative Feedback Theory. {yields} To design the controller, fairly accurate linear models are identified for the SG. {yields} The designed controller is verified using a developed novel global locally linear neuro-fuzzy model of the SG. {yields} Both of the linear and nonlinear models are based on the SG mathematical thermal-hydraulic model developed using the simulation computer code. {yields} The proposed method is easy to apply and guarantees desired closed loop performance. - Abstract: In this paper, a robust water level control system for the horizontal steam generator (SG) using the quantitative feedback theory (QFT) method is presented. To design a robust QFT controller for the nonlinear uncertain SG, control oriented linear models are identified. Then, the nonlinear system is modeled as an uncertain linear time invariant (LTI) system. The robust designed controller is applied to the nonlinear plant model. This nonlinear model is based on a locally linear neuro-fuzzy (LLNF) model. This model is trained using the locally linear model tree (LOLIMOT) algorithm. Finally, simulation results are employed to show the effectiveness of the designed QFT level controller. It is shown that it will ensure the entire designer's water level closed loop specifications.

  17. Automatic control of the water level of steam generators from 0% to 100% of the load

    International Nuclear Information System (INIS)

    Hocepied, R.; Debelle, J.; Timmermans, A.; Lams, J.-L.; Baeyens, R.; Eussen, G.; Bassem, G.

    1978-01-01

    The water level of a steam generator is hard to control manually and it is practically impossible for a human operator to react correctly to every important perturbation. These phenomena are further accentuated during the start-up at low load and at low feedwater temperature. The control schemes traditionally provided do not permit satisfactory automatic level control during all operating circumstances. Adaptions of the control system permit all the problems encountered to be solved: automatic control of the level in the steam generators is possible from 0% to 100% of the load and also when large-scale perturbations occur. Such a result has been obtained by use of systematic methods for the analysis of the steam generator's behaviour. These methods have also been used to verify the performance of the control system. The control system installed at the Doel nuclear power station prevents most of the reactor or turbine trip-outs caused by level deviations occurring during start-up and low-load operation. It also minimizes the effects on the unit of incidents such as tripping the unit on house load, safety tripping, fast run-back on reduced load, etc. The principles used are applicable to the control of steam generators of all pressurized water reactor power stations. (author)

  18. Regulation of the water level in the steam generator using modal control

    International Nuclear Information System (INIS)

    Benoit, Guy.

    1981-11-01

    The nuclear power reactors type P.W.R. (900 MWe) have three steam generators (S.G.). The problem of the water level in the S.G. is analogous to that for a system with non-minimum phase. This causes a serious trouble for the stability of the regulation, which is actually realized by using the PID regulator. The first part of this study is devoted to construct a mathematical model which represents the S.G. This model is simulated on a digital computer, which order is six. The validity of this model is checked using actual measured signals which have been collected from the BUGEY III power reactor. In the second part, the mathematical representation for simulating the regulation of the level in the S.G. using the modal control is given. The simulation of the actual system is given in the third part. This actual system is composed from the S.G. as well as the PI and PID for regulating the water level. As results from this study, it can be concluded that, the modal control improves the regulation of the water level. The accuracy of the steam flow measurement at low rate is poor. So, the actual regulating system using the measurements has a reduced performance performance. The control modal which is represented in this study overcome this problem [fr

  19. Multi-model predictive control method for nuclear steam generator water level

    International Nuclear Information System (INIS)

    Hu Ke; Yuan Jingqi

    2008-01-01

    The dynamics of a nuclear steam generator (SG) is very different according to the power levels and changes as time goes on. Therefore, it is an intractable as well as challenging task to improve the water level control system of the SG. In this paper, a robust model predictive control (RMPC) method is developed for the level control problem. Based on a multi-model framework, a combination of a local nominal model with a polytopic uncertain linear parameter varying (LPV) model is built to approximate the system's non-linear behavior. The optimization problem solved here is based on a receding horizon scheme involving the linear matrix inequality (LMI) technique. Closed loop stability and constraints satisfaction in the entire operating range are guaranteed by the feasibility of the optimization problem. Finally, simulation results show the effectiveness and the good performance of the proposed method

  20. The C language auto-generation of reactor trip logic caused by steam generator water level using CASE tools

    International Nuclear Information System (INIS)

    Kim, Jang Yeol; Lee, Jang Soo

    1999-01-01

    The purpose is to produce a model of nuclear reactor trip logic caused by the steam generator water level of Wolsung 2/3/4 unit through an activity chart and a statechart and to produce C language automatically using statechart-based formalism and statemate MAGNUM toolset suggested by David Harel Formalism. It was worth attempting auto-generation of C language through we manually made Software Requirement specification(SRS) for safety-critical software using statechart-based formalism. Most of the phase of the software life-cycle except the software requirement specification of an analysis phase were generated automatically by Computer Aided Software Engineering(CASE) tools. It was verified that automatically produced C language has high productivity, portability, and quality through the simulation. (Author). 6 refs., 6 figs

  1. Moisture separator for steam generator level measurement system

    International Nuclear Information System (INIS)

    Cantineau, B.J.

    1987-01-01

    A steam generator level measurement system having a reference leg which is kept full of water by a condensation pot, has a liquid/steam separator in the connecting line between the condensation pot and the steam phase in the steam generator to remove excess liquid from the steam externally of the steam generator. This ensures that the connecting line does not become blocked. The separator pot has an expansion chamber which slows down the velocity of the steam/liquid mixture to aid in separation, and a baffle, to avoid liquid flow into the line connected to the condensate pot. Liquid separated is returned to the steam generator below the water level through a drain line. (author)

  2. Reevaluation of steam generator level trip set point

    Energy Technology Data Exchange (ETDEWEB)

    Shim, Yoon Sub; Soh, Dong Sub; Kim, Sung Oh; Jung, Se Won; Sung, Kang Sik; Lee, Joon [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1994-06-01

    The reactor trip by the low level of steam generator water accounts for a substantial portion of reactor scrams in a nuclear plant and the feasibility of modification of the steam generator water level trip system of YGN 1/2 was evaluated in this study. The study revealed removal of the reactor trip function from the SG water level trip system is not possible because of plant safety but relaxation of the trip set point by 9 % is feasible. The set point relaxation requires drilling of new holes for level measurement to operating steam generators. Characteristics of negative neutron flux rate trip and reactor trip were also reviewed as an additional work. Since the purpose of the trip system modification for reduction of a reactor scram frequency is not to satisfy legal requirements but to improve plant performance and the modification yields positive and negative aspects, the decision of actual modification needs to be made based on the results of this study and also the policy of a plant owner. 37 figs, 6 tabs, 14 refs. (Author).

  3. Water level detection pipeline

    International Nuclear Information System (INIS)

    Koshikawa, Yukinobu; Imanishi, Masatoshi; Niizato, Masaru; Takagi, Masahiro

    1998-01-01

    In the present invention, water levels of a feedwater heater and a drain tank in a nuclear power plant are detected at high accuracy. Detection pipeline headers connected to the upper and lower portions of a feedwater heater or a drain tank are connected with each other. The connection line is branched at appropriate two positions and an upper detection pipeline and a lower detection pipeline are connected thereto, and a gauge entrance valve is disposed to each of the detection pipelines. A diaphragm of a pressure difference generator is connected to a flange formed to the end portion. When detecting the change of water level in the feedwater heater or the drain tank as a change of pressure difference, gauge entrance valves on the exit side of the upper and lower detection pipelines are connected by a connection pipe. The gauge entrance valve is closed, a tube is connected to the lower detection pipe to inject water to the diaphragm of the pressure difference generator passing through the connection pipe thereby enabling to calibrate the pressure difference generator. The accuracy of the calibration of instruments is improved and workability thereof upon flange maintenance is also improved. (I.S.)

  4. A Quick Review on Steam Generator Water Level Tracking Methods and Its Uncertainties

    Energy Technology Data Exchange (ETDEWEB)

    Park, Ki Moon; Lee, Jeong Ik [KAIST, Daejeon (Korea, Republic of)

    2016-05-15

    The tracking of the SG water level is important for maintaining the heat removal of the reactor and the power plant safety. In addition, the SG water level is important for the reactor trip and the actuation of SG back-up feedwater system as well. The SG water level is mainly controlled by the Feed Water Control System (FWCS) during either normal operation or transients therefore, the selection of the FWCS control parameters is also important. In this paper, methods of SG water level calculation are first reviewed and future works to perform sensitivity study of the SG water level calculation with a system analysis code will be identified. This is partially shown from Loss-of-feedwater experiments carried out in PACTEL and the LOF-10 experiment. The experiment was chosen to test the modeling capabilities of TRACE code for VVER SG. The experiment measured the water level with the pressure differential and the code calculated the water level directly from the code results. In this paper, three previously suggested parameters which can be used as an indicator of the SG water level are briefly introduced: (1) downcomer collapsed water level, (2) water mass inventory and (3) pressure differential. From the review of previous works, it was identified that most of the system analysis code calculates the SG water level directly by using the downcomer collapsed level. In contrast, the pressure difference is measured as used for the SG water level tracking in a real nuclear power plant or experiment.

  5. Steam Generator control in Nuclear Power Plants by water mass inventory

    Energy Technology Data Exchange (ETDEWEB)

    Dong Wei [North Carolina State University, Department of Nuclear Engineering, Box 7909, Raleigh, NC 27695-7909 (United States); Doster, J. Michael [North Carolina State University, Department of Nuclear Engineering, Box 7909, Raleigh, NC 27695-7909 (United States)], E-mail: doster@eos.ncsu.edu; Mayo, Charles W. [North Carolina State University, Department of Nuclear Engineering, Box 7909, Raleigh, NC 27695-7909 (United States)

    2008-04-15

    Control of water mass inventory in Nuclear Steam Generators is important to insure sufficient cooling of the nuclear reactor. Since downcomer water level is measurable, and a reasonable indication of water mass inventory near steady-state, conventional feedwater control system designs attempt to maintain downcomer water level within a relatively narrow operational band. However, downcomer water level can temporarily react in a reverse manner to water mass inventory changes, commonly known as shrink and swell effects. These complications are accentuated during start-up or low power conditions. As a result, automatic or manual control of water level is difficult and can lead to high reactor trip rates. This paper introduces a new feedwater control strategy for Nuclear Steam Generators. The new method directly controls water mass inventory instead of downcomer water level, eliminating complications from shrink and swell all together. However, water mass inventory is not measurable, requiring an online estimator to provide a mass inventory signal based on measurable plant parameters. Since the thermal-hydraulic response of a Steam Generator is highly nonlinear, a linear state-observer is not feasible. In addition, difficulties in obtaining flow regime and density information within the Steam Generator make an estimator based on analytical methods impractical at this time. This work employs a water mass estimator based on feedforward neural networks. By properly choosing and training the neural network, mass signals can be obtained which are suitable for stable, closed-loop water mass inventory control. Theoretical analysis and simulation results show that water mass control can significantly improve the operation and safety of Nuclear Steam Generators.

  6. Steam Generator control in Nuclear Power Plants by water mass inventory

    International Nuclear Information System (INIS)

    Dong Wei; Doster, J. Michael; Mayo, Charles W.

    2008-01-01

    Control of water mass inventory in Nuclear Steam Generators is important to insure sufficient cooling of the nuclear reactor. Since downcomer water level is measurable, and a reasonable indication of water mass inventory near steady-state, conventional feedwater control system designs attempt to maintain downcomer water level within a relatively narrow operational band. However, downcomer water level can temporarily react in a reverse manner to water mass inventory changes, commonly known as shrink and swell effects. These complications are accentuated during start-up or low power conditions. As a result, automatic or manual control of water level is difficult and can lead to high reactor trip rates. This paper introduces a new feedwater control strategy for Nuclear Steam Generators. The new method directly controls water mass inventory instead of downcomer water level, eliminating complications from shrink and swell all together. However, water mass inventory is not measurable, requiring an online estimator to provide a mass inventory signal based on measurable plant parameters. Since the thermal-hydraulic response of a Steam Generator is highly nonlinear, a linear state-observer is not feasible. In addition, difficulties in obtaining flow regime and density information within the Steam Generator make an estimator based on analytical methods impractical at this time. This work employs a water mass estimator based on feedforward neural networks. By properly choosing and training the neural network, mass signals can be obtained which are suitable for stable, closed-loop water mass inventory control. Theoretical analysis and simulation results show that water mass control can significantly improve the operation and safety of Nuclear Steam Generators

  7. A model predictive controller for the water level of nuclear steam generators

    International Nuclear Information System (INIS)

    Na, Man Gyun

    2001-01-01

    In this work, the model predictive control method was applied to a linear model and a nonlinear model of steam generators. The parameters of a linear model for steam generators are very different according to the power levels. The model predictive controller was designed for the linear steam generator model at a fixed power level. The proposed controller designed at the fixed power level showed good performance for any other power levels by changing only the input-weighting factor. As the input-weighting factor usually increases, its relative stability does so. The stem generator has some nonlinear characteristics. Therefore, the proposed algorithm has been implemented for a nonlinear model of the nuclear steam generator to verify its real performance and also, showed good performance. (author)

  8. Method of measuring reactor water level

    International Nuclear Information System (INIS)

    Shinohara, Kaoru.

    1979-01-01

    Purpose: To provide a water level measuring system so that a reactor water level detecting signal can be corrected in correspondence to a recirculation flow, thereby to carry out a correct water level detection in a wide range of the reactor. Method: According to the operation record of a precursor reactor, the ratio Δh of the lowering of the water level due to the recirculation flow is lowered in proportion to the ratiowith respect to the rated differential pressure of the recirculation flow. Accordingly, the flow of recirculation pump is measured by an elbow differential pressure generator utilizing an elbow of a pipe, and the measured value is multiplied by a gain by a ratio setter, and therefter, an addition computation is carried out by an adder for correcting the signal from a water level detector. When the signal from the water level detector is corrected in this manner, the influence of the lowering of the water level due to the recirculation flow can be removed, and an interlocker predetermined in the defined water level can be actuated, thus the influence of the dynamic pressure due to the recirculation flow acting on the instrumental pipe line detecting the reactor water level can be removed effectively. (Yoshino, Y.)

  9. A study on water level control of PWR steam generator at low power and the self-tuning of its fuzzy controller

    International Nuclear Information System (INIS)

    Na, N.; Kwon, K.; Ham, C.; Bien, Z.

    1994-01-01

    The water level control system of a steam generator in a pressurized water reactor and its control problems during the operation at low power is analysed. In particular, a strategy for a water level control system, which is based on the use of a fuzzy logic controller, is proposed. The control strategy includes dynamic tuning for the large transient. The fuzzy variable of the flow rate during the power operation is obtained from the bypass valve opening and not from the incorrect measured signal at the low flow rate. The practical self-tuning algorithm is based on the optimal control performance

  10. User's manual for levelized power generation cost using a microcomputer

    International Nuclear Information System (INIS)

    Fuller, L.C.

    1984-08-01

    Microcomputer programs for the estimation of levelized electrical power generation costs are described. Procedures for light-water reactor plants and coal-fired plants include capital investment cost, operation and maintenance cost, fuel cycle cost, nuclear decommissioning cost, and levelized total generation cost. Programs are written in Pascal and are run on an Apple II Plus microcomputer

  11. Emotion-driven level generation

    OpenAIRE

    Togelius, Julian; Yannakakis, Georgios N.

    2016-01-01

    This chapter examines the relationship between emotions and level generation. Grounded in the experience-driven procedural content generation framework we focus on levels and introduce a taxonomy of approaches for emotion-driven level generation. We then review four characteristic level generators of our earlier work that exemplify each one of the approaches introduced. We conclude the chapter with our vision on the future of emotion-driven level generation.

  12. Clinch river breeder reactor plant steam generator water quality

    Energy Technology Data Exchange (ETDEWEB)

    Van Hoesen, D; Lowe, P A

    1975-07-01

    The recent problems experienced by some LWR Steam Generators have drawn attention to the importance of system water quality and water/ steam side corrosion. Several of these reactor plants have encountered steam generator failures due to accelerated tube corrosion caused, in part, by poor water quality and corrosion control. The CRBRP management is aware of these problems, and the implications that they have for the Clinch River Breeder Reactor Plant (CPBRP) Steam Generator System (SGS). Consequently, programs are being implemented which will: (1) investigate the corrosion mechanisms which may be present in the CRBRP SGS; (2) assure steam generator integrity under design and anticipated off-normal water quality conditions; and (3) assure that the design water quality levels are maintained at all times. However, in order to understand the approach being used to examine this potential problem, it is first necessary to look at the CRBRP SGS and the corrosion mechanisms which may be present.

  13. Clinch river breeder reactor plant steam generator water quality

    International Nuclear Information System (INIS)

    Van Hoesen, D.; Lowe, P.A.

    1975-01-01

    The recent problems experienced by some LWR Steam Generators have drawn attention to the importance of system water quality and water/ steam side corrosion. Several of these reactor plants have encountered steam generator failures due to accelerated tube corrosion caused, in part, by poor water quality and corrosion control. The CRBRP management is aware of these problems, and the implications that they have for the Clinch River Breeder Reactor Plant (CPBRP) Steam Generator System (SGS). Consequently, programs are being implemented which will: 1) investigate the corrosion mechanisms which may be present in the CRBRP SGS; 2) assure steam generator integrity under design and anticipated off-normal water quality conditions; and 3) assure that the design water quality levels are maintained at all times. However, in order to understand the approach being used to examine this potential problem, it is first necessary to look at the CRBRP SGS and the corrosion mechanisms which may be present

  14. User's manual for levelized power generation cost using an IBM PC

    International Nuclear Information System (INIS)

    Fuller, L.C.

    1985-06-01

    Programs for the estimation of levelized electric power generation costs using the BASIC interpreter on an IBM PC are described. Procedures for light-water reactor plants and coal-fired plants include capital investment cost, operation and maintenance cost, fuel cycle cost, nuclear decommissioning cost, and levelized total generation cost

  15. Digital control system of a steam generator water level by LQG optimal method

    International Nuclear Information System (INIS)

    Lee, Yoon Joon

    1993-01-01

    A digital control system for the steam generator water level control is developed using LQG optimal design method. To describe the more realistic situaton, a feedwater valve actuator is assumed to be of the first order lagger and is included in the overall control system. By composing the digital control circuit in such a way that the overall control system consists of two sub-systems of feedwater station and feedback loop digital controller, the design procedure is divided into two independent steps. The feedwater station system is described in the error dynamics of an ordinary regulator system. The optimal gains are obtained by LQ method which imposes the constraints of the feedwater valve motion as well as on the output deviations. Developed also is a Kalman observer on account of the flow measurement uncertainty at low power. Then a digital controller on the feedback loop is designed so that the system maintains the same stability margins for all power ranges. The simulation results show thst the optimal digital system has a good control characteristics despite the adverse dynamics of a steam generator at low power. (Author)

  16. LPGC, Levelized Steam Electric Power Generator Cost

    International Nuclear Information System (INIS)

    Coen, J.J.; Delene, J.G.

    1994-01-01

    1 - Description of program or function: LPGC is a set of nine microcomputer programs for estimating power generation costs for large steam-electric power plants. These programs permit rapid evaluation using various sets of economic and technical ground rules. The levelized power generation costs calculated may be used to compare the relative economics of nuclear and coal-fired plants based on life-cycle costs. Cost calculations include capital investment cost, operation and maintenance cost, fuel cycle cost, decommissioning cost, and total levelized power generation cost. These programs can be used for quick analyses of power generation costs using alternative economic parameters, such as interest rate, escalation rate, inflation rate, plant lead times, capacity factor, fuel prices, etc. The two major types of electric generating plants considered are pressurized-water reactor (PWR) and pulverized coal-fired plants. Data are also provided for the Large Scale Prototype Breeder (LSPB) type liquid metal reactor. Costs for plant having either one or two units may be obtained. 2 - Method of solution: LPGC consists of nine individual menu-driven programs controlled by a driver program, MAINPWR. The individual programs are PLANTCAP, for calculating capital investment costs; NUCLOM, for determining operation and maintenance (O and M) costs for nuclear plants; COALOM, for computing O and M costs for coal-fired plants; NFUEL, for calculating levelized fuel costs for nuclear plants; COALCOST, for determining levelized fuel costs for coal-fired plants; FCRATE, for computing the fixed charge rate on the capital investment; LEVEL, for calculating levelized power generation costs; CAPITAL, for determining capitalized cost from overnight cost; and MASSGEN, for generating, deleting, or changing fuel cycle mass balance data for use with NFUEL. LPGC has three modes of operation. In the first, each individual code can be executed independently to determine one aspect of the total

  17. Steam generator water lancing

    International Nuclear Information System (INIS)

    Kamler, F.; Schneider, W.

    1992-01-01

    The tubesheet and tube support plate deposits in CANDU steam generators are notable for their hardness. Also notable is the wide variety of steam generator access situations. Because of the sludge hardness and the difficulty of the access, traditional water lancing processes which directed jets from the central tube free lane or from the periphery of the bundle have proven unsuitable. This has led to the need for some very unique inter tube water lancing devices which could direct powerful water jets directly onto the deposits. This type of process was applied to the upper broached plates of the Bruce A steam generators, which had become severely blocked. It has since been applied to various other steam generator situations. This paper describes the flexlance equipment development, qualification, and performance in the various CANDU applications. 4 refs., 2 tabs., 7 figs

  18. Mitigation of steam generator tube rupture in a pressurized water reactor with passive safety systems

    Science.gov (United States)

    McDermott, Daniel J.; Schrader, Kenneth J.; Schulz, Terry L.

    1994-01-01

    The effects of steam generator tube ruptures in a pressurized water reactor are mitigated by reducing the pressure in the primary loop by diverting reactor coolant through the heat exchanger of a passive heat removal system immersed in the in containment refueling water storage tank in response to a high feed water level in the steam generator. Reactor coolant inventory is maintained by also in response to high steam generator level introducing coolant into the primary loop from core make-up tanks at the pressure in the reactor coolant system pressurizer. The high steam generator level is also used to isolate the start-up feed water system and the chemical and volume control system to prevent flooding into the steam header. 2 figures.

  19. Next generation light water reactors

    International Nuclear Information System (INIS)

    Omoto, Akira

    1992-01-01

    In the countries where the new order of nuclear reactors has ceased, the development of the light water reactors of new type has been discussed, aiming at the revival of nuclear power. Also in Japan, since it is expected that light water reactors continue to be the main power reactor for long period, the technology of light water reactors of next generation has been discussed. For the development of nuclear power, extremely long lead time is required. The light water reactors of next generation now in consideration will continue to be operated till the middle of the next century, therefore, they must take in advance sufficiently the needs of the age. The improvement of the way men and the facilities should be, the simple design, the flexibility to the trend of fuel cycle and so on are required for the light water reactors of next generation. The trend of the development of next generation light water reactors is discussed. The construction of an ABWR was started in September, 1991, as No. 6 plant in Kashiwazaki Kariwa Power Station. (K.I.)

  20. Total Water Level Fun Facts: The Relative Contribution of Extreme Total Water Levels Along the US West Coast

    Science.gov (United States)

    Serafin, K.; Ruggiero, P.; Stockdon, H. F.

    2016-02-01

    In the fall of 2014, parts of the US West Coast endured some of the highest monthly mean sea level anomalies on record, likely due to the presence of "the blob" (Bond et al., 2015), an anomalously warm water mass in the NE Pacific. However, despite the significantly above average water levels, the coastline experienced only marginal coastal flooding and erosion hazards because the ensuing winter lacked significant storms, underscoring the fact that extreme total water levels (TWLs) are compound events. To better understand how several individual processes combine to cause devastating coastal hazards, we investigate the relative contribution that each component (waves, tides, and non-tidal residuals) has on extreme TWLs on sandy beaches. Water level records along the US West Coast are decomposed into mean sea level, astronomical tide, and non-tidal residuals (NTRs). The NTR is further split into an intra-annual seasonal signal, monthly mean sea level anomalies (inter-annual variability), and meteorological surge. TWL time series are then generated by combining water levels with wave runup, computed using wave data and beach morphology. We use this data-driven, structural function approach to investigate the spatial variability of the relative contribution of each component to the maximum TWL event on record. We also use a probabilistic, full simulation TWL model (Serafin and Ruggiero, 2014) to generate multiple, synthetic TWL records, to explore the relative contribution of each component to extreme TWL return levels. We assess the sensitivity to local beach morphology by computing TWLs for a range of observed beach slopes. Extreme TWLs are higher in Oregon and Washington than in California. Wave runup typically comprises > 50% of the TWL signal, while NTRs often compose < 5%, illustrating the importance wave climate has on the potential for extreme TWLs. While waves are typically larger in the North, California experiences greater contributions to extreme TWLs from

  1. Experience in adjusting of the level regulation system of steam generators of the Rovno NPP

    International Nuclear Information System (INIS)

    Patselyuk, S.N.; Sokolov, A.G.; Kazakov, V.I.; Dorosh, Yu.A.

    1984-01-01

    A system of feed water level control in steam generators at the Rovno NPP with WWER-440 reactors which comprises start-up as well as main regulators is described. The start-up regulator (single-pulsed with a signal by the level) keeps the level in the steam generator at loadings up to 30% of the nominal reactor power Nsub(nom.) The main regulator is connected in the three-pulsed circuit and it receives signals by steam and water flow rate and by the level in the steam generator. The main regulator has been started only at loadings above 40% Nsub(nom.). After reconstruction it was used in the 15-100% Nsub(nom.) range. Characteristics of the level control system in the steam generator at perturbations intoduced by the main circulating pump (MCP) and turbine disconnection as well as change in feed water flow rate have been studied. The studies have revealed that the system ensures necessary quality of control in stationary modes. The system operates stably at perturbations of feed water flow rate up to 50% Nsub(nom.). Perturbations by MCP connections and disconnections is most difficult for control system

  2. Water box for steam generator

    International Nuclear Information System (INIS)

    Lecomte, Robert; Viaud, Michel.

    1975-01-01

    This invention relates to a water box for connecting an assembly composed of a vertical steam generator and a vertical pump to the vessel of the nuclear reactor, the assembly forming the primary cooling system of a pressurised water reactor. This invention makes it easy to dismantle the pump on the water box without significant loss of water in the primary cooling system of the reactor and particularly without it being necessary to drain the water contained in the steam generator beforehand. It makes it possible to shorten the time required for dismantling the primary pump in order to service or repair it and makes dismantling safer in that the dismantling does not involve draining the steam generator and therefore the critical storage of a large amount of cooling water that has been in contact with the fuel assemblies of the nuclear reactor core [fr

  3. PWR type reactor equipped with a primary circuit loop water level gauge

    International Nuclear Information System (INIS)

    Suzuki, Mitsuhiro.

    1990-01-01

    The time of lowering a water level to less than the position of high temperature side pipeway nozzle has been rather delayed because of the swelling of mixed water level due to heat generation of the reactor core. Further, there has been a certain restriction for the installation, maintenance and adjustment of a water level gauge since it is at a position under high radiation exposure. Then, a differential pressure type water level gauge with temperature compensation is disposed at a portion below a water level gauge of a pressurizer and between the steam generator exit plenum and the lower end of the loop seal. Further, a similar water level system is disposed to all of the loops of the primary circulation circuits. In a case that the amount of water contained in a reactor container should decreased upon occurrence of loss of coolant accidents caused by small rupture and stoppage of primary circuit pumps, lowering of the water level preceding to the lowering of the water level in the reactor core is detected to ensure the amount of water. Since they are disposed to all of the loops and ensure the excess margin, reliability for the detection of the amount of contained water can be improved by averaging time for the data of the water level and averaging the entire systems, even when there are vibrations in the fluid or pressure in the primary circuit. (N.H.)

  4. Determination of arsenic in ambient water at sub-part-per-trillion levels by hydride generation Pd coated platform collection and GFAAS detection.

    Science.gov (United States)

    Liang, L; Lazoff, S; Chan, C; Horvat, M; Woods, J S

    1998-11-01

    A method for trace determination of total arsenic in ambient waters is described. Arsenic is separated on-line from a large volume water sample by hydride generation and purging, pre-collected on a Pd coated pyrolytic platform cuvette using a simple and inexpensive system, and finally detected by GFAAS. Instrument parameters, hydride generation, transportation, and collection were optimized. The analytical behavior for major species including As(3+), As(5+), monomethyl As (MMA), and dimethyl As (DMA) were investigated individually. Problems arising from use of the system were discussed and eliminated. The necessity of sample digestion and an efficient digestion method were studied. Sample digestion for water with low organic content such as tap water and clean ground water and some clean surface water can be omitted. The method detection limit (MDL) is 0.3 ng l(-1) for a 25 ml water sample. Recoveries close to 100% with R.S.D.rain, sewage effluent, and saline water from different origins in the US, China, and Canada were collected and analyzed using ultra clean sampling and analysis techniques. The background levels of As in most water analyzed were established for the first time, and found to be far above the EPA's health effect criteria, 18 ng l(-1).

  5. Socio–economic benefits and pollution levels of water resources ...

    African Journals Online (AJOL)

    Communities are dependent on wetlands resources for income generation. However, anthropogenic activities that result into pollution of water are one of the major public health problems. Assessment of socio–economic activities and pollution levels of domestic water sources in Gulu Municipality, Pece wetland was done.

  6. Detecting drawdowns masked by environmental stresses with water-level models

    Science.gov (United States)

    Garcia, C.A.; Halford, K.J.; Fenelon, J.M.

    2013-01-01

    Detecting and quantifying small drawdown at observation wells distant from the pumping well greatly expands the characterized aquifer volume. However, this detection is often obscured by water level fluctuations such as barometric and tidal effects. A reliable analytical approach for distinguishing drawdown from nonpumping water-level fluctuations is presented and tested here. Drawdown is distinguished by analytically simulating all pumping and nonpumping water-level stresses simultaneously during the period of record. Pumping signals are generated with Theis models, where the pumping schedule is translated into water-level change with the Theis solution. This approach closely matched drawdowns simulated with a complex three-dimensional, hypothetical model and reasonably estimated drawdowns from an aquifer test conducted in a complex hydrogeologic system. Pumping-induced changes generated with a numerical model and analytical Theis model agreed (RMS as low as 0.007 m) in cases where pumping signals traveled more than 1 km across confining units and fault structures. Maximum drawdowns of about 0.05 m were analytically estimated from field investigations where environmental fluctuations approached 0.2 m during the analysis period.

  7. Development of an iodine generator for reclaimed water purification in manned spacecraft applications

    Science.gov (United States)

    Wynveen, R. A.; Powell, J. D.; Schubert, F. H.

    1973-01-01

    A successful 30-day test is described of a prototype Iodine Generating and Dispensing System (IGDS). The IGDS was sized to iodinate the drinking water nominally consumed by six men, 4.5 to 13.6 kg (10 to 30 lb) water per man-day with a + or - 10 to 20% variation with iodine (I2) levels of 0.5 to 20 parts per million (ppm). The I2 treats reclaimed water to prevent or eliminate microorganism contamination. Treatment is maintained with a residual of I2 within the manned spacecraft water supply. A simplified version of the chlorogen water disinfection concept, developed by life systems for on-site generation of chlorine (Cl2), was used as a basis for IGDS development. Potable water contaminated with abundant E. Coliform Group organisms was treated by electrolytically generated I2 at levels of 5 to 10 ppm. In all instances, the E. coli were eliminated.

  8. Water waves generated by underwater explosion

    CERN Document Server

    Mehaute, Bernard Le

    1996-01-01

    This is the first book on explosion-generated water waves. It presents the theoretical foundations and experimental results of the generation and propagation of impulsively generated waves resulting from underwater explosions. Many of the theories and concepts presented herein are applicable to other types of water waves, in particular, tsunamis and waves generated by the fall of a meteorite. Linear and nonlinear theories, as well as experimental calibrations, are presented for cases of deep and shallow water explosions. Propagation of transient waves on dissipative, nonuniform bathymetries to

  9. Gas generation from low-level radioactive waste: Concerns for disposal

    International Nuclear Information System (INIS)

    Siskind, B.

    1992-01-01

    The Advisory Committee on Nuclear Waste (ACNW) has urged the Nuclear Regulatory Commission (NRC) to reexamine the topic of hydrogen gas generation from low-level radioactive waste (LLW) in closed spaces to ensure that the slow buildup of hydrogen from water-bearing wastes in sealed containers does not become a problem for long-term safe disposal. Brookhaven National Laboratory (BNL) has prepared a report, summarized in this paper, for the NRC to respond to these concerns. The paper discusses the range of values for G(H 2 ) reported for materials of relevance to LLW disposal; most of these values are in the range of 0.1 to 0.6. Most studies of radiolytic hydrogen generation indicate a leveling off of pressurization, probably because of chemical kinetics involving, in many cases, the radiolysis of water within the waste. Even if no leveling off occurs, realistic gas leakage rates (indicating poor closure by gaskets on drums and liners) will result in adequate relief of pressure for radiolytic gas generation from the majority of commercial sector LLW packages. Biodegradative gas generation, however, could pose a pressurization hazard even at realistic gas leakage rates. Recommendations include passive vents on LLW containers (as already specified for high integrity containers) and upper limits to the G values and/or the specific activity of the LLW

  10. Small leak detection by measuring surface oscillation during sodium-water reaction in steam generator

    International Nuclear Information System (INIS)

    Nei, Hiromichi; Hori, Masao

    1977-01-01

    Small leak sodium-water reaction tests were conducted to develop various kinds of leak detectors for the sodium-heated steam generator in FBR. The super-heated steam was injected into sodium in a reaction vessel having a sodium free surface, simulating the steam generator. The level gauge in the reaction vessel generated the most reliable signal among detectors, as long as the leak rates were relatively high. The level gauge signal was estimated to be the sodium surface oscillation caused by hydrogen bubbles produced in sodium-water reaction. Experimental correlation was derived, predicting the amplitude as a function of leak rate, hydrogen dissolution ratio, bubble rise velocity and other parameters concerned, assuming that the surface oscillation is in proportion to the gas hold-up. The noise amplitude under normal operation without water leak was increased with sodium flow rate and found to be well correlated with Froud number. These two correlations predict that a water leak in a ''MONJU'' class (300 MWe) steam generator could possibly be detected by level gauges at a leak rate above 2 g/sec. (auth.)

  11. Chemistry management of generator stator water system

    International Nuclear Information System (INIS)

    Sankar, N.; Santhanam, V.S.; Ayyar, S.R.; Umapathi, P.; Jeena, P.; Hari Krishna, K.; Rajendran, D.

    2015-01-01

    Chemistry management of water cooled turbine generators with hollow copper conductors is very essential to avoid possible re-deposition of released copper oxides on stator windings, which otherwise may cause flow restrictions by partial plugging of copper hollow conductors and impair cooling. The phenomenon which is of more concern is not strictly of corrosion failure, but the consequences caused by the re-deposition of copper oxides that were formed by reaction of copper with oxygen. There were also some Operating experiences (OE) related to Copper oxide fouling in the system resulting shut down/off-line of plants. In Madras Atomic Power Station (MAPS), the turbine generator stator windings are of Copper material and cooled by demineralized water passing through the hollow conductors. The heated water from the stator is cooled by process water. A part of the stator water is continuously passed through a mixed bed polisher to remove any soluble ionic contaminants to maintain the purity of system water and also maintain copper content as low as possible to avoid possible re-deposition of released copper oxides on stator windings. The chemistry regime employed is neutral water with dissolved oxygen content between 1000-2000 ppb. Chemistry management of Stator water system was reviewed to know its effectiveness. Detailed chemical analyses of the spent resins from the polishing unit were carried out in various campaigns which indicated only part exhaustion of the polishing unit resins and reasonably low levels of copper entrapment in the resins, thus highlighting the effectiveness of the in-practice chemistry regime. (author)

  12. Design of fuzzy learning control systems for steam generator water level control

    International Nuclear Information System (INIS)

    Park, Gee Yong

    1996-02-01

    A fuzzy learning algorithm is developed in order to construct the useful control rules and tune the membership functions in the fuzzy logic controller used for water level control of nuclear steam generator. The fuzzy logic controllers have shown to perform better than conventional controllers for ill-defined or complex processes such as nuclear steam generator. Whereas the fuzzy logic controller does not need a detailed mathematical model of a plant to be controlled, its structure is to be made on the basis of the operator's linguistic information experienced from the plant operations. It is not an easy work and also there is no systematic way to translate the operator's linguistic information into quantitative information. When the linguistic information of operators is incomplete, tuning the parameters of fuzzy controller is to be performed for better control performance. It is the time and effort consuming procedure that controller designer has to tune the structure of fuzzy logic controller for optimal performance. And if the number of control inputs is many and the rule base is constructed in multidimensional space, it is very difficult for a controller designer to tune the fuzzy controller structure. Hence, the difficulty in putting the experimental knowledge into quantitative (or numerical) data and the difficulty in tuning the rules are the major problems in designing fuzzy logic controller. In order to overcome the problems described above, a learning algorithm by gradient descent method is included in the fuzzy control system such that the membership functions are tuned and the necessary rules are created automatically for good control performance. For stable learning in gradient descent method, the optimal range of learning coefficient not to be trapped and not to provide too slow learning speed is investigated. With the optimal range of learning coefficient, the optimal value of learning coefficient is suggested and with this value, the gradient

  13. Pressurized-water coolant nuclear reactor steam generator

    International Nuclear Information System (INIS)

    Mayer, H.; Schroder, H.J.

    1975-01-01

    A description is given of a pressurized-water coolant nuclear reactor steam generator having a vertical housing for the steam generating water and containing an upstanding heat exchanger to which the pressurized-water coolant passes and which is radially surrounded by a guide jacket supporting a water separator on its top. By thermosiphon action the steam generating water flows upward through and around the heat exchanger within the guide chamber to the latter's top from which it flows radially outwardly and downwardly through a down draft space formed between the outside of the jacket and the housing. The water separator discharges separated water downwardly. The housing has a feedwater inlet opening adjacent to the lower portion of the heat exchanger, providing preheating of the introduced feedwater. This preheated feedwater is conveyed by a duct upwardly to a location where it mixes with the water discharged from the water separator

  14. BWR [boiling water reactor] core criticality versus water level during an ATWS [anticipated transient without scram] event

    International Nuclear Information System (INIS)

    Sehgal, B.R.; Peng, C.M.; Maly, J.

    1988-01-01

    The BWR [boiling water reactor] emergency procedures guidelines recommend management of core water level to reduce the power generated during an anticipated transient without scram (ATWS) event. BWR power level variation has traditionally been calculated in the system codes using a 1-D [one-dimensional] 2-group neutron kinetics model to determine criticality. This methodology used also for calculating criticality of the partially covered BWR cores has, however, never been validated against data. In this paper, the power level versus water level issues in an ATWS severe accident are introduced and the accuracy of the traditional methodology is investigated by comparing with measured data. It is found that the 1-D 2-group treatment is not adequate for accurate predictions of criticality and therefore the system power level for the water level variations that may be encountered in a prototypical ATWS severe accident. It is believed that the current predictions for power level may be too high

  15. Evaluate prevailing climate change on Great Lakes water levels

    International Nuclear Information System (INIS)

    Islam, M.

    2009-01-01

    'Full text:'In this paper, results of a comprehensive water mass balance modeling for the Great Lakes against prevailing and different anticipated climate change scenarios would be presented. Modeling is done in evaluating the changes in the lake storages and then changes in the lake's water level considering present condition, uncertainty and variability of climate and hydrologic conditions in the future. Inflow-outflow and consequent changes in the five Great Lake's storages are simulated for the last 30 years and then projected to evaluate the changes in the lake storages for the next 50 years. From the predicted changes in the lake storage data, water level is calculated using mass to linear conversion equation. Modeling and analysis results are expected to be helpful in understanding the possible impacts of the climate change on the Great Lakes water environment and preparing strategic plan for the sustainable management of lake's water resources. From the recent past, it is observed that there is a depleting trend in the lakes water level and hence there is a potential threat to lake's water environment and uncertainty of the availability of quality and quantity of water for the future generations, especially against prevailing and anticipated climate changes. For this reason, it is an urgent issue of understanding and quantifying the potential impacts of climate change on the Great Lake's water levels and storages. (author)

  16. Relations between vegetation and water level in groundwater dependent terrestrial ecosystems (GWDTEs)

    DEFF Research Database (Denmark)

    Munch Johansen, Ole; Andersen, Dagmar Kappel; Ejrnæs, Rasmus

    2018-01-01

    , management and conservation of fens are constrained by limited knowledge on the relations between vegetation and measurable hydrological conditions. This study investigates the relations between vegetation and water level dynamics in groundwater dependent wetlands in Denmark. A total of 35 wetland sites...... across Denmark were included in the study. The sites represent a continuum of wetlands with respect to vegetation and hydrological conditions. Water level was measured continuously using pressure transducers at each site. Metrics expressing different hydrological characteristics, such as mean water level...... and low and high water level periods, were calculated based on the water level time series. A complete plant species list was recorded in plots covering 78.5 m2 at each site. Community metrics such as total number of species and the number of bryophytes were generated from the species lists and Ellenberg...

  17. Multi-generational drinking of bottled low mineral water impairs bone quality in female rats.

    Directory of Open Access Journals (Sweden)

    Zhiqun Qiu

    Full Text Available Because of reproductions and hormone changes, females are more sensitive to bone mineral loss during their lifetime. Bottled water has become more popular in recent years, and a large number of products are low mineral water. However, research on the effects of drinking bottled low mineral water on bone health is sparse.To elucidate the skeletal effects of multi-generational bottled water drinking in female rats.Rats continuously drank tap water (TW, bottled natural water (bNW, bottled mineralized water (bMW, or bottled purified water (bPW for three generations.The maximum deflection, elastic deflection, and ultimate strain of the femoral diaphysis in the bNW, bMW, and bPW groups and the fracture strain in the bNW and bMW groups were significantly decreased. The tibiae calcium levels in both the bNW and bPW groups were significantly lower than that in the TW group. The tibiae and teeth magnesium levels in both the bNW and bPW groups were significantly lower than those in the TW group. The collagen turnover markers PICP (in both bNW and bPW groups were significantly lower than that in the TW group. In all three low mineral water groups, the 1,25-dihydroxy-vitamin D levels were significantly lower than those in the TW group.Long-term drinking of low mineral water may disturb bone metabolism and biochemical properties and therefore weaken biomechanical bone properties in females. Drinking tap water, which contains adequate minerals, was found to be better for bone health. To our knowledge, this is the first report on drinking bottled low mineral water and female bone quality on three generation model.

  18. Generating para-water from para-hydrogen: A Gedankenexperiment.

    Science.gov (United States)

    Ivanov, Konstantin L; Bodenhausen, Geoffrey

    2018-07-01

    A novel conceptual approach is described that is based on the transfer of hyperpolarization from para-hydrogen in view of generating a population imbalance between the two spin isomers of H 2 O. The approach is analogous to SABRE (Signal Amplification By Reversible Exchange) and makes use of the transfer of spin order from para-hydrogen to H 2 O in a hypothetical organometallic complex. The spin order transfer is expected to be most efficient at avoided level crossings. The highest achievable enrichment levels of para- and ortho-water are discussed. Copyright © 2018 Elsevier Inc. All rights reserved.

  19. Biogas generation and water management; Biogaserzeugung und Wasserwirtschaft

    Energy Technology Data Exchange (ETDEWEB)

    Fohrmann, Reinhard [IWW Rheinisch-Westfaelisches Institut fuer Wasser Beratungs- und Entwicklungsgesellschaft mbH, Muelheim an der Ruhr (Germany)

    2012-12-15

    Is it possible to attenuate the consequences of the increasing development of biogas generation for the water production by means of a meshing of energy industry and water management? On the occasion of the 25th Muelheim water technology symposium, experts discuss on opportunities and risks of the biogas generation.

  20. GNSS-Reflectometry based water level monitoring

    Science.gov (United States)

    Beckheinrich, Jamila; Schön, Steffen; Beyerle, Georg; Apel, Heiko; Semmling, Maximilian; Wickert, Jens

    2013-04-01

    Due to climate changing conditions severe changes in the Mekong delta in Vietnam have been recorded in the last years. The goal of the German Vietnamese WISDOM (Water-related Information system for the Sustainable Development Of the Mekong Delta) project is to build an information system to support and assist the decision makers, planners and authorities for an optimized water and land management. One of WISDOM's tasks is the flood monitoring of the Mekong delta. Earth reflected L-band signals from the Global Navigation Satellite System show a high reflectivity on water and ice surfaces or on wet soil so that GNSS-Reflectometry (GNSS-R) could contribute to monitor the water level in the main streams of the Mekong delta complementary to already existing monitoring networks. In principle, two different GNSS-R methods exist: the code- and the phase-based one. As the latter being more accurate, a new generation of GORS (GNSS Occultation, Reflectometry and Scatterometry) JAVAD DELTA GNSS receiver has been developed with the aim to extract precise phase observations. In a two week lasting measurement campaign, the receiver has been tested and several reflection events at the 150-200 m wide Can Tho river in Vietnam have been recorded. To analyze the geometrical impact on the quantity and quality of the reflection traces two different antennas height were tested. To track separately the direct and the reflected signal, two antennas were used. To derive an average height of the water level, for a 15 min observation interval, a phase model has been developed. Combined with the coherent observations, the minimum slope has been calculated based on the Least- Squares method. As cycle slips and outliers will impair the results, a preprocessing of the data has been performed. A cycle slip detection strategy that allows for automatic detection, identification and correction is proposed. To identify outliers, the data snooping method developed by Baarda 1968 is used. In this

  1. A moist air condensing device for sustainable energy production and water generation

    International Nuclear Information System (INIS)

    Ming, Tingzhen; Gong, Tingrui; Richter, Renaud K. de; Wu, Yongjia; Liu, Wei

    2017-01-01

    Highlights: • A novel device based upon a SCPP system is proposed for electricity production and water generation. • The collector is replaced by black tubes around the chimney. • The overall performance of SCPP for energy production and water generation was analyzed. • The system total energy efficiency of a SCPP with a height of 3000 m can be nearly 7%. - Abstract: A solar chimney power plant (SCPP) is not only a solar thermal application system to achieve output power, but also a device extracting freshwater from the humid air. In this article, we proposed a SCPP with collector being replaced by black tubes around the chimney to warm water and air. The overall performance of SCPP was analyzed by using a one-dimensional compressible fluid transfer model to calculate the system characteristic parameters, such as chimney inlet air velocity, the condensation level, amount of condensed water, output power, and efficiency. It was found that increasing the chimney inlet air temperature is an efficient way to increase chimney inlet air velocity and wind turbine output power. The operating conditions, such as air temperature and air relative humidity, have significant influence on the condensation level. For water generation, chimney height is the most decisive factor, the mass flow rate of condensed water decreases with increasing wind turbine pressure drop. To achieve the optimum peak output power by wind turbine, we should set the pressure drop factor as about 0.7. In addition, increasing chimney height is also an efficient way to improve the SCPP efficiency. Under ideal conditions, the system total efficiency of a SCPP with a height of 3000 m can be up to nearly 7%.

  2. Effect of condenser water in-leakage on steam generator water chemistry

    International Nuclear Information System (INIS)

    Balakrishnan, P.V.

    1978-01-01

    Corrosive environments may be generated within steam genrators from condenser cooling water in-leakage. Theoretical as well as experimental evaluation of the aggressiveness of such environments is being carried out for the condenser-cooling waters used at CANDU-PHW nuclear power stations. Calculations have shown that highly concentrated chloride solutions - acidic in the case of sea-water in-leakage, and alkaline in the rest of the cases considered - would be produced within the steam generator. Experiments in a model boiler showed that sea-water in-leakage caused rapid corrosion of carbon steel components when only AVT (all volatile treatment) was used for water chemistry control. Use of a non-volatile reagent, as in the congruent phosphate treatment, avoided the rapid corrosion of carbon steel. On the basis of our studies, congruent phosphate treatment during sea water in-leakage appears desirable. (author)

  3. Bioinspired Bifunctional Membrane for Efficient Clean Water Generation.

    Science.gov (United States)

    Liu, Yang; Lou, Jinwei; Ni, Mengtian; Song, Chengyi; Wu, Jianbo; Dasgupta, Neil P; Tao, Peng; Shang, Wen; Deng, Tao

    2016-01-13

    Solving the problems of water pollution and water shortage is an urgent need for the sustainable development of modern society. Different approaches, including distillation, filtration, and photocatalytic degradation, have been developed for the purification of contaminated water and the generation of clean water. In this study, we explored a new approach that uses solar light for both water purification and clean water generation. A bifunctional membrane consisting of a top layer of TiO2 nanoparticles (NPs), a middle layer of Au NPs, and a bottom layer of anodized aluminum oxide (AAO) was designed and fabricated through multiple filtration processes. Such a design enables both TiO2 NP-based photocatalytic function and Au NP-based solar-driven plasmonic evaporation. With the integration of these two functions into a single membrane, both the purification of contaminated water through photocatalytic degradation and the generation of clean water through evaporation were demonstrated using simulated solar illumination. Such a demonstration should also help open up a new strategy for maximizing solar energy conversion and utilization.

  4. Using inferential sensors for quality control of Everglades Depth Estimation Network water-level data

    Science.gov (United States)

    Petkewich, Matthew D.; Daamen, Ruby C.; Roehl, Edwin A.; Conrads, Paul

    2016-09-29

    The Everglades Depth Estimation Network (EDEN), with over 240 real-time gaging stations, provides hydrologic data for freshwater and tidal areas of the Everglades. These data are used to generate daily water-level and water-depth maps of the Everglades that are used to assess biotic responses to hydrologic change resulting from the U.S. Army Corps of Engineers Comprehensive Everglades Restoration Plan. The generation of EDEN daily water-level and water-depth maps is dependent on high quality real-time data from water-level stations. Real-time data are automatically checked for outliers by assigning minimum and maximum thresholds for each station. Small errors in the real-time data, such as gradual drift of malfunctioning pressure transducers, are more difficult to immediately identify with visual inspection of time-series plots and may only be identified during on-site inspections of the stations. Correcting these small errors in the data often is time consuming and water-level data may not be finalized for several months. To provide daily water-level and water-depth maps on a near real-time basis, EDEN needed an automated process to identify errors in water-level data and to provide estimates for missing or erroneous water-level data.The Automated Data Assurance and Management (ADAM) software uses inferential sensor technology often used in industrial applications. Rather than installing a redundant sensor to measure a process, such as an additional water-level station, inferential sensors, or virtual sensors, were developed for each station that make accurate estimates of the process measured by the hard sensor (water-level gaging station). The inferential sensors in the ADAM software are empirical models that use inputs from one or more proximal stations. The advantage of ADAM is that it provides a redundant signal to the sensor in the field without the environmental threats associated with field conditions at stations (flood or hurricane, for example). In the

  5. Corrosion induced clogging and plugging in water-cooled generator cooling circuit

    International Nuclear Information System (INIS)

    Park, B.G.; Hwang, I.S.; Rhee, I.H.; Kim, K.T.; Chung, H.S.

    2002-01-01

    Water-cooled electrical generators have been experienced corrosion-related problems that are restriction of flow through water strainers caused by collection of excessive amounts of copper corrosion products (''clogging''), and restriction of flow through the copper strands in the stator bars caused by growth or deposition of corrosion products on the walls of the hollow strands (''plugging''). These phenomena result in unscheduled shutdowns that would be a major concern because of the associated loss in generating capacity. Water-cooled generators are operated in one of two modes. They are cooled either with aerated water (dissolved oxygen >2 ppm) or with deaerated water (dissolved oxygen <50 ppb). Both modes maintain corrosion rates at satisfactorily low levels as long as the correct oxygen concentrations are maintained. However, it is generally believed that very much higher copper corrosion rates result at the intermediate oxygen concentrations of 100-1000 ppb. Clogging and plugging are thought to be associated with these intermediate concentrations, and many operators have suggested that the period of change from high-to-low or from low-to-high oxygen concentration is particularly damaging. In order to understand the detailed mechanism(s) of the copper oxide formation, release and deposition and to identify susceptible conditions in the domain of operating variables, a large-scale experiments are conducted using six hollow strands of full length connected with physico-chemically scaled generator cooling water circuit. To ensure a close simulation of thermal-hydraulic conditions in a generator stator, strands of the loop will be ohmically heated using AC power supply. Experiments is conducted to cover oxygen excursions in both high dissolved oxygen and low dissolved oxygen conditions that correspond to two representative operating condition at fields. A thermal upset condition is also simulated to examine the impact of thermal stress. During experiments

  6. Direct Drive Generator for Renewable Power Conversion from Water Currents

    International Nuclear Information System (INIS)

    Segergren, Erik

    2005-01-01

    In this thesis permanent magnet direct drive generator for power conversion from water currents is studied. Water currents as a power source involves a number of constrains as well as possibilities, especially when direct drive and permanent magnets are considered. The high power fluxes and low current velocities of a water current, in combination with its natural variations, will affect the way the generator is operated and, flowingly, the appearance of the generator. The work in this thesis can, thus, be categorized into two general topics, generator technology and optimization. Under the first topic, fundamental generator technology is used to increase the efficiency of a water current generator. Under the latter topic, water current generators are optimized to a specific environment. The conclusion drawn from this work is that it is possible to design very low speed direct drive generators with good electromagnetic properties and wide efficiency peak

  7. Speciation of arsenic in water samples by high-performance liquid chromatography-hydride generation-atomic absorption spectrometry at trace levels using a post-column reaction system

    Energy Technology Data Exchange (ETDEWEB)

    Stummeyer, J. [Bundesanstalt fuer Geowissenschaften und Rohstoffe, Hannover (Germany); Harazim, B. [Bundesanstalt fuer Geowissenschaften und Rohstoffe, Hannover (Germany); Wippermann, T. [Bundesanstalt fuer Geowissenschaften und Rohstoffe, Hannover (Germany)

    1996-02-01

    Anion-exchange HPLC has been combined with hydride generation - atomic absorption spectrometry (HG-AAS) for the routine speciation of arsenite, arsenate, monomethylarsenic acid and dimethylarsinic acid. The sensitivity of the AAS-detection was increased by a post-column reaction system to achieve complete formation of volatile arsines from the methylated species and arsenate. The system allows the quantitative determination of 0.5 {mu}g/l of each arsenic compound in water samples. The stability of synthetical and natural water containing arsenic at trace levels was investigated. To preserve stored water samples, a method for quantitative separation of arsenate at high pH-values with the basic anion-exchange resin Dowex 1 x 8 was developed. (orig.)

  8. Water releasing electric generating device for nuclear power plant

    International Nuclear Information System (INIS)

    Umehara, Toshihiro; Tomohara, Yasutaka; Usui, Yoshihiko.

    1994-01-01

    Warm sea water discharged after being used for cooling in an equipment of a coastal nuclear powder plant is discharged from a water discharge port to a water discharge pit, and a conduit vessel is disposed in front of the water discharge port for receiving overflown warm sea water. The warm sea water taken to the conduit vessel is converted to a fallen flow and charged to a turbine generator under water, and electric power is generated by the water head energy of the fallen flow before it is discharged to the water discharge pit. The conduit vessel incorporates a foam preventing unit having spiral flow channels therein, so that the warm sea water taken to the conduit vessel is flown into the water discharge pit after consuming the water head energy while partially branched and flown downwardly and gives lateral component to the downwarding flowing direction. Then, warm sea water is made calm when it is flown into the water discharge pit and, accordingly, generation of bubbles on the water surface of the water discharge pit is avoided. (N.H.)

  9. Game theory competition analysis of reservoir water supply and hydropower generation

    Science.gov (United States)

    Lee, T.

    2013-12-01

    The total installed capacity of the power generation systems in Taiwan is about 41,000 MW. Hydropower is one of the most important renewable energy sources, with hydropower generation capacity of about 4,540 MW. The aim of this research is to analyze competition between water supply and hydropower generation in water-energy systems. The major relationships between water and energy systems include hydropower generation by water, energy consumption for water system operation, and water consumption for energy system. In this research, a game-theoretic Cournot model is formulated to simulate oligopolistic competition between water supply, hydropower generation, and co-fired power generation in water-energy systems. A Nash equilibrium of the competitive market is derived and solved by GAMS with PATH solver. In addition, a case study analyzing the competition among water supply and hydropower generation of De-ji and Ku-Kuan reservoirs, Taipower, Star Energy, and Star-Yuan power companies in central Taiwan is conducted.

  10. The 2010 Mario AI Championship: Level Generation Track

    DEFF Research Database (Denmark)

    Shaker, Noor; Togelius, Julian; Yannakakis, Georgios N.

    2011-01-01

    The Level Generation Competition, part of the IEEE CIS-sponsored 2010 Mario AI Championship, was to our knowledge the world’s first procedural content generation competition. Competitors participated by submitting level generators — software that generates new levels for a version of Super Mario...

  11. Enhancement of efficacy of process water monitors in detecting heavy water leak in steam generator blow down lines

    International Nuclear Information System (INIS)

    Mitra, S.R.; Kohale, S.D.; Parida, B.K.; Gathe, G.D.; Pati, C.K.; Mudgal, B.K.; Niraj; Pawar, S.K.

    2006-01-01

    The Steam Generator (SG) serves as an interface between primary and secondary cycle in Pressurized Heavy Water Reactor (PHWR). Failure of steam generator tubes result in leaking of active heavy water in the secondary closed loop. In Tarapur Atomic Power Station-3 and 4 (TAPS- 3 and 4), Scintillator detectors are provided to detect on line heavy water leakages in SG and moderator heat exchangers by monitoring Nitrogen-16 ( 16 N) and Oxygen-19 ( 19 O) activities. Efficacy of detection of these activities at designed detector position on SG blow down line in presence of background radiation field is analysed theoretically. The count rate of 19 O and 16 N estimated at the detector position inside Reactor Building (RB) shows that detectors only respond to very high leak rates due to presence of high ambient radiation level even though sensitivity is appreciably good. For detector position in RB in the accessible areas and out side the RE containment, the travel time for the blow down feed water becomes moderately and very long respectively resulting in poor sensitivity. However the results show that wherever background levels is low, the efficacy of leak detection becomes considerably better than the results obtained when detector is placed inside RB. The study was validated during the reactor operation by recording the detector count rates due to prevalent ambient radiation level near to the detectors. Subsequently the detectors were relocated in an area inside RB where relocation was feasible, travel time of the blow down feed water was moderate and the area had an relatively low ambient radiation level. This paper discusses the methodology adopted during the study and results obtained during theoretical estimation and practical validation. (author)

  12. Hydrogen sulfide generation in shipboard oily-water waste. Part 3. Ship factors

    Energy Technology Data Exchange (ETDEWEB)

    Hodgeman, D.K.; Fletcher, L.E.; Upsher, F.J.

    1995-04-01

    The chemical and microbiological composition of bilge-water in ships of the Royal Australian Navy has been investigated in relation to the formation of hydrogen sulfide by sulfate-reducing bacteria. Sulfate-reducing bacteria were found in most ships in populations up to 800,000 per mL. Sulfate in the wastes is provided by sea-water. Sea-water constitutes up to 60% (median 20%) of the wastes analysed. Evidence for generation of hydrogen sulfide in the ships was found directly as sulfide or indirectly as depressed sulfate concentrations. The low levels of sulfide found in bilge-water from machinery spaces suggested the ventilation systems were effectively removing the gas from the working area. The effect of storage of the wastes under conditions which simulated the oily- water holding tanks of ships were also investigated. Some wastes were found to produce large quantities of hydrogen sulfide on storage. The wastes that failed to produce hydrogen sulfide were investigated to identify any specific nutritional deficiencies. Some organic substances present in bilge-water, such as lactate or biodegradable cleaning agents, and phosphate strongly influenced the generation of hydrogen sulfide in stored oily-water wastes.

  13. Determination of moisture content in steams and variation in moisture content with operating boiler level by analyzing sodium content in steam generator water and steam condensate of a nuclear power plant using ion chromatographic technique

    International Nuclear Information System (INIS)

    Pal, P.K.; Bohra, R.C.

    2015-01-01

    Dry steam with moisture content less than <1% is the stringent requirements in a steam generator for good health of the turbine. In order to confirm the same, determination of sodium is done in steam generator water and steam condensate using Flame photometer in ppm level and ion chromatograph in ppb level. Depending on the carry over of sodium in steam along with the water droplet (moisture), the moisture content in steam was calculated and was found to be < 1% which is requirements of the system. The paper described the salient features of a PHWR, principle of Ion Chromatography, chemistry parameters of Steam Generators and calculation of moisture content in steam on the basis of sodium analysis. (author)

  14. Water and waste water management Generation Victoria - Latrobe Valley

    Energy Technology Data Exchange (ETDEWEB)

    Longmore, G. [Hazelwood Power Corporation, VIC (Australia); Pacific Power (International) Pty. Ltd., Sydney, NSW (Australia)

    1995-12-31

    Water is a necessary resource for coal fired power plant and waste water is generated. The efficient management of water and waste water systems becomes an important operational environmental factor. This paper describes the development and implementation of a ten year water and waste water management strategy for the Latrobe Valley Group of brown coal fired power stations in Victoria. In early 1991, a team was put together of representatives from each power site to develop the strategy entitled `SECV Latrobe Valley Water and Wastewater Management Strategy`. The strategy was developed with extensive public consultation, which was a factor in protracting the process such that the final document was not promulgated until late 1992. However, the final comprehensive document endorsed and agreed by management, has since attracted favourable comment as a model of its type. (author). 2 figs.

  15. Water and waste water management Generation Victoria - Latrobe Valley

    International Nuclear Information System (INIS)

    Longmore, G.

    1995-01-01

    Water is a necessary resource for coal fired power plant and waste water is generated. The efficient management of water and waste water systems becomes an important operational environmental factor. This paper describes the development and implementation of a ten year water and waste water management strategy for the Latrobe Valley Group of brown coal fired power stations in Victoria. In early 1991, a team was put together of representatives from each power site to develop the strategy entitled 'SECV Latrobe Valley Water and Wastewater Management Strategy'. The strategy was developed with extensive public consultation, which was a factor in protracting the process such that the final document was not promulgated until late 1992. However, the final comprehensive document endorsed and agreed by management, has since attracted favourable comment as a model of its type. (author). 2 figs

  16. Culinary and pressure irrigation water system hydroelectric generation

    Energy Technology Data Exchange (ETDEWEB)

    Christiansen, Cory [Water Works Engineers, Pleasant Grove City, UT (United States)

    2016-01-29

    Pleasant Grove City owns and operates a drinking water system that included pressure reducing stations (PRVs) in various locations and flow conditions. Several of these station are suitable for power generation. The City evaluated their system to identify opportunities for power generation that can be implemented based on the analysis of costs and prediction of power generation and associated revenue. The evaluation led to the selection of the Battle Creek site for development of a hydro-electric power generating system. The Battle Creek site includes a pipeline that carries spring water to storage tanks. The system utilizes a PRV to reduce pressure before the water is introduced into the tanks. The evaluation recommended that the PRV at this location be replaced with a turbine for the generation of electricity. The system will be connected to the utility power grid for use in the community. A pelton turbine was selected for the site, and a turbine building and piping system were constructed to complete a fully functional power generation system. It is anticipated that the system will generate approximately 440,000 kW-hr per year resulting in $40,000 of annual revenue.

  17. Proposal of electric power generation from generators to water edge in the region of Sarapiqui

    International Nuclear Information System (INIS)

    Rodriguez Fallas, Cindy Veronica

    2013-01-01

    A proposed electric power generation is developed from generators to water edge in the region of Sarapiqui. The environmental characteristics, such as the hydrological network, hydrogeology, soil type, life zones, climatology, precipitation, temperature, evapotranspiration and water supply and demand, of rivers crossed by basin in the region of Sarapiqui, are determined by bibliographic consultations to implement the proposal. The most recent production statistics of the electric subsector of Costa Rica are described to reveal the growing annual demand and need for satisfaction. The zone of Sarapiqui is diagnosed as the right place to allow the generation of electric power from generators to water edge [es

  18. Reactor water level control device

    International Nuclear Information System (INIS)

    Utagawa, Kazuyuki.

    1993-01-01

    A device of the present invention can effectively control fluctuation of a reactor water level upon power change by reactor core flow rate control operation. That is, (1) a feedback control section calculates a feedwater flow rate control amount based on a deviation between a set value of a reactor water level and a reactor water level signal. (2) a feed forward control section forecasts steam flow rate change based on a reactor core flow rate signal or a signal determining the reactor core flow rate, to calculate a feedwater flow rate control amount which off sets the steam flow rate change. Then, the sum of the output signal from the process (1) and the output signal from the process (2) is determined as a final feedwater flow rate control signal. With such procedures, it is possible to forecast the steam flow rate change accompanying the reactor core flow rate control operation, thereby enabling to conduct preceding feedwater flow rate control operation which off sets the reactor water level fluctuation based on the steam flow rate change. Further, a reactor water level deviated from the forecast can be controlled by feedback control. Accordingly, reactor water level fluctuation upon power exchange due to the reactor core flow rate control operation can rapidly be suppressed. (I.S.)

  19. Water plasma generation under atmospheric pressure for HFC destruction

    International Nuclear Information System (INIS)

    Watanabe, Takayuki; Tsuru, Taira

    2008-01-01

    The purpose of this paper is to investigate the decomposition process of hydrofluoroethylene (HFC-134a) by water plasmas. The water plasma was generated by DC arc discharge with a cathode of hafnium embedded into a copper rod and a nozzle-type copper anode. The advantage of the water plasma torch is the generation of 100%-water plasma by DC discharge. The distinctive steam generation leads to the portable light-weight plasma generation system that does not require the gas supply unit, as well as the high energy efficiency owing to the nonnecessity of the additional water-cooling. HFC-134a was injected into the water plasma jet to decompose it in the reaction tube. Neutralization vessel was combined to the reaction tube to absorb F 2 and HF generated from the HFC-134a decomposition. The decomposition was performed with changing the feed rate of HFC-134a up to 185 mmol/min. The decomposition efficiency of 99.9% can be obtained up to 0.43 mmol/kJ of the ratio of HFC-134a feed rate to the arc power, hence the maximum feed rate was estimated to be 160 g/h at 1 kW of the arc power

  20. Water level monitoring device in nuclear reactor

    International Nuclear Information System (INIS)

    Miura, Kiyohide; Otake, Tomohiro.

    1988-01-01

    Purpose: To monitor the water level in a pressure vessel of BWR type nuclear reactors at high accuracy by improving the compensation functions. Constitution: In the conventional water level monitor in a nuclear reactor, if the pressure vessel is displaced by the change of the pressure in the reactor or the temperature of the reactor water, the relative level of the reference water head in a condensation vessel is changed to cause deviation between the actual water level and the indicated water level to reduce the monitoring accuracy. According to the invention, means for detecting the position of the reference water head and means for detection the position in the condensation vessel are disposed to the pressure vessel. Then, relative positional change between the condensation vessel and the reference water head is calculated based on detection sinals from both of the means. The water level is compensated and calculated by water level calculation means based on the relative positional change, water level signals from the level gage and the pressure signals from the pressure gage. As a result, if the pressure vessel is displaced due to the change of the temperature or pressure, it is possible to measure the reactor water level accurately thereby remakably improve the reliability for the water level control in the nuclear reactor. (Horiuchi, T.)

  1. Water withdrawal and consumption reduction analysis for electrical energy generation system

    Science.gov (United States)

    Nouri, Narjes

    There is an increasing concern over shrinking water resources. Water use in the energy sector primarily occurs in electricity generation. Anticipating scarcer supplies, the value of water is undoubtedly on the rise and design, implementation, and utilization of water saving mechanisms in energy generation systems are becoming inevitable. Most power plants generate power by boiling water to produce steam to spin electricity-generating turbines. Large quantities of water are often used to cool the steam in these plants. As a consequence, most fossil-based power plants in addition to consuming water, impact the water resources by raising the temperature of water withdrawn for cooling. A comprehensive study is conducted in this thesis to analyze and quantify water withdrawals and consumption of various electricity generation sources such as coal, natural gas, renewable sources, etc. Electricity generation for the state of California is studied and presented as California is facing a serious drought problem affecting more than 30 million people. Integrated planning for the interleaved energy and water sectors is essential for both water and energy savings. A linear model is developed to minimize the water consumption while considering several limitations and restrictions. California has planned to shut down some of its hydro and nuclear plants due to environmental concerns. Studies have been performed for various electricity generation and water saving scenarios including no-hydro and no-nuclear plant and the results are presented. Modifications to proposed different scenarios have been applied and discussed to meet the practical and reliability constraints.

  2. Development of water demand coefficients for power generation from renewable energy technologies

    International Nuclear Information System (INIS)

    Ali, Babkir; Kumar, Amit

    2017-01-01

    Highlights: • Water consumption and withdrawals coefficients for renewable power generation were developed. • Six renewable energy sources (biomass, nuclear, solar, wind, hydroelectricity, and geothermal) were studied. • Life cycle water footprints for 60 electricity generation pathways were considered. • Impact of cooling systems for some power generation pathways was assessed. - Abstract: Renewable energy technology-based power generation is considered to be environmentally friendly and to have a low life cycle greenhouse gas emissions footprint. However, the life cycle water footprint of renewable energy technology-based power generation needs to be assessed. The objective of this study is to develop life cycle water footprints for renewable energy technology-based power generation pathways. Water demand is evaluated through consumption and withdrawals coefficients developed in this study. Sixty renewable energy technology-based power generation pathways were developed for a comprehensive comparative assessment of water footprints. The pathways were based on the use of biomass, nuclear, solar, wind, hydroelectricity, and geothermal as the source of energy. During the complete life cycle, power generation from bio-oil extracted from wood chips, a biomass source, was found to have the highest water demand footprint and wind power the lowest. During the complete life cycle, the water demand coefficients for biomass-based power generation pathways range from 260 to 1289 l of water per kilowatt hour and for nuclear energy pathways from 0.48 to 179 l of water per kilowatt hour. The water demand for power generation from solar energy-based pathways ranges from 0.02 to 4.39 l of water per kilowatt hour, for geothermal pathways from 0.04 to 1.94 l of water per kilowatt hour, and for wind from 0.005 to 0.104 l of water per kilowatt hour. A sensitivity analysis was conducted with varying conversion efficiencies to evaluate the impact of power plant performance on

  3. Cleaning of OPR1000 Steam Generator by Ultrasonic Cavitation in Water

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Wootae [Korea Hydro and Nuclear Power Co., Ltd, Daejeon (Korea, Republic of); Kim, Sangtae; Yoon, Sangjung; Choi, Yongseok [Saean Engineering Corporation, Seoul (Korea, Republic of)

    2013-05-15

    Magnetic wheels are attached to the transducers to prevent tube damage which may be caused by wear between the transducers and SG tubes. To remove heat generated by transducers, we used water to water heat exchanger. Sludge removed from tube sheet area of the steam generator was pumped to filtering station for removing impurities in it. We designed an ultrasonic cleaning system for application to OPR1000 S/G. The technology was developed for removing sludge in OPR1000 S/G. However, the technology could easily be applied to other types of S/Gs. For cleaning OPR1000 SG, we designed an ultrasonic cleaning system with 12 transducers, 15 generators, a WRS, and a water treatment system. An experiment with a single transducer and the full scale OPR1000 S/G mock-up did not show very satisfactory result in ultrasound energy level. However, we expect sufficient effects if we apply 12 or more transducers in this case considering our previous experimental results as shown in the references. The ultrasonic cleaning system will be ready in August this year for performance test. After several experiments and the experiments followed, we are planning to apply this cleaning system for removing sludge in Korean OPR1000 S/Gs.

  4. Investigating the water consumption for electricity generation at Turkish power plants

    Science.gov (United States)

    El-Khozondar, Balkess; Aydinalp Koksal, Merih

    2017-11-01

    The water-energy intertwined relationship has recently gained more importance due to the high water consumption in the energy sector and to the limited availability of the water resources. The energy and electricity demand of Turkey is increasing rapidly in the last two decades. More thermal power plants are expected to be built in the near future to supply the rapidly increasing demand in Turkey which will put pressure on water availability. In this study, the water consumption for electricity generation at Turkish power plants is investigated. The main objectives of this study are to identify the amount of water consumed to generate 1 kWh of electricity for each generation technology currently used in Turkey and to investigate ways to reduce the water consumption at power plants expected to be built in the near future to supply the increasing demand. The various electricity generation technology mixture scenarios are analyzed to determine the future total and per generation water consumption, and water savings based on changes of cooling systems used for each technology. The Long-range Energy Alternatives Planning (LEAP) program is used to determine the minimum water consuming electricity generation technology mixtures using optimization approaches between 2017 and 2035.

  5. The Sugawara generators at arbitrary level

    International Nuclear Information System (INIS)

    Gebert, R.W.; Koepsell, K.; Nicolai, H.

    1996-04-01

    We construct an explicit representation of the Sugawara generators for arbitrary level in terms of the homogeneous Heisenberg subalgebra, which generalizes the well-known expression at level 1. This is achieved by employing a physical vertex operator realization of the affine algebra at arbitrary level, in contrast to the Frenkel-Kac-Segal construction which uses unphysical oscillators and is restricted to level 1. At higher level, the new operators are transcendental functions of DDF oscillators unlike the quadratic expressions for the level-1 generators. An essential new feature of our construction is the appearance, beyond level 1, of new types of poles in the operator product expansions in addition to the ones at coincident points, which entail (controllable) non-localities in our formulas. We demonstrate the utility of the new formalism by explicitly working out some higher-level examples. Our results have important implications for the problem of constructing explicit representations for higher-level root spaces of hyperbolic Kac-Moody algebras, and E 10 in particular. (orig.)

  6. Ozone pretreatment of process waste water generated in course of fluoroquinolone production.

    Science.gov (United States)

    Daoud, Fares; Pelzer, David; Zuehlke, Sebastian; Spiteller, Michael; Kayser, Oliver

    2017-10-01

    During production of active pharmaceutical ingredients, process waste water is generated at several stages of manufacturing. Whenever possible, the resulting waste water will be processed by conventional waste water treatment plants. Currently, incineration of the process waste water is the method to eliminate compounds with high biological activity. Thus, ozone treatment followed by biological waste water treatment was tested as an alternative method. Two prominent representatives of the large group of fluoroquinolone antibiotics (ciprofloxacin and moxifloxacin) were investigated, focussing on waste water of the bulk production. Elimination of the target compounds and generation of their main transformation products were determined by liquid chromatography - high resolution mass spectrometry (LC-HRMS). The obtained results demonstrated, that the concentration of moxifloxacin and its metabolites can be effectively reduced (>99.7%) prior entering the receiving water. On the contrary, the concentration of ciprofloxacin and its metabolites remained too high for safe discharge, necessitating application of prolonged ozonation for its further degradation. The required ozonation time can be estimated based on the determined kinetics. To assure a low biological activity the ecotoxicity of the ozonated waste water was investigated using three trophic levels. By means of multiple-stage mass spectrometry (MS n ) experiments several new transformation products of the fluoroquinolones were identified. Thus, previously published proposed structures could be corrected or confirmed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. The water implications of generating electricity: water use across the United States based on different electricity pathways through 2050

    International Nuclear Information System (INIS)

    Macknick, J; Sattler, S; Clemmer, S; Rogers, J; Averyt, K

    2012-01-01

    The power sector withdraws more freshwater annually than any other sector in the US. The current portfolio of electricity generating technologies in the US has highly regionalized and technology-specific requirements for water. Water availability differs widely throughout the nation. As a result, assessments of water impacts from the power sector must have a high geographic resolution and consider regional, basin-level differences. The US electricity portfolio is expected to evolve in coming years, shaped by various policy and economic drivers on the international, national and regional level; that evolution will impact power sector water demands. Analysis of future electricity scenarios that incorporate technology options and constraints can provide useful insights about water impacts related to changes to the technology mix. Utilizing outputs from the regional energy deployment system (ReEDS) model, a national electricity sector capacity expansion model with high geographical resolution, we explore potential changes in water use by the US electric sector over the next four decades under various low carbon energy scenarios, nationally and regionally. (letter)

  8. Molecular cobalt pentapyridine catalysts for generating hydrogen from water

    Science.gov (United States)

    Long, Jeffrey R; Chang, Christopher J; Sun, Yujie

    2013-11-05

    A composition of matter suitable for the generation of hydrogen from water is described, the positively charged cation of the composition including the moiety of the general formula. [(PY5Me.sub.2)CoL].sup.2+, where L can be H.sub.2O, OH.sup.-, a halide, alcohol, ether, amine, and the like. In embodiments of the invention, water, such as tap water or sea water can be subject to low electric potentials, with the result being, among other things, the generation of hydrogen.

  9. Improvement design study on steam generator of MHR-50/100 aiming higher safety level after water ingress accident

    International Nuclear Information System (INIS)

    Oyama, S.; Minatsuki, I.; Shimizu, K.

    2012-01-01

    Mitsubishi Heavy Industries, Ltd. (MHI) has been studying on MHI original High Temperature Gas cooled Reactor (HTGR), namely MHR-50/100, for commercialization with supported by JAEA. In the heat transfer system, steam generator (SG) is one of the most important components because it should be imposed a function of heat transfer from reactor power to steam turbine system and maintaining a nuclear grade boundary. Then we especially focused an effort of a design study on the SG having robustness against water ingress accident based on our design experience of PWR, FBR and HTGR. In this study, we carried out a sensitivity analysis from the view point of economic and plant efficiency. As a result, the SG design parameter of helium inlet/outlet temperature of 750 deg. C/300 deg. C, a side-by-side layout and one unit of SG attached to a reactor were selected. In the next, a design improvement of SG was carried out from the view point of securing the level of inherent safety without reliance on active steam dump system during water ingress accident considering the situation of the Fukushima nuclear power plant disaster on March 11, 2011. Finally, according to above basic design requirement to SG, we performed a conceptual design on adapting themes of SG structure improvement. (authors)

  10. Water level measurement uncertainty during BWR instability

    International Nuclear Information System (INIS)

    Torok, R.C.; Derbidge, T.C.; Healzer, J.M.

    1994-01-01

    This paper addresses the performance of the water-level measurement system in a boiling water reactor (BWR) during severe instability oscillations which, under some circumstances, can occur during an anticipated transient without SCRAM (ATWS). Test data from a prototypical mock-up of the water-level measurement system was used to refine and calibrate a water-level measurement system model. The model was then used to predict level measurement system response, using as boundary conditions vessel pressures calculated by ppercase RETRAN for an ATWS/instability event.The results of the study indicate that rapid pressure changes in the reactor pressure vessel which cause oscillations in downcomer water level, coupled with differences in instrument line lengths, can produce errors in the sensed water level. Using nominal parameters for the measurement system components, a severe instability transient which produced a 0.2 m peak-to-minimum water-level oscillation in the vessel downcomer was predicted to produce pressure difference equivalent to a 0.7 m level oscillation at the input to the differential pressure transmitter, 0.5 m oscillation at the output of the transmitter, and an oscillation of 0.3 m on the water-level indicator in the control room. The level measurement system error, caused by downcomer water-level oscillations and instrument line length differential, is mitigated by damping both in the differential pressure transmitter used to infer level and in the control room display instrument. ((orig.))

  11. Iodine generator for reclaimed water purification

    Science.gov (United States)

    Wynveen, R. A.; Powell, J. D.; Schubert, F. H. (Inventor)

    1977-01-01

    The system disclosed is for controlling the iodine level in a water supply in a spacecraft. It includes an iodine accumulator which stores crystalline iodine, an electrochemical valve to control the input of iodine to the drinking water and an iodine dispenser. A pump dispenses fluid through the iodine dispenser and an iodine sensor to a potable water tank storage. The iodine sensor electronically detects the iodine level in the water, and through electronic means, produces a correction current control. The correction current control operates the electro-chemical iodine valve to release iodine from the iodine accumulator into the iodine dispenser.

  12. Set up for simultaneous water desalination and power generation

    International Nuclear Information System (INIS)

    Hasan, S.W.; Mookhi, M.B.; Sadiq, M.A.; Hasan, Z.; Zaidi, S.I.; Shah, W.A.

    2010-01-01

    Instead of following the conventional fuel oriented power generation methods and dissipating its heat into environment, we evaporate saline water into steam and use its energy to generate power. Using this scheme would make sea water usable in power generation which at the moment is only being used for cooling purposes in the power plants. The steam used for generating electricity is eventually collected, condensed and used for potable purposes. The proposed scheme may be seen as Steam Power Generation with additional feature of desalination. We set up an experimental test bed in order to calculate the electric power available using this scheme. To ensure safety for human consumption, we also perform chemical tests on the desalinated water to see whether it is fit to be used for drinking and agricultural purposes. Our conclusions are based on actual experiments and laboratory tests; procedures outlined here may be used at larger scale for more in-depth analyses. We also highlight future extensions and modifications in this work. (author)

  13. Climate change and the vulnerability of electricity generation to water stress in the European Union

    Science.gov (United States)

    Behrens, Paul; van Vliet, Michelle T. H.; Nanninga, Tijmen; Walsh, Brid; Rodrigues, João F. D.

    2017-08-01

    Thermoelectric generation requires large amounts of water for cooling. Recent warm periods have led to curtailments in generation, highlighting concerns about security of supply. Here we assess EU-wide climate impacts for 1,326 individual thermoelectric plants and 818 water basins in 2020 and 2030. We show that, despite policy goals and a decrease in electricity-related water withdrawal, the number of regions experiencing some reduction in power availability due to water stress rises from 47 basins to 54 basins between 2014 and 2030, with further plants planned for construction in stressed basins. We examine the reasons for these pressures by including water demand for other uses. The majority of vulnerable basins lie in the Mediterranean region, with further basins in France, Germany and Poland. We investigate four adaptations, finding that increased future seawater cooling eases some pressures. This highlights the need for an integrated, basin-level approach in energy and water policy.

  14. High-level water purifying technology. Kodo josui shori gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    Tsugura, H; Tsukiashi, K [Meidensha Corp., Tokyo (Japan)

    1993-07-01

    Research and development have been carried out on a high-level water purifying system using ozone and activated charcoals to supply drinking water free of carcinogenic matters and odors. This system comprises a system to utilize ozone by using silent discharge and oxygen enriching device, and a living organism/activated charcoal treatment system. The latter system utilizes living organisms deposited on activated charcoal surfaces to remove polluting substances including ammonia. The treatment experimenting equipment comprises an ozone generating system, an ozone treating column, an activated charcoal treating column, an ozone/activated charcoal control device, and a water amount and quality measuring system. An experiment was carried out using an experimental plant with a capacity of 20 m[sup 3]/day on water taken from the sedimentation process at an actual water purifying plant. As a result, trihalomethane formation potential was removed at about 40% in the ozone treatment, and at 70% in the whole treatment combining the ozone and living organism/activated charcoal treatments. For parameterization of palatability of water, a method is being studied that utilizes nuclear magnetic resonance to investigate degrees of water cluster. The method is regarded promising. 1 ref., 4 figs.

  15. Estimation of water level and steam temperature using ensemble Kalman filter square root (EnKF-SR)

    Science.gov (United States)

    Herlambang, T.; Mufarrikoh, Z.; Karya, D. F.; Rahmalia, D.

    2018-04-01

    The equipment unit which has the most vital role in the steam-powered electric power plant is boiler. Steam drum boiler is a tank functioning to separate fluida into has phase and liquid phase. The existence in boiler system has a vital role. The controlled variables in the steam drum boiler are water level and the steam temperature. If the water level is higher than the determined level, then the gas phase resulted will contain steam endangering the following process and making the resulted steam going to turbine get less, and the by causing damages to pipes in the boiler. On the contrary, if less than the height of determined water level, the resulted height will result in dry steam likely to endanger steam drum. Thus an error was observed between the determined. This paper studied the implementation of the Ensemble Kalman Filter Square Root (EnKF-SR) method in nonlinear model of the steam drum boiler equation. The computation to estimate the height of water level and the temperature of steam was by simulation using Matlab software. Thus an error was observed between the determined water level and the steam temperature, and that of estimated water level and steam temperature. The result of simulation by Ensemble Kalman Filter Square Root (EnKF-SR) on the nonlinear model of steam drum boiler showed that the error was less than 2%. The implementation of EnKF-SR on the steam drum boiler r model comprises of three simulations, each of which generates 200, 300 and 400 ensembles. The best simulation exhibited the error between the real condition and the estimated result, by generating 400 ensemble. The simulation in water level in order of 0.00002145 m, whereas in the steam temperature was some 0.00002121 kelvin.

  16. Two-Level Semantics and Code Generation

    DEFF Research Database (Denmark)

    Nielson, Flemming; Nielson, Hanne Riis

    1988-01-01

    A two-level denotational metalanguage that is suitable for defining the semantics of Pascal-like languages is presented. The two levels allow for an explicit distinction between computations taking place at compile-time and computations taking place at run-time. While this distinction is perhaps...... not absolutely necessary for describing the input-output semantics of programming languages, it is necessary when issues such as data flow analysis and code generation are considered. For an example stack-machine, the authors show how to generate code for the run-time computations and still perform the compile...

  17. Statistical analysis and mapping of water levels in the Biscayne aquifer, water conservation areas, and Everglades National Park, Miami-Dade County, Florida, 2000–2009

    Science.gov (United States)

    Prinos, Scott T.; Dixon, Joann F.

    2016-02-25

    Statistical analyses and maps representing mean, high, and low water-level conditions in the surface water and groundwater of Miami-Dade County were made by the U.S. Geological Survey, in cooperation with the Miami-Dade County Department of Regulatory and Economic Resources, to help inform decisions necessary for urban planning and development. Sixteen maps were created that show contours of (1) the mean of daily water levels at each site during October and May for the 2000–2009 water years; (2) the 25th, 50th, and 75th percentiles of the daily water levels at each site during October and May and for all months during 2000–2009; and (3) the differences between mean October and May water levels, as well as the differences in the percentiles of water levels for all months, between 1990–1999 and 2000–2009. The 80th, 90th, and 96th percentiles of the annual maximums of daily groundwater levels during 1974–2009 (a 35-year period) were computed to provide an indication of unusually high groundwater-level conditions. These maps and statistics provide a generalized understanding of the variations of water levels in the aquifer, rather than a survey of concurrent water levels. Water-level measurements from 473 sites in Miami-Dade County and surrounding counties were analyzed to generate statistical analyses. The monitored water levels included surface-water levels in canals and wetland areas and groundwater levels in the Biscayne aquifer.

  18. Negotiating water across levels: A peace and conflict "Toolbox" for water diplomacy

    Science.gov (United States)

    Grech-Madin, Charlotte; Döring, Stefan; Kim, Kyungmee; Swain, Ashok

    2018-04-01

    As a key policy tool, water diplomacy offers greater political engagement in the cooperative management of shared water. A range of initiatives has been dedicated to this end, almost invariably oriented around the interactions of nation states. Crucially, however, practitioners of water diplomacy also need to address water governance at sub-state levels. As a political, multi-level, and normative field, peace and conflict research offers a pluralism of approaches designed to bring actors together at all levels. Drawing upon this research, this paper offers new focal points for water diplomacy that can enhance its policy effectiveness and enrich its underlying academic current. More specifically, it presents three hitherto undervalued tools for water diplomacy: at the interstate level, to uncover the rich body of political norms that bind states to shared understandings of acceptable practice around water. At the intrastate level, to incorporate ethnography of water users and civil society groups' responses to state-led waterworks projects, and at the communal level to employ disaggregated georeferenced data on water resources in conflict-prone areas. Taken together, these analytical tools provide a multi-faceted political gauge of the dynamics of water diplomacy, and add vital impetus to develop water diplomacy across multiple levels of policy engagement.

  19. Operating experience with steam generator water chemistry in Japanese PWR plants

    International Nuclear Information System (INIS)

    Onimura, K.; Hattori, T.

    1991-01-01

    Since the first PWR plant in Japan started its commercial operation in 1970, seventeen plants are operating as of the end of 1990. First three units initially applied phosphate treatment as secondary water chemistry control and then changed to all volatile treatment (AVT) due to phosphate induced wastage of steam generator tubing. The other fourteen units operate exclusively under AVT. In Japan, several corrosion phenomena of steam generator tubing, resulted from secondary water chemistry, have been experienced, but occurrence of those phenomena has decreased by means of improvement on impurity management, boric acid treatment and high hydrazine operation. Recently secondary water chemistry in Japanese plants are well maintained in every stage of operation. This paper introduces brief summary of the present status of steam generators and secondary water chemistry in Japan and ongoing activities of investigation for future improvement of reliability of steam generator. History and present status of secondary water chemistry in Japanese PWRs were introduced. In order to get improved water chemistry, the integrity of secondary system equipments is essential and the improvement in water chemistry has been achieved with the improvement in equipments and their usage. As a result of those efforts, present status of secondary water is excellent. However, further development for crevice chemistry monitoring technique and an advanced water chemistry data management system is desired for the purpose of future improvement of reliability of steam generator

  20. Generating Electricity from Water through Carbon Nanomaterials.

    Science.gov (United States)

    Xu, Yifan; Chen, Peining; Peng, Huisheng

    2018-01-09

    Over the past ten years, electricity generation from water in carbon-based materials has aroused increasing interest. Water-induced mechanical-to-electrical conversion has been discovered in carbon nanomaterials, including carbon nanotubes and graphene, through the interaction with flowing water as well as moisture. In this Concept article, we focus on the basic principles of electric energy harvesting from flowing water through carbon nanomaterials, and summarize the material modification and structural design of these nanogenerators. The current challenges and potential applications of power conversion with carbon nanomaterials are finally highlighted. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Reducing scram frequency by modifying/eliminating steam generator low-low level reactor trip setpoint for Maanshan nuclear power plant

    International Nuclear Information System (INIS)

    Yuann, R.Y.; Chiang, S.C.; Hsiue, J.K.; Chen, P.C.

    1987-01-01

    The feasibility of modification/elimination of steam generator low-low level reactor trip setpoint is evaluated by using RETRAN-02 code for the purpose of reducing scram frequency in Maanshan 3-loop pressurized water reactor. The ANS Condition II event loss of normal feedwater and condition IV event feedwater system line break are the basis for steam generator low-low level reactor trip setpoint sensitivity analysis, including various initial reactor power levels, reactivity feedback coefficients, and system functions assumptions etc., have been performed for the two basis events with steam generator low-low level reactor trip setpoint at 0% narrow range and without this trip respectively. The feasibility of modifying/eliminating current steam generator low-low level reactor trip setpoint is then determined based on whether the analysis results meet with the ANS Condition II and IV acceptance criteria or not

  2. A method for generating hydrogen from water

    International Nuclear Information System (INIS)

    Godin, Paul; Mascarello, Jean; Millet, Jacques.

    1974-01-01

    Description is given of a method and an installation for generating hydrogen from water, through an endothermic cycle of several successive chemical reactions involving intermediate substances regenerated during said cycle, said reactions occuring at different temperatures. The reaction which takes place at the highest temperature is carried out electrochemically. This can be applied to power-generating units comprising a nuclear reactor [fr

  3. Effects of Water Level Increase on Phytoplankton Assemblages in a Drinking Water Reservoir

    Directory of Open Access Journals (Sweden)

    Yangdong Pan

    2018-03-01

    Full Text Available Excessive water level fluctuation may affect physico-chemical characteristics, and consequently ecosystem function, in lakes and reservoirs. In this study, we assessed the changes of phytoplankton assemblages in response to water level increase in Danjiangkou Reservoir, one of the largest drinking water reservoirs in Asia. The water level increased from a low of 137 m to 161 m in 2014 as a part of the South–North Water Diversion Project. Phytoplankton assemblages were sampled four times per year before, during and after the water level increase, at 10 sites. Environmental variables such as total nitrogen as well as phytoplankton biomass decreased after the water level increase. Non-metric multi-dimensional scaling analysis indicated that before the water level increase, phytoplankton assemblages showed distinct seasonal variation with diatom dominance in both early and late seasons while such seasonal variation was much less evident after the water level increase. Month and year (before and after explained 13% and 6% of variance in phytoplankton assemblages (PERMANOVA, p < 0.001 respectively, and phytoplankton assemblages were significantly different before and after the water level increase. Both chlorophytes and cyanobacteria became more abundant in 2015. Phytoplankton compositional change may largely reflect the environmental changes, such as hydrodynamics mediated by the water level increase.

  4. Forecasting Water Levels Using Artificial Neural Networks

    Directory of Open Access Journals (Sweden)

    Shreenivas N. Londhe

    2011-06-01

    Full Text Available For all Ocean related activities it is necessary to predict the actual water levels as accurate as possible. The present work aims at predicting the water levels with a lead time of few hours to a day using the technique of artificial neural networks. Instead of using the previous and current values of observed water level time series directly as input and output the water level anomaly (difference between the observed water level and harmonically predicted tidal level is calculated for each hour and the ANN model is developed using this time series. The network predicted anomaly is then added to harmonic tidal level to predict the water levels. The exercise is carried out at six locations, two in The Gulf of Mexico, two in The Gulf of Maine and two in The Gulf of Alaska along the USA coastline. The ANN models performed reasonably well for all forecasting intervals at all the locations. The ANN models were also run in real time mode for a period of eight months. Considering the hurricane season in Gulf of Mexico the models were also tested particularly during hurricanes.

  5. Wastage of Steam Generator Tubes by Sodium-Water Reaction

    International Nuclear Information System (INIS)

    Jeong, Ji Young; Kim, Jong Man; Kim, Tae Joon; Choi, Jong Hyeun; Kim, Byung Ho; Lee, Yong Bum; Park, Nam Cook

    2010-01-01

    The Korea Advanced LIquid MEtal Reactor (KALIMER) steam generator is a helical coil, vertically oriented, shell-and-tube type heat exchanger with fixed tube-sheet. The conceptual design and outline drawing of the steam generator are shown in Figure 1. Flow is counter-current, with sodium on the shell side and water/steam on the tube side. Sodium flow enters the steam generator through the upper inlet nozzles and then flows down through the tube bundle. Feedwater enters the steam generator through the feedwater nozzles at the bottom of steam generator. Therefore, if there is a hole or a crack in a heat transfer tube, a leakage of water/steam into the sodium may occur, resulting in a sodium-water reaction. When such a leak occurs, so-called 'wastage' is the result which may cause damage to or a failure of the adjacent tubes. If a steam generator is operated for some time in this condition, it is possible that it might create an intermediate leak state which would then give rise to the problems of a multi-target wastage in a very short time. Therefore, it is very important to predict these phenomena quantitatively from the view of designing a steam generator and its leak detection systems. For this, multi-target wastage tests for modified 9Cr-1Mo steel tube bundle by intermediate leaks are being prepared

  6. Water levels shape fishing participation in flood-control reservoirs

    Science.gov (United States)

    Miranda, Leandro E.; Meals, K. O.

    2013-01-01

    We examined the relationship between fishing effort (hours fished) and average March–May water level in 3 flood control reservoirs in Mississippi. Fishing effort increased as water level rose, peaked at intermediate water levels, and decreased at high water levels. We suggest that the observed arched-shaped relationship is driven by the shifting influence of fishability (adequacy of the fishing circumstances from an angler's perspective) and catch rate along a water level continuum. Fishability reduces fishing effort during low water, despite the potential for higher catch rates. Conversely, reduced catch rates and fishability at high water also curtail effort. Thus, both high and low water levels seem to discourage fishing effort, whereas anglers seem to favor intermediate water levels. Our results have implications for water level management in reservoirs with large water level fluctuations.

  7. Greater-than-Class C low-level radioactive waste characterization. Appendix A-3: Basis for greater-than-Class C low-level radioactive waste light water reactor projections

    International Nuclear Information System (INIS)

    Mancini, A.; Tuite, P.; Tuite, K.; Woodberry, S.

    1994-09-01

    This study characterizes low-level radioactive waste types that may exceed Class C limits at light water reactors, estimates the amounts of waste generated, and estimates radionuclide content and distribution within the waste. Waste types that may exceed Class C limits include metal components that become activated during operations, process wastes such as cartridge filters and decontamination resins, and activated metals from decommissioning activities. Operating parameters and current management practices at operating plants are reviewed and used to estimate the amounts of low-level waste exceeding Class C limits that is generated per fuel cycle, including amounts of routinely generated activated metal components and process waste. Radionuclide content is calculated for specific activated metals components. Empirical data from actual low-level radioactive waste are used to estimate radionuclide content for process wastes. Volumes and activities are also estimated for decommissioning activated metals that exceed Class C limits. To estimate activation levels of decommissioning waste, six typical light water reactors are modeled and analyzed. This study does not consider concentration averaging

  8. 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)

  9. Sodium-Water Reaction approach and mastering for ASTRID Steam Generator design

    International Nuclear Information System (INIS)

    Saez, Manuel; Allou, Alexandre; Beauchamp, François; Bertrand, Carole; Rodriguez, Gilles; Menou, Sylvain; Prele, Gérard

    2013-01-01

    Conclusions: • Modular Steam Generator concept selected for ASTRID: → Brings flexibility for the expertise of failed modules after their removal; → Intrinsically limit the mechanical consequences of a postulated large Sodium-Water Reaction. • Sodium-Water-Air Reaction studies include both prevention and mitigation aspects, with dedicated tools to be developed through R&D. • Regarding Safety analysis, the possibility to move from the scenario of instantaneous failure of the whole Steam Generator tube bundle toward a scenario with sequenced failure needs to be investigated. • The Steam Generator is one of the key components in the Sodium-cooled Fast Reactor system for it provides an interface between sodium and water. The design objective for the Steam Generator is related to the improvement of mastering of Sodium-Water Reaction. • Potential Sodium-Water Reactions can be eliminated by adopting a Gas based Power Conversion System

  10. Automatic generation of water distribution systems based on GIS data.

    Science.gov (United States)

    Sitzenfrei, Robert; Möderl, Michael; Rauch, Wolfgang

    2013-09-01

    In the field of water distribution system (WDS) analysis, case study research is needed for testing or benchmarking optimisation strategies and newly developed software. However, data availability for the investigation of real cases is limited due to time and cost needed for data collection and model setup. We present a new algorithm that addresses this problem by generating WDSs from GIS using population density, housing density and elevation as input data. We show that the resulting WDSs are comparable to actual systems in terms of network properties and hydraulic performance. For example, comparing the pressure heads for an actual and a generated WDS results in pressure head differences of ±4 m or less for 75% of the supply area. Although elements like valves and pumps are not included, the new methodology can provide water distribution systems of varying levels of complexity (e.g., network layouts, connectivity, etc.) to allow testing design/optimisation algorithms on a large number of networks. The new approach can be used to estimate the construction costs of planned WDSs aimed at addressing population growth or at comparisons of different expansion strategies in growth corridors.

  11. STUDY ON OPERATING CHARACTERISTECS OF WATER HAMMER GENERATING DEVICE FOR TREATMENT OF MICROORGANISM

    Science.gov (United States)

    Hamada, Tatsuhisa; Endo, Shigekatsu; Oda, Akira; Shimizu, Yasushi

    The phenomenon that has been actualized due to the water quality deterioration because of the inflow of drainage and the industrial wastewater includes the phenomenon that is called water-bloom generated in the freshwater environment made a eutrophic. This is becoming a serious problem to secure the water.Mixing with the drinking water has already been confirmed, and the generation of water-bloom is becoming a big social problem, and fundamental measures have not been established yet.On the other hand, authors are proving the pressure to be a fast the pressure speed of the impact pressure by the water hammer and effective in the destruction of the blue-green algae.In this studies, the hydraulics flow characteristics of an effective water hammer pressure generator to the shredding of the water-bloom cell were examined.As a result, there was a boundary in the region where the water hammer was generated by length and the water supply head of conduit, and the water hammer pressure was able to be understood to be influenced according to the angle of the valve that generated the water hammer in addition in the water hammer generator.The demonstration in the locale was confirmed based on these and the scale etc. of an effective device to the doing water-bloom processing were able to be confirmed by continuous running.

  12. Development of the Next Generation Type Water Recovery System

    Science.gov (United States)

    Oguchi, Mitsuo; Tachihara, Satoru; Maeda, Yoshiaki; Ueoka, Terumi; Soejima, Fujito; Teranishi, Hiromitsu

    According to NASA, an astronaut living on the International Space Station (ISS) requires approximately 7 kg of water per day. This includes 2 kg of drinking water as well as sanitary fresh water for hand washing, gargling, etc. This water is carried to the space station from the earth, so when more people are staying on the space station, or staying for a longer period of time, the cost of transporting water increases. Accordingly, water is a valuable commodity, and restrictions are applied to such activities as brushing teeth, washing hair, and washing clothes. The life of an astronaut in space is not necessarily a healthy one. JAXA has experience in the research of water recovery systems. Today, utilizing knowledge learned through experiences living on the space station and space shuttles, and taking advantage of the development of new materials for device construction, it is possible to construct a new water recovery system. Therefore, JAXA and New Medican Tech Corporation (NMT) have created a system for collaborative development. Based on the technologies of both companies, we are proceeding to develop the next generation of water recovery devices in order to contribute to safe, comfortable, and healthy daily life for astronauts in space. The goal of this development is to achieve a water purification system based on reverse osmosis (RO) membranes that can perform the following functions. • Preprocessing that removes ammonia and breaks down organic matter contained in urine. • Post-processing that adds minerals and sterilizes the water. • Online TOC measurement for monitoring water quality. • Functions for measuring harmful substances. The RO membrane is an ultra-low-pressure type membrane with a 0.0001 micron (0.1 nanometer) pore size and an operating pressure of 0.4 to 0.6 MPa. During processing with the RO membrane, nearly all of the minerals contained in the cleaned water are removed, resulting in water that is near the quality of deionized water

  13. Radon levels in a water distribution network

    International Nuclear Information System (INIS)

    Alabdula'aly, A.I.

    1997-01-01

    The capital city of Saudi Arabia, Riyadh, relies on both desalinated sea water as well as treated groundwater to meet all its water requirements. About 66% of the water demand is met by desalinated sea water, and the remaining is supplied by six groundwater treatment plants located in the vicinity of the city and supplied with water from 161 wells. The desalinated sea water is blended with only one plant product water and pumped to the distribution network, whereas the other five plants product water is pumped directly to the network. A study of 222 Rn levels in the city distribution network was carried out in which 89 samples were collected from different locations representing the city districts. All samples have shown low radon levels with an average concentration of 0.2 Bq l -1 and a range values of 0.1-1.0 Bq l -1 . The level of radon in different parts of the network was found to be influenced by the water sources to which they are supplied. The lowest radon levels were observed in districts supplied mostly by desalinated sea water. (Author)

  14. The German Final Repository Konrad for Low and Intermediate Level Waste with Negligible Heat Generation - Water Law Issues

    International Nuclear Information System (INIS)

    Boetsch, W.; Grundler, D.; Kugel, K.; Brennecke, P.; Steyer, S.

    2009-01-01

    A survey on the conceptual realization of the requirements due to water law aspects within the license the KONRAD repository for radioactive waste with negligible heat generation in Germany is given [1]. The regulatory decision for the implementation and operation of the repository KONRAD includes, among other things, water law issues. In particular, the KONRAD license includes waste requirements concerning non-radioactive hazardous material (waste package constituents) which have to be considered producing KONRAD waste packages. The intended philosophy of waste acceptance and waste package quality assurance measures to be considered by the KONRAD site operator as well as by the waste producer will be presented. It will demonstrate the selected procedure of the waste declaration and acceptance and describe the structure and logic of tools and aids to comply with the legal requirements of the license and its collateral clause issued under water law. (authors)

  15. Process for water-gas generation from degassed combustibles

    Energy Technology Data Exchange (ETDEWEB)

    1906-05-23

    A process for water-gas generation in a continuous operation from degassed combustibles in the lower part of a vertical exterior-heated retort, whose middle part can serve to degas the combustibles, is described. It is characterized in that the water vapor employed is obtained by vaporizing water in the upper part of the retort by means of the waste heat from the heating gases, which had effected the coking of the combustibles before the water-gas recovery or after the latter.

  16. Application of Artificial Neural Network into the Water Level Modeling and Forecast

    Directory of Open Access Journals (Sweden)

    Marzenna Sztobryn

    2013-06-01

    Full Text Available The dangerous sea and river water level increase does not only destroy the human lives, but also generate the severe flooding in coastal areas. The rapidly changes in the direction and velocity of wind and associated with them sea level changes could be the severe threat for navigation, especially on the fairways of small fishery harbors located in the river mouth. There is the area of activity of two external forcing: storm surges and flood wave. The aim of the work was the description of an application of Artificial Neural Network (ANN methodology into the water level forecast in the case study field in Swibno harbor located is located at 938.7 km of the Wisla River and at a distance of about 3 km up the mouth (Gulf of Gdansk - Baltic Sea.

  17. Contribution of climate-driven change in continental water storage to recent sea-level rise

    Science.gov (United States)

    Milly, P. C. D.; Cazenave, A.; Gennero, C.

    2003-01-01

    Using a global model of continental water balance, forced by interannual variations in precipitation and near-surface atmospheric temperature for the period 1981–1998, we estimate the sea-level changes associated with climate-driven changes in storage of water as snowpack, soil water, and ground water; storage in ice sheets and large lakes is not considered. The 1981–1998 trend is estimated to be 0.12 mm/yr, and substantial interannual fluctuations are inferred; for 1993–1998, the trend is 0.25 mm/yr. At the decadal time scale, the terrestrial contribution to eustatic (i.e., induced by mass exchange) sea-level rise is significantly smaller than the estimated steric (i.e., induced by density changes) trend for the same period, but is not negligibly small. In the model the sea-level rise is driven mainly by a downtrend in continental precipitation during the study period, which we believe was generated by natural variability in the climate system. PMID:14576277

  18. Radiological study of the sludge generated in a station drinking water treatment

    International Nuclear Information System (INIS)

    Baeza, A.; Salas, A.; Gragera, J.

    2011-01-01

    The purification process involves removing the water or at least reducing the legally permitted levels of undesirable substances that become part of the precipitates that originate, called sludge. The importance of the study is given because it will find, in the event that the process effectively reduce its radioactive contents, significant activities of the radionuclides eliminated. In this sense, the concentration of radioactive sludge and, above all, the chemical forms in which these radionuclides are retained condition the danger of the waste produced on the basis of their potential availability. In this study, we analyzed the sludge generated in a water treatment plant that has operated under both routine operation and in conditions designed to optimize the reduction of the radioactive contents for uranium and radium present in the treated water. (Author)

  19. Water levels in the Yucca Mountain area, Nevada, 1993

    International Nuclear Information System (INIS)

    Tucci, P.; Goemaat, R.L.; Burkhardt, D.J.

    1996-01-01

    Water levels were monitored in 28 wells in the Yucca Mountain area, Nevada, during 1993. Seventeen wells were monitored periodically, generally on a monthly basis, and 11 wells representing 18 intervals were monitored hourly. All wells monitor water levels in Tertiary volcanic rocks, except one that monitors water levels in Paleozoic carbonate rocks. Water levels were measured using calibrated steel tapes and pressure transducers; steel-tape measurements were corrected for mechanical stretch, thermal expansion, and borehole deviation to obtain precise water-level altitudes. Water-level altitudes in the Tertiary volcanic rocks ranged from about 728 meters above sea level east of Yucca Mountain to about 1,034 meters above sea level north of Yucca Mountain. Water-level altitudes in the well monitoring the Paleozoic carbonate rocks varied between 752 and 753 meters above sea level during 1993. Water levels were an average of about 0.04 meter lower than 1992 water levels. All data were acquired in accordance with a quality-assurance program to support the reliability of the data

  20. On grey levels in random CAPTCHA generation

    Science.gov (United States)

    Newton, Fraser; Kouritzin, Michael A.

    2011-06-01

    A CAPTCHA is an automatically generated test designed to distinguish between humans and computer programs; specifically, they are designed to be easy for humans but difficult for computer programs to pass in order to prevent the abuse of resources by automated bots. They are commonly seen guarding webmail registration forms, online auction sites, and preventing brute force attacks on passwords. In the following, we address the question: How does adding a grey level to random CAPTCHA generation affect the utility of the CAPTCHA? We treat the problem of generating the random CAPTCHA as one of random field simulation: An initial state of background noise is evolved over time using Gibbs sampling and an efficient algorithm for generating correlated random variables. This approach has already been found to yield highly-readable yet difficult-to-crack CAPTCHAs. We detail how the requisite parameters for introducing grey levels are estimated and how we generate the random CAPTCHA. The resulting CAPTCHA will be evaluated in terms of human readability as well as its resistance to automated attacks in the forms of character segmentation and optical character recognition.

  1. Real-time Geographic Information System (GIS) for Monitoring the Area of Potential Water Level Using Rule Based System

    Science.gov (United States)

    Anugrah, Wirdah; Suryono; Suseno, Jatmiko Endro

    2018-02-01

    Management of water resources based on Geographic Information System can provide substantial benefits to water availability settings. Monitoring the potential water level is needed in the development sector, agriculture, energy and others. In this research is developed water resource information system using real-time Geographic Information System concept for monitoring the potential water level of web based area by applying rule based system method. GIS consists of hardware, software, and database. Based on the web-based GIS architecture, this study uses a set of computer that are connected to the network, run on the Apache web server and PHP programming language using MySQL database. The Ultrasound Wireless Sensor System is used as a water level data input. It also includes time and geographic location information. This GIS maps the five sensor locations. GIS is processed through a rule based system to determine the level of potential water level of the area. Water level monitoring information result can be displayed on thematic maps by overlaying more than one layer, and also generating information in the form of tables from the database, as well as graphs are based on the timing of events and the water level values.

  2. Management of low level waste generated from ISER

    International Nuclear Information System (INIS)

    Mizushina, Tomoyuki

    1987-01-01

    Low level wastes are generated during nuclear power plant operation. In the case of ISER, low level wastes from the reactor are basically the same as of existing light water reactors. Various low level wastes, including solid, liquid and gaseous, are listed and discussed. In normal operation, high-activity wastes are not subjected to any treatment. For contaminated equipment or reactor parts, it may be desirable to transfer most of the activity to liquid phase through an appropriate decontamination procedure. Highly active solid wastes are usually fixed in a solid form through incorporation into either concrete or asphalt as containment material. Decantation and filtration treatments are usually sufficient before dilution and release of liquid wastes into the environment. Except for ordinary gas filtration, there in normally no other treatment. Under certain circumstances, however, it may be important to apply the decay storage before release to the atmosphere. In accidental circumstances, specific filtration is recommended or even sometimes needed. There are some alternatives for storage and-or disposal of low level wastes. In many cases, shallow land burial is chosen as a realistic method for storage and-or disposal of solid waste. In chosing a disposal method, the radiation dose rate from solid wastes or the specific activity should be taken into account. Boric acid is a retarder for cement setting. This effect of boric acid is inhibited by adding a complexing agent before mixing the waste with cement. (Nogami, K.)

  3. A Hydro-Economic Model for Water Level Fluctuations: Combining Limnology with Economics for Sustainable Development of Hydropower

    Science.gov (United States)

    Hirsch, Philipp Emanuel; Schillinger, Sebastian; Weigt, Hannes; Burkhardt-Holm, Patricia

    2014-01-01

    Water level fluctuations in lakes lead to shoreline displacement. The seasonality of flooding or beaching of the littoral area affects nutrient cycling, redox gradients in sediments, and life cycles of aquatic organisms. Despite the ecological importance of water level fluctuations, we still lack a method that assesses water levels in the context of hydropower operations. Water levels in reservoirs are influenced by the operator of a hydropower plant, who discharges water through the turbines or stores water in the reservoir, in a fashion that maximizes profit. This rationale governs the seasonal operation scheme and hence determines the water levels within the boundaries of the reservoir's water balance. For progress towards a sustainable development of hydropower, the benefits of this form of electricity generation have to be weighed against the possible detrimental effects of the anthropogenic water level fluctuations. We developed a hydro-economic model that combines an economic optimization function with hydrological estimators of the water balance of a reservoir. Applying this model allowed us to accurately predict water level fluctuations in a reservoir. The hydro-economic model also allowed for scenario calculation of how water levels change with climate change scenarios and with a change in operating scheme of the reservoir (increase in turbine capacity). Further model development will enable the consideration of a variety of additional parameters, such as water withdrawal for irrigation, drinking water supply, or altered energy policies. This advances our ability to sustainably manage water resources that must meet both economic and environmental demands. PMID:25526619

  4. A hydro-economic model for water level fluctuations: combining limnology with economics for sustainable development of hydropower.

    Science.gov (United States)

    Hirsch, Philipp Emanuel; Schillinger, Sebastian; Weigt, Hannes; Burkhardt-Holm, Patricia

    2014-01-01

    Water level fluctuations in lakes lead to shoreline displacement. The seasonality of flooding or beaching of the littoral area affects nutrient cycling, redox gradients in sediments, and life cycles of aquatic organisms. Despite the ecological importance of water level fluctuations, we still lack a method that assesses water levels in the context of hydropower operations. Water levels in reservoirs are influenced by the operator of a hydropower plant, who discharges water through the turbines or stores water in the reservoir, in a fashion that maximizes profit. This rationale governs the seasonal operation scheme and hence determines the water levels within the boundaries of the reservoir's water balance. For progress towards a sustainable development of hydropower, the benefits of this form of electricity generation have to be weighed against the possible detrimental effects of the anthropogenic water level fluctuations. We developed a hydro-economic model that combines an economic optimization function with hydrological estimators of the water balance of a reservoir. Applying this model allowed us to accurately predict water level fluctuations in a reservoir. The hydro-economic model also allowed for scenario calculation of how water levels change with climate change scenarios and with a change in operating scheme of the reservoir (increase in turbine capacity). Further model development will enable the consideration of a variety of additional parameters, such as water withdrawal for irrigation, drinking water supply, or altered energy policies. This advances our ability to sustainably manage water resources that must meet both economic and environmental demands.

  5. A hydro-economic model for water level fluctuations: combining limnology with economics for sustainable development of hydropower.

    Directory of Open Access Journals (Sweden)

    Philipp Emanuel Hirsch

    Full Text Available Water level fluctuations in lakes lead to shoreline displacement. The seasonality of flooding or beaching of the littoral area affects nutrient cycling, redox gradients in sediments, and life cycles of aquatic organisms. Despite the ecological importance of water level fluctuations, we still lack a method that assesses water levels in the context of hydropower operations. Water levels in reservoirs are influenced by the operator of a hydropower plant, who discharges water through the turbines or stores water in the reservoir, in a fashion that maximizes profit. This rationale governs the seasonal operation scheme and hence determines the water levels within the boundaries of the reservoir's water balance. For progress towards a sustainable development of hydropower, the benefits of this form of electricity generation have to be weighed against the possible detrimental effects of the anthropogenic water level fluctuations. We developed a hydro-economic model that combines an economic optimization function with hydrological estimators of the water balance of a reservoir. Applying this model allowed us to accurately predict water level fluctuations in a reservoir. The hydro-economic model also allowed for scenario calculation of how water levels change with climate change scenarios and with a change in operating scheme of the reservoir (increase in turbine capacity. Further model development will enable the consideration of a variety of additional parameters, such as water withdrawal for irrigation, drinking water supply, or altered energy policies. This advances our ability to sustainably manage water resources that must meet both economic and environmental demands.

  6. Evaluation of yield and water-level relations

    International Nuclear Information System (INIS)

    Cushman, R.L.; Purtymun, W.D.

    1975-10-01

    Yield and water relations in the Los Alamos supply wells were evaluated because of the increasing demand for water. Water-level declines were extrapolated for 10 yr, to 1983, on the basis of past records. On the basis of current pumpage, the extrapolations indicate that nonpumping water levels in individual wells will decline from 10 to 30 ft. Well characteristics were compiled to provide an individual history of each well, and recommendations for improving water production are presented

  7. Water-level fluctuations influence sediment porewater ...

    Science.gov (United States)

    Reservoirs typically have elevated fish mercury (Hg) levels compared to natural lakes and rivers. A unique feature of reservoirs is water-level management which can result in sediment exposure to the air. The objective of this study is to identify how reservoir water-level fluctuations impact Hg cycling, particularly the formation of the more toxic and bioaccumulative methylmercury (MeHg). Total-Hg (THg), MeHg, stable isotope methylation rates and several ancillary parameters were measured in reservoir sediments (including some in porewater and overlying water) that are seasonally and permanently inundated. The results showed that sediment and porewater MeHg concentrations were over 3-times higher in areas experiencing water-level fluctuations compared to permanently inundated sediments. Analysis of the data suggest that the enhanced breakdown of organic matter in sediments experiencing water-level fluctuations has a two-fold effect on stimulating Hg methylation: 1) it increases the partitioning of inorganic Hg from the solid phase into the porewater phase (lower log Kd values) where it is more bioavailable for methylation; and 2) it increases dissolved organic carbon (DOC) in the porewater which can stimulate the microbial community that can methylate Hg. Sulfate concentrations and cycling were enhanced in the seasonally inundated sediments and may have also contributed to increased MeHg production. Overall, our results suggest that reservoir management a

  8. Development of life cycle water-demand coefficients for coal-based power generation technologies

    International Nuclear Information System (INIS)

    Ali, Babkir; Kumar, Amit

    2015-01-01

    Highlights: • We develop water consumption and withdrawals coefficients for coal power generation. • We develop life cycle water footprints for 36 coal-based electricity generation pathways. • Different coal power generation technologies were assessed. • Sensitivity analysis of plant performance and coal transportation on water demand. - Abstract: This paper aims to develop benchmark coefficients for water consumption and water withdrawals over the full life cycle of coal-based power generation. This study considered not only all of the unit operations involved in the full electricity generation life cycle but also compared different coal-based power generating technologies. Overall this study develops the life cycle water footprint for 36 different coal-based electricity generation pathways. Power generation pathways involving new technologies of integrated gasification combined cycle (IGCC) or ultra supercritical technology with coal transportation by conventional means and using dry cooling systems have the least complete life cycle water-demand coefficients of about 1 L/kW h. Sensitivity analysis is conducted to study the impact of power plant performance and coal transportation on the water demand coefficients. The consumption coefficient over life cycle of ultra supercritical or IGCC power plants are 0.12 L/kW h higher when conventional transportation of coal is replaced by coal-log pipeline. Similarly, if the conventional transportation of coal is replaced by its transportation in the form of a slurry through a pipeline, the consumption coefficient of a subcritical power plant increases by 0.52 L/kW h

  9. The Water Footprint as an indicator of environmental sustainability in water use at the river basin level.

    Science.gov (United States)

    Pellicer-Martínez, Francisco; Martínez-Paz, José Miguel

    2016-11-15

    One of the main challenges in water management is to determine how the current water use can condition its availability to future generations and hence its sustainability. This study proposes the use of the Water Footprint (WF) indicator to assess the environmental sustainability in water resources management at the river basin level. The current study presents the methodology developed and applies it to a case study. The WF is a relatively new indicator that measures the total volume of freshwater that is used as a production factor. Its application is ever growing in the evaluation of water use in production processes. The calculation of the WF involves water resources (blue), precipitation stored in the soil (green) and pollution (grey). It provides a comprehensive assessment of the environmental sustainability of water use in a river basin. The methodology is based upon the simulation of the anthropised water cycle, which is conducted by combining a hydrological model and a decision support system. The methodology allows the assessment of the environmental sustainability of water management at different levels, and/or ex-ante analysis of how the decisions made in water planning process affect sustainability. The sustainability study was carried out in the Segura River Basin (SRB) in South-eastern Spain. The SRB is among the most complex basins in Europe, given its special peculiarities: competition for the use, overexploitation of aquifers, pollution, alternative sources, among others. The results indicate that blue water use is not sustainable due to the generalised overexploitation of aquifers. They also reveal that surface water pollution, which is not sustainable, is mainly caused by phosphate concentrations. The assessment of future scenarios reveals that these problems will worsen if no additional measures are implemented, and therefore the water management in the SRB is environmentally unsustainable in both the short- and medium-term. Copyright © 2016

  10. Steam Generator Owners Group PWR secondary water chemistry guidelines

    International Nuclear Information System (INIS)

    Welty, C.S. Jr.; Green, S.J.

    1985-01-01

    In 1981 the Steam Generator Owners Group (SGOG), a group of domestic and foreign pressurized water reactor (PWR) owners, developed and issued the PWR secondary water chemistry guidelines. The guidelines were prepared in response to the growing recognition that a majority of the problems causing reduced steam generator reliability (e.g., denting, wasteage, pitting, etc.) were related to secondary (steam) side water purity. The guidelines were subsequently issued as an Electric Power Research Institute (EPRI) report. In 1984 they were revised to reflect industry experience in adopting the original issuance and to incorporate new information on causes of corrosion damage. The guidelines have been endorsed and their adoption recommended by the SGOG

  11. Steam generator for pressurized-water reactors

    International Nuclear Information System (INIS)

    Michel, E.

    1971-01-01

    In the steam generator for a PWR the central fall space of a U-tube bundel heat exchanger is used as a preliminary cyclon separator. The steam escaping upwards, which is largely free of water, can flow through the residual heating surface, i.e. the U-tube turns. In this way substantial drying and less superheating by the heat still added becomes possible. In its upper part the central fall space for the water separated in the preliminary separator, enclosed by a cylindrical guide wall and the U-tube bundle, is provided with tangential inlet slots. Through these, the water-steam mixture steams out of the section of the vertical legs of the U-tube bundle into the fall space. Above the inlet slots the rising space is closed by means of a turn-round plate. At the lower end of the guide wall outlet, slots are provided for the water flowing downwards and radially outwards into the unfilled space. (DG/PB) [de

  12. Generation of hydrogen free radicals from water for fuels by electric field induction

    International Nuclear Information System (INIS)

    Nong, Guangzai; Chen, Yiyi; Li, Ming; Zhou, Zongwen

    2015-01-01

    Highlights: • Hydrogen free radicals are generated from water splitting. • Hydrogen fuel is generated from water by electric field induction. • Hydrocarbon fuel is generated from CO_2 and water by electric field induction. - Abstract: Water is the most abundant resource for generating hydrogen fuel. In addition to dissociating H"+ and "−OH ions, certain water molecules dissociate to radicals under an electric field are considered. Therefore, an electric field inducing reactor is constructed and operated to generate hydrogen free radicals in this paper. Hydrogen free radicals begin to be generated under a 1.0 V electric field, and increasing the voltage and temperature increases the number of hydrogen free radicals. The production rate of hydrogen free radicals is 0.245 mmol/(L h) at 5.0 V and room temperature. The generated hydrogen free radicals are converted to polymer fuel and hydrogen fuel at production rates of 0.0093 mmol/(L h) and 0.0038 mmol/(L h) respectively, under 5.0 V and 0.25 mA. The results provide a way to generate hydrogen free radicals, which might be used to generate hydrocarbon fuel in industrial manufacture.

  13. Long-Term Ground-Water Levels and Transmissivity in the Blackstone River Basin, Northern Rhode Island

    Science.gov (United States)

    Eggleston, Jack R.; Church, Peter E.; Barbaro, Jeffrey R.

    2007-01-01

    Ground water provides about 7.7 million gallons per day, or 28 percent of total water use in the Rhode Island part of the Blackstone River Basin. Primary aquifers in the basin are stratified glacial deposits, composed mostly of sand and gravel along valley bottoms. The ground-water and surface-water system in the Blackstone River Basin is under stress due to population growth, out-of-basin water transfers, industrialization, and changing land-use patterns. Streamflow periodically drops below the Aquatic Base Flow standard, and ground-water withdrawals add to stress on aquatic habitat during low-flow periods. Existing hydrogeologic data were reviewed to examine historical water-level trends and to generate contour maps of water-table altitudes and transmissivity of the sand and gravel aquifer in the Blackstone River Basin in Rhode Island. On the basis of data from four long-term observation wells, water levels appear to have risen slightly in the study area during the past 55 years. Analysis of available data indicates that increased rainfall during the same period is a likely contributor to the water-level rise. Spatial patterns of transmissivity are shown over larger areas and have been refined on the basis of more detailed data coverage as compared to previous mapping studies.

  14. Subtask 1.24 - Optimization of Cooling Water Resources for Power Generation

    Energy Technology Data Exchange (ETDEWEB)

    Daniel Stepan; Richard Shockey; Bethany Kurz; Wesley Peck

    2009-03-31

    The Energy & Environmental Research Center (EERC) has developed an interactive, Web-based decision support system (DSS{copyright} 2007 EERC Foundation) to provide power generation utilities with an assessment tool to address water supply issues when planning new or modifying existing generation facilities. The Web-based DSS integrates water and wastewater treatment technology and water law information with a geographic information system-based interactive map that links to state and federal water quality and quantity databases for North Dakota, South Dakota, Minnesota, Wyoming, Montana, Nebraska, Wisconsin, and Iowa.

  15. Water levels in the Yucca Mountain Area, Nevada, 1996

    International Nuclear Information System (INIS)

    Graves, R.P.

    1998-01-01

    Water levels were monitored in 24 wells in the Yucca Mountain area, Nevada, during 1996. Twenty-two wells representing 28 depth intervals were monitored periodically, generally on a monthly basis, and 2 wells representing 3 depth intervals were monitored both hourly and periodically. All wells monitor water levels in Tertiary volcanic rocks except one that monitors water levels in paleozoic carbonate rocks. Water levels were measured using either calibrated steel tapes or a pressure sensor. Mean water-level altitudes in the Tertiary volcanic rocks ranged from about 727.86 to about 1,034.58 meters above sea level during 1996. The mean water-level altitude in the well monitoring the Paleozoic carbonate rocks was about 752.57 meters above sea level during 1996. Mean water-level altitudes for 1996 were an average of about 0.06 meter lower than 1995 mean water-level altitudes and 0.03 meter lower than 1985--95 mean water-level altitudes. During 1996, water levels in the Yucca Mountain area could have been affected by long-term pumping at the C-hole complex that began on May 8, 1996. Through December 31, 1996, approximately 196 million liters were pumped from well UE-25 c number-sign 3 at the C-hole complex. Other ground-water pumpage in the Yucca Mountain area includes annual pumpage from water-supply wells UE-25 J-12 and UE-25 J-13 of approximately 163 and 105 million liters, respectively, and pumpage from well USW G-2 for hydraulic testing during February and April 1996 of approximately 6 million liters

  16. Identification of Trihalomethanes (THMs Levels in Water Supply: A Case Study in Perlis, Malaysia

    Directory of Open Access Journals (Sweden)

    Ab Jalil Mohd Faizal

    2018-01-01

    Full Text Available In Malaysia, chlorination is used for drinking water disinfection at water treatment plants due to its cost-effectiveness and efficiency. However, the use of chlorine poses potential health risks due to the formation of disinfection by-products such as trihalomethanes (THMs. THMs are formed due to the reaction between chlorine and some natural organic matter. The objective of the study is to analyze the level of THMs in the water supply in Perlis, Malaysia. The water samples were collected from end-user tap water near the water treatment plant (WTP located in Perlis, including Timah Tasoh WTP, Kampung Sungai Baru WTP, Arau Phase I, II, III, and IV WTPs. The THMs were analyzed using a Gas Chromatography-Mass Spectrometry (GC/MS. The results showed that the water supply from Timah Tasoh WTP generates the most THMs, whereas Kuala Sungai Baru shows the fewest amounts of total THMs. In conclusion, the presence of THMs in tap water has caused great concern since these components can cause cancer in humans. Therefore, the identification of THM formation is crucial in order to make sure that the tap water quality remains at acceptable safety levels.

  17. Identification of Trihalomethanes (THMs) Levels in Water Supply: A Case Study in Perlis, Malaysia

    Science.gov (United States)

    Jalil, Mohd Faizal Ab; Hamidin, Nasrul; Anas Nagoor Gunny, Ahmad; Nihla Kamarudzaman, Ain

    2018-03-01

    In Malaysia, chlorination is used for drinking water disinfection at water treatment plants due to its cost-effectiveness and efficiency. However, the use of chlorine poses potential health risks due to the formation of disinfection by-products such as trihalomethanes (THMs). THMs are formed due to the reaction between chlorine and some natural organic matter. The objective of the study is to analyze the level of THMs in the water supply in Perlis, Malaysia. The water samples were collected from end-user tap water near the water treatment plant (WTP) located in Perlis, including Timah Tasoh WTP, Kampung Sungai Baru WTP, Arau Phase I, II, III, and IV WTPs. The THMs were analyzed using a Gas Chromatography-Mass Spectrometry (GC/MS). The results showed that the water supply from Timah Tasoh WTP generates the most THMs, whereas Kuala Sungai Baru shows the fewest amounts of total THMs. In conclusion, the presence of THMs in tap water has caused great concern since these components can cause cancer in humans. Therefore, the identification of THM formation is crucial in order to make sure that the tap water quality remains at acceptable safety levels.

  18. Wetland Ecohydrology: stochastic description of water level fluctuations across the soil surface

    Science.gov (United States)

    Tamea, S.; Muneepeerakul, R.; Laio, F.; Ridolfi, L.; Rodriguez-Iturbe, I.

    2009-12-01

    Wetlands provide a suite of social and ecological critical functions such as being habitats of disease-carrying vectors, providing buffer zones against hurricanes, controlling sediment transport, filtering nutrients and contaminants, and a repository of great biological diversity. More recently, wetlands have also been recognized as crucial for carbon storage in the context of global climate change. Despite such importance, quantitative approaches to many aspects of wetlands are far from adequate. Therefore, improving our quantitative understanding of wetlands is necessary to our ability to maintain, manage, and restore these invaluable environments. In wetlands, hydrologic factors and ecosystem processes interplay and generate unique characteristics and a delicate balance between biotic and abiotic elements. The main hydrologic driver of wetland ecosystems is the position of the water level that, being above or below ground, determines the submergence or exposure of soil. When the water level is above the soil surface, soil saturation and lack of oxygen causes hypoxia, anaerobic functioning of microorganisms and anoxic stress in plants, that might lead to the death of non-adapted organisms. When the water level lies below the soil surface, the ecosystem becomes groundwater-dependent, and pedological and physiological aspects play their role in the soil water balance. We propose here a quantitative description of wetland ecohydrology, through a stochastic process-based water balance, driven by a marked compound Poisson noise representing rainfall events. The model includes processes such as rainfall infiltration, evapotranspiration, capillary rise, and the contribution of external water bodies, which are quantified in a simple yet realistic way. The semi-analytical steady-state probability distributions of water level spanning across the soil surface are validated with data from the Everglades (Florida, USA). The model and its results allow for a quantitative

  19. Evaluation of Steam Generator Level behavior for Determination of Turbine Runback rate on COPs trip for Yonggwang 1 and 2 Power Uprating Units

    International Nuclear Information System (INIS)

    Lee, Kyung Jin; Hwang, Su Hyun; Yoo, Tae Geun; Chung, Soon Il; An, Byung Chang; Park, Jung Gu

    2010-01-01

    4.5% power uprate project has been progressing for the first time in Yonggwang 1 and 2(YGN1 and 2). Reviews for design change due to the power uprate were accomplished. Steam generator level behavior was one of the most important parameters because it could be cause of reactor trip or turbine trip. As the results of the reviews, YGN1 and 2 had to reassess it for change of turbine runback rate when turbine runback occurs due to the condensate operating pumps (COP) trip. This study has been carried out for evaluating the steam generator level behavior for determination of turbine runback rate on COPs trip for Yonggwang 1 and 2 Power Uprating Units. The steam generator water level evaluation program for YGN1 and 2 (SLEP-Y1) has been developed for it. The program includes models for the steam generator water level response. SLEP-Y1 is programmed with advanced continuous system simulation language (ACSL). The language has been used to simulate physical systems as a commercial tool used to evaluate system designs

  20. Prevention and mitigation of steam generator water hammer events in PWRs

    International Nuclear Information System (INIS)

    Han, J.T.; Anderson, N.

    1983-01-01

    Water hammer in nuclear power plants is an unresolved safety issue under study by the Nuclear Regulatory Commission (NRC). This article summarizes (1) the causes of steam generator water hammer (SGWH) events in pressurized-water reactors (PWRs), (2) various methods used to prevent or mitigate SGWH events, and (3) modifications that have been made at each operating PWR. The NRC staff considers the issue of SGWH in top feedring designs to be technically resolved. This article does not address technical findings relevant to water hammer in preheat-type steam generators

  1. Study on low pressure evaporation of fresh water generation system model

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Han Shik; Wibowo, Supriyanto; Shin, Yong Han; Jeong, Hyo Min [Gyeongsang National University, Tongyeong (Korea, Republic of); Fajar, Berkah [University of Diponegoro, Semarang (Indonesia)

    2012-02-15

    A low pressure evaporation fresh water generation system is designed for converting brackish water or seawater into fresh water by distillation in low pressure and temperature. Distillation through evaporation of feed water and subsequent vapor condensation as evaporation produced fresh water were studied; tap water was employed as feed water. The system uses the ejector as a vacuum creator of the evaporator, which is one of the most important parts in the distillation process. Hence liquid can be evaporated at a lower temperature than at normal or atmospheric conditions. Various operating conditions, i.e. temperature of feed water and different orifice diameters, were applied in the experiment to investigate the characteristics of the system. It was found that these parameters have a significant effect on the performance of fresh water generation systems with low pressure evaporation.

  2. Denitrifying Bioreactors Resist Disturbance from Fluctuating Water Levels

    Directory of Open Access Journals (Sweden)

    Sarah K. Hathaway

    2017-06-01

    Full Text Available Nitrate can be removed from wastewater streams, including subsurface agricultural drainage systems, using woodchip bioreactors to promote microbial denitrification. However, the variations in water flow in these systems could make reliable performance from this microbially-mediated process a challenge. In the current work, the effects of fluctuating water levels on nitrate removal, denitrifying activity, and microbial community composition in laboratory-scale bioreactors were investigated. The performance was sensitive to changing water level. An average of 31% nitrate was removed at high water level and 59% at low water level, despite flow adjustments to maintain a constant theoretical hydraulic retention time. The potential activity, as assessed through denitrifying enzyme assays, averaged 0.0008 mg N2O-N/h/dry g woodchip and did not show statistically significant differences between reactors, sampling depths, or operational conditions. In the denitrifying enzyme assays, nitrate removal consistently exceeded nitrous oxide production. The denitrifying bacterial communities were not significantly different from each other, regardless of water level, meaning that the denitrifying bacterial community did not change in response to disturbance. The overall bacterial communities, however, became more distinct between the two reactors when one reactor was operated with periodic disturbances of changing water height, and showed a stronger effect at the most severely disturbed location. The communities were not distinguishable, though, when comparing the same location under high and low water levels, indicating that the communities in the disturbed reactor were adapted to fluctuating conditions rather than to high or low water level. Overall, these results describe a biological treatment process and microbial community that is resistant to disturbance via water level fluctuations.

  3. Water Level Station History

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Images contain station history information for 175 stations in the National Water Level Observation Network (NWLON). The NWLON is a network of long-term,...

  4. Development of reactor water level sensor for extreme conditions

    Energy Technology Data Exchange (ETDEWEB)

    Miura, K; Ogasawara, T [Sukegawa Electric Co., Ltd., Hitachi, Ibaraki (Japan); Shibata, Akira; Nakamura, Jinichi; Saito, Takashi; Tsuchiya, Kunihiko [Japan Atomic Energy Agency, Oarai Research and Development Center, Oarai, Ibaraki (Japan)

    2012-03-15

    In the Fukushima accident, measurement failure of water level was one of the most important factors which caused serious situation. The differential pressure type water level indicators are widely used in various place of nuclear power plant but after the accident of TMI-2, the need of other reliable method has been required. The BICOTH type and the TRICOTH type water level indicator for light water power reactors had been developed for in-pile water level indicator but currently those are not adopted to nuclear power plant. In this study, the development of new type water level indicator composed of thermocouple and heater is described. Demonstration test and characteristic evaluation of the water level indicator were performed and we had obtained satisfactory results. (author)

  5. Low-level arsenic exposure via drinking water consumption and female fecundity - A preliminary investigation

    Energy Technology Data Exchange (ETDEWEB)

    Susko, Michele L. [Department of Epidemiology and Biostatistics, University at Albany, State University of New York, Rensselaer, New York (United States); Bloom, Michael S., E-mail: mbloom@albany.edu [Department of Epidemiology and Biostatistics, University at Albany, State University of New York, Rensselaer, New York (United States); Department of Environmental Health Sciences, University at Albany, State University of New York, Rensselaer, New York (United States); Neamtiu, Iulia A. [Health Department, Environmental Health Center, Cluj-Napoca (Romania); IMOGEN Research Institute, Cluj-Napoca (Romania); Appleton, Allison A. [Department of Epidemiology and Biostatistics, University at Albany, State University of New York, Rensselaer, New York (United States); Surdu, Simona [Department of Environmental Health Sciences, University at Albany, State University of New York, Rensselaer, New York (United States); Pop, Cristian [Physico-chemical and Biotoxicological Analysis Laboratory, Environmental Health Center, Cluj-Napoca (Romania); Cluj School of Public Health - College of Political, Administrative and Communication Sciences, Babeș-Bolyai University, Cluj-Napoca (Romania); Faculty of Environmental Science and Engineering, Babeș-Bolyai University, Cluj-Napoca (Romania); Fitzgerald, Edward F. [Department of Epidemiology and Biostatistics, University at Albany, State University of New York, Rensselaer, New York (United States); Department of Environmental Health Sciences, University at Albany, State University of New York, Rensselaer, New York (United States); Anastasiu, Doru [University of Medicine and Pharmacy “Victor Babeș”, Timișoara (Romania); Obstetrics and Gynecology Department of the Emergency County Hospital, Timișoara (Romania); and others

    2017-04-15

    High level arsenic exposure is associated with reproductive toxicity in experimental and observational studies; however, few data exist to assess risks at low levels. Even less data are available to evaluate the impact of low level arsenic exposure on human fecundity. Our aim in this pilot study was a preliminary evaluation of associations between low level drinking water arsenic contamination and female fecundity. This retrospective study was conducted among women previously recruited to a hospital-based case-control study of spontaneous pregnancy loss in Timiá¹£ County, Romania. Women (n=94) with planned pregnancies of 5–20 weeks gestation completed a comprehensive physician-administered study questionnaire and reported the number of menstrual cycles attempting to conceive as the time to pregnancy (TTP). Drinking water samples were collected from residential drinking water sources and we determined arsenic levels using hydride generation-atomic absorption spectrometry (HG-AAS). Multivariable Cox-proportional hazards regression with Efron approximation was employed to evaluate TTP as a function of drinking water arsenic concentrations among planned pregnancies, adjusted for covariates. There was no main effect for drinking water arsenic exposure, yet the conditional probability for pregnancy was modestly lower among arsenic exposed women with longer TTPs, relative to women with shorter TTPs, and relative to unexposed women. For example, 1 µg/L average drinking water arsenic conferred 5%, 8%, and 10% lower likelihoods for pregnancy in the 6th, 9th, and 12th cycles, respectively (P=0.01). While preliminary, our results suggest that low level arsenic contamination in residential drinking water sources may further impair fecundity among women with longer waiting times; however, this hypothesis requires confirmation by a future, more definitive study. - Highlights: • We assessed low level drinking water arsenic as a predictor of fecundability. • Arsenic did

  6. Low-level arsenic exposure via drinking water consumption and female fecundity - A preliminary investigation

    International Nuclear Information System (INIS)

    Susko, Michele L.; Bloom, Michael S.; Neamtiu, Iulia A.; Appleton, Allison A.; Surdu, Simona; Pop, Cristian; Fitzgerald, Edward F.; Anastasiu, Doru

    2017-01-01

    High level arsenic exposure is associated with reproductive toxicity in experimental and observational studies; however, few data exist to assess risks at low levels. Even less data are available to evaluate the impact of low level arsenic exposure on human fecundity. Our aim in this pilot study was a preliminary evaluation of associations between low level drinking water arsenic contamination and female fecundity. This retrospective study was conducted among women previously recruited to a hospital-based case-control study of spontaneous pregnancy loss in Timiá¹£ County, Romania. Women (n=94) with planned pregnancies of 5–20 weeks gestation completed a comprehensive physician-administered study questionnaire and reported the number of menstrual cycles attempting to conceive as the time to pregnancy (TTP). Drinking water samples were collected from residential drinking water sources and we determined arsenic levels using hydride generation-atomic absorption spectrometry (HG-AAS). Multivariable Cox-proportional hazards regression with Efron approximation was employed to evaluate TTP as a function of drinking water arsenic concentrations among planned pregnancies, adjusted for covariates. There was no main effect for drinking water arsenic exposure, yet the conditional probability for pregnancy was modestly lower among arsenic exposed women with longer TTPs, relative to women with shorter TTPs, and relative to unexposed women. For example, 1 µg/L average drinking water arsenic conferred 5%, 8%, and 10% lower likelihoods for pregnancy in the 6th, 9th, and 12th cycles, respectively (P=0.01). While preliminary, our results suggest that low level arsenic contamination in residential drinking water sources may further impair fecundity among women with longer waiting times; however, this hypothesis requires confirmation by a future, more definitive study. - Highlights: • We assessed low level drinking water arsenic as a predictor of fecundability. • Arsenic did

  7. Makeup water system performance and impact on PWR steam generator corrosion

    International Nuclear Information System (INIS)

    Bell, M.J.; Sawocha, S.G.; Smith, L.A.

    1984-01-01

    The object of this EPRI-funded project was to assess the possible relation of pressurized water reactor (PWR) steam generator corrosion at fresh water sites to makeup water impurity ingress. Makeup water system design, operation and performance reviews were based on site visits, plant design documents, performance records and grab sample analyses. Design features were assessed in terms of their effect on makeup system performance. Attempts were made to correlate the makeup plant source water, system design characteristics, and typical makeup water qualities to steam generator corrosion observations, particularly intergranular attack (IGA). Direct correlations were not made since many variables are involved in the corrosion process and in the case of IGA, the variables have not been clearly established. However, the study did demonstrate that makeup systems can be a significant source of contaminants that are suspected to lead to both IGA and denting. Additionally, it was noted that typical makeup system performance with respect to organic removal was not good. The role of organics in steam generator damage has not been quantified and may deserve further study

  8. Steam generators in indirect-cycle water-cooled reactors

    International Nuclear Information System (INIS)

    Fajeau, M.

    1976-01-01

    In the indirect cycle water-cooled nuclear reactors, the steam generators are placed between the primary circuit and the turbine. They act both as an energy transmitter and as a leaktigh barrier against fission or corrosion products. Their study is thus very important from a performance and reliability point of view. Two main types are presented here: the U-tube and the once-through steam generators [fr

  9. Contaminant transport modelling in tidal influenced water body for low level liquid waste discharge out

    International Nuclear Information System (INIS)

    Singh, Sanjay; Naidu, Velamala Simhadri

    2018-01-01

    Low level liquid waste is generated from nuclear reactor operation and reprocessing of spent fuel. This waste is discharged into the water body after removing bulk of its radioactivity. Dispersion of contaminant mainly depends on location of outfall and hydrodynamics of water body. For radiological impact assessment, in most of the analytical formulations, source term is taken as continuous release. However, this may not be always true as the water level is influenced by tidal movement and the selected outfall may come under intertidal zone in due course of the tidal cycle. To understand these phenomena, a case study has been carried out to evaluate hydrodynamic characteristics and dilution potential of outfall located in inter-tidal zone using numerical modelling

  10. Method and apparatus for enhanced heat recovery from steam generators and water heaters

    Science.gov (United States)

    Knight, Richard A.; Rabovitser, Iosif K.; Wang, Dexin

    2006-06-27

    A heating system having a steam generator or water heater, at least one economizer, at least one condenser and at least one oxidant heater arranged in a manner so as to reduce the temperature and humidity of the exhaust gas (flue gas) stream and recover a major portion of the associated sensible and latent heat. The recovered heat is returned to the steam generator or water heater so as to increase the quantity of steam generated or water heated per quantity of fuel consumed. In addition, a portion of the water vapor produced by combustion of fuel is reclaimed for use as feed water, thereby reducing the make-up water requirement for the system.

  11. Water levels in the Yucca Mountain area, Nevada, 1995

    International Nuclear Information System (INIS)

    Graves, R.P.; Goemaat, R.L.

    1998-01-01

    Water levels were monitored in 28 wells in the Yucca Mountain area, Nevada, during 1995. Seventeen wells representing 18 depth intervals were monitored periodically, generally on a monthly basis, 2 wells representing 3 depth intervals were monitored hourly, and 9 wells representing 15 depth intervals were monitored both periodically and hourly. All wells monitor water levels in Tertiary volcanic rocks except one that monitors water levels in Paleozoic carbonate rocks. Water levels were measured using calibrated steel tapes, a multiconductor cable unit, and/or pressure transducers. Mean water-level altitudes in the Tertiary volcanic rocks ranged from about 728 to about 1,034 meters above sea level during 1995. The mean water-level altitude in the well monitoring the Paleozoic carbonate rocks was about 753 meters above sea level during 1995. Mean water level altitudes were only an average of about 0.01 meters higher than 1994 mean water level altitudes. A single-well aquifer test was conducted on well UE-25 WT number-sign 12 during August and September 1995. Well USW 0-2 was also pumped during October and November 1995, in preparation for single-well aquifer test at that well. All data were acquired in accordance with a quality-assurance program to support the reliability of the data

  12. Analysis of water-level fluctuations in Wisconsin wells

    Science.gov (United States)

    Patterson, G.L.; Zaporozec, A.

    1987-01-01

    More than 60 percent of the residents of Wisconsin use ground water as their primary water source. Water supplies presently are abundant, but ground-water levels continually fluctuate in response to natural factors and human-related stresses. A better understanding of the magnitude, duration, and frequency of past fluctuations, and the factors controlling these fluctuations may help anticipate future changes in ground-water levels.

  13. Experiments of a 100 kV-level pulse generator based on metal-oxide varistor

    Science.gov (United States)

    Cui, Yan-cheng; Wu, Qi-lin; Yang, Han-wu; Gao, Jing-ming; Li, Song; Shi, Cheng-yu

    2018-03-01

    This paper introduces the development and experiments of a 100 kV-level pulse generator based on a metal-oxide varistor (MOV). MOV has a high energy handling capacity and nonlinear voltage-current (V-I) characteristics, which makes it useful for high voltage pulse shaping. Circuit simulations based on the measured voltage-current characteristics of MOV verified the shaping concept and showed that a circuit containing a two-section pulse forming network (PFN) will result in better defined square pulse than a simple L-C discharging circuit. A reduced-scale experiment was carried out and the result agreed well with simulation prediction. Then a 100 kV-level pulse generator with multiple MOVs in a stack and a two-section pulse forming network (PFN) was experimented. A pulse with a voltage amplitude of 90 kV, rise time of about 50 ns, pulse width of 500 ns, and flat top of about 400 ns was obtained with a water dummy load of 50 Ω. The results reveal that the combination of PFN and MOV is a practical way to generate high voltage pulses with better flat top waveforms, and the load voltage is stable even if the load's impedance varies. Such pulse generator can be applied in many fields such as surface treatment, corona plasma generation, industrial dedusting, and medical disinfection.

  14. Acoustic Leak Detection Testing Using KAERI Sodium-Water Reaction Signals for a SFR Steam Generator

    International Nuclear Information System (INIS)

    Kim, Tae-Joon; Jeong, Ji-Young; Kim, Jong-Man; Kim, Byung-Ho; Hahn, Do-Hee; Yugay, Valeriy S.

    2009-01-01

    The results of an experimental study of water in a sodium leak noise spectrum formation at 0.004-0.54 g/sec, various rates of water into a sodium leak, smaller than 1.0 g/sec, are presented. We focused on studying a micro leak detection with an increasing rate of water into sodium. On the basis of the experimental leak noise data manufactured in KAERI the simple dependency of an acoustic signal level from the rate of a micro and small leak at different frequency bands is presented to understand the principal analysis for the development of an acoustic leak detection methodology used in a K- 600 steam generator

  15. The secondary water chemistry and its quality specification of PWR steam generators

    International Nuclear Information System (INIS)

    Zhang Guiqin.

    1984-01-01

    Reasonably organizing the secondary water chemistry of a steam generator is of great importance for improving thermal-hydraulic characteristics and avoiding or alleviating probability of its internals failures by corrosion. In this paper emphasis is put on importance and task of the secondary water chemistry, the meaning and the control demand for feedwater and boiler water specification. At the same time, the current situation on the secondary water chemistry of PWR steam generators is reviewed generally. (Author)

  16. How much water is required for coal power generation: An analysis of gray and blue water footprints.

    Science.gov (United States)

    Ma, Xiaotian; Yang, Donglu; Shen, Xiaoxu; Zhai, Yijie; Zhang, Ruirui; Hong, Jinglan

    2018-04-28

    Although water resource shortage is closely connected with coal-based electricity generation, relevant water footprint analyses remain limited. This study aims to address this limitation by conducting a water footprint analysis of coal-based electricity generation in China for the first time to inform decision-makers about how freshwater consumption and wastewater discharge can be reduced. In China, 1 kWh of electricity supply obtained 1.78 × 10 -3  m 3 of gray water footprint in 2015, and the value is 1.3 times the blue water footprint score of 1.35 × 10 -3  m 3 /kWh. Although water footprint of 1 kWh of electricity supply decreased, the national total gray water footprint increased significantly from 2006 to 2015 with increase in power generating capacity. An opposite trend was observed for blue water footprint. Indirect processes dominated the influence of gray water footprint, whereas direct freshwater consumption contributed 63.6% to blue water footprint. Ameliorating key processes, including transportation, direct freshwater consumption, direct air emissions, and coal washing could thus bring substantial environmental benefits. Moreover, phosphorus, mercury, hexavalent chromium, arsenic, COD, and BOD 5 were key substances of gray water footprint. Results indicated that the combination of railway and water transportation should be prioritized. The targeted transition toward high coal washing rate and pithead power plant development provides a possibility to relieve environmental burdens, but constraints on water resources in coal production sites have to be considered. Copyright © 2018 Elsevier B.V. All rights reserved.

  17. Trace-level mercury removal from surface water

    International Nuclear Information System (INIS)

    Klasson, K.T.; Bostick, D.T.

    1998-01-01

    Many sorbents have been developed for the removal of mercury and heavy metals from waters; however, most of the data published thus far do not address the removal of mercury to the target levels represented in this project. The application to which these sorbents are targeted for use is the removal of mercury from microgram-per-liter levels to low nanogram-per-liter levels. Sorbents with thiouronium, thiol, amine, sulfur, and proprietary functional groups were selected for these studies. Mercury was successfully removed from surface water via adsorption onto Ionac SR-4 and Mersorb resins to levels below the target goal of 12 ng/L in batch studies. A thiol-based resin performed the best, indicating that over 200,000 volumes of water could be treated with one volume of resin. The cost of the resin is approximately $0.24 per 1,000 gal of water

  18. The temperature control and water quality regulation for steam generator secondary side hydrostatic test

    International Nuclear Information System (INIS)

    Xiao Bo; Liu Dongyong

    2014-01-01

    The secondary side hydrostatic test for the steam generator of M310 unit is to verify the pressure tightness of steam generator secondary side tube sheet and related systems. As for the importance of the steam generator, the water temperature and water quality of hydrostatic test has strict requirements. The discussion on the water temperature control and water quality regulation for the secondary loop hydrostatic test of Fuqing Unit 1 contribute greatly to the guiding work for the preparation of the steam generator pressure test for M310 unit. (authors)

  19. Tide-surge historical assessment of extreme water levels for the St. Johns River: 1928-2017

    Science.gov (United States)

    Bacopoulos, Peter

    2017-10-01

    An historical storm population is developed for the St. Johns River, located in northeast Florida-US east coast, via extreme value assessment of an 89-year-long record of hourly water-level data. Storm surge extrema and the corresponding (independent) storm systems are extracted from the historical record as well as the linear and nonlinear trends of mean sea level. Peaks-over-threshold analysis reveals the top 16 most-impactful (storm surge) systems in the general return-period range of 1-100 years. Hurricane Matthew (2016) broke the record with a new absolute maximum water level of 1.56 m, although the peak surge occurred during slack tide level (0.00 m). Hurricanes and tropical systems contribute to return periods of 10-100 years with water levels in the approximate range of 1.3-1.55 m. Extratropical systems and nor'easters contribute to the historical storm population (in the general return-period range of 1-10 years) and are capable of producing extreme storm surges (in the approximate range of 1.15-1.3 m) on par with those generated by hurricanes and tropical systems. The highest astronomical tide is 1.02 m, which by evaluation of the historical record can contribute as much as 94% to the total storm-tide water level. Statically, a hypothetical scenario of Hurricane Matthew's peak surge coinciding with the highest astronomical tide would yield an overall storm-tide water level of 2.58 m, corresponding to an approximate 1000-year return period by historical comparison. Sea-level trends (linear and nonlinear) impact water-level return periods and constitute additional risk hazard for coastal engineering designs.

  20. Low-level arsenic exposure via drinking water consumption and female fecundity - A preliminary investigation.

    Science.gov (United States)

    Susko, Michele L; Bloom, Michael S; Neamtiu, Iulia A; Appleton, Allison A; Surdu, Simona; Pop, Cristian; Fitzgerald, Edward F; Anastasiu, Doru; Gurzau, Eugen S

    2017-04-01

    High level arsenic exposure is associated with reproductive toxicity in experimental and observational studies; however, few data exist to assess risks at low levels. Even less data are available to evaluate the impact of low level arsenic exposure on human fecundity. Our aim in this pilot study was a preliminary evaluation of associations between low level drinking water arsenic contamination and female fecundity. This retrospective study was conducted among women previously recruited to a hospital-based case-control study of spontaneous pregnancy loss in Timiṣ County, Romania. Women (n=94) with planned pregnancies of 5-20 weeks gestation completed a comprehensive physician-administered study questionnaire and reported the number of menstrual cycles attempting to conceive as the time to pregnancy (TTP). Drinking water samples were collected from residential drinking water sources and we determined arsenic levels using hydride generation-atomic absorption spectrometry (HG-AAS). Multivariable Cox-proportional hazards regression with Efron approximation was employed to evaluate TTP as a function of drinking water arsenic concentrations among planned pregnancies, adjusted for covariates. There was no main effect for drinking water arsenic exposure, yet the conditional probability for pregnancy was modestly lower among arsenic exposed women with longer TTPs, relative to women with shorter TTPs, and relative to unexposed women. For example, 1µg/L average drinking water arsenic conferred 5%, 8%, and 10% lower likelihoods for pregnancy in the 6th, 9th, and 12th cycles, respectively (P=0.01). While preliminary, our results suggest that low level arsenic contamination in residential drinking water sources may further impair fecundity among women with longer waiting times; however, this hypothesis requires confirmation by a future, more definitive study. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Drought Resilience of Water Supplies for Shale Gas Extraction and Related Power Generation in Texas

    Science.gov (United States)

    Reedy, R. C.; Scanlon, B. R.; Nicot, J. P.; Uhlman, K.

    2014-12-01

    There is considerable concern about water availability to support energy production in Texas, particularly considering that many of the shale plays are in semiarid areas of Texas and the state experienced the most extreme drought on record in 2011. The Eagle Ford shale play provides an excellent case study. Hydraulic fracturing water use for shale gas extraction in the play totaled ~ 12 billion gallons (bgal) in 2012, representing ~7 - 10% of total water use in the 16 county play area. The dominant source of water is groundwater which is not highly vulnerable to drought from a recharge perspective because water is primarily stored in the confined portion of aquifers that were recharged thousands of years ago. Water supply drought vulnerability results primarily from increased water use for irrigation. Irrigation water use in the Eagle Ford play was 30 billion gallons higher in the 2011 drought year relative to 2010. Recent trends toward increased use of brackish groundwater for shale gas extraction in the Eagle Ford also reduce pressure on fresh water resources. Evaluating the impacts of natural gas development on water resources should consider the use of natural gas in power generation, which now represents 50% of power generation in Texas. Water consumed in extracting the natural gas required for power generation is equivalent to ~7% of the water consumed in cooling these power plants in the state. However, natural gas production from shale plays can be overall beneficial in terms of water resources in the state because natural gas combined cycle power generation decreases water consumption by ~60% relative to traditional coal, nuclear, and natural gas plants that use steam turbine generation. This reduced water consumption enhances drought resilience of power generation in the state. In addition, natural gas combined cycle plants provide peaking capacity that complements increasing renewable wind generation which has no cooling water requirement. However, water

  2. R and D areas for next generation desalination and water purification technologies

    International Nuclear Information System (INIS)

    Raha, A.; Rao, I.S.; Srivastava, V.K.; Tewari, P.K.

    2007-01-01

    By 2020, desalination and water purification technologies are expected to contribute significantly to ensure a safe, sustainable, affordable and adequate water supply. The cost of producing water from the current generation desalination technologies has declined over time at a rate of only approximately 4% per year. So we need to accelerate our research and development (R and D) activities with a near and long term objective for evolution of current generation desalination technology and to create revolutionary next generation advanced desalination and water purification technologies which will offer a promise of step reduction in cost of producing water. There are five broad technological areas-thermal technologies, membrane technologies, alternate technologies, concentrate management technologies, reuse and recycle technologies that encompass the spectrum of desalination technology. In this paper high priority research areas in all the above technologies areas are discussed to make decision about research direction that will help to mitigate our nation's future water supply challenges. (author)

  3. An experimental study of water absorption characteristics for generator stator winding insulation

    International Nuclear Information System (INIS)

    Lee, D. S.; Bae, Y. C.; Kim, H. S.; Kim, Y. H.; Lee, H.

    2004-01-01

    Leaking water coolant into stator electrical insulation is a growing concern for the aging water-cooled generator since leaks in the generator water-cooled stator winding can affect machine availability and insulation life. But a domestic techniques of such field are insufficient and depend wholly on GE or TOSHIBA technique. Therefore this paper introduces measuring principle and developed measuring system, which has been used to detecting wet absorption. We accomplished the experiment with a stator promotion of virtue which is used in actual power plant. Also, experimental method of generator stator winding, which is investigated into wet absorption test

  4. Water level indicator

    International Nuclear Information System (INIS)

    Murase, Michio; Araki, Hidefumi.

    1996-01-01

    A difference of pressure between a standard pressure conduit in communication with a gas phase of a reactor pressure vessel and a water level pressure conduit in communication with a liquid phase of the pressure vessel is detected by a pressure difference gage. A communication pipe and a standard level vessel are disposed between the pressure vessel and the standard pressure conduit, and a standard liquid surface on the side of the standard pressure conduit is formed in the standard level vessel. A gas releaser is disposed to the gas phase portion of the standard level vessel. The gas releaser equipment is constituted by a porous material, a permeation membrane and a gas exhaustion hole. The gas phase of the standard level vessel is divided by a partition plate into a first gas phase being in contact with a connection portion with the communication pipe and a second gas phase in contact with the gas releaser. A gas flow channel hole and a condensate descending hole are disposed to the partition plate. Since incondensible gases accumulated to the standard level vessel are effectively exhausted, the incondensible gases are prevented from being dissolved into liquid. (I.N.)

  5. Experimental Study on Behavior of Bow-tie Tree Generation by Using Heavy Water

    Science.gov (United States)

    Kumazawa, Takao; Nakagawa, Wataru; Tsurumaru, Hidekazu

    Bow-tie tree (BTT) generated from contaminant, e.g., metal, carbon, amber(over cured resin) or void in insulator is a significant deterioration factor of XLPE power cable. However, essential role of water in generation and progress of BTT is not yet sufficiently cleared. In order to investigate the role of water we paid attention to difference in chemical properties of light water (H2O) and heavy water (D2O), moreover we evaluated influence of isotopic effect due to hydrogen and deuterium on behavior of BTT generation. In accelerated aging test the number of BTT in XLPE sample, in which copper powder of 500ppm was contaminated as BTT cores, dipped in heavy water (D2O:100wt%) decreased to one third compared with light water(D2O:0wt%). Furthermore, the maximum length of BTT decreased with increase in concentration of heavy water. The experimental results show that heavy water exerted a depression effect on generation and progress of BTT. We considered that the depression effect due to hydrogen isotope appeared by inhibiting ionization and elution of BTT cores, because salt-solubility and ionic mobility of heavy water are about 15 to 20% smaller than those of light water. Therefore, the essential role of water seemed to be production and transport of ions in XLPE.

  6. Safety reviews of next-generation light-water reactors

    International Nuclear Information System (INIS)

    Kudrick, J.A.; Wilson, J.N.

    1997-01-01

    The Nuclear Regulatory Commission (NRC) is reviewing three applications for design certification under its new licensing process. The U.S. Advanced Boiling Water Reactor (ABWR) and System 80+ designs have received final design approvals. The AP600 design review is continuing. The goals of design certification are to achieve early resolution of safety issues and to provide a more stable and predictable licensing process. NRC also reviewed the Utility Requirements Document (URD) of the Electric Power Research Institute (EPRI) and determined that its guidance does not conflict with NRC requirements. This review led to the identification and resolution of many generic safety issues. The NRC determined that next-generation reactor designs should achieve a higher level of safety for selected technical and severe accident issues. Accordingly, NRC developed new review standards for these designs based on (1) operating experience, including the accident at Three Mile Island, Unit 2; (2) the results of probabilistic risk assessments of current and next-generation reactor designs; (3) early efforts on severe accident rulemaking; and (4) research conducted to address previously identified generic safety issues. The additional standards were used during the individual design reviews and the resolutions are documented in the design certification rules. 12 refs

  7. Heat exchanging tube behaviour in steam generators of pressurized water reactors

    International Nuclear Information System (INIS)

    Pastor, D.; Oertel, K.

    1979-01-01

    Based on a comprehensive failure statistics, materials corrosion chemistry and thermohydraulics problems of the tubings of steam generators are considered. A historical review of failures in the tubings of steam generators in pressurized water reactors reflects the often successless measures by designers, manufacturers and operating organizations for preventing failures, especially with regard to materials selection and water regime. It is stated that laboratory tests could not give sufficient information about safe and stable operation of nuclear steam generators unless real constructive, hydrodynamic, thermodynamical and chemical conditions of operation had been taken into account. (author)

  8. Some problems of leaks in sodium-water steam generator

    International Nuclear Information System (INIS)

    Kozlov, F.A.; Sergeev, G.V.; Sednev, A.R.; Makarov, V.M.

    1976-01-01

    The paper contains data on wastage of steam generator structural materials and high-nickel alloys in the zone of water leakage into sodium as well as investigation results for self-enlargement of water leaks into sodium through defects in these materials. It is shown that the rate of material damage in the zone of sodium-water reaction and in the channel with water leaking-out decreases with increasing nickel content in steels and strongly depends on sodium temperature. The paper presents experimentally obtained dependences of leakage self-enlargement rates on sodium temperature and leakage size

  9. Ground-water levels and quality data for Georgia

    Science.gov (United States)

    ,

    1979-01-01

    This report begins a publication format that will present annually both water-level and water-quality data in Georgia. In this format the information is presented in two-page units: the left page includes text which summarizes the information for an area or subject and the right page consists of one or more illustrations. Daily mean water-level fluctuations and trends are shown in hydrographs for the previous year and fluctuations for the monthly mean water level the previous 10 years for selected observation wells. The well data best illustrate the effects of changes in recharge and discharge in the various ground-water reservoirs in the State. A short narrative explains fluctuations and trends in each hydrograph. (Woodard-USGS)

  10. Hideout of sea water impurities in steam generator tube deposits: laboratory and field studies

    International Nuclear Information System (INIS)

    Balakrishnan, P.V.; Turner, C.W.; Thompson, R.; Sawochka, S.

    1996-01-01

    Sea water impurities hide out within thin (∼10 μm) deposits on steam generator tubes, as demonstrated by both laboratory studies using segments of fouled steam generator tubes pulled in 1992 from Crystal River-3 nuclear power station and field hideout return studies performed during recent plant shutdowns. Laboratory tests performed at 279 o C (534 o F) and heat fluxes ranging from 35 to 114 kW/m 2 (11,100 - 36,150 Btu/h.ft 2 ), conditions typical of the lower tubesheet to the first support plate region of a once-through steam generator, showed that impurity hideout can occur in thin free-span tube deposits. The extent of hideout increased with increasing heat flux. Soluble species, such as sodium and chloride ions, returned promptly to the bulk water from the deposits when the heat flux was turned off, whereas less soluble species, such as calcium sulfate and magnesium hydroxide, returned more slowly. Recent field hideout return studies performed at Crystal River-3 where the water level in the steam generators was maintained below the first tube support plate during the shutdown, thus wetting only the thin deposits in the free span and the small sludge pile, corroborate the laboratory findings, showing that hideout does indeed occur in the free-span regions of the tubes. These findings suggest that hideout within tube deposits has to be accounted for in the calculation of crevice chemistry from hideout return studies and in controlling the bulk chemistry using the molar ratio criterion. (author). 3 refs., 4 tabs., 3 figs

  11. Toward Estimating Wetland Water Level Changes Based on Hydrological Sensitivity Analysis of PALSAR Backscattering Coefficients over Different Vegetation Fields

    Directory of Open Access Journals (Sweden)

    Ting Yuan

    2015-03-01

    Full Text Available Synthetic Aperture Radar (SAR has been successfully used to map wetland’s inundation extents and types of vegetation based on the fact that the SAR backscatter signal from the wetland is mainly controlled by the wetland vegetation type and water level changes. This study describes the relation between L-band PALSAR  and seasonal water level changes obtained from Envisat altimetry over the island of Île Mbamou in the Congo Basin where two distinctly different vegetation types are found. We found positive correlations between and water level changes over the forested southern Île Mbamou whereas both positive and negative correlations were observed over the non-forested northern Île Mbamou depending on the amount of water level increase. Based on the analysis of sensitivity, we found that denser vegetation canopy leads to less sensitive  variation with respect to the water level changes regardless of forested or non-forested canopy. Furthermore, we attempted to estimate water level changes which were then compared with the Envisat altimetry and InSAR results. Our results demonstrated a potential to generate two-dimensional maps of water level changes over the wetlands, and thus may have substantial synergy with the planned Surface Water and Ocean Topography (SWOT mission.

  12. Innovated feed water distributing system of VVER steam generators

    International Nuclear Information System (INIS)

    Matal, O.; Sousek, P.; Simo, T.; Lehota, M.; Lipka, J.; Slugen, V.

    2000-01-01

    Defects in feed water distributing system due to corrosion-erosion effects have been observed at many VVER 440 steam generators (SG). Therefore analysis of defects origin and consequently design development and testing of a new feed water distributing system were performed. System tests in-situ supported by calculations and comparison of measured and calculated data were focused on demonstration of long term reliable operation, definition of water flow and water chemical characteristics at the SG secondary side and their measurements and study of dynamic characteristics needed for the innovated feed water distributing system seismic features approval. The innovated feed water distributing system was installed in the SGs of two VVER units already. (author)

  13. Operational Principle of Water Level Detector for Agricultural and ...

    African Journals Online (AJOL)

    This paper proposes a design to automatically detect the level of water in a reservoir (storage tank) at a preset level and initializes an information to the users in case of low water level. The functionality of this sensor depends basically on the electrical conductivity of water (probes) which varies, depending on the level of its ...

  14. Passive system with steam-water injector for emergency supply of NPP steam generators

    International Nuclear Information System (INIS)

    Il'chenko, A.G.; Strakhov, A.N.; Magnitskij, D.N.

    2009-01-01

    The calculation results of reliability indicators of emergency power supply system and emergency feed-water supply system of serial WWER-1000 unit are presented. To ensure safe water supply to steam generators during station blackout it was suggested using additional passive emergency feed-water system with a steam-water injector working on steam generators dump steam. Calculated analysis of steam-water injector operating capacity was conducted at variable parameters of steam at the entrance to injector, corresponding to various moments of time from the beginning of steam-and-water damping [ru

  15. Portable device for generation of ultra-pure water vapor feeds

    Science.gov (United States)

    Velin, P.; Stenman, U.; Skoglundh, M.; Carlsson, P.-A.

    2017-11-01

    A portable device for the generation of co-feeds of water vapor has been designed, constructed, and evaluated for flexible use as an add-on component to laboratory chemical reactors. The vapor is formed by catalytic oxidation of hydrogen, which benefits the formation of well-controlled minute concentrations of ultra-pure water. Analysis of the effluent stream by on-line mass spectrometry and Fourier transform infrared spectroscopy confirms that water vapor can be, with high precision, generated both rapidly and steadily over extended periods in the range of 100 ppm to 3 vol. % (limited by safety considerations) using a total flow of 100 to 1500 ml/min at normal temperature and pressure. Further, the device has been used complementary to a commercial water evaporator and mixing system to span water concentrations up to 12 vol. %. Finally, an operando diffuse reflective infrared Fourier transform spectroscopic measurement of palladium catalysed methane oxidation in the absence and presence of up to 1.0 vol. % water has been carried out to demonstrate the applicability of the device for co-feeding well-controlled low concentrations of water vapor to a common type of spectroscopic experiment. The possibilities of creating isotopically labeled water vapor as well as using tracer gases for dynamic experiments are discussed.

  16. Wavelet network controller for nuclear steam generators

    International Nuclear Information System (INIS)

    Habibiyan, H; Sayadian, A; Ghafoori-Fard, H

    2005-01-01

    Poor control of steam generator water level is the main cause of unexpected shutdowns in nuclear power plants. Particularly at low powers, it is a difficult task due to shrink and swell phenomena and flow measurement errors. In addition, the steam generator is a highly complex, nonlinear and time-varying system and its parameters vary with operating conditions. Therefore, it seems that design of a suitable controller is a necessary step to enhance plant availability factor. The purpose of this paper is to design, analyze and evaluate a water level controller for U-tube steam generators using wavelet neural networks. Computer simulations show that the proposed controller improves transient response of steam generator water level and demonstrate its superiority to existing controllers

  17. Short-time variations of the ground water level

    International Nuclear Information System (INIS)

    Nilsson, Lars Y.

    1977-09-01

    Investigations have demonstrated that the ground water level of aquifers in the Swedish bedrock shows shorttime variations without changing their water content. The ground water level is among other things affected by regular tidal movements occuring in the ''solid'' crust of the earth variations in the atmospheric pressure strong earthquakes occuring in different parts of the world These effects proves that the system of fissures in the bedrock are not stable and that the ground water flow is influenced by both water- and airfilled fissures

  18. Modelling soil water dynamics and crop water uptake at the field level

    NARCIS (Netherlands)

    Kabat, P.; Feddes, R.A.

    1995-01-01

    Parametrization approaches to model soil water dynamics and crop water uptake at field level were analysed. Averaging and numerical difficulties in applying numerical soil water flow models to heterogeneous soils are highlighted. Simplified parametrization approaches to the soil water flow, such as

  19. Water resources data for Virginia, water year 1991. Volume 2. Ground-water-level and ground-water-quality records. Water-data report (Annual), 1 October 1991-30 September 1992

    International Nuclear Information System (INIS)

    Prugh, B.J.; Powell, E.D.

    1993-01-01

    Water-resources data for the 1992 water year for Virginia consist of records of water levels and water quality of ground-water wells. The report (Volume 2. Ground-Water-Level and Ground-Water-Quality Records) contains water levels at 356 observation wells and water quality at 2 wells. Locations of these wells are given in the report

  20. Estimation Of Height Of Oil -Water Contact Above Free Water Level ...

    African Journals Online (AJOL)

    An estimate of oil-water contact (OWC) and the understanding of the capillary behaviour of hydrocarbon reservoirs are vital for optimum reservoir characterization, hydrocarbon exploration and production. Hence, the height of oil-water contact above free water level for different rock types from some Niger Delta reservoirs ...

  1. Mitigation of Hydrogen Gas Generation from the Reaction of Water with Uranium Metal in K Basins Sludge

    International Nuclear Information System (INIS)

    Sinkov, Sergey I.; Delegard, Calvin H.; Schmidt, Andrew J.

    2010-01-01

    Means to decrease the rate of hydrogen gas generation from the chemical reaction of uranium metal with water were identified by surveying the technical literature. The underlying chemistry and potential side reactions were explored by conducting 61 principal experiments. Several methods achieved significant hydrogen gas generation rate mitigation. Gas-generating side reactions from interactions of organics or sludge constituents with mitigating agents were observed. Further testing is recommended to develop deeper knowledge of the underlying chemistry and to advance the technology aturation level. Uranium metal reacts with water in K Basin sludge to form uranium hydride (UH3), uranium dioxide or uraninite (UO2), and diatomic hydrogen (H2). Mechanistic studies show that hydrogen radicals (H·) and UH3 serve as intermediates in the reaction of uranium metal with water to produce H2 and UO2. Because H2 is flammable, its release into the gas phase above K Basin sludge during sludge storage, processing, immobilization, shipment, and disposal is a concern to the safety of those operations. Findings from the technical literature and from experimental investigations with simple chemical systems (including uranium metal in water), in the presence of individual sludge simulant components, with complete sludge simulants, and with actual K Basin sludge are presented in this report. Based on the literature review and intermediate lab test results, sodium nitrate, sodium nitrite, Nochar Acid Bond N960, disodium hydrogen phosphate, and hexavalent uranium [U(VI)] were tested for their effects in decreasing the rate of hydrogen generation from the reaction of uranium metal with water. Nitrate and nitrite each were effective, decreasing hydrogen generation rates in actual sludge by factors of about 100 to 1000 when used at 0.5 molar (M) concentrations. Higher attenuation factors were achieved in tests with aqueous solutions alone. Nochar N960, a water sorbent, decreased hydrogen

  2. Mitigation of Hydrogen Gas Generation from the Reaction of Water with Uranium Metal in K Basins Sludge

    Energy Technology Data Exchange (ETDEWEB)

    Sinkov, Sergey I.; Delegard, Calvin H.; Schmidt, Andrew J.

    2010-01-29

    Means to decrease the rate of hydrogen gas generation from the chemical reaction of uranium metal with water were identified by surveying the technical literature. The underlying chemistry and potential side reactions were explored by conducting 61 principal experiments. Several methods achieved significant hydrogen gas generation rate mitigation. Gas-generating side reactions from interactions of organics or sludge constituents with mitigating agents were observed. Further testing is recommended to develop deeper knowledge of the underlying chemistry and to advance the technology aturation level. Uranium metal reacts with water in K Basin sludge to form uranium hydride (UH3), uranium dioxide or uraninite (UO2), and diatomic hydrogen (H2). Mechanistic studies show that hydrogen radicals (H·) and UH3 serve as intermediates in the reaction of uranium metal with water to produce H2 and UO2. Because H2 is flammable, its release into the gas phase above K Basin sludge during sludge storage, processing, immobilization, shipment, and disposal is a concern to the safety of those operations. Findings from the technical literature and from experimental investigations with simple chemical systems (including uranium metal in water), in the presence of individual sludge simulant components, with complete sludge simulants, and with actual K Basin sludge are presented in this report. Based on the literature review and intermediate lab test results, sodium nitrate, sodium nitrite, Nochar Acid Bond N960, disodium hydrogen phosphate, and hexavalent uranium [U(VI)] were tested for their effects in decreasing the rate of hydrogen generation from the reaction of uranium metal with water. Nitrate and nitrite each were effective, decreasing hydrogen generation rates in actual sludge by factors of about 100 to 1000 when used at 0.5 molar (M) concentrations. Higher attenuation factors were achieved in tests with aqueous solutions alone. Nochar N960, a water sorbent, decreased hydrogen

  3. Geographical distribution of drinking-water with high iodine level and association between high iodine level in drinking-water and goitre: a Chinese national investigation.

    Science.gov (United States)

    Shen, Hongmei; Liu, Shoujun; Sun, Dianjun; Zhang, Shubin; Su, Xiaohui; Shen, Yanfeng; Han, Hepeng

    2011-07-01

    Excessive iodine intake can cause thyroid function disorders as can be caused by iodine deficiency. There are many people residing in areas with high iodine levels in drinking-water in China. The main aim of the present study was to map the geographical distribution of drinking-water with high iodine level in China and to determine the relationship between high iodine level in drinking-water and goitre prevalence. Iodine in drinking-water was measured in 1978 towns of eleven provinces in China, with a total of 28,857 water samples. We randomly selected children of 8-10 years old, examined the presence of goitre and measured their urinary iodine in 299 towns of nine provinces. Of the 1978 towns studied, 488 had iodine levels between 150 and 300 μg/l in drinking-water, and in 246 towns, the iodine level was >300 μg/l. These towns are mainly distributed along the original Yellow River flood areas, the second largest river in China. Of the 56 751 children examined, goitre prevalence was 6.3 % in the areas with drinking-water iodine levels of 150-300 μg/l and 11.0 % in the areas with drinking-water iodine >300 μg/l. Goitre prevalence increased with water and urinary iodine levels. For children with urinary iodine >1500 μg/l, goitre prevalence was 3.69 times higher than that for those with urinary iodine levels of 100-199 μg/l. The present study suggests that drinking-water with high iodine levels is distributed in eleven provinces of China. Goitre becomes more prevalent with the increase in iodine level in drinking-water. Therefore, it becomes important to prevent goitre through stopping the provision of iodised salt and providing normal drinking-water iodine through pipelines in these areas in China.

  4. Facility for generating crew waste water product for ECLSS testing

    Science.gov (United States)

    Buitekant, Alan; Roberts, Barry C.

    1990-01-01

    An End-use Equipment Facility (EEF) has been constructed which is used to simulate water interfaces between the Space Station Freedom Environmental Control and Life Support Systems (ECLSS) and man systems. The EEF is used to generate waste water to be treated by ECLSS water recovery systems. The EEF will also be used to close the water recovery loop by allowing test subjects to use recovered hygiene and potable water during several phases of testing. This paper describes the design and basic operation of the EEF.

  5. Water leak detection in steam generator of SUPER PHENIX

    International Nuclear Information System (INIS)

    Brunet, M.; Garnaud, P.; Ghaleb, D.; Kong, N.

    1988-01-01

    With the intent of detecting water leaks inside steam generators, we developed a third system, called acoustic detector, to complement hydrogen detectors and rupture disks (burst disks). The role of the acoustic system is to enable rapid intervention in the event of a leak growing rapidly which could rupture neighbouring tubes. In such a case, the detectable flow rate of the leak varies from a few tens of g/s to a few hundred g/s. At the SUPER PHENIX, three teams work in [20-100 kHz] and CEA/STA* [50-300 kHz]. The simulation of water leaks in the steam generator by the argon injections performed to date at 50% of the rated power has shown promising results. An anomaly in the evolution of the background noise at more than 50% loading of one of the two instrumented steam generators would make difficult any extrapolation to full power behaviour. (author)

  6. Development of a small-sized generator of ozonated water using an electro-conductive diamond electrode.

    Science.gov (United States)

    Sekido, Kota; Kitaori, Noriyuki

    2008-12-01

    A small-sized generator of ozonated water was developed using an electro-conductive diamond. We studied the optimum conditions for producing ozonated water. As a result, we developed a small-sized generator of ozonated water driven by a dry-cell for use in the average household. This generator was easily able to produce ozonated water with an ozone concentration (over 4 mg/L) sufficient for disinfection. In addition, we verified the high disinfecting performance of the water produced in an actual hospital.

  7. Energy balance and flow in steam generator part with sodium-water reaction

    International Nuclear Information System (INIS)

    Matal, O.

    1980-01-01

    Relations were derived for the calculation of heat liberated during the sodium water reaction in a tube failure in different parts of a steam generator. The results are graphically shown in i-T diagrams. Heat removal is described from the reaction zone to water and steam in undisturbed tubes and to the steam generator metal structure. (author)

  8. Generation of Efficient High-Level Hardware Code from Dataflow Programs

    OpenAIRE

    Siret , Nicolas; Wipliez , Matthieu; Nezan , Jean François; Palumbo , Francesca

    2012-01-01

    High-level synthesis (HLS) aims at reducing the time-to-market by providing an automated design process that interprets and compiles high-level abstraction programs into hardware. However, HLS tools still face limitations regarding the performance of the generated code, due to the difficulties of compiling input imperative languages into efficient hardware code. Moreover the hardware code generated by the HLS tools is usually target-dependant and at a low level of abstraction (i.e. gate-level...

  9. The Water - Energy Nexus Of Hydropower. Are The Trade-Offs Between Electricity Generation And Water Supply Negligible?

    Science.gov (United States)

    Scherer, L.; Pfister, S.

    2015-12-01

    Hydropower ranks first among renewable sources of power production and provides globally about 16% of electricity. While it is praised for its low greenhouse gas emissions, it is accused of its large water consumption which surpasses that of all conventional and most renewable energy sources (except for bioenergy) by far. Previous studies mostly applied a gross evaporation approach where all the current evaporation from the plant's reservoir is allocated to hydropower. In contrast, we only considered net evaporation as the difference between current evaporation and actual evapotranspiration before the construction of the reservoir. In addition, we take into account local water stress, its monthly fluctuations and storage effects of the reservoir in order to assess the impacts on water availability for other users. We apply the method to a large dataset of almost 1500 globally distributed hydropower plants (HPPs), covering ~43% of global annual electricity generation, by combining reservoir information from the Global Reservoir and Dam (GRanD) database with information on electricity generation from the CARMA database. While we can confirm that the gross water consumption of hydropower is generally large (production-weighted average of 97 m3/GJ), other users are not necessarily deprived of water. In contrast, they also benefit in many cases from the reservoir because water is rather stored in the wet season and released in the dry season, thereby alleviating water stress. The production-weighted water scarcity footprint of the analyzed HPPs amounts to -41 m3 H2Oe/GJ. It has to be noted that the impacts among individual plants vary a lot. Larger HPPs generally consume less water per unit of electricity generated, but also the benefits related to alleviating water scarcity are lower. Overall, reservoirs promote both, energy and water security. Other environmental impacts such as flow alterations and social impacts should, however, also be considered, as they can be

  10. Electrokinetic Power Generation from Liquid Water Microjets

    Energy Technology Data Exchange (ETDEWEB)

    Duffin, Andrew M.; Saykally, Richard J.

    2008-02-15

    Although electrokinetic effects are not new, only recently have they been investigated for possible use in energy conversion devices. We have recently reported the electrokinetic generation of molecular hydrogen from rapidly flowing liquid water microjets [Duffin et al. JPCC 2007, 111, 12031]. Here, we describe the use of liquid water microjets for direct conversion of electrokinetic energy to electrical power. Previous studies of electrokinetic power production have reported low efficiencies ({approx}3%), limited by back conduction of ions at the surface and in the bulk liquid. Liquid microjets eliminate energy dissipation due to back conduction and, measuring only at the jet target, yield conversion efficiencies exceeding 10%.

  11. Photocatalysis in Generation of Hydrogen from Water

    KAUST Repository

    Takanabe, Kazuhiro

    2015-04-18

    Solar energy can be converted by utilizing the thermal or photoelectric effects of photons. Concentrated solar power systems utilize thermal energy from the sun by either making steam and then generating power or shifting the chemical equilibrium of a reaction (e.g., water splitting or CO2 reduction) that occurs at extremely high temperatures. The photocatalytic system contains powder photocatalysts. Each photocatalyst particle should collect sufficient photons from the solar flux to cause the required multielectron reactions to occur. The band gap and band edge positions of semiconductors are the most critical parameters for assessing the suitability of photocatalysts for overall water splitting. The most important requirement when selecting photocatalyst materials is the band positions relative to hydrogen and oxygen evolution potentials. For most photocatalysts, surface modification by cocatalysts was found to be essential to achieve overall water splitting.

  12. On site power generation protects water supply for Ajax, Ontario

    Energy Technology Data Exchange (ETDEWEB)

    Morsy, Mohamed

    2011-01-15

    The Ajax water supply plant treats and distribute water for the town of Ajax and the nearby City of Pickering and the operations staff manages two other treatment plants supplying the City of Oshawa and the Town of Whitby, and a dozen pumping stations, reservoirs and elevated tanks. The plant requires around 2 MW of continuous power to supply its 150,000 customers. Although local utility power is reliable, standby generators are mandated by the Ontario Ministry of the Environment. When power goes out problems can result in the plant and system. To avoid these, the Ajax plant staff selected Cummins Power Generation who delivered one 350 kW and two 1500 kW generator sets with automatic transfer switches and paralleling switchgear. These digital systems parallel and synchronize the generator sets with each other and with the utility, which allows the plant to provide continuous service. The plant is designed for twice its current capacity and is ready to handle future requirements.

  13. Expressional Changes of Water Transport-related Molecules in the Efferent Ductules and Initial Segment of Mouse Treated with Bisphenol A-Containing Drinking Water for Two Generations.

    Science.gov (United States)

    Han, Su-Yong; Lee, Ki-Ho

    2013-09-01

    Bisphenol A (BPA) is an estrogenic endocrine disrupter. However, depending on a way of treatment, the harmful effects of BPA have not been confirmed. Also, trans-generational effects of BPA on male reproduction are still controversial. Because the reabsorption of testicular fluid in the efferent ductules (ED) and initial segment (IS) is important for sperm maturation, the present study was designed to determine trans-generational effect of BPA administrated orally on expression of water transport-related molecules in the mouse ED and IS. Ethanol-dissolved BPA was diluted in water to be 100 ng (low), 10 μg (medium), and 1 mg/Ml water (high). BPA-containing water was provided for two generations. Expression of ion transporters and water channels in the ED and IS were measured by relative real-time PCR analysis. In the ED, BPA treatment caused expressional increases of carbonic anhydrase II, cystic fibrosis transmembrane regulator, Na(+)/K(+) ATPase α1 subunit, and aquaporin (AQP) 1. No change of Na(+)/H(+) exchange (NHE) 3 expression was detected. BPA treatment at medium dose resulted in an increase of AQP9 expression. In the IS, the highest expressional levels of all molecules tested were observed in medium-dose BPA treatment. Generally, high-dose BPA treatment resulted in a decrease or no change of gene expression. Fluctuation of NHE3 gene expression by BPA treatment at different concentrations was detected. These findings suggest that trans-generational exposure to BPA, even at low dose, could affect gene expression of water-transport related molecules. However, such effects of BPA would be differentially occurred in the ED and IS.

  14. Cosine components in water levels at Yucca Mountain

    International Nuclear Information System (INIS)

    Rice, J.; Lehman, L.; Keen, K.

    1990-01-01

    Water-level records from wells at Yucca Mountain, Nevada are analyzed periodically to determine if they contain periodic (cosine) components. Water-level data from selected wells are input to an iterative numerical procedure that determines a best fitting cosine function. The available water-level data, with coverage of up to 5 years, appear to be representative of the natural water-level changes. From our analysis of 9 water-level records, it appears that there may be periodic components (periods of 2-3 years) in the groundwater-level fluctuations at Yucca Mountain, Nevada, although some records are fit better than others by cosine functions. It also appears that the periodic behavior has a spatial distribution. Wells west of Yucca Mountain have different periods and phase shifts from wells on and east of Yucca Mountain. Interestingly, a similar spatial distribution of groundwater chemistry at Yucca Mountain is reported by Matuska (1988). This suggests a physical cause may underlie the different physical and chemical groundwater conditions. Although a variety of natural processes could cause water-level fluctuations, hydrologic processes are the most likely, because the periodicities are only a few years. A possible cause could be periodic recharge related to a periodicity in precipitation. It is interesting that Cochran et al., (1988), show a crude two-year cycle of precipitation for 1961 to 1970 in southern Nevada. Why periods and phase shifts may differ across Yucca Mountain is unknown. Different phase shifts could indicate different lag times of response to hydrologic stimuli. Difference in periods could mean that the geologic media is heterogeneous and displays heterogeneous response to a single stimulus, or that stimuli differ in certain regions, or that a hydraulic barrier separates the groundwater system into two regions having different water chemistry and recharge areas. 13 refs., 5 figs., 1 tab

  15. Liquid level control system for vapour generator

    International Nuclear Information System (INIS)

    Singh, G.

    1984-01-01

    A system for regulating the liquid level in a vapor generator, in which the incoming flow of feed liquid is regulated in response to the difference between the measured liquid level and a reference level, the difference between the exiting vapor mass flow rate and the incoming liquid mass flow rate, and a function of the measured incoming liquid temperature. The temperature function produces a gain value, which increases in response to decreasing incoming liquid temperature. The purpose of the temperature function is to stabilize the level control under transient conditions (e.g. sudden lose of load). (author)

  16. A contribution to severe accident monitoring: Level measurement of the Incontainment Refueling Water Storage Tank (IRWST), design and qualification

    Energy Technology Data Exchange (ETDEWEB)

    Schumilov, A.; Weber, P.; Esteves, S.

    2012-07-01

    A level measurement sensor for monitoring the water level in the in-containment refueling water storage tank (IRWST) of the EPRTM (generation 3+ pressurized water reactor) during leakage and severe accidents has been developed by AREVA. The development has been accompanied by many functional and material analyses as well as tests to assure the resistivity under extreme conditions, such as high irradiation dose of 5 MGy, increased temperature up to 160 degree centigrade in conjunction with saturated steam conditions. Moreover, the sensor has been designed and experimentally verified to resist the impact of seismic events and airplane crashes as well.

  17. Membrane-based processes for sustainable power generation using water

    KAUST Repository

    Logan, Bruce E.; Elimelech, Menachem

    2012-01-01

    Water has always been crucial to combustion and hydroelectric processes, but it could become the source of power in membrane-based systems that capture energy from natural and waste waters. Two processes are emerging as sustainable methods for capturing energy from sea water: pressure-retarded osmosis and reverse electrodialysis. These processes can also capture energy from waste heat by generating artificial salinity gradients using synthetic solutions, such as thermolytic salts. A further source of energy comes from organic matter in waste waters, which can be harnessed using microbial fuel-cell technology, allowing both wastewater treatment and power production. © 2012 Macmillan Publishers Limited. All rights reserved.

  18. Membrane-based processes for sustainable power generation using water

    KAUST Repository

    Logan, Bruce E.

    2012-08-15

    Water has always been crucial to combustion and hydroelectric processes, but it could become the source of power in membrane-based systems that capture energy from natural and waste waters. Two processes are emerging as sustainable methods for capturing energy from sea water: pressure-retarded osmosis and reverse electrodialysis. These processes can also capture energy from waste heat by generating artificial salinity gradients using synthetic solutions, such as thermolytic salts. A further source of energy comes from organic matter in waste waters, which can be harnessed using microbial fuel-cell technology, allowing both wastewater treatment and power production. © 2012 Macmillan Publishers Limited. All rights reserved.

  19. An analysis of the water-level monitoring system for a boiling-water reactor

    International Nuclear Information System (INIS)

    Carlson, R.W.; Belblidia, L.A.; Russell, J.L. Jr.

    1985-01-01

    The water-level instrumentation system is very important to the overall safety of a BWR. This system is being monitored by the Safety Parameter Display System (SPDS) that is being installed in Georgia Power Company's Plant Hatch. One of the most significant functions of the SPDS is the comparison of redundant instrument readings and formation of the best estimate of each parameter from those readings which are consistent. When comparing water-level instrument readings, it is necessary to correct the individual readings for differences between current and calibration conditions as well as for differences between calibration conditions for the multiple instruments. This paper documents the examination of the water-level instrumentation system at Plant Hatch and presents the development of the equations that were used to determine the differences between indicated and actual water levels. (author)

  20. Next-generation mammalian genetics toward organism-level systems biology.

    Science.gov (United States)

    Susaki, Etsuo A; Ukai, Hideki; Ueda, Hiroki R

    2017-01-01

    Organism-level systems biology in mammals aims to identify, analyze, control, and design molecular and cellular networks executing various biological functions in mammals. In particular, system-level identification and analysis of molecular and cellular networks can be accelerated by next-generation mammalian genetics. Mammalian genetics without crossing, where all production and phenotyping studies of genome-edited animals are completed within a single generation drastically reduce the time, space, and effort of conducting the systems research. Next-generation mammalian genetics is based on recent technological advancements in genome editing and developmental engineering. The process begins with introduction of double-strand breaks into genomic DNA by using site-specific endonucleases, which results in highly efficient genome editing in mammalian zygotes or embryonic stem cells. By using nuclease-mediated genome editing in zygotes, or ~100% embryonic stem cell-derived mouse technology, whole-body knock-out and knock-in mice can be produced within a single generation. These emerging technologies allow us to produce multiple knock-out or knock-in strains in high-throughput manner. In this review, we discuss the basic concepts and related technologies as well as current challenges and future opportunities for next-generation mammalian genetics in organism-level systems biology.

  1. Prevention and mitigation of steam-generator water-hammer events in PWR plants

    International Nuclear Information System (INIS)

    Han, J.T.; Anderson, N.

    1982-11-01

    Water hammer in nuclear power plants is an unresolved safety issue under study at the NRC (USI A-1). One of the identified safety concerns is steam generator water hammer (SGWH) in pressurized-water reactor (PWR) plants. This report presents a summary of: (1) the causes of SGWH; (2) various fixes employed to prevent or mitigate SGWH; and (3) the nature and status of modifications that have been made at each operating PWR plant. The NRC staff considers that the issue of SGWH in top feedring designs has been technically resolved. This report does not address technical findings relevant to water hammer in preheat type steam generators. 10 figures, 2 tables

  2. Nanoporous Membrane for Medical Grade Water Generation, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — For NASA exploration missions to the Moon and Mars, medical grade water generation is a necessity. Adsorption filter technology has shown some promise, but requires...

  3. Improvements to feed water system of vapor generators of nuclear power stations

    International Nuclear Information System (INIS)

    Byerlex, W.M.

    1976-01-01

    The description is given of a feed water system related to the steam generators for nuclear power stations and which have a water feed ring around their upper part. This water intake system enables water hammer to be avoided even during operation under low load [fr

  4. Effects of electrolysis time and electric potential on chlorine generation of electrolyzed deep ocean water

    Directory of Open Access Journals (Sweden)

    Guoo-Shyng Wang Hsu

    2017-10-01

    Full Text Available Electrolyzed water is a sustainable disinfectant, which can comply with food safety regulations and is environmentally friendly. A two-factor central composite design was adopted for studying the effects of electrolysis time and electric potential on the chlorine generation efficiency of electrolyzed deep ocean water (DOW. DOW was electrolyzed in a glass electrolyzing cell equipped with platinum–plated titanium anode and cathode. The results showed that chlorine concentration reached maximal level in the batch process. Prolonged electrolysis reduced chlorine concentration in the electrolyte and was detrimental to electrolysis efficiency, especially under high electric potential conditions. Therefore, the optimal choice of electrolysis time depends on the electrolyzable chloride in DOW and cell potential adopted for electrolysis. The higher the electric potential, the faster the chlorine level reaches its maximum, but the lower the electric efficiency will be.

  5. Modeling of soluble impurities distribution in the steam generator secondary water

    International Nuclear Information System (INIS)

    Matal, O.; Simo, T.; Kucak, L.; Urban, F.

    1997-01-01

    A model was developed to compute concentration of impurities in the WWER 440 steam generator (SG) secondary water along the tube bundle. Calculated values were verified by concentration values obtained from secondary water sample chemical analysis. (orig.)

  6. Velocity flow field and water level measurements in shoaling and breaking water waves

    CSIR Research Space (South Africa)

    Mukaro, R

    2010-01-01

    Full Text Available In this paper we report on the laboratory investigations of breaking water waves. Measurements of the water levels and instantaneous fluid velocities were conducted in water waves breaking on a sloping beach within a glass flume. Instantaneous water...

  7. Integrity of high-velocity water slug generated by an impacting technique

    Science.gov (United States)

    Dehkhoda, Sevda; Bourne, Neil

    2013-06-01

    A pulsed water jet is a series of discrete water slugs travelling at high velocity. Immediately after striking a target, these slugs apply high-intensity, short-duration transient stress known as the water hammer pressure, followed by low-intensity, long-duration stationary stress at the stagnation pressure. The magnitude and duration of the water hammer and stagnation pressures are controlled by the size and quality of the water slugs. The use of water jets for rock cutting in mining operations is a centuries-old technology; however, practical methods for producing high-energy water slugs repeatedly have proven difficult. This can be partly due to the fact that the geometrical properties of a jet and so its effectiveness in creating damage is controlled and influenced by the method that is employed to generate the water slugs. This paper investigates the integrity of a single water slug produced using an impacting technique where a hammer strikes a piston, resting on top of a water-filled chamber. The coherence of the generated water pulse was of concern in this study. If repeated shock reflections within the chamber were transmitted or were carried into the internal geometry of nozzle, the emerging jet could pulsate. The impact impulse of the formed water jet was measured in a Kel-F target material using an embedded PVDF (Polyvinylidene fluoride) shock gauge. The recorded stress waveform was then used to study the quality and endurance of the water pulse stream as it travelled through air.

  8. Mechanisms of wave‐driven water level variability on reef‐fringed coastlines

    Science.gov (United States)

    Buckley, Mark L.; Lowe, Ryan J.; Hansen, Jeff E; van Dongeren, Ap R.; Storlazzi, Curt

    2018-01-01

    Wave‐driven water level variability (and runup at the shoreline) is a significant cause of coastal flooding induced by storms. Wave runup is challenging to predict, particularly along tropical coral reef‐fringed coastlines due to the steep bathymetric profiles and large bottom roughness generated by reef organisms, which can violate assumptions in conventional models applied to open sandy coastlines. To investigate the mechanisms of wave‐driven water level variability on a reef‐fringed coastline, we performed a set of laboratory flume experiments on an along‐shore uniform bathymetric profile with and without bottom roughness. Wave setup and waves at frequencies lower than the incident sea‐swell forcing (infragravity waves) were found to be the dominant components of runup. These infragravity waves were positively correlated with offshore wave groups, signifying they were generated in the surf zone by the oscillation of the breakpoint. On the reef flat and at the shoreline, the low‐frequency waves formed a standing wave pattern with energy concentrated at the natural frequencies of the reef flat, indicating resonant amplification. Roughness elements used in the flume to mimic large reef bottom roughness reduced low frequency motions on the reef flat and reduced wave run up by 30% on average, compared to the runs over a smooth bed. These results provide insight into sea‐swell and infragravity wave transformation and wave setup dynamics on steep‐sloped coastlines, and the effect that future losses of reef bottom roughness may have on coastal flooding along reef‐fringed coasts.

  9. Water leak detection in steam generator of Super Phenix

    International Nuclear Information System (INIS)

    Kong, N.; Brunet, M.; Garnaud, P.; Ghaleb, D.

    1990-01-01

    With the intent of detecting water leaks inside steam generators, we developed a third system, called acoustic detector, to complement hydrogen detectors and rupture disks (burst disks). The role of the acoustic system is to enable rapid intervention in the event of a leak growing rapidly which could rupture neighbouring tubes. In such a case, the detectable flow rate of the leak varies from a few tens of g/s to a few hundred g/s. At the Super Phenix, three teams work in parallel in complementary frequency bands: EDF (0-20 kHz), CEA/SPCI (20-100 kHz) and CEA/STA (50-300 kHz). The simulation of water leaks in the steam generator by the argon injections performed to date at 50% of the rated power has shown promising results. An anomaly in the evolution of the background noise at more than 50% loading of one of the two instrumented steam generators would make difficult any extrapolation to full power behaviour. 5 refs, 6 figs, 1 tab

  10. Climate-driven changes in water level

    DEFF Research Database (Denmark)

    Hansen, Rikke Bjerring; Olsen, Jesper; Jeppesen, Erik

    2013-01-01

    level rose. Moreover, Nymphaeaceae trichosclereids were abundant during the period of algal enrichment. Cladoceran taxa associated with floating leaved plants or benthic habitats responded in a complex way to changes in water level, but the cladoceran assemblages generally reflected deep lake conditions...... hydrology driven by precipitation. The isotopic, sedimentary and plant macrofossil records suggested that the lake level started to decrease around 8400 cal. yr BP, the decrease accelerating during 8350-8260 before an abrupt increase during 8260-8210. This pattern shows that the climate anomaly started...... rates of cladoceran subfossils and algal pigments, possibly due to increased turbidity and reduced nutrient input during this drier period. Pigment analysis also showed added importance of diatoms and cryptophytes during this climate anomaly, while cyanobacteria became more important when the water...

  11. Molecular metal-Oxo catalysts for generating hydrogen from water

    Science.gov (United States)

    Long, Jeffrey R; Chang, Christopher J; Karunadasa, Hemamala I

    2015-02-24

    A composition of matter suitable for the generation of hydrogen from water is described, the positively charged cation of the composition having the general formula [(PY5W.sub.2)MO].sup.2+, wherein PY5W.sub.2 is (NC.sub.5XYZ)(NC.sub.5H.sub.4).sub.4C.sub.2W.sub.2, M is a transition metal, and W, X, Y, and Z can be H, R, a halide, CF.sub.3, or SiR.sub.3, where R can be an alkyl or aryl group. The two accompanying counter anions, in one embodiment, can be selected from the following Cl.sup.-, I.sup.-, PF.sub.6.sup.-, and CF.sub.3SO.sub.3.sup.-. In embodiments of the invention, water, such as tap water containing electrolyte or straight sea water can be subject to an electric potential of between 1.0 V and 1.4 V relative to the standard hydrogen electrode, which at pH 7 corresponds to an overpotential of 0.6 to 1.0 V, with the result being, among other things, the generation of hydrogen with an optimal turnover frequency of ca. 1.5 million mol H.sub.2/mol catalyst per h.

  12. Modeling of soluble impurities distribution in the steam generator secondary water

    Energy Technology Data Exchange (ETDEWEB)

    Matal, O.; Simo, T. [Energovyzkum s.r.o., Brno (Switzerland); Kucak, L.; Urban, F. [Slovak Technical Univ., Bratislava (Slovakia)

    1997-12-31

    A model was developed to compute concentration of impurities in the WWER 440 steam generator (SG) secondary water along the tube bundle. Calculated values were verified by concentration values obtained from secondary water sample chemical analysis. (orig.). 2 refs.

  13. Modeling of soluble impurities distribution in the steam generator secondary water

    Energy Technology Data Exchange (ETDEWEB)

    Matal, O; Simo, T [Energovyzkum s.r.o., Brno (Switzerland); Kucak, L; Urban, F [Slovak Technical Univ., Bratislava (Slovakia)

    1998-12-31

    A model was developed to compute concentration of impurities in the WWER 440 steam generator (SG) secondary water along the tube bundle. Calculated values were verified by concentration values obtained from secondary water sample chemical analysis. (orig.). 2 refs.

  14. Effect of addition of water-soluble salts on the hydrogen generation of aluminum in reaction with hot water

    International Nuclear Information System (INIS)

    Razavi-Tousi, S.S.; Szpunar, J.A.

    2016-01-01

    Aluminum powder was ball milled for different durations of time with different weight percentages of water-soluble salts (NaCl and KCl). The hydrogen generation of each mixture in reaction with hot water was measured. A scanning electron microscope (SEM) as well as energy-dispersive spectroscopy (EDS) were used to investigate the morphology, surfaces and cross sections of the produced particles. The results show that the presence of salts in the microstructure of the aluminum considerably increases the hydrogen generation rate. At shorter milling times, the salt covers the aluminum particles and becomes embedded in layers within the aluminum matrix. At higher milling durations, salt and aluminum phases form composite particles. A higher percentage of the second phase significantly decreases the milling time needed for activation of the aluminum particles. Based on the EDS results from cross sections of the milled particles, a mechanism for improvement of the hydrogen generation rate in the presence of salts is suggested. - Highlights: • Milling and water soluble salts have a synergic effect on hydrogen generation. • Salt and aluminum form composite particles by milling. • Salt is dissolved in water leaving aluminum with much fresh surfaces for the reaction. • The chemical effect of salt on the reaction is negligible compared to its structural effect.

  15. Steam generator tube failures: experience with water-cooled nuclear power reactors during 1976

    International Nuclear Information System (INIS)

    Tatone, O.S.; Pathania, R.S.

    1978-02-01

    A survey was conducted of experience with steam generator tubes at nuclear power stations during 1976. Failures were reported at 25 out of 68 water-cooled reactors. The causes of these failures and the repair and inspection procedures designed to cope with them are summarized. Examination of the data indicates that corrosion was the major cause of steam generator tube failures. Improvements are needed in steam generator design, condenser integrity and secondary water chemistry control. (author)

  16. Contamination levels of domestic water sources in Maiduguri ...

    African Journals Online (AJOL)

    The study examines the levels of contamination of domestic water sources in Maiduguri Metropolis area of Borno State based on their physicochemical and bacteriological properties. It was informed by the global concern on good drinking water quality which is an indicator of development level; hence the focus on domestic ...

  17. CONTRIBUTION TO INDOOR OZONE LEVELS OF AN OZONE GENERATOR

    Science.gov (United States)

    This report gives results of a study of a commonly used commercially available ozone generator, undertaken to determine its impact on indoor ozone levels. xperiment were conducted in a typical mechanically ventilated office and in a test house. he generated ozone and the in-room ...

  18. Implications of small water leak reactions on sodium heated steam generator design

    Energy Technology Data Exchange (ETDEWEB)

    Smedley, J A

    1975-07-01

    Various types of sodium water reactions have been looked on as possibly causing hazard conditions in sodium heated steam generator units ranging from the very improbable boiler tube double ended guillotine fracture to the almost certain occurrence of micro-leaks. Within this range small water leaks reactions have attracted particular interest and the present paper looks at the principles of associating the reactions with detection and protection systems for Commercial Fast Reactors. A method is developed for assessing whether adequate protection has been provided against the effects of small water leak reactions in a steam generator unit. (author)

  19. Effects of tritiated water ingestion on mice: II. Damage at cellular vis-a-vis subcellular level monitored up to four generations

    International Nuclear Information System (INIS)

    Srivastava, P.N.; Sharan, R.N.; Pozzi, L.

    1983-01-01

    Damage at cellular level is measured using colony forming units in spleen (CFU-S) technique while that at subcellular level by DNA unwinding technique. The damage is monitored up to four generations in Swiss albino mice. The results show drastically reduced colony forming ability in mice bone marrow cells (BMC). On plotting survival fractions (percent of control) for BMC against generations of mice, the plateau is found around 50% survival. The role of DNA in colony forming ability of BMC is tested. The results indicate that, at least, initial impairment of colony ability is not DNA dependent but related to some other factor(s)

  20. Water Hardness Level and ItAND#8217;s Health Effects

    Directory of Open Access Journals (Sweden)

    Necmettin Kocak

    2011-04-01

    Full Text Available Water hardness is a term used to define the number of ions contained in the water, especially quantity sulphate, carbonate salts of calcium and magnesium. This characteristis of water is a important quality in it’s use as drinking water, industrial water and service water. The temporary hardness level of water cames from bicarbonate salts of calcium and magnesium whereas chloride, sulphate, nitrate, phosphate, silicate salts of calcium and magnesium. In order to indicate the hardness level of water samples French Hardness Level is used in our country. There is a larger amounth of calcium and magnesium salts in hard water samples. These minerals have very important functions in the human body. In this study, the importance of hard water in terms of human health has been assessed under light of current information. The studies about the preventive role of hard water in cardiovascular diseases, cerebrovascular diseases, stroke and many types of cancer areviewed. These studies Express that higher levels of calcium and magnesium hard water provide a higher reduction in these disease. Water, which must be consumed as 2 liters per dayis very important for human life. Hard water contains a lot of the minerals that must be taker daily, especially calcium and magnesium. It’s advised that water for consumption to have medium hardness. The hardness level of water is an aesthetic quality. Thus, in populations having a taste for soft water, the effort of individuals to softer the network water provided by municipalities using different equipments, in addition to their preference of soft water in plastic or glass bottles for consumption could imply lack of benefit of hard water for population health and also bring out some risks in terms of water hygiene. [TAF Prev Med Bull 2011; 10(2.000: 187-192

  1. Sodium/water reactions in steam generators of liquid metal fast breeder reactors

    International Nuclear Information System (INIS)

    Hori, M.

    1980-01-01

    The status of the research and development on sodium/water reactions resulting from the leakage of water into sodium in LMFBR steam generators is reviewed. The importance of sodium/water reaction phenomena in the design and operation of steam generators is discussed. The effects of sodium/water reactions are evaluated and methods of protection against these phenomena are surveyed. The products of chemical reactions between sodium and water under steam generator conditions are H 2 , NaOH, Na 2 O and NaH. Together with the temperature rise due to the associated exothermic reaction, these reaction products cause effects such as self-wastage, single- and multi-target wastage, and rapid pressure increase, depending on the size of the leak hole or the magnitude of leak rate. As for the wastage phenomena of small leaks, the effects of various factors have been studied and experimental correlations, as well as some theoretical work, have been performed. To investigate the pressure phenomena of a large leak, large-scale tests have been conducted by various organizations, and the computer codes to analyse these phenomena have been developed and verified by experiments. In the design of steam generators, an initial failure up to a hypothetical double-ended guillotine rupture of a single heat transfer tube is widely used as the design basis leak. Protection systems for LMFBR plants consist of leak detection devices, leak termination devices, and reaction pressure relief devices. From analyses based on research and development activities, as well as from experience with leaks in steam generator test loops and reactor plants, it has been confirmed that protection systems can satisfactorily be designed to accommodate leak incidents in LMFBR plants. (author)

  2. Effects of shutdown chemistry on steam generator radiation levels at Point Beach Unit 2. Interim report

    International Nuclear Information System (INIS)

    Kormuth, J.W.

    1982-05-01

    A refueling shutdown chemistry test was conducted at a PWR, Point Beach Unit 2. The objective was to yield reactor coolant chemistry data during the cooldown/shutdown process which might establish a relationship between shutdown chemistry and its effects on steam generator radiation fields. Of particular concern were the effects of the presence of hydrogen in the coolant as contrasted to an oxygenated coolant. Analysis of reactor coolant samples showed a rapid soluble release (spike) in Co-58, Co-60, and nickel caused by oxygenation of the coolant. The measurement of radioisotope specific activities indicates that the material undergoing dissolution during the shutdown originated from different sources which had varying histories of activation. The test program developed no data which would support theories that oxygenation of the coolant while the steam generators are full of water contributes to increased steam generator radiation levels

  3. Effects of electrolysis time and electric potential on chlorine generation of electrolyzed deep ocean water.

    Science.gov (United States)

    Hsu, Guoo-Shyng Wang; Lu, Yi-Fa; Hsu, Shun-Yao

    2017-10-01

    Electrolyzed water is a sustainable disinfectant, which can comply with food safety regulations and is environmentally friendly. A two-factor central composite design was adopted for studying the effects of electrolysis time and electric potential on the chlorine generation efficiency of electrolyzed deep ocean water (DOW). DOW was electrolyzed in a glass electrolyzing cell equipped with platinum-plated titanium anode and cathode. The results showed that chlorine concentration reached maximal level in the batch process. Prolonged electrolysis reduced chlorine concentration in the electrolyte and was detrimental to electrolysis efficiency, especially under high electric potential conditions. Therefore, the optimal choice of electrolysis time depends on the electrolyzable chloride in DOW and cell potential adopted for electrolysis. The higher the electric potential, the faster the chlorine level reaches its maximum, but the lower the electric efficiency will be. Copyright © 2016. Published by Elsevier B.V.

  4. Energy-Water Nexus Relevant to Baseload Electricity Source Including Mini/Micro Hydropower Generation

    Science.gov (United States)

    Fujii, M.; Tanabe, S.; Yamada, M.

    2014-12-01

    Water, food and energy is three sacred treasures that are necessary for human beings. However, recent factors such as population growth and rapid increase in energy consumption have generated conflicting cases between water and energy. For example, there exist conflicts caused by enhanced energy use, such as between hydropower generation and riverine ecosystems and service water, between shale gas and ground water, between geothermal and hot spring water. This study aims to provide quantitative guidelines necessary for capacity building among various stakeholders to minimize water-energy conflicts in enhancing energy use. Among various kinds of renewable energy sources, we target baseload sources, especially focusing on renewable energy of which installation is required socially not only to reduce CO2 and other greenhouse gas emissions but to stimulate local economy. Such renewable energy sources include micro/mini hydropower and geothermal. Three municipalities in Japan, Beppu City, Obama City and Otsuchi Town are selected as primary sites of this study. Based on the calculated potential supply and demand of micro/mini hydropower generation in Beppu City, for example, we estimate the electricity of tens through hundreds of households is covered by installing new micro/mini hydropower generation plants along each river. However, the result is based on the existing infrastructures such as roads and electric lines. This means that more potentials are expected if the local society chooses options that enhance the infrastructures to increase micro/mini hydropower generation plants. In addition, further capacity building in the local society is necessary. In Japan, for example, regulations by the river law and irrigation right restrict new entry by actors to the river. Possible influences to riverine ecosystems in installing new micro/mini hydropower generation plants should also be well taken into account. Deregulation of the existing laws relevant to rivers and

  5. Evaluating changes to reservoir rule curves using historical water-level data

    Science.gov (United States)

    Mower, Ethan; Miranda, Leandro E.

    2013-01-01

    Flood control reservoirs are typically managed through rule curves (i.e. target water levels) which control the storage and release timing of flood waters. Changes to rule curves are often contemplated and requested by various user groups and management agencies with no information available about the actual flood risk of such requests. Methods of estimating flood risk in reservoirs are not easily available to those unfamiliar with hydrological models that track water movement through a river basin. We developed a quantile regression model that uses readily available daily water-level data to estimate risk of spilling. Our model provided a relatively simple process for estimating the maximum applicable water level under a specific flood risk for any day of the year. This water level represents an upper-limit umbrella under which water levels can be operated in a variety of ways. Our model allows the visualization of water-level management under a user-specified flood risk and provides a framework for incorporating the effect of a changing environment on water-level management in reservoirs, but is not designed to replace existing hydrological models. The model can improve communication and collaboration among agencies responsible for managing natural resources dependent on reservoir water levels.

  6. Reading Ground Water Levels with a Smartphone

    Science.gov (United States)

    van Overloop, Peter-Jules

    2015-04-01

    Most ground water levels in the world are measured manually. It requires employees of water management organizations to visit sites in the field and execute a measurement procedure that requires special tools and training. Once the measurement is done, the value is jotted down in a notebook and later, at the office, entered in a computer system. This procedure is slow and prone to human errors. A new development is the introduction of modern Information and Communication Technology to support this task and make it more efficient. Two innovations are introduced to measure and immediately store ground water levels. The first method is a measuring tape that gives a sound and light when it just touches the water in combination with an app on a smartphone with which a picture needs to be taken from the measuring tape. Using dedicated pattern recognition algorithms, the depth is read on the tape and it is verified if the light is on. The second method estimates the depth using a sound from the smartphone that is sent into the borehole and records the reflecting waves in the pipe. Both methods use gps-localization of the smartphone to store the depths in the right location in the central database, making the monitoring of ground water levels a real-time process that eliminates human errors.

  7. The effect of plutonium dioxide water surface coverage on the generation of hydrogen and oxygen

    Energy Technology Data Exchange (ETDEWEB)

    Veirs, Douglas K. [Los Alamos National Laboratory; Berg, John M. [Los Alamos National Laboratory; Crowder, Mark L. [Savannah River National Laboratory

    2012-06-20

    The conditions for the production of oxygen during radiolysis of water adsorbed onto plutonium dioxide powder are discussed. Studies in the literature investigating the radiolysis of water show that both oxygen and hydrogen can be generated from water adsorbed on high-purity plutonium dioxide powder. These studies indicate that there is a threshold in the amount of water below which oxygen is not generated. The threshold is associated with the number of monolayers of adsorbed water and is shown to occur at approximately two monolayers of molecularly adsorbed water. Material in equilibrium with 50% relative humidity (RH) will be at the threshold for oxygen generation. Using two monolayers of molecularly adsorbed water as the threshold for oxygen production, the total pressure under various conditions is calculated assuming stoichiometric production of hydrogen and oxygen. The specific surface area of the oxide has a strong effect on the final partial pressure. The specific surface areas resulting in the highest pressures within a 3013 container are evaluated. The potential for oxygen generation is mitigated by reduced relative humidity, and hence moisture adsorption, at the oxide surface which occurs if the oxide is warmer than the ambient air. The potential for oxygen generation approaches zero as the temperature difference between the ambient air and the material approaches 6 C.

  8. Co-seismic response of water level in the Jingle well (China) associated with the Gorkha Nepal (Mw 7.8) earthquake

    Science.gov (United States)

    He, Anhua; Fan, Xuefang; Zhao, Gang; Liu, Yang; Singh, Ramesh P.; Hu, Yuliang

    2017-09-01

    Changes in co-seismic water levels associated with the Gorkha Nepal earthquake (25 April 2015, Mw 7.8) were recorded in the Jingle well in Shanxi Province China (longitude E112.03°, latitude N38.35°, about 2769 km from epicenter). Based on the observed water levels, we clearly identified signals relating to P, S and surface waves. However, the water temperature recorded at a depth of 350 m shows no co-seismic changes. A spectrum analysis of co-seismic variations of water level shows that the oscillation frequency and amplitude of water level in the borehole are determined by the natural frequency of the borehole, which is not associated with the propagation of seismic waves. The borehole-aquifer system shows a large amplification associated with ground vibrations generated by earthquakes. Considering the local hydro-geological map and the temperature gradient of the Jingle well, a large volume ;groundwater reservoir; model can be used to explain these processes. Due to seismic wave propagation, the volume of a well-confined aquifer expands and contracts forming fractures that change the water flow. In the well-confined aquifer, water levels oscillate simultaneously with high amplitude ground shaking during earthquakes. However, the water in the center of the ;underground reservoir; remains relatively stationary, without any changes in the water temperature. In addition, a possible precursor wave is recorded in the water level at the Jingle well prior to the Gorkha earthquake.

  9. Nuclide, metal and non metal levels in percolated water from soils fertilized with phosphogypsum

    International Nuclear Information System (INIS)

    Silva, Camilla Bof; Knupp, Eliana Aparecida Nonato; Palmieri, Helena E.L.; Jacomino, Vanusa Maria Feliciano; Taddei, Maria Helena; Ciqueira, Maria Celia

    2009-01-01

    Systematic generation of residues is more and more worrying in today.s world; adequate storage and reutilization are of great importance. Since generation of residues has become impossible to avoid, the possibility of reuse must be studied and researched. An example of these residues is phosphogypsum, which is generated in phosphoric acid production at the rate of around 4.8 tons for each ton of phosphoric acid produced. Many studies seek to reuse phosphogypsum in agriculture as a source of calcium and sulfur, potassium or aluminum, especially in soils from Brazil's cerrado regions. Though phosphogypsum is mainly composed of dehydrated calcium sulfate, it can have high levels of heavy metals, non metals (As and Se), fluorides and natural radionuclides. Thus, its uncontrolled use as a soil conditioner can lead to contamination of underground water. (author)

  10. Voyageurs National Park: Water-level regulation and effects on water quality and aquatic biology

    Science.gov (United States)

    Christensen, Victoria G.; Maki, Ryan P.; LeDuc, Jaime F.

    2018-01-01

    Following dam installations in the remote Rainy Lake Basin during the early 1900s, water-level fluctuations were considered extreme (1914–1949) compared to more natural conditions. In 1949, the International Joint Commission (IJC), which sets rules governing dam operation on waters shared by the United States and Canada, established the first rule curves to regulate water levels on these waterbodies. However, rule curves established prior to 2000 were determined to be detrimental to the ecosystem. Therefore, the IJC implemented an order in 2000 to change rule curves and to restore a more natural water regime. After 2000, measured chlorophyll-a concentrations in the two most eutrophic water bodies decreased whereas concentrations in oligotrophic lakes did not show significant water-quality differences. Fish mercury data were inconclusive, due to the variation in water levels and fish mercury concentrations, but can be used by the IJC as part of a long term data set.

  11. Some environmental effects of emissions from CANDU nuclear generating stations and heavy water plants

    International Nuclear Information System (INIS)

    Effer, W.R.

    Non-radioactive releases during normal operation of Ontario Hydro's nuclear generating stations and heavy water plants are summarized and related to existing regulations and guidelines. Low-grade heat in the circulating cooling water discharge is the most important of the non-radioactive effluents. Some of the hydrological, biological and water quality aspects of thermal discharges are discussed in relation to the operation of Ontario Hydro's thermal generating stations on the Great Lakes. Chemical releases to air or water include chlorine, hydrogen sulphide, water treatment plant effluents, oily waste water and sewage lagoon effluents. The significance of the first two of these releases to the environment is reviewed, particularly in relation to Great Lakes water quality and biological concerns. (author)

  12. Diffuse radiation increases global ecosystem-level water-use efficiency

    Science.gov (United States)

    Moffat, A. M.; Reichstein, M.; Cescatti, A.; Knohl, A.; Zaehle, S.

    2012-12-01

    Current environmental changes lead not only to rising atmospheric CO2 levels and air temperature but also to changes in air pollution and thus the light quality of the solar radiation reaching the land-surface. While rising CO2 levels are thought to enhance photosynthesis and closure of stomata, thus leading to relative water savings, the effect of diffuse radiation on transpiration by plants is less clear. It has been speculated that the stimulation of photosynthesis by increased levels of diffuse light may be counteracted by higher transpiration and consequently water depletion and drought stress. Ultimately, in water co-limited systems, the overall effect of diffuse radiation will depend on the sensitivity of canopy transpiration versus photosynthesis to diffuse light, i.e. whether water-use efficiency changes with relative levels of diffuse light. Our study shows that water-use efficiency increases significantly with higher fractions of diffuse light. It uses the ecosystem-atmosphere gas-exchange observations obtained with the eddy covariance method at 29 flux tower sites. In contrast to previous global studies, the analysis is based directly on measurements of diffuse radiation. Its effect on water-use efficiency was derived by analyzing the multivariate response of carbon and water fluxes to radiation and air humidity using a purely empirical approach based on artificial neural networks. We infer that per unit change of diffuse fraction the water-use efficiency increases up to 40% depending on diffuse fraction levels and ecosystem type. Hence, in regions with increasing diffuse radiation positive effects on primary production are expected even under conditions where water is co-limiting productivity.

  13. Towards a better understanding of flood generation and surface water inundation mechanisms using NASA remote sensing data products

    Science.gov (United States)

    Lucey, J.; Reager, J. T., II; Lopez, S. R.

    2017-12-01

    Floods annually cause several weather-related fatalities and financial losses. According to NOAA and FEMA, there were 43 deaths and 18 billion dollars paid out in flood insurance policies during 2005. The goal of this work is to improve flood prediction and flood risk assessment by creating a general model of predictability of extreme runoff generation using various NASA products. Using satellite-based flood inundation observations, we can relate surface water formation processes to changes in other hydrological variables, such as precipitation, storage and soil moisture, and understand how runoff generation response to these forcings is modulated by local topography and land cover. Since it is known that a flood event would cause an abnormal increase in surface water, we examine these underlying physical relationships in comparison with the Dartmouth Flood Observatory archive of historic flood events globally. Using ground water storage observations (GRACE), precipitation (TRMM or GPCP), land use (MODIS), elevation (SRTM) and surface inundation levels (SWAMPS), an assessment of geological and climate conditions can be performed for any location around the world. This project utilizes multiple linear regression analysis evaluating the relationship between surface water inundation, total water storage anomalies and precipitation values, grouped by average slope or land use, to determine their statistical relationships and influences on inundation data. This research demonstrates the potential benefits of using global data products for early flood prediction and will improve our understanding of runoff generation processes.

  14. Reactor water level measuring device

    International Nuclear Information System (INIS)

    Kuroki, Reiji; Asano, Tamotsu.

    1996-01-01

    A condensation vessel is connected to the upper portion of a reactor pressure vessel by way of a pipeline. The lower portion of the condensation vessel is connected to a low pressure side of a differential pressure transmission device by way of a reference leg pipeline. The high pressure side of the differential pressure transmission device is connected to the lower portion of the pressure vessel by way of a pipeline. The condensation vessel is equipped with a temperature sensor. When a temperature of a gas phase portion in the condensation vessel is lowered below a predetermined level, and incondensible gases in the condensation vessel starts to be dissolved in water, signals are sent from the temperature sensor to a control device and a control valve is opened. With such a constitution, CRD driving water flows into the condensation vessel, and water in which gases at the upper portion of the condensation vessel is dissolved flows into the pressure vessel by way of a pipeline. Then, gases dissolved in a reference water column in the reference leg pipeline are eliminated and the value of a reference water pressure does not change even upon abrupt lowering of pressure. (I.N.)

  15. 1-Hydroxypyrene Levels in Blood Samples of Rats After Exposure to Generator Fumes

    Science.gov (United States)

    Ifegwu, Clinton; Igwo-Ezikpe, Miriam N.; Anyakora, Chimezie; Osuntoki, Akinniyi; Oseni, Kafayat A.; Alao, Eragbae O.

    2013-01-01

    Polynuclear Aromatic Hydrocarbons (PAHs) are a major component of fuel generator fumes. Carcinogenicity of these compounds has long been established. In this study, 37 Swiss albino rats were exposed to generator fumes at varied distances for 8 hours per day for a period of 42 days and the level of 1-hydroxypyrene in their blood was evaluated. This study also tried to correlate the level of blood 1-hyroxypyrene with the distance from the source of pollution. Plasma was collected by centrifuging the whole blood sample followed by complete hydrolysis of the conjugated 1-hydroxypyrene glucuronide to yield the analyte of interest, 1-hydroxypyrene, which was achieved using beta glucuronidase. High performance liquid chromatography (HPLC) with UV detector was used to determine the 1-hydroxypyrene concentrations in the blood samples. The mobile phase was water:methanol (12:88 v/v) isocratic run at the flow rate of 1.2 mL/min with CI8 stationary phase at 250 nm. After 42 days of exposure, blood concentration level of 1-hydroxypyrene ranged from 34 μg/mL to 26.29 μg/mL depending on the distance from source of exposure. The control group had no 1-hydroxypyrene in their blood. After the period of exposure, percentage of death correlated with the distance from the source of exposure. Percentage of death ranged from 56% to zero depending on the proximity to source of pollution. PMID:24179393

  16. NOAA Next Generation Radar (NEXRAD) Level 3 Products

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset consists of Level 3 weather radar products collected from Next-Generation Radar (NEXRAD) stations located in the contiguous United States, Alaska,...

  17. Operational water consumption and withdrawal factors for electricity generating technologies: a review of existing literature

    International Nuclear Information System (INIS)

    Macknick, J; Newmark, R; Heath, G; Hallett, K C

    2012-01-01

    This report provides estimates of operational water withdrawal and water consumption factors for electricity generating technologies in the United States. Estimates of water factors were collected from published primary literature and were not modified except for unit conversions. The water factors presented may be useful in modeling and policy analyses where reliable power plant level data are not available. Major findings of the report include: water withdrawal and consumption factors vary greatly across and within fuel technologies, and water factors show greater agreement when organized according to cooling technologies as opposed to fuel technologies; a transition to a less carbon-intensive electricity sector could result in either an increase or a decrease in water use, depending on the choice of technologies and cooling systems employed; concentrating solar power technologies and coal facilities with carbon capture and sequestration capabilities have the highest water consumption values when using a recirculating cooling system; and non-thermal renewables, such as photovoltaics and wind, have the lowest water consumption factors. Improved power plant data and further studies into the water requirements of energy technologies in different climatic regions would facilitate greater resolution in analyses of water impacts of future energy and economic scenarios. This report provides the foundation for conducting water use impact assessments of the power sector while also identifying gaps in data that could guide future research. (letter)

  18. Operational Water Withdrawal and Consumption Factors for Electricity Generation Technology in China—A Literature Review

    Directory of Open Access Journals (Sweden)

    Jinjing Gao

    2018-04-01

    Full Text Available As two indispensable resources for human development, energy and water are closely related. China, as the world’s largest consumer of electricity, is also experiencing very serious water shortages. Understanding the water consumption intensity in various types of electric power production technologies according to China’s national conditions is a prerequisite for understanding the potential impact of electrical power production on water resources. Therefore, following the steps of a meta-analysis, this paper provides a literature review on operational water withdrawal and consumption factors for electricity generation technology in China. We observed that 50% of water consumption for electricity generation was for coal power, whereas there was no research on the water consumption intensity of natural gas power generation, and a shortage of studies on water intake during electrical power production. The average water consumption intensity of hydropower is the largest. The results indicate that compared with other fuel types, hydropower is not a sustainable energy with respect to water conservation, and the study of hydropower applications should be improved in China.

  19. Mapping Water Level Dynamics over Central Congo River Using PALSAR Images, Envisat Altimetry, and Landsat NDVI Data

    Science.gov (United States)

    Kim, D.; Lee, H.; Jung, H. C.; Beighley, E.; Laraque, A.; Tshimanga, R.; Alsdorf, D. E.

    2016-12-01

    Rivers and wetlands are very important for ecological habitats, and it plays a key role in providing a source of greenhouse gases (CO2 and CH4). The floodplains ecosystems depend on the process between the vegetation and flood characteristics. The water level is a prerequisite to an understanding of terrestrial water storage and discharge. Despite the lack of in situ data over the Congo Basin, which is the world's third largest in size ( 3.7 million km2), and second only to the Amazon River in discharge ( 40,500 m3 s-1 annual average between 1902 and 2015 in the main Brazzaville-Kinshasa gauging station), the surface water level dynamics in the wetlands have been successfully estimated using satellite altimetry, backscattering coefficients (σ0) from Synthetic Aperture Radar (SAR) images and, interferometric SAR technique. However, the water level estimation of the Congo River remains poorly quantified due to the sparse orbital spacing of radar altimeters. Hence, we essentially have limited information only over the sparsely distributed the so-called "virtual stations". The backscattering coefficients from SAR images have been successfully used to distinguish different vegetation types, to monitor flood conditions, and to access soil moistures over the wetlands. However, σ0 has not been used to measure the water level changes over the open river because of very week return signal due to specular scattering. In this study, we have discovered that changes in σ0 over the Congo River occur mainly due to the water level changes in the river with the existence of the water plants (macrophytes, emergent plants, and submersed plant), depending on the rising and falling stage inside the depression of the "Cuvette Centrale". We expand the finding into generating the multi-temporal water level maps over the Congo River using PALSAR σ0, Envisat altimetry, and Landsat Normalized Difference Vegetation Index (NDVI) data. We also present preliminary estimates of the river

  20. Market Designs for High Levels of Variable Generation: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Milligan, M.; Holttinen, H.; Kiviluoma, J.; Orths, A.; Lynch, M.; Soder, L.

    2014-10-01

    Variable renewable generation is increasing in penetration in modern power systems, leading to higher variability in the supply and price of electricity as well as lower average spot prices. This raises new challenges, particularly in ensuring sufficient capacity and flexibility from conventional technologies. Because the fixed costs and lifetimes of electricity generation investments are significant, designing markets and regulations that ensure the efficient integration of renewable generation is a significant challenge. This papers reviews the state of play of market designs for high levels of variable generation in the United States and Europe and considers new developments in both regions.

  1. Evaluation of heat transfer tube failure propagation due to sodium-water reaction in steam generator

    International Nuclear Information System (INIS)

    Nei, Hiromichi

    1978-01-01

    An evaluation was made of heat transfer tube failure propagation due to sodium-water reaction wastage in a sodium heated steam generator, by comparing an empirically derived wastage equation with leak detector responses. The experimental data agreed well with the wastage equation even for different values of distance-to-nozzle diameter ratio, though the formula had been based on wastage data obtained for only one given distance. The time taken for failure propagation was estimated for a prototype steam generator, and compared with the responses characteristics of acoustic detectors and level gages. It was found that there exists a range of leak rate between 0.5 and 100 g/sec, where the level gage can play a useful role in leak detection. The acoustic detector can be expected to respond more rapidly than the cover gas pressure gage, if noise is kept below ten times the value observed in an experimental facility, SWAT-2. (auth.)

  2. Power generation and heating performances of integrated system of ammonia–water Kalina–Rankine cycle

    International Nuclear Information System (INIS)

    Zhang, Zhi; Guo, Zhanwei; Chen, Yaping; Wu, Jiafeng; Hua, Junye

    2015-01-01

    Highlights: • Integrated system of ammonia–water Kalina–Rankine cycle (AWKRC) is investigated. • Ammonia–water Rankine cycle is operated for cogenerating room heating-water in winter. • Kalina cycle with higher efficiency is operated for power generation in other seasons. • Power recovery efficiency accounts thermal efficiency and waste heat absorbing ratio. • Heating water with 70 °C and capacity of 55% total reclaimed heat load is cogenerated. - Abstract: An integrated system of ammonia–water Kalina–Rankine cycle (AWKRC) for power generation and heating is introduced. The Kalina cycle has large temperature difference during evaporation and small one during condensation therefore with high thermal efficiency for power generation, while the ammonia–water Rankine cycle has large temperature difference during condensation as well as evaporation, thus it can be adopted to generate heating-water as a by-product in winter. The integrated system is based on the Kalina cycle and converted to the Rankine cycle with a set of valves. The performances of the AWKRC system in different seasons with corresponding cycle loops were studied and analyzed. When the temperatures of waste heat and cooling water are 300 °C and 25 °C respectively, the thermal efficiency and power recovery efficiency of Kalina cycle are 20.9% and 17.4% respectively in the non-heating seasons, while these efficiencies of the ammonia–water Rankine cycle are 17.1% and 13.1% respectively with additional 55.3% heating recovery ratio or with comprehensive efficiency 23.7% higher than that of the Kalina cycle in heating season

  3. Auto Detection For High Level Water Content For Oil Well

    Science.gov (United States)

    Janier, Josefina Barnachea; Jumaludin, Zainul Arifin B.

    2010-06-01

    Auto detection of high level water content for oil well is a system that measures the percentage of water in crude oil. This paper aims to discuss an auto detection system for measuring the content of water level in crude oil which is applicable for offshore and onshore oil operations. Data regarding water level content from wells can be determined by using automation thus, well with high water level can be determined immediately whether to be closed or not from operations. Theoretically the system measures the percentage of two- fluid mixture where the fluids have different electrical conductivities which are water and crude oil. The system made use of grid sensor which is a grid pattern like of horizontal and vertical wires. When water occupies the space at the intersection of vertical and horizontal wires, an electrical signal is detected which proved that water completed the circuit path in the system. The electrical signals are counted whereas the percentage of water is determined from the total electrical signals detected over electrical signals provided. Simulation of the system using the MultiSIM showed that the system provided the desired result.

  4. Severe accident analysis of a steam generator tube rupture accident using MAAP-CANDU to support level 2 PSA for the Point Lepreau Generating Station Refurbishment Project

    Energy Technology Data Exchange (ETDEWEB)

    Petoukhov, S.M.; Brown, M.J. [Canadian Nuclear Laboratories, Chalk River, ON (Canada)

    2015-07-01

    A Level 2 Probabilistic Safety Assessment was performed for the Point Lepreau Generating Station. The MAAP-CANDU code was used to simulate the progression of postulated severe core damage accidents and fission product releases. This paper discusses the results for the reference case of the Steam Generator Tube Rupture initiating event. The reference case, dictated by the Level 2 Probabilistic Safety Assessment, was extreme and assumed most safety-related plant systems were not available: all steam generator feedwater; the emergency water supply; the moderator, shield and shutdown cooling systems; and all stages of emergency core cooling. The reference case also did not credit any post Fukushima lessons or any emergency mitigating equipment. The reference simulation predicted severe core damage beginning at 3.7 h, containment failure at 6.4 h, moderator boil off by 8.2 h, and calandria vessel failure at 42 h. A total release of 5.3% of the initial inventory of radioactive isotopes of Cs, Rb and I was predicted by the end of the simulation (139 h). Almost all noble gas fission products were released to the environment, primarily after the containment failure. No hydrogen/carbon monoxide burning was predicted. (author)

  5. Acoustic Leak Detection under Micro and Small Water Steam Leaks into Sodium for a Protection of the SFR Steam Generator

    International Nuclear Information System (INIS)

    Kim, Tae-Joon; Jeong, Ji-Young; Kim, Jong-Man; Kim, Byung-Ho; Hahn, Do-Hee; Yugay, Valeriy S.

    2008-01-01

    The results of an experimental study of water in a sodium leak noise spectrum formation related with a leak noise attenuation and absorption, and at various rates of water into a sodium leak, smaller than 1.0 g/s, are presented. We focused on studying the micro leak dynamics with an increasing rate of water into sodium owing to a self-development from 0.005 till 0.27 g/s. Conditions and ranges for the existence of bubbling and jetting modes in a water steam outflow into circulating sodium through an injector device, for simulating a defect in a wall of a heat-transmitting tube of a sodium water steam generator were determined. On the basis of the experimental leak noise data the simple dependency of an acoustic signal level from the rate of a micro and small leak at different frequency bands is presented to understand the principal analysis for the development of an acoustic leak detection methodology used in a K- 600 steam generator, with the operational experiences for the noise analysis and measurements in BN-600

  6. Intercomparison of low-level tritium in water

    International Nuclear Information System (INIS)

    Sipka, V.; Zupancic, M.; Hadzisehovic, M.; Bacic, S.; Vukovic, Z.

    1989-01-01

    In 1985 the Section of Isotope Hydrology of the IAEA organized the fourth intercomparison for low-level tritium counting in waters. Four water samples with different 3 H concentration were sent to 85 laboratories willing to participate. The results from the different laboratories were presented in the unified questionnaires and coded. The participation in the intercomparisons for every laboratory doing low-level 3 H measurements in the waters is very important and useful. This is a best way to check the entire procedure and methods of the measurements and the reliability of the standards used. Since our laboratories are doing the natural 3 H concentration measurement in the waters for the environmental control and hydrology reasons it was necessary to take part in this intercomparison. Our standard procedure was applied. The 3 H activity in the samples was measured by liquid scintillation counting after an electrolytic enrichment. The results of our measurements of the four water samples, received from the organizers, are presented on the figures and tables presenting summary of the intercomparison. It is clear that our measurement (procedure and standards) have given satisfactory results (author)

  7. Large-leak sodium-water reaction analysis for steam generators

    International Nuclear Information System (INIS)

    Sakano, K.; Shindo, Y.; Hori, M.

    1975-01-01

    The guillotine rupture of 4 tubes is assumed as a design basis regarding the large-leak sodium-water reaction in the system of the MONJU steam generator. Three kinds of analyses were performed with the view to showing the integrity of the steam generator system on the reaction. The first one is the analysis of the initial pressure spike, assuming the initial guillotine rupture of 1 tube. The analysis was performed by utilizing one-dimensional sphere-cylinder model code SWAC-7 and two-dimensional axisymmetric code PISCES 2DL. The second one is the analysis of the secondary peak pressure and its propagation in the system, assuming the instantaneous guillotine rupture of 4 tubes. The third one is the analysis of the dynamic deformation of the steam generator shell. The integrity of the steam generator system was shown by the analyses. (author)

  8. Large-leak sodium-water reaction analysis for steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Sakano, K; Shindo, Y; Hori, M

    1975-07-01

    The guillotine rupture of 4 tubes is assumed as a design basis regarding the large-leak sodium-water reaction in the system of the MONJU steam generator. Three kinds of analyses were performed with the view to showing the integrity of the steam generator system on the reaction. The first one is the analysis of the initial pressure spike, assuming the initial guillotine rupture of 1 tube. The analysis was performed by utilizing one-dimensional sphere-cylinder model code SWAC-7 and two-dimensional axisymmetric code PISCES 2DL. The second one is the analysis of the secondary peak pressure and its propagation in the system, assuming the instantaneous guillotine rupture of 4 tubes. The third one is the analysis of the dynamic deformation of the steam generator shell. The integrity of the steam generator system was shown by the analyses. (author)

  9. Steam generator for a pressurized-water coolant nuclear reactor

    International Nuclear Information System (INIS)

    Schroeder, H.J.; Berger, W.

    1975-01-01

    A description is given of a steam generator which has a vertical cylindrical housing having a steam output outlet, a horizontal tube sheet closing the lower end of this housing, and an inverted U-shaped tube bundle inside of the housing and having vertical inlet and outlet legs with their ends mounted in the tube sheet. Beneath the tube sheet there are inlet and outlet manifolds for the respective ends of the tube bundle so that pressurized-water coolant from a pressurized-water coolant nuclear reactor can be circulated through the tube bundle

  10. The Evaluation of Steam Generator Level Measurement Model for OPR1000 Using RETRAN-3D

    International Nuclear Information System (INIS)

    Doo Yong Lee; Soon Joon Hong; Byung Chul Lee; Heok Soon Lim

    2006-01-01

    Steam generator level measurement is important factor for plant transient analyses using best estimate thermal hydraulic computer codes since the value of steam generator level is used for steam generator level control system and plant protection system. Because steam generator is in the saturation condition which includes steam and liquid together and is the place that heat exchange occurs from primary side to secondary side, computer codes are hard to calculate steam generator level realistically without appropriate level measurement model. In this paper, we prepare the steam generator models using RETRAN-3D that include geometry models, full range feedwater control system and five types of steam generator level measurement model. Five types of steam generator level measurement model consist of level measurement model using elevation difference in downcomer, 1D level measurement model using fluid mass, 1D level measurement model using fluid volume, 2D level measurement model using power and fluid mass, and 2D level measurement model using power and fluid volume. And we perform the evaluation of the capability of each steam generator level measurement model by simulating the real plant transient condition, the title is 'Reactor Trip by The Failure of The Deaerator Level Control Card of Ulchin Unit 3'. The comparison results between real plant data and RETRAN-3D analyses for each steam generator level measurement model show that 2D level measurement model using power and fluid mass or fluid volume has more realistic prediction capability compared with other level measurement models. (authors)

  11. The steam generating heavy water reactor

    International Nuclear Information System (INIS)

    Middleton, J.E.

    1975-01-01

    A review is presented on the evolution of the SGHWR concept by the United Kingdom Atomic Energy Authority and the production of early commercial designs, together with later development by the Design and Construction Companies. This is followed by a description of the current commercial design. Possible future developments are suggested. The many advantageous features of the concept are mentioned with a view to supporting optimism for the future of the system. Headings include the following: safety criteria and risk assessment; emergency core cooling system design and development; protective systems; reactor coolant system; reactivity control; off-load refuelling; pressure containment; 'fence' header coolant circuit design; feed water injection; continuous spray cooling; low pressure cooling systems for residual heat removal during refuelling; high pressure cooling system for guaranteed feed water supply; auxiliary systems; structural materials; calandria and neutron shields; fuel element development; alternative loop circuit design; future developments (use of hydraulic diodes to provide a substantial reverse flow resistance by the generation of a vortex; multi-drum and multi-pump schemes; refuelling alternatives; coolant circuit inversion; use of superheat channels). (U.K.)

  12. Type GQS-1 high pressure steam manifold water level monitoring system

    International Nuclear Information System (INIS)

    Li Nianzu; Li Beicheng; Jia Shengming

    1993-10-01

    The GQS-1 high pressure steam manifold water level monitoring system is an advanced nuclear gauge that is suitable for on-line detecting and monitor in high pressure steam manifold water level. The physical variable of water level is transformed into electrical pulses by the nuclear sensor. A computer is equipped for data acquisition, analysis and processing and the results are displayed on a 14 inch color monitor. In addition, a 4 ∼ 20 mA output current is used for the recording and regulation of water level. The main application of this gauge is for on-line measurement of high pressure steam manifold water level in fossil-fired power plant and other industries

  13. Earthquake-induced water-level fluctuations at Yucca Mountain, Nevada, June 1992

    International Nuclear Information System (INIS)

    O'Brien, G.M.

    1993-01-01

    This report presents earthquake-induced water-level and fluid-pressure data for wells in the Yucca Mountain area, Nevada, during June 1992. Three earthquakes occurred which caused significant water-level and fluid-pressure responses in wells. Wells USW H-5 and USW H-6 are continuously monitored to detect short-term responses caused by earthquakes. Two wells, monitored hourly, had significant, longer-term responses in water level following the earthquakes. On June 28, 1992, a 7.5-magnitude earthquake occurred near Landers, California causing an estimated maximum water-level change of 90 centimeters in well USW H-5. Three hours later a 6.6-magnitude earthquake occurred near Big Bear Lake, California; the maximum water-level fluctuation was 20 centimeters in well USW H-5. A 5.6-magnitude earthquake occurred at Little Skull Mountain, Nevada, on June 29, approximately 23 kilometers from Yucca Mountain. The maximum estimated short-term water-level fluctuation from the Little Skull Mountain earthquake was 40 centimeters in well USW H-5. The water level in well UE-25p number-sign 1, monitored hourly, decreased approximately 50 centimeters over 3 days following the Little Skull Mountain earthquake. The water level in UE-25p number-sign 1 returned to pre-earthquake levels in approximately 6 months. The water level in the lower interval of well USW H-3 increased 28 centimeters following the Little Skull Mountain earthquake. The Landers and Little Skull Mountain earthquakes caused responses in 17 intervals of 14 hourly monitored wells, however, most responses were small and of short duration. For several days following the major earthquakes, many smaller magnitude aftershocks occurred causing measurable responses in the continuously monitored wells

  14. Development of fuzzy algorithm with learning function for nuclear steam generator level control

    International Nuclear Information System (INIS)

    Park, Gee Yong; Seong, Poong Hyun

    1993-01-01

    A fuzzy algorithm with learning function is applied to the steam generator level control of nuclear power plant. This algorithm can make its rule base and membership functions suited for steam generator level control by use of the data obtained from the control actions of a skilled operator or of other controllers (i.e., PID controller). The rule base of fuzzy controller with learning function is divided into two parts. One part of the rule base is provided to level control of steam generator at low power level (0 % - 30 % of full power) and the other to level control at high power level (30 % - 100 % of full power). Response time of steam generator level control at low power range with this rule base is shown to be shorter than that of fuzzy controller with direct inference. (Author)

  15. An integrated assessment of energy-water nexus at the state level in the United States: Projections and analyses under different scenarios through 2095

    Science.gov (United States)

    Liu, L.; Patel, P. L.; Hejazi, M. I.; Kyle, P.; Davies, E. G.; Zhou, Y.; Clarke, L.; Edmonds, J.

    2013-12-01

    Water withdrawals for thermoelectric power plants account for approximately half of the total water use in the United States. With growing electricity demands in the future and limited water supplies in many water-scarce states in the U.S., grasping the trade-off between energy and water requires an integrated modeling approach that can capture the interactions among energy, water availability, climate, technology, and economic factors at various scales. In this study, the Global Change Assessment Model (GCAM), a technologically-detailed integrated model of the economy, energy, agriculture and land use, water, and climate systems, with 14 geopolitical regions that are further dissaggregated into up to 18 agro-ecological zones, was extended to model the electricity and water systems at the state level in the U.S. More specifically, GCAM was employed to estimate future state-level electricity generation and demands, and the associated water withdrawals and consumptions under a set of six scenarios with extensive levels of details on generation fuel portfolio, cooling technology mix, and water use intensities. The state-level estimates were compared against available inventories where good agreement was achieved on national and regional levels. We then explored the electric-sector water use up to 2095, focusing on implications from: 1) socioeconomics and growing demands, 2) the adoption of climate mitigation policy (e.g., RCP4.5 W/m2 vs. a reference scenario), 3) the transition of cooling systems, 4) constraints on electricity trading across states (full trading vs. limited trading), and 5) the adoption of water saving technologies. Overall, the fast retirement of once-through cooling, together with the gradual transition from fossil fuels dominant to a mixture of different fuels, accelerate the decline of water withdrawals and correspondingly compensate consumptive water use. Results reveal that U.S. electricity generation expands significantly as population grows

  16. Life cycle water use for electricity generation: a review and harmonization of literature estimates

    International Nuclear Information System (INIS)

    Meldrum, J; Nettles-Anderson, S; Heath, G; Macknick, J

    2013-01-01

    This article provides consolidated estimates of water withdrawal and water consumption for the full life cycle of selected electricity generating technologies, which includes component manufacturing, fuel acquisition, processing, and transport, and power plant operation and decommissioning. Estimates were gathered through a broad search of publicly available sources, screened for quality and relevance, and harmonized for methodological differences. Published estimates vary substantially, due in part to differences in production pathways, in defined boundaries, and in performance parameters. Despite limitations to available data, we find that: water used for cooling of thermoelectric power plants dominates the life cycle water use in most cases; the coal, natural gas, and nuclear fuel cycles require substantial water per megawatt-hour in most cases; and, a substantial proportion of life cycle water use per megawatt-hour is required for the manufacturing and construction of concentrating solar, geothermal, photovoltaic, and wind power facilities. On the basis of the best available evidence for the evaluated technologies, total life cycle water use appears lowest for electricity generated by photovoltaics and wind, and highest for thermoelectric generation technologies. This report provides the foundation for conducting water use impact assessments of the power sector while also identifying gaps in data that could guide future research. (letter)

  17. Separating decadal global water cycle variability from sea level rise.

    Science.gov (United States)

    Hamlington, B D; Reager, J T; Lo, M-H; Karnauskas, K B; Leben, R R

    2017-04-20

    Under a warming climate, amplification of the water cycle and changes in precipitation patterns over land are expected to occur, subsequently impacting the terrestrial water balance. On global scales, such changes in terrestrial water storage (TWS) will be reflected in the water contained in the ocean and can manifest as global sea level variations. Naturally occurring climate-driven TWS variability can temporarily obscure the long-term trend in sea level rise, in addition to modulating the impacts of sea level rise through natural periodic undulation in regional and global sea level. The internal variability of the global water cycle, therefore, confounds both the detection and attribution of sea level rise. Here, we use a suite of observations to quantify and map the contribution of TWS variability to sea level variability on decadal timescales. In particular, we find that decadal sea level variability centered in the Pacific Ocean is closely tied to low frequency variability of TWS in key areas across the globe. The unambiguous identification and clean separation of this component of variability is the missing step in uncovering the anthropogenic trend in sea level and understanding the potential for low-frequency modulation of future TWS impacts including flooding and drought.

  18. Rapid Generation of Superheated Steam Using a Water-containing Porous Material

    Science.gov (United States)

    Mori, Shoji; Okuyama, Kunito

    Heat treatment by superheated steam has been utilized in several industrial fields including sterilization, desiccation, and cooking. In particular, cooking by superheated steam is receiving increased attention because it has advantages of reducing the salt and fat contents in foods as well as suppressing the oxidation of vitamin C and fat. In this application, quick startup and cut-off responses are required. Most electrically energized steam generators require a relatively long time to generate superheated steam due to the large heat capacities of the water in container and of the heater. Zhao and Liao (2002) introduced a novel process for rapid vaporization of subcooled liquid, in which a low-thermal-conductivity porous wick containing water is heated by a downward-facing grooved heating block in contact with the upper surface of the wick structure. They showed that saturated steam is generated within approximately 30 seconds from room-temperature water at a heat flux 41.2 kW⁄m2. In order to quickly generate superheated steam of approximately 300°C, which is required for cooking, the heat capacity of the heater should be as small as possible and the imposed heat flux should be so high enough that the porous wick is able to dry out in the vicinity of the contact with the heater and that the resulting heater temperature becomes much higher than the saturation temperature. The present paper proposes a simple structured generator to quickly produce superheated steam. Only a fine wire heater is contacted spirally on the inside wall in a hollow porous material. The start-up, cut-off responses and the rate of energy conversion for input power are investigated experimentally. Superheated steam of 300°C is produced in approximately 19 seconds from room-temperature water for an input power of 300 W. The maximum rate of energy conversion in the steady state is approximately 0.9.

  19. Optimization of steam generators of NPP with WWER in operation with variable load

    Science.gov (United States)

    Parchevskii, V. M.; Shchederkina, T. E.; Gur'yanova, V. V.

    2017-11-01

    The report addresses the issue of the optimal water level in the horizontal steam generators of NPP with WWER. On the one hand, the level needs to be kept at the lower limit of the allowable range, as gravity separation, steam will have the least humidity and the turbine will operate with higher efficiency. On the other hand, the higher the level, the greater the supply of water in the steam generator, and therefore the higher the security level of the unit, because when accidents involving loss of cooling of the reactor core, the water in the steam generators, can be used for cooling. To quantitatively compare the damage from higher level to the benefit of improving the safety was assessed of the cost of one cubic meter of water in the steam generators, the formulated objective function of optimal levels control. This was used two-dimensional separation characteristics of steam generators. It is demonstrated that the security significantly shifts the optimal values of the levels toward the higher values, and this bias is greater the lower the load unit.

  20. Nitrates in drinking water and methemoglobin levels in pregnancy: a longitudinal study.

    Science.gov (United States)

    Manassaram, Deana M; Backer, Lorraine C; Messing, Rita; Fleming, Lora E; Luke, Barbara; Monteilh, Carolyn P

    2010-10-14

    Private water systems are more likely to have nitrate levels above the maximum contaminant level (MCL). Pregnant women are considered vulnerable to the effects of exposure to high levels of nitrates in drinking water due to their altered physiological states. The level of methemoglobin in the blood is the biomarker often used in research for assessing exposure to nitrates. The objective of this study was to assess methemoglobin levels and examine how various factors affected methemoglobin levels during pregnancy. We also examined whether differences in water use practices existed among pregnant women based on household drinking water source of private vs. public supply. A longitudinal study of 357 pregnant women was conducted. Longitudinal regression models were used to examine changes and predictors of the change in methemoglobin levels over the period of gestation. Pregnant women showed a decrease in methemoglobin levels with increasing gestation although nitrate intake from tap water among pregnant women around 36 weeks gestation (β = 0.046, p = 0.986). Four women had tap water nitrate levels above the MCL of 10 mg/L. At enrollment, a greater proportion of women who reported using water treatment devices were private wells users (66%) compared to public system users (46%) (p nitrate from water (p nitrate levels primarily below the MCL for drinking water were unlikely to show methemoglobin levels above the physiologic normal. Water use practices such as the use of treatment devices to remove nitrates varied according to water source and should be considered in the assessment of exposure to nitrates in future studies.

  1. Linking levels of societal and ecosystems metabolism of water in a Mediterranean watershed

    Science.gov (United States)

    Cabello, V.

    2014-12-01

    Water resources degradation is a complex environmental problem that involves multiple dimensions and scales of analysis. The Socio-Ecological Systems Water Metabolism has been proposed as a general holistic framework to deal with integrated analysis of water use sustainability (Madrid and Giampietro 2014). The innovation of the approach is that it sets the research focus beyond the classical supply-demand modeling to societal integrity and ecosystems integrity. To do so, it integrates quantitative grammars of water use (relating water exchange to societal and ecosystems organization) and qualitative methods (discourse analysis). This work presents the first case study focused at a river basin extent: the Upper Andarax, in South-East Spain. Water metabolism is indicated at multiple levels for ecosystems and society. To deal with the interfaces among them, relational indicators of water exploitation, water use and impact over ecosystems are used alongside policies and narratives analysis.While being a rather not intensively exploited river basin (year Water Exploitation Index~0.3 blue water,~0.15 green water), impacts over water bodies are yet important (periodic aquifer overdraft, biological degradation of the river) especially during dry season. Perceived mayor problems of water sustainability are generated by the not integration of different policies at European, national and regional scales: while the water authority establishes a compulsory reduction over water withdrawal to attend environmental flows, agricultural markets force to raise productivity increasing water demands. Adaptation strategies are divided among irrigation efficiency improvement and a reorientation of the economy towards touristic activities. Both of them entail specific trade-offs to be deemed. Aquifer-river interactions and climate change impacts are yet mayor research challenges.

  2. A improved tidal method without water level

    Science.gov (United States)

    Luo, xiaowen

    2017-04-01

    Now most tide are obtained use water Level and pressure type water gage, but it is difficult to install them and reading is in low accuracy in this method . In view of above-mentioned facts, In order to improve tide accuracy, A improved method is introduced.sea level is obtained in given time using high-precision GNSS buoy combined instantaneous position from pressure gage. two steps are as following, (1) the GNSS time service is used as the source of synchronization reference in tidal measurement; (2) centimeter-level sea surface positions are obtained in real time using difference GNSS The improved method used in seafloor topography survey,in 145 cross points, 95% meet the requirements of the Hydrographic survey specification. It is effective method to obtain higher accuracy tide.

  3. Shockwave generation by a semiconductor bridge operation in water

    Energy Technology Data Exchange (ETDEWEB)

    Zvulun, E.; Toker, G.; Gurovich, V. Tz.; Krasik, Ya. E. [Physics Department, Technion, Haifa 32000 (Israel)

    2014-05-28

    A semiconductor bridge (SCB) is a silicon device, used in explosive systems as the electrical initiator element. In recent years, SCB plasma has been extensively studied, both electrically and using fast photography and spectroscopic imaging. However, the value of the pressure buildup at the bridge remains unknown. In this study, we operated SCB devices in water and, using shadow imaging and reference beam interferometry, obtained the velocity of the shock wave propagation and distribution of the density of water. These results, together with a self-similar hydrodynamic model, were used to calculate the pressure generated by the exploding SCB. In addition, the results obtained showed that the energy of the water flow exceeds significantly the energy deposited into the exploded SCB. The latter can be explained by the combustion of the aluminum and silicon atoms released in water, which acts as an oxidizing medium.

  4. The exposure of Sydney (Australia) to earthquake-generated tsunamis, storms and sea level rise: a probabilistic multi-hazard approach.

    Science.gov (United States)

    Dall'Osso, F; Dominey-Howes, D; Moore, C; Summerhayes, S; Withycombe, G

    2014-12-10

    Approximately 85% of Australia's population live along the coastal fringe, an area with high exposure to extreme inundations such as tsunamis. However, to date, no Probabilistic Tsunami Hazard Assessments (PTHA) that include inundation have been published for Australia. This limits the development of appropriate risk reduction measures by decision and policy makers. We describe our PTHA undertaken for the Sydney metropolitan area. Using the NOAA NCTR model MOST (Method for Splitting Tsunamis), we simulate 36 earthquake-generated tsunamis with annual probabilities of 1:100, 1:1,000 and 1:10,000, occurring under present and future predicted sea level conditions. For each tsunami scenario we generate a high-resolution inundation map of the maximum water level and flow velocity, and we calculate the exposure of buildings and critical infrastructure. Results indicate that exposure to earthquake-generated tsunamis is relatively low for present events, but increases significantly with higher sea level conditions. The probabilistic approach allowed us to undertake a comparison with an existing storm surge hazard assessment. Interestingly, the exposure to all the simulated tsunamis is significantly lower than that for the 1:100 storm surge scenarios, under the same initial sea level conditions. The results have significant implications for multi-risk and emergency management in Sydney.

  5. Comparison of 1972 and 1996 water levels in the Goleta central ground-water subbasin, Santa Barbara County, California

    Science.gov (United States)

    Kaehler, Charles A.; Pratt, David A.; Paybins, Katherine S.

    1997-01-01

    Ground-water levels for 1996 were compared with 1972 water levels to determine if a "drought buffer" currently exists. The drought buffer was defined previously, in a litigated settlement involving the Goleta Water District, as the 1972 water level in the Central ground-water subbasin. To make this deter mination, a network of 15 well sites was selected, water levels were measured monthly from April through December 1996, and the 1996 water-level data were compared with1972 data. The study was done in cooperation with the Goleta Water District. The 1972-1996 water-level-altitude changes for corresponding months of the comparison years were averaged for each network well. These averaged changes ranged from a rise of 9.4 ft for well 2N2 to a decline of 45.0 ft for well 8K8. The results of the comparison indicate a rise in water level at 1 site (well 2N2) and a decline at 14 sites. The mean of the 14 negative average values was a decline of 24.0 ft. The altitude of the bottom of well 2N2 was higher than the bottom altitudes at the other network sites, and this well is located a few feet from a fault that acts as a hydrologic barrier. The results of the water-level comparison for the Central subbasin were influenced to some unknown degree by the areal distribution of the set of wells selected for the network and the vertical dis tribution of the perforated intervals of the wells. For this reason, the mean water-level change--a decline of 21.8 ft--calculated from the averages of the month-to-month changes for the 15 network sites, should be used with caution. In addition, the number of usable individual monthly comparison measurements available for an individual site ranged from one to nine, and averaged six. Therefore, a weighted mean of the monthly averages was calculated on the basis of the number of comparison measurements available for each site. The weighted mean is a decline of 20.9 ft. All Central subbasin wells that were idle (that is, were not being pumped

  6. A Microdrop Generator for the Calibration of a Water Vapor Isotope Ratio Spectrometer

    NARCIS (Netherlands)

    Iannone, Rosario Q.; Romanini, Daniele; Kassi, Samir; Meijer, Harro A. J.; Kerstel, Erik R. Th.

    A microdrop generator is described that produces water vapor with a known isotopic composition and volume mixing ratio for the calibration of a near-infrared diode laser water isotope ratio spectrometer. The spectrometer is designed to measure in situ the water vapor deuterium and oxygen ((17)O and

  7. Dye-Sensitized Photocatalytic Water Splitting and Sacrificial Hydrogen Generation: Current Status and Future Prospects

    Directory of Open Access Journals (Sweden)

    Pankaj Chowdhury

    2017-05-01

    Full Text Available Today, global warming and green energy are important topics of discussion for every intellectual gathering all over the world. The only sustainable solution to these problems is the use of solar energy and storing it as hydrogen fuel. Photocatalytic and photo-electrochemical water splitting and sacrificial hydrogen generation show a promise for future energy generation from renewable water and sunlight. This article mainly reviews the current research progress on photocatalytic and photo-electrochemical systems focusing on dye-sensitized overall water splitting and sacrificial hydrogen generation. An overview of significant parameters including dyes, sacrificial agents, modified photocatalysts and co-catalysts are provided. Also, the significance of statistical analysis as an effective tool for a systematic investigation of the effects of different factors and their interactions are explained. Finally, different photocatalytic reactor configurations that are currently in use for water splitting application in laboratory and large scale are discussed.

  8. Detection of steam generator tube leaks in pressurized water reactors

    International Nuclear Information System (INIS)

    Roach, W.H.

    1985-01-01

    This report addresses the early detection of small steam generator tube leaks in pressurized water reactors. It discusses the third, and final, year's work on an NRC-funded project examining diagnostic instrumentation in water reactors. The first two years were broad in coverage, concentrating on anticipatory measurements for detection of potential problems in both pressurized- and boiling-water reactors, with recommendations for areas of further study. One of these areas, the early detection of small steam tube leaks in PWRs, formed the basis of study for the last year of the project. Four tasks are addressed in this study of the detection of steam tube leaks. (1) Determination of which physical parameters indicate the onset of steam generator tube leaks. (2) Establishing performance goals for diagnostic instruments which could be used for early detection of steam generator tube leaks. (3) Defining the diagnostic instrumentation and their location which satisfy Items 1 and 2 above. (4) Assessing the need for diagnostic data processing and display. Parameters are identified, performance goals established, and sensor types and locations are specified in the report, with emphasis on the use of existing instrumentation with a minimum of retrofitting. A simple algorithm is developed which yields the leak rate as a function of known or measurable quantities. The conclusion is that leak rates of less than one-tenth gram per second should be detectable with existing instrumentation. (orig./HP)

  9. Levels of toxaphene congeners in fish from Danish waters

    DEFF Research Database (Denmark)

    Fromberg, Arvid; Cederberg, Tommy Licht; Hilbert, G.

    2000-01-01

    The levels of toxaphene congeners, in addition to PCB congeners and organochlorine pesticides, were determined in various fish samples from different Danish waters. While PCB-153 and p,p'-DDE show different levels depending on the fishing area, with highest levels in fish from the Western Baltic...... Sea, toxaphene was detected in all the samples investigated at a more constant level. The distribution of the three toxaphene congeners Parlar #26, #50 and #62 depends on the fishing area, with the Western Baltic Sea being different from the other waters by having almost equal levels of toxaphene...

  10. Verification of Dinamika-5 code on experimental data of water level behaviour in PGV-440 under dynamic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Beljaev, Y.V.; Zaitsev, S.I.; Tarankov, G.A. [OKB Gidropress (Russian Federation)

    1995-12-31

    Comparison of the results of calculational analysis with experimental data on water level behaviour in horizontal steam generator (PGV-440) under the conditions with cessation of feedwater supply is presented in the report. Calculational analysis is performed using DIMANIKA-5 code, experimental data are obtained at Kola NPP-4. (orig.). 2 refs.

  11. Verification of Dinamika-5 code on experimental data of water level behaviour in PGV-440 under dynamic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Beljaev, Y V; Zaitsev, S I; Tarankov, G A [OKB Gidropress (Russian Federation)

    1996-12-31

    Comparison of the results of calculational analysis with experimental data on water level behaviour in horizontal steam generator (PGV-440) under the conditions with cessation of feedwater supply is presented in the report. Calculational analysis is performed using DIMANIKA-5 code, experimental data are obtained at Kola NPP-4. (orig.). 2 refs.

  12. Scaling up nanoscale water-driven energy conversion into evaporation-driven engines and generators

    Science.gov (United States)

    Chen, Xi; Goodnight, Davis; Gao, Zhenghan; Cavusoglu, Ahmet H.; Sabharwal, Nina; Delay, Michael; Driks, Adam; Sahin, Ozgur

    2015-06-01

    Evaporation is a ubiquitous phenomenon in the natural environment and a dominant form of energy transfer in the Earth's climate. Engineered systems rarely, if ever, use evaporation as a source of energy, despite myriad examples of such adaptations in the biological world. Here, we report evaporation-driven engines that can power common tasks like locomotion and electricity generation. These engines start and run autonomously when placed at air-water interfaces. They generate rotary and piston-like linear motion using specially designed, biologically based artificial muscles responsive to moisture fluctuations. Using these engines, we demonstrate an electricity generator that rests on water while harvesting its evaporation to power a light source, and a miniature car (weighing 0.1 kg) that moves forward as the water in the car evaporates. Evaporation-driven engines may find applications in powering robotic systems, sensors, devices and machinery that function in the natural environment.

  13. Use of inexpensive pressure transducers for measuring water levels in wells

    Science.gov (United States)

    Keeland, B.D.; Dowd, J.F.; Hardegree, W.S.

    1997-01-01

    Frequent measurement of below ground water levels at multiple locations is an important component of many wetland ecosystem studies. These measurements, however, are usually time consuming, labor intensive, and expensive. This paper describes a water-level sensor that is inexpensive and easy to construct. The sensor is placed below the expected low water level in a shallow well and, when connected to a datalogger, uses a pressure transducer to detect groundwater or surface water elevations. Details of pressure transducer theory, sensor construction, calibration, and examples of field installations are presented. Although the transducers must be individually calibrated, the sensors have a linear response to changing water levels (r2 ??? .999). Measurement errors resulting from temperature fluctuations are shown to be about 4 cm over a 35??C temperature range, but are minimal when the sensors are installed in groundwater wells where temperatures are less variable. Greater accuracy may be obtained by incorporating water temperature data into the initial calibration (0.14 cm error over a 35??C temperature range). Examples of the utility of these sensors in studies of groundwater/surface water interactions and the effects of water level fluctuations on tree growth are provided. ?? 1997 Kluwer Academic Publishers.

  14. Water use/reuse and wastewater management practices at selected Canadian coal fired generating stations

    Energy Technology Data Exchange (ETDEWEB)

    Kissel, R.

    1984-08-01

    Recommended Codes of Practice are currently being developed by Environment Canada aimed at ensuring that the aquatic environment is not significantly impacted upon by wastewater discharges from steam electric generating stations. A study was carried out to: develop a reliable data base of the physical and chemical characteristics of water and wastewater streams at representative generating stations; study advanced water reuse/recirculation and wastewater management to evaluate their potential future use in power generating stations; and to examine and evaluate the relevant aspects of best practical technology as proposed by Environment Canada in the Recommended Codes of Practice. Studies were carried out at Dalhousie Generating Station (GS), New Brunswick, Poplar River GS, Saskatchewan, Battle River GS, Alberta, and Milner GS, Alberta. The studies included on-site flow monitoring and sampling, chemical analyses, treatability studies and engineering analyses of water and wastewater systems. Extensive chemical characterizations of the water and wastewater streams were completed. Some problems were identified with the recirculating bottom ash system at Dalhousie which was a significant wastewater producer, coal pile runoff which caused significant wastewater, and iron which was the principal discharge criteria metal. 14 refs., 41 figs., 2 tabs.

  15. Consumptive Water Use from Electricity Generation in the Southwest under Alternative Climate, Technology, and Policy Futures.

    Science.gov (United States)

    Talati, Shuchi; Zhai, Haibo; Kyle, G Page; Morgan, M Granger; Patel, Pralit; Liu, Lu

    2016-11-15

    This research assesses climate, technological, and policy impacts on consumptive water use from electricity generation in the Southwest over a planning horizon of nearly a century. We employed an integrated modeling framework taking into account feedbacks between climate change, air temperature and humidity, and consequent power plant water requirements. These direct impacts of climate change on water consumption by 2095 differ with technology improvements, cooling systems, and policy constraints, ranging from a 3-7% increase over scenarios that do not incorporate ambient air impacts. Upon additional factors being changed that alter electricity generation, water consumption increases by up to 8% over the reference scenario by 2095. With high penetration of wet recirculating cooling, consumptive water required for low-carbon electricity generation via fossil fuels will likely exacerbate regional water pressure as droughts become more common and population increases. Adaptation strategies to lower water use include the use of advanced cooling technologies and greater dependence on solar and wind. Water consumption may be reduced by 50% in 2095 from the reference, requiring an increase in dry cooling shares to 35-40%. Alternatively, the same reduction could be achieved through photovoltaic and wind power generation constituting 60% of the grid, consistent with an increase of over 250% in technology learning rates.

  16. Drinking cholera: salinity levels and palatability of drinking water in coastal Bangladesh.

    Science.gov (United States)

    Grant, Stephen Lawrence; Tamason, Charlotte Crim; Hoque, Bilqis Amin; Jensen, Peter Kjaer Mackie

    2015-04-01

    To measure the salinity levels of common water sources in coastal Bangladesh and explore perceptions of water palatability among the local population to investigate the plausibility of linking cholera outbreaks in Bangladesh with ingestion of saline-rich cholera-infected river water. Hundred participants took part in a taste-testing experiment of water with varying levels of salinity. Salinity measurements were taken of both drinking and non-drinking water sources. Informal group discussions were conducted to gain an in-depth understanding of water sources and water uses. Salinity levels of non-drinking water sources suggest that the conditions for Vibrio cholerae survival exist 7-8 days within the local aquatic environment. However, 96% of participants in the taste-testing experiment reported that they would never drink water with salinity levels that would be conducive to V. cholerae survival. Furthermore, salinity levels of participant's drinking water sources were all well below the levels required for optimal survival of V. cholerae. Respondents explained that they preferred less salty and more aesthetically pleasing drinking water. Theoretically, V. cholerae can survive in the river systems in Bangladesh; however, water sources which have been contaminated with river water are avoided as potential drinking water sources. Furthermore, there are no physical connecting points between the river system and drinking water sources among the study population, indicating that the primary driver for cholera cases in Bangladesh is likely not through the contamination of saline-rich river water into drinking water sources. © 2015 John Wiley & Sons Ltd.

  17. Water-level and recoverable water in storage changes, High Plains aquifer, predevelopment to 2015 and 2013–15

    Science.gov (United States)

    McGuire, Virginia L.

    2017-06-01

    The High Plains aquifer underlies 111.8 million acres (about 175,000 square miles) in parts of eight States—Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. Water-level declines began in parts of the High Plains aquifer soon after the beginning of substantial irrigation with groundwater in the aquifer area (about 1950). This report presents water-level changes and change in recoverable water in storage in the High Plains aquifer from predevelopment (about 1950) to 2015 and from 2013 to 2015.The methods to calculate area-weighted, average water-level changes; change in recoverable water in storage; and total recoverable water in storage used geospatial data layers organized as rasters with a cell size of 500 meters by 500 meters, which is an area of about 62 acres. Raster datasets of water-level changes are provided for other uses.Water-level changes from predevelopment to 2015, by well, ranged from a rise of 84 feet to a decline of 234 feet. Water-level changes from 2013 to 2015, by well, ranged from a rise of 24 feet to a decline of 33 feet. The area-weighted, average water-level changes in the aquifer were an overall decline of 15.8 feet from predevelopment to 2015 and a decline of 0.6 feet from 2013 to 2015. Total recoverable water in storage in the aquifer in 2015 was about 2.91 billion acre-feet, which was a decline of about 273.2 million acre-feet since predevelopment and a decline of 10.7 million acre-feet from 2013 to 2015.

  18. Influence of water depth on the sound generated by air-bubble vibration in the water musical instrument

    Science.gov (United States)

    Ohuchi, Yoshito; Nakazono, Yoichi

    2014-06-01

    We have developed a water musical instrument that generates sound by the falling of water drops within resonance tubes. The instrument can give people who hear it the healing effect inherent in the sound of water. The sound produced by falling water drops arises from air- bubble vibrations. To investigate the impact of water depth on the air-bubble vibrations, we conducted experiments at varying values of water pressure and nozzle shape. We found that air-bubble vibration frequency does not change at a water depth of 50 mm or greater. Between 35 and 40 mm, however, the frequency decreases. At water depths of 30 mm or below, the air-bubble vibration frequency increases. In our tests, we varied the nozzle diameter from 2 to 4 mm. In addition, we discovered that the time taken for air-bubble vibration to start after the water drops start falling is constant at water depths of 40 mm or greater, but slower at depths below 40 mm.

  19. Towards risk-based drought management in the Netherlands: making water supply levels transparent to water users

    Science.gov (United States)

    Maat Judith, Ter; Marjolein, Mens; Vuren Saskia, Van; der Vat Marnix, Van

    2016-04-01

    To prepare the Dutch Delta for future droughts and water scarcity, a nation-wide 4-year project, called Delta Programme, assessed the impact of climate change and socio-economic development, and explored strategies to deal with these impacts. The Programme initiated a joint approach to water supply management with stakeholders and developed a national adaptation plan that is able to adapt to future uncertain conditions. The adaptation plan consists of a set of preferred policy pathways - sequences of possible actions and measures through time - to achieve targets while responding in a flexible manner to uncertain developments over time, allowing room to respond to new opportunities and insights. With regard to fresh water allocation, the Delta Programme stated that supplying water of sufficient quality is a shared responsibility that requires cohesive efforts among users in the main and regional water system. The national and local authorities and water users involved agreed that the water availability and, where relevant, the water quality should be as transparent and predictable as possible under normal, dry and extremely dry conditions. They therefore introduced the concept of "water supply service levels", which should describe water availability and quality that can be delivered with a certain return period, for all regions and all relevant water users in the Netherlands. The service levels form an addition to the present policy and should be decided on by 2021. At present water allocation during periods of (expected) water shortage occurs according to a prearranged ranking system (a water hierarchy scheme based on a list of priorities), if water availability drops below a critical low level. The aim is to have supply levels available that are based on the probability of occurrence and economic impact of water shortage, and that are transparent for all water users in the regional water systems and the main water system. As part of the European project

  20. Assessment of a new seasonal to inter-annual operational Great Lakes water supply, water levels, and connecting channel flow forecasting system

    Science.gov (United States)

    Gronewold, A.; Fry, L. M.; Hunter, T.; Pei, L.; Smith, J.; Lucier, H.; Mueller, R.

    2017-12-01

    The U.S. Army Corps of Engineers (USACE) has recently operationalized a suite of ensemble forecasts of Net Basin Supply (NBS), water levels, and connecting channel flows that was developed through a collaboration among USACE, NOAA's Great Lakes Environmental Research Laboratory, Ontario Power Generation (OPG), New York Power Authority (NYPA), and the Niagara River Control Center (NRCC). These forecasts are meant to provide reliable projections of potential extremes in daily discharge in the Niagara and St. Lawrence Rivers over a long time horizon (5 years). The suite of forecasts includes eight configurations that vary by (a) NBS model configuration, (b) meteorological forcings, and (c) incorporation of seasonal climate projections through the use of weighting. Forecasts are updated on a weekly basis, and represent the first operational forecasts of Great Lakes water levels and flows that span daily to inter-annual horizons and employ realistic regulation logic and lake-to-lake routing. We will present results from a hindcast assessment conducted during the transition from research to operation, as well as early indications of success rates determined through operational verification of forecasts. Assessment will include an exploration of the relative skill of various forecast configurations at different time horizons and the potential for application to hydropower decision making and Great Lakes water management.

  1. Determination of the exposition rapidity in the level 49.90 of the reactor building for the decrease in the water level of the spent fuel pool

    International Nuclear Information System (INIS)

    Mijangos D, Z. E.; Herrera H, S. F.; Cruz G, M. A.; Amador C, C.

    2014-10-01

    The fuel assemblies storage in the nuclear power plant of Laguna Verde (NPP-L V) represents a crucial aspect, due to the generated dose by the decay heat of the present radio-nuclides in the assemblies retired of the reactor core, after their useful life. These spent assemblies are located inside the spent fuel pool (SFP), in the level 49.90 m in the Reload Floor of the Reactor building of NPP-L V. This leads to the protection at personnel applying the ALARA (As Low As Reasonably Achievable) criteria, fulfilling the established dose criteria by the Regulator Body the Comision Nacional de Seguridad Nuclear y Salvaguardias (CNSNS). Considering the loss scenario of the cooling system of the SFP, in which the SFP water vaporizes, is important to know the water level in which the limit of effective dose equivalent is fulfilled for the personnel. Also, is important for the instrumentation of the SFP, for the useful life of the same instruments. In this work is obtained the exposition rapidity corresponding to different water levels of SFP in the Reload Floor of NPP-L V, to identify the minimum level of water where the limit of effective dose equivalent is fulfilled of 25 rem s to the personnel, established in the Article 48 of the General Regulation of Radiological Safety of CNSNS and the Chapter 50 Section 67 of the 10-Cfr of Nuclear Regulatory Commission in USA. The water level is also identified where the exposition rapidity is of 15 m R/hr, being the value of the set point of the area radiation monitor D21-Re-N003-1, located to 125 cm over the level 49.90 meters of the Reload Floor of NPP-L V. (Author)

  2. Automatic deodorizing system for waste water from radioisotope facilities using an ozone generator

    International Nuclear Information System (INIS)

    Kawamura, Hiroko; Hirata, Yasuki

    2002-01-01

    We applied an ozone generator to sterilize and to deodorize the waste water from radioisotope facilities. A small tank connected to the generator is placed outside of the drainage facility founded previously, not to oxidize the other apparatus. The waste water is drained 1 m 3 at a time from the tank of drainage facility, treated with ozone and discharged to sewer. All steps proceed automatically once the draining work is started remotely in the office. The waste water was examined after the ozone treatment for 0 (original), 0.5, 1.0, 1.5 and 2.0 h. Regarding original waste water, the sum of coliform groups varied with every examination repeated - probably depend on the colibacilli used in experiments; hydrogen sulfide, biochemical oxygen demand and the offensive odor increased with increasing coliform groups. The ozone treatment remarkably decreased hydrogen sulfide and the offensive odor, decreased coliform groups when the original water had rich coliforms. (author)

  3. Automatic deodorizing system for waste water from radioisotope facilities using an ozone generator

    Energy Technology Data Exchange (ETDEWEB)

    Kawamura, Hiroko; Hirata, Yasuki [Kyushu Univ., Fukuoka (Japan). Radioisotope Center; Taguchi, Kenji [Riken Co. Ltd., Kitakyushu, Fukuoka (Japan)

    2002-03-01

    We applied an ozone generator to sterilize and to deodorize the waste water from radioisotope facilities. A small tank connected to the generator is placed outside of the drainage facility founded previously, not to oxidize the other apparatus. The waste water is drained 1 m{sup 3} at a time from the tank of drainage facility, treated with ozone and discharged to sewer. All steps proceed automatically once the draining work is started remotely in the office. The waste water was examined after the ozone treatment for 0 (original), 0.5, 1.0, 1.5 and 2.0 h. Regarding original waste water, the sum of coliform groups varied with every examination repeated - probably depend on the colibacilli used in experiments; hydrogen sulfide, biochemical oxygen demand and the offensive odor increased with increasing coliform groups. The ozone treatment remarkably decreased hydrogen sulfide and the offensive odor, decreased coliform groups when the original water had rich coliforms. (author)

  4. Development of next-generation light water reactor

    International Nuclear Information System (INIS)

    Ishibashi, Fumihiko; Yasuoka, Makoto

    2010-01-01

    The Next-Generation Light Water Reactor Development Program, a national project in Japan, was inaugurated in April 2008. The primary objective of this program is to meet the need for the replacement of existing nuclear power plants in Japan after 2030. With the aim of setting a global standard design, the reactor to be developed offers greatly improved safety, reliability, and economic efficiency through several innovative technologies, including a reactor core system with uranium enrichment of 5 to 10%, a seismic isolation system, long-life materials, advanced water chemistry, innovative construction techniques, optimized passive and active safety systems, innovative digital technologies, and so on. In the first three years, a plant design concept with these innovative features is to be established and the effectiveness of the program will be reevaluated. The major part of the program will be completed in 2015. Toshiba is actively engaged in both design studies and technology development as a founding member of this program. (author)

  5. Removal of Inorganic, Microbial, and Particulate Contaminants from a Fresh Surface Water: Village Marine Tec. Expeditionary Unit Water Purifier, Generation 1

    Science.gov (United States)

    The Village Marine Tec. Generation 1 Expeditionary Unit Water Purifier (EUWP) is a mobile skid-mounted system employing ultrafiltration (UF) and reverse osmosis (RO) to produce drinking water from a variety of different water quality sources. The UF components were evaluated to t...

  6. A Comparative Evaluation of Procedural Level Generators in the Mario AI Framework

    DEFF Research Database (Denmark)

    Horn, Britton; Dahlskog, Steve; Shaker, Noor

    dierent from another in terms of its output. To remedy this, we have conducted a large-scale comparative evaluation of level generators for the Mario AI Benchmark, a research-friendly clone of the classic platform game Super Mario Bros. In all, we compare the output of seven dierent level generators from...

  7. Crest Level Optimization of the Multi Level Overtopping based Wave Energy Converter Seawave Slot-Cone Generator

    DEFF Research Database (Denmark)

    Kofoed, Jens Peter; Osaland, E.

    2005-01-01

    The paper describes the optimization of the crest levels and geometrical layout of the SSG structure, focusing on maximizing the obtained potential energy in the overtopping water. During wave tank testing at AAU average overtopping rates into the individual reservoirs have been measured. The ini......The paper describes the optimization of the crest levels and geometrical layout of the SSG structure, focusing on maximizing the obtained potential energy in the overtopping water. During wave tank testing at AAU average overtopping rates into the individual reservoirs have been measured....... The initial tests led to an expression describing the derivative of the overtopping rate with respect to the vertical distance. Based on this, numerical optimizations of the crest levels, for a number of combinations of wave conditions, have been performed. The hereby found optimal crest levels have been...

  8. Consumption of low-moderate level arsenic contaminated water does not increase spontaneous pregnancy loss: a case control study.

    Science.gov (United States)

    Bloom, Michael S; Neamtiu, Iulia A; Surdu, Simona; Pop, Cristian; Lupsa, Ioana Rodica; Anastasiu, Doru; Fitzgerald, Edward F; Gurzau, Eugen S

    2014-10-13

    Previous work suggests an increased risk for spontaneous pregnancy loss linked to high levels of inorganic arsenic (iAs) in drinking water sources (>10 μg/L). However, there has been little focus to date on the impact of low-moderate levels of iAs in drinking water (control study in Timis County, Romania. We recruited women with incident spontaneous pregnancy loss of 5-20 weeks completed gestation as cases (n = 150), and women with ongoing pregnancies matched by gestational age (±1 week) as controls (n = 150). Participants completed a physician-administered questionnaire and we collected water samples from residential drinking sources. We reconstructed residential drinking water exposure histories using questionnaire data weighted by iAs determined using hydride generation-atomic absorption spectrometry (HG-AAS). Logistic regression models were used to generate odds ratios (OR) and 95% confidence intervals (CI) for associations between iAs exposure and loss, conditioned on gestational age and adjusted for maternal age, cigarette smoking, education and prenatal vitamin use. We explored potential interactions in a second set of models. Drinking water arsenic concentrations ranged from 0.0 to 175.1 μg/L, with median 0.4 μg/L and 90th%tile 9.4 μg/L. There were no statistically significant associations between loss and average or peak drinking water iAs concentrations (OR 0.98, 95% CI 0.96-1.01), or for daily iAs intake (OR 1.00, 95% CI 0.98-1.02). We detected modest evidence for an interaction between average iAs concentration and cigarette smoking during pregnancy (P = 0.057) and for daily iAs exposure and prenatal vitamin use (P = 0.085). These results suggest no increased risk for spontaneous pregnancy loss in association with low to moderate level drinking water iAs exposure. Though imprecise, our data also raise the possibility for increased risk among cigarette smokers. Given the low exposures overall, these data should reassure pregnant

  9. Levels for Hotline Miami 2: Wrong Number Using Procedural Content Generations

    Directory of Open Access Journals (Sweden)

    Joseph Alexander Brown

    2018-04-01

    Full Text Available Procedural Content Generation is the automatic process for generating game content in order to allow for a decrease in developer resources while adding to the replayability of a digital game. It has been found to be highly effective as a method when utilized in rougelike games, of which Hotline Miami 2: Wrong Number shares a number of factors. Search based procedural content, in this case, a genetic algorithm, allows for the creation of levels which meet with a number of designer set requirements. The generator proposed provides for an automatic creation of game content for a commercially available game: the level design, object placement, and enemy placement.

  10. Effects of water-emulsified fuel on a diesel engine generator's thermal efficiency and exhaust.

    Science.gov (United States)

    Syu, Jin-Yuan; Chang, Yuan-Yi; Tseng, Chao-Heng; Yan, Yeou-Lih; Chang, Yu-Min; Chen, Chih-Chieh; Lin, Wen-Yinn

    2014-08-01

    Water-emulsified diesel has proven itself as a technically sufficient improvement fuel to improve diesel engine fuel combustion emissions and engine performance. However, it has seldom been used in light-duty diesel engines. Therefore, this paper focuses on an investigation into the thermal efficiency and pollution emission analysis of a light-duty diesel engine generator fueled with different water content emulsified diesel fuels (WD, including WD-0, WD-5, WD-10, and WD-15). In this study, nitric oxide, carbon monoxide, hydrocarbons, and carbon dioxide were analyzed by a vehicle emission gas analyzer and the particle size and number concentration were measured by an electrical low-pressure impactor. In addition, engine loading and fuel consumption were also measured to calculate the thermal efficiency. Measurement results suggested that water-emulsified diesel was useful to improve the thermal efficiency and the exhaust emission of a diesel engine. Obviously, the thermal efficiency was increased about 1.2 to 19.9%. In addition, water-emulsified diesel leads to a significant reduction of nitric oxide emission (less by about 18.3 to 45.4%). However the particle number concentration emission might be increased if the loading of the generator becomes lower than or equal to 1800 W. In addition, exhaust particle size distributions were shifted toward larger particles at high loading. The consequence of this research proposed that the water-emulsified diesel was useful to improve the engine performance and some of exhaust emissions, especially the NO emission reduction. Implications: The accumulated test results provide a good basis to resolve the corresponding pollutants emitted from a light-duty diesel engine generator. By measuring and analyzing transforms of exhaust pollutant from this engine generator, the effects of water-emulsified diesel fuel and loading on emission characteristics might be more clear. Understanding reduction of pollutant emissions during the use

  11. Investigation of the Effect of Water Removal from Wells Surrounding Parishan Lake on Groundwater and Surface Water Levels

    International Nuclear Information System (INIS)

    Shafiei, M.; Raini Sarjaz, M.; Fazloli, R.; Gholami Sefidkouhi, M. A.

    2017-01-01

    In recent decades the human impacts on global warming and, its consequences, climate change, stirred up earth ecosystems balance and has created many problems all over the world. Unauthorized underground water removal, especially in arid and semi-arid regions of Iran, along with recent decade drought occurrences significantly lowered underground and surface water levels. To investigate the impacts of water removal from surrounding wells in Parishan Lake water level, during 1996 to 2009 interval, 8 buffer layers surrounding the lake were mapped in ArcGIS 9.3 environment. Each buffer layer wells and their total annual discharges were determined. Using SPSS 16 software, the regression equations between wells water levels and water discharges were computed. By employing Thiessen function and creating Thiessen network (TIN) around observation wells, decline of groundwater levels was evaluated. Finally regression equations between wells discharges and groundwater level declines were created. The findings showed that there are highly significant correlations (p ≤ 0.01), in all buffer layers, between water levels and wells discharges. Investigation of the observation wells surrounding lake showed that severe groundwater level declines has been started since the beginning of the first decade of the 21st century. Using satellite images in ArcGIS 9.3 environment it was confirmed that lake’s area has been reduced significantly. In conclusion, it is obvious that human interferences on lake’s natural ecosystem by digging unauthorized wells and removing underground water more than annual recharges significantly impacted surface and groundwater levels.

  12. Economic sustainability, water security and multi-level governance of local water schemes in Nepal

    Directory of Open Access Journals (Sweden)

    Emma Hakala

    2017-07-01

    Full Text Available This article explores the role of multi-level governance and power structures in local water security through a case study of the Nawalparasi district in Nepal. It focuses on economic sustainability as a measure to address water security, placing this thematic in the context of a complicated power structure consisting of local, district and national administration as well as external development cooperation actors. The study aims to find out whether efforts to improve the economic sustainability of water schemes have contributed to water security at the local level. In addition, it will consider the interactions between water security, power structures and local equality and justice. The research builds upon survey data from the Nepalese districts of Nawalparasi and Palpa, and a case study based on interviews and observation in Nawalparasi. The survey was performed in water schemes built within a Finnish development cooperation programme spanning from 1990 to 2004, allowing a consideration of the long-term sustainability of water management projects. This adds a crucial external influence into the intra-state power structures shaping water management in Nepal. The article thus provides an alternative perspective to cross-regional water security through a discussion combining transnational involvement with national and local points of view.

  13. Radioactivity levels in well water supplies within the greater Chicago area

    International Nuclear Information System (INIS)

    Kristoff, L.M.; Lordi, D.T.; Lue-Hing, C.

    1976-01-01

    The radiological analysis of well water supplies within the geographical boundaries of the Metropolitan Sanitary District of Greater Chicago was prompted by the relatively high total alpha levels encountered in wastewaters of a MSDGC water reclamation plant as compared to the wastewaters of the other waste treatment plants. Consequently, 87 wells constituting 42 water supplies were sampled and analyzed for total alpha and beta radioactivity. The wells were grouped according to depth. In general, both total alpha and total beta radioactivity concentrations were found to be a function of well depth. The relatively higher total alpha and beta activities in the wastewaters to one of the treatment plants was attributed to the higher levels found in the well water supply. Comparison with the USEPA's Drinking Water Regulations for Radionuclides (July 9, 1976) showed the maximum total alpha level of 15 pCi/liter was exceeded in 3 wells and 32 of the deep well waters had total alpha level greater than 5 pCi/liter. The total beta level of 50 pCi/liter was exceeded in 8 wells

  14. Carboxyhaemoglobin levels in water-pipe and cigarette smokers ...

    African Journals Online (AJOL)

    South African Medical Journal ... Water-pipe smoking is growing in popularity, especially among young people, because of the social nature of the smoking session and the assumption that the ... We aimed to measure carboxyhaemoglobin (COHb) blood levels before and after water-pipe and cigarette smoking sessions.

  15. Process for superheating the steam generated by a light water nuclear reactor

    International Nuclear Information System (INIS)

    Vakil, H.B.; Brown, D.H.

    1976-01-01

    A process is submitted for superheating the pressurised steam generated in a light water nuclear reactor in which the steam is brought to 340 0 C at least. This superheated steam is used to operate a turbo-generator unit. The characteristic of the process is that an exothermal chemical reaction is used to generate the heat utilised during the superheating stage. The chemical reaction is a mechanisation, oxidation-reduction or hydrogenation reaction [fr

  16. NOAA Next Generation Radar (NEXRAD) Level 2 Base Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset consists of Level II weather radar data collected from Next-Generation Radar (NEXRAD) stations located in the contiguous United States, Alaska, Hawaii,...

  17. Typhoon and elevated radon level in a municipal water supply

    International Nuclear Information System (INIS)

    Mao, Cheng-Hsin; Weng, Pao-Shan

    2000-01-01

    The Municipal Water Supply at Hsinchu City is a water treatment plant using poly- aluminum chloride (PAC) for coagulation and then followed by precipitation and filtration. Its capacity is 70,000 m 3 /day. The raw water is drawn from the nearby river. Since the subject of interest is the radon level during typhoon season, the sampling period was from March to December 1999. Commercially available electret was used for water samples taken from the five ponds in the plant. This technique relies on the measurement of radon in air above a water sample enclosed in a sealed vessel. The concentration of airbone radon released from water was determined by means of the electret ion chamber. During the first sampling period there came two typhoons. One is called Magie during June 10-17, and the other called Sam during August 20-26. The first typhoon led to the radon level measured from the water samples as high as 705 Bq/m 3 , while the second caused even higher radon level as high as 772 Bq/m 3 . Similar results were obtained for the second sampling period after August till December 1999. For those measured without typhoon influence, the average radon was lower from the coagulation pond yet without coagulation process during March through August 1999. However, water samples taken from the pond after precipitation did not show similar results in radon level. (author)

  18. Impacts of water level fluctuation on mesotrophic rich fens: acidification versus eutrophication

    NARCIS (Netherlands)

    Cusell, C.; Lamers, L.P.M.; van Wirdum, G.; Kooijman, A.

    2013-01-01

    Water levels in areas with intensive agriculture have often been strictly controlled for decades. Recently, more natural fluctuating water levels have been propagated to improve the ecological quality of wetlands in these areas. This study investigated the effects of water levels on protected

  19. Water level affects availability of optimal feeding habitats for threatened migratory waterbirds

    DEFF Research Database (Denmark)

    Aharon-Rotman, Yaara; McEvoy, John; Zheng Zhaoju

    2017-01-01

    within the lake. Changing the natural hydrological system will affect waterbirds dependent on water level changes for food availability and accessibility. We tracked two goose species with different feeding behaviors (greater white-fronted geese Anser albifrons [grazing species] and swan geese Anser......Extensive ephemeral wetlands at Poyang Lake, created by dramatic seasonal changes in water level, constitute the main wintering site for migratory Anatidae in China. Reductions in wetland area during the last 15years have led to proposals to build a Poyang Dam to retain high winter water levels...... cygnoides [tuber-feeding species]) during two winters with contrasting water levels (continuous recession in 2015; sustained high water in 2016, similar to those predicted post-Poyang Dam), investigating the effects of water level change on their habitat selection based on vegetation and elevation. In 2015...

  20. Dynamic study of steam generation from low-grade waste heat in a zeolite–water adsorption heat pump

    International Nuclear Information System (INIS)

    Xue, Bing; Meng, Xiangrui; Wei, Xinli; Nakaso, Koichi; Fukai, Jun

    2015-01-01

    A novel zeolite–water adsorption heat pump system based on a direct-contact heat exchange method to generate steam from low-grade waste gas and water has been proposed and examined experimentally. Superheated steam (200 °C, 0.1 MPa) is generated from hot water (70–80 °C) and dry air (100–130 °C). A dynamic model for steam generation process is developed to describe local mass and heat transfer. This model features a three-phase calculation and a moving water–gas interface. The calculations are carried out in the zeolite–water and zeolite–gas regions. Model outputs are compared with experimental results for validation. The thermal response inside the reactor and mass of steam generated is well predicted. Numerical results show that preheat process with low-temperature steam is an effective method to achieve local equilibrium quickly, thus generation process is enhanced by prolonging the time and increasing mass of the generated steam. Besides, high-pressure steam generation up to 0.5 MPa is possible from the validated dynamic model. Future work could be emphasized on enhancing high-pressure steam generation with preheat process or mass recovery operation

  1. Water levels of the Ozark aquifer in northern Arkansas, 2013

    Science.gov (United States)

    Schrader, Tony P.

    2015-07-13

    The Ozark aquifer is the largest aquifer, both in area of outcrop and thickness, and the most important source of freshwater in the Ozark Plateaus physiographic province, supplying water to northern Arkansas, southeastern Kansas, southern Missouri, and northeastern Oklahoma. The study area includes 16 Arkansas counties lying completely or partially within the Ozark Plateaus of the Interior Highlands major physiographic division. The U.S. Geological Survey, in cooperation with the Arkansas Natural Resources Commission and the Arkansas Geological Survey, conducted a study of water levels in the Ozark aquifer within Arkansas. This report presents a potentiometric-surface map of the Ozark aquifer within the Ozark Plateaus of northern Arkansas, representing water-level conditions for the early spring of 2013 and selected water-level hydrographs.

  2. User’s manual for the Automated Data Assurance and Management application developed for quality control of Everglades Depth Estimation Network water-level data

    Science.gov (United States)

    Petkewich, Matthew D.; Daamen, Ruby C.; Roehl, Edwin A.; Conrads, Paul

    2016-09-29

    The generation of Everglades Depth Estimation Network (EDEN) daily water-level and water-depth maps is dependent on high quality real-time data from over 240 water-level stations. To increase the accuracy of the daily water-surface maps, the Automated Data Assurance and Management (ADAM) tool was created by the U.S. Geological Survey as part of Greater Everglades Priority Ecosystems Science. The ADAM tool is used to provide accurate quality-assurance review of the real-time data from the EDEN network and allows estimation or replacement of missing or erroneous data. This user’s manual describes how to install and operate the ADAM software. File structure and operation of the ADAM software is explained using examples.

  3. The testing of a steam-water separating device used for vertical steam generators

    International Nuclear Information System (INIS)

    Ding Xunshen; Cui Baoyuan; Xue Yunkui; Liu Shixun

    1989-01-01

    The air-water screening tests of a steam-water separating device used for vertical steam generators at low pressure are introduced. The article puts emphasis on the qualification test of the steam-water separating device at hot conditions in a high temperature and pressure water test rig. The performance of the comprehensive test of the steam-water separating device indicates that the humidity of the steam at the drier exit is much less than the specified amount of 0.25%

  4. Radium-226 levels in Italian drinking waters and foods

    International Nuclear Information System (INIS)

    Mastinu, G.G.; Santaroni, G.P.

    1980-01-01

    Levels of 226 Ra in Italian waters and foods were measured. Results were similar to those found in other countries, except for some mineral waters with 226 Ra concentrations above 1 pCi/liter andup to 19 pCi/liter. No difinite correlation was found between the 226 Ra concentrations measured and the high natural background radiation levels determined in central Italy in previous work

  5. Removal of actinides from high-level wastes generated in the reprocessing of commercial fuels

    International Nuclear Information System (INIS)

    Bond, W.D.; Leuze, R.E.

    1975-09-01

    Progress is reported on a technical feasibility study of removing the very long-lived actinides (uranium, neptunium, plutonium, americium, and curium) from high-level wastes generated in the commercial reprocessing of spent nuclear fuels. The study was directed primarily at wastes from the reprocessing of light water reactor (LWR) fuels and specifically to developing satisfactory methods for reducing the actinide content of these wastes to values that would make 1000-year-decayed waste comparable in radiological toxicity to natural uranium ore deposits. Although studies are not complete, results thus far indicate the most promising concept for actinide removal includes both improved recovery of actinides in conventional fuel reprocessing and secondary processing of the high-level wastes. Secondary processing will be necessary for the removal of americium and curium and perhaps some residual plutonium. Laboratory-scale studies of separations methods that appear most promising are reported and conceptual flowsheets are discussed. (U.S.)

  6. 46 CFR 52.01-110 - Water-level indicators, water columns, gauge-glass connections, gauge cocks, and pressure gauges...

    Science.gov (United States)

    2010-10-01

    ... § 52.01-110 Water-level indicators, water columns, gauge-glass connections, gauge cocks, and pressure... 46 Shipping 2 2010-10-01 2010-10-01 false Water-level indicators, water columns, gauge-glass connections, gauge cocks, and pressure gauges (modifies PG-60). 52.01-110 Section 52.01-110 Shipping COAST...

  7. Aspects on the gas generation and migration in repositories for high level waste in salt formations

    International Nuclear Information System (INIS)

    Ruebel, Andre; Buhmann, Dieter; Meleshyn, Artur; Moenig, Joerg; Spiessl, Sabine

    2013-07-01

    In a deep geological repository for high-level waste, gases may be produced during the post-closure phase by several processes. The generated gases can potentially affect safety relevant features and processes of the repository, like the barrier integrity, the transport of liquids and gases in the repository and the release of gaseous radionuclides from the repository into the biosphere. German long-term safety assessments for repositories for high-level waste in salt which were performed prior 2010 did not explicitly consider gas transport and the consequences from release of volatile radionuclides. Selected aspects of the generation and migration of gases in repositories for high-level waste in a salt formation are studied in this report from the viewpoint of the performance assessment. The knowledge on the availability of water in the repository, in particular the migration of salt rock internal fluids in the temperature field of the radioactive waste repository towards the emplacement drifts, was compiled and the amount of water was roughly estimated. Two other processes studied in this report are on the one hand the release of gaseous radionuclides from the repository and their potential impact in the biosphere and on the other hand the transport of gases along the drifts and shafts of the repository and their interaction with the fluid flow. The results presented show that there is some gas production expected to occur in the repository due to corrosion of container material from water disposed of with the backfill and inflowing from the host rock during the thermal phase. If not dedicated gas storage areas are foreseen in the repository concept, these gases might exceed the storage capacity for gases in the repository. Consequently, an outflow of gases from the repository could occur. If there are failed containers for spent fuel, radioactive gases might be released from the containers into the gas space of the backfill and subsequently transported together

  8. Determination of radon in soil and water in parts of Accra, and generation of preliminary radon map for Ghana

    International Nuclear Information System (INIS)

    Osei, Peter

    2016-07-01

    The research was focused on determining the radon levels in soil and water in parts of Accra, generate a preliminary radon map for Ghana and estimate a pilot reference level for the country, using the data obtained from this research and collated data from other researchers. The radon gas measurement was done with the passive method, using the SSNTDs which are sensitive to alpha particles emitted by radon. Cellulose nitrate LR – 115 type II alpha particle detectors were used. The detectors were chemically etched in a 2.5 M NaOH solution at a temperature of 60 °C for 90 minutes, after two weeks and two months of exposure to soil and water respectively. The images of the etched detectors were acquired by means of a scanner and then tracks counted with ImageJ software. Inverse Distance Weighing (IDW) method of ArcGIS 10.2 was used to spatially distribute the radon concentration on a map. The average soil radon concentration in the study area ranges from 0.191 kBqm"-"3 to 3.416 kBqm"-"3 with a mean of 1.193 kBqm"-"3. The radon concentration in water from the study area ranges from 0.00346 BqL"-"1 to 0.00538 BqL"-"1 with an average of 0.00456 BqL"-"1. A strong negative correlation has been established between radon in soil and water in the study area. The preliminary national average indoor, water and soil radon concentrations are 137 Bqm"-"3, 361.93 Bqm"-"3 and 3716.74 Bqm"-"3 respectively. The average levels of water and indoor radon exceeded WHO’s reference level of 100 Bqm"-"3. Accordingly, the pilot national indoor radon reference level for Ghana is set as 200 Bqm"-"3. (au)

  9. Lake Storage Measurements For Water Resources Management: Combining Remotely Sensed Water Levels and Surface Areas

    Science.gov (United States)

    Brakenridge, G. R.; Birkett, C. M.

    2013-12-01

    Presently operating satellite-based radar altimeters have the ability to monitor variations in surface water height for large lakes and reservoirs, and future sensors will expand observational capabilities to many smaller water bodies. Such remote sensing provides objective, independent information where in situ data are lacking or access is restricted. A USDA/NASA (http://www.pecad.fas.usda.gov/cropexplorer/global_reservoir/) program is performing operational altimetric monitoring of the largest lakes and reservoirs around the world using data from the NASA/CNES, NRL, and ESA missions. Public lake-level products from the Global Reservoir and Lake Monitor (GRLM) are a combination of archived and near real time information. The USDA/FAS utilizes the products for assessing international irrigation potential and for crop production estimates; other end-users study climate trends, observe anthropogenic effects, and/or are are involved in other water resources management and regional water security issues. At the same time, the Dartmouth Flood Observatory (http://floodobservatory.colorado.edu/), its NASA GSFC partners (http://oas.gsfc.nasa.gov/floodmap/home.html), and associated MODIS data and automated processing algorithms are providing public access to a growing GIS record of the Earth's changing surface water extent, including changes related to floods and droughts. The Observatory's web site also provide both archival and near real time information, and is based mainly on the highest spatial resolution (250 m) MODIS bands. Therefore, it is now possible to provide on an international basis reservoir and lake storage change measurements entirely from remote sensing, on a frequently updating basis. The volume change values are based on standard numerical procedures used for many decades for analysis of coeval lake area and height data. We provide first results of this combination, including prototype displays for public access and data retrieval of water storage

  10. IRIS - Generation IV Advanced Light Water Reactor for Countries with Small and Medium Electricity Grids

    International Nuclear Information System (INIS)

    Carelli, M. D.

    2002-01-01

    An international consortium of industry, laboratory, university and utility establishments, led by Westinghouse, is developing a Generation IV Reactor, International Reactor Innovative and Secure (IRIS). IRIS is a modular, integral, light water cooled, low-to-medium power (100-350 MWe) reactor which addresses the requirements defined by the US DOE for Generation IV reactors, i.e., fuel cycle sustainability, enhanced reliability and safety, and improved economics. It features innovative, advanced engineering, but it does not require new technology development since it relies on the proven technology of light water reactors. This paper presents the current reference IRIS design, which features a 1000 MWt thermal core with proven 5%-enriched uranium oxide fuel and four-year long straight burn fuel cycle, integral reactor vessel housing helical tube steam generators and immersed spool pumps. Other major contributors to the high level of safety and economic attractiveness are the safety by design and optimized maintenance approaches, which allow elimination of some classes of accidents, lower capital cost, long operating cycle, and high capacity factors. The path forward for possible future extension to a eight-year cycle will be also discussed. IRIS has a large potential worldwide market because of its proven technology, modularity, low financing, compatibility with existing grids and very limited infrastructure requirements. It is especially appealing to developing countries because of ease of operation and because its medium power is more adaptable to smaller grids. (author)

  11. Power Generation for River and Tidal Generators

    Energy Technology Data Exchange (ETDEWEB)

    Muljadi, Eduard [National Renewable Energy Lab. (NREL), Golden, CO (United States); Wright, Alan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Gevorgian, Vahan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Donegan, James [Ocean Renewable Power Company (ORPC), Portland, ME (United States); Marnagh, Cian [Ocean Renewable Power Company (ORPC), Portland, ME (United States); McEntee, Jarlath [Ocean Renewable Power Company (ORPC), Portland, ME (United States)

    2016-06-01

    Renewable energy sources are the second largest contributor to global electricity production, after fossil fuels. The integration of renewable energy continued to grow in 2014 against a backdrop of increasing global energy consumption and a dramatic decline in oil prices during the second half of the year. As renewable generation has become less expensive during recent decades, and it becomes more accepted by the global population, the focus on renewable generation has expanded from primarily wind and solar to include new types with promising future applications, such as hydropower generation, including river and tidal generation. Today, hydropower is considered one of the most important renewable energy sources. In river and tidal generation, the input resource flow is slower but also steadier than it is in wind or solar generation, yet the level of water turbulent flow may vary from one place to another. This report focuses on hydrokinetic power conversion.

  12. Dual-Level Material and Psychological Assessment of Urban Water Security in a Water-Stressed Coastal City

    Directory of Open Access Journals (Sweden)

    Yajing Huang

    2015-04-01

    Full Text Available The acceleration of urbanization and industrialization has been gradually aggravating water security issues, such as water shortages, water pollution, and flooding or drought disasters and so on. Water security issues have become a great challenge to urban sustainable development. In this context, we proposed a dual-level material and psychological assessment method to assess urban water security. Psychological security coefficients were introduced in this method to combine material security and residents’ security feelings. A typical water-stressed coastal city in China (Dalian was chosen as a case study. The water security status of Dalian from 2010 to 2012 was analysed dynamically. The results indicated that the Dalian water security statuses from 2010 to 2012 were basically secure, but solutions to improve water security status and solve water resource problems are still required. This dual-level material and psychological assessment for urban water security has improved conventional material assessment through the introduction of psychological security coefficients, which can benefit decision-making for urban water planning, management and protection.

  13. Generational differences on work engagement levels of government healthcare institution employees

    Directory of Open Access Journals (Sweden)

    Veronica Hlongwane

    2015-04-01

    Full Text Available The objective of this study was to explore generational differences on work engagement levels of employees in a South African government healthcare institution. The Ultrech Work Engagement Scale measured the participants’ levels of work engagement and it was administered to a random sample size of government healthcare institution employees (n=289. Statistical analyses of the data were conducted and the results of ANOVA indicated that the levels of work engagement significantly differ depending on the employees’ generational cohort or group for the dimensions vigour, dedication and absorption. In terms of contributions and practical implications, recommendations are made regarding proposed organisational development interventions to enhance employees’ work engagement levels in a healthcare institution context as well as to conduct future research.

  14. Electrolyzed-water generator 'SaniBoy'; Eisei jokinsuik kyokyu sochi 'SaniBoy'

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, M; Kakiuchi, H; Muto, K [Fuji Electric Co. Ltd., Tokyo (Japan)

    2000-03-10

    In the food industry, injuries due to food poisoning have been increasing. Especially the mass outbreak of food poisoning by Escherichia coli such as O-157 in 1996 gave warning on the importance of food sanitation management. Public efforts such as the Hazard Analysis and Critical Control Point (HACCP) system have been made to prevent food poisoning. Recently, disinfection made by electrolyzing water with some salt added has attracted attention. Fuji Electric has developed the generator 'SaniBoy' that produces weak alkaline electrolyzed water without wasting water. The environment-friendly 'SaniBoy' will contribute to sanitation in various fields. (author)

  15. Simulating spontaneously generated coherence in a four-level atomic system

    International Nuclear Information System (INIS)

    Li Aijun; Gao Jinyue; Wu Jinhui; Wang Lei

    2005-01-01

    We study the spontaneous emission property of a four-level atomic system driven by two coherent fields. By numerical calculations in the bare state picture, we show that such interesting phenomena as extremely narrow peaks and spontaneous emission quenching can be realized, which are well understood by qualitative explanations in the partially and fully dressed state pictures. Especially, this coherently driven atomic system has two close-lying levels in the partially dressed state picture so that spontaneously generated coherence arises. Using our considered scheme it is feasible to carry out experiments based on spontaneously generated coherence because all rigorous requirements have been avoided in the bare state picture

  16. MODELING AND STUDY OF HYDROELECTRIC GENERATING SETS OF SMALL HYDRO POWER PLANTS WITH FREQUENCY-CONTROLLED PERMANENT MAGNET SYNCHRONOUS GENERATORS

    Directory of Open Access Journals (Sweden)

    R. I. Mustafayev

    2016-01-01

    Full Text Available Currently, the hydroelectric generating sets of small HPPs with Pelton turbines employ as their generating units conventional synchronous generators with electromagnetic excitation. To deal with the torque pulsatile behaviour, they generally install a supplementary flywheel on the system shaft that levels the pulsations. The Pelton turbine power output is adjusted by the needle changing water flow in the nozzle, whose advancement modifies the nozzle area and eventually – the flow. They limit the needle full stroke time to 20–40 sec. since quick shutting the nozzle for swift water flow reduction may result in pressure surges. For quick power adjustment so-called deflectors are employed, whose task is retraction of water jets from the Pelton turbine buckets. Thus, the mechanical method of power output regulation requires agreement between the needle stroke inside the turbine nozzles and the deflector. The paper offers employing frequency-controlled synchronous machines with permanent magnets qua generating units for the hydroelectric generating sets of small HPPs with Pelton turbines. The developed computer model reveals that this provides a higher level of adjustability towards rapid-changing loads in the grid. Furthermore, this will replace the power output mechanical control involving the valuable deflector drive and the turbine nozzle needles with electrical revolution rate and power output regulation by a frequency converter located in the generator stator circuit. Via frequency start, the controllable synchronous machine ensures stable operation of the hydroelectric generating set with negligibly small amount of water (energy carrier. Finally, in complete absence of water, the frequency-relay start facilitates shifting the generator operation to the synchronous capacitor mode, which the system operating parameter fluctograms obtained through computer modeling prove. 

  17. Water-level changes and directions of ground-water flow in the shallow aquifer, Fallon area, Churchill County, Nevada

    Science.gov (United States)

    Seiler, R.L.; Allander, K.K.

    1993-01-01

    The Truckee-Carson-Pyramid Lake Water Rights Settlement Act of 1990 directed the U.S. Fish and Wildlife Service to acquire water rights for wetland areas in the Carson Desert, Nevada. The public is concerned that htis acquisition of water rights and delivery of the water directly to wildlife areas would result in less recharge to the shallow ground water in the Fallon area and cause domestic wells to go dry. In January 1992, the U.S. Geological Survey, in cooperation with U.S. Fish and Wildlife Service, began a study of the shallow ground-water system in the Fallon area in Churchill County, Nevada. A network of 126 wells in the study area was monitored. Between January and November 1992, water levels in most wells declined, usually less than 2 feet. The maximum measured decline over this period was 2.68 feet in a well near Stillwater Marsh. Between April and July, however, water levels rose in irrigated areas, typically 1 to 2 feet. Newlands Project water deliveries to the study area began soon after the turn of the century. Since then, water levels have risen more than 15 feet across much of the study area. Water lost from unlined irrigtiaon canals caused the stage in Big Soda Lake to rise nearly 60 feet; ground-water levels near the lake have risen 30 to 40 feet. The depth to water in most irrigated areas is now less than 10 feet. The altitude of the water table ranges from 4.025 feet above sea level 11 miles west of Fallon to 3,865 feet in the Stillwater Marsh area. Ground water flows eastward and divides; some flow goes to the northeast toward the Carson Sink and Stillwater areas, and some goes southeastward to Carson Lake.

  18. Inactivation of Heterosigma akashiwo in ballast water by circular orifice plate-generated hydrodynamic cavitation.

    Science.gov (United States)

    Feng, Daolun; Zhao, Jie; Liu, Tian

    2016-01-01

    The discharge of alien ballast water is a well-known, major reason for marine species invasion. Here, circular orifice plate-generated hydrodynamic cavitation was used to inactivate Heterosigma akashiwo in ballast water. In comparison with single- and multihole orifice plates, the conical-hole orifice plate yielded the highest inactivation percentage, 51.12%, and consumed only 6.84% energy (based on a 50% inactivation percentage). Repeating treatment, either using double series-connection or circling inactivation, elevated the inactivation percentage, yet consumed much more energy. The results indicate that conical-hole-generated hydrodynamic cavitation shows great potential as a pre-inactivation method for ballast water treatment.

  19. Sea Levels Online: Sea Level Variations of the United States Derived from National Water Level Observation Network Stations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Water level records are a combination of the fluctuations of the ocean and the vertical land motion at the location of the station. Monthly mean sea level (MSL)...

  20. Brackish Water Desalination Coupled With Wastewater Treatment and Electricity Generation

    Directory of Open Access Journals (Sweden)

    Zainab Ziad Ismail

    2015-05-01

    Full Text Available A new bio-electrochemical system was proposed for simultaneous removal of organic matters and salinity from actual domestic wastewater and synthetically prepared saline water, respectively. The performance of a three-chambered microbial osmotic fuel cell (MOFC provided with forward osmosis (FO membrane and cation exchange membrane (CEM was evaluated with respect to the chemical oxygen demand (COD removal from wastewater, electricity generation, and desalination of saline water. The MOFC wasinoculated with activated sludge and fueled with actual domestic wastewater. Results revealed that maximum removal efficiency of COD from wastewater, TDS removal efficiency from saline water, power density, and current density were 96%, 90%, 30.02 mW/m2, and 107.20 mA/m2, respectively.

  1. In Conversation: David Brooks on Water Scarcity and Local-level ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2010-11-26

    Nov 26, 2010 ... While sound water management requires action from all levels, ... Local management is certainly an essential component in managing the world's water crisis. ... case studies that show the promise of local water management.

  2. Groundwater-level change and evaluation of simulated water levels for irrigated areas in Lahontan Valley, Churchill County, west-central Nevada, 1992 to 2012

    Science.gov (United States)

    Smith, David W.; Buto, Susan G.; Welborn, Toby L.

    2016-09-14

    The acquisition and transfer of water rights to wetland areas of Lahontan Valley, Nevada, has caused concern over the potential effects on shallow aquifer water levels. In 1992, water levels in Lahontan Valley were measured to construct a water-table map of the shallow aquifer prior to the effects of water-right transfers mandated by the Fallon Paiute-Shoshone Tribal Settlement Act of 1990 (Public Law 101-618, 104 Stat. 3289). From 1992 to 2012, approximately 11,810 water-righted acres, or 34,356 acre-feet of water, were acquired and transferred to wetland areas of Lahontan Valley. This report documents changes in water levels measured during the period of water-right transfers and presents an evaluation of five groundwater-flow model scenarios that simulated water-level changes in Lahontan Valley in response to water-right transfers and a reduction in irrigation season length by 50 percent.Water levels measured in 98 wells from 2012 to 2013 were used to construct a water-table map. Water levels in 73 of the 98 wells were compared with water levels measured in 1992 and used to construct a water-level change map. Water-level changes in the 73 wells ranged from -16.2 to 4.1 feet over the 20-year period. Rises in water levels in Lahontan Valley may correspond to annual changes in available irrigation water, increased canal flows after the exceptionally dry and shortened irrigation season of 1992, and the increased conveyance of water rights transferred to Stillwater National Wildlife Refuge. Water-level declines generally occurred near the boundary of irrigated areas and may be associated with groundwater pumping, water-right transfers, and inactive surface-water storage reservoirs. The largest water-level declines were in the area near Carson Lake.Groundwater-level response to water-right transfers was evaluated by comparing simulated and observed water-level changes for periods representing water-right transfers and a shortened irrigation season in areas near Fallon

  3. Predictive modelling of noise level generated during sawing of rocks

    Indian Academy of Sciences (India)

    This paper presents an experimental and statistical study on noise level generated during of rock sawing by circular diamond sawblades. Influence of the operating variables and rock properties on the noise level are investigated and analysed. Statistical analyses are then employed and models are built for the prediction of ...

  4. Impact of water-level changes to aquatic vegetation in small oligotrophic lakes

    Directory of Open Access Journals (Sweden)

    Egert VANDEL

    2016-06-01

    Full Text Available This study demonstrates the effect of drastic water-level changes to the aquatic vegetation in three small oligotrophic lakes situated in Kurtna Kame Field in north-eastern Estonia. The area holds around 40 lakes in 30 km2 of which 18 lakes are under protection as Natura Habitat lakes (Natura 2000 network. The area is under a strong human impact as it is surrounded by oil shale mines, sand quarry, peat harvesting field etc. The most severe impact comes from the groundwater intake established in 1972 in the vicinity of three studied lakes. The exploitation of groundwater led to drastic water-level drops. In 1980s the water-level drops were measured to be up to 3 to 4 meters compared to the levels of 1946. Lake Martiska and Lake Kuradijärv were severely affected and only 29% and 45% of lake area respectively and 21% of initial volume remained. Both lakes were described as oligotrophic lakes before severe human impact and held characteristic macrophytes such as Isoëtes lacustris L., Sparganium angustifolium Michx and Lobelia dortmanna L. As the water level declined the lakes lost their rare characteristic species and can now be described more as a meso- or even eutrophic lakes. When the volume of groundwater abstraction decreased in the 1990s the water levels started to recover but did not reach the natural levels of pre-industrialized era. Also the vegetation did not show any signs of recovery. In 2012 the pumping rates increased again causing a new rapid decline in water levels which almost exceed the previous minimum levels. The water-level monitoring alongside with the macrophyte monitoring data gives us a good case study on how the long term abrupt water-level changes can affect the aquatic vegetation

  5. Device for controlling water supply to nuclear reactor

    International Nuclear Information System (INIS)

    Iwasaki, Toshio.

    1974-01-01

    Object: To smoothly control automatic water supply for realizing stable operation of a nuclear reactor by providing a flow rate limiting signal selection circuit and a preferential circuit in a water supply control device for a nuclear reactor wherein the speed of a recirculation pump may be changed in two-steps. Structure: Opening angle signals for a water supply regulating valve are controlled by a nuclear reactor water level signal, a vapor flow rate signal and a supplied water flow rate signal through an adder and an adjuster in response to a predetermined water level setting signal. When the water in the reactor is maintained at a predetermined level, a selection circuit receives a water pump condition signal for selecting one of the signals from a supplied water rate limiting signal generator generating signals for indicating whether one or two water supply pumps are operated. A low value preferential circuit passes the lower of the values generated from the selection circuit and the adder. The selection circuit receives a recirculation pump condition signal and selects either one of the signals from the supplied water flow rate limiting signal generator operated at high speed or low speed. A high value preferential circuit passes the higher value

  6. Concentration of radionuclides in fresh water fish downstream of Rancho Seco Nuclear Generating Plant

    International Nuclear Information System (INIS)

    Noshkin, V.E.; Eagle, R.J.; Dawson, J.M.; Brunk, J.L.; Wong, X.M.

    1984-01-01

    Fish were collected for radionuclide analysis over a 5-month period in 1984 from creeks downstream of the Rancho Seco Nuclear Generating Plant, which has been discharging quantities of some fission and activation products to the waterway since 1981. Among the fish, the bluegill was selected for intensive study because it is very territorial and the radionuclide concentrations detected should be representative of the levels in the local environment at the downstream locations sampled. Among the gamma-emitting radionuclides routinely released, only 134 Cs and 137 Cs were detected in the edible flesh of fish. Concentrations in the flesh of fish decreased with distance from the plant. The relationship between concentration and distance was determined to be exponential. Exponential equations were generated to estimate concentrations in fish at downstream locations where no site-specific information was available. Mean concentrations of 137 Cs in bluegill collected during April, May, July and August from specific downstream stations were not significantly different in spite of the release of 131 mCi to the creeks between April and August. The concentrations in fish are not responding to changes in water concentrations brought about by plant discharges. Diet appears to be a more significant factor than size or weight or water concentration in regulating body burdens of 137 Cs in these fish

  7. Radio Frequency Based Water Level Monitor and Controller for ...

    African Journals Online (AJOL)

    Similarly, the control unit of the prototype performs automatic switching control of on and off on a single phase centrifugal water pump, 220volts, 0.5hp motor via a motor driver circuit (relay). It also incorporates a buzzer that beeps briefly when water level hits 100%, thus causing the pump to be switched off but when water ...

  8. Water-level altitudes 2009 and water-level changes in the Chicot, Evangeline, and Jasper Aquifers and compaction 1973-2008 in the Chicot and Evangeline Aquifers, Houston-Galveston Region, Texas

    Science.gov (United States)

    Kasmarek, Mark C.; Houston, Natalie A.; Ramage, Jason K.

    2009-01-01

    This report, done in cooperation with the Harris-Galveston Subsidence District, the City of Houston, the Fort Bend Subsidence District, and the Lone Star Groundwater Conservation District, is one in an annual series of reports that depicts water-level altitudes and water-level changes in the Chicot, Evangeline, and Jasper aquifers, and compaction in the Chicot and Evangeline aquifers in the Houston-Galveston region, Texas. The report (excluding appendixes) contains 16 sheets and 15 tables: 3 sheets are maps showing current-year (2009) water-level altitudes for each aquifer, respectively; 3 sheets are maps showing 1-year (2008-09) water-level changes for each aquifer, respectively; 3 sheets are maps showing 5-year (2004-09) water-level changes for each aquifer, respectively; 4 sheets are maps showing long-term (1990-2009 and 1977-2009) water-level changes for the Chicot and Evangeline aquifers, respectively; 1 sheet is a map showing long-term (2000-2009) water-level change for the Jasper aquifer; 1 sheet is a map showing site locations of borehole extensometers; and 1 sheet comprises graphs showing measured compaction of subsurface material at the sites from 1973 or later through 2008, respectively. Tables listing the data used to construct the aquifer-data maps and the compaction graphs are included.

  9. A sub-tank water-saving drinking water station

    Science.gov (United States)

    Zhang, Ting

    2017-05-01

    "Thousands of boiling water" problem has been affecting people's quality of life and good health, and now most of the drinking fountains cannot effectively solve this problem, at the same time, ordinary drinking water also has high energy consumption, there are problems such as yin and yang water. Our newly designed dispenser uses a two-tank heating system. Hot water after heating, into the insulation tank for insulation, when the water tank in the water tank below a certain water level, the cold water and then enter the heating tank heating. Through the water flow, tank volume and other data to calculate the time required for each out of water, so as to determine the best position of the water level control, summed up the optimal program, so that water can be continuously uninterrupted supply. Two cans are placed up and down the way, in the same capacity on the basis of the capacity of the container, the appropriate to reduce its size, and increase the bottom radius, reduce the height of its single tank to ensure that the overall height of two cans compared with the traditional single change. Double anti-dry design, to ensure the safety of the use of drinking water. Heating tank heating circuit on and off by the tank of the float switch control, so that the water heating time from the tank water level control, to avoid the "thousands of boiling water" generation. The entry of cold water is controlled by two solenoid valves in the inlet pipe, and the opening and closing of the solenoid valve is controlled by the float switch in the two tanks. That is, the entry of cold water is determined by the water level of the two tanks. By designing the control scheme cleverly, Yin and yang water generation. Our design completely put an end to the "thousands of boiling water", yin and yang water, greatly improving the drinking water quality, for people's drinking water safety provides a guarantee, in line with the concept of green and healthy development. And in the small

  10. Measurement of low levels of cesium-137 in water

    International Nuclear Information System (INIS)

    Milham, R.C.; Kantelo, M.V.

    1984-10-01

    Large volume water sampling systems were developed to measure very low levels of cesium-137 in river water and in finished water from water treatment plants. Three hundred to six hundred liters of filtered water are passed through the inorganic ion exchanger potassium cobalti-ferrocyanide to remove greater than 90% of the cesium. Measurement of cesium-137 by gamma ray spectrometry results in a sensitivity of 0.001 pCi/L. Portable as well as stationary samplers were developed to encompass a variety of applications. Results of a one year study of water from the Savannah River and from water treatment plants processing Savannah River water are presented. 3 references, 7 figures

  11. Water-level altitudes 2015 and water-level changes in the Chicot, Evangeline, and Jasper aquifers and compaction 1973-2014 in the Chicot and Evangeline aquifers, Houston-Galveston region, Texas

    Science.gov (United States)

    Kasmarek, Mark C.; Ramage, Jason K.; Houston, Natalie A.; Johnson, Michaela R.; Schmidt, Tiffany S.

    2015-01-01

    Most of the land-surface subsidence in the Houston-Galveston region, Texas, has occurred as a direct result of groundwater withdrawals for municipal supply, commercial and industrial use, and irrigation that depressured and dewatered the Chicot and Evangeline aquifers, thereby causing compaction of the aquifer sediments, mostly in the fine-grained silt and clay layers. This report, prepared by the U.S. Geological Survey in cooperation with the Harris-Galveston Subsidence District, City of Houston, Fort Bend Subsidence District, Lone Star Groundwater Conservation District, and Brazoria County Groundwater Conservation District, is one in an annual series of reports depicting water-level altitudes and water-level changes in the Chicot, Evangeline, and Jasper aquifers and measured cumulative compaction of subsurface sediments in the Chicot and Evangeline aquifers in the Houston-Galveston region. The report contains regional-scale maps depicting approximate 2015 water-level altitudes (represented by measurements made during December 2014–March 2015) for the Chicot, Evangeline, and Jasper aquifers; maps depicting 1-year (2014–15) water-level changes for each aquifer; maps depicting approximate contoured 5-year (2010–15) water-level changes for each aquifer; maps depicting approximate contoured long-term (1990–2015 and 1977–2015) water-level changes for the Chicot and Evangeline aquifers; a map depicting approximate contoured long-term (2000–15) water-level changes for the Jasper aquifer; a map depicting locations of borehole-extensometer sites; and graphs depicting measured cumulative compaction of subsurface sediments at the borehole extensometers during 1973–2014. Three tables listing the water-level data used to construct each water-level map for each aquifer and a table listing the measured cumulative compaction data for each extensometer site and graphs are included.

  12. Water-level altitudes 2012 and water-level changes in the Chicot, Evangeline, and Jasper aquifers and compaction 1973-2011 in the Chicot and Evangeline aquifers, Houston-Galveston region, Texas

    Science.gov (United States)

    Kasmarek, Mark C.; Johnson, Michaela R.; Ramage, Jason K.

    2012-01-01

    Most of the subsidence in the Houston–Galveston region, Texas, has occurred as a direct result of groundwater withdrawals for municipal supply, commercial and industrial use, and irrigation that depressured and dewatered the Chicot and Evangeline aquifers and caused compaction of the clay layers of the aquifer sediments. This report—prepared by the U.S. Geological Survey in cooperation with the Harris– Galveston Subsidence District, City of Houston, Fort Bend Subsidence District, Lone Star Groundwater Conservation District, and Brazoria County Groundwater Conservation District—is one in an annual series of reports depicting water-level altitudes and water-level changes in the Chicot, Evangeline, and Jasper aquifers and compaction in the Chicot and Evangeline aquifers in the Houston–Galveston region. The report contains maps showing approximate water-level altitudes for 2012 (calculated from measurements of water levels in wells made during December 2011–February 2012) for the Chicot, Evangeline, and Jasper aquifers; maps showing 1-year (2011–12) water-level-altitude changes for each aquifer; maps showing 5-year (2007–12) water-levelaltitude changes for each aquifer; maps showing long-term (1990–2012 and 1977–2012) water-level-altitude changes for the Chicot and Evangeline aquifers; a map showing long-term (2000–12) water-level-altitude change for the Jasper aquifer; a map showing locations of borehole extensometer sites; and graphs showing measured compaction of subsurface sediments at the extensometers from 1973 (or later) through 2011. Tables listing the data that were used to construct each water-level map for each aquifer and the cumulative compaction graphs are included.

  13. Graphite-water steam-generating reactor in the USSR

    Energy Technology Data Exchange (ETDEWEB)

    Dollezhal, N A [AN SSSR, Moscow

    1981-10-01

    One of the types of power reactor used in the USSR is the graphite-water steam-generating reactor RBMK. This produces saturated steam at a pressure of 7MPa. Reactors giving 1GWe each have been installed at the Leningrad, Kursk, Chernobyl and other power stations. Further stations using reactors of this type are being built. A description is given of the fuel element design, and of the layout of the plant. The main characteristics of RBMK reactors using fuel of rated and higher enrichment are listed.

  14. Remote-controlled television for locating leaking tubes in pressurized-water reactor steam generators

    International Nuclear Information System (INIS)

    Cormault, P.; Denis, J.

    1978-01-01

    The Scarabee system is designed for observation of the tubes in water boxes of pressurized-water reactor nuclear-power-station steam generators. It consists essentially of a camera and a projector used as a marker, both of which swivel freely. The whole unit is housed in a water-tight container which can easily be decontaminated. Remote control of camera and marker movement is carried out from a console. (author)

  15. SNR-steam generator design with respect to large sodium water reactions

    International Nuclear Information System (INIS)

    Jong, J.J. de; Kellner, A.; Florie, C.J.L.

    1984-01-01

    This paper deals with the experiences gained during the licensing procedure for the steam generators for the SNR 300 LMFBR regarding large sodium-water reactions. A description is given of the different calculations executed to investigate the effects of large leaks on the 85 MW helical coiled and straight tube steam generators. The investigations on the helical coiled steam generators are divided in the formulations of fluid behaviour, dynamic force calculations, dynamic response calculation and finally stress analyses. Several results are shown. The investigations on the straight tube steam generators are performed using models describing fluid-structure interaction, coupled with stress analyses. Several results are presented. A description is given of the problems and necessary construction changes during the licensing process. Advises are given for future analyses and design concepts for second generation commercial size LMFBR steam generators with respect to large leaks; based on the experience, gained with SNR 300, and using some new calculations for SNR 2. (author)

  16. Estimation of urban surface water at subpixel level from neighborhood pixels using multispectral remote sensing image (Conference Presentation)

    Science.gov (United States)

    Xie, Huan; Luo, Xin; Xu, Xiong; Wang, Chen; Pan, Haiyan; Tong, Xiaohua; Liu, Shijie

    2016-10-01

    by neighboring pure land or pure water pixels within a distance. To obtaining the most representative endmembers in SMA, we designed an adaptive iterative endmember selection method based on the spatial similarity of adjacent pixels. According to the spectral similarity in a spatial adjacent region, the spectrum of land endmember is determined by selecting the most representative land pixel in a local window, and the spectrum of water endmember is determined by calculating an average of the water pixels in the local window. The proposed hierarchical processing method based on WI and SMA (WISMA) is applied to urban areas for reliability evaluation using the Landsat-8 Operational Land Imager (OLI) images. For comparison, four methods at pixel level and subpixel level were chosen respectively. Results indicate that the water maps generated by the proposed method correspond as closely with the truth water maps with subpixel precision. And the results showed that the WISMA achieved the best performance in water mapping with comprehensive analysis of different accuracy evaluation indexes (RMSE and SE).

  17. Water-level altitudes 2013 and water-level changes in the Chicot, Evangeline, and Jasper aquifers and compaction 1973--2012 in the Chicot and Evangeline aquifers, Houston-Galveston region, Texas

    Science.gov (United States)

    Kasmarek, Mark C.; Johnson, Michaela R.; Ramage, Jason K.

    2013-01-01

    Most of the subsidence in the Houston-Galveston region, Texas, has occurred as a direct result of groundwater withdrawals for municipal supply, commercial and industrial use, and irrigation that depressured and dewatered the Chicot and Evangeline aquifers, thereby causing compaction mostly in the clay and silt layers of the aquifer sediments. This report, prepared by the U.S. Geological Survey in cooperation with the Harris-Galveston Subsidence District, City of Houston, Fort Bend Subsidence District, Lone Star Groundwater Conservation District, and Brazoria County Groundwater Conservation District, is one in an annual series of reports depicting water-level altitudes and water-level changes in the Chicot, Evangeline, and Jasper aquifers and measured compaction of subsurface sediments in the Chicot and Evangeline aquifers in the Houston-Galveston region. The report contains maps depicting approximate water-level altitudes for 2013 (represented by measurements made during December 2012-February 2013) for the Chicot, Evangeline, and Jasper aquifers; maps depicting 1-year (2012-13) water-level changes for each aquifer; maps depicting 5-year (2008--13) water-level changes for each aquifer; maps depicting long-term (1990-2013 and 1977-2013) water-level changes for the Chicot and Evangeline aquifers; a map depicting long-term (2000-13) water-level changes for the Jasper aquifer; a map depicting locations of borehole-extensometer sites; and graphs depicting measured compaction of subsurface sediments at the extensometers during 1973-2012. Tables listing the data used to construct each water-level map for each aquifer and the compaction graphs are included.

  18. Return momentum effect on reactor coolant water level distribution during mid-loop conditions

    International Nuclear Information System (INIS)

    Seo, Jae Kwang; Yang, Jae Young; Park, Goon Cherl

    2001-01-01

    An accurate prediction of the Reactor Coolant System( RCS) water level is of importance in the determination of the allowable operating range to ensure safety during mid-loop operations. However, complex hydrualic phenomena induced by the Shutdown Cooling System (SCS) return momentum causes different water levels from those in the loop where the water level indicators are located. This was apparently observed at the pre-core cold hydro test of the Younggwang Nuclear Unit 3 (YGN 3) in Korea. In this study, in order to analytically understand the effect of the SCS return momentum on the RCS water level distribution, a model using a one-dimensional momentum and energy conservation for cylindrical channel, hydraulic jump in operating cold leg, water level build-up at the Reactor Vessel (RV) inlet nozzle, Bernoulli constant in downcomer region, and total water volume conservation has been developed. The model predicts the RCS water levels at various RCS locations during the mid-loop conditions and the calculation results were compared with the test data. The analysis shows that the hydraulic jump in the operating cold legs, in conjuction with the pressure drop throughout the RCS, is the main cause creating the water level differences at various RCS locations. The prediction results provide good explanations for the test data and show the significant effect of the SCS return momentum on the RCS water levels

  19. Coupling of sea level and tidal range changes, with implications for future water levels.

    Science.gov (United States)

    Devlin, Adam T; Jay, David A; Talke, Stefan A; Zaron, Edward D; Pan, Jiayi; Lin, Hui

    2017-12-05

    Are perturbations to ocean tides correlated with changing sea-level and climate, and how will this affect high water levels? Here, we survey 152 tide gauges in the Pacific Ocean and South China Sea and statistically evaluate how the sum of the four largest tidal constituents, a proxy for the highest astronomical tide (HAT), changes over seasonal and interannual time scales. We find that the variability in HAT is significantly correlated with sea-level variability; approximately 35% of stations exhibit a greater than ±50 mm tidal change per meter sea-level fluctuation. Focusing on a subset of three stations with long records, probability density function (PDF) analyses of the 95% percentile exceedance of total sea level (TSL) show long-term changes of this high-water metric. At Hong Kong, the increase in tides significantly amplifies the risk caused by sea-level rise. Regions of tidal decrease and/or amplification highlight the non-linear response to sea-level variations, with the potential to amplify or mitigate against the increased flood risk caused by sea-level rise. Overall, our analysis suggests that in many regions, local flood level determinations should consider the joint effects of non-stationary tides and mean sea level (MSL) at multiple time scales.

  20. Power generation versus fuel production in light water hybrid reactors

    International Nuclear Information System (INIS)

    Greenspan, E.

    1977-06-01

    The economic potentials of fissile-fuel-producing light-water hybrid reactors (FFP-LWHR) and of fuel-self-sufficient (FSS) LWHR's are compared. A simple economic model is constructed that gives the capital investment allowed for the hybrid reactor so that the cost of electricity generated in the hybrid based energy system equals the cost of electricity generated in LWR's. The power systems considered are LWR, FSS-LWHR, and FFP-LWHR plus LWR, both with and without plutonium recycling. The economic potential of FFP-LWHR's is found superior to that of FSS-LWHR's. Moreover, LWHR's may compete, economically, with LWR's. Criteria for determining the more economical approach to hybrid fuel or power production are derived for blankets having a linear dependence between F and M. The examples considered favor the power generation rather than fuel production

  1. Miniaturized Water Flow and Level Monitoring System for Flood Disaster Early Warning

    Science.gov (United States)

    Ifedapo Abdullahi, Salami; Hadi Habaebi, Mohamed; Surya Gunawan, Teddy; Rafiqul Islam, MD

    2017-11-01

    This study presents the performance of a prototype miniaturised water flow and water level monitoring sensor designed towards supporting flood disaster early warning systems. The design involved selection of sensors, coding to control the system mechanism, and automatic data logging and storage. During the design phase, the apparatus was constructed where all the components were assembled using locally sourced items. Subsequently, under controlled laboratory environment, the system was tested by running water through the inlet during which the flow rate and rising water levels are automatically recorded and stored in a database via Microsoft Excel using Coolterm software. The system is simulated such that the water level readings measured in centimeters is output in meters using a multiplicative of 10. A total number of 80 readings were analyzed to evaluate the performance of the system. The result shows that the system is sensitive to water level rise and yielded accurate measurement of water level. But, the flow rate fluctuates due to the manual water supply that produced inconsistent flow. It was also observed that the flow sensor has a duty cycle of 50% of operating time under normal condition which implies that the performance of the flow sensor is optimal.

  2. Evaluation of long-term water-level declines in basalt aquifers near Mosier, Oregon

    Science.gov (United States)

    Burns, Erick R.; Morgan, David S.; Lee, Karl K.; Haynes, Jonathan V.; Conlon, Terrence D.

    2012-01-01

    local combination of geology and well construction have resulted in aquifer commingling at a particular well, the well needs to be tested by measuring intraborehole flow. During geophysical testing of one known commingling well, the flow rate through the well between aquifers ranged between 70 and 135 gallons per minute (11-22 percent of total annual pumping in the study area). Historically, when aquifer water levels were 150-200 feet higher, this flow rate would have been correspondingly higher. 5. Because aquifer commingling through well boreholes is likely the dominant cause of aquifer declines, flow simulations were conducted to evaluate the benefit of repairing wells in specified locations and the benefit of recharging aquifers using diverted flow from study area creeks. As part of this analysis, maps were generated that show which areas are more vulnerable to commingling. These maps indicate that the value of repairing wells in the area generally coincident with the OWRD administrative area is higher than in areas farther upstream in the watershed. Simulation results also indicate that artificial recharge of the aquifers using diverted creek water will not significantly improve water levels in the aquifer system unless at least some commingling wells are repaired first. Repairs would entail construction of wells in a manner that prevents commingling of multiple aquifers. The value of artificially recharging the aquifers improves as more wells are repaired because the aquifer system more efficiently stores water.

  3. Determination of leveled costs of electric generation for gas plants, coal and nuclear

    International Nuclear Information System (INIS)

    Alonso V, G.; Palacios H, J.C.; Ramirez S, J.R.; Gomez, A.

    2005-01-01

    The present work analyzes the leveled costs of electric generation for different types of nuclear reactors known as Generation III, these costs are compared with the leveled costs of electric generation of plants with the help of natural gas and coal. In the study several discount rates were used to determine their impact in the initial investment. The obtained results are comparable with similar studies and they show that it has more than enough the base of the leveled cost the nuclear option it is quite competitive in Mexico. Also in this study it is also thinks about the economic viability of a new nuclear power station in Mexico. (Author)

  4. Determination of Heavy Metal Levels in Various Industrial Waste Waters

    Directory of Open Access Journals (Sweden)

    Mustafa Şahin Dündar

    2012-06-01

    Full Text Available Important part of the environmetal pollution consists of waste water and water pollution. The water polluted by anthropogenical, industrial, and agricultural originated sources are defined as waste waters which are the main pollution sources for reservoirs, rivers, lakes, and seas. In this work, waste waters of leather, textile, automotive side, and metal plating industries were used to determine the levels of Cu, Zn, Cr, Pb and Ni by using Flame Atomic Absorption Spectrometer. As a result, highest mean levels of copper in supernatants of plating and textile industries were observed as 377,18 ng ml-1, respectively 103 ng ml-1 lead and 963,6 ng ml-1 nickel in plating industry, 1068,2 ng ml-1 zinc and 14557,1 ng ml-1 chromium in plating and leather industries were determined.

  5. User instructions for levelized power generation cost codes using an IBM-type PC

    International Nuclear Information System (INIS)

    Coen, J.J.; Delene, J.G.

    1989-01-01

    Programs for the calculation of levelized power generation costs using an IBM or compatible PC are described. Cost calculations for nuclear plants and coal-fired plants include capital investment cost, operation and maintenance cost, fuel cycle cost, decommissioning cost, and total levelized power generation cost. 7 refs., 36 figs., 4 tabs

  6. Water-Level Analysis for Cumberland Sound, Georgia

    National Research Council Canada - National Science Library

    Kraus, Nicholas

    1997-01-01

    .... The channel through St Marys Entrance is maintained at a 50-ft depth through significant dredging that occurred from 1986-1988 Questions arose as to whether this dredging had raised the water level in Cumberland Sound. The U.S...

  7. Development of active acoustic method for water leak detection of LMFBR steam generators

    International Nuclear Information System (INIS)

    Kumagai, Hiromichi; Yoshida, Kazuo; Kinoshita, Izumi

    2001-01-01

    In order to prevent the expansion of tube damage and to maintain structural integrity in the steam generators (SGs) of fast breeder reactors (FBRs), it is necessary to detect precisely and immediately the leakage of water from heat transfer tubes. Therefore, an active acoustic method, which detects the sound attenuation due to bubbles generated in the sodium-water reactions, is being developed. In this study, in order to evaluate the detection sensitivity of the active method, the signal processing methods for emitter and receiver and the detection method for leakage are investigated experimentally. In-water experiments performed by using an SG full-sector model that simulates the actual SGs. As an experimental result, the received sound attenuation for 10s was more than 10dB from air bubble injection when injected bubble of 10 l/s (equivalence water leak rate about 10 g/s.) The attenuation of sound are least affected by bubble injection position of heat transfer tubes bunch department. It is clarified that the background noise hardly influenced water leak detection performance as a result of having examined influence of background noise. (author)

  8. Advancements in oxygen generation and humidity control by water vapor electrolysis

    Science.gov (United States)

    Heppner, D. B.; Sudar, M.; Lee, M. C.

    1988-01-01

    Regenerative processes for the revitalization of manned spacecraft atmospheres or other manned habitats are essential for realization of long-term space missions. These processes include oxygen generation through water electrolysis. One promising technique of water electrolysis is the direct conversion of the water vapor contained in the cabin air to oxygen. This technique is the subject of the present program on water vapor electrolysis development. The objectives were to incorporate technology improvements developed under other similar electrochemical programs and add new ones; design and fabricate a mutli-cell electrochemical module and a testing facility; and demonstrate through testing the improvements. Each aspect of the water vapor electrolysis cell was reviewed. The materials of construction and sizing of each element were investigated analytically and sometime experimentally. In addition, operational considerations such as temperature control in response to inlet conditions were investigated. Three specific quantitative goals were established.

  9. Surface Water Connectivity, Flow Pathways and Water Level Fluctuation in a Cold Region Deltaic Ecosystem

    Science.gov (United States)

    Peters, D. L.; Niemann, O.; Skelly, R.; Monk, W. A.; Baird, D. J.

    2017-12-01

    The Peace-Athabasca Delta (PAD) is a 6000 km2 deltaic floodplain ecosystem of international importance (Wood Buffalo National Park, Ramsar Convention, UNESCO World Heritage, and SWOT satellite water level calibration/validation site). The low-relief floodplain formed at the confluence of the Peace, Athabasca and Birch rivers with Lake Athabasca. More than 1000 wetland and lake basins have varying degrees of connectivity to the main flow system. Hydroperiod and water storage is influenced by ice-jam and open-water inundations and prevailing semi-arid climate that control water drawdown. Prior studies have identified pathways of river-to-wetland floodwater connection and historical water level fluctuation/trends as a key knowledge gaps, limiting our knowledge of deltaic ecosystem status and potential hydroecological responses to climate change and upstream water alterations to flow contributions. To address this knowledge gap, surface elevation mapping of the PAD has been conducted since 2012 using aerial remote sensing Light Detection and Ranging (LiDAR), plus thousands of ground based surface and bathymetric survey points tied to Global Positioning System (GPS) were obtained. The elevation information was used to develop a high resolution digital terrain model to simulate and investigate surface water connectivity. Importantly, the surveyed areas contain a set of wetland monitoring sites where ground-based surface water connectivity, water level/depth, water quality, and aquatic ecology (eg, vegetation, macroinvertebrate and muskrat) have been examined. The goal of this presentation is to present an assessment of: i) surface water fluctuation and connectivity for PAD wetland sites; ii) 40+ year inter-annual hydroperiod reconstruction for a perched basin using a combination of field measurements, remote sensing estimates, and historical documents; and iii) outline an approach to integrate newly available hydro-bio-geophysical information into a novel, multi

  10. Hydrostatic Water Level Systems At Homestake DUSEL

    Science.gov (United States)

    Stetler, L. D.; Volk, J. T.

    2009-12-01

    Two arrays of Fermilab-style hydrostatic water level sensors have been installed in the former Homestake gold mine in Lead, SD, the site of the new Deep Underground Science and Engineering Laboratory (DUSEL). Sensors were constructed at Fermilab from 8.5 cm diameter PVC pipe (housing) that was sealed on the ends and fit with a proximity sensor. The instrument have a height of 10 cm. Two ports in each sensor housing provide for connectivity, the upper port for air and the bottom port for water. Multiple instruments connected in series provide a precise water level and differences in readings between successive sensors provide for ground tilt to be resolved. Sensor resolution is 5 μm per count and has a range of approximately 1.25 cm. Data output from each sensor is relayed to a Fermilab-constructed readout card that also has temperature/relative humidity and barometric pressure sensors connected. All data are relayed out of the mine by fiber optic cable and can be recorded by Ethernet at remote locations. The current arrays have been installed on the 2000-ft level (610 m) and consist of six instruments in each array. Three sensors were placed in a N-S oriented drift and three in an E-W oriented drift. Using this orientation, it is anticipated that tilt direction may be resolved in addition to overall tilt magnitude. To date the data show passage of earth tides and frequency analysis has revealed five components to this signal, three associated with the semi-diurnal (~12.4 hr) and two with the diurnal (~24.9 hr) tides. Currently, installation methods are being analyzed between concrete pillar and rib-mounting using the existing setup on the 2000-ft level. Using these results, two additional arrays of Fermilab instruments will be installed on the 4550-ft and 4850-ft levels (1387 and 1478 m, respectively). In addition to Fermilab instruments, several high resolution Budker tiltmeters (1 μm resolution) will be installed in the mine workings in the near future, some

  11. Water-level altitudes 2014 and water-level changes in the Chicot, Evangeline, and Jasper aquifers and compaction 1973-2013 in the Chicot and Evangeline aquifers, Houston-Galveston region, Texas

    Science.gov (United States)

    Kasmarek, Mark C.; Johnson, Michaela R.; Ramage, Jason K.

    2014-01-01

    Most of the land-surface subsidence in the Houston-Galveston region, Texas, has occurred as a direct result of groundwater withdrawals for municipal supply, commercial and industrial use, and irrigation that depressured and dewatered the Chicot and Evangeline aquifers, thereby causing compaction of the aquifer sediments, mostly in the fine-grained clay and silt layers. This report, prepared by the U.S. Geological Survey in cooperation with the Harris-Galveston Subsidence District, City of Houston, Fort Bend Subsidence District, Lone Star Groundwater Conservation District, and Brazoria County Groundwater Conservation District, is one in an annual series of reports depicting water-level altitudes and water-level changes in the Chicot, Evangeline, and Jasper aquifers and measured compaction of subsurface sediments in the Chicot and Evangeline aquifers in the Houston-Galveston region. The report contains maps depicting approximate 2014 water-level altitudes (represented by measurements made during December 2013–March 2014) for the Chicot, Evangeline, and Jasper aquifers; maps depicting 1-year (2013–14) water-level changes for each aquifer; maps depicting contoured 5-year (2009–14) water-level changes for each aquifer; maps depicting contoured long-term (1990–2014 and 1977–2014) water-level changes for the Chicot and Evangeline aquifers; a map depicting contoured long-term (2000–14) water-level changes for the Jasper aquifer; a map depicting locations of borehole-extensometer sites; and graphs depicting measured cumulative compaction of subsurface sediments at the borehole extensometers during 1973–2013. Tables listing the data used to construct each water-level map for each aquifer and the compaction graphs are included.

  12. Acoustic sodium-water reaction detection of the Phenix steam generators

    International Nuclear Information System (INIS)

    Carminati, M.; Martin, L.; Sauzaret, A.

    1990-01-01

    The systems for acoustic sodium-water reaction detection and hydrogen detection of the Phenix steam generators as well as systems for monitoring signals analysis and processing are described. It is reported that the results obtained during operation and calibration phases are very encouraging and that industrial equipment showing the same performance are being examined. 6 figs

  13. Determination of PWR core water level using ex-core detectors signals

    International Nuclear Information System (INIS)

    Bernal, Alvaro; Abarca, Agustin; Miro, Rafael; Verdu, Gumersindo

    2013-01-01

    The core water level provides relevant neutronic and thermalhydraulic information of the reactor such as power, k eff and cooling ability; in fact, core water level monitoring could be used to predict LOCA and cooling reduction which may deal with core damage. Although different detection equipment is used to monitor several parameters such as the power, core water level monitoring is not an evident task. However, ex-core detectors can measure the fast neutrons leaking the core and several studies demonstrate the existence of a relationship between fast neutron leakage and core water level due to the shielding effect of the water. In addition, new ex-core detectors are being developed, such as silicon carbide semiconductor radiation detectors, monitoring the neutron flux with higher accuracy and in higher temperatures conditions. Therefore, a methodology to determine this relationship has been developed based on a Monte Carlo calculation using MCNP code and applying variance reduction with adjoint functions based on the adjoint flux obtained with the discrete ordinates code TORT. (author)

  14. The Nuclear option for U.S. electrical generating capacity additions utilizing boiling water reactor technology

    International Nuclear Information System (INIS)

    Garrity, T.F.; Wilkins, D.R.

    1993-01-01

    The technology status of the Advanced Boiling Water (ABWR) and Simplified Boiling Water (SBWR) reactors are presented along with an analysis of the economic potential of advanced nuclear power generation systems based on BWR technology to meet the projected domestic electrical generating capacity need through 2005. The forecasted capacity needs are determined for each domestic North American Electric Reliability Council (NERC) region. Extensive data sets detailing each NERC region's specific generation and load characteristics, and capital and fuel cost parameters are utilized in the economic analysis of the optimal generation additions to meet this need by use of an expansion planning model. In addition to a reference case, several sensitivity cases are performed with regard to capital costs and fuel price escalation

  15. Projections of extreme water level events for atolls in the western Tropical Pacific

    Science.gov (United States)

    Merrifield, M. A.; Becker, J. M.; Ford, M.; Yao, Y.

    2014-12-01

    Conditions that lead to extreme water levels and coastal flooding are examined for atolls in the Republic of the Marshall Islands based on a recent field study of wave transformations over fringing reefs, tide gauge observations, and wave model hindcasts. Wave-driven water level extremes pose the largest threat to atoll shorelines, with coastal levels scaling as approximately one-third of the incident breaking wave height. The wave-driven coastal water level is partitioned into a mean setup, low frequency oscillations associated with cross-reef quasi-standing modes, and wind waves that reach the shore after undergoing high dissipation due to breaking and bottom friction. All three components depend on the water level over the reef; however, the sum of the components is independent of water level due to cancelling effects. Wave hindcasts suggest that wave-driven water level extremes capable of coastal flooding are infrequent events that require a peak wave event to coincide with mid- to high-tide conditions. Interannual and decadal variations in sea level do not change the frequency of these events appreciably. Future sea-level rise scenarios significantly increase the flooding threat associated with wave events, with a nearly exponential increase in flooding days per year as sea level exceeds 0.3 to 1.0 m above current levels.

  16. Direct measurements of secondary water inventory of steam generator PGV-213 in operation

    Energy Technology Data Exchange (ETDEWEB)

    Tarankov, G.A.; Trunov, N.B.; Dranchenko, B.N.; Kamiagin, W.W. [OKB Gidropress (Russian Federation)

    1997-12-31

    Results of weight measurement of PGV-213 steam generator during filling in, heating-up and power increase are described. Special measurement system based on stress gauges has been developed. Method of derivation of secondary water inventory is described. Comparison of the data for two steam generators prove accuracy of the measurements. (orig.). 1 refs.

  17. Direct measurements of secondary water inventory of steam generator PGV-213 in operation

    Energy Technology Data Exchange (ETDEWEB)

    Tarankov, G A; Trunov, N B; Dranchenko, B N; Kamiagin, W W [OKB Gidropress (Russian Federation)

    1998-12-31

    Results of weight measurement of PGV-213 steam generator during filling in, heating-up and power increase are described. Special measurement system based on stress gauges has been developed. Method of derivation of secondary water inventory is described. Comparison of the data for two steam generators prove accuracy of the measurements. (orig.). 1 refs.

  18. Condensation induced water hammer in steam generators

    International Nuclear Information System (INIS)

    Jones, O.C. Jr.; Saha, P.; Wu, B.J.C.; Ginsberg, T.

    1979-06-01

    The case of condensation induced water hammer in nuclear steam generators is summarized, including both feed ring-type and economizer-type geometries. A slug impact model is described and used to demonstrate the parametric dependence of the impact pressures on heat transfer rates, initial pressures, and relative initial slug and void lengths. The results of the parametric study are related also to the economizer geometry and a suggested alternative model is presented. The importance of concerns regarding attenuation of shocks in two-phase media is delineated, and a simple experiment is described which was used to determine negligible attenuation within the accuracy of the experiment for void fractions up to over 30% in bubbly and slug flows

  19. Combined wind, hydropower and photovoltaic systems for generation of electric power and control of water resources

    International Nuclear Information System (INIS)

    Abid, M.; Karimov, K.S.; Akhmedov, K.M.

    2011-01-01

    In this paper the present day energy consumption and potentialities of utilization of wind- and hydropower resources in some Central and Southern Asian Republics, in particular, in the Republic of Tajikistan, Kyrgyzstan and Pakistan are presented. The maximum consumption of electric power is observed in winter time when hydropower is the minimum, but wind power is the maximum. At the same time water is needed mostly in summer time for irrigation and in winter time for generation of electric power. This results in conflicts between countries that utilize water mostly for irrigation and those which use water for generation of electric power. It is proposed that the utilization of water with the supplement of wind and solar energy will facilitate the proper and efficient management of water resources in Central Asia. In the future in Tajikistan, wind power systems with a capacity of 30-100 MW and more will be installed, providing power balance of the country in winter; hence saving water in reservoirs, especially in drought years. This will provide the integration of electricity generated by wind, hydroelectric power and photovoltaic system in the unified energy system of the country. (author)

  20. Effects of Chemistry Parameters of Primary Water affecting Leakage of Steam Generator Tube Cracks

    Energy Technology Data Exchange (ETDEWEB)

    Shin, D. M.; Cho, N. C.; Kang, Y. S.; Lee, K. H. [KHNP CRI, Daejeon (Korea, Republic of)

    2016-10-15

    Degradation of steam generator (SG) tubes can affect pressure boundary tightness. As a defense-in-depth measure, primary to secondary leak monitoring program for steam generators is implemented, and operation is allowed under leakage limits in nuclear power plants. Chemistry parameters that affect steam generator tube leakage due to primary water stress corrosion cracking (PWSCC) are investigated in this study. Tube sleeves were installed to inhibit leakage and improve tube integrity as a part of maintenance methods. Steam generators occurred small leak during operation have been replaced with new steam generators according to plant maintenance strategies. The correlations between steam generator leakage and chemistry parameters are presented. Effects of primary water chemistry parameters on leakage from tube cracks were investigated for the steam generators experiencing small leak. Unit A experienced small leakage from steam generator tubes in the end of operation cycle. It was concluded that increased solubility of oxides due to high pHT could make leakage paths, and low boron concentration lead to less blockage in cracks. Increased dissolved hydrogen may retard crack propagations, but it did not reduce leak rate of the leaking steam generator. In order to inhibit and reduce leakage, pH{sub T} was controlled by servicing cation bed operation. The test results of decreasing pHT indicate low pHT can reduce leak rate of PWSCC cracks in the end of cycle.

  1. Effects of Chemistry Parameters of Primary Water affecting Leakage of Steam Generator Tube Cracks

    International Nuclear Information System (INIS)

    Shin, D. M.; Cho, N. C.; Kang, Y. S.; Lee, K. H.

    2016-01-01

    Degradation of steam generator (SG) tubes can affect pressure boundary tightness. As a defense-in-depth measure, primary to secondary leak monitoring program for steam generators is implemented, and operation is allowed under leakage limits in nuclear power plants. Chemistry parameters that affect steam generator tube leakage due to primary water stress corrosion cracking (PWSCC) are investigated in this study. Tube sleeves were installed to inhibit leakage and improve tube integrity as a part of maintenance methods. Steam generators occurred small leak during operation have been replaced with new steam generators according to plant maintenance strategies. The correlations between steam generator leakage and chemistry parameters are presented. Effects of primary water chemistry parameters on leakage from tube cracks were investigated for the steam generators experiencing small leak. Unit A experienced small leakage from steam generator tubes in the end of operation cycle. It was concluded that increased solubility of oxides due to high pHT could make leakage paths, and low boron concentration lead to less blockage in cracks. Increased dissolved hydrogen may retard crack propagations, but it did not reduce leak rate of the leaking steam generator. In order to inhibit and reduce leakage, pH_T was controlled by servicing cation bed operation. The test results of decreasing pHT indicate low pHT can reduce leak rate of PWSCC cracks in the end of cycle

  2. Development and application of YSJ-1 type oil-water interface level gauge

    International Nuclear Information System (INIS)

    Sun Punan

    2003-01-01

    A new type nuclear device for measuring the oil-water interface level as well as the total liquid level was presented. A series of new methods, such as non-linear fitting of the level, automatic compensations for the deviation caused by the decay of radioactive source, the medium's temperature, etc., were employed. Comparing with other non-nuclear techniques, this device has the following advantages: non-contact surveying, anti-interference of paraffin wax coagulating and a little of repairing. The measuring range is 0-200cm for total liquid level and 0-100cm for oil-water interface level respectively. The measurement precision is 1% for total liquid level and 2% for the interface level respectively. The respond time is ≤10s, the long time stability ≤0.5% FS/48h and the temperature influence ≤0.01% FS /degree C. The gauge can be used in surveying oil-water interface level and total liquid level in oil-water separation tanks on oil fields. It is also suitable to measure the interface level of two kinds of liquids as well as the total liquid level in various storage tanks

  3. Generation of Domestic Hot Water, Space Heating and Driving Pattern Profiles for Integration Analysis of Active Loads in Low Voltage Grids

    DEFF Research Database (Denmark)

    Diaz de Cerio Mendaza, Iker; Pigazo, Alberto; Bak-Jensen, Birgitte

    2013-01-01

    at household level. Despite of the well-known flexible service that this kind of loads can provide, their flexibility is highly dependent of the domestic hot water and space heating demand and the driving habits of each user. This paper presents two methodologies employed to randomly generate thermal power......The changes in the Danish energy sector, consequence of political agreements, are expected to have direct impact in the actual power distribution systems. Large number of electric boiler, heat pumps and electric vehicles are planned and will cope large percentage of the future power consumption...... demand and electric vehicle driving profiles, to be used for power grid calculations. The generated thermal profiles relied on a statistical analysis made from real domestic hot water and space heating data from 25 households of a typical Danish residential area. The driving profiles instead were formed...

  4. Application of an electrochemical chlorine-generation system combined with solar energy as appropriate technology for water disinfection.

    Science.gov (United States)

    Choi, Jusol; Park, Chan Gyu; Yoon, Jeyong

    2013-02-01

    Affordable water disinfection is key to reducing the waterborne disease experienced worldwide where resources are limited. A simple electrochemical system that can generate chlorine as a disinfectant from the electrolysis of sodium chloride is an appropriate technology to produce clean water, particularly if driven by solar energy. This study examined the affordability of an electrochemical chlorine generation system using solar energy and developed the necessary design information for its implementation. A two-electrode batch reactor, equipped with commercial IrO(2)-coated electrodes and a solar panel (approximate area 0.2 m(2)), was used to produce chlorine from a 35g/L solution of NaCl. Within 1 h, sufficient chlorine (0.8 g) was generated to produce clean drinking water for about 80 people for 1 day (target microorganism: Escherichia coli; daily drinking water requirement: 2 L per person; chlorine demand: 4 mg/L; solar power: 650 W/m(2) in Seoul, Korea. Small household batteries were demonstrated to be a suitable alternative power source when there is insufficient solar irradiation. Using a 1 m(2) solar panel, the reactor would take only 15 min in Seoul, Korea, or 7 min in the tropics (solar power 1300 W/m(2)), to generate 1 g of chlorine. The solar-powered electrochemical chlorine generation system for which design information is provided here is a simple and affordable way to produce chlorine with which to convert contaminated water into clean drinking water.

  5. A modified routine analysis of arsenic content in drinking-water in Bangladesh by hydride generation-atomic absorption spectrophotometry.

    Science.gov (United States)

    Wahed, M A; Chowdhury, Dulaly; Nermell, Barbro; Khan, Shafiqul Islam; Ilias, Mohammad; Rahman, Mahfuzar; Persson, Lars Ake; Vahter, Marie

    2006-03-01

    The high prevalence of elevated levels of arsenic in drinking-water in many countries, including Bangladesh, has necessitated the development of reliable and rapid methods for the determination of a wide range of arsenic concentrations in water. A simple hydride generation-atomic absorption spectrometry (HG-AAS) method for the determination of arsenic in the range of microg/L to mg/L concentrations in water is reported here. The method showed linearity over concentrations ranging from 1 to 30 microg/L, but requires dilution of samples with higher concentrations. The detection limit ranged from 0.3 to 0.5 microg/L. Evaluation of the method, using internal quality-control (QC) samples (pooled water samples) and spiked internal QC samples throughout the study, and Standard Reference Material in certain lots, showed good accuracy and precision. Analysis of duplicate water samples at another laboratory also showed good agreement. In total, 13,286 tubewell water samples from Matlab, a rural area in Bangladesh, were analyzed. Thirty-seven percent of the water samples had concentrations below 50 microg/L, 29% below the WHO guideline value of 10 microg/L, and 17% below 1 microg/L. The HG-AAS was found to be a precise, sensitive, and reasonably fast and simple method for analysis of arsenic concentrations in water samples.

  6. Critical water stress levels in Pinus patula seedlings and their ...

    African Journals Online (AJOL)

    Critical water stress levels in Pinus patula seedlings and their relation to measures of seedling morphology. ... Southern Forests: a Journal of Forest Science ... A pot trial was implemented to determine the effect of soil water stress following transplanting on shoot water potential and stomatal conductance of Pinus patula ...

  7. Generation, transport and conduct of radioactive wastes of low and intermediate level

    International Nuclear Information System (INIS)

    Lizcano, D.; Jimenez, J.

    2005-01-01

    The technological development of the last decades produced an increment in the application of the radiations in different human activities. The effect of it has been it the production of radioactive wastes of all the levels. In Mexico, some of the stages of the administration of the waste of low and intermediate level have not been completely resolved, as the case of the treatment and the final storage. In this work aspects of the generation, the transport and the administration of radioactive waste of low and intermediate level produced in the non energy applications from the radioactive materials to national level, indicating the generated average quantities, transported and tried annually by the National Institute of Nuclear Research (ININ). The main generators of wastes in Mexico, classified according to the activity in which the radioactive materials are used its are listed. Some of the main processes of treatment of radioactive wastes broadly applied in the world and those that are used at the moment in our country are also presented. (Author)

  8. Water Level Fluctuations in the Congo Basin Derived from ENVISAT Satellite Altimetry

    Directory of Open Access Journals (Sweden)

    Mélanie Becker

    2014-09-01

    Full Text Available In the Congo Basin, the elevated vulnerability of food security and the water supply implies that sustainable development strategies must incorporate the effects of climate change on hydrological regimes. However, the lack of observational hydro-climatic data over the past decades strongly limits the number of studies investigating the effects of climate change in the Congo Basin. We present the largest altimetry-based dataset of water levels ever constituted over the entire Congo Basin. This dataset of water levels illuminates the hydrological regimes of various tributaries of the Congo River. A total of 140 water level time series are extracted using ENVISAT altimetry over the period of 2003 to 2009. To improve the understanding of the physical phenomena dominating the region, we perform a K-means cluster analysis of the altimeter-derived river level height variations to identify groups of hydrologically similar catchments. This analysis reveals nine distinct hydrological regions. The proposed regionalization scheme is validated and therefore considered reliable for estimating monthly water level variations in the Congo Basin. This result confirms the potential of satellite altimetry in monitoring spatio-temporal water level variations as a promising and unprecedented means for improved representation of the hydrologic characteristics in large ungauged river basins.

  9. Water levels in continuously monitored wells in the Yucca Mountain area, Nevada, 1985--88

    International Nuclear Information System (INIS)

    Luckey, R.R.; Lobmeyer, D.H.; Burkhardt, D.J.

    1993-01-01

    Water levels have been monitored hourly in 15 wells completed in 23 depth intervals in the Yucca Mountain area, Nevada. Water levels were monitored using pressure transducers and were recorded by data loggers. The pressure transducers were periodically calibrated by raising and lowering them in the wells. The water levels were normally measured at approximately the same time that the transducers were calibrated. Where the transducer output appeared reasonable, it was converted to water levels using the calibrations and manual water- level measurements. The amount of transducer output that was converted to water levels ranged from zero for several intervals to about 98 percent for one interval. Fourteen of the wells were completed in Tertiary volcanic rocks and one well was completed in Paleozoic carbonate rocks. Each well monitored from one to four depth intervals. Water-level fluctuation caused by barometric pressure changes and earth tides were observed

  10. Effect of turbine materials on power generation efficiency from free water vortex hydro power plant

    International Nuclear Information System (INIS)

    Sritram, P; Treedet, W; Suntivarakorn, R

    2015-01-01

    The objective of this research was to study the effect of turbine materials on power generation efficiency from the water free vortex hydro power plant made of steel and aluminium. These turbines consisted of five blades and were twisted with angles along the height of water. These blades were the maximum width of 45 cm. and height of 32 cm. These turbines were made and experimented for the water free vortex hydro power plant in the laboratory with the water flow rate of 0.68, 1.33, 1.61, 2.31, 2.96 and 3.63 m 3 /min and an electrical load of 20, 40, 60, 80 and 100 W respectively. The experimental results were calculated to find out the torque, electric power, and electricity production efficiency. From the experiment, the results showed that the maximum power generation efficiency of steel and aluminium turbine were 33.56% and 34.79% respectively. From the result at the maximum water flow rate of 3.63 m 3 /min, it was found that the torque value and electricity production efficiency of aluminium turbine was higher than that of steel turbine at the average of 8.4% and 8.14%, respectively. This result showed that light weight of water turbine can increase the torque and power generation efficiency. (paper)

  11. Predictive modelling of noise level generated during sawing of rocks ...

    Indian Academy of Sciences (India)

    This paper presents an experimental and statistical study on noise level generated .... hardness were determined according to related ISRM (1981) suggested methods. Thin section ..... tistical Package for the Social Sciences). Additionally, the ...

  12. Recent Changes in Land Water Storage and Its Contribution to Sea Level Variations

    Science.gov (United States)

    Wada, Yoshihide; Reager, John T.; Chao, Benjamin F.; Wang, Jida; Lo, Min-Hui; Song, Chunqiao; Li, Yuwen; Gardner, Alex S.

    2016-01-01

    Sea level rise is generally attributed to increased ocean heat content and increased rates glacier and ice melt. However, human transformations of Earth's surface have impacted water exchange between land, atmosphere, and ocean, ultimately affecting global sea level variations. Impoundment of water in reservoirs and artificial lakes has reduced the outflow of water to the sea, while river runoff has increased due to groundwater mining, wetland and endorheic lake storage losses, and deforestation. In addition, climate-driven changes in land water stores can have a large impact on global sea level variations over decadal timescales. Here, we review each component of negative and positive land water contribution separately in order to highlight and understand recent changes in land water contribution to sea level variations.

  13. Ground-water levels in aquifers used for residential supply, Campton Township, Kane County, Illinois

    Science.gov (United States)

    Kay, Robert T.; Kraske, Kurt A.

    1996-01-01

    The U.S. Geological Survey, in cooperation with the Campton Township Board of Trustees, measured water levels in the aquifers used for residential supply in Campton Township, Kane County, Illinois. Aquifers used for residential supply are the shallow and deep aquifers in the glacial drift, composed of unconsolidated sand and gravels; the Alexandrian-Maquoketa aquifer, composed of dolomite and shale of the Alexandrian Series and the Maquoketa Group; the Galena-Platteville aquifer, composed of dolomite of the Platteville and Galena Groups; and the Ancell aquifer, composed of sandstones of the Glenwood Formation and the St. Peter Sanstone. Water-level altitudes in the shallow drift aquifers generally follow surface topography. Analysis of water-level data does not clearly indicate overutilization of these aquifers. Water-level altitudes in the deep drift aquifers decrease from west to east. Comparison of historical depth to water measurements with current (1995) measurements indicates large decreases in water levels in some areas. The deep drift aquifers may be overutilized at these locations. Water-level altitudes in the Alexandrian-Maquoketa aquifer generally decrease from west to east. The potentiometric surface of the aquifer follows the bedrock-surface topography in some locations. Localized low water-level altitudes and large decreases in water levels indicate the Alexandrian-Maquoketa aquifer is overutilized in several areas. Water-level altitudes in the wells finished in the Galena- Platteville aquifer vary by more than 300 feet. Large decreases in water levels in wells finished in the Galena-Platteville aquifer indicate the Galena-Platteville and Alexandrian-Maquoketa aquifers are overutilized in the northern part of the township. Water-level altitudes in the wells finished in the Ancell aquifer are also highly variable. There is no indication that the Ancell aquifer is overutilized.

  14. Mitigation of organically bound sulphate from water treatment plants at Bruce NGS and impact on steam generator secondary side chemistry control

    Energy Technology Data Exchange (ETDEWEB)

    Nashiem, R.; Davloor, R.; Harper, B.; Smith, K. [Bruce Power, Tiverton, Ontario (Canada); Gauthier, C. [CTGIX Services Inc., Burlington, Ontario (Canada); Schexnailder, S. [GE Water and Process Technologies, Dallas, Texas (United States)

    2010-07-01

    Bruce Power is the source of more than 20 per cent of Ontario's electricity and currently operates six reactor units at the Bruce Nuclear Generating Station A (two units) and B (four units) stations located on Lake Huron. This paper discusses the challenges faced and operating experience (OPEX) gained in meeting WANO 1.0 chemistry performance objectives for steam generator secondary side chemistry control, particularly with control of steam generator sulphates. A detailed sampling and analysis program conducted as part of this study concluded that a major contributor to steam generator (SG) elevated sulphates is Organically Bound Sulphate (OBS) in Water Treatment Plants (WTP) effluent. The Bruce A and B WTPs consist of clarification with downstream sand and carbon filtration for Lake Water pre-treatment, which are followed by conventional Ion Exchange (IX) demineralization. Samples taken from various locations in the process stream were analyzed for a variety of parameters including both organic bound and inorganic forms of sulphate. The results are inconclusive with respect to finding the definitive source of OBS. This is primarily due to the condition that the OBS in the samples, which are in relatively low levels, are masked during chemical analysis by the considerably higher inorganic sulphate background. Additionally, it was also determined that on-line Total Organic Carbon (TOC) levels at different WTP locations did not always correlate well with OBS levels in the effluent, such that TOC could not be effectively used as a control parameter to improve OBS performance of the WTP operation. Improvement efforts at both plants focused on a number of areas including optimization of clarifier operation, replacement of IX resins, addition of downstream mobile polishing trailers, testing of new resins and adsorbents, pilot-scale testing with a Reverse Osmosis (RO) rig, review of resin regeneration and backwashing practices, and operating procedure improvements

  15. Mitigation of organically bound sulphate from water treatment plants at Bruce NGS and impact on steam generator secondary side chemistry control

    International Nuclear Information System (INIS)

    Nashiem, R.; Davloor, R.; Harper, B.; Smith, K.; Gauthier, C.; Schexnailder, S.

    2010-01-01

    Bruce Power is the source of more than 20 per cent of Ontario's electricity and currently operates six reactor units at the Bruce Nuclear Generating Station A (two units) and B (four units) stations located on Lake Huron. This paper discusses the challenges faced and operating experience (OPEX) gained in meeting WANO 1.0 chemistry performance objectives for steam generator secondary side chemistry control, particularly with control of steam generator sulphates. A detailed sampling and analysis program conducted as part of this study concluded that a major contributor to steam generator (SG) elevated sulphates is Organically Bound Sulphate (OBS) in Water Treatment Plants (WTP) effluent. The Bruce A and B WTPs consist of clarification with downstream sand and carbon filtration for Lake Water pre-treatment, which are followed by conventional Ion Exchange (IX) demineralization. Samples taken from various locations in the process stream were analyzed for a variety of parameters including both organic bound and inorganic forms of sulphate. The results are inconclusive with respect to finding the definitive source of OBS. This is primarily due to the condition that the OBS in the samples, which are in relatively low levels, are masked during chemical analysis by the considerably higher inorganic sulphate background. Additionally, it was also determined that on-line Total Organic Carbon (TOC) levels at different WTP locations did not always correlate well with OBS levels in the effluent, such that TOC could not be effectively used as a control parameter to improve OBS performance of the WTP operation. Improvement efforts at both plants focused on a number of areas including optimization of clarifier operation, replacement of IX resins, addition of downstream mobile polishing trailers, testing of new resins and adsorbents, pilot-scale testing with a Reverse Osmosis (RO) rig, review of resin regeneration and backwashing practices, and operating procedure improvements

  16. Water lancing of Bruce-A Unit 3 and 4 steam generators

    International Nuclear Information System (INIS)

    Puzzuoli, F.V.; Murchie, B.; Allen, S.

    1995-01-01

    During the Bruce-A 1993 Unit 4 and 1994 Unit 3 outages, three water lancing operations were carried out along with chemical cleaning as part of the station boiler refurbishment program. The water lancing activities focused on three boiler areas.. 1) support plates to clean partially or completely blocked broach holes and prevent boiler water level oscillations, 2) hot leg U-bend supports (HLUBS) to remove deposits contributing to boiler tube stress corrosion cracking (SCC) and 3) tube sheets to dislodge sludge piles that potentially threaten boiler tube integrity and to flush out post chemical cleaning insoluble residues. The combination of water lancing and chemical cleaning effectively reduced broach hole blockage from up to 100% to 0-10% or less. As a result, boilers in Units 3 and 4 will operate for some time to come without concerns over water level oscillations. However, deposits remained in most tube support plate land areas. (author)

  17. Photocatalytic hydrogen generation from water under visible light using core/shell nano-catalysts.

    Science.gov (United States)

    Wang, X; Shih, K; Li, X Y

    2010-01-01

    A microemulsion technique was employed to synthesize nano-sized photocatalysts with a core (CdS)/shell (ZnS) structure. The primary particles of the photocatalysts were around 10 nm, and the mean size of the catalyst clusters in water was about 100 nm. The band gaps of the catalysts ranged from 2.25 to 2.46 eV. The experiments of photocatalytic H(2) generation showed that the catalysts (CdS)(x)/(ZnS)(1-x) with x ranging from 0.1 to 1 were able to produce hydrogen from water photolysis under visible light. The catalyst with x=0.9 had the highest rate of hydrogen production. The catalyst loading density also influenced the photo-hydrogen production rate, and the best catalyst concentration in water was 1 g L(-1). The stability of the nano-catalysts in terms of size, morphology and activity was satisfactory during an extended test period for a specific hydrogen production rate of 2.38 mmol g(-1) L(-1) h(-1) and a quantum yield of 16.1% under visible light (165 W Xe lamp, lambda>420 nm). The results demonstrate that the (CdS)/(ZnS) core/shell nano-particles are a novel photo-catalyst for renewable hydrogen generation from water under visible light. This is attributable to the large band-gap ZnS shell that separates the electron/hole pairs generated by the CdS core and hence reduces their recombinations.

  18. Immobilized High-Level Waste (HLW) Interim Storage Alternative Generation and analysis and Decision Report - second Generation Implementing Architecture

    International Nuclear Information System (INIS)

    CALMUS, R.B.

    2000-01-01

    Two alternative approaches were previously identified to provide second-generation interim storage of Immobilized High-Level Waste (IHLW). One approach was retrofit modification of the Fuel and Materials Examination Facility (FMEF) to accommodate IHLW. The results of the evaluation of the FMEF as the second-generation IHLW interim storage facility and subsequent decision process are provided in this document

  19. Relative Sea Level, Tidal Range, and Extreme Water Levels in Boston Harbor from 1825 to 2016

    Science.gov (United States)

    Talke, S. A.; Kemp, A.; Woodruff, J. D.

    2017-12-01

    Long time series of water-level measurements made by tide gauges provide a rich and valuable observational history of relative sea-level change, the frequency and height of extreme water levels and evolving tidal regimes. However, relatively few locations have available tide-gauge records longer than 100 years and most of these places are in northern Europe. This spatio-temporal distribution hinders efforts to understand global-, regional- and local-scale trends. Using newly-discovered archival measurements, we constructed a 200 year, instrumental record of water levels, tides, and storm surges in Boston Harbor. We detail the recovery, datum reconstruction, digitization, quality assurance, and analysis of this extended observational record. Local, decadally-averaged relative sea-level rose by 0.28 ± 0.05 m since the 1820s, with an acceleration of 0.023 ±0.009 mm/yr2. Approximately 0.13 ± 0.02 m of the observed RSL rise occurred due to ongoing glacial isostatic adjustment, and the remainder occurred due to changes in ocean mass and volume associated with the onset of modern mean sea-level rise. Change-point analysis of the new relative sea level record confirms that anthropogenic rise began in 1924-1932, which is in agreement with global mean sea level estimates from the global tide gauge network. Tide range decreased by 5.5% between 1830 and 1910, likely due in large part to anthropogenic development. Storm tides in Boston Harbor are produced primarily by extratropical storms during the November-April time frame. The three largest storm tides occurred in 1851, 1909, and 1978. Because 90% of the top 20 storm tides since 1825 occurred during a spring tide, the secular change in tide range contributes to a slight reduction in storm tide magnitudes. However, non-stationarity in storm hazard was historically driven primarily by local relative sea-level rise; a modest 0.2 m increase in relative sea level reduces the 100 year high water mark to a once-in-10 year event.

  20. Subseasonal to Seasonal Predictions of U.S. West Coast High Water Levels

    Science.gov (United States)

    Khouakhi, A.; Villarini, G.; Zhang, W.; Slater, L. J.

    2017-12-01

    Extreme sea levels pose a significant threat to coastal communities, ecosystems, and assets, as they are conducive to coastal flooding, coastal erosion and inland salt-water intrusion. As sea levels continue to rise, these sea level extremes - including occasional minor coastal flooding experienced during high tide (nuisance floods) - are of concern. Extreme sea levels are increasing at many locations around the globe and have been attributed largely to rising mean sea levels associated with intra-seasonal to interannual climate processes such as the El Niño-Southern Oscillation (ENSO). Here, intra-seasonal to seasonal probabilistic forecasts of high water levels are computed at the Toke Point tide gage station on the US west coast. We first identify the main climate drivers that are responsible for high water levels and examine their predictability using General Circulation Models (GCMs) from the North American Multi-Model Ensemble (NMME). These drivers are then used to develop a probabilistic framework for the seasonal forecasting of high water levels. We focus on the climate controls on the frequency of high water levels using the number of exceedances above the 99.5th percentile and above the nuisance flood level established by the National Weather Service. Our findings indicate good forecast skill at the shortest lead time, with the skill that decreases as we increase the lead time. In general, these models aptly capture the year-to-year variability in the observational records.

  1. A feasibility study on active ultrasonic techniques for water into sodium leak detection on FBR steam generator units

    International Nuclear Information System (INIS)

    Girard, J.P.; Garnaud, P.; Journeau, C.; Demarais, R.

    1990-01-01

    In the framework of the European Fast Breeder Project one of the aims is to provide the ferritic straight tube steam generator with a fast and reliable leak detection system. The first studies of water sodium leaks, based on the passive listening of noise source, are described. Considerable experience has been acquired of this technique and one of the conclusions is that a high level of reliability may require a sophisticated surveillance algorithm. Further works on the subject should lead to demonstration phase in 1993-1995 on a real and representative steam generator unit in order to have the benefit of a long term run of the surveillance method prior to industrial use in a compulsory safety system. 1 ref., 10 figs

  2. Water levels in wells J-11 and J-12, 1989-91, Yucca Mountain Area, Nevada

    International Nuclear Information System (INIS)

    Boucher, M.S.

    1994-01-01

    Water levels have been measured in the Yucca Mountain area, Nevada, since 1981 in order to gain a better understanding of the ground-water flow system in the area. Water levels in wells J-11 and J-12 have been periodically measured using calibrated reeled steel tapes since 1989, however, calculation of water-level altitude was not possible prior to 1993 due to missing reference elevations. These elevations were determined in 1993 by the U.S. Geological Survey. During 1989-91, water-level altitudes for well J-11 ranged from 732.09 to 732.40 meters and the mean water-level altitude was 732.19 meters. During 1989-91, water-level altitudes for well J-12 ranged from 727.84 to 728.03 meters, and the mean water-level altitude was 727.95 meters

  3. Water Orientation at Ceramide/Water Interfaces Studied by Heterodyne-Detected Vibrational Sum Frequency Generation Spectroscopy and Molecular Dynamics Simulation

    KAUST Repository

    Adhikari, Aniruddha

    2016-10-10

    Lipid/water interaction is essential for many biological processes. The water structure at the nonionic lipid interface remains little known, and there is no scope of a priori prediction of water orientation at nonionic interfaces, either. Here, we report our study combining advanced nonlinear spectroscopy and molecular dynamics simulation on the water orientation at the ceramide/water interface. We measured χ spectrum in the OH stretch region of ceramide/isotopically diluted water interface using heterodyne-detected vibrational sum-frequency generation spectroscopy and found that the interfacial water prefers an overall hydrogen-up orientation. Molecular dynamics simulation indicates that this preferred hydrogen-up orientation of water is determined by a delicate balance between hydrogen-up and hydrogen-down orientation induced by lipid-water and intralipid hydrogen bonds. This mechanism also suggests that water orientation at neutral lipid interfaces depends highly on the chemical structure of the lipid headgroup, in contrast to the charged lipid interfaces where the net water orientation is determined solely by the charge of the lipid headgroup.

  4. The potential for reusing grey water and its generation rates for sustainable potable water security in Kuwait

    Directory of Open Access Journals (Sweden)

    RAWA AL-JARALLAH

    2013-06-01

    Full Text Available This study was conducted to achieve the following objectives: (1 to investigate the water consumption patterns of Kuwaiti households, (2 to determine the per use water consumption rate for plumbing fixtures and their frequency of daily use and (3 to estimate the amount of grey water generated per person per day to explore the potential for reusing grey water in Kuwait. To achieve these objectives, a preliminary study was conducted to determine the per use water consumption rate for each plumbing fixture. An intensive study was then conducted using data from 53 households in different districts in Kuwait. The average daily freshwater consumption rate per person was found to be 283 L, half of which was converted to grey water. Reuse of grey water could reduce the freshwater consumption and hence wastewater treatment by 72.73 million imperial gallons per day (MIGD, which could lead to a savings of KD 87.6 (US $318.55 million from the annual freshwater production budget and between KD 15.93 (US $57.92 and KD 27.08 (US $98.46 million from the annual wastewater treatment budget.

  5. Model-Aided Altimeter-Based Water Level Forecasting System in Mekong River

    Science.gov (United States)

    Chang, C. H.; Lee, H.; Hossain, F.; Okeowo, M. A.; Basnayake, S. B.; Jayasinghe, S.; Saah, D. S.; Anderson, E.; Hwang, E.

    2017-12-01

    Mekong River, one of the massive river systems in the world, has drainage area of about 795,000 km2 covering six countries. People living in its drainage area highly rely on resources given by the river in terms of agriculture, fishery, and hydropower. Monitoring and forecasting the water level in a timely manner, is urgently needed over the Mekong River. Recently, using TOPEX/Poseidon (T/P) altimetry water level measurements in India, Biancamaria et al. [2011] has demonstrated the capability of an altimeter-based flood forecasting system in Bangladesh, with RMSE from 0.6 - 0.8 m for lead times up to 5 days on 10-day basis due to T/P's repeat period. Hossain et al. [2013] further established a daily water level forecasting system in Bangladesh using observations from Jason-2 in India and HEC-RAS hydraulic model, with RMSE from 0.5 - 1.5 m and an underestimating mean bias of 0.25 - 1.25 m. However, such daily forecasting system relies on a collection of Jason-2 virtual stations (VSs) to ensure frequent sampling and data availability. Since the Mekong River is a meridional river with few number of VSs, the direct application of this system to the Mekong River becomes challenging. To address this problem, we propose a model-aided altimeter-based forecasting system. The discharge output by Variable Infiltration Capacity hydrologic model is used to reconstruct a daily water level product at upstream Jason-2 VSs based on the discharge-to-level rating curve. The reconstructed daily water level is then used to perform regression analysis with downstream in-situ water level to build regression models, which are used to forecast a daily water level. In the middle reach of the Mekong River from Nakhon Phanom to Kratie, a 3-day lead time forecasting can reach RMSE about 0.7 - 1.3 m with correlation coefficient around 0.95. For the lower reach of the Mekong River, the water flow becomes more complicated due to the reversal flow between the Tonle Sap Lake and the Mekong River

  6. GPS water level measurements for Indonesia's Tsunami Early Warning System

    Directory of Open Access Journals (Sweden)

    T. Schöne

    2011-03-01

    Full Text Available On Boxing Day 2004, a severe tsunami was generated by a strong earthquake in Northern Sumatra causing a large number of casualties. At this time, neither an offshore buoy network was in place to measure tsunami waves, nor a system to disseminate tsunami warnings to local governmental entities. Since then, buoys have been developed by Indonesia and Germany, complemented by NOAA's Deep-ocean Assessment and Reporting of Tsunamis (DART buoys, and have been moored offshore Sumatra and Java. The suite of sensors for offshore tsunami detection in Indonesia has been advanced by adding GPS technology for water level measurements.

    The usage of GPS buoys in tsunami warning systems is a relatively new approach. The concept of the German Indonesian Tsunami Early Warning System (GITEWS (Rudloff et al., 2009 combines GPS technology and ocean bottom pressure (OBP measurements. Especially for near-field installations where the seismic noise may deteriorate the OBP data, GPS-derived sea level heights provide additional information.

    The GPS buoy technology is precise enough to detect medium to large tsunamis of amplitudes larger than 10 cm. The analysis presented here suggests that for about 68% of the time, tsunamis larger than 5 cm may be detectable.

  7. Specific features of emergency processes associated with water leacs into sodium in a reverse steam generator

    International Nuclear Information System (INIS)

    Sroelov, V.S.; Nikol'skij, R.V.; Chernobrovkin, Yu.V.; Privalov, Yu.V.; Bocharin, P.P.; Shtynda, Yu.E.

    1986-01-01

    Experimental and theoretical data characterizing the development of emergency processes arising in the course of water leaks into sodium in a reverse steam generator (sodium in tubes, water in intertube space) are considered. The results of calculations performed for BOR-60 reactor steam generator at initial leaks of 0.01 and 0.55 g/s are presented. It is shown that in the reverse steam generator the development of accident occurs much slower than in steam generators of traditional design. At same stage of accident sodium is displaced from the damaged tube and as a result the destruction of tube material discontinues. The conclusion is drawn that by the development of emergency protection systems for reverse steam generator the requirements for sensitivity and fast response of leak detectors could be reduced

  8. Generating high-brightness and coherent soft x-ray pulses in the water window with a seeded free-electron laser

    Directory of Open Access Journals (Sweden)

    Kaishang Zhou

    2017-01-01

    Full Text Available We propose a new scheme to generate high-brightness and temporal coherent soft x-ray radiation in a seeded free-electron laser. The proposed scheme is based on the coherent harmonic generation (CHG and superradiant principles. A CHG scheme is first used to generate a coherent signal at ultrahigh harmonics of the seed. This coherent signal is then amplified by a series of chicane-undulator modules via the fresh bunch and superradiant processes in the following radiator. Using a representative of a realistic set of parameters, three-dimensional simulations have been carried out and the simulations results demonstrated that 10 GW-level ultrashort (∼20  fs coherent radiation pulses in the water window can be achieved by using a 1.6 GeV electron beam based on the proposed technique.

  9. Carbon Capture and Water Emissions Treatment System (CCWESTRS) at Fossil-Fueled Electric Generating Plants

    Energy Technology Data Exchange (ETDEWEB)

    P. Alan Mays; Bert R. Bock; Gregory A. Brodie; L. Suzanne Fisher; J. Devereux Joslin; Donald L. Kachelman; Jimmy J. Maddox; N. S. Nicholas; Larry E. Shelton; Nick Taylor; Mark H. Wolfe; Dennis H. Yankee; John Goodrich-Mahoney

    2005-08-30

    2025. Other potential benefits of the demonstration include developing a passive technology for water treatment for trace metal and nutrient release reductions, using power plant by-products to improve coal mine land reclamation and carbon sequestration, developing wildlife habitat and green-space around production facilities, generating Total Maximum Daily Load (TMDL) credits for the use of process water, and producing wood products for use by the lumber and pulp and paper industry. Project activities conducted during the five year project period include: Assessing tree cultivation and other techniques used to sequester carbon; Project site assessment; Greenhouse studies to determine optimum plant species and by-product application; Designing, constructing, operating, monitoring, and evaluating the CCWESTRS system; and Reporting (ongoing). The ability of the system to sequester carbon will be the primary measure of effectiveness, measured by accessing survival and growth response of plants within the CCWESTRS. In addition, costs associated with design, construction, and monitoring will be evaluated and compared to projected benefits of other carbon sequestration technologies. The test plan involves the application of three levels each of two types of power plant by-products--three levels of FGD gypsum mulch, and three levels of ash pond irrigation water. This design produces nine treatment levels which are being tested with two species of hardwood trees (sweet gum and sycamore). The project is examining the effectiveness of applications of 0, 8-cm, and 15-cm thick gypsum mulch layers and 0, 13 cm, and 25 cm of coal fly ash water for irrigation. Each treatment combination is being replicated three times, resulting in a total of 54 treatment plots (3 FGD gypsum levels X 3 irrigation water levels x 2 tree species x 3 replicates). Survival and growth response of plant species in terms of sequestering carbon in plant material and soil will be the primary measure of

  10. Elevated levels of radioactivity in water wells in Los Angeles and Orange Counties, California

    International Nuclear Information System (INIS)

    Weigand, J.; Yamamoto, G.; Gaston, W.

    1987-01-01

    Levels of gross alpha particle radioactivity nearly three times the maximum contamination levels (MCL) have been detected for several years in well waters and related surface waters in Los Angeles and Orange Counties, California. A few elevated levels of uranium have also been recorded. The affected wells and related surface waters represent only a minor fraction of the water sampled and tested in this area. None of the excessive radioactivity is believed to persist in the municipal waters sold to the public, due to the customary blending of waters from several wells or sources which water purveyors practice. This papers is a preliminary survey of the occurrence, possible sources, fate, and implications of these elevated radioactivity levels

  11. Human impacts on tides overwhelm the effect of sea level rise on extreme water levels in the Rhine-Meuse delta

    NARCIS (Netherlands)

    Vellinga, N. E.; Hoitink, A. J F; van der Vegt, M.; Zhang, W.; Hoekstra, P.

    2014-01-01

    With the aim to link tidal and subtidal water level changes to human interventions, 70. years of water level data for the Rhine-Meuse tidal river network is analysed using a variety of statistical methods. Using a novel parameterization of probability density functions, mean high and low water

  12. Steam generator materials and secondary side water chemistry in nuclear power stations

    International Nuclear Information System (INIS)

    Rudelli, M.D.

    1979-04-01

    The main purpose of this work is to summarize the European and North American experiences regarding the materials used for the construction of the steam generators and their relative corrosion resistance considering the water chemestry control method. Reasons underlying decision for the adoption of Incoloy 800 as the material for the secondary steam generator system for Atucha I Nuclear Power Plant (Atucha Reactor) and Embalse de Rio III Nuclear Power Plant (Cordoba Reactor) are pointed out. Backup information taken into consideration for the decision of utilizing the All Volatil Treatment for the water chemistry control of the Cordoba Reactor is detailed. Also all the reasonswhich justify to continue with the congruent fosfatic method for the Atucha Reactor are analyzed. Some investigation objectives which would eventually permit the revision of the decisions taken on these subjects are proposed. (E.A.C.) [es

  13. Automated generation of partial Markov chain from high level descriptions

    International Nuclear Information System (INIS)

    Brameret, P.-A.; Rauzy, A.; Roussel, J.-M.

    2015-01-01

    We propose an algorithm to generate partial Markov chains from high level implicit descriptions, namely AltaRica models. This algorithm relies on two components. First, a variation on Dijkstra's algorithm to compute shortest paths in a graph. Second, the definition of a notion of distance to select which states must be kept and which can be safely discarded. The proposed method solves two problems at once. First, it avoids a manual construction of Markov chains, which is both tedious and error prone. Second, up the price of acceptable approximations, it makes it possible to push back dramatically the exponential blow-up of the size of the resulting chains. We report experimental results that show the efficiency of the proposed approach. - Highlights: • We generate Markov chains from a higher level safety modeling language (AltaRica). • We use a variation on Dijkstra's algorithm to generate partial Markov chains. • Hence we solve two problems: the first problem is the tedious manual construction of Markov chains. • The second problem is the blow-up of the size of the chains, at the cost of decent approximations. • The experimental results highlight the efficiency of the method

  14. NOS CO-OPS Water Level Data, Verified, Hourly

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset has verified (quality-controlled), hourly, water level (tide) data from NOAA NOS Center for Operational Oceanographic Products and Services (CO-OPS)....

  15. Investigation of natural radioactivity level of the waters in Inner Mongolia

    International Nuclear Information System (INIS)

    Du Xuelin; Li Wenyuan; Fu Su

    1993-01-01

    The authors reports the investigation results of natural radioactivity level in rivers, lakes, reservoirs, springs, wells and tap water in Inner Mongolia Autonomous Region. There were totally 326 samples collected from 178 measuring points. The results show that the radioactivity level of varied water bodies of the region was within normal natural background

  16. Linking electricity and water models to assess electricity choices at water-relevant scales

    International Nuclear Information System (INIS)

    Sattler, S; Rogers, J; Macknick, J; Lopez, A; Yates, D; Flores-Lopez, F

    2012-01-01

    Hydrology/water management and electricity generation projections have been modeled separately, but there has been little effort in intentionally and explicitly linking the two sides of the water–energy nexus. This paper describes a platform for assessing power plant cooling water withdrawals and consumption under different electricity pathways at geographic and time scales appropriate for both electricity and hydrology/water management. This platform uses estimates of regional electricity generation by the Regional Energy Deployment System (ReEDS) as input to a hydrologic and water management model—the Water Evaluation and Planning (WEAP) system. In WEAP, this electricity use represents thermoelectric cooling water withdrawals and consumption within the broader, regional water resource context. Here we describe linking the electricity and water models, including translating electricity generation results from ReEDS-relevant geographies to the water-relevant geographies of WEAP. The result of this analysis is water use by the electric sector at the regional watershed level, which is used to examine the water resource implications of these electricity pathways. (letter)

  17. Detection of steam generator tube leaks in pressurized water reactors

    International Nuclear Information System (INIS)

    Roach, W.H.

    1984-11-01

    This report addresses the early detection of small steam generator tube leaks in pressurized water reactors. It identifies physical parameters, establishes instrumentation performance goals, and specifies sensor types and locations. It presents a simple algorithm that yields the leak rate as a function of known or measurable quantities. Leak rates of less than one-tenth gram per second should be detectable with existing instrumentation

  18. Low-Cost Alternative for the Measurement of Water Levels in Surface Water Streams

    Directory of Open Access Journals (Sweden)

    Luis E. PEÑA

    2017-11-01

    Full Text Available Flood risk management and water resources planning involve a deep knowledge of surface streams so that mitigation strategies and climate change adaptations can be implemented. Commercially, there is a wide range of technologies for the measurement of hydroclimatic variables; however, many of these technologies may not be affordable for institutions with limited budgets. This paper has two main objectives: 1 Present the design of an ultrasound-based water level measurement system, and 2 Propose a methodological alternative for the development of instruments, according to the needs of institutions conducting monitoring of surface waterbodies. To that end, the proposed methodology is based on selection processes defined according to the specific needs of each waterbody. The prototype was tested in real-world scale, with the potential to obtain accurate measurements. Lastly, we present the design of the ultrasound-based water level measurement instrument, which can be built at a low cost. Low-cost instruments can potentially contribute to the sustainable instrumental autonomy of environmental entities and help define measurement and data transmission standards based on the specific requirements of the monitoring.

  19. Generation of Electricity from Abattoir Waste Water with the Aid of a ...

    African Journals Online (AJOL)

    Michael Horsfall

    Generation of Electricity from Abattoir Waste Water with the Aid of a Relatively Cheap. Source of Catholyte ... in recent times is the microbial fuel cell technology. This technology ..... fuel cell in the presence and absence of a proton exchange.

  20. Water levels and groundwater and surface-water exchanges in lakes of the northeast Twin Cities Metropolitan Area, Minnesota, 2002 through 2015

    Science.gov (United States)

    Jones, Perry M.; Trost, Jared J.; Erickson, Melinda L.

    2016-10-19

    OverviewThis study assessed lake-water levels and regional and local groundwater and surface-water exchanges near northeast Twin Cities Metropolitan Area lakes applying three approaches: statistical analysis, field study, and groundwater-flow modeling.  Statistical analyses of lake levels were completed to assess the effect of physical setting and climate on lake-level fluctuations of selected lakes. A field study of groundwater and surface-water interactions in selected lakes was completed to (1) estimate potential percentages of surface-water contributions to well water across the northeast Twin Cities Metropolitan Area, (2) estimate general ages for waters extracted from the wells, and (3) assess groundwater inflow to lakes and lake-water outflow to aquifers downgradient from White Bear Lake.  Groundwater flow was simulated using a steady-state, groundwater-flow model to assess regional groundwater and surface-water exchanges and the effects of groundwater withdrawals, climate, and other factors on water levels of northeast Twin Cities Metropolitan Area lakes.

  1. Development of capacitive sensor for automatically measuring tumbler water level with FEA simulation.

    Science.gov (United States)

    Wei, Qun; Kim, Mi-Jung; Lee, Jong-Ha

    2018-01-01

    Drinking water has several advantages that have already been established, such as improving blood circulation, reducing acid in the stomach, etc. However, due to people not noticing the amount of water they consume every time they drink, most people drink less water than the recommended daily allowance. In this paper, a capacitive sensor for developing an automatic tumbler to measure water level is proposed. Different than in previous studies, the proposed capacitive sensor was separated into two sets: the main sensor for measuring the water level in the tumbler, and the reference sensor for measuring the incremental level unit. In order to confirm the feasibility of the proposed idea, and to optimize the shape of the sensor, a 3D model of the capacitive sensor with the tumbler was designed and subjected to Finite Element Analysis (FEA) simulation. According to the simulation results, the electrodes were made of copper and assembled in a tumbler manufactured by a 3D printer. The tumbler was filled with water and was subjected to experiments in order to assess the sensor's performance. The comparison of experimental results to the simulation results shows that the measured capacitance value of the capacitive sensor changed linearly as the water level varied. This proves that the proposed sensor can accurately measure the water level in the tumbler. Additionally, by use of the curve fitting method, a compensation algorithm was found to match the actual level with the measured level. The experimental results proved that the proposed capacitive sensor is able to measure the actual water level in the tumbler accurately. A digital control part with micro-processor will be designed and fixed on the bottom of the tumbler for developing a smart tumbler.

  2. In vitro comparison of noise levels produced by different CPAP generators.

    Science.gov (United States)

    Kirchner, Lieselotte; Wald, Martin; Jeitler, Valerie; Pollak, Arnold

    2012-01-01

    Minimization of noise exposure is an important aim of modern neonatal intensive care medicine. Binasal continuous positive airway pressure (CPAP) generators are among the most important sources of continuous noise in neonatal wards. The aim of this study was to find out which CPAP generator creates the least noise. In an experimental setup, two jet CPAP generators (Infant Flow® generator and MediJet®) and two conventional CPAP generators (Bubble CPAP® and Baby Flow®) were compared. Noise production was measured in decibels in an A-weighted scale [dB(A)] in a closed incubator at 2 mm lateral distance from the end of the nasal prongs. Reproduction of constant airway pressure and air leak was achieved by closure of the nasal prongs with a type of adhesive tape that is semipermeable to air. The noise levels produced by the four generators were significantly different (p CPAP® and 55 dB(A) for the Baby Flow®. Conventional CPAP generators work more quietly than the currently available jet CPAP generators. Copyright © 2011 S. Karger AG, Basel.

  3. Water-level altitudes 2017 and water-level changes in the Chicot, Evangeline, and Jasper Aquifers and compaction 1973–2016 in the Chicot and Evangeline Aquifers, Houston-Galveston region, Texas

    Science.gov (United States)

    Kasmarek, Mark C.; Ramage, Jason K.

    2017-08-16

    Most of the land-surface subsidence in the Houston-Galveston region, Texas, has occurred as a direct result of groundwater withdrawals for municipal supply, commercial and industrial use, and irrigation that depressured and dewatered the Chicot and Evangeline aquifers, thereby causing compaction of the aquifer sediments, mostly in the fine-grained silt and clay layers. This report, prepared by the U.S. Geological Survey in cooperation with the Harris-Galveston Subsidence District, City of Houston, Fort Bend Subsidence District, Lone Star Groundwater Conservation District, and Brazoria County Groundwater Conservation District, is one in an annual series of reports depicting water-level altitudes and water-level changes in the Chicot, Evangeline, and Jasper aquifers and measured cumulative compaction of subsurface sediments in the Chicot and Evangeline aquifers in the Houston-Galveston region. This report contains regional-scale maps depicting approximate 2017 water-level altitudes (represented by measurements made during December 2016 through March 2017) and long-term water-level changes for the Chicot, Evangeline, and Jasper aquifers; a map depicting locations of borehole-extensometer (hereinafter referred to as “extensometer”) sites; and graphs depicting measured long-term cumulative compaction of subsurface sediments at the extensometers during 1973–2016.In 2017, water-level-altitude contours for the Chicot aquifer ranged from 200 feet (ft) below the North American Vertical Datum of 1988 (hereinafter referred to as “datum”) in two localized areas in southwestern and northwestern Harris County to 200 ft above datum in west-central Montgomery County. The largest water-level-altitude decline (120 ft) depicted by the 1977–2017 water-level-change contours for the Chicot aquifer was in northwestern Harris County. A broad area where water-level altitudes declined in the Chicot aquifer extends from northwestern, north-central, and southwestern Harris County

  4. Occurrence of organotin compounds in river sediments under the dynamic water level conditions in the Three Gorges Reservoir Area, China.

    Science.gov (United States)

    Gao, Jun-Min; Zhang, Ke; Chen, You-Peng; Guo, Jin-Song; Wei, Yun-Mei; Jiang, Wen-Chao; Zhou, Bin; Qiu, Hui

    2015-06-01

    The Three Gorges Project is the largest hydro project in the world, and the water level of the Three Gorges Reservoir (TGR) is dynamic and adjustable with the aim of flood control and electrical power generation. It is necessary to investigate the pollutants and their underlying contamination processes under dynamic water levels to determine their environmental behaviors in the Three Gorges Reservoir Area (TGRA). Here, we report the assessment of organotin compounds (OTs) pollution in the river sediments of the TGRA. Surface sediment samples were collected in the TGRA at low and high water levels. Tributyltin (TBT), triphenyltin (TPhT), and their degradation products in sediments were quantified by gas chromatography-mass spectrometry. Butyltins (BTs) and phenyltins (PhTs) were detected in sediments, and BTs predominated over PhTs in the whole study area under dynamic water level conditions. The concentrations of OTs in sediments varied markedly among locations, and significant concentrations were found in river areas with high levels of boat traffic and wastewater discharge. Sediments at all stations except Cuntan were lightly contaminated with TBT, and total organic carbon (TOC) was a significant factor affecting the fate of TBT in the TGRA. The butyltin and phenyltin degradation indices showed no recent inputs of TBT or TPhT into this region, with the exception of fresh TPhT input at Xiakou Town. Shipping activity, wastewater discharge, and agriculture are the most likely sources of OTs in the TGRA.

  5. On the derivation of specific yield and soil water retention characteristics in peatlands from rainfall, microrelief and water level data - Theory and Practice

    Science.gov (United States)

    Dettmann, Ullrich; Bechtold, Michel

    2016-04-01

    Water level depth is one of the crucial state variables controlling the biogeochemical processes in peatlands. For flat soil surfaces, water level depth dynamics as response to boundary fluxes are primarily controlled by the water retention characteristics of the soil in and above the range of the water level fluctuations. For changing water levels, the difference of the integrals of two soil moisture profiles (ΔAsoil), of a lower and a upper water level, is equal to the amount of water received or released by the soil. Dividing ΔAsoil by the water level change, results into a variable that is known as specific yield (Sy). For water level changes approaching the soil surface, changes in soil water storage are small due to the thin unsaturated zone that remains. Consequentially, Sy values approach zero with an abrupt transition to 1 in case of inundation. However, on contrary, observed water level rises due to precipitation events at various locations showed increasing Sy values for water level changes at shallow depths (Sy = precipitation/water level change; Logsdon et al., 2010). The increase of Sy values can be attributed in large parts to the influence of the microrelief on water level changes in these wet landscapes that are characterized by a mosaic of inundated and non-inundated areas. Consequentially, water level changes are dampened by partial inundation. In this situation, total Sy is composed of a spatially-integrated below ground and above ground contribution. We provide a general one-dimensional expression that correctly represents the effect of a microrelief on the total Sy. The one-dimensional expression can be applied for any soil hydraulic parameterizations and soil surface elevation frequency distributions. We demonstrate that Sy is influenced by the microrelief not only when surface storage directly contributes to Sy by (partial) inundation but also when water levels are lower than the minimum surface elevation. With the derived one

  6. Coupling of HEC-HMS and HEC-ResSim in Modeling the Fluctuation of Water Level in Devils Lake Using Heterogeneous Data

    Science.gov (United States)

    Munna, H. S.; Lim, Y. H.

    2010-12-01

    Devils Lake, located in Ramsey and Benson County in North Dakota is a sub-basin of the Red River of the North. Although it lies entirely within the Red River Basin, it has no natural outlet at current water levels. Since its inception during the glacier period, Devils Lake has been either rising or falling over the last 10,000 years. Geologic evidence shows that the water level in Devils Lake has fluctuated widely from completely dry (about 1400 feet AMSL) to overflowing into the Sheyenne River (about 1459 feet AMSL). The uncontrolled growth of the lake has been an alarming issue for North Dakota for the past few years as it causes continuous flooding in the surrounding areas. A hydro-climatic model that can provide simulations of the water level of this lake for a 20 or 50 year time frame can be a useful decision making tool. In a mission to achieve that, heterogeneous data obtained from various sources were used to model the lake. Runoff from precipitation is one of the major inputs to the lake and to model that, eight major watersheds that feed directly to the lake were identified using Digital Elevation Models (DEMs) of thirty meter resolution in ArcGIS environment. Hydrology and Arc Hydro tools were used to delineate the watersheds and sub-basins to generate the runoff using the HEC HMS model. The precipitation time series data collected from both NASA and ground stations were used separately to calibrate the runoff model. The generation of time series runoff values for individual basins for four consecutive years (2001-2004) was applied into HEC-ResSim, a reservoir simulation model, to estimate the lake level series considering the elevation-area-storage relationship and evaporation series from previous USGS studies. It is eminent that seepage under the lake played a key role in calibrating the model with observed elevations. The value of seepage flow was varied over increasing elevations as it depends on the height of water column. The model showed an

  7. Effects of Barometric Fluctuations on Well Water-Level Measurements and Aquifer Test Data

    Energy Technology Data Exchange (ETDEWEB)

    FA Spane, Jr.

    1999-12-16

    The Pacific Northwest National Laboratory, as part of the Hanford Groundwater Monitoring Project, examines the potential for offsite migration of contamination within underlying aquifer systems. Well water-level elevation measurements from selected wells within these aquifer systems commonly form the basis for delineating groundwater-flow patterns (i.e., flow direction and hydraulic gradient). In addition, the analysis of water-level responses obtained in wells during hydrologic tests provides estimates of hydraulic properties that are important for evaluating groundwater-flow velocity and transport characteristics. Barometric pressure fluctuations, however, can have a discernible impact on well water-level measurements. These barometric effects may lead to erroneous indications of hydraulic head within the aquifer. Total hydraulic head (i.e., sum of the water-table elevation and the atmospheric pressure at the water-table surface) within the aquifer, not well water-level elevation, is the hydrologic parameter for determining groundwater-flow direction and hydraulic gradient conditions. Temporal variations in barometric pressure may also adversely affect well water-level responses obtained during hydrologic tests. If significant, adjustments or removal of these barometric effects from the test-response record may be required for quantitative hydraulic property determination. This report examines the effects of barometric fluctuations on well water-level measurements and evaluates adjustment and removal methods for determining areal aquifer head conditions and aquifer test analysis. Two examples of Hanford Site unconfined aquifer tests are examined that demonstrate barometric response analysis and illustrate the predictive/removal capabilities of various methods for well water-level and aquifer total head values. Good predictive/removal characteristics were demonstrated with best corrective results provided by multiple-regression deconvolution methods.

  8. Response of littoral macrophytes to water level fluctuations in a storage reservoir

    Directory of Open Access Journals (Sweden)

    Krolová M.

    2013-05-01

    Full Text Available Lakes and reservoirs that are used for water supply and/or flow regulations have usually poorly developed littoral macrophyte communities, which impairs ecological potential in terms of the EU Water Framework Directive. The aim of our study was to reveal controlling factors for the growth of littoral macrophytes in a storage reservoir with fluctuating water level (Lipno Reservoir, Czech Republic. Macrophytes occurred in this reservoir only in the eulittoral zone i.e., the shoreline region between the highest and the lowest seasonal water levels. Three eulittoral sub-zones could be distinguished: the upper eulittoral with a stable community of perennial species with high cover, the middle eulittoral with relatively high richness of emergent and amphibious species present at low cover values, and the lower eulittoral devoid of permanent vegetation. Cover and species composition in particular sub-zones were primarily influenced by the duration and timing of flooding, followed by nutrient limitation and strongly reducing conditions in the flooded organic sediment. Our results stress the ecological importance of eulittoral zone in reservoirs with fluctuating water levels where macrophyte growth can be supported by targeted management of water level, thus helping reservoir managers in improving the ecological potential of this type of water bodies.

  9. Nuclear power generation cost methodology

    International Nuclear Information System (INIS)

    Delene, J.G.; Bowers, H.I.

    1980-08-01

    A simplified calculational procedure for the estimation of nuclear power generation cost is outlined. The report contains a discussion of the various components of power generation cost and basic equations for calculating that cost. An example calculation is given. The basis of the fixed-charge rate, the derivation of the levelized fuel cycle cost equation, and the heavy water charge rate are included as appendixes

  10. Water-level altitudes 2011 and water-level changes in the Chicot, Evangeline, and Jasper aquifers and compaction 1973-2010 in the Chicot and Evangeline aquifers, Houston-Galveston region, Texas

    Science.gov (United States)

    Johnson, Michaela R.; Ramage, Jason K.; Kasmarek, Mark C.

    2011-01-01

    Most of the subsidence in the Houston–Galveston region has occurred as a direct result of groundwater withdrawals for municipal supply, industrial use, and irrigation that depressured and dewatered the Chicot and Evangeline aquifers causing compaction of the clay layers of the aquifer sediments. This report, prepared by the U.S. Geological Survey, in cooperation with the Harris–Galveston Subsidence District, City of Houston, Fort Bend Subsidence District, and Lone Star Groundwater Conservation District, is one in an annual series of reports depicting water-level altitudes and water-level changes in the Chicot, Evangeline, and Jasper aquifers and compaction in the Chicot and Evangeline aquifers in the Houston–Galveston region. The report contains maps showing 2011 water-level altitudes for the Chicot, Evangeline, and Jasper aquifers; maps showing 1-year (2010–11) water-level-altitude changes for each aquifer; maps showing 5-year (2006–11) water-level-altitude changes for each aquifer; maps showing long-term (1990–2011 and 1977–2011) water-level-altitude changes for the Chicot and Evangeline aquifers; a map showing long-term (2000–11) water-level-altitude change for the Jasper aquifer; a map showing locations of borehole extensometer sites; and graphs showing measured compaction of subsurface material at the extensometers from 1973, or later, through 2010. Tables listing the data used to construct each aquifer-data map and the compaction graphs are included.Water levels in the Chicot, Evangeline, and Jasper aquifers were measured during December 2010–February 2011. In 2011, water-level-altitude contours for the Chicot aquifer ranged from 200 feet below North American Vertical Datum of 1988 (hereinafter, datum) in a small area in southwestern Harris County to 200 feet above datum in central to southwestern Montgomery County. Water-level-altitude changes in the Chicot aquifer ranged from a 40-foot decline to a 33-foot rise (2010–11), from a 10-foot

  11. Water-level altitudes 2010 and water-level changes in the Chicot, Evangeline, and Jasper aquifers and compaction 1973-2009 in the Chicot and Evangeline aquifers, Houston-Galveston region, Texas

    Science.gov (United States)

    Kasmarek, Mark C.; Johnson, Michaela R.; Ramage, Jason K.

    2010-01-01

    Most of the subsidence in the Houston-Galveston region has occurred as a direct result of groundwater withdrawals for municipal supply, industrial use, and irrigation that depressured and dewatered the Chicot and Evangeline aquifers causing compaction of the clay layers of the aquifer sediments. This report, prepared by the U.S. Geological Survey, in cooperation with the Harris-Galveston Subsidence District, City of Houston, Fort Bend Subsidence District, and Lone Star Groundwater Conservation District, is one in an annual series of reports depicting water-level altitudes and water-level changes in the Chicot, Evangeline, and Jasper aquifers and compaction in the Chicot and Evangeline aquifers in the Houston-Galveston region. The report contains maps showing 2010 water-level altitudes for the Chicot, Evangeline, and Jasper aquifers, respectively; maps showing 1-year (2009-10) water-level-altitude changes for each aquifer; maps showing 5-year (2005-10) water-level-altitude changes for each aquifer; maps showing long-term (1990-2010 and 1977-2010) water-level-altitude changes for the Chicot and Evangeline aquifers; a map showing long-term (2000-10) water-level-altitude change for the Jasper aquifer; a map showing locations of borehole extensometer sites; and graphs showing measured compaction of subsurface material at the extensometers from 1973, or later, through 2009. Tables listing the data used to construct each aquifer-data map and the compaction graphs are included. Water levels in the Chicot, Evangeline, and Jasper aquifers were measured during December 2009-March 2010. In 2010, water-level-altitude contours for the Chicot aquifer ranged from 200 feet below National Geodetic Vertical Datum of 1929 or North American Vertical Datum of 1988 (hereinafter, datum) in a small area in southwestern Harris County to 200 feet above datum in central to southwestern Montgomery County. Water-level-altitude changes in the Chicot aquifer ranged from a 49-foot decline to a 67

  12. Feasibility Analysis of Liquefying Oxygen Generated from Water Electrolysis Units on Lunar Surface

    Science.gov (United States)

    Jeng, Frank F.

    2009-01-01

    Concepts for liquefying oxygen (O2) generated from water electrolysis subsystems on the Lunar surface were explored. Concepts for O2 liquefaction units capable of generating 1.38 lb/hr (0.63 kg/hr) liquid oxygen (LOX) were developed. Heat and mass balance calculations for the liquefaction concepts were conducted. Stream properties, duties of radiators, heat exchangers and compressors for the selected concepts were calculated and compared.

  13. Franson Interference Generated by a Two-Level System

    Science.gov (United States)

    Peiris, M.; Konthasinghe, K.; Muller, A.

    2017-01-01

    We report a Franson interferometry experiment based on correlated photon pairs generated via frequency-filtered scattered light from a near-resonantly driven two-level semiconductor quantum dot. In contrast to spontaneous parametric down-conversion and four-wave mixing, this approach can produce single pairs of correlated photons. We have measured a Franson visibility as high as 66%, which goes beyond the classical limit of 50% and approaches the limit of violation of Bell's inequalities (70.7%).

  14. Water-level fluctuation in wetlands as a function of landscape condition in the prairie pothole region

    Science.gov (United States)

    Euliss, Ned H.; Mushet, David M.

    1996-01-01

    We evaluated water-level fluctuation (maximum water depth - minimum water depth/catchment size) in 12 temporary, 12 seasonal, and 12 semipermanent wetlands equally distributed among landscapes dominated by tilled agricultural lands and landscapes dominated by grassland. Water levels fluctuated an average of 14.14 cm in wetlands within tilled agricultural landscapes, while water levels in wetlands within grassland landscapes fluctuated an average of only 4.27 cm. Tillage reduces the natural capacity of catch meets to mitigate surface flow into wetland basins during precipitation events, resulting in greater water-level fluctuations in wetlands with tilled catchments. In addition, water levels in temporary and seasonal wetlands fluctuated an average of 13.74 cm and 11.82 cm, respectively, while water levels in semipermanent wetlands fluctuated only 2.77 cm. Semipermanent wetlands receive a larger proportion of their water as input from ground water than do either temporary or seasonal wetlands. This input of water from the ground has a stabilizing effect on water-levels of semipermanent wetlands. Increases in water-level fluctuation due to tillage or due to alteration of ground-water hydrology may ultimately affect the composition of a wetland's flora and fauna. In this paper, we also describe an inexpensive device for determining absolute maximum and minimum water levels in wetlands.

  15. Hydrogen generation from water using Mg nanopowder produced by arc plasma method

    Directory of Open Access Journals (Sweden)

    Masahiro Uda, Hideo Okuyama, Tohru S Suzuki and Yoshio Sakka

    2012-01-01

    Full Text Available We report that hydrogen gas can be easily produced from water at room temperature using a Mg nanopowder (30–1000 nm particles, average diameter 265 nm. The Mg nanopowder was produced by dc arc melting of a Mg ingot in a chamber with mixed-gas atmosphere (20% N2–80% Ar at 0.1 MPa using custom-built nanopowder production equipment. The Mg nanopowder was passivated with a gas mixture of 1% O2 in Ar for 12 h in the final step of the synthesis, after which the nanopowder could be safely handled in ambient air. The nanopowder vigorously reacted with water at room temperature, producing 110 ml of hydrogen gas per 1 g of powder in 600 s. This amount corresponds to 11% of the hydrogen that could be generated by the stoichiometric reaction between Mg and water. Mg(OH2 flakes formed on the surface of the Mg particles as a result of this reaction. They easily peeled off, and the generation of hydrogen continued until all the Mg was consumed.

  16. Does water-level fluctuation affect mercury methylation in wetland soils?

    Energy Technology Data Exchange (ETDEWEB)

    Branfireun, B.A.; Mitchell, C.P.J.; Iraci, J.M. [Toronto Univ., ON (Canada). Dept. of Geography; Krabbenhoft, D.P. [United States Geological Survey, Middleton, WI (United States); Fowle, D.A. [Kansas Univ., Lawrence, KS (United States). Dept. of Geology; Neudahl, L. [Minnesota Power, Duluth, MN (United States)

    2006-07-01

    Mercury (Hg) concentrations in fish vary considerably in freshwater lakes and reservoirs. However, the variations are not generally consistent with physical factors such as basin characteristics, wetland cover or lake chemistry. Pronounced differences in Hg concentrations in fish have been noted in the reservoirs of the St. Louis River system near Duluth Minnesota. The differences were observed between headwater reservoir systems with seasonal flooding and drawdown, and a peaking reservoir with approximately daily water level fluctuations during seasonal lower flow periods. It was suggested that these differences could be attributed to water level fluctuations in the reservoir which influenced the actual production of methylmercury (MeHg) in the surrounding wetland soils. In response to this hypothesis, the authors investigated the role of water level fluctuation in the production and mobilization of MeHg in sediments from wetlands that lie adjacent to a headwater reservoir, a peaking reservoir, and a nearby natural flowage lake used as a control. Preliminary field surveys of the wetland soils revealed that although the average MeHg concentrations in the headwater and peaking reservoir wetlands were not considerably different, both were much higher than the natural lake. Each site demonstrated high variability, but maximum MeHg concentrations ranged from 29.2 ng/g for the peaking reservoir to 4.44 ng/g at the natural lake. A laboratory experiment was therefore performed in which sediments from each wetland were subjected to different water level regimes. The purpose was to assess Hg methylation potential. Stable Hg isotopes were used at the beginning and end of the experiment. In order to determine if water level fluctuation can significantly change the methylation potential of wetland soils on its own, the microbial consortia will also be assessed during the laboratory experiment.

  17. Effects of water level on three wetlands soil seed banks on the Tibetan Plateau.

    Directory of Open Access Journals (Sweden)

    Miaojun Ma

    Full Text Available BACKGROUND: Although the effect of water level on germination in soil seed banks has been documented in many ecosystems, the mechanism is not fully understood, and to date no empirical studies on this subject exist. Further, no work has been done on the effect of water level on seed banks of drying and saline-alkaline wetlands in alpine areas on the Tibetan Plateau. METHODOLOGY: We examined the effects of water level (0 cm, 5 cm and 10 cm on seed germination and seedling establishment from soil seed banks at 0-5 cm and 5-10 cm depths in typical, drying, and saline-alkaline wetlands. We also explore the potential role of soil seed bank in restoration of drying and saline-alkaline wetlands. PRINCIPAL FINDINGS: Species richness decreased with increase in water level, but there almost no change in seed density. A huge difference exists in species composition of the seed bank among different water levels in all three wetlands, especially between 0 cm and 5 cm and 0 cm and 10 cm. Similarity of species composition between seed bank and plant community was higher in 0 cm water level in drying wetland than in the other two wetlands. The similarity was much higher in 0 cm water level than in 5 cm and 10 cm water levels in all three wetlands. Species composition of the alpine wetland plant community changed significantly after drying and salinization, however, species composition of the seed bank was unchanged regardless of the environment change. CONCLUSIONS/SIGNIFICANCE: Water level greatly affects seed bank recruitment and plant community establishment. Further, different water levels in restored habitats are likely to determine its species composition of the plant community. The seed bank is important in restoration of degraded wetlands. Successful restoration of drying and salinization wetlands could depend on the seed bank.

  18. Do Amplitudes of Water Level Fluctuations Affect the Growth and Community Structure of Submerged Macrophytes?

    Science.gov (United States)

    Wang, Mo-Zhu; Liu, Zheng-Yuan; Luo, Fang-Li; Lei, Guang-Chun; Li, Hong-Li

    2016-01-01

    Submerged macrophytes are subjected to potential mechanical stresses associated with fluctuating water levels in natural conditions. However, few experimental studies have been conducted to further understand the effects of water level fluctuating amplitude on submerged macrophyte species and their assemblages or communities. We designed a controlled experiment to investigate the responses of three submerged macrophyte species (Hydrilla verticillata, Ceratophyllum demersum and Elodea nuttallii) and their combinations in communities to three amplitudes (static, ± 30 cm, ± 60 cm) of water level fluctuations. Results showed that water level fluctuating amplitude had little effects on the community performance and the three tested species responded differently. H. verticillata exhibited more growth in static water and it was negatively affected by either of the water level fluctuations amplitude, however, growth parameters of H. verticillata in two fluctuating water level treatments (i.e., ± 30 cm, ± 60 cm) were not significantly different. On the other hand, the growth of C. demersum was not significantly correlated with different amplitude treatments. However, it became more abundant when water levels fluctuated. E. nuttallii was inhibited by the two fluctuating water level treatments, and was less in growth parameters compared to the other species especially in water level fluctuating conditions. The inherent differences in the adaptive capabilities of the tested species indicate that C. demersum or other species with similar responses may be dominant species to restore submerged macrophyte communities with great fluctuating water levels. Otherwise, H. verticillata, E. nuttallii or other species with similar responses could be considered for constructing the community in static water conditions. PMID:26735689

  19. Do Amplitudes of Water Level Fluctuations Affect the Growth and Community Structure of Submerged Macrophytes?

    Science.gov (United States)

    Wang, Mo-Zhu; Liu, Zheng-Yuan; Luo, Fang-Li; Lei, Guang-Chun; Li, Hong-Li

    2016-01-01

    Submerged macrophytes are subjected to potential mechanical stresses associated with fluctuating water levels in natural conditions. However, few experimental studies have been conducted to further understand the effects of water level fluctuating amplitude on submerged macrophyte species and their assemblages or communities. We designed a controlled experiment to investigate the responses of three submerged macrophyte species (Hydrilla verticillata, Ceratophyllum demersum and Elodea nuttallii) and their combinations in communities to three amplitudes (static, ± 30 cm, ± 60 cm) of water level fluctuations. Results showed that water level fluctuating amplitude had little effects on the community performance and the three tested species responded differently. H. verticillata exhibited more growth in static water and it was negatively affected by either of the water level fluctuations amplitude, however, growth parameters of H. verticillata in two fluctuating water level treatments (i.e., ± 30 cm, ± 60 cm) were not significantly different. On the other hand, the growth of C. demersum was not significantly correlated with different amplitude treatments. However, it became more abundant when water levels fluctuated. E. nuttallii was inhibited by the two fluctuating water level treatments, and was less in growth parameters compared to the other species especially in water level fluctuating conditions. The inherent differences in the adaptive capabilities of the tested species indicate that C. demersum or other species with similar responses may be dominant species to restore submerged macrophyte communities with great fluctuating water levels. Otherwise, H. verticillata, E. nuttallii or other species with similar responses could be considered for constructing the community in static water conditions.

  20. Do Amplitudes of Water Level Fluctuations Affect the Growth and Community Structure of Submerged Macrophytes?

    Directory of Open Access Journals (Sweden)

    Mo-Zhu Wang

    Full Text Available Submerged macrophytes are subjected to potential mechanical stresses associated with fluctuating water levels in natural conditions. However, few experimental studies have been conducted to further understand the effects of water level fluctuating amplitude on submerged macrophyte species and their assemblages or communities. We designed a controlled experiment to investigate the responses of three submerged macrophyte species (Hydrilla verticillata, Ceratophyllum demersum and Elodea nuttallii and their combinations in communities to three amplitudes (static, ± 30 cm, ± 60 cm of water level fluctuations. Results showed that water level fluctuating amplitude had little effects on the community performance and the three tested species responded differently. H. verticillata exhibited more growth in static water and it was negatively affected by either of the water level fluctuations amplitude, however, growth parameters of H. verticillata in two fluctuating water level treatments (i.e., ± 30 cm, ± 60 cm were not significantly different. On the other hand, the growth of C. demersum was not significantly correlated with different amplitude treatments. However, it became more abundant when water levels fluctuated. E. nuttallii was inhibited by the two fluctuating water level treatments, and was less in growth parameters compared to the other species especially in water level fluctuating conditions. The inherent differences in the adaptive capabilities of the tested species indicate that C. demersum or other species with similar responses may be dominant species to restore submerged macrophyte communities with great fluctuating water levels. Otherwise, H. verticillata, E. nuttallii or other species with similar responses could be considered for constructing the community in static water conditions.

  1. Ground-water discharge determined from measurements of evapotranspiration, other available hydrologic components, and shallow water-level changes, Oasis Valley, Nye County, Nevada

    International Nuclear Information System (INIS)

    Reiner, S.R.; Laczniak, R.J.; DeMeo, G.A.; Smith LaRue, J.; Elliott, P.E.; Nylund, W.E.; Fridrich, C.J.

    2002-01-01

    Oasis Valley is an area of natural ground-water discharge within the Death Valley regional ground-water flow system of southern Nevada and adjacent California. Ground water discharging at Oasis Valley is replenished from inflow derived from an extensive recharge area that includes the northwestern part of the Nevada Test Site (NTS). Because nuclear testing has introduced radionuclides into the subsurface of the NTS, the U.S. Department of Energy currently is investigating the potential transport of these radionuclides by ground water flow. To better evaluate any potential risk associated with these test-generated contaminants, a number of studies were undertaken to accurately quantify discharge from areas downgradient in the regional ground-water flow system from the NTS. This report refines the estimate of ground-water discharge from Oasis Valley. Ground-water discharge from Oasis Valley was estimated by quantifying evapotranspiration (ET), estimating subsurface outflow, and compiling ground-water withdrawal data. ET was quantified by identifying areas of ongoing ground-water ET, delineating areas of ET defined on the basis of similarities in vegetation and soil-moisture conditions and computing ET rates for each of the delineated areas. A classification technique using spectral-reflectance characteristics determined from satellite imagery acquired in 1992 identified eight unique areas of ground-water ET. These areas encompass about 3,426 acres of sparsely to densely vegetated grassland, shrubland, wetland, and open water. Annual ET rates in Oasis Valley were computed with energy-budget methods using micrometeorological data collected at five sites. ET rates range from 0.6 foot per year in a sparse, dry saltgrass environment to 3.1 feet per year in dense meadow vegetation. Mean annual ET from Oasis Valley is estimated to be about 7,800 acre-feet. Mean annual ground-water discharge by ET from Oasis Valley, determined by removing the annual local precipitation

  2. Characterising Bedrock Aquifer Systems in Korea Using Paired Water-Level Monitoring Data

    Directory of Open Access Journals (Sweden)

    Jae Min Lee

    2017-06-01

    Full Text Available This study focused on characterising aquifer systems based on water-level changes observed systematically at 159 paired groundwater monitoring wells throughout Korea. Using spectral analysis, principal component analysis (PCA, and cross-correlation analysis with linear regression, aquifer conditions were identified from the comparison of water-level changes in shallow alluvial and deep bedrock monitoring wells. The spectral analysis could identify the aquifer conditions (i.e., unconfined, semi-confined and confined of 58.5% of bedrock wells and 42.8% of alluvial wells: 93 and 68 wells out of 159 wells, respectively. Even among the bedrock wells, 50 wells (53.7% exhibited characteristics of the unconfined condition, implying significant vulnerability of the aquifer to contaminants from the land surface and shallow depths. It appears to be better approach for deep bedrock aquifers than shallow alluvial aquifers. However, significant portions of the water-level changes remained unclear for categorising aquifer conditions due to disturbances in data continuity. For different aquifer conditions, PCA could show typical pattern and factor scores of principal components. Principal component 1 due to wet-and-dry seasonal changes and water-level response time was dominant covering about 55% of total variances of each aquifer conditions, implying the usefulness of supplementary method of aquifer characterisation. Cross-correlation and time-lag analysis in the water-level responses to precipitations clearly show how the water levels in shallow and deep wells correspond in time scale. No significant differences in time-lags was found between shallow and deep wells. However, clear time-lags were found to be increasing from unconfined to confined conditions: from 1.47 to 2.75 days and from 1.78 to 2.75 days for both shallow alluvial and deep bedrock wells, respectively. In combination of various statistical methods, three types of water-level fluctuation

  3. A Multiple-Iterated Dual Control Model for Groundwater Exploitation and Water Level Based on the Optimal Allocation Model of Water Resources

    Directory of Open Access Journals (Sweden)

    Junqiu Liu

    2018-04-01

    Full Text Available In order to mitigate environmental and ecological impacts resulting from groundwater overexploitation, we developed a multiple-iterated dual control model consisting of four modules for groundwater exploitation and water level. First, a water resources allocation model integrating calculation module of groundwater allowable withdrawal was built to predict future groundwater recharge and discharge. Then, the results were input into groundwater numerical model to simulate water levels. Groundwater exploitation was continuously optimized using the critical groundwater level as the feedback, and a groundwater multiple-iterated technique was applied to the feedback process. The proposed model was successfully applied to a typical region in Shenyang in northeast China. Results showed the groundwater numerical model was verified in simulating water levels, with a mean absolute error of 0.44 m, an average relative error of 1.33%, and a root-mean-square error of 0.46 m. The groundwater exploitation reduced from 290.33 million m3 to 116.76 million m3 and the average water level recovered from 34.27 m to 34.72 m in planning year. Finally, we proposed the strategies for water resources management in which the water levels should be controlled within the critical groundwater level. The developed model provides a promising approach for water resources allocation and sustainable groundwater management, especially for those regions with overexploited groundwater.

  4. Testing and use of radar water level sensors by the U.S. Geological Survey

    Science.gov (United States)

    Fulford, Janice M.

    2016-01-01

    The United States Geological Survey uses water-level (or stage) measurements to compute streamflow at over 8000 stream gaging stations located throughout the United States (waterwatch.usgs.gov, 2016). Streamflow (or discharge) is computed at five minute to hourly intervals from a relationship between water level and discharge that is uniquely determined for each station. The discharges are posted hourly to WaterWatch (waterwatch. usgs.gov) and are used by water managers to issue flood warnings and manage water supply and by other users of water information to make decisions. The accuracy of the water-level measurement is vital to the accuracy of the computed discharge. Because of the importance of water-level measurements, USGS has an accuracy policy of 0.02 ft or 0.2 percent of reading (whichever is larger) (Sauer and Turnipseed, 2010). Older technologies, such as float and shaft-encoder systems, bubbler systems and submersible pressure sensors, provide the needed accuracy but often require extensive construction to install and are prone to malfunctioning and damage from floating debris and sediment. No stilling wells or orifice lines need to be constructed for radar installations. During the last decade testing by the USGS Hydrologic Instrumentation Facility(HIF) found that radar water-level sensors can provide the needed accuracy for water-level measurements and because the sensor can be easily attached to bridges, reduce the construction required for installation. Additionally, the non-contact sensing of water level minimizes or eliminates damage and fouling from floating debris and sediment. This article is a brief summary of the testing efforts by the USGS HIF and field experiences with models of radar water-level sensors in streamflow measurement applications. Any use of trade names in this article is for descriptive purposes only and does not imply endorsement by the U.S. Government.

  5. Studying the processes of sodium-water interaction in the BOR-60 reactor micromodule steam generator

    International Nuclear Information System (INIS)

    Tsykanov, V.A.; Antipin, G.K.; Borisov, V.V.

    1981-01-01

    Main results of experimental studies of emergency regimes of micromodule steam generator (MSG) at small and big leaks of water into sodium, realized using the 30 MW MSG, operating in the BOR-o0 reactor, are considered. The aims of the study are as follows: the modelling of macroleak in ''Nadja'' steam generator for the BN-350 reactor; testing the conceptions of alarm signalling and MSG protection; testing under real conditions of new perspective systems of leak detection; gaining the experimence and development of the ways to eliminate the consequences of accident caused by big water leak into sodium; accumulation of knowledge on restoration of MSG operating ability after accident; experimental test of calculational techniques for big leak accidents to use them in future for calculational studies of similar situations at other reactors equipped with sodium-water steam generators; refinement of characteristics of hydrodynamic and thermal effects interaction zone for big leak in real circuit during the plant operation. A series of experiments with the imitation of water leak into sodium by means of argon and steam supply through injection devices, located before the steam superheater module of one of the sections and between evaporator module of the same section, is conducted. The range of steam flow rate is 0.02-0.45 g/s. Duration of steam supply is 100-400 s. A conclusion is made that the results obtained can be used for steam generator of the BN-350 reactor [ru

  6. Microbial Challenge Testing of Single Liquid Cathode Feed Water Electrolysis Cells for the International Space Station (ISS) Oxygen Generator Assembly (OGA)

    Science.gov (United States)

    Roy, Robert J.; Wilson, Mark E.; Diderich, Greg S.; Steele, John W.

    2011-01-01

    The International Space Station (ISS) Oxygen Generator Assembly (OGA) operational performance may be adversely impacted by microbiological growth and biofilm formation over the electrolysis cell membranes. Biofilms could hinder the transport of water from the bulk fluid stream to the membranes and increase the cell concentration overpotential resulting in higher cell voltages and a shorter cell life. A microbial challenge test was performed on duplicate single liquid-cathode feed water electrolysis cells to evaluate operational performance with increasing levels of a mixture of five bacteria isolated from ISS and Space Shuttle potable water systems. Baseline performance of the single water electrolysis cells was determined for approximately one month with deionized water. Monthly performance was also determined following each inoculation of the feed tank with 100, 1000, 10,000 and 100,000 cells/ml of the mixed suspension of test bacteria. Water samples from the feed tank and recirculating water loops for each cell were periodically analyzed for enumeration and speciation of bacteria and total organic carbon. While initially a concern, this test program has demonstrated that the performance of the electrolysis cell is not adversely impacted by feed water containing the five species of bacteria tested at a concentration measured as high as 1,000,000 colony forming units (CFU)/ml. This paper presents the methodologies used in the conduct of this test program along with the performance test results at each level of bacteria concentration.

  7. A linear bi-level multi-objective program for optimal allocation of water resources.

    Directory of Open Access Journals (Sweden)

    Ijaz Ahmad

    Full Text Available This paper presents a simple bi-level multi-objective linear program (BLMOLP with a hierarchical structure consisting of reservoir managers and several water use sectors under a multi-objective framework for the optimal allocation of limited water resources. Being the upper level decision makers (i.e., leader in the hierarchy, the reservoir managers control the water allocation system and tend to create a balance among the competing water users thereby maximizing the total benefits to the society. On the other hand, the competing water use sectors, being the lower level decision makers (i.e., followers in the hierarchy, aim only to maximize individual sectoral benefits. This multi-objective bi-level optimization problem can be solved using the simultaneous compromise constraint (SICCON technique which creates a compromise between upper and lower level decision makers (DMs, and transforms the multi-objective function into a single decision-making problem. The bi-level model developed in this study has been applied to the Swat River basin in Pakistan for the optimal allocation of water resources among competing water demand sectors and different scenarios have been developed. The application of the model in this study shows that the SICCON is a simple, applicable and feasible approach to solve the BLMOLP problem. Finally, the comparisons of the model results show that the optimization model is practical and efficient when it is applied to different conditions with priorities assigned to various water users.

  8. Water-level altitudes 2016 and water-level changes in the Chicot, Evangeline, and Jasper aquifers and compaction 1973–2015 in the Chicot and Evangeline aquifers, Houston-Galveston region, Texas

    Science.gov (United States)

    Kasmarek, Mark C.; Ramage, Jason K.; Johnson, Michaela R.

    2016-10-07

    Most of the land-surface subsidence in the Houston-Galveston region, Texas, has occurred as a direct result of groundwater withdrawals for municipal supply, commercial and industrial use, and irrigation that depressured and dewatered the Chicot and Evangeline aquifers, thereby causing compaction of the aquifer sediments, mostly in the fine-grained silt and clay layers. This report, prepared by the U.S. Geological Survey in cooperation with the Harris-Galveston Subsidence District, City of Houston, Fort Bend Subsidence District, Lone Star Groundwater Conservation District, and Brazoria County Groundwater Conservation District, is one in an annual series of reports depicting water-level altitudes and water-level changes in the Chicot, Evangeline, and Jasper aquifers and measured cumulative compaction of subsurface sediments in the Chicot and Evangeline aquifers in the Houston-Galveston region. The report contains regional-scale maps depicting approximate 2016 water-level altitudes (represented by measurements made during December 2015–March 2016) for the Chicot, Evangeline, and Jasper aquifers; maps depicting 1-year (2015–16) water-level changes for each aquifer; maps depicting approximate contoured 5-year (2011–16) water-level changes for each aquifer; maps depicting approximate contoured long-term (1990–2016 and 1977–2016) water-level changes for the Chicot and Evangeline aquifers; a map depicting approximate contoured long-term (2000–16) water-level changes for the Jasper aquifer; a map depicting locations of borehole-extensometer sites; and graphs depicting measured long-term cumulative compaction of subsurface sediments at the extensometers during 1973–2015. Tables listing the water-level data used to construct each water-level map for each aquifer and the measured long-term cumulative compaction data for each extensometer site are included. Graphs depicting water-level measurement data also are included; these graphs can be used to approximate

  9. Innovative Disposal Practices at the Nevada Test Site to Meet Its Low-Level Waste Generators' Future Disposal Needs

    International Nuclear Information System (INIS)

    Di Sanza, E.F.; Carilli, J.T.

    2006-01-01

    Low-level radioactive waste (LLW) streams which have a clear, defined pathway to disposal are becoming less common as U.S. Department of Energy accelerated cleanup sites enters their closure phase. These commonly disposed LLW waste streams are rapidly being disposed and the LLW inventory awaiting disposal is dwindling. However, more complex waste streams that have no path for disposal are now requiring attention. The U.S. Department of Energy (DOE) National Nuclear Security Administration Nevada Site Office (NSO) Environmental Management Program is charged with the responsibility of carrying out the disposal of onsite and off-site defense-generated and research-related LLW at the Nevada. Test Site (NTS). The NSO and its generator community are constantly pursuing new LLW disposal techniques while meeting the core mission of safe and cost-effective disposal that protects the worker, the public and the environment. From trenches to present-day super-cells, the NTS disposal techniques must change to meet the LLW generator's disposal needs. One of the many ways the NTS is addressing complex waste streams is by designing waste specific pits and trenches. This ensures unusual waste streams with high-activity or large packaging have a disposal path. Another option the NTS offers is disposal of classified low-level radioactive-contaminated material. In order to perform this function, the NTS has a safety plan in place as well as a secure facility. By doing this, the NTS can accept DOE generated classified low-level radioactive-contaminated material that would be equivalent to U.S. Nuclear Regulatory Commission Class B, C, and Greater than Class C waste. In fiscal year 2006, the NTS will be the only federal disposal facility that will be able to dispose mixed low-level radioactive waste (MLLW) streams. This is an activity that is highly anticipated by waste generators. In order for the NTS to accept MLLW, generators will have to meet the stringent requirements of the NTS

  10. Supporting inland waterway transport on German waterways by operational forecasting services - water-levels, discharges, river ice

    Science.gov (United States)

    Meißner, Dennis; Klein, Bastian; Ionita, Monica; Hemri, Stephan; Rademacher, Silke

    2017-04-01

    Inland waterway transport (IWT) is an important commercial sector significantly vulnerable to hydrological impacts. River ice and floods limit the availability of the waterway network and may cause considerable damages to waterway infrastructure. Low flows significantly affect IWT's operation efficiency usually several months a year due to the close correlation of (low) water levels / water depths and (high) transport costs. Therefore "navigation-related" hydrological forecasts focussing on the specific requirements of water-bound transport (relevant forecast locations, target parameters, skill characteristics etc.) play a major role in order to mitigate IWT's vulnerability to hydro-meteorological impacts. In light of continuing transport growth within the European Union, hydrological forecasts for the waterways are essential to stimulate the use of the free capacity IWT still offers more consequently. An overview of the current operational and pre-operational forecasting systems for the German waterways predicting water levels, discharges and river ice thickness on various time-scales will be presented. While short-term (deterministic) forecasts have a long tradition in navigation-related forecasting, (probabilistic) forecasting services offering extended lead-times are not yet well-established and are still subject to current research and development activities (e.g. within the EU-projects EUPORIAS and IMPREX). The focus is on improving technical aspects as well as on exploring adequate ways of disseminating and communicating probabilistic forecast information. For the German stretch of the River Rhine, one of the most frequented inland waterways worldwide, the existing deterministic forecast scheme has been extended by ensemble forecasts combined with statistical post-processing modules applying EMOS (Ensemble Model Output Statistics) and ECC (Ensemble Copula Coupling) in order to generate water level predictions up to 10 days and to estimate its predictive

  11. Levels of trace elements in MWSS drinking water

    International Nuclear Information System (INIS)

    Andal, T.T.

    1998-01-01

    As a water supplier for the metropolis, vigilance over the water quality has not been taken for granted at the Metropolitan Waterworks and Sewerage System (MWSS). By the early 1980's, a control laboratory equipped with modern facilities had been set up to supplement the already existing control laboratory at Filter Plant II handling physical, chemical, bacteriological, biological and mineral analyses and examinations, efficiently. The new central laboratory is intended to monitor trace elements, organic constituents and other elements with health related impact so as to assure the consumers of a safe drinking water supply at all times. This presentation reviews the levels of trace element pollution in MWSS tap water, then and now, in justification of the rehabilitation projects along the distribution network, in the treatment plants and other pertinent innovations corresponding to budgeted capital outlays as invested by the system. (author)

  12. Association between water fluoride and the level of children's intelligence: a dose-response meta-analysis.

    Science.gov (United States)

    Duan, Q; Jiao, J; Chen, X; Wang, X

    2018-01-01

    Higher fluoride concentrations in water have inconsistently been associated with the levels of intelligence in children. The following study summarizes the available evidence regarding the strength of association between fluoridated water and children's intelligence. Meta-analysis. PubMed, Embase, and Cochrane Library databases were systematically analyzed from November 2016. Observational studies that have reported on intelligence levels in relation to high and low water fluoride contents, with 95% confidence intervals (CIs) were included. Further, the results were pooled using inverse variance methods. The correlation between water fluoride concentration and intelligence level was assessed by a dose-response meta-analysis. Twenty-six studies reporting data on 7258 children were included. The summary results indicated that high water fluoride exposure was associated with lower intelligence levels (standardized mean difference : -0.52; 95% CI: -0.62 to -0.42; P intelligence (P intelligence levels. Greater exposure to high levels of fluoride in water was significantly associated with reduced levels of intelligence in children. Therefore, water quality and exposure to fluoride in water should be controlled in areas with high fluoride levels in water. Copyright © 2017. Published by Elsevier Ltd.

  13. An optimized Fuzzy Logic Controller by Water Cycle Algorithm for power management of Stand-alone Hybrid Green Power generation

    International Nuclear Information System (INIS)

    Sarvi, Mohammad; Avanaki, Isa Nasiri

    2015-01-01

    Highlights: • A new method to improve the performance of renewable power management is proposed. • The proposed method is based on Fuzzy Logic optimized by the Water Cycle Algorithm. • The proposed method characteristics are compared with two other methods. • The comparisons confirm that the proposed method is robust and effectiveness one. - Abstract: This paper aims to improve the power management system of a Stand-alone Hybrid Green Power generation based on the Fuzzy Logic Controller optimized by the Water Cycle Algorithm. The proposed Stand-alone Hybrid Green Power consists of wind energy conversion and photovoltaic systems as primary power sources and a battery, fuel cell, and Electrolyzer as energy storage systems. Hydrogen is produced from surplus power generated by the wind energy conversion and photovoltaic systems of Stand-alone Hybrid Green Power and stored in the hydrogen storage tank for fuel cell later using when the power generated by primary sources is lower than load demand. The proposed optimized Fuzzy Logic Controller based power management system determines the power that is generated by fuel cell or use by Electrolyzer. In a hybrid system, operation and maintenance cost and reliability of the system are the important issues that should be considered in studies. In this regard, Water Cycle Algorithm is used to optimize membership functions in order to simultaneously minimize the Loss of Power Supply Probability and operation and maintenance. The results are compared with the particle swarm optimization and the un-optimized Fuzzy Logic Controller power management system to prove that the proposed method is robust and effective. Reduction in Loss of Power Supply Probability and operation and maintenance, are the most advantages of the proposed method. Moreover the level of the State of Charge of the battery in the proposed method is higher than other mentioned methods which leads to increase battery lifetime.

  14. Hydrogen and methane generation from large hydraulic plant: Thermo-economic multi-level time-dependent optimization

    International Nuclear Information System (INIS)

    Rivarolo, M.; Magistri, L.; Massardo, A.F.

    2014-01-01

    Highlights: • We investigate H 2 and CH 4 production from very large hydraulic plant (14 GW). • We employ only “spilled energy”, not used by hydraulic plant, for H 2 production. • We consider the integration with energy taken from the grid at different prices. • We consider hydrogen conversion in chemical reactors to produce methane. • We find plants optimal size using a time-dependent thermo-economic approach. - Abstract: This paper investigates hydrogen and methane generation from large hydraulic plant, using an original multilevel thermo-economic optimization approach developed by the authors. Hydrogen is produced by water electrolysis employing time-dependent hydraulic energy related to the water which is not normally used by the plant, known as “spilled water electricity”. Both the demand for spilled energy and the electrical grid load vary widely by time of year, therefore a time-dependent hour-by-hour one complete year analysis has been carried out, in order to define the optimal plant size. This time period analysis is necessary to take into account spilled energy and electrical load profiles variability during the year. The hydrogen generation plant is based on 1 MWe water electrolysers fuelled with the “spilled water electricity”, when available; in the remaining periods, in order to assure a regular H 2 production, the energy is taken from the electrical grid, at higher cost. To perform the production plant size optimization, two hierarchical levels have been considered over a one year time period, in order to minimize capital and variable costs. After the optimization of the hydrogen production plant size, a further analysis is carried out, with a view to converting the produced H 2 into methane in a chemical reactor, starting from H 2 and CO 2 which is obtained with CCS plants and/or carried by ships. For this plant, the optimal electrolysers and chemical reactors system size is defined. For both of the two solutions, thermo

  15. Generation of ultra-fast cumulative water jets by sub-microsecond underwater electrical explosion of conical wire arrays

    Energy Technology Data Exchange (ETDEWEB)

    Shafer, D.; Gurovich, V. Tz.; Gleizer, S.; Gruzinsky, K.; Krasik, Ya. E. [Physics Department, Technion, Haifa 32000 (Israel)

    2015-12-15

    The results of experiments with underwater electrical explosion of modified conical arrays of copper and aluminum wires are presented. A pulsed generator producing a 550 kA-amplitude current with a 400 ns rise time was used in the explosion of the arrays. The array explosion generates water flows converging at the axis of the cone. This flow generates a fast-moving water jet with a velocity exceeding 1.8 × 10{sup 5 }cm/s, which was observed being ejected from the surface of the water covering the array. The positions of the water jet were measured by multiple-exposure fast framing imaging. In experiments, the apex angle of the array, the thickness of the water layer above the arrays, or the material of the wires was altered, which changed the resulting velocities and shapes of the emitted jets. A model that considers the converging stationary flow of a slightly compressible fluid is suggested. The velocities and shapes of the jets obtained by this model agree well with the experimentally measured jet velocities.

  16. Coherent Water Window X Ray by Phase-Matched High-Order Harmonic Generation in Neutral Media

    International Nuclear Information System (INIS)

    Takahashi, Eiji J.; Kanai, Tsuneto; Ishikawa, Kenichi L.; Nabekawa, Yasuo; Midorikawa, Katsumi

    2008-01-01

    We demonstrate the generation of a coherent water window x ray by extending the plateau region of high-order harmonics under a neutral-medium condition. The maximum harmonic photon energies attained are 300 and 450 eV in Ne and He, respectively. Our proposed generation scheme, combining a 1.6 μm laser driver and a neutral Ne gas medium, is efficient and scalable in output yields of the water window x ray. Thus, the precept of the design parameter for a single-shot live-cell imaging by contact microscopy is presented

  17. Solid polymer electrolyte water electrolysis system development. [to generate oxygen for manned space station applications

    Science.gov (United States)

    1975-01-01

    Solid polymer electrolyte technology used in a water electrolysis system (WES) to generate oxygen and hydrogen for manned space station applications was investigated. A four-man rated, low pressure breadboard water electrolysis system with the necessary instrumentation and controls was fabricated and tested. A six man rated, high pressure, high temperature, advanced preprototype WES was developed. This configuration included the design and development of an advanced water electrolysis module, capable of operation at 400 psig and 200 F, and a dynamic phase separator/pump in place of a passive phase separator design. Evaluation of this system demonstrated the goal of safe, unattended automated operation at high pressure and high temperature with an accumulated gas generation time of over 1000 hours.

  18. Origin of elevated water levels encountered in Pahute Mesa emplacement boreholes: Preliminary investigations

    International Nuclear Information System (INIS)

    Brikowski, T.; Chapman, J.; Lyles, B.; Hokett, S.

    1993-11-01

    The presence of standing water well above the predicted water table in emplacement boreholes on Pahute Mesa has been a recurring phenomenon at the Nevada Test Site (NTS). If these levels represent naturally perched aquifers, they may indicate a radionuclide migration hazard. In any case, they can pose engineering problems in the performance of underground nuclear tests. The origin of these elevated waters is uncertain. Large volumes of water are introduced during emplacement drilling, providing ample source for artificially perched water, yet elevated water levels can remain constant for years, suggesting a natural origin instead. In an effort to address the issue of unexpected standing water in emplacement boreholes, three different sites were investigated in Area 19 on Pahute Mesa by Desert Research Institute (DRI) staff from 1990-93. These sites were U-19az, U-19ba, and U-19bh. As of this writing, U-19bh remains available for access; however, nuclear tests were conducted at the former two locations subsequent to this investigations. The experiments are discussed in chronological order. Taken together, the experiments indicate that standing water in Pahute Mesa emplacement holes originates from the drainage of small-volume naturally perched zones. In the final study, the fluids used during drilling of the bottom 100 m of emplacement borehole U-19bh were labeled with a chemical tracer. After hole completion, water level rose in the borehole, while tracer concentration decreased. In fact, total mass of tracer in the borehole remained constant, while water levels rose. After water levels stabilized in this hole, no change in tracer mass was observed over two years, indicating that no movement of water out of the borehole is taking place (as at U- 19ba). Continued labeling tests of standing water are recommended to confirm the conclusions made here, and to establish their validity throughout Pahute Mesa

  19. Reverse osmosis using for water demineralization for supplying the NPP and TPP steam generators

    International Nuclear Information System (INIS)

    Mamet, A.P.; Sitnyakovskij, Yu.A.

    2000-01-01

    Paper analyzes the conditions affecting the efficiency of water reverse-osmosis demineralization for NPP and TPP steam generators and presents an example of efficient application of a membrane reverse-osmosis facility serving as the first stage of water demineralization at the Mosehnergo Joint-Stock Company heating and power plant no. 23 to feed boilers [ru

  20. Loading forces in shallow water running in two levels of immersion.

    Science.gov (United States)

    Haupenthal, Alessandro; Ruschel, Caroline; Hubert, Marcel; de Brito Fontana, Heiliane; Roesler, Helio

    2010-07-01

    To analyse the vertical and anteroposterior components of the ground reaction force during shallow water running at 2 levels of immersion. Twenty-two healthy adults with no gait disorders, who were familiar with aquatic exercises. Subjects performed 6 trials of water running at a self-selected speed in chest and hip immersion. Force data were collected through an underwater force plate and running speed was measured with a photocell timing light system. Analysis of covariance was used for data analysis. Vertical forces corresponded to 0.80 and 0.98 times the subject's body weight at the chest and hip level, respectively. Anteroposterior forces corresponded to 0.26 and 0.31 times the subject's body weight at the chest and hip level, respectively. As the water level decreased the subjects ran faster. No significant differences were found for the force values between the immersions, probably due to variability in speed, which was self-selected. When thinking about load values in water running professionals should consider not only the immersion level, but also the speed, as it can affect the force components, mainly the anteroposterior one. Quantitative data on this subject could help professionals to conduct safer aqua-tic rehabilitation and physical conditioning protocols.

  1. Flood Finder: Mobile-based automated water level estimation and mapping during floods

    International Nuclear Information System (INIS)

    Pongsiriyaporn, B; Jariyavajee, C; Laoharawee, N; Narkthong, N; Pitichat, T; Goldin, S E

    2014-01-01

    Every year, Southeast Asia faces numerous flooding disasters, resulting in very high human and economic loss. Responding to a sudden flood is difficult due to the lack of accurate and up-to- date information about the incoming water status. We have developed a mobile application called Flood Finder to solve this problem. Flood Finder allows smartphone users to measure, share and search for water level information at specified locations. The application uses image processing to compute the water level from a photo taken by users. The photo must be of a known reference object with a standard size. These water levels are more reliable and consistent than human estimates since they are derived from an algorithmic measuring function. Flood Finder uploads water level readings to the server, where they can be searched and mapped by other users via the mobile phone app or standard browsers. Given the widespread availability of smartphones in Asia, Flood Finder can provide more accurate and up-to-date information for better preparation for a flood disaster as well as life safety and property protection

  2. Laser controllable generation and manipulation of micro-bubbles in water

    Science.gov (United States)

    Angelsky, O. V.; Bekshaev, A. Ya.; Maksimyak, P. P.; Maksimyak, A. P.; Hanson, S. G.; Kontush, S. M.

    2018-01-01

    Micrometer-sized vapor bubbles are formed due to local heating of the water suspension containing absorptive pigment particles of 100 nm diameter. The heating is performed by the CW near-infrared laser radiation. By changing the laser power, four regimes are realized: (1) bubble generation, (2) stable growth of the existing bubbles; (3) stationary existence of the bubbles and (4) bubbles' shrinkage and collapse. The generation and evolution of single bubbles and ensembles of bubbles with controllable sizes and numbers is demonstrated. The bubbles are grouped within the laserilluminated region. They can be easily moved and transported together with the focal spot. The results can be useful for applications associated with the precise manipulation and the species delivery in nano- and micro-engineering problems.

  3. High Efficiency Generation of Hydrogen Fuels Using Solar Thermochemical Splitting of Water

    Energy Technology Data Exchange (ETDEWEB)

    Heske, Clemens; Moujaes, Samir; Weimer, Alan; Wong, Bunsen; Siegal, Nathan; McFarland, Eric; Miller, Eric; Lewis, Michele; Bingham, Carl; Roth, Kurth; Sabacky, Bruce; Steinfeld, Aldo

    2011-09-29

    The objective of this work is to identify economically feasible concepts for the production of hydrogen from water using solar energy. The ultimate project objective was to select one or more competitive concepts for pilot-scale demonstration using concentrated solar energy. Results of pilot scale plant performance would be used as foundation for seeking public and private resources for full-scale plant development and testing. Economical success in this venture would afford the public with a renewable and limitless source of energy carrier for use in electric power load-leveling and as a carbon-free transportation fuel. The Solar Hydrogen Generation Research (SHGR) project embraces technologies relevant to hydrogen research under the Office of Hydrogen Fuel Cells and Infrastructure Technology (HFCIT) as well as concentrated solar power under the Office of Solar Energy Technologies (SET). Although the photoelectrochemical work is aligned with HFCIT, some of the technologies in this effort are also consistent with the skills and technologies found in concentrated solar power and photovoltaic technology under the Office of Solar Energy Technologies (SET). Hydrogen production by thermo-chemical water-splitting is a chemical process that accomplishes the decomposition of water into hydrogen and oxygen using only heat or a combination of heat and electrolysis instead of pure electrolysis and meets the goals for hydrogen production using only water and renewable solar energy as feed-stocks. Photoelectrochemical hydrogen production also meets these goals by implementing photo-electrolysis at the surface of a semiconductor in contact with an electrolyte with bias provided by a photovoltaic source. Here, water splitting is a photo-electrolytic process in which hydrogen is produced using only solar photons and water as feed-stocks. The thermochemical hydrogen task engendered formal collaborations among two universities, three national laboratories and two private sector

  4. A bio-inspired molecular water oxidation catalyst for renewable hydrogen generation: an examination of salt effects

    Science.gov (United States)

    Brimblecombe, Robin; Rotstein, Miriam; Koo, Annette; Dismukes, G. Charles; Swiegers, Gerhard F.; Spiccia, Leone

    2009-08-01

    Most transport fuels are derived from fossil fuels, generate greenhouse gases, and consume significant amounts of water in the extraction, purification, and/or burning processes. The generation of hydrogen using solar energy to split water, ideally from abundant water sources such as sea water or other non-potable sources, could potentially provide an unlimited, clean fuel for the future. Solar, electrochemical water splitting typically combines a photoanode at which water oxidation occurs, with a cathode for proton reduction to hydrogen. In recent work, we have found that a bioinspired tetra-manganese cluster catalyzes water oxidation at relatively low overpotentials (0.38 V) when doped into a Nafion proton conduction membrane deposited on a suitable electrode surface, and illuminated with visible light. We report here that this assembly is active in aqueous and organic electrolyte solutions containing a range of different salts in varying concentrations. Similar photocurrents were obtained using electrolytes containing 0.0 - 0.5 M sodium sulfate, sodium perchlorate or sodium chloride. A slight decline in photocurrent was observed for sodium perchlorate but only at and above 5.0 M concentration. In acetonitrile and acetone solutions containing 10% water, increasing the electrolyte concentration was found to result in leaching of the catalytic species from the membrane and a decrease in photocurrent. Leaching was not observed when the system was tested in an ionic liquid containing water, however, a lower photocurrent was generated than observed in aqueous electrolyte. We conclude that immersion of the membrane in an aqueous solution containing an electrolyte concentration of 0.05 - 0.5M represent good conditions for operation for the cubium/Nafion catalytic system.

  5. Observations and estimates of wave-driven water level extremes at the Marshall Islands

    Science.gov (United States)

    Merrifield, M. A.; Becker, J. M.; Ford, M.; Yao, Y.

    2014-10-01

    Wave-driven extreme water levels are examined for coastlines protected by fringing reefs using field observations obtained in the Republic of the Marshall Islands. The 2% exceedence water level near the shoreline due to waves is estimated empirically for the study sites from breaking wave height at the outer reef and by combining separate contributions from setup, sea and swell, and infragravity waves, which are estimated based on breaking wave height and water level over the reef flat. Although each component exhibits a tidal dependence, they sum to yield a 2% exceedence level that does not. A hindcast based on the breaking wave height parameterization is used to assess factors leading to flooding at Roi-Namur caused by an energetic swell event during December 2008. Extreme water levels similar to December 2008 are projected to increase significantly with rising sea level as more wave and tide events combine to exceed inundation threshold levels.

  6. Water-Level Data Analysis for the Saturated Zone Site-Scale Flow and Transport Model

    International Nuclear Information System (INIS)

    Tucci, P.

    2001-01-01

    This Analysis/Model Report (AMR) documents an updated analysis of water-level data performed to provide the saturated-zone, site-scale flow and transport model (CRWMS M and O 2000) with the configuration of the potentiometric surface, target water-level data, and hydraulic gradients for model calibration. The previous analysis was presented in ANL-NBS-HS-000034, Rev 00 ICN 01, Water-Level Data Analysis for the Saturated Zone Site-Scale Flow and Transport Model (USGS 2001). This analysis is designed to use updated water-level data as the basis for estimating water-level altitudes and the potentiometric surface in the SZ site-scale flow and transport model domain. The objectives of this revision are to develop computer files containing (1) water-level data within the model area (DTN: GS010908312332.002), (2) a table of known vertical head differences (DTN: GS0109083 12332.003), and (3) a potentiometric-surface map (DTN: GS010608312332.001) using an alternate concept from that presented in ANL-NBS-HS-000034, Rev 00 ICN 01 for the area north of Yucca Mountain. The updated water-level data include data obtained from the Nye County Early Warning Drilling Program (EWDP) and data from borehole USW WT-24. In addition to being utilized by the SZ site-scale flow and transport model, the water-level data and potentiometric-surface map contained within this report will be available to other government agencies and water users for ground-water management purposes. The potentiometric surface defines an upper boundary of the site-scale flow model, as well as provides information useful to estimation of the magnitude and direction of lateral ground-water flow within the flow system. Therefore, the analysis documented in this revision is important to SZ flow and transport calculations in support of total system performance assessment

  7. Linking economic water use, freshwater ecosystem impacts, and virtual water trade in a Great Lakes watershed

    Science.gov (United States)

    Mubako, S. T.; Ruddell, B. L.; Mayer, A. S.

    2013-12-01

    The impact of human water uses and economic pressures on freshwater ecosystems is of growing interest for water resource management worldwide. This case study for a water-rich watershed in the Great Lakes region links the economic pressures on water resources as revealed by virtual water trade balances to the nature of the economic water use and the associated impacts on the freshwater ecosystem. A water accounting framework that combines water consumption data and economic data from input output tables is applied to quantify localized virtual water imports and exports in the Kalamazoo watershed which comprises ten counties. Water using economic activities at the county level are conformed to watershed boundaries through land use-water use relationships. The counties are part of a region implementing the Michigan Water Withdrawal Assessment Process, including new regulatory approaches for adaptive water resources management under a riparian water rights framework. The results show that at local level, there exists considerable water use intensity and virtual water trade balance disparity among the counties and between water use sectors in this watershed. The watershed is a net virtual water importer, with some counties outsourcing nearly half of their water resource impacts, and some outsourcing nearly all water resource impacts. The largest virtual water imports are associated with agriculture, thermoelectric power generation and industry, while the bulk of the exports are associated with thermoelectric power generation and commercial activities. The methodology is applicable to various spatial levels ranging from the micro sub-watershed level to the macro Great Lakes watershed region, subject to the availability of reliable water use and economic data.

  8. Comparison of lead removal behaviors and generation of water-soluble sodium compounds in molten lead glass under a reductive atmosphere

    Science.gov (United States)

    Okada, Takashi; Nishimura, Fumihiro; Xu, Zhanglian; Yonezawa, Susumu

    2018-06-01

    We propose a method of reduction-melting at 1000 °C, using a sodium-based flux, to recover lead from cathode-ray tube funnel glass. To recover the added sodium from the treated glass, we combined a reduction-melting process with a subsequent annealing step at 700 °C, generating water-soluble sodium compounds in the molten glass. Using this combined process, this study compares lead removal behavior and the generation of water-soluble sodium compounds (sodium silicates and carbonates) in order to gain fundamental information to enhance the recovery of both lead and sodium. We find that lead removal increases with increasing melting time, whereas the generation efficiency of water-soluble sodium increases and decreases periodically. In particular, near 90% lead removal, the generation of water-soluble sodium compounds decreased sharply, increasing again with the prolongation of melting time. This is due to the different crystallization and phase separation efficiencies of water-soluble sodium in molten glass, whose structure continuously changes with lead removal. Previous studies used a melting time of 60 min in the processes. However, in this study, we observe that a melting time of 180 min enhances the water-soluble sodium generation efficiency.

  9. Amount of leachant and water absorption levels of wood treated with borates and water repellents.

    Science.gov (United States)

    Baysal, Ergun; Sonmez, Abdullah; Colak, Mehmet; Toker, Hilmi

    2006-12-01

    Wood protection efficacy of borates against biological agents, flame retardancy, and suitability to the environment is well known. Since borates can be applied to timber as water based solutions, they are preferred economically as well. Even though they are highly mobile in wood, boron compounds are widely used in timber preservation. Borates migrate in liquid and increase the hygroscopicity of wood in damp conditions. This study deals with the physical restriction of water access in wood by impregnating water repellent agents into wood to limit amount of leachant and water absorption levels of wood after boron treatment. Borates were incorporated with polyethylene glycol-400 (PEG-400) their bulking effect in wood was considered. Results indicated that the amount of leachates from wood treated with borates in PEG-400 was remarkably higher compared to those of wood treated with the aqueous solutions of borates. Water absorption (WA) levels of wood treated with aqueous solutions of borates were higher than those of their treated samples with the solutions in PEG-400. Secondary treatments of wood with the water repellent (WR) chemicals following borate impregnation reduced the leaching of chemicals from wood in water and also WA of the specimens were less than those of the wood treated with only borates from aqueous and PEG solutions. Styrene (St) was the most effective monomer among the other agents used in terms of immobility effect on borates and WA.

  10. National profile on commercially generated low-level radioactive mixed waste

    Energy Technology Data Exchange (ETDEWEB)

    Klein, J.A.; Mrochek, J.E.; Jolley, R.L.; Osborne-Lee, I.W.; Francis, A.A.; Wright, T. [Oak Ridge National Lab., TN (United States)

    1992-12-01

    This report details the findings and conclusions drawn from a survey undertaken as part of a joint US Nuclear Regulatory Commission and US Environmental Protection Agency-sponsored project entitled ``National Profile on Commercially Generated Low-Level Radioactive Mixed Waste.`` The overall objective of the work was to compile a national profile on the volumes, characteristics, and treatability of commercially generated low-level mixed waste for 1990 by five major facility categories-academic, industrial, medical, and NRC-/Agreement State-licensed goverment facilities and nuclear utilities. Included in this report are descriptions of the methodology used to collect and collate the data, the procedures used to estimate the mixed waste generation rate for commercial facilities in the United States in 1990, and the identification of available treatment technologies to meet applicable EPA treatment standards (40 CFR Part 268) and, if possible, to render the hazardous component of specific mixed waste streams nonhazardous. The report also contains information on existing and potential commercial waste treatment facilities that may provide treatment for specific waste streams identified in the national survey. The report does not include any aspect of the Department of Energy`s (DOES) management of mixed waste and generally does not address wastes from remedial action activities.

  11. National profile on commercially generated low-level radioactive mixed waste

    International Nuclear Information System (INIS)

    Klein, J.A.; Mrochek, J.E.; Jolley, R.L.; Osborne-Lee, I.W.; Francis, A.A.; Wright, T.

    1992-12-01

    This report details the findings and conclusions drawn from a survey undertaken as part of a joint US Nuclear Regulatory Commission and US Environmental Protection Agency-sponsored project entitled ''National Profile on Commercially Generated Low-Level Radioactive Mixed Waste.'' The overall objective of the work was to compile a national profile on the volumes, characteristics, and treatability of commercially generated low-level mixed waste for 1990 by five major facility categories-academic, industrial, medical, and NRC-/Agreement State-licensed goverment facilities and nuclear utilities. Included in this report are descriptions of the methodology used to collect and collate the data, the procedures used to estimate the mixed waste generation rate for commercial facilities in the United States in 1990, and the identification of available treatment technologies to meet applicable EPA treatment standards (40 CFR Part 268) and, if possible, to render the hazardous component of specific mixed waste streams nonhazardous. The report also contains information on existing and potential commercial waste treatment facilities that may provide treatment for specific waste streams identified in the national survey. The report does not include any aspect of the Department of Energy's (DOES) management of mixed waste and generally does not address wastes from remedial action activities

  12. Collapse of a cavitation bubble generated by low voltage discharge in water

    Directory of Open Access Journals (Sweden)

    Zima Patrik

    2012-04-01

    Full Text Available The article presents experimental results of the optical study of cavitation bubble collapse close to a solid boundary in water. The bubble was generated by discharge of two low-voltage capacitors. High-speed CCD camera was used to record the time evolution of the bubble size. High-power halogen lamp was used for illumination. The system was synchronized by pulse generator connected to an oscilloscope. The velocity of the re-entrant jet was estimated from the time resolved photography for different maximum bubble sizes.

  13. Steam-generator tube failures: world experience in water-cooled nuclear power reactors in 1974

    International Nuclear Information System (INIS)

    Hare, M.G.

    1976-01-01

    Steam-generator tube failures were reported at 25 of 59 water-cooled nuclear power reactors surveyed in 1974, compared to 11 of 49 in 1973. A summary is presented of these failures, most of which, where the cause is known, were the result of corrosion. Water chemistry control, inspection and repair procedures, and failure rates are discussed

  14. Correlation of a generation-recombination center with a deep level trap in GaN

    International Nuclear Information System (INIS)

    Nguyen, X. S.; Lin, K.; Zhang, Z.; Arehart, A. R.; Ringel, S. A.; McSkimming, B.; Speck, J. S.; Fitzgerald, E. A.; Chua, S. J.

    2015-01-01

    We report on the identification of a deep level trap centre which contributes to generation-recombination noise. A n-GaN epilayer, grown by MOCVD on sapphire, was measured by deep level transient spectroscopy (DLTS) and noise spectroscopy. DLTS found 3 well documented deep levels at E c  − 0.26 eV, E c  − 0.59 eV, and E c  − 0.71 eV. The noise spectroscopy identified a generation recombination centre at E c  − 0.65 ± 0.1 eV with a recombination lifetime of 65 μs at 300 K. This level is considered to be the same as the one at E c  − 0.59 eV measured from DLTS, as they have similar trap densities and capture cross section. This result shows that some deep levels contribute to noise generation in GaN materials

  15. Projecting Future Sea Level Rise for Water Resources Planning in California

    Science.gov (United States)

    Anderson, J.; Kao, K.; Chung, F.

    2008-12-01

    Sea level rise is one of the major concerns for the management of California's water resources. Higher water levels and salinity intrusion into the Sacramento-San Joaquin Delta could affect water supplies, water quality, levee stability, and aquatic and terrestrial flora and fauna species and their habitat. Over the 20th century, sea levels near San Francisco Bay increased by over 0.6ft. Some tidal gauge and satellite data indicate that rates of sea level rise are accelerating. Sea levels are expected to continue to rise due to increasing air temperatures causing thermal expansion of the ocean and melting of land-based ice such as ice on Greenland and in southeastern Alaska. For water planners, two related questions are raised on the uncertainty of future sea levels. First, what is the expected sea level at a specific point in time in the future, e.g., what is the expected sea level in 2050? Second, what is the expected point of time in the future when sea levels will exceed a certain height, e.g., what is the expected range of time when the sea level rises by one foot? To address these two types of questions, two factors are considered: (1) long term sea level rise trend, and (2) local extreme sea level fluctuations. A two-step approach will be used to develop sea level rise projection guidelines for decision making that takes both of these factors into account. The first step is developing global sea level rise probability distributions for the long term trends. The second step will extend the approach to take into account the effects of local astronomical tides, changes in atmospheric pressure, wind stress, floods, and the El Niño/Southern Oscillation. In this paper, the development of the first step approach is presented. To project the long term sea level rise trend, one option is to extend the current rate of sea level rise into the future. However, since recent data indicate rates of sea level rise are accelerating, methods for estimating sea level rise

  16. Electrolytically generated hydrogen warm water cleanses the keratin-plug-clogged hair-pores and promotes the capillary blood-streams, more markedly than normal warm water does

    Directory of Open Access Journals (Sweden)

    Yoshiharu Tanaka

    2018-01-01

    Full Text Available Biomedical properties of hydrogen water have been extensively investigated, but the effect of hydrogen on good healthy subjects remains unclear. This study was designed to explore the hygiene improvement by electrolytically generated hydrogen warm water (40°C on capillary blood streams, skin moisture, and keratin plugs in skin pores in normal good healthy subjects with their informed consents. Fingertip-capillary blood stream was estimated after hand-immersing in hydrogen warm water by videography using a CCD-based microscope, and the blood flow levels increased to about 120% versus normal warm water, after 60 minutes of the hand-immersing termination. Skin moisture of subjects was assessed using an electro-conductivity-based skin moisture meter. Immediately after taking a bath filled with hydrogen warm water, the skin moisture increased by 5–10% as compared to before bathing, which was kept on for the 7-day test, but indistinct, because of lower solubility of hydrogen in “warm” water than in room-temperature water. Cleansing of keratin plugs in skin-pores was assessed by stereoscopic microscopy and scanning electron microscopy. After hydrogen warm water bathing, the numbers of cleansed keratin plugs also increased on cheek of subjects 2.30- to 4.47-fold as many as the control for normal warm water. And areas of cleansed keratin plugs in the cheeks increased about 1.3-fold as much as the control. More marked improvements were observed on cheeks than on nostrils. Hydrogen warm water may thoroughly cleanse even keratin-plugs of residual amounts that could not be cleansed by normal warm water, through its permeability into wide-ranged portions of hair-pores, and promote the fingertip blood streams more markedly than merely through warmness due to normal warm water.

  17. Investigation on the use digital controls instead of PID analog controls in the level control of steam generators of nuclear power PWR

    International Nuclear Information System (INIS)

    Alvarenga, Marco Antonio Bayout

    2012-01-01

    The aim of this study is to identify current alternatives for the implementation of digital controllers in the level control of steam generators of nuclear power PWR (Pressurized Water Reaetor). It is intended to identify the types of digital controls that are available from the theoretical and conceptual viewpoints for this purpose. We investigate the advantages and disadvantages of each controller model. From this assessment are pointed the most suitable models in hierarchical scale. This evaluation also serves to suggest possible types of control installation as a whole, where the level control of the steam generators becomes just one of many controls that are part of the plant. In this case, the use of digital controls allows the non-linear and multivariable treatment which is characteristic of complex systems, such as the nuclear power generation. The treatment of nonlinearities and multivariable aspects allows a more detailed study of the stability of these plants when they are subject to transients or several accidents, such as the case of losing external power of transients. In the specific case of steam generators, the instabilities result from the emergence of the shrink and swell phenomenas, depending on the load variations of thermonuclear plant. The application of several types and digital controllers, considering these inherent characteristics of the level control of steam generators, allows to infer which types of controllers are more appropriate to treat instabilities of this type and to make conjectures in its use for the cases of more complex instabilities, considering the integration of all nucleus-plant controls.

  18. Influence of sodium water reaction on MONJU steam generator

    International Nuclear Information System (INIS)

    Takahashi, T.; Ohmori, Y.; Hoshi, Y.

    1984-01-01

    Despite the strenuous efforts improving the reliability of steam generators, it is required to ascertain the safe shutdown at Design Basis Leak and also to take the necessary actions to minimize the plant damage for more realistic small leaks. The process of Monju DBL selection and its supporting R and D works are included in this paper, together with the evaluation of system and critical components in direct connection with DBL. The detail plant shutdown procedures (including auxiliary system sequential action) at the time of water leaks are also explained. (author)

  19. Estabilishing requirements for the next generation of pressurized water reactors--reducing the uncertainty

    International Nuclear Information System (INIS)

    Chernock, W.P.; Corcoran, W.R.; Rasin, W.H.; Stahlkopf, K.E.

    1987-01-01

    The Electric Power Research Institute is managing a major effort to establish requirements for the next generation of U.S. light water reactors. This effort is the vital first step in preserving the viability of the nuclear option to contribute to meet U.S. national electric power capacity needs in the next century. Combustion Engineering, Inc. and Duke Power Company formed a team to participate in the EPRI program which is guided by a Utility Steering committee consisting of experienced utility technical executives. A major thrust of the program is to reduce the uncertainties which would be faced by the utility executives in choosing the nuclear option. The uncertainties to be reduced include those related to safety, economic, operational, and regulatory aspects of advanced light water reactors. This paper overviews the Requirements Document program as it relates to the U.S. Advanced Light Water Reactor (ALWR) effort in reducing these uncertainties and reports the status of efforts to establish requirements for the next generation of pressurized water reactors. It concentrates on progress made in reducing the uncertainties which would deter selection of the nuclear option for contributing to U.S. national electric power capacity needs in the next century and updates previous reports in the same area. (author)

  20. Generation of µW level plateau harmonics at high repetition rate.

    Science.gov (United States)

    Hädrich, S; Krebs, M; Rothhardt, J; Carstens, H; Demmler, S; Limpert, J; Tünnermann, A

    2011-09-26

    The process of high harmonic generation allows for coherent transfer of infrared laser light to the extreme ultraviolet spectral range opening a variety of applications. The low conversion efficiency of this process calls for optimization or higher repetition rate intense ultrashort pulse lasers. Here we present state-of-the-art fiber laser systems for the generation of high harmonics up to 1 MHz repetition rate. We perform measurements of the average power with a calibrated spectrometer and achieved µW harmonics between 45 nm and 61 nm (H23-H17) at a repetition rate of 50 kHz. Additionally, we show the potential for few-cycle pulses at high average power and repetition rate that may enable water-window harmonics at unprecedented repetition rate. © 2011 Optical Society of America

  1. Advanced methods for modeling water-levels and estimating drawdowns with SeriesSEE, an Excel add-in

    Science.gov (United States)

    Halford, Keith; Garcia, C. Amanda; Fenelon, Joe; Mirus, Benjamin B.

    2012-12-21

    Water-level modeling is used for multiple-well aquifer tests to reliably differentiate pumping responses from natural water-level changes in wells, or “environmental fluctuations.” Synthetic water levels are created during water-level modeling and represent the summation of multiple component fluctuations, including those caused by environmental forcing and pumping. Pumping signals are modeled by transforming step-wise pumping records into water-level changes by using superimposed Theis functions. Water-levels can be modeled robustly with this Theis-transform approach because environmental fluctuations and pumping signals are simulated simultaneously. Water-level modeling with Theis transforms has been implemented in the program SeriesSEE, which is a Microsoft® Excel add-in. Moving average, Theis, pneumatic-lag, and gamma functions transform time series of measured values into water-level model components in SeriesSEE. Earth tides and step transforms are additional computed water-level model components. Water-level models are calibrated by minimizing a sum-of-squares objective function where singular value decomposition and Tikhonov regularization stabilize results. Drawdown estimates from a water-level model are the summation of all Theis transforms minus residual differences between synthetic and measured water levels. The accuracy of drawdown estimates is limited primarily by noise in the data sets, not the Theis-transform approach. Drawdowns much smaller than environmental fluctuations have been detected across major fault structures, at distances of more than 1 mile from the pumping well, and with limited pre-pumping and recovery data at sites across the United States. In addition to water-level modeling, utilities exist in SeriesSEE for viewing, cleaning, manipulating, and analyzing time-series data.

  2. Determination of natural radionuclides in wastes generated in the potable water treatment plants of the Zona da Mata of the State of Pernambuco-Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Albuquerque, Adriana M. de A.; França, Fernanda Cláudia S. da S.; Silveira, Patrícia B. da; Hazin, Clovis A.; Honorato, Eliane V., E-mail: chazin@elogica.com.br, E-mail: valentim@cnen.gov.br, E-mail: adrianamuniz.a@gmail.com [Centro Regional de Ciências Nucleares do Nordeste (CRCN/CNEN-PE), Recife, PE (Brazil)

    2017-07-01

    The water purification procedure aims to obtain a product appropriate for human consumption, minimizing the concentration of contaminants and toxic substances present in the water. Among these contaminants, some radionuclides of natural origin, such as uranium, thorium and their descendants, have been identified. Previous studies have shown that the stages of purification are quite effective in removing the radionuclides contained in the water. The removal is due to co-precipitation of the radionuclides with the suspended materials. The precipitated material is accumulated and characterized as a Technologically Enhanced Naturally Occurring Radioactive Materials (TENORM) by the United States Environmental Protection Agency (USEPA). This wastes can present significant levels of radioactivity and, when discarded in the environment without any treatment, can generate a problem of environmental impact and a risk to the health of the population. In this way, some gamma emitters of the series of U and Th, as well as {sup 40}K were determined in the residues generated at the Potable Water Treatment Plants PWTPs in six municipalities of Pernambuco. The results obtained corroborate the classification of the residues generated in the PWTPs as concentrators of the radioactive components contained in the water supplied to the system and reinforce the need for the release to the environment, which is the usual way of disposal of this waste, to be carried out only after considering the radiation protection standards established by CNEN. (author)

  3. Determination of natural radionuclides in wastes generated in the potable water treatment plants of the Zona da Mata of the State of Pernambuco-Brazil

    International Nuclear Information System (INIS)

    Albuquerque, Adriana M. de A.; França, Fernanda Cláudia S. da S.; Silveira, Patrícia B. da; Hazin, Clovis A.; Honorato, Eliane V.

    2017-01-01

    The water purification procedure aims to obtain a product appropriate for human consumption, minimizing the concentration of contaminants and toxic substances present in the water. Among these contaminants, some radionuclides of natural origin, such as uranium, thorium and their descendants, have been identified. Previous studies have shown that the stages of purification are quite effective in removing the radionuclides contained in the water. The removal is due to co-precipitation of the radionuclides with the suspended materials. The precipitated material is accumulated and characterized as a Technologically Enhanced Naturally Occurring Radioactive Materials (TENORM) by the United States Environmental Protection Agency (USEPA). This wastes can present significant levels of radioactivity and, when discarded in the environment without any treatment, can generate a problem of environmental impact and a risk to the health of the population. In this way, some gamma emitters of the series of U and Th, as well as 40 K were determined in the residues generated at the Potable Water Treatment Plants PWTPs in six municipalities of Pernambuco. The results obtained corroborate the classification of the residues generated in the PWTPs as concentrators of the radioactive components contained in the water supplied to the system and reinforce the need for the release to the environment, which is the usual way of disposal of this waste, to be carried out only after considering the radiation protection standards established by CNEN. (author)

  4. Fluctuations of Lake Orta water levels: preliminary analyses

    Directory of Open Access Journals (Sweden)

    Helmi Saidi

    2016-04-01

    Full Text Available While the effects of past industrial pollution on the chemistry and biology of Lake Orta have been well documented, annual and seasonal fluctuations of lake levels have not yet been studied. Considering their potential impacts on both the ecosystem and on human safety, fluctuations in lake levels are an important aspect of limnological research. In the enormous catchment of Lake Maggiore, there are many rivers and lakes, and the amount of annual precipitation is both high and concentrated in spring and autumn. This has produced major flood events, most recently in November 2014. Flood events are also frequent on Lake Orta, occurring roughly triennially since 1917. The 1926, 1951, 1976 and 2014 floods were severe, with lake levels raised from 2.30 m to 3.46 m above the hydrometric zero. The most important event occurred in 1976, with a maximum level equal to 292.31 m asl and a return period of 147 years. In 2014 the lake level reached 291.89 m asl and its return period was 54 years. In this study, we defined trends and temporal fluctuations in Lake Orta water levels from 1917 to 2014, focusing on extremes. We report both annual maximum and seasonal variations of the lake water levels over this period. Both Mann-Kendall trend tests and simple linear regression were utilized to detect monotonic trends in annual and seasonal extremes, and logistic regression was used to detect trends in the number of flood events. Lake level decreased during winter and summer seasons, and a small but statistically non-significant positive trend was found in the number of flood events over the period. We provide estimations of return period for lake levels, a metric which could be used in planning lake flood protection measures.

  5. Development of the water-lubricated thrust bearing of the hydraulic turbine generator

    International Nuclear Information System (INIS)

    Inoue, K; Deguchi, K; Okude, K; Fujimoto, R

    2012-01-01

    In hydropower plant, a large quantities of turbine oil is used as machine control pressure oil and lubricating oil. If the oil leak out from hydropower plant, it flows into a river. And such oil spill has an adverse effect on natural environment because the oil does not degrade easily. Therefore the KANSAI and Hitachi Mitsubishi Hydro developed the water-lubricated thrust bearing for vertical type hydraulic turbine generator. The water-lubricated bearing has advantages in risk avoidance of river pollution because it does not need oil. For proceeding the development of the water-lubricated thrust bearing, we studied following items. The first is the examination of the trial products of water lubricating liquid. The second is the study of bearing structure which can satisfy bearing performance such as temperature characteristic and so on. The third is the mock-up testing for actual application in the future. As a result, it was found that the water-lubricated thrust bearing was technically applicable to actual equipments.

  6. Ground-water development and the effects on ground-water levels and water quality in the town of Atherton, San Mateo County, California

    Science.gov (United States)

    Metzger, Loren F.; Fio, John L.

    1997-01-01

    The installation of at least 100 residential wells in the town of Atherton, California, during the 198792 drought has raised concerns about the increased potential for land subsidence and salt water intrusion. Data were collected and monitor ing networks were established to assess current processes and to monitor future conditions affect ing these processes. Data include recorded pump age, recorded operation time, and measured pumpage rates from 38 wells; water levels from 49 wells; water chemistry samples from 20 wells, and land-surface elevation data from 22 survey sites, including one National Geodetic Survey estab lished bench mark. Geologic, lithologic, climato logic, well construction, well location, and historical information obtained from available reports and local, state, and Federal agencies were used in this assessment. Estimates of annual residential pumpage from 269 assumed active residential wells in the study area indicate that the average annual total pumping rate is between 395 and 570 acre-feet per year. The nine assumed active institutional wells are estimated to pump a total of about 200 acre- feet per year, or 35 to 50 percent of the total resi dential pumpage. Assuming that 510 acre-feet per year is the best estimate of annual residential pumpage, total pumpage of 710 acre-feet per year would represent about 19 percent of the study area's total water supply, as estimated. Depth-to-water-level measurements in wells during April 1993 through September 1995 typically ranged from less than 20 feet below land surface nearest to San Francisco Bay to more than 70 feet below land surface in upslope areas near exposed bedrock, depending on the season. This range, which is relatively high historically, is attributed to above normal rainfall between 1993 and 1995. Water levels expressed as hydraulic heads indicate the presence of three different hydrologic subareas on the basis of hydraulic-head contour configurations and flow direction. That all

  7. Ion exchange treatment of rinse water generated in the galvanizing process.

    Science.gov (United States)

    Marañón, Elena; Fernández, Yolanda; Castrillón, Leonor

    2005-01-01

    A study was conducted of the viability of using the cationic exchange resins Amberlite IR-120 and Lewatit SP-112 to treat rinse water generated in the galvanizing process as well as acidic wastewater containing zinc (Zn) and iron (Fe). Solutions containing either 100 mg/L of Zn at pH 5.6 (rinse water) or Fe and Zn at concentrations of 320 and 200 mg/L at pH 1.5 (acidic water), respectively, were percolated through packed beds until the resins were exhausted. Breakthrough capacities obtained ranged between 1.1 and 1.5 meq metal/mL resin. The elution of metal and the regeneration of resins were performed with hydrochloric acid. The influence of the flowrate used during the loading stage was also studied, with 0.5 bed volumes/min (3.2 cm/min) found to be the optimum flowrate.

  8. Use of Produced Water in Recirculated Cooling Systems at Power Generating Facilities

    Energy Technology Data Exchange (ETDEWEB)

    C. McGowin; M. DiFilippo; L. Weintraub

    2006-06-30

    Tree ring studies indicate that, for the greater part of the last three decades, New Mexico has been relatively 'wet' compared to the long-term historical norm. However, during the last several years, New Mexico has experienced a severe drought. Some researchers are predicting a return of very dry weather over the next 30 to 40 years. Concern over the drought has spurred interest in evaluating the use of otherwise unusable saline waters to supplement current fresh water supplies for power plant operation and cooling and other uses. The U.S. Department of Energy's National Energy Technology Laboratory sponsored three related assessments of water supplies in the San Juan Basin area of the four-corner intersection of Utah, Colorado, Arizona, and New Mexico. These were (1) an assessment of using water produced with oil and gas as a supplemental supply for the San Juan Generating Station (SJGS); (2) a field evaluation of the wet-surface air cooling (WSAC) system at SJGS; and (3) the development of a ZeroNet systems analysis module and an application of the Watershed Risk Management Framework (WARMF) to evaluate a range of water shortage management plans. The study of the possible use of produced water at SJGS showed that produce water must be treated to justify its use in any reasonable quantity at SJGS. The study identified produced water volume and quality, the infrastructure needed to deliver it to SJGS, treatment requirements, and delivery and treatment economics. A number of produced water treatment alternatives that use off-the-shelf technology were evaluated along with the equipment needed for water treatment at SJGS. Wet surface air-cooling (WSAC) technology was tested at the San Juan Generating Station (SJGS) to determine its capacity to cool power plant circulating water using degraded water. WSAC is a commercial cooling technology and has been used for many years to cool and/or condense process fluids. The purpose of the pilot test was to

  9. The nuclear physical method for high pressure steam manifold water level gauging and its error

    International Nuclear Information System (INIS)

    Li Nianzu; Li Beicheng; Jia Shengming

    1993-10-01

    A new method, which is non-contact on measured water level, for measuring high pressure steam manifold water level with nuclear detection technique is introduced. This method overcomes the inherent drawback of previous water level gauges based on other principles. This method can realize full range real time monitoring on the continuous water level of high pressure steam manifold from the start to full load of boiler, and the actual value of water level can be obtained. The measuring errors were analysed on site. Errors from practical operation in Tianjin Junliangcheng Power Plant and in laboratory are also presented

  10. Aquaponic Growbed Water Level Control Using Fog Architecture

    Science.gov (United States)

    Asmi Romli, Muhamad; Daud, Shuhaizar; Raof, Rafikha Aliana A.; Awang Ahmad, Zahari; Mahrom, Norfadilla

    2018-05-01

    Integrated Multi-Trophic Aquaculture (IMTA) is an advance method of aquaculture which combines species with different nutritional needs to live together. The combination between aquatic live and crops is called aquaponics. Aquatic waste that normally removed by biofilters in normal aquaculture practice will be absorbed by crops in this practice. Aquaponics have few common components and growbed provide the best filtration function. In growbed a siphon act as mechanical structure to control water fill and flush process. Water to the growbed comes from fish tank with multiple flow speeds based on the pump specification and height. Too low speed and too fast flow rate can result in siphon malfunctionality. Pumps with variable speed do exist but it is costly. Majority of the aquaponic practitioner use single speed pump and try to match the pump speed with siphon operational requirement. In order to remove the matching requirement some control need to be introduced. Preliminarily this research will show the concept of fill-and-flush for multiple pumping speeds. The final aim of this paper is to show how water level manage