The need to study of bounding accident in reprocessing plant

International Nuclear Information System (INIS)

Segawa, Satoshi; Fujita, Kunio

2013-01-01

There is a clear consensus that the severe accident corresponds to the core damage accident for power reactors. On the other hand, for FCFs, there is no clear consensus on what is the accident to assess the safety in the region of beyond design basis, or what is the accident which has very low probability but large consequence. The need to examine a bounding consequence of each type of accident is explained to advance the rationality of safety management and regulation and, as a result, to reinforce the safety of a reprocessing plant. The likelihood of occurrence of an accident causing a bounding consequence should correspond to that of a severe accident at a nuclear power plant. The bounding consequence will be derived using the deterministic method and sound engineering judgment supplemented by the probabilistic method. Once an agreement on such a concept is reached among regulators, operators and related experts it will help to provide a solid basis to ensure the safety of a reprocessing plant independent of that of a nuclear power plant. In this paper, we show a preliminary risk profile of RRP calculated by QSA (Quantitative Safety Assessment) which JNFL developed. The profile shows that bounding consequences of various accidents in a range of occurrence frequency corresponding to a severe accident at a nuclear power plant. And we find that the bounding consequence of high-level liquid waste boiling is the largest among all in this range. Therefore, the risk of this event is shown in this paper as an example. To build a common consensus about bounding accidents among concerned parties will encourage regulatory body to introduce such an idea for more effective regulation with scientific rationality. Additionally the study of bounding accidents can contribute to substantial development for accident management strategy as reprocessing operators. (authors)

Tight upper bound for the maximal quantum value of the Svetlichny operators

Science.gov (United States)

Li, Ming; Shen, Shuqian; Jing, Naihuan; Fei, Shao-Ming; Li-Jost, Xianqing

2017-10-01

It is a challenging task to detect genuine multipartite nonlocality (GMNL). In this paper, the problem is considered via computing the maximal quantum value of Svetlichny operators for three-qubit systems and a tight upper bound is obtained. The constraints on the quantum states for the tightness of the bound are also presented. The approach enables us to give the necessary and sufficient conditions of violating the Svetlichny inequality (SI) for several quantum states, including the white and color noised Greenberger-Horne-Zeilinger (GHZ) states. The relation between the genuine multipartite entanglement concurrence and the maximal quantum value of the Svetlichny operators for mixed GHZ class states is also discussed. As the SI is useful for the investigation of GMNL, our results give an effective and operational method to detect the GMNL for three-qubit mixed states.

Some problems in operator theory on bounded symmetric domains

Czech Academy of Sciences Publication Activity Database

Engliš, Miroslav

2004-01-01

Roč. 81, č. 1 (2004), s. 51-71 ISSN 0167-8019. [Representations of Lie groups, harmonic analysis on homogeneous spaces and quantization. Leiden, 07.12.2002-13.12.2002] R&D Projects: GA ČR GA201/03/0041 Institutional research plan: CEZ:AV0Z1019905 Keywords : homogeneous multiplication operators * bounded symmetric domains Subject RIV: BA - General Mathematics Impact factor: 0.354, year: 2004

Numerical Solution of Time-Dependent Problems with a Fractional-Power Elliptic Operator

Science.gov (United States)

Vabishchevich, P. N.

2018-03-01

A time-dependent problem in a bounded domain for a fractional diffusion equation is considered. The first-order evolution equation involves a fractional-power second-order elliptic operator with Robin boundary conditions. A finite-element spatial approximation with an additive approximation of the operator of the problem is used. The time approximation is based on a vector scheme. The transition to a new time level is ensured by solving a sequence of standard elliptic boundary value problems. Numerical results obtained for a two-dimensional model problem are presented.

Simulation bounds for system availability

International Nuclear Information System (INIS)

Tietjen, G.L.; Waller, R.A.

1976-01-01

System availability is a dominant factor in the practicality of nuclear power electrical generating plants. A proposed model for obtaining either lower bounds or interval estimates on availability uses observed data on ''n'' failure-to-repair cycles of the system to estimate the parameters in the time-to-failure and time-to-repair models. These estimates are then used in simulating failure/repair cycles of the system. The availability estimate is obtained for each of 5000 samples of ''n'' failure/repair cycles to form a distribution of estimates. Specific percentile points of those simulated distributions are selected as lower simulation bounds or simulation interval bounds for the system availability. The method is illustrated with operational data from two nuclear plants for which an exponential time-to-failure and a lognormal time-to-repair are assumed

Some simple conditions of bound states of Schroedinger operators in dimension d >= 3

International Nuclear Information System (INIS)

Exner, P.

1984-01-01

A necessary condition for existence of bound states below a given energy of a Schroedinger operator H=-Δ+V on L 2 (Rsup(d)), d>=3, together with a lower bound to the ground-state energy of H are derived using the Sobolev inequalities. It generalizes some recent results to the dimensions d>3 and to the potentials that are not necessarily rapidly decreasing. Comparison to other known necessary conditions is given. The examples of the d-dimensional hydrogen-like atom and the d-dimensional harmonic oscillator are discussed. In both of them the bound to the ground-state energy becomes remarkably tight for large values of d

A closed graph theorem for order bounded operators | Harm van der ...

African Journals Online (AJOL)

... theory to prove a version of the closed graph theorem for order bounded operators on Archimedean vector lattices. This illustrates the usefulness of convergence spaces in dealing with problems in vector lattice theory, problems that may fail to be amenable to the usual Hausdorff-Kuratowski-Bourbaki concept of topology.

The asymptotic behavior of Frobenius-Perron operator with local lower-bound function

International Nuclear Information System (INIS)

Ding Yiming

2003-01-01

Let (X,Σ,μ) be a σ-finite measure space, S:X→X be a nonsingular transformation and P S :L 1 →L 1 be the Frobenius-Perron operator associated with S. It is proved that if P S satisfies the local lower-bound function condition then for every f is a subset of D the sequence {P S n f} converges strongly to a stationary density of P S as n→∞. The statistical stability of S is also concerned via the local lower-bound function method

Compact composition operators on real Banach spaces of complex-valued bounded Lipschitz functions

Directory of Open Access Journals (Sweden)

Davood Alimohammadi

2014-10-01

Full Text Available We characterize compact composition operators on real Banachspaces of complex-valued bounded Lipschitz functions on metricspaces, not necessarily compact, with Lipschitz involutions anddetermine their spectra.

Gas-fired power plants: Investment timing, operating flexibility and CO2 capture

International Nuclear Information System (INIS)

Fleten, Stein-Erik; Naesaekkaelae, Erkka

2010-01-01

We analyze investments in gas-fired power plants based on stochastic electricity and natural gas prices. A simple but realistic two-factor model is used for price processes, enabling analysis of the value of operating flexibility, the opportunity to abandon the capital equipment, as well as finding thresholds for energy prices for which it is optimal to enter into the investment. We develop a method to compute upper and lower bounds on plant values and investment threshold levels. Our case study uses representative power plant investment and operations data, and historical forward prices from well-functioning energy markets. We find that when the decision to build is considered, the abandonment option does not have significant value, whereas the operating flexibility and time-to-build option have significant effect on the building threshold. Furthermore, the joint value of the operating flexibility and the abandonment option is much smaller than the sum of their separate values, because both are options to shut down. The effects of emission costs on the value of installing CO 2 capture technology are also analyzed.

New approximation to the bound states of Schroedinger operators with coulomb interaction

International Nuclear Information System (INIS)

Nunez, M.A.; Izquierdo B., G.

1994-01-01

In this work, the authors present a mathematical formulation of the physical fact that the bound states of a quantum system confined into a box Ω (with impenetrable walls) are similar to those of the unconfined system, if the box Ω is sufficiently large, and it is shown how the bound states of atomic and molecular Hamiltonians can be approximated by those of the system confined for a box Ω large enough (Dirichlet eigenproblem in Ω). Thus, a method for computing bound states is obtained which has the advantage of reducing the problem to the case of compact operators. This implies that a broad class of numerical and analytic techniques used for solving the Dirichlet problem, may be applied in full strength to obtain accurate computations of energy levels, wave functions, and other physical properties of interest

On the bound states of Schrodinger operators with -interactions on conical surfaces

Czech Academy of Sciences Publication Activity Database

Lotoreichik, Vladimir; Ourmieres-Bonafos, T.

2016-01-01

Roč. 41, č. 6 (2016), s. 999-1028 ISSN 0360-5302 Institutional support: RVO:61389005 Keywords : conical and hyperconical surfaces * delta-interaction * existence of bound states * Schrodinger operator * spectral asymptotics Subject RIV: BE - Theoretical Physics Impact factor: 1.608, year: 2016

Economic Operation of Power Systems with Significant Wind Power Penetration

DEFF Research Database (Denmark)

Farashbashi-Astaneh, Seyed-Mostafa

This dissertation addresses economic operation of power systems with high penetration of wind power. Several studies are presented to address the economic operation of power systems with high penetration of variable wind power. The main concern in such power systems is high variability...... and unpredictability. Unlike conventional power plants, the output power of a wind farm is not controllable. This brings additional complexity to operation and planning of wind dominant power systems. The key solution in face of wind power uncertainty is to enhance power system flexibility. The enhanced flexibility......, cooperative wind-storage operation is studied. Lithium-Ion battery units are chosen as storage units. A novel formulation is proposed to investigate optimal operation of a storage unit considering power system balancing conditions and wind power imbalances. An optimization framework is presented to increase...

14 CFR 27.695 - Power boost and power-operated control system.

Science.gov (United States)

2010-01-01

... Systems § 27.695 Power boost and power-operated control system. (a) If a power boost or power-operated... failure of all engines. (b) Each alternate system may be a duplicate power portion or a manually operated... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Power boost and power-operated control...

14 CFR 29.695 - Power boost and power-operated control system.

Science.gov (United States)

2010-01-01

... Systems § 29.695 Power boost and power-operated control system. (a) If a power boost or power-operated... failure of all engines. (b) Each alternate system may be a duplicate power portion or a manually operated... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Power boost and power-operated control...

Computation of Lie transformations from a power series: Bounds and optimum truncation

International Nuclear Information System (INIS)

Gjaja, I.

1996-01-01

The problem considered is the computation of an infinite product (composition) of Lie transformations generated by homogeneous polynomials of increasing order from a given asymptotic power series. Bounds are computed for the infinitesimal form of the Lie transformations and for the domain of analyticity of the first n of them. Even when the power series is convergent, the estimates exhibit a factorial-type growth, and thus do not guarantee convergence of the product. The optimum truncation is determined by minimizing the remainder after the first n Lie transformations have been applied

Performance analysis for minimally nonlinear irreversible refrigerators at finite cooling power

Science.gov (United States)

Long, Rui; Liu, Zhichun; Liu, Wei

2018-04-01

The coefficient of performance (COP) for general refrigerators at finite cooling power have been systematically researched through the minimally nonlinear irreversible model, and its lower and upper bounds in different operating regions have been proposed. Under the tight coupling conditions, we have calculated the universal COP bounds under the χ figure of merit in different operating regions. When the refrigerator operates in the region with lower external flux, we obtained the general bounds (0 present large values, compared to a relative small loss from the maximum cooling power. If the cooling power is the main objective, it is desirable to operate the refrigerator at a slightly lower cooling power than at the maximum one, where a small loss in the cooling power induces a much larger COP enhancement.

Frames of exponentials:lower frame bounds for finite subfamilies, and approximation of the inverse frame operator

DEFF Research Database (Denmark)

Christensen, Ole; Lindner, Alexander M

2001-01-01

We give lower frame bounds for finite subfamilies of a frame of exponentials {e(i lambdak(.))}k is an element ofZ in L-2(-pi,pi). We also present a method for approximation of the inverse frame operator corresponding to {e(i lambdak(.))}k is an element ofZ, where knowledge of the frame bounds for...

Power-law versus log-law in wall-bounded turbulence: A large-eddy simulation perspective

KAUST Repository

Cheng, W.; Samtaney, Ravi

2014-01-01

The debate whether the mean streamwise velocity in wall-bounded turbulent flows obeys a log-law or a power-law scaling originated over two decades ago, and continues to ferment in recent years. As experiments and direct numerical simulation can

Nuclear power plant operator licensing

International Nuclear Information System (INIS)

1997-01-01

The guide applies to the nuclear power plant operator licensing procedure referred to the section 128 of the Finnish Nuclear Energy Degree. The licensing procedure applies to shift supervisors and those operators of the shift teams of nuclear power plant units who manipulate the controls of nuclear power plants systems in the main control room. The qualification requirements presented in the guide also apply to nuclear safety engineers who work in the main control room and provide support to the shift supervisors, operation engineers who are the immediate superiors of shift supervisors, heads of the operational planning units and simulator instructors. The operator licensing procedure for other nuclear facilities are decided case by case. The requirements for the basic education, work experience and the initial, refresher and complementary training of nuclear power plant operating personnel are presented in the YVL guide 1.7. (2 refs.)

Efficient compliance with prescribed bounds on operational parameters by means of hypothesis testing using reactor data

International Nuclear Information System (INIS)

Sermer, P.; Olive, C.; Hoppe, F.M.

2000-01-01

- A common problem in any reactor operations is to comply with a requirement that certain operational parameters are constrained to lie within some prescribed bounds. The fundamental issue which is to be addressed in any compliance description can be stated as follows: The compliance definition, compliance procedures and allowances for uncertainties in data and accompanying methodologies, should be well defined and justifiable. To this end, a mathematical framework for compliance, in which the computed or measured estimates of process parameters are considered random variables, is described in this paper. This allows a statistical formulation of the definition of compliance with licence or otherwise imposed limits. An important aspect of the proposed methodology is that the derived statistical tests are obtained by a Monte Carlo procedure using actual reactor operational data. The implementation of the methodology requires a routine surveillance of the reactor core in order to perform the underlying statistical tests. The additional work required for surveillance is balanced by the fact that the resulting actions on the reactor operations, implemented in station procedures, make the reactor 'safer' by increasing the operating margins. Furthermore, increased margins are also achieved by efficient solution techniques which may allow an increase in reactor power. A rigorous analysis of a compliance problem using statistical hypothesis testing based on extreme value probability distributions and actual reactor operational data leads to effective solutions in the areas of licensing, nuclear safety, reliability and competitiveness of operating nuclear reactors. (author)

Scalability under a Power Bound using the GREMLINs Framework

International Nuclear Information System (INIS)

Maiterth, Matthias

2015-01-01

With the move towards exascale, system and software developers will have to deal with issues of extreme parallelism. The system properties affected most by the increase in node and core count are the shared resources on node and across the system. The increase in parallelism leads to reduced memory and bandwidth when regarding individual cores. Since power is a limiting factor for supercomputers, and power is not fully utilized in current systems, overprovisioning compute resources is a viable approach to maximized power utilization. To maximize system performance in regard to these changing conditions, it is necessary to understand how resource restrictions impact performance and system behavior. For the purpose of understanding anticipated system properties the GREMLINs Framework was developed. The framework gives the opportunity to add power restrictions, hinder memory properties and introduce faults to study resilience, among others. These features give the opportunity to use current petascale technology to study problems system designers and software developers will have to face when moving towards exascale and beyond. This work describes the initial release of the GREMLINs Framework, developed for this work, and shows how it can be used to study the scaling behavior of proxy applications. These proxy applications represent a selection of HPC workloads important to the scientific community. The proxy applications studied are AMG2013, an algebraic multi-grid linear system solver, CoMD, a classical molecular dynamics proxy application and NEKBONE, an application that uses a high order spectral element method to solve the Navier-Stokes equations. The main interest of these studies lies in analysis regarding their power behavior at scale under a power bound. These findings show how the GREMLINs Framework can help systems and software designers to attain better application performance and can also be used as basis for CPU power balancing tools to use power more

Scalability under a Power Bound using the GREMLINs Framework

Energy Technology Data Exchange (ETDEWEB)

Maiterth, Matthias [Ludwig Maximilian Univ., Munich (Germany)

2015-02-16

With the move towards exascale, system and software developers will have to deal with issues of extreme parallelism. The system properties affected most by the increase in node and core count are the shared resources on node and across the system. The increase in parallelism leads to reduced memory and bandwidth when regarding individual cores. Since power is a limiting factor for supercomputers, and power is not fully utilized in current systems, overprovisioning compute resources is a viable approach to maximized power utilization. To maximize system performance in regard to these changing conditions, it is necessary to understand how resource restrictions impact performance and system behavior. For the purpose of understanding anticipated system properties the GREMLINs Framework was developed. The framework gives the opportunity to add power restrictions, hinder memory properties and introduce faults to study resilience, among others. These features give the opportunity to use current petascale technology to study problems system designers and software developers will have to face when moving towards exascale and beyond. This work describes the initial release of the GREMLINs Framework, developed for this work, and shows how it can be used to study the scaling behavior of proxy applications. These proxy applications represent a selection of HPC workloads important to the scientific community. The proxy applications studied are AMG2013, an algebraic multi-grid linear system solver, CoMD, a classical molecular dynamics proxy application and NEKBONE, an application that uses a high order spectral element method to solve the Navier-Stokes equations. The main interest of these studies lies in analysis regarding their power behavior at scale under a power bound. These findings show how the GREMLINs Framework can help systems and software designers to attain better application performance and can also be used as basis for CPU power balancing tools to use power more

47 CFR 73.751 - Operating power.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 4 2010-10-01 2010-10-01 false Operating power. 73.751 Section 73.751... International Broadcast Stations § 73.751 Operating power. No international broadcast station shall be authorized to install, or be licensed for operation of, transmitter equipment with: (a) A rated carrier power...

Thermal power plant design and operation

CERN Document Server

Sarkar, Dipak

2015-01-01

Thermal Power Plant: Design and Operation deals with various aspects of a thermal power plant, providing a new dimension to the subject, with focus on operating practices and troubleshooting, as well as technology and design. Its author has a 40-long association with thermal power plants in design as well as field engineering, sharing his experience with professional engineers under various training capacities, such as training programs for graduate engineers and operating personnel. Thermal Power Plant presents practical content on coal-, gas-, oil-, peat- and biomass-fueled thermal power

Containment and Consensus-based Distributed Coordination Control for Voltage Bound and Reactive Power Sharing in AC Microgrid

DEFF Research Database (Denmark)

Han, Renke; Meng, Lexuan; Ferrari-Trecate, Giancarlo

2017-01-01

This paper offers a highly flexible and reliable control strategy to achieve voltage bounded regulation and accurate reactive power sharing coordinately in AC Micro-Grids. A containment and consensus-based distributed coordination controller is proposed, by which each output voltage magnitude can...... be bounded within a reasonable range and the accurate reactive power sharing among distributed generators can be also achieved. Combined with the two proposed controllers and electrical part of the AC Micro-Grid, a small signal model is fully developed to analyze the sensitivity of different control...... parameters. The effectiveness of the proposed controller in case of load variation, communication failure, plug-and-play capability are verified by the experimental setup as an islanded Micro-Grid....

New approach to calculate bound state eigenvalues

International Nuclear Information System (INIS)

Gerck, E.; Gallas, J.A.C.

1983-01-01

A method of solving the radial Schrodinger equation for bound states is discussed. The method is based on a new piecewise representation of the second derivative operator on a set of functions that obey the boundary conditions. This representation is trivially diagonalised and leads to closed form expressions of the type E sub(n)=E(ab+b+c/n+...) for the eigenvalues. Examples are given for the power-law and logarithmic potentials. (Author) [pt

Technical support for nuclear power operations

International Nuclear Information System (INIS)

1999-04-01

This report prepared by the group of senior experts from nuclear operating organizations in Member states, addresses the problem of improving the operating performance of nuclear power plants. Safe and reliable operation is essential for strengthening the viability of nuclear power in the increasingly competitive market of electric power. Basic principles and requirements concerning technical procedures and developed practices are discussed. Report reflects the best current international practices and presents those management initiatives that go beyond the mandated regulatory compliance and could lead to enhancement od operational safety and improved plant performance. By correlating experiences and presenting collective effective practices it is meant to assist nuclear power plant managers in achieving improvement in operation through the contribution of effective technical support

The operation of nuclear power plants

International Nuclear Information System (INIS)

Brosche, D.

1992-01-01

The duties to be performed in managing the operation of a nuclear power plant are highly diverse, as will be explained in this contribution by the examples of the Grafenrheinfeld Nuclear Power Station. The excellent safety record and the high availabilities of German nuclear power plants demonstrate that their operators have adopted the right approaches. Systematic evaluation of the operating experience accumulated inhouse and in other plants is of great significance in removing weak spots and improving operation. The manifold and complex activities in the structure of organization and of activities in a nuclear power plant require a high degree of division of labor. (orig.) [de

Optimization of power system operation

CERN Document Server

Zhu, Jizhong

2015-01-01

This book applies the latest applications of new technologies topower system operation and analysis, including new and importantareas that are not covered in the previous edition. Optimization of Power System Operation covers both traditional andmodern technologies, including power flow analysis, steady-statesecurity region analysis, security constrained economic dispatch,multi-area system economic dispatch, unit commitment, optimal powerflow, smart grid operation, optimal load shed, optimalreconfiguration of distribution network, power system uncertaintyanalysis, power system sensitivity analysis, analytic hierarchicalprocess, neural network, fuzzy theory, genetic algorithm,evolutionary programming, and particle swarm optimization, amongothers. New topics such as the wheeling model, multi-areawheeling, the total transfer capability computation in multipleareas, are also addressed. The new edition of this book continues to provide engineers andac demics with a complete picture of the optimization of techn...

Operation of nuclear power plants

International Nuclear Information System (INIS)

Severa, P.

1988-04-01

The textbook for training nuclear power plant personnel is centred on the most important aspects of operating modes of WWER-440 reactors. Attention is devoted to the steady state operation of the unit, shutdown, overhaul with refuelling, physical and power start-up. Also given are the regulations of shift operation and the duties of individual categories of personnel during the shift and during the change of shifts. (Z.M.). 3 figs., 1 tab

Power generation assets. Energy constraints, upper bounds and hedging strategies

Energy Technology Data Exchange (ETDEWEB)

Enge, Thomas

2010-09-20

The overall topic of this thesis is the valuation of power generation assets under energy and risk constraints. Our focus is on the modeling aspect i.e. to find the right balance between accuracy and computational feasibility. We define a new not yet investigated unit commitment problem that introduces an energy constraint to a thermal power plant. We define a continuous stochastic dynamic program with a nested mixed integer program (MIP). We introduce a fast implementation approach by replacing the MIP with an efficient matrix calculation and use principal component analysis to reduce the number of risk factors. We also provide a fast heuristic valuation approach for comparison. As both models can only provide lower bounds of the asset value, we investigate the theory of upper bounds for a proper validation of our power plant results. We review the primal dual algorithm for swing options by Meinshausen and Hambly and in particular clarify their notation and implementation. Then we provide an extension for swing options with multiple exercises at the same stage that we developed together with Prof. Bender, University of Braunschweig. We outline Prof. Bender's proof and describe the implementation in detail. Finally we provide a risk analysis for our thermal power plant. In particular we investigate strategies to reduce spot price risk to which power plants are significantly exposed. First, we focus on the measurement of spot price risk and propose three appropriate risk figures (Forward delta as opposed to Futures delta, synthetic spot delta and Earnings-at-Risk) and illustrate their application using a business case. Second we suggest risk mitigation strategies for both periods, before and in delivery. The latter tries to alter the dispatch policy i.e. pick less risky hours and accept a (desirably only slightly) smaller return. We introduce a benchmark that weighs risk versus return and that we will call EaR-efficient option value. We propose a mitigation

Training of power plant operating personnel

International Nuclear Information System (INIS)

Kraftwerksschule, E.V.

1986-01-01

In Germany, professional training of power plant operating personnel became an important issue in the fifties, when power plant parameters as well as complexity of instrumentation and control increased considerably. Working Groups of VGB Technische Vereiningung der Grosskraftwerketreiber e.v. (Association of Large Power Plant Operators) developed a professional career for power plant operating personnel and defined pre-requisites, scope and objectives of training. In 1957 the German utilities founded KRAFTWERKSSCHULE E.V. (kws) as a school for theoretical training and for guidance of practical training in the power plants. KWS is a non-profit organisation and independent of authorities. Today KWS has 127 members in Germany and in 6 other countries. The objectives of KWS include the training of: -Kraftwerker (control room operators; - Kraftwerksmesiter (shift supervisors); and - shift engineers; according the guidelines of the VGB

Fractional power operation of tokamak reactors

International Nuclear Information System (INIS)

Mau, T.K.; Vold, E.L.; Conn, R.W.

1986-01-01

Methods to operate a tokamak fusion reactor at fractions of its rated power, identify the more effective control knobs and assess the impact of the requirements of fractional power operation on full power reactor design are explored. In particular, the role of burn control in maintaining the plasma at thermal equilibrium throughout these operations is studied. As a prerequisite to this task, the critical physics issues relevant to reactor performance predictions are examined and some insight into their impact on fractional power operation is offered. The basic tool of analysis consists of a zero-dimensional (0-D) time-dependent plasma power balance code which incorporates the most advanced data base and models in transport and burn plasma physics relevant to tokamaks. Because the plasma power balance is dominated by the transport loss and given the large uncertainty in the confinement model, the authors have studied the problem for a wide range of energy confinement scalings. The results of this analysis form the basis for studying the temporal behavior of the plasma under various thermal control mechanisms. Scenarios of thermally stable full and fractional power operations have been determined for a variety of transport models, with either passive or active feedback burn control. Important power control parameters, such as gas fueling rate, auxiliary power and other plasma quantities that affect transport losses, have also been identified. The results of these studies vary with the individual transport scaling used and, in particular, with respect to the effect of alpha heating power on confinement

Organizing nuclear power plant operation

International Nuclear Information System (INIS)

Adams, H.W.; Rekittke, K.

1987-01-01

With the preliminary culmination in the convoy plants of the high standard of engineered safeguards in German nuclear power plants developed over the past twenty years, the interest of operators has now increasingly turned to problems which had not been in the focus of attention before. One of these problems is the organization of nuclear power plant operation. In order to enlarge the basis of knowledge, which is documented also in the rules published by the Kerntechnischer Ausschuss (Nuclear Technology Committee), the German Federal Minister of the Interior has commissioned a study of the organizational structures of nuclear power plants. The findings of that study are covered in the article. Two representative nuclear power plants in the Federal Republic of Germany were selected for the study, one of them a single-unit plant run by an independent operating company in the form of a private company under German law (GmbH), the other a dual-unit plant operated as a dependent unit of a utility. The two enterprises have different structures of organization. (orig.) [de

The continuous spectrum and the effect of parametric resonance. The case of bounded operators

International Nuclear Information System (INIS)

Skazka, V V

2014-01-01

The paper is concerned with the Mathieu-type differential equation u ″ =−A 2 u+εB(t)u in a Hilbert space H. It is assumed that A is a bounded self-adjoint operator which only has an absolutely continuous spectrum and B(t) is almost periodic operator-valued function. Sufficient conditions are obtained under which the Cauchy problem for this equation is stable for small ε and hence free of parametric resonance. Bibliography: 10 titles

Operating US power reactors

International Nuclear Information System (INIS)

Silver, E.G.

1988-01-01

This update, which appears regularly in each issue of Nuclear Safety, surveys the operations of those power reactors in the US which have been issued operating licenses. Table 1 shows the number of such reactors and their net capacities as of September 30, 1987, the end of the three-month period covered in this report. Table 2 lists the unit capacity and forced outage rate for each licensed reactor for each of the three months (July, August, and September 1987) covered in this report and the cumulative values of these parameters since the beginning of commercial operation. In addition to the tabular data, this article discusses other significant occurrences and developments that affected licensed US power reactors during this reporting period. Status changes at Braidwood Unit 1, Nine Mile Point 2, and Beaver Valley 2 are discussed. Other occurrences discussed are: retraining of control-room operators at Peach Bottom; a request for 25% power for Shoreham, problems at Fermi 2 which delayed the request to go to 75% power; the results of a safety study of the N Reactor at Hanford; a proposed merger of Pacific Gas and Electric with Sacramento Municipal Utility District which would result in the decommissioning of Rancho Seco; the ordered shutdown of Oyster Creek; a minor radioactivity release caused by a steam generator tube rupture at North Anna 1; and 13 fines levied by the NRC on reactor licensees

A lower bound on the relative error of mixed-state cloning and related operations

International Nuclear Information System (INIS)

Rastegin, A E

2003-01-01

We extend the concept of the relative error to mixed-state cloning and related physical operations, in which the ancilla contains some information a priori about the input state. The lower bound on the relative error is obtained. It is shown that this result provides further support for a stronger no-cloning theorem

Optimization Criteria of Power Transformer Operation

Directory of Open Access Journals (Sweden)

A. A. Gonchar

2006-01-01

Full Text Available It has been shown that minimum losses in active power of a power transformer do not correspond to its maximum efficiency. For a transformer being operated there are no so called «zones of its economical operation». In this case strictly specified value of active power losses corresponds to a particular current of the winding.

ANALYSIS OF OPTIMUM OPERATING MODES OF POWER TRANSFORMERS UNDER OPERATING CONDITIONS

Directory of Open Access Journals (Sweden)

I. V. Khomenko

2016-12-01

Full Text Available Purpose. The study of parallel operation optimal modes of transformer equipment for a variety of operating conditions: same or different types of transformers, with or without reactive power flows. Methodology. Losses of energy in transformers make 30 % of all losses. Therefore the choice of the economically justified parallel operation of transformers is effective action to reduce losses. Typically, in the calculations of reactive power flows in the transformers are not taken into account. It is interesting to analyze the optimal operating conditions of transformers with and without reactive power flows. Results. Calculations for transformers in distribution networks showed that the inclusion of reactive power flows in transformers significant impact on the calculated optimum regimes of transformers.

Formulae and Bounds connected to Optimal Design and Homogenization of Partial Differential Operators and Integral Functionals

Energy Technology Data Exchange (ETDEWEB)

Lukkassen, D.

1996-12-31

When partial differential equations are set up to model physical processes in strongly heterogeneous materials, effective parameters for heat transfer, electric conductivity etc. are usually required. Averaging methods often lead to convergence problems and in homogenization theory one is therefore led to study how certain integral functionals behave asymptotically. This mathematical doctoral thesis discusses (1) means and bounds connected to homogenization of integral functionals, (2) reiterated homogenization of integral functionals, (3) bounds and homogenization of some particular partial differential operators, (4) applications and further results. 154 refs., 11 figs., 8 tabs.

Operational characteristics of nuclear power plants - modelling of operational safety

International Nuclear Information System (INIS)

Studovic, M.

1984-01-01

By operational experience of nuclear power plants and realize dlevel of availability of plant, systems and componenst reliabiliuty, operational safety and public protection, as a source on nature of distrurbances in power plant systems and lessons drawn by the TMI-2, in th epaper are discussed: examination of design safety for ultimate ensuring of safe operational conditions of the nuclear power plant; significance of the adequate action for keeping proess parameters in prescribed limits and reactor cooling rquirements; developed systems for measurements detection and monitoring all critical parameters in the nuclear steam supply system; contents of theoretical investigation and mathematical modeling of the physical phenomena and process in nuclear power plant system and components as software, supporting for ensuring of operational safety and new access in staff education process; program and progress of the investigation of some physical phenomena and mathematical modeling of nuclear plant transients, prepared at faculty of mechanical Engineering in Belgrade. (author)

Operation Modeling of Power Systems Integrated with Large-Scale New Energy Power Sources

Directory of Open Access Journals (Sweden)

Hui Li

2016-10-01

Full Text Available In the most current methods of probabilistic power system production simulation, the output characteristics of new energy power generation (NEPG has not been comprehensively considered. In this paper, the power output characteristics of wind power generation and photovoltaic power generation are firstly analyzed based on statistical methods according to their historical operating data. Then the characteristic indexes and the filtering principle of the NEPG historical output scenarios are introduced with the confidence level, and the calculation model of NEPG’s credible capacity is proposed. Based on this, taking the minimum production costs or the best energy-saving and emission-reduction effect as the optimization objective, the power system operation model with large-scale integration of new energy power generation (NEPG is established considering the power balance, the electricity balance and the peak balance. Besides, the constraints of the operating characteristics of different power generation types, the maintenance schedule, the load reservation, the emergency reservation, the water abandonment and the transmitting capacity between different areas are also considered. With the proposed power system operation model, the operation simulations are carried out based on the actual Northwest power grid of China, which resolves the new energy power accommodations considering different system operating conditions. The simulation results well verify the validity of the proposed power system operation model in the accommodation analysis for the power system which is penetrated with large scale NEPG.

Operating Experience with Power Reactors. Proceedings of the Conference on Operating Experience with Power Reactors. Vol. I

Energy Technology Data Exchange (ETDEWEB)

NONE

1963-10-15

At the beginning of 1963 nuclear power plants produced some 3 500 000kW of electrical power to different distribution grids around the world. Much significant operating experience has been gained with these power reactors, but this experience is often not collected in such a way as to make it easily available. The International Atomic Energy Agency convened a Conference on Operating Experience with Power Reactors in Vienna from 4-8 June 1963 which was attended by 240 participants representing 27 of the Agency's Member States and six international organizations. At the Conference, 42 papers giving detailed experience with more than 20 nuclear power stations were discussed. Although similar meetings on a national or regional scale have been held earlier in various countries, this is the first arranged by the Agency on a world-wide basis. Some of the detailed material may have been given earlier but for the most part it represents new and recently acquired experience, and for the first time it has been possible to compile in one place such extensive material on the operating experience with power reactors. The Conference discussed the experience gained both generally in the context of national and international nuclear power development programmes, and more specifically in the detailed operating experience with different power reactor stations. In addition, various plant components, fuel cycles, staffing of nuclear plants and licensing of such staff were treated. It is hoped that these Proceedings will be of interest not only to nuclear plant designers and operators who daily encounter problems similar to those discussed by the Conference, but also to those guiding the planning and implementation of power development programmes.

Operating Experience with Power Reactors. Proceedings of the Conference on Operating Experience with Power Reactors. Vol. II

Energy Technology Data Exchange (ETDEWEB)

NONE

1963-10-15

At the beginning of 1963 nuclear power plants produced some 3 500 000 kW of electrical power to different distribution grids around the world. Much significant operating experience has been gained with these power reactors, but this experience is often not collected in such a way as to make it easily available. The International Atomic Energy Agency convened a Conference on Operating Experience with Power Reactors in Vienna from 4 -8 June 1963 which was attended by 240 participants representing 27 of the Agency's Member States and six international organizations. At the Conference, 42 papers giving detailed experience with more than 20 nuclear power stations were discussed. Although similar meetings on a national or regional scale have been held earlier in various countries, this is the first arranged by the Agency on a world-wide basis. Some of the detailed material may have been given earlier but for the most part it represents new and recently acquired experience, and for the first time it has been possible to compile in one place such extensive material on the operating experience with power reactors. The Conference discussed the experience gained both generally in the context of national and international nuclear power development programmes, and more specifically in the detailed operating experience with different power reactor stations. In addition, various plant components, fuel cycles, staffing of nuclear plants and licensing of such staff were treated. It is hoped that these Proceedings will be of interest not only to nuclear , plant designers and operators who daily encounter problems similar to those discussed by the Conference, but also to those guiding the planning and implementation of power development programmes.

Supervision functions - Secure operation of sustainable power systems

DEFF Research Database (Denmark)

Morais, Hugo; Zhang, Xinxin; Lind, Morten

2013-01-01

of power systems operation control. The use of PMUs allows more penetration of DG mainly, with technologies based on renewable resources with intermittent and unpredictable operation such a wind power. This paper introduces the Secure Operation of Sustainable Power Systems (SOSPO) project. The SOSPO...... project tries to respond to the question "How to ensure a secure operation of the future power system where the operating point is heavily is fluctuating?" focusing in the Supervision module architecture and in the power system operation states. The main goal of Supervision module is to determine...... the power system operation state based on new stability and security parameters derived from PMUs measurement and coordinate the use of automatic and manual control actions. The coordination of the control action is based not only in the static indicators but also in the performance evaluation of control...

Information needs in nuclear power plants during low power operation modes

Energy Technology Data Exchange (ETDEWEB)

Tommila, Teemu; Fantoni, Paolo F.; Zander, Ralf M.

1998-02-01

During the past few years an increasing attention has been paid to the safety of shutdown and refuelling operations. It has turned out that the risks during shutdown may be comparable to the risks of power operation. The goal of this report is to identify information requirements related to low power operating modes of nuclear power plants. These include, for example, warm and cold shutdowns, refuelling and maintenance, as well as related state transitions such as start-up and shut-down. The focus of the report is on planned refuelling outages and the role of the control room in managing the outage activities. As a starting point, the basic terminology and characteristics of low power operation are discussed. The current situation at nuclear power plants and some recent developments in information technology are reviewed. End-users' requirements and enabling technologies are combined in order to identify the opportunities for new information technology tools in low power operation. The required features of process control systems and maintenance information systems are described. Common plant modelling techniques, open software architectures and functional structuring of the process control system are suggested to be the key issues in the long-term development of operator support systems. On a shorter time scale, new tools solving limited practical problems should be developed and evaluated. This would provide a basis for the features needed for low power operation, including for example, outage planning, on-line risk monitoring, management of outage tasks, adaptive alarm handling, computerised procedures and task-oriented human interfaces. (author)

Capacity Bounds for Parallel Optical Wireless Channels

KAUST Repository

Chaaban, Anas; Rezki, Zouheir; Alouini, Mohamed-Slim

2016-01-01

A system consisting of parallel optical wireless channels with a total average intensity constraint is studied. Capacity upper and lower bounds for this system are derived. Under perfect channel-state information at the transmitter (CSIT), the bounds have to be optimized with respect to the power allocation over the parallel channels. The optimization of the lower bound is non-convex, however, the KKT conditions can be used to find a list of possible solutions one of which is optimal. The optimal solution can then be found by an exhaustive search algorithm, which is computationally expensive. To overcome this, we propose low-complexity power allocation algorithms which are nearly optimal. The optimized capacity lower bound nearly coincides with the capacity at high SNR. Without CSIT, our capacity bounds lead to upper and lower bounds on the outage probability. The outage probability bounds meet at high SNR. The system with average and peak intensity constraints is also discussed.

Non-symmetric elliptic operators on bounded Lipschitz domains in the plane

Directory of Open Access Journals (Sweden)

David J. Rule

2007-10-01

Full Text Available We consider divergence form elliptic operators $L = mathop{ m div} A abla$ in $mathbb{R}^2$ with a coefficient matrix $A = A(x$ of bounded measurable functions independent of the $t$-direction. The aim of this note is to demonstrate how the proof of the main theorem in [4] can be modified to bounded Lipschitz domains. The original theorem states that the $L^p$ Neumann and regularity problems are solvable for $1 < p < p_0$ for some $p_0$ in domains of the form ${(x,t : phi(x < t}$, where $phi$ is a Lipschitz function. The exponent $p_0$ depends only on the ellipticity constants and the Lipschitz constant of $phi$. The principal modification of the argument for the original result is to prove the boundedness of the layer potentials on domains of the form ${X = (x,t : phi(mathbf{e}cdot X < mathbf{e}^perpcdot X }$, for a fixed unit vector $mathbf{e} = (e_1,e_2$ and $mathbf{e}^perp = (-e_2,e_1$. This is proved in [4] only in the case $mathbf{e} = (1,0$. A simple localisation argument then completes the proof.

Change-management. From commercial power operation to post power operation and decommissioning

International Nuclear Information System (INIS)

Wasinger, Karl

2015-01-01

Transition from power generation to decommissioning challenges utilities. Power generation is mainly characterized by a stable working environment and constant workload, decommissioning and dismantling, however, by transformation and change. Also, changing requirements for the workforce's skills challenge the organization and its senior management. Ensuring effective and efficient performance, while maintaining motivation of staff, requires adjustment of management processes as well as of operational organization and human resources management. AREVA has more than 20 years of experience in decommissioning of own nuclear fuel cycle plants in France, as well as of other large plants and power reactors in Germany, the United Kingdom and the US. Therefore, the group has developed and successfully implemented integrated change management processes. The implementation of well-established and proven methods, developed by the productive industry and adjusted to the nuclear regulatory requirements, significantly improves the performance and efficiency of means and methods in use. The AREVA Performance Improvement Process defines concrete approaches to identify and improve potential deficits of productivity in six main areas (decommissioning scenarios and stra-tegies, waste treatment and logistics, operations management, supply chain, regulatory monitoring and controls as well as dismantling operation). Nuclear plant and facility owners around the world benefit from AREVA experts well experienced in execution of large and complex decommissioning projects.

Development and application of nuclear power operation database

International Nuclear Information System (INIS)

Shao Juying; Fang Zhaoxia

1996-01-01

The article describes the development of the Nuclear Power Operation Database which include Domestic and Overseas Nuclear Event Scale Database, Overseas Nuclear Power Operation Abnormal Event Database, Overseas Nuclear Power Operation General Reliability Database and Qinshan Nuclear Power Operation Abnormal Event Database. The development includes data collection and analysis, database construction and code design, database management system selection. The application of the database to provide support to the safety analysis of the NPPs which have been in commercial operation is also introduced

Universal bounds in even-spin CFTs

Energy Technology Data Exchange (ETDEWEB)

Qualls, Joshua D. [Department of Physics, National Taiwan University,Taipei, Taiwan (China)

2015-12-01

We prove using invariance under the modular S− and ST−transformations that every unitary two-dimensional conformal field theory (CFT) having only even-spin primary operators (with no extended chiral algebra and with right- and left-central charges c,c̃>1) contains a primary operator with dimension Δ{sub 1} satisfying 0<Δ{sub 1}<((c+c̃)/24)+0.09280…. After deriving both analytical and numerical bounds, we discuss how to extend our methods to bound higher conformal dimensions before deriving lower and upper bounds on the number of primary operators in a given energy range. Using the AdS{sub 3}/CFT{sub 2} dictionary, the bound on Δ{sub 1} proves the lightest massive excitation in appropriate theories of 3D matter and gravity with cosmological constant Λ<0 can be no heavier than 1/8G{sub N}+O(√(−Λ)); the bounds on the number of operators are related via AdS/CFT to the entropy of states in the dual gravitational theory. In the flat-space approximation, the limiting mass is exactly that of the lightest BTZ black hole.

Generalized Robin Boundary Conditions, Robin-to-Dirichlet Maps, and Krein-Type Resolvent Formulas for Schr\\"odinger Operators on Bounded Lipschitz Domains

OpenAIRE

Gesztesy, Fritz; Mitrea, Marius

2008-01-01

We study generalized Robin boundary conditions, Robin-to-Dirichlet maps, and Krein-type resolvent formulas for Schr\\"odinger operators on bounded Lipschitz domains in $\\bbR^n$, $n\\ge 2$. We also discuss the case of bounded $C^{1,r}$-domains, $(1/2)

Operator support system for nuclear power plants

International Nuclear Information System (INIS)

Mori, Nobuyuki; Tai, Ichiro; Sudo, Osamu; Naito, Norio.

1987-01-01

The nuclear power generation in Japan maintains the high capacity factor, and its proportion taken in the total generated electric power exceeded 1/4, thus it has become the indispensable energy source. Recently moreover, the nuclear power plants which are harmonious with operators and easy to operate are demanded. For realizing this, the technical development such as the heightening of operation watching performance, the adoption of automation, and the improvement of various man-machine systems for reducing the burden of operators has been advanced by utilizing electronic techniques. In this paper, the trend of the man-machine systems in nuclear power plants, the positioning of operation support system, the support in the aspects of information, action and knowledge, the example of a new central control board, the operation support system using a computer, an operation support expert system and the problems hereafter are described. As the development of the man-machine system in nuclear power plants, the upgrading from a present new central control board system PODIA through A-PODIA, in which the operational function to deal with various phenomena arising in plants and safety control function are added, to 1-PODIA, in which knowledge engineering technology is adopted, is expected. (Kako, I.)

33 CFR 209.141 - Coordination of hydroelectric power operations with power marketing agencies.

Science.gov (United States)

2010-07-01

... Commanders will develop, in coordination with their respective power marketing agency, a system for exchanging operating information. The system will include general operating information and information on... power operations with power marketing agencies. 209.141 Section 209.141 Navigation and Navigable Waters...

Operation and maintenance of nuclear power plants

International Nuclear Information System (INIS)

Ackermann, G.

1987-01-01

This textbook gives a systematic introduction into the operational and maintenance activities in nuclear power plants with pressurized water reactors. Subjects: (1) Setup and operational behaviour of power reactors, (2) setup of nuclear power plants, (3) radiation protection and nuclear safety, (4) nuclear fuel, (5) constructional layout of nuclear power plants, (6) management, and (7) maintenance. 158 figs., 56 tabs

Role of check operators in achieving operational excellence at Virginia Power's nuclear stations

International Nuclear Information System (INIS)

Shriver, B.L.; Williams, T.M.; Stewart, W.L.

1987-01-01

Virginia Power has implemented a Check Operator Program as a part of its commitment to excellence in the operation of the North Anna and Surry nuclear power stations. The Check Operator Program utilizes highly qualified licensed personnel to independently evaluate the performance of licensed operators and senior operators during normal, abnormal and simulated emergency conditions. Emphasis is placed upon individual and team performance as well as the procedures and training which support the operators. The check operators report to line management to ensure that their recommendations are implemented into the overall operations philosophy of the power station

Preparation and practice for nuclear power plant operation

International Nuclear Information System (INIS)

Wu Xuesong; Lu Tiezhong

2015-01-01

The operational preparation of the nuclear power plant is an important work in nuclear power plant production preparation. Due to the construction period of nuclear power plant from starting construction to production is as long as five years, the professional requirements of nuclear power operation are very strict, and the requirements for nuclear safety are also extremely high. Especially after the Fukushima accident, higher requirements for the safe operation of nuclear power plant are posed by competent authorities of the national level, regulatory authorities and each nuclear power groups. Based on the characteristics of the construction phase of nuclear power plant and in combination with engineering practice, this paper expounds the system established in the field of nuclear power plant operation and generally analyses the related management innovation. (authors)

Spinless Salpeter equation: Laguerre bounds on energy levels

International Nuclear Information System (INIS)

Lucha, W.; Schoeberl, F.F.

1996-08-01

The spinless Salpeter equation may be considered either as a standard approximation to the Bethe-Salpeter formalism, designed for the description of bound states within a relativistic quantum field theory, or as the most simple, to a certain extent relativistic generalization of the customary non relativistic Schroedinger formalism. Because of the presence of the rather difficult-to-handle square-root operator of the relativistic kinetic energy in the corresponding Hamiltonian, very frequently the corresponding (discrete) spectrum of energy eigenvalues cannot be determined analytically. Therefore, we show how to calculate, by some clever choice of basis vectors in the Hilbert space of solutions, for the rather large class of power-law potentials, at least (sometimes excellent) upper bounds on these energy eigenvalues, for the lowest-lying levels this even analytically. (author)

Unmanned operation of Hydro Power Plants

International Nuclear Information System (INIS)

Regula, E.

2008-01-01

Intentions to launch unmanned operation are no news, the very first occurred in Hydro Power Plants (HPP) at the time when the first computer technology was implemented into process of power generation, i.e. no later than in 1960 s . ENEL entering Slovenske elektrarne not only revived but significantly accelerated the implementation process of unmanned operation. Experience of ENEL says that unmanned operation means better reliability of the HPP and this is the priority. (author)

Permanent cessation of Tokai power plant's operation

International Nuclear Information System (INIS)

Satoh, T.

1998-01-01

Tokai power plant (166MWe, Magnox type: GCR) is the first commercial reactor in Japan and has been kept operating stable since its commissioning in July 1996. During this period it has produced electricity of approximately 27.7 billion KWh (as of March 1997) and its stable operation has contributed greatly to the stable supply of electricity in Japan. Furthermore, technologies in various fields have been developed, demonstrated and accumulated through the construction and operation of Tokai power plant. It also contributes to training for many nuclear engineers, and constructions and operations of nuclear power stations by other Japanese power companies. As a pioneer, it has been achieved to develop and popularize Japanese nuclear power generation. On the other hand, Tokai power plant has small capacity in its electric power output, even though the size of the reactor and heat exchangers are rather bigger than those of LWR due to the characteristics of GCR. Therefore, the generation cost is higher than the LWR. Since there is no plant whose reactor type is the same as that of Tokai power plant, the costs for maintenance and fuel cycle are relatively higher than that of LWR. Finally we concluded that the longer we operate it, the less we can take advantage of it economically. As a result of the evaluation for the future operation of Tokai power plant including the current status for supply of electricity by the Japanese utilities and study of decommissioning by Japanese government, we decided to have a plan of stopping its commercial operation of Tokai power plant in the end of March, 1998, when we completely consume its fuel that we possess. From now on, we set about performing necessary studies and researches on the field of plant characterization, remote-cutting, waste disposal for carrying out the decommissioning of Tokai power plant safely and economically. We are going to prepare the decommissioning planning for Tokai power plant in a few years based on the

Highly excited bound-state resonances of short-range inverse power-law potentials

Energy Technology Data Exchange (ETDEWEB)

Hod, Shahar [The Ruppin Academic Center, Emeq Hefer (Israel); The Hadassah Academic College, Jerusalem (Israel)

2017-11-15

We study analytically the radial Schroedinger equation with long-range attractive potentials whose asymptotic behaviors are dominated by inverse power-law tails of the form V(r) = -β{sub n}r{sup -n} with n > 2. In particular, assuming that the effective radial potential is characterized by a short-range infinitely repulsive core of radius R, we derive a compact analytical formula for the threshold energy E{sub l}{sup max} = E{sub l}{sup max}(n, β{sub n}, R), which characterizes the most weakly bound-state resonance (the most excited energy level) of the quantum system. (orig.)

Entropic cohering power in quantum operations

Science.gov (United States)

Xi, Zhengjun; Hu, Ming-Liang; Li, Yongming; Fan, Heng

2018-02-01

Coherence is a basic feature of quantum systems and a common necessary condition for quantum correlations. It is also an important physical resource in quantum information processing. In this paper, using relative entropy, we consider a more general definition of the cohering power of quantum operations. First, we calculate the cohering power of unitary quantum operations and show that the amount of distributed coherence caused by non-unitary quantum operations cannot exceed the quantum-incoherent relative entropy between system of interest and its environment. We then find that the difference between the distributed coherence and the cohering power is larger than the quantum-incoherent relative entropy. As an application, we consider the distributed coherence caused by purification.

Using management of aging in German nuclear power plants - aspects of KTA 1403 pertaining to residual power operation, post-shutdown operation and residual operation

International Nuclear Information System (INIS)

Barreiro, Pablo; Bever, Thomas; Brast, Gerhard; Elsche, Bjoern; Reese, Sven H.; Grossmann, Patrick; Widera, Martin; Huettner, Frank; Linnemann, Thomas; Smit, Swen-Olaf; Zander, Ralf-Michael

2013-01-01

Management of aging in nuclear power plants originated in the United States of America and became a topic of debate in Germany from the late 1990s onward. On the basis of the existing plant-specific measures practiced comprehensively, KTA 1403, ''Management of Aging in Nuclear Power Plants'', was drafted and finalized in 2010. This publication first presents the context of AM with regard to German nuclear power plants, including references to national and international historical developments. Against this backdrop, the difference between management of aging and lifetime management is discussed next. This is followed by a description of the status of the AM process in nuclear power plants currently in operation, especially organizational plant-specific implementation. As a consequence of the decision by the German federal government to discontinue the peaceful use of nuclear power in Germany and the associated 13th amendment to the Atomic Energy Act of July 31, 2011, a considerable part of the German nuclear power plant park already lost its right of power operation. In this situation, aspects of AM are discussed for plants in the no-power, post-operation and residual operation phases. Finally, experience accumulated in plant-specific execution of the AM process on the basis of KTA 1403 is considered and summarized.

Modifications at operating nuclear power plants

International Nuclear Information System (INIS)

Duffy, T.J.; Gazda, P.A.

1985-01-01

Modifications at operating nuclear power plants offer the structural engineer many challenges in the areas of scheduling of work, field adjustments, and engineering staff planning. The scheduling of structural modification work for operating nuclear power plants is normally closely tied to planned or unplanned outages of the plant. Coordination between the structural engineering effort, the operating plant staff, and the contractor who will be performing the modifications is essential to ensure that all work can be completed within the allotted time. Due to the inaccessibility of some areas in operating nuclear power plants or the short time available to perform the structural engineering in the case of an unscheduled outrage, field verification of a design is not always possible prior to initiating the construction of the modification. This requires the structural engineer to work closely with the contractor to promptly resolve problems due to unanticipated interferences or material procurement problems that may arise during the course of construction. The engineering staff planning for structural modifications at an operating nuclear power plant must be flexible enough to permit rapid response to the common ''fire drills,'' but controlled enough to ensure technically correct designs and to minimize the expenditure of man-hours and the resulting engineering cost

Independent System Operators and Biomass Power

International Nuclear Information System (INIS)

Porter, Kevin L.

1999-01-01

Since the Federal Energy Regulatory Commission issued its landmark open access transmission rule in 1996, the idea of creating and establishing independent system operators (ISOs) has gained momentum. ISOs may help combine individual utility transmission systems into more regional transmission networks, which ultimately will allow biomass companies to transmit power over longer distances while paying a single transmission rate. To the extent that ISOs are combined or operated with power exchanges, however, biomass companies will likely face even more competitive market pressures. Few operators have experience with ISOs and power exchanges, but preliminary results show that short-term electricity market prices are probably too low for most biomass companies to compete against. Without policy measures, biomass companies may have to pursue strategic opportunities with short-term, spot-market sales; direct bilateral sales to customers; alternative power exchanges; and perhaps a ''green'' power market and sales to ancillary service markets. In addition, prices will likely be more volatile in a restructured market so biomass generators should be selling during those times

Operator training simulator for nuclear power plant

International Nuclear Information System (INIS)

Shiozuka, Hiromi

1977-01-01

In nuclear power plants, training of the operators is important. In Japan, presently there are two training centers, one is BWR operation training center at Okuma-cho, Fukushima Prefecture, and another the nuclear power generation training center in Tsuruga City, Fukui Prefecture, where the operators of PWR nuclear power plants are trained. This report describes the BWR operation training center briefly. Operation of a nuclear power plant is divided into three stages of start-up, steady state operation, and shut down. Start-up is divided into the cold-state start-up after the shut down for prolonged period due to periodical inspection or others and the hot-state start-up from stand-by condition after the shut down for a short time. In the cold-state start-up, the correction of reactivity change and the heating-up control to avoid excessive thermal stress to the primary system components are important. The BWR operation training center offers the next three courses, namely beginner's course, retraining course and specific training course. The training period is 12 weeks and the number of trainees is eight/course in the beginner's course. The simulator was manufactured by modeling No. 3 plant of Fukushima First Nuclear Power Station, Tokyo Electric Power Co. The simulator is composed of the mimic central control panel and the digital computer. The software system comprises the monitor to supervise the whole program execution, the logic model simulating the plant interlock system and the dynamic model simulating the plant physical phenomena. (Wakatsuki, Y.)

Integrated approach to optimize operation and maintenance costs for operating nuclear power plants

International Nuclear Information System (INIS)

2006-06-01

In the context of increasingly open electricity markets and the 'unbundling' of generating companies from former utility monopolies, an area of major concern is the economic performance of the existing fleet of nuclear power plants. Nuclear power, inevitably, must compete directly with other electricity generation sources. Coping with this competitive pressure is a challenge that the nuclear industry should meet if the nuclear option is to remain a viable one. This competitive environment has significant implications for nuclear plant operations, including, among others, the need for the more cost effective management of plant activities, and the greater use of analytical tools to balance the costs and benefits of proposed activities, in order to optimize operation and maintenance costs, and thus insure the economic competitiveness of existing nuclear power plants. In the framework of the activities on Nuclear Economic Performance Information System (NEPIS), the IAEA embarked in developing guidance on optimization of operation and maintenance costs for nuclear power plants. The report was prepared building on the fundamental that optimization of operation and maintenance costs of a nuclear power plant is a key component of a broader integrated business strategic planning process, having as overall result achievement of organization's business objectives. It provides advice on optimization of O and M costs in the framework of strategic business planning, with additional details on operational planning and controlling. This TECDOC was elaborated in 2004-2005 in the framework of the IAEA's programme on Nuclear Power Plant Operating Performance and Life Cycle Management, with the support of two consultants meetings and one technical meeting and based on contributions provided by participants. It can serve as a useful reference for the management and operation staff within utilities, nuclear power plant operators and regulators and other organizations involved in

Method of operating BWR type power plants

International Nuclear Information System (INIS)

Koyama, Kazuaki.

1981-01-01

Purpose: To improve the operation efficiency of BWR type reactors by reducing the time from the start-up of the reactor to the start-up of the turbine and electrical generator, as well as decrease the pressure difference in each of the sections of the pressure vessel to thereby extend its life span. Method: The operation comprises switching the nuclear reactor from the shutdown mode to the start-up mode, increasing the reactor power to a predetermined level lower than a rated power while maintaining the reactor pressure to a predetermined level lower than a rated pressure, starting up a turbine and an electrical generator in the state of the predetermined reactor pressure and the reactor power to connect the electrical generator to the power transmission system and, thereafter, increasing the reactor pressure and the reactor power to the predetermined rated pressure and rated power respectively. This can shorten the time from the start-up of the reactor to the start of the power transmission system, whereby the operation efficiency of the power plant can be improved. (Moriyama, K.)

The armenian power system operation stability investigation accounting putting new power systems into operation

International Nuclear Information System (INIS)

Yeghiazaryan, L.V.; Hakobyan, S.G.; Gharibyan, G.V.; Harutyunyan, G.S.; Galstyan, G.H.

2010-01-01

The description of the power systems operation stability failure caused by the system significant emergency states occurred during the last working period in Armenian and USA power systems is performed. With the use of PSSTME-31 software portfolio of Siemens Firm a design model is developed and transient electromechanical process calculations for Armenian power system are performed. The accuracy of the model is checked by comparing real-time transient state parameters and their reproduction calculation results.The Armenia - Iran current power transmission lines permissible limit under the condition of the static and dynamic stability requirements and in case of the new thermal power units maintenance are defined

Institute of Nuclear Power Operations (INPO)

International Nuclear Information System (INIS)

Pack, R.W.

1980-01-01

The electric utility industry established the Institute of Nuclear Power Operations, or INPO, the purpose of which is to ensure the highest quality of operations in nuclear power plants. INPO will be an industry self-help instrument focusing on human factors. From top management to the operator trainee, it will measure utility performance against benchmarks of excellence and help utilities reach those benchmarks throughout training and operating programs. INPO will see that the utilities ferret out lessons for all from the abnormal operating experiences of any. It will do everything possible to assist utilities in meeting its certification requirements, but will have the clout to see that those requirements are met. INPO is also managing the nationwide system of utility emergency response capability

Power System Operation with Large Scale Wind Power Integration

DEFF Research Database (Denmark)

Suwannarat, A.; Bak-Jensen, B.; Chen, Z.

2007-01-01

to the uncertain nature of wind power. In this paper, proposed models of generations and control system are presented which analyze the deviation of power exchange at the western Danish-German border, taking into account the fluctuating nature of wind power. The performance of the secondary control of the thermal......The Danish power system starts to face problems of integrating thousands megawatts of wind power, which produce in a stochastic behavior due to natural wind fluctuations. With wind power capacities increasing, the Danish Transmission System Operator (TSO) is faced with new challenges related...... power plants and the spinning reserves control from the Combined Heat and Power (CHP) units to achieve active power balance with the increased wind power penetration is presented....

Power reactors operational diagnosis

International Nuclear Information System (INIS)

Dach, K.; Pecinka, L.

1976-01-01

The definition of reactor operational diagnostics is presented and the fundamental trends of research are determined. The possible sources of power reactor malfunctions, the methods of defect detection, the data evaluation and the analysis of the results are discussed in detail. In view of scarcity of a theoretical basis and of insufficient in-core instrumentation, operational diagnostics cannot be as yet incorporated in a computer-aided reactor control system. (author)

Operating modes and practical power flow analysis of bidirectional isolated power interface for distributed power systems

International Nuclear Information System (INIS)

Wen, Huiqing; Su, Bin

2016-01-01

Highlights: • Four operating modes of Dual-Phase-Shift control for Dual Active Bridge converter are presented. • Effects of “minor parameters” such as the deadtime and power device voltage drops are analyzed. • Accurate power flow models with Dual-Phase-Shift control are developed and verified with experimental results. • Optimal operating mode is determined with respect to the efficiency improvement. • Measured efficiency of the Dual Active Bridge converter is improved up to 14%. - Abstract: Due to the intermittent nature of the renewable energy sources including photovoltaic and wind energy, the energy storage systems are essential to stabilize dc bus voltage. Considering the discharge depth of super-capacitors and energy-storage batteries, the bidirectional isolated power interface will operate for a wide range of voltage and power. This study focuses on in-depth analysis of the dual-active-bridge dc–dc converter that is controlled by the dual-phase-shift scheme to improve the conversion efficiency in distributed power system. The power flow of each operating mode with dual-phase-shift control is characterized based on a detailed analysis of the effects of “minor parameters”, including the deadtime and power device voltage drops. The complete output power plane of the dual-active-bridge converter with dual-phase-shift control is obtained and compared with experimental results. The optimal operating mode is determined according to the practical output power range and the power flow characteristics. Experimental evaluation shows the effectiveness of the proposed power flow model with dual-phase-shift control and significant efficiency improvement using the optimal mode of dual-phase-shift compared with the conventional phase shift control.

Power ramping/cycling experience and operational recommendations in KWU power plants

International Nuclear Information System (INIS)

Jan, R. von; Wunderlich, F.; Holzer, R.

1980-01-01

The power cycling and ramping experience of KWU is based on experiments in test and commercial reactors, and on evaluation of plant operation (PHWR, PWR and BWR). Power cycling of fuel rods have never lead to PCI failures. In ramping experiments, for fast ramps PCI failure thresholds of 480/420 W/cm are obtained at 12/23 GWd/t(U) burn-up for pressurized PWR fuel. No failures occurred during limited exceedance of the threshold with reduced ramp rate. Operational recommendations used by KWU are derived from experiments and plant experience. The effects of ramping considerations on plant operation is discussed. No rate restrictions are required for start-ups during an operating cycle or load follow operation within set limits for the distortion of the local power distribution. In a few situations, e.g. start-up after refueling, ramp rates of 1 to 5 %/h are recommended depending on plant and fuel design

China’s Nuclear Power Plants in Operation

Institute of Scientific and Technical Information of China (English)

无

2011-01-01

Qinshan Plant Phase I Located in Haiyan,Zhejiang Province,Qinshan Nuclear Power Plant Phase I is t he first 300-megawatt pressurized water reactor (PWR) nuclear power plant independently designed,constructed,operated and managed by China.The plant came into commercial operation in April 1994.

Use of wind power forecasting in operational decisions.

Energy Technology Data Exchange (ETDEWEB)

Botterud, A.; Zhi, Z.; Wang, J.; Bessa, R.J.; Keko, H.; Mendes, J.; Sumaili, J.; Miranda, V. (Decision and Information Sciences); (INESC Porto)

2011-11-29

The rapid expansion of wind power gives rise to a number of challenges for power system operators and electricity market participants. The key operational challenge is to efficiently handle the uncertainty and variability of wind power when balancing supply and demand in ths system. In this report, we analyze how wind power forecasting can serve as an efficient tool toward this end. We discuss the current status of wind power forecasting in U.S. electricity markets and develop several methodologies and modeling tools for the use of wind power forecasting in operational decisions, from the perspectives of the system operator as well as the wind power producer. In particular, we focus on the use of probabilistic forecasts in operational decisions. Driven by increasing prices for fossil fuels and concerns about greenhouse gas (GHG) emissions, wind power, as a renewable and clean source of energy, is rapidly being introduced into the existing electricity supply portfolio in many parts of the world. The U.S. Department of Energy (DOE) has analyzed a scenario in which wind power meets 20% of the U.S. electricity demand by 2030, which means that the U.S. wind power capacity would have to reach more than 300 gigawatts (GW). The European Union is pursuing a target of 20/20/20, which aims to reduce greenhouse gas (GHG) emissions by 20%, increase the amount of renewable energy to 20% of the energy supply, and improve energy efficiency by 20% by 2020 as compared to 1990. Meanwhile, China is the leading country in terms of installed wind capacity, and had 45 GW of installed wind power capacity out of about 200 GW on a global level at the end of 2010. The rapid increase in the penetration of wind power into power systems introduces more variability and uncertainty in the electricity generation portfolio, and these factors are the key challenges when it comes to integrating wind power into the electric power grid. Wind power forecasting (WPF) is an important tool to help

Generalized bounds for convex multistage stochastic programs

CERN Document Server

Künzi, H; Fandel, G; Trockel, W; Basile, A; Drexl, A; Dawid, H; Inderfurth, K; Kürsten, W; Schittko, U

2005-01-01

This work was completed during my tenure as a scientific assistant and d- toral student at the Institute for Operations Research at the University of St. Gallen. During that time, I was involved in several industry projects in the field of power management, on the occasion of which I was repeatedly c- fronted with complex decision problems under uncertainty. Although usually hard to solve, I quickly learned to appreciate the benefit of stochastic progr- ming models and developed a strong interest in their theoretical properties. Motivated both by practical questions and theoretical concerns, I became p- ticularly interested in the art of finding tight bounds on the optimal value of a given model. The present work attempts to make a contribution to this important branch of stochastic optimization theory. In particular, it aims at extending some classical bounding methods to broader problem classes of practical relevance. This book was accepted as a doctoral thesis by the University of St. Gallen in June 2004.1...

A note on supercyclic operators in locally convex spaces

OpenAIRE

Albanese, Angela A.; Jornet, David

2018-01-01

We treat some questions related to supercyclicity of continuous linear operators when acting in locally convex spaces. We extend results of Ansari and Bourdon and consider doubly power bounded operators in this general setting. Some examples are given.

The Federal Administrative Court confirms unlawfulness of nuclear power moratorium. Political primacy is only valid in the bounds of justice

International Nuclear Information System (INIS)

Leidinger, Tobias

2014-01-01

With its decision on December 20 th , the Federal Administrative Court (BVwerfG) came to the legally valid conclusion that after the Fukushima nuclear power plant accident, the supervision court order related to the law on nuclear installation by the Hessian Ministry for the Environment, in order to stop operating nuclear power plants Biblis A and B for 3 months or rather not to put in operation again, was unlawful (BVwerfG 7 B 18.13 und 7 B 19.13). Beforehand, the Hessian Administrative Court (Hess. VGH) had already pronounced its judgement on February 27 th 2013. The supervising orders were part of the so-called nuclear power moratorium. They were issued after the resolution of the federal government, at demand of the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU) towards their nearby countries, and were identically executed by the supervisory authority of the other site-countries. Besides Biblis in Hesse, nuclear power plants in Neckarwestheim I and Philippsburg 1, Baden-Wurttemberg, Isar 1 in Bavaria, Unterweser in Lower Saxony, as well as Brunsbuettel in Schleswig-Holstein, were affected. However only RWE took legal action and was now affirmed - after the Hessian VGH verdict- by the highest German administrative court: The nuclear power moratorium - the first step to withdrawal of nuclear power in Germany - was unlawful. The decision taken by the BVerwG - as well as the one by the Hessian VGH - indicates a juridical clear and precise argumentation. The partially polemic and unobjective critic, which the VHG-verdict experienced, did not disguise, just as little as the political conflict concerning the withdrawal from nuclear energy, the view of federal judges, regarding the decision-relevant questions nor did they influence their reply. The political primacy finds its limits in the bounds of justice. Existing rights do not become thus a paper waste because there is a fundamental decision. This takes effectiveness for

Nuclear power plant operating experience, 1976

International Nuclear Information System (INIS)

1977-11-01

This report is the third in a series of reports issued annually that summarize the operating experience of U.S. nuclear power plants in commercial operation. Power generation statistics, plant outages, reportable occurrences, fuel element performance, occupational radiation exposure and radioactive effluents for each plant are presented. Summary highlights of these areas are discussed. The report includes 1976 data from 55 plants--23 boiling water reactor plants and 32 pressurized water reactor plants

Modeling Control Situations in Power System Operations

DEFF Research Database (Denmark)

Saleem, Arshad; Lind, Morten; Singh, Sri Niwas

2010-01-01

for intelligent operation and control must represent system features, so that information from measurements can be related to possible system states and to control actions. These general modeling requirements are well understood, but it is, in general, difficult to translate them into a model because of the lack...... of explicit principles for model construction. This paper presents a work on using explicit means-ends model based reasoning about complex control situations which results in maintaining consistent perspectives and selecting appropriate control action for goal driven agents. An example of power system......Increased interconnection and loading of the power system along with deregulation has brought new challenges for electric power system operation, control and automation. Traditional power system models used in intelligent operation and control are highly dependent on the task purpose. Thus, a model...

Bounds on the order of vanishing of eigenfunctions of Schroedinger operators

International Nuclear Information System (INIS)

Hoffmann-Ostenhof, M.; Hoffmann-Ostenhof, T.

1990-01-01

We study L 2 -solutions of (-Δ+V-E)ψ = 0 in R n , n ≥ 2 and derive a sharp upper bound to l x 0 (ψ) in terms of x 0 , E and V under rather restrictive assumptions on V. We show for V smooth that an upper bound to l x 0 (ψ) implies an upper bound to the dimension of the eigenspace associated to E. 16 refs. (Authors)

Universal bounds on spectral measures of one-dimensional Schrödinger operators

CERN Document Server

Remling, C

2002-01-01

Consider a Schrödinger operator $H=-d^2/dx^2+V(x)$ on $L_2(0,\\infty)$ and suppose that an initial piece of the potential $V(x)$, $0bounds on the spectral measure of intervals with a certain minimum length. This length scale is set by the eigenvalues of the problems on $[0,N]$. So in a sense (and perhaps somewhat surprisingly) the behavior of $V(x)$ becomes less important if $x$ grows. The results of this paper are developments of classical work of Chebyshev and Markov on orthogonal polynomials.

Operator training simulator for BWR nuclear power plant

International Nuclear Information System (INIS)

Watanabe, Tadasu

1988-01-01

For the operation management of nuclear power stations with high reliability and safety, the role played by operators is very important. The effort of improving the man-machine interface in the central control rooms of nuclear power stations is energetically advanced, but the importance of the role of operators does not change. For the training of the operators of nuclear power stations, simulators have been used from the early stage. As the simulator facilities for operator training, there are the full scope simulator simulating faithfully the central control room of an actual plant and the small simulator mainly aiming at learning the plant functions. For BWR nuclear power stations, two full scope simulators are installed in the BWR Operator Training Center, and the training has been carried out since 1974. The plant function learning simulators have been installed in respective electric power companies as the education and training facilities in the companies. The role of simulators in operator training, the BTC No.1 simulator of a BWR-4 of 780 MWe and the BTC No.2 simulator of a BWR-5 of 1,100 MWe, plant function learning simulators, and the design of the BTC No.2 simulator and plant function learning simulators are reported. (K.I.)

Tendencies in operating power reactors

International Nuclear Information System (INIS)

Brinckmann, H.F.

1987-01-01

A survey is given about new tendencies in operating power reactors. In order to meet the high demands for control and monitoring of power reactors modern procedures are applicated such as the incore-neutron flux detection by means of electron emission detectors and multi-component activation probes, the noise diagnostics as well as high-efficient automation systems

An analyser for power plant operations

International Nuclear Information System (INIS)

Rogers, A.E.; Wulff, W.

1990-01-01

Safe and reliable operation of power plants is essential. Power plant operators need a forecast of what the plant will do when its current state is disturbed. The in-line plant analyser provides precisely this information at relatively low cost. The plant analyser scheme uses a mathematical model of the dynamic behaviour of the plant to establish a numerical simulation. Over a period of time, the simulation is calibrated with measurements from the particular plant in which it is used. The analyser then provides a reference against which to evaluate the plant's current behaviour. It can be used to alert the operator to any atypical excursions or combinations of readings that indicate malfunction or off-normal conditions that, as the Three Mile Island event suggests, are not easily recognised by operators. In a look-ahead mode, it can forecast the behaviour resulting from an intended change in settings or operating conditions. Then, when such changes are made, the plant's behaviour can be tracked against the forecast in order to assure that the plant is behaving as expected. It can be used to investigate malfunctions that have occurred and test possible adjustments in operating procedures. Finally, it can be used to consider how far from the limits of performance the elements of the plant are operating. Then by adjusting settings, the required power can be generated with as little stress as possible on the equipment. (6 figures) (Author)

Automation system for operation of nuclear power plant

International Nuclear Information System (INIS)

Kinoshita, Mitsuo; Fukuzaki, Koji; Kato, Kanji

1991-01-01

The automation system comprises a general monitor control device incorporating a plurality of emergency operation plannings concerning an automatic processing, and judging whether the operation is to be conducted or not depending on the plannings based on the data planed by a plant, a control device for controlling the plant in accordance with the planning when monitor control device judges that the operation should be done due to the emergency operation plannings and an operation planning device aiding the formation of the operation plannings. When the state of the power plant exceeds a normal control region, the reactor power is lowered automatically by so much as a predetermined value or to a predetermined level, to automatically return the plant state to the normal control region. In this way, the plant operation efficiency can be improved. Further, after automatic operation, since operation plannings for recovering original operation plannings are prepared efficiently and recovered operation plannings are started in a short period of time, the operators' burden can be mitigated and power saving can be attained. (N.H.)

An analysis of nuclear power plant operating costs

International Nuclear Information System (INIS)

1988-01-01

This report presents the results of a statistical analysis of nonfuel operating costs for nuclear power plants. Most studies of the economic costs of nuclear power have focused on the rapid escalation in the cost of constructing a nuclear power plant. The present analysis found that there has also been substantial escalation in real (inflation-adjusted) nonfuel operating costs. It is important to determine the factors contributing to the escalation in operating costs, not only to understand what has occurred but also to gain insights about future trends in operating costs. There are two types of nonfuel operating costs. The first is routine operating and maintenance expenditures (O and M costs), and the second is large postoperational capital expenditures, or what is typically called ''capital additions.'' O and M costs consist mainly of expenditures on labor, and according to one recently completed study, the majoriy of employees at a nuclear power plant perform maintenance activities. It is generally thought that capital additions costs consist of large maintenance expenditures needed to keep the plants operational, and to make plant modifications (backfits) required by the Nuclear Regulatory Commission (NRC). Many discussions of nuclear power plant operating costs have not considered these capital additions costs, and a major finding of the present study is that these costs are substantial. The objective of this study was to determine why nonfuel operating costs have increased over the past decade. The statistical analysis examined a number of factors that have influenced the escalation in real nonfuel operating costs and these are discussed in this report. 4 figs, 19 tabs

Higher operational safety of nuclear power plants by evaluating the behaviour of operating personnel

International Nuclear Information System (INIS)

Mertins, M.; Glasner, P.

1990-01-01

In the GDR power reactors have been operated since 1966. Since that time operational experiences of 73 cumulative reactor years have been collected. The behaviour of operating personnel is an essential factor to guarantee the safety of operation of the nuclear power plant. Therefore a continuous analysis of the behaviour of operating personnel has been introduced at the GDR nuclear power plants. In the paper the overall system of the selection, preparation and control of the behaviour of nuclear power plant operating personnel is presented. The methods concerned are based on recording all errors of operating personnel and on analyzing them in order to find out the reasons. The aim of the analysis of reasons is to reduce the number of errors. By a feedback of experiences the nuclear safety of the nuclear power plant can be increased. All data necessary for the evaluation of errors are recorded and evaluated by a computer program. This method is explained thoroughly in the paper. Selected results of error analysis are presented. It is explained how the activities of the personnel are made safer by means of this analysis. Comparisons with other methods are made. (author). 3 refs, 4 figs

Degenerate quantum codes and the quantum Hamming bound

International Nuclear Information System (INIS)

Sarvepalli, Pradeep; Klappenecker, Andreas

2010-01-01

The parameters of a nondegenerate quantum code must obey the Hamming bound. An important open problem in quantum coding theory is whether the parameters of a degenerate quantum code can violate this bound for nondegenerate quantum codes. In this article we show that Calderbank-Shor-Steane (CSS) codes, over a prime power alphabet q≥5, cannot beat the quantum Hamming bound. We prove a quantum version of the Griesmer bound for the CSS codes, which allows us to strengthen the Rains' bound that an [[n,k,d

Strong Wilson polygons from the lodge of free and bound mesons

Energy Technology Data Exchange (ETDEWEB)

Bonini, Alfredo; Fioravanti, Davide [Sezione INFN di Bologna, Dipartimento di Fisica e Astronomia, Università di Bologna,Via Irnerio 46, 40126 Bologna (Italy); Piscaglia, Simone [Dipartimento di Fisica and INFN, Università di Torino,Via P. Giuria 1, 10125 Torino (Italy); Rossi, Marco [Dipartimento di Fisica dell’Università della Calabria and INFN, Gruppo collegato di Cosenza,Arcavacata di Rende, 87036 Cosenza (Italy)

2016-04-05

Previously predicted by the S-matrix bootstrap of the excitations over the GKP quantum vacuum, the appearance of a new particle at strong coupling — formed by one fermion and one anti-fermion — is here confirmed: this two-dimensional meson shows up, along with its infinite tower of bound states, while analysing the fermionic contributions to the Operator Product Expansion (collinear regime) of the Wilson null polygon loop. Moreover, its existence, free and bound, turns out to be a powerful idea in re-summing all the contributions (at large coupling) for a general n-gon (n≥6) to a Thermodynamic Bethe Ansatz, which is proven to be equivalent to the known one and suggests new structures for a special Y-system.

Spanish Power Exchange Market Concepts and Operating Experience

International Nuclear Information System (INIS)

Gonzalez, J. J.; Gamito, C.

2000-01-01

On January, 1st, 1998, the Spanish Electricity Market started operations. All generators, distributors, commercialization companies, and final consumers negotiate al power exchanges either through the spot market or using bilateral contracts. The Spanish Power Exchange Market Operator (Compania Operadora del Mercado Espanol de electricidad, OMEL) is responsible for the management of the market and for the economic settlement and billing of a transactions on the Power Exchange market, and the technical operational process handled by the System Operator. This paper describes in detail the Spanish market principles and the experience gathered through the design, installation and first two years of market operation. The paper presents also the Spanish market results from January 1998 up to December 1999 indicating each specific market results and aggregate statistics. (Author)

Research of the Power Plant Operational Modes

Directory of Open Access Journals (Sweden)

Koismynina Nina M.

2017-01-01

Full Text Available In this article the algorithm of the power plant operational modes research is offered. According to this algorithm the program for the modes analysis and connection power transformers choice is developed. The program can be used as educational means for studying of the power plant electric part, at the same time basic data are provided. Also the program can be used for the analysis of the working power plants modes. Checks of the entered data completeness and a choice correctness of the operational modes are provided in the program; in all cases of a deviation from the correct decisions to the user the relevant information is given.

The operating organization for nuclear power plants. Safety guide

International Nuclear Information System (INIS)

2001-01-01

This Safety Guide was prepared under the IAEA programme for safety standards for nuclear power plants. The present publication is a revision of the IAEA Safety Guide on Management of Nuclear Power Plants for Safe Operation issued in 1984. It supplements Section 2 of the Safety Requirements publication on Safety of Nuclear Power Plants: Operation. Nuclear power technology is different from the customary technology of power generation from fossil fuel and by hydroelectric means. One major difference between the management of nuclear power plants and that of conventional generating plants is the emphasis that should be placed on nuclear safety, quality assurance, the management of radioactive waste and radiological protection, and the accompanying national regulatory requirements. This Safety Guide highlights the important elements of effective management in relation to these aspects of safety. The attention to be paid to safety requires that the management recognize that personnel involved in the nuclear power programme should understand, respond effectively to, and continuously search for ways to enhance safety in the light of any additional requirements socially and legally demanded of nuclear energy. This will help to ensure that safety policies that result in the safe operation of nuclear power plants are implemented and that margins of safety are always maintained. The structure of the organization, management standards and administrative controls should be such that there is a high degree of assurance that safety policies and decisions are implemented, safety is continuously enhanced and a strong safety culture is promoted and supported. The objective of this publication is to guide Member States in setting up an operating organization which facilitates the safe operation of nuclear power plants to a high level internationally. The second objective is to provide guidance on the most important organizational elements in order to contribute to a strong safety

The operating organization for nuclear power plants. Safety guide

International Nuclear Information System (INIS)

2005-01-01

This Safety Guide was prepared under the IAEA programme for safety standards for nuclear power plants. The present publication is a revision of the IAEA Safety Guide on Management of Nuclear Power Plants for Safe Operation issued in 1984. It supplements Section 2 of the Safety Requirements publication on Safety of Nuclear Power Plants: Operation. Nuclear power technology is different from the customary technology of power generation from fossil fuel and by hydroelectric means. One major difference between the management of nuclear power plants and that of conventional generating plants is the emphasis that should be placed on nuclear safety, quality assurance, the management of radioactive waste and radiological protection, and the accompanying national regulatory requirements. This Safety Guide highlights the important elements of effective management in relation to these aspects of safety. The attention to be paid to safety requires that the management recognize that personnel involved in the nuclear power programme should understand, respond effectively to, and continuously search for ways to enhance safety in the light of any additional requirements socially and legally demanded of nuclear energy. This will help to ensure that safety policies that result in the safe operation of nuclear power plants are implemented and that margins of safety are always maintained. The structure of the organization, management standards and administrative controls should be such that there is a high degree of assurance that safety policies and decisions are implemented, safety is continuously enhanced and a strong safety culture is promoted and supported. The objective of this publication is to guide Member States in setting up an operating organization which facilitates the safe operation of nuclear power plants to a high level internationally. The second objective is to provide guidance on the most important organizational elements in order to contribute to a strong safety

The operating organization for nuclear power plants. Safety guide

International Nuclear Information System (INIS)

2004-01-01

This Safety Guide was prepared under the IAEA programme for safety standards for nuclear power plants. The present publication is a revision of the IAEA Safety Guide on Management of Nuclear Power Plants for Safe Operation issued in 1984. It supplements Section 2 of the Safety Requirements publication on Safety of Nuclear Power Plants: Operation. Nuclear power technology is different from the customary technology of power generation from fossil fuel and by hydroelectric means. One major difference between the management of nuclear power plants and that of conventional generating plants is the emphasis that should be placed on nuclear safety, quality assurance, the management of radioactive waste and radiological protection, and the accompanying national regulatory requirements. This Safety Guide highlights the important elements of effective management in relation to these aspects of safety. The attention to be paid to safety requires that the management recognize that personnel involved in the nuclear power programme should understand, respond effectively to, and continuously search for ways to enhance safety in the light of any additional requirements socially and legally demanded of nuclear energy. This will help to ensure that safety policies that result in the safe operation of nuclear power plants are implemented and that margins of safety are always maintained. The structure of the organization, management standards and administrative controls should be such that there is a high degree of assurance that safety policies and decisions are implemented, safety is continuously enhanced and a strong safety culture is promoted and supported. The objective of this publication is to guide Member States in setting up an operating organization which facilitates the safe operation of nuclear power plants to a high level internationally. The second objective is to provide guidance on the most important organizational elements in order to contribute to a strong safety

Improving operator quality at Genkai Nuclear Power Plant

International Nuclear Information System (INIS)

Kuwano, Takeshi.

1989-01-01

Improvement in operator quality, or improvement in an operator's skill and professional knowledge, is of prime importance because of its great influence on safe and steady plant operation. This paper describes the education and training of reactor operators at the Genkai pressurized water reactor nuclear power plant with respect to the following topics: organization of Genkai power plant; education and training program management; training at the Nuclear Training Center; training and education on-site including emergency procedures training, normal operating procedures training, informational study of emergency conditions in existing plants, and all-around training of operators; qualifying tests for supervisors; and operator motivation

Bounded Tamper Resilience

DEFF Research Database (Denmark)

Damgård, Ivan Bjerre; Faust, Sebastian; Mukherjee, Pratyay

2013-01-01

Related key attacks (RKAs) are powerful cryptanalytic attacks where an adversary can change the secret key and observe the effect of such changes at the output. The state of the art in RKA security protects against an a-priori unbounded number of certain algebraic induced key relations, e.......g., affine functions or polynomials of bounded degree. In this work, we show that it is possible to go beyond the algebraic barrier and achieve security against arbitrary key relations, by restricting the number of tampering queries the adversary is allowed to ask for. The latter restriction is necessary......-protocols (including the Okamoto scheme, for instance) are secure even if the adversary can arbitrarily tamper with the prover’s state a bounded number of times and obtain some bounded amount of leakage. Interestingly, for the Okamoto scheme we can allow also independent tampering with the public parameters. We show...

Anomalous dimension of subleading-power N-jet operators

Science.gov (United States)

Beneke, Martin; Garny, Mathias; Szafron, Robert; Wang, Jian

2018-03-01

We begin a systematic investigation of the anomalous dimension of subleading power N-jet operators in view of resummation of logarithmically enhanced terms in partonic cross sections beyond leading power. We provide an explicit result at the one-loop order for fermion-number two N-jet operators at the second order in the power expansion parameter of soft-collinear effective theory.

Fatigue assessments in operating nuclear power plants

International Nuclear Information System (INIS)

Gosselin, S.R.; Deardorff, A.F.; Peltola, D.W.

1994-01-01

In November 1991, the ASME Section XI Task Group on Operating Plant Fatigue Assessment was formed to develop criteria and evaluation methodology for evaluating the effects of cyclic operation in operating nuclear power plants. The objective was to develop guidelines for inclusion in Section XI that could be used by plant operators in evaluating fatigue concerns and their impact on serviceability. This paper discusses the work performed by the Task Group. It explores the concept of ''Fatigue Design Basis'' versus ''Fatigue Operating Basis'' by examining the roles of ASME Section III and ASME Section XI in the design and operation of the nuclear power plants. Guidelines are summarized that may help plant operators perform effective design transient cycle evaluations and optimize cycle counting and fatigue usage tracking. The alternative fatigue evaluation approach using flaw tolerance is also introduced

Inhalation Exposure to PM-Bound Polycyclic Aromatic Hydrocarbons Released from Barbecue Grills Powered by Gas, Lump Charcoal, and Charcoal Briquettes.

Science.gov (United States)

Badyda, Artur J; Widziewicz, Kamila; Rogula-Kozłowska, Wioletta; Majewski, Grzegorz; Jureczko, Izabela

2018-01-01

The present study seeks to define the possible cancer risk arising from the inhalation exposure to particle (PM)-bound polycyclic aromatic hydrocarbons (PAHs) present in barbecue emission gases and to compare the risk depending on the type of fuel used for grill powering. Three types of fuel were compared: liquid propane gas, lump charcoal, and charcoal briquettes. PM 2.5 and PM 2.5-100 were collected during grilling. Subsequently, 16 PAHs congeners were extracted from the PM samples and measured quantitatively using gas chromatography. The content of PM-bound PAHs was used to calculate PAHs deposition in the respiratory tract using the multiple path particle dosimetry model. Finally, a probabilistic risk model was developed to assess the incremental lifetime cancer risk (ILCR) faced by people exposed to PAHs. We found a distinctly greater PAHs formation in case of grills powered by charcoal briquettes. The summary concentration of PAHs (Σ16PAH) ranged from inhale barbecue particles for 5 h a day, 40 days a year exceeds the acceptable level set by the U.S. Environmental Protection Agency. We conclude that the type of heat source used for grilling influences the PM-bound PAHs formation. The greatest concentration of PAHs is generated when grilling over charcoal briquettes. Loading grills with food generates conspicuously more PAHs emissions. Traditional grilling poses cancer risk much above the acceptable limit, as opposed to much less risk involving gas powered grills.

Shutdown and low-power operation at commercial nuclear power plants in the United States

International Nuclear Information System (INIS)

1993-09-01

The report contains the results of the NRC Staff's evaluation of shutdown and low-power operations at US commercial nuclear power plants. The report describes studies conducted by the staff in the following areas: Operating experience related to shutdown and low-power operations, probabilistic risk assessment of shutdown and low-power conditions and utility programs for planning and conducting activities during periods the plant is shut down. The report also documents evaluations of a number of technical issues regarding shutdown and low-power operations performed by the staff, including the principal findings and conclusions. Potential new regulatory requirements are discussed, as well as potential changes in NRC programs. A draft report was issued for comment in February 1992. This report is the final version and includes the responses to the comments along with the staff regulatory analysis of potential new requirements

Experiences of operation for Ikata Nuclear Power Station

International Nuclear Information System (INIS)

Kashimoto, Shigeyuki

1979-01-01

No. 1 plant in the Ikata Nuclear Power Station, Shikoku Electric Power Co., Inc., is a two-loop PWR unit with electric output of 566 MW, and it began the commercial operation on September 30, 1977, as the first nuclear power station in Shikoku. It is the 13th LWR and 7th PWR in Japan. The period of construction was 52 months since it had been started in June, 1973. During the period, it became the object of the first administrative litigation to seek the cancellation of permission to install the reactor, and it was subjected to the influence of the violent economical variation due to the oil shock, but it was completed as scheduled. After the start of operation, it continued the satisfactory operation, and generated about 2.35 billion KWh for 4300 operation hours. It achieved the rate of utilization of 96.7%. Since March 28, 1978, the first periodical inspection was carried out, and abnormality was not found in the reactor, the steam generator and the fuel at all. The period of inspection was 79 days and shorter than expected. The commercial operation was started again on June 14. The outline of the Ikata Nuclear Power Station, its state of operation, and the periodical inspection are reported. Very good results were able to be reported on the operation for one year, thanks to the valuable experiences offered by other electric power companies. (Kako, I.)

Method to operate power reactors with light water cooling

International Nuclear Information System (INIS)

Aleite, W.; Bock, H.W.

1976-01-01

The invention provides a possibility to 'condition' the fuel of a power plant used in base load operation, i.e. to bring it to such a high power density level that the local excesses arising with the occasional total power changes, remain below the power densities reached in normal operation (conditioning level). (orig./RW) [de

Generalized Hofmann quantum process fidelity bounds for quantum filters

Science.gov (United States)

Sedlák, Michal; Fiurášek, Jaromír

2016-04-01

We propose and investigate bounds on the quantum process fidelity of quantum filters, i.e., probabilistic quantum operations represented by a single Kraus operator K . These bounds generalize the Hofmann bounds on the quantum process fidelity of unitary operations [H. F. Hofmann, Phys. Rev. Lett. 94, 160504 (2005), 10.1103/PhysRevLett.94.160504] and are based on probing the quantum filter with pure states forming two mutually unbiased bases. Determination of these bounds therefore requires far fewer measurements than full quantum process tomography. We find that it is particularly suitable to construct one of the probe bases from the right eigenstates of K , because in this case the bounds are tight in the sense that if the actual filter coincides with the ideal one, then both the lower and the upper bounds are equal to 1. We theoretically investigate the application of these bounds to a two-qubit optical quantum filter formed by the interference of two photons on a partially polarizing beam splitter. For an experimentally convenient choice of factorized input states and measurements we study the tightness of the bounds. We show that more stringent bounds can be obtained by more sophisticated processing of the data using convex optimization and we compare our methods for different choices of the input probe states.

Load following operation of nuclear power plants for meeting power system requirements

International Nuclear Information System (INIS)

Isoda, Hachiro

1987-01-01

This paper describes a calculating program on the availability factors of nuclear, thermal and pumed storage hydro power stations and some calculated results for typical three load factors, 55 %, 60 % and 71 %, are provided when the share of the nuclea power station in the generation facilities is increased. The load following requirement of the nuclear power station is also provided. Load following requirement: If there is a 10 % pumped storage hydro power station, the nuclear power station enables to be operated with its rated output up to 30 % - 35 % of its share. Its daily load following operation for 40 % and 50 % nuclear power station needs every weekend and every day respectively. Availability factor: The availability factor of the nuclear power station manages to get 80 % (maximum availability factor of the nuclear power station in this study) up to 30 % share of it with 10 % pumpued storage hydro power station. When the nuclear power station shares 40 % and 50 %, its availability factor decreases down 1 % and 5 % respectively. (author)

Qualification of nuclear power plant operations personnel

International Nuclear Information System (INIS)

1984-01-01

With the ultimate aim of reducing the possibility of human error in nuclear power plant operations, the Guidebook discusses the organizational aspects, the staffing requirements, the educational systems and qualifications, the competence requirements, the ways to establish, preserve and verify competence, the specific aspects of personnel management and training for nuclear power plant operations, and finally the particular situations and difficulties to be overcome by utilities starting their first nuclear power plant. An important aspect presented in the Guidebook is the experience in training and qualification of nuclear power plant personnel in various countries: Argentina, Belgium, Canada, Czechoslovakia, France, Federal Republic of Germany, Spain, Sweden, United Kingdom and United States of America

Heat kernel estimates for pseudodifferential operators, fractional Laplacians and Dirichlet-to-Neumann operators

DEFF Research Database (Denmark)

Gimperlein, Heiko; Grubb, Gerd

2014-01-01

The purpose of this article is to establish upper and lower estimates for the integral kernel of the semigroup exp(−t P) associated to a classical, strongly elliptic pseudodifferential operator P of positive order on a closed manifold. The Poissonian bounds generalize those obtained for perturbat......The purpose of this article is to establish upper and lower estimates for the integral kernel of the semigroup exp(−t P) associated to a classical, strongly elliptic pseudodifferential operator P of positive order on a closed manifold. The Poissonian bounds generalize those obtained...... for perturbations of fractional powers of the Laplacian. In the selfadjoint case, extensions to t∈C+  are studied. In particular, our results apply to the Dirichlet-to-Neumann semigroup....

Power-law versus log-law in wall-bounded turbulence: A large-eddy simulation perspective

Science.gov (United States)

Cheng, W.; Samtaney, R.

2014-01-01

The debate whether the mean streamwise velocity in wall-bounded turbulent flows obeys a log-law or a power-law scaling originated over two decades ago, and continues to ferment in recent years. As experiments and direct numerical simulation can not provide sufficient clues, in this study we present an insight into this debate from a large-eddy simulation (LES) viewpoint. The LES organically combines state-of-the-art models (the stretched-vortex model and inflow rescaling method) with a virtual-wall model derived under different scaling law assumptions (the log-law or the power-law by George and Castillo ["Zero-pressure-gradient turbulent boundary layer," Appl. Mech. Rev. 50, 689 (1997)]). Comparison of LES results for Reθ ranging from 105 to 1011 for zero-pressure-gradient turbulent boundary layer flows are carried out for the mean streamwise velocity, its gradient and its scaled gradient. Our results provide strong evidence that for both sets of modeling assumption (log law or power law), the turbulence gravitates naturally towards the log-law scaling at extremely large Reynolds numbers.

Power-law versus log-law in wall-bounded turbulence: A large-eddy simulation perspective

KAUST Repository

Cheng, W.

2014-01-29

The debate whether the mean streamwise velocity in wall-bounded turbulent flows obeys a log-law or a power-law scaling originated over two decades ago, and continues to ferment in recent years. As experiments and direct numerical simulation can not provide sufficient clues, in this study we present an insight into this debate from a large-eddy simulation (LES) viewpoint. The LES organically combines state-of-the-art models (the stretched-vortex model and inflow rescaling method) with a virtual-wall model derived under different scaling law assumptions (the log-law or the power-law by George and Castillo [“Zero-pressure-gradient turbulent boundary layer,” Appl. Mech. Rev.50, 689 (1997)]). Comparison of LES results for Re θ ranging from 105 to 1011 for zero-pressure-gradient turbulent boundary layer flows are carried out for the mean streamwise velocity, its gradient and its scaled gradient. Our results provide strong evidence that for both sets of modeling assumption (log law or power law), the turbulence gravitates naturally towards the log-law scaling at extremely large Reynolds numbers.

Operational safety of nuclear power plants

International Nuclear Information System (INIS)

Tanguy, P.

1987-01-01

The operational safety of nuclear power plants has become an important safety issue since the Chernobyl accident. A description is given of the various aspects of operational safety, including the importance of human factors, responsibility, the role and training of the operator, the operator-machine interface, commissioning and operating procedures, experience feedback, and maintenance. The lessons to be learnt from Chernobyl are considered with respect to operator errors and the management of severe accidents. Training of personnel, operating experience feedback, actions to be taken in case of severe accidents, and international cooperation in the field of operational safety, are also discussed. (U.K.)

Decontamination of operational nuclear power plants

International Nuclear Information System (INIS)

1981-06-01

In order to reduce the radiation fields around nuclear power plants, and, consequently, to limit the radiation exposure of and dose commitments to the operating and maintenance personnel, the contamination build-up should be kept to a minimum. The most fruitful approach, from the point of view of economics and efficiency, is to tackle the problems of contamination and decontamination in the design and construction phases of the reactor. To do this, knowledge gained from the operation of existing power reactors should be used to make improvements in new designs. New structural materials with low corrosion rates or whose constituents are not activated by neutrons should also be used. For older reactors, in most cases it is already too late to incorporate design changes without extensive and expensive modifications. For these plants, decontamination remains the most efficient way to reduce radiation fields. The aim of this report is to deal with the different decontamination methods that may be applied to nuclear power plant circuits and equipment during operation. The factors that have to be considered in determining the type and the extent of the methods used are the engineering and the planning of the decontamination operation and the treatment of the resulting waste generated during the process are also discussed

Training and qualification of nuclear power plant operators

International Nuclear Information System (INIS)

Ohsuga, Y.

2008-01-01

Based on training experiences of the nuclear power plant operators of pressurized water reactors (PWR) at the Nuclear Power Training Center Ltd. (NTC) in Japan, training programs were reviewed referring to US training programs. A systematic approach is deployed to them, which mainly consist of on-the-job training and the NTC training courses to meet the needs of all operators from beginners to experienced veterans according to their experiences and objectives. The NTC training is conducted using the simulators that simulate the nuclear power plant dynamics through the use of computers. The operators trained at the NTC work in the central control room of every PWR power plant. The NTC also carries out the qualification examinations for the shift managers. (T. Tanaka)

Coherence-limited solar power conversion: the fundamental thermodynamic bounds and the consequences for solar rectennas

Science.gov (United States)

Mashaal, Heylal; Gordon, Jeffrey M.

2014-10-01

Solar rectifying antennas constitute a distinct solar power conversion paradigm where sunlight's spatial coherence is a basic constraining factor. In this presentation, we derive the fundamental thermodynamic limit for coherence-limited blackbody (principally solar) power conversion. Our results represent a natural extension of the eponymous Landsberg limit, originally derived for converters that are not constrained by the radiation's coherence, and are irradiated at maximum concentration (i.e., with a view factor of unity to the solar disk). We proceed by first expanding Landsberg's results to arbitrary solar view factor (i.e., arbitrary concentration and/or angular confinement), and then demonstrate how the results are modified when the converter can only process coherent radiation. The results are independent of the specific power conversion mechanism, and hence are valid for diffraction-limited as well as quantum converters (and not just classical heat engines or in the geometric optics regime). The derived upper bounds bode favorably for the potential of rectifying antennas as potentially high-efficiency solar converters.

Quality assurance during operation of nuclear power plants

International Nuclear Information System (INIS)

1981-01-01

This Safety Guide provides requirements and recommendations for the establishment and implementation of quality assurance for activities important to safety during commissioning, operation and decommissioning of a nuclear power plant, hereinafter referred to in this Guide as the operation phase or operation. It applies to activities such as: operating, inspecting, testing, commissioning, refuelling, maintaining, repairing, modifying and eventual shut-down and decommissioning of nuclear power plants. It applies also to associated activities related to safety, such as environmental monitoring and responses to emergencies

Operation reports of nuclear power plants

International Nuclear Information System (INIS)

1983-01-01

The requirements aiming to standardize the program of nuclear power plant operation report, required by Brazilian Energy Commission - CNEN - to evaluate the activities related to the nuclear technical safety and to the radiation protection during the units operational phase, are showed. (E.G.) [pt

Annual report on nuclear power station operational management, 1984

International Nuclear Information System (INIS)

1985-09-01

As of the end of fiscal year 1984, 28 nuclear power plants were in operation in Japan, the total power output of which was 20.56 million kW, equivalent to 22.9 % of the total generated electric power in Japan. Now nuclear power generation bears a very important role in the stable supply and cost stabilization of electric power. The result of the capacity factor in fiscal year 1984 was 73.9 %, which showed that the nuclear power generation and safety management technologies in Japan are at the top level in the world. However, in order that nuclear power generation accomplishes the role as main power source sufficiently hereafter by increasing the number of plants, the reliability and economical efficiency must be further improved, and especially the safety management and operational management become important. For the purpose, the operational experience accumulated so far must be effectively utilized. In this book, the outline of the administration on the safety regulation of nuclear power generation, the state of operation of nuclear power plants, the state of accidents and failures, the state of regular inspections and so on are summarized. Also the state of radioactive waste management and the radiation control for workers are reported. (Kako, I.)

Operating experience at Scottish Nuclear's power stations

International Nuclear Information System (INIS)

Blackburn, P.

1991-01-01

A brief history is presented of the design and operation of the four Scottish nuclear power stations currently run by Scottish Nuclear, namely Hunterston 'A' and 'B' and the Torness reactors. A design flaw in the Magnox reactor at Hunterston 'A' led to it being operated at lower than optimal temperature and hence producing less power. For Hunterston 'B' reactor the Advanced Gas Cooled design prototype was used. Operating setbacks and successes are noted. The design chosen for Torness embraced all the good points of Hunterston 'B' but sought to eliminate its faults. After 26 years of successful operation Hunterston 'A' is now being decommissioned, while the other three stations continue to generate electricity successfully. (UK)

Operational results in the Onagawa Nuclear Power Station

International Nuclear Information System (INIS)

Hasegawa, Kanichi; Kato, Katsuya; Terada, Hideo; Kamata, Takakage; Kaimura, Yoshiharu

1986-01-01

In the Onagawa Nuclear Power Station, Unit 1 (BWR type, with electric output 524 MW) started operation in June 1, 1984. The power plant has then continued non-stop operation up to April 2, 1985, thus exhibiting its base load plant. In fiscal 1984, the continuous operation is for 342 days; the capacity factor is about 96.1 %, which is the world's top. During the period, the radioactivity releases to the environment in both liquid and gaseous wastes are below the detection limits. The collective exposure dose for plant personnel is merely 6 man-rem. Subsequently, its 1st periodical inspection was started on April 3, 1985, and finished in July the same year. So, the power plant is now again in operation. (Mori, K.)

Statistical operation of nuclear power plants

International Nuclear Information System (INIS)

Gauzit, Maurice; Wilmart, Yves

1976-01-01

A comparison of the statistical operating results of nuclear power stations as issued in the literature shows that the values given for availability and the load factor often differ considerably from each other. This may be due to different definitions given to these terms or even to a poor translation from one language into another. A critical analysis of these terms as well as the choice of a parameter from which it is possible to have a quantitative idea of the actual quality of the operation obtained is proposed. The second section gives, on an homogenous basis and from the results supplied by 83 nuclear power stations now in operation, a statistical analysis of their operating results: in particular, the two light water lines, during 1975, as well as the evolution in terms of age, of the units or the starting conditions of the units during their first two operating years. Test values thus obtained are compared also to those taken 'a priori' as hypothesis in some economic studies [fr

Operator psychological selection system for nuclear power plant

International Nuclear Information System (INIS)

He Xuhong; Huang Xiangrui

2004-01-01

Based on a detailed job analysis of nuclear power plant operator including operation procedures analysis, interview with personnel familiar with operator job, and 9 events happened in the past in the plant involved operator error analysis, several operator work characteristics and performance influence factors are obtained. According to these specific characteristics and factors, referring to the psychological selection research results in the other related critical occupational fields, a full psychological selection system of nuclear power plant operator is forwarded in this paper, including 21 dimensions in 3 facets as general psychological ability, personality and psychological healthy. Practical measurement methods for the proposed selection dimensions are discussed in the end

Nuclear electric power safety, operation, and control aspects

CERN Document Server

Knowles, J Brian

2013-01-01

Assesses the engineering of renewable sources for commercial power generation and discusses the safety, operation, and control aspects of nuclear electric power From an expert who advised the European Commission and UK government in the aftermath of Three Mile Island and Chernobyl comes a book that contains experienced engineering assessments of the options for replacing the existing, aged, fossil-fired power stations with renewable, gas-fired, or nuclear plants. From geothermal, solar, and wind to tidal and hydro generation, Nuclear Electric Power: Safety, Operation, and Control Aspects ass

Operating experience of Fugen Nuclear Power Station

International Nuclear Information System (INIS)

Ohteru, Shigeru; Kaneko, Jun; Kawahara, Toshio; Matsumoto, Mitsuo

1987-01-01

The prototype ATR 'Fugen' developed as one of the national project has verified the performance and reliability of the advanced thermal reactor system through the operation for about eight years since 1979, and the elucidation of the characteristics in plutonium utilization and the development and verification of the tuilizing techniques have been advanced. Besides, the operational results and the achievement of the technical development are successively reflected to the design of a demonstration reactor. In this paper, the outline of Fugan and the operational results are reported. The ATR Fugen Power Station is that of the prototype reactor of heavy water moderated, boiling light water cooled, pressure tube type, having the electric output of 165 MW. It started the full scale operation on March 20, 1979, and as of January, 1987, the total generated electric power reached about 7 billion kWh, the time of power generation was about 43,000 h, and the average capacity factor was 60.6 %. Plutonium utilization techniques, the flow characteristics and the dynamic plant characteristics of a pressure tube type reactor, the operational characteristics of a heavy water system and the techniques of handling heavy water containing tritium, and the operational reliability and maintainability of the machinery and equipment installed have been studied. (Kako, I.)

Operating Experience at the Aagesta Nuclear Power Station

Energy Technology Data Exchange (ETDEWEB)

Sandstroem, S [ed.

1966-09-15

Sweden's first nuclear power reactor Agesta, achieved criticality on July 17, 1963. Full power (65 MW{sub t}) was attained on March 20, 1964. Aagesta is a heavy water cooled and moderated pressure vessel reactor used for production of electricity as well as for district heating. The design, assembly and construction etc, of the reactor was described in detail in a staff report by AB Atomenergi, 'The Aagesta Nuclear Power Station' edited by B McHugh, which was published in September, 1964. In the book experiences from the commissioning and the first operation of the reactor were reported as well as findings from the extensive reactor physics studies made during this period. The report now presented is written by members of the operating team at Aagesta since its start. It reflects in general the experiences up to the end of 1965. The Aagesta Log, however, covers the period up to the normal summer stop 1966. The reactor has hitherto produced 506,000 MWh power of which 48,700 MWh have been electric power. In July 1965 the responsibility for the reactor operation was taken over by the Swedish State Power Board from AB Atomenergi, which company had started the reactor and operated it until the summer break 1965.

Operating Experience at the Aagesta Nuclear Power Station

International Nuclear Information System (INIS)

Sandstroem, S.

1966-09-01

Sweden's first nuclear power reactor Agesta, achieved criticality on July 17, 1963. Full power (65 MW t ) was attained on March 20, 1964. Aagesta is a heavy water cooled and moderated pressure vessel reactor used for production of electricity as well as for district heating. The design, assembly and construction etc, of the reactor was described in detail in a staff report by AB Atomenergi, 'The Aagesta Nuclear Power Station' edited by B McHugh, which was published in September, 1964. In the book experiences from the commissioning and the first operation of the reactor were reported as well as findings from the extensive reactor physics studies made during this period. The report now presented is written by members of the operating team at Aagesta since its start. It reflects in general the experiences up to the end of 1965. The Aagesta Log, however, covers the period up to the normal summer stop 1966. The reactor has hitherto produced 506,000 MWh power of which 48,700 MWh have been electric power. In July 1965 the responsibility for the reactor operation was taken over by the Swedish State Power Board from AB Atomenergi, which company had started the reactor and operated it until the summer break 1965

Operating Experience at the Aagesta Nuclear Power Station

Energy Technology Data Exchange (ETDEWEB)

Sandstroem, S. (ed.)

1966-09-15

Sweden's first nuclear power reactor Agesta, achieved criticality on July 17, 1963. Full power (65 MW{sub t}) was attained on March 20, 1964. Aagesta is a heavy water cooled and moderated pressure vessel reactor used for production of electricity as well as for district heating. The design, assembly and construction etc, of the reactor was described in detail in a staff report by AB Atomenergi, 'The Aagesta Nuclear Power Station' edited by B McHugh, which was published in September, 1964. In the book experiences from the commissioning and the first operation of the reactor were reported as well as findings from the extensive reactor physics studies made during this period. The report now presented is written by members of the operating team at Aagesta since its start. It reflects in general the experiences up to the end of 1965. The Aagesta Log, however, covers the period up to the normal summer stop 1966. The reactor has hitherto produced 506,000 MWh power of which 48,700 MWh have been electric power. In July 1965 the responsibility for the reactor operation was taken over by the Swedish State Power Board from AB Atomenergi, which company had started the reactor and operated it until the summer break 1965.

The number of bound states for a discrete Schroedinger operator on ZN, N≥1, lattices

International Nuclear Information System (INIS)

Karachalios, N I

2008-01-01

We consider the discrete Schroedinger operator -Δ d +U in Z N , N≥1 in the case of a potential with negative part in an appropriate l σ -space (decays with an appropriate rate). We present a discrete analog of the method of Li and Yau (1983 Commun. Math. Phys. 88 309-18), proving an explicit upper estimate on the number of bound states N d (0)={j:μ j ≤0}, which is independent of the dimension of the lattice. This is a major difference with the continuous counterpart estimate, which is not valid when N = 1, 2. As a consequence, a dimension-independent smallness criterion for the existence of bound states is derived in contrast to the continuous case as well as to the discrete case of vanishing potential. A short comment is made on possible applications of the results to the study of the dynamics of some particular spatially discrete nonlinear systems

Explicit Bounds and Sharp Results for the Composition Operators Preserving the Exponential Class

Directory of Open Access Journals (Sweden)

Fernando Farroni

2016-01-01

Full Text Available Let f:Ω⊂Rn→Rn be a quasiconformal mapping whose Jacobian is denoted by Jf and let EXP(Ω be the space of exponentially integrable functions on Ω. We give an explicit bound for the norm of the composition operator Tf: u∈EXP(Ω↦u∘f-1∈EXP(f(Ω and, as a related question, we study the behaviour of the norm of log⁡Jf in the exponential class. The A∞ property of Jf is the counterpart in higher dimensions of the area distortion formula due to Astala in the plane and it is the key tool to prove the sharpness of our results.

Systemwide Power Management with Argo

Energy Technology Data Exchange (ETDEWEB)

Ellsworth, Daniel; Patki, Tapasya; Perarnau, Swann; Seo, Sangmin; Yoshii, Kazutomo; Hoffmann, Henry; Schulz, Martin; Beckman, Pete

2016-05-23

The Argo project is a DOE initiative for designing a modular operating system/runtime for the next generation of supercomputers. A key focus area in this project is power management, which is one of the main challenges on the path to exascale. In this paper, we discuss ideas for systemwide power management in the Argo project. We present a hierarchical and scalable approach to maintain a power bound at scale, and we highlight some early results.

Tianwan nuclear power plant operation and management practices

International Nuclear Information System (INIS)

Gu Yingbing

2010-01-01

Tianwan Nuclear Power Station is a high-tech cooperation project in nuclear sector in the spirit of promoting the political relationship, economic trading and international strategic partnership between China and Russia. It was listed as one of the key nuclear projects to be constructed during the 'Ninth Five-Year' Plan. In this article the author summarizes and feedbacks the practices of operation management in Tianwan Nuclear Power Station in 7 aspects of safety culture construction, operation team building, daily operation management, operation document management, plant chemistry control and management, solid, liquid and gaseous waste management and control of operation performance indicators. (author)

47 CFR 73.664 - Determining operating power.

Science.gov (United States)

2010-10-01

... BROADCAST SERVICES Television Broadcast Stations § 73.664 Determining operating power. (a) The operating... substantially zero reactance and a resistance equal to the transmission line characteristic impedance. During...

Atomic power plant and its operation method

International Nuclear Information System (INIS)

Yamamoto, Fumiaki; Higashio, Satoru.

1986-01-01

Purpose: To improve operation performance by partially restraining local over power in the axial power distribution of the reactor core by properly controlling the reactor pressure and furthermore by smoothly and properly performing reactor start-up operation in a short time while maintaining fuel integrity. Method: With the reactor pressure input to the pressure controller from the pressure detector, the valve opening of the main steam adjusting valve is adjusted so that the pressure will decrease when the reactor is started up. Also the adjusting valve is controlled so that the pressure will be lower than the set value of rated pressure, thus changing the axial distribution of void. In the meantime, with the stored state of xenon stored along with the increase of reactor power taken into consideration, the reactor pressure is increased as high as the rated value until the reactor power reaches to the rated power, thereby alleviating the local increase of reactor power without changing the whole reactor power and also enabling substantial reduction of reactor start-up time while maintaining reactor integrity. (Horiuchi, T.)

Scattering theory methods for bound state problems

International Nuclear Information System (INIS)

Raphael, R.B.; Tobocman, W.

1978-01-01

For the analysis of the properties of a bound state system one may use in place of the Schroedinger equation the Lippmann-Schwinger (LS) equation for the wave function or the LS equation for the reactance operator. Use of the LS equation for the reactance operator constrains the solution to have correct asymptotic behaviour, so this approach would appear to be desirable when the bound state wave function is to be used to calculate particle transfer form factors. The Schroedinger equation based N-level analysis of the s-wave bound states of a square well is compared to the ones based on the LS equation. It is found that the LS equation methods work better than the Schroedinger equation method. The method that uses the LS equation for the wave function gives the best results for the wave functions while the method that uses the LS equation for the reactance operator gives the best results for the binding energies. The accuracy of the reactance operator based method is remarkably insensitive to changes in the oscillator constant used for the harmonic oscillator function basis set. It is also remarkably insensitive to the number of nodes in the bound state wave function. (Auth.)

Nuclear power plant operational data compilation system

International Nuclear Information System (INIS)

Silberberg, S.

1980-01-01

Electricite de France R and D Division has set up a nuclear power plant operational data compilation system. This data bank, created through American documents allows results about plant operation and operational material behaviour to be given. At present, French units at commercial operation are taken into account. Results obtained after five years of data bank operation are given. (author)

Increase of hydroelectric power plant operation reliability

International Nuclear Information System (INIS)

Koshumbaev, M.B.

2006-01-01

The new design of the turbine of hydroelectric power plant (HPP) is executed in the form of a pipe with plates. Proposed solution allows increasing the hydroelectric power plant capacity at existing head and water flow. At that time the HPP turbine reliability is increase, its operation performances are improving. Design efficiency is effective mostly for small-scale and micro-HPP due to reliable operation, low-end technology, and harmless ecological application. (author)

Design and development of high voltage high power operational ...

Indian Academy of Sciences (India)

Applications of power operational amplifiers (opamps) are increasing day by day in the industry as they are used in audio amplifiers, Piezo transducer systems and the electron deflection systems. Power operational amplifiers have all the features of a general purpose opamp except the additional power handling capability.

Optimum operation of a small power production facility

Energy Technology Data Exchange (ETDEWEB)

Capehart, B.L.; Mahoney, J.F.; Sivazlian, B.D.

1983-09-01

To help reduce the U.S.A.'s dependence on imported oil for electrical power generation, the 1978 National Energy Act established regulations to promote construction and operation of cogeneration and small power production facilities. Many of these facilities are presently under construction, with a great number planned. This paper examines the operation of a small power production facility with on-site generation and storage, on-site use, and connection to an electric utility grid system for the purpose of both selling excess power and buying power. It is assumed that the buying and selling price of electricity varies frequently during the day and that the relevant price and demand data may be accurately projected into the near future. With this system description, a mathematical model is formulated and solved by linear programming to obtain a series of periodic buy and sell decisions so as to maximize the profit from operating the small power production facility. Results are presented to illustrate the methodology for determining potential profits.

Bounds on Minimum Energy per Bit for Optical Wireless Relay Channels

Directory of Open Access Journals (Sweden)

A. D. Raza

2014-09-01

Full Text Available An optical wireless relay channel (OWRC is the classical three node network consisting of source, re- lay and destination nodes with optical wireless connectivity. The channel law is assumed Gaussian. This paper studies the bounds on minimum energy per bit required for reliable communication over an OWRC. It is shown that capacity of an OWRC is concave and energy per bit is monotonically increasing in square of the peak optical signal power, and consequently the minimum energy per bit is inversely pro- portional to the square root of asymptotic capacity at low signal to noise ratio. This has been used to develop upper and lower bound on energy per bit as a function of peak signal power, mean to peak power ratio, and variance of channel noise. The upper and lower bounds on minimum energy per bit derived in this paper correspond respectively to the decode and forward lower bound and the min-max cut upper bound on OWRC capacity

Power operation, measurement and methods of calculation of power distribution

International Nuclear Information System (INIS)

Lindahl, S.O.; Bernander, O.; Olsson, S.

1982-01-01

During the initial fuel loading of a BWR core, extensive checks and measurements of the fuel are performed. The measurements are designed to verify that the reactor can always be safely operated in compliance with the regulatory constraints. The power distribution within the reactor core is evaluated by means of instrumentation and elaborate computer calculations. The power distribution forms the basis for the evaluation of thermal limits. The behaviour of the reactor during the ordinary modes of operation as well as during transients shall be well understood and such that the integrity of the fuel and the reactor systems is always well preserved. (author)

Centralized operation and monitoring system for nuclear power plants

International Nuclear Information System (INIS)

Kudo, Mitsuru; Sato, Hideyuki; Murata, Fumio

1988-01-01

According to the prospect of long term energy demand, in 2000, the nuclear power generation facilities in Japan are expected to take 15.9% of the total energy demand. From this fact, it is an important subject to supply nuclear power more stably, and in the field of instrumentation and control, many researches and developments and the incessant effort of improvement have been continued. In the central operation and monitoring system which is the center of the stable operation of nuclear power plants, the man-machine technology aiding operators by electronic and computer application technologies has been positively developed and applied. It is considered that hereafter, for the purpose of rationally heightening the operation reliability of the plants, the high quality man-machine system freely using the most advanced technologies such as high reliability digital technology, optical information transmission, knowledge engineering and so on is developed and applied. The technical trend of operation and monitoring system, the concept of heightening operation and monitoring capability, the upgrading of operation and monitoring system, and the latest operation, monitoring and control systems for nuclear power plants and waste treatment facilities are described. (K.I.)

Simplified reactive power management strategy for complex power grids under stochastic operation and incomplete information

DEFF Research Database (Denmark)

Vlachogiannis, Ioannis (John)

2009-01-01

grids is a major issue for system operators. Under these circumstances an online reactive power management strategy with minimum risk concerning all uncertain and stochastic parameters is proposed. Therefore, new concepts such as reactive power-weighted node-to-node linking and reactive power control......In the current released energy market, the large-scale complex transmission networks and the distribution ones with dispersed energy sources and "intelligent" components operate under uncertainties, stochastic and prior incomplete information. A safe and reliable operation of such complex power...... capability are introduced. A distributed and interconnected stochastic learning automata system is implemented to manage, in a unified and unique way, the reactive power in complex power grids with stochastic reactive power demand and detect the vulnerable part. The proposed simplified strategy can also...

Multiparticle entanglement manipulation under positive partial transpose preserving operations

International Nuclear Information System (INIS)

Ishizaka, Satoshi; Plenio, Martin B.

2005-01-01

We consider the transformation of multipartite states in the single-copy setting under positive-partial-transpose-preserving operations (PPT operations) and obtain both qualitative and quantitative results. First, for some pure-state transformations that are impossible under local operations and classical communication (LOCC), we demonstrate that they become possible with a surprisingly large success probability under PPT operations. Furthermore, we clarify the convertibility of arbitrary multipartite pure states under PPT operations and show that a drastic simplification in the classification of pure-state entanglement occurs when the set of operations is switched from LOCC to PPT operations. Indeed, the infinitely many types of LOCC-incomparable entanglement are reduced to only one type under the action of PPT operations. This is a clear manifestation of the increased power afforded by the use of PPT-bound entanglement. In addition, we further enlarge the set of operations to clarify the effect of another type of bound entanglement, multipartite unlockable bound entanglement, and show that a further simplification occurs. As compared to pure states a more complicated situation emerges in mixed-state settings. While single-copy distillation becomes possible under PPT operations for some mixed states it remains impossible for other mixed states

Measurement uncertainty recapture (MUR) power uprates operation at Kuosheng Nuclear Power Station

International Nuclear Information System (INIS)

Chang Chinjang; Wang Tunglu; Lin Chihpao

2009-01-01

Measurement Uncertainty Recapture PowerUprates (MUR PU) are achieved through the use of state-of-the-art feedwater flow measurement devices, i.e., ultrasonic flow meters (UFMs), that reduce the degree of uncertainty associated with feedwater flow measurement and in turn provide for a more accurate calculation of thermal power. The Institute of Nuclear Energy Research (INER) teamed with Sargent and Lundy, LLC (S and L), Pacific Engineers and Constructors, Ltd (PECL), and AREVA to develop a program and plan for the Kuosheng Nuclear Power Station (KNPS) MUR PU Engineering Service Project and for the assistance to Kuosheng MUR PU operation. After regulator's approval of the licensing requests, KSNPS conducted the power ascension test and switchover to the new rated thermal power for Unit 2 and Unit 1 on 7/7/2007 and 11/30/2007, respectively. From then on, KNPS became the first nuclear power plant implementing MUR PU operation in Taiwan and in Asia. (author)

Evaluation of nuclear power plant operator's ability

International Nuclear Information System (INIS)

Wei Li; He Xuhong; Zhao Bingquan

2004-01-01

Based on the quantitative research on nuclear power plant (NPP) operator's psychological characteristics and performance, the Borda's method of fuzzy mathematics combined with the character of operator's task is used to evaluate their abilities. The result provides the reference for operator's reliability research and psychological evaluation. (author)

Spectrum of the multigroup neutron transport operator for bounded spatial domains

International Nuclear Information System (INIS)

Larsen, E.W.

1979-01-01

The spectrum of the multigroup neutron transport operator A is studied for bounded spatial regions D which consist of a finite number of material subregions. Our main results provide simple conditions on the material cross sections which guarantee that (1) A possesses eigenvalues in the finite plane; (2) A possesses a ''leading'' eigenvalue lambda 0 which is real, not less than the real part of any other eigenvalue, and to which there corresponds at least one nonnegative eigenfunction psi/sub lambda/0; and (3) A possesses a ''dominant'' eigenvalue lambda 0 which is real, simple, greater than the real part of any other eigenvalue, and whose eigenfunction psi/sub lambda/0 satisfies psi/sub lambda/0> or =0 and ∫psi/sub lambda/0d 2 Ω>0. We give examples to illustrate the results and to show that a leading eigenvalue need not be simple, nor its eigenfunction(s) positive

Thermalization Time Bounds for Pauli Stabilizer Hamiltonians

Science.gov (United States)

Temme, Kristan

2017-03-01

We prove a general lower bound to the spectral gap of the Davies generator for Hamiltonians that can be written as the sum of commuting Pauli operators. These Hamiltonians, defined on the Hilbert space of N-qubits, serve as one of the most frequently considered candidates for a self-correcting quantum memory. A spectral gap bound on the Davies generator establishes an upper limit on the life time of such a quantum memory and can be used to estimate the time until the system relaxes to thermal equilibrium when brought into contact with a thermal heat bath. The bound can be shown to behave as {λ ≥ O(N^{-1} exp(-2β overline{ɛ}))}, where {overline{ɛ}} is a generalization of the well known energy barrier for logical operators. Particularly in the low temperature regime we expect this bound to provide the correct asymptotic scaling of the gap with the system size up to a factor of N -1. Furthermore, we discuss conditions and provide scenarios where this factor can be removed and a constant lower bound can be proven.

Island operation - modelling of a small hydro power system

Energy Technology Data Exchange (ETDEWEB)

Skarp, Stefan

2000-02-01

Simulation is a useful tool for investigating a system behaviour. It is a way to examine operating situations without having to perform them in reality. If someone for example wants to test an operating situation where the system possibly will demolish, a computer simulation could be a both cheaper and safer way than to do the test in reality. This master thesis performs and analyses a simulation, modelling an electronic power system. The system consists of a minor hydro power station, a wood refining industry, and interconnecting power system components. In the simulation situation the system works in a so called island operation. The thesis aims at making a capacity analysis of the current system. Above all, the goal is to find restrictions in load power profile of the consumer, under given circumstances. The computer software used in simulations is Matlab and its additional program PSB (Power System Blockset). The work has been carried out in co-operation with the power supplier Skellefteaa Kraft, where the problem formulation of this master thesis was founded.

Operational costs induced by fluctuating wind power production in Germany and Scandinavia

Energy Technology Data Exchange (ETDEWEB)

Meibom, P. [Risoe National Lab., DTU, System Analysis Dept., Roskilde (Denmark); Weber, C. [Univ. Duisburg-Essen, Chai og Energy Management (Germany); Barth, R.; Brand, H. [Univ. of Stuttgart, Inst. of Energy Economics and the Rational Use of Energy (Germany)

2007-05-15

Adding wind power generation in a power system changes the operational patterns of the existing units due to the variability and unpredictability of wind power production. For large amounts of wind power production the expectation is that the operational costs of the other power plants will increase due to more operation time in part-load and more start-ups. The change in operational costs induced by the wind power production can only be calculated by comparing the operational costs in two power system configurations: with wind power production and with alternative production having properties like conventional production, i.e. being predictable and less variable. The choice of the characteristics of the alternative production is not straight forward and will therefore influence the operational costs induced by wind power production. This paper presents a method for calculating the change in operational costs due to wind power production using a stochastic optimization model covering the power systems in Germany and the Nordic countries. Two cases of alternative production are used to calculate the change in operational costs namely perfectly predictable wind power production enabling calculation of the costs connected to unpredictability, and constant wind power production enabling calculation of the operational costs connected to variability of wind power production. A 2010 case with three different wind power production penetration levels is analysed in the paper. (au)

Energy Storage in Power System Operation: The Power Nodes Modeling Framework

DEFF Research Database (Denmark)

Heussen, Kai; Koch, Stephan; Ulbig, Andreas

2010-01-01

for designing operation strategies for power systems based on ubiquitous energy storage, for example to buer non-dispatchable generation, as well as for the evaluation of the operational performance in terms of energy eciency, reliability and cost. After introducing the modeling approach and a categorization......In this paper, a novel concept for the description of energy storage in power systems with dispatchable and non-dispatchable generators and loads is presented. It is based on a system-perspective consideration of energy storage, generation and consumption. This means that grid-relevant aspects...

Decomposing Objectives and Functions in Power System Operation and Control

DEFF Research Database (Denmark)

Heussen, Kai; Lind, Morten

2009-01-01

mix of challenges posed by renewable energy sources, demand response technologies and smartgrid concepts, affecting all areas of power system operation. Both, new control modes and changes in market design are required. This paper presents a mean-ends perspective to the analysis of the control......The introduction of many new energy solutions requires the adaptation of classical operation paradigms in power systems. In the standard paradigm, a power system is some equivalent of a synchronous generators, a power line and an uncontrollable load. This paradigm has been challenged by a diverse...... structures and operation paradigms in present power systems. In a top-down approach, traditional frequency- and area-control mechanisms are formalized. It is demonstrated that future power system operation paradigms with different generation control modes and controllable demand can be modeled in a coherent...

Quality assurance during operation of nuclear power plants

International Nuclear Information System (INIS)

1994-01-01

The general requirements applicable to the quality assurance of the Finnish nuclear power plants are presented in the Council of State Decision (395/91) and in the guide YVL 1.4. This guide specifies the quality assurance requirements to be applied during the operation of the nuclear power plants as well as of the other nuclear facilities. Quality assurance applies to all the activities and organizations with a bearing on the safe operation of the nuclear power plants. (5 refs.)

Interband type-II miniband-to-bound state diode lasers for the midinfrared

International Nuclear Information System (INIS)

Mermelstein, C.; Schmitz, J.; Kiefer, R.; Walther, M.; Wagner, J.

2004-01-01

A design for midinfrared diode lasers based on interband type-II miniband-to-bound state transitions is proposed and has been demonstrated experimentally. Type-II miniband-to-bound state laser structures emitting at 3.25 μm with active regions consisting of 5 and 10 W periods were grown by solid-source molecular-beam epitaxy and processed into ridge waveguide lasers. Substrate-side down mounted devices with a 10 period active region and uncoated facets could be operated in continuous-wave (cw) mode up to 185 K and as high as 260 K in pulsed mode. A high characteristic temperature of 100 K has been achieved for heat-sink temperatures below 140 K, decreasing to 33 K for the 140 to 185 K interval. At 110 K, a 5 period laser structure exhibited a threshold current density of 177 A/cm 2 and a slope efficiency of 61 mW/A. Single-ended output powers of 144 mW in cw mode and exceeding 330 mW in pulsed operation were obtained for a substrate-side down mounted 5 period diode laser with high-reflection/antireflection coated mirror facets, operated at 110 K

Economic evaluation of nuclear reactor operation utilizing power effect

International Nuclear Information System (INIS)

Budinsky, M.; Mydliar, J.

1988-01-01

The operation of a reactor at the so-called power effect may substantially increase the burnup of fuel to be removed. The aim of the evaluation of such reactor operation is the optimal determination of the time over which the yield of the higher use of fuel exceeds economic losses resulting from the increased share of constant expenditure of the price of generated kWh of electric power which ensues from such operation. A mathematical model is presented for such evaluation of reactor operation with regard to benefits for the national economy which is the basis of the ESTER 2 computer program. The calculations show that the prices of generated and delivered kWh are minimally 2% less than the prices of generated power without the power effect use. The minimum ranges in the interval of 30 to 50 days. The dependence of the price of generated and delivered kWh from the point of view of the operator of the power plant as well as the component of fuel price of generated kWh will not reach the minimum even after 50 days of operation. From the operating and physical points of view the duration of power effect is not expected to exceed 20 to 30 days which means that from the point of view of the national economy the price of generated and delivered kWh will be 1.6 to 2% less and the fuel component of the price of the generated kWh will be 3 to 4.5% lower. (Z.M.). 5 figs., 3 refs

Annual report on operational management of nuclear power stations, 1979-1980

International Nuclear Information System (INIS)

1981-04-01

This report was compiled by the Agency of Natural Resoures and Energy. The commercial nuclear power stations in Japan started the operation in 1966 for the first time, and as of the end of March, 1981, 22 plants with more than 15.5 million kW capacity were in operation. Nuclear power generation is regarded as the top-rated substitute energy for petroleum, and the target of its development in 1990 is about 52 million kW. The government and the people are exerting utmost efforts to attain the target. The result of the rate of operation of nuclear power stations reached 60.8% in 1980, but it is important to maintain the good, stable state of operation by perfecting the operational management hereafter in order to establish the position of LWRs. At present, the operational management officers of the government stay in nationwide power stations, and supervise the state of operations, thus the system of operational management was strengthened after the Three Mile Island accident in the U.S., and the improvement in the rate of operation is expected. A table shows the nuclear power stations in operation and under construction. The state of operations of individual nuclear power plants in 1979 and 1980, the accidents and failures occurred in nuclear power plants from 1966 to 1980, the minor troubles, the conditions in the regular inspections of individual nuclear power plants, radioactive waste management and the radiation exposure of workers are reported. (Kako, I.)

Designing for Wide-Area Situation Awareness in Future Power Grid Operations

Science.gov (United States)

Tran, Fiona F.

Power grid operation uncertainty and complexity continue to increase with the rise of electricity market deregulation, renewable generation, and interconnectedness between multiple jurisdictions. Human operators need appropriate wide-area visualizations to help them monitor system status to ensure reliable operation of the interconnected power grid. We observed transmission operations at a control centre, conducted critical incident interviews, and led focus group sessions with operators. The results informed a Work Domain Analysis of power grid operations, which in turn informed an Ecological Interface Design concept for wide-area monitoring. I validated design concepts through tabletop discussions and a usability evaluation with operators, earning a mean System Usability Scale score of 77 out of 90. The design concepts aim to support an operator's complete and accurate understanding of the power grid state, which operators increasingly require due to the critical nature of power grid infrastructure and growing sources of system uncertainty.

Operation of Finnish nuclear power plants

International Nuclear Information System (INIS)

Tossavainen, K.

1994-03-01

In the third quarter of 1993, all of Finland's four nuclear power plant units were in power operation, with the exception of the annual maintenance outages of the Loviisa units. The load factor average of the plant units was 83.6 %. None of the events which occurred during this annual quarter had any bearing on nuclear or radiation safety. (4 figs., 5 tabs.)

Semi-bounded partial differential operators

CERN Document Server

Cialdea, Alberto

2014-01-01

This book examines the conditions for the semi-boundedness of partial differential operators, which are interpreted in different ways. For example, today we know a great deal about L2-semibounded differential and pseudodifferential operators, although their complete characterization in analytic terms still poses difficulties, even for fairly simple operators. In contrast, until recently almost nothing was known about analytic characterizations of semi-boundedness for differential operators in other Hilbert function spaces and in Banach function spaces. This book works to address that gap. As such, various types of semi-boundedness are considered and a number of relevant conditions which are either necessary and sufficient or best possible in a certain sense are presented. The majority of the results reported on are the authors’ own contributions.

Liquid Nitrogen Temperature Operation of a Switching Power Converter

Science.gov (United States)

Ray, Biswajit; Gerber, Scott S.; Patterson, Richard L.; Myers, Ira T.

1995-01-01

The performance of a 42/28 V, 175 W, 50 kHz pulse-width modulated buck dc/dc switching power converter at liquid nitrogen temperature (LNT) is compared with room temperature operation. The power circuit as well as the control circuit of the converter, designed with commercially available components, were operated at LNT and resulted in a slight improvement in converter efficiency. The improvement in power MOSFET operation was offset by deteriorating performance of the output diode rectifier at LNT. Performance of the converter could be further improved at low temperatures by using only power MOSFET's as switches. The use of a resonant topology will further improve the circuit performance by reducing the switching noise and loss.

Use of computer codes to improve nuclear power plant operation

International Nuclear Information System (INIS)

Misak, J.; Polak, V.; Filo, J.; Gatas, J.

1985-01-01

For safety and economic reasons, the scope for carrying out experiments on operational nuclear power plants (NPPs) is very limited and any changes in technical equipment and operating parameters or conditions have to be supported by theoretical calculations. In the Nuclear Power Plant Scientific Research Institute (NIIAEhS), computer codes are systematically used to analyse actual operating events, assess safety aspects of changes in equipment and operating conditions, optimize the conditions, preparation and analysis of NPP startup trials and review and amend operating instructions. In addition, calculation codes are gradually being introduced into power plant computer systems to perform real time processing of the parameters being measured. The paper describes a number of specific examples of the use of calculation codes for the thermohydraulic analysis of operating and accident conditions aimed at improving the operation of WWER-440 units at the Jaslovske Bohunice V-1 and V-2 nuclear power plants. These examples confirm that computer calculations are an effective way of solving operating problems and of further increasing the level of safety and economic efficiency of NPP operation. (author)

Operation of Finnish nuclear power plants

International Nuclear Information System (INIS)

Lehtinen, Pekka

1987-05-01

These general reviews of the operation of the Finnish nuclear power plants concentrate on such events and discoveries related to reactor and radiation safety that the regulatory body, the Finnish Centre for Radiation and Nuclear Safety, regards as noteworthy. The report also includes a summary of the radiation safety of the personnel and the environment, as well as tabulated data on the production and load factors of the plants. In the report period, no event essentially degraded plant safety nor posed a radiation hazard to the perssonnel or the environment. For remedying certain defects found in the administrative procedures concerning plant operation and maintenance, the Loviisa power plant was shut down for several days

OPRA capacity bounds for selection diversity over generalized fading channels

KAUST Repository

Hanif, Muhammad Fainan

2014-05-01

Channel side information at the transmitter can increase the average capacity by enabling optimal power and rate adaptation. The resulting optimal power and rate adaptation (OPRA) capacity rarely has a closed-form analytic expression. In this paper, lower and upper bounds on OPRA capacity for selection diversity scheme are presented. These bounds hold for variety of fading channels including log-normal and generalized Gamma distributed models and have very simple analytic expressions for easy evaluation even for kth best path selection. Some selected numerical results show that the newly proposed bounds closely approximate the actual OPRA capacity. © 2014 IEEE.

Operating the Irish power system with increased levels of wind power

DEFF Research Database (Denmark)

Tuohy, A.; Denny, E.; Meibom, Peter

2008-01-01

This paper summarises some of the main impacts of large amounts of wind power installed in the island of Ireland. Using results from various studies performed on this system, it is shown that wind power will impact on all time frames, from seconds to daily planning of the system operation. Results...... from studies examining operation of the system with up to approximately 40% of electricity provided by wind show that some of the most important aspects to be considered include the type of wind turbine technology, the provision of reserve to accommodate wind forecasting error and the method used...

Computerized operation manual (COM) of nuclear power plants

International Nuclear Information System (INIS)

Szegi, Z.

1985-01-01

This paper is to be presented at the International Seminar on Diagnoses of and Response to Abnormal Occurrences at Nuclear Power Plants organized by the International Atomic Energy Agency. The topic of presentation is the Computerized Operational Manual. This system supports the operator at disturbance situations by displaying quickly and unambiguously the operational instructions and the relevant information without mistakes. By the computerized manual the operator can determine the instruction-subsystem which reflects the real state of the power unit. From this point the system guides the operator on how to drive the unit to another determined state by providing the operational instructions at any time. A data bank is also included which contains information concerning rules restricting on maintenance and repair. The system will be realized at Paks NPP. (author)

Operating experience with BWR nuclear power

International Nuclear Information System (INIS)

Bonsdorf, Magnus von.

1986-01-01

The two-unit nuclear power station in Olkiluoto on the western coast of Finland produces about 20 per cent of the electricity consumption of the country. The first unit, TVO-I was first connected to the national grid in September 1978 and TVO-II in February 1980. The original rated power output of each unit was 660 MWe, corresponding to the thermal power of 2000 MW from the reactor. Technical modifications allowed the power to be uprated by 8%. The operating statistics (load factors etc.) are given and the outage experience discussed. The radiological history shows very low radioactivity and dose levels have been maintained at the plant. (UK)

Generalized Toeplitz operators and cyclic vectors

International Nuclear Information System (INIS)

Gassier, G.; Mahzouli, H.; Zerouali, E.H.

2003-04-01

We give in this paper some asymptotic Von Neumann inequalities for power bounded operators in the class C ρ intersection C 1 . and some spacial von Neumann inequalities associated with non zero elements of the point spectrum, when it is non void, of generalized Toeplitz operators. Introducing perturbed kernel, we consider classes C R which extend the classical classes C ρ . We give results about absolute continuity with respect to the Haar measure for operators in class C R intersection C 1 . This allows us to give new results on cyclic vectors for such operators and provides invariant subspaces for their powers. Relationships between cyclic vectors for T and T* involving generalized Toeplitz operators are given and the commutativity of {T}', the commutant of T is discussed. (author)

Determination of the self-adjoint matrix Schrödinger operators without the bound state data

Science.gov (United States)

Xu, Xiao-Chuan; Yang, Chuan-Fu

2018-06-01

(i) For the matrix Schrödinger operator on the half line, it is shown that the scattering data, which consists of the scattering matrix and the bound state data, uniquely determines the potential and the boundary condition. It is also shown that only the scattering matrix uniquely determines the self-adjoint potential and the boundary condition if either the potential exponentially decreases fast enough or the potential is known a priori on (), where a is an any fixed positive number. (ii) For the matrix Schrödinger operator on the full line, it is shown that the left (or right) reflection coefficient uniquely determine the self-adjoint potential if either the potential exponentially decreases fast enough or the potential is known a priori on (or ()), where b is an any fixed number.

Simplified reactive power management strategy for complex power grids under stochastic operation and incomplete information

International Nuclear Information System (INIS)

Vlachogiannis, John G.

2009-01-01

In the current released energy market, the large-scale complex transmission networks and the distribution ones with dispersed energy sources and 'intelligent' components operate under uncertainties, stochastic and prior incomplete information. A safe and reliable operation of such complex power grids is a major issue for system operators. Under these circumstances an online reactive power management strategy with minimum risk concerning all uncertain and stochastic parameters is proposed. Therefore, new concepts such as reactive power-weighted node-to-node linking and reactive power control capability are introduced. A distributed and interconnected stochastic learning automata system is implemented to manage, in a unified and unique way, the reactive power in complex power grids with stochastic reactive power demand and detect the vulnerable part. The proposed simplified strategy can also consider more stochastic aspects such as variable grid's topology. Results of the proposed strategy obtained on the networks of IEEE 30-bus and IEEE 118-bus systems demonstrate the effectiveness of the proposed strategy.

14 CFR 29.672 - Stability augmentation, automatic, and power-operated systems.

Science.gov (United States)

2010-01-01

... power-operated systems. 29.672 Section 29.672 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Construction Control Systems § 29.672 Stability augmentation, automatic, and power-operated systems. If the functioning of stability augmentation or other automatic or power-operated system is necessary to show...

14 CFR 27.672 - Stability augmentation, automatic, and power-operated systems.

Science.gov (United States)

2010-01-01

... power-operated systems. 27.672 Section 27.672 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Construction Control Systems § 27.672 Stability augmentation, automatic, and power-operated systems. If the functioning of stability augmentation or other automatic or power-operated systems is necessary to show...

Bounding approach in BUC implementation in pool at WWER-440

International Nuclear Information System (INIS)

Havluj, F.

2006-01-01

As new fuel designs (with higher enrichment) are introduced, spent fuel storage facilities might not fulfill criticality safety criteria when using fresh fuel approach to the criticality analyses. Since optimum moderation conditions evaluation even in wet storage systems is required by some regulatory bodies, any credit for soluble boron cannot be taken. Thus, the only suitable way to prove subcriticality of the given spent fuel system with higher enriched/burnt fuel is burnup credit implementation. This paper outlines burnup credit implementation methodology as demonstrated on criticality evaluation of WWER-440 reactor pool at NPP Dukovany. Operational history effects, isotopic set choice, as well as computational issues (SCALE 4.4a was used both for depletion and criticality calculations) are discussed, maintaining strictly conservative approach. Bounding approach in operational history treatment was carefully examined. Criticality evaluation using selection of (as expected) conservative values of operational parameters (specific power, fuel and moderator temperatures, boron content in moderator,..) was compared to criticality evaluation of real fuel assemblies from the NPP database. Therefore, bounding approach was justified and it was shown that it is not excessively conservative. Presented methodology can be applied on any similar spent fuel facility. Suggestions for future research are noted (mainly end-effect evaluation and consideration of profiled fuel) and urgent need of validation of depletion codes for WWER systems is emphasized (Authors)

Reliability research to nuclear power plant operators based on several methods

International Nuclear Information System (INIS)

Fang Xiang; Li Fu; Zhao Bingquan

2009-01-01

The paper utilizes many kinds of international reliability research methods, and summarizes the review of reliability research of Chinese nuclear power plant operators in past over ten years based on the simulator platform of nuclear power plant. The paper shows the necessity and feasibility of the research to nuclear power plant operators from many angles including human cognition reliability, fuzzy mathematics model and psychological research model, etc. It will be good to the safe operation of nuclear power plant based on many kinds of research methods to the reliability research of nuclear power plant operators. (authors)

Wind Power Forecasting Error Frequency Analyses for Operational Power System Studies: Preprint

Energy Technology Data Exchange (ETDEWEB)

Florita, A.; Hodge, B. M.; Milligan, M.

2012-08-01

The examination of wind power forecasting errors is crucial for optimal unit commitment and economic dispatch of power systems with significant wind power penetrations. This scheduling process includes both renewable and nonrenewable generators, and the incorporation of wind power forecasts will become increasingly important as wind fleets constitute a larger portion of generation portfolios. This research considers the Western Wind and Solar Integration Study database of wind power forecasts and numerical actualizations. This database comprises more than 30,000 locations spread over the western United States, with a total wind power capacity of 960 GW. Error analyses for individual sites and for specific balancing areas are performed using the database, quantifying the fit to theoretical distributions through goodness-of-fit metrics. Insights into wind-power forecasting error distributions are established for various levels of temporal and spatial resolution, contrasts made among the frequency distribution alternatives, and recommendations put forth for harnessing the results. Empirical data are used to produce more realistic site-level forecasts than previously employed, such that higher resolution operational studies are possible. This research feeds into a larger work of renewable integration through the links wind power forecasting has with various operational issues, such as stochastic unit commitment and flexible reserve level determination.

The control of operational risk in nuclear power plant operations - Some cross-cultural perspectives

International Nuclear Information System (INIS)

Suchard, A.; Rochlin, G.

1992-01-01

The operation of nuclear power plants requires the management of a complex technology under exacting performance and safety criteria. Organizations operating nuclear power plants are faced with the challenge of simultaneously meeting technical, organizational, and social demands, striving toward perfection in a situation where learning by trial and error can be too costly. In this process, they interact with regulatory bodies who seek to help minimize operational risk by imposing and upholding safety standards. The character of this interaction differs in various countries, as does the larger cultural setting. The study generally pursued the question of how organizations operating complex and demanding technologies adapt to such requirements and circumstances, and how they can succeed in delivering nearly error-free performance. One aspect of this study includes the comparison of organizational and cultural environments for nuclear power plant operations in the US, France, Germany, Sweden, and Switzerland. The research involved in-depth, continuous observations on location and interviews with plant personnel, especially control operators, at one plant in each country

Operating history of U.S. nuclear power reactors

International Nuclear Information System (INIS)

1974-01-01

The operating history of U. S. nuclear power plants through December 31, 1974 has been collected. Included are those nuclear reactor facilities which produce electricity, even if in token amounts, or which are part of a development program concerned with the generation of electricity through the use of a nuclear reactor as a heat source. The information is based on data furnished by facility operators. The charts are plotted in terms of cumulative thermal energy as a function of time. Since only those shutdowns of five days or more are shown, the charts do not give a detailed history of plant operation. They do, however, give an overview of the operating history of a variety of developmental and experimental nuclear power reactors. The data show the yearly gross generation of electricity for each U. S. nuclear plant and, for civilian power plants, information on reactor availability and plant capacity factor. (U.S.)

Operational limits and conditions and operating procedures for nuclear power plants. Safety guide

International Nuclear Information System (INIS)

2005-01-01

This Safety Guide was prepared as part of the Agency's programme for establishing safety standards relating to nuclear power plants. The present Safety Guide supersedes the IAEA Safety Guide on Operational Limits and Conditions for Nuclear Power Plants which was issued in 1979 as Safety Series No. 50-SG-O3. For a nuclear power plant to be operated in a safe manner, the provisions made in the final design and subsequent modifications shall be reflected in limitations on plant operating parameters and in the requirements on plant equipment and personnel. Under the responsibility of the operating organization, these shall be developed during the design safety evaluation as a set of operational limits and conditions (OLCs). A major contribution to compliance with the OLCs is made by the development and utilization of operating procedures (OPs) that are consistent with and fully implement the OLCs. The requirements for the OLCs and OPs are established in Section 5 of the IAEA Safety Requirements publication Safety of Nuclear Power Plants: Operation, which this Safety Guide supplements. The purpose of this Safety Guide is to provide guidance on the development, content and implementation of OLCs and OPs. The Safety Guide is directed at both regulators and owners/operators. This Safety Guide covers the concept of OLCs, their content as applicable to land based stationary power plants with thermal neutron reactors, and the responsibilities of the operating organization regarding their establishment, modification, compliance and documentation. The OPs to support the implementation of the OLCs and to ensure their observance are also within the scope of this Safety Guide. The particular aspects of the procedures for maintenance, surveillance, in-service inspection and other safety related activities in connection with the safe operation of nuclear power plants are outside the scope of this Safety Guide but can be found in other IAEA Safety Guides. Section 2 indicates the

Operational limits and conditions and operating procedures for nuclear power plants. Safety guide

International Nuclear Information System (INIS)

2000-01-01

This Safety Guide was prepared as part of the Agency's programme for establishing safety standards relating to nuclear power plants. The present Safety Guide supersedes the IAEA Safety Guide on Operational Limits and Conditions for Nuclear Power Plants which was issued in 1979 as Safety Series No. 50-SG-O3. For a nuclear power plant to be operated in a safe manner, the provisions made in the final design and subsequent modifications shall be reflected in limitations on plant operating parameters and in the requirements on plant equipment and personnel. Under the responsibility of the operating organization, these shall be developed during the design safety evaluation as a set of operational limits and conditions (OLCs). A major contribution to compliance with the OLCs is made by the development and utilization of operating procedures (OPs) that are consistent with and fully implement the OLCs. The requirements for the OLCs and OPs are established in Section 5 of the IAEA Safety Requirements publication Safety of Nuclear Power Plants: Operation, which this Safety Guide supplements. The purpose of this Safety Guide is to provide guidance on the development, content and implementation of OLCs and OPs. The Safety Guide is directed at both regulators and owners/operators. This Safety Guide covers the concept of OLCs, their content as applicable to land based stationary power plants with thermal neutron reactors, and the responsibilities of the operating organization regarding their establishment, modification, compliance and documentation. The OPs to support the implementation of the OLCs and to ensure their observance are also within the scope of this Safety Guide. The particular aspects of the procedures for maintenance, surveillance, in-service inspection and other safety related activities in connection with the safe operation of nuclear power plants are outside the scope of this Safety Guide but can be found in other IAEA Safety Guides. Section 2 indicates the

The sharp bounds on general sum-connectivity index of four operations on graphs

Directory of Open Access Journals (Sweden)

Shehnaz Akhter

2016-09-01

Full Text Available Abstract The general sum-connectivity index χ α ( G $\\chi_{\\alpha}(G$ , for a (molecular graph G, is defined as the sum of the weights ( d G ( a 1 + d G ( a 2 α $(d_{G}(a_{1}+d_{G}(a_{2}^{\\alpha}$ of all a 1 a 2 ∈ E ( G $a_{1}a_{2}\\in E(G$ , where d G ( a 1 $d_{G}(a_{1}$ (or d G ( a 2 $d_{G}(a_{2}$ denotes the degree of a vertex a 1 $a_{1}$ (or a 2 $a_{2}$ in the graph G; E ( G $E(G$ denotes the set of edges of G, and α is an arbitrary real number. Eliasi and Taeri (Discrete Appl. Math. 157:794-803, 2009 introduced four new operations based on the graphs S ( G $S(G$ , R ( G $R(G$ , Q ( G $Q(G$ , and T ( G $T(G$ , and they also computed the Wiener index of these graph operations in terms of W ( F ( G $W(F(G$ and W ( H $W(H$ , where F is one of the symbols S, R, Q, T. The aim of this paper is to obtain sharp bounds on the general sum-connectivity index of the four operations on graphs.

Operational costs induced by fluctuating wind power production in Germany and Scandinavia

DEFF Research Database (Denmark)

Meibom, Peter; Weber, C.; Barth, R.

2009-01-01

Adding wind power generation in a power system changes the operational patterns of the existing units due to the variability and partial predictability of wind power production. For large amounts of wind power production, the expectation is that the specific operational costs (fuel costs, start......-up costs, variable operation and maintenance costs, costs of consuming CO2 emission permits) of the other power plants will increase due to more operation time in part-load and more start-ups. The change in operational costs induced by the wind power production can only be calculated by comparing...... the operational costs in two power system configurations: with wind power production and with alternative wind production having properties such as conventional production, that is, being predictable and less variable. The choice of the characteristics of the alternative production is not straightforward...

Operating experience with nuclear power plants 2015. Pt. 1

Energy Technology Data Exchange (ETDEWEB)

Anon.

2016-07-01

The VGB Technical Committee ''Nuclear Plant Operation'' has been exchanging operating experience about nuclear power plants for more than 30 years. Plant operators from several European countries are participating in the exchange. A report is given on the operating results achieved in 2015, events important to plant safety, special and relevant repair, and retrofit measures from Germany. The second part of this report will focus on nuclear power plant in Belgium, Finland, the Netherlands, Switzerland, and Spain.

Nonlinear control for core power of pressurized water nuclear reactors using constant axial offset strategy

Directory of Open Access Journals (Sweden)

Gholam Reza Ansarifar

2015-12-01

Full Text Available One of the most important operations in nuclear power plants is load following, in which an imbalance of axial power distribution induces xenon oscillations. These oscillations must be maintained within acceptable limits otherwise the nuclear power plant could become unstable. Therefore, bounded xenon oscillation is considered to be a constraint for the load following operation. In this paper, the design of a sliding mode control (SMC, which is a robust nonlinear controller, is presented. SMC is a means to control pressurized water nuclear reactor (PWR power for the load following operation problem in a way that ensures xenon oscillations are kept bounded within acceptable limits. The proposed controller uses constant axial offset (AO strategy to ensure xenon oscillations remain bounded. The constant AO is a robust state constraint for the load following problem. The reactor core is simulated based on the two-point nuclear reactor model with a three delayed neutron groups. The stability analysis is given by means of the Lyapunov approach, thus the control system is guaranteed to be stable within a large range. The employed method is easy to implement in practical applications and moreover, the SMC exhibits the desired dynamic properties during the entire output-tracking process independent of perturbations. Simulation results are presented to demonstrate the effectiveness of the proposed controller in terms of performance, robustness, and stability. Results show that the proposed controller for the load following operation is so effective that the xenon oscillations are kept bounded in the given region.

Optimal Coordinated EV Charging with Reactive Power Support in Constrained Distribution Grids

Energy Technology Data Exchange (ETDEWEB)

Paudyal, Sumit; Ceylan, Oğuzhan; Bhattarai, Bishnu P.; Myers, Kurt S.

2017-07-01

Electric vehicle (EV) charging/discharging can take place in any P-Q quadrants, which means EVs could support reactive power to the grid while charging the battery. In controlled charging schemes, distribution system operator (DSO) coordinates with the charging of EV fleets to ensure grid’s operating constraints are not violated. In fact, this refers to DSO setting upper bounds on power limits for EV charging. In this work, we demonstrate that if EVs inject reactive power into the grid while charging, DSO could issue higher upper bounds on the active power limits for the EVs for the same set of grid constraints. We demonstrate the concept in an 33-node test feeder with 1,500 EVs. Case studies show that in constrained distribution grids in coordinated charging, average costs of EV charging could be reduced if the charging takes place in the fourth P-Q quadrant compared to charging with unity power factor.

Operations quality assurance for nuclear power plants

International Nuclear Information System (INIS)

1987-01-01

This standard covers the quality assurance of all activities concerned with the operation and maintenance of plant equipment and systems in CANDU-based nuclear power plants during the operations phase, the period between the completion of commissioning and the start of decommissioning

Research on wind power grid-connected operation and dispatching strategies of Liaoning power grid

Science.gov (United States)

Han, Qiu; Qu, Zhi; Zhou, Zhi; He, Xiaoyang; Li, Tie; Jin, Xiaoming; Li, Jinze; Ling, Zhaowei

2018-02-01

As a kind of clean energy, wind power has gained rapid development in recent years. Liaoning Province has abundant wind resources and the total installed capacity of wind power is in the forefront. With the large-scale wind power grid-connected operation, the contradiction between wind power utilization and peak load regulation of power grid has been more prominent. To this point, starting with the power structure and power grid installation situation of Liaoning power grid, the distribution and the space-time output characteristics of wind farm, the prediction accuracy, the curtailment and the off-grid situation of wind power are analyzed. Based on the deep analysis of the seasonal characteristics of power network load, the composition and distribution of main load are presented. Aiming at the problem between the acceptance of wind power and power grid adjustment, the scheduling strategies are given, including unit maintenance scheduling, spinning reserve, energy storage equipment settings by the analysis of the operation characteristics and the response time of thermal power units and hydroelectric units, which can meet the demand of wind power acceptance and provide a solution to improve the level of power grid dispatching.

IAEA activity on operator support systems in nuclear power plants

International Nuclear Information System (INIS)

Dounaev, V.; Fujita, Y.; Juslin, K.; Haugset, K.; Lux, I.; Naser, J.

1994-01-01

Various operator support systems for nuclear power plants are already operational or under development in the IAEA Member States. Operator support systems are based on intelligent data processing and, in addition to plant operation, they are also becoming more important for safety. A key feature of operator support systems is their availability to restructure data to increase its relevance for a given situation. This can improve the user's ability to identify plant mode, system state, and component state and to identify and diagnose faults. Operator support systems can also assist the user in planning and implementing corrective actions to improve the nuclear power plant's availability and safety. In September 1991, the IAEA Committee for Contractual Scientific Services approved the Co-ordinated Research Programme (CRP) on ''Operator Support Systems in Nuclear Power Plants'' in the framework of the Project ''Man-Machine Interface Studies''. The main objective of this programme is to provide guidance and technology transfer for the development and implementation of operator support systems. This includes the experience with human-machine interfaces and closely related issues such as instrumentation and control, the use of computers in nuclear power plants, and operator qualification. (author)

Operation of Finnish nuclear power plants

International Nuclear Information System (INIS)

Lehtinen, Pekka

1987-07-01

These general reviews of the operation of the Finnish nuclear power plants concentrate on such events and discoveries related to reactor and radiation safety that the regulatory body, the Finnish Centre for Radiation and Nuclear Safety, regards as noteworthy. The report also includes a summary of the radiation safety of the personnel and the environment, as well as tabulated data on the production and load factors of the plants. No event in the report period, or in the whole year of 1986, essentially degraded plant safety nor posed a radiation hazard to the personnel or the environment. For remedying certain defects found in the adminstrative procedures concerning plant operation and maintenance, the Loviisa power plant was shut down for several days in September

Booster main magnet power supply, present operation and potential future upgrades

Energy Technology Data Exchange (ETDEWEB)

Bajon, E.; Bannon, M.; Marneris, I.; Danowski, G.; Sandberg, J.; Savatteri, S.

2011-03-28

The Brookhaven Booster Main Magnet Power Supply (MMPS) is a 24 pulse thyristor control supply, rated at 5500 Amps, +/-2000 Volts, or 3000 Amps, +/-6000 Volts. The power supply is fed directly from the power utility and the peak magnet power is 18 MWatts. This peak power is seen directly at the incoming ac line. This power supply has been in operation for the last 18 years. This paper will describe the present topology and operation of the power supply, the feedback control system and the different modes of operation of the power supply. Since the power supply has been in operation for the last 18 years, upgrading this power supply is essential. A new power supply topology has been studied where energy is stored in capacitor banks. DC to DC converters are used to convert the dc voltage stored in the capacitor banks to pulsed DC voltage into the magnet load. This enables the average incoming power from the ac line to be constant while the peak magnet power is pulsed to +/- 18 MWatts. Simulations and waveforms of this power supply will be presented.

Summary of operating experience at Swedish nuclear power plants in 1984

International Nuclear Information System (INIS)

1985-01-01

The four owners on nuclear power plants in Sweden - The Swedish State Power Board, Forsmarks Kraftgrupp AB, Sydkraft AB and OKG AKTIEBOLAG - formed in 1980 the Nuclear Safety Board of the Swedish Utilities as a joint body for collaboration in safety matters. The Board participates in coordination of the safety work of the utilities and conducts its own safety projects, whereever this is more efficient than the utilities' working independently. The work of the Board shall contribute to optimizing safety in the operation of the Swedish nuclear power plants. The most important function of the Board is to collect, process and evaluate information on operational disturbances and incidents at Swedish and foreign nuclear power plants and then use the knowledge thus gained to improve the safety of the operation of the Swedish nuclear power plants (experience feedback). The work with Experience Feedback proceeds in three stages: Event follow-up, Fault analysis and Feedback of results. The Board runs a system for experience feedback (ERF). ERF is a computer-based information and communication system. ERF provides the Board with a daily update of operating experience in both Swedish and foreign nuclear power plants. Each Swedish nuclear power station supplies the ERF system with data on, among other things, operation and operational distrubances. Important experiences are thereby fed back to plant operation. Experience from foreign nuclear power stations can be of interest to the Swedish nuclear power plants. This information comes to RKS and is reviewed daily. The information that is considered relevant to Swedish plants is fed after analysis into the ERF system. Conversely, foreign nuclear power stations can obtain information from the operation of the Swedish plants. (author)

Aiding operator performance at low power feedwater control

International Nuclear Information System (INIS)

Woods, D.D.

1986-01-01

Control of the feedwater system during low power operations (approximately 2% to 30% power) is a difficult task where poor performance (excessive trips) has a high cost to utilities. This paper describes several efforts in the human factors aspects of this task that are underway to improve feedwater control. A variety of knowledge acquisition techniques have been used to understand the details of what makes feedwater control at low power difficult and what knowledge and skill distinguishes expert operators at this task from less experienced ones. The results indicate that there are multiple factors that contribute to task difficulty

Operational flexibility and economics of power plants in future low-carbon power systems

NARCIS (Netherlands)

Brouwer, Anne Sjoerd; van den Broek, Machteld; Seebregts, Ad; Faaij, André

2015-01-01

Future power systems will require large shares of low-carbon generators such as renewables and power plants with Carbon Capture and Storage (CCS) to keep global warming below 2. °C. Intermittent renewables increase the system-wide demand for flexibility and affect the operation of thermal power

Existence of k⁻¹ power-law scaling in the equilibrium regions of wall-bounded turbulence explained by Heisenberg's eddy viscosity.

Science.gov (United States)

Katul, Gabriel G; Porporato, Amilcare; Nikora, Vladimir

2012-12-01

The existence of a "-1" power-law scaling at low wavenumbers in the longitudinal velocity spectrum of wall-bounded turbulence was explained by multiple mechanisms; however, experimental support has not been uniform across laboratory studies. This letter shows that Heisenberg's eddy viscosity approach can provide a theoretical framework that bridges these multiple mechanisms and explains the elusiveness of the "-1" power law in some experiments. Novel theoretical outcomes are conjectured about the role of intermittency and very-large scale motions in modifying the k⁻¹ scaling.

Quantum Cramer–Rao Bound for a Massless Scalar Field in de Sitter Space

Directory of Open Access Journals (Sweden)

Marcello Rotondo

2017-10-01

Full Text Available How precisely can we estimate cosmological parameters by performing a quantum measurement on a cosmological quantum state? In quantum estimation theory, the variance of an unbiased parameter estimator is bounded from below by the inverse of measurement-dependent Fisher information and ultimately by quantum Fisher information, which is the maximization of the former over all positive operator-valued measurements. Such bound is known as the quantum Cramer –Rao bound. We consider the evolution of a massless scalar field with Bunch–Davies vacuum in a spatially flat FLRW spacetime, which results in a two-mode squeezed vacuum out-state for each field wave number mode. We obtain the expressions of the quantum Fisher information as well as the Fisher informations associated to occupation number measurement and power spectrum measurement, and show the specific results of their evolution for pure de Sitter expansion and de Sitter expansion followed by a radiation-dominated phase as examples. We will discuss these results from the point of view of the quantum-to-classical transition of cosmological perturbations and show quantitatively how this transition and the residual quantum correlations affect the bound on the precision.

Bounds and estimates for the linearly perturbed eigenvalue problem

International Nuclear Information System (INIS)

Raddatz, W.D.

1983-01-01

This thesis considers the problem of bounding and estimating the discrete portion of the spectrum of a linearly perturbed self-adjoint operator, M(x). It is supposed that one knows an incomplete set of data consisting in the first few coefficients of the Taylor series expansions of one or more of the eigenvalues of M(x) about x = 0. The foundations of the variational study of eigen-values are first presented. These are then used to construct the best possible upper bounds and estimates using various sets of given information. Lower bounds are obtained by estimating the error in the upper bounds. The extension of these bounds and estimates to the eigenvalues of the doubly-perturbed operator M(x,y) is discussed. The results presented have numerous practical application in the physical sciences, including problems in atomic physics and the theory of vibrations of acoustical and mechanical systems

Continuous bounded cohomology of locally compact groups

CERN Document Server

2001-01-01

Recent research has repeatedly led to connections between important rigidity questions and bounded cohomology. However, the latter has remained by and large intractable. This monograph introduces the functorial study of the continuous bounded cohomology for topological groups, with coefficients in Banach modules. The powerful techniques of this more general theory have successfully solved a number of the original problems in bounded cohomology. As applications, one obtains, in particular, rigidity results for actions on the circle, for representations on complex hyperbolic spaces and on Teichmüller spaces. A special effort has been made to provide detailed proofs or references in quite some generality.

Nuclear power plant operation 2016. Pt. 1

Energy Technology Data Exchange (ETDEWEB)

Anon.

2017-05-15

A report is given on the operating results achieved in 2016, events important to plant safety, special and relevant repair, and retrofit measures from nuclear power plants in Germany. Reports about nuclear power plants in Belgium, Finland, the Netherlands, Switzerland, and Spain will be published in a further issue.

Intelligent operation system for nuclear power plants

International Nuclear Information System (INIS)

Morioka, Toshihiko; Fukumoto, Akira; Suto, Osamu; Naito, Norio.

1987-01-01

Nuclear power plants consist of many systems and are operated by skillful operators with plenty of knowledge and experience of nuclear plants. Recently, plant automation or computerized operator support systems have come to be utilized, but the synthetic judgment of plant operation and management remains as human roles. Toshiba is of the opinion that the activities (planning, operation and maintenance) should be integrated, and man-machine interface should be human-friendly. We have begun to develop the intelligent operation system aiming at reducing the operator's role within the fundamental judgment through the use of artificial intelligence. (author)

Probabilistic Linguistic Power Aggregation Operators for Multi-Criteria Group Decision Making

Directory of Open Access Journals (Sweden)

Agbodah Kobina

2017-12-01

Full Text Available As an effective aggregation tool, power average (PA allows the input arguments being aggregated to support and reinforce each other, which provides more versatility in the information aggregation process. Under the probabilistic linguistic term environment, we deeply investigate the new power aggregation (PA operators for fusing the probabilistic linguistic term sets (PLTSs. In this paper, we firstly develop the probabilistic linguistic power average (PLPA, the weighted probabilistic linguistic power average (WPLPA operators, the probabilistic linguistic power geometric (PLPG and the weighted probabilistic linguistic power geometric (WPLPG operators. At the same time, we carefully analyze the properties of these new aggregation operators. With the aid of the WPLPA and WPLPG operators, we further design the approaches for the application of multi-criteria group decision-making (MCGDM with PLTSs. Finally, we use an illustrated example to expound our proposed methods and verify their performances.

Frequency Control for Island Operation of Bornholm Power System

DEFF Research Database (Denmark)

Cha, Seung-Tae; Wu, Qiuwei; Zhao, Haoran

2014-01-01

the primary frequency control and the DG units are used to provide the secondary frequency control. As such, the proposed control scheme can strike a balance of the frequency control speed and the energy used from the BESS for the frequency control support. The real-time model of the Bornholm power system......This paper presents a coordinated control strategy of a battery energy storage system (BESS) and distributed generation (DG) units for the island operation of the Danish island of Bornholm. The Bornholm power system is able to transit from the grid connected operation with the Nordic power system...... to the isolated island operation. In order to ensure the secure island operation, the coordinated control of the BESS and the DG has been proposed to stabilize the frequency of the system after the transition to the island operation. In the proposed coordinate control scheme, the BESS is used to provide...

Power System Operation with Large-Scale Wind Power in Liberalised Environments

International Nuclear Information System (INIS)

Ummels, B.C.

2009-01-01

The disadvantages of producing electricity from fossil fuels are that their supply is finite and unevenly distributed across the earth. Conventional power stations also emit greenhouse gases. Therefore, sustainable alternatives must be developed, such as wind power. The disadvantages of wind are that it may or may not blow and that it is unpredictable. Th generation of electricity must however always equal the consumption. This makes the integration of wind power in the electricity system more difficult. This thesis investigates the integration of wind power into the existing power system. Simulation models are developed and used to explore the operation of power systems with a lot of wind power. The simulations provide a picture of the reliability, cost and emission of CO2 of the generation of electricity, with and without wind power. The research also takes into account electricity exchange on international markets. Possible solutions for integrating wind power, such as flexible power plants and energy storage, are investigated as well

Improving nuclear power plant safety through operator aids

International Nuclear Information System (INIS)

1987-12-01

In October 1986, the IAEA convened a one-week Technical Committee Meeting on Improving Nuclear Power Plant Safety Through Operator Aids. The term ''operator aid'' or more formally ''operator support system'' refers to a class of devices designed to be added to a nuclear power plant control station to assist an operator in performing his job and thereby decrease the probability of operator error. The addition of a carefully planned and designed operator aid should result in an increase in nuclear power plant safety and reliability. Operator aids encompass a wide range of devices from the very simple, such as color coding a display to distinguish it out of a group of similar displays, to the very complex, such as a computer-generated video display which concentrates a number of scattered indicator readings located around a control room into a concise display in front of the operator. This report provides guidelines and information to help make a decision as to whether an operator aid is needed, what kinds of operator aids are available and whether it should be purchased or developed by the utility. In addition, a discussion is presented on advanced operator aids to provide information on what may become available in the future. The broad scope of these guidelines makes it most suitable for use by a multi-disciplinary team. The document consists of two parts. The recommendations and results of the meeting discussions are given in the first part. The second part is the annex where the papers presented at the Technical Committee Meeting are printed. A separate abstract was prepared for each of the 10 papers. Refs, figs and tabs

New bounds on isotropic Lorentz violation

International Nuclear Information System (INIS)

Carone, Christopher D.; Sher, Marc; Vanderhaeghen, Marc

2006-01-01

Violations of Lorentz invariance that appear via operators of dimension four or less are completely parametrized in the Standard Model Extension (SME). In the pure photonic sector of the SME, there are 19 dimensionless, Lorentz-violating parameters. Eighteen of these have experimental upper bounds ranging between 10 -11 and 10 -32 ; the remaining parameter, k-tilde tr , is isotropic and has a much weaker bound of order 10 -4 . In this Brief Report, we point out that k-tilde tr gives a significant contribution to the anomalous magnetic moment of the electron and find a new upper bound of order 10 -8 . With reasonable assumptions, we further show that this bound may be improved to 10 -14 by considering the renormalization of other Lorentz-violating parameters that are more tightly constrained. Using similar renormalization arguments, we also estimate bounds on Lorentz-violating parameters in the pure gluonic sector of QCD

Operation of Finnish nuclear power plants

International Nuclear Information System (INIS)

Tossavainen, K.

1991-02-01

During the third quarter of 1990 the Finnish nuclear power plant units Loviisa 1 and 2 and TVO I and II were in commercial operation for most of the time. The annual maintenance outages of the Loviisa plant units were held during the report period. All events during this quarter are classified as Level hero (Below Scale) on the International Nuclear Event Scale. Occupational radiation doses and external releases of radioactivity were below authorised limits. Only small amounts of radioactive substances originating in nuclear power plants were detected in samples taken in the vicinity of nuclear power plants

Operation of Finnish nuclear power plants

International Nuclear Information System (INIS)

Tossavainen, K.

1992-09-01

The Finnish nuclear power plant units Loviisa 1 and 2 as well as TVO I and II were in operation for almost all the time in the first quarter of 1992. The load factor average was 99.8%. All events which are classified on the International Nuclear Event Scale were level 0/below scale on the Scale. Occupational radiation doses and releases of radioactive material off-site remained well below authorised limits. Only quantities of radioactive material insignificant to radiation exposure, originating from the nuclear power plants, were detected in samples collected in the vicinity of the nuclear power plants

Training and qualification of nuclear power plant operators (4)

International Nuclear Information System (INIS)

Ohsuga, Y.

2009-01-01

Training center using the simulators, instructor training, training upgrade, deployment of digital control panel and review of training were described with overseas practice. Recently, nuclear power plant on-site simulators were also used for respective operator training. Operator teamwork training, training team performance upgrade, reflection of operating experiences in nuclear power plant accidents, development of training support equipments and management of training records were needed to review and upgrade training and qualification programs. (T. Tanaka)

The distribution of wind power forecast errors from operational systems

Energy Technology Data Exchange (ETDEWEB)

Hodge, Bri-Mathias; Ela, Erik; Milligan, Michael

2011-07-01

Wind power forecasting is one important tool in the integration of large amounts of renewable generation into the electricity system. Wind power forecasts from operational systems are not perfect, and thus, an understanding of the forecast error distributions can be important in system operations. In this work, we examine the errors from operational wind power forecasting systems, both for a single wind plant and for an entire interconnection. The resulting error distributions are compared with the normal distribution and the distribution obtained from the persistence forecasting model at multiple timescales. A model distribution is fit to the operational system forecast errors and the potential impact on system operations highlighted through the generation of forecast confidence intervals. (orig.)

47 CFR 73.51 - Determining operating power.

Science.gov (United States)

2010-10-01

...'s input power directly from the RF voltage, RF current, and phase angle; or (2) calculating the product of the licensed antenna or common point resistance at the operating frequency (see § 73.54), and... the resistance has been determined. (b) The authorized antenna input power for each station shall be...

The economics of long-term operation of nuclear power plants

International Nuclear Information System (INIS)

Lokhov, Alexey; Huerta, Alejandro; Dufresne, Luc; Giraud, Anne; Osouf, Nicolas

2012-01-01

Refurbishment and long-term operation (LTO) of existing nuclear power plants (NPPs) today are crucial to the competitiveness of the nuclear industry in OECD countries as existing nuclear power plants produce base-load power at a reliable cost. A number of nuclear power plants, most notably 73 units in the United States (up to 2012), have been granted lifetime extensions of up to 60 years, a development that is being keenly watched in other OECD countries. In many of these (e.g. France, Switzerland), there is no legal end to the operating licence, but continued operation is based on the outcomes of periodic safety reviews. This study analyses technical and economic data on the upgrade and lifetime extension experience in OECD countries. A multi-criteria assessment methodology is used considering various factors and parameters reflecting current and future financial conditions of operation, political and regulatory risks, the state of the plants' equipment and the general role of nuclear power in the country's energy policy. The report shows that long-term operation of nuclear power plants has significant economic advantages for most utilities envisaging LTO programmes. In most cases, the continued operation of NPPs for at least ten more years is profitable even taking into account the additional costs of post-Fukushima modifications, and remains cost-effective compared to alternative replacement sources

Safety of nuclear power plants: Operation. Safety requirements

International Nuclear Information System (INIS)

2004-01-01

The safety of a nuclear power plant is ensured by means of its proper siting, design, construction and commissioning, followed by the proper management and operation of the plant. In a later phase, proper decommissioning is required. This Safety Requirements publication supersedes the Code on the Safety of Nuclear Power Plants: Operation, which was issued in 1988 as Safety Series No. 50-C-O (Rev. 1). The purpose of this revision was: to restructure Safety Series No. 50-C-O (Rev. 1) in the light of the basic objectives, concepts and principles in the Safety Fundamentals publication The Safety of Nuclear Installations. To be consistent with the requirements of the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources. And to reflect current practice and new concepts and technical developments. Guidance on fulfillment of these Safety Requirements may be found in the appropriate Safety Guides relating to plant operation. The objective of this publication is to establish the requirements which, in the light of experience and the present state of technology, must be satisfied to ensure the safe operation of nuclear power plants. These requirements are governed by the basic objectives, concepts and principles that are presented in the Safety Fundamentals publication The Safety of Nuclear Installations. This publication deals with matters specific to the safe operation of land based stationary thermal neutron nuclear power plants, and also covers their commissioning and subsequent decommissioning

Safety of nuclear power plants: Operation. Safety requirements

International Nuclear Information System (INIS)

2003-01-01

The safety of a nuclear power plant is ensured by means of its proper siting, design, construction and commissioning, followed by the proper management and operation of the plant. In a later phase, proper decommissioning is required. This Safety Requirements publication supersedes the Code on the Safety of Nuclear Power Plants: Operation, which was issued in 1988 as Safety Series No. 50-C-O (Rev. 1). The purpose of this revision was: to restructure Safety Series No. 50-C-O (Rev. 1) in the light of the basic objectives, concepts and principles in the Safety Fundamentals publication The Safety of Nuclear Installations. To be consistent with the requirements of the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources. And to reflect current practice and new concepts and technical developments. Guidance on fulfillment of these Safety Requirements may be found in the appropriate Safety Guides relating to plant operation. The objective of this publication is to establish the requirements which, in the light of experience and the present state of technology, must be satisfied to ensure the safe operation of nuclear power plants. These requirements are governed by the basic objectives, concepts and principles that are presented in the Safety Fundamentals publication The Safety of Nuclear Installations. This publication deals with matters specific to the safe operation of land based stationary thermal neutron nuclear power plants, and also covers their commissioning and subsequent decommissioning

Safety of nuclear power plants: Operation. Safety requirements

International Nuclear Information System (INIS)

2000-01-01

The safety of a nuclear power plant is ensured by means of its proper siting, design, construction and commissioning, followed by the proper management and operation of the plant. In a later phase, proper decommissioning is required. This Safety Requirements publication supersedes the Code on the Safety of Nuclear Power Plants: Operation, which was issued in 1988 as Safety Series No. 50-C-O (Rev. 1). The purpose of this revision was: to restructure Safety Series No. 50-C-O (Rev. 1) in the light of the basic objectives, concepts and principles in the Safety Fundamentals publication The Safety of Nuclear Installations; to be consistent with the requirements of the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources; and to reflect current practice and new concepts and technical developments. Guidance on fulfillment of these Safety Requirements may be found in the appropriate Safety Guides relating to plant operation. The objective of this publication is to establish the requirements which, in the light of experience and the present state of technology, must be satisfied to ensure the safe operation of nuclear power plants. These requirements are governed by the basic objectives, concepts and principles that are presented in the Safety Fundamentals publication The Safety of Nuclear Installations. This publication deals with matters specific to the safe operation of land based stationary thermal neutron nuclear power plants, and also covers their commissioning and subsequent decommissioning

Radiation protection during operation of nuclear power plants

International Nuclear Information System (INIS)

1983-01-01

This Guide describes a Radiation Protection Programme for nuclear power plants. It includes: (1) An outline of the basic principles as well as practical aspects of the programme; (2) A description of the responsibilities of the operating organization to establish an effective programme based upon these principles; (3) A description of the administrative and technical measures to establish and implement the programme. This Guide also deals with the operational aspects to be considered by the operating organization in reviewing design in order to facilitate implementation of the Radiation Protection Programme. This Guide covers the requirements for a Radiation Protection Programme for all operational states of the nuclear power plant. It also includes guidelines for handling planned special exposures and for coping with unplanned exposures and contamination of personnel, areas, and equipment. Additional information concerning emergency situations involving releases of radioactive materials is given in Safety Guides 50-SG-O6, ''Preparedness of the Operating Organization (Licensee) for Emergencies at Nuclear Power Plants'', and 50-SG-G6, ''Preparedness of Public Authorities for Emergencies at Nuclear Power Plants''. This Guide covers the principles of dose limitation to site personnel and to the public, but it does not include detailed instructions on the techniques used for the actual measurement and evaluation of the exposures. This Guide does not include detailed instructions on environmental surveys, but it does mention principal steps in environmental monitoring which may be required for confirmation of the acceptability of radioactive discharges

Safe operation of power plants. Pt. 1

International Nuclear Information System (INIS)

Freymeyer, P.

1977-01-01

Electrotechniques were given a dominating role in the construction of nuclear power plants. The operation of power plants - particularly nuclear power plants - is impossible without the use of electrotechnical and control means. Despite of all reserve in the development and despite of the conservative attitude it is necessary to use the newest results of development and to incite the development ot new electronic systems for the solution of these tasks. (orig.) [de

Selected financial and operating ratios of public power systems

International Nuclear Information System (INIS)

Moody, D.

1993-01-01

In 1992, the American Public Power Association published its fourth report on financial and operating ratios. Based on 1990 data for the largest public power distribution systems, the report examined 21 categories of ratio indicators that can be used by public power distribution systems to assess their performance relative to the utilities of of comparable size and in the same geographic region. The 394 utilities summarized in the report are those that are required to file financial statements with the Energy Information Administration (EIA). Ratios were calculated from financial and operating data reported by utilities to the EIA. Data are presented for the following ratios: (1) revenue per kW/hr; (2) revenue for customer; (3) debt to total assets; (4) operating ratio; (5) current ratio; (6) times interest earned; (7) net income per revenue dollar; (8) uncollectible accounts per revenue dollar; (9) retail MW hr sales per manpower generation employee; (10) retail customers per nonpower generation employee; (11) total operation and maintenane expense per kW hr sold; (12) total operation and maintenance expense per retail customer; (13) total power supply expense kW hr sold; (14) purchased power cost per kW hr; (15) production expense per not kW hr; (16) retail customers for with reader; (17) distribution operation and maintenance expenses per retail customer; (18) distribution operation and maintenance expenses per circuit mile; (19) customer accounting, customer service and sales expenses per retail customers; (20) administration and general expenses per retail customer; (21) labor expense per worker-hour; (22) OSHA incidence rate; and (23) the system average interruptible duration index

Safety of Nuclear Power Plants: Commissioning and Operation

International Nuclear Information System (INIS)

2011-01-01

The safety of a nuclear power plant is ensured by means of proper site selection, design, construction and commissioning, and the evaluation of these, followed by proper management, operation and maintenance of the plant. In a later phase, a proper transition to decommissioning is required. The organization and management of plant operations ensures that a high level of safety is achieved through the effective management and control of operational activities. This publication is a revision of the Safety Requirements publication Safety of Nuclear Power Plants: Operation, which was issued in 2000 as IAEA Safety Standards Series No. NS-R-2. The purpose of this revision was to restructure Safety Standards Series No. NS-R-2 in the light of new operating experience and new trends in the nuclear industry; to introduce new requirements that were not included in Safety Standards Series No. NS-R-2 on the operation of nuclear power plants; and to reflect current practices, new concepts and technical developments. This update also reflects feedback on the use of the standards, both from Member States and from the IAEA's safety related activities. The publication is presented in the new format for Safety Requirements publications. The present publication reflects the safety principles of the Fundamental Safety Principles. It has been harmonized with IAEA Safety Standards Series No. GS-R-3 on The Management System for Facilities and Activities. Guidance on the fulfilment of the safety requirements is provided in supporting Safety Guides. The terminology used in this publication is defined and explained in the IAEA Safety Glossary. The objective of this publication is to establish the requirements which, in the light of experience and the present state of technology, must be satisfied to ensure the safe operation of nuclear power plants. These requirements are governed by the safety objective and safety principles that are established in the Fundamental Safety Principles. This

Vehicle-to-Grid for islanded power system operation in Bornholm

DEFF Research Database (Denmark)

Pillai, Jayakrishnan Radhakrishna; Bak-Jensen, Birgitte

2010-01-01

Vehicle-to-Grid (V2G) systems are an emerging concept of utilizing the battery storage of electric vehicles (EVs) for providing power system regulation services. This technology could be used to balance the variable electricity generated from various renewable energy sources. This article considers...... a model of an aggregated electric vehicle based battery storage to support an isolated power system operating with a large wind power penetration in the Danish island of Bornholm. From the simulation results, the EV battery storages represented by the V2G systems are able to integrate more fluctuating...... wind power. The islanded Bornholm power system operates satisfactory for the case of replacing most of the conventional generator reserves with V2G systems, which may represent a future operation scenario....

Operational limits and conditions for nuclear power plants

International Nuclear Information System (INIS)

1979-01-01

This Safety Guide was prepared as part of the Agency's programme, referred to as the NUSS programme, for establishing Codes of Practice and Safety Guides relating to nuclear power plants. It covers the concept of operational limits and conditions, their content as applicable to various types of thermal reactors, and the responsibilities of the operating organization regarding their establishment, modification, compliance and documentation. The principles of the operational limits and conditions are established in section 3 of the Agency's Code of Practice on Safety in Nuclear Power Plant Operation, including Commissioning and Decommissioning (IAEA Safety Series No. 50-C-O), which this present Safety Guide supplements. In order to present all pertinent information in this Guide, the provisions of section 3 of the Code are repeated

The reactor plasma physics of tandem mirror startup and fractional power operation

International Nuclear Information System (INIS)

Kantrowitz, F.D.; Firestone, M.A.; Guebel, D.M.; Mau, T.K.

1984-01-01

Plasma behavior and the performance of plasma technologies are studied during the startup and fractional power operation of tandem mirrors. Five phases of machine operation are identified, some of which require plasma. The plasma phases include plasma initiation and heating, a standby phase with plasma at the density and temperature characteristics of full design performance in reactors, a deuterium-tritium fractional power operating phase in which the fusion plasma undergoes staged power increases to full power, and rated power operating phase. Plasma initiation and heating uses electron cyclotron resonance heating preionization of background gas in the plug and ion cyclotron resonance heating in the central cell. Operation of the radio-frequency systems, the neutral beams, and the direct converter are studied to determine constraints affecting plasma operation. Studies of fractional power operation, carried out using a quasi-steady-state analysis, show that the plasma Q value can be made remarkably insensitive to the level of fusion power by controlling the plasma radius. Copper insert coils used to increase the maximum choke field require considerable power and cause the recirculating power fraction to increase sharply as the fusion power is reduced. Moreover, when an efficient drift pumping scheme is used, achieved improvements in plasma Q by using high-field choke coils must be weighed against their power consumption and other technological difficulties

Nuclear power plant operation experience - a feedback programme

International Nuclear Information System (INIS)

Banica, I.; Sociu, F.; Margaritescu, C.

1994-01-01

An effective high quality maintenance programme is required for the safe reliable operation of a nuclear power plant. To achieve the objectives of such a programme, both plant management and staff must be highly dedicated and motivated to perform high quality work at all levels. Operating and maintenance experience data collections and analysis are necessary in order to enhance the safety of the plant and reliability of the structures systems and components throughout their operating life. Significant events, but also minor incident, may reveal important deficiencies or negative trends adverse to safety. Therefore, a computer processing system for collecting, classifying and evaluating abnormal events or findings concerning operating-maintenance and for feeding back the results of the lessons learned from experience into the design and the operation of our nuclear power plant is considered to be of paramount importance. (Author)

The function of people in a nuclear power plant in operation

International Nuclear Information System (INIS)

Pickel, E.

1986-01-01

Based mainly on the operating experience of Obrigheim nuclear power plant - a two-loop pressurized water reactor with about 120,000 operating hours - the function of people in the very complex technical field of operation including supervision, maintenance and repair of a nuclear power plant is presented with special attention to safety related activities. The boundaries are indicated where automatic actions for safety and economic reasons are necessary and where manually operated systems are possible or even desirable. Typical examples and figures will show, how the operating people influenced the operation and availability of Obrigheim nuclear power plant. (orig./GL)

The optimization of nuclear power plants operation modes in emergency situations

Science.gov (United States)

Zagrebayev, A. M.; Trifonenkov, A. V.; Ramazanov, R. N.

2018-01-01

An emergency situations resulting in the necessity for temporary reactor trip may occur at the nuclear power plant while normal operating mode. The paper deals with some of the operation c aspects of nuclear power plant operation in emergency situations and during threatened period. The xenon poisoning causes limitations on the variety of statements of the problem of calculating characteristics of a set of optimal reactor power off controls. The article show a possibility and feasibility of new sets of optimization tasks for the operation of nuclear power plants under conditions of xenon poisoning in emergency circumstances.

Operating experience feedback on lose of offsite power supply for nuclear power plant

International Nuclear Information System (INIS)

Jiao Feng; Hou Qinmai; Che Shuwei

2013-01-01

The function of the service power system of a nuclear power plant is to provide safe and reliable power supply for the nuclear power plant facilities. The safety of nuclear power plant power supply is essential for nuclear safety. The serious accident of Fukushima Daiichi nuclear power plant occurred due to loss of service power and the ultimate heat sink. The service power system has two independent offsite power supplies as working power and auxiliary power. This article collected events of loss of offsite power supply in operating nuclear power plants at home and abroad, and analyzed the plant status and cause of loss of offsite power supply events, and proposed improvement measures for dealing with loss of offsite power supply. (authors)

14 CFR 101.25 - Operating limitations for Class 2-High Power Rockets and Class 3-Advanced High Power Rockets.

Science.gov (United States)

2010-01-01

... Power Rockets and Class 3-Advanced High Power Rockets. 101.25 Section 101.25 Aeronautics and Space... OPERATING RULES MOORED BALLOONS, KITES, AMATEUR ROCKETS AND UNMANNED FREE BALLOONS Amateur Rockets § 101.25 Operating limitations for Class 2-High Power Rockets and Class 3-Advanced High Power Rockets. When operating...

US nuclear power plant operating cost and experience summaries

International Nuclear Information System (INIS)

Kohn, W.E.; Reid, R.L.; White, V.S.

1998-02-01

NUREG/CR-6577, U.S. Nuclear Power Plant Operating Cost and Experience Summaries, has been prepared to provide historical operating cost and experience information on U.S. commercial nuclear power plants. Cost incurred after initial construction are characterized as annual production costs, representing fuel and plant operating and maintenance expenses, and capital expenditures related to facility additions/modifications which are included in the plant capital asset base. As discussed in the report, annual data for these two cost categories were obtained from publicly available reports and must be accepted as having different degrees of accuracy and completeness. Treatment of inconclusive and incomplete data is discussed. As an aid to understanding the fluctuations in the cost histories, operating summaries for each nuclear unit are provided. The intent of these summaries is to identify important operating events; refueling, major maintenance, and other significant outages; operating milestones; and significant licensing or enforcement actions. Information used in the summaries is condensed from annual operating reports submitted by the licensees, plant histories contained in Nuclear Power Experience, trade press articles, and the Nuclear Regulatory Commission (NRC) web site (www.nrc.gov)

US nuclear power plant operating cost and experience summaries

Energy Technology Data Exchange (ETDEWEB)

Kohn, W.E.; Reid, R.L.; White, V.S.

1998-02-01

NUREG/CR-6577, U.S. Nuclear Power Plant Operating Cost and Experience Summaries, has been prepared to provide historical operating cost and experience information on U.S. commercial nuclear power plants. Cost incurred after initial construction are characterized as annual production costs, representing fuel and plant operating and maintenance expenses, and capital expenditures related to facility additions/modifications which are included in the plant capital asset base. As discussed in the report, annual data for these two cost categories were obtained from publicly available reports and must be accepted as having different degrees of accuracy and completeness. Treatment of inconclusive and incomplete data is discussed. As an aid to understanding the fluctuations in the cost histories, operating summaries for each nuclear unit are provided. The intent of these summaries is to identify important operating events; refueling, major maintenance, and other significant outages; operating milestones; and significant licensing or enforcement actions. Information used in the summaries is condensed from annual operating reports submitted by the licensees, plant histories contained in Nuclear Power Experience, trade press articles, and the Nuclear Regulatory Commission (NRC) web site (www.nrc.gov).

Bound entanglement and local realism

International Nuclear Information System (INIS)

Kaszlikowski, Dagomir; Zukowski, Marek; Gnacinski, Piotr

2002-01-01

We show using a numerical approach, which gives necessary and sufficient conditions for the existence of local realism, that the bound entangled state presented in Bennett et al. [Phys. Rev. Lett. 82, 5385 (1999)] admits a local and realistic description. We also find the lowest possible amount of some appropriate entangled state that must be ad-mixed to the bound entangled state so that the resulting density operator has no local and realistic description and as such can be useful in quantum communication and quantum computation

The advantages and disadvantages of centralized control of air power at operational level

Science.gov (United States)

Arisoy, Uǧur

2014-05-01

People do not want to see and hear a war. In today's world, if war is inevitable, the use of air power is seen as the preferable means of conducting operations instead of financially burdensome land battles which are more likely to cause heavy loss of life. The use of Air Power has gained importance in NATO operations in the Post-Cold War era. For example, air power has undertaken a decisive role from the beginning to the end of the operation in Libya. From this point of view, the most important issue to consider is how to direct air power more effectively at operational level. NATO's Core JFAC (Joint Force Air Command) was established in 2012 to control joint air power at operational level from a single center. US had experienced JFAC aproach in the Operation Desert Storm in 1991. UK, France, Germany, Italy and Spain are also directing their air power from their JFAC structures. Joint air power can be directed from a single center at operational level by means of JFAC. JFAC aproach provides complex planning progress of Air Power to be controled faster in a single center. An Air Power with a large number of aircrafts, long range missiles of cutting-edge technology may have difficulties in achieving results unless directed effectively. In this article, directing air power more effectively at operational level has been studied in the framework of directing air power from a single center carried out by SWOT analysis technique. "Directing Air Power at operational level from a single center similar to JFAC-like structure" is compared with "Directing Air Power at operational level from two centers similar to AC (Air Command) + CAOC (Combined Air Operations Center) structure" As a result of this study, it is assessed that directing air power at operational level from a single center would bring effectiveness to the air campaign. The study examines directing air power at operational level. Developments at political, strategic and tactical levels have been ignored.

Knowledge base for power plant operation and its application to operation guide

International Nuclear Information System (INIS)

Doi, Atsushi; Sakaguchi, Toshiaki

1986-01-01

The present study is aimed at constructing a knowledge base for supervisory control operation in power plants and developing an operation guidance by using it. Examination is made to provide dignosis procedures on the basis of an existing alarm system. An operation guidance procedure for diagnosis is proposed which is to be followed when several alarms are sounded simultaneously in a power plant, and application of the procedure to an existing plant is examined. The operation manual for the plant includes 75 description items for six alarms. It is shown that the number of items related to these alarms can be reduced by 70 % by rearranging them according to the procedure. Another investigation is conducted to provide an operation manual for diagnosis to be used when one alarm is sounded in a plant. The quality of the manual developed is on nearly the same level with that for the existing plant examined. When a knowledge base is to be constructed from an existing operation manual, the processing operation generally requires a certain level of linguistic comprehension ability, such as for judgment of synonyms. It is demonstrated that the procedure proposed here is able to develop a high-quality knowledge base with standardized terminology. The procedure can also serve to construct operation manuals for plants in other industrial fields. (Nogami, K.)

Safety goals for nuclear power plant operation

International Nuclear Information System (INIS)

1983-05-01

This report presents and discusses the Nuclear Regulatory Commission's, Policy Statement on Safety Goals for the Operation of Nuclear Power Plants. The safety goals have been formulated in terms of qualitative goals and quantitative design objectives. The qualitative goals state that the risk to any individual member of the public from nuclear power plant operation should not be a significant contributor to that individual's risk of accidental death or injury and that the societal risks should be comparable to or less than those of viable competing technologies. The quantitative design objectives state that the average risks to individual and the societal risks of nuclear power plant operation should not exceed 0.1% of certain other risks to which members of the US population are exposed. A subsidiary quantitative design objective is established for the frequency of large-scale core melt. The significance of the goals and objectives, their bases and rationale, and the plan to evaluate the goals are provided. In addition, public comments on the 1982 proposed policy statement and responses to a series of questions that accompanied the 1982 statement are summarized

Quantum engine efficiency bound beyond the second law of thermodynamics.

Science.gov (United States)

Niedenzu, Wolfgang; Mukherjee, Victor; Ghosh, Arnab; Kofman, Abraham G; Kurizki, Gershon

2018-01-11

According to the second law, the efficiency of cyclic heat engines is limited by the Carnot bound that is attained by engines that operate between two thermal baths under the reversibility condition whereby the total entropy does not increase. Quantum engines operating between a thermal and a squeezed-thermal bath have been shown to surpass this bound. Yet, their maximum efficiency cannot be determined by the reversibility condition, which may yield an unachievable efficiency bound above unity. Here we identify the fraction of the exchanged energy between a quantum system and a bath that necessarily causes an entropy change and derive an inequality for this change. This inequality reveals an efficiency bound for quantum engines energised by a non-thermal bath. This bound does not imply reversibility, unless the two baths are thermal. It cannot be solely deduced from the laws of thermodynamics.

Low Power Operation of Temperature-Modulated Metal Oxide Semiconductor Gas Sensors.

Science.gov (United States)

Burgués, Javier; Marco, Santiago

2018-01-25

Mobile applications based on gas sensing present new opportunities for low-cost air quality monitoring, safety, and healthcare. Metal oxide semiconductor (MOX) gas sensors represent the most prominent technology for integration into portable devices, such as smartphones and wearables. Traditionally, MOX sensors have been continuously powered to increase the stability of the sensing layer. However, continuous power is not feasible in many battery-operated applications due to power consumption limitations or the intended intermittent device operation. This work benchmarks two low-power, duty-cycling, and on-demand modes against the continuous power one. The duty-cycling mode periodically turns the sensors on and off and represents a trade-off between power consumption and stability. On-demand operation achieves the lowest power consumption by powering the sensors only while taking a measurement. Twelve thermally modulated SB-500-12 (FIS Inc. Jacksonville, FL, USA) sensors were exposed to low concentrations of carbon monoxide (0-9 ppm) with environmental conditions, such as ambient humidity (15-75% relative humidity) and temperature (21-27 °C), varying within the indicated ranges. Partial Least Squares (PLS) models were built using calibration data, and the prediction error in external validation samples was evaluated during the two weeks following calibration. We found that on-demand operation produced a deformation of the sensor conductance patterns, which led to an increase in the prediction error by almost a factor of 5 as compared to continuous operation (2.2 versus 0.45 ppm). Applying a 10% duty-cycling operation of 10-min periods reduced this prediction error to a factor of 2 (0.9 versus 0.45 ppm). The proposed duty-cycling powering scheme saved up to 90% energy as compared to the continuous operating mode. This low-power mode may be advantageous for applications that do not require continuous and periodic measurements, and which can tolerate slightly higher

Safety of Nuclear Power Plants: Commissioning and Operation

International Nuclear Information System (INIS)

2011-01-01

This publication is a revision of Safety Requirements No. NS-R-2, Safety of Nuclear Power Plants: Operation, and has been extended to cover the commissioning stage. It describes the requirements to be met to ensure the safe operation of nuclear power plants. Over recent years there have been developments in areas such as long term operation, plant ageing, periodic safety review, probabilistic safety analysis and risk informed decision making processes. It became necessary to revise the IAEA's safety requirements in these areas and to correct and/or improve the publication on the basis of feedback from its application by both the IAEA and its Member States. In addition, the requirements are governed by, and must apply, the safety objective and safety principles that are established in the Fundamental Safety Principles. Contents: 1. Introduction; 2. Safety objectives and principles; 3. The management and organizational structure of the operating organization; 4. Management of operational safety; 5. Operational safety programmes; 6. Plant commissioning; 7. Plant operations; 8. Maintenance, testing, surveillance and inspection; 9. Preparation for decommissioning.

Integrated operation and management system for a 700MW combined cycle power plant

Energy Technology Data Exchange (ETDEWEB)

Shiroumaru, I. (Yanai Power Plant Construction Office, Chugoku Electric Power Co., Inc., 1575-5 Yanai-Miyamoto-Shiohama, Yanai-shi, Yamaguchi-ken (JP)); Iwamiya, T. (Omika Works, Hitachi, Ltd., 5-2-1 Omika-cho, Hitachi-shi, Ibaraki-ken (JP)); Fukai, M. (Hitachi Works, Hitachi, Ltd., 3-1-1 Saiwai-cho, Hitachi-shi, Ibaraki-ken (JP))

1992-03-01

Yanai Power Plant of the Chugoku Electric Power Co., Inc. (Yamaguchi Pref., Japan) is in the process of constructing a 1400MW state-of-the-art combined cycle power plant. The first phase, a 350MW power plant, started operation on a commercial basis in November, 1990. This power plant has achieved high efficiency and high operability, major features of a combined cycle power plant. The integrated operation and management system of the power plant takes care of operation, maintenance, control of general business, etc., and was built using the latest computer and digital control and communication technologies. This paper reports that it is expected that this system will enhance efficient operation and management for the power plant.

Ignition and time-dependent fractional power operation of tokamak reactors

International Nuclear Information System (INIS)

Vold, E.L.; Mau, T.K.; Conn, R.W.

1986-01-01

The eventual utilization of a tokamak fusion reactor for commercial power necessitates a thorough understanding of the operational requirements at full and fractional power levels and during transitions from one operating level to another. In this study we examine the role of burn control in maintaining the reactor plasma at equilibrium to avoid thermal runaway during fractional power operation. Because these requirements rely so heavily on the assumptions that govern the plasma transport, this study focuses on time-dependent analyses and a comparison of ignition requirements using a range of energy confinement

Operation management of thermal power plant. Karyoku plant no unten kanri

Energy Technology Data Exchange (ETDEWEB)

1994-06-15

Nowadays, thermal power plants are getting bigger and bigger in capacity. At the same time, high reliability to the frequent start and stop due to the demand change as well as effective economy. This paper describes the total operation management system. It included the start and stop, normal operation, specified operation, water quality, operation management involving the environmental problems, protection of machinery and equipment in case of emergency, measures against the failure, and the measures against the disaster. The outline of the normal operation is as follows: from the cost economical point of view, the kind of fuel is changed according to the load; i.e., coal for basic operation, LNG for basic to medium operation, and oil for medium to peak operation. The change in demand cannot be followed by the hydroelectric power. The adjustment of the power depending on the load change can be achieved by the thermal power generation. The automatic frequency control, economical load distribution control are also done. In the nighttime, the minimum load operation is required. The voltage change operation below the rated value or the phase-advancing operation is also done depending on the load conditions. 21 figs., 6 tabs.

ALARA for nuclear power plant operation

International Nuclear Information System (INIS)

Knapp, P.J.

1979-01-01

The concept of maintaining radiation exposures as low as reasonably achievable (ALARA) is outlined in connection with nuclear power plant operations. The basis of the concept is reviewed and a specific example of ALARA action is presented. (author)

Designing nuclear power plants for improved operation and maintenance

International Nuclear Information System (INIS)

1996-09-01

The purpose of this publication is to compile demonstrated, experience based design guidelines for improving the operability and maintainability of nuclear power plants. The guidelines are for use principally in the design of new nuclear power plants, but should also be useful in upgrading existing designs. The guidelines derive from the experience of operating and maintaining existing nuclear power plants as well as from the design of recent plants. In particular these guidelines are based on and consistent with both the EPRI advanced Light Water Reactor Utility Requirements Document, Volume 1, and the European Utility Requirements for LWR Nuclear Power Plants. 6 refs, 1 fig

Designing nuclear power plants for improved operation and maintenance

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-09-01

The purpose of this publication is to compile demonstrated, experience based design guidelines for improving the operability and maintainability of nuclear power plants. The guidelines are for use principally in the design of new nuclear power plants, but should also be useful in upgrading existing designs. The guidelines derive from the experience of operating and maintaining existing nuclear power plants as well as from the design of recent plants. In particular these guidelines are based on and consistent with both the EPRI advanced Light Water Reactor Utility Requirements Document, Volume 1, and the European Utility Requirements for LWR Nuclear Power Plants. 6 refs, 1 fig.

Power plant operation and management in a deregulated market

Energy Technology Data Exchange (ETDEWEB)

Carraretto, Cristian [Department of Mechanical Engineering, University of Padova, Via Venezia, 1-35131 Padova (Italy)

2006-05-15

This paper analyzes the influence of electricity deregulation on the design, operation and management of the power plants owned by strategic and non-strategic producers. After a sensitivity analysis aimed at finding market conditions of profitable operation for thermal and hydroelectric power plants, a Nash-equilibrium market model is used to determine producers' optimum strategies, depending on their relative market power and overall production characteristics. Attention is then focused on the operation of single thermal power plants. Their short-term management plans and consequent effects on emission levels and residual life are described. The available reserve for primary and secondary control deriving from producers' market strategies is discussed. Some design options to improve combined cycles contribution to reserve service are finally described. The paper discusses these problems with a general approach, and uses many cases and examples derived from the current Italian scenario. (author)

Power plant operation and management in a deregulated market

International Nuclear Information System (INIS)

Carraretto, Cristian

2006-01-01

This paper analyzes the influence of electricity deregulation on the design, operation and management of the power plants owned by strategic and non-strategic producers. After a sensitivity analysis aimed at finding market conditions of profitable operation for thermal and hydroelectric power plants, a Nash-equilibrium market model is used to determine producers' optimum strategies, depending on their relative market power and overall production characteristics. Attention is then focused on the operation of single thermal power plants. Their short-term management plans and consequent effects on emission levels and residual life are described. The available reserve for primary and secondary control deriving from producers' market strategies is discussed. Some design options to improve combined cycles contribution to reserve service are finally described. The paper discusses these problems with a general approach, and uses many cases and examples derived from the current Italian scenario. (author)

Optimal Bounds in Parametric LTL Games

Directory of Open Access Journals (Sweden)

Martin Zimmermann

2011-06-01

Full Text Available We consider graph games of infinite duration with winning conditions in parameterized linear temporal logic, where the temporal operators are equipped with variables for time bounds. In model checking such specifications were introduced as "PLTL" by Alur et al. and (in a different version called "PROMPT-LTL" by Kupferman et al.. We present an algorithm to determine optimal variable valuations that allow a player to win a game. Furthermore, we show how to determine whether a player wins a game with respect to some, infinitely many, or all valuations. All our algorithms run in doubly-exponential time; so, adding bounded temporal operators does not increase the complexity compared to solving plain LTL games.

Institute of nuclear power operations perspectives on PSA applications

International Nuclear Information System (INIS)

Webster, W.E.; Miller, W.J. Jr.

1996-01-01

The investment to develop a PSA is very substantial, and therefore, there is motivation to recover this investment through further use of the techniques used to develop it. It is not surprising that nuclear power plant staff are beginning to use PSA to make operational decisions. The Institute of Nuclear Power Operations is interested in those factors that impact the conduct of plant operations and therefore is actively monitoring the increased usage of PSA techniques. The purpose of this paper is to provide some thoughts and perspectives on the use of PSA as a factor in operational decision making, including decision making in activities performed by engineering, maintenance and operation personnel. (author)

Analysis Bounding Double Shell Tank (DST) Performance for the Hanford Tank Waste Operation Simulator Case 2

International Nuclear Information System (INIS)

SMITH, D.F.

2002-01-01

The purpose of this analysis is to compare the latest Tank Farm Contractor Operation and Utilization Plan (HNF-SD-WM-SP-012, Rev. 3) ''Case 2'' operating scenarios with a previous bounding analysis for the Double-Shell Tank (DST) System in order to provide a technical assessment against the current set of DST System performance requirements. A later update to HNF-SD-WM-SP-012 (i.e., Rev. 3A), released in late December 2001, did not impact the results of this analysis. This analysis provides technical support for revising the Performance Requirements for the Double-Shell Tank System, HNF-2168, Rev. 3, used as the basis for defining performance requirements noted in System Specification for the Double-Shell Tank System, HNF-SD-WM-TRD-007. Rev. 1

Amplification of non-Markovian decay due to bound state absorption into continuum

International Nuclear Information System (INIS)

Garmon, S.; Simine, L.; Segal, D.; Petrosky, T.

2013-01-01

It is known that quantum systems yield non-exponential (power law) decay on long time scales, associated with continuum threshold effects contributing to the survival probability for a prepared initial state. For an open quantum system consisting of a discrete state coupled to continuum, we study the case in which a discrete bound state of the full Hamiltonian approaches the energy continuum as the system parameters are varied. We find in this case that at least two regions exist yielding qualitatively different power law decay behaviors; we term these the long time 'near zone' and long time 'far zone'. In the near zone the survival probability falls off according to a t -1 power law, and in the far zone i t falls off as t -3 . We show that the timescale T Q separating these two regions is inversely related to the gap between the discrete bound state energy and the continuum threshold. In the case that the bound state is absorbed into the continuum and vanishes, then the time scale T Q diverges and the survival probability follows the t -1 power law even on asymptotic scales. Conversely, one could study the case of an anti-bound state approaching the threshold before being ejected from the continuum to form a bound state. Again the t -1 power law dominates precisely at the point of ejection. (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Demand side resource operation on the Irish power system with high wind power penetration

DEFF Research Database (Denmark)

Keane, A.; Tuohy, A.; Meibom, Peter

2011-01-01

part of the power system plant mix and contribute to the flexible operation of a power system. A model for demand side resources is proposed here that captures its key characteristics for commitment and dispatch calculations. The model is tested on the all island Irish power system, and the operation...... of the functions of conventional peaking plant. Demand side resources are also shown to be capable of improving the reliability of the system, with reserve capability identified as a key requirement in this respect....... of the model is simulated over one year in both a stochastic and deterministic mode, to illustrate the impact of wind and load uncertainty. The results illustrate that demand side resources can contribute to the efficient, flexible operation of systems with high penetrations of wind by replacing some...

Operating experience in nuclear power plants

International Nuclear Information System (INIS)

Anon.

1984-01-01

The nuclear power plants in the Federal Republic of Germany kept their portion of power supply into the public grid system constant in 1983, compared to 1982. The generation had an absolute increase of 3.6% and amounts now to 65.9 TWh. Particularly mentioned should be the generation of the Grafenrheinfeld Nuclear Power Plant which is holding the 'World Record' with 9.969 TWh. The availability of the plants was generally satisfactory, as far as long-term retrofit measures with long outage periods were not necessary, as it was the case in Brunsbuettel and Wuergassen. The planned retrofit phases have been completed in all power plants. As far as safety is concerned, there was no reason to recommended a change of the present fundamental planning- and operation aspects. (orig.) [de

Extensions of the results on powers of -hyponormal and -hyponormal operators

Directory of Open Access Journals (Sweden)

Yang Changsen

2006-01-01

Full Text Available Firstly, we will show the following extension of the results on powers of -hyponormal and -hyponormal operators: let and be positive integers, if is -hyponormal for , then: (i in case , and hold, (ii in case , and hold. Secondly, we will show an estimation on powers of -hyponormal operators for which implies the best possibility of our results. Lastly, we will show a parallel estimation on powers of -hyponormal operators as follows: let , then the following hold for each positive integer and : (i there exists a log-hyponormal operator such that , (ii there exists a -hyponormal operator such that .

14 CFR 25.672 - Stability augmentation and automatic and power-operated systems.

Science.gov (United States)

2010-01-01

... power-operated systems. 25.672 Section 25.672 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Construction Control Systems § 25.672 Stability augmentation and automatic and power-operated systems. If the functioning of stability augmentation or other automatic or power-operated systems is necessary to show...

14 CFR 23.672 - Stability augmentation and automatic and power-operated systems.

Science.gov (United States)

2010-01-01

... power-operated systems. 23.672 Section 23.672 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... and power-operated systems. If the functioning of stability augmentation or other automatic or power-operated systems is necessary to show compliance with the flight characteristics requirements of this part...

A methodology for nuclear power plant operational events evaluation

International Nuclear Information System (INIS)

Araujo, Jeferson

2015-01-01

Operational events are normal occurrences in industrial plants and in nuclear power plants. The evaluation of operational events gains importance when it comes specifically to nuclear power plants due to the proportions that the impact and the consequences of these events may cause to the installation itself, their workers, the external area of the nuclear installation, the environment and to the public in general. These consequences, for the operation of these facilities can range from very little, until the consequences that lead to accidents and can cause significant impacts. Operational events may be associated or have influence in many fields of knowledge, such as operation, maintenance, engineering, Radiological Protection, physical protection, chemistry, Human or Organizational Factors and external events, among others. The accident at the Fukushima Daichi nuclear power plant, shows the importance of exhausting all the studies concerning operational events in order to improve the operational safety of nuclear plants, considering all the causes and possible consequences. In this context, the evaluation of operational events discipline emerges as an important and relevant tool to contribute to the maintenance and/or improvement of the operational safety of nuclear installations. Not without reason the nuclear industry actively participates in programs of exchange of operational experience, where relevant events are thoroughly evaluated and discussed in specific forums, such as power plant operators, regulators and/or joint technical meetings, always with the purpose to prevent, minimize or mitigate its consequences. Any evaluation of operational events passes necessarily by an in-depth study of the circumstances of the event, culminating with the identification of your cause and proposition of corrective actions to prevent recurrence of similar events. Additionally, the events should not be studied individually, but evaluated within a temporal context in order

A methodology for nuclear power plant operational events evaluation

Energy Technology Data Exchange (ETDEWEB)

Araujo, Jeferson, E-mail: jeferson@cnen.gov.br [Comissao Nacional de Energia Nuclear (CGRC/CNEN), Rio de janeiro, RJ (Brazil). Coordenacao Geral de Reatores e do Ciclo de Combustivel; Costa, Sergio Dias, E-mail: sergiodiascosta@hotmail.com [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

2015-07-01

Operational events are normal occurrences in industrial plants and in nuclear power plants. The evaluation of operational events gains importance when it comes specifically to nuclear power plants due to the proportions that the impact and the consequences of these events may cause to the installation itself, their workers, the external area of the nuclear installation, the environment and to the public in general. These consequences, for the operation of these facilities can range from very little, until the consequences that lead to accidents and can cause significant impacts. Operational events may be associated or have influence in many fields of knowledge, such as operation, maintenance, engineering, Radiological Protection, physical protection, chemistry, Human or Organizational Factors and external events, among others. The accident at the Fukushima Daichi nuclear power plant, shows the importance of exhausting all the studies concerning operational events in order to improve the operational safety of nuclear plants, considering all the causes and possible consequences. In this context, the evaluation of operational events discipline emerges as an important and relevant tool to contribute to the maintenance and/or improvement of the operational safety of nuclear installations. Not without reason the nuclear industry actively participates in programs of exchange of operational experience, where relevant events are thoroughly evaluated and discussed in specific forums, such as power plant operators, regulators and/or joint technical meetings, always with the purpose to prevent, minimize or mitigate its consequences. Any evaluation of operational events passes necessarily by an in-depth study of the circumstances of the event, culminating with the identification of your cause and proposition of corrective actions to prevent recurrence of similar events. Additionally, the events should not be studied individually, but evaluated within a temporal context in order

Plant operational states analysis in low power and shutdown PSA

International Nuclear Information System (INIS)

He Jiandong; Qiu Yongping; Zhang Qinfang; An Hongzhen; Li Maolin

2013-01-01

The purpose of Plant Operational States (POS) analysis is to disperse the continuous and dynamic process of low power and shutdown operation, which is the basis of developing event tree models for accident sequence analysis. According to the design of a 300 MW Nuclear Power Plant Project, operating experience and procedures of the reference plant, a detailed POS analysis is carried out based on relative criteria. Then, several kinds of POS are obtained, and the duration of each POS is calculated according to the operation records of the reference plant. The POS analysis is an important element in low power and shutdown PSA. The methodology and contents provide reference for POS analysis. (authors)

Operation of SST-1 TF power supply during SST-1 campaigns

International Nuclear Information System (INIS)

Sharma, Dinesh Kumar; Vora, Murtuza M.; Ojha, Amit; Singh, Akhilesh Kumar; Bhavsar, Chirag

2015-01-01

Highlights: • SST-1 TF power supply is 12 pulse SCR converter circuit. • TF power supply protection, measurement and control scheme are explained. • Quench, emergency and normal shot process is explained and results of SST-1 campaigns are shown. • Dynamic control of TF current. • The paper shows the results of last ten SST-1 campaigns. - Abstract: SST-1 TF power supply provides the direct current for the required magnetic field of TF coil. TF power supply includes transformer, 12-pulse converter, bus bar, water-cooled cable, protection and measuring equipments, and isolator, VME DAC system and GUI software. TF power supply is operated through GUI software built in TCL/Tk. VME DAC system monitors the parameters, provides On/Off commands, voltage and current references and initiates predefined reference to emergency shutdown. The emergency shutdown is hardwired to TF power supply from central control. During quench power supply converter opens DCCB and dump resistor is connected in the circuit and VME DAC system acquires bus bar voltage, dump voltage and dump current. Operation of TF power supply also requires monitoring of SCR and transformer temperature and water flow rate of water-cooled cable during high current long pulse shot. Before start up of TF power supply a quench simulation is performed to check the readiness of protection. This paper describes pre startup operation, normal shot operation, emergency and quench process, dynamic control and complete shutdown operation of TF power supply.

Operation of SST-1 TF power supply during SST-1 campaigns

Energy Technology Data Exchange (ETDEWEB)

Sharma, Dinesh Kumar, E-mail: dinesh@ipr.res.in; Vora, Murtuza M.; Ojha, Amit; Singh, Akhilesh Kumar; Bhavsar, Chirag

2015-10-15

Highlights: • SST-1 TF power supply is 12 pulse SCR converter circuit. • TF power supply protection, measurement and control scheme are explained. • Quench, emergency and normal shot process is explained and results of SST-1 campaigns are shown. • Dynamic control of TF current. • The paper shows the results of last ten SST-1 campaigns. - Abstract: SST-1 TF power supply provides the direct current for the required magnetic field of TF coil. TF power supply includes transformer, 12-pulse converter, bus bar, water-cooled cable, protection and measuring equipments, and isolator, VME DAC system and GUI software. TF power supply is operated through GUI software built in TCL/Tk. VME DAC system monitors the parameters, provides On/Off commands, voltage and current references and initiates predefined reference to emergency shutdown. The emergency shutdown is hardwired to TF power supply from central control. During quench power supply converter opens DCCB and dump resistor is connected in the circuit and VME DAC system acquires bus bar voltage, dump voltage and dump current. Operation of TF power supply also requires monitoring of SCR and transformer temperature and water flow rate of water-cooled cable during high current long pulse shot. Before start up of TF power supply a quench simulation is performed to check the readiness of protection. This paper describes pre startup operation, normal shot operation, emergency and quench process, dynamic control and complete shutdown operation of TF power supply.

Operation of Finnish nuclear power plants

International Nuclear Information System (INIS)

Tossavainen, K.

1992-03-01

The Finnish nuclear power plant units Loviisa 1 and 2 as well as TVO I and II were in operation for almost the whole third quarter of 1991. Longer interruptions in electricity generation were caused by the annual maintenances of the Loviisa plant units. The load factor average was 81.7 %. In a test conducted during the annual maintenance outage of Loviisa 1 it was detected that the check valve of the discharge line of one pressurized emergency make-up tank did not open sufficiently at the tank's hydrostatic pressure. In connection with a 1988 modification, a too tightly dimensioned bearing had been mounted on the valve's axle rod and the valve had not been duly tested after the operation. The event is classified as Level 1 on the International Nuclear Event Scale. Other events in this quarter which are classified according to the International Nuclear Event Scale are Level Zero (Below Scale). Occupational radiation doses and releases of radioactive material off-site were below authorised limits in this quarter. Only small amounts of radioactive materials originating in nuclear power plants were detected in samples taken in the vicinity of nuclear power plants

Development of a computerized operator support system for BWR power plant

International Nuclear Information System (INIS)

Monta, K.; Sekimizu, K.; Sato, N.; Araki, T.; Mori, N.

1985-01-01

A computerized operator support system for BWR power plant has been developed since 1980 supported by the Japanese government. The main functions of the systems are post trip operational guidance, disturbance analysis, standby system management, operational margin monitoring and control rod operational guidance. The former two functions aim at protection against incidents during operation of nuclear power plants and the latter three functions aim at their prevention. As the final stage of the development, these functions are combined with the plant supervision function and are organized as an advanced man-machine interface for BWR power plant. During the above process, operator task analyses are performed to enable synthesis of these support functions for right fit to operator tasks and to realize a hierarchical structure for CRT displays for right fit to operators cognitive needs. (author)

Entropic Lower Bound for Distinguishability of Quantum States

Directory of Open Access Journals (Sweden)

Seungho Yang

2015-01-01

Full Text Available For a system randomly prepared in a number of quantum states, we present a lower bound for the distinguishability of the quantum states, that is, the success probability of determining the states in the form of entropy. When the states are all pure, acquiring the entropic lower bound requires only the density operator and the number of the possible states. This entropic bound shows a relation between the von Neumann entropy and the distinguishability.

Annual report of operation management in nuclear power stations, fiscal year 1985

International Nuclear Information System (INIS)

1986-09-01

Twenty years have elapsed since the first practical nuclear reactor in Japan started the operation. In the generated power in fiscal year 1985, that of nuclear power stations for the first time overtook that of thermal power stations, and now the age of nuclear power as the main and oil power as the subordinate has begun. As of the end of fiscal year 1985, there were 32 nuclear power plants in operation, having total output capacity of 24.521 million kW. In fiscal year 1985, nuclear power plants generated about 159 billion kWh, which is about 26 % of electric power supply. As to the capacity factor, 76 % was attained in fiscal year 1985, and this is ranked in the top group of LWR-operating countries in the world. It showed that the Japanese technology of nuclear power generation is at the top level in the world. However, in order to increase nuclear power generation and to accomplish the role of main electric power source hereafter, it is necessary to further increase the reliability and economical efficiency. The list of nuclear power stations in Japan, the state of operation of nuclear power stations, the state of accidents and troubles, the state of regular inspection, the management of radioactive wastes and the radiation exposure of workers in nuclear power stations, the operational management and others are reported. (Kako, I.)

Determination Of Maximum Power Of The RSG-Gas At Power Operation Mode Using One Line Cooling System

International Nuclear Information System (INIS)

Hastuti, Endiah Puji; Kuntoro, Iman; Darwis Isnaini, M.

2000-01-01

In the frame of minimizing the operation-cost, operation mode using one line cooling system is being evaluated. Maximum reactor power shall be determined to assure that the existing safety criteria are not violated. The analysis was done by means of a core thermal hydraulic code, COOLOD-N. The code solves core thermal hydraulic equation at steady state conditions. By varying the reactor power as the input, thermal hydraulic parameters such as fuel cladding and fuel meat temperatures as well as safety margin against flow instability were calculated. Imposing the safety criteria to the results, maximum permissible power for this operation was obtained as much as 17.1 MW. Nevertheless, for operation the maximum power is limited to 15MW

Method for Prediction of the Power Output from Photovoltaic Power Plant under Actual Operating Conditions

Science.gov (United States)

Obukhov, S. G.; Plotnikov, I. A.; Surzhikova, O. A.; Savkin, K. D.

2017-04-01

Solar photovoltaic technology is one of the most rapidly growing renewable sources of electricity that has practical application in various fields of human activity due to its high availability, huge potential and environmental compatibility. The original simulation model of the photovoltaic power plant has been developed to simulate and investigate the plant operating modes under actual operating conditions. The proposed model considers the impact of the external climatic factors on the solar panel energy characteristics that improves accuracy in the power output prediction. The data obtained through the photovoltaic power plant operation simulation enable a well-reasoned choice of the required capacity for storage devices and determination of the rational algorithms to control the energy complex.

Generalizations of the results on powers of -hyponormal operators

Directory of Open Access Journals (Sweden)

Ito Masatoshi

2001-01-01

Full Text Available Recently, as a nice application of Furuta inequality, Aluthge and Wang (J. Inequal. Appl., 3 (1999, 279–284 showed that "if is a -hyponormal operator for , then is -hyponormal for any positive integer ," and Furuta and Yanagida (Scientiae Mathematicae, to appear proved the more precise result on powers of -hyponormal operators for . In this paper, more generally, by using Furuta inequality repeatedly, we shall show that "if is a -hyponormal operator for , then is -hyponormal for any positive integer " and a generalization of the results by Furuta and Yanagida in (Scientiae Mathematicae, to appear on powers of -hyponormal operators for .

Initiating nuclear power programmes: Responsibilities and capabilities of owners and operators

International Nuclear Information System (INIS)

2009-01-01

There is an increasing interest in developing nuclear power due to growing energy needs, limitations on natural resources and concern for the environment. However, the introduction and development of nuclear power is a major undertaking. This requires building the necessary national infrastructure to construct and operate nuclear power plants in a safe, secure and technically sound manner. Many IAEA Member States that do not yet have nuclear power programmes have expressed their interest to the IAEA about the possibility of introducing nuclear power plants to help meet their energy needs. To assist these Member States, the IAEA is preparing a series of guides and reports. An overall description of the issues was presented by the IAEA in a brochure entitled Considerations to Launch a Nuclear Power Programme (GOV/INF/2007/2), which was targeted mainly at policy makers. A subsequent IAEA Nuclear Energy Series publication, Milestones in the Development of a National Infrastructure for Nuclear Power (NG-G-3.1), describes 19 infrastructure issues that should be addressed through the three phases of development outlined in the brochure, Considerations to Launch a Nuclear Power Programme. The IAEA is preparing a number of guides addressing these issues. Once a firm decision has been made by a government to proceed with the development of a nuclear programme, a number of organizations must be developed. A key organization for the successful construction and operation of the first nuclear power plant is the owner/operator, who provides ownership and management of the project. The owner/operator must clearly understand what must be done and how it has to act, who are partners and supporters and the corresponding interactions that have to be established. The owner or operator may be state owned or a private company. It may be an existing utility, or a specially established project organization. Its responsibilities include bidding, construction, licensing, commissioning

Operational experience, availability and reliability of nuclear power plants

International Nuclear Information System (INIS)

Kueffer, K.

1980-01-01

This lecture - presents a survey on nuclear power production and plant performance in the Western World covering all reactor types and light-water reactors in particular and discusses key parameters such as load factors and non-availability analysis. - outlines the main reasons for the reliable performance of Swiss nuclear power plants - quality equipment - operator qualification and training - engineering know how on site - maintenance philosophy and outage planning - information system and feedback of experience - explains the management functions as applied at the Beznau Nuclear Power Station to ensure high power productivity and reliability - improvement - a feedback control system - analysis of production losses - optimization in shut-down planning - minimizing disturbances during plant operation - optimizing personnel qualification and efficiency. (orig.)

Recent Operating Experience involving Power Electronics Failure in Korea Nuclear Power Plants

International Nuclear Information System (INIS)

Lee, Jaedo

2015-01-01

Recently, modern power electronics devices for electrical component were steadily increased in electrical systems which used for main power control and protection. To upgrade the system reliability we recommended the redundancy for electrical equipment trip system. The past several years, Korean Nuclear power plants have changed the electrical control and protection systems (Auto Voltage Regulator, Power Protection Relay) for main generator and main power protection relay systems. In this paper we deal with operating experience involving modern solid state power electronics failure in Korean nuclear power plants. One of the failures we will discuss the degraded phenomenon of power electronics device for CEDMCS(Control Element Drive Mechanism Control System). As the result of the failure we concerned about the modification for trip source of main generator excitation systems and others. We present an interesting issue for modern solid state devices (IGBT, Thyristors). (authors)

Potential radiological impacts of upper-bound operational accidents during proposed waste disposal alternatives for Hanford defense waste

Energy Technology Data Exchange (ETDEWEB)

Mishima, J.; Sutter, S.L.; Hawley, K.A.; Jenkins, C.E.; Napier, B.A.

1986-02-01

The Geologic Disposal Alternative, the In-Place Stabilization and Disposal Alternative, and the Reference Disposal Alternative are being evaluated for disposal of Hanford defense high-level, transuranic, and tank wastes. Environmental impacts associated with disposal of these wastes according to the alternatives listed above include potential doses to the downwind population from operation during the application of the handling and processing techniques comprising each disposal alternative. Scenarios for operational accident and abnormal operational events are postulated, on the basis of the currently available information, for the application of the techniques employed for each waste class for each disposal alternative. From these scenarios, an upper-bound airborne release of radioactive material was postulated for each waste class and disposal alternative. Potential downwind radiologic impacts were calculated from these upper-bound events. In all three alternatives, the single postulated event with the largest calculated radiologic impact for any waste class is an explosion of a mixture of ferri/ferro cyanide precipitates during the mechanical retrieval or microwave drying of the salt cake in single shell waste tanks. The anticipated downwind dose (70-year dose commitment) to the maximally exposed individual is 3 rem with a total population dose of 7000 man-rem. The same individual would receive 7 rem from natural background radiation during the same time period, and the same population would receive 3,000,000 man-rem. Radiological impacts to the public from all other postulated accidents would be less than that from this accident; furthermore, the radiological impacts resulting from this accident would be less than one-half that from the natural background radiation dose.

Potential radiological impacts of upper-bound operational accidents during proposed waste disposal alternatives for Hanford defense waste

International Nuclear Information System (INIS)

Mishima, J.; Sutter, S.L.; Hawley, K.A.; Jenkins, C.E.; Napier, B.A.

1986-02-01

The Geologic Disposal Alternative, the In-Place Stabilization and Disposal Alternative, and the Reference Disposal Alternative are being evaluated for disposal of Hanford defense high-level, transuranic, and tank wastes. Environmental impacts associated with disposal of these wastes according to the alternatives listed above include potential doses to the downwind population from operation during the application of the handling and processing techniques comprising each disposal alternative. Scenarios for operational accident and abnormal operational events are postulated, on the basis of the currently available information, for the application of the techniques employed for each waste class for each disposal alternative. From these scenarios, an upper-bound airborne release of radioactive material was postulated for each waste class and disposal alternative. Potential downwind radiologic impacts were calculated from these upper-bound events. In all three alternatives, the single postulated event with the largest calculated radiologic impact for any waste class is an explosion of a mixture of ferri/ferro cyanide precipitates during the mechanical retrieval or microwave drying of the salt cake in single shell waste tanks. The anticipated downwind dose (70-year dose commitment) to the maximally exposed individual is 3 rem with a total population dose of 7000 man-rem. The same individual would receive 7 rem from natural background radiation during the same time period, and the same population would receive 3,000,000 man-rem. Radiological impacts to the public from all other postulated accidents would be less than that from this accident; furthermore, the radiological impacts resulting from this accident would be less than one-half that from the natural background radiation dose

Application of bounding spectra to seismic design of piping based on the performance of above ground piping in power plants subjected to strong motion earthquakes

International Nuclear Information System (INIS)

Stevenson, J.D.

1995-02-01

This report extends the potential application of Bounding Spectra evaluation procedures, developed as part of the A-46 Unresolved Safety Issue applicable to seismic verification of in-situ electrical and mechanical equipment, to in-situ safety related piping in nuclear power plants. The report presents a summary of earthquake experience data which define the behavior of typical U.S. power plant piping subject to strong motion earthquakes. The report defines those piping system caveats which would assure the seismic adequacy of the piping systems which meet those caveats and whose seismic demand are within the bounding spectra input. Based on the observed behavior of piping in strong motion earthquakes, the report describes the capabilities of the piping system to carry seismic loads as a function of the type of connection (i.e. threaded versus welded). This report also discusses in some detail the basic causes and mechanisms for earthquake damages and failures to power plant piping systems

Inertial Fusion Power Plant Concept of Operations and Maintenance

Energy Technology Data Exchange (ETDEWEB)

Anklam, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Knutson, B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Dunne, A. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kasper, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sheehan, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Lang, D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Roberts, V. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Mau, D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2015-01-15

Parsons and LLNL scientists and engineers performed design and engineering work for power plant pre-conceptual designs based on the anticipated laser fusion demonstrations at the National Ignition Facility (NIF). Work included identifying concepts of operations and maintenance (O&M) and associated requirements relevant to fusion power plant systems analysis. A laser fusion power plant would incorporate a large process and power conversion facility with a laser system and fusion engine serving as the heat source, based in part on some of the systems and technologies advanced at NIF. Process operations would be similar in scope to those used in chemical, oil refinery, and nuclear waste processing facilities, while power conversion operations would be similar to those used in commercial thermal power plants. While some aspects of the tritium fuel cycle can be based on existing technologies, many aspects of a laser fusion power plant presents several important and unique O&M requirements that demand new solutions. For example, onsite recovery of tritium; unique remote material handling systems for use in areas with high radiation, radioactive materials, or high temperatures; a five-year fusion engine target chamber replacement cycle with other annual and multi-year cycles anticipated for major maintenance of other systems, structures, and components (SSC); and unique SSC for fusion target waste recycling streams. This paper describes fusion power plant O&M concepts and requirements, how O&M requirements could be met in design, and how basic organizational and planning issues can be addressed for a safe, reliable, economic, and feasible fusion power plant.

Power grid operation risk management: V2G deployment for sustainable development

Science.gov (United States)

Haddadian, Ghazale J.

The production, transmission, and delivery of cost--efficient energy to supply ever-increasing peak loads along with a quest for developing a low-carbon economy require significant evolutions in the power grid operations. Lower prices of vast natural gas resources in the United States, Fukushima nuclear disaster, higher and more intense energy consumptions in China and India, issues related to energy security, and recent Middle East conflicts, have urged decisions makers throughout the world to look into other means of generating electricity locally. As the world look to combat climate changes, a shift from carbon-based fuels to non-carbon based fuels is inevitable. However, the variability of distributed generation assets in the electricity grid has introduced major reliability challenges for power grid operators. While spearheading sustainable and reliable power grid operations, this dissertation develops a multi-stakeholder approach to power grid operation design; aiming to address economic, security, and environmental challenges of the constrained electricity generation. It investigates the role of Electric Vehicle (EV) fleets integration, as distributed and mobile storage assets to support high penetrations of renewable energy sources, in the power grid. The vehicle-to-grid (V2G) concept is considered to demonstrate the bidirectional role of EV fleets both as a provider and consumer of energy in securing a sustainable power grid operation. The proposed optimization modeling is the application of Mixed-Integer Linear Programing (MILP) to large-scale systems to solve the hourly security-constrained unit commitment (SCUC) -- an optimal scheduling concept in the economic operation of electric power systems. The Monte Carlo scenario-based approach is utilized to evaluate different scenarios concerning the uncertainties in the operation of power grid system. Further, in order to expedite the real-time solution of the proposed approach for large-scale power systems

A Real-Time Simulation Platform for Power System Operation

DEFF Research Database (Denmark)

Cha, Seung-Tae; Østergaard, Jacob; Wu, Qiuwei

2010-01-01

This paper describes the real-time digital simulation platform that can be used for power system operation, analysis, and power system modeling. This particular platform gives grid operators, planners and researchers the opportunity to observe how a power system behaves and can be used...... in real time. Various phenomena commonly encountered when dealing with the two-area system is studied. Despite its small size, it mimics very closely the behavior of typical systems in actual operation. The electromagnetic transient type of simulation made in RSCAD enables the study of fast and detailed...... phenomena like single-phase faults in the two-area network and to observe their effects on a larger time scale. Also, the case study of 11 bus system with 5 generators has been also used and the results are presented....

Low Power Operation of Temperature-Modulated Metal Oxide Semiconductor Gas Sensors

Directory of Open Access Journals (Sweden)

Javier Burgués

2018-01-01

Full Text Available Mobile applications based on gas sensing present new opportunities for low-cost air quality monitoring, safety, and healthcare. Metal oxide semiconductor (MOX gas sensors represent the most prominent technology for integration into portable devices, such as smartphones and wearables. Traditionally, MOX sensors have been continuously powered to increase the stability of the sensing layer. However, continuous power is not feasible in many battery-operated applications due to power consumption limitations or the intended intermittent device operation. This work benchmarks two low-power, duty-cycling, and on-demand modes against the continuous power one. The duty-cycling mode periodically turns the sensors on and off and represents a trade-off between power consumption and stability. On-demand operation achieves the lowest power consumption by powering the sensors only while taking a measurement. Twelve thermally modulated SB-500-12 (FIS Inc. Jacksonville, FL, USA sensors were exposed to low concentrations of carbon monoxide (0–9 ppm with environmental conditions, such as ambient humidity (15–75% relative humidity and temperature (21–27 °C, varying within the indicated ranges. Partial Least Squares (PLS models were built using calibration data, and the prediction error in external validation samples was evaluated during the two weeks following calibration. We found that on-demand operation produced a deformation of the sensor conductance patterns, which led to an increase in the prediction error by almost a factor of 5 as compared to continuous operation (2.2 versus 0.45 ppm. Applying a 10% duty-cycling operation of 10-min periods reduced this prediction error to a factor of 2 (0.9 versus 0.45 ppm. The proposed duty-cycling powering scheme saved up to 90% energy as compared to the continuous operating mode. This low-power mode may be advantageous for applications that do not require continuous and periodic measurements, and which can tolerate

Computational Efficiency of Economic MPC for Power Systems Operation

DEFF Research Database (Denmark)

Standardi, Laura; Poulsen, Niels Kjølstad; Jørgensen, John Bagterp

2013-01-01

In this work, we propose an Economic Model Predictive Control (MPC) strategy to operate power systems that consist of independent power units. The controller balances the power supply and demand, minimizing production costs. The control problem is formulated as a linear program that is solved...

On the absence of resonances for Schrodinger operators with non-trapping potentials in the classical limit

International Nuclear Information System (INIS)

Klein, M.

1985-01-01

We provide bounds on resolvents of dilated Schrodinger operators via exterior scaling. This depends crucially on a non-trapping condition on the potential which has a clear interpretation in classical mechanics. These bounds are a powerful tool to prove absence of resonances due to the tail of the potential in the shape resonance problem

Operation of Finnish nuclear power plants

International Nuclear Information System (INIS)

Tossavainen, K.

1991-08-01

In the Quarterly Reports on the operation of the Finnish nuclear power plants such events and observations are described relating to nuclear and radiation safety which the Finnish Centre for Radiation and Nuclear Safety considers safety significant. Also other events of general interest are reported. The report also includes a summary of the radiation safety of the plants' workers and the environment, as well as tabulated data on the production and load factors of the plants. The Finnish nuclear power plant units Loviisa 1 and 2 as well as TVO I and II were in commercial operation during the whole first quarter of 1991. The load factor average was 99.1 %. Failures have been detected in the uppermost spacing lattices of nuclear fuel bundles removed from the Loviisa nuclear reactors. Further investigations into the significance of the failures have been initiated. In this quarter, renewed cooling systems for the instrumentation area were introduced at Loviisa 1. The modifications made in the systems serve to ensure reliable cooling of the area even during the hottest summer months when the possibility exists that the temperature of the automation equipment could rise too high causing malfunctions which could endanger plant safety. Occupational radiation doses and external releases of radioactivity were below prescribed limits in this quarter. Only small amounts of radioactive substances originating in nuclear power plants were detected in samples taken in the vicinity of nuclear power plants

Training device for nuclear power plant operators

International Nuclear Information System (INIS)

Schoessow, G. J.

1985-01-01

A simulated nuclear energy power plant system with visible internal working components comprising a reactor adapted to contain a liquid with heating elements submerged in the liquid and capable of heating the liquid to an elevated temperature, a steam generator containing water and a heat exchanger means to receive the liquid at an elevated temperature, transform the water to steam, and return the spent liquid to the reactor; a steam turbine receiving high energy steam to drive the turbine and discharging low energy steam to a condenser where the low energy steam is condensed to water which is returned to the steam generator; an electric generator driven by the turbine; indicating means to identify the physical status of the reactor and its contents; and manual and automatic controls to selectively establish normal or abnormal operating conditions in the reactor, steam generator, pressurizer, turbine, electric generator, condenser, and pumps; and to be selectively adjusted to bring the reactor to acceptable operating condition after being placed in an abnormal operation. This device is particularly useful as an education device in demonstrating nuclear reactor operations and in training operating personnel for nuclear reactor systems and also as a device for conducting research on various safety systems to improve the safety of nuclear power plants

Smart Shipboard Power System Operation and Management

DEFF Research Database (Denmark)

Kanellos, Fotis D.; Anvari-Moghaddam, Amjad; Guerrero, Josep M.

2016-01-01

as all-electric ships (AESs), the need for more cost-effective and emission-aware solutions is augmented. Such onboard systems are prone to sudden load variations due to the changing weather conditions as well as mission profile, thus they require effective power management systems (PMSs) to operate...... optimally under different working conditions. In this paper, coordinated optimal power management at the supply/demand side of a given AES is studied with regard to different objectives and related technical/environmental constraints. The optimal power management problem is formulated as a mixed...

Validity and design of environmental surveillance systems for operating nuclear power plants. Final report

International Nuclear Information System (INIS)

Eichholz, G.G.

1977-12-01

The composition and procedures of environmental surveillance programs at completed and operating nuclear power plants have been examined with respect to their validity, continuing significance and cost. It was found that many programs contain components that are mainly an extension of preoperational baseline measurements that need not be continued indefinitely and that others lack the statistical validity to make their continued application meaningful. To identify the practical limits imposed by counting statistics and realistic equipment capacity measurements were done on iodine-131 and cesium-137 containing samples to establish detectability limits and proportionate costs for sample preparation and counting. It was found that under commercial conditions effective detectability limits and expected confidence limits were substantially higher than those mentioned in NRC Regulatory Guides. This imposes a need for either selecting fewer samples and counting them for longer times or accepting a lesser accuracy on more samples, within the bounds of reasonable cost per sample

Professional adaptability of nuclear power plant operators

International Nuclear Information System (INIS)

He Xuhong; Huang Xiangrui

2006-01-01

The paper concerns in the results of analysis for nuclear power plant (NPP) operator job and analysis for human errors related NPP accidents. Based on the principle of ergonomics a full psychological selection system of the professional adaptability of NPP operators including cognitive ability, personality and psychological health was established. The application way and importance of the professional adaptability research are discussed. (authors)

Assuring human operator alertness at night in power plants

International Nuclear Information System (INIS)

Moore-Ede, M.C.

1988-01-01

The human body is not designed for peak alertness and performance at night, nor is it well-equipped to cope with the frequent day-night inversions required by rotating shift work schedules. As a result, the human operator can become the weak link in a complex technological operation such as a nuclear power plant. The high degree of dependence on human operator vigilance, decision-making ability and performance that is required in nuclear power plant operations can conflict with the human sleepiness and error-proneness which naturally occur during the night shift or after extended periods without adequate sleep. An opportunity to address these problems has come from a series of major research advances in basic circadian physiology

Study of operating procedures in nuclear power plants: Practices and problems

International Nuclear Information System (INIS)

Morgenstern, M.H.; Barnes, V.E.; McGuire, M.V.; Radford, L.R.; Wheeler, W.A.

1987-02-01

This report describes the project activities, findings, and recommendations of a project entitled ''Program Plan for Assessing and Upgrading Operating Procedures for Nuclear Power Plants.'' The project was performed by the Pacific Northwest Laboratory and Battelle Human Affairs Research Centers for the Division of Human Factors Technology, Office of Nuclear Reactor Regulation, US Nuclear Regulatory Commission (NRC). The project team analyzed and evaluated samples of normal and abnormal operating procedures from 31 commercial nuclear power plant sites operating in the United States. The project team also visited nine nuclear power plants in the United States to obtain information on the development, use, and control of operating procedures. A peer review group was convened to advise the project team on the conduct of the project and to review and comment on the project report. The report contains findings on the usability of operating procedures and on practices concerning the development, use, an control of operating procedures in nuclear power plants. The report includes recommendations to the NRC on the need to upgrade the quality of operating procedures. The report also discusses an approach to a program plan to assess and upgrade operating procedures

A study on the operator's communication pattern characteristics under abnormal operating situation of nuclear power plants

International Nuclear Information System (INIS)

Kim, S. H.; Park, J.

2008-01-01

The quality of a probabilistic safety assessment (PSA) has become more important and a human reliability analysis (HRA) is known as a major contributor to the uncertainty of a PSA. As a part of enhancing the HRA quality, a study was initiated to find out characteristics of communication pattern and to evaluate communication quality of the operators of nuclear power plants. Korea Atomic Energy Research Institute (KAERI) is developing evaluation methods for the effect of human-induced events on risk/performance. This paper describes a study on the operator's communication pattern characteristics under abnormal operating situation of nuclear power plants. The study was carried out in four stages; 1) Video recording 2) Audio scripting 3) Message Classification 4) Communication Pattern Analysis. We recorded eight abnormal simulator training programs from Younggwang nuclear power plant training center. After that we performed message classification and carried out communication pattern analysis. We compared communication patterns of abnormal operating situation with emergency operating situation.As results of analysis, the role of SRO (senior reactor operator) under abnormal operating situation was decreased than the activities under emergency operating situation because each operator (reactor operator, turbine operator, safety supervisor) in main control room (MCR) performs the activity to control by himself with corresponding field engineers with his basic knowledge of the system. On the other hand, the operator's decision making processes and activities under abnormal operating situation were dramatically increased than the emergency operating situation. (authors)

Power electronics basics operating principles, design, formulas, and applications

CERN Document Server

Rozanov, Yuriy; Chaplygin, Evgeny; Voronin, Pavel

2015-01-01

Power Electronics Basics: Operating Principles, Design, Formulas, and Applications provides fundamental knowledge for the analysis and design of modern power electronic devices. This concise and user-friendly resource:Explains the basic concepts and most important terms of power electronicsDescribes the power assemblies, control, and passive components of semiconductor power switchesCovers the control of power electronic devices, from mathematical modeling to the analysis of the electrical processesAddresses pulse-width modulation, power quality control, and multilevel, modular, and multicell

Study on the identification of main drivers affecting the performance of human operators during low power and shutdown operation

International Nuclear Information System (INIS)

Kim, Ar Ryum; Park, Jinkyun; Kim, Ji Tae; Kim, Jaewhan; Seong, Poong Hyun

2016-01-01

Highlights: • The performance of human operator during LPSD operation is significantly important. • Human performance is affected by drivers such as procedure, training, and etc. • Main drivers during LPSD operation at domestic NPPs were suggested. • It is expected that it will be used for estimating human reliability during LPSD operation. - Abstract: In the past, many researchers believed that a reactor during low power and shutdown operation was sufficiently safe. This belief has been changed by the number of accidents during such types of operation, which is significantly high. Also, it was pointed out that one of the main differences between low power and shutdown operation and full power operation is the significance of human action because there are huge amounts of human actions due to extensive maintenance and testing while automatic control and safety functions may be disabled and procedures are insufficient or incomplete. This paper suggests the main drivers in performing human reliability analysis. For this study, we reviewed eight reports relating to human performance during low power and shutdown operation and applied a root cause analysis method for 53 human or human-related events at domestic nuclear power plants to derive the main drivers that affect the occurrence of those events. As a result, several main drivers were derived, such as procedures, training, experience of personnel, and workload/stress. It is expected that these main drivers will be used to perform human reliability analysis for low power and shutdown operation.

Review of the total system related to operation of nuclear-powered ship

International Nuclear Information System (INIS)

Takamasa, Tomoji; Miyashita, Kunio

2000-01-01

It is essential to establish a marine reactor having excellent safety and reliability, which is capable of competing economically with conventional ships, and which can be accepted by international society, in order to be prepared for practical application of future nuclear-powered ships. For this purpose, it is important not only to demonstrate a marine reactor using a model or test device to simulate actual operation, but also to establish the environmental requirements for operation of a nuclear-powered ship, such as safety standards that are operationally and internationally common for ships, and to establish a repair base for nuclear-powered ships. Systems research for the practical application of nuclear-powered ships was conducted for five years, fiscal years 1992 through 1996, by a group in the Japan Atomic Energy Research Institute (JAERI), under the project title 'Review of the total system related to operation of nuclear-powered ships.' The project sought to summarize requirements for the practical application of nuclear-powered ships from the standpoint of the need side, e.g., what nuclear-powered ships will be requested, and what functions will be provided under the expected future social environment; to show a complete system concept for the operation of nuclear-powered ships; and to clarify the situations creating demand for nuclear-powered ships, as well as the system and environmental conditions to be established for operation of practical nuclear-powered ships. Study considerations included the size of the operation system for a nuclear-powered ship, a scenario for introducing a nuclear-powered container ship, and economic evolution from the effects on the whole shipping system, based on container ships, of introducing a nuclear-powered ship. The results of these considerations were made the framework for constructing an entire system and evaluating its economy. The treatment and disposal of radioactive waste from a nuclear-powered ship, and the

Computing and cognition in future power plant operations

International Nuclear Information System (INIS)

Kisner, R.A.; Sheridan, T.B.

1983-01-01

The intent of this paper is to speculate on the nature of future interactions between people and computers in the operation of power plants. In particular, the authors offer a taxonomy for examining the differing functions of operators in interacting with the plant and its computers, and the differing functions of the computers in interacting with the plant and its operators

Computing and cognition in future power-plant operations

International Nuclear Information System (INIS)

Kisner, R.A.; Sheridan, T.B.

1983-01-01

The intent of this paper is to speculate on the nature of future interactions between people and computers in the operation of power plants. In particular, the authors offer a taxonomy for examining the differing functions of operators in interacting with the plant and its computers, and the differing functions of the computers in interacting with the plant and its operators

Operation of Finnish nuclear power plants

International Nuclear Information System (INIS)

Tossavainen, K.

1992-05-01

The Finnish nuclear power plant units Loviisa 1 and 2 as well as TVO I and II were in operation for almost the whole fourth quarter of 1991. The load factor average was 94.7 % (the whole year 90.9 %). All the events in the last annual quarter, which are classified on the International Nuclear Event Scale, were below scale/level 0. Also the events which occurred in the other quarters of the year 1991 were rated at the scale's lowest levels. Occupational radiation doses and releases of radioactive material off-site remained well below authorised limits. Only quantities of radioactive material insignificant to radiation exposure originating in nuclear power plants were detected in the samples collected in the vicinity of the nuclear power plants

Risk contribution from low power, shutdown, and other operational modes beyond full power

Energy Technology Data Exchange (ETDEWEB)

Whitehead, D.W.; Brown, T.D. [Sandia National Labs., Albuquerque, NM (United States); Chu, T.L. [Brookhaven National Lab., Upton, NY (United States)] [and others

1995-04-01

During 1989 the Nuclear Regulatory Commission (NRC) initiated an extensive program to carefully examine the potential risks during low power and shutdown operations. Two plants, Surry (a pressurized water reactor) and Grand Gulf (a boiling water reactor), were selected for study by Brookhaven National Laboratory and Sandia National Laboratories, respectively. The program objectives included assessing the risks of severe accidents initiated during plant operational states other than full power and comparing estimated core damage frequencies, important accident sequences, and other qualitative and quantitative results with full power accidents as assessed in NUREG-1150. The scope included a Level 3 probabilistic risk assessment (PRA) for traditional internal events and a Level 1 PRA on fire, flooding, and seismically induced core damage sequences. A phased approach was used in Level 1. In Phase 1 the concept of plant operational states (POSs) was developed to provide a better representation of the plant as it transitions from power to nonpower operation. This included a coarse screening analysis of all POSs to identify vulnerable plant configurations, to characterize (on a high, medium, or low basis) potential frequencies of core damage accidents, and to provide a foundation for a detailed Phase 2 analysis. In Phase 2, selected POSs from both Grand Gulf and Surry were chosen for detailed analysis. For Grand Gulf, POS 5 (approximately cold shutdown as defined by Grand Gulf Technical Specifications) during a refueling outage was selected. For Surry, three POSs representing the time the plant spends in midloop operation were chosen for analysis. These included POS 6 and POS 10 of a refueling outage and POS 6 of a drained maintenance outage. Level 1 and Level 2/3 results from both the Surry and Grand Gulf analyses are presented.

Risk contribution from low power, shutdown, and other operational modes beyond full power

International Nuclear Information System (INIS)

Whitehead, D.W.; Brown, T.D.; Chu, T.L.; Pratt, W.T.

1995-01-01

During 1989 the Nuclear Regulatory Commission (NRC) initiated an extensive program to carefully examine the potential risks during low power and shutdown operations. Two plants, Surry (a pressurized water reactor) and Grand Gulf (a boiling water reactor), were selected for study by Brookhaven National Laboratory and Sandia National Laboratories, respectively. The program objectives included assessing the risks of severe accidents initiated during plant operational states other than full power and comparing estimated core damage frequencies, important accident sequences, and other qualitative and quantitative results with full power accidents as assessed in NUREG-1150. The scope included a Level 3 probabilistic risk assessment (PRA) for traditional internal events and a Level 1 PRA on fire, flooding, and seismically induced core damage sequences. A phased approach was used in Level 1. In Phase 1 the concept of plant operational states (POSs) was developed to provide a better representation of the plant as it transitions from power to nonpower operation. This included a coarse screening analysis of all POSs to identify vulnerable plant configurations, to characterize (on a high, medium, or low basis) potential frequencies of core damage accidents, and to provide a foundation for a detailed Phase 2 analysis. In Phase 2, selected POSs from both Grand Gulf and Surry were chosen for detailed analysis. For Grand Gulf, POS 5 (approximately cold shutdown as defined by Grand Gulf Technical Specifications) during a refueling outage was selected. For Surry, three POSs representing the time the plant spends in midloop operation were chosen for analysis. These included POS 6 and POS 10 of a refueling outage and POS 6 of a drained maintenance outage. Level 1 and Level 2/3 results from both the Surry and Grand Gulf analyses are presented

Operational safety performance and economical efficiency evaluation for nuclear power plants

International Nuclear Information System (INIS)

Liu Yachun; Zou Shuliang

2012-01-01

The economical efficiency of nuclear power includes a series of environmental parameters, for example, cleanliness. Nuclear security is the precondition and guarantee for its economy, and both are the direct embodiment of the social benefits of nuclear power. Through analyzing the supervision and management system on the effective operation of nuclear power plants, which has been put forward by the International Atomic Energy Agency (IAEA), the World Association of Nuclear Operators (WANO), the U.S. Nuclear Regulatory Commission (NRC), and other organizations, a set of indexs on the safety performance and economical efficiency of nuclear power are explored and established; Based on data envelopment analysis, a DEA approach is employed to evaluate the efficiency of the operation performance of several nuclear power plants, Some primary conclusion are achieved on the basis of analyzing the threshold parameter's sensitivity and relativity which affected operational performance. To address the conflicts between certain security and economical indicators, a multi-objective programming model is established, where top priority is given to nuclear safety, and the investment behavior of nuclear power plant is thereby optimized. (authors)

Operation and maintenance of thermal power stations best practices and health monitoring

CERN Document Server

Chanda, Pradip

2016-01-01

This book illustrates operation and maintenance practices/guidelines for economic generation and managing health of a thermal power generator beyond its regulatory life. The book provides knowledge for professionals managing power station operations, through its unique approach to chemical analysis of water, steam, oil etc. to identify malfunctioning/defects in equipment/systems much before the physical manifestation of the problem. The book also contains a detailed procedure for conducting performance evaluation tests on different equipment, and for analyzing test results for predicting maintenance requirements, which has lent a new dimension to power systems operation and maintenance practices. A number of real life case studies also enrich the book. This book will prove particularly useful to power systems operations professionals in the developing economies, and also to researchers and students involved in studying power systems operations and control. .

Wireless Power Control for Tactical MANET: Power Rate Bounds

Science.gov (United States)

2016-09-01

J; P. Hande; T. Lan; C. W. Tan [2008] Power Control in Cellular Networks, Now Publishers Inc., Hanover, MA. 12. Chaves, Fabiano de Sousa; F. R. P...Asymptotically Fast Convergence, IEEE Selected Areas in Communications, 18(3). 36. Jian, Tao; Nicholas D. Sidiropoulos; Georgios B. Giannakis [2003] Kalman...Power Control and Its Imperfections in CDMA Cellular Systems, IEEE Transactions on Vehicular Technologies, 48, pages 1706–1777. 75. Tan , Chee Wei

Experience gained in the operation of the Beznau nuclear power station

International Nuclear Information System (INIS)

Kueffer, K. von.

1976-01-01

The 24th December 1969, when the Beznau 1 nuclear power station was placed in commercial operation, marked the beginning of electricity production from nuclear energy in Switzerland. Beznau 2 followed on the 15th March 1972. Together with the Muehleberg nuclear power station, nuclear energy accounts for approximately 20 percent of the total electricity production in Switzerland. Until the end of 1975, Switzerland's three nuclear power stations had a mean energy utilisation factor of 71.3 percent which, as compared with a mean energy utilization factor of 60.5 percent for all the nuclear power stations in the West, suggests fairly good operational results. Problems that arose during operation are discussed in detail. By way of summary it is stated that the operation of the Beznau nuclear power station has so far proved a success. The production of electrical energy has always remained within the limits imposed by the law and by the safety aspects. (Auth.)

Management of nuclear power plants for safe operation

International Nuclear Information System (INIS)

Kueffer, K.

1980-01-01

This lecture covers management aspects which have an immediate bearing on safety and identifies the objectives and tasks of management which are required for safe operation of a nuclear power plant and is based on the Codes of Practice and Safety Guides of the IAEA as well as arrangements in use at the Swiss Nuclear Power Station Beznau. This lecture - discusses the factors to be considered in structuring the operating organization, the support to be provided to plant management, the services and facilities needed and the management system for assuring the safety tasks are performed - describes the responsibilities of plant management and operating organization - outlines the requirements for recruitment, training and retraining as well as qualification and authorization of personnel - describes the programmes for maintenance, testing, examination, inspection, radiological protection, quality assurance, waste management, fuel management, emergency arrangement and security - describes the development of plant operating procedures including procedures to protect the personnel - outlines the requirements for initial and subsequent operation - describes the importance for evaluation and feedback of operating experience - describes the procedures for changes in hardware, procedures and set points - outlines the information flow and the requirements in reference to records and reports. (orig./RW)

Safeguard management for operation security in nuclear power plants (NPPs)

International Nuclear Information System (INIS)

Woo, Tae-Ho; Lee, Un-Chul

2011-01-01

Safeguard modeling is conducted for the successful operations in the nuclear power plants (NPPs). The characteristics of the secure operation in NPPs are investigated using the network effect method which is quantified by the Monte-Carlo algorithm. Fundamentally, it is impossible to predict the exact time of a terror incident. So, the random sampling for the event frequency is a reasonable method, including the characteristics of network effect method such as the zero-sum quantification. The performance of operation with safeguard is the major concern of this study. There are three kinds of considerations as the neutronics, thermo-hydraulics, and safeguard properties which are organized as an aspect of safeguard considerations. The result, therefore, can give the stability of the operations when the power is decided. The maximum value of secure operation is 12.0 in the third month and the minimum value is 1.0 in the 18th and 54th months, in a 10 years period. Thus, the stability of the secure power operation increases 12 times higher than the lowest value according to this study. This means that the secure operation is changeable in the designed NPPs and the dynamical situation of the secure operation can be shown to the operator.

Nuclear power plant operating experience. Annual report, 1978

International Nuclear Information System (INIS)

Beebe, M.R.

1979-12-01

This report is the fifth in a series of reports issued annually that summarizes the operating experience of US nuclear power plants in commercial operation. Power generation statistics, plant outages, reportable occurrences, fuel element performance, occupational radiation exposure for each plant are presented. Summary highlights of these areas are discussed. The report includes 1978 data from 65 plants - 25 boiling water reactor plants and 40 pressurized water reactor plants. Discussion of radioactive effluents which has been a part of this report in previous years, has not been included in this issue because of late acquisition of data

Boundary operators in effective string theory

Energy Technology Data Exchange (ETDEWEB)

Hellerman, Simeon [Kavli Institute for the Physics and Mathematics of the Universe, The University of Tokyo,Kashiwa, Chiba 277-8582 (Japan); Swanson, Ian [Kavli Institute for the Physics and Mathematics of the Universe, The University of Tokyo,Kashiwa, Chiba 277-8582 (Japan)

2017-04-13

Various universal features of relativistic rotating strings depend on the organization of allowed local operators on the worldsheet. In this paper, we study the set of Neumann boundary operators in effective string theory, which are relevant for the controlled study of open relativistic strings with freely moving endpoints. Relativistic open strings are thought to encode the dynamics of confined quark-antiquark pairs in gauge theories in the planar approximation. Neumann boundary operators can be organized by their behavior under scaling of the target space coordinates X{sup μ}, and the set of allowed X-scaling exponents is bounded above by +1/2 and unbounded below. Negative contributions to X-scalings come from powers of a single invariant, or “dressing' operator, which is bilinear in the embedding coordinates. In particular, we show that all Neumann boundary operators are dressed by quarter-integer powers of this invariant, and we demonstrate how this rule arises from various ways of regulating the short-distance singularities of the effective theory.

Tokamak power reactor ignition and time dependent fractional power operation

International Nuclear Information System (INIS)

Vold, E.L.; Mau, T.K.; Conn, R.W.

1986-06-01

A flexible time-dependent and zero-dimensional plasma burn code with radial profiles was developed and employed to study the fractional power operation and the thermal burn control options for an INTOR-sized tokamak reactor. The code includes alpha thermalization and a time-dependent transport loss which can be represented by any one of several currently popular scaling laws for energy confinement time. Ignition parameters were found to vary widely in density-temperature (n-T) space for the range of scaling laws examined. Critical ignition issues were found to include the extent of confinement time degradation by alpha heating, the ratio of ion to electron transport power loss, and effect of auxiliary heating on confinement. Feedback control of the auxiliary power and ion fuel sources are shown to provide thermal stability near the ignition curve

Operation Characteristics Optimization of Low Power Three-Phase Asynchronous Motors

Directory of Open Access Journals (Sweden)

VLAD, I.

2014-02-01

Full Text Available Most published papers on low power asynchronous motors were aimed to achieve better operational performances in different operating conditions. The optimal design of the general-purpose motors requires searching and selecting an electric machine to meet minimum operating costs criterion and certain customer imposed restrictive conditions. In this paper, there are many significant simulations providing qualitative and quantitative information on reducing active and reactive energy losses in motors, and on parameters and constructive solution. The optimization study applied the minimal operating costs criterion, and it took into account the starting restrictive conditions. Thirteen variables regarding electromagnetic stresses and main constructive dimensions were considered. The operating costs of the optimized motor decreased with 25.6%, as compared to the existing solution. This paper can be a practical and theoretical support for the development and implementation of modern design methods, based on theoretical and experimental study of stationary and transient processes in low power motors, to increase efficiency and power factor.

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

DEFF Research Database (Denmark)

Biegel, Benjamin; Madjidian, Daria; Spudic, Vedrana

2013-01-01

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

Is it possible long-tern operation of Spanish nuclear power plants?

International Nuclear Information System (INIS)

Regano, M.

2004-01-01

The long term operation of nuclear power plants beyond 40 years is a reality. Worlswide accumulated operating experience, national and international R and D projects related with the ageing of materials and the specific studies presented to the NRC by more than thirty American plant guarantee that the operation of nuclear power plants beyond 40 years will be carried out with the same or greater safety and reliability factors. The advantages of the long term operation of Spain nuclear power plants are obvious. The implementation of this option will play an important role in complying with the Kyoto compromises, avoiding the emission of 50 million tons of CO2 will contribute to guaranteeing the supply of electricity by generating an additional 600,000 GWh and will contribute to keeping electricity prices down. The total generating cost for the long term operation of nuclear power plants is approximately half that of a new coal or combined cycle plant. Spain is hugely dependent on energy. In this situation, all energies are necessary and the long term operation of nuclear power plants can of course play an important role in covering the gap between offer and demand, guaranteeing supply in the most economic way possible and with the greatest respect for the environment. (Author)

Power suppressed operators and gauge invariance in soft-collinear effective theory

International Nuclear Information System (INIS)

Bauer, Christian W.; Pirjol, Dan; Stewart, Iain W.

2003-01-01

The form of collinear gauge invariance for power suppressed operators in the soft-collinear effective theory (SCET) is discussed. Using a field redefinition we show that it is possible to make any power suppressed ultrasoft-collinear operators invariant under the original leading order gauge transformations. Our manipulations avoid gauge fixing. The Lagrangians to O(λ 2 ) are given in terms of these new fields. We then give a simple procedure for constructing power suppressed soft-collinear operators in SCET II by using an intermediate theory SCET I

Models and Techniques for Proving Data Structure Lower Bounds

DEFF Research Database (Denmark)

Larsen, Kasper Green

In this dissertation, we present a number of new techniques and tools for proving lower bounds on the operational time of data structures. These techniques provide new lines of attack for proving lower bounds in both the cell probe model, the group model, the pointer machine model and the I...... bound of tutq = (lgd􀀀1 n). For ball range searching, we get a lower bound of tutq = (n1􀀀1=d). The highest previous lower bound proved in the group model does not exceed ((lg n= lg lg n)2) on the maximum of tu and tq. Finally, we present a new technique for proving lower bounds....../O-model. In all cases, we push the frontiers further by proving lower bounds higher than what could possibly be proved using previously known techniques. For the cell probe model, our results have the following consequences: The rst (lg n) query time lower bound for linear space static data structures...

Operation of Finnish nuclear power plants

International Nuclear Information System (INIS)

Tossavainen, K.

1990-03-01

In the Quarterly Reports on the operation of the Finnish nuclear power plants such incidents and observations are described relating to nuclear and radiation safety which the regulatory body, the Finnish Centre for Radiation and Nuclear Safety, considers safety-related. During the third quarter of 1989 the Finnish nuclear power plant units Loviisa 1 and 2 and TVO I and II were in commercial operation for most of the time. Nuclear electricity accounted for 39.0% of the total Finnish electricity production in this quarter. The load factor average of the nuclear power plant units was 78.9%. At Loviisa 1, two holes were found in the feedwater distributor of one steam generator. Corresponding wall thinning corrosion was also detected in the walls of two other distributors. The holes were found on the feedwater distributor upper surface in the joint of the secondary circuit feedwater pipe. One hole was about 20 mm x 50 mm in size and the other was a pit hole ca 5 mm in diameter. Metal power had entered the primary circuit at TVO I. This was observed during a post-scram plant start-up. Several control rod drive units had become jammed so tight that control rod withdrawal failed. Metal powder did not hamper reactor scram under the prevailing circumstances because the drive units are prone to jamming only after a control rod is almost fully inserted and because the forces which insert a control rod by various means (electrical, hydraulic) are 6-8 fold compared with the withdrawing force

Reducing Conservatism of Analytic Transient Response Bounds via Shaping Filters

Science.gov (United States)

Kwan, Aiyueh; Bedrossian, Nazareth; Jan, Jiann-Woei; Grigoriadis, Karolos; Hua, Tuyen (Technical Monitor)

1999-01-01

Recent results show that the peak transient response of a linear system to bounded energy inputs can be computed using the energy-to-peak gain of the system. However, analytically computed peak response bound can be conservative for a class of class bounded energy signals, specifically pulse trains generated from jet firings encountered in space vehicles. In this paper, shaping filters are proposed as a Methodology to reduce the conservatism of peak response analytic bounds. This Methodology was applied to a realistic Space Station assembly operation subject to jet firings. The results indicate that shaping filters indeed reduce the predicted peak response bounds.

A Stochastic Operational Planning Model for Smart Power Systems

Directory of Open Access Journals (Sweden)

Sh. Jadid

2014-12-01

Full Text Available Smart Grids are result of utilizing novel technologies such as distributed energy resources, and communication technologies in power system to compensate some of its defects. Various power resources provide some benefits for operation domain however, power system operator should use a powerful methodology to manage them. Renewable resources and load add uncertainty to the problem. So, independent system operator should use a stochastic method to manage them. A Stochastic unit commitment is presented in this paper to schedule various power resources such as distributed generation units, conventional thermal generation units, wind and PV farms, and demand response resources. Demand response resources, interruptible loads, distributed generation units, and conventional thermal generation units are used to provide required reserve for compensating stochastic nature of various resources and loads. In the presented model, resources connected to distribution network can participate in wholesale market through aggregators. Moreover, a novel three-program model which can be used by aggregators is presented in this article. Loads and distributed generation can contract with aggregators by these programs. A three-bus test system and the IEEE RTS are used to illustrate usefulness of the presented model. The results show that ISO can manage the system effectively by using this model

Adequacy of operating reserves for power systems in future european wind power scenarios

DEFF Research Database (Denmark)

Das, Kaushik; Litong-Palima, Marisciel; Maule, Petr

2015-01-01

operating reserves. To study the effects of these imbalances, anticipated wind scenarios for European power systems are modelled for 2020 and 2030. Wind power forecasts for different time scales and real-time available wind power are modelled. Based on these studies, this paper qualitatively analyzes......Wind power generation is expected to increase in Europe by large extent in future. This will increase variability and uncertainty in power systems. Imbalances caused due to uncertainty in wind power forecast can trigger frequency instability in the system. These imbalances are handled using...... the adequacy of primary and secondary reserves requirements for future European power systems. This paper also discusses the challenges due to the uncertainty in wind power forecasts and their possible solutions for wind installation scenarios for 2020 and 2030....

Irreducible normalizer operators and thresholds for degenerate quantum codes with sublinear distances

Science.gov (United States)

Pryadko, Leonid P.; Dumer, Ilya; Kovalev, Alexey A.

2015-03-01

We construct a lower (existence) bound for the threshold of scalable quantum computation which is applicable to all stabilizer codes, including degenerate quantum codes with sublinear distance scaling. The threshold is based on enumerating irreducible operators in the normalizer of the code, i.e., those that cannot be decomposed into a product of two such operators with non-overlapping support. For quantum LDPC codes with logarithmic or power-law distances, we get threshold values which are parametrically better than the existing analytical bound based on percolation. The new bound also gives a finite threshold when applied to other families of degenerate quantum codes, e.g., the concatenated codes. This research was supported in part by the NSF Grant PHY-1416578 and by the ARO Grant W911NF-11-1-0027.

BN-600 power unit 15-year operating experience

International Nuclear Information System (INIS)

Saraev, O.M.; Oshkanov, N.N.; Vylomov, V.V.

1996-01-01

Comprehensive experience has been gained with the operating fast reactor BN-600 with a power out of 600 MWe. This paper includes important performance results and gives also an overview of the experience gained from BN-600 NPP commercial operation during 15 years. (author). 2 figs, 1 tab

Distributed Optimization of Sustainable Power Dispatch and Flexible Consumer Loads for Resilient Power Grid Operations

Science.gov (United States)

Srikantha, Pirathayini

Today's electric grid is rapidly evolving to provision for heterogeneous system components (e.g. intermittent generation, electric vehicles, storage devices, etc.) while catering to diverse consumer power demand patterns. In order to accommodate this changing landscape, the widespread integration of cyber communication with physical components can be witnessed in all tenets of the modern power grid. This ubiquitous connectivity provides an elevated level of awareness and decision-making ability to system operators. Moreover, devices that were typically passive in the traditional grid are now `smarter' as these can respond to remote signals, learn about local conditions and even make their own actuation decisions if necessary. These advantages can be leveraged to reap unprecedented long-term benefits that include sustainable, efficient and economical power grid operations. Furthermore, challenges introduced by emerging trends in the grid such as high penetration of distributed energy sources, rising power demands, deregulations and cyber-security concerns due to vulnerabilities in standard communication protocols can be overcome by tapping onto the active nature of modern power grid components. In this thesis, distributed constructs in optimization and game theory are utilized to design the seamless real-time integration of a large number of heterogeneous power components such as distributed energy sources with highly fluctuating generation capacities and flexible power consumers with varying demand patterns to achieve optimal operations across multiple levels of hierarchy in the power grid. Specifically, advanced data acquisition, cloud analytics (such as prediction), control and storage systems are leveraged to promote sustainable and economical grid operations while ensuring that physical network, generation and consumer comfort requirements are met. Moreover, privacy and security considerations are incorporated into the core of the proposed designs and these

Usefulness of bound-state approximations in reaction theory

International Nuclear Information System (INIS)

Adhikari, S.K.

1981-01-01

A bound-state approximation when applied to certain operators, such as the many-body resolvent operator for a two-body fragmentation channel, in many-body scattering equations, reduces such equations to equivalent two-body scattering equations which are supposed to provide a good description of the underlying physical process. In this paper we test several variants of bound-state approximations in the soluble three-boson Amado model and find that such approximations lead to weak and unacceptable kernels for the equivalent two-body scattering equations and hence to a poor description of the underlying many-body process

Safety and operation of the Stade nuclear power plant

International Nuclear Information System (INIS)

Salcher, H.

1991-01-01

The concept of PreussenElektra is to continuously increase the existing safety standard of the Stade nuclear power station using experience gained from faults and operation in nuclear power stations and the progressive state of the art. Modifications to achieve the most gentle operation of the plant have been completed and other are on-going. To do so instruments were attached to those components which are susceptible to fatigue to record the transients and extensive calculatory records were kept. Although the plant has almost 20 years successful operation behind it, it can still stand up well to comparisons with more recent plants as far as safety aspects are concerned. 6 figs

Operating experience from Swedish nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-06-01

The total production of electricity from Swedish nuclear power plants was 70.5 TWh during 1998, which is the second highest yearly production ever. Production losses due to low demand totaled 5.1 TWh combined for all twelve units and production losses due to coastdown operation totaled an additional 0.5 TWh. The reason for this low power demand was a very good supply of water to the hydropower system. Hydroelectric power production was 73.6 TWh, an increase by roughly 5 TWh since 1997. Hence, the hydroelectric power production substantially exceeded the 64 TWh expected during a normal year, i.e. a year with average rainfall. Remaining production sources, mainly fossil fuel electricity production combined with district heating, contributed with 10 TWh. The total electricity production was 154.2 TWh, the highest yearly production ever. The total electricity consumption including transmission losses was 143.5 TWh. This is also the highest consumption ever and an increase by one percent compared to 1997. The preliminary net result of the electric power trade shows a net export by 10.7 TWh. The figures above are calculated from the preliminary production results. A comprehensive report on electric power supply and consumption in Sweden is given in the 1998 Annual Report from the Swedish Power Association. Besides Oskarshamn 1, all plants have periodically been operated in load-following mode, mostly because of the abundant supply of hydropower. The energy availability for the three boiling water reactors at Forsmark averaged 93.3 % and for the three pressure water reactors at Ringhals 91.0 %, both figures are the highest ever noted. In the section `Special Reports` three events of importance to safety that occurred during 1998 are reported. The events were all rated as level 1 according to the International Nuclear Event Scale (INES) Figs, tabs.; Also available in Swedish

Operating experience from Swedish nuclear power plants

International Nuclear Information System (INIS)

1999-01-01

The total production of electricity from Swedish nuclear power plants was 70.5 TWh during 1998, which is the second highest yearly production ever. Production losses due to low demand totaled 5.1 TWh combined for all twelve units and production losses due to coastdown operation totaled an additional 0.5 TWh. The reason for this low power demand was a very good supply of water to the hydropower system. Hydroelectric power production was 73.6 TWh, an increase by roughly 5 TWh since 1997. Hence, the hydroelectric power production substantially exceeded the 64 TWh expected during a normal year, i.e. a year with average rainfall. Remaining production sources, mainly fossil fuel electricity production combined with district heating, contributed with 10 TWh. The total electricity production was 154.2 TWh, the highest yearly production ever. The total electricity consumption including transmission losses was 143.5 TWh. This is also the highest consumption ever and an increase by one percent compared to 1997. The preliminary net result of the electric power trade shows a net export by 10.7 TWh. The figures above are calculated from the preliminary production results. A comprehensive report on electric power supply and consumption in Sweden is given in the 1998 Annual Report from the Swedish Power Association. Besides Oskarshamn 1, all plants have periodically been operated in load-following mode, mostly because of the abundant supply of hydropower. The energy availability for the three boiling water reactors at Forsmark averaged 93.3 % and for the three pressure water reactors at Ringhals 91.0 %, both figures are the highest ever noted. In the section 'Special Reports' three events of importance to safety that occurred during 1998 are reported. The events were all rated as level 1 according to the International Nuclear Event Scale (INES)

Research on professional adaptability psychological selection indices of nuclear power plant operators

International Nuclear Information System (INIS)

Liu Jingquan; Li Zhe; Li Maoyou

2010-01-01

Based on the analysis of the work characteristics of nuclear power plant operators and the comparison of professional psychological selection indices for different occupations, the indices of psychological selection system which is applicable to nuclear power plant operators are proposed in this paper, using the method named 'taking classes,cross-comparison'. The index results of the suggested psychological selection system reflects all the professional requirements on the nuclear power plant operators, which can also be used for the recruitment, training and the retraining programs for operators. (authors)

Supporting Control Room Operators in Highly Automated Future Power Networks

DEFF Research Database (Denmark)

Chen, Minjiang; Catterson, Victoria; Syed, Mazheruddin

2017-01-01

Operating power systems is an extremely challenging task, not least because power systems have become highly interconnected, as well as the range of network issues that can occur. It is therefore a necessity to develop decision support systems and visualisation that can effectively support the hu...... the human operators for decisionmaking in the complex and dynamic environment of future highly automated power system. This paper aims to investigate the decision support functions associated with frequency deviation events for the proposed Web of Cells concept....

Application of expert system to nuclear power plant operation and guidance system

International Nuclear Information System (INIS)

Goto, M.; Takada, Y.

1990-01-01

For a nuclear power plant, it is important that an expert system supplies useful information to the operator to meet the increasing demand for high-level plant operation. It is difficult to build a user-friendly expert system that supplies useful information in real time using existing general-purpose expert system shells. Therefore a domain-specific expert system shell with a useful knowledge representation for problem-solving in nuclear power plant operation was selected. The Plant Table (P/T) representation format was developed for description of a production system for nuclear power plant operation knowledge. The P/T consists of plant condition representation designed to process multiple inputs and single output. A large number of operation inputs for several plant conditions are divided into 'timing conditions', 'preconditions' and 'completion conditions' to facilitate knowledge-base build-up. An expert system for a Nuclear Power Plant Operation and Guidance System utilizing the P/T was developed to assist automatic plant operation and surveillance test operation. In these systems, automatic plant operation signals to the plant equipment and operation guidance messages to the operators are both output based on the processing and assessment of plant operation conditions by the P/T. A surveillance test procedure guide for major safety-related systems, such as those for emergency core cooling systems, is displayed on a CRT (Cathode Ray Tube) and test results are printed out. The expert system for a Nuclear Power Plant Operation and Guidance System has already been successfully applied to Japanese BWR plants

Current trends in codal requirements for safety in operation of nuclear power plants

International Nuclear Information System (INIS)

Srivasista, K.; Shah, Y.K.; Gupta, S.K.

2006-01-01

The Code of practice on safety in nuclear power plant operation states the requirements to be met during operation of a nuclear power plant for assuring safety. Among various stages of authorization, regulatory body issues authorization for operation of a nuclear power plant, monitors and enforces regulatory requirements. The responsible organization shall have overall responsibility and the plant management shall have the primary responsibility for ensuring safe and efficient operation of its nuclear power plants. A set of codal requirements covering technical and administrative aspects are mandatory for the plant management to implement to ensure that the nuclear power plant is operated in accordance with the design intent. Requirements on operating procedures and instructions establish operation and maintenance, inspection and testing of the plant in a planned and systematic way. The requirements on emergency preparedness programme establish with a reasonable assurance that, in the event of an emergency situation, appropriate measures can be taken to mitigate the consequences. Commissioning requirements verify performance criteria during commissioning to ensure that the design intent and QA requirements are met. Several modifications in systems important to safety required during operation of a nuclear power plant are regulated. However new operational codal requirements arising out of periodic safety review, operational experience feedback, life management, probabilistic safety assessment, physical security, safety convention and obligations and decommissioning are not covered in the present code of practice for safety in nuclear power plant operation. Codal provisions on 'Review by operating organization on aspects of design having implications on operability' are also required to be addressed. The merits in developing such a methodology include acceptance of the design by operating organization, ensuring maintainability, proper layout etc. in the new designs

Optimal Wind Power Uncertainty Intervals for Electricity Market Operation

Energy Technology Data Exchange (ETDEWEB)

Wang, Ying; Zhou, Zhi; Botterud, Audun; Zhang, Kaifeng

2018-01-01

It is important to select an appropriate uncertainty level of the wind power forecast for power system scheduling and electricity market operation. Traditional methods hedge against a predefined level of wind power uncertainty, such as a specific confidence interval or uncertainty set, which leaves the questions of how to best select the appropriate uncertainty levels. To bridge this gap, this paper proposes a model to optimize the forecast uncertainty intervals of wind power for power system scheduling problems, with the aim of achieving the best trade-off between economics and reliability. Then we reformulate and linearize the models into a mixed integer linear programming (MILP) without strong assumptions on the shape of the probability distribution. In order to invest the impacts on cost, reliability, and prices in a electricity market, we apply the proposed model on a twosettlement electricity market based on a six-bus test system and on a power system representing the U.S. state of Illinois. The results show that the proposed method can not only help to balance the economics and reliability of the power system scheduling, but also help to stabilize the energy prices in electricity market operation.

Thermal power plant operating regimes in future British power systems with increasing variable renewable penetration

International Nuclear Information System (INIS)

Edmunds, Ray; Davies, Lloyd; Deane, Paul; Pourkashanian, Mohamed

2015-01-01

Highlights: • This work investigates thermal power operating regimes in future power systems. • Gas plants have low utilisation in the scenarios considered. • Ramping intensity increases for gas plants and pumped storage. • Coal plants frequently operate at minimum stable levels and start-ups increase. • Grid emission intensity and total emission production remains substantial. - Abstract: This work investigates the operational requirements of thermal power plants in a number of potential future British power systems with increasing variable renewable penetration. The PLEXOS Integrated Energy Model has been used to develop the market models, with PLEXOS employing mixed integer programming to solve the unit commitment and economic dispatch problem, subject to a number of constraints. Initially, a model of the British power system was developed and validated. Subsequently, a 2020 test model was developed to analyse a number of future system structures with differing fuel and carbon prices and generation mixes. The study has found that in three of the four scenarios considered, the utilisation of gas power plants will be relatively low, but remains fundamental to the security of supply. Also, gas plants will be subject to more intense ramping. The findings have consequent implications for energy policy as expensive government interventions may be required to prevent early decommissioning of gas capacity, should the prevailing market conditions not guarantee revenue adequacy.

Scheduled Operation of PV Power Station Considering Solar Radiation Forecast Error

Science.gov (United States)

Takayama, Satoshi; Hara, Ryoichi; Kita, Hiroyuki; Ito, Takamitsu; Ueda, Yoshinobu; Saito, Yutaka; Takitani, Katsuyuki; Yamaguchi, Koji

Massive penetration of photovoltaic generation (PV) power stations may cause some serious impacts on a power system operation due to their volatile and unpredictable output. Growth of uncertainty may require larger operating reserve capacity and regulating capacity. Therefore, in order to utilize a PV power station as an alternative for an existing power plant, improvement in controllability and adjustability of station output become very important factor. Purpose of this paper is to develop the scheduled operation technique using a battery system (NAS battery) and the meteorological forecast. The performance of scheduled operation strongly depends on the accuracy of solar radiation forecast. However, the solar radiation forecast contains error. This paper proposes scheduling method and rescheduling method considering the trend of forecast error. More specifically, the forecast error scenario is modeled by means of the clustering analysis of the past actual forecast error. Validity and effectiveness of the proposed method is ascertained through computational simulations using the actual PV generation data monitored at the Wakkanai PV power station and solar radiation forecast data provided by the Japan Weather Association.

Operating experience with nuclear power stations in Member States in 1997

International Nuclear Information System (INIS)

1998-12-01

This report is twenty-ninth in the IAEA series of annual reports on operating experience with nuclear power stations in Member States. The report is a direct output from the Agency's Power Reactor Information System (PRIS), whose database contains all operating experience data published in Agency's operating experience annual reports published since 1971 and basic information on power reactors, including design data. According to the information available to the Agency at the end of 1997, there were 437 nuclear power reactors having a total capacity of 351795 MW(e). During 1997 three new reactors having total capacity of 3555 MW(e) were connected to the grid in France and the Republic of Korea. There were 36 nuclear power plants under construction in the world. Load, operation and availability factors are used as the basic performance factors. In addition to annual performance data and outage information, the report contains a historical summary of performance and outages during the lifetime of individual plants and five figures illustrating worldwide performance and statistical data

Theory model and experiment research about the cognition reliability of nuclear power plant operators

International Nuclear Information System (INIS)

Fang Xiang; Zhao Bingquan

2000-01-01

In order to improve the reliability of NPP operation, the simulation research on the reliability of nuclear power plant operators is needed. Making use of simulator of nuclear power plant as research platform, and taking the present international reliability research model-human cognition reliability for reference, the part of the model is modified according to the actual status of Chinese nuclear power plant operators and the research model of Chinese nuclear power plant operators obtained based on two-parameter Weibull distribution. Experiments about the reliability of nuclear power plant operators are carried out using the two-parameter Weibull distribution research model. Compared with those in the world, the same results are achieved. The research would be beneficial to the operation safety of nuclear power plant

Research on psychological evaluation method for nuclear power plant operators

International Nuclear Information System (INIS)

Fang Xiang; He Xuhong; Zhao Bingquan

2007-01-01

The qualitative and quantitative psychology evaluation methods to the nuclear power plant operators were analyzed and discussed in the paper. The comparison analysis to the scope and result of application was carried out between method of outline figure fitted and method of fuzzy synthetic evaluation. The research results can be referenced to the evaluation of nuclear power plant operators. (authors)

Bounds on the performance of a class of digital communication systems

Science.gov (United States)

Polk, D. R.; Gupta, S. C.; Cohn, D. L.

1973-01-01

Bounds on the capacity of a class of digital communication channels are derived. Equating the bounds on capacity to rate-distortion functions of (typical) sources in turn produces bounds on the performance of a class of digital communication systems. For ratios of squared quantization level to noise variance much less than one, the power requirements for this class of digital communication systems are shown to be within approximately 3 dB of the theoretical optimum.

Automatic Power Control for Daily Load-following Operation using Model Predictive Control Method

Energy Technology Data Exchange (ETDEWEB)

Yu, Keuk Jong; Kim, Han Gon [KH, Daejeon (Korea, Republic of)

2009-10-15

Under the circumstances that nuclear power occupies more than 50%, nuclear power plants are required to be operated on load-following operation in order to make the effective management of electric grid system and enhanced responsiveness to rapid changes in power demand. Conventional reactors such as the OPR1000 and APR1400 have a regulating system that controls the average temperature of the reactor core relation to the reference temperature. This conventional method has the advantages of proven technology and ease of implementation. However, this method is unsuitable for controlling the axial power shape, particularly the load following operation. Accordingly, this paper reports on the development of a model predictive control method which is able to control the reactor power and the axial shape index. The purpose of this study is to analyze the behavior of nuclear reactor power and the axial power shape by using a model predictive control method when the power is increased and decreased for a daily load following operation. The study confirms that deviations in the axial shape index (ASI) are within the operating limit.

Selection/licensing of nuclear power plant operators

International Nuclear Information System (INIS)

Saari, L.M.

1983-07-01

An important aspect of nuclear power plant (NPP) safety is the reactor operator in the control room. The operators are the first individuals to deal with an emergency situation, and thus, effective performance on their part is essential for safe plant operations. Important issues pertaining to NPP reactor operators would fall within the personnel subsystem of our safety system analysis. While there are many potential aspects of the personnel subsystem, a key first step in this focus is the selection of individuals - attempting to choose individuals for the job of reactor operator who will safely perform the job. This requires a valid (job-related) selection process. Some background information on the Nuclear Regulatory Commission (NRC) licensing process used for selecting NPP reactor operators is briefly presented and a description of a research endeavor now underway at Battelle for developing a valid reactor operator licensing examination is included

Personality Factors and Nuclear Power Plant Operators: Initial License Success

Science.gov (United States)

DeVita-Cochrane, Cynthia

Commercial nuclear power utilities are under pressure to effectively recruit and retain licensed reactor operators in light of poor candidate training completion rates and recent candidate failures on the Nuclear Regulatory Commission (NRC) license exam. One candidate failure can cost a utility over $400,000, making the successful licensing of new operators a critical path to operational excellence. This study was designed to discover if the NEO-PI-3, a 5-factor measure of personality, could improve selection in nuclear utilities by identifying personality factors that predict license candidate success. Two large U.S. commercial nuclear power corporations provided potential participant contact information and candidate results on the 2014 NRC exam from their nuclear power units nation-wide. License candidates who participated (n = 75) completed the NEO-PI-3 personality test and results were compared to 3 outcomes on the NRC exam: written exam, simulated operating exam, and overall exam result. Significant correlations were found between several personality factors and both written and operating exam outcomes on the NRC exam. Further, a regression analysis indicated that personality factors, particularly Conscientiousness, predicted simulated operating exam scores. The results of this study may be used to support the use of the NEO-PI-3 to improve operator selection as an addition to the current selection protocol. Positive social change implications from this study include support for the use of a personality measure by utilities to improve their return-on-investment in candidates and by individual candidates to avoid career failures. The results of this study may also positively impact the public by supporting the safe and reliable operation of commercial nuclear power utilities in the United States.

The operating staff of nuclear power plants

International Nuclear Information System (INIS)

Schlegel, G.; Christ, W.

1988-01-01

The training of its staff is one of the pillars of the safe and economical operation of a power plant. This is why power plant owners began to systematically train their staff already in the 50s, and why they created central training facilities. Staff members who have undergone this training make an indispensable contribution to the acceptedly high safety and availability of German power plants. The substantial cost of creating training facilities and of schooling plant staff is considered to be an investment for the future. Low labour turnover permits careful observation and development of staff and leads to a high standard of knowledge and experience. (orig./HSCH) [de

Psychological characteristics of licensed nuclear power plant operators

International Nuclear Information System (INIS)

Sajwaj, T.; Ford, T.; McGee, R.K.

1987-01-01

The safe production of electricity by nuclear power plants has been the focus of considerable attention. Much of this concern has been focused on equipment and procedural issues, with less attention to the psychological factors that affect the operations staff of the plants, i.e., those individuals who are most directly responsible for a plant's operations. Stress and type A qualities would be significant for these individuals because of their relationships to job performance and health. Of equal significance would be work-related factors, such as job involvement and work pressure. Also of interest would be hostile tendencies because of the need for cooperation and communications among operations staff. Two variables could influence these psychological factors. One is the degree of responsibility for a plant's nuclear reactors. The individuals with the greatest responsibility are licensed by the US Nuclear Regulatory Commission (NRC). There are also individuals with less direct responsibilities who are not licensed. A second variable is the operating status of the plant, whether or not the plant is currently producing electricity. Relative to ensuring the safe operation of nuclear power plants, these data suggest a positive view of licensed operators. Of interest are the greater stress scores in the licensed staff of the operating plant in contrast with their peers in the nonoperating plant

Licensing operators for commercial nuclear power plants

International Nuclear Information System (INIS)

Hannon, J.N.

1988-01-01

The human element in the operation of commercial nuclear power plants is of utmost importance. Not only must the operators be technically competent in the execution of numerous complicated tasks, they must be capable of working together as a team to diagnose dynamic plant conditions to ensure that their plants are operated safely. The significance of human interaction skills and crew communications has been demonstrated most vividly in TMI and Chernobyl. It follows that the NRC must retain its high standards for licensing operators. This paper discusses activities and initiatives being employed by the NRC to enhance the reliability of its licensing examinations, and to build a highly qualified examiner work force

Electric Vehicles for Improved Operation of Power Systems with High Wind Power Penetration

OpenAIRE

Larsen, Esben; Chandrashekhara, Divya K; Østergaard, Jacob

2008-01-01

In a power system with a high share of wind energy the wind fluctuation causes a variation in the power generation, which must be compensated from other sources. The situation in Denmark with a penetration of more than 20% wind in yearly average is presented. The introduction of electric drive vehicles (EDV) as flexible loads can improve the system operation. Bidirectional power exchange through batteries (vehicle to grid) can be seen as a storage system in the grid. An analysis of possible e...

Management quality in spanish nuclear power plant operation

International Nuclear Information System (INIS)

Perez de Zabalza Ramos, F.

1995-01-01

This paper analyzes the reasons that lead nuclear power plants to require engineering support that is not usual in other types of industrial installations, namely the complexity of the plant and the economic consequences of a possible shutdown. At the time of unit startup, the need to use the services of experienced engineers for the technical support of nuclear power plants induced plant owners to turn to the engineering companies which had participated in the design of the plants. The paper lists the wide range of plant support services which these engineering companies can provide, both from their central offices and on site, especially in the field of change orders and documentation update. The paper also describes the satisfactory development of management parameters in Spanish nuclear power plants both in terms of load factor and comparison of operating and maintenance costs, and how engineering companies have contributed to this achievement, by reducing costs with no loss in the technical quality of their services. Finally, the paper describes how the engineering companies have had to adapt to a shrinking market without losing quality and how they achieved this by diversifying their services. In this context there are two areas of concern. the first area of concern is the competition from certain companies with oversized staff, who attempt to employ them in operation support for nuclear power stations, a field which does not correspond to the training and background of said staff. This could lead to a loss of quality or economic efficiency of nuclear power plants, whose operation up to now has proven satisfactory. The second area of concern is the operator's tendency to use their own resources for engineering support, making more difficult the renewal of human resources and thus leading to a decrease in productivity, and in the transfer of practical and theoretical experience from one plant to another, as well as in the transmission of the latest know

Analytical modeling of nuclear power station operator reliability

International Nuclear Information System (INIS)

Sabri, Z.A.; Husseiny, A.A.

1979-01-01

The operator-plant interface is a critical component of power stations which requires the formulation of mathematical models to be applied in plant reliability analysis. The human model introduced here is based on cybernetic interactions and allows for use of available data from psychological experiments, hot and cold training and normal operation. The operator model is identified and integrated in the control and protection systems. The availability and reliability are given for different segments of the operator task and for specific periods of the operator life: namely, training, operation and vigilance or near retirement periods. The results can be easily and directly incorporated in system reliability analysis. (author)

EDP systems for the operational management of nuclear power plant

International Nuclear Information System (INIS)

Doerler, R.

1987-01-01

An EDP-aided operational management system is to be understood as the total of all organizational conditions (structural organization, procedural organization) and technical means, and is intended to give the individual person a better overview to fulfill his/her responsibilities. The introduction of such a system is aimed at providing the operating personnel with a set of tools matching today's technology for management and administration systems which will enable them to fulfill their tasks in an optimum way. Powerful EDP systems are already used in many nuclear power plants to control and monitor operating processes and to collect and evaluate operational data. (orig./DG) [de

Bounded variation and around

CERN Document Server

Appell, Jürgen; Merentes Díaz, Nelson José

2013-01-01

This monographis a self-contained exposition of the definition and properties of functionsof bounded variation and their various generalizations; the analytical properties of nonlinear composition operators in spaces of such functions; applications to Fourier analysis, nonlinear integral equations, and boundary value problems. The book is written for non-specialists. Every chapter closes with a list of exercises and open problems.

Tools for model-independent bounds in direct dark matter searches

DEFF Research Database (Denmark)

Cirelli, M.; Del Nobile, E.; Panci, P.

2013-01-01

We discuss a framework (based on non-relativistic operators) and a self-contained set of numerical tools to derive the bounds from some current direct detection experiments on virtually any arbitrary model of Dark Matter elastically scattering on nuclei.......We discuss a framework (based on non-relativistic operators) and a self-contained set of numerical tools to derive the bounds from some current direct detection experiments on virtually any arbitrary model of Dark Matter elastically scattering on nuclei....

Wind power plant in grid operation

International Nuclear Information System (INIS)

Heier, S.

1993-01-01

There are new prospects for electrical energy supply in coastal regions and on islands if one succeeds in integrating the available wind energy, dependent on the weather, into existing and to be developed supply structures. Apart from the supply of energy, effects on the grid and on the electrical consumer are gaining in importance. For wind power plants, the operating behaviour is appreciably determined by the electro-technical concept. The mechanical/electrical energy conversion with the corresponding grid connection and plant control play an important part here. Results of measurements and computer simulation make the differences in the behaviour of wind power plants clear. (orig.) [de

Operation status display and monitoring system for BWR nuclear power plant

International Nuclear Information System (INIS)

Wakabayashi, Yasuo; Hayakawa, Hiroyasu; Kawamura, Atsuo; Kaneda, Mitsunori.

1982-01-01

Lately, the development of the system has been made for BWR plants, which monitors the operating status not only in normal operation but also in abnormal state and also for plant safety. Recently, the improvement of man-machine interface has been tried through the practical use of technique which displays data collectively on a CRT screen relating them mutually. As one of those results, the practical use of an electronic computer and color CRT display for No. 1 unit in the Fukushima No. 2 Nuclear Power Station (2F-1), Tokyo Electric Power Co., is described. Also, new centralized control panels containing such systems were used for the 1100 MWe BWR nuclear power plants now under construction, No. 3 unit of the Fukushima No. 2 Power Station and No. 1 unit of Kashiwazaki-Kariwa Nuclear Power Station (2F-3 and K-1, respectively). The display and monitoring system in 2F-1 plant is the first one in which a computer and color CRTs were practically employed for a BWR plant in Japan, and already in commercial operation. The advanced operating status monitoring system, to which the result of evaluation of the above system was added, was incorporated in the new centralized control panels presently under production for 2F-3 and K-1 plants. The outline of the system, the functions of an electronic computer, plant operating status monitor, surveillance test guide, the automation of plant operation and auxiliary operation guide are reported for these advanced monitoring system. It was confirmed that these systems are useful means to improve the man-machine communication for plant operation minitoring. (Wakatsuki, Y.)

Investigation of the Bilibin reactor operation in the regime of automatic power and frequency control in isolated power system

International Nuclear Information System (INIS)

Sankovskij, G.A.; Molochkov, V.I.; Dolgov, V.V.; Soldatov, G.E.; Minashin, M.E.

1981-01-01

The results of experimental investigations of the power unit operation of the Bilibin nuclear power and heating plant (BNPHP) in the regime of automatic power and frequency control in an isolated power system are presented. The BNPHP comprises four similar power units. Each unit includes a steam generating setup - the channel water-graphite reactor with tubular fuel elements with natural circulation of boiling water at all the power levels as well as a turbosetup with two heat selectors and a turbogenerator. The turbine operates on dry saturated steam (with intermediate separation) which is brought from the drum-separator of the reactor natural circulation circuit. The BNPHP operates according to the controller schedule since the start-up of the first power unit. The BNPHP unit power varifies within the 50-100% range 3-4 times per day (by the number of maxima in the schedule of the power system loadings). Two design flowsheets of the unit power control and dynamic characteristics of the system for both vatiants are considered. It is concluded that both investigated automatic control systems are seviceable and deviations of the reactor parameters within the transients are not dangerous for heat release from the core. The plant is better shielded from external mainly short-term perturbations coming from the power system when the system operates in accordance with the first variant of the flowsheet [ru

Operation of Power Grids with High Penetration of Wind Power

Science.gov (United States)

Al-Awami, Ali Taleb

The integration of wind power into the power grid poses many challenges due to its highly uncertain nature. This dissertation involves two main components related to the operation of power grids with high penetration of wind energy: wind-thermal stochastic dispatch and wind-thermal coordinated bidding in short-term electricity markets. In the first part, a stochastic dispatch (SD) algorithm is proposed that takes into account the stochastic nature of the wind power output. The uncertainty associated with wind power output given the forecast is characterized using conditional probability density functions (CPDF). Several functions are examined to characterize wind uncertainty including Beta, Weibull, Extreme Value, Generalized Extreme Value, and Mixed Gaussian distributions. The unique characteristics of the Mixed Gaussian distribution are then utilized to facilitate the speed of convergence of the SD algorithm. A case study is carried out to evaluate the effectiveness of the proposed algorithm. Then, the SD algorithm is extended to simultaneously optimize the system operating costs and emissions. A modified multi-objective particle swarm optimization algorithm is suggested to identify the Pareto-optimal solutions defined by the two conflicting objectives. A sensitivity analysis is carried out to study the effect of changing load level and imbalance cost factors on the Pareto front. In the second part of this dissertation, coordinated trading of wind and thermal energy is proposed to mitigate risks due to those uncertainties. The problem of wind-thermal coordinated trading is formulated as a mixed-integer stochastic linear program. The objective is to obtain the optimal tradeoff bidding strategy that maximizes the total expected profits while controlling trading risks. For risk control, a weighted term of the conditional value at risk (CVaR) is included in the objective function. The CVaR aims to maximize the expected profits of the least profitable scenarios, thus

New Clean Air Act complicates power plant operation, design

International Nuclear Information System (INIS)

Smock, R.W.

1991-01-01

In November the president signed into law the new Clean Air Act, ushering in a new era in the power generation industry. This paper reviews the six important sections of the Clean Air Act and their impact on power plant operation and design

Hydrogen-powered lawn mower: 14 years of operation

International Nuclear Information System (INIS)

Yvon, K.; Lorenzoni, J.-L.

2006-01-01

Our hydrogen-powered lawn mower [Yvon K, Lorenzoni J-L. Hydrogen powered lawn mower. Int J Hydrogen Energy 1993; 18, 345-48] has been operated without major interruption during the past 14 years. The commercial model was originally running on gasoline and was adapted to hydrogen by making small adjustments to the carburettor and by installing a hydrogen reservoir containing solid-state metal hydrides. During the evaluation period the only maintenance work was changing the lubricating oil of the engine once a year, and reactivating the metal hydride powder by external heating after an accidental inlet of air into the reservoir. There occurred no technical failure, and there was no safety incident, neither during operation nor during recharging of hydrogen. This demonstrates that a hydrogen-operated device of this type is mature for use by greater public. Cost and marketing issues are discussed. (author)

Operator continued fraction and bound states

International Nuclear Information System (INIS)

Pindor, M.

1984-01-01

The effective Hamiltonian of the model space perturbation theory (multilevel Rayleigh-Schroedinger theory) is expressed as an operator continued fraction. In the case of a nondegenerate model space the expression becomes an operator branched continued fraction. The method is applied to the harmonic oscillator with the kinetic energy treated as the perturbation and to the anharmonic oscillator

In the way. How nuclear power plants are plugging and thwart wind energy; Im Weg. Wie AKW das Netz verstopfen und die Windkraft ausbremsen

Energy Technology Data Exchange (ETDEWEB)

NONE

2018-01-15

The contribution discusses the complex situation due to the fact that the remaining nuclear power plants in Germany operate with full power and force wind and solar energy plants to reduce their power production resulting in electricity shortages. The situation is bound to political decisions and their interpretation by nuclear operators concerning the nuclear phaseout agreement.

French experience in operating pressurized water reactor power stations. Ten years' operation of the Ardennes power station

International Nuclear Information System (INIS)

Teste du Bailler, A.; Vedrinne, J.F.

1978-01-01

In the paper the experience gained over ten years' operation of the Ardennes (Chooz) nuclear power station is summarized from the point of view of monitoring and control equipment. The reactor was the first pressurized water reactor to be installed in France; it is operated jointly by France and Belgium. The equipment, which in many cases consists of prototypes, was developed for industrial use and with the experience that has now been gained it is possible to evaluate its qualities and defects, the constraints which it imposes and the action that has to be taken in the future. (author)

Optimal Operation of Energy Storage in Power Transmission and Distribution

Science.gov (United States)

Akhavan Hejazi, Seyed Hossein

In this thesis, we investigate optimal operation of energy storage units in power transmission and distribution grids. At transmission level, we investigate the problem where an investor-owned independently-operated energy storage system seeks to offer energy and ancillary services in the day-ahead and real-time markets. We specifically consider the case where a significant portion of the power generated in the grid is from renewable energy resources and there exists significant uncertainty in system operation. In this regard, we formulate a stochastic programming framework to choose optimal energy and reserve bids for the storage units that takes into account the fluctuating nature of the market prices due to the randomness in the renewable power generation availability. At distribution level, we develop a comprehensive data set to model various stochastic factors on power distribution networks, with focus on networks that have high penetration of electric vehicle charging load and distributed renewable generation. Furthermore, we develop a data-driven stochastic model for energy storage operation at distribution level, where the distribution of nodal voltage and line power flow are modelled as stochastic functions of the energy storage unit's charge and discharge schedules. In particular, we develop new closed-form stochastic models for such key operational parameters in the system. Our approach is analytical and allows formulating tractable optimization problems. Yet, it does not involve any restricting assumption on the distribution of random parameters, hence, it results in accurate modeling of uncertainties. By considering the specific characteristics of random variables, such as their statistical dependencies and often irregularly-shaped probability distributions, we propose a non-parametric chance-constrained optimization approach to operate and plan energy storage units in power distribution girds. In the proposed stochastic optimization, we consider

Wind power integration connection and system operational aspects

CERN Document Server

Fox, Brendan

2014-01-01

Wind Power Integration provides a wide-ranging discussion on all major aspects of wind power integration into electricity supply systems. This second edition has been fully revised and updated to take account of the significant growth in wind power deployment in the past few years. New discussions have been added to describe developments in wind turbine generator technology and control, the network integration of wind power, innovative ways to integrate wind power when its generation potential exceeds 50% of demand, case studies on how forecasting errors have affected system operation, and an update on how the wind energy sector has fared in the marketplace. Topics covered include: the development of wind power technology and its world-wide deployment; wind power technology and the interaction of various wind turbine generator types with the utility network; and wind power forecasting and the challenges faced by wind energy in modern electricity markets.

Management for nuclear power plants for safe operation

International Nuclear Information System (INIS)

Kueffer, K.

1981-01-01

This lecture covers management aspects which have an immediate bearing on safety and identifies the objectives and tasks of management which are required for safe operation of a nuclear power plant and is based on the Codes of Practice and Safety Guides of the IAEA as well as arrangements in use at the Swiss Nuclear Power Station Beznau. (orig./RW)

Bound states of 'dressed' particles

International Nuclear Information System (INIS)

Shirokov, M.I.

1994-01-01

A new approach to the problem of bound states in relativistic quantum field theories is suggested. It uses the creation - destruction operators of 'dresses' particles which have been granted by Faddeev's (1963) 'dressing' formalism. Peculiarities of the proposed approach as compared to the known ones are discussed. 8 refs. (author)

Ensuring the operational safety of nuclear power plants with WWER reactors

International Nuclear Information System (INIS)

Shasharin, G.A.; Veretennikov, G.A.; Abagyan, A.A.; Lesnoj, S.A.

1984-01-01

At the start of 1983, 27 nuclear power producing units with reactor facilities of the WWER type were in operation in the Soviet Union and other countries. In 1982 the average load factor for nuclear power plants with WWER reactors was 73 per cent. There was not a single nuclear accident or even damage with any significant radiation consequences in the WWER reactors during the entire period of their operation. The most modern nuclear power plants with WWER-440 and WWER-1000 reactors meet all present-day international requirements. Safe operation of the plants is achieved by a variety of measures, the most important of which include: procedures for increasing the reliability of plant equipment and systems; ensuring exact compliance with plant operating instructions; ensuring reliable operation of plant safety systems; action directed towards maintaining the skills of plant personnel at a level adequate to ensure the taking of proper action during transient processes and accident situations. The paper discusses concrete steps for ensuring safe nuclear power plant operation along these lines. In particular, measures such as the following are described: the use of a system for collecting and processing information on equipment failures and defects; the development and introduction of methods of early defect diagnosis; the performance of complex testing of safety systems; the training of highly skilled personnel for nuclear power plants at educational combines and at teaching and training centres making use of simulators; arranging accident-prevention training and special instruction for personnel. (author)

Independent verification in operations at nuclear power plants

International Nuclear Information System (INIS)

Donderi, D.C.; Smiley, A.; Ostry, D.J.; Moray, N.P.

1995-09-01

A critical review of approaches to independent verification in operations used in nuclear power plant quality assurance programs in other countries, was conducted for this study. This report identifies the uses of independent verification and provides an assessment of the effectiveness of the various approaches. The findings indicate that at Canadian nuclear power plants as much, if not more, independent verification is performed than at power plants in the other countries included in the study. Additional requirements in this area are not proposed for Canadian stations. (author)

Impact of generalized Yukawa interactions on the lower Higgs-mass bound

Energy Technology Data Exchange (ETDEWEB)

Gies, Holger [Friedrich-Schiller-Universitaet Jena, Theoretisch-Physikalisches Institut, Jena (Germany); Friedrich-Schiller-Universitaet Jena, Abbe Center of Photonics, Jena (Germany); Helmholtz-Institut Jena, Jena (Germany); Sondenheimer, Rene [Friedrich-Schiller-Universitaet Jena, Theoretisch-Physikalisches Institut, Jena (Germany); Warschinke, Matthias [Friedrich-Schiller-Universitaet Jena, Theoretisch-Physikalisches Institut, Jena (Germany); Chiba University, Department of Physics, Graduate School of Science, Chiba (Japan)

2017-11-15

We investigate the impact of operators of higher canonical dimension on the lower Higgs-mass consistency bound by means of generalized Higgs-Yukawa interactions. Analogously to higher-order operators in the bare Higgs potential in an effective field theory approach, the inclusion of higher-order Yukawa interactions, e.g., φ{sup 3} anti ψψ, leads to a diminishing of the lower Higgs-mass bound and thus to a shift of the scale of new physics towards larger scales by a few orders of magnitude without introducing a metastability in the effective Higgs potential. We observe that similar renormalization group mechanisms near the weak-coupling fixed point are at work in both generalizations of the microscopic action. Thus, a combination of higher-dimensional operators with generalized Higgs as well as Yukawa interactions does not lead to an additive shift of the lower mass bound, but it relaxes the consistency bounds found recently only slightly. On the method side, we clarify the convergence properties of different projection and expansion schemes for the Yukawa potential used in the functional renormalization group literature so far. (orig.)

Effect on antenna structure of high power rf during plasma operation

International Nuclear Information System (INIS)

Haste, G.R.; Thomas, C.E.; Fadnek, A.; Carter, M.D.; Beaumont, B.; Becoulet, A.; Kuus, H.; Saoutic, B.

1993-01-01

High-power, long-pulse operation on the Tore Supra tokamak results in considerable stress on the plasma-facing components. The ICH antennas must deliver high-power rf(up to 4 MW per antenna) in this environment. The antenna structure is therefore subjected to the power flux resulting from the interaction between rf and the edge plasma. The structure's response during operation is described, as is the condition of the antenna after prolonged use

20 years' operation of the Rheinsberg nuclear power plant

International Nuclear Information System (INIS)

Lehmann, R.; Quasniczka, H.; Fiss, W.; Hentschel, G.; Schulz, K.D.

1986-01-01

After a 20 years' operation of the Rheinsberg nuclear power plant a review of the operating results achieved, performance of the main equipment, research and development works performed, and experience gained with education and training of plant staff is given. (author)

Education and training of operators and maintenance staff at Hamaoka Nuclear Power Stations

International Nuclear Information System (INIS)

Makido, Hideki; Hayashi, Haruhisa

1999-01-01

At Hamaoka Nuclear Power Station, in order to ensure higher safety and reliability of plant operation, education and training is provided consistently, on a comprehensive basis, for all operating, maintenance and other technical staff, aimed at developing more capable human resources in the nuclear power division. To this end, Hamaoka Nuclear Power Station has the 'Nuclear Training Center' on its site. The training center provides the technical personnel including operators and maintenance personnel with practical training, utilizing simulators for operation training and the identical facilities with those at the real plant. Thus, it plays a central role in promoting comprehensive education and training concerning nuclear power generation. Our education system covers knowledge and skills necessary for the safe and stable operation of nuclear power plant, targeting new employees to managerial personnel. It is also organized systematically in accordance with experience and job level. We will report the present education and training of operators and maintenance personnel at Hamaoka Nuclear Training Center. (author)

The 77 K operation of a multi-resonant power converter

Science.gov (United States)

Ray, Biswajit; Gerber, Scott S.; Patterson, Richard L.; Myers, Ira T.

1995-01-01

The liquid-nitrogen temperature (77 K) operation of a 55 W, 200 kHz, 48/28 V zero-voltage switching multi-resonant dc/dc converter designed with commercially available components is reported. Upon dipping the complete converter (power and control circuits) into liquid-nitrogen, the converter performance improved as compared to the room-temperature operation. The switching frequency, resonant frequency, and the characteristic impedance did not change significantly. Accordingly, the zero-voltage switching was maintained from no-load to full-load for the specified line variations. Cryoelectronics can provide high density power converters, especially for high power applications.

Efficiency versus speed in quantum heat engines: Rigorous constraint from Lieb-Robinson bound

Science.gov (United States)

Shiraishi, Naoto; Tajima, Hiroyasu

2017-08-01

A long-standing open problem whether a heat engine with finite power achieves the Carnot efficiency is investgated. We rigorously prove a general trade-off inequality on thermodynamic efficiency and time interval of a cyclic process with quantum heat engines. In a first step, employing the Lieb-Robinson bound we establish an inequality on the change in a local observable caused by an operation far from support of the local observable. This inequality provides a rigorous characterization of the following intuitive picture that most of the energy emitted from the engine to the cold bath remains near the engine when the cyclic process is finished. Using this description, we prove an upper bound on efficiency with the aid of quantum information geometry. Our result generally excludes the possibility of a process with finite speed at the Carnot efficiency in quantum heat engines. In particular, the obtained constraint covers engines evolving with non-Markovian dynamics, which almost all previous studies on this topic fail to address.

Bounds on dark matter interactions with electroweak gauge bosons

Energy Technology Data Exchange (ETDEWEB)

Cotta, R. C.; Hewett, J. L.; Le, M. -P.; Rizzo, T. G.

2013-12-01

We investigate scenarios in which dark matter interacts with the Standard Model primarily through electroweak gauge bosons. We employ an effective field theory framework wherein the Standard Model and the dark matter particle are the only light states in order to derive model-independent bounds. Bounds on such interactions are derived from dark matter production by weak boson fusion at the LHC, indirect detection searches for the products of dark matter annihilation and from the measured invisible width of the Z ⁰ . We find that limits on the UV scale, Λ , reach weak scale values for most operators and values of the dark matter mass, thus probing the most natural scenarios in the weakly interacting massive particle dark matter paradigm. Our bounds suggest that light dark matter ( m _χ ≲ m _Z / 2 or m _χ ≲ 100 – 200 GeV , depending on the operator) cannot interact only with the electroweak gauge bosons of the Standard Model, but rather requires additional operator contributions or dark sector structure to avoid overclosing the Universe.

Non-Power Reactor Operator Licensing Examiner Standards

International Nuclear Information System (INIS)

1994-06-01

The Non-Power Reactor Operator Licensing Examiner Standards provide policy and guidance to NRC examiners and establish the procedures and practices for examining and licensing of applicants for NRC operator licenses pursuant to Part 55 of Title 10 of the Code of Federal Regulations (10 CFR Part 55). They are intended to assist NRC examiners and facility licensees to understand the examination process better and to provide for equitable and consistent administration of examinations to all applicants by NRC examiners. These standards are not a substitute for the operator licensing regulations and are subject to revision or other internal operator examination licensing policy changes. As appropriate, this standard will be revised periodically to accommodate comments and reflect new information or experience

High power operation of cladding pumped holmium-doped silica fibre lasers.

Science.gov (United States)

Hemming, Alexander; Bennetts, Shayne; Simakov, Nikita; Davidson, Alan; Haub, John; Carter, Adrian

2013-02-25

We report the highest power operation of a resonantly cladding-pumped, holmium-doped silica fibre laser. The cladding pumped all-glass fibre utilises a fluorine doped glass layer to provide low loss cladding guidance of the 1.95 µm pump radiation. The operation of both single mode and large-mode area fibre lasers was demonstrated, with up to 140 W of output power achieved. A slope efficiency of 59% versus launched pump power was demonstrated. The free running emission was measured to be 2.12-2.15 µm demonstrating the potential of this architecture to address the long wavelength operation of silica based fibre lasers with high efficiency.

Operational characteristics of nuclear power plants - modelling of operational safety; Pogonske karakteristike nuklearnih elektrana - modelsko izucavanje pogonske sigurnosti