Practical constraints on fuel management a utility perspective

International Nuclear Information System (INIS)

Grier, C.A.

1986-01-01

The practical and potential constraints of performing fuel management at a large utility are reviewed. Based on approximately six years of experience in performing fuel management the constraints due to commercial, technical, utility system, design methods, and personnel and computer resources are discussed in detail

Mox fuel utilization in ATR

OpenAIRE

下村 和生; 川太 徳夫

1987-01-01

ATR, a heavy-water moderated boiling-light-water cooled reactor developed in Japan, is a unique reactor with out-standing flexibility regarding nuclear fuel utilization, because it has superior properties concerning the utilization of plutonium, recovered uranium and depleted uranium. The development of this type of reactor is expected to contribute both to the stable supply of energy and to the establishment of plutonium utilization in Japan. Much effort has been and will be made on the deve...

Fuel utilization in a progressive conversion reactor (PCR)

International Nuclear Information System (INIS)

Leyse, C.F.; Judd, J.L.

1981-05-01

Preliminary studies indicate that for once-through fuel cycles, the PCR offers potential improvements over current LWRs in the following major areas: improved uranium utilization (reduced uranium demand), degraded plutonium product in spent fuel, reduced plutonium content of spent fuel, reduced amount of spent fuel, reduced fissile content of spent fuel, and reduced separative work

Assessment of maximum available work of a hydrogen fueled compression ignition engine using exergy analysis

International Nuclear Information System (INIS)

Chintala, Venkateswarlu; Subramanian, K.A.

2014-01-01

This work is aimed at study of maximum available work and irreversibility (mixing, combustion, unburned, and friction) of a dual-fuel diesel engine (H 2 (hydrogen)–diesel) using exergy analysis. The maximum available work increased with H 2 addition due to reduction in irreversibility of combustion because of less entropy generation. The irreversibility of unburned fuel with the H 2 fuel also decreased due to the engine combustion with high temperature whereas there is no effect of H 2 on mixing and friction irreversibility. The maximum available work of the diesel engine at rated load increased from 29% with conventional base mode (without H 2 ) to 31.7% with dual-fuel mode (18% H 2 energy share) whereas total irreversibility of the engine decreased drastically from 41.2% to 39.3%. The energy efficiency of the engine with H 2 increased about 10% with 36% reduction in CO 2 emission. The developed methodology could also be applicable to find the effect and scope of different technologies including exhaust gas recirculation and turbo charging on maximum available work and energy efficiency of diesel engines. - Highlights: • Energy efficiency of diesel engine increases with hydrogen under dual-fuel mode. • Maximum available work of the engine increases significantly with hydrogen. • Combustion and unburned fuel irreversibility decrease with hydrogen. • No significant effect of hydrogen on mixing and friction irreversibility. • Reduction in CO 2 emission along with HC, CO and smoke emissions

Emf, maximum power and efficiency of fuel cells

International Nuclear Information System (INIS)

Gaggioli, R.A.; Dunbar, W.R.

1990-01-01

This paper discusses the ideal voltage of steady-flow fuel cells usually expressed by Emf = -ΔG/nF where ΔG is the Gibbs free energy of reaction for the oxidation of the fuel at the supposed temperature of operation of the cell. Furthermore, the ideal power of the cell is expressed as the product of the fuel flow rate with this emf, and the efficiency of a real fuel cell, sometimes called the Gibbs efficiency, is defined as the ratio of the actual power output to this ideal power. Such viewpoints are flawed in several respects. While it is true that if a cell operates isothermally the maximum conceivable work output is equal to the difference between the Gibbs free energy of the incoming reactants and that of the leaving products, nevertheless, even if the cell operates isothermally, the use of the conventional ΔG of reaction assumes that the products of reaction leave separately from one another (and from any unused fuel), and when ΔS of reaction is positive it assumes that a free heat source exists at the operating temperature, whereas if ΔS is negative it neglects the potential power which theoretically could be obtained form the heat released during oxidation. Moreover, the usual cell does not operate isothermally but (virtually) adiabatically

News technology utilization fossil fuel

Directory of Open Access Journals (Sweden)

Blišanová Monika

2004-09-01

Full Text Available Fossil fuel – “alternative energy“ is coal, petroleum, natural gas. Petroleum and natural gas are scarce resources, but they are delimited. Reserves petroleum will be depleted after 39 years and reserves natural gas after 60 years.World reserves coal are good for another 240 years. Coal is the most abundant fossil fuel. It is the least expensive energy source for generating electricity. Many environmental problems associated with use of coal:in coal production, mining creates environmental problems.On Slovakia representative coal only important internal fuel – power of source and coal is produced in 5 locality. Nowadays, oneself invest to new technology on utilization coal. Perspective solution onself shows UCG, IGCC.

Program on MOX fuel utilization in light water reactors

International Nuclear Information System (INIS)

Kenda, Hirofumi

2000-01-01

MOX fuel utilization program by the Japanese electric power companies was released in February, 1997. Principal philosophy for MOX fuel design is that MOX fuel shall be compatible with Uranium fuel and behavior of core loaded with MOX fuel shall be similar to that of conventional core. MOX fuel is designed so that geometry and nuclear capability of MOX fuel are equivalent to Uranium fuel. (author)

Analysis of nuclear fuel utilization strategies

International Nuclear Information System (INIS)

Souza, J.A.M. de; Rubini, L.A.; Silva, R.P.

1981-01-01

Having in mind a rational utilization of the national uranium reserves, in the alternatives considered here in both the recycling of irradiated fuel and the introduction of fast breeder reactors (FBR's) in the electric energy generation system are analyzed. Present thermal reactors (PWR's) would be, thus, gradually replaced, and the plutonium produced by them used as fuel for the next generation of FBR's. (Author) [pt

Hydrogen utilization efficiency in PEM fuel cells

Energy Technology Data Exchange (ETDEWEB)

Metkemeyer, R; Achard, P; Rouveyre, L; Picot, D [Ecole des Mines de Paris, Centre D' energrtique, Sophia Antipolis (France)

1998-07-01

In this paper, we present the work carried out within the framework of the FEVER project (Fuel cell Electric Vehicle for Efficiency and Range), an European project coordinated by Renault, joining Ecole des Mines de Paris, Ansaldo, De Nora, Air Liquide and Volvo. For the FEVER project, where an electrical air compressor is used for oxidant supply, there is no need for hydrogen spill over, meaning that the hydrogen stoichiometry has to be as close to one as possible. To determine the optimum hydrogen utilization efficiency for a 10 kW Proton Exchange Membrane Fuel Cell (PEMFC) fed with pure hydrogen, a 4 kW prototype fuel cell was tested with and without a hydrogen recirculator at the test facility of Ecole des Mines de Paris. Nitrogen cross over from the cathodic compartment to the anodic compartment limits the hydrogen utilization of the fuel cell without recirculator to 97.4 % whereas 100% is feasible when a recirculator is used. 5 refs.

Spent fuel storage requirements

International Nuclear Information System (INIS)

Fletcher, J.

1982-06-01

Spent fuel storage requirements, as projected through the year 2000 for U.S. LWRs, were calculated using information supplied by the utilities reflecting plant status as of December 31, 1981. Projections through the year 2000 combined fuel discharge projections of the utilities with the assumed discharges of typical reactors required to meet the nuclear capacity of 165 GWe projected by the Energy Information Administration (EIA) for the year 2000. Three cases were developed and are summarized. A reference case, or maximum at-reactor (AR) capacity case, assumes that all reactor storage pools are increased to their maximum capacities as estimated by the utilities for spent fuel storage utilizing currently licensed technologies. The reference case assumes no transshipments between pools except as currently licensed by the Nuclear Regulatory Commission (NRC). This case identifies an initial requirement for 13 MTU of additional storage in 1984, and a cumulative requirement for 14,490 MTU additional storage in the year 2000. The reference case is bounded by two alternative cases. One, a current capacity case, assumes that only those pool storage capacity increases currently planned by the operating utilities will occur. The second, or maximum capacity with transshipment case, assumes maximum development of pool storage capacity as described above and also assumes no constraints on transshipment of spent fuel among pools of reactors of like type (BWR, PWR) within a given utility. In all cases, a full core discharge capability (full core reserve or FCR) is assumed to be maintained for each reactor, except that only one FCR is maintained when two reactors share a common pool. For the current AR capacity case the indicated storage requirements in the year 2000 are indicated to be 18,190 MTU; for the maximum capacity with transshipment case they are 11,320 MTU

Utility industry evaluation of the metal fuel facility and metal fuel performance for liquid metal reactors

International Nuclear Information System (INIS)

Burstein, S.; Gibbons, J.P.; High, M.D.; O'Boyle, D.R.; Pickens, T.A.; Pilmer, D.F.; Tomonto, J.R.; Weinberg, C.J.

1990-02-01

A team of utility industry representatives evaluated the liquid metal reactor metal fuel process and facility conceptual design being developed by Argonne National Laboratory (ANL) under Department of Energy sponsorship. The utility team concluded that a highly competent ANL team was making impressive progress in developing high performance advanced metal fuel and an economic processing and fabrication technology. The utility team concluded that the potential benefits of advanced metal fuel justified the development program, but that, at this early stage, there are considerable uncertainties in predicting the net overall economic benefit of metal fuel. Specific comments and recommendations are provided as a contribution towards enhancing the development program. 6 refs

Utilities' nuclear fuel economic evaluation methods

International Nuclear Information System (INIS)

Sonz, L.A.

1987-01-01

This paper presents the typical perceptions, methods, considerations, and procedures used by an operating electric utility in the economic evaluation of nuclear fuel preparation and utilization scenarios. The means given are probably not an exclusive review of those available, but are the author's recollection of systems employed to select and recommend preferable courses of action. Economic evaluation of proposed nuclear fuel scenarios is an important, but not exclusive, means of deciding on corporate action. If the economic evaluation is performed and coordinated with the other corporate considerations, such as technical and operational ability, electrical system operations management, tax effects, capital management, rates impact, etc., then the resultant recommendation may be employed to the benefit of the customers and, consequently, to the corporation

Standardized, utility-DOE compatible, spent fuel storage-transport systems

International Nuclear Information System (INIS)

Smith, M.L.

1991-01-01

Virginia Power has developed and licensed a facility for dry storage of spent nuclear fuel in metal spent fuel storage casks. The modifications to the design of these casks necessary for licensing for both storage and transport of spent fuel are discussed along with the operational advantages of dual purpose storage-transport casks. Dual purpose casks can be used for storage at utility and DOE sites (MRS or repository) and for shipment between these sites with minimal spent fuel handling. The cost for a standardized system of casks that are compatible for use at both DOE and utility sites is discussed along with possible arrangements for sharing both the cost and benefits of dual purpose storage-transport casks

Utilization of alternative fuels in diesel engines

Science.gov (United States)

Lestz, S. A.

1984-01-01

Performance and emission data are collected for various candidate alternate fuels and compare these data to that for a certified petroleum based number two Diesel fuel oil. Results for methanol, ethanol, four vegetable oils, two shale derived oils, and two coal derived oils are reported. Alcohol fumigation does not appear to be a practical method for utilizing low combustion quality fuels in a Diesel engine. Alcohol fumigation enhances the bioactivity of the emitted exhaust particles. While it is possible to inject many synthetic fuels using the engine stock injection system, wholly acceptable performance is only obtained from a fuel whose specifications closely approach those of a finished petroleum based Diesel oil. This is illustrated by the contrast between the poor performance of the unupgraded coal derived fuel blends and the very good performance of the fully refined shale derived fuel.

Optimal initial fuel distribution in a thermal reactor for maximum energy production

International Nuclear Information System (INIS)

Moran-Lopez, J.M.

1983-01-01

Using the fuel burnup as objective function, it is desired to determine the initial distribution of the fuel in a reactor in order to obtain the maximum energy possible, for which, without changing a fixed initial fuel mass, the results for different initial fuel and control poison configurations are analyzed and the corresponding running times compared. One-dimensional, two energy-group theory is applied to a reflected cylindrical reactor using U-235 as fuel and light water as moderator and reflector. Fissions in both fast and thermal groups are considered. The reactor is divided into several annular regions, and the constant flux approximation in each depletion step is then used to solve the fuel and fission-product poisons differential equations in each region. The computer code OPTIME was developed to determine the time variation of core properties during the fuel cycle. At each depletion step, OPTIME calls ODMUG, [12] a criticality search program, from which the spatially-averaged neutron fluxes and control poison cross sections are obtained

Emergency fuels utilization guidebook. Alternative Fuels Utilization Program

Energy Technology Data Exchange (ETDEWEB)

1980-08-01

The basic concept of an emergency fuel is to safely and effectively use blends of specification fuels and hydrocarbon liquids which are free in the sense that they have been commandeered or volunteered from lower priority uses to provide critical transportation services for short-duration emergencies on the order of weeks, or perhaps months. A wide variety of liquid hydrocarbons not normally used as fuels for internal combustion engines have been categorized generically, including limited information on physical characteristics and chemical composition which might prove useful and instructive to fleet operators. Fuels covered are: gasoline and diesel fuel; alcohols; solvents; jet fuels; kerosene; heating oils; residual fuels; crude oils; vegetable oils; gaseous fuels.

Problems related to fossil fuels utilization

International Nuclear Information System (INIS)

Rota, R.

1999-01-01

Fossil fuels still present the main energy source in the world since about 90% of the energy produced comes from combustion. This paper, based on the lectures given at the conference of Energy and Environment hold at the Accademia dei Lincei in 1998, presents a short review of some of the problems related to the utilization of fossil fuels, such as their availability in the medium period, the effect of pollutant dispersion in the atmosphere as well as the available technologies to deal with such problems [it

Firing the furnace? An econometric analysis of utilities' fuel choice

International Nuclear Information System (INIS)

Tauchmann, H.

2006-01-01

This paper attempts to estimate how the fuel mix of German electricity producers does react to fuel price changes. The empirical analysis is based on panel data (1968-1998) of major utilities. Two different aspects of fuel choice are distinguished: at the one hand, the construction of usually fuel-specific capacities for electric power generation, i.e. investment decisions that determine the fuel mix in the long run; at the other, fuel use conditional on existing generation capacities, i.e. short-run inter-fuel substitution. According to the results from panel unit root tests, both the econometric models which describe these two aspects are specified in changes rather than levels. The partly discrete nature of investment decisions is taken into account, by constructing a discrete model of capacity adjustment. Our estimation results suggest that the fuel mix of electric utilities is price inelastic either if long-term investment or short-term inter-fuel substitution is considered. Finally, the empirical results are used to predict the potential impacts of CO 2 emissions trading on fuel choice in the German electric power industry

Firing the furnace? An econometric analysis of utilities' fuel choice

International Nuclear Information System (INIS)

Tauchmann, H.

2006-01-01

This paper attempts to estimate how the fuel mix of German electricity producers does react to fuel price changes. The empirical analysis is based on panel data (1968-1998) of major utilities. Two different aspects of fuel choice are distinguished: at the one hand, the construction of usually fuel-specific capacities for electric power generation, i.e. investment decisions that determine the fuel mix in the long run; at the other, fuel use conditional on existing generation capacities, i.e. short-run inter-fuel substitution. According to the results from panel unit root tests, both the econometric models which describe these two aspects are specified in changes rather than levels. The partly discrete nature of investment decisions is taken into account, by constructing a discrete model of capacity adjustment. Our estimation results suggest that the fuel mix of electric utilities is price inelastic either if long-term investment or short-term inter-fuel substitution is considered. Finally, the empirical results are used to predict the potential impacts of CO 2 emissions trading on fuel choice in the German electric power industry. (Author)

Evaluation of parameters effect on the maximum fuel temperature in the core thermal and hydraulic design of HTTR

International Nuclear Information System (INIS)

Fujimoto, Nozomu; Maruyama, Soh; Sudo, Yukio; Fujii, Sadao; Niguma, Yoshinori.

1988-10-01

This report presents the results of quantitative evaluation on the effects of the dominant parameters on the maximum fuel temperature in the core thermal hydraulic design of the High Temperature Engineering Test Reactor(HTTR) of 30 MW in thermal power, 950 deg C in reactor outlet coolant temperature and 40 kg/cm 2 G in coolant pressure. The dominant parameters investigated are 1) Gap conductance. 2) Effect of eccertricity of fuel compacts in graphite sleeve. 3) Effect of spacer ribs on heat transfer coefficients. 4) Contact probability of fuel compact and graphite sleeve. 5) Validity of uniform radial power density in the fuel compacts. 6) Effect of impurity gas on gap conductance. 7) Effect of FP gas on gap conductance. The effects of these items on the maximum fuel temperature were quantitalively identified as hot spot factors. A probability of the appearance of the maximum fuel temperature was also evaluated in this report. (author)

Fuel cell heat utilization system; Nenryo denchi netsuriyo sochi

Energy Technology Data Exchange (ETDEWEB)

Urata, T. [Tokyo (Japan); Omura, T. [Tokyo (Japan)

1995-07-04

In the conventional fuel cell heat utilization system, the waste heat is recovered to be utilized by either the waste heat recovery heat exchanger or the waste heat recovery steam. In the employment of the waste heat recovery heat exchanger system, however, the utility value is decreased when the temperature of the waste heat is lowered. Contrarily, in the employment of the waste heat recovery steam system, the supplementary water requirement is increased corresponding to the amount of waste heat recovery steam, resulting in the cost increase for water treatment. This invention solves the problem. In the invented fuel cell heat utilization system, a pressurized water from the steam separator is introduced into the second circuit to utilize directly the heat in the heat utilization system without employing the heat exchanger. If a blowdown valve is installed between the second circuit heat utilization system and the steam separator, the heat loss due to the blowdown can be reduced, since the low temperature water is blown down after being utilized in the heat utilization system. 4 figs.

Configuration of LWR fuel enrichment or burnup yielding maximum power

International Nuclear Information System (INIS)

Bartosek, V.; Zalesky, K.

1976-01-01

An analysis is given of the spatial distribution of fuel burnup and enrichment in a light-water lattice of given dimensions with slightly enriched uranium, at which the maximum output is achieved. It is based on the spatial solution of neutron flux using a one-group diffusion model in which linear dependence may be expected of the fission cross section and the material buckling parameter on the fuel burnup and enrichment. Two problem constraints are considered, i.e., the neutron flux value and the specific output value. For the former the optimum core configuration remains qualitatively unchanged for any reflector thickness, for the latter the cases of a reactor with and without reflector must be distinguished. (Z.M.)

76 FR 3517 - Standards of Performance for Fossil-Fuel-Fired, Electric Utility, Industrial-Commercial...

Science.gov (United States)

2011-01-20

... Standards of Performance for Fossil-Fuel-Fired, Electric Utility, Industrial-Commercial-Institutional, and... following: Category NAICS \\1\\ Examples of regulated entities Industry 221112 Fossil fuel-fired electric utility steam generating units. Federal Government 22112 Fossil fuel-fired electric utility steam...

Application of fuel cells with heat recovery for integrated utility systems

Science.gov (United States)

Shields, V.; King, J. M., Jr.

1975-01-01

This paper presents the results of a study of fuel cell powerplants with heat recovery for use in an integrated utility system. Such a design provides for a low pollution, noise-free, highly efficient integrated utility. Use of the waste heat from the fuel cell powerplant in an integrated utility system for the village center complex of a new community results in a reduction in resource consumption of 42 percent compared to conventional methods. In addition, the system has the potential of operating on fuels produced from waste materials (pyrolysis and digester gases); this would provide further reduction in energy consumption.

Direct synthesis of Pt-free catalyst on gas diffusion layer of fuel cell and usage of high boiling point fuels for efficient utilization of waste heat

International Nuclear Information System (INIS)

Nandan, Ravi; Goswami, Gopal Krishna; Nanda, Karuna Kar

2017-01-01

Graphical abstract: Direct-grown boron-doped carbon nanotubes on gas-diffusion layer as efficient Pt-free cathode catalyst for alcohol fuel cells, high boiling point fuels used to obtain hot fuels for the enhancement of cell performance that paves the way for the utilization of waste heat. Display Omitted -- Highlights: •One-step direct synthesis of boron-doped carbon nanotubes (BCNTs) on gas diffusion layer (GDL). •Home built fuel-cell testing using BCNTs on GDL as Pt-free cathode catalyst. •BCNTs exhibit concentration dependent oxygen reduction reaction and the cell performance. •Effective utilization of waste heat to raise the fuel temperature. •Fuel selectivity to raise the fuel temperature and the overall performance of the fuel cells. -- Abstract: Gas diffusion layers (GDL) and electrocatalysts are integral parts of fuel cells. It is, however, a challenging task to grow Pt-free robust electrocatalyst directly on GDL for oxygen reduction reaction (ORR) – a key reaction in fuel cells. Here, we demonstrate that boron-doped carbon nanotubes (BCNTs) grown directly on gas-diffusion layer (which avoid the need of ionomer solution used for catalyst loading) can be used as efficient Pt-free catalyst in alcohol fuel cells. Increase in boron concentration improves the electrochemical ORR activity in terms of onset and ORR peak positions, half-wave potentials and diffusion-limited current density that ensure the optimization of the device performance. The preferential 4e − pathway, excellent cell performance, superior tolerance to fuel crossover and long-term stability makes directly grown BCNTs as an efficient Pt-free cathode catalyst for cost-effective fuel cells. The maximum power density of the fuel cell is found to increase monotonically with boron concentration. In addition to the application of BCNTs in fuel cell, we have introduced the concept of hot fuels so that waste heat can effectively be used and external power sources can be avoided. The fuel

Fuel utilization experience in Bohunice NPP and regulatory requirements for implementation of progressive fuel management strategies

Energy Technology Data Exchange (ETDEWEB)

Patenyi, V [Nuclear Regulatory Authority, Bratislava (Slovakia); Darilek, P; Majercik, J [Vyskumny Ustav Jadrovych Elektrarni, Trnava (Slovakia)

1994-12-31

The experience gained in fuel utilization and the basic requirements for fuel licensing in the Slovak NPPs is described. The original project of WWER-440 reactors supposes 3-year fuel cycle with cycle length of about 320 full power days (FPD). Since 1984 it was reduced to 290 FPD. Based on the experience of other countries, a 4-year fuel cycle utilization started in 1987. It is illustrated with data from the Bohunice NPP units. Among 504 fuel assemblies left for the fourth burnup cycle no leakage was observed. The mean burnup achieved in the different units varied from 33.1 to 38.5 Mwd/kg U. The new fuel assemblies used are different from the recent ones in construction, thermohydraulics, water-uranium ratio, enrichment and material design. To meet the safety criteria, regulatory requirements for exploitation of new fuel in WWER-440 were formulated by the Nuclear Regulatory Authority of Slovak Republic. 1 tab., 5 refs.

A fiber optics system for monitoring utilization of ZnO adsorbent beds during desulfurization for logistic fuel cell applications

Science.gov (United States)

Sujan, Achintya; Yang, Hongyun; Dimick, Paul; Tatarchuk, Bruce J.

2016-05-01

An in-situ fiber optic based technique for direct measurement of capacity utilization of ZnO adsorbent beds by monitoring bed color changes during desulfurization for fuel cell systems is presented. Adsorbents composed of bulk metal oxides (ZnO) and supported metal oxides (ZnO/SiO2 and Cusbnd ZnO/SiO2) for H2S removal at 22 °C are examined. Adsorbent bed utilization at breakthrough is determined by the optical sensor as the maximum derivative of area under UV-vis spectrum from 250 to 800 nm observed as a function of service time. Since the response time of the sensor due to bed color change is close to bed breakthrough time, a series of probes along the bed predicts utilization of the portion of bed prior to H2S breakthrough. The efficacy of the optical sensor is evaluated as a function of inlet H2S concentration, H2S flow rate and desulfurization in presence of CO, CO2 and moisture in feed. A 6 mm optical probe is employed to measure utilization of a 3/16 inch ZnO extrudate bed for H2S removal. It is envisioned that with the application of the optical sensor, desulfurization can be carried out at high adsorbent utilization and low operational costs during on-board miniaturized fuel processing for logistic fuel cell power systems.

Fact sheet on fuel manufacturing and utilization

International Nuclear Information System (INIS)

2006-01-01

The Nuclear Fuel Cycle and Materials Section (NFCMS) supports Member States to improve in-pile fuel performance and management of materials; and to develop advanced fuel technologies for ensuring reliability and economic efficiency of the nuclear fuel cycle, provides assistance to Member States to support fuel-manufacturing capability, including quality assurance techniques, optimization of manufacturing parameters and radiation protection, supports the development fuel modeling expertise in Member States, covering both normal operation and postulated and severe accident conditions, provides information and support for the operation of Nuclear Power Plant to ensure that the environment and water chemistry is appropriate for fuel operation, supports fuel failure investigations, including equipment for failed fuel detection and for post-irradiation examination and inspection, as well as fuel repair, provides information and support research into the basic properties of fuel materials, including UO2, MOX, (Th, Pu)O2, (Th, U233)O2 fuels and zirconium alloy cladding and fuel assembly components and offers guidance on the relationship with back-end requirement (interim storage, transport, reprocessing, disposal), fuel utilization and management, MOX fuels, alternative fuels and advanced fuel technology and materials, economic and other aspects of nuclear fuel use (e.g. environmental impact). Recently NFCMS provided support to a Member State manufacturing Gadolinia doped fuel and provided in-mast sipping equipment to a Nuclear Power Plant to allow the determination of fuel failure. Member States interested in fuel performance and manufacture should contact the Technical Cooperation Department of the Agency and Member States interested in knowing more about the Agency's programme on source management should contact: C. Ganguly, Section Head, V. Inozemtsev, J. Killeen

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

Directory of Open Access Journals (Sweden)

Rezaeian Mahdi

2015-01-01

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

Method and apparatus for storing nuclear fuel assemblies in maximum density racks

International Nuclear Information System (INIS)

Wachter, W.J.; Robbins, T.R.

1979-01-01

A maximum density storage rack is provided for long term or semipermanent storage of spent nuclear fuel assemblies. The rack consists of storage cells arranged in a regular array, such as a checkerboard, and intended to be immersed in water. Initially, cap members are placed on alternate cells in such a manner that at least 50% of the cells are left open, some of the caps being removable. Spent fuel assemblies are then placed in the open cells until all of them are filled. The level of reactivity of each of the stored fuel assemblies is then determined by accurate calculation or by measurement, and the removable caps are removed and rearranged so that other cells are opened, permitting the storage of additional fuel assemblies in a pattern based on the actual reactivity such that criticality is prevented

Performance of a methane-fueled single-cell SOFC stack at various levels of fuel utilization

International Nuclear Information System (INIS)

Ahmed, K.; Bolden, R.; Ramprakash and Foger, K.

1998-01-01

Fuel-gas mixtures representing 10 to 85% utilization of a methane-steam mixture at S/C=2 were fed to a single cell stack with a Ni-based anode at 875 deg C. Cell voltage and power output were recorded at current densities of 50 to 350 mA/cm 2 . The accompanying anode off-gas composition at some of these conditions were measured using on-line gas chromatograph and compared with the compositions predicted by a thermodynamic model based on the assumption of no carbon formation. Electrical losses were measured at a chosen current density at various levels of fuel utilization by the galvanostatic current-interruption technique. Cell voltage stability was monitored for up to 1000 h at two levels of fuel utilization. The stack performance was simulated using a mathematical model of the stack; the simulations were compared with the stack test data. Copyright (1998) Australasian Ceramic Society

Electric utility fuel choice behavior in the United States

Energy Technology Data Exchange (ETDEWEB)

Joskow, P.L.; Mishkin, F.S.

1977-10-01

Electric utility fuel choice behavior is analyzed by a conditional logit model to determine the effects of changing oil prices of five plants. Three of the plants faced favorable expected coal prices and, like many areas of the country, were insensitive to changing oil prices. This was not the case at the New England plant, however, where relatively small price increases would decrease the likelihood of choosing oil as an alternative fuel for new plants. The modeling of utility behavior in fuel decisions is felt to be applicable to other industries where a continuum of decision possibilities does not reasonably characterize choice alternatives. New behavior models are urged in order to obtain better predictions of the effects of a changing economic environment. 10 references.

Government--utility interaction on spent fuel disposition

International Nuclear Information System (INIS)

Mills, L.E.

1978-01-01

The question of the needs of the electrical power industry for spent fuel storage in light of the moratorium on fuel reprocessing is addressed. The author feels that since the Federal government has assumed the responsibility for spent fuel storage, it is imperative that a firm plan, program, legislation, and funding be forthcoming immediately. Designation of an existing government site with existing nuclear activities in order to expedite the establishment of a storage facility is recommended. It is felt that the timing for such a site should be ''at the earliest possible date.'' Without storage facilities being provided by the government, utilities will be forced to build storage facilities at the reactor sites. This course of action is not considered cost effective but certainly preferable to shutting down the reactors. It is emphasized that spent fuel storage must be an interim solution and certainly not a final solution to the fuel reprocessing and waste disposal aspects of nuclear technology

A comparison of hydrogen-fueled fuel cells and combustion engines for electric utility applications

International Nuclear Information System (INIS)

Schoenung, S.M.

2000-01-01

Hydrogen-fueled systems have been proposed for a number of stationary electric generation applications including remote power generation, load management, distribution system peak shaving, and reliability or power quality enhancement. Hydrogen fueling permits clean, low pollution operation. This is particularly true for systems that use hydrogen produced from electrolysis, rather than the reforming of hydrocarbon fuels. Both fuel cells and combustion engines are suitable technologies for using hydrogen in many electric utility applications. This paper presents results from several studies performed for the U.S. Department of Energy Hydrogen Program. A comparison between the two technologies shows that, whereas fuel cells are somewhat more energy efficient, combustion engine technology is less expensive. In this paper, a comparison of the two technologies is presented, with an emphasis on distributed power and power quality applications. The special case of a combined distributed generation I hydrogen refueling station is also addressed. The comparison is made on the basis of system costs and benefits, but also includes a comparison of technology status: power ratings and response time. A discussion of pollutant emissions and pollutant control strategies is included. The results show those electric utility applications for which each technology is best suited. (author)

Where U.S. utilities seek fuel to power reactors after 1985

International Nuclear Information System (INIS)

Anon.

1977-01-01

How utilities try to assure uranium supplies emerged Feb. 25 at a press conference in Canberra with four representatives of utilities that supply 20% of the operating nuclear capacity in the United States. Earlier, the speakers indicated that American import requirements would far exceed Australian estimates of the potential export market for Australian uranium. Australia, with the world's largest uncommitted uranium reserves, is wary of exporting because the opposition Labor Party adamantly opposes uranium development. If Labor returns to power, it could decide not to honor contracts by the present government. Participants included: Bernard Cherry, fuel manager at General Public Utilities; Colin Campbell of the Yankee Atomic Service Co., which provides engineering and fuel-supply service for seven New England nuclear plants; Jack Gilleland, assistant manager of power at the Tennessee Valley Authority; and Ralph Bostian, manager for systems results and fuel management at the Duke Power Co. When asked about available uranium supplies from Africa, the participants were dubious about those supplies; this led to a discussion on why the utilities are seeking their own sources. The answers are obvious. ERDA has indicated that about one-half of the operating reactors have fuel coverage beyond six reloads and about one-half of the reactors under construction have fuel coverage beyond two reloads

Radial power distribution shaping within a PWR fuel assembly utilizing asymmetrically loaded gadolinia-bearing fuel pins

International Nuclear Information System (INIS)

Stone, I.Z.

1992-01-01

As in-core fuel management designs evolve to meet the demands of increasing energy output, more innovative methods are developed to maintain power peaking within acceptable thermal margin limits. In-core fuel management staff must utilize various loading pattern strategies such as cross-core movement of fuel assemblies, multibatch enrichment schemes, and burnable absorbers as the primary means of controlling the radial power distribution. The utilization of fresh asymmetrically loaded gadolinia-bearing assemblies as a fuel management tool provides an additional means of controlling the radial power distribution. At Siemens Nuclear Power Corporation (SNP), fresh fuel assemblies fabricated with asymmetrically loaded gadolinia-bearing fuel rods have been used successfully for several cycles of reactor operation. Asymmetric assemblies are neutronically modeled using the same tools and models that SNP uses to model symmetrically loaded gadolinia-bearing fuel assemblies. The CASMO-2E code is used to produce the homogenized macroscopic assembly cross sections for the nodal core simulator. Optimum fuel pin locations within the asymmetrical assembly are determined using the pin-by-pin PDQ7 assembly core model for each new assembly design. The optimum pin location is determined by the rod loading that minimizes the peak-to-average pin power

Nuclear fuel utilization at the Kozloduy NPP

Energy Technology Data Exchange (ETDEWEB)

Boyadzhiev, Z [Kombinat Atomna Energetika, Kozloduj (Bulgaria); Kharalampieva, Ts; Pejchinov, Ts

1996-12-31

Data on core loading and operation conditions during past fuel cycles of the Units 1 to 6 at the Kozloduy NPP are presented. The Units 1 and 2 have reached average discharge fuel burn-up of 31 MW d/kg U, the Unit 3 - 34 MW d/kg U and the Unit 4 - 36.5 MW d/kg U. By use of dummies and low-leakage core loading patterns for WWER-440 cores an effective reduction in reactor pressure vessel irradiation is obtained. By increasing the enrichment level and improving the characteristics of the Units 3 and 4, a design fuel cycles duration has been reduced by 5-10% in number of assemblies. Core loading design has been modelled using computer codes SPPS-1, BIPR-7, ALBOM, PROROC. A 3-year fuel cycle utilizing 4.4% enriched fuel proved to be more efficient for WWER-1000 by 15% reduction in fuel cost compared to the 2-year cycle. Future developments include improvements of the in-core monitoring system and process on-line simulation based on more accurate computer codes. 7 refs., 6 figs., 10 tabs.

A design study of high breeding ratio sodium cooled metal fuel core without blanket fuels

International Nuclear Information System (INIS)

Kobayashi, Noboru; Ogawa, Takashi; Ohki, Shigeo; Mizuno, Tomoyasu; Ogata, Takanari

2009-01-01

The metal fuel core is superior to the mixed oxide fuel core because of its high breeding ratio and compact core size resulting from hard neutron spectrum and high heavy metal densities. Utilizing these characteristics, a conceptual design for a high breeding ratio was performed without blanket fuels. The design conditions were set so a sodium void worth of less than 8 $, a core height of less than 150 cm, the maximum cladding temperature of 650degC, and the maximum fuel pin bundle pressure drop of 0.4 MPa. The breeding ratio of the resultant core was 1.34 with 6wt% zirconium content fuel. Applying 3wt% zirconium content fuel enhanced the breeding ratio up to 1.40. (author)

The maximum allowable temperature of zircaloy-2 fuel cladding under dry storage conditions

International Nuclear Information System (INIS)

Mayuzumi, M.; Yoshiki, S.; Yasuda, T.; Nakatsuka, M.

1990-09-01

Japan plans to reprocess and reutilise the spent nuclear fuel from nuclear power generation. However, the temporary storage of spent fuel is assuming increasing importance as a means of ensuring flexibility in the nuclear fuel cycle. Our investigations of various methods of storage have shown that casks are the most suitable means of storing small quantities of spent fuel of around 500 t, and research and development are in progress to establish dry storage technology for such casks. The soundness of fuel cladding is being investigated. The most important factor in evaluating soundness in storage under inert gas as currently envisaged is creep deformation and rupture, and a number of investigations have been made of the creep behaviour of cladding. The present study was conducted on the basis of existing in-house results in collaboration with Nippon Kakunenryo Kaihatsu KK (Nippon Nuclear Fuel Department Co.), which has hot lab facilities. Tests were run on the creep deformation behaviour of irradiated cladding, and the maximum allowable temperature during dry storage was investigated. (author)

A scheme of better utilization of PWR spent fuels

International Nuclear Information System (INIS)

Chung, Bum Jin; Kang, Chang Soon

1991-01-01

The recycle of PWR spent fuels in a CANDU reactor, so called the tandem fuel cycle is investigated in this study. This scheme of utilizing PWR spent fuels will ease the shortage of spent fuel storage capacity as well as will improve the use of uranium resources. The minimum modification the design of present CANDU reactor is seeked in the recycle. Nine different fuel types are considered in this work and are classified into two categories: refabrication and reconfiguration. For refabrication, PWR spent fuels are processed and refabricated into the present 37 rod lattice structure of fuel bundle, and for reconfiguration, meanwhile, spent fuels are simply disassembled and rods are cut to fit into the present grid configuration of fuel bundle without refabrication. For each fuel option, the neutronics calculation of lattice was conducted to evaluate the allowable burn up and distribution. The fuel cycle cost of each option was also computed to assess the economic justification. The results show that most tandem fuel cycle option considered in this study are technically feasible as well as economically viable. (Author)

Innovative nuclear thermal rocket concept utilizing LEU fuel for space application

International Nuclear Information System (INIS)

Nam, Seung Hyun; Venneri, Paolo; Choi, Jae Young; Jeong, Yong Hoon; Chang, Soon Heung

2015-01-01

Space is one of the best places for humanity to turn to keep learning and exploiting. A Nuclear Thermal Rocket (NTR) is a viable and more efficient option for human space exploration than the existing Chemical Rockets (CRs) which are highly inefficient for long-term manned missions such as to Mars and its satellites. NERVA derived NTR engines have been studied for the human missions as a mainstream in the United States of America (USA). Actually, the NERVA technology has already been developed and successfully tested since 1950s. The state-of-the-art technology is based on a Hydrogen gas (H_2) cooled high temperature reactor with solid core utilizing High-Enriched Uranium (HEU) fuel to reduce heavy metal mass and to use fast or epithermal neutron spectrums enabling simple core designs. However, even though the NTR designs utilizing HEU is the best option in terms of rocket performance, they inevitably provoke nuclear proliferation obstacles on all Research and Development (R and D) activities by civilians and non-nuclear weapon states, and its eventual commercialization. To surmount the security issue to use HEU fuel for a NTR, a concept of the innovative NTR engine, Korea Advanced NUclear Thermal Engine Rocket utilizing Low-Enriched Uranium fuel (KANUTER-LEU) is presented in this paper. The design goal of KANUTER-LEU is to make use of a LEU fuel for its compact reactor, but does not sacrifice the rocket performance relative to the traditional NTRs utilizing HEU. KANUTER-LEU mainly consists of a fission reactor utilizing H_2 propellant, a propulsion system and an optional Electricity Generation System as a bimodal engine. To implement LEU fuel for the reactor, the innovative engine adopts W-UO_2 CERMET fuel to drastically increase uranium density and thermal neutron spectrum to improve neutron economy in the core. The moderator and structural material selections also consider neutronic and thermo-physical characteristics to reduce non-fission neutron loss and

Greater utilization of wood residue fuels through improved financial planning

International Nuclear Information System (INIS)

Billings, C.D.; Ziemke, M.C.; Stanford, R.

1991-01-01

Recent events have focused attention on the promotion of greater utilization of biomass fuel. Considerations include the need to reduce increases in global warming and also to improve ground level air quality by limiting the use of fossil fuels. However, despite all these important environmentally related considerations, economics remains the most important factor in the decision process used to determine the feasibility of using available renewable fuels instead of more convenient fossil fuels. In many areas of the Southeast, this decision process involves choosing between wood residue fuels such as bark, sawdust and shavings and presently plentiful natural gas. The primary candidate users of wood residue fuels are industries that use large amounts of heat and electric power and are located near centers of activity in the forest products industry such as sawmills, veneer mills and furniture factories. Given that such facilities both produce wood residues and need large amounts of heat and electricity, it is understandable that these firms are often major users of wood-fired furnaces and boilers. The authors have observed that poor or incomplete financial planning by the subject firms is a major barrier to economic utilization of inexpensive and widely available renewable fuels. In this paper, the authors suggest that wider usage of improved financial planning could double the present modest annual incidence of new commercial wood-fueled installation

Ultraclean Fuels Production and Utilization for the Twenty-First Century: Advances toward Sustainable Transportation Fuels

Energy Technology Data Exchange (ETDEWEB)

Fox, Elise B.; Liu, Zhong-Wen; Liu, Zhao-Tie

2013-11-21

Ultraclean fuels production has become increasingly important as a method to help decrease emissions and allow the introduction of alternative feed stocks for transportation fuels. Established methods, such as Fischer-Tropsch, have seen a resurgence of interest as natural gas prices drop and existing petroleum resources require more intensive clean-up and purification to meet stringent environmental standards. This review covers some of the advances in deep desulfurization, synthesis gas conversion into fuels and feed stocks that were presented at the 245th American Chemical Society Spring Annual Meeting in New Orleans, LA in the Division of Energy and Fuels symposium on "Ultraclean Fuels Production and Utilization".

Hawaii alternative fuels utilization program. Phase 3, final report

Energy Technology Data Exchange (ETDEWEB)

Kinoshita, C.M.; Staackmann, M.

1996-08-01

The Hawaii Alternative Fuels Utilization Program originated as a five-year grant awarded by the US Department of Energy (USDOE) to the Hawaii Natural Energy Institute (HNEI) of the University of Hawaii at Manoa. The overall program included research and demonstration efforts aimed at encouraging and sustaining the use of alternative (i.e., substitutes for gasoline and diesel) ground transportation fuels in Hawaii. Originally, research aimed at overcoming technical impediments to the widespread adoption of alternative fuels was an important facet of this program. Demonstration activities centered on the use of methanol-based fuels in alternative fuel vehicles (AFVs). In the present phase, operations were expanded to include flexible fuel vehicles (FFVs) which can operate on M85 or regular unleaded gasoline or any combination of these two fuels. Additional demonstration work was accomplished in attempting to involve other elements of Hawaii in the promotion and use of alcohol fuels for ground transportation in Hawaii.

Alternative routes to improved fuel utilization: Analysis of near-term economic incentives

International Nuclear Information System (INIS)

Salo, J.P.; Vieno, T.; Vira, J.

1984-01-01

The potential for savings in the nuclear fuel cycle costs is discussed from the point of view of a single utility. The analysis is concentrated on the existing and near-term economic incentives for improved fuel utilization, and the context is that of a small country without domestic fuel cycle services. In the uranium fuel cycle the extended burnup produces savings in the uranium feed as well as in the fuel fabrication and waste management requirements. The front-end fuel cycle cost impact is evaluated for BWRs. In the back-end part the situation is more specific of the concrete back-end solution. Estimates for savings in the cost of direct disposal of spent fuel are presented for a Finnish case. The economics of recycle is reviewed from a recent study on the use of MOX fuel in the Finnish BWRs. The results from a comparison with once-through alternative show that spent fuel reprocessing with consequent recycle of uranium and plutonium would be economically justified only with very high uranium prices. (author)

Utilization of particle fuels in different reactor concepts

International Nuclear Information System (INIS)

1983-04-01

To date, particle fuel is only used in high temperature reactors (HTR). In this reactor type the particles exist of oxide fuel with a diameter of about 0.5 mm and are surrounded by various coatings in order to safely enclose fission products and decrease the radioactive release into the primary circuit. However, it is felt that fuel based upon spherical particles could have some advantages compared with pellets both on fabrication and in-core behaviour in several reactor concepts. This fuel is now of general interest and there is a high level of research and development activity in some countries. In order to collect, organize additional information and summarize experience on utilization of particle fuels in different reactor concepts, a questionnaire was prepared by IAEA in 1980 and sent to Member States, which might be involved in relevant developments. This survey has been prepared by a group of consultants and is mainly based on the responses to the IAEA questionnaire

The Design Features of the Double-Banked AMBIDEXTER Utilizing DUPIC Fuel

Energy Technology Data Exchange (ETDEWEB)

Ham, Tae Kyu [KHNP Central Research Institute, Daejeon (Korea, Republic of); Lee, Young Joon; Hong, Sung Taek [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Seo, Myung Hwan [Korea Radioactive Waste Agency, Daejeon (Korea, Republic of); Kwon, Tae An [KHNP, Daejeon (Korea, Republic of); Oh, Se Kee [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

2016-10-15

Since the on-site spent fuel storage capabilities at reactors in Korea are expected to be saturated in a few years, the government has been pressed to find a solution for the spent nuclear fuel. So far one of workable means for reducing the load would be utilizing DUPIC fuel cycle technology. The technology was developed through Korea-Canada-U.S. collaboration to utilize the LWR spent fuel for the CANDU reactor. However, by various sociopolitical reasons, the DUPIC technology has not been yet commercialized. As the other alternatives to use the DUPIC technology, Gen-IV reactors would be pertinent. In the following session, the design features of a molten salt reactor system that can burn DUPIC fuel are explained. The followings are derived as conclusions after considering all the factors; The AMDEC, compared to ORIGEN2 simulations, can calculate the nuclides concentration changes within 1% deviation in various core zones and reactor system components by using different library sets which are weighted with each neutron spectrum; Fuel-flow effects coupled with nuclear reactions is well reflected in the AMDEC.

Utilization of Alcohol Fuel in Spark Ignition and Diesel Engines.

Science.gov (United States)

Berndt, Don; Stengel, Ron

These five units comprise a course intended to prepare and train students to conduct alcohol fuel utilization seminars in spark ignition and diesel engines. Introductory materials include objectives and a list of instructor requirements. The first four units cover these topics: ethanol as an alternative fuel (technical and economic advantages,…

A study on KMRR utilization for fuel development

International Nuclear Information System (INIS)

Kang, Young Hwan; Ryu, Woo Seog; Park, Ji Yeon; Joo, Kee Nam; Park, Jong Man; Park, Se Jin

1991-01-01

The most effective utilization scheme of the KMRR was studied in the field of nuclear fuel development through reviewing literatural documents on irradiation facilities and in-pile test. It is suggested that the KMRR should be used for verification tests of advanced fuels and for power ramping / cycling tests of fuel rods. In addition, the characterization tests for fuel development and the basic material research should be also performed. In-pile loops for fuel verification and/or power ramping / cycling tests are proposed to be installed in advance, and capsules are necessary for power ramping / cycling tests, fuel characterization tests and / or material tests. Instrumentation technologies for thermocouple, SPND (Self-Powered Neutron Detector) and pressure transducer, and the in-situ dimensional measuring systems have to be developed to obtain the useful and various results from irradiation tests in the KMRR. A mock-up test rod for characterizing fuel thermal response was manufactured and the related technologies as well as the design specification were set up. An equipment for microdrilling and grooving of fuel pellets and an apparatus for diffusion-bonding between zircaloy-4 and stainless steel were made. A study to verify the integrity of test rod weldments is presented using out-of pile corrosion test. (Author)

Cost and quality of fuels for electric utility plants 1991

International Nuclear Information System (INIS)

1992-01-01

Data for 1991 and 1990 receipts and costs for fossil fuels discussed in the Executive Summary are displayed in Tables ES1 through ES7. These data are for electric generating plants with a total steam-electric and combined-cycle nameplate capacity of 50 or more megawatts. Data presented in the Executive Summary on generation, consumption, and stocks of fossil fuels at electric utilities are based on data collected on the Energy Information Administration, Form EIA-759, ''Monthly Power Plant Report.'' These data cover all electric generating plants. The average delivered cost of coal, petroleum, and gas each decreased in 1991 from 1990 levels. Overall, the average annual cost of fossil fuels delivered to electric utilities in 1991 was $1.60 per million Btu, a decrease of $0.09 per million Btu from 1990. This was the lowest average annual cost since 1978 and was the result of the abundant supply of coal, petroleum, and gas available to electric utilities. US net generation of electricity by all electric utilities in 1991 increased by less than I percent--the smallest increase since the decline that occurred in 1982.3 Coal and gas-fired steam net generation, each, decreased by less than I percent and petroleum-fired steam net generation by nearly 5 percent. Nuclear-powered net generation, however, increased by 6 percent. Fossil fuels accounted for 68 percent of all generation; nuclear, 22 percent; and hydroelectric, 10 percent. Sales of electricity to ultimate consumers in 1991 were 2 percent higher than during 1990

The Sport-Utility Vehicle: Debating Fuel-Economy Standards in Thermodynamics

Science.gov (United States)

Mayer, Shannon

2008-01-01

This paper describes a debate about national fuel-economy standards for sport-utility vehicles (SUVs) used as a foundation for exploring a public policy issue in the physical science classroom. The subject of automobile fuel economy benefits from a familiarity with thermodynamics, specifically heat engines, and is therefore applicable to a broad…

Concept of automated system for spent fuel utilization ('Reburning') from compact nuclear reactors

International Nuclear Information System (INIS)

Ianovski, V.V.; Lozhkin, O.V.; Nesterov, M.M.; Tarasov, N.A.; Uvarov, V.I.

1997-01-01

On the basic concept of an automated system of nuclear power installation safety is developed the utilization project of spent fuel from compact nuclear reactors. The main features of this project are: 1. design and creation of the mobile model-industrial installation; 2. development of the utilization and storage diagram of the spent fuel from compact nuclear reactors, with the specific recommendation for the natatorial means using both for the nuclear fuel reburning, for its transportation in places of the storage; 3. research of an opportunity during the utilization process to obtain additional power resources, ozone and others to increase of justifying expenses at the utilization; 4. creation of new generation engineering for the automation of remote control processes in the high radiation background conditions. 7 refs., 1 fig

Feasibility study on utilization of radiation from spent fuel in storage facility

International Nuclear Information System (INIS)

Wataru, Masumi; Sakamoto, Kazuaki; Saegusa, Toshiari; Sakaya, Tadatsugu; Fujiwara, Hiroaki.

1997-01-01

Spent fuels of nuclear power plant are stored safely until reprocessing because they are radioactive in addition to energy resources. It is foreseen that the amount of the stored spent fuel increases in the long term. Therefore, in the government, discussion on the storage away from reactor is in progress as well as one at reactor. Spent fuel emits a radioactive ray for a long time. In the storage facility, radiation is shielded not to have a detrimental influence upon the health and environment. If radioactive ray is incorrectly handled, it is hazardous for the health and the environment. But, it is very useful if it is properly utilized under a careful management. In the industry, radioactive ray by isotopes (e.g. Co-60) is used widely. In a view of the effective utilization of energy, the promotion of the siting, the regional development and the creation of employment opportunities of local inhabitants, it is preferable to make use of radiation from the spent fuel. In this study, feasibility of utilization of radiation energy from the spent fuel in a storage facility was evaluated. (author)

Improving fuel utilization in open-hearth production

Energy Technology Data Exchange (ETDEWEB)

Rozin, S Ye

1981-01-01

According to calculations, open-hearth shops employing oxygen can save from 20-25 kilograms of conventional fuel per ton of steel with O/sub 2/ consumption of 40-50 cubic meters per ton. Research indicates that O/sub 2/ is used most effectively during that melt period which can be shortened to the maximum extent. The use of paired lance oil nozzles with tilted jets which work in sync with reversing of the primary flame made it possible to increase furnace output by 2-3% and reduce fuel consumption by 2-3%. When building new, or rehabilitating existing, KU (expansion not given) and other equipment in the gas removal section, allowance must be made for the prospects of intensification of the process, variation in the resistance of the furnace during a run and other factors. Proper planning of preventive maintenance is essential for fuel conservation. It is well known that the specific fuel consumption increases by 10-20%, and steel production drops, during the final third than open-hearth furnance run. The possible margin for increasing output of open-hearth furnaces amounts to 10-20%, and 5-15% in terms of fuel economy. The primary elements involved in controlling the heat conditions are the study of the furnace operating indicators as a function of the mode parameters and periodic checking of the combustion performance and draft conditions; there must be increased interest in using and fulfilling the most progressive norms.

Enhancing substrate utilization and power production of a microbial fuel cell with nitrogen-doped carbon aerogel as cathode catalyst.

Science.gov (United States)

Tardy, Gábor Márk; Lóránt, Bálint; Lóka, Máté; Nagy, Balázs; László, Krisztina

2017-07-01

Catalytic efficiency of a nitrogen-doped, mesoporous carbon aerogel cathode catalyst was investigated in a two-chambered microbial fuel cell (MFC) applying graphite felt as base material for cathode and anode, utilizing peptone as carbon source. This mesoporous carbon aerogel containing catalyst layer on the cathode increased the maximum power density normalized to the anode volume to 2.7 times higher compared to the maximum power density obtained applying graphite felt cathode without the catalyst layer. At high (2 and 3) cathode/anode volume ratios, maximum power density exceeded 40 W m -3 . At the same time, current density and specific substrate utilization rate increased by 58% resulting in 31.9 A m -3 and 18.8 g COD m -3  h -1 , respectively (normalized to anode volume). Besides the increase of the power and the rate of biodegradation, the investigated catalyst decreased the internal resistance from the range of 450-600 to 350-370 Ω. Although Pt/C catalyst proved to be more efficient, a considerable decrease in the material costs might be achieved by substituting it with nitrogen-doped carbon aerogel in MFCs. Such cathode still displays enhanced catalytic effect.

Fuel utilization improvement in PWRs using the denatured 233U-Th cycle

International Nuclear Information System (INIS)

Jones, H.M.; Schwenk, G.A.; Toops, E.C.; Yotinen, V.O.

1980-06-01

A number of changes in PWR core design and/or operating strategy were evaluated to assess the fuel utilization improvement achievable by their implementation in a PWR using thorium-based fuel and operating in a recycle mode. The reference PWR for this study was identical to the B and W Standard Plant except that the fuel pellets were of denatured ( 233 U/ 238 U-Th)O 2 . An initial scoping study identified the three most promising improvement concepts as (1) a very tight lattice, (2) thorium blankets, and (3) ThO 2 rods placed in available guide tubes. A conceptual core design incorporating these changes was then developed, and the fuel utilization of this modified design was compared with that of the reference case

The burnable poisons utilization for fissile enriched CANDU fuel bundle

Energy Technology Data Exchange (ETDEWEB)

Serghiuta, D; Nainer, O [Team 3 Solutions, Don Mills, ON (Canada)

1996-12-31

Utilization of burnable poison for the fissile enriched fueled CANDU 6 Mk1 core is investigated. The main incentives for this analysis are the reduction of void reactivity effects, the maximization of the fissile content of fresh fuel bundles, and the achievement of better power shape control, in order to preserve the power envelope of the standard 37 rod fuel bundle. The latter allows also the preservation of construction parameters of the standard core (for example: number and location of reactivity devices). It also permits the use of regular shift fueling schemes. The paper makes analyses of MOX weapons-grade plutonium and 1.2% SEU fueled CANDU 6 Mk 1 cores. (author). 6 refs., 4 tabs., 10 figs.

Fuel channel in-service inspection programs program design for maximum cost effectiveness

International Nuclear Information System (INIS)

Van den Brekel, N.C.

1995-01-01

Inspection is an integral part of fuel channel life management strategy. Inspection data is used to assess the state of reactor core integrity and provide the information necessary to optimize long term maintenance programs. This paper will provide an overview of the structured approach to developing fuel channel inspection programs within OHN. The inspection programs are designed to balance the resources utilized (cost, outage time, and dose expenditure) with the benefits provided by the inspection data obtained (improved knowledge of component status, degradation mechanisms and rates, etc..). The CANDU community has yet to have a fuel channel operate for a full 30 year design life. Since research programs can not fully simulate reactor operating conditions, inspections become an essential feature of the life management strategy as the components age. Inspection programs often include activities designed to develop predictive capability for long term fuel channel behaviour and provide early warning of changes in behaviour. It should be noted that although this paper addresses the design of fuel channel inspection programs, the basic principles presented can be applied to the design of inspection programs for any major power plant component or system. (author)

Some possibilities for improvement of fuel utilization in nuclear power plants

International Nuclear Information System (INIS)

Kocic, A.; Marinkovic, N.

1983-01-01

Methods for improving the nuclear fuel utilization with the emphasis on LWRs are being dealt with in this paper. Some basic results concerning tubular fuel pellets of the Krsko nuclear power plants are presented, showing promising possibilities for uranium saving from the neutronics point of view. (author)

Utilization of pulverized fuel ash in Malta

International Nuclear Information System (INIS)

Camilleri, Josette; Sammut, Michael; Montesin, Franco E.

2006-01-01

In Malta all of the waste produced is mixed and deposited at various sites around the island. None of these sites were purpose built, and all of the waste is above groundwater level. The landfills are not engineered and do not contain any measures to collect leachate and gases emanating from the disposal sites. Another waste, which is disposed of in landfills, is pulverized fuel ash (PFA), which is a by-product of coal combustion by the power station. This has been disposed of in landfill, because its use has been precluded due to the radioactivity of the ashes. The aim of this study was to analyze the chemical composition of the pulverized fuel ash and to attempt to utilize it as a cement replacement in normal concrete mixes in the construction industry. The levels of radiation emitted from the ashes were measured by gamma spectrometry. The results of this study revealed that although at early ages cement replacement by PFA resulted in a reduction in compressive strength (P = 0), when compared to the reference concrete at later ages the strengths measured on concrete cores were comparable to the reference concrete (P > 0.05). The utilization of PFA up to 20% cement replacement in concrete did not raise the radioactivity of the concrete. In conclusion, utilization of PFA in the construction industry would be a better way of disposing of the ashes rather than controlling the leachate and any radioactivity emitted by the landfilled ashes

Increasing TRIGA fuel lifetime with 12 wt.% U TRIGA fuel

Energy Technology Data Exchange (ETDEWEB)

Naughton, W F; Cenko, M J; Levine, S H; Witzig, W F [Pennsylvania State University (United States)

1974-07-01

In-core fuel management studies have been performed for the Penn State Breazeale Reactor (PSBR) wherein 12 wt % U fuel elements are used to replace the standard 8.5 wt % U TRIGA fuel. The core configuration used to develop a calculational model was a 90-element hexagonal array, which is representative of the PSBR core, and consists of five hexagonal rings surrounding a central thimble containing water. The technique employed for refueling the core fully loaded with 8.5 wt % U fuel involves replacing 8.5 wt % U fuel with 12 wt % U fuel using an in-out reloading scheme. A batch reload consists of 6 new 12 wt % U fuel elements. Placing the 12 wt % U fuel in the B ring produces fuel temperatures ({approx}450 {sup o}C) that are well below the 800{sup o}C maximum limitation when the PSBR is operating at its maximum allowed power of 1 Megawatt. The advantages of using new 12 wt % U fuel to replace the burned up 8.5 wt % U fuel in the B ring over refueling strictly with 8.5 wt % U-Zr TRIGA fuel are clearly delineated in Table 1 where cost calculations used the General Atomic pre-1972 prices for TRIGA fuel, i.e., $1500 and $1650 for an 8.5 and 12 wt % U fuel element, respectively. Experimental results obtained to date utilizing the 12 wt % U fuel elements agree with the computed results. (author)

Thorium utilization: conversion ratio and fuel needs in thermal reactors

International Nuclear Information System (INIS)

Oosterkamp, W.J.

1975-01-01

As a preparatory study for thorium utilization in thermal reactors a study has been made of the fuel comsumption in existing reactor types. A quantitative description is given of the influence of enrichment, burnup, amount of structural material, choise of coolant and control requirements on the convertion ratio. The enrichment is an important factor and a low fuel comsumption can be achieved by increasing the enrichment

Spent-fuel-storage requirements: an update of DOE/RL-82-1

International Nuclear Information System (INIS)

1983-01-01

Spent fuel storage requirements as projected through the year 2000 for US light water reactor (LWR) nuclear power plants were calculated using information supplied by the utilities reflecting plant status as of September 30, 1982. Projections through the year 2000 combined fuel discharge projections of the utilities with the assumed discharges of typical reactors required to meet the nuclear capacity of 132 gigawatts electrical (GWe) projected by the Energy Information Administration (EIA) for the year 2000. Three cases were developed and are summarized. A reference case, or maximum at-reactor (AR) capacity case, assumes that all reactor storage pools are increased to their maximum capacities, as estimated by the utilities, for spent fuel storage utilizing currently licensed technologies. Rod consolidation and dry storage technologies were not considered. The reference case assumes no transshipments between pools except as currently licensed by the Nuclear Regulatory Commission (NRC). This case identifies an initial requirement for 13 metric tons uranium (MTU) of additional storage in 1984, and a cumulative requirement for 13,090 MTU additional storage in the year 2000. The reference case is bounded by two alternative cases. One, a current capacity case, assumes that only those pool storage capacity increases currently planned by the operating utilities will occur. The second, or maximum capacity with transshipment case, assumes maximum development of pool storage capacity as described above and also assumes no constraints on transshipment of spent fuel among pools of reactors of like type (BWR) within a given utility. In all cases, a full core discharge capability is assumed to be maintained for each reactor, except that only one FCR is maintained when two reactors share a common pool. 1 figure, 12 tables

Design features of the Light Water Breeder Reactor (LWBR) which improve fuel utilization in light water reactors (LWBR development program)

International Nuclear Information System (INIS)

Hecker, H.C.; Freeman, L.B.

1981-08-01

This report surveys reactor core design features of the Light Water Breeder Reactor which make possible improved fuel utilization in light water reactor systems and breeding with the uranium-thorium fuel cycle. The impact of developing the uranium-thorium fuel cycle on utilization of nuclear fuel resources is discussed. The specific core design features related to improved fuel utilization and breeding which have been implemented in the Shippingport LWBR core are presented. These design features include a seed-blanket module with movable fuel for reactivity control, radial and axial reflcetor regions, low hafnium Zircaloy for fuel element cladding and structurals, and a closely spaced fuel rod lattice. Also included is a discussion of several design modifications which could further improve fuel utilization in future light water reactor systems. These include further development of movable fuel control, use of Zircaloy fuel rod support grids, and fuel element design modifications

A Method of Maximum Power Control in Single-phase Utility Interactive Photovoltaic Generation System by using PWM Current Source Inverter

Science.gov (United States)

Neba, Yasuhiko

This paper deals with a maximum power point tracking (MPPT) control of the photovoltaic generation with the single-phase utility interactive inverter. The photovoltaic arrays are connected by employing the PWM current source inverter to the utility. The use of the pulsating dc current and voltage allows the maximum power point to be searched. The inverter can regulate the array voltage and keep the arrays to the maximum power. This paper gives the control method and the experimental results.

Analysis of oxy-fuel combustion power cycle utilizing a pressurized coal combustor

OpenAIRE

Gazzino, Marco; Hong, Jongsup; Chaudhry, Gunaranjan; Brisson II, John G; Field, Randall; Ghoniem, Ahmed F

2009-01-01

Growing concerns over greenhouse gas emissions have driven extensive research into new power generation cycles that enable carbon dioxide capture and sequestration. In this regard, oxy-fuel combustion is a promising new technology in which fuels are burned in an environment of oxygen and recycled combustion gases. In this paper, an oxy-fuel combustion power cycle that utilizes a pressurized coal combustor is analyzed. We show that this approach recovers more thermal energy from the flue gases...

Effect of in-pile degradation of the meat thermal conductivity on the maximum temperature of the plate-type U-Mo dispersion fuels

International Nuclear Information System (INIS)

Medvedev, Pavel G.

2009-01-01

Effect of in-pile degradation of thermal conductivity on the maximum temperature of the plate-type research reactor fuels has been assessed using the steady-state heat conduction equation and assuming convection cooling. It was found that due to very low meat thickness, characteristic for this type of fuel, the effect of thermal conductivity degradation on the maximum fuel temperature is minor. For example, the fuel plate featuring 0.635 mm thick meat operating at heat flux of 600 W/cm2 would experience only a 20 C temperature rise if the meat thermal conductivity degrades from 0.8 W/cm-s to 0.3 W/cm-s. While degradation of meat thermal conductivity in dispersion-type U-Mo fuel can be very substantial due to formation of interaction layer between the particles and the matrix, and development of fission gas filled porosity, this simple analysis demonstrates that this phenomenon is unlikely to significantly affect the temperature-based safety margin of the fuel during normal operation.

Supplier-independent fuel management from the viewpoint of a large German utility - Objectives and experience

International Nuclear Information System (INIS)

Kallmeyer, D.H.; Petersen, K.

1986-01-01

Internationally, many nuclear power operating utilities tend to have alternative fuel supplies and as a consequence also have to build up a supplier-independent fuel management. The main reasons are competition within the fuel assembly market as a price-regulating mechanism; quality comparison and corresponding improvements in fuel technology, documentation system and licensing support activities; improved necessity on the part of the manufacturer to be open for innovations; improved supply reliability by redundant manufacturer qualification; and gain of know-how for the utility by collection and comparison of the state of the art of the different suppliers in the important technical and physical disciplines

Advance reactor and fuel-cycle systems--potentials and limitations for United States utilities

International Nuclear Information System (INIS)

Zebroski, E.L.; Williams, R.F.

1979-01-01

This paper reviews the potential benefits and limitations of advance reactor and fuel-cycle systems for United States utilities. The results of the review of advanced technologies show that for the near and midterm, the only advance reactor and fuel-cycle system with significant potential for United States utilities is the current LWR, and evolutionary, not revolutionary, enhancements. For the long term, the liquid-metal breeder reactor continues to be the most promising advance nuclear option. The major factors leading to this conclusion are summarized

Spent fuel storage requirements 1987

International Nuclear Information System (INIS)

1987-09-01

Historical inventories of spent fuel and utility estimates of future discharges from US commercial nuclear reactors are presented through the year 2005. The ultimate needs for additional storage capacity are estimated. These estimtes are based on the maximum capacities within current and planned at-reactor facilities and on any planned transshipments of fuel to other reactors or facilities. Historical data through December, 1986, and projected discharges through the end of reactor life are used in this analysis. The source data was supplied by the utilities to the DOE Energy Information Administration (EIA) through the 1987 RW-859 data survey. 14 refs., 4 figs., 9 tabs

Uranium resource utilization improvements in the once-through PWR fuel cycle

International Nuclear Information System (INIS)

Matzie, R.A.

1980-04-01

In support of the Nonproliferation Alternative Systems Assessment Program (NASAP), Combustion Engineering, Inc. performed a comprehensive analytical study of potential uranium utilization improvement options that can be backfit into existing PWRs operating on the once-through uranium fuel cycle. A large number of potential improvement options were examined as part of a preliminary survey of candidate options. The most attractive of these, from the standpoint of uranium utilization improvement, economic viability, and ease of implementation, were then selected for detailed analysis and were included in a single composite improvement case. This composite case represents an estimate of the total savings in U 3 O 8 consumption that can be achieved in current-design PWRs by implementing improvements which can be developed and demonstrated in the near term. The improvement options which were evaluated in detail and included in the composite case were a new five-batch, extended-burnup fuel management scheme, low-leakage fuel management, modified lattice designs, axial blankets, reinsertion of initial core batches, and end-of-cycle stretchout

Spent fuel transportation - lessons drawn and ways forward: European utilities perspective

International Nuclear Information System (INIS)

Debes, M.; Schimmele, J.G.; Sannen, H.; Patak, H.

2001-01-01

Surface contamination that was found on surfaces of spent fuel shipping containers (flasks) in 1998 was treated differently by authorities in different European countries. In two countries, Germany and Switzerland, spent fuel shipments were stopped for an indefinite period by Government authorities. This paper, co-authored by representatives of utilities from four European countries, explains the rationale for surface contamination limits in transport regulations and attempts to place the observed contamination in proper perspective. (author)

UTILIZATION OF SECONDARY COMBUSTIBLE POWER RESOURCES FOR PRODUCTION OF MUNICIPAL AND HOUSEHOLD FUEL

Directory of Open Access Journals (Sweden)

N. I. Berezovsky

2005-01-01

Full Text Available The paper shows an advantage to utilize secondary power resources (lignin, wastes of fine coal with its dressing, sawdust in mixture with local types of fuel (peat in order to fulfill power supply purpose, namely: obtaining hot water in boilers of small capacity and obtaining household fuel.

Fuel Flexible Combustion Systems for High-Efficiency Utilization of Opportunity Fuels in Gas Turbines

Energy Technology Data Exchange (ETDEWEB)

Venkatesan, Krishna

2011-11-30

The purpose of this program was to develop low-emissions, efficient fuel-flexible combustion technology which enables operation of a given gas turbine on a wider range of opportunity fuels that lie outside of current natural gas-centered fuel specifications. The program encompasses a selection of important, representative fuels of opportunity for gas turbines with widely varying fundamental properties of combustion. The research program covers conceptual and detailed combustor design, fabrication, and testing of retrofitable and/or novel fuel-flexible gas turbine combustor hardware, specifically advanced fuel nozzle technology, at full-scale gas turbine combustor conditions. This project was performed over the period of October 2008 through September 2011 under Cooperative Agreement DE-FC26-08NT05868 for the U.S. Department of Energy/National Energy Technology Laboratory (USDOE/NETL) entitled "Fuel Flexible Combustion Systems for High-Efficiency Utilization of Opportunity Fuels in Gas Turbines". The overall objective of this program was met with great success. GE was able to successfully demonstrate the operability of two fuel-flexible combustion nozzles over a wide range of opportunity fuels at heavy-duty gas turbine conditions while meeting emissions goals. The GE MS6000B ("6B") gas turbine engine was chosen as the target platform for new fuel-flexible premixer development. Comprehensive conceptual design and analysis of new fuel-flexible premixing nozzles were undertaken. Gas turbine cycle models and detailed flow network models of the combustor provide the premixer conditions (temperature, pressure, pressure drops, velocities, and air flow splits) and illustrate the impact of widely varying fuel flow rates on the combustor. Detailed chemical kinetic mechanisms were employed to compare some fundamental combustion characteristics of the target fuels, including flame speeds and lean blow-out behavior. Perfectly premixed combustion experiments were conducted to

Role of transportation in the utilities' management of spent fuel storage

International Nuclear Information System (INIS)

Newman, D.F.

1985-01-01

Additional spent fuel storage can be provided by using a combination of wet and dry storage technologies, with the technology or technologies used in any specific instance being determined by the particular circumstances involved. The capability for spent fuel storage at a reactor site can be enhanced using any one or a combination of the following: expansion of existing pool storage capacity; more efficient use of available capacity; and addition of an independent spent fuel storage installation (ISFSI). Each of these methods, which are described more fully below, have characteristics that may make them more or less suitable for use, depending on the nuclear power plant where they will be deployed, the magnitude of the need for additional storage, the utility's overall spent fuel management strategy, and other factors. 15 refs., 2 figs., 2 tabs

Microbial penetration and utilization of organic aircraft fuel-tank coatings.

Science.gov (United States)

Crum, M G; Reynolds, R J; Hedrick, H G

1967-11-01

Microorganisms have been found as contaminants in various types of aircraft fuel tanks. Their presence introduces problems in the operation of the aircraft, including destruction of components such as the organic coatings used as protective linings in the fuel tanks. Microbial penetration and utilization of the currently used organic coatings, EC 776, DV 1180, PR 1560, and DeSoto 1080, were determined by changes in electrical resistances of the coatings; mycelial weight changes; growth counts of the bacteria; and manometric determinations on Pseudomonas aeruginosa (GD-FW B-25) and Cladosporium resinae (QMC-7998). The results indicate EC 776 and DV 1180 to be less resistant to microbial degradation than the other coatings. Organic coatings, serving as a source of nutrition, would be conducive to population buildups in aircraft fuel tanks.

Direct Carbon Fuel Cell System Utilizing Solid Carbonaceous Fuels

Energy Technology Data Exchange (ETDEWEB)

Turgut Gur

2010-04-30

This 1-year project has achieved most of its objective and successfully demonstrated the viability of the fluidized bed direct carbon fuel cell (FB-DCFC) approach under development by Direct Carbon technologies, LLC, that utilizes solid carbonaceous fuels for power generation. This unique electrochemical technology offers high conversion efficiencies, produces proportionately less CO{sub 2} in capture-ready form, and does not consume or require water for gasification. FB-DCFC employs a specialized solid oxide fuel cell (SOFC) arrangement coupled to a Boudouard gasifier where the solid fuel particles are fluidized and reacted by the anode recycle gas CO{sub 2}. The resulting CO is electrochemically oxidized at the anode. Anode supported SOFC structures employed a porous Ni cermet anode layer, a dense yttria stabilized zirconia membrane, and a mixed conducting porous perovskite cathode film. Several kinds of untreated solid fuels (carbon and coal) were tested in bench scale FBDCFC prototypes for electrochemical performance and stability testing. Single cells of tubular geometry with active areas up to 24 cm{sup 2} were fabricated. The cells achieved high power densities up to 450 mW/cm{sup 2} at 850 C using a low sulfur Alaska coal char. This represents the highest power density reported in the open literature for coal based DCFC. Similarly, power densities up to 175 mW/cm{sup 2} at 850 C were demonstrated with carbon. Electrical conversion efficiencies for coal char were experimentally determined to be 48%. Long-term stability of cell performance was measured under galvanostatic conditions for 375 hours in CO with no degradation whatsoever, indicating that carbon deposition (or coking) does not pose any problems. Similar cell stability results were obtained in coal char tested for 24 hours under galvanostatic conditions with no sign of sulfur poisoning. Moreover, a 50-cell planar stack targeted for 1 kW output was fabricated and tested in 95% CO (balance CO{sub 2

Solid oxide fuel cell bi-layer anode with gadolinia-doped ceria for utilization of solid carbon fuel

Energy Technology Data Exchange (ETDEWEB)

Kellogg, Isaiah D. [Department of Mechanical and Aerospace Engineering, Missouri University of Science and Technology, 290A Toomey Hall, 400 West 13th Street, Rolla, MO 65409 (United States); Department of Materials Science and Engineering, Missouri University of Science and Technology, 223 McNutt Hall, 1400 N. Bishop, Rolla, MO 65409 (United States); Koylu, Umit O. [Department of Mechanical and Aerospace Engineering, Missouri University of Science and Technology, 290A Toomey Hall, 400 West 13th Street, Rolla, MO 65409 (United States); Dogan, Fatih [Department of Materials Science and Engineering, Missouri University of Science and Technology, 223 McNutt Hall, 1400 N. Bishop, Rolla, MO 65409 (United States)

2010-11-01

Pyrolytic carbon was used as fuel in a solid oxide fuel cell (SOFC) with a yttria-stabilized zirconia (YSZ) electrolyte and a bi-layer anode composed of nickel oxide gadolinia-doped ceria (NiO-GDC) and NiO-YSZ. The common problems of bulk shrinkage and emergent porosity in the YSZ layer adjacent to the GDC/YSZ interface were avoided by using an interlayer of porous NiO-YSZ as a buffer anode layer between the electrolyte and the NiO-GDC primary anode. Cells were fabricated from commercially available component powders so that unconventional production methods suggested in the literature were avoided, that is, the necessity of glycine-nitrate combustion synthesis, specialty multicomponent oxide powders, sputtering, or chemical vapor deposition. The easily-fabricated cell was successfully utilized with hydrogen and propane fuels as well as carbon deposited on the anode during the cyclic operation with the propane. A cell of similar construction could be used in the exhaust stream of a diesel engine to capture and utilize soot for secondary power generation and decreased particulate pollution without the need for filter regeneration. (author)

Understanding the Benefits and Limitations of Increasing Maximum Rotor Tip Speed for Utility-Scale Wind Turbines

International Nuclear Information System (INIS)

Ning, A; Dykes, K

2014-01-01

For utility-scale wind turbines, the maximum rotor rotation speed is generally constrained by noise considerations. Innovations in acoustics and/or siting in remote locations may enable future wind turbine designs to operate with higher tip speeds. Wind turbines designed to take advantage of higher tip speeds are expected to be able to capture more energy and utilize lighter drivetrains because of their decreased maximum torque loads. However, the magnitude of the potential cost savings is unclear, and the potential trade-offs with rotor and tower sizing are not well understood. A multidisciplinary, system-level framework was developed to facilitate wind turbine and wind plant analysis and optimization. The rotors, nacelles, and towers of wind turbines are optimized for minimum cost of energy subject to a large number of structural, manufacturing, and transportation constraints. These optimization studies suggest that allowing for higher maximum tip speeds could result in a decrease in the cost of energy of up to 5% for land-based sites and 2% for offshore sites when using current technology. Almost all of the cost savings are attributed to the decrease in gearbox mass as a consequence of the reduced maximum rotor torque. Although there is some increased energy capture, it is very minimal (less than 0.5%). Extreme increases in tip speed are unnecessary; benefits for maximum tip speeds greater than 100-110 m/s are small to nonexistent

Understanding the Benefits and Limitations of Increasing Maximum Rotor Tip Speed for Utility-Scale Wind Turbines

Science.gov (United States)

Ning, A.; Dykes, K.

2014-06-01

For utility-scale wind turbines, the maximum rotor rotation speed is generally constrained by noise considerations. Innovations in acoustics and/or siting in remote locations may enable future wind turbine designs to operate with higher tip speeds. Wind turbines designed to take advantage of higher tip speeds are expected to be able to capture more energy and utilize lighter drivetrains because of their decreased maximum torque loads. However, the magnitude of the potential cost savings is unclear, and the potential trade-offs with rotor and tower sizing are not well understood. A multidisciplinary, system-level framework was developed to facilitate wind turbine and wind plant analysis and optimization. The rotors, nacelles, and towers of wind turbines are optimized for minimum cost of energy subject to a large number of structural, manufacturing, and transportation constraints. These optimization studies suggest that allowing for higher maximum tip speeds could result in a decrease in the cost of energy of up to 5% for land-based sites and 2% for offshore sites when using current technology. Almost all of the cost savings are attributed to the decrease in gearbox mass as a consequence of the reduced maximum rotor torque. Although there is some increased energy capture, it is very minimal (less than 0.5%). Extreme increases in tip speed are unnecessary; benefits for maximum tip speeds greater than 100-110 m/s are small to nonexistent.

Design study of Thorium-232 and Protactinium-231 based fuel for long life BWR

Energy Technology Data Exchange (ETDEWEB)

Trianti, N.; Su' ud, Z.; Riyana, E. S. [Nuclear Physics and Biophysics Research Division Department of Physics - Institut Teknologi Bandung (ITB) Jalan Ganeca 10 Bandung 40132 (Indonesia)

2012-06-06

A preliminary design study for the utilization of thorium added with {sup 231}Pa based fuel on BWR type reactor has been performed. In the previous research utilization of fuel based Thorium-232 and Uranium-233 show 10 years operation time with maximum excess-reactivity about 4.075% dk/k. To increase reactor operation time and reduce excess-reactivity below 1% dk/k, Protactinium (Pa-231) is used as Burnable Poison. Protactinium-231 has very interesting neutronic properties, which enable the core to reduce initial excess-reactivity and simultaneously increase production of {sup 233}U to {sup 231}Pa in burn-up process. Optimizations of the content of {sup 231}Pa in the core enables the BWR core to sustain long period of operation time with reasonable burn-up reactivity swing. Based on the optimization of fuel element composition (Th and Pa) in various moderation ratio we can get reactor core with longer operation time, 20 {approx} 30 years operation without fuel shuffling or refuelling, with average power densities maximum of about 35 watt/cc, and maximum excess-reactivity 0.56% dk/k.

Nuclear fuel financing by USA investor-owned utilities

International Nuclear Information System (INIS)

Cave, W.F.

1981-01-01

Investor-owned utilities in the USA currently have almost 60 nuclear plants in commercial operation and an additional 90 plants under construction or awaiting operating licenses. To understand the specific techniques implemented to finance nuclear fuel and the advantages which they provide to individual companies, the total financing needs of the industry, the traditional pattern which utility external financing has taken, and the varied financial and regulatory bodies whose often conflicting objectives management must attempt to reconcile, must be understood. The aim of this paper is to aid such an understanding. The subject is discussed under the following headings: industry background; regulation and rating agencies; management objectives; financing structure; advantages (low financing cost; regulatory treatment; freer nature of agreement; access to commercial paper market; appropriate financing time-span; rating benefits; accounting treatment); conclusions. (U.K.)

A mathematical model of the maximum power density attainable in an alkaline hydrogen/oxygen fuel cell

Science.gov (United States)

Kimble, Michael C.; White, Ralph E.

1991-01-01

A mathematical model of a hydrogen/oxygen alkaline fuel cell is presented that can be used to predict the polarization behavior under various power loads. The major limitations to achieving high power densities are indicated and methods to increase the maximum attainable power density are suggested. The alkaline fuel cell model describes the phenomena occurring in the solid, liquid, and gaseous phases of the anode, separator, and cathode regions based on porous electrode theory applied to three phases. Fundamental equations of chemical engineering that describe conservation of mass and charge, species transport, and kinetic phenomena are used to develop the model by treating all phases as a homogeneous continuum.

Current status of U.S. coal utilization and non-fuel uses of fossil fuels

International Nuclear Information System (INIS)

Song, C.S.; Schobert, H.; Scaroni, A.W.

1997-01-01

An understanding of the current situation is important for projecting the future direction of coal utilization. The world's annual consumption of coal in 1995 was 5104.01 million short tons (MST, 1 short ton = 0.907 metric ton). Coal plays a very important role in the US energy supply; US coal production in 1995 totaled 1033 MST, including 611.1 MST of bituminous coal, 328.4 MST of subbituminous coal, 86.1 MST of lignite, and 4.1 MST of anthracite. US coal consumption totaled 940.6 MST, with 88.1% in electric utilities, 3.5% in coke plants, 7.8% for other industrial uses, and only 0.6% in the residential and commercial sectors. The amount of fossil resources used for non-fuel purposes accounted for 8.4% of the total annual consumption in 1995. Non-fuel uses of fossil fuels particularly coal may become more important in the future. The demonstrated coal reserves in the world are large enough for consumption for over 220 years at the 1995 level, while proven oil reserves are only about 40 times the world's 1995 consumption level. Coal has several positive attributes when considered as a feedstock for aromatic chemicals, specialty chemicals, and carbon-based materials. Existing nonfuel uses of coals include (1) high temperature carbonization of bituminous and subbituminous coals to make metallurgical coke; (2) gasification of coal to make synthesis gases and other chemicals; (3) use of coal in manufacturing other materials such as activated carbons, carbon molecular sieves (CMS) and production of phosphorus (phosphoric acid); (4) the use of coal tars from carbonization and gasification for making aromatic and phenolic chemicals; (5) the use of coal tar pitch for making carbon fibers and activated carbon fibers; and (6) other non-fuel products derived from coal including combustion by-products. Coal may become more important both as an energy source and as the source of chemical feedstocks in the 21st century

Comparison of candidate solar array maximum power utilization approaches. [for spacecraft propulsion

Science.gov (United States)

Costogue, E. N.; Lindena, S.

1976-01-01

A study was made of five potential approaches that can be utilized to detect the maximum power point of a solar array while sustaining operations at or near maximum power and without endangering stability or causing array voltage collapse. The approaches studied included: (1) dynamic impedance comparator, (2) reference array measurement, (3) onset of solar array voltage collapse detection, (4) parallel tracker, and (5) direct measurement. The study analyzed the feasibility and adaptability of these approaches to a future solar electric propulsion (SEP) mission, and, specifically, to a comet rendezvous mission. Such missions presented the most challenging requirements to a spacecraft power subsystem in terms of power management over large solar intensity ranges of 1.0 to 3.5 AU. The dynamic impedance approach was found to have the highest figure of merit, and the reference array approach followed closely behind. The results are applicable to terrestrial solar power systems as well as to other than SEP space missions.

Reactor-specific spent fuel discharge projections, 1984 to 2020

International Nuclear Information System (INIS)

Heeb, C.M.; Libby, R.A.; Holter, G.M.

1985-04-01

The original spent fuel utility data base (SFDB) has been adjusted to produce agreement with the EIA nuclear energy generation forecast. The procedure developed allows the detail of the utility data base to remain intact, while the overall nuclear generation is changed to match any uniform nuclear generation forecast. This procedure adjusts the weight of the reactor discharges as reported on the SFDB and makes a minimal (less than 10%) change in the original discharge exposures in order to preserve discharges of an integral number of fuel assemblies. The procedure used in developing the reactor-specific spent fuel discharge projections, as well as the resulting data bases themselves, are described in detail in this report. Discussions of the procedure cover the following topics: a description of the data base; data base adjustment procedures; addition of generic power reactors; and accuracy of the data base adjustments. Reactor-specific discharge and storage requirements are presented. Annual and cumulative discharge projections are provided. Annual and cumulative requirements for additional storage are shown for the maximum at-reactor (AR) storage assumption, and for the maximum AR with transshipment assumption. These compare directly to the storage requirements from the utility-supplied data, as reported in the Spent Fuel Storage Requirements Report. The results presented in this report include: the disaggregated spent fuel discharge projections; and disaggregated projections of requirements for additional spent fuel storage capacity prior to 1998. Descriptions of the methodology and the results are included in this report. Details supporting the discussions in the main body of the report, including descriptions of the capacity and fuel discharge projections, are included. 3 refs., 6 figs., 12 tabs

Reactor-specific spent fuel discharge projections: 1985 to 2020

International Nuclear Information System (INIS)

Heeb, C.M.; Libby, R.A.; Walling, R.C.; Purcell, W.L.

1986-09-01

The creation of four spent-fuel data bases that contain information on the projected amounts of spent fuel to be discharged from US commercial nuclear reactors through the year 2020 is described. The data bases contain detailed spent-fuel information from existing, planned, and projected pressurized water reactors (PWR) and boiling water reactors (BWR). The projections are based on individual reactor information supplied by the US reactor owners. The basic information is adjusted to conform to Energy Information Agency (EIA) forecasts for nuclear installed capacity, generation, and spent fuel discharged. The EIA cases considered are: (1) No New Orders with Extended Burnup, (2) No New Orders with Constant Burnup, (3) Middle Case with Extended Burnup, and (4) Middle Case with Constant Burnup. Detailed, by-reactor tables are provided for annual discharged amounts of spent fuel, for storage requirements assuming maximum-at-reactor storage, and for storage requirements assuming maximum-at-reactor plus intra-utility transshipment of spent fuel

Utilization coke dust as fuel in the cement industry

International Nuclear Information System (INIS)

Nawaz, S.

2006-01-01

Utilization of coke dust available from coal carbonization plants, as a fuel in the cement industry has been undertaken and discussed in this research paper. The parameters studied include physical and chemical evaluation of the coke dust and its economic feasibility/ suitability as fuel for the cement plants. Detailed studies have been carried out on the above referred parameters. In addition a comparative study has been done to access its suitability in comparison to other fuels especially imported coal. It has been found that the coke dust contained about 66% fixed carbon, 29% ash, 4% volatile matter, 1% moisture and 0.48% sulphur. It gross calorific value was found to be 5292 Kcal/kg. The detailed analysis of coke dust ash was also performed to determine as to how its constituents will compare with the cement constituents. Keeping in view the experimental results/ data generated on the coke dust, it has been concluded that it can be quite a good substitute for imported coal. In doing so a substantial financial saving can be achieved which ranges 40-45%. (author)

Cost and quality of fuels for electric utility plants, 1994

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-07-14

This document presents an annual summary of statistics at the national, Census division, State, electric utility, and plant levels regarding the quantity, quality, and cost of fossil fuels used to produce electricity. Purpose of this publication is to provide energy decision-makers with accurate, timely information that may be used in forming various perspectives on issues regarding electric power.

Spent fuel storage requirements, 1988

International Nuclear Information System (INIS)

1988-10-01

Historical inventories of spent fuel and Department of Energy (DOE) estimates of future discharges from US commercial nuclear reactors are presented for the next 20 years, through the year 2007. The eventual needs for additional spent fuel storage capacity are estimated. These estimates are based on the maximum capacities within current and planned at-reactor facilities and on any planned transshipments of fuel to other reactors or facilities. Historical data through December 1987 and projected discharges through the end of reactor life are used in this analysis. The source data was supplied by the utilities to DOE through the 1988 RW-859 data survey and by DOE estimates of future nuclear capacity, generation, and spent fuel discharges. 12 refs., 3 figs., 28 tabs

Back-end fuel cycle efficiencies with respect to improved uranium utilization

International Nuclear Information System (INIS)

Kuczera, B.; Hennies, H.H.

1983-01-01

The world-wide nuclear power plant (NPP) capacity is at present 160 GW(e). If one adds the power stations under construction and ordered, a plant capacity of approximately 480 GW(e) is obtained for 1990, with the share of LWRs making up more than 80%. A modern LWR consumes in the open fuel cycle about 4400 metric tonnes of natural uranium per GW(e), assuming a lifetime of 30 years and a load factor of 70%. Considering the natural uranium reserves known at present and exploitable under economic conditions, it can be conveniently estimated that, with the present NPP capacity extension perspective, the natural uranium resources may be exhausted in a few decades. This trend can be counteracted in a flexible manner by various approaches in fuel cycle technology and strategy: (i) by steady further development of the established LWR technology the uranium consumption can be reduced by about 15%; (ii) closing the nuclear fuel cycle on the basis of LWRs (i.e. thermal uranium and plutonium recycling) implies up to 40% savings in natural uranium consumption; (iii) more recent considerations include the advanced pressurized water reactor (APWR). The APWR combines the proven PWR technology with a newly developed tight lattice core with greatly improved conversion characteristics (conversion ratio = 0.90 to 0.95). In terms of uranium utilization, the APWR has an efficiency three to five times higher than a PWR; (iv) Commercial introduction of FBR systems results in an optimal utilization of uranium which, at the same time, guarantees the supply of nuclear fuel well beyond the present century. For a corresponding transition period an energy supply system can be conceived which relies essentially on extended back-end fuel cycle capacities. These would facilitate a symbiosis of PWR, APWR and FBR, characterized by high flexibility with respect to long-term developments on the energy market. (author)

Reactor-specific spent fuel discharge projections, 1987-2020

International Nuclear Information System (INIS)

Walling, R.C.; Heeb, C.M.; Purcell, W.L.

1988-03-01

The creation of five reactor-specific spent fuel data bases that contain information on the projected amounts of spent fuel to be discharged from U.S. commercial nuclear reactors through the year 2020 is described. The data bases contain detailed spent fuel information from existing, planned, and projected pressurized water reactors (PWR) and boiling water eactors (BWR), and one existing high temperature gas reactor (HTGR). The projections are based on individual reactor information supplied by the U.S. reactor owners. The basic information is adjusted to conform to Energy Information Administration (EIA) forecasts for nuclear installed capacity, generation, and spent fuel discharged. The EIA cases considered are: No New Orders (assumes increasing burnup), No New Orders with No Increased Burnup, Upper Reference (assumes increasing burnup), Upper Reference with No Increased Burnup, and Lower Reference (assumes increasing burnup). Detailed, by-reactor tables are provided for annual discharged amounts of spent fuel, for storage requirements assuming maximum at-reactor storage, and for storage requirements assuming maximum at-reactor storage plus intra-utility transshipment of spent fuel. 8 refs., 8 figs., 10 tabs

Application of energy management coupled with fuel switching on a hydrotreater unit

Directory of Open Access Journals (Sweden)

Eman M. Gabr

2016-03-01

Full Text Available In the last decades, saving energy and protecting environment became the most important topics for search and survey. The energy engineer for any chemical process is obliged by restrictions of “Kyoto Protocol” for limitation of carbon dioxide emissions from fuel combustion, so he does his best to reduce utility consumption and thus reduce gas emission. Proper designing of the heat exchanger network (HEN for any process is an effective and successful method to minimize utility consumption and therefore minimize gas emission (mainly carbon gases (CO2 and sulfur gases (SOx. Fuel switching coupled with energy targeting achieved the least gas emission. In this work we choose a hydrotreater unit of a petroleum refinery as a case study due to its effective role and its obvious consumption of utility. We applied the methodology of energy targeting through HEN design (using pinch technology at several values of mean temperature difference (ΔTmin; where the maximum percentage of energy saving was 37% for hot and cold utility which directly leads to percentage reduction of gas emission by 29% for CO2 and 17% for SOx. Switching fuel oil to other types of fuel realized gas emission reduction percentage where the maximum reduction established was through natural gas fuel type and reached 54% for CO2 and 90% for SOx. Comparison between existing design and the optimum ΔTmin HEN led to few modifications with the least added capital cost for the hydrotreater existing design to revamp it through four scenarios; the first one depended on fuel switching to natural gas while the second one switched fuel to diesel oil, in the third scenario we applied heat integration only and the fourth one used both of heat integration and fuel switching in a parallel way.

Temperature distribution determination of JPSR power reactor fuel element and cladding

International Nuclear Information System (INIS)

Sudarmono

1996-01-01

In order to utilize of fuel rod efficiency, a concept of JAERI passive Safety Reactor (JPSR) has been developed in Japan Atomic Energy Research Institute. In the JPSR design, UO 2 . are adopted as a fuel rod. The temperature distribution in the fuel rod and cladding in the hottest channel is a potential limiting design constraint of the JPSR. In the present determination, temperature distribution of the fuel rod and cladding for JPSR were PET:formed using COBRA-IV-I to evaluate the safety margin of the present JPSR design. In this method, the whole core was represented by the 1/4 sector and divided into 50 subchannels and 40 axial nodes. The temperature become maximum at the elevation of 1.922 and 2.196 m in the typical cell under operating condition. The maximum temperature in the center of the fuel rod surface of the fuel rod and cladding were 1620,4 o C, 722,8 o C, and 348,6 o C. The maximum results of temperature in the center of the fuel rod and cladding; were 2015,28 o C and 550 o C which were observed at 3.1 second in the typical cell

H.R. 5433: This Act may be cited as the Nuclear Fuel Utilization and Domestic Production Act of 1988. Introduced in the House of Representatives, One Hundredth Congress, Second Session, September 30, 1988

International Nuclear Information System (INIS)

Anon.

1988-01-01

H.R. 5433 is a bill to assist in creating a viable domestic uranium enrichment industry, to insure the maximum economic utilization of the existing diffusion plant assets, to establish mechanisms which would permit the creation of a privately owned corporation to utilize the Federal Government's investment in centrifuge technology and in the centrifuge assets, to establish alternate sources of enrichment supply, so as to create American jobs, to return moneys to the Government and to increase American industrial competitiveness in world wide nuclear fuel sales

Consumer preferences for alternative fuel vehicles: Comparing a utility maximization and a regret minimization model

International Nuclear Information System (INIS)

Chorus, Caspar G.; Koetse, Mark J.; Hoen, Anco

2013-01-01

This paper presents a utility-based and a regret-based model of consumer preferences for alternative fuel vehicles, based on a large-scale stated choice-experiment held among company car leasers in The Netherlands. Estimation and application of random utility maximization and random regret minimization discrete choice models shows that while the two models achieve almost identical fit with the data and differ only marginally in terms of predictive ability, they generate rather different choice probability-simulations and policy implications. The most eye-catching difference between the two models is that the random regret minimization model accommodates a compromise-effect, as it assigns relatively high choice probabilities to alternative fuel vehicles that perform reasonably well on each dimension instead of having a strong performance on some dimensions and a poor performance on others. - Highlights: • Utility- and regret-based models of preferences for alternative fuel vehicles. • Estimation based on stated choice-experiment among Dutch company car leasers. • Models generate rather different choice probabilities and policy implications. • Regret-based model accommodates a compromise-effect

The comparison of alternatives for nuclear spent fuel management using multi-attribute utility function

International Nuclear Information System (INIS)

Yang, J. W.; Kang, C. S.

1999-01-01

It is necessary to find a solution immediately to nuclear spent fuel management that is temporarily stored in on-site spent fuel storage before the saturation of the storage. However the choice of alternative for nuclear spent fuel management consists of complex process that are affected by economic, technical and social factors. And it is not easy to quantify these factors; public opinion, probability of diplomatic problem and contribution to development of nuclear technology. Therefore the analysis of the affecting factors and assessment of alternatives are required. This study performed the comparison of the alternatives for nuclear spent fuel management using MAU (Multi-Attribute Utility Function) and AHP(Analytic Hierarchy Process)

Spent fuel storage requirements 1989--2020

International Nuclear Information System (INIS)

1989-10-01

Historical inventories of spent fuel are combined with Department of Energy (DOE) projections of future discharges from commercial nuclear reactors in the US to provide estimates of spent fuel storage requirements over the next 32 years, through the year 2020. The needs for storage capacity beyond that presently available in the pools are estimated. These estimates incorporate the maximum capacities within current and planned in-pool storage facilities and any planned transshipments of fuel to other reactors or facilities. Historical data through December 1988 are derived from the 1989 Form RW-859 data survey of nuclear utilities. Projected discharges through the end of reactor life are based on DOE estimates of future nuclear capacity, generation, and spent fuel discharges. 14 refs., 3 figs., 28 tabs

Spent fuel storage requirements 1993--2040

International Nuclear Information System (INIS)

1994-09-01

Historical inventories of spent fuel are combined with U.S. Department of Energy (DOE) projections of future discharges from commercial nuclear reactors in the United States to provide estimates of spent fuel storage requirements through the year 2040. The needs are estimated for storage capacity beyond that presently available in the reactor storage pools. These estimates incorporate the maximum capacities within current and planned in-pool storage facilities and any planned transshipments of spent fuel to other reactors or facilities. Existing and future dry storage facilities are also discussed. The nuclear utilities provide historical data through December 1992 on the end of reactor life are based on the DOE/Energy Information Administration (EIA) estimates of future nuclear capacity, generation, and spent fuel discharges

Reactor-specific spent fuel discharge projections: 1986 to 2020

International Nuclear Information System (INIS)

Heeb, C.M.; Walling, R.C.; Purcell, W.L.

1987-03-01

The creation of five reactor-specific spent fuel data bases that contain information on the projected amounts of spent fuel to be discharged from US commercial nuclear reactors through the year 2020 is described. The data bases contain detailed spent-fuel information from existing, planned, and projected pressurized water reactors (PWR) and boiling water reactors (BWR). The projections are based on individual reactor information supplied by the US reactor owners. The basic information is adjusted to conform to Energy Information Agency (EIA) forecasts for nuclear installed capacity, generation, and spent fuel discharged. The EIA cases considered are: (1) No new orders with extended burnup, (2) No new orders with constant burnup, (3) Upper reference (which assumes extended burnup), (4) Upper reference with constant burnup, and (5) Lower reference (which assumes extended burnup). Detailed, by-reactor tables are provided for annual discharged amounts of spent fuel, for storage requirements assuming maximum-at-reactor storage, and for storage requirements assuming maximum-at-reactor plus intra-utility transshipment of spent fuel. 6 refs., 8 figs., 8 tabs

Maximum neutron flux in thermal reactors

International Nuclear Information System (INIS)

Strugar, P.V.

1968-12-01

Direct approach to the problem is to calculate spatial distribution of fuel concentration if the reactor core directly using the condition of maximum neutron flux and comply with thermal limitations. This paper proved that the problem can be solved by applying the variational calculus, i.e. by using the maximum principle of Pontryagin. Mathematical model of reactor core is based on the two-group neutron diffusion theory with some simplifications which make it appropriate from maximum principle point of view. Here applied theory of maximum principle are suitable for application. The solution of optimum distribution of fuel concentration in the reactor core is obtained in explicit analytical form. The reactor critical dimensions are roots of a system of nonlinear equations and verification of optimum conditions can be done only for specific examples

Making the grid the backup: Utility applications for fuel cell power

Energy Technology Data Exchange (ETDEWEB)

Eklof, S.L. [Sacramento Municipal Utility District (SMUD), Sacramento, CA (United States)

1996-12-31

Fuel cells are recognized as a versatile power generation option and accepted component of SMUD`s ART Program. SMUD has received wide support and recognition for promoting and implementing fuel cell power plants, as well as other innovative generation, based primarily on technological factors. Current economic and technical realities in the electric generation market highlight other important factors, such as the cost involved to develop a slate of such resources. The goal now is to develop only those select quality resources most likely to become commercially viable in the near future. The challenge becomes the identification of candidate technologies with the greatest potential, and then matching the technologies with the applications that will help to make them successful. Utility participation in this development is critical so as to provide the industry with case examples of advanced technologies that can be applied in a way beneficial to both the utility and its customers. The ART resource acquisitions provide the experience base upon which to guide this selection process, and should bring about the cost reductions and reliability improvements sought.

Specimen rotation system of the WSU TRIGA-fueled reactor

International Nuclear Information System (INIS)

Lovas, Thomas A.

1976-01-01

The specimen rotation system presently in use at the WSU reactor has been designed to provide maximum utilization of the irradiation capabilities achieved through use of TRIGA-type fuel. This paper describes the system with particular emphasis on characteristics which are advantageous to experimenters. (author)

Fuel assembly

International Nuclear Information System (INIS)

Fushimi, Atsushi; Shimada, Hidemitsu; Aoyama, Motoo; Nakajima, Junjiro

1998-01-01

In a fuel assembly for an n x n lattice-like BWR type reactor, n is determined to 9 or greater, and the enrichment degree of plutonium is determined to 4.4% by weight or less. Alternatively, n is determined to 10 or greater, and the enrichment degree of plutonium is determined to 5.2% by weight or less. An average take-out burnup degree is determined to 39GWd/t or less, and the matrix is determined to 9 x 9 or more, or the average take-out burnup degree is determined to 51GWd/t, and the matrix is determined to 10 x 10 or more and the increase of the margin of the maximum power density obtained thereby is utilized for the compensation of the increase of distortion of power distribution due to decrease of the kinds of plutonium enrichment degree, thereby enabling to reduce the kind of the enrichment degree of MOX fuel rods to one. As a result, the manufacturing step for fuel pellets can be simplified to reduce the manufacturing cost for MOX fuel assemblies. (N.H.)

Long-term fuel cycle scenarios for advanced utilization of plutonium from LWRs

International Nuclear Information System (INIS)

Sato, Osamu; Tatematsu, Kenji

2005-01-01

The Innovative Water Reactor for Flexible fuel cycle (FLWR) realizes multiple recycling and breeding of Pu, which enables effective utilization of the uranium resource, and is based on well-developed LWR technologies. This reactor offers flexibility for the future nuclear fuel cycle situation. Three scenarios were defined for future deployment of nuclear power generation and fuel cycle systems in Japan and analyzed from the view point of Pu recycle, natural uranium consumption and stock of spent fuels. The LWR with long-term Pu recycle with or without MOX fuel reprocessing needs uranium of about 9 thousands tons per year and accumulated uranium consumption of 1.5 million tons in 2150. If the FLWR with net conversion ratio of 0.89 and 1.04 would be introduced in 2025 and 2050 or 2030, it would suppress ultimate required natural uranium and control the uranium consumption about less than 1.2 million tons in 2150, while the FLWR in 2025 and FBR with breeding ratio of 1.16 in 2050 will at 0.9 million tons after in 2100. (T. Tanaka)

About Economy of Fuel at Thermal Power Stations due to Optimization of Utilization Diagram of Power-Generating Equipment

Directory of Open Access Journals (Sweden)

M. V. Svechko

2008-01-01

Full Text Available Problems of rational fuel utilization becomes more and more significant especially for thermal power stations (TPS. Thermal power stations have complicated starting-up diagrams and utilization modes of their technological equipment. Method of diagram optimization of TPS equipment utilization modes has been developed. The method is based on computer analytical model with application of spline-approximation of power equipment characteristics. The method allows to economize fuel consumption at a rate of 15-20 % with accuracy of the predicted calculation not more than 0.25 %.

Improving fuel utilization in SmAHTR with spectral shift control design: Proof of concept

International Nuclear Information System (INIS)

Kotlyar, D.; Lindley, B.A.; Mohamed, H.

2017-01-01

Highlights: • Improving the fuel utilization in a graphite moderated reactor by adopting the ‘spectral shift’ concept. • The feasibility of this concept was tested in the Small Advanced High-Temperature Reactor. • At BOL, the reactor is under-moderated, with excess neutrons being primarily breeding 239 Pu. • Graphite is continuously inserted thermalizing the neutron spectrum and increasing reactivity. • The extra 239 Pu bred during the cycle is then burned, allowing the cycle to be extended. - Abstract: This paper presents a spectral shift design based approach to improve the fuel utilization factor or alternatively to increase the cycle length in a graphite moderated reactor. The feasibility of this concept was tested in the Small Advanced High-Temperature Reactor (SmAHTR). This is a small sized Fluoride-salt-cooled high-temperature reactor (FHR) that uses tri-isotropic (TRISO)-coated particle fuels and graphite moderator materials. A major benefit of the TRISO particles is the ability to mitigate fission product release in the case of an accident. However, the fabrication costs associated with TRISO particles are expected to be significantly higher than the traditional UO 2 fuel. The preliminary studies presented in the paper are focused on extending the achievable irradiation period without increasing the value of the enrichment. In order to increase the discharge burnup, the design includes graphite structures that are initially removed from the core. This imposes a harder spectrum, which enhances the breeding of 239 Pu. Then, the graphite structures are gradually and continuously inserted into the core to sustain criticality. This procedure shifts the hard spectrum into a more thermal one and enables a more efficient utilization of 239 Pu. The preliminary results indicate that this design achieves considerably longer irradiation periods and hence lower fuel cycle costs than the reference design.

Sequential flow membraneless microfluidic fuel cell with porous electrodes

Energy Technology Data Exchange (ETDEWEB)

Salloum, Kamil S.; Posner, Jonathan D. [Department of Mechanical and Aerospace Engineering, Arizona State University, Tempe, AZ 85287-6106 (United States); Hayes, Joel R.; Friesen, Cody A. [School of Materials, Arizona State University, Tempe, AZ 85287-8706 (United States)

2008-05-15

A novel convective flow membraneless microfluidic fuel cell with porous disk electrodes is described. In this fuel cell design, the fuel flows radially outward through a thin disk shaped anode and across a gap to a ring shaped cathode. An oxidant is introduced into the gap between anode and cathode and advects radially outward to the cathode. This fuel cell differs from previous membraneless designs in that the fuel and the oxidant flow in series, rather than in parallel, enabling independent control over the fuel and oxidant flow rate and the electrode areas. The cell uses formic acid as a fuel and potassium permanganate as the oxidant, both contained in a sulfuric acid electrolyte. The flow velocity field is examined using microscale particle image velocimetry and shown to be nearly axisymmetric and steady. The results show that increasing the electrolyte concentration reduces the cell Ohmic resistance, resulting in larger maximum currents and peak power densities. Increasing the flow rate delays the onset of mass transport and reduces Ohmic losses resulting in larger maximum currents and peak power densities. An average open circuit potential of 1.2 V is obtained with maximum current and power densities of 5.35 mA cm{sup -2} and 2.8 mW cm{sup -2}, respectively (cell electrode area of 4.3 cm{sup 2}). At a flow rate of 100 {mu}L min{sup -1} a fuel utilization of 58% is obtained. (author)

Utilization of Minor Actinides as a Fuel Component for Ultra-Long Life VHTR Configurations: Designs, Advantages and Limitations

International Nuclear Information System (INIS)

Tsvetkov, Pavel V.

2009-01-01

This project assessed the advantages and limitations of using minor actinides as a fuel component to achieve ultra-long life Very High Temperature Reactor (VHTR) configurations. Researchers considered and compared the capabilities of pebble-bed and prismatic core designs with advanced actinide fuels to achieve ultra-long operation without refueling. Since both core designs permit flexibility in component configuration, fuel utilization, and fuel management, it is possible to improve fissile properties of minor actinides by neutron spectrum shifting through configuration adjustments. The project studied advanced actinide fuels, which could reduce the long-term radio-toxicity and heat load of high-level waste sent to a geologic repository and enable recovery of the energy contained in spent fuel. The ultra-long core life autonomous approach may reduce the technical need for additional repositories and is capable to improve marketability of the Generation IV VHTR by allowing worldwide deployment, including remote regions and regions with limited industrial resources. Utilization of minor actinides in nuclear reactors facilitates developments of new fuel cycles towards sustainable nuclear energy scenarios.

Utilization of Minor Actinides as a Fuel Component for Ultra-Long Life Bhr Configurations: Designs, Advantages and Limitations

Energy Technology Data Exchange (ETDEWEB)

Dr. Pavel V. Tsvetkov

2009-05-20

This project assessed the advantages and limitations of using minor actinides as a fuel component to achieve ultra-long life Very High Temperature Reactor (VHTR) configurations. Researchers considered and compared the capabilities of pebble-bed and prismatic core designs with advanced actinide fuels to achieve ultra-long operation without refueling. Since both core designs permit flexibility in component configuration, fuel utilization, and fuel management, it is possible to improve fissile properties of minor actinides by neutron spectrum shifting through configuration adjustments. The project studied advanced actinide fuels, which could reduce the long-term radio-toxicity and heat load of high-level waste sent to a geologic repository and enable recovery of the energy contained in spent fuel. The ultra-long core life autonomous approach may reduce the technical need for additional repositories and is capable to improve marketability of the Generation IV VHTR by allowing worldwide deployment, including remote regions and regions with limited industrial resources. Utilization of minor actinides in nuclear reactors facilitates developments of new fuel cycles towards sustainable nuclear energy scenarios.

Spent fuel storage requirements, 1991--2040

International Nuclear Information System (INIS)

1991-12-01

Historical inventories of spent fuel are combined with US Department of Energy (DOE) projections of future discharges from commercial nuclear reactors in the United States to provide estimates of spent fuel storage requirements over the next 50 years, through the year 2040. The needs for storage capacity beyond that presently available in the pools are estimated. These estimates incorporate the maximum capacities within current and planned in-pool storage facilities and any planned transshipments of fuel to other reactors or facilities. Existing and future dry storage facilities are also discussed. Historical data through December 1990 are derived from the 1991 Form RW-859 data survey of nuclear utilities. Projected discharges through the end of reactor life are based on DOE estimates of future nuclear capacity, generation, and spent fuel discharges

Using distributed fuel cells to compete with established utilities under rules permitting retail wheeling

International Nuclear Information System (INIS)

Miller, D.A.; Mathur, A.

1996-01-01

Regulatory reform in the electricity industry clearly has many implications for the corporate structure of electric utilities, the pricing of energy products and services, and the quality of service received by customers. But it also has implications for the selection of energy generating technologies. The rise of the cogenerator and independent power producer has been a major force in the expanded use of combined-cycle power plants and their technological advancement. The next stage of increased deregulation, retail wheeling, must also lead to further technological change, because the economic climate determines the operational characteristics required of new generating resources. This paper discusses the use of distributed fuel cells to compete with established utilities in areas where retail wheeling has been instituted. It will cover in detail the unique advantages of the technology under this industry configuration. The paper will pay particular attention to the operational and design characteristics of fuel cells that will provide companies the flexibility they require to compete successfully. Finally, the paper will discuss the implications for the use of distributed fuel cells of alternative retail wheeling implementation schemes

Final Report: Utilizing Alternative Fuel Ignition Properties to Improve SI and CI Engine Efficiency

Energy Technology Data Exchange (ETDEWEB)

Wooldridge, Margaret; Boehman, Andre; Lavoie, George; Fatouraie, Mohammad

2017-11-30

Experimental and modeling studies were completed to explore leveraging physical and chemical fuel properties for improved thermal efficiency of internal combustion engines. Fundamental studies of the ignition chemistry of ethanol and iso-octane blends and constant volume spray chamber studies of gasoline and diesel sprays supported the core research effort which used several reciprocating engine platforms. Single cylinder spark ignition (SI) engine studies were carried out to characterize the impact of ethanol/gasoline, syngas (H2 and CO)/gasoline and other oxygenate/gasoline blends on engine performance. The results of the single-cylinder engine experiments and other data from the literature were used to train a GT Power model and to develop a knock criteria based on reaction chemistry. The models were used to interpret the experimental results and project future performance. Studies were also carried out using a state of the art, direct injection (DI) turbocharged multi- cylinder engine with piezo-actuated fuel injectors to demonstrate the promising spray and spark timing strategies from single-cylinder engine studies on the multi-cylinder engine. Key outcomes and conclusions of the studies were: 1. Efficiency benefits of ethanol and gasoline fuel blends were consistent and substantial (e.g. 5-8% absolute improvement in gross indicated thermal efficiency (GITE)). 2. The best ethanol/gasoline blend (based on maximum thermal efficiency) was determined by the engine hardware and limits based on component protection (e.g. peak in-cylinder pressure or maximum turbocharger inlet temperature) – and not by knock limits. Blends with <50% ethanol delivered significant thermal efficiency gains with conventional SI hardware while maintain good safety integrity to the engine hardware. 3. Other compositions of fuel blends including syngas (H2 and CO) and other dilution strategies provided significant efficiency gains as well (e.g. 5% absolute improvement in ITE). 4. When the

Hierarchical Load Tracking Control of a Grid-connected Solid Oxide Fuel Cell for Maximum Electrical Efficiency Operation

DEFF Research Database (Denmark)

Li, Yonghui; Wu, Qiuwei; Zhu, Haiyu

2015-01-01

efficiency operation obtained at different active power output levels, a hierarchical load tracking control scheme for the grid-connected SOFC was proposed to realize the maximum electrical efficiency operation with the stack temperature bounded. The hierarchical control scheme consists of a fast active...... power control and a slower stack temperature control. The active power control was developed by using a decentralized control method. The efficiency of the proposed hierarchical control scheme was demonstrated by case studies using the benchmark SOFC dynamic model......Based on the benchmark solid oxide fuel cell (SOFC) dynamic model for power system studies and the analysis of the SOFC operating conditions, the nonlinear programming (NLP) optimization method was used to determine the maximum electrical efficiency of the grid-connected SOFC subject...

the effect of advanced fuel designs on fuel utilization

International Nuclear Information System (INIS)

Sarikaya, B.; Colak, U.; Tombakoglu, M.; Yilmazbayhan, A.

1997-01-01

Fuel management is one of the key topic in nuclear engineering. It is possible to increase fuel burnup and reactor lifetime by using advanced fuel management strategies. In order to increase the cycle lifetime, required amount of excess reactivity must be added to system. Burnable poisons can be used to compensate this excess reactivity. Usually gadolinium (Gd) is used as burnable poison. But the use of Gd presents some difficulties that have not been encountered with the use of boron

Spent fuel storage requirements, 1990--2040

International Nuclear Information System (INIS)

Walling, R.; Bierschbach, M.

1990-11-01

Historical inventories of spent fuel are combined with US Department of Energy (DOE) projections of future discharges from commercial nuclear reactors in the United States to provide estimates of spent fuel storage requirements over the next 51 years, through the year 2040. The needs for storage capacity beyond that presently available in the pools are estimated. These estimates incorporate the maximum capacities within current and planned in-pool storage facilities and any planned transshipments of fuel to other reactors or facilities. Existing and future dry storage facilities are also discussed. Historical data through December 1989 are derived from the 1990 Form RW-859 data survey of nuclear utilities. Projected discharges through the end of reactor life are based on DOE estimates of future nuclear capacity, generation, and spent fuel discharges. 15 refs., 3 figs., 11 tabs

ON THE NECESSITY OF CHANGES IN THE STRATEGY OF UTILIZATION SHIP BOILER TECHNICAL CONDITION MAINTENANCE IN THE ASPECT OF LNG APPLIED AS FUEL

Directory of Open Access Journals (Sweden)

Andrzej ADAMKIEWICZ

2017-01-01

Full Text Available Heavy oils (HFO fuels used on ships play a part in degradation of technical condition of heat exchange surfaces of utiliza-tion boilers especially on the exhaust gas side. Presence of sulphur in these fuels is the main factor favouring degrada-tion. The upper limit for sulphur content in the fuel used outside the SECA areas equal to 3.5% is currently in force, at least until the year 2020 or 2025. The recommended by classification societies overhauls of utilization boilers are, there-fore characterized by a specially chosen strategy thanks to which it is possible to maintain their appropriate technical condition. The requirement to use fuels with low sulphur content (LSFO, which are significantly more expensive than MDO fuels, in the areas of controlled sulphur emissions also led to a further introduction of alternative fuels, such as methanol and above all liquefied natural gas (LNG, onto ships. That is especially valid for the ship owners whose vessels e.g. ferries sail mainly within SCECA This article analyses the consequences of the introduced fuel change on utilization boiler maintenance. A change in the technical condition maintenance strategy for utilization boilers has been suggested.

A performance comparison of urban utility vehicles powered with IC engine and solid polymer fuel cell technologies

International Nuclear Information System (INIS)

Teachman, M.E.; Scott, D.S.

1993-01-01

Utility vehicles provide ground transportation for crew and electric power at work sites that lack grid supply. The performances of utility vehicles designed with conventional architectures (spark ignition engine for propulsion and a motor generator for electric power) and with a fuel cell/battery architectures, are compared over a range of vehicle missions. Results indicate that fuel cell/battery hybrid systems are lighter than conventional systems for missions requiring short driving distances and work site power levels exceeding 10 kW. Conventional spark ignition engine/gen-set power systems are lighter for missions requiring more than 1 hour of driving and less than 10 kW of work site power. Fuel cell/battery systems are more efficient than spark ignition engine/gen-set systems for all missions. 7 figs., 3 tabs., 20 refs

Spent fuel storage requirements for nuclear utilities and OCRWM [Office of Civilian Radioactive Waste Management

International Nuclear Information System (INIS)

Wood, T.W.

1990-03-01

Projected spent fuel generation at US power reactors exceeds estimated aggregate pool storage capacity by approximately 30,000 metric tons of uranium (MTU). Based on the current repository schedule, little of the spent fuel inventory will be disposed of prior to shutdown of existing reactors, and a large additional capacity for surface storage of spent fuel will be required, either at reactors or at a centralized DOE storage site. Allocation of this storage requirement across the utility-DOE interface, and the resulting implications for reactor sites and the performance of the federal waste management system, were studied during the DOE MRS System Study and again subsequent to the reassessment of the repository schedule. Spent fuel logistics and cost results from these analyses will be used in definition of spent fuel storage capacity requirements for the federal system. 9 refs., 8 figs., 1 tab

Nuclear fuel cycle activities with an utility

International Nuclear Information System (INIS)

Schwarz, E.

1977-01-01

The lecture will deal with the following topics: Fuel requirements: establishing fuel requirements - first core - reloads. Calculation of required uranium and separation work: reload planning - long term - short term - during refuelling; exactness of calculations: contracts: 1) Uranium and conversion; 2) Enrichment services; 3) Fuel elements; 4) Ownership; 5) Accidential loss of material; 6) Flexibility in time and amounts; 7) Specifications, surcharges; 8) Terms of payment; 9) Fuel containers, ownership, retransport; fuel reserves: 1) Natural uranium (concentrates or reserves in the ground); 2) Enriched uranium; 3) Fuel elements; 4) Cost of reserves; 5) Exchange in case of need. Handling of contracts: 1) Schedule for deliveries; Notes for deliveries; 3) Fuel accounting and balance; 4) Formalities (export and import licenses, customs etc.). Fuel cost: 1) Prices; 2) Fuel cost calculations for comparison of bids and cost forecast. (orig.) [de

Impact of fuel fabrication and fuel management technologies on uranium management

International Nuclear Information System (INIS)

Arnsberger, P.L.; Stucker, D.L.

1994-01-01

Uranium utilization in commercial pressurized water reactors is a complex function of original NSSS design, utility energy requirements, fuel assembly design, fuel fabrication materials and fuel fabrication materials and fuel management optimization. Fuel design and fabrication technologies have reacted to the resulting market forcing functions with a combination of design and material changes. The technologies employed have included ever-increasing fuel discharge burnup, non-parasitic structural materials, burnable absorbers, and fissile material core zoning schemes (both in the axial and radial direction). The result of these technological advances has improved uranium utilization by roughly sixty percent from the infancy days of nuclear power to present fuel management. Fuel management optimization technologies have also been developed in recent years which provide fuel utilization improvements due to core loading pattern optimization. This paper describes the development and impact of technology advances upon uranium utilization in modern pressurized water reactors. 10 refs., 3 tabs., 10 figs

Thorium Fuel Utilization Analysis on Small Long Life Reactor for Different Coolant Types

Science.gov (United States)

Permana, Sidik

2017-07-01

A small power reactor and long operation which can be deployed for less population and remote area has been proposed by the IAEA as a small and medium reactor (SMR) program. Beside uranium utilization, it can be used also thorium fuel resources for SMR as a part of optimalization of nuclear fuel as a “partner” fuel with uranium fuel. A small long-life reactor based on thorium fuel cycle for several reactor coolant types and several power output has been evaluated in the present study for 10 years period of reactor operation. Several key parameters are used to evaluate its effect to the reactor performances such as reactor criticality, excess reactivity, reactor burnup achievement and power density profile. Water-cooled types give higher criticality than liquid metal coolants. Liquid metal coolant for fast reactor system gives less criticality especially at beginning of cycle (BOC), which shows liquid metal coolant system obtains almost stable criticality condition. Liquid metal coolants are relatively less excess reactivity to maintain longer reactor operation than water coolants. In addition, liquid metal coolant gives higher achievable burnup than water coolant types as well as higher power density for liquid metal coolants.

Research reactor utilization, safety, decommissioning, fuel and waste management. Posters of an international conference

International Nuclear Information System (INIS)

2005-01-01

For more than 50 years research reactors have played an important role in the development of nuclear science and technology. They have made significant contributions to a large number of disciplines as well as to the educational and research programmes of about 70 countries world wide. About 675 research reactors have been built to date, of which some 278 are now operating in 59 countries (86 of them in 38 developing Member States). Altogether over 13,000 reactor-years of cumulative operational experience has been gained during this remarkable period. The objective of this conference was to foster the exchange of information on current research reactor concerns related to safety, operation, utilization, decommissioning and to provide a forum for reactor operators, designers, managers, users and regulators to share experience, exchange opinions and to discuss options and priorities. The topical areas covered were: a) Utilization, including new trends and directions for utilization of research reactors. Effective management of research reactors and associated facilities. Engineering considerations and experience related to refurbishment and modifications. Strategic planning and marketing. Classical applications (nuclear activation analysis, isotope production, neutron beam applications, industrial irradiations, medical applications). Training for operators. Educational programmes using a reactor. Current developments in design and fabrication of experimental facilities. Irradiation facilities. Projects for regional uses of facilities. Core management and calculation tools. Future trends for reactors. Use of simulators for training and educational programmes. b) Safety, including experience with the preparation and review of safety analysis reports. Human factors in safety analysis. Management of extended shutdown periods. Modifications: safety analysis, regulatory aspects, commissioning programmes. Engineering safety features. Safety culture. Safety peer reviews and

maximum neutron flux at thermal nuclear reactors

International Nuclear Information System (INIS)

Strugar, P.

1968-10-01

Since actual research reactors are technically complicated and expensive facilities it is important to achieve savings by appropriate reactor lattice configurations. There is a number of papers, and practical examples of reactors with central reflector, dealing with spatial distribution of fuel elements which would result in higher neutron flux. Common disadvantage of all the solutions is that the choice of best solution is done starting from the anticipated spatial distributions of fuel elements. The weakness of these approaches is lack of defined optimization criteria. Direct approach is defined as follows: determine the spatial distribution of fuel concentration starting from the condition of maximum neutron flux by fulfilling the thermal constraints. Thus the problem of determining the maximum neutron flux is solving a variational problem which is beyond the possibilities of classical variational calculation. This variational problem has been successfully solved by applying the maximum principle of Pontrjagin. Optimum distribution of fuel concentration was obtained in explicit analytical form. Thus, spatial distribution of the neutron flux and critical dimensions of quite complex reactor system are calculated in a relatively simple way. In addition to the fact that the results are innovative this approach is interesting because of the optimization procedure itself [sr

Barnwell Nuclear Fuels Plant applicability study. Volume II. BNFP: utilization alternatives, evaluations, and conclusions

International Nuclear Information System (INIS)

1978-04-01

Descriptions and status of the Barnwell separations facility and related fuel cycle facilities are given. Alternative uses other than reprocessing, evaluation of uses for reprocessing alternatives, resource utilization and its relationship to U.S. security objectives, and evaluation of ownership-management options are discussed

15 N utilization in nitride nuclear fuels for advanced nuclear power reactors and accelerator - driven systems

International Nuclear Information System (INIS)

Axente, D.

2005-01-01

15 N utilization for nitride nuclear fuels production for nuclear power reactors and accelerator - driven systems is presented. Nitride nuclear fuel is the obvious choice for advanced nuclear reactors and ADS because of its favorable properties: a high melting point, excellent thermal conductivity, high fissile density, lower fission gas release and good radiation tolerance. The application of nitride fuels in nuclear reactors and ADS requires use of 15 N enriched nitrogen to suppress 14 C production due to (n,p) reaction on 14 N. Accelerator - driven system is a recent development merging of accelerator and fission reactor technologies to generate electricity and transmute long - lived radioactive wastes as minor actinides: Np, Am, Cm. A high-energy proton beam hitting a heavy metal target produces neutrons by spallation. The neutrons cause fission in the fuel, but unlike in conventional reactors, the fuel is sub-critical and fission ceases when the accelerator is turned off. Nitride fuel is a promising candidate for transmutation in ADS of minor actinides, which are converted into nitrides with 15 N for that purpose. Tacking into account that the world wide market is about 20 to 40 Kg 15 N annually, the supply of that isotope for nitride fuel production for nuclear power reactors and ADS would therefore demand an increase in production capacity by a factor of 1000. For an industrial plant producing 100 t/y 15 N, using present technology of isotopic exchange in NITROX system, the first separation stage of the cascade would be fed with 10M HNO 3 solution of 600 mc/h flow - rate. If conversion of HNO 3 into NO, NO 2 , at the enriching end of the columns, would be done with gaseous SO 2 , for a production plant of 100 t/y 15 N a consumption of 4 million t SO 2 /y and a production of 70 % H 2 SO 4 waste solution of 4.5 million mc/y are estimated. The reconversion of H 2 SO 4 into SO 2 in order to recycle of SO 2 is a problem to be solved to compensate the cost of SO 2

Maximum Power from a Solar Panel

Directory of Open Access Journals (Sweden)

Michael Miller

2010-01-01

Full Text Available Solar energy has become a promising alternative to conventional fossil fuel sources. Solar panels are used to collect solar radiation and convert it into electricity. One of the techniques used to maximize the effectiveness of this energy alternative is to maximize the power output of the solar collector. In this project the maximum power is calculated by determining the voltage and the current of maximum power. These quantities are determined by finding the maximum value for the equation for power using differentiation. After the maximum values are found for each time of day, each individual quantity, voltage of maximum power, current of maximum power, and maximum power is plotted as a function of the time of day.

Thermal analysis model for the temperature distribution of the CANDU spent fuel assembly

International Nuclear Information System (INIS)

Choi, Hae Yun; Kwon, Jong Soo; Park, Seong Hoon; Kim, Seong Rea; Lee, Gi Won

1996-01-01

The purpose of this technical is to introduce the methodology and experimental process for the experimental research work with the mock-up test performed to verify and validate the MAXROT code which is a thermal analysis method for Wolsong (CANDU) spent fuel dry storage canister. The experiment was conducted simulating the heat transfer characteristics of combinations of equilateral triangular and square pitch arrays of heater rods, similar to a CANDU spent fuel bundle. After assembly of the heater rod bundle into the containment vessel, the experimental apparatus was operated under the same operating and boundary conditions as an interim dry storage condition at the nuclear power plant site. The reduced data from this experiment has been utilized to verity a model developed to predict the maximum fuel rod surface temperature in a fuel bundle. These test procedures and the experiment can be utilized to establish the fine thermal analysis method applicable to dry storage system for the spent fuel. 12 figs., 5 tabs., 36 refs. (Author) .new

Thermal analysis model for the temperature distribution of the CANDU spent fuel assembly

Energy Technology Data Exchange (ETDEWEB)

Choi, Hae Yun; Kwon, Jong Soo; Park, Seong Hoon; Kim, Seong Rea; Lee, Gi Won [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1996-01-01

The purpose of this technical is to introduce the methodology and experimental process for the experimental research work with the mock-up test performed to verify and validate the MAXROT code which is a thermal analysis method for Wolsong (CANDU) spent fuel dry storage canister. The experiment was conducted simulating the heat transfer characteristics of combinations of equilateral triangular and square pitch arrays of heater rods, similar to a CANDU spent fuel bundle. After assembly of the heater rod bundle into the containment vessel, the experimental apparatus was operated under the same operating and boundary conditions as an interim dry storage condition at the nuclear power plant site. The reduced data from this experiment has been utilized to verity a model developed to predict the maximum fuel rod surface temperature in a fuel bundle. These test procedures and the experiment can be utilized to establish the fine thermal analysis method applicable to dry storage system for the spent fuel. 12 figs., 5 tabs., 36 refs. (Author) .new.

Utilization of Used Nuclear Fuel in a Potential Future US Fuel Cycle Scenario - 13499

Energy Technology Data Exchange (ETDEWEB)

Worrall, Andrew [Oak Ridge National Laboratory, P.O. BOX 2008 MS6172, Oak Ridge, TN, 37831-6172 (United States)

2013-07-01

from the FRs due to time in the core, cooling time, reprocessing, and re-fabrication time is built into the analysis, along with impacts in delays and other key assumptions and sensitivities have been investigated. The results of this assessment highlight how the UNF from future reactors (LWRs and FRs) and the resulting fissile materials (U and Pu) from reprocessing can be effectively utilized, and show that the timings of future nuclear programs are key considerations (both for reactors and fuel cycle facilities). The analysis also highlights how the timings are relevant to managing the UNF and how such an analysis can therefore assist in informing the potential future R and D strategy and needs of the US fuel cycle programs and reactor technology. (authors)

Utilization of Used Nuclear Fuel in a Potential Future US Fuel Cycle Scenario - 13499

International Nuclear Information System (INIS)

Worrall, Andrew

2013-01-01

from the FRs due to time in the core, cooling time, reprocessing, and re-fabrication time is built into the analysis, along with impacts in delays and other key assumptions and sensitivities have been investigated. The results of this assessment highlight how the UNF from future reactors (LWRs and FRs) and the resulting fissile materials (U and Pu) from reprocessing can be effectively utilized, and show that the timings of future nuclear programs are key considerations (both for reactors and fuel cycle facilities). The analysis also highlights how the timings are relevant to managing the UNF and how such an analysis can therefore assist in informing the potential future R and D strategy and needs of the US fuel cycle programs and reactor technology. (authors)

Accelerator-driven transmutation of spent fuel elements

Science.gov (United States)

Venneri, Francesco; Williamson, Mark A.; Li, Ning

2002-01-01

An apparatus and method is described for transmuting higher actinides, plutonium and selected fission products in a liquid-fuel subcritical assembly. Uranium may also be enriched, thereby providing new fuel for use in conventional nuclear power plants. An accelerator provides the additional neutrons required to perform the processes. The size of the accelerator needed to complete fuel cycle closure depends on the neutron efficiency of the supported reactors and on the neutron spectrum of the actinide transmutation apparatus. Treatment of spent fuel from light water reactors (LWRs) using uranium-based fuel will require the largest accelerator power, whereas neutron-efficient high temperature gas reactors (HTGRs) or CANDU reactors will require the smallest accelerator power, especially if thorium is introduced into the newly generated fuel according to the teachings of the present invention. Fast spectrum actinide transmutation apparatus (based on liquid-metal fuel) will take full advantage of the accelerator-produced source neutrons and provide maximum utilization of the actinide-generated fission neutrons. However, near-thermal transmutation apparatus will require lower standing

In-reactor cladding breach of EBR-II driver-fuel elements

International Nuclear Information System (INIS)

Seidel, B.R.; Einziger, R.E.

1977-01-01

Knowledge of performance and minimum useful element lifetime of Mark-II driver-fuel elements is required to maintain a high plant operating capacity factor with maximum fuel utilization. To obtain such knowledge, intentional cladding breach has been obtained in four run-to-cladding-breach Mark-II experimental driver-fuel subassemblies operating under normal conditions in EBR-II. Breach and subsequent fission-product release proved benign to reactor operations. The breaches originated on the outer surface of the cladding in the root of the restrainer dimples and were intergranular. The Weibull distribution of lifetime accurately predicts the observed minimum useful element lifetime of 10 at.% burnup, with breach ensuing shortly thereafter

Determination of maximum water temperature within the spent fuel pool of Angra Nuclear Power Plant - Unit 3

Energy Technology Data Exchange (ETDEWEB)

Werner, F.L., E-mail: fernanda.werner@poli.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Departamento de Engenharia Nuclear; Alves, A.S.M., E-mail: asergi@eletronuclear.gov.br [Eletrobras Termonuclear (Eletronuclear), Rio de Janeiro, RJ (Brazil); Frutuoso e Melo, P.F., E-mail: frutuoso@nuclear.ufrj.br [Coordenacao de Pos-Graduacao e Pesquisa de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil)

2017-07-01

In this paper, a mathematical model for the determination of the maximum water temperature within the spent fuel pool of Angra Nuclear Power Plant – Unit 3 was developed. The model was obtained from the boundary layer analysis and the application of Navier-Stokes equation to a vertical flat plate immersed in a water flow under free convection regime. Both types of pressure loss coefficients through the flow channel were considers in the modeling, the form coefficient for fuel assemblies (FAs) and the loss due to rod friction. The resulting equations enabled the determination of a mixed water temperature below the storage racks (High Density Storage Racks) as well as the estimation of a temperature gradient through the racks. The model was applied to the authorized operation of the plant (power operation, plant outage and upset condition) and faulted conditions (loss of coolant accidents and external events). The results obtained are in agreement with Brazilian and international standards. (author)

Determination of maximum water temperature within the spent fuel pool of Angra Nuclear Power Plant - Unit 3

International Nuclear Information System (INIS)

Werner, F.L.; Frutuoso e Melo, P.F.

2017-01-01

In this paper, a mathematical model for the determination of the maximum water temperature within the spent fuel pool of Angra Nuclear Power Plant – Unit 3 was developed. The model was obtained from the boundary layer analysis and the application of Navier-Stokes equation to a vertical flat plate immersed in a water flow under free convection regime. Both types of pressure loss coefficients through the flow channel were considers in the modeling, the form coefficient for fuel assemblies (FAs) and the loss due to rod friction. The resulting equations enabled the determination of a mixed water temperature below the storage racks (High Density Storage Racks) as well as the estimation of a temperature gradient through the racks. The model was applied to the authorized operation of the plant (power operation, plant outage and upset condition) and faulted conditions (loss of coolant accidents and external events). The results obtained are in agreement with Brazilian and international standards. (author)

Addressing fuel recycling in solid oxide fuel cell systems fed by alternative fuels

DEFF Research Database (Denmark)

Rokni, Masoud

2017-01-01

An innovative study on anode recirculation in solid oxide fuel cell systems with alternative fuels is carried out and investigated. Alternative fuels under study are ammonia, pure hydrogen, methanol, ethanol, DME and biogas from biomass gasification. It is shown that the amount of anode off......%. Furthermore, it is founded that for the case with methanol, ethanol and DME then at high utilization factors, low anode recirculation is recommended while at low utilization factors, high anode recirculation is recommended. If the plant is fed by biogas from biomass gasification then for each utilization...

Normalizing the maximum permissible seal failure of the fuel cladding of VVER and the activity of the fission products in the coolant

International Nuclear Information System (INIS)

Luzanova, L.M.; Miglo, V.N.; Slavyagin, P.D.

1993-01-01

In most countries developing a nuclear power industry based on pressurized water reactors, one of the conditions for issuing a license under normal operating conditions for issuing a license stipulates that the fuel elements may not lose their hermetic seal either under normal operating conditions or during presumable disturbances of the conditions of normal use. At a conference on radiation safety the ALARA principle was taken to be fundamental, it being attempted to keep the activity of the coolant of the primary circuit, including the fission products emerging from unsealed fuel elements, to a level as low as reasonably possible. As many years of experience in the nuclear power industry have shown, nuclear power stations are in many cases operated with nonhermetic fuel elements in the core. Therefore, from the point of view of safety and economy, the best way to operate a power plant is to try to ensure maximum burnup of the fuel of the unsealed elements as they operate within the limits of safe activity of the fission products in the fuel circuits

Advanced fuel development at AECL: What does the future hold for CANDU fuels/fuel cycles?

Energy Technology Data Exchange (ETDEWEB)

Kupferschmidt, W.C.H. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

2013-07-01

This paper outlines advanced fuel development at AECL. It discusses expanding the limits of fuel utilization, deploy alternate fuel cycles, increase fuel flexibility, employ recycled fuels; increase safety and reliability, decrease environmental impact and develop proliferation resistant fuel and fuel cycle.

Maximum power output and load matching of a phosphoric acid fuel cell-thermoelectric generator hybrid system

Science.gov (United States)

Chen, Xiaohang; Wang, Yuan; Cai, Ling; Zhou, Yinghui

2015-10-01

Based on the current models of phosphoric acid fuel cells (PAFCs) and thermoelectric generators (TGs), a new hybrid system is proposed, in which the effects of multi-irreversibilities resulting from the activation, concentration, and ohmic overpotentials in the PAFC, Joule heat and heat leak in the TG, finite-rate heat transfer between the TG and the heat reservoirs, and heat leak from the PAFC to the environment are taken into account. Expressions for the power output and efficiency of the PAFC, TG, and hybrid system are analytically derived and directly used to discuss the performance characteristics of the hybrid system. The optimal relationship between the electric currents in the PAFC and TG is obtained. The maximum power output is numerically calculated. It is found that the maximum power output density of the hybrid system will increase about 150 Wm-2, compared with that of a single PAFC. The problem how to optimally match the load resistances of two subsystems is discussed. Some significant results for practical hybrid systems are obtained.

Fabrication of the fuel elements cladding for utilization in the fluidized bed nuclear reactor

International Nuclear Information System (INIS)

Schaeffer, L.; Sefidvash, F.

1986-01-01

A method for the fabrication of cladding of the spherical fuel elements for the utilization in the fluidized bed nuclear reactor is presented. Some prelimminary experiments were performed to adopt a method which adapt itself to mass production with the desired high quality. Still methods for cladding fabrication are under study. (Author) [pt

MOX fuel: a contribution to disarmament. U.S. utilities' response to DOE's plutonium disposition decision

International Nuclear Information System (INIS)

Wallace, M.

1997-01-01

The author is chairman of the Nuclear Energy Institute Plutonium Disposition Working Group, which includes 11 nuclear utilities, including Ontario Hydro, and all the European fabricators of mixed oxide (MOX) fuel. A feasibility study is going on, to see if Russian or other weapons grade plutonium made into MOX fuel can be used in US, Canadian, or other power reactors. The US nuclear power industry is going through a period of change, and its primary responsibility must be the safe, reliable and economic operation of its plants. There is no current US MOX capacity, but the Europeans have have manufactured and burned over 400 tons of MOX fuel since 1963. Canada may be involved, initially through a pilot-scale experiment in NRU reactor

A review on the heterogeneous thorium fuel concept for PWR applications

International Nuclear Information System (INIS)

Joo, H. K.; Noh, J. M.; Yoo, J. W.; Kim, K. H.

2001-08-01

Seed-blanket unit (SBU) and whole assembly seed and blanket (WASB) are being investigated for the PWR application as well as homogeneous thorium fuel under the US NERI program. For the verification of HELIOS capability for thorium analysis, the characteristics of heterogeneous thorium fuels was evaluated by HELIOS color-set calculation and compared with the calculation results of the US NERI. The infinite multiplication factors from HELIOS calculation are in good agreement with CASMO-4 except for SBU which uses metallic fuel for seed material. The maximum relative difference in power distribution is occurred in WASB case, and is about 5% compared to MCNP. The isotopic concentrations for Am-241, Am-243, and Cm-244 of HELIOS agree well with CASMO-4's, but show a significant discrepancy from MOCUP mainly caused by the old data of cross section and decay constants in ORIGEN. The nonproliferation characteristic of thorium-based fuel such as critical mass, spontaneous fission rate, decay heat generation rate are superior to the conventional uranium fuel. Even though the diversion of U-233 produced in blanket is a technically difficult, the enrichment of uranium isotopes including U-233 is slightly over the limit for safeguard aspects. The urnaium contents in thorium fuel is need to be adjusted in order to meet the safeguard limit. A preliminary assessment of fuel economics was performed based on the uranium utilization and SWU utilization. The natural uranium utilization factors of heterogeneous thorium-based fuel increased by 10δ18%, but the SWU utilization factor decreased by 6-δ11% compared to uranium fuel. The cost of uranium purchase of 50USI/KgU and SWU cost of 110USI/SWU-Kg, recommended by OECD/NEA, gives a comparable economics of thorium-based fuel to uraium fuel. The detailed fuel cycle analysis will take account of the other factors like the variation of uranium purchase cost and SWU cost, fabrication cost of thorium fuel, thorium purchase cost, the capcity

A review on the heterogeneous thorium fuel concept for PWR applications

Energy Technology Data Exchange (ETDEWEB)

Joo, H. K.; Noh, J. M.; Yoo, J. W.; Kim, K. H

2001-08-01

Seed-blanket unit (SBU) and whole assembly seed and blanket (WASB) are being investigated for the PWR application as well as homogeneous thorium fuel under the US NERI program. For the verification of HELIOS capability for thorium analysis, the characteristics of heterogeneous thorium fuels was evaluated by HELIOS color-set calculation and compared with the calculation results of the US NERI. The infinite multiplication factors from HELIOS calculation are in good agreement with CASMO-4 except for SBU which uses metallic fuel for seed material. The maximum relative difference in power distribution is occurred in WASB case, and is about 5% compared to MCNP. The isotopic concentrations for Am-241, Am-243, and Cm-244 of HELIOS agree well with CASMO-4's, but show a significant discrepancy from MOCUP mainly caused by the old data of cross section and decay constants in ORIGEN. The nonproliferation characteristic of thorium-based fuel such as critical mass, spontaneous fission rate, decay heat generation rate are superior to the conventional uranium fuel. Even though the diversion of U-233 produced in blanket is a technically difficult, the enrichment of uranium isotopes including U-233 is slightly over the limit for safeguard aspects. The urnaium contents in thorium fuel is need to be adjusted in order to meet the safeguard limit. A preliminary assessment of fuel economics was performed based on the uranium utilization and SWU utilization. The natural uranium utilization factors of heterogeneous thorium-based fuel increased by 10{delta}18%, but the SWU utilization factor decreased by 6-{delta}11% compared to uranium fuel. The cost of uranium purchase of 50USI/KgU and SWU cost of 110USI/SWU-Kg, recommended by OECD/NEA, gives a comparable economics of thorium-based fuel to uraium fuel. The detailed fuel cycle analysis will take account of the other factors like the variation of uranium purchase cost and SWU cost, fabrication cost of thorium fuel, thorium purchase cost

Direct Utilization of Liquid Fuels in SOFC for Portable Applications: Challenges for the Selection of Alternative Anodes

Directory of Open Access Journals (Sweden)

Massimiliano Cimenti

2009-06-01

Full Text Available Solid oxide fuel cells (SOFC have the advantage of being able to operate with fuels other than hydrogen. In particular, liquid fuels are especially attractive for powering portable applications such as small power generators or auxiliary power units, in which case the direct utilization of the fuel would be convenient. Although liquid fuels are easier to handle and transport than hydrogen, their direct use in SOFC can lead to anode deactivation due to carbon formation, especially on traditional nickel/yttria stabilized zirconia (Ni/YSZ anodes. Significant advances have been made in anodic materials that are resistant to carbon formation but often these materials are less electrochemically active than Ni/YSZ. In this review the challenges of using liquid fuels directly in SOFC, in terms of gas-phase and catalytic reactions within the anode chamber, will be discussed and the alternative anode materials so far investigated will be compared.

Apollo-L2, an advanced fuel tokamak reactor utilizing direct conversion

International Nuclear Information System (INIS)

Emmert, G.A.; Kulcinski, G.L.; Blanchard, J.P.; El-Guebaly, L.A.; Khater, H.Y.; Santarius, J.F.; Sawan, M.E.; Sviatoslavsky, I.N.; Wittenberg, L.J.; Witt, R.J.

1989-01-01

A scoping study of a tokamak reactor fueled by a D- 3 He plasma is presented. The Apollo D- 3 He tokamak capitalizes on recent advances in high field magnets (20 T) and utilizes rectennas to convert the synchrotron radiation directly to electricity. The low neutron wall loading (0.1 MW/m 2 ) permits a first wall lasting the life of the plant and enables the reactor to be classified as inherently safe. The cost of electricity is less than that from a similar power level DT reactor. 10 refs., 1 fig., 4 tabs

Fuel quality issues in stationary fuel cell systems.

Energy Technology Data Exchange (ETDEWEB)

Papadias, D.; Ahmed, S.; Kumar, R. (Chemical Sciences and Engineering Division)

2012-02-07

Fuel cell systems are being deployed in stationary applications for the generation of electricity, heat, and hydrogen. These systems use a variety of fuel cell types, ranging from the low temperature polymer electrolyte fuel cell (PEFC) to the high temperature solid oxide fuel cell (SOFC). Depending on the application and location, these systems are being designed to operate on reformate or syngas produced from various fuels that include natural gas, biogas, coal gas, etc. All of these fuels contain species that can potentially damage the fuel cell anode or other unit operations and processes that precede the fuel cell stack. These detrimental effects include loss in performance or durability, and attenuating these effects requires additional components to reduce the impurity concentrations to tolerable levels, if not eliminate the impurity entirely. These impurity management components increase the complexity of the fuel cell system, and they add to the system's capital and operating costs (such as regeneration, replacement and disposal of spent material and maintenance). This project reviewed the public domain information available on the impurities encountered in stationary fuel cell systems, and the effects of the impurities on the fuel cells. A database has been set up that classifies the impurities, especially in renewable fuels, such as landfill gas and anaerobic digester gas. It documents the known deleterious effects on fuel cells, and the maximum allowable concentrations of select impurities suggested by manufacturers and researchers. The literature review helped to identify the impurity removal strategies that are available, and their effectiveness, capacity, and cost. A generic model of a stationary fuel-cell based power plant operating on digester and landfill gas has been developed; it includes a gas processing unit, followed by a fuel cell system. The model includes the key impurity removal steps to enable predictions of impurity breakthrough

Submersible microbial fuel cell for electricity production from sewage sludge

DEFF Research Database (Denmark)

Zhang, Yifeng; Olias, Lola Gonzalez; Kongjan, Prawit

2011-01-01

A submersible microbial fuel cell (SMFC) was utilized to treat sewage sludge and simultaneously generate electricity. Stable power generation (145± 5 mW/m2, 470 Ω) was produced continuously from raw sewage sludge for 5.5 days. The maximum power density reached 190±5 mW/m2. The corresponding total...... system to treat sewage sludge and simultaneously recover energy....

Maximum power per VA control of vector controlled interior ...

Indian Academy of Sciences (India)

Thakur Sumeet Singh

2018-04-11

Apr 11, 2018 ... Department of Electrical Engineering, Indian Institute of Technology Delhi, New ... The MPVA operation allows maximum-utilization of the drive-system. ... Permanent magnet motor; unity power factor; maximum VA utilization; ...

Alternative fuel cycle options: performance characteristics and impact on nuclear power growth potential

International Nuclear Information System (INIS)

Chang, Y.I.; Till, C.E.; Rudolph, R.R.; Deen, J.R.; King, M.J.

1977-09-01

The fuel utilization characteristics for LWR, SSCR, CANDU and LMFBR reactor concepts are quantified for various fuel cycle options, including once-through cycles, thorium cycles, and denatured cycles. The implications of various alternative reactor deployment strategies on the long-term nuclear power growth potential are then quantified in terms of the maximum nuclear capacity that can be achieved and the growth pattern over time, subject to the constraint of a fixed uranium-resource base. The overall objective of this study is to shed light on any large differences in the long-term potential that exist between various alternative reactor/fuel cycle deployment strategies

Carbon deposition thresholds on nickel-based solid oxide fuel cell anodes I. Fuel utilization

Science.gov (United States)

Kuhn, J.; Kesler, O.

2015-03-01

In the first of a two part publication, the effect of fuel utilization (Uf) on carbon deposition rates in solid oxide fuel cell nickel-based anodes was studied. Representative 5-component CH4 reformate compositions (CH4, H2, CO, H2O, & CO2) were selected graphically by plotting the solutions to a system of mass-balance constraint equations. The centroid of the solution space was chosen to represent a typical anode gas mixture for each nominal Uf value. Selected 5-component and 3-component gas mixtures were then delivered to anode-supported cells for 10 h, followed by determination of the resulting deposited carbon mass. The empirical carbon deposition thresholds were affected by atomic carbon (C), hydrogen (H), and oxygen (O) fractions of the delivered gas mixtures and temperature. It was also found that CH4-rich gas mixtures caused irreversible damage, whereas atomically equivalent CO-rich compositions did not. The coking threshold predicted by thermodynamic equilibrium calculations employing graphite for the solid carbon phase agreed well with empirical thresholds at 700 °C (Uf ≈ 32%); however, at 600 °C, poor agreement was observed with the empirical threshold of ∼36%. Finally, cell operating temperatures correlated well with the difference in enthalpy between the supplied anode gas mixtures and their resulting thermodynamic equilibrium gas mixtures.

High platinum utilization in ultra-low Pt loaded PEM fuel cell cathodes prepared by electrospraying

Energy Technology Data Exchange (ETDEWEB)

Martin, S.; Garcia-Ybarra, P.L.; Castillo, J.L. [Dept. Fisica Matematica y de Fluidos, Facultad de Ciencias, UNED, Senda del Rey 9, 28040 Madrid (Spain)

2010-10-15

Cathode electrodes for proton exchange membrane fuel cells (PEMFCs) with ultra-low platinum loadings as low as 0.012 mg{sub Pt}cm{sup -2} have been prepared by the electrospray method. The electrosprayed layers have nanostructured fractal morphologies with dendrites formed by clusters (about 100 nm diameter) of a few single catalyst particles rendering a large exposure surface of the catalyst. Optimization of the control parameters affecting this morphology has allowed us to overcome the state of the art for efficient electrodes prepared by electrospraying. Thus, using these cathodes in membrane electrode assemblies (MEAs), a high platinum utilization in the range 8-10 kW g{sup -1} was obtained for the fuel cell operating at 40 C and atmospheric pressure. Moreover, a platinum utilization of 20 kW g{sup -1} was attained under more suitable operating conditions (70 C and 3.4 bar over-pressure). These results substantially improve the performances achieved previously with other low platinum loading electrodes prepared by electrospraying. (author)

Effects of Transverse Power Distribution on Fuel Temperature

International Nuclear Information System (INIS)

Jo, Daeseong; Park, Jonghark; Seo, Chul Gyo; Chae, Heetaek

2014-01-01

In the present study, transverse power distributions with segments of 4 and 18 are evaluated. Based on the power distribution, the fuel temperatures are evaluated with a consideration of lateral heat conduction. In the present study, the effect of the transverse power distribution on the fuel temperature is investigated. The transverse power distributions with variation of fuel segment number are evaluated. The maximum power peaking with 12 segments is higher than that with 4 segments. Based on the calculation, 6-order polynomial is generated to express the transverse power distributions. The maximum power peaking factor increases with segments. The averaged power peaking is 2.10, and the maximum power peaking with 18 segments is 2.80. With the uniform power distribution, the maximum fuel temperature is found in the middle of the fuel. As the power near the side ends of the fuel increases, the maximum fuel temperature is found near the side ends. However, the maximum fuel temperature is not found where the maximum transverse power is. This is because the high power locally released from the edge of the fuel is laterally conducted to the cladding. As a result of the present study, it can be concluded that the effect of the high power peaking at the edge of the fuel on the fuel outer wall temperature is not significant

Thorium utilization in a small long-life HTR. Part II: Seed-and-blanket fuel blocks

Energy Technology Data Exchange (ETDEWEB)

Ding, Ming, E-mail: dingming@hrbeu.edu.cn [Delft University of Technology, Reactor Institute Delft, Mekelweg 15, 2629 JB Delft (Netherlands); Harbin Engineering University, Nantong Street 145, 150001 Harbin (China); Kloosterman, Jan Leen [Delft University of Technology, Reactor Institute Delft, Mekelweg 15, 2629 JB Delft (Netherlands)

2014-02-15

Highlights: • Seed-and-blanket (S and B) fuel blocks are proposed for a small block-type HTR. • S and B fuel blocks consist of a seed region (UO{sub 2}) and a blanket region (ThO{sub 2}). • The neutronic performance of S and B fuel blocks are analyzed using SCALE 6. • Three S and B fuel blocks with a reactivity swing of 0.1 Δk are recommended. • S and B fuel blocks are compared with thorium MOX fuel blocks. - Abstract: In order to utilize thorium in high temperature gas-cooled reactors (HTRs), the concept of seed-and-blanket (S and B) fuel block is introduced into the U-Battery, which is a long-life block-type HTR with a thermal power of 20 MWth. A S and B fuel block consists of a seed region with uranium in the center, and a blanket region with thorium. The neutronic performance, such as the multiplication factor, conversion ratio and reactivity swing, of a typical S and B fuel block was investigated by SCALE 6.0 by parametric analysis of the composition parameters and geometric parameters of the fuel block for the U-Battery application. Since the purpose of U-235 in the S and B fuel block is to ignite the fission reactions in the fuel block, 20% enriched uranium is recommended for the S and B fuel block. When the ratio of the number of carbon to heavy metal atoms changes with the geometric parameters of the fuel block in the range of 200–250, the reactivity swing reaches very small values. Furthermore, for a reactivity swing of 0.1 Δk during 10 effective full power years, three configurations with 36, 54 and 78 UO{sub 2} fuel rods are recommended for the application of the U-Battery. The comparison analysis of the S and B fuel block with the Th/U MOX fuel block shows that the former has a longer lifetime and a lower reactivity swing.

High performance monolithic power management system with dynamic maximum power point tracking for microbial fuel cells.

Science.gov (United States)

Erbay, Celal; Carreon-Bautista, Salvador; Sanchez-Sinencio, Edgar; Han, Arum

2014-12-02

Microbial fuel cell (MFC) that can directly generate electricity from organic waste or biomass is a promising renewable and clean technology. However, low power and low voltage output of MFCs typically do not allow directly operating most electrical applications, whether it is supplementing electricity to wastewater treatment plants or for powering autonomous wireless sensor networks. Power management systems (PMSs) can overcome this limitation by boosting the MFC output voltage and managing the power for maximum efficiency. We present a monolithic low-power-consuming PMS integrated circuit (IC) chip capable of dynamic maximum power point tracking (MPPT) to maximize the extracted power from MFCs, regardless of the power and voltage fluctuations from MFCs over time. The proposed PMS continuously detects the maximum power point (MPP) of the MFC and matches the load impedance of the PMS for maximum efficiency. The system also operates autonomously by directly drawing power from the MFC itself without any external power. The overall system efficiency, defined as the ratio between input energy from the MFC and output energy stored into the supercapacitor of the PMS, was 30%. As a demonstration, the PMS connected to a 240 mL two-chamber MFC (generating 0.4 V and 512 μW at MPP) successfully powered a wireless temperature sensor that requires a voltage of 2.5 V and consumes power of 85 mW each time it transmit the sensor data, and successfully transmitted a sensor reading every 7.5 min. The PMS also efficiently managed the power output of a lower-power producing MFC, demonstrating that the PMS works efficiently at various MFC power output level.

Development of the spent fuel disassembling process by utilizing the 3D graphic design technology

International Nuclear Information System (INIS)

Song, T. K.; Lee, J. Y.; Kim, S. H.; Yun, J. S.

2001-01-01

For developing the spent fuel disassembling process, the 3D graphic simulation has been established by utilizing the 3D graphic design technology which is widely used in the industry. The spent fuel disassembling process consists of a downender, a rod extraction device, a rod cutting device, a pellet extracting device and a skeleton compaction device. In this study, the 3D graphical design model of these devices is implemented by conceptual design and established the virtual workcell within kinematics to motion of each device. By implementing this graphic simulation, all the unit process involved in the spent fuel disassembling processes are analyzed and optimized. The 3D graphical model and the 3D graphic simulation can be effectively used for designing the process equipment, as well as the optimized process and maintenance process

On application of a new hybrid maximum power point tracking (MPPT) based photovoltaic system to the closed plant factory

International Nuclear Information System (INIS)

Jiang, Joe-Air; Su, Yu-Li; Shieh, Jyh-Cherng; Kuo, Kun-Chang; Lin, Tzu-Shiang; Lin, Ta-Te; Fang, Wei; Chou, Jui-Jen; Wang, Jen-Cheng

2014-01-01

Highlights: • Hybrid MPPT method was developed and utilized in a PV system of closed plant factory. • The tracking of the maximum power output of PV system can be achieved in real time. • Hybrid MPPT method not only decreases energy loss but increases power utilization. • The feasibility of applying PV system to the closed plant factory has been examined. • The PV system significantly reduced CO 2 emissions and curtailed the fossil fuels. - Abstract: Photovoltaic (PV) generation systems have been shown to have a promising role for use in high electric-load buildings, such as the closed plant factory which is dependent upon artificial lighting. The power generated by the PV systems can be either directly supplied to the buildings or fed back into the electrical grid to reduce the high economic costs and environmental impact associated with the traditional energy sources such as nuclear power and fossil fuels. However, PV systems usually suffer from low energy-conversion efficiency, and it is therefore necessary to improve their performance by tackling the energy loss issues. The maximum power point tracking (MPPT) control technique is essential to the PV-assisted generation systems in order to achieve the maximum power output in real time. In this study, we integrate the previously proposed direct-prediction MPP method with a perturbation and observation (P and O) method to develop a new hybrid MPPT method. The proposed MPPT method is further utilized in the PV inverters in a PV system installed on the roof of a closed plant factory at National Taiwan University. The tested PV system is constructed as a two-stage grid-connected photovoltaic power conditioning (PVPC) system with a boost-buck full bridge design configuration. A control scheme based on the hybrid MPPT method is also developed and implemented in the PV inverters of the PVPC system to achieve tracking of the maximum power output of the PV system in real time. Based on experimental results

Environmental impact of fossil fuel utilization in the thermal power plant

International Nuclear Information System (INIS)

Ghasem D Najafpour; Seyed Jafar Mehdizadeh; Abdul Rahman Mohamed

2000-01-01

Carbon dioxide causes green house effect, has been considered as a pollutant source of our safe environment. Since combustion of fossil fuel may create tremendous amount of carbon dioxide, detecting any pollutant sources would be important to eliminate the pollution sources. Evaluation of smoke dispersion that has been generated by a power plant utilizing fossil fuel is the objective of this paper. The concentration of NO, and SO, in the soil, have been analyzed from a distance of 3 to 4 km far from power plant. The experimental results shown. that the concentration of toxic gases was a little above the international standards. Replacement of fossil fuel by natural gas caused NO, concentration to be developed in the atmosphere, therefore usage of natural gas is limited by environmental protection agencies. Beside the nuclear power plant, the power generated by other sources. are limited. Electric power generated by water dam is not a major contribution of electric power demand. Therefore generation of electricity by any other energy sources, which are friendly to the environment, is recommended. Other sources of energy, such as wind power, solar energy, geothermal, ocean thennal and renewable source of energy can be considered safe for the environment. The goal of environmental management system would be to meet the minimum requirements were established and demanded by the local environmental protection agency or international standard organization (ISO-14000). (Author)

Developing RCM Strategy for Hydrogen Fuel Cells Utilizing On Line E-Condition Monitoring

International Nuclear Information System (INIS)

Baglee, D; Knowles, M J

2012-01-01

Fuel cell vehicles are considered to be a viable solution to problems such as carbon emissions and fuel shortages for road transport. Proton Exchange Membrane (PEM) Fuel Cells are mainly used in this purpose because they can run at low temperatures and have a simple structure. Yet high maintenance costs and the inherent dangers of maintaining equipment using hydrogen are two main issues which need to be addressed. The development of appropriate and efficient strategies is currently lacking with regard to fuel cell maintenance. A Reliability Centered Maintenance (RCM) approach offers considerable benefit to the management of fuel cell maintenance since it includes an identification and consideration of the impact of critical components. Technological developments in e-maintenance systems, radio-frequency identification (RFID) and personal digital assistants (PDAs) have proven to satisfy the increasing demand for improved reliability, efficiency and safety. RFID technology is used to store and remotely retrieve electronic maintenance data in order to provide instant access to up-to-date, accurate and detailed information. The aim is to support fuel cell maintenance decisions by developing and applying a blend of leading-edge communications and sensor technology including RFID. The purpose of this paper is to review and present the state of the art in fuel cell condition monitoring and maintenance utilizing RCM and RFID technologies. Using an RCM analysis critical components and fault modes are identified. RFID tags are used to store the critical information, possible faults and their cause and effect. The relationship between causes, faults, symptoms and long term implications of fault conditions are summarized. Finally conclusions are drawn regarding suggested maintenance strategies and the optimal structure for an integrated, cost effective condition monitoring and maintenance management system.

Developing RCM Strategy for Hydrogen Fuel Cells Utilizing On Line E-Condition Monitoring

Science.gov (United States)

Baglee, D.; Knowles, M. J.

2012-05-01

Fuel cell vehicles are considered to be a viable solution to problems such as carbon emissions and fuel shortages for road transport. Proton Exchange Membrane (PEM) Fuel Cells are mainly used in this purpose because they can run at low temperatures and have a simple structure. Yet high maintenance costs and the inherent dangers of maintaining equipment using hydrogen are two main issues which need to be addressed. The development of appropriate and efficient strategies is currently lacking with regard to fuel cell maintenance. A Reliability Centered Maintenance (RCM) approach offers considerable benefit to the management of fuel cell maintenance since it includes an identification and consideration of the impact of critical components. Technological developments in e-maintenance systems, radio-frequency identification (RFID) and personal digital assistants (PDAs) have proven to satisfy the increasing demand for improved reliability, efficiency and safety. RFID technology is used to store and remotely retrieve electronic maintenance data in order to provide instant access to up-to-date, accurate and detailed information. The aim is to support fuel cell maintenance decisions by developing and applying a blend of leading-edge communications and sensor technology including RFID. The purpose of this paper is to review and present the state of the art in fuel cell condition monitoring and maintenance utilizing RCM and RFID technologies. Using an RCM analysis critical components and fault modes are identified. RFID tags are used to store the critical information, possible faults and their cause and effect. The relationship between causes, faults, symptoms and long term implications of fault conditions are summarized. Finally conclusions are drawn regarding suggested maintenance strategies and the optimal structure for an integrated, cost effective condition monitoring and maintenance management system.

Experimental program to determine maximum temperatures for dry storage of spent fuel

International Nuclear Information System (INIS)

Knox, C.A.; Gilbert, E.R.; White, G.D.

1985-02-01

Although air is used as a cover gas in some dry storage facilities, other facilities use inert cover gases which must be monitored to assure inertness of the atmosphere. Thus qualifying air as a cover gas is attractive for the dry storage of spent fuels. At sufficiently high temperatures, air can react with spent fuel (UO 2 ) at the site of cladding breaches that formed during reactor irradiation or during dry storage. The reaction rate is temperature dependent; hence the rates can be maintained at acceptable levels if temperatures are low. Tests with spent fuel are being conducted at Pacific Northwest Laboratory (PNL) to determine the allowable temperatures for storage of spent fuel in air. Tests performed with nonirradiated UO 2 pellets indicated that moisture, surface condition, gamma radiation, gadolinia content of the fuel pellet, and temperature are important variables. Tests were then initiated on spent fuel to develop design data under simulated dry storage conditions. Tests have been conducted at 200 and 230 0 C on spent fuel in air and 275 0 C in moist nitrogen. The results for nonirradiated UO 2 and published data for irradiated fuel indicate that above 230 0 C, oxidation rates are unacceptably high for extended storage in air. The tests with spent fuel will be continued for approximately three years to enable reliable extrapolations to be made for extended storage in air and inert gases with oxidizing constituents. 6 refs., 6 figs., 3 tabs

On the nuclear fuel and fossil fuel reserves

International Nuclear Information System (INIS)

Fettweis, G.

1978-01-01

A short discussion of the nuclear fuel and fossil fuel reserves and the connected problem of prices evolution is presented. The need to regard fuel production under an economic aspect is emphasized. Data about known and assessed fuel reserves, world-wide and with special consideration of Austria, are reviewed. It is concluded that in view of the fuel reserves situation an energy policy which allows for a maximum of options seems adequate. (G.G.)

Power generation from furfural using the microbial fuel cell

Energy Technology Data Exchange (ETDEWEB)

Luo, Yong; Liu, Guangli; Zhang, Renduo; Zhang, Cuiping [School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, Guangdong 510275 (China)

2010-01-01

Furfural is a typical inhibitor in the ethanol fermentation process using lignocellulosic hydrolysates as raw materials. In the literature, no report has shown that furfural can be utilized as the fuel to produce electricity in the microbial fuel cell (MFC), a device that uses microbes to convert organic compounds to generate electricity. In this study, we demonstrated that electricity was successfully generated using furfural as the sole fuel in both the ferricyanide-cathode MFC and the air-cathode MFC. In the ferricyanide-cathode MFC, the maximum power densities reached 45.4, 81.4, and 103 W m{sup -3}, respectively, when 1000 mg L{sup -1} glucose, a mixture of 200 mg L{sup -1} glucose and 5 mM furfural, and 6.68 mM furfural were used as the fuels in the anode solution. The corresponding Coulombic efficiencies (CE) were 4.0, 7.1, and 10.2% for the three treatments, respectively. For pure furfural as the fuel, the removal efficiency of furfural reached up to 95% within 12 h. In the air-cathode MFC using 6.68 mM furfural as the fuel, the maximum values of power density and CE were 361 mW m{sup -2} (18 W m{sup -3}) and 30.3%, respectively, and the COD removal was about 68% at the end of the experiment (about 30 h). Increase in furfural concentrations from 6.68 to 20 mM resulted in increase in the maximum power densities from 361 to 368 mW m{sup -2}, and decrease in CEs from 30.3 to 20.6%. These results indicated that some toxic and biorefractory organics such as furfural might still be suitable resources for electricity generation using the MFC technology. (author)

Fuel cycle cost comparisons with oxide and silicide fuels

Energy Technology Data Exchange (ETDEWEB)

Matos, J E; Freese, K E [RERTR Program, Argonne National Laboratory (United States)

1983-09-01

This paper addresses fuel cycle cost comparisons for a generic 10 MW reactor with HEU aluminide fuel and with LEU oxide and silicide fuels in several fuel element geometries. The intention of this study is to provide a consistent assessment of various design options from a cost point of view. The status of the development and demonstration of the oxide and silicide fuels are presented in several papers in these proceedings. Routine utilization of these fuels with the uranium densities considered here requires that they are successfully demonstrated and licensed. Thermal-hydraulic safety margins, shutdown margins, mixed cores, and transient analyses are not addressed here, but analyses of these safety issues are in progress for a limited number of the most promising design options. Fuel cycle cost benefits could result if a number of reactors were to utilize fuel elements with the same number or different numbers of the same standard fuel plate. Data is presented to quantify these potential cost benefits. This analysis shows that there are a number of fuel element designs using LEU oxide or silicide fuels that have either the same or lower total fuel cycle costs than the HEU design. Use of these fuels with the uranium densities considered requires that they are successfully demonstrated and licensed. All safety criteria for the reactor with these fuel element designs need to be satisfied as well. With LEU oxide fuel, 31 g U/cm{sup 3} 1 and 0.76 mm--thick fuel meat, elements with 18-22 plates 320-391 g {sup 235}U) result in the same or lower total costs than with the HEU element 23 plates, 280 g {sup 235}U). Higher LEU loadings (more plates per element) are needed for larger excess reactivity requirements. However, there is little cost advantage to using more than 20 of these plates per element. Increasing the fuel meat thickness from 0.76 mm to 1.0 mm with 3.1 g U/cm{sup 3} in the design with 20 plates per element could result in significant cost reductions if the

Aspects on optimization of natural uranium fuel utilization in heavy water reactors

International Nuclear Information System (INIS)

1978-08-01

This paper is dealing with a possibility to decrease the natural uranium consumption of CANDU PHWR using the once-through cycle. This possibility is based on the utilization of slightly enriched uranium. The optimal two-zone structure of a reactor using natural uranium is found out. The optimal criterium is the maximization of the burnup (equivalent to minimization of uranium requirements) with a constraint on power density radial uniformity factor. As regards the enriched uranium, the optimal enrichment and the two-zone structure of a reactor which minimizes the natural uranium requirement with constraints on uniformity factor and maximum burnup are established. Corresponding to a maximum burnup of 16,000 MWd/t and 1% enrichment, the natural uranium requirement is found to be 10% less than that of the natural uranium reactor

Analysis of oxy-fuel combustion power cycle utilizing a pressurized coal combustor

International Nuclear Information System (INIS)

Hong, Jongsup; Chaudhry, Gunaranjan; Brisson, J.G.; Field, Randall; Gazzino, Marco; Ghoniem, Ahmed F.

2009-01-01

Growing concerns over greenhouse gas emissions have driven extensive research into new power generation cycles that enable carbon dioxide capture and sequestration. In this regard, oxy-fuel combustion is a promising new technology in which fuels are burned in an environment of oxygen and recycled combustion gases. In this paper, an oxy-fuel combustion power cycle that utilizes a pressurized coal combustor is analyzed. We show that this approach recovers more thermal energy from the flue gases because the elevated flue gas pressure raises the dew point and the available latent enthalpy in the flue gases. The high-pressure water-condensing flue gas thermal energy recovery system reduces steam bleeding which is typically used in conventional steam cycles and enables the cycle to achieve higher efficiency. The pressurized combustion process provides the purification and compression unit with a concentrated carbon dioxide stream. For the purpose of our analysis, a flue gas purification and compression process including de-SO x , de-NO x , and low temperature flash unit is examined. We compare a case in which the combustor operates at 1.1 bars with a base case in which the combustor operates at 10 bars. Results show nearly 3% point increase in the net efficiency for the latter case.

Gas engine driven freon-free heat supply system complying with multiple fuels (eco-energy city project)

Energy Technology Data Exchange (ETDEWEB)

Yagyu, Sumio; Maekawa, Koich; Sugawara, Koich; Hayashida, Masaru; Fujishima, Ichiro; Fukuyama, Yuji; Morikawa, Tomoyuki; Yamato, Tadao; Obata, Norio [Advanced Technology Lab., Kubota Corp., Amagasaki, Hyogo (Japan)

1999-07-01

This paper describes recent results at Kubota to develop a gas engine driven freon-free heat supply system. Utilizing a gas mixture which consists of CO and H{sub 2} supplied from a broad area energy utilization network, the system produces four heat sources (263 K, 280 K, 318 K, and 353 K) for air-conditioning, hot water supply, and refrigeration in a single system. It also conforms to fuel systems that utilize methane and hydrogen. This multi-functional heat supply system is composed of an efficient gas engine (methanol gas engine) and a freon-free heat pump (heat-assisted Stirling heat pump). The heat-assisted Stirling heat pump is mainly driven by engine shaft power and is partially assisted by thermal power provided by engine exhaust heat. By proportioning the two energy sources to match the characteristics of the driving engine, the heat pump is supplied with the maximum share of the original energy fueling the engine. Developing the system will establish freon-free thermal utilization system technology that satisfies both wide heat demands and various fuel systems. (orig.)

Reactivity effect of non-uniformly distributed fuel in fuel solution systems

International Nuclear Information System (INIS)

Hirano, Yasushi; Yamane, Yoshihiro; Nishina, Kojiro; Mitsuhashi, Ishi.

1991-01-01

A numerical method to determine the optimal fuel distribution for minimum critical mass, or maximum k-effective, is developed using the Maximum Principle in order to evaluate the maximum effect of non-uniformly distributed fuel on reactivity. This algorithm maximizes the Hamiltonian directly by an iterative method under a certain constraint-the maintenance of criticality or total fuel mass. It ultimately reaches the same optimal state of a flattened fuel importance distribution as another algorithm by Dam based on perturbation theory. This method was applied to two kinds of spherical cores with water reflector in the simulating reprocessing facility. In the slightly-enriched uranyl nitrate solution core, the minimum critical mass decreased by less than 1% at the optimal moderation state. In the plutonium nitrate solution core, the k-effective increment amounted up to 4.3% Δk within the range of present study. (author)

Nonlinear analyses of spent-fuel racks for consolidated fuel loading

International Nuclear Information System (INIS)

Kabir, A.F.; Godha, P.C.; Malik, L.E.; Bolourchi, S.

1987-01-01

Storage racks for spent-fuel assemblies in nuclear power plants are designed to withstand various combinations of loads generated by gravity, seismic, thermal, and accidental fuel drops. Due to the need for storing increased amounts of spent fuel in the existing fuel pools, many nuclear power utilities are evaluating existing fuel racks to safely carry the additional loads. The current study presents the seismic analyses of existing fuel racks of Northeast Utility Company's Millstone Unit Number 1 (BWR Mark I) nuclear plant to accommodate a 2:1 fuel consolidation. This objective requires rigorous nonlinear analyses to establish the full available capacities of the racks and thereby avoid expensive modifications or minimize any needed upgrades

Performance and emissions of a supercharged dual-fuel engine fueled by hydrogen-rich coke oven gas

Energy Technology Data Exchange (ETDEWEB)

Roy, M.M.; Tomita, E.; Kawahara, N.; Harada, Y.; Sakane, A. [Okayama University, Okayama (Japan). Dept. of Mechanical Engineering

2009-12-15

This study investigated the engine performance and emissions of a supercharged dual-fuel engine fueled by hydrogen-rich coke oven gas and ignited by a pilot amount of diesel fuel. The engine was tested for use as a cogeneration engine, so power output while maintaining a reasonable thermal efficiency was important. Experiments were carried out at a constant pilot injection pressure and pilot quantity for different fuel-air equivalence ratios and at various injection timings without and with exhaust gas recirculation (EGR). The experimental strategy was to optimize the injection timing to maximize engine power at different fuel-air equivalence ratios without knocking and within the limit of the maximum cylinder pressure. The engine was tested first without EGR condition up to the maximum possible fuel-air equivalence ratio of 0.65. A maximum indicated mean effective pressure (IMEP) of 1425 kPa and a thermal efficiency of 39% were obtained. However, the nitrogen oxides (NOx) emissions were high. A simulated EGR up to 50% was then performed to obtain lower NOx emissions. The maximum reduction of NOx was 60% or more maintaining the similar levels of IMEP and thermal efficiency. Two-stage combustion was obtained; this is an indicator of maximum power output conditions and a precursor of knocking combustion.

Mechanical behaviors of the dispersion nuclear fuel plates induced by fuel particle swelling and thermal effect II: Effects of variations of the fuel particle diameters

International Nuclear Information System (INIS)

Ding Shurong; Wang Qiming; Huo Yongzhong

2010-01-01

In order to predict the irradiation mechanical behaviors of plate-type dispersion nuclear fuel elements, the total burnup is divided into two stages: the initial stage and the increasing stage. At the initial stage, the thermal effects induced by the high temperature differences between the operation temperatures and the room temperature are mainly considered; and at the increasing stage, the intense mechanical interactions between the fuel particles and the matrix due to the irradiation swelling of fuel particles are focused on. The large-deformation thermo-elasto-plasticity finite element analysis is performed to evaluate the effects of particle diameters on the in-pile mechanical behaviors of fuel elements. The research results indicate that: (1) the maximum Mises stresses and equivalent plastic strains at the matrix increase with the fuel particle diameters; the effects of particle diameters on the maximum first principal stresses vary with burnup, and the considered case with the largest particle diameter holds the maximum values all along; (2) at the cladding near the interface between the fuel meat and the cladding, the Mises stresses and the first principal stresses undergo major changes with increasing burnup, and different variations exist for different particle diameter cases; (3) the maximum Mises stresses at the fuel particles rise with the particle diameters.

The fuel cycle scoping system

International Nuclear Information System (INIS)

Dooley, G.D.; Malone, J.P.

1986-01-01

The Fuel Cycle Scoping System (FCSS) was created to fill the need for a scoping tool which provides the utilities with the ability to quickly evaluate alternative fuel management strategies, tails assay choices, fuel fabrication quotes, fuel financing alternatives, fuel cycle schedules, and other fuel cycle perturbations. The FCSS was specifically designed for PC's that support dBASE-III(TM), a relational data base software system by Ashton-Tate. However, knowledge of dBASE-III is not necessary in order to utilize the FCSS. The FCSS is menu driven and can be utilized as a teaching tool as well as a scoping tool

Conditioning of nuclear reactor fuel

International Nuclear Information System (INIS)

1975-01-01

A method of conditioning the fuel of a nuclear reactor core to minimize failure of the fuel cladding comprising increasing the fuel rod power to a desired maximum power level at a rate below a critical rate which would cause cladding damage is given. Such conditioning allows subsequent freedom of power changes below and up to said maximum power level with minimized danger of cladding damage. (Auth.)

Improving the performance of dual fuel engines running on natural gas/LPG by using pilot fuel derived from jojoba seeds

Energy Technology Data Exchange (ETDEWEB)

Selim, Mohamed Y.E. [Mechanical Engineering Department, College of Engineering, UAE University, Jimmi, Al-Ain, P.O. Box 17555, Abu Dhabi (United Arab Emirates); Radwan, M.S.; Saleh, H.E. [Mechanical Power Engineering Department, Faculty of Engineering at Mattaria, Helwan University, Cairo (Egypt)

2008-06-15

The use of jojoba methyl ester as a pilot fuel was investigated for almost the first time as a way to improve the performance of dual fuel engine running on natural gas or liquefied petroleum gas (LPG) at part load. The dual fuel engine used was Ricardo E6 variable compression diesel engine and it used either compressed natural gas (CNG) or LPG as the main fuel and jojoba methyl ester as a pilot fuel. Diesel fuel was used as a reference fuel for the dual fuel engine results. During the experimental tests, the following have been measured: engine efficiency in terms of specific fuel consumption, brake power output, combustion noise in terms of maximum pressure rise rate and maximum pressure, exhaust emissions in terms of carbon monoxide and hydrocarbons, knocking limits in terms of maximum torque at onset of knocking, and cyclic variability data of 100 engine cycles in terms of maximum pressure and its pressure rise rate average and standard deviation. The tests examined the following engine parameters: gaseous fuel type, engine speed and load, pilot fuel injection timing, pilot fuel mass and compression ratio. Results showed that using the jojoba fuel with its improved properties has improved the dual fuel engine performance, reduced the combustion noise, extended knocking limits and reduced the cyclic variability of the combustion. (author)

Handbook of fuel cell performance

Energy Technology Data Exchange (ETDEWEB)

Benjamin, T.G.; Camara, E.H.; Marianowski, L.G.

1980-05-01

The intent of this document is to provide a description of fuel cells, their performances and operating conditions, and the relationship between fuel processors and fuel cells. This information will enable fuel cell engineers to know which fuel processing schemes are most compatible with which fuel cells and to predict the performance of a fuel cell integrated with any fuel processor. The data and estimates presented are for the phosphoric acid and molten carbonate fuel cells because they are closer to commercialization than other types of fuel cells. Performance of the cells is shown as a function of operating temperature, pressure, fuel conversion (utilization), and oxidant utilization. The effect of oxidant composition (for example, air versus O/sub 2/) as well as fuel composition is examined because fuels provided by some of the more advanced fuel processing schemes such as coal conversion will contain varying amounts of H/sub 2/, CO, CO/sub 2/, CH/sub 4/, H/sub 2/O, and sulfur and nitrogen compounds. A brief description of fuel cells and their application to industrial, commercial, and residential power generation is given. The electrochemical aspects of fuel cells are reviewed. The phosphoric acid fuel cell is discussed, including how it is affected by operating conditions; and the molten carbonate fuel cell is discussed. The equations developed will help systems engineers to evaluate the application of the phosphoric acid and molten carbonate fuel cells to commercial, utility, and industrial power generation and waste heat utilization. A detailed discussion of fuel cell efficiency, and examples of fuel cell systems are given.

Automatic maximum entropy spectral reconstruction in NMR

International Nuclear Information System (INIS)

Mobli, Mehdi; Maciejewski, Mark W.; Gryk, Michael R.; Hoch, Jeffrey C.

2007-01-01

Developments in superconducting magnets, cryogenic probes, isotope labeling strategies, and sophisticated pulse sequences together have enabled the application, in principle, of high-resolution NMR spectroscopy to biomolecular systems approaching 1 megadalton. In practice, however, conventional approaches to NMR that utilize the fast Fourier transform, which require data collected at uniform time intervals, result in prohibitively lengthy data collection times in order to achieve the full resolution afforded by high field magnets. A variety of approaches that involve nonuniform sampling have been proposed, each utilizing a non-Fourier method of spectrum analysis. A very general non-Fourier method that is capable of utilizing data collected using any of the proposed nonuniform sampling strategies is maximum entropy reconstruction. A limiting factor in the adoption of maximum entropy reconstruction in NMR has been the need to specify non-intuitive parameters. Here we describe a fully automated system for maximum entropy reconstruction that requires no user-specified parameters. A web-accessible script generator provides the user interface to the system

A complete fuel development facility utilizing a dual core TRIGA reactor system

Energy Technology Data Exchange (ETDEWEB)

Middleton, A; Law, G C [General Atomic Co., San Diego, CA (United States)

1974-07-01

half maximum during a 15,000 MW peak pulse is about 4 msec with an integrated flux of 1.5 x 10{sup 15} nvt. The experimental facilities include a tangential and a radial beam tube from each reactor leading to an adjacent underground beam room, an underwater neutron radiography system for radiography of irradiated fuel samples and an underwater graphite thermal column. A hot cell complex for post-irradiation examination of fuel specimens is connected directly to the reactor pool by a transfer canal, permitting transfer of radioactive specimens without the need for shielded casks. The facility also has many small laboratories for preparing, analyzing, and setting up experiments. Thus, although the prime purpose of the Dual-Core TRIGA Reactor Facility is to develop power reactor fuel elements, the facility is also well-equipped for research in other areas. An extensive neutron physics program (neutron beam physics, neutron radiography and neutron physics using the thermal column) will be possible at the same time as the reactors are being used to irradiate and test fuel samples. (author)

REFCO83, Nuclear Fuel Cycle Cost Economics Using Discounted Cash Flow Analysis

International Nuclear Information System (INIS)

Delene, J.G.; Hermann, O.W.

2001-01-01

1 - Description of program or function: REFCO83 utilizes a discounted cash flow (DCF) analysis procedure to calculate batch, cycle, and lifetime levelized average nuclear fuel cycle costs. The DCF analysis establishes an energy 'cost' associated with the fuel by requiring that the revenues from the sale of energy be adequate to pay the required return on outstanding capital, to pay all expenses including taxes, and to retire the outstanding investment to zero by the end of the economic life of the set of fuel investments. The program uses reactor mass flow information together with individual fuel cost parameters and utility capital structure and money costs to calculate levelized costs cumulatively through any batch or cycle. 2 - Method of solution: A fuel cycle cost component is considered to be any fuel material purchase, processing cost, or discharge material credit in the complete fuel cycle. The costs for each individual component, i.e. uranium, enrichment, etc., may either be expensed or capitalized for tax purposes or, in the case of waste disposal, the cost may also be made proportional to power production. To properly account for the effect of income taxes, all calculations in REFCO83 are done using 'then' current dollars, including price escalations caused by inflation. The database used for the default values for REFCO83 was taken from the Nuclear Energy Cost Data Base. 3 - Restrictions on the complexity of the problem: The maximum number of fuel batches is 120

Fuel assemblies

International Nuclear Information System (INIS)

Nagano, Mamoru; Yoshioka, Ritsuo

1983-01-01

Purpose: To effectively utilize nuclear fuels by increasing the reactivity of a fuel assembly and reduce the concentration at the central region thereof upon completion of the burning. Constitution: A fuel assembly is bisected into a central region and a peripheral region by disposing an inner channel box within a channel box. The flow rate of coolants passing through the central region is made greater than that in the peripheral region. The concentration of uranium 235 of the fuel rods in the central region is made higher. In such a structure, since the moderating effect in the central region is improved, the reactivity of the fuel assembly is increased and the uranium concentration in the central region upon completion of the burning can be reduced, fuel economy and effective utilization of uranium can be attained. (Kamimura, M.)

Behavior of strontium- and magnesium-doped gallate electrolyte in direct carbon solid oxide fuel cells

International Nuclear Information System (INIS)

Zhang, Li; Xiao, Jie; Xie, Yongmin; Tang, Yubao; Liu, Jiang; Liu, Meilin

2014-01-01

Highlights: • La 0.9 Sr 0.1 Ga 0.8 Mg 0.2 O 3−δ (LSGM) can be used as electrolyte of direct carbon SOFCs. • DC-SOFC with LSGM electrolyte gives higher performance than that with YSZ. • LSGM-electrolyte DC-SOFC gives maximum power density of 383 mW cm −2 at 850 °C. • Operation of LSGM-DC-SOFC at 210 mA cm −2 lasts 72 min, with fuel utilization of 60%. - Abstract: Perovskite-type La 0.9 Sr 0.1 Ga 0.8 Mg 0.2 O 3−δ (LSGM) is synthesized by conventional solid state reaction. Its phase composition, microstructure, relative density, and oxygen-ionic conductivity are investigated. Tubular electrolyte-supported solid oxide fuel cells (SOFCs) are prepared with the LSGM as electrolyte and gadolinia doped ceria (GDC) mixed with silver as anode. The SOFCs are operated with Fe-loaded activated carbon as fuel and ambient air as oxidant. A typical single cell gives a maximum power density of 383 mW cm −2 at 850 °C, which is nearly 1.3 times higher than that of the similar cell with YSZ as electrolyte. A stability test of 72 min is carried out at a constant current density of 210 mA cm −2 , with a fuel utilization of 60%, indicating that LaGaO 3 -based electrolyte is promising to be applied in direct carbon SOFCs (DC-SOFCs)

Room at the Mountain: Estimated Maximum Amounts of Commercial Spent Nuclear Fuel Capable of Disposal in a Yucca Mountain Repository

International Nuclear Information System (INIS)

Kessler, John H.; Kemeny, John; King, Fraser; Ross, Alan M.; Ross, Benjamen

2006-01-01

The purpose of this paper is to present an initial analysis of the maximum amount of commercial spent nuclear fuel (CSNF) that could be emplaced into a geological repository at Yucca Mountain. This analysis identifies and uses programmatic, material, and geological constraints and factors that affect this estimation of maximum amount of CSNF for disposal. The conclusion of this initial analysis is that the current legislative limit on Yucca Mountain disposal capacity, 63,000 MTHM of CSNF, is a small fraction of the available physical capacity of the Yucca Mountain system assuming the current high-temperature operating mode (HTOM) design. EPRI is confident that at least four times the legislative limit for CSNF (∼260,000 MTHM) can be emplaced in the Yucca Mountain system. It is possible that with additional site characterization, upwards of nine times the legislative limit (∼570,000 MTHM) could be emplaced. (authors)

Starch-fueled microbial fuel cells by two-step and parallel fermentation using Shewanella oneidensis MR-1 and Streptococcus bovis 148.

Science.gov (United States)

Uno, Megumi; Phansroy, Nichanan; Aso, Yuji; Ohara, Hitomi

2017-08-01

Shewanella oneidensis MR-1 generates electricity from lactic acid, but cannot utilize starch. On the other hand, Streptococcus bovis 148 metabolizes starch and produces lactic acid. Therefore, two methods were trialed for starch-fueled microbial fuel cell (MFC) in this study. In electric generation by two-step fermentation (EGT) method, starch was first converted to lactic acid by S. bovis 148. The S. bovis 148 were then removed by centrifugation, and the fermented broth was preserved for electricity generation by S. oneidensis MR-1. Another method was electric generation by parallel fermentation (EGP) method. In this method, the cultivation and subsequent fermentation processes of S. bovis 148 and S. oneidensis MR-1 were performed simultaneously. After 1, 2, and 3 terms (5-day intervals) of S. oneidensis MR-1 in the EGT fermented broth of S. bovis 148, the maximum currents at each term were 1.8, 2.4, and 2.8 mA, and the maximum current densities at each term were 41.0, 43.6, and 49.9 mW/m 2 , respectively. In the EGP method, starch was also converted into lactic acid with electricity generation. The maximum current density was 140-200 mA/m 2 , and the maximum power density of this method was 12.1 mW/m 2 . Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

GEM, Fuel Cycle Cost and Economics for Thermal Reactor, Present Worth Analysis

International Nuclear Information System (INIS)

Hughes, J.A.; Hang, D.F.

1974-01-01

1- Description of problem or function: GEM is used to predict fuel cycle costs for any type nuclear system (i.e., BWR, HTGR, PWR, LMFBR, GCFR,... ). The current version is limited to thermal reactors. GEM is designed for production use by large utilities which have several reactor types on their system. GEM has been written so as to accommodate all major fuel management activities undertaken by a utility - (1) fuel bid analysis, (2) evaluation of actual day to day operation, and (3) system simulation and optimization studies. 2 - Method of solution: Costs are calculated using present-worth techniques and continuous compounding. The equations are based on an investor-owned utility capitalization structure which easily covers the range of industrial, private, and public (government) owned utilities. Three distinct types of analysis (cash flow, allocated costs, yearly cash flow) are performed, each yielding identical results. Using these as a basis many other analyses are undertaken. 3 - Restrictions on the complexity of the problem: Dimensions of all arrays are carried as variables throughout the analysis. The maximum size of each array is set by the user in program MAIN. Current values are set so that maxima are: 50 batches per case study, 20 year batch life, 30 year case study, 120 batch burn time-steps, 20 individual payments (sales) associated with each cost component

Optimization of process parameters in flash pyrolysis of waste tyres to liquid and gaseous fuel in a fluidized bed reactor

International Nuclear Information System (INIS)

Edwin Raj, R.; Robert Kennedy, Z.; Pillai, B.C.

2013-01-01

Highlights: ► Non-recyclable, hazards, under-utilized waste tyre was converted to useful fuel. ► Design of experiment was used to optimize the process parameters. ► Fuel compatibility for IC engines was tested by standard fuel testing procedures. ► Optimized process parameters were tested and the empirical model validated. - Abstract: Pyrolysis process offers solution to utilize huge quantity of worn out automobile tyres to produce fuel for energy needs. Shredded tyre wastes were subjected to pyrolysis at atmospheric pressure under inert gas atmosphere in a fluidized bed combustion setup. The shredded tyre particle size, the feed rate of the feed stock, and the pyrolysis temperature were varied systematically as per the designed experiment to study their influence on product yield. Maximizing the oil yield and subduing the gas and char yield is the objective to optimize the process parameters. A low pyrolysis temperature of 440 °C with low feed rate increases the residence time in the combustion reactor yielding maximum oil. The physical properties of raw pyrolysis oil, distilled oil and the evolved gases were done to find its suitability to utilize them as alternatives to the conventional fuels

Maximum neutron flux in thermal reactors; Maksimum neutronskog fluksa kod termalnih reaktora

Energy Technology Data Exchange (ETDEWEB)

Strugar, P V [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Yugoslavia)

1968-07-01

Direct approach to the problem is to calculate spatial distribution of fuel concentration if the reactor core directly using the condition of maximum neutron flux and comply with thermal limitations. This paper proved that the problem can be solved by applying the variational calculus, i.e. by using the maximum principle of Pontryagin. Mathematical model of reactor core is based on the two-group neutron diffusion theory with some simplifications which make it appropriate from maximum principle point of view. Here applied theory of maximum principle are suitable for application. The solution of optimum distribution of fuel concentration in the reactor core is obtained in explicit analytical form. The reactor critical dimensions are roots of a system of nonlinear equations and verification of optimum conditions can be done only for specific examples.

Overview of reductants utilized in nuclear fuel reprocessing/recycling

Energy Technology Data Exchange (ETDEWEB)

Patricia Paviet-Hartmann; Catherine Riddle; Keri Campbell; Edward Mausolf

2013-10-01

Most of the aqueous processes developed, or under consideration worldwide for the recycling of used nuclear fuel (UNF) utilize the oxido-reduction properties of actinides to separate them from other radionuclides. Generally, after acid dissolution of the UNF, (essentially in nitric acid solution), actinides are separated from the raffinate by liquid-liquid extraction using specific solvents, associated along the process, with a particular reductant that will allow the separation to occur. For example, the industrial PUREX process utilizes hydroxylamine as a plutonium reductant. Hydroxylamine has numerous advantages: not only does it have the proper attributes to reduce Pu(IV) to Pu(III), but it is also a non-metallic chemical that is readily decomposed to innocuous products by heating. However, it has been observed that the presence of high nitric acid concentrations or impurities (such as metal ions) in hydroxylamine solutions increase the likelihood of the initiation of an autocatalytic reaction. Recently there has been some interest in the application of simple hydrophilic hydroxamic ligands such as acetohydroxamic acid (AHA) for the stripping of tetravalent actinides in the UREX process flowsheet. This approach is based on the high coordinating ability of hydroxamic acids with tetravalent actinides (Np and Pu) compared with hexavalent uranium. Thus, the use of AHA offers a route for controlling neptunium and plutonium in the UREX process by complexant based stripping of Np(IV) and Pu(IV) from the TBP solvent phase, while U(VI) ions are not affected by AHA and remain solvated in the TBP phase. In the European GANEX process, AHA is also used to form hydrophilic complexes with actinides and strip them from the organic phase into nitric acid. However, AHA does not decompose completely when treated with nitric acid and hampers nitric acid recycling. In lieu of using AHA in the UREX + process, formohydroxamic acid (FHA), although not commercially available, hold

Method for verifying the pressure in a nuclear reactor fuel rod

International Nuclear Information System (INIS)

Jones, W.J.

1979-01-01

Disclosed is a method of accurately verifying the pressure contained in a sealed pressurized fuel rod by utilizing a pressure balance measurement technique wherein an end of the fuel rod extends through and is sealed in a wall of a small chamber. The chamber is pressurized to the nominal (desired) fuel rod pressure and the fuel rod is then pierced to interconnect the chamber and fuel rod. The deviation of chamber pressure is noted. The final combined pressure of the fuel rod and drill chamber is substantially equal to the nominal rod pressure; departure of the combined pressure from nominal is in direct proportion to departure of rod pressure from nominal. The maximum error in computing the rod pressure from the deviation of the combined pressure from nominal is estimated at plus or minus 3.0 psig for rod pressures within the specified production limits. If the rod pressure is corrected for rod void volume using a digital printer data record, the accuracy improves to about plus or minus 2.0 psig

Analysis of neutronics benchmarks for the utilization of mixed oxide fuel in light water reactor using DRAGON code

International Nuclear Information System (INIS)

Nithyadevi, Rajan; Thilagam, L.; Karthikeyan, R.; Pal, Usha

2016-01-01

Highlights: • Use of advanced computational code – DRAGON-5 using advanced self shielding model USS. • Testing the capability of DRAGON-5 code for the analysis of light water reactor system. • Wide variety of fuels LEU, MOX and spent fuel have been analyzed. • Parameters such as k ∞ , one, few and multi-group macroscopic cross-sections and fluxes were calculated. • Suitability of deterministic methodology employed in DRAGON-5 code is demonstrated for LWR. - Abstract: Advances in reactor physics have led to the development of new computational technologies and upgraded cross-section libraries so as to produce an accurate approximation to the true solution for the problem. Thus it is necessary to revisit the benchmark problems with the advanced computational code system and upgraded cross-section libraries to see how far they are in agreement with the earlier reported values. Present study is one such analysis with the DRAGON code employing advanced self shielding models like USS and 172 energy group ‘JEFF3.1’ cross-section library in DRAGLIB format. Although DRAGON code has already demonstrated its capability for heavy water moderator systems, it is now tested for light water reactor (LWR) and fast reactor systems. As a part of validation of DRAGON for LWR, a VVER computational benchmark titled “Neutronics Benchmarks for the Utilization of Mixed-Oxide Fuel-Volume 3” submitted by the Russian Federation has been taken up. Presently, pincell and assembly calculations are carried out considering variation in fuel temperature (both fresh and spent), moderator temperatures and boron content in the moderator. Various parameters such as infinite neutron multiplication (k ∞ ) factor, one group integrated flux, few group homogenized cross-sections (absorption, nu-fission) and reaction rates (absorption, nu-fission) of individual isotopic nuclides are calculated for different reactor states. Comparisons of results are made with the reported Monte Carlo

An experimental assessment on the influence of high octane fuels on biofuel based dual fuel engine performance, emission, and combustion

Directory of Open Access Journals (Sweden)

Masimalai Senthilkumar

2017-01-01

Full Text Available This paper presents an experimental study on the effect of different high octane fuels (such as eucalyptus oil, ethanol, and methanol on engine’s performance behaviour of a biofuel based dual fuel engine. A single cylinder Diesel engine was modified and tested under dual fuel mode of operation. Initially the engine was run using neat diesel, neat mahua oil as fuels. In the second phase, the engine was operated in dual fuel mode by using a specially designed variable jet carburettor to supply the high octane fuels. Engine trials were made at 100% and 40% loads (power outputs with varying amounts of high octane fuels up-to the maximum possible limit. The performance and emission characteristics of the engine were obtained and analysed. Results indicated significant improvement in brake thermal efficiency simultaneous reduction in smoke and NO emissions in dual fuel operation with all the inducted fuels. At 100% load the brake thermal efficiency increased from 25.6% to a maximum of 32.3, 30.5, and 28.4%, respectively, with eucalyptus oil, ethanol, and methanol as primary fuels. Smoke was reduced drastically from 78% with neat mahua oil a minimum of 41, 48, and 53%, respectively, with eucalyptus oil, ethanol, and methanol at the maximum efficiency point. The optimal energy share for the best engine behaviour was found to be 44.6, 27.3, and 23.2%, respectively, for eucalyptus oil, ethanol, and methanol at 100% load. Among the primary fuels tested, eucalyptus oil showed the maximum brake thermal efficiency, minimum smoke and NO emissions and maximum energy replacement for the optimal operation of the engine.

Application of fuel cell for pyrite and heavy metal containing mining waste

Science.gov (United States)

Keum, H.; Ju, W. J.; Jho, E. H.; Nam, K.

2015-12-01

Once pyrite and heavy metal containing mining waste reacts with water and air it produces acid mine drainage (AMD) and leads to the other environmental problems such as contamination of surrounding soils. Pyrite is the major source of AMD and it can be controlled using a biological-electrochemical dissolution method. By enhancing the dissolution of pyrite using fuel cell technology, not only mining waste be beneficially utilized but also be treated at the same time by. As pyrite-containing mining waste is oxidized in the anode of the fuel cell, electrons and protons are generated, and electrons moves through an external load to cathode reducing oxygen to water while protons migrate to cathode through a proton exchange membrane. Iron-oxidizing bacteria such as Acidithiobacillus ferrooxidans, which can utilize Fe as an electron donor promotes pyrite dissolution and hence enhances electrochemical dissolution of pyrite from mining waste. In this study mining waste from a zinc mine in Korea containing 17 wt% pyrite and 9% As was utilized as a fuel for the fuel cell inoculated with A. ferrooxidans. Electrochemically dissolved As content and chemically dissolved As content was compared. With the initial pH of 3.5 at 23℃, the dissolved As concentration increased (from 4.0 to 13 mg/L after 20 d) in the fuel cell, while it kept decreased in the chemical reactor (from 12 to 0.43 mg/L after 20 d). The fuel cell produced 0.09 V of open circuit voltage with the maximum power density of 0.84 mW/m2. Dissolution of As from mining waste was enhanced through electrochemical reaction. Application of fuel cell technology is a novel treatment method for pyrite and heavy metals containing mining waste, and this method is beneficial for mining environment as well as local community of mining areas.

Optimization of a fuel cell powertrain for a sport utility vehicle. Paper no. IGEC-1-087

International Nuclear Information System (INIS)

Stevens, M.B.; Mendes, C.; Mali, T.J.; Fowler, M.W.; Fraser, R.A.

2005-01-01

A central composite design was utilized to study the effects of fuel cell powertrain sizing and efficiencies on vehicle performance based on a Chevrolet Equinox platform. Simulations were performed using the Powertrain System Analysis Toolkit (PSAT), a vehicle simulator that constructs and executes various Simulink vehicle models. Once parametric equations relating performance metrics and subcomponent sizing and efficiency were fit, optimal design points were obtained using non-linear optimization. Optimized architectures were used to compare fuel cell powertrains incorporating ultracapacitors, nickel-metal hydride battery packs, and lithium-ion battery packs. The performance metrics also provided a basis for comparison with conventional, battery, and hybrid configurations. The fuel cell configurations exhibited similar or improved acceleration performance, with approximately double the mileage of the stock vehicle. The range of the fuel cell Equinox was reduced from the stock vehicle to approximately 300 miles. The battery vehicles showed the highest efficiencies and mileages, but exhibited an unacceptable range of approximately 100 miles. The hybrid configuration showed notable improvements over the stock vehicle, but still lacked the degree of benefits provided by the fuel cell (FCVs) and battery electric vehicles (BEVs). Also, the acceleration time for the hybrid vehicle was sluggish, likely due to the increase weight of the configuration. The work described in this study was performed by members of the University Of Waterloo Alternate Fuels Team (UWAFT) as part of the Challenge X Vehicle Competition. (author)

Compliance problems of small utility systems with the Powerplant and Industrial Fuel Use Act of 1978: volume II - appendices

Energy Technology Data Exchange (ETDEWEB)

None

1981-01-01

A study of the problems of compliance with the Powerplant and Industrial Fuel Use Act of 1978 experienced by electric utility systems which have a total generating capacity of less than 2000 MW is presented. This volume presents the following appendices: (A) case studies (Farmington, New Mexico; Lamar, Colorado; Dover, Delaware; Wolverine Electric Cooperative, Michigan; Central Telephone and Utilities, Kansas; Sierra Pacific Power Company, Nevada; Vero Beach, Florida; Lubbock, Texas; Western Farmers Cooperative, Oklahoma; and West Texas Utilities Company, Texas); (B) contacts and responses to study; (C) joint action legislation chart; (D) Texas Municipal Power Agency case study; (E) existing generating units jointly owned with small utilities; (F) future generating units jointly owned with small utilities; (G) Federal Register Notice of April 17, 1980, and letter of inquiry to utilities; (H) small utility responses; and (I) Section 744, PIFUA. (WHK)

Fuel and fuel pin behaviour in a high burnup fast breeder fuel subassembly: Results of destructive post-irradiation examinations of the KNK II/1 fuel subassembly NY-205

International Nuclear Information System (INIS)

Patzer, G.

1991-05-01

The report gives a summarizing overview of the design characteristics, of the irradiation history and of the results of the destructive post-irradiation examinations of the fuel pins of the high-burnup fuel subassembly NY-205 of the KNK II first core. This element was operated for about 10 years and reached a maximum local burnup of 175 MWd/kg(HM) and a maximum neutron dose of 67 dpa-NRT. The main design data of this subassembly agree with those of the SNR 300 Mark-Ia, and it reached more than twice of the burnup and a similar neutron dose as foreseen for the SNR 300 fuel subassemblies [de

Advanced Reactor Technology Options for Utilization and Transmutation of Actinides in Spent Nuclear Fuel

International Nuclear Information System (INIS)

2009-09-01

Renewed interest in the potential of nuclear energy to contribute to a sustainable worldwide energy mix is strengthening the IAEA's statutory role in fostering the peaceful uses of nuclear energy, in particular the need for effective exchanges of information and collaborative research and technology development among Member States on advanced nuclear power technologies (Articles III-A.1 and III-A.3). The major challenges facing the long term development of nuclear energy as a part of the world's energy mix are improvement of the economic competitiveness, meeting increasingly stringent safety requirements, adhering to the criteria of sustainable development, and public acceptability. The concern linked to the long life of many of the radioisotopes generated from fission has led to increased R and D efforts to develop a technology aimed at reducing the amount of long lived radioactive waste through transmutation in fission reactors or accelerator driven hybrids. In recent years, in various countries and at an international level, more and more studies have been carried out on advanced and innovative waste management strategies (i.e. actinide separation and elimination). Within the framework of the Project on Technology Advances in Fast Reactors and Accelerator Driven Systems (http://www.iaea.org/inisnkm/nkm/aws/fnss/index.html), the IAEA initiated a number of activities on utilization of plutonium and transmutation of long lived radioactive waste, accelerator driven systems, thorium fuel options, innovative nuclear reactors and fuel cycles, non-conventional nuclear energy systems, and fusion/fission hybrids. These activities are implemented under the guidance and with the support of the IAEA Nuclear Energy Department's Technical Working Group on Fast Reactors (TWG-FR). This publication compiles the analyses and findings of the Coordinated Research Project (CRP) on Studies of Advanced Reactor Technology Options for Effective Incineration of Radioactive Waste (2002

Fuel R and D to improve fuel reliability

International Nuclear Information System (INIS)

Yang, Rosa; Cheng, Bo; Deshon, Jeff; Edsinger, Kurt; Ozer, Odelli

2006-01-01

Light water reactor fuel is operating in an increasingly challenging environment. Fuel burnup extension and cycle length increase both can increase the local duty. Reactor water chemistry modifications for the purpose of protection the plant system materials have the potential of increasing fuel surface deposition and cladding corrosion and hydriding. The status of fuel performance in US reactors is summarized and an update of the Fuel Reliability Program' established by the utility industry to ensure reliability is provided. (author)

Strategies for a competitive nuclear fuel

International Nuclear Information System (INIS)

Alvarez, J. M.; Rebollo, L.

2001-01-01

In the new framework of electricity generation, Nuclear Power Plants are operated by the electric utilities based on the competition required by an increasingly deregulated and liberalized market so that there is frequently a competition between the strategies of innovation and standardisation. On one had, innovation promotes the use of new technologies, products and/or processes locking for a reduction of costs based on the increase of the operating margins, while, on the other hand, standardisation promotes the use of well known and consolidated technologies, products and/or processes looking for getting the maximum benefit from the accumulated previous operating experience. In order to evaluate the standardisation versus the innovation an analysis of risks and opportunities of each of these strategies applied to the industry of the nuclear fuel has been suggested. As a results of it, a combined strategy innovation + standardisation based on the integration of both basic strategies in a complementary mode, has been suggested, the disadvantages of each of these strategies being compensated with the advantages of the other one. in this way, the total risk is minimized, the global opportunities are maximized and the main overall objective of getting the maximum benefit of the combination of both strategies looking for a competitive nuclear fuel is guaranteed. (Author)

Used fuel packing plant for CANDU fuel

Energy Technology Data Exchange (ETDEWEB)

Menzies, I.; Thayer, B.; Bains, N., E-mail: imenzies@atsautomation.com [ATS Automation, Cambridge, ON (Canada); Murchison, A., E-mail: amurchison@nwmo.ca [NWMO, Toronto, ON (Canada)

2015-07-01

Large forgings have been selected to containerize Light Water Reactor used nuclear fuel. CANDU fuel, which is significantly smaller in size, allows novel approaches for containerization. For example, by utilizing commercially available extruded ASME pipe a conceptual design of a Used Fuel Packing Plant for containerization of used CANDU fuel in a long lived metallic container has been developed. The design adopts a modular approach with multiple independent work cells to transfer and containerize the used fuel. Based on current technologies and concepts from proven industrial systems, the Used Fuel Packing Plant can assemble twelve used fuel containers per day considering conservative levels of process availability. (author)

Heat transfer in a fuel pin shipping container

International Nuclear Information System (INIS)

Ingham, J.G.

1980-01-01

Maximum cladding temperatures occur when the IDENT 1578 fuel pin shipping container is installed in the T-3 Cask. The maximum allowable cladding temperature of 800 0 F is reached when the rate of energy deposited in the 19-pin basket reaches 400 watts. Since 45% of the energy which is generated in the fuel escapes the 19-pin basket without being deposited, mostly gamma energy, the maximum allowable rate of heat generation is 400/.55 = 727 watts. Similarly, the maximum allowable cladding temperature of 800 0 F is reached when the rate of energy deposited in the 40-pin basket reaches 465 watts. Since 33% of the energy which is generated in the fuel escapes the 40-pin basket without being deposited, mostly gamma energy, the maximum allowable rate of heat generation is 465/.66 = 704 watts. The IDENT 1578 fuel pin shipping container therefore meets its thermal design criteria. IDENT 1578 can handle fuel pins with a decay heat load of 600 watts while maintaining the maximum fuel pin cladding temperature below 800 0 F. The emissivities which were determined from the test results for the basket tubes and container are relatively low and correspond to new, shiny conditions. As the IDENT 1578 container is exposed to high temperatures for extended periods of time during the transportation of fuel pins, the emissivities will probably increase. This will result in reduced temperatures

Kinetic parameters of a material test research reactor fueled with various low enriched uranium dispersion fuels

International Nuclear Information System (INIS)

Muhammad, Farhan; Majid, Asad

2009-01-01

The effects of using different low enriched uranium fuels, having same uranium density, on the kinetic parameters of a material test research reactor were studied. For this purpose, the original aluminide fuel (UAl x -Al) containing 4.40 gU/cm 3 of an MTR was replaced with silicide (U 3 Si-Al and U 3 Si 2 -Al) and oxide (U 3 O 8 -Al) dispersion fuels having the same uranium density as of the original fuel. Simulations were carried out to calculate prompt neutron generation time, effective delayed-neutron fraction, core excess reactivity and neutron flux spectrum. Nuclear reactor analysis codes including WIMS-D4 and CITATION were used to carry out these calculations. It was observed that both the silicide fuels had the same prompt neutron generation time 0.02% more than that of the original aluminide fuel, while the oxide fuel had a prompt neutron generation time 0.05% less than that of the original aluminide fuel. The effective delayed-neutron fraction decreased for all the fuels; the decrease was maximum at 0.06% for U 3 Si 2 -Al followed by 0.03% for U 3 Si-Al, and 0.01% for U 3 O 8 -Al fuel. The U 3 O 8 -Al fueled reactor gave the maximum ρ excess at BOL which was 21.67% more than the original fuel followed by U 3 Si-Al which was 2.55% more, while that of U 3 Si 2 -Al was 2.50% more than the original UAl x -Al fuel. The neutron flux of all the fuels was more thermalized, than in the original fuel, in the active fuel region of the core. The thermalization was maximum for U 3 O 8 -Al followed by U 3 Si-Al and then U 3 Si 2 -Al fuel.

Behavior of strontium- and magnesium-doped gallate electrolyte in direct carbon solid oxide fuel cells

Energy Technology Data Exchange (ETDEWEB)

Zhang, Li; Xiao, Jie; Xie, Yongmin [The Key Laboratory of Fuel Cell Technology of Guangdong Province, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510641 (China); Tang, Yubao [Key Laboratory of Sensor Analysis of Tumor Marker Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao o 266042 (China); Liu, Jiang, E-mail: jiangliu@scut.edu.cn [The Key Laboratory of Fuel Cell Technology of Guangdong Province, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510641 (China); New Energy Research Institute, College of Environment and Energy, South China University of Technology, Guangzhou 510006 (China); Liu, Meilin [New Energy Research Institute, College of Environment and Energy, South China University of Technology, Guangzhou 510006 (China); School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, GA 30332-0245 (United States)

2014-09-01

Highlights: • La{sub 0.9}Sr{sub 0.1}Ga{sub 0.8}Mg{sub 0.2}O{sub 3−δ} (LSGM) can be used as electrolyte of direct carbon SOFCs. • DC-SOFC with LSGM electrolyte gives higher performance than that with YSZ. • LSGM-electrolyte DC-SOFC gives maximum power density of 383 mW cm{sup −2} at 850 °C. • Operation of LSGM-DC-SOFC at 210 mA cm{sup −2} lasts 72 min, with fuel utilization of 60%. - Abstract: Perovskite-type La{sub 0.9}Sr{sub 0.1}Ga{sub 0.8}Mg{sub 0.2}O{sub 3−δ} (LSGM) is synthesized by conventional solid state reaction. Its phase composition, microstructure, relative density, and oxygen-ionic conductivity are investigated. Tubular electrolyte-supported solid oxide fuel cells (SOFCs) are prepared with the LSGM as electrolyte and gadolinia doped ceria (GDC) mixed with silver as anode. The SOFCs are operated with Fe-loaded activated carbon as fuel and ambient air as oxidant. A typical single cell gives a maximum power density of 383 mW cm{sup −2} at 850 °C, which is nearly 1.3 times higher than that of the similar cell with YSZ as electrolyte. A stability test of 72 min is carried out at a constant current density of 210 mA cm{sup −2}, with a fuel utilization of 60%, indicating that LaGaO{sub 3}-based electrolyte is promising to be applied in direct carbon SOFCs (DC-SOFCs)

Impact on burnup performance of coated particle fuel design in pebble bed reactor with ROX fuel

International Nuclear Information System (INIS)

Ho, Hai Quan; Obara, Toru

2015-01-01

The pebble bed reactor (PBR), a kind of high-temperature gas-cooled reactor (HTGR), is expected to be among the next generation of nuclear reactors as it has excellent passive safety features, as well as online refueling and high thermal efficiency. Rock-like oxide (ROX) fuel has been studied at the Japan Atomic Energy Agency (JAEA) as a new once-through type fuel concept. Rock-like oxide used as fuel in a PBR can be expected to achieve high burnup and improve chemical stabilities. In the once-through fuel concept, the main challenge is to achieve as high a burnup as possible without failure of the spent fuel. The purpose of this study was to investigate the impact on burnup performance of different coated fuel particle (CFP) designs in a PBR with ROX fuel. In the study, the AGR-1 Coated Particle design and Deep-Burn Coated Particle design were used to make the burnup performance comparison. Criticality and core burnup calculations were performed by MCPBR code using the JENDL-4.0 library. Results at equilibrium showed that the two reactors utilizing AGR-1 Coated Particle and Deep-Burn Coated Particle designs could be critical with almost the same multiplication factor k eff . However, the power peaking factor and maximum power per fuel ball in the AGR-1 coated particle design was lower than that of Deep-Burn coated particle design. The AGR-1 design also showed an advantage in fissions per initial fissile atoms (FIFA); the AGR-1 coated particle design produced a higher FIFA than the Deep-Burn coated particle design. These results suggest that the difference in coated particle fuel design can have an effect on the burnup performance in ROX fuel. (author)

Industrial coal utilization

Energy Technology Data Exchange (ETDEWEB)

None

1979-01-01

The effects of the National Energy Act on the use of coal in US industrial and utility power plants are considered. Innovative methods of using coal in an environmentally acceptable way are discussed: furnace types, fluidized-bed combustion, coal-oil-mixtures, coal firing in kilns and combustion of synthetic gas and liquid fuels. Fuel use in various industries is discussed with trends brought about by uncertain availability and price of natural gas and fuel oils: steel, chemical, cement, pulp and paper, glass and bricks. The symposium on Industrial Coal Utilization was sponsored by the US DOE, Pittsburgh Energy Technology Center, April 3 to 4, 1979. Twenty-one papers have been entered individually into the EDB. (LTN)

Recovery and utilization of valuable metals from spent nuclear fuel. 3: Mutual separation of valuable metals

International Nuclear Information System (INIS)

Kirishima, K.; Shibayama, H.; Nakahira, H.; Shimauchi, H.; Myochin, M.; Wada, Y.; Kawase, K.; Kishimoto, Y.

1993-01-01

In the project ''Recovery and Utilization of Valuable Metals from Spent Fuel,'' mutual separation process of valuable metals recovered from spent fuel has been studied by using the simulated solution contained Pb, Ru, Rh, Pd and Mo. Pd was separated successfully by DHS (di-hexyl sulfide) solvent extraction method, while Pb was recovered selectively from the raffinate by neutralization precipitation of other elements. On the other hand, Rh was roughly separated by washing the precipitate with alkaline solution, so that Rh was refined by chelate resin CS-346. Outline of the mutual separation process flow sheet has been established of the combination of these techniques. The experimental results and the process flow sheet of mutual separation of valuable metals are presented in this paper

Sharp Reduction in Maximum LEU Fuel Temperatures during Loss of Coolant Accidents in a PBMR DPP-400 core by means of Optimised Placement of Neutron Poisons: Implications for Pu fuel-cycles

International Nuclear Information System (INIS)

Serfontein, Dawid E.

2013-01-01

The optimisation of the power profiles by means of placing an optimised distribution of neutron poison concentrations in the central reflector resulted in a large reduction in the maximum DLOFC temperature, which may produce far reaching safety and licensing benefits. Unfortunately this came at the expense of losing the ability to execute effective load following. The neutron poisons also caused a large reduction of 22% in the average burn-up of the fuel. Further optimisation is required to counter this reduction in burn-up

Solid fuel applications to transportation engines

Energy Technology Data Exchange (ETDEWEB)

Rentz, Richard L.; Renner, Roy A.

1980-06-01

The utilization of solid fuels as alternatives to liquid fuels for future transportation engines is reviewed. Alternative liquid fuels will not be addressed nor will petroleum/solid fuel blends except for the case of diesel engines. With respect to diesel engines, coal/oil mixtures will be addressed because of the high interest in this specific application as a result of the large number of diesel engines currently in transportation use. Final assessments refer to solid fuels only for diesel engines. The technical assessments of solid fuels utilization for transportation engines is summarized: solid fuel combustion in transportation engines is in a non-developed state; highway transportation is not amenable to solid fuels utilization due to severe environmental, packaging, control, and disposal problems; diesel and open-cycle gas turbines do not appear worthy of further development, although coal/oil mixtures for slow speed diesels may offer some promise as a transition technology; closed-cycle gas turbines show some promise for solid fuels utilization for limited applications as does the Stirling engine for use of cleaner solid fuels; Rankine cycle engines show good potential for limited applications, such as for locomotives and ships; and any development program will require large resources and sophisticated equipment in order to advance the state-of-the-art.

New technology and fuel cycles

International Nuclear Information System (INIS)

Mooradian, A.J.

1979-06-01

The means of improving uranium utilization in nuclear power reactors are reviewed with respect to economic considerations, assurance of adequate fuel supplies and risk of weapons proliferation. Reference is made to what can be done to improve fuel economy in existing reactor systems operating on a once-through fuel cycle and the potential for improvement offered by fuel recycle in those systems. The state of development of new reactor systems that offer significant savings in uranium utilization is also reviewed and conclusions are made respecting the policy implications of the search for fuel economy. (author)

HTGR fuel and fuel cycle technology

International Nuclear Information System (INIS)

Lotts, A.L.; Coobs, J.H.

1976-08-01

The status of fuel and fuel cycle technology for high-temperature gas-cooled reactors (HTGRs) is reviewed. The all-ceramic core of the HTGRs permits high temperatures compared with other reactors. Core outlet temperatures of 740 0 C are now available for the steam cycle. For advanced HTGRs such as are required for direct-cycle power generation and for high-temperature process heat, coolant temperatures as high as 1000 0 C may be expected. The paper discusses the variations of HTGR fuel designs that meet the performance requirements and the requirements of the isotopes to be used in the fuel cycle. Also discussed are the fuel cycle possibilities, which include the low-enrichment cycle, the Th- 233 U cycle, and plutonium utilization in either cycle. The status of fuel and fuel cycle development is summarized

Evaluation of Particle Counter Technology for Detection of Fuel Contamination Detection Utilizing Fuel System Supply Point

Science.gov (United States)

2014-06-19

product used as a diesel product for ground use (1). Free water contamination (droplets) may appear as fine droplets or slugs of water in the fuel...methods and test procedures for the calibration and use of automatic particle counters. The transition of this technology to the fuel industry is...UNCLASSIFIED 6 UNCLASSIFIED Receipt Vehicle Fuel Tank Fuel Injector Aviation Fuel DEF (AUST) 5695B 18/16/13 Parker 18

A stochastic-deterministic approach for evaluation of uncertainty in the predicted maximum fuel bundle enthalpy in a CANDU postulated LBLOCA event

Energy Technology Data Exchange (ETDEWEB)

Serghiuta, D.; Tholammakkil, J.; Shen, W., E-mail: Dumitru.Serghiuta@cnsc-ccsn.gc.ca [Canadian Nuclear Safety Commission, Ottawa, Ontario (Canada)

2014-07-01

A stochastic-deterministic approach based on representation of uncertainties by subjective probabilities is proposed for evaluation of bounding values of functional failure probability and assessment of probabilistic safety margins. The approach is designed for screening and limited independent review verification. Its application is illustrated for a postulated generic CANDU LBLOCA and evaluation of the possibility distribution function of maximum bundle enthalpy considering the reactor physics part of LBLOCA power pulse simulation only. The computer codes HELIOS and NESTLE-CANDU were used in a stochastic procedure driven by the computer code DAKOTA to simulate the LBLOCA power pulse using combinations of core neutronic characteristics randomly generated from postulated subjective probability distributions with deterministic constraints and fixed transient bundle-wise thermal hydraulic conditions. With this information, a bounding estimate of functional failure probability using the limit for the maximum fuel bundle enthalpy can be derived for use in evaluation of core damage frequency. (author)

Techno-Economic Analysis of Biogas Utilization as an Alternative Fuel

Directory of Open Access Journals (Sweden)

Merry Indahsari Devi

2014-07-01

Full Text Available This paper will discuss the feasibility and economic analysis of biogas energy as a supply for the diesel engine generator. The techno-economic analysis was performed by using three parameters which are Net Present Value (NPV, Internal Rate of Return (IRR, and Payback Period (PP as the feasibility indicators of the biogas power plant project. Calculation of substitution was obtained from the comparison between data of diesel engine using diesel fuel and dual-fuel with biogas. Economic calculations include the substitution percentage of diesel fuel by biogas for dual-fuel. Meanwhile, the calculation of savings was based on the ratio of energy content between diesel fuel and biogas. The eventual outcome is determined using economic comparison between the use of diesel fuel and dual-fuel mode. Feasibility shows that the pilot plant of 1 to 6 kWh using diesel fuel and dual-fuel are not feasible while techno-economic parameter analysis shows that NPV<0, IRRfuel is still not.

Energy at the author's house for saving conventional fuels

International Nuclear Information System (INIS)

Nandwani, S.S.

2006-01-01

About 20 years ago, we decided to make our house. Being working on the utilization of solar energy and with the objective of saving maximum conventional fuel and some family budget, we dicided to make use of maximum this free and clean fuel. After buying the land with proper orientation, we installed different cheap devices and left the proper provision for another devices to installed in future. At present we solar energy mainly for cooking, water heating for bath and dish washing, drying clothes/fruits/vegetables, purification (pasteurization) of water. In addition. we also use solar cells for some electrical devices like solar radio, solar lamp for emergency, charging batteries and mobile phone etc. For our family of five persons, having 3 coloured TV, 2 computers using many hours of Internet, without any use of fuel other than electricity and sun, our electricity consumption is of the order of 270 (dry/summer)-350 (wet/rainy) kWh/month, depending on the season (US$16-21/month). This is roughly 40-50% of the electricity consumed by my other colleagues who do not use solar energy. With this saving, the initial cost of solar devices (US$1200-1400) is already recovered. In this presentation, construction and results of working of these solar thermal, electrical devices and other energy saving means at our house are mentioned.(Author)

Japan's fuel recycling policy

International Nuclear Information System (INIS)

Anon.

1991-01-01

The Atomic Energy Commission (AEC) has formulated Japanese nuclear fuel recycling plan for the next 20 years, based on the idea that the supply and demand of plutonium should be balanced mainly through the utilization of plutonium for LWRs. The plan was approved by AEC, and is to be incorporated in the 'Long term program for development and utilization of nuclear energy' up for revision next year. The report on 'Nuclear fuel recycling in Japan' by the committee is characterized by Japanese nuclear fuel recycling plan and the supply-demand situation for plutonium, the principle of the possession of plutonium not more than the demand in conformity with nuclear nonproliferation attitude, and the establishment of a domestic fabrication system of uranium-plutonium mixed oxide fuel. The total plutonium supply up to 2010 is estimated to be about 85 t, on the other hand, the demand will be 80-90 t. The treatment of plutonium is the key to the recycling and utilization of nuclear fuel. By around 2000, the private sector will commercialize the fabrication of the MOX fuel for LWRs at the annual rate of about 100 t. Commitment to nuclear nonproliferation, future nuclear fuel recycling program in Japan, MOX fuel fabrication system in Japan and so on are reported. (K.I.)

MOX fuel design and development consideration

International Nuclear Information System (INIS)

Yamate, K.; Abeta, S.; Suzuki, K.; Doi, S.

1997-01-01

Pu thermal utilization in Japan will be realized in several plants in late 1990's, and will be expanded gradually. For this target, adequacy of methods for MOX fuel design, nuclear design, and safety analysis has been evaluated by the committee of competent authorities organized by government in advance of the licensing application. There is no big difference of physical properties and irradiation behaviors between MOX fuel and UO 2 fuel, because Pu content of MOX fuel for Pu thermal utilization is low. The fuel design code for UO 2 fuel will be applied with some modifications, taking into account of characteristic of MOX fuel. For nuclear design, new code system is to be applied to treat the heterogeneity in MOX fuel assembly and the neutron spectrum interaction with UO 2 fuel more accurately. For 1/3 MOX fueled core in three loop plant, it was confirmed that the fuel rod mechanical design could meet the design criteria, with slight reduction of initial back-fitting pressure, and with appropriate fuel loading patterns in the core to match power with UO 2 fuel. With the increase of MOX fuel fraction in the core, control rod worth and boron worth decrease. Compensating the decrease by adding control rod and utilizing enriched B-10 in safety injection system, 100% MOX fueled core could be possible. Up to 1/3 MOX fueled core in three loop plant, no such modifications of the plant is necessary. The fraction of MOX fuel in PWR is designed to less than 1/3 in the present program. In order to improve Pu thermal utilization in future, various R and D program on fuel design and nuclear design are being performed, such as the irradiation program of MOX fuel manufactured through new process to the extent of high burnup. (author). 8 refs, 9 figs, 2 tabs

Fuel performance, design and development

International Nuclear Information System (INIS)

Prasad, P.N.; Tripathi, Rahul Mani; Soni, Rakesh; Ravi, M.; Vijay Kumar, S.; Dwivedi, K.P.; Pandarinathan, P.R.; Neema, L.K.

2006-01-01

The normal fuel configurations for operating 220 MWe and 540 MWe PHWRs are natural uranium dioxide 19-element and 37- element fuel bundle types respectively. The fuel configuration for BWRs is 6 x 6 fuel. So far, about 330 thousand PHWR fuel bundles and 3500 number of BWR bundles have been irradiated in the 14 PHWRs and 2 BWRs. Improvements in fuel design, fabrication, quality control and operating practices are continuously carried out towards improving fuel utilization as well as reducing fuel failure rate. Efforts have been put to improve the fuel bundle utilization by increasing the fuel discharge burnup of the natural uranium bundles The overall fuel failure rate currently is less than 0.1 % . Presently the core discharge burnups in different reactors are around 7500 MWD/TeU. The paper gives the fuel performance experience over the years in the different power reactors and actions taken to improve fuel performance over the years. (author)

Nuclear fuel, with emphasis on its utilization in pressurized water reactor

International Nuclear Information System (INIS)

Khazaneh, R.; Roshanzamir, M.

1997-01-01

Production processes of nuclear fuel on one hand and using nuclear fuels in reactors, particularly PWR Type reactors on the other hand is investigated. The first chapter reviews the relationship between fuel and reactors; The principals of reactor physics in relation with fuel are described shortly. The second chapter reviews uranium exploration and extraction as well as production of uranium concentrate and uranium dioxides. The third chapter is specified to the different procedures of uranium enrichment. In the fourth chapter, processing of uranium dioxide powder and fuel pellet is described. In the fifth chapter fabrication of fuel rod and fuel assemblies is explained thoroughly. The sixth chapter devoted to the different phenomena which occur ed in fuel structure and can during operational time of reactor; damage to fuel rods and developing theoretical models to describe these phenomena and analysis of fuel structure. The seventh chapter discusses how fuel rods are to be experimented during fabrication, operation and development of technology. The eighth chapter explains different fuels such as uranium compounds and mixed oxide fuel of uranium Gadolinium and uranium plutonium and the process of fabrication of zircaloy. In the tenth chapter, fuel reprocessing is investigated and the difficulties of developing this technology is referred

Development of CANDU advanced fuel bundle

International Nuclear Information System (INIS)

Suk, H. C.; Hwang, W.; Rhee, B. W.; Jung, S. H.; Chung, C. H.

1992-05-01

This research project is underway in cooperation with AECL to develop the CANDU advanced fuel bundle (so-called, CANFLEX) which can enhance reactor safety and fuel economy in comparison with the current CANDU fuel and which can be used with natural uranium, slightly enriched uranium and other advanced fuel cycle. As the final schedule, the advanced fuel will be verified by carrying out a large scale demonstration of the bundle irradiation in a commercial CANDU reactor for 1996 and 1997, and consequently will be used in the existing and future CANDU reactors in Korea. The research activities during this year include the detail design of CANFLEX fuel with natural enriched uranium (CANFLEX-NU). Based on this design, CANFLEX fuel was mocked up. Out-of-pile hydraulic scoping tests were conducted with the fuel in the CANDU Cold Test Loop to investigate the condition under which maximum pressure drop occurs and the maximum value of the bundle pressure drop. (Author)

China's spent fuel treatment: The present status and prospects

International Nuclear Information System (INIS)

Jiang Yunqing

1999-01-01

In the mid 1980s, China launched the development of nuclear power dominated by PWRs and opted for the closed fuel cycle strategy. On the basis of irradiated fuel reprocessing for defence purpose, an R and D programme for civil reprocessing has been implemented. Currently, China's spent fuel arising is limited but its amount will sharply increase with nuclear power expansion early next century. Spent fuel stored at reactor site for at least 5 years will be transported either by a combination of sea and rail or by road directly to the Lanzhou Nuclear Fuel Complex. A wet centralized storage facility with a 550 tHM capacity has been built for interim storage of spent fuel. Also, a multi-purpose reprocessing pilot plant with a maximum throughput of 400 kg HM/d is now under construction and will be put into commissioning by the turn of the century. A large-scale commercial reprocessing plant, perhaps with a capacity of 800 tHM/a, will be set up around 2020. Recovered uranium and plutonium from reprocessing will go to a demonstration plant and be manufactured into MOX fuel for FBR and PWR. The defence radwaste from reprocessing is at present being conditioned into the proper forms and will be disposed in appropriate repositories. All expertise and experience gained from these practices will be utilized in the future civil radwaste management. (author)

Nuclear fuel activities in Canada

Energy Technology Data Exchange (ETDEWEB)

Cox, D S [Fuel Development Branch, Chalk River Labs., AECL (Canada)

1997-12-01

Nuclear fuel activities in Canada are considered in the presentation on the following directions: Canadian utility fuel performance; CANDU owner`s group fuel programs; AECL advanced fuel program (high burnup fuel behaviour and development); Pu dispositioning (MOX) activities. 1 tab.

Sensitivity of dual fuel engine combustion and knocking limits to gaseous fuel composition

Energy Technology Data Exchange (ETDEWEB)

Selim, M.Y.E. [United Arab Emirates University, Al-Ain (United Arab Emirates). Dept. of Mechanical Engineering

2004-02-01

Combustion noise, knock and ignition limits data are measured and presented for a dual fuel engine running on dual fuels of Diesel and three gaseous fuels separately. The gaseous fuels used are liquefied petroleum gas, pure methane and compressed natural gas mixture. The maximum pressure rise rate during combustion is presented as a measure of combustion noise, and the knocking and ignition limits are presented as torque output at the onset of knocking and ignition failure. Experimental investigation on the dual fuel engine revealed the noise generated from combustion, knocking and ignition limits for all gases at different design and operating conditions. A Ricardo E6 Diesel version engine is converted to run on dual fuel of Diesel and the tested gaseous fuel and is used throughout the work. The engine is fully computerized, and the cylinder pressure data, crank angle data and engine operating variables are stored in a PC for off line analysis. The effects of engine speeds, loads, pilot injection angle, pilot fuel quantity and compression ratio on combustion noise, knocking torque, thermal efficiency and maximum pressure are examined for the dual engine running on the three gaseous fuels separately. The combustion noise, knocking and ignition limits are found to relate to the type of gaseous fuels and to the engine design and operating parameters. (author)

Sensitivity of dual fuel engine combustion and knocking limits to gaseous fuel composition

International Nuclear Information System (INIS)

Selim, Mohamed Y.E.

2004-01-01

Combustion noise, knock and ignition limits data are measured and presented for a dual fuel engine running on dual fuels of Diesel and three gaseous fuels separately. The gaseous fuels used are liquefied petroleum gas, pure methane and compressed natural gas mixture. The maximum pressure rise rate during combustion is presented as a measure of combustion noise, and the knocking and ignition limits are presented as torque output at the onset of knocking and ignition failure. Experimental investigation on the dual fuel engine revealed the noise generated from combustion, knocking and ignition limits for all gases at different design and operating conditions. A Ricardo E6 Diesel version engine is converted to run on dual fuel of Diesel and the tested gaseous fuel and is used throughout the work. The engine is fully computerized, and the cylinder pressure data, crank angle data and engine operating variables are stored in a PC for off line analysis. The effects of engine speeds, loads, pilot injection angle, pilot fuel quantity and compression ratio on combustion noise, knocking torque, thermal efficiency and maximum pressure are examined for the dual engine running on the three gaseous fuels separately. The combustion noise, knocking and ignition limits are found to relate to the type of gaseous fuels and to the engine design and operating parameters

Energetic utilization of Solid Recovered Fuels with wood chips in a stoker-fired furnace; Energetische Nutzung von Solid Recovered Fuels mit Holzhackschnitzeln in einer Rostfeuerung

Energy Technology Data Exchange (ETDEWEB)

Nowak, Piotr; Gehrmann, Hans-Joachim; Seifert, Helmut; Pfrang-Stotz, Gudrun; Paur, Hanns-Rudolf [Karlsruher Institut fuer Technologie (KIT), Eggenstein-Leopoldshafen (Germany). Inst. fuer Technische Chemie (ITC); Schubert, Stefanie [TOMRA Sorting Solutions, Muelheim-Kaerlich (Germany). Test Facility Recycling TITECH; Glorius, Thomas [Remondis GmbH, Region Rheinland, Erftstadt (Germany). Stoffstrommanagement

2013-03-01

Very often, in Germany biofuels are utilized energetically in a pure energetic mode predominantly in EEG incinerator plants. Further clear increases of efficiencies only are possible within a cocombustion in power plant processes with enhanced vapour parameters or in cogeneration power plants, respectively. In the course of an international collaborative project, first experiments at demonstration scale at two fluidized bed boilers at the power plant Wachtberg (Frechen, Federal Republic of Germany) it could be shown, that alternative fuels with an enhanced amount of biomass can be cocombusted without disadvantageous impacts on the emissions. The addition of sulphur to the mono-combustion of biofuels and substitute fuels reduced the total amount of chlorine. But the addition of sulphur also resulted in clearly harder coverings in waste heat recovery boilers by means of the formation of anhydrite as well as to an enhanced dust loading. The substitute fuel online analysis system from TOMRA Sorting Solutions (Wedel/Hamburg, Federal Republic of Germany) was installed in front of the stoker-fired furnace for the online-monitoring of the operation parameters chlorine, water and calorific value.

ELECTRICITY GENERATION FROM SWINE WASTEWATER USING MICROBIAL FUEL CELL

Directory of Open Access Journals (Sweden)

Chimezie Jason Ogugbue

2015-11-01

Full Text Available Electricity generation from swine wastewater using microbial fuel cell (MFC was investigated. Swine wastewater was collected into dual-chambered (aerobic and anaerobic fuel cell. The maximum power output using copper and carbon electrodes were 250.54 and 52.33 µW, while 10.0 and 5.0 cm salt bridge length between the cathode and anode were 279.50 and 355.26 µW, respectively. Potassium permanganate and ordinal water gave a maximum power output of 1287.8 and 13 9.18 µW. MFCs utilize microbial communities to degrade organic materials found within wastewater and converted stored chemical energy to electrical energy in a single step. The initial bacterial and fungal counts were 7.4×106 and 1.1×103 CFU ml-1. Bacterial counts steadily increased with time to 1.40×107 CFU ml-1 while fungal count declined to 4.4×106 CFU ml-1 after day 60. The declined in microbial counts may be attributed to the time necessary for acclimatization of microbes to the anode. The genera identified were Bacillus, Citrobacter, Pseudomonas, Lactobacillus, Escherichia coli, Aspergillus and Rhizopus. These microbes acted as primary and secondary utilizers, utilizing carbon and other organics of the wastewater. Chemical parameters indicated that the biochemical oxygen demand ranged from 91.4–23.2 mg/L, giving 75% while the chemical oxygen demand ranged from 243.1–235.2 mg/L, representing 3.3%. Although, the metabolic activities of microbes were responsible for the observed degradation, leading to electricity, the overall power output depended on the distance between the anode and cathode compartment, types of electrode materials and mediators and oxygen reaction at the cathode.

Performance and long term degradation of 7 W micro-tubular solid oxide fuel cells for portable applications

Science.gov (United States)

Torrell, M.; Morata, A.; Kayser, P.; Kendall, M.; Kendall, K.; Tarancón, A.

2015-07-01

Micro-tubular SOFCs have shown an astonishing thermal shock resistance, many orders of magnitude larger than planar SOFCs, opening the possibility of being used in portable applications. However, only few studies have been devoted to study the degradation of large-area micro-tubular SOFCs. This work presents microstructural, electrochemical and long term degradation studies of single micro-tubular cells fabricated by high shear extrusion, operating in the intermediate range of temperatures (T∼700 °C). A maximum power of 7 W per cell has been measured in a wide range of fuel utilizations between 10% and 60% at 700 °C. A degradation rate of 360 mW/1000 h (8%) has been observed for cells operated over more than 1500 h under fuel utilizations of 40%. Higher fuel utilizations lead to strong degradations associated to nickel oxidation/reduction processes. Quick thermal cycling with heating ramp rates of 30 °C /min yielded degradation rates of 440 mW/100 cycles (9%). These reasonable values of degradation under continuous and thermal cycling operation approach the requirements for many portable applications including auxiliary power units or consumer electronics opening this typically forbidden market to the SOFC technology.

Maximum Entropy in Drug Discovery

Directory of Open Access Journals (Sweden)

Chih-Yuan Tseng

2014-07-01

Full Text Available Drug discovery applies multidisciplinary approaches either experimentally, computationally or both ways to identify lead compounds to treat various diseases. While conventional approaches have yielded many US Food and Drug Administration (FDA-approved drugs, researchers continue investigating and designing better approaches to increase the success rate in the discovery process. In this article, we provide an overview of the current strategies and point out where and how the method of maximum entropy has been introduced in this area. The maximum entropy principle has its root in thermodynamics, yet since Jaynes’ pioneering work in the 1950s, the maximum entropy principle has not only been used as a physics law, but also as a reasoning tool that allows us to process information in hand with the least bias. Its applicability in various disciplines has been abundantly demonstrated. We give several examples of applications of maximum entropy in different stages of drug discovery. Finally, we discuss a promising new direction in drug discovery that is likely to hinge on the ways of utilizing maximum entropy.

Drying of bio fuel utilizing waste heat; Torkning av biobraenslen med spillvaerme

Energy Technology Data Exchange (ETDEWEB)

Johansson, Inge; Larsson, Sara; Wennberg, Olle [S.E.P. Scandinavian Energy Project AB, Goeteborg (Sweden)

2004-10-01

Many industries today have large sources of low grade heat (waste heat), however this energy is mainly lost with effluents to air and water. The aim of this study has been to investigate the technical and economical aspects of utilizing this low grade heat to dry biofuel. The project has been mainly focused towards the forest industry since they have both large amounts of biofuel and waste heat available. Drying of biofuel could generate added revenue (or reduced purchase costs) and through that also create larger incentives for further energy saving modifications to the main process. Due to the higher moisture content together with the risk of frozen bark in the winter time, additional fuels (such as oil) to combust bark in the existing boiler. This is mainly the case when mechanical dewatering is not available. Drying of bark results in an added energy value, which makes it possible to combust the bark without additional fuel. The primary energy demand, in the form of electricity and optional additional heating at load peaks, is low when waste heat is used for the drying process. In this way it is possible to increase the biofuel potential, since the primary energy input to the drying process is essentially lower then the increased energy value of the fuel. Drying also decreases the biological degradation of the fuel. Taking all the above into consideration, waste heat drying could result in a 25 % increase of the biofuel potential in the forest industry in Sweden, without additional cutting of wood. A survey has been done to state which commercial technologies are available for biofuel drying with waste heat. An inquiry was sent out to a number of suppliers and included a few different cases. Relations for approximating investment cost as well as electric power demand were created based on the answers from the inquiry. These relations have then been used in the economical evaluations made for a number of cases representing both sawmills and pulp and paper mills

Pebble bed reactor fuel cycle optimization using particle swarm algorithm

Energy Technology Data Exchange (ETDEWEB)

Tavron, Barak, E-mail: btavron@bgu.ac.il [Planning, Development and Technology Division, Israel Electric Corporation Ltd., P.O. Box 10, Haifa 31000 (Israel); Shwageraus, Eugene, E-mail: es607@cam.ac.uk [Department of Engineering, University of Cambridge, Trumpington Street, Cambridge CB2 1PZ (United Kingdom)

2016-10-15

Highlights: • Particle swarm method has been developed for fuel cycle optimization of PBR reactor. • Results show uranium utilization low sensitivity to fuel and core design parameters. • Multi-zone fuel loading pattern leads to a small improvement in uranium utilization. • Thorium mixes with highly enriched uranium yields the best uranium utilization. - Abstract: Pebble bed reactors (PBR) features, such as robust thermo-mechanical fuel design and on-line continuous fueling, facilitate wide range of fuel cycle alternatives. A range off fuel pebble types, containing different amounts of fertile or fissile fuel material, may be loaded into the reactor core. Several fuel loading zones may be used since radial mixing of the pebbles was shown to be limited. This radial separation suggests the possibility to implement the “seed-blanket” concept for the utilization of fertile fuels such as thorium, and for enhancing reactor fuel utilization. In this study, the particle-swarm meta-heuristic evolutionary optimization method (PSO) has been used to find optimal fuel cycle design which yields the highest natural uranium utilization. The PSO method is known for solving efficiently complex problems with non-linear objective function, continuous or discrete parameters and complex constrains. The VSOP system of codes has been used for PBR fuel utilization calculations and MATLAB script has been used to implement the PSO algorithm. Optimization of PBR natural uranium utilization (NUU) has been carried out for 3000 MWth High Temperature Reactor design (HTR) operating on the Once Trough Then Out (OTTO) fuel management scheme, and for 400 MWth Pebble Bed Modular Reactor (PBMR) operating on the multi-pass (MEDUL) fuel management scheme. Results showed only a modest improvement in the NUU (<5%) over reference designs. Investigation of thorium fuel cases showed that the use of HEU in combination with thorium results in the most favorable reactor performance in terms of

Pebble bed reactor fuel cycle optimization using particle swarm algorithm

International Nuclear Information System (INIS)

Tavron, Barak; Shwageraus, Eugene

2016-01-01

Highlights: • Particle swarm method has been developed for fuel cycle optimization of PBR reactor. • Results show uranium utilization low sensitivity to fuel and core design parameters. • Multi-zone fuel loading pattern leads to a small improvement in uranium utilization. • Thorium mixes with highly enriched uranium yields the best uranium utilization. - Abstract: Pebble bed reactors (PBR) features, such as robust thermo-mechanical fuel design and on-line continuous fueling, facilitate wide range of fuel cycle alternatives. A range off fuel pebble types, containing different amounts of fertile or fissile fuel material, may be loaded into the reactor core. Several fuel loading zones may be used since radial mixing of the pebbles was shown to be limited. This radial separation suggests the possibility to implement the “seed-blanket” concept for the utilization of fertile fuels such as thorium, and for enhancing reactor fuel utilization. In this study, the particle-swarm meta-heuristic evolutionary optimization method (PSO) has been used to find optimal fuel cycle design which yields the highest natural uranium utilization. The PSO method is known for solving efficiently complex problems with non-linear objective function, continuous or discrete parameters and complex constrains. The VSOP system of codes has been used for PBR fuel utilization calculations and MATLAB script has been used to implement the PSO algorithm. Optimization of PBR natural uranium utilization (NUU) has been carried out for 3000 MWth High Temperature Reactor design (HTR) operating on the Once Trough Then Out (OTTO) fuel management scheme, and for 400 MWth Pebble Bed Modular Reactor (PBMR) operating on the multi-pass (MEDUL) fuel management scheme. Results showed only a modest improvement in the NUU (<5%) over reference designs. Investigation of thorium fuel cases showed that the use of HEU in combination with thorium results in the most favorable reactor performance in terms of

Fuel assembly and reactor core

International Nuclear Information System (INIS)

Aoyama, Motoo; Koyama, Jun-ichi; Uchikawa, Sadao; Bessho, Yasunori; Nakajima, Akiyoshi; Maruyama, Hiromi; Ozawa, Michihiro; Nakamura, Mitsuya.

1990-01-01

The present invention concerns fuel assemblies charged in a BWR type reactor and the reactor core. The fuel assembly comprises fuel rods containing burnable poisons and fuel rods not containing burnable poisons. Both of the highest and the lowest gadolinia concentrations of the fuel rods containing gadolinia as burnable poisons are present in the lower region of the fuel assembly. This can increase the spectral shift effect without increasing the maximum linear power density. (I.N.)

Development of compaction technique for spent fuel skeletons

Energy Technology Data Exchange (ETDEWEB)

Yoon, Ji Sup; Kim, Young Hwan; Jung, Jae Hoo [Korea Atomic Energy Research Institute, Taejon (Korea)

1999-12-01

To increase the utilization of uranium resources contained in the spent fuel, the spent fuel is reused. For this, the spent fuel is dismantled or spent fuel rod is extracted from the spent fuel assembly. When the rod is extracted, the remaining components of spent fuel assembly, so called a NFBC(Non-Fuel Bearing Components), should be compacted for the final disposal. To this end, several companies developed the NFBC compactors. German company, named as GNS has developed the direct compression devices of the NFBCs for the rod consolidation and installed it at the PKA(2) of pilot conditioning plant. B and W (Babcock and Wilcox) in USA adopted cutting method rather than the compression method and developed the special cutting devices of NFBC which can be applied underwater environment. In this study the characteristics of these two methods was investigated, in terms of fabrication cost of devices, maintainability in a high radioactive environment, required power and work volume for operation. Also, the optimal power source is selected by comparing the maximum power versus the work volume for operation. In addition to these, the reduction ratio of the bulk volume is obtained while varying the cutting length of the NFBC through a series of experiments. Based on the results of analysis and experiments, the cutting method after compression is selected as an optimal volume reduction method and its design specification is obtained. 8 refs., 62 figs., 32 tabs. (Author)

Evaluation of utilizing spent fuel and plutonium by optimization model for nuclear fuel cycle

International Nuclear Information System (INIS)

Yoshida, Naoto; Fujii, Yasumasa; Komiyama, Ryoichi

2016-01-01

The nuclear power generation has played an important role in power generation mix as a base load power supply. On the other hand, increasing spent fuel and separated plutonium is a long-standing problem. It is expected that advanced fast reactor and high temperature gas reactor could reduce nuclear waste and effectively consume it as valuable resources. Specific scenarios about spent fuel and the gross weight of plutonium are assumed in this study, and the installable potential of fuel cycle and the most suitable reactor mix are analyzed. The model is formulated as liner programing. The model identifies the best strategy of mix of nuclear reactor types to minimize the present value of total cost in a forecast period. As a result, Fast Breeder Reactor and High Temperature Gas Reactor reduce stored spent fuel and increase the consumptions of plutonium. (author)

Quantitative and qualitative investigation of the fuel utilization and introducing a novel calculation idea based on transfer phenomena in a polymer electrolyte membrane (PEM) fuel cell

International Nuclear Information System (INIS)

Yousefkhani, M. Baghban; Ghadamian, H.; Massoudi, A.; Aminy, M.

2017-01-01

Highlights: • Investigation of fuel utilization in PEMFC within transfer phenomenon approach. • The main defect of the theoretical calculation of U_F depends on Nernst equation. • U_F has a differential nature so it is employed to do theoretical calculation. - Abstract: In this study, fuel utilization (U_F) of a PEMFC have been investigated within transfer phenomenon approach. Description of the U_F and fuel consumption measurement is the main factor to obtain the U_F. The differences between the experimental study and theoretical calculations results in the previous research articles reveal the available theoretical equations should be studied more based on the fundamental affairs of the U_F. Hence, there is a substantial issue that the U_F description satisfies the principles, and then it can be validated by the experimental results. The results of this study indicate that the U_F and power grew by 1.1% and 1%, respectively, based on one degree increased temperature. In addition, for every 1 kPa pressure increment, U_F improved considerably by 0.25% and 0.173% in the 40 °C and 80 °C, respectively. Furthermore, in the constant temperature, the power improved by 22% based on one atmospheric growth of the pressure. Results of this research show that the U_F has a differential nature, therefore differential equations will be employed to do an accurate theoretical calculation. Accordingly, it seems that the main defect of the theoretical calculation depends on Nernst equation that can be modified by a differential nature coefficient.

INPR ACPR utilization in fuel behaviour studies under accidental condition

International Nuclear Information System (INIS)

Negut, Gheorghe; Popov, Mircea

1990-01-01

This paper is dedicated to the experimental program, investigating CANDU type fuel behaviour in transient condition, as well as the facilities supporting this program. The tests Reactivity Initiated Accident type. The experiments were performed within TRIGA ACPR facility, installed at INSTITUTE for NUCLEAR POWER REACTORS, Pitesti, ROMANIA. Studies of the safety issues took a great international developement during last years. In USA, Japan, owners of the similar reactors, and USSR there are a big commitment to such programs, intended to establish the nuclear fuel behaviour under RIA-conditions. In our country, too, there are programs aiming a complete testing of the CANDU type fuels. As it is known, RIA is not a CANDU specific accident, but the fuel behaviour in such conditions can give useful informations on the fuel cladding failure threshold and about reflooding post LOCA heat transfer condition. Based on some papers and specific requirements it was initiated and developed a safety research program on CANDU type fuel using the ACPR. The paper describes the reactor,test capsule, instrumentation, fuel samples, tests, post irradiation results. (orig.)

Failed fuel action plan guidelines: Special report

International Nuclear Information System (INIS)

1987-11-01

The objective of this document is to provide a generic guideline that can be used to formulate a failed fuel action plan (FFAP) for specific application by a utility. This document is intended to be part of a comprehensive fuel reliability monitoring, management, and improvement program. The utilities may utilize this document as one resource in developing a failed fuel action plan. This document is not intended to be used as a failed fuel action plan standard. This document is intended to provide guidance on: management responsibilities; fuel performance parameters; cost/benefit analysis; action levels; long-term improvement methods; and data collection, analysis, and trending. 3 refs., 4 figs., 6 tabs

A study on the dissymmetrical microporous layer structure of a direct methanol fuel cell

International Nuclear Information System (INIS)

Wang Tongtao; Lin Caishun; Fang Yong; Ye Feng; Miao Ruiying; Wang Xindong

2008-01-01

The effect of carbon type, carbon loading and microporous layer structure in the microporous layer on the performance of a direct methanol fuel cell (DMFC) at low temperature was investigated using electrochemical polarization techniques, electrochemical impedance spectroscopy, scanning electron microscope and other methods. Vulcan XC-72 carbon was found to be most suitable as a microporous layer for low temperature DMFC. Maximum fuel cell performance was obtained utilizing a microporous layer with carbon loading of 1.0 mg cm -2 when air was used as an oxidant. A membrane electrode assembly with 1.0 mg cm -2 Vulcan XC-72 carbon with 20 wt.% Teflon in the cathode and no microporous layer in the anode showed a maximum power density of 36.7 mW cm -2 at 35 deg. C under atmospheric pressure. The AC impedance study proved that a cell with a dissymmetrical microporous layer structure had lower internal resistance and mass transfer resistance, thus obtaining better performance

Nanofluidic fuel cell

Science.gov (United States)

Lee, Jin Wook; Kjeang, Erik

2013-11-01

Fuel cells are gaining momentum as a critical component in the renewable energy mix for stationary, transportation, and portable power applications. State-of-the-art fuel cell technology benefits greatly from nanotechnology applied to nanostructured membranes, catalysts, and electrodes. However, the potential of utilizing nanofluidics for fuel cells has not yet been explored, despite the significant opportunity of harnessing rapid nanoscale reactant transport in close proximity to the reactive sites. In the present article, a nanofluidic fuel cell that utilizes fluid flow through nanoporous media is conceptualized and demonstrated for the first time. This transformative concept captures the advantages of recently developed membraneless and catalyst-free fuel cell architectures paired with the enhanced interfacial contact area enabled by nanofluidics. When compared to previously reported microfluidic fuel cells, the prototype nanofluidic fuel cell demonstrates increased surface area, reduced activation overpotential, superior kinetic characteristics, and moderately enhanced fuel cell performance in the high cell voltage regime with up to 14% higher power density. However, the expected mass transport benefits in the high current density regime were constrained by high ohmic cell resistance, which could likely be resolved through future optimization studies.

Projection of US LWR spent fuel storage requirements

International Nuclear Information System (INIS)

Fletcher, J.F.; Cole, B.M.; Purcell, W.L.; Rau, R.G.

1982-11-01

The spent fuel storage requirements projection is based on data supplied for each operating or planned nuclear power power plant by the operting utilities. The data supplied by the utilities encompassed details of plant operating history, past records of fuel discharges, current inventories in reactor spent fuel storage pools, and projections of future discharge patterns. Data on storage capacity of storage pools and on characterization of the discharged fuel are also included. The data supplied by the utilities, plus additional data from other appropriate sources, are maintained on a computerized data base by Pacific Northwest Laboratory. The spent fuel requirements projection was based on utility data updated and verified as of December 31, 1981

Effect of exhaust gas recirculation on some combustion characteristics of dual fuel engine

Energy Technology Data Exchange (ETDEWEB)

Selim, Mohamed Y.E. [United Arab Emirates Univ., Dept. of Mechanical Engineering, Al-Ain (United Arab Emirates)

2003-03-01

Combustion pressure rise rate and thermal efficiency data are measured and presented for a dual fuel engine running on a dual fuel of Diesel and compressed natural gas and utilizing exhaust gas recirculation (EGR). The maximum pressure rise rate during combustion is presented as a measure of combustion noise. The experimental investigation on the dual fuel engine revealed the noise generated from combustion and the thermal efficiency at different EGR ratios. A Ricardo E6 Diesel version engine is converted to run on a dual fuel of Diesel and compressed natural gas and having an exhaust gas recycling system is used throughout the work. The engine is fully computerized, and the cylinder pressure data and crank angle data are stored in a PC for offline analysis. The effects of EGR ratio, engine speeds, loads, temperature of recycled exhaust gases, intake charge pressure and engine compression ratio on combustion noise and thermal efficiency are examined for the dual fuel engine. The combustion noise and thermal efficiency of the dual fuel engine are found to be affected when EGR is used in the dual fuel engine. (Author)

Modulated diesel fuel injection strategy for efficient-clean utilization of low-grade biogas

International Nuclear Information System (INIS)

Wang, Xiaole; Qian, Yong; Zhou, Qiyan; Lu, Xingcai

2016-01-01

Highlights: • Influences of direct injection strategy on biogas RCCI mode are researched. • Excessive early pilot injection timing leads to the retard of combustion. • Overall indicated thermal efficiency of low-grade biogas can be higher than 40%. • Pilot injection timing has strong influence on particle size distribution. • Composition of biogas has a great influence on the gas emissions. - Abstract: Recently, as a kind of renewable fuel, low-grade biogas has been researched to apply in internal combustion engine. In this paper, an experimental study was conducted to study the influence of injection strategies on the efficient utilization of low-grade biogas in Reactivity Controlled Compression Ignition (RCCI) mode with port fuel injection of biogas and in-cylinder direct injection of diesel based on a modified electronic controlled high-pressure directly injected compression ignition engine. Considered the high proportion of inert gas in biogas, a four-components simulated gas (H_2:CO:CH_4:N_2 = 5:40:5:50 vol%) has been selected as test fuels to simulate biogas. The effects of several injection control parameters such as pilot injection timing, main injection timing, common rail pressure and pilot injection ratio on the combustion and emissions are analyzed in detail. The research demonstrates that the main injection timing can effectively control the combustion phase and excessive early pilot injection timing leads to retard of combustion. CO emissions are relatively high due to homogenous charge of biogas. NOx and smoke emissions can be effectively controlled. In RCCI mode, the indicated thermal efficiency of biogas/diesel can reach 40%.

Modified fuel assembly design for pressurized water reactors with improved fuel utilization

International Nuclear Information System (INIS)

Galperin, A.; Ronen, Y.

1983-01-01

A method for reactivity control through variation of the moderator content in the reactor core was proposed. The main idea is to adjust the amount of water in the core from a low value at beginning of cycle to a high value at end of cycle, so as to compensate for fissile material burnup and buildup of fission products. The possible implementation of this idea may be carried out by introducing a number of hollow tubes into the fuel assembly between the fuel rods. Then variation of the moderator content in the core may be managed through a change of the water level in these tubes. cated a potential savings in the fuel cycle requirements and costs. Preliminary steady-state thermal-hydraulic calculations indicate the possibility of implementing the proposed method in the existing pressurized water reactor plants. Feasibility of the proposed design may be finally established after rigorous thermal hydraulics as well as safety analysis calculations. Furthermore, there is need to elaborate the mechanical design of the pressure vessel internals together with cost benefit analysis

Electron density distribution in Si and Ge using multipole, maximum ...

Indian Academy of Sciences (India)

Si and Ge has been studied using multipole, maximum entropy method (MEM) and ... and electron density distribution using the currently available versatile ..... data should be subjected to maximum possible utility for the characterization of.

Experimental investigation on dual fuel operation of acetylene in a DI diesel engine

Energy Technology Data Exchange (ETDEWEB)

Lakshmanan, T. [Department of Mechanical Engineering, Rajarajeswari Engineering College, Adayalampattu, Chennai, 600095 (India); Nagarajan, G. [Internal Combustion Engineering Division, College of Engineering, Anna University, Chennai, 600025 (India)

2010-05-15

Depletion of fossils fuels and environmental degradation have prompted researchers throughout the world to search for a suitable alternative fuel for diesel engine. One such step is to utilize renewable fuels in diesel engines by partial or total replacement of diesel in dual fuel mode. In this study, acetylene gas has been considered as an alternative fuel for compression ignition engine, which has excellent combustion properties. Investigation has been carried out on a single cylinder, air cooled, direct injection (DI), compression ignition engine designed to develop the rated power output of 4.4 kW at 1500 rpm under variable load conditions, run on dual fuel mode with diesel as injected primary fuel and acetylene inducted as secondary gaseous fuel at various flow rates. Acetylene aspiration resulted in lower thermal efficiency. Smoke, HC and CO emissions reduced, when compared with baseline diesel operation. With acetylene induction, due to high combustion rates, NO{sub x} emission significantly increased. Peak pressure and maximum rate of pressure rise also increased in the dual fuel mode of operation due to higher flame speed. It is concluded that induction of acetylene can significantly reduce smoke, CO and HC emissions with a small penalty on efficiency. (author)

Fuel Production from Seawater and Fuel Cells Using Seawater.

Science.gov (United States)

Fukuzumi, Shunichi; Lee, Yong-Min; Nam, Wonwoo

2017-11-23

Seawater is the most abundant resource on our planet and fuel production from seawater has the notable advantage that it would not compete with growing demands for pure water. This Review focuses on the production of fuels from seawater and their direct use in fuel cells. Electrolysis of seawater under appropriate conditions affords hydrogen and dioxygen with 100 % faradaic efficiency without oxidation of chloride. Photoelectrocatalytic production of hydrogen from seawater provides a promising way to produce hydrogen with low cost and high efficiency. Microbial solar cells (MSCs) that use biofilms produced in seawater can generate electricity from sunlight without additional fuel because the products of photosynthesis can be utilized as electrode reactants, whereas the electrode products can be utilized as photosynthetic reactants. Another important source for hydrogen is hydrogen sulfide, which is abundantly found in Black Sea deep water. Hydrogen produced by electrolysis of Black Sea deep water can also be used in hydrogen fuel cells. Production of a fuel and its direct use in a fuel cell has been made possible for the first time by a combination of photocatalytic production of hydrogen peroxide from seawater and dioxygen in the air and its direct use in one-compartment hydrogen peroxide fuel cells to obtain electric power. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

The design of in-pile test section for fuel test loop

Energy Technology Data Exchange (ETDEWEB)

Park, K. N.; Lee, J. M.; Shim, B. S.; Zee, D. Y.; Park, S. H.; Ahn, S. H.; Lee, J. Y.; Kim, Y. J. [KAERI, Taejon (Korea, Republic of)

2004-07-01

As an equipment for nuclear fuel's general performance irradiation test in HANARO, Fuel Test Loop(FTL) has been developed that can irradiate the pin to the maximum number of 3 at the core irradiation hole(IR1 hole) by considering for it's utility and user's irradiation requirement. 3-Pin FTL consists of In-Pile Test Section (IPS) and Out-of-Pile System (OPS). IPS consists for IPS Vessel assembly, In-Pool Piping, IPS Support, In-Pool Piping Support etc. Design that such IPS considers interference item consisted to do not bear in existing facilities by one. IVA that is connected to the OPS are controlled and regulated by means of system pressure, system temperature and the water quality. IPS Vessel assembly is consisted of outer pressure vessel, inner pressure vessel, IPS head, inner assembly and test fuel carrier. After 3-Pin FTL development which is expected to be finished by the 2006, FTL will be used for the irradiation test of the new PWR-type fuel and can maximize the usage of HANARO.

[Electricity generation from sweet potato fuel ethanol wastewater using microbial fuel cell technology].

Science.gov (United States)

Cai, Xiao-Bo; Yang, Yi; Sun, Yan-Ping; Zhang, Liang; Xiao, Yao; Zhao, Hai

2010-10-01

Air cathode microbial fuel cell (MFC) were investigated for electricity production from sweet potato fuel ethanol wastewater containing 5000 mg/L of chemical oxygen demand (COD). Maximum power density of 334.1 mW/m2, coulombic efficiency (CE) of 10.1% and COD removal efficiency of 92.2% were approached. The effect of phosphate buffer solution (PBS) and COD concentration on the performance of MFC was further examined. The addition of PBS from 50 mmol/L to 200 mmol/L increased the maximum power density and CE by 33.4% and 26.0%, respectively. However, the COD removal efficiency was not relative to PBS concentration in the wastewater. When the COD increased from 625 mg/L to 10 000 mg/L, the maximum value of COD removal efficiency and the maximum power density were gained at the wastewater strength of 5 000 mg/L. But the CE ranged from 28.9% to 10.3% with a decreasing trend. These results demonstrate that sweet potato fuel ethanol wastewater can be used for electricity generation in MFC while at the same time achieving wastewater treatment. The increasing of PBS concentration can improve the power generation of MFC. The maximum power density of MFC increases with the rise of COD concentration, but the electricity generation will decrease for the acidification of high wastewater concentration.

Analysis of energy cascade utilization in a chemically recuperated scramjet with indirect combustion

International Nuclear Information System (INIS)

Qin, Jiang; Cheng, Kunlin; Zhang, Silong; Zhang, Duo; Bao, Wen; Han, Jiecai

2016-01-01

The working process of scramjet with regenerative cooling, which was actually the chemical recuperation process, was analyzed in view of energy cascade utilization. The indirect combustion was realized through pyrolysis reaction of fuel. The relative yields of thermal exergy obtained by indirect combustion have been predicted both assuming an ideal pyrolysis reaction and using the experimental results of thermal pyrolysis of n-decane. The results showed that the influence mechanism of regenerative cooling improved the scramjet engine performance by the energy cascade utilization, and the combustion process was supposed to be designed with the cooling process together to utilize the chemical energy of fuel in a more effective way. A maximum value of 11% of the relative yield was obtained with the ideal pyrolysis reaction while a value less than 3% existed in the thermal pyrolysis experiments because of the domination of chemical kinetics rather than chemical thermodynamics in the real experiments. In spite of the difference between the ideal and the present experimental results, the indirect combustion was prospective to achieve a better energy cascade utilization in a chemically recuperated scramjet if the pyrolysis reaction was further optimized. The results in this paper were beneficial for the performance optimization of a regenerative cooling scramjet. - Highlights: • A new method of energy cascade utilization in a chemically recuperated scramjet. • 11% exergy loss is reduced by ideal pyrolysis reaction with indirect combustion. • Regenerative cooling with chemical recuperation can improve engine performance.

Preliminary Thermohydraulic Analysis of a New Moderated Reactor Utilizing an LEU-Fuel for Space Nuclear Thermal Propulsion

International Nuclear Information System (INIS)

Nam, Seung Hyun; Choi, Jae Young; Venneria, Paolo F.; Jeong, Yong Hoon; Chang, Soon Heung

2015-01-01

The Korea Advanced NUclear Thermal Engine Rocket utilizing an LEU fuel (KANUTER-LEU) is a non-proliferative and comparably efficient NTR engine with relatively low thrust levels of 40 - 50 kN for in-space transportation. The small modular engine can expand mission versatility, when flexibly used in a clustered engine arrangement, so that it can perform various scale missions from low-thrust robotic science missions to high-thrust manned missions. In addition, the clustered engine system can enhance engine redundancy and ensuing crew safety as well as the thrust. The propulsion system is an energy conversion system to transform the thermal energy of the reactor into the kinetic energy of the propellant to produce the powers for thrust, propellant feeding and electricity. It is mainly made up of a propellant Feeding System (PFS) comprising a Turbo-Pump Assembly (TPA), a Regenerative Nozzle Assembly (RNA), etc. For this core design study, an expander cycle is assumed to be the propulsion system. The EGS converts the thermal energy of the EHTGR in the idle operation (only 350 kW th power) to electric power during the electric power mode. This paper presents a preliminary thermohydraulic design analysis to explore the design space for the new reactor and to estimate the referential engine performance. The new non-proliferative NTR engine concept, KANUTER-LEU, is under designing to surmount the nuclear proliferation obstacles on allR and Dactivities and eventual commercialization for future generations. To efficiently implement a heavy LEU fuel for the NTR engine, its reactor design innovatively possesses the key characteristics of the high U density fuel with high heating and H 2 corrosion resistances, the thermal neutron spectrum core and also minimizing non-fission neutron loss, and the compact reactor design with protectively cooling capability. To investigate feasible design space for the moderated EHTGR-LEU and resultant engine performance, the preliminary design

Design of an optical thermal sensor for proton exchange membrane fuel cell temperature measurement using phosphor thermometry

Science.gov (United States)

Inman, Kristopher; Wang, Xia; Sangeorzan, Brian

Internal temperatures in a proton exchange membrane (PEM) fuel cell govern the ionic conductivities of the polymer electrolyte, influence the reaction rate at the electrodes, and control the water vapor pressure inside the cell. It is vital to fully understand thermal behavior in a PEM fuel cell if performance and durability are to be optimized. The objective of this research was to design, construct, and implement thermal sensors based on the principles of the lifetime-decay method of phosphor thermometry to measure temperatures inside a PEM fuel cell. Five sensors were designed and calibrated with a maximum uncertainty of ±0.6 °C. Using these sensors, surface temperatures were measured on the cathode gas diffusion layer of a 25 cm 2 PEM fuel cell. The test results demonstrate the utility of the optical temperature sensor design and provide insight into the thermal behavior found in a PEM fuel cell.

Thorium-based nuclear fuel: current status and perspectives

International Nuclear Information System (INIS)

1987-03-01

Until the present time considerable efforts have already been made in the area of fabrication, utilization and reprocessing of Th-based fuels for different types of reactors, namely: by FRG and USA - for HTRs; FRG and Brazil, Italy - for LWRs; India - for HWRs and FBRs. Basic research of thorium fuels and thorium fuel cycles are also being undertaken by Australia, Canada, China, France, FRG, Romania, USSR and other countries. Main emphasis has been given to the utilization of thorium fuels in once-through nuclear fuel cycles, but in some projects closed thorium-uranium or thorium-plutonium fuel cycles are also considered. The purpose of the Technical Committee on the Utilization of Thorium-Based Nuclear Fuel: Current Status and Perspective was to review the world thorium resources, incentives for further exploration, obtained experience in the utilization of Th-based fuels in different types of reactors, basic research, fabrication and reprocessing of Th-based fuels. As a result of the panel discussion the recommendations on future Agency activities and list of major worldwide activities in the area of Th-based fuel were developed. A separate abstract was prepared for each of the 9 papers in this proceedings series

Design of a thermally integrated bioethanol-fueled solid oxide fuel cell system integrated with a distillation column

Science.gov (United States)

Jamsak, W.; Douglas, P. L.; Croiset, E.; Suwanwarangkul, R.; Laosiripojana, N.; Charojrochkul, S.; Assabumrungrat, S.

Solid oxide fuel cell systems integrated with a distillation column (SOFC-DIS) have been investigated in this study. The MER (maximum energy recovery) network for SOFC-DIS system under the base conditions (C EtOH = 25%, EtOH recovery = 80%, V = 0.7 V, fuel utilization = 80%, T SOFC = 1200 K) yields Q Cmin = 73.4 and Q Hmin = 0 kW. To enhance the performance of SOFC-DIS, utilization of internal useful heat sources from within the system (e.g. condenser duty and hot water from the bottom of the distillation column) and a cathode recirculation have been considered in this study. The utilization of condenser duty for preheating the incoming bioethanol and cathode recirculation for SOFC-DIS system were chosen and implemented to the SOFC-DIS (CondBio-CathRec). Different MER designs were investigated. The obtained MER network of CondBio-CathRec configuration shows the lower minimum cold utility (Q Cmin) of 55.9 kW and total cost index than that of the base case. A heat exchanger loop and utility path were also investigated. It was found that eliminate the high temperature distillate heat exchanger can lower the total cost index. The recommended network is that the hot effluent gas is heat exchanged with the anode heat exchanger, the external reformer, the air heat exchanger, the distillate heat exchanger and the reboiler, respectively. The corresponding performances of this design are 40.8%, 54.3%, 0.221 W cm -2 for overall electrical efficiency, Combine Heat and Power (CHP) efficiency and power density, respectively. The effect of operating conditions on composite curves on the design of heat exchanger network was investigated. The obtained composite curves can be divided into two groups: the threshold case and the pinch case. It was found that the pinch case which T SOFC = 1173 K yields higher total cost index than the CondBio-CathRec at the base conditions. It was also found that the pinch case can become a threshold case by adjusting split fraction or operating at

Fuel-cycle cost comparisons with oxide and silicide fuels

International Nuclear Information System (INIS)

Matos, J.E.; Freese, K.E.

1982-01-01

This paper addresses fuel cycle cost comparisons for a generic 10 MW reactor with HEU aluminide fuel and with LEU oxide and silicide fuels in several fuel element geometries. The intention of this study is to provide a consistent assessment of various design options from a cost point of view. Fuel cycle cost benefits could result if a number of reactors were to utilize fuel elements with the same number or different numbers of the same standard fuel plate. Data are presented to quantify these potential cost benefits. This analysis shows that there are a number of fuel element designs using LEU oxide or silicide fuels that have either the same or lower total fuel cycle costs than the HEU design. Use of these fuels with the uranium densities considered requires that they are successfully demonstrated and licensed

Advanced core physics and thermal hydraulics analysis of boiling water reactors using innovative fuel concepts

International Nuclear Information System (INIS)

Winter, Dominik

2014-01-01

fuel produce the same amount of energy as the conventional uranium-based fuel. The results of the studies show that in the ThPu and in the MOX fuels partially significant smaller quantities of most of the long-lived actinides are produced. The time-averaged power profile along the active height in the assemblies loaded with the heterogeneous fuel is broader distributed and the maximum temperature in both fuel types is approximately 250 K lower than the maximum temperature in the UO 2 fuel. This yields to a decrease in the Doppler broadening of the resonance lines in the absorption cross section as well as to smaller temperature gradients in the material structures of the assembly. The fuel burnup is correlated with the power profile, hence, an axially more constant fuel utilization in comparison to uranium-based fuels with a homogeneous enrichment is observed. Regarding the initial activity of the spent fuels, it is shown that the contribution of the fission products to the total activity is negligible in the case of ThPu and MOX which is contrary to the UO 2 fuel, where the total activity is dominated by the fission products at the very beginning of the storage time. However, due to the high fraction of plutonium in the innovative fuels, the total activity decreases slower than the total activity of the UO 2 fuel by a factor of two (MOX) and 2.5 (ThPu). On the other hand, this behavior is typical for conventional mixed oxide fuels. At core level, the uranium-based fuel assemblies are replaced with 11% and 18% of the assemblies heterogeneously loaded with the MOX and the ThPu fuels, respectively. An optimum loading pattern is achieved with a minimum peaking factor for both core models. The assemblies loaded with the innovative fuels influence the residual UO 2 fuel assemblies and the operational behavior of the entire core by (amongst others) an extension of the operational cycle of about 22%. This extension is explained as follows: for the utilization of - MOX: an

The Assessment Of High Temperature Reactor Fuel (Characteristics Of HTTR Fuel)

International Nuclear Information System (INIS)

Dewita, Erlan; Tuka, Veronica; Gunandjar

1996-01-01

HTTR is one of the reactor type with Helium coolant and outlet coolant temperature of 950 o C. One possibility of HTTR application is the coo generation of steam in high temperature and electric power for supply energy to industry in the future. Considering to the high operating temperature of HTTR, therefore it is needed the reactor fuel which have good mechanical, chemical and physical stability to the high temperature, and stable to the influence of fission fragment and neutron during irradiation. This assessment of the HTTR fuel characteristic based on the experiment data to find information of HTTR operation feasibility. Result of the assessment indicated that fission gas release at burn-up of 3.6 % FIMA which was the same as the maximum burn up in the HTTR design was fairly lower than the maximum release estimated in the design (5 x 10 - 4), which is R/B from the fuel fabricated by the prismatic block fuel method would be low (between 10 - 9 dan 10 - 8)

Fuel peat utilization in Finland: resource use and emissions

International Nuclear Information System (INIS)

Leijting, J.

1999-01-01

The aim of the study was to inventorize the emissions and other stressors caused by fuel peat use in Finland. The life cycle approach was used to organise and compile the burdens associated with the fuel peat utilisation sector in the years 1994 and 1995. Fuel peat accounts for about 6.5 % of the total primary energy production in Finland. The study showed that most emissions out into the air occur during combustion of peat in energy plants. The emissions account for about 13 - 14 % of the CO 2 emissions released by fossil fuel utilisation in Finland, for 12 % of the SO 2 for 8 % of the N 2 O and approximately 4 % of the NOR emissions released by anthropogenic sources in Finland. Phosphorus releases into waters contributes for about 0.2 % while nitrogen releases account for 0.3 % in the total anthropogenic discharge in Finland. (orig.) 88 refs

Reliability analysis of dispersion nuclear fuel elements

Science.gov (United States)

Ding, Shurong; Jiang, Xin; Huo, Yongzhong; Li, Lin an

2008-03-01

Taking a dispersion fuel element as a special particle composite, the representative volume element is chosen to act as the research object. The fuel swelling is simulated through temperature increase. The large strain elastoplastic analysis is carried out for the mechanical behaviors using FEM. The results indicate that the fission swelling is simulated successfully; the thickness increments grow linearly with burnup; with increasing of burnup: (1) the first principal stresses at fuel particles change from tensile ones to compression ones, (2) the maximum Mises stresses at the particles transfer from the centers of fuel particles to the location close to the interfaces between the matrix and the particles, their values increase with burnup; the maximum Mises stresses at the matrix exist in the middle location between the two particles near the mid-plane along the length (or width) direction, and the maximum plastic strains are also at the above region.

Reliability analysis of dispersion nuclear fuel elements

Energy Technology Data Exchange (ETDEWEB)

Ding Shurong [Department of Mechanics and Engineering Science, Fudan University, Shanghai 200433 (China)], E-mail: dsr1971@163.com; Jiang Xin [Department of Mechanics and Engineering Science, Fudan University, Shanghai 200433 (China); Huo Yongzhong [Department of Mechanics and Engineering Science, Fudan University, Shanghai 200433 (China)], E-mail: yzhuo@fudan.edu.cn; Li Linan [Department of Mechanics, Tianjin University, Tianjin 300072 (China)

2008-03-15

Taking a dispersion fuel element as a special particle composite, the representative volume element is chosen to act as the research object. The fuel swelling is simulated through temperature increase. The large strain elastoplastic analysis is carried out for the mechanical behaviors using FEM. The results indicate that the fission swelling is simulated successfully; the thickness increments grow linearly with burnup; with increasing of burnup: (1) the first principal stresses at fuel particles change from tensile ones to compression ones, (2) the maximum Mises stresses at the particles transfer from the centers of fuel particles to the location close to the interfaces between the matrix and the particles, their values increase with burnup; the maximum Mises stresses at the matrix exist in the middle location between the two particles near the mid-plane along the length (or width) direction, and the maximum plastic strains are also at the above region.

Method of inserting fuel rod

International Nuclear Information System (INIS)

Kamimoto, Shuji; Imoo, Makoto; Tsuchida, Kenji.

1991-01-01

The present invention concerns a method of inserting a fuel rod upon automatic assembling, automatic dismantling and reassembling of a fuel assembly in a light water moderated reactor, as well as a device and components used therefor. That is, a fuel rod is inserted reliably to an aimed point of insertion by surrounding the periphery of the fuel rod to be inserted with guide rods, and thereby suppressing the movement of the fuel rod during insertion. Alternatively, a fuel rod is inserted reliably to a point of insertion by inserting guide rods at the periphery of the point of insertion for the fuel rod to be inserted thereby surrounding the point of insertion with the guide rods or fuel rods. By utilizing fuel rods already present in the fuel assembly as the guide rods described above, the fuel rod can be inserted reliably to the point of insertion with no additional devices. Dummy fuel rods are previously inserted in a fuel assembly which are then utilized as the above-mentioned guide rods to accurately insert the fuel rod to the point of insertion. (I.S.)

Dodewaard fuel supply agreement - a model for the future

International Nuclear Information System (INIS)

Raven, L.F.; Hubers, C.

1980-01-01

An Agreement between the Utility GKN and the Fuel Supplier BNFL has eliminated any Utility imposed penalty clauses for fuel failure due to operational conditions and, consequently, there are no restrictions imposed by the Fuel Supplier on the reactor operational manoeuvres. The result is that the Utility can now decide if the risk of fuel clad failure during a reactor power ramp outweighs the financial loss due to slower ramp rates. It is the Utility and not the Fuel Supplier who is in the best position to make this judgment provided adequate operational experience and computer codes are available to quantify the risk. The paper discusses the reactor operational experience, including the fuel failure rate and the confirmation of PCI failure by post irradiation examination. It establishes the practicality of the Agreement for the Dodewaard reactor and suggests such arrangements could be beneficial to other Utilities. (author)

Fissile fuel doubling time characteristics for reactor lifetime fuel logistics

International Nuclear Information System (INIS)

Heindler, M.; Harms, A.A.

1978-01-01

The establishment of nuclear fuel requirements and their efficient utilization requires a detailed knowledge of some aspects of fuel dynamics and processing during the reactor lifetime. It is shown here that the use of the fuel stockpile inventory concept can serve effectively for this fuel management purpose. The temporal variation of the fissile fuel doubling time as well as nonequilibrium core conditions are among the characteristics which thus become more evident. These characteristics - rather than a single figure-of-merit - clearly provide an improved description of the expansion capacity and/or fuel requirements of a nuclear reactor energy system

US versus non-US utility procurement practices

International Nuclear Information System (INIS)

Clark, H.

1991-01-01

Utilities, particularly in the USA, have often been accused by the uranium industry of behaving like a herd with respect to their activities in the nuclear fuel market. While I disagree with this characterization, I do recognize that utilities in general have certain common motivations influencing their nuclear fuel procurement activities which may make them appear to follow each other. This paper reviews these motivations, how they differ between US and non-US utilities, how such differences lead to different procurement practices in the USA and elsewhere, the resulting impacts on the nuclear fuel market, and the changes, if, any, which one may expect in the future. The discussion in this paper is geared mainly towards the uranium market, though the concepts discussed are also somewhat applicable to the other components of nuclear fuel. (author)

Spent fuel transportation in the United States: commercial spent fuel shipments through December 1984

International Nuclear Information System (INIS)

1986-04-01

This report has been prepared to provide updated transportation information on light water reactor (LWR) spent fuel in the United States. Historical data are presented on the quantities of spent fuel shipped from individual reactors on an annual basis and their shipping destinations. Specifically, a tabulation is provided for each present-fuel shipment that lists utility and plant of origin, destination and number of spent-fuel assemblies shipped. For all annual shipping campaigns between 1980 and 1984, the actual numbers of spent-fuel shipments are defined. The shipments are tabulated by year, and the mode of shipment and the casks utilized in shipment are included. The data consist of the current spent-fuel inventories at each of the operating reactors as of December 31, 1984. This report presents historical data on all commercial spent-fuel transportation shipments have occurred in the United States through December 31, 1984

Integral nuclear fuel element assembly

International Nuclear Information System (INIS)

Schluderberg, D. C.

1985-01-01

An integral nuclear fuel element assembly utilizes longitudinally finned fuel pins. The continuous or interrupted fins of the fuel pins are brazed to fins of juxtaposed fuel pins or directly to the juxtaposed fuel pins or both. The integrally brazed fuel assembly is designed to satisfy the thermal and hydraulic requirements of a fuel assembly lattice having moderator to fuel atom ratios required to achieve high conversion and breeding ratios

Multi level optimization of burnable poison utilization for advanced PWR fuel management

Science.gov (United States)

Yilmaz, Serkan

The objective of this study was to develop an unique methodology and a practical tool for designing burnable poison (BP) pattern for a given PWR core. Two techniques were studied in developing this tool. First, the deterministic technique called Modified Power Shape Forced Diffusion (MPSFD) method followed by a fine tuning algorithm, based on some heuristic rules, was developed to achieve this goal. Second, an efficient and a practical genetic algorithm (GA) tool was developed and applied successfully to Burnable Poisons (BPs) placement optimization problem for a reference Three Mile Island-1 (TMI-1) core. This thesis presents the step by step progress in developing such a tool. The developed deterministic method appeared to perform as expected. The GA technique produced excellent BP designs. It was discovered that the Beginning of Cycle (BOC) Kinf of a BP fuel assembly (FA) design is a good filter to eliminate invalid BP designs created during the optimization process. By eliminating all BP designs having BOC Kinf above a set limit, the computational time was greatly reduced since the evaluation process with reactor physics calculations for an invalid solution is canceled. Moreover, the GA was applied to develop the BP loading pattern to minimize the total Gadolinium (Gd) amount in the core together with the residual binding at End-of-Cycle (EOC) and to keep the maximum peak pin power during core depletion and Soluble boron concentration at BOC both less than their limit values. The number of UO2/Gd2O3 pins and Gd 2O3 concentrations for each fresh fuel location in the core are the decision variables and the total amount of the Gd in the core and maximum peak pin power during core depletion are in the fitness functions. The use of different fitness function definition and forcing the solution movement towards to desired region in the solution space accelerated the GA runs. Special emphasize is given to minimizing the residual binding to increase core lifetime as

Modular dry storage of spent fuel

International Nuclear Information System (INIS)

Baxter, J.W.

1982-01-01

Long term uncertainties in US spent fuel reprocessing and storage policies and programs are forcing the electric utilities to consider means of storing spent fuel at the reactor site in increasing quantitities and for protracted periods. Utilities have taken initial steps in increasing storage capacity. Existing wet storage pools have in many cases been reracked to optimize their capacity for storing spent fuel assemblies

Investigation of research and development subjects for the Very High Burnup Fuel

International Nuclear Information System (INIS)

Hayashi, Kimio; Amano, Hidetoshi; Suzuki, Yasufumi; Furuta, Teruo; Nagase, Fumihisa; Suzuki, Masahide

1993-06-01

A concept of the Very High Burnup Fuel aiming at a maximum fuel assembly burnup of 100 GWd/t has been proposed in terms of burnup extension, utilization of Pu and transmutation of transuranium elements (TRU: Np, Am and Cm). The authors have investigated research and development (R and D) subjects of the fuel pellet and the cladding material of the Fuel. The present report describes the results on the fuel pellet. First, the chemical state of the Fuel and fission products (FP) was inferred through an FP-inventory and an equilibrium-thermodynamics calculations. Besides, knowledge obtained from post-irradiation examinations was surveyed. Next, an investigation was made on irradiation behavior of U/Pu mixed oxide (MOX) fuel with high enrichment of Pu, as well as on fission-gas release and swelling behavior of high burnup fuels. Reprocessibility of the Fuel, particularly solubility of the spent fuel, was also examined. As for the TRU-added fuel, material property data on TRU oxides were surveyed and summarized as a database. And the subjects on the production and the irradiation behavior were examined on the basis of experiences of MOX fuel production and TRU-added fuel irradiation. As a whole, the present study revealed the necessity of accumulating fundamental data and knowledge required for design and assessment of the fuel pellet, including the information on properties and irradiation performance of the TRU-added fuel. Finally, the R and D subjects were summarized, and a proposal was made on the way of development of the fuel pellet and cladding materials. (author)

Small-scale production and utilization of wood fuels; Puupolttoaineen pientuotanto ja -kaeyttoe - katsaus tutkimus- projekteihin

Energy Technology Data Exchange (ETDEWEB)

Tuomi, S [Work Efficiency Inst., Rajamaeki (Finland)

1997-12-31

The objective of the research on small-scale production of wood fuels was to promote the forest owners` own utilization and procurement of firewood. The profitability of firewood was improved by developing new farm-tractor mountable equipment and methods for forest owners and small-entrepreneurs for harvesting of first-thinning wood and other small-dimeter wood. Totally new solution for machine felling of small trees and chopwood production were developed to serial production level. Recyclable processing and delivery units were developed for delivery of chopwood. A calculation model for analysing the costs of small-scale production of firewood became ready. A guide on the development of heating-entrepreneur activities, serving the entrepreneurs, was published. The objective of the firewood utilization research was to reduce the technical barriers of the utilization of firewood in small-house and real-estate scales. The main aim was to reduce the flue-gas emissions. The emissions of the fireplaces were reduced by developing the construction of fireplaces, catalytic combustion and heating methods. An automatic stoker-burner was developed for real-estate scale and a boiler series was designed for biofuels

Small-scale production and utilization of wood fuels; Puupolttoaineen pientuotanto ja -kaeyttoe - katsaus tutkimus- projekteihin

Energy Technology Data Exchange (ETDEWEB)

Tuomi, S. [Work Efficiency Inst., Rajamaeki (Finland)

1996-12-31

The objective of the research on small-scale production of wood fuels was to promote the forest owners` own utilization and procurement of firewood. The profitability of firewood was improved by developing new farm-tractor mountable equipment and methods for forest owners and small-entrepreneurs for harvesting of first-thinning wood and other small-dimeter wood. Totally new solution for machine felling of small trees and chopwood production were developed to serial production level. Recyclable processing and delivery units were developed for delivery of chopwood. A calculation model for analysing the costs of small-scale production of firewood became ready. A guide on the development of heating-entrepreneur activities, serving the entrepreneurs, was published. The objective of the firewood utilization research was to reduce the technical barriers of the utilization of firewood in small-house and real-estate scales. The main aim was to reduce the flue-gas emissions. The emissions of the fireplaces were reduced by developing the construction of fireplaces, catalytic combustion and heating methods. An automatic stoker-burner was developed for real-estate scale and a boiler series was designed for biofuels

The role of spent fuel test facilities in the fuel cycle strategy

International Nuclear Information System (INIS)

Huang, S. T.; Gross, D. L.; Snyder, N. W.; Woods, W. D.

1988-01-01

Disposal of commercial spent nuclear fuels in the major industrialized countries may be categorized into two broad approaches: a once-through policy which will dispose of spent fuels and recycle fissile materials. Within reprocess spent fuels and recycle fissile materials. Within each policy, various technical, licensing, institutional and public issues exist. These issues tend to complicate the formulation of an effective and acceptable fuel cycle strategy which will meet various cost, schedule, and legislative constraints. This paper examines overall fuel cycle strategies from the viewpoint of these underlying technical issues and assesses the roles of spent fuel test facilities in the overall fuel cycles steps. Basic functions of such test facilities are also discussed. The main emphasis is placed on the once-through policy although the reprocessing / recycle policy is also discussed. Benefits of utilizing test facilities in the fuel cycle strategies are explored. The results indicate that substantial benefits may be obtained in terms of minimizing programmatic risks, increasing public confidence, and more effective utilization of overall budgetary resources by structuring and highlighting the test facilities as an important element in the overall strategy

BWR fuel performance

International Nuclear Information System (INIS)

Baily, W.E.; Armijo, J.S.; Jacobson, J.; Proebstle, R.A.

1979-01-01

The General Electric experience base on BWR fuel includes over 29,000 fuel assemblies which contain 1,600,000 fuel rods. Over the last five years, design, process and operating changes have been introduced which have had major effects in improving fuel performance. Monitoring this fuel performance in BWRs has been accomplished through cooperative programs between GE and utilities. Activities such as plant fission product monitoring, fuel sipping and fuel and channel surveillance programs have jointly contributed to the value of this extensive experience base. The systematic evaluation of this data has established well-defined fuel performance trends which provide the assurance and confidence in fuel reliability that only actual operating experience can provide

Utilization of the cyanobacteria Anabaena sp CH1 in biological carbon dioxide mitigation processes

Energy Technology Data Exchange (ETDEWEB)

Chiang, C.L.; Lee, C.M.; Chen, P.C. [Hungkuang University, Taichung (Taiwan)

2011-05-15

Before switching totally to alternative fuel stage, CO{sub 2} mitigation process has considered a transitional strategy for combustion of fossil fuels inevitably. In comparison to other CO{sub 2} mitigation options, such as oceanic or geologic injection, the biological photosynthetic process would present a far superior and sustainable solution under both environmental and social considerations. The utilization of the cyanobacteria Anabaena sp. CH1 in carbon dioxide mitigation processes is analyzed in our research. It was found that an original developed photobioreactor with internal light source exhibits high light utilization. Anabaena sp. CH1 demonstrates excellent CO{sub 2} tolerance even at 15% CO{sub 2} level. This enables flue gas from power plant to be directly introduced to Anabaena sp. CH1 culture. Double light intensity and increased 47% CO{sub 2} bubble retention time could enhance CO{sub 2} removal efficiencies by 79% and 67%, respectively. A maximum CO{sub 2} fixation rate of 1.01 g CO{sub 2} L{sup -1} day{sup -1} was measured experimentally.

Controlling fuel costs: Procurement strategies and regulatory standards

International Nuclear Information System (INIS)

Einhorn, H.A.; Levi, B.I.

1992-01-01

Since the oil price shocks and inflation of the 1970s, regulatory authorities and utilities have devoted considerable attention to controlling energy costs while maintaining reliable service. Although much of this concern has been directed towards capital cost containment, increasing scrutiny has been applied to a broad range of variable costs, especially to fuel procurement expenditures. With some 40% to 65% of the electric utility industry's annual operation and maintenance expenses paid to secure fuel supplies, even a small difference in fuel costs could have a substantial impact on costs to ratepayers. This increased attention to fuel cost containment can be expected to intensify as implementation of the 1990 amendments to the Clean Air Act affects fuel purchase decisions. To assure that fuel is purchased in a responsible and cost-effective manner, some state jurisdictions have initiated periodic reviews (audits) of the procurement practices that electric utilities follow when purchasing fuel. While a utility must demonstrate how it purchases fuel, there is wide variation in interest and scope of audits among jurisdictions. In this paper, the authors review: (1) the regulatory environment within which fuel procurement and audits occur, and (2) some particularly controversial issues that will receive increasing attention as the practice of conducting fuel procurement audits spreads

Fuel utilization improvements in a once-through PWR fuel cycle. Final report on Task 6

International Nuclear Information System (INIS)

Dabby, D.

1979-06-01

In studying the position of the United States Department of Energy, Non-proliferation Alternative Systems Assessment Program, this report determines the uranium saving associated with various improvement concepts applicable to a once-through fuel cycle of a standard four-loop Westinghouse Pressurized Water Reactor. Increased discharged fuel burnup from 33,000 to 45,000 MWD/MTM could achieve a 12% U 3 O 8 saving by 1990. Improved fuel management schemes combined with coastdown to 60% power, could result in U 3 O 8 savings of 6%

Nuclear fuels and development of nuclear fuel elements

International Nuclear Information System (INIS)

Sundaram, C.V.; Mannan, S.L.

1989-01-01

Safe, reliable and economic operation of nuclear fission reactors, the source of nuclear power at present, requires judicious choice, careful preparation and specialised fabrication procedures for fuels and fuel element structural materials. These aspects of nuclear fuels (uranium, plutonium and their oxides and carbides), fuel element technology and structural materials (aluminium, zircaloy, stainless steel etc.) are discussed with particular reference to research and power reactors in India, e.g. the DHRUVA research reactor at BARC, Trombay, the pressurised heavy water reactors (PHWR) at Rajasthan and Kalpakkam, and the Fast Breeder Test Reactor (FBTR) at Kalpakkam. Other reactors like the gas-cooled reactors operating in UK are also mentioned. Because of the limited uranium resources, India has opted for a three-stage nuclear power programme aimed at the ultimate utilization of her abundant thorium resources. The first phase consists of natural uranium dioxide-fuelled, heavy water-moderated and cooled PHWR. The second phase was initiated with the attainment of criticality in the FBTR at Kalpakkam. Fast Breeder Reactors (FBR) utilize the plutonium and uranium by-products of phase 1. Moreover, FBR can convert thorium into fissile 233 U. They produce more fuel than is consumed - hence, the name breeders. The fuel parameters of some of the operating or proposed fast reactors in the world are compared. FBTR is unique in the choice of mixed carbides of plutonium and uranium as fuel. Factors affecting the fuel element performance and life in various reactors e.g. hydriding of zircaloys, fuel pellet-cladding interaction etc. in PHWR and void swelling; irradiation creep and helium embrittlement of fuel element structural materials in FBR are discussed along with measures to overcome some of these problems. (author). 15 refs., 9 tabs., 23 figs

Power Peaking Effect of OTTO Fuel Scheme Pebble Bed Reactor

Science.gov (United States)

Setiadipura, T.; Suwoto; Zuhair; Bakhri, S.; Sunaryo, G. R.

2018-02-01

Pebble Bed Reactor (PBR) type of Hight Temperature Gas-cooled Reactor (HTGR) is a very interesting nuclear reactor design to fulfill the growing electricity and heat demand with a superior passive safety features. Effort to introduce the PBR design to the market can be strengthen by simplifying its system with the Once-through-then-out (OTTO) cycle PBR in which the pebble fuel only pass the core once. Important challenge in the OTTO fuel scheme is the power peaking effect which limit the maximum nominal power or burnup of the design. Parametric survey is perform in this study to investigate the contribution of different design parameters to power peaking effect of OTTO cycle PBR. PEBBED code is utilized in this study to perform the equilibrium PBR core analysis for different design parameter and fuel scheme. The parameters include its core diameter, height-per-diameter (H/D), power density, and core nominal power. Results of this study show that diameter and H/D effectsare stronger compare to the power density and nominal core power. Results of this study might become an importance guidance for design optimization of OTTO fuel scheme PBR.

Joint venturing in the fuel, energy and environmental arena: Opportunities for utility subsidiaries and developers

International Nuclear Information System (INIS)

Rowley, D.A.

1992-01-01

We have witnessed major changes in the 1980s in the US fuel, energy and environmental areas. From the structure of heavily-regulated local and regional monopolies that predated World War 2, Federal and State governments have begun moving toward a more market-oriented approach to fuel supply, fuel transport and power generation with the goal of increasing competition to effect lower prices for consumers. Although some utilities have resisted this trend - arguing, for example, that third-party power purchasing threatens system reliability - others have joined the market by diversifying into the non-regulated side of the industry. Similarly, beginning with creation of the Superfund, continuing with last year's amendments to the Clean Air Act, and on into the future with anticipated changes for water, solid waste, and other areas, Congress and the EPA have created a regulatory structure that cries out for more capital yet makes such investment more risky. This paper examines joint venture strategies in the context of developing new business in the energy and environmental areas. This paper focuses on the interaction of three aspects of such efforts: (1) the issues of primary importance to the entity engaging in such efforts, (2) the impact of various strategies on the resolution of the issues, and (3) the use of joint ventures to maximize benefits and minimize risks

Fuel Class Higher Alcohols

KAUST Repository

Sarathy, Mani

2016-08-17

This chapter focuses on the production and combustion of alcohol fuels with four or more carbon atoms, which we classify as higher alcohols. It assesses the feasibility of utilizing various C4-C8 alcohols as fuels for internal combustion engines. Utilizing higher-molecular-weight alcohols as fuels requires careful analysis of their fuel properties. ASTM standards provide fuel property requirements for spark-ignition (SI) and compression-ignition (CI) engines such as the stability, lubricity, viscosity, and cold filter plugging point (CFPP) properties of blends of higher alcohols. Important combustion properties that are studied include laminar and turbulent flame speeds, flame blowout/extinction limits, ignition delay under various mixing conditions, and gas-phase and particulate emissions. The chapter focuses on the combustion of higher alcohols in reciprocating SI and CI engines and discusses higher alcohol performance in SI and CI engines. Finally, the chapter identifies the sources, production pathways, and technologies currently being pursued for production of some fuels, including n-butanol, iso-butanol, and n-octanol.

Natural gas for utility generation

International Nuclear Information System (INIS)

Moore, T.

1992-01-01

Forecasters predict that natural gas will be the dominant fuel choice for utility capacity additions in the coming decade and that power generation will be by far the largest growth market for gas sales. While gas's low emissions, high efficiency potential, and present low cost argue persuasively for a surge in gas-fired generation, many utilities have been slow to commit to a gas future, citing reasoned concern about long-term price trends and the ability of gas suppliers to deliver the fuel where and when it will be needed. Meanwhile, the relatively low cost of gas-fired units is providing an opportunity for independent power producers to compete strongly with utilities for generation contracts. EPRI studies suggest that a sound, competitive strategy will be based not on how much gas a utility burns, but rather on how this capacity fits into its overall generating mix at various fuel price levels. Gas suppliers will need to pay special attention to the operating needs of power generators if they are to solidify this important market

Electric utilities and clean air

International Nuclear Information System (INIS)

Evans, J.E.

1991-01-01

This paper reports that electricity has become essential to American life. Approximately 70 percent of the nation's electricity is produced by burning fossil fuels, with coal, the most abundant, domestically-available, extracted natural resource, providing over 55 percent of the total electricity consumed. Emissions resulting from the burning of fossil fuels are regulated by both the federal and state governments. In 1970, Congress passed the comprehensive Clean Air Act which established a national program to protect the nation's air quality. In 1977, additional strict regulations were passed, which mandated even more stringent emission controls for factories, power plants and auto emissions. Prior to passage of the Clean Air Act of 1990, utilities were required to adhere to three major types of clean air regulations: National Ambient Air Quality Standards (NAAQS), New Source Performance Standards (NSPS), and Prevention of Significant Deterioration (PSD) review. NAAQS established limits for the maximum concentration levels of specific air pollutants in the ambient atmosphere. For example, for an area to be in compliance with the NAAQS for sulfur dioxide (SO 2 ), its annual average SO 2 concentration must not exceed 0.03 ppm of SO 2 and a peak 24 hour level of 0.14 ppm of SO 2 must not be exceeded more than once per year

Survey of thorium utilization in power reactor systems

International Nuclear Information System (INIS)

Schwartz, M.H.; Schleifer, P.; Dahlberg, R.C.

1976-01-01

It is clear that thorium-fueled thermal power reactor systems based on current technology can play a vital role in serving present and long-term energy needs. Advanced thorium converters and thermal breeders can provide an expanded resource base from which the world's growing energy demands can be met. Utilization of a symbiotic system of fast breeders and thorium-fueled thermal reactors can be particularly effective in providing low cost power while conserving uranium resources. Breeder reactors are characterized by high capital costs and very low fuel costs since they produce more fuel than they consume. This excess fuel can be used to fuel thermal converter reactors whose capital costs are low. This symbiosis is optimized when 233 U is bred in the fast breeders and then used to fuel high-conversion-ratio thermal converter reactors operating on the thorium-uranium fuel cycle. The thorium-cycle HTGR, after undergoing more than fifteen years of development in both the United States and Europe, provides for the optimum utilization of our limited uranium resources. Other thermal reactor systems, previously operating on the uranium cycle, also show potential in their capability to utilize the thorium cycle effectively

Effect of long-term storage of LWR spent fuel on Pu-thermal fuel cycle

International Nuclear Information System (INIS)

Kurosawa, Masayoshi; Naito, Yoshitaka; Suyama, Kenya; Itahara, Kuniyuki; Suzuki, Katsuo; Hamada, Koji

1998-01-01

According to the Long-term Program for Research, Development and Utilization of Nuclear Energy (June, 1994) in Japan, the Rokkasho Reprocessing Plant will be operated shortly after the year 2000, and the planning of the construction of the second commercial plant will be decided around 2010. Also, it is described that spent fuel storage has a positive meaning as an energy resource for the future utilization of Pu. Considering the balance between the increase of spent fuels and the domestic reprocessing capacity in Japan, it can be expected that the long-term storage of UO 2 spent fuels will be required. Then, we studied the effect of long-term storage of spent fuels on Pu-thermal fuel cycle. The burnup calculation were performed on the typical Japanese PWR fuel, and the burnup and criticality calculations were carried out on the Pu-thermal cores with MOX fuel. Based on the results, we evaluate the influence of extending the spent fuel storage term on the criticality safety, shielding design of the reprocessing plant and the core life time of the MOX core, etc. As the result of this work on long-term storage of LWR spent fuels, it becomes clear that there are few demerits regarding the lifetime of a MOX reactor core, and that there are many merits regarding the safety aspects of the fuel cycle facilities. Furthermore, long-term storage is meaningful as energy storage for effective utilization of Pu to be improved by technological innovation in future, and it will allow for sufficient time for the important policymaking of nuclear fuel cycle establishment in Japan. (author)

Alcohol fuels program technical review

Energy Technology Data Exchange (ETDEWEB)

None

1981-07-01

The last issue of the Alcohol Fuels Process R/D Newsletter contained a work breakdown structure (WBS) of the SERI Alcohol Fuels Program that stressed the subcontracted portion of the program and discussed the SERI biotechnology in-house program. This issue shows the WBS for the in-house programs and contains highlights for the remaining in-house tasks, that is, methanol production research, alcohol utilization research, and membrane research. The methanol production research activity consists of two elements: development of a pressurized oxygen gasifier and synthesis of catalytic materials to more efficiently convert synthesis gas to methanol and higher alcohols. A report is included (Finegold et al. 1981) that details the experimental apparatus and recent results obtained from the gasifier. The catalysis research is principally directed toward producing novel organometallic compounds for use as a homogeneous catalyst. The utilization research is directed toward the development of novel engine systems that use pure alcohol for fuel. Reforming methanol and ethanol catalytically to produce H/sub 2/ and CO gas for use as a fuel offers performance and efficiency advantages over burning alcohol directly as fuel in an engine. An application of this approach is also detailed at the end of this section. Another area of utilization is the use of fuel cells in transportation. In-house researchers investigating alternate electrolyte systems are exploring the direct and indirect use of alcohols in fuel cells. A workshop is being organized to explore potential applications of fuel cells in the transportation sector. The membrane research group is equipping to evaluate alcohol/water separation membranes and is also establishing cost estimation and energy utilization figures for use in alcohol plant design.

Development of MOX fuel database

International Nuclear Information System (INIS)

Ikusawa, Yoshihisa; Ozawa, Takayuki

2007-03-01

We developed MOX Fuel Database, which included valuable data from several irradiation tests in FUGEN and Halden reactor, for help of LWR MOX use. This database includes the data of fabrication and irradiation, and the results of post-irradiation examinations for seven fuel assemblies, i.e. P06, P2R, E03, E06, E07, E08 and E09, irradiated in FUGEN. The highest pellet peak burn-up reached ∼48GWd/t in MOX fuels, of which the maximum plutonium content was ∼6 wt%, irradiated in E09 fuel assembly without any failure. Also the data from the instrumented MOX fuels irradiated in HBWR to study the irradiation behavior of BWR MOX fuels under the steady state condition (IFA-514/565 and IFA-529), under the load-follow operation condition (IFA-554/555) and under the transit condition (IFA-591) are included in this database. The highest assembly burn-up reached ∼56 GWd/t in IFA-565 steady state irradiation test, and the maximum linear power of MOX fuel rods was 58.3-68.4 kW/m without any failure in IFA-591 ramp test. In addition, valuable instrument data, i.e. cladding elongation, fuel stack elongation, fuel center temperature and rod inner pressure were obtained from IFA-554/555 load-follow test. (author)

Schemes for fuel conservation for PHWRs due for complete fuel discharge

International Nuclear Information System (INIS)

Bansal, Ravi; Kumar, Deepak; Tejram

2009-01-01

Narora Atomic Power Station (NAPS) consists of twin units of pressurized heavy water reactors (PHWR) using natural uranium as fuel and heavy water as moderator and coolant. On-power bi-directional refueling is employed at NAPS. En Masse Coolant Channel Replacement (EMCCR) necessitates the low burn-up bundles present in core to be utilized. The different schemes of In-core fuel management viz. internal, total internal and external recycling were worked out to utilize these low burn-up bundles. This led to saving of: (a) 2011 natural uranium bundles at NAPS and (b) 4 and half months in NAPS-1 and 3 and half months in case of NAPS-2 in core de-fueling time. (author)

Basic criteria and application examples of German utility PLIM concept

International Nuclear Information System (INIS)

Sgarz, G.; Metzner, K.J.

2002-01-01

As a consequence of the consensus negotiations between the present Federal German Government and the German utilities the new Atomic Energy Law was set into force in April 2002. The main issues are: 1. Phase out of NPP-operation after a maximum lifetime of 32 years without any claims for compensation. 2. Termination of spent fuel reprocessing and switching over to direct final storage. Stop of spent fuel casks shipment in 2005. 3. Intermediate storage facilities are to be provided on each power plant site. 4. The promotion clause for nuclear energy is cancelled, the construction of new NPP's is prohibited. 5. The NPP safety status has to be kept on a high level standard. A periodic safety assessment must be performed 'according to the state of the art' based on up-to-date codes and standards in a 10-year interval. As a consequence, the future German policies and strategies are based on this law

Experimental irradiation of UMo fuel: Pie results and modeling of fuel behaviour

International Nuclear Information System (INIS)

Languille, A.; Plancq, D.; Huet, F.; Guigon, B.; Lemoine, P.; Sacristan, P.; Hofman, G.; Snelgrove, J.; Rest, J.; Hayes, S.; Meyer, M.; Vacelet, H.; Leborgne, E.; Dassel, G.

2002-01-01

Seven full-sized U Mo plates containing ca. 8 g/cm 3 of uranium in the fuel meat have been irradiated since the beginning of the French U Mo development program. The first three of them with 20% 235 U enrichment were irradiated at maximum surfacic power under 150 W/cm 2 in the OSIRIS reactor up to 50% burn-up and are under examination. Their global behaviour is satisfactory: no failure and a low swelling. The other four plates were irradiated in the HFR Petten at maximum surfacic power between 150 and 250 W/cm 2 with two enrichments 20 and 35%. The experiment was stopped after two cycles due to a fuel failure. The post- irradiation examinations were completed in 2001 in Petten. Examinations showed a correct behaviour of 20% enriched plates and an abnormal behaviour of the two other plates (35%-enriched) with a clad failure on the plate 4. The fuel failure appears to result from a combination of factors that led to high corrosion cladding and high fuel meat temperatures. (author)

Postirradiation examinations of fuel pins from the GCFR F-1 series of mixed-oxide fuel pins at 5.5 at. % burnup

International Nuclear Information System (INIS)

Strain, R.V.; Johnson, C.E.

1978-05-01

Postirradiation examinations were performed on five fuel pins from the Gas-Cooled Fast-Breeder Reactor F-1 experiment irradiated in EBR-II to a peak burnup of approximately 5.5 at. %. These encapsulated fuel pins were irradiated at peak-power linear ratings from approximately 13 to 15 kW/ft and peak cladding inside diameter temperatures from approximately 625 to 760 0 C. The maximum diametral change that occurred during irradiation was 0.2% ΔD/D 0 . The maximum fuel-cladding chemical interaction depth was 2.6 mils in fuel pin G-1 and 1 mil or less in the other three pins examined destructively. Significant migration of the volatile fission products occurred axially to the fuel-blanket interfaces. Teh postirradiation examination data indicate that fuel melted at the inner surface of the annular fuel pellets in the two highest power rating fuel pins, but little axial movement of fuel occurred

Postirradiation examinations of fuel pins from the GCFR F-1 series of mixed-oxide fuel pins at 5. 5 at. % burnup

Energy Technology Data Exchange (ETDEWEB)

Strain, R V; Johnson, C E

1978-05-01

Postirradiation examinations were performed on five fuel pins from the Gas-Cooled Fast-Breeder Reactor F-1 experiment irradiated in EBR-II to a peak burnup of approximately 5.5 at. %. These encapsulated fuel pins were irradiated at peak-power linear ratings from approximately 13 to 15 kW/ft and peak cladding inside diameter temperatures from approximately 625 to 760/sup 0/C. The maximum diametral change that occurred during irradiation was 0.2% ..delta..D/D/sub 0/. The maximum fuel-cladding chemical interaction depth was 2.6 mils in fuel pin G-1 and 1 mil or less in the other three pins examined destructively. Significant migration of the volatile fission products occurred axially to the fuel-blanket interfaces. Teh postirradiation examination data indicate that fuel melted at the inner surface of the annular fuel pellets in the two highest power rating fuel pins, but little axial movement of fuel occurred.

Dry spent fuel storage licensing

International Nuclear Information System (INIS)

Sturz, F.C.

1995-01-01

In the US, at-reactor-site dry spent fuel storage in independent spent fuel storage installations (ISFSI) has become the principal option for utilities needing storage capacity outside of the reactor spent fuel pools. Delays in the geologic repository operational date at or beyond 2010, and the increasing uncertainty of the US Department of Energy's (DOE) being able to site and license a Monitored Retrievable Storage (MRS) facility by 1998 make at-reactor-site dry storage of spent nuclear fuel increasingly desirable to utilities and DOE to meet the need for additional spent fuel storage capacity until disposal, in a repository, is available. The past year has been another busy year for dry spent fuel storage licensing. The licensing staff has been reviewing 7 applications and 12 amendment requests, as well as participating in inspection-related activities. The authors have licensed, on a site-specific basis, a variety of dry technologies (cask, module, and vault). By using certified designs, site-specific licensing is no longer required. Another new cask has been certified. They have received one new application for cask certification and two amendments to a certified cask design. As they stand on the brink of receiving multiple applications from DOE for the MPC, they are preparing to meet the needs of this national program. With the range of technical and licensing options available to utilities, the authors believe that utilities can meet their need for additional spent fuel storage capacity for essentially all reactor sites through the next decade

Determination of hot spot factors for calculation of the maximum fuel temperatures in the core thermal and hydraulic design of HTTR

International Nuclear Information System (INIS)

Maruyama, Soh; Yamashita, Kiyonobu; Fujimoto, Nozomu; Murata, Isao; Shindo, Ryuichi; Sudo, Yukio

1988-12-01

The Japan Atomic Energy Research Institute (JAERI) has been designing the High Temperature Engineering Test Reactor (HTTR), which is 30 MW in thermal power, 950deg C in reactor outlet coolant temperature and 40 kg/cm 2 G in primary coolant pressure. This report summarizes the hot spot factors and their estimated values used in the evaluation of the maximum fuel temperature which is one of the major items in the core thermal and hydraulic design of the HTTR. The hot spot factors consist of systematic factors and random factors. They were identified and their values adopted in the thermal and hydraulic design were determined considering the features of the HTTR. (author)

Optimal robust control strategy of a solid oxide fuel cell system

Science.gov (United States)

Wu, Xiaojuan; Gao, Danhui

2018-01-01

Optimal control can ensure system safe operation with a high efficiency. However, only a few papers discuss optimal control strategies for solid oxide fuel cell (SOFC) systems. Moreover, the existed methods ignore the impact of parameter uncertainty on system instantaneous performance. In real SOFC systems, several parameters may vary with the variation of operation conditions and can not be identified exactly, such as load current. Therefore, a robust optimal control strategy is proposed, which involves three parts: a SOFC model with parameter uncertainty, a robust optimizer and robust controllers. During the model building process, boundaries of the uncertain parameter are extracted based on Monte Carlo algorithm. To achieve the maximum efficiency, a two-space particle swarm optimization approach is employed to obtain optimal operating points, which are used as the set points of the controllers. To ensure the SOFC safe operation, two feed-forward controllers and a higher-order robust sliding mode controller are presented to control fuel utilization ratio, air excess ratio and stack temperature afterwards. The results show the proposed optimal robust control method can maintain the SOFC system safe operation with a maximum efficiency under load and uncertainty variations.

The Analysis Of Spent Fuel Utilization For A Gamma Irradiator

International Nuclear Information System (INIS)

MS, Pudjijanto; Setiyanto

2002-01-01

The gamma irradiator using RSG-GAS spent fuels was analyzed. The cylindrical geometry of the irradiator was designed by locating the spent fuels the cylindrical periphery. The analysis was focused to evaluate the feasibilities of the irradiator as a fruits and vegetables irradiator. The spent fuels activities were calculated using Origen2 code, while the dose rate at the irradiation positions was determined by linear attenuation model with transport coefficient. The evaluated results showed that the cylindrical geometry of irradiators with diameter around 1-1.5 m gave the effective dose rate for fruits and vegetables preservation. It can be concluded that one can use the RSG-GAS spent fuels effectively as a gamma irradiator for certain applications

Licensing and advanced fuel designs

International Nuclear Information System (INIS)

Davidson, S.L.; Novendstern, E.H.

1991-01-01

For the past 15 years, Westinghouse has been actively involved in the development and licensing of fuel designs that contain major advanced features. These designs include the optimized fuel assembly, The VANTAGE 5 fuel assembly, the VANTAGE 5H, and most recently the VANTAGE+ fuel assembly. Each of these designs was supported by extensive experimental data, safety evaluations, and design efforts and required intensive interaction with the US Nuclear Regulatory Commission (NRC) during the review and approval process. This paper presents a description of the licensing approach and how it was utilized by the utilities to facilitate the licensing applications of the advanced fuel designs for their plants. The licensing approach described in this paper has been successfully applied to four major advanced fuel design changes ∼40 plant-specific applications, and >350 cycle-specific reloads in the past 15 years

Utilization of the waste gases from a petroleum refinery as fuel

International Nuclear Information System (INIS)

Torres Contreras, Jose Francisco

2012-01-01

The fuels waste gases that are burned in a flare stack were proposed as an alternative for its utilization. The current operation of the flare stack system of a petroleum refinery was analyzed. The historical information of the equipment and original design of the same was used. From the calculations that were performed, it is expected that the delivered heat for the flare gases approaching to 65 MJ/M 3 , so it would be an effective fuel for be used in furnaces and boilers. A new flare stack system and a system for recovery of the waste gases of process is proposed. The new flare stack system must have a liquid separator of 2,3 meters of diameter, a length of 6,4 meters and a capacity of 26,1 cubic meters. The velocity of the gas to the exit of the separator has been of 80,7 m/s. The liquid hydrocarbon flow that has exited the separator has been of 71 m 3 /h, with a speed of 0,91 m/s and a pump of 2,75 HP is required. The liquid seal of flare stack systems must have a minimum height of 1,05 m. The gas recovery system to burn in the flare stack should be located between the liquid separator and liquid seal of the flare stack systems. For an average consumption of 150 m 3 /h of fuel gas for furnaces and boilers, the gas recovery system must have with a compressor of 4,75 HP, a liquid separator of 50 m 3 and a pump of 2,50 HP. The gas recovery system has had with an absorber of 7 plates for washing of the stream acid gas with MEA, at 40 degrees celsius and an pressure of operating of 67 kPa, and a flow of 55,88 kg/h at amine solution. The flare gas flow has been recommended to be analyzed chemically, as well as the measurement of the flow of gas streams plant consumption and gases flare. A technical-economic feasibility study of the process should be realized. (author) [es

Efficient utilization of waste date pits for the synthesis of green diesel and jet fuel fractions

International Nuclear Information System (INIS)

Al-Muhtaseb, Ala’a H.; Jamil, Farrukh; Al-Haj, Lamya; Al-Hinai, Mohab A.; Baawain, Mahad; Myint, Myo Tay Zar; Rooney, David

2016-01-01

Highlights: • Active catalysts Pt/C and Pd/C were developed from waste date pits. • Catalysts showed good activity in hydrodeoxygenation of date pit oil to alkane fuels. • The liquid product fractions lay within the range of the jet fuel and green diesel. • Green diesel fraction obtained by Pd/C was 72.03% and jet fuel was 30.39%. • Date pits can be a promising platform for the production of catalysts and biofuels. - Abstract: Date pits are considered one of the major agricultural wastes in Oman. The present work involves the synthesis of active catalysts from waste date pits carbon produced by carbonization and impregnation with Pt and Pd metals. Synthesized catalysts Pt/C and Pd/C were characterized by XRD, SEM, TEM, EDX, BET and XPS. The activity of the catalysts’ performance was evaluated by the hydrodeoxygenation of date pits oil for the production of second-generation biofuels, which includes jet fuel and green diesel fractions. Results indicate that the synthesized catalysts were highly active for the hydrodeoxygenation of date pits oil. Based on the elemental analysis, the degree of deoxygenation (DOD) of product oil was 97.5% and 89.4% for the Pd/C and Pt/C catalysts respectively. The high DOD was also confirmed by product analyses that mainly consist of paraffinic hydrocarbons. Results also showed that between the two catalysts, Pd/C showed a higher activity towards hydrodeoxygenation, a conclusion that was based on the high DOD of the product oil due to hydrocarbons formation. Based on the type of components in the product oil, the maximum fraction of hydrocarbons formed lay within the range of 72.03% and 72.78% green diesel, and 30.39% and 28.25% jet fuel using Pd/C and Pt/C catalysts respectively. It can be concluded that waste date pits can be a promising platform for the production of catalysts and biofuels.

A cost-benefit analysis of spent fuel management

International Nuclear Information System (INIS)

Lamorlette, G.

2001-01-01

The back end of the fuel cycle is an area of economic risk for utilities having nuclear power plants to generate electricity. A cost-benefit analysis is a method by which utilities can evaluate advantages and drawbacks of alternative back end fuel cycle strategies. The present paper analyzes how spent fuel management can influence the risks and costs incurred by a utility over the lifetime of its power plants and recommends a recycling strategy. (author)

Status of operation and utilization of JRR-4

International Nuclear Information System (INIS)

Tsuruta, H.; Niiho, T.; Matsuura, H.; Iida, K.; Ikeda, Y.; Funayama, Y.

1988-01-01

Japan Research Reactor No.4 (JRR-4) is a swimming pool type research reactor, 93% enriched uranium ETR-type fuel used, light water moderated and cooled. It was initially constructed to pursue mainly shielding experiments for nuclear ship. Today, it is widely utilized for many researches and experiments and reactor operation training of Nuclear Engineering School students. The construction of JRR-4 started in June 1962 and the initial criticality reached on January 28, 1965. The maximum power of JRR-4 was raised to 3500 kW in October 1976. The reactor has been operated satisfactorily for about 23 years since the initial criticality. In this paper, a general description is given on the JRR-4 including future plans. (author)

Cermet fuel reactors

International Nuclear Information System (INIS)

Cowan, C.L.; Palmer, R.S.; Van Hoomissen, J.E.; Bhattacharyya, S.K.; Barner, J.O.

1987-09-01

Cermet fueled nuclear reactors are attractive candidates for high performance space power systems. The cermet fuel consists of tungsten-urania hexagonal fuel blocks characterized by high strength at elevated temperatures, a high thermal conductivity and resultant high thermal shock resistance. Key features of the cermet fueled reactor design are (1) the ability to achieve very high coolant exit temperatures, and (2) thermal shock resistance during rapid power changes, and (3) two barriers to fission product release - the cermet matrix and the fuel element cladding. Additionally, thre is a potential for achieving a long operating life because of (1) the neutronic insensitivity of the fast-spectrum core to the buildup of fission products and (2) the utilization of a high strength refractory metal matrix and structural materials. These materials also provide resistance against compression forces that potentially might compact and/or reconfigure the core. In addition, the neutronic properties of the refractory materials assure that the reactor remains substantially subcritical under conditions of water immersion. It is concluded that cermet fueled reactors can be utilized to meet the power requirements for a broad range of advanced space applications. 4 refs., 4 figs., 3 tabs

UNEP (United Nations Environment Program) discussed the environmental impacts of extraction, transportation, and utilization of fossil fuels

Energy Technology Data Exchange (ETDEWEB)

1978-07-01

The UNEP (United Nations Environment Program) discussed the environmental impacts of extraction, transportation, and utilization of fossil fuels at a meeting in Warsaw, the first in a series of UNEP undertakings, to be followed by studies on nuclear energy and renewable energy sources. The major issues examined at the meeting were human health effects of atmospheric emissions, especially SO/sub 2/; effects of SO/sub 2/ on vegetation and bodies of fresh water; long-term ecologic effects of oil spills in the sea; and potential effects on climate from atmospheric CO/sub 2/ arising from fossil fuel combustion. A doubling of the atmospheric CO/sub 2/ concentration would cause an estimated 1.5/sup 0/-3.0/sup 0/C increase in the surface air temperature. With an amount of CO/sub 2/ equivalent to 0.5 x 10/sup 10/ tonnes of carbon annually injected into the atmosphere from fossil fuels, of which only 0.27 x 10/sup 10/ tonnes are removed by some exchange processes with ocean or land. A 17% increase in atmospheric CO/sub 2/ over the 1976 concentration of 332 ppm is expected by the year 2000.

Spent nuclear fuel shipping cask handling capabilities of commercial light water reactors

International Nuclear Information System (INIS)

Daling, P.M.; Konzek, G.J.; Lezberg, A.J.; Votaw, E.F.; Collingham, M.I.

1985-04-01

This report describes an evaluation of the cask handling capabilities of those reactors which are operating or under construction. A computerized data base that includes cask handling information was developed with information from the literature and utility-supplied data. The capability of each plant to receive and handle existing spent fuel shipping casks was then evaluated. Modal fractions were then calculated based on the results of these evaluations and the quantities of spent fuel projected to be generated by commercial nuclear power plants through 1998. The results indicated that all plants are capable of receiving and handling truck casks. Up to 118 out of 130 reactors (91%) could potentially handle the larger and heavier rail casks if the maximum capability of each facility is utilized. Design and analysis efforts and physical modifications to some plants would be needed to achieve this high rail percentage. These modifications would be needed to satisfy regulatory requirements, increase lifting capabilities, develop rail access, or improve other deficiencies. The remaining 12 reactors were determined to be capable of handling only the smaller truck casks. The percentage of plants that could receive and handle rail casks in the near-term would be reduced to 64%. The primary reason for a plant to be judged incapable of handling rail casks in the near-term was a lack of rail access. The remaining 36% of the plants would be limited to truck shipments. The modal fraction calculations indicated that up to 93% of the spent fuel accumulated by 1998 could be received at federal storage or disposal facilities via rail (based on each plant's maximum capabilities). If the near-term cask handling capabilities are considered, the rail percentage is reduced to 62%

Modern approach to the problem of fossil gas fuels replacement by alternative fuels

Energy Technology Data Exchange (ETDEWEB)

Soroka, Boris [Gas Institute, National Academy of Sciences, Kiev (Ukraine)

2013-07-01

New scientific and engineering fundamentals of fuels substitution have been developed instead of obsolete methodology “Interchangeability of Fuel Gases” developed in USA and existing from the middle of XX{sup th} century. To perform the complex prediction of total or partial substitution of given flow rate of natural gas NG for alternative gases AG the following parameters are to be predicted: plant utilization efficiencies – regarding fuel and energy utilization, the last in form of heat Ș{sub H} and exergy Ș{sub eff} efficiencies, saving or overexpenditure of the NG flow rate in the gas mixture with AG, specific fuel consumption b f and specific issue of harmful substances C{sub t} – pollutants in the combustion products (C{sub NO{sub x}} ) and greenhouse gases (C {sub CO{sub 2}} ). Certification of alternative gas fuels and fuel mixtures as a commodity products is carried out in frame of our approach with necessary set of characteristics, similar to those accepted in the world practice. Key words: alternative fuel, fuel replacement (substitution), natural gas, process gases, theoretical combustion temperature, thermodynamic equilibrium computations, total enthalpy.

REDUCING POWER PRODUCTION COSTS BY UTILIZING PETROLEUM COKE

Energy Technology Data Exchange (ETDEWEB)

Kevin C. Galbreath; Donald L. Toman; Christopher J. Zygarlicke

1999-09-01

Petroleum coke, a byproduct of the petroleum-refining process, is an attractive primary or supplemental fuel for power production primarily because of a progressive and predictable increase in the production volumes of petroleum coke (1, 2). Petroleum coke is most commonly blended with coal in proportions suitable to meet sulfur emission compliance. Petroleum coke is generally less reactive than coal; therefore, the cofiring of petroleum coke with coal typically improves ignition, flame stability, and carbon loss relative to the combustion of petroleum coke alone. Although petroleum coke is a desirable fuel for producing relatively inexpensive electrical power, concerns about the effects of petroleum coke blending on combustion and pollution control processes exist in the coal-fired utility industry (3). The Energy & Environmental Research Center (EERC) completed a 2-year technical assessment of petroleum coke as a supplemental fuel. A survey questionnaire was sent to seven electric utility companies that are currently cofiring coal and petroleum coke in an effort to solicit specific suggestions on research needs and fuel selections. An example of the letter and survey questionnaire is presented in Appendix A. Interest was expressed by most utilities in evaluating the effects of petroleum coke blending on grindability, combustion reactivity, fouling, slagging, and fly ash emissions control. Unexpectedly, concern over corrosion was not expressed by the utilities contacted. Although all seven utilities responded to the question, only two utilities, Northern States Power Company (NSP) and Ameren, sent fuels to the EERC for evaluation. Both utilities sent subbituminous coals from the Power River Basin and petroleum shot coke samples. Petroleum shot coke is produced unintentionally during operational upsets in the petroleum refining process. This report evaluates the effects of petroleum shot coke blending on grindability, fuel reactivity, fouling/slagging, and

Hydrogen as a renewable and sustainable solution in reducing global fossil fuel consumption

International Nuclear Information System (INIS)

Midilli, Adnan; Dincer, Ibrahim

2008-01-01

In this paper, hydrogen is considered as a renewable and sustainable solution for reducing global fossil fuel consumption and combating global warming and studied exergetically through a parametric performance analysis. The environmental impact results are then compared with the ones obtained for fossil fuels. In this regard, some exergetic expressions are derived depending primarily upon the exergetic utilization ratios of fossil fuels and hydrogen: the fossil fuel based global waste exergy factor, hydrogen based global exergetic efficiency, fossil fuel based global irreversibility coefficient and hydrogen based global exergetic indicator. These relations incorporate predicted exergetic utilization ratios for hydrogen energy from non-fossil fuel resources such as water, etc., and are used to investigate whether or not exergetic utilization of hydrogen can significantly reduce the fossil fuel based global irreversibility coefficient (ranging from 1 to +∞) indicating the fossil fuel consumption and contribute to increase the hydrogen based global exergetic indicator (ranging from 0 to 1) indicating the hydrogen utilization at a certain ratio of fossil fuel utilization. In order to verify all these exergetic expressions, the actual fossil fuel consumption and production data are taken from the literature. Due to the unavailability of appropriate hydrogen data for analysis, it is assumed that the utilization ratios of hydrogen are ranged between 0 and 1. For the verification of these parameters, the variations of fossil fuel based global irreversibility coefficient and hydrogen based global exergetic indicator as the functions of fossil fuel based global waste exergy factor, hydrogen based global exergetic efficiency and exergetic utilization of hydrogen from non-fossil fuels are analyzed and discussed in detail. Consequently, if exergetic utilization ratio of hydrogen from non-fossil fuel sources at a certain exergetic utilization ratio of fossil fuels increases

BWR Fuel Assemblies Physics Analysis Utilizing 3D MCNP Modeling

International Nuclear Information System (INIS)

Chiang, Ren-Tai; Williams, John B.; Folk, Ken S.

2008-01-01

MCNP is used to model a partially controlled BWR fresh fuel four assemblies (2x2) system for better understanding BWR fuel behavior and for benchmarking production codes. The impact of the GE14 plenum regions on axial power distribution is observed by comparing against the GE13 axial power distribution, in which the GE14 relative power is lower than the GE13 relative power at the 15. node and at the 16. node due to presence of the plenum regions in GE14 fuel in these two nodes. The segmented rod power distribution study indicates that the azimuthally dependent power distribution is very significant for the fuel rods next to the water gap in the uncontrolled portion. (authors)

BWR Fuel Assemblies Physics Analysis Utilizing 3D MCNP Modeling

Energy Technology Data Exchange (ETDEWEB)

Chiang, Ren-Tai [University of Florida, Gainesville, Florida 32611 (United States); Williams, John B.; Folk, Ken S. [Southern Nuclear Company, Birmingham, Alabama 35242 (United States)

2008-07-01

MCNP is used to model a partially controlled BWR fresh fuel four assemblies (2x2) system for better understanding BWR fuel behavior and for benchmarking production codes. The impact of the GE14 plenum regions on axial power distribution is observed by comparing against the GE13 axial power distribution, in which the GE14 relative power is lower than the GE13 relative power at the 15. node and at the 16. node due to presence of the plenum regions in GE14 fuel in these two nodes. The segmented rod power distribution study indicates that the azimuthally dependent power distribution is very significant for the fuel rods next to the water gap in the uncontrolled portion. (authors)

ABB high burnup fuel

International Nuclear Information System (INIS)

Andersson, S.; Helmersson, S.; Nilsson, S.; Jourdain, P.; Karlsson, L.; Limback, M.; Garde, A.M.

1999-01-01

Fuel designed and fabricated by ABB is now operating in 40 PWRs and BWRs in Europe, the United States and Korea. An excellent fuel reliability track record has been established. High burnups are proven for both PWR and BWR. Thermal margin improving features and advanced burnable absorber concepts enable the utilities to adopt demanding duty cycles to meet new economic objectives. In particular we note the excellent reliability record of ABB PWR fuel equipped with Guardian TM debris filter proven to meet the 6 rod-cycles fuel failure goal, and the out-standing operating record of the SVEA 10 x 10 fuel, where ABB is the only vendor to date with batch experience to high burnup. ABB is dedicated to maintain high fuel reliability as well as continually improve and develop a broad line of PWR and BWR products. ABB's development and fuel follow-up activities are performed in close co-operation with its utility customers. This paper provides an overview of recent fuel performance and reliability experience at ABB. Selected development and validation activities for PWR and BWR fuel are presented, for which the ABB test facilities in Windsor (TF-2 loop, mechanical test laboratory) and Vaesteras (FRIGG, BURE) are essential. (authors)

Simultaneous measurement of glucose transport and utilization in the human brain

Science.gov (United States)

Shestov, Alexander A.; Emir, Uzay E.; Kumar, Anjali; Henry, Pierre-Gilles; Seaquist, Elizabeth R.

2011-01-01

Glucose is the primary fuel for brain function, and determining the kinetics of cerebral glucose transport and utilization is critical for quantifying cerebral energy metabolism. The kinetic parameters of cerebral glucose transport, KMt and Vmaxt, in humans have so far been obtained by measuring steady-state brain glucose levels by proton (1H) NMR as a function of plasma glucose levels and fitting steady-state models to these data. Extraction of the kinetic parameters for cerebral glucose transport necessitated assuming a constant cerebral metabolic rate of glucose (CMRglc) obtained from other tracer studies, such as 13C NMR. Here we present new methodology to simultaneously obtain kinetic parameters for glucose transport and utilization in the human brain by fitting both dynamic and steady-state 1H NMR data with a reversible, non-steady-state Michaelis-Menten model. Dynamic data were obtained by measuring brain and plasma glucose time courses during glucose infusions to raise and maintain plasma concentration at ∼17 mmol/l for ∼2 h in five healthy volunteers. Steady-state brain vs. plasma glucose concentrations were taken from literature and the steady-state portions of data from the five volunteers. In addition to providing simultaneous measurements of glucose transport and utilization and obviating assumptions for constant CMRglc, this methodology does not necessitate infusions of expensive or radioactive tracers. Using this new methodology, we found that the maximum transport capacity for glucose through the blood-brain barrier was nearly twofold higher than maximum cerebral glucose utilization. The glucose transport and utilization parameters were consistent with previously published values for human brain. PMID:21791622

Globalization of the nuclear fuel cycle impact of developments on fuel management

Energy Technology Data Exchange (ETDEWEB)

Van Den Durpel, L.; Bertel, E. [OCDE-NEA, Nuclear Development Div., 92 - Issy-les-Moulineaux (France)

1999-07-01

Nuclear energy will have to cope more and more with a rapid changing environment due to economic competitive pressure and the de-regulatory progress. In current economic environment, utilities will have to focus strongly on the reduction of their total generation costs, covering the fuel cycle costs, which are only partly under their control. Developments in the fuel cycle will be in the short-term rather evolutionary addressing the current needs of utilities. However, within the context of sustainable development and more and more inclusion of externalities in energy generation costs, more performing developments in the fuel cycle could become important and feasible. A life-cycle design approach of the fuel cycle will be requested in order to cover all factors in order to decrease significantly the nuclear energy generation cost to compete with other alternative fuels in the long-term. This paper will report on some of the trends one could distinguish in the fuel cycle with emphasis on cost reduction. OECD/NEA is currently conducting a study on the fuel cycle aiming to assess current and future nuclear fuel cycles according the potential for further improvement of the full added-value chain of these cycles from a mainly technological and economical perspective including environmental and social considerations. (authors)

Globalisation of the nuclear fuel cycle - impact of developments on fuel management

International Nuclear Information System (INIS)

Durpel, L. van den; Bertel, E.

2000-01-01

Nuclear energy will have to cope more and more with a rapid changing environment due to economic competitive pressure and the deregulatory progress. In current economic environment, utilities will have to focus strongly on the reduction of their total generation costs, covering the fuel cycle costs, which are only partly under their control. Developments in the fuel cycle will be in the short-term rather evolutionary addressing the current needs of utilities. However, within the context of sustainable development and more and more inclusion of externalities in energy generation costs, more performing developments in the fuel cycle could become important and feasible. A life-cycle design approach of the fuel cycle will be requested in order to cover all factors in order to decrease significantly the nuclear energy generation cost to complete with other alternative fuels in the long-term. This paper will report on some of the trends one could distinguish in the fuel cycle with emphasis on cost reduction. OECD/NEA is currently conducting a study on the fuel cycle aiming to assess current and future nuclear fuel cycles according to the potential for further improvement of the full added-value chain of these cycles from a mainly technological and economic perspective including environmental and social considerations. (orig.) [de

Effects of ambient conditions on fuel cell vehicle performance

Science.gov (United States)

Haraldsson, K.; Alvfors, P.

Ambient conditions have considerable impact on the performance of fuel cell hybrid vehicles. Here, the vehicle fuel consumption, the air compressor power demand, the water management system and the heat loads of a fuel cell hybrid sport utility vehicle (SUV) were studied. The simulation results show that the vehicle fuel consumption increases with 10% when the altitude increases from 0 m up to 3000 m to 4.1 L gasoline equivalents/100 km over the New European Drive Cycle (NEDC). The increase is 19% on the more power demanding highway US06 cycle. The air compressor is the major contributor to this fuel consumption increase. Its load-following strategy makes its power demand increase with increasing altitude. Almost 40% of the net power output of the fuel cell system is consumed by the air compressor at the altitude of 3000 m with this load-following strategy and is thus more apparent in the high-power US06 cycle. Changes in ambient air temperature and relative humidity effect on the fuel cell system performance in terms of the water management rather in vehicle fuel consumption. Ambient air temperature and relative humidity have some impact on the vehicle performance mostly seen in the heat and water management of the fuel cell system. While the heat loads of the fuel cell system components vary significantly with increasing ambient temperature, the relative humidity did not have a great impact on the water balance. Overall, dimensioning the compressor and other system components to meet the fuel cell system requirements at the minimum and maximum expected ambient temperatures, in this case 5 and 40 °C, and high altitude, while simultaneously choosing a correct control strategy are important parameters for efficient vehicle power train management.

Preliminary Thermohydraulic Analysis of a New Moderated Reactor Utilizing an LEU-Fuel for Space Nuclear Thermal Propulsion

Energy Technology Data Exchange (ETDEWEB)

Nam, Seung Hyun; Choi, Jae Young; Venneria, Paolo F.; Jeong, Yong Hoon; Chang, Soon Heung [KAIST, Daejeon (Korea, Republic of)

2015-10-15

The Korea Advanced NUclear Thermal Engine Rocket utilizing an LEU fuel (KANUTER-LEU) is a non-proliferative and comparably efficient NTR engine with relatively low thrust levels of 40 - 50 kN for in-space transportation. The small modular engine can expand mission versatility, when flexibly used in a clustered engine arrangement, so that it can perform various scale missions from low-thrust robotic science missions to high-thrust manned missions. In addition, the clustered engine system can enhance engine redundancy and ensuing crew safety as well as the thrust. The propulsion system is an energy conversion system to transform the thermal energy of the reactor into the kinetic energy of the propellant to produce the powers for thrust, propellant feeding and electricity. It is mainly made up of a propellant Feeding System (PFS) comprising a Turbo-Pump Assembly (TPA), a Regenerative Nozzle Assembly (RNA), etc. For this core design study, an expander cycle is assumed to be the propulsion system. The EGS converts the thermal energy of the EHTGR in the idle operation (only 350 kW{sub th} power) to electric power during the electric power mode. This paper presents a preliminary thermohydraulic design analysis to explore the design space for the new reactor and to estimate the referential engine performance. The new non-proliferative NTR engine concept, KANUTER-LEU, is under designing to surmount the nuclear proliferation obstacles on allR and Dactivities and eventual commercialization for future generations. To efficiently implement a heavy LEU fuel for the NTR engine, its reactor design innovatively possesses the key characteristics of the high U density fuel with high heating and H{sub 2} corrosion resistances, the thermal neutron spectrum core and also minimizing non-fission neutron loss, and the compact reactor design with protectively cooling capability. To investigate feasible design space for the moderated EHTGR-LEU and resultant engine performance, the

The low-enrichment fuel development program

International Nuclear Information System (INIS)

Stahl, D.

1993-01-01

In the 1950s and 1960s, low-power research reactors were built around the world utilized MTR-type fuel elements containing 20% enriched uranium. However, the demand for higher specific power created a need for greater uranium-235 concentrations. Early difficulties in increasing uranium content led to the substitution of highly enriched uranium in place of the 20% enriched fuel previously utilized. The highly enriched material also yielded other benefits including longer core residence time, higher specific reactivity, and somewhat lower cost. Highly enriched material then became readily available and was used for high-power reactors as well as in low-power reactors where 20% enriched material would have sufficed. The trend toward higher and higher specific power also led to the development of the dispersion-type fuels which utilized highly enriched uranium at a concentration of about 40 wt%. In the 1970's, however, concerns were raised about the proliferation resistance of fuels and fuel cycles. As a consequence, the U.S. Department of State has recently prohibited the foreign shipment of highly enriched material, except where prior contractual obligation or special merit exists. This will impact on the availability and utilization of highly enriched uranium for research and test reactor fuel. It has also stimulated development programs on fuels with higher uranium content which would allow the use of uranium of lower enrichment. The purpose of this report is to briefly describe the overall fuel-development program which is coordinated by Argonne National Laboratory for the Department of Energy, and to indicate the current and potential uranium loadings. Other reports will address the individual fuel-development activities in greater detail

HTGR fuel and fuel cycle technology

International Nuclear Information System (INIS)

Lotts, A.L.; Homan, F.J.; Balthesen, E.; Turner, R.F.

1977-01-01

Significant advances have occurred in the development of HTGR fuel and fuel cycle. These accomplishments permit a wide choice of fuel designs, reactor concepts, and fuel cycles. Fuels capable of providing helium outlet temperatures of 750 0 C are available, and fuels capable of 1000 0 C outlet temperatures may be expected from extension of present technology. Fuels have been developed for two basic HTGR designs, one using a spherical (pebble bed) element and the other a prismatic element. Within each concept a number of variations of geometry, fuel composition, and structural materials are permitted. Potential fuel cycles include both low-enriched and high-enriched Th- 235 U, recycle Th- 233 U, and Th-Pu or U-Pu cycles. This flexibility offered by the HTGR is of great practical benefit considering the rapidly changing economics of power production. The inflation of ore prices has increased optimum conversion ratios, and increased the necessity of fuel recycle at an early date. Fuel element makeup is very similar for prismatic and spherical designs. Both use spherical fissile and fertile particles coated with combinations of pyrolytic carbon and silicon carbide. Both use carbonaceous binder materials, and graphite as the structural material. Weak-acid resin (WAR) UO 2 -UC 2 fissile fuels and sol-gel-derived ThO 2 fertile fuels have been selected for the Th- 233 U cycle in the prismatic design. Sol-gel-derived UO 2 UC 2 is the reference fissile fuel for the low-enriched pebble bed design. Both the United States and Federal Republic of Germany are developing technology for fuel cycle operations including fabrication, reprocessing, refabrication, and waste handling. Feasibility of basic processes has been established and designs developed for full-scale equipment. Fuel and fuel cycle technology provide the basis for a broad range of applications of the HTGR. Extension of the fuels to higher operating temperatures and development and commercial demonstration of fuel

Status of core conversion with LEU silicide fuel in JRR-4

Energy Technology Data Exchange (ETDEWEB)

Nakajima, Teruo; Ohnishi, Nobuaki; Shirai, Eiji [Japan Atomic Energy Research Institute, Ibaraki-ken (Japan)

1997-08-01

Japan Research Reactor No.4 (JRR-4) is a light water moderated and cooled, 93% enriched uranium ETR-type fuel used and swimming pool type reactor with thermal output of 3.5MW. Since the first criticality was achieved on January 28, 1965, JRR-4 has been used for shielding experiments, radioisotope production, neutron activation analyses, training for reactor engineers and so on for about 30 years. Within the framework of the RERTR Program, the works for conversion to LEU fuel are now under way, and neutronic and thermal-hydraulic calculations emphasizing on safety and performance aspects are being carried out. The design and evaluation for the core conversion are based on the Guides for Safety Design and Evaluation of research and testing reactor facilities in Japan. These results show that the JRR-4 will be able to convert to use LEU fuel without any major design change of core and size of fuel element. LEU silicide fuel (19.75%) will be used and maximum neutron flux in irradiation hole would be slightly decreased from present neutron flux value of 7x10{sup 13}(n/cm{sup 2}/s). The conversion works are scheduled to complete in 1998, including with upgrade of the reactor building and utilization facilities.

Status of core conversion with LEU silicide fuel in JRR-4

International Nuclear Information System (INIS)

Nakajima, Teruo; Ohnishi, Nobuaki; Shirai, Eiji

1997-01-01

Japan Research Reactor No.4 (JRR-4) is a light water moderated and cooled, 93% enriched uranium ETR-type fuel used and swimming pool type reactor with thermal output of 3.5MW. Since the first criticality was achieved on January 28, 1965, JRR-4 has been used for shielding experiments, radioisotope production, neutron activation analyses, training for reactor engineers and so on for about 30 years. Within the framework of the RERTR Program, the works for conversion to LEU fuel are now under way, and neutronic and thermal-hydraulic calculations emphasizing on safety and performance aspects are being carried out. The design and evaluation for the core conversion are based on the Guides for Safety Design and Evaluation of research and testing reactor facilities in Japan. These results show that the JRR-4 will be able to convert to use LEU fuel without any major design change of core and size of fuel element. LEU silicide fuel (19.75%) will be used and maximum neutron flux in irradiation hole would be slightly decreased from present neutron flux value of 7x10 13 (n/cm 2 /s). The conversion works are scheduled to complete in 1998, including with upgrade of the reactor building and utilization facilities

Irradiation tests on PHWR type fuel elements in TRIGA research reactor of INR Pitesti

Energy Technology Data Exchange (ETDEWEB)

Horhoianu, Grigore [Institute for Nuclear Research, Pitesti (Romania). Nuclear Fuel Engineering Lab.; Sorescu, Ion [Institute for Nuclear Research, Pitesti (Romania). TRIGA Reactor Loop Facility; Parvan, Marcel [Institute for Nuclear Research, Pitesti (Romania). Hot Cells Lab.

2012-12-15

Nine PHWR type fuel elements with reduced length were irradiated in loop A of the TRIGA Research Reactor of INR Pitesti. The primary objective of the test was to determine the performance of nuclear fuel fabricated at INR Pitesti at high linear powers in pressurized water conditions. Six fuel elements were irradiated with a ramp power history, achieving a maximum power of 45 kW/m during pre-ramp and of 64 kW/m in the ramp. The maximum discharge burnup was of 216 MWh/kgU. Another three fuel elements with reduced length were irradiated with declining power history. At the beginning of irradiation the fuel elements achieved a maximum linear power of 66 kW/m. The maximum fuel power was about 1.3 times the maximum expected in PHWR. The maximum discharge burnup was 205 MWh/kgU. The elements were destructively examined in the hot cells of INR Pitesti. Temperature-sensitive parameters such as UO{sub 2} grain growth, fission-gas release and sheath deformations were examined. The tests proved the feasibility of irradiating PHWR type fuel elements at linear powers up to 66 kW/m under pressurized water conditions and demonstrated the possibility of more flexible operation of this fuel in power reactors. This paper presents the results of the investigation. (orig.)

High Burnup Fuel Performance and Safety Research

Energy Technology Data Exchange (ETDEWEB)

Bang, Je Keun; Lee, Chan Bok; Kim, Dae Ho (and others)

2007-03-15

The worldwide trend of nuclear fuel development is to develop a high burnup and high performance nuclear fuel with high economies and safety. Because the fuel performance evaluation code, INFRA, has a patent, and the superiority for prediction of fuel performance was proven through the IAEA CRP FUMEX-II program, the INFRA code can be utilized with commercial purpose in the industry. The INFRA code was provided and utilized usefully in the universities and relevant institutes domesticallly and it has been used as a reference code in the industry for the development of the intrinsic fuel rod design code.

Liquid fuel production from hemicellulose. 2 Volumes

Energy Technology Data Exchange (ETDEWEB)

1983-03-01

Hemicellulose was derived from a variety of pretreated wood substrates. A variety of different fungi was screened for the ability of their culture filtrates to hydrolyse hemicellulose to its composite sugars. Three strains of Clostridia were screened to see which could produce higher amounts of solvents from those sugars. C. acetobutylicum proved to produce highest amounts of butanol and conditions for maximum solvent production by this anaerobe were defined. Six strains of facultative anaerobes were screened for their ability to produce power solvents from hemicellulose derived sugars. Klebsiella pneumoniae could efficiently utilize all the major sugars present in wood hemicellulose with 2,3-butanediol being the major end product. The conditions for maximum diol production by K. pneumoniae grown on sugars normally found in hemicellulose hydrolysates were defined. The utilization of wood hemicellulose hydrolyzates by microorganisms for the production of liquid fuels was investigated. Pretreatment of aspen wood by steam-explosion was optimized with respect to maximizing the pentosan yields in the water-soluble fractions of steam-treated substrates. These fractions were then hydrolyzed by dilute sulphuric acid or by the xylanase enzyme(s) present in the culture filtrates of Trichoderma harzianum. The relative efficiencies of hydrolysis were compared with respect to the release of reducing sugars and monosaccharides. The hemicellulose hydrolyzates were then used as substrates for fermentation. Butanediol yields of 0.4-0.5 g per g of sugar consumed were achieved using K. pneumoniae up to 0.16 g butanol could be attained per g of hemicellulose sugar utilized. 102 refs., 50 figs., 169 tabs.

Gas-cooled Fast Reactor (GFR) fuel and In-Core Fuel Management

International Nuclear Information System (INIS)

Weaver, K.D.; Sterbentz, J.; Meyer, M.; Lowden, R.; Hoffman, E.; Wei, T.Y.C.

2004-01-01

The Gas-Cooled Fast Reactor (GCFR) has been chosen as one of six candidates for development as a Generation IV nuclear reactor based on: its ability to fully utilize fuel resources; minimize or reduce its own (and other systems) actinide inventory; produce high efficiency electricity; and the possibility to utilize high temperature process heat. Current design approaches include a high temperature (2 850 C) helium cooled reactor using a direct Brayton cycle, and a moderate temperature (550 C - 650 C) helium or supercritical carbon dioxide (S-CO 2 ) cooled reactor using direct or indirect Brayton cycles. These design choices have thermal efficiencies that approach 45% to 50%, and have turbomachinery sizes that are much more compact compared to steam plants. However, there are challenges associated with the GCFR, which are the focus of current research. This includes safety system design for decay heat removal, development of high temperature/high fluence fuels and materials, and development of fuel cycle strategies. The work presented here focuses on the fuel and preliminary in-core fuel management, where advanced ceramic-ceramic (cercer) dispersion fuels are the main focus, and average burnups to 266 M Wd/kg appear achievable for the reference Si C/(U,TRU)C block/plate fuel. Solid solution (pellet) fuel in composite ceramic clad (Si C/Si C) is also being considered, but remains as a backup due to cladding fabrication challenges, and high centerline temperatures in the fuel. (Author)

Fuel oil and kerosene sales 1997

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-08-01

The Fuel Oil and Kerosene Sales 1997 report provides information, illustrations and state-level statistical data on end-use sales of kerosene; No. 1, No. 2, and No. 4 distillate fuel oil; and residual fuel oil. State-level kerosene sales include volumes for residential, commercial, industrial, farm, and all other uses. State-level distillate sales include volumes for residential, commercial, industrial, oil company, railroad, vessel bunkering, military, electric utility, farm, on-highway, off highway construction, and other uses. State-level residual fuel sales include volumes for commercial, industrial, oil company, vessel bunkering, military, electric utility, and other uses. 24 tabs.

Fuel oil and kerosene sales 1997

International Nuclear Information System (INIS)

1998-08-01

The Fuel Oil and Kerosene Sales 1997 report provides information, illustrations and state-level statistical data on end-use sales of kerosene; No. 1, No. 2, and No. 4 distillate fuel oil; and residual fuel oil. State-level kerosene sales include volumes for residential, commercial, industrial, farm, and all other uses. State-level distillate sales include volumes for residential, commercial, industrial, oil company, railroad, vessel bunkering, military, electric utility, farm, on-highway, off highway construction, and other uses. State-level residual fuel sales include volumes for commercial, industrial, oil company, vessel bunkering, military, electric utility, and other uses. 24 tabs

Fuel assemblies for use in nuclear reactors

International Nuclear Information System (INIS)

Mochida, Takaaki.

1987-01-01

Purpose: To increase the plutonium utilization amount and improve the uranium-saving effect in the fuel assemblies of PWR type reactor using mixed uranium-plutonium oxides. Constitution: MOX fuel rods comprising mixed plutonium-uranium oxides are disposed to the outer circumference of a fuel assembly and uranium fuel rods only composed of uranium oxides are disposed to the central portion thereof. In such a fuel assembly, since the uranium fuel rods are present at the periphery of the control rod, the control rod worth is the same as that of the uranium fuel assembly in the prior art. Further, since about 25 % of the entire fuel rods is composed of the MOX fuel rods, the plutonium utilization amount is increased. Further, since the MOX fuel rods at low enrichment degree are present at the outer circumferential portion, mismatching at the boundary to the adjacent MOX fuel assembly is reduced and the problem of local power peaking increase in the MOX fuel assembly is neither present. (Kamimura, M.)

Steam reforming of fuel to hydrogen in fuel cells

Science.gov (United States)

Fraioli, Anthony V.; Young, John E.

1984-01-01

A fuel cell capable of utilizing a hydrocarbon such as methane as fuel and having an internal dual catalyst system within the anode zone, the dual catalyst system including an anode catalyst supporting and in heat conducting relationship with a reforming catalyst with heat for the reforming reaction being supplied by the reaction at the anode catalyst.

Diesel fuel filtration system

International Nuclear Information System (INIS)

Schneider, D.

1996-01-01

The American nuclear utility industry is subject to tight regulations on the quality of diesel fuel that is stored at nuclear generating stations. This fuel is required to supply safety-related emergency diesel generators--the backup power systems associated with the safe shutdown of reactors. One important parameter being regulated is the level of particulate contamination in the diesel fuel. Carbon particulate is a natural byproduct of aging diesel fuel. Carbon particulate precipitates from the fuel's hydrocarbons, then remains suspended or settles to the bottom of fuel oil storage tanks. If the carbon particulate is not removed, unacceptable levels of particulate contamination will eventually occur. The oil must be discarded or filtered. Having an outside contractor come to the plant to filter the diesel fuel can be costly and time consuming. Time is an even more critical factor if a nuclear plant is in a Limiting Condition of Operation (LCO) situation. A most effective way to reduce both cost and risk is for a utility to build and install its own diesel fuel filtration system. The cost savings associated with designing, fabricating and operating the system inhouse can be significant, and the value of reducing the risk of reactor shutdown because of uncertified diesel fuel may be even higher. This article describes such a fuel filtering system

Thermal-stress analysis of HTGR fuel and control rod fuel blocks in in-block carbonization and annealing furnace

International Nuclear Information System (INIS)

Gwaltney, R.C.; McAfee, W.J.

1977-01-01

The equivalent solid plate method, in conjunction with two-dimensional plane stress and plane strain analyses, was used in assessing the thermal stress behavior of HTGR fuel and control rod fuel blocks. For the control rod fuel blocks, particular attention was given to ascertaining the effects of the reserve shutdown hole and the control rod channel holes. The assumed safety factor of 2 on the failure criteria was considered adequate to account for neglecting the axial temperature gradient in the plane analyses of the ends of the blocks. The analyses indicated that the maximum calculated tensile stress values were smaller than the criteria values except for the plane strain analysis of the control rod fuel block end surfaces and the axisymmetric analysis of the fuel block as a circular cylinder. However, most of the maximum calculated strain values were greater than the criteria values

The KNK II/1 fuel assembly NY-205: Compilation of the irradiation history and the fuel and fuel pin fabrication data of the INTERATOM data bank system BESEX

International Nuclear Information System (INIS)

Patzer, G.; Geier, F.

1988-01-01

The fuel assembly NY-205 has been irradiated during the first and the second core of KNK II with a total residence time of 832 equivalent full-power days. A maximum burnup of 175.000 MWd/tHM or 18.6 % was reached with a maximum steel damage of 66 dpa-NRT. For the cladding the materials 1.4970 and 1.4981 have been used in different metallurgical conditions, and for the Uranium/Plutonium mixed- oxide fuel the most important variants of the major fabrication parameters had been realized. The assembly will be brought to the Hot Cells of the KfK Karlsruhe for post-irradiation examination in February 1988, so that the knowledge of the fabrication data is of interest for the selection of fuel pins and for the evaluation of the examination results. Therefore this report compiles the fuel and fuel pin fabrication data from the INTERATOM data bank system BESEX and additionally, an overview of the irradiation history of the assembly is given [de

Anode-Engineered Protonic Ceramic Fuel Cell with Excellent Performance and Fuel Compatibility

NARCIS (Netherlands)

Hua, B.; Yan, N.; Li, M.; Sun, Y.-F.; Zhang, Y.-Q.; Li, J.; Etsell, T.; Sarkar, P.; Luo, J.L.

2016-01-01

Directly utilizing hydrocarbon fuels, particularly methane, is advantageous yet challenging in high-performance protonic ceramic fuel cells. In this work, this technological hurdle is well addressed by selective deposition of secondary electrocatalysts within the porous Ni-cermet anode. This novel

Recent trends in global production and utilization of bio-ethanol fuel

International Nuclear Information System (INIS)

Balat, Mustafa; Balat, Havva

2009-01-01

Bio-fuels are important because they replace petroleum fuels. A number of environmental and economic benefits are claimed for bio-fuels. Bio-ethanol is by far the most widely used bio-fuel for transportation worldwide. Production of bio-ethanol from biomass is one way to reduce both consumption of crude oil and environmental pollution. Using bio-ethanol blended gasoline fuel for automobiles can significantly reduce petroleum use and exhaust greenhouse gas emission. Bio-ethanol can be produced from different kinds of raw materials. These raw materials are classified into three categories of agricultural raw materials: simple sugars, starch and lignocellulose. Bio-ethanol from sugar cane, produced under the proper conditions, is essentially a clean fuel and has several clear advantages over petroleum-derived gasoline in reducing greenhouse gas emissions and improving air quality in metropolitan areas. Conversion technologies for producing bio-ethanol from cellulosic biomass resources such as forest materials, agricultural residues and urban wastes are under development and have not yet been demonstrated commercially.

A methodology for thermodynamic simulation of high temperature, internal reforming fuel cell systems

Science.gov (United States)

Matelli, José Alexandre; Bazzo, Edson

This work presents a methodology for simulation of fuel cells to be used in power production in small on-site power/cogeneration plants that use natural gas as fuel. The methodology contemplates thermodynamics and electrochemical aspects related to molten carbonate and solid oxide fuel cells (MCFC and SOFC, respectively). Internal steam reforming of the natural gas hydrocarbons is considered for hydrogen production. From inputs as cell potential, cell power, number of cell in the stack, ancillary systems power consumption, reformed natural gas composition and hydrogen utilization factor, the simulation gives the natural gas consumption, anode and cathode stream gases temperature and composition, and thermodynamic, electrochemical and practical efficiencies. Both energetic and exergetic methods are considered for performance analysis. The results obtained from natural gas reforming thermodynamics simulation show that the hydrogen production is maximum around 700 °C, for a steam/carbon ratio equal to 3. As shown in the literature, the found results indicate that the SOFC is more efficient than MCFC.

Experimental fuel channel for samples irradiation at the RB reactor

International Nuclear Information System (INIS)

Pesic, M.; Markovic, H.; Sokcic-Kostic, M.; Miric, I.; Prokic, M.; Strugar, P.

1984-12-01

An 80% enriched UO 2 fuel channel at the RB nuclear reactor in the 'Boris Kidric' Institute of Nuclear Sciences is modified for samples irradiation by fast neutrons. Maximum sample diameter is 25 mm and length up to 1000 mm. Characteristics of neutron and gamma radiation fields of this new experimental channel are investigated. In the centre of the channel, the main contribution to the total neutron absorbed dose, i.e. 0.29 Gy/Wh of reactor operation, is due to the fast neutron spectrum component. Only 0.05 Gy and 0.07 Gy in the total neutron absorbed dose are due to intermediate and thermal neutrons, respectively. At the same time the gamma absorbed dose is 0.35 Gy. The developed experimental fuel channel, EFC, has wide possibilities for utilization, from fast neutron spectrum studies, electronic component irradiations, dosemeters testing, up to cross-section measurements. (author)

Modified fuel channel for sample irradiation at the RB reactor

International Nuclear Information System (INIS)

Pesic, M.; Markovic, H.; Sokcic, M.; Miric, I.; Prokic, M.; Strugar, P.

1983-01-01

Fuel channel of 80% enriched UO 2 at RB reactor in Boris Kidric Institute of nuclear sciences is modified for sample irradiation in the fast neutron field. Maximum sample diameter is 25 mm and length up to 100 mm. Characteristics of neutron as well as gamma radiation fields of this new experimental channel are investigated. In the center of channel, the main contribution to the total neutron absorbed dose i.e. 0.29 Gy per 1 Wh of reactor operation, is due to the fast neutron spectrum component. Only 0.05 Gy and 0.07 Gy in the total neutron absorbed dose are due to epithermal and thermal neutrons respectively. At the same time gamma absorption dose is 0.35 Gy. The development of experimental fuel channel GRK has wide possibility for utilization, from electronic components fast neutron studies, dosimeters testing, to cross section measurements for fast neutron energies. (author)

Resourceful utilization technology for natural gas

International Nuclear Information System (INIS)

Matsumura, Y.

1994-01-01

This paper is a description of new applications that will contribute in increasing the demand for natural gas. First, technical issues to turn natural gas into a more resourceful fuel (efficient transportation and storage, integrated utilization of energies, uses as non-fuel), and also pitch-based high performance carbon materials and utilization techniques in the field of energy (isotropic carbon fiber, activated carbon fiber, spherical carbon micro-beads, high modulus carbon fiber). (TEC)

Estimates of Canadian fuel fabrication costs for alternative fuel cycles and systems

International Nuclear Information System (INIS)

Blahnik, C.

1979-04-01

Unit fuel fabrication costs are estimated for alternate fuel cycles and systems that may be of interest in Ontario Hydro's strategy analyses. A method is proposed for deriving the unit fuel fabrication price to be paid by a Canadian utility as a function of time (i.e. the price that reflects the changing demand/supply situation in the particular scenario considered). (auth)

Development of the vibration analysis technique of fuel rod and research on the methodology of fuel fretting wear analysis

International Nuclear Information System (INIS)

Kang, Heung Seok; Kim, Kyung Kyu; Yoon, Hyung Hoo; Song, Ki Nam

1998-12-01

The FEM program has been developed to predict the natural frequencies, the FEM program has been developed to predict the natural frequencies, and mode shapes of fuel rod subjected to axial force and continuously supported by a rotational and vent spring system, and to calculate the minimum reaction forces of the spacer grid spring when the maximum vibration amplitude of fuel rod is known. This program has been verified by commercial ANSYS program and the vibration test of dummy rods in air. The test equipment were set to get the fifth modes of test rods. Partial slip problem has been studied for the analysis of fuel fretting problem. Firstly, the assumption of semi-infiniteness of the contact bodies were validated by finite element (FE) analysis. From FE results, a classical bodies were validated by finite element (FE) analysis. From FE results, a classical theory of elasticity was utilized with regarding the problem as a plane problem. Secondly, the Mindlin-Cattaneo problem was re-evaluated, which gave the fundamental idea for developing the numerical tool for the shear traction on the contact. Shear force of sequentially-changing directions was considered and the corresponding shear traction was evaluated by extending the numerical tool for the Mindlin-Cattaneo problem

Development of the vibration analysis technique of fuel rod and research on the methodology of fuel fretting wear analysis

Energy Technology Data Exchange (ETDEWEB)

Kang, Heung Seok; Kim, Kyung Kyu; Yoon, Hyung Hoo; Song, Ki Nam

1998-12-01

The FEM program has been developed to predict the natural frequencies, the FEM program has been developed to predict the natural frequencies, and mode shapes of fuel rod subjected to axial force and continuously supported by a rotational and vent spring system, and to calculate the minimum reaction forces of the spacer grid spring when the maximum vibration amplitude of fuel rod is known. This program has been verified by commercial ANSYS program and the vibration test of dummy rods in air. The test equipment were set to get the fifth modes of test rods. Partial slip problem has been studied for the analysis of fuel fretting problem. Firstly, the assumption of semi-infiniteness of the contact bodies were validated by finite element (FE) analysis. From FE results, a classical bodies were validated by finite element (FE) analysis. From FE results, aclassical theory of elasticity was utilized with regarding the problem as a plane problem. Secondly, the Mindlin-Cattaneo problem was re-evaluated, which gave the fundamental idea for developing the numerical tool for the shear traction on the contact. Shear force of sequentially-changing directions was considered and the corresponding shear traction was evaluated by extending the numerical tool for the Mindlin-Cattaneo problem.

Impact Analysis for Fuel Assemblies in Spent Fuel Storage Rack

International Nuclear Information System (INIS)

Oh, Jinho

2013-01-01

The design and structural integrity evaluation of a spent fuel storage rack (SFSR) utilized for storing and protecting the spent fuel assemblies generated during the operation of a reactor are very important in terms of nuclear safety and waste management. The objective of this study is to show the validity of the SFSR design as well as fuel assembly through a structural integrity evaluation based on a numerical analysis. In particular, a dynamic time history analysis considering the gaps between the fuel assemblies and the walls of the storage cell pipes in the SFSR was performed to check the structural integrity of the fuel assembly and storage cell pipe

Impact Analysis for Fuel Assemblies in Spent Fuel Storage Rack

Energy Technology Data Exchange (ETDEWEB)

Oh, Jinho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2013-07-01

The design and structural integrity evaluation of a spent fuel storage rack (SFSR) utilized for storing and protecting the spent fuel assemblies generated during the operation of a reactor are very important in terms of nuclear safety and waste management. The objective of this study is to show the validity of the SFSR design as well as fuel assembly through a structural integrity evaluation based on a numerical analysis. In particular, a dynamic time history analysis considering the gaps between the fuel assemblies and the walls of the storage cell pipes in the SFSR was performed to check the structural integrity of the fuel assembly and storage cell pipe.

Spent fuel transport in fuel cycle

International Nuclear Information System (INIS)

Labrousse, M.

1977-01-01

The transport of radioactive substances is a minor part of the fuel cycle because the quantities of matter involved are very small. However the length and complexity of the cycle, the weight of the packing, the respective distances between stations, enrichment plants and reprocessing plants are such that the problem is not negligible. In addition these transports have considerable psychological importance. The most interesting is spent fuel transport which requires exceptionally efficient packaging, especially where thermal and mechanical resistance are concerned. To meet the safety criteria necessary for the protection of both public and users it was decided to use the maximum capacity consistent with rail transport and to avoid coolant fluids under pressure. Since no single type of packing is suitable for all existing stations an effort has been made to standardise handling accessories, and future trands are towards maximum automation. A discussion on the various technical solutions available for the construction of these packing systems is followed by a description of those used for the two types of packaging ordered by COGEMA [fr

Evaluation of plutonium, uranium, and thorium use in power reactor fuel cycles

International Nuclear Information System (INIS)

Kasten, P.R.; Homan, F.J.

1977-01-01

The increased cost of uranium and separative work has increased the attractiveness of plutonium use in both uranium and thorium fuel cycles in thermal reactors. A technology, fuel utilization, and economic evaluation is given for uranium and thorium fuel cycles in various reactor types, along with the use of plutonium and 238 U. Reactors considered are LWRs, HWRs, LWBRs, HTGRs, and FBRs. Key technology factors are fuel irradiation performance and associated physical property values. Key economic factors are unit costs for fuel fabrication and reprocessing, and for refabrication of recycle fuels; consistent cost estimates are utilized. In thermal reactors, the irradiation performance of ceramic fuels appears to be satisfactory. At present costs for uranium ore and separative work, recycle of plutonium with thorium rather than uranium is preferable from fuel utilization and economic viewpoints. Further, the unit recovery cost of plutonium is lower from LWR fuels than from natural-uranium HWR fuels; use of LWR product permits plutonium/thorium fueling to compete with uranium cycles. Converting uranium cycles to thorium cycles increases the energy which can be extracted from a given uranium resource. Thus, additional fuel utilization improvement can be obtained by fueling all thermal reactors with thorium, but this requires use of highly enriched uranium; use of 235 U with thorium is most economic in HTGRs followed by HWRs and then LWRs. Marked improvement in long-term fuel utilization can be obtained through high thorium loadings and short fuel cycle irradiations as in the LWBR, but this imposes significant economic penalties. Similar operating modes are possible in HWRs and HTGRs. In fast reactors, use of the plutonium-uranium cycle gives advantageous fuel resource utilization in both LMFBRs and GCFRs; use of the thorium cycle provides more negative core reactivity coefficients and more flexibility relative to use of recycle fuels containing uranium of less than 20

The fuel cell as a energy center. The chances of utilization of sewage gas; Die Brennstoffzelle als Energiezentrum. Die Chancen der Verwertung von Klaergas

Energy Technology Data Exchange (ETDEWEB)

Berger, P. [CFC Solutions GmbH, Muenchen (Germany)

2008-07-01

The basis of the fuel cell power station of the CFC Solutions GmbH (Munich, Federal Republic of Germany) is the carbonate fuel cell, with which arbitrary gaseous fuels can be used for power generation. The reformation of the methane containing gaseous fuel to hydrogen in the fuel cell requires heat energy, which is obtained as waste heat of the cell reaction. Apart from the electricity by the fuel cell power station heat energy is produced. Thus the fuel cell power station also can be used for the production of process steam and production of coldness by means of an absorption refrigeration system. A further advantage is that for the fuel cell power station no hydrogen have to be manufactured. In comparison to the motoric heat and power cogeneration or small gas turbines thee are further advantages for fuel cell power stations: a) high electrical efficiency within the kilowatt range; b) high temperature useful heat; c) efficient cooling; d) Flexibility with the fuel (natural gas, fermentation gas, sewage gas); e) good extent of utilization of the power station; f) flexible interpretation and operation according to user requirement; g) premium power and USV applications; g) smallest emission to exhaust gas and noises.

Practical introduction of thorium fuel cycles

International Nuclear Information System (INIS)

Kasten, P.R.

1982-01-01

The pracitcal introduction of throrium fuel cycles implies that thorium fuel cycles compete economically with uranium fuel cycles in economic nuclear power plants. In this study the reactor types under consideration are light water reactors (LWRs), heavy water reactors (HWRs), high-temperature gas-cooled reactors (HTGRs), and fast breeder reactors (FBRs). On the basis that once-through fuel cycles will be used almost exclusively for the next 20 or 25 years, introduction of economic thorium fuel cycles appears best accomplished by commercial introduction of HTGRs. As the price of natural uranium increases, along with commercialization of fuel recycle, there will be increasing incentive to utilize thorium fuel cycles in heavy water reactors and light water reactors as well as in HTGRs. After FBRs and fuel recycle are commercialized, use of thorium fuel cycles in the blanket of FBRs appears advantageous when fast breeder reactors and thermal reactors operate in a symbiosis mode (i.e., where 233 U bred in the blanket of a fast breeder reactor is utilized as fissile fuel in thermal converter reactors)

The PWR fuel cycle. Utilization of uranium in a reactor

International Nuclear Information System (INIS)

Mignot, E.

After having briefly described the core of a pressurized water reactor, the fuel is examined and, in particular, the change in reactivity that governs the renewal of the fuel. The present French nuclear units are taken as example and it is shown that with the development of the nuclear complex, it is no longer possible to reason on the basis of an isolated reactor, since the running of a reactor is set by the network and its working constraints become a priority. The optimization of the fuel control must therefore cover the total cost [fr

Final environmental impact statement: US Spent Fuel Policy. Charge for spent fuel storage

International Nuclear Information System (INIS)

1980-05-01

The United States Government policy relating to nuclear fuel reprocessing, which was announced by President Carter on April 7, 1977, provides for an indefinite deferral of reprocessing, and thus commits light water reactor (LWR) plants to a once-through fuel cycle during that indefinite period. In a subsequent action implementing that policy, the Department of Energy (DOE) on October 18, 1977 announced a spent fuel policy which would enable domestic, and on a selective basis, foreign utilities to deliver spent fuel to the US Government for interim storage and final geologic disposal, and pay the Government a fee for such services. This volume addresses itself to whether the fee charged for these services, by its level or its structure, would have any effect on the environmental impacts of implementing the Spent Fuel Policy itself. This volume thus analyzes the fee and various alternatives to determine the interaction between the fee and the degree of participation by domestic utilities and foreign countries in the proposed spent fuel program for implementing the Spent Fuel Policy. It also analyzes the effect, if any, of the fee on the growth of nuclear power

Assessment of ethanol-fueled IMHEX{reg_sign} fuel cell power plants in distributed generation

Energy Technology Data Exchange (ETDEWEB)

Woods, R. [M-C Power Corp., Burr Ridge, IL (United States); Lefeld, J. [PSI Energy, Plainfield, IN (United States)

1993-12-31

Ethanol-fueled cell power plants presents several significant opportunities for the power generation industry. The potential exists to reduce pollution, help the nation shift from its dependence on imported fuels, reduce global warming, and strengthen the economy. Two important developments can be merged to create a clean, high-technology, bio-based energy system: the production of ethanol fuels and the application of fuel cell power plants. Utilization of ethanol will be in dual-fueled applications initially, and evolve toward the primary fuel as the need for renewable energy sources increase and the economic competitiveness improves. This assessment addresses the major issues of this proposed concept and outlines the benefits anticipated to the environment, US agriculture, energy supplies, and electric power customers. Economic and technical aspects of the concept are also reviewed. One of PSI Energy`s primary interests is the utilization of renewable fuels supplied by their customer base. The IMHEX{reg_sign} fuel cell is an advanced electric power generation technology currently under development by M-C Power. Commercial applications within the power generation industry are scheduled to begin during the late 1990s.

Uranium Fuel Plant. Applicants environmental report

International Nuclear Information System (INIS)

1975-05-01

The Uranium Fuel Plant, located at the Cimarron Facility, was constructed in 1964 with operations commencing in 1965 in accordance with License No. SNM-928, Docket No. 70-925. The plant has been in continuous operation since the issuance of the initial license and currently possesses contracts extending through 1978, for the production of nuclear fuels. The Uranium Plant is operated in conjunction with the Plutonium Facility, each sharing common utilities and sanitary wastes disposal systems. The operation has had little or no detrimental ecological impact on the area. For the operation of the Uranium Fuel Fabrication Plant, initial equipment provided for the production of UO 2 , UF 4 , uranium metal and recovery of scrap materials. In 1968, the plant was expanded by increasing the UO 2 and pellet facilities by the installation of another complete production line for the production of fuel pellets. In 1969, fabrication facilities were added for the production of fuel elements. Equipment initially installed for the recovery of fully enriched scrap has not been used since the last work was done in 1970. Economically, the plant has benefited the Logan County area, with approximately 104 new jobs with an annual payroll of approximately $1.3 million. In addition, $142,000 is annually paid in taxes to state, local and federal governments, and local purchases amount to approximately $1.3 million. This was all in land that was previously used for pasture land, with a maximum value of approximately 37,000 dollars. Environmental effects of plant operation have been minimal. A monitoring and measurement program is maintained in order to ensure that the ecology of the immediate area is not affected by plant operations

Limitations of Commercializing Fuel Cell Technologies

Science.gov (United States)

Nordin, Normayati

2010-06-01

Fuel cell is the technology that, nowadays, is deemed having a great potential to be used in supplying energy. Basically, fuel cells can be categorized particularly by the kind of employed electrolyte. Several fuel cells types which are currently identified having huge potential to be utilized, namely, Solid Oxide Fuel Cells (SOFC), Molten Carbonate Fuel Cells (MCFC), Alkaline Fuel Cells (AFC), Phosphoric Acid Fuel Cells (PAFC), Polymer Electron Membrane Fuel Cell (PEMFC), Direct Methanol Fuel Cells (DMFC) and Regenerative Fuel Cells (RFC). In general, each of these fuel cells types has their own characteristics and specifications which assign the capability and suitability of them to be utilized for any particular applications. Stationary power generations and transport applications are the two most significant applications currently aimed for the fuel cell market. It is generally accepted that there are lots of advantages if fuel cells can be excessively commercialized primarily in context of environmental concerns and energy security. Nevertheless, this is a demanding task to be accomplished, as there is some gap in fuel cells technology itself which needs a major enhancement. It can be concluded, from the previous study, cost, durability and performance are identified as the main limitations to be firstly overcome in enabling fuel cells technology become viable for the market.

Nuclear fuel quality assurance

International Nuclear Information System (INIS)

1976-01-01

Full text: Quality assurance is used extensively in the design, construction and operation of nuclear power plants. This methodology is applied to all activities affecting the quality of a nuclear power plant in order to obtain confidence that an item or a facility will perform satisfactorily in service. Although the achievement of quality is the responsibility of all parties participating in a nuclear power project, establishment and implementation of the quality assurance programme for the whole plant is a main responsibility of the plant owner. For the plant owner, the main concern is to achieve control over the quality of purchased products or services through contractual arrangements with the vendors. In the case of purchase of nuclear fuel, the application of quality assurance might be faced with several difficulties because of the lack of standardization in nuclear fuel and the proprietary information of the fuel manufacturers on fuel design specifications and fuel manufacturing procedures. The problems of quality assurance for purchase of nuclear fuel were discussed in detail during the seminar. Due to the lack of generally acceptable standards, the successful application of the quality assurance concept to the procurement of fuel depends on how much information can be provided by the fuel manufacturer to the utility which is purchasing fuel, and in what form and how early this information can be provided. The extent of information transfer is basically set out in the individual vendor-utility contracts, with some indirect influence from the requirements of regulatory bodies. Any conflict that exists appears to come from utilities which desire more extensive control over the product they are buying. There is a reluctance on the part of vendors to permit close insight of the purchasers into their design and manufacturing procedures, but there nevertheless seems to be an increasing trend towards release of more information to the purchasers. It appears that

An evaluation of once-through homogeneous thorium fuel cycle for light water reactors

International Nuclear Information System (INIS)

Joo, H. K.; Noh, J. M.; Yoo, J. W.

2002-01-01

The other ways enhancing the economic potential of thorium fuel has been assessed ; the utilization of lower enriched uranium in thorium-uranium fuel, duplex thorium fuel concept, thorium utilization in the mixed core with uranium fuel assembly and thorium blanket utilization in the uranium core. The fuel economics of the proposed ways of thorium fuel increased compared to the previous homogeneous thorium fuel cycle. Compared to uranium fuel cycle, however, they do not show any economic incentives. From the view of proliferation resistance potential, thorium fuel option has the advantage to reduce the inventory of plutonium production. Any of proposed thorium options are less economical than uranium fuel option, the thorium fuel option has the potential to be utilized in the future for the sake of the effective consumption of excessive plutonium and the preparation against the using up of uranium resource

Maximum power point tracking

International Nuclear Information System (INIS)

Enslin, J.H.R.

1990-01-01

A well engineered renewable remote energy system, utilizing the principal of Maximum Power Point Tracking can be m ore cost effective, has a higher reliability and can improve the quality of life in remote areas. This paper reports that a high-efficient power electronic converter, for converting the output voltage of a solar panel, or wind generator, to the required DC battery bus voltage has been realized. The converter is controlled to track the maximum power point of the input source under varying input and output parameters. Maximum power point tracking for relative small systems is achieved by maximization of the output current in a battery charging regulator, using an optimized hill-climbing, inexpensive microprocessor based algorithm. Through practical field measurements it is shown that a minimum input source saving of 15% on 3-5 kWh/day systems can easily be achieved. A total cost saving of at least 10-15% on the capital cost of these systems are achievable for relative small rating Remote Area Power Supply systems. The advantages at larger temperature variations and larger power rated systems are much higher. Other advantages include optimal sizing and system monitor and control

Japanese utilities' plutonium utilization program

International Nuclear Information System (INIS)

Matsuo, Yuichiro.

1996-01-01

Japan's 10 utility companies are working and will continue to work towards establishing a fully closed nuclear fuel cycle. The key goals of which are: (1) reprocessing spent fuel; (2) recycling recovered uranium and plutonium; and (3) commercializing fast breeder technology by around the year 2030. This course of action by the Japanese electric power industry is in full accordance with Japan's national policy outlined in the government's report ''The Long-Term Program for Research, Development, and Nuclear Energy,'' which was published in June 1994. The Japanese civilian nuclear program is a long-term program that looks into the 21st century and beyond. It is quite true that sustaining the recycling option for energy security and the global environment demands a large investment. For it to be accepted by the public, safety must be the highest priority and will be pursued at a great cost if necessary. In its history, Japan has learned that as technology advances, costs will come down. The Japanese utility industry will continue investment in technology without compromising safety until the recycling option becomes more competitive with other options. This effort will be equally applied to the development of the commercial FBRs. The Japanese utility industry is confident that Japan's stable policy and strong objective to develop competitive and peaceful technology will contribute to the global economy and the environment without increasing the threat of plutonium proliferation

Fuel Services

International Nuclear Information System (INIS)

Silberstein, A.

1982-09-01

FRAGEMA has developed most types of inspection equipments to work on irradiated fuel assemblies and on single fuel rods during reactor outages with an efficiency compatible with the utilities operating priorities. In order to illustrate this statement, two specific examples of inspection equipments are shortly described: the on-site removable fuel rod assembly examination stand, and the fuel assembly multiple examination device. FRAGEMA has developed techniques for the identifiction of the leaking fuel rods in the fuel assembly and the tooling necessary to perform the replacement of the faulted element. These examples of methods, techniques and equipments described and the experience accumulated through their use allow FRAGEMA to qualify for offering the supply of the corresponding software, hardware or both whenever an accurate understanding of the fuel behaviour is necessary and whenever direct intervention on the assembly and associated components is necessary due to safety, operating or economical reasons

Decommissioning and re-utilization of the Musashi Reactor

International Nuclear Information System (INIS)

Tomio Tanzawa; Nobukazu Iijima; Norikazu Horiuchi; Tadashi Yoshida; Tetsuo Matsumoto; Naoto Hagura; Ryouhei Kamiya

2008-01-01

The Musashi Institute of Technology Research Reactor (the Musashi Reactor) is a TRIGA-? with maximum thermal power of 100 kW. The decommissioning was decided in May, 2003. The reactor facility is now under decommissioning. The phased decommissioning was selected. Phase 1 consists of permanent shutdown of the reactor and stopping the operational functions, and transportation of the spent nuclear fuels. After completion of the transportation, the reactor facility is characterized as the storage of low level radioactive materials. This is phase 2. Activities of phase 1 were completed and the facility is now under phase 2. Activities of phase 3 consist of dismantling the reactor tank and the shielding, and delivering the radioactive waste to a waste disposal facility. The phase 3 will be started on condition that the undertaking of the waste disposal for research reactors will be established. On the other hand, re-utilization of the facility has being studied, and 'realistic' reactor simulator was turned out by utilizing the reactor installations such as control rod drive and operation console. (authors)

Economical analysis to utilize MTR fuel elements using silicides in research reactors

International Nuclear Information System (INIS)

Bergallo, Juan E.; Novara, Oscar E.; Adelfang, Pablo

2000-01-01

According to international programs on reducing enrichment in research reactors and the necessity to maintain their operation, new fuel elements have been developed in order to meet both objectives. Thus, U-Si alloy fuel elements for research reactors are becoming of greater interest for the international markets. It became necessary to make an economic study about the convenience of introducing this type of fuel elements in the RA-3 reactor and to know the potentiality of this fuel. The economical behavior of the reactor operation has been evaluated comparing the actual U 3 O 8 nuclear fuel cycle with U 3 Si 2 nuclear fuels. Results obtained show that the main economical factor to determine the change of fuels is the cost of fabrication, and the change is advisable up to an 80% difference. The other factors related to the cost of nuclear fuel cycle are not relevant or have real minor impacts. (author)

Nuclear fuel management optimization for LWRs

International Nuclear Information System (INIS)

Turinsky, Paul J.

1997-01-01

LWR in core nuclear fuel management involves the placement of fuel and control materials so that a specified objective is achieved within constraints. Specifically, one is interested in determining the core loading pattern (LP of fuel assemblies and burnable poisons and for BWR, also control rod insertion versus cycle exposure. Possible objectives include minimization of feed enrichment and maximization of cycle energy production, discharge burnup or thermal margin. Constraints imposed relate to physical constraints, e.g. no discrete burnable poisons in control rod locations, and operational and safety constraints, e.g. maximum power peaking limit. The LP optimization problem is a large scale, nonlinear, mixed-integer decision variables problem with active constraints. Even with quarter core symmetry imposed, there are above 10 100 possible LPs. The implication is that deterministic optimization methods are not suitable, so in this work we have pursued using the stochastic Simulated Annealing optimization method. Adaptive penalty functions are used to impose certain constraints, allowing unfeasible regions of the search space to be transverse. Since ten of thousands of LPs must be examined to achieve high computational efficiency, higher-order Generalized Perturbation Theory is utilized to solve the Nodal Expansion Method for of the two-group neutron diffusion. These methods have been incorporated into the FORMOSA series of codes and used to optimize PWR and BWR reload cores. (author). 9 refs., 3 tabs

Advanced-fuel reversed-field pinch reactor (RFPR)

International Nuclear Information System (INIS)

Hagenson, R.L.; Krakowski, R.A.

1981-10-01

The utilization of deuterium-based fuels offers the potential advantages of greater flexibility in blanket design, significantly reduced tritium inventory, potential reduction in radioactivity level, and utilization of an inexhaustible fuel supply. The conventional DT-fueled Reversed-Field Pinch Reactor (RFPR) designs are reviewed, and the recent extension of these devices to advanced-fuel (catalyzed-DD) operation is presented. Attractive and economically competitive DD/RFPR systems are identified having power densities and plasma parameters comparable to the DT systems. Converting an RFP reactor from DT to DD primarily requires increasing the magnetic field levels a factor of two, still requiring only modest magnet coil fields (less than or equal to 4 T). When compared to the mainline tokamak, the unique advantages of the RFP (e.g., high beta, low fields at the coils, high ohmic-heating power densities, unrestricted aspect ratio) are particularly apparent for the utilization of advanced fuels

Status of SFR Metal Fuel Development

International Nuclear Information System (INIS)

Lee, Chan Bock; Lee, Byoung Oon; Kim, Ki Hwan; Kim, Sung Ho

2013-01-01

Conclusion: • Metal fuel recycling in SFR: - Enhanced utilization of uranium resource; - Efficient transmutation of minor actinides; - Inherent passive reactor safety; - Proliferation resistance with pyro-electrochemical fuel recycling. • Demonstration of technical feasibility of recycling TRU metal fuel by 2020: - Remote fuel fabrication; - Irradiation performance up to high burnup

Synergistic fuel cycles of the future

International Nuclear Information System (INIS)

Meneley, D.A.; Dastur, A.R.

1997-01-01

Good neutron economy is the basis of the fuel cycle flexibility in the CANDU reactor. This paper describes the fuel cycle options available to the CANDU owner with special emphasis on resource conservation and waste management. CANDU fuel cycles with low initial fissile content operate with relatively high conversion ratio. The natural uranium cycle provides over 55 % of energy from the plutonium that is created during fuel life. Resource utilization is over 7 MWd/kg NU. This can be improved by slight enrichment (between 0.9 and 1.2 wt % U235) of the fuel. Resource utilization increases to 11 MWd/kg NU with the Slightly Enriched Uranium cycle. Thorium based cycles in CANDU operate at near-breeder efficiency. Obey provide attractive options when used with natural uranium or separated (reactor grade and weapons grade) plutonium as driver fuels. In the latter case, the energy from the U233 plus the initial plutonium content amounts to 3.4 GW(th).d/kg Pu-fissile. The same utilization is expected from the use of FBR plutonium in a CANDU thorium cycle. Extension of natural resource is achieved by the use of spent fuels in CANDU. The LWR/CANDU Tandem cycle leads to an additional 77 % of energy through the use of reprocessed LWR fuel (which has a fissile content of 1.6 wt %) in CANDU. Dry reprocessing of LWR fuel with the OREOX process (a more safeguardable alternative to the PUREX process) provides an additional 50 % energy. Uranium recovered (RU) from separation of plutonium contained in spent LWR fuel provides an additional 15 MWd/kg RU. CANDU's low fissile requirement provides the possibility, through the use of non-fertile targets, of extracting energy from the minor actinides contained in spent fuel. In addition to the resource utilization advantage described above, there is a corresponding reduction in waste arisings with such cycles. This is especially significant when separated plutonium is available as a fissile resource. (author)

NUPEC proves reliability of LWR fuel assemblies

International Nuclear Information System (INIS)

Anon.

1987-01-01

It is very important in assuring the safety of nuclear reactors to confirm the reliability of fuel assemblies. The test program of the Nuclear Power Engineering Center on the reliability of fuel assemblies has verified the high performance and reliability of Japanese LWR fuels, and confirmed the propriety of their design and fabrication. This claim is based on the data obtained from the fuel assemblies irradiated in commercial reactors. The NUPEC program includes irradiation test which has been conducted for 11 years since fiscal 1976, and the maximum thermal loading test using the out of pile test facilities simulating a real reactor which has been continued since fiscal 1978. The irradiation test on BWR fuel assemblies in No.3 reactor in Fukushima No.1 Nuclear Power Station, Tokyo Electric Power Co., Inc., and on PWR fuel assemblies in No.3 reactor in Mihama Power Station, Kansai Electric Power Co., Inc., and the maximum thermal loading test on BWR and PWR fuel assemblies are reported. The series of postirradiation examination of the fuel assemblies used for commercial reactors was conducted for the first time in Japan, and the highly systematic data on 27 items were obtained. (Kako, I.)

IFBA credit in the Shearon Harris fuel racks with Vantage 5 fuel

International Nuclear Information System (INIS)

Boyd, W.A.; Schmidt, R.F.; Erwin, R.D.

1989-01-01

At the Shearon Harris nuclear plant, fuel management strategies are being considered which will result in feed fuel enrichments approaching 5.0 w/o U-235. These types of enrichments require a new criticality analysis to raise the existing fuel rack enrichment limit. It is receiving Westinghouse Vantage 5 fuel with integral fuel burnable absorber (IFBA) rods providing the depletable neutron absorber. An analysis was performed on the fuel racks which demonstrates that fuel enriched up to 5.0 w/o U-235 can be stored by taking credit for the IFBA rods present in the high enriched fuel assemblies. This is done by calculating the maximum Vantage 5 fuel assembly reactivity that can be placed in the fuel racks and meet the criticality K-eff limit. A methodology is also developed which conservatively calculates the minimum number of IFBA rods needed per assembly to meet the fuel rack storage limits. This eliminates the need for core designers to determine assembly K-inf terms for every different enrichment/IFBA combination

Using of cotton oil soapstock biodiesel-diesel fuel blends as an alternative diesel fuel

Energy Technology Data Exchange (ETDEWEB)

Keskin, Ali [Technical Education Faculty, Mersin University, 33500 Mersin (Turkey); Guerue, Metin [Engineering and Architectural Faculty, Gazi University, 06570 Maltepe, Ankara (Turkey); Altiparmak, Duran [Technical Education Faculty, Gazi University, 06500 Ankara (Turkey); Aydin, Kadir [Engineering and Architectural Faculty, Cukurova University, 01330 Adana (Turkey)

2008-04-15

In this study, usability of cotton oil soapstock biodiesel-diesel fuel blends as an alternative fuel for diesel engines were studied. Biodiesel was produced by reacting cotton oil soapstock with methyl alcohol at determined optimum condition. The cotton oil biodiesel-diesel fuel blends were tested in a single cylinder direct injection diesel engine. Engine performances and smoke value were measured at full load condition. Torque and power output of the engine with cotton oil soapstock biodiesel-diesel fuel blends decreased by 5.8% and 6.2%, respectively. Specific fuel consumption of engine with cotton oil soapstock-diesel fuel blends increased up to 10.5%. At maximum torque speeds, smoke level of engine with blend fuels decreased up to 46.6%, depending on the amount of biodiesel. These results were compared with diesel fuel values. (author)

Using of cotton oil soapstock biodiesel-diesel fuel blends as an alternative diesel fuel

International Nuclear Information System (INIS)

Keskin, Ali; Guerue, Metin; Altiparmak, Duran; Aydin, Kadir

2008-01-01

In this study, usability of cotton oil soapstock biodiesel-diesel fuel blends as an alternative fuel for diesel engines were studied. Biodiesel was produced by reacting cotton oil soapstock with methyl alcohol at determined optimum condition. The cotton oil biodiesel-diesel fuel blends were tested in a single cylinder direct injection diesel engine. Engine performances and smoke value were measured at full load condition. Torque and power output of the engine with cotton oil soapstock biodiesel-diesel fuel blends decreased by 5.8% and 6.2%, respectively. Specific fuel consumption of engine with cotton oil soapstock-diesel fuel blends increased up to 10.5%. At maximum torque speeds, smoke level of engine with blend fuels decreased up to 46.6%, depending on the amount of biodiesel. These results were compared with diesel fuel values. (author)

The evolving nuclear fuel cycle

International Nuclear Information System (INIS)

Gale, J.D.; Hanson, G.E.; Coleman, T.A.

1993-01-01

Various economics and political pressures have shaped the evolution of nuclear fuel cycles over the past 10 to 15 yr. Future trends will no doubt be similarly driven. This paper discusses the influences that long cycles, high discharge burnups, fuel reliability, and costs will have on the future nuclear cycle. Maintaining the economic viability of nuclear generation is a key issue facing many utilities. Nuclear fuel has been a tremendous bargain for utilities, helping to offset major increases in operation and maintenance (O ampersand M) expenses. An important factor in reducing O ampersand M costs is increasing capacity factor by eliminating outages

Fuel Class Higher Alcohols

KAUST Repository

Sarathy, Mani

2016-01-01

This chapter focuses on the production and combustion of alcohol fuels with four or more carbon atoms, which we classify as higher alcohols. It assesses the feasibility of utilizing various C4-C8 alcohols as fuels for internal combustion engines

Fuel assembly for nuclear reactor

International Nuclear Information System (INIS)

Yamanaka, Akihiro; Haikawa, Katsumasa; Haraguchi, Yuko; Nakamura, Mitsuya; Aoyama, Motoo; Koyama, Jun-ichi.

1996-01-01

In a BWR type fuel assembly comprising first fuel rods filled with nuclear fission products and second fuel rods filled with burnable poisons and nuclear fission products, the concentration of the burnable poisons mixed to a portion of the second fuel rods is controlled so that it is reduced at the upper portion and increased at the lower portion in the axial direction. In addition, a product of the difference of an average concentration of burnable poisons between the upper portion and the lower portion and the number of fuel rods is determined to higher than a first set value determined corresponding to the limit value of a maximum linear power density. The sum of the difference of the average concentration of the burnable poisons between the upper portion and the lower portion of the second fuel rod and the number of the second fuel rods is determined to lower than a second set value determined corresponding to a required value of a surplus reactivity. If the number of the fuel rods mixed with the burnable poisons is increased, the infinite multiplication factor at an initial stage of the burning is lowered and, if the concentration of the mixed burnable poisons is increased, the time of exhaustion of the burnable poisons is delayed. As a result, the maximum value of the infinite multiplication factor is suppressed thereby enabling to control surplus reactivity. (N.H.)

An assessment of the effectiveness of fuel cycle technologies for the national energy security enhancement in the electricity sector

International Nuclear Information System (INIS)

Kim, Hyun Jun; Jun, Eunju; Chang, Soon Heung; Kim, Won Joon

2009-01-01

Energy security, in the 21st century, draws significant attention in most countries worldwide, because the national security and sustainable development depend largely on energy security. The anticipated fossil energy depletion and the instability of their supply drive many countries to consider nuclear energy as their alternative energy source for the enhancement of their national energy security. In this study, indicators measuring the level of energy security in the electric power sector are developed and applied for the assessment of the effectiveness of four electric power system schemes which deploy different nuclear fuel cycle technologies, with consideration for the diversification of the energy markets and the vulnerability to economic disruption. Results show that the contribution of the closed fuel cycle scheme is larger than the once-through fuel cycle scheme in the perspective of energy security. In addition, the completely closed fuel cycle with the spent fuel recycling enhances the national energy security to the maximum extent compared to all other fuel cycle schemes. Since a completely closed fuel cycle is hardly affected by the uranium price changes, this scheme is found to be the most favorable scheme, ensuring the stable profit of utilities and stabilizing the electricity tariff. In addition, the completely closed fuel cycle scheme provides the best enhancement of national energy security with respect to energy supply, under reasonable price conditions. The indicators developed in this study can be utilized as a useful instrument for the measurement of the level of the energy security, especially by the countries importing energy resources for the generation of electric power.

Power Reactor Fuel Reprocessing Plant-1: a stepping stone in Indian PHWR spent fuel reprocessing

International Nuclear Information System (INIS)

Pradhan, Sanjay; Dubey, K.; Qureshi, F.T.; Lokeswar, S.P.

2017-01-01

India has low reserves of uranium and high reserves of thorium. In order to optimize resource utilization India has adopted a closed fuel cycle to ensure long-term energy security. The optimum resource utilization is feasible only by adopting reprocessing, conditioning and recycle options. It is very much imperative to view spent fuel as a vital resource material and not a waste to be disposed off. Thus, spent nuclear fuel reprocessing forms an integral part of the Indian Nuclear Energy Programme. Aqueous reprocessing based on PUREX technology is in use for more than 50 years and has reached a matured status

An essay pertaining to the supply and price of natural gas as fuel for electric utilities and independent power producers; and, the related growth of non-utility generators to meet capacity shortfalls in the next decade

International Nuclear Information System (INIS)

Clements, J.R.

1990-01-01

This paper addresses the impact natural gas and petroleum prices have on how the electric power industry decides to meet increasing demand for electric power. The topics of the paper include the pricing impact of the Iraq-Kuwait conflict, the BTU parity argument, electric utility capacity shortfalls in 1993, the growth of the non-utility generator and the independent power developer market, natural gas as the desired fuel of the decade, the financial strategy in acquiring natural gas reserves, the cost and availability of natural gas supplies for non-utility generators, and the reluctance of the gas producers to enter long term contracts

Biomethane as transport fuel – A comparison with other biogas utilization pathways in northern Italy

International Nuclear Information System (INIS)

Patrizio, P.; Leduc, S.; Chinese, D.; Dotzauer, E.; Kraxner, F.

2015-01-01

Highlights: • CHP and biomethane generation were investigated as biogas utilization pathways. • A spatially explicit biogas supply chain optimization model was developed. • Biomethane as vehicle fuel has lower investment and operational costs than CHP. • CHP has most favorable economics thanks to high carbon reduction potential. - Abstract: Italy is a large producer of biogas from anaerobic digestion, which is mainly used for power generation with limited use of cogenerated heat. Other utilization pathways, such as biomethane injection into the natural gas grid or biomethane used as a vehicle fuel, remain unexplored. Given the dense grid of natural gas pipelines and existing Compressed Natural Gas (CNG) refueling stations in northern Italy, significant market opportunities for biogas could also arise in the heating and transport sectors. The main objectives of this paper are to explore the potential role of agricultural biogas in different utilization pathways. Biogas combustion for simultaneous production of heat and power in small Combined Heat and Power (CHP) facilities is also assessed, as is upgrading to biomethane for transport or natural gas grid injection in the specific context of northern Italy. The spatially explicit optimization model BeWhere is used to identify optimal locations where greenfield biogas plants could be installed and to determine the most economic and environmentally beneficial mix of conversion technologies and plant capacities. Carbon price, for instance in the form of tradable emission permits, is assessed as a policy instrument and compared with other options such as price premiums on biomethane or electricity costs. Results show that starting from a carbon price of 15 EUR/tCO_2, the cogeneration option is preferable if plants are located in the proximity of existing district heating infrastructure. CNG plants are only competitive starting at a carbon price of 70 EUR/tCO_2 in areas with high feedstock availability. The

Burn-Up Calculation of the Fuel Element in RSG-GAS Reactor using Program Package BATAN-FUEL

International Nuclear Information System (INIS)

Mochamad Imron; Ariyawan Sunardi

2012-01-01

Calculation of burn lip distribution of 2.96 gr U/cc Silicide fuel element at the 78 th reactor cycle using computer code program of BATAN-FUEL has been done. This calculation uses inputs such as generated power, operation time and a core assumption model of 5/1. Using this calculation model burn up for the entire fuel elements at the reactor core are able to be calculated. From the calculation it is obtained that the minimum burn up of 6.82% is RI-50 at the position of A-9, while the maximum burn up of 57.57% is RI 467 at the position of 8-7. Based on the safety criteria as specified in the Safety Analysis Report (SAR) RSG-GAS reactor, the maximum fuel burn up allowed is 59.59%. It then can be concluded that pattern that elements placement at the reactor core are properly and optimally done. (author)

Nuclear fuel lease accounting