The Oklo natural fossil fission reactors in Gabon, Equatorial Africa, have been studied as a natural analogue for spent nuclear fuel in a geological environment. For these studies, it is important to know what has happened to these reactors since they formed. This review is focussed on existing geological and geochronological information concerning the Oklo reactors and the surrounding ore. A sequence of geological and geochemical events in the Oklo area, as described in the literature, is given. The data and the studies behind this established geochronology are discussed and evaluated. Of the regional geology, special attention is given to the dating of the Francevillian sediments, and the intrusion of a dolerite dyke swarm. The processes that led to the mineralisation at Oklo, the subsequent formation of the nuclear reactors and later migration of fission ...
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Full text: The nuclear renaissance, anticipated by AREVA in the beginning of the century is now happening in several countries around the world. The fundamentals being the increasing demand of energy, the volatility of fossil fuel prices, the awareness of climate change threat connected with the extensive use of fossil fuels. The EPRTM reactor present significant improvements compared to previous generation reactors enabling to reach an outstanding safety level (redundancy of safety systems, airplane crash resistance), to improve the economics (extended plant lifetime, flexibility and availability during operation and, increased efficiency and fuel utilization) while limiting the impact on workers and the environment. Several countries have been implementing the transition to third generation reactors. The presentation will analyze different examples in order to draw the lessons ...
BackgroundImproving the understanding of childhood malarial anaemia may help in the design of appropriate management strategies.MethodsA...Full Text Available
This paper reports on the first U.S. tanker converted to a floating production, storage, and offloading (FPSO) unit which takes up station in Gombe-Beta field off Gabon by Dec. 1. FPSO Ocean Producer will work under a 3 year, day rate contract let late in 1990 by Amoco-Gabon Bombe Marin co., a unit of Amoco Production Co. (OGJ, Dec. 24, 1990, p. 27). Gombe-Beta field is in the Atlantic Ocean about 70 miles south of Port Gentil, Gabon. Ocean Producer will be moored in 50 ft of water 3.7 miles off Gabon, with Bombe-Beta's unmanned production platform about 820 ft astern. The vessel will be held in position by a disconnectable, asymmetric, six point, spread mooring system, It is owned and operated by Oceaneering International Services Ltd. (OISL). Affiliate Oceaneering Production Systems (OPS) converted the 78,061 dwt oil tanker MT Baltimore Sea at a capital cost of $25 million at Gulf Copper ...
The Materials and Components Technology Division (MCT) provides a research and development capability for the design, fabrication, and testing of high-reliability materials, components, and instrumentation. Current divisional programs related to nuclear energy support the development of the Integral Fast Reactor (IFR): life extension and accident analyses for light water reactors (LWRs); fuels development for research and test reactors; fusion reactor first-wall and blanket technology; and safe shipment of hazardous materials. MCT Conservation and Renewables programs include major efforts in high-temperature superconductivity, tribology, nondestructive evaluation (NDE), and thermal sciences. Fossil Energy Programs in MCT include materials development, NDE technology, and Instrumentation design. The division also has a complementary instrumentation effort in support of Arms Control ...
An almost primordial trend in the conversion and use of energy is an increased complexity and cost of conversion systems designed to utilize cheaper and more-abundant fuels; this trend is exemplified by the progression fossil fission {yields} fusion. The present projections of the latter indicate that capital costs of the fusion ``burner`` far exceed any commensurate savings associated with the cheapest and most-abundant of fuels. These projections suggest competitive fusion power only if internal costs associate with the use of fossil or fission fuels emerge to make them either uneconomic, unacceptable, or both with respect to expensive fusion systems. This ``implementation-by-default`` plan for fusion is re-examined by identifying in general terms fusion power-plant embodiments that might compete favorably under conditions where internal costs (both economic and environmental) of fossil and/or fission are not as great as ...
A generic reactor model is used to examine the economic viability of electricity generation by magnetic fusion. The simple model uses components which are representative of those used in previous reactor studies of deuterium-tritium burning tokamaks, stellarators, bumpy tori, reverse field pinches and tandem mirrors. Conservative costing assumptions are made. The generic reactor is not a tokamak but rather it is intended to emphasize what is common to all magnetic fusion reactors. The reactor uses a superconducting toroidal coil set to produce the dominant magnetic field. To this extent it is a less good approximation to systems, such as the reversed field pinch in which the main field is produced by a plasma current. The main output of the study is the cost of electricity as a function of the weight and size of the fusion core - blanket, shield, structure and coils. The model shows ...
BackgroundThe malaria vaccine candidate antigen RTS,S includes parts of the pre-erythrocytic stage circumsporozoite protein fused to the Hepatitis B surface antigen. Two Adjuvant...Full Text Available
Activities are reported by the Reactor Systems Section, Research Instrument Section, and the Measurement and Controls Engineering Section. Reactor system activities include dynamic analysis, survillanc and diagnostic methods, design and evaluation, detectors, facilities support, process instrumentation development, and special assignments. Activities in the Research Instrument Section include the Navy-ORNL RADIAC development program, advanced ..gamma.. and x ray detector systems, neutron detection and subcriticality measurements, circuit development, position-sensitive detectors, stand-alone computers, environmental monitoring-detectors and systems, plant security, engineering support for fusion energy division, engineering support for accelerator physics, and communications: radio, closed-circuit tv, and computer. Activities in the Measurement and Controls Engineering Section include the AVLIS program; gas centrifuge enrichment technology ...
Hydrogen is a potential alternative energy source and produced commercially by methane (natural gas) or LPG steam reforming, a process that requires high temperatures, which are produced by burning fossil fuels. However, since this process emits large amounts of CO_2, replacement of the combustion heat source with a nuclear heat source for 773-1173 K processes has been proposed in order to eliminate these CO_2 emissions. This paper proposes a novel method of low-temperature nuclear hydrogen production by reforming dimethyl ether (DME) with steam produced by a low-temperature nuclear reactor at about 573 K. The authors identified conditions that provide high hydrogen production fraction at low pressure and temperatures of about 523-573 K. By setting this low-temperature hydrogen production process at about 573K upstream from a turbine, it was found theoretically that the total energy utilization efficiency is about 50% and very high. By setting ...
The competitiveness of a new nuclear plant vs. a new oil or gas fired combined cycle plant or a coal fired plant in East-Asia, is reviewed in the paper. Both the nuclear and the fossil fired plants are evaluated as either utility financed or independent power producer (IPP) financed. Two types of advanced light water reactors (ALWRs) are considered in this paper, namely evolutionary ALWRs (1200 MWe size) and passive ALWRs (600 MWe class). A range of capital and total generation costs for each plant type is reported here. The comparison centers on three elements of overall competitiveness: generation costs, hard currency requirements, and employment requirements. Each of these aspects is considered perspective. Year-by-Year generation cost history over the plant lifetime is shown in some cases. It is found here that a utility financed evolutionary and passive ALWRs are broadly competitive with an IPP financed gas fired combined cycle plant and ...
This paper reports that the excess of U.S. electrical generating capacity which has existed for the past 15 years is coming to an end as we enter the 1990s. Environmental and energy security issues associated with fossil fuels are kindling renewed interest in the nuclear option. The importance of these issues are underscored by the National Energy Strategy (NES) which calls for actions which are designed to ensure that the nuclear power option is available to utilities. Utilities, utility associations, and nuclear suppliers, under the leadership of the Nuclear Power Oversight Committee (NPOC), have jointly developed a 14 point strategic plan aimed at establishing a predictable regulatory environment, standardized and pre-licensed Advanced Light Water Reactor (ALWR) nuclear plants, resolving the long-term waste management issue, and other enabling conditions. GE is participating in this national effort and GE's family of advanced nuclear power ...
Alloy 800 was developed in 1949 by The International Nickel Company, Inc. The basic composition, nominally 32wt.%Ni, 20.5wt.%Cr and 46wt.%Fe, was designed to provide a stable, fully austenitic structure and to impart high strength combined with resistance to oxidation, carburization and corrosion in a wide variety of aggressive industrial environments at elevated temperatures. In the short span of twenty-five years, alloy 800 has earned a unique position in the family of heat- and corrosion-resistant materials. Established uses include a wide range of applications in the industrial heating field, in the petro-chemical industry, in domestic appliances and in food processing equipment. The good performance of alloy 800 in these applications has led to its use as boiler tube material both in fossil-fired plants and in HTGR and PWR nuclear power systems. Recently, it was specified for a PHW CANDU reactor and it is now being considered as heat ...
The excess of US electrical generating capacity which has existed for the past 15 years is coming to an end as we enter the 1990s. Environmental and energy security issues associated with fossil fuels are kindling renewed interest in the nuclear option. The importance of these issues are underscored by the National Energy Strategy (NES) which calls for actions which open-quotes are designed to ensure that the nuclear power option is available to utilities.close quotes Utilities, utility associations, and nuclear suppliers, under the leadership of the Nuclear Power Oversight Committee (NPOC), have jointly developed a 14-point strategic plan aimed at establishing a predictable regulatory environment, standardized and pre-licensed Advanced Light Water Reactor (ALWR) nuclear plants, resolving the long-term waste management issue, and other open-quotes enabling conditions.close quotes GE is participating in this national effort and GE's family of ...
Most of the anthropogenic emissions of carbon dioxide result from the combustion of fossil fuels for energy production. Photosynthesis has long been recognized as a means, at least in theory, to sequester anthropogenic carbon dioxide. Aquatic microalgae have been identified as fast growing species whose carbon fixing rates are higher than those of land-based plants by one order of magnitude. Physical Sciences Inc. (PSI), Aquasearch, and the Hawaii Natural Energy Institute at the University of Hawaii are jointly developing technologies for recovery and sequestration of CO{sub 2} from stationary combustion systems by photosynthesis of microalgae. The research is aimed primarily at demonstrating the ability of selected species of microalgae to effectively fix carbon from typical power plant exhaust gases. This report covers the reporting period 1 April to 30 June 2003 in which PSI, Aquasearch and University of Hawaii conducted their tasks. Based on the work during the ...
Considering the present situation of thermal energy in Romania and having in view the fact that Romania is a Kyoto protocol signatory state one estimates that the development of the nuclear energy will have a promising growth. According with the statement of the National Energetic Observer, Romania became a net energy resource importer for the past 30 years and the estimations about the future are not optimistic. The finite reserves of fossil fuel (coal and natural gas), the gradual reduction of their share in the national energy balance with a tendency to become insignificant after 2025, as well as the present situation of the thermal power plants which are already beyond their operation life, all these indicate the nuclear energy as being the most reliable and sustainable future source for thermal energy production. Having in view these circumstances the paper aims at a short presentation of the existing nuclear solutions for district heating. Also, reviewed are ...
After a long period of stagnation in the UK, Europe and the USA, there is now a real expectation that new nuclear plants will be under construction shortly. Several factors have contributed to this change of position in the UK: the growing realisation that effective action is needed to offset greenhouse gas emissions; higher prices for fossil fuels; increasing reliance on overseas supplies of oil and gas; the limitations of wind and wave power and distribution; security of supply; the gradual realisation in the deregulated electricity generation market that nuclear power is competitive and the pending closure of most of the UK's nuclear fleet within less than 15 years. All these factors have led to a reversal of the UK Government's attitude to nuclear power, which has now ruled in favour of allowing a new generation of nuclear plants being built. This paper summarises some of the arguments that have led to this decision and the ramifications of it. In particular, ...
Electrical power is generated by steam turbines (steam being produced by coal, oil, gas or nuclear reactors), hydro units, gas turbines, internal combustion engines, jet engines, and pumped storage plants. Nuclear Power Plants generate only 15% of the total electrical power in the US. Nuclear Power Plants being cheaper to run are generally base loaded. The pumped-storage and gas turbine plants have ideal characteristics for peaking duty. In the pumping mode, pumped storage plants are used to provide additional system load and in the generating mode, they supply reactive power during peak load demands. Gas turbine plants have higher running costs, but are used as peaking units with a fast start capability. Fossil power plants need a minimum of 1 hour to stabilize expansion in the boiler and turbine generator. Due to a more competitive power supply market due to deregulation, most of the utilizes plan generation only for the next three years. ...
Biocatalytic Desulfurization (BDS) represents an alternative approach to the reduction of sulfur in fossil fuels. The objective is to use bacteria to selectively remove sulfur from petroleum and middle distillate fractions, without the concomitant release of carbon. Recently, bacteria have been developed which have the ability to desulfurize dibenzothiophene (DBT) and other organosulfur molecules. These bacteria are being developed for use in a biocatalyst-based desulfurization process. Analysis of preliminary conceptual engineering designs has shown that this process has the potential to complement conventional technology as a method to temper the sulfur levels in crude oil, or remove the recalcitrant sulfur in middle distillates to achieve the deep desulfurization mandated by State and Federal regulations. This paper describes the results of initial feasibility studies, sensitivity analyses and conceptual design work. Feasibility studies with various crude oils ...
Carbon capture and storage have been receiving increasing interest lately, mainly as an option to reduce CO{sub 2} emissions from the power sector. The concept could be adapted for production of H{sub 2} as well, which would provide a carbon free energy carrier that could be used for example as transportation fuel. In this doctoral thesis, the option to use chemical-looping technologies to produce H{sub 2} from fossil fuels with CO{sub 2} capture is explored. In chemical-looping combustion, direct contact between fuel and combustion air is avoided. Instead, a solid oxygen carrier performs the task of bringing oxygen from the air to the fuel. Thus, the resulting CO{sub 2} and H{sub 2}O are not diluted with N{sub 2}, and pure CO{sub 2} can easily be recovered by cooling and condensation. The heat of reaction is the same as for ordinary combustion. Chemical-looping reforming uses the same basic principles as chemical-looping combustion, but operates at under ...
... its infancy. However, the geological record of many fossil fungi is well established (Elsik, 1996; Kalgutkar and Jansonius, ... 1988). A comprehensive account of the history of fossil fungi, and the impor...
Inferences concerning the lives of extinct animals are difficult to obtain from the fossil record. Here we present a novel approach to the study of extinct carnivores, using a comparison between fossil...Full Text Available
The fossil record is a unique source of evidence for important evolutionary phenomena such as transitions between major clades. Frustratingly, relevant fossils are still comparatively rare, most transitions...Full Text Available
This publication provides statistical data on net generation, fuel consumption, fossil fuel stocks, electricity sales, revenue, and average revenue per kilowatthour of electricity sold. Data on fossil fuel stocks and costs are also included.
In this paper an analysis will be performed to assess the economical competitiveness of Nuclear Power against other base load technologies. There are several plans to build more nuclear power plants in western countries; these plans are result among other things of the fossil fuel high prices and the concern for the global warming. France started the construction of one EPR at Flamanville in 2007 and at the end of 2008 there were 17 applications before NRC for construction and operation licenses (COL) to build as much as 26 new reactor units in USA, among the designs selected are the US-EPR, APWR, ESBWR, ABWR and AP1000. Currently, there is a lot of uncertainty about what is the overnight cost for a new generation III nuclear power plant and the vendors are not providing too much information. However, it is expected that under the new economy conditions the overnight cost will be between 2500 and 3500 USD/kW, the output electricity power of the ...
The trend towards more effective use of fossil fuels and reduced environmental pollution represents a major task of improvement within the refinery processes. The highly isomerized and high octane paraffins produced from isobutane and light olefins by alkylation fulfill all the requirements for reformulated gasoline. This doctoral thesis discusses new catalyst systems because of their potential in alkylation. A slurry reactor apparatus for solid-acid catalysed isobutane/butene alkylation was developed and used to investigate the performance of various heterogeneous catalysts. The selected materials were mainly zeolite types with faujasite structures. The samples were characterized by various methods before alkylation. In general, the order of decreasing catalyst activity after 3 h of reaction at 80{sup o}C was found to be: H-EMT >> H-FAU, dealuminated H-FAU >> NS.500, TA-Y, CeY-98 > Nafion-H. The order of decreasing alkylate ...
The Coal and Electric Data and Renewables Division; Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), Department of Energy prepares the EPM. This publication provides monthly statistics at the State, Census division, and US levels for net generation, fossil fuel consumption and stocks, quantity and quality of fossil fuels, cost of fossil fuels, electricity sales, revenue, and average revenue per kilowatthour of electricity sold. Data on net generation, fuel consumption, fuel stocks, quantity and cost of fossil fuels are also displayed for the North American Electric Reliability Council (NERC) regions. The EIA publishes statistics in the EPM on net generation by energy source; consumption, stocks, quantity, quality, and cost of fossil fuels; and capability of new generating units by company and plant. 68 tabs.
The Coal and Electric Data and Renewables Division; Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), Department of Energy prepares the EPM. This publication provides monthly statistics at the State, Census division, and U.S. levels for net generation, fossil fuel consumption and stocks, quantity and quality of fossil fuels, cost of fossil fuels, electricity sales, revenue, and average revenue per kilowatthour of electricity sold. Data on net generation, fuel consumption, fuel stocks, quantity and cost of fossil fuels are also displayed for the North American Electric Reliability Council (NERC) regions. The EIA publishes statistics in the EPM on net generation by energy source; consumption, stocks, quantity, quality, and cost of fossil fuels; and capability of new generating units by company and plant.
By August 2007, there were 438 nuclear power plants (NPPs) in operation worldwide, with a total capacity of 371.7 GW(e). Further, 31 units, totaling 24.1 GW(e), were under construction. During 2006 nuclear power produced 2659.7 billion kWh of electricity, which was 15.2% of the world's total. The vast majority of these plants use water-cooled reactors. Based on information provided by its Member States, the IAEA projects that nuclear power will grow significantly, producing between 2760 and 2810 billion kWh annually by 2010, between 3120 and 3840 billion kWh annually by 2020, and between 3325 and 5040 billion kWh annually by 2030. There are several reasons for these rising expectations for nuclear power: - Nuclear power's lengthening experience and good performance: The industry now has more than 12 000 reactor years of experience, and the global average nuclear plant availability during 2006 reached 83%; - Growing energy needs: All forecasts ...
By August 2007, there were 438 nuclear power plants (NPPs) in operation worldwide, with a total capacity of 371.7 GW(e). Further, 31 units, totaling 24.1 GW(e), were under construction. During 2006 nuclear power produced 2659.7 billion kWh of electricity, which was 15.2% of the world's total. The vast majority of these plants use water-cooled reactors. Based on information provided by its Member States, the IAEA projects that nuclear power will grow significantly, producing between 2760 and 2810 billion kWh annually by 2010, between 3120 and 3840 billion kWh annually by 2020, and between 3325 and 5040 billion kWh annually by 2030. There are several reasons for these rising expectations for nuclear power: - Nuclear power's lengthening experience and good performance: The industry now has more than 12 000 reactor years of experience, and the global average nuclear plant availability during 2006 reached 83%; - Growing energy needs: All forecasts ...
By August 2007, there were 438 nuclear power plants (NPPs) in operation worldwide, with a total capacity of 371.7 GW(e). Further, 31 units, totaling 24.1 GW(e), were under construction. During 2006 nuclear power produced 2659.7 billion kWh of electricity, which was 15.2% of the world's total. The vast majority of these plants use water-cooled reactors. Based on information provided by its Member States, the IAEA projects that nuclear power will grow significantly, producing between 2760 and 2810 billion kWh annually by 2010, between 3120 and 3840 billion kWh annually by 2020, and between 3325 and 5040 billion kWh annually by 2030. There are several reasons for these rising expectations for nuclear power: - Nuclear power's lengthening experience and good performance: The industry now has more than 12 000 reactor years of experience, and the global average nuclear plant availability during 2006 reached 83%; - Growing energy needs: All forecasts ...
Abstracts are presented for about 40 papers. The Fossil Energy Advanced Research and Technology Development Materials program is an integrated materials research activity of the fossil energy coal program, whose objective is to conduct R and D for all advanced coal conversion and utilization technologies. The program is aimed at understanding materials behavior in coal system environments and the development of new materials for improving plant operations and reliability. A generic approach is used for addressing multiple coal technologies; for example, the hot-gas particulate filter development is applicable to pressurized fluidized bed combustion, integrated coal gasification combined-cycle, coal combustion, and indirectly fired combined-cycle systems.
This is the 1st revision of the INIS/ETDE Joint Thesaurus. It contains 20 953 valid descriptors and 8 600 forbidden terms. It was last updated in December 2003. The Joint Thesaurus contains the controlled terminology for indexing all information within the subject scope of both INIS (International Nuclear Information System) and ETDE (Energy Technology Data Exchange) information systems. The terminology is intended for use in subject description for input or retrieval of information in those systems. The thesaurus is a terminological control device used in translating from the natural language of documents, indexers or users into a more constrained system language It is also a controlled and dynamic vocabulary of semantically and generically related terms which covers a specific domain of knowledge. The domain of knowledge covered by this Thesaurus includes physics (in particular, plasma physics, atomic and molecular physics, and especially nuclear and high-energy physics), chemistry, ...
The pathway to hydrogen generation entirely from renewable energy and material sources probably goes by a transitional period with the utilization of hybrid fossil/renewable integrated systems. Solar steam reforming of methane is set in this context, specifically suited for a country like Italy whose actual energy policy is mainly based on the imported NG, but also characterized by convenient solar radiation levels in the Southern Regions. A new solar SMR process is being developed by ENEA, using molten nitrates as solar heat carriers and storage medium at about 550 C. The potential of this process have been proved theoretically by process simulation studies. Engineering and experimental activities aimed to the development of a prototype apparatus are now in progress in ENEA's laboratories. It is remarkable that the developed technology (MS powered SMR) can find interesting impact in the in industrial chemistry wherever it is convenient decoupling the heat ...
In light of the recent rapid increase in the fossil fuel prices it is meaningful to evaluate the impact of these price changes in the economics of dual-purpose desalination projects producing electricity and fresh water simultaneously. The price of crude oil and LNG (Liquefied Natural Gas) has increased by about 200% and 100% during the past three or four years. The uranium price has also increased by nearly 500% during the same period. The purpose of this paper is to analyze and compare the economics of SMART (System-integrated Modular Advanced ReacTor) which is being developed as a small size PWR type and the LNG Combine Cycle coupled with MED (Multi-Effect Distillation) which are being acknowledged as promising energy sources for the future in Korea. The methods of analysis used in this paper are the lifetime leveled cost method for the power and water cost calculation and the power credit method for the total cost allocation. DEEP ...
In light of the recent rapid increase in the fossil fuel prices it is meaningful to evaluate the impact of these price changes in the economics of dual-purpose desalination projects producing electricity and fresh water simultaneously. The price of crude oil and LNG (Liquefied Natural Gas) has increased by about 200% and 100% during the past three or four years. The uranium price has also increased by nearly 500% during the same period. The purpose of this paper is to analyze and compare the economics of SMART (System-integrated Modular Advanced ReacTor) which is being developed as a small size PWR type and the LNG Combine Cycle coupled with MED (Multi-Effect Distillation) which are being acknowledged as promising energy sources for the future in Korea. The methods of analysis used in this paper are the lifetime leveled cost method for the power and water cost calculation and the power credit method for the total cost allocation. DEEP ...
Within the United Kingdom, the regulatory body having responsibility for the licensing of nuclear installations is the Health and Safety Executive (HSE). The Nuclear Installations Inspectorate (NII) is that part of HSE which administers this function. Discussions on the applicability of quality assurance (QA) to licensed sites began in 1974, and an internal report was published in 1975. In parallel with work going on at the International Atomic Energy Agency (IAEA) to prepare Quality Assurance for Safety in Nuclear Power Plants: A Code of Practice, Safety Series No. 50-C-QA, NII published a second report in 1978 entitled A Guide to the Quality Assurance Programme for Nuclear Power Plants. In 1980, the construction of advanced gas cooled reactors at Heysham 2 and at Torness was licensed, and a condition was attached to the licences requiring the licensees to submit their QA arrangements to the NII for approval. The licensees' response was to produce separate QA ...
The sulfur-iodine (SI) thermochemical cycle is one of the main candidate methods to produce hydrogen from non-fossil sources like nuclear (GEN IV reactor) or solar thermal power. A major issue for the successful implementation of the SI cycle is the selection of technically viable and economic materials for construction of process components, particularly heat exchangers. Challenging conditions are encountered in each of the three sections of the SI cycle due to the corrosive chemicals present, including sulfuric acid, iodine, hydroiodic acid, sulfur dioxide, hydrogen, oxygen, and others. In Section I, aqueous, non-aqueous (liquid iodine), and gaseous multi-component phases are present at about 120 {sup o}C and 0.7 MPa. Section II involves gaseous and aqueous phases of sulfuric acid, sulfur dioxide, and oxygen at up to about 830 {sup o}C and 3.6 MPa. In Section III , aqueous, non-aqueous, and gaseous phases, at up to 310 {sup o}C and 2.2 MPa, ...
... Another solution, hybrid vehicles, combine two sources of energy (electric and chemical), reducing the global consumption of fossil fuels. Fuel cell vehicles are also one of the most promising technologies for the future, with the capacity to use any fuel - hydrogen being the ideal fuel ecologically, but constrained by infrastructure and storage issues. This book explores all these different solutions for moving our vehicles from fossil ...
Research is presented on oil and gas technologies, advanced systems for fossil fuels, environmental technologies for remediation and waste management, applied energy science on heavy oil and plastics coprocessing, and fossil fuel and hydrocarbon conversion using hydrogen rich plasma.
This document contains the outline and viewgraphs used in the speech. Topics covered are: conventional oil and gas recovery; unconventional oil and gas sources; oil shale resources; conventional coal combustion; advanced fossil power systems; fluidized bed combustion; coal/oil or coal/water mixtures; and gaseous and liquid fuels from coal. (DMC)
The etching method developed made it possible to observe under the microscope the finest components of the anatomical structure of coal-forming plants. The dependence of the effectiveness of etching of tissues on the concentrations of geopolymers (protocellulose and protolignin) in them was found. The study of tissues of this kind by the methods of local analysis (for example, X-ray microanalysis) allowed us to obtain the characteristics of the above geopolymers and to use them for the identification of the primary biochemical composition of fossil organic matter.
The Electric Power Monthly (EPM) presents monthly electricity statistics for a wide audience including Congress, Federal and State agencies, the electric utility industry, and the general public. The purpose of this publication is to provide energy decisionmakers with accurate and timely information that may be used in forming various perspectives on electric issues that lie ahead. The Coal and Electric Data and Renewables Division; Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), Department of Energy prepares the EPM. This publication provides monthly statistics at the State, Census division, and US levels for net generation, fossil fuel consumption and stocks, quantity and quality of fossil fuels, cost of fossil fuels, electricity sales, revenue, and average revenue per kilowatthour of electricity sold. Data on net generation, fuel consumption, fuel stocks, quantity and cost ...
The Electric Power Monthly (EPM) presents monthly electricity statistics for a wide audience including congress, Federal and State agencies, the electric utility industry, and the general public. The purpose of this publication is to provide energy decisionmakers with accurate and timely information that may be used in forming various perspectives on electric issues that lie ahead. This publication provides monthly statistics at the State, Census division, and US levels for net generation, fossil fuel consumption and stocks, quantity and quality of fossil fuels, cost of fossil fuels, electricity retail sales, associated revenue, and average revenue per kilowatthour of electricity sold. In addition, data on net generation, fuel consumption, fuel stocks, quantity and cost of fossil fuels are also displayed for the North American Electric Reliability Council (NERC) regions. The EIA publishes statistics in ...
The impacts of the availability of low-carbon technologies on the regional distribution of mitigation costs are analyzed in a global multi-regional integrated assessment model. Three effects on regional consumption losses are distinguished: domestic measures, trade of fossil energy carriers and trade of emission permits. Key results are: (i) GDP losses and a redirection of investments in the energy system towards capital-intensive technologies are major contributions to regional consumption losses. (ii) A devaluation of tradable fossil energy endowments contributes largely to the mitigation costs of fossil fuel exporters. (iii) In case of reduced availability of low-carbon technologies, the permit market volume and associated monetary redistributions increase. The results suggest that the ...
High energy consumption and the world population increase will lead to a shrinking use of fossil fuels. The combustion of Fossil fuel leads to the increase of carbon dioxide concentration in the atmosphere which leads to the probable increase of global warming. Therefore, concerns about carbon dioxide emissions may discourage widespread dependence on fossil fuels and encourage the development and use of renewable energy systems employing a variety of technologies Renewable energy systems have themselves an environmental impact. Land use and material employed are two areas that may have an adverse impact to the positive environmental picture of the renewable energy systems. The objective of this paper is to analyze these impacts with the use of a very powerful tool, the Life Cycle Assessment. (author)
Major advances in 'Energy and Materials Cycles' have been achieved in the removal of heavy metals from the solid residues of municipal waste incineration. It has been conclusively shown that the oxidation/reduction conditions established during the thermal treatment of filter ash have a decisive influence on the evaporation of groups of heavy metals. With respect to biomass gasification, studies have been carried out with respect to the best way of extracting pure hydrogen from the low calorific value gas that is typically obtained from a biomass gasifier. The overarching goal of the laboratory 'High Temperature Solar Technology' is the use of solar energy for the production of solar fuels, or for the reduction of CO{sub 2} emissions in large scale industrial processes that are conventionally carried out with the use of fossil fuels. In a short-term project targeted at the solar production of lime, highly encouraging results (98% ...
Research reported here reveals that the reduction of CO{sub 2} emissions into the atmosphere, is mainly dependent on the decrease of the use of fossil fuels, but also on the development of environment-friendly technology and greening of the environment. 2 refs.
The solar thermal production of zinc is considered for the conversion of solar energy into storable and transportable chemical fuels. The ultimate objective is to develop a technically and economically viable technology that can produce solar zinc. The program strategy for achieving such a goal involves research on two paths: a direct path via the solar thermal splitting of ZnO in the absence of fossil fuels, and an indirect path via the solar carbothermal/CH{sub 4}-thermal reduction of Zn O, with fossil fuels (coke or natural gas) as chemical reducing agents. Both paths make use of concentrated solar energy for high-temperature process heat. The direct path brings us to the complete substitution of fossil fuels with solar fuels for a sustainable energy supply system. The indirect path creates a link between today`s fossil-fuel-based technology and tomorrow`s solar chemical technology and builds bridges ...
A schematic diagram of the decision making process for air pollution control equipment for the conversion of a fossil-fired generating unit from oil to coal is presented and explained.
BackgroundIt is important to generate biofuels and society must be weaned from its dependency on fossil fuels. In order to produce biofuels, lignocellulose is pretreated and the...Full Text Available
The economics of renewable energy technologies when deployed in a decentralised manner are more favourable than the simple cost of the fossil fuel generated electricity displaced. They have capital and maintenance cost savings associated with the electrical transmission in infrastructures which are avoided. Worked examples are presented. (UK)
In this review we attempt to reconstruct the evolutionary history of hominin life history from extant and fossil evidence. We utilize demographic life history theory and distinguish life history variables,...Full Text Available
Only half of the carbon dioxide produced by burning fossil fuels stays in the atmosphere. It is thought that the oceans absorb the rest. To understand the world's climate it is necessary to know how the atmosphere, ocean and biosphere interact.
We investigated the deep-sea fossil record of benthic ostracodes during periods of rapid climate and oceanographic change over the past 20,000 years in a core from intermediate depth in the northwestern...Full Text Available
Chemical looping combustion (CLC) is a novel technology where CO{sub 2} is inherently separated during combustion. Due to the existence of sulfur contaminants in the fossil fuels, the gaseous products of sulfur species and the interaction of sulfur contaminants with oxygen carrier are a big concern in the CLC practice. The reactivity of NiO/Al{sub 2}O{sub 3} oxygen carrier reduction with a gas mixture of CO/H{sub 2} and H{sub 2}S is investigated by means of a thermogravimetric analyzer (TGA) and Fourier Transform Infrared spectrum analyzer in this study. An X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and scanning electron microscope (SEM) are used to evaluate the phase characterization of reacted oxygen carrier, and the formation mechanisms of the gaseous products of sulfur species are elucidated in the process of chemical looping combustion with a gaseous fuel containing hydrogen sulfide. The results show that the rate of NiO reduction with ...
This is the second revision of the ETDE/INIS Joint Thesaurus, including all updates up to September 2006. It contains 21 147 valid descriptors and 9 114 forbidden terms. The Joint Thesaurus contains the controlled terminology for indexing all information within the subject scopes of the International Nuclear Information System (INIS) and the Energy Technology Data Exchange (ETDE). The terminology is intended for use in subject descriptions for input or retrieval of information in these systems. The thesaurus is a terminological control device used in translating from the natural language of documents, indexers or users into a more constrained system language It is also a controlled and dynamic vocabulary of semantically and generically related terms which covers a specific domain of knowledge. The basic terminology in this thesaurus goes back to the 1969 edition of the EURATOM Thesaurus. The structure subsequently given to that terminology was the result of a systematic study performed ...
We consider energy investment, when a choice has to be made between fossil fuel and biomass fired production technologies. A dynamic model is presented to illustrate the effect of the different degrees of input price uncertainty on the choice of technology and the timing of the investment. It is shown that when the choice of technology is irreversible, it may be optimal to postpone the investment even if it would otherwise be optimal to invest in one or both of the plant types. We provide a numerical example based on cost, estimates of two different power plant types. (author)
This report--the forty-fifth of a series--is a compendium of monthly progress reports for the ORNL research and development programs that are in support of the increased utilization of coal and other fossil fuel alternatives to oil and gas as sources of clean energy. The projects reported this month include those for coal conversion process development, materials engineering, alkali metal vapor topping cycles, a coal equipment test program, an AFB coal combustor for cogeneration (CCC), engineering and support studies, process and program assistance, evironmental assessment studies, magnetic beneficiation, and AFBC demonstration plant.
Constantly increasing resource efficiency together with the broad introduction of CCS technologies is fundamental for a continuous use of fossil fuels in power generation against the background of up-coming requirements for CO2 emission reduction. In principle, CCS means up-grading conventional power plant technology with proven CO2 removal processes. However, this leads to additional losses, auxiliary power demand and cost. System integration, development or at least adaption of components and processes are the main requirements in this context. Different technology solutions and recent developments will be addressed as well as challenges when implementing in demonstration projects.
The NPPs safety system in Germany is discussed. It is shown that there exists no threat for the German NPPs at the peace times. They release insignificant quantities of radioactive substances into the water and atmosphere. The average equivalent dose constitutes 0.0005 mSv annually. The annual equivalent dose for the personnel is equal to 4.4 mSv. At the same time, the NPPs contribute to a certain degree to the environmental medium improvement, preventing the ingress therein of the sulfur and carbon dioxide, dust and nitrogen oxides by application of fossil fuels. Attention is also paid to reprocessing facilities and also to the nuclear fuel wastes disposal. The advantages of the nuclear power engineering in comparison with the fossil fuel power engineering are enumerated
The samples comprise the foliage of four pteridosperm-medullosalean plant fossil species of differing preservation states and one of a cordaitean species from two Canadian Maritime sub-basins of Carboniferous age (300 Ma; Sydney and Stellarton coalfields, Nova Scotia, respectively). Included in the sample set were some coal samples from Sydney Coalfield, along with published data for coal macerals for comparison. By applying Schulze's maceration process to the fossil foliage to obtain the cuticles, five sample forms evolved, viz. compressions, cuticles and fossilized cuticles, and acidic and alkaline solutions from Schulze's process, to which was added the Sydney coal samples as the sixth form. Area integration of the absorbance spectra from solid and liquid state Fourier transform infrared (FTIR) spectroscopy, produced functional chemical parameters which were organized into a data matrix of eight ...
Recent achievements and tendency on reactor physics activities in Japan are reviewed according to topics published in journals or discussed at the Japan Research Committee on Reactor Physics.
... and support cost, and post-retirement disposal cost) of ... from reactors, and the reactors and other ... the ship's hull and reactor compartment enough to ...
AECL Publications on Reactor Safety in CANDU Reactors are listed in this bibliography. The listing is chronological and the accompanying index is by subject. The bibliography will be brought up to date annually. (auth).
Historically, the bulk production of electricity has been achieved by burning fossil fuels, with unavoidable gaseous emissions, including large quantities of carbon dioxide: an average-sized modern coal-burning power station is responsible for more than 10 Mt of CO{sub 2} each year. This paper details typical emissions from present-day power stations and discusses the options for their reduction. Acknowledging that the cuts achieved in the past decade in the UK CO{sub 2} emissions have been achieved largely by fuel switching, the remaining possibilities offered by this method are discussed. Switching to less-polluting fossil fuels will achieve some measure of reduction, but the basic problem of CO{sub 2} emissions continues. Of the alternatives to fossil fuels, only nuclear power represents a zero-carbon large-scale energy source. Unfortunately, public concerns over safety and radioactive waste have still to be assuaged. ...
An overview is presented of the FFTF reactor and plant together with descriptions of core components, core internals, core system, primary and secondary control rod system, reactor instrumentation, reactor vessel and closure head, and supporting test programs. (DG)
An overview is presented of the FFTF reactor and plant together with descriptions of core components, core internals, core system, primary and secondary control rod system, reactor instrumentation, reactor vessel and closure head, and supporting test programs.
ObjectivesFor thermoelectricity both low thermal conductivity and high electrical conductivity are required. High electrical conductivity should be established via a high carriers concentration and a high mobility.~%~The aim of this feasibility study is to investigate a method of modulation doping of Si nanowires in order to generate high carrier concentrations without the need for impurity doping, thus retaining high mobilities.~%~~%~The objectives are (in chronological order):~%~- reduction of the wire [continued...]DescriptionIn recent years, the increasing dependence of society on fossil fuels for socio-economical development has become a cause of great concern. The possibility of a reduced availability of fossil fuels, and the effect of these fuels on climate change, have encouraged research into alternative energy sources. Many of these alternatives are old ideas, implemented using modern techniques. This proposal plans ...
Abstract Four stratigraphic sections in the southern part of the Columbia Basin preserve a sequence of aeolian and non-aeolian sediments ranging in age from 943 to >470 14C ka based on accelerator mass spectrometry radiocarbon dating of fossil molluscs, geochemistry of Cascade Mountain-sourced tephra and association with formally recognized pedostratigraphic units (the Washtucna and Old Maid Coulee soils). Study sections are interpreted as representing concurrent deposition of loess and distal Missoula Flood rhythmites in valleys tributary to main drainages backflooded during the Missoula Floods, and formation of carbonate and iron-rich soils. Sediments belong to the formally recognized L-1 and L-2 loess units established for the Palouse loess, which were deposited in the Columbia Basin su...
Ichnogenera belonging to cleft-foot and wedge-foot bivalves can in most cases be distinguished. This paper addresses the taxonomy of locomotion traces made by wedge-foot bivalves. Ichnogenera Ptychoplasma Fenton and Fenton and Oravaichnium Plicka and Uhrova are reviewed together with related ichnotaxa. Both are interpreted as the locomotion traces of non-cleft, wedge-foot bivalves. Both are usually preserved as hypichnial ridges that include a distinctive bioprint of amygdaloid segments. Ptychoplasma is dominated by amygdaloid segments whereas Oravaichnium is wall-like with only sporadic amygdaloid segments. Ichnospecies of Ptychoplasma are distinguished on the basis of their continuity: P. excelsum Fenton and Fenton (the type) is a relatively continuous trace fossil consisting largely of ...
Environmental and security concerns are stimulating global interest in hydrogen power, renewable energy, and advanced transportation technologies, but no significant movement away from oil and a carbon-based world economy is expected soon. Over the longer-term, however, a transition from fossil fuels to a non-carbon-based economy will likely occur, affecting the type of environment future generations may encounter. Key challenges will face the world's energy industry over the next few decades to ensure a smooth transition-challenges which will require government and industry solutions beginning as early as today. This paper identifies four critical challenges in energy and the choices which will have to be made on how best to confront growing pollution caused by fossil fuels and how to facilitate an eventual revolutionary-like transition to a non-carbon-based global economy.
A fragmented fossil bone incised with the figure of a proboscidean was recently found at Vero Beach, Florida near the location where Late Pleistocene fauna and human bones were recovered from 1913 to 1916. This engraving may represent the oldest and only existing example of Terminal Pleistocene art depicting a proboscidean in the Americas. Because of the uniqueness, rarity, and potential antiquity of this specimen, caution demanded that a variety of tests be used in an attempt to verify its authenticity. The mineralized bone was identified as mammoth, mastodon, or giant sloth. Rare earth element analysis was consistent with the fossil bone being ancient and originating at or near the Old Vero site (8-IR-9). Forensic analysis suggests the markings on the bone are not recent. Optical microsc...
Here we present a revision of the fossil record of chitons (Mollusca, Polyplacophora) of Late Pleistocene and Holocene marine deposits of Uruguay and discuss their potential for palaeoenvironmental reconstruction. Chitons were recorded as isolated valves in bivalve- and gastropod-rich assemblages. They are represented by the species Chaetopleura angulata (Spengler), C. isabellei (d'Orbigny), C. asperrima (Gould) and Ischnochiton striolatus (Gray). The last two species are recorded for the first time as fossils not only in Uruguay but also in South America. Exclusively recorded for the Late Pleistocene is the warm water species I. striolatus, whose current southern range limit is located in Santa Catarina, Brazil. Higher temperatures than at present are inferred for the Uruguayan coast duri...
This handbook breaks down the complex field of nuclear reactor calculations into major steps. Each step presents a detailed analysis of the problems to be solved, the parameters involved, and the elaborate computer programs developed to perform the calculations. This book bridges the gap between nuclear reactor theory and the implementation of that theory, including the problems to be encountered and the level of confidence that should be given to the methods described. Volume II: Monte Carlo Calculations for Nuclear Reactors. In-Core Management of Four Reactor Types. In-Core Management in CANDU-PHW Reactors. Reactor Dynamics. The Theory of Neutron Leakage in Reactor Lattices. Index.
Information is presented concerning reactor research activities; isotope geology; NERC radiocarbon laboratory; teaching activities; and reactor operation.
The MEX-15 is a conceptual design of a Multipurpose Reactor with thermal power of 15 MW and this reactor is pool type with fuel plates U{sub 3}0{sub 8}-Al of low enrichment uranium. This report presents the static calculation for the MEX-15 reactor using SRAC code system and was developed under the collaboration agreement between ININ-JAERI in Research Reactor Technology Development Division of Department of Research Reactor in Tokai Research Establishment. (Author)
The TVR heavy water research reactor was deployed at Moscow Institute of Theoretical and Experimental Physics. In 1990, the final batch of the spent nuclear fuel from this reactor was shipped to Production Association (PA) 'Mayak' for reprocessing. The SNF removal was a stage of the reactor decommissioning activities. The designs of the TVR reactor and its fuel elements are similar to the RA reactor designs. Two ways of the RA reactor SNF transportation to PA 'Mayak' have been considered: in aluminum barrels and in additional canisters using respectively TUK-32 and TUK-19 shipping casks. The practical experience and the equipment used to prepare for the TVR reactor SNF removal can be helpful to the RA reactor personnel in finding the best way to perform these engineering operations. (author)
This is the twenty-ninth edition of Reference Data Series No. 2, Nuclear Power Reactors in the World, which is published once per year, and presents the most recent reactor data available to the IAEA. It contains the following summarized information: - General information as of the end of 2008 on power reactors operating or under construction, and shut down; - Performance data on reactors operating in the Agency's Member States, as reported to the IAEA. The IAEA's Power Reactor Information System (PRIS) is a comprehensive data source on nuclear power reactors in the world. It includes specification and performance history data of operating reactors as well as reactors under construction or reactors being decommissioned. PRIS data are collected by the IAEA through the designated national ...
JRR-3 is a research reactor of 10 MWt output, which attained the criticality in 1962. All the design, manufacture, installation and others of this reactor were carried out by Japanese technologies, except the fuel and heavy water as the moderator and coolant, therefore it is nicknamed Home-made No.1 Reactor. Recently, due to the change in the state of utilizing research reactors and the rise of quality in the utilization, JRR-3 has become to be unable to meet sufficiently the needs of users. The plan of reconstructing the JRR-3 was considered under such situation, and in order to reuse the reactor building, the reactor proper is removed, and an entirely new, high performance, versatile reactor is to be constructed. In this paper, as to the removal works of the JRR-3 reactor proper, the method of execution, design, the ...
Fusion energy has been studied in many countries such as U.S., France, Japan, Korea etc. Because it would provide much more energy for a given weight of fuel than any technology currently in use, and the fuel itself (primarily deuterium) exists abundantly in the Earth's ocean. Nuclear fusion reactor uses tritium and deuterium as fuel while nuclear fission reactor uses uranium and plutonium as fuel. Besides, inherent design characteristics and driving condition of nuclear fusion reactor is different from those of nuclear fission reactor. Therefore, we cannot apply the regulation rules of nuclear fission reactor to nuclear fusion reactor without change and thus it is needed to development of the safety regulation concept which reflects the characteristics of nuclear fusion reactor. Safety regulation of nuclear fusion ...
As in the years before, the situation of steam boiler engineering was characterized by the following influencing parameters: Slow increase in electric power consumption; enhanced controversy over the CO{sub 2} emissions of fossil-fuel combustion; controversy over nuclear power; too much enthusiasm about the applications of additive and renewable energy. In all, six turbines with capacities over 100 MW were started but only one turbine of 180 MW was newly ordered. (orig./GL).
The use of robots in powerplants is an option that can no longer be ignored. Robots can reduce worker exposure to harmful environments and minimize downtime. As a result, electric utilities are using them more than ever. As robots become more widely accepted, more are being developed to handle an expanding variety of applications. This report begins with an overview of the use of robotics in the electric-utility industry; following that are sections detailing applications for nuclear plants, fossil-fired stations, and transmission and distribution facilities.
Research is presented on oil and gas technologies, advanced systems, soil remediation and remediation of acid mine drainage, applied science research in plastics and petroleum coprocessing, and fossil fuel and hydrocarbon conversion using a hydrogen rich plasmas.
DescriptionFossil fuels have a detrimental effect on the environment. They lead to the increase in atmospheric carbon dioxide which has been documented over the last 150 years. In contrast, some sources of renewable energy are near carbon neutral. Renewable energy produced from biomass constitutes such a type of energy and so has many potential advantages. The Energy White Paper (DTI et al., 2003) identifies bioenergy as an important means of meeting the Government's energy and environment objectives, in [continued...
It has been understood that production of hydrogen from fossil and carbonaceous fuels with reduced CO{sub 2} emission to the atmosphere is key to the production of hydrogen-rich fuels for mitigating the CO{sub 2} greenhouse gas climate change problem. The conventional methods of hydrogen production from fossil fuels (coal, oil, gas and biomass) include steam reforming and water gas shift mainly of natural gas (SRM). In order to suppress CO{sub 2} emission from the steam reforming process, CO{sub 2} must be concentrated and sequestered either in or under the ocean or underground (in aquifers, or depleted oil or gas wells). Up to about 40% of the energy is lost in this process. An alternative process is the pyrolysis or the thermal decomposition of methane, natural gas (TDM) to hydrogen and carbon. The carbon can either be sequestered or sold on the market as a materials commodity or used as a fuel at a later date under less severe CO{sub 2} ...
Owing to exceptional biomolecule preservation, fossil avian eggshell has been used extensively in geochronology and palaeodietary studies. Here, we show, to our knowledge, for the first time that fossil eggshell is a previously unrecognized source of ancient DNA (aDNA). We describe the successful isolation and amplification of DNA from fossil eggshell up to 19 ka old. aDNA was successfully characterized from eggshell obtained from New Zealand (extinct moa and ducks), Madagascar (extinct elephant birds) and Australia (emu and owl). Our data demonstrate excellent preservation of the nucleic acids, evidenced by retrieval of both mitochondrial and nuclear DNA from many of the samples. Using confocal microscopy and quantitative PCR, this study critically evaluates approaches to maximize DNA recovery from powdered eggshell. Our quantitative PCR experiments also demonstrate that moa eggshell has approximately 125 times lower ...
Biofuels will have more intense impact on the energetic grid of the planet, because known fossil fuels reserves are being exhausted. The biofuel production relies on the transformation process of some organic material in the desired hydrocarbon product. Because of the natural characteristics of the related processes, fibre optic sensors appear to be adequate candidates to be used.
The objective of this study was to identify and assess the present and future dimensions of environmental effects and impacts of various energy generation alternatives, and to place safety and environmental risks associated with the nuclear industry in Canada in perspective with the risks from other sources. It was found that nuclear power generation involves a comparable risk to that of conventional methods of thermoelectric power generation.
Research programs from the following sections and programs are summarized: aquatic ecology, environmental resources, earth sciences, terrestrial ecology, advanced fossil energy program, toxic substances program, environmental impacts program, biomass, low-level waste research and development program, US DOE low-level waste management program, and waste isolation program.
The collection of papers in this issue of Mycologia documents considerable improvements in taxon sampling and phylogenetic resolution regarding the Fungal Tree of Life. The new data will stimulate new attempts to date divergences and correlate events in fungal evolution with those of other organisms. Here, we review the history of dating fungal divergences by nucleic acid variation and then use a dataset of 50 genes for 25 selected fungi, plants and animals to investigate divergence times in kingdom Fungi. In particular, we test the choice of fossil calibration points on dating divergences in fungi. At the scale of our analysis, substitution rates varied without showing significant within-lineage correlation, so we used the Langley-Fitch method in the R8S package of computer programs to estimate node ages. Different calibration points had a dramatic effect on estimated divergence dates. The estimate for the age of the Ascomycota/Basidiomycota split was 1808000000 y ...
Tabulated data are presented from air monitoring studies in the vicinity of the Chalk Point fossil-fuel power plant located in a coastal region of Maryland. (ERA citation 02:057363)
Results are reported from dye tests of the dispersion of the vapor plume from the natural draft cooling tower of a fossil-fuel power plant located in the coastal region of Maryland.
Bio gasification, i. e. anaerobic digestion, is a well known sustainable option for the management of organic solid wastes and sludges. the produced biogas is a valuable bio fuel to replace fossil fuels in different technical applications (like heating, electricity, transport fuel generation) which in turn determine its quality requirements. (Author)
Mitsubishi Research Institute has analyzed the energy demand of a typical Japanese city, Yokohama, as well as the distribution of fossil-energy flow, and the final consumption by sectors. It has evaluated the effectiveness of various energy conservation measures, (e.g., cogeneration, electric cars, insulation,...) in countering the global warming trend. This study defines a viable methodology which may be utilized, in the future, in examining the effectiveness of environmental policies. (TEC). 1 tab., 4 figs.
Pollutant emissions due to fossil fuel and biomass energy utilization in Turkey have been estimated. Standard emission factors were used for estimating the levels of particulate matter, sulfur oxides, nitrogen oxides, carbon monoxide, volatile organic compounds, and aldehydes. The results are presented for different fuels and energy-consuming sectors for the reference year 1987. Total Turkish emissions vs energy consumption are presented for every fifth year since. 1960. (author).
This handbook breaks down the complex field of nuclear reactor calculations into major steps. Each step presents a detailed analysis of the problems to be solved, the parameters involved, and the elaborate computer programs developed to perform the calculations. This book bridges the gap between nuclear reactor theory and the implementation of that theory, including the problems to be encountered and the level of confidence that should be given to the methods described. Volume III: Control Rods and Burnable Absorber Calculations. Perturbation Theory for Nuclear Reactor Analysis. Thermal Reactors Calculations. Fast Reactor Calculations. Seed-Blanket Reactors. Index.
The results for development of methods and computer programs for integrated optimization of parameters of perspective fast reactors are given. The possibilities of the program for the reactor campaign calculation are analysed. This program is based on utilisation of the Bubnov-Galerkin method and Wigner disturbance theory. The possibility of application of approximation methods for the optimization researches is discussed. The results of development of the programs for complex reactor computations with account of control rods system and change of physical parameters in the reactor campaign are discussed. (author).
The days of high-temperature reactors in the Federal Republic of Germany are numbered. The AVR has been decommissioned, and an application has been filed for licensing the decommissioning of the THTR. Nevertheless, Prof. Dr. Rudolf Schulten who is the director of Juelich Nuclear Research Center's Institute for Reactor Development, and also full professor of Aachen Technical University in the field of reactor safety, predicts a good future for the HTR reactor line on a worldwide level, due to the inherent safety of this reactor type. (orig.).
In the framework of a global analysis of the various available sources of energy, Japan has reserved a prominent place to the nuclear energy, and in the long-term view, to the breeder reactor which will be due for commercial deployment in 2010. To achieve these objectives, three stages are envisaged, one of the experimental reactor Joyo (in service), one of the demonstration reactor Monju (its construction has been decided), and one of the pre-commercial reactor (due to be taken in hand at the beginning of the Nineties). Efforts will be made in parallel concerning the fuel cycle.
The Neutron Radiography Reactor (NRAD) operated by Argonne National Laboratory is described in this paper. NRAD was designed to allow radiography of highly absorbing reactor fuel assemblies in the vertical position on the routine basis. 7 figs.
Quantities and compositions of non-tritium radioactive waste are estimated for some current conceptual fusion reactor designs, and disposal of large amounts of radioactive waste appears necessary. Although the initial radioactivity of fusion reactor and f...
This study assesses the feasibility of removing the FFTF reactor vessel from its current location in the reactor cavity inside the Containment vessel to a transporter for relocation to a burial pit in the 200 Area.
The device of the present invention improves reactor safety by suppressing lowering of water level in a shroud which surrounds a reactor core, even upon occurrence of rupture of pipelines in an emergency reactor core cooling system in a recycling pump-incorporated type reactor. Namely, an opening of each of cooling systems which forms the emergency reactor core cooling device in a reactor pressure vessel is disposed above the upper end of the reactor core. Further, it also comprises an independent high pressure water injection system, gravitational dropping type water injection system and an automatic depressurization system. With such a constitution, even if rupture of pipelines in the system should be assumed, coolants never flow directly from the shroud which surrounds the reactor core. In addition, there are no ...
THe high-temperature reactor is one of the alternatives for the now predominantly employed water-reactors. In a recently published book designer Rudolf Schulten outlines his concept. In this article the book is reviewed. (author). 1 ref.; 1 fig.
THe high-temperature reactor is one of the alternatives for the now predominantly employed water-reactors. In a recently published book designer Rudolf Schulten outlines his concept. In this article the book is reviewed. (author). 1 ref.; 1 fig.
The commissioning of four CANDU-600 reactors is discussed, with mention of some design features. The four are Point Lepreau, Gentilly-2, Wolsung and Cordoba reactors. The commissioning of Pickering-5 is also mentioned, and so are some events affecting other CANDU reactors.
For light water reactors, loss of coolant is an important point in safety analysis, whereas for gas-cooled reactors the ingress of water into the core region is an incident of safety relevance. The applicability of the computer code system GAMTEREX to pebble beds of spherical high-temperature gas-cooled reactor fuel elements with simulated water ingress is verified by experiment. The measurements were performed at a Siemens-Argonaut reactor, using its ring core as a driver zone for a pebble-bed core in the center of the reactor.
The days of high-temperature reactors in the Federal Republic of Germany are numbered. The AVR has been decommissioned, and an application has been filed for licensing the decommissioning of the THTR. Nevertheless, Prof. Dr. Rudolf Schulten who is the director of Juelich Nuclear Research Center's Institute for Reactor Development, and also full professor of Aachen Technical University in the field of reactor safety, predicts a good future for the HTR reactor line on a worldwide level, due to the inherent safety of this reactor type. (orig.).
Actinides other than the main uranium or plutonium isotopes take a growing part in the different stages of the nuclear cycle. For the French nuclear power program based on the development of light water reactors and fast breeders, many evaluations of the secondary actinides build up are made for the both reactor types using mainly the existing reactor codes. The comparison of these foreseen compositions with experimental results allows to perform some adjustments of the neutronic data. The secondary actinide compositions are given for some typical fuels and their consequences on the nuclear cycle are discussed. An hypothetical burning of these wastes in fast reactors has been studied and the main conclusions are reported.
Division of Remote Handling and Robotics (DRHR) at Bhabha Atomic Research Centre (BARC) has been working on design and development of Reactivity Control Mechanisms for Nuclear Research Reactors (Dhruva, KAMINI and recently Critical Facility of Advanced Heavy Water Reactor (AHWR)) as well as Power Reactors in India (Pressurized Heavy Water Reactors of 220 MWe at Narora and recently India's first 540 MWe PHWR Unit -1 and 2 at Tarapur). This paper gives a brief account of evolution of reactivity control mechanisms for nuclear research and power reactors in India. (author)
Chemical looping combustion is a novel technology that can be used to meet the demand on energy production without CO{sub 2} emission. To improve CO{sub 2} capture efficiency in the process of chemical looping combustion of coal, a prototype configuration for chemical looping combustion of coal is made in this study. It comprises a fast fluidized bed as an air reactor, a cyclone, a spout-fluid bed as a fuel reactor and a loop-seal. The loop-seal connects the spout-fluid bed with the fast fluidized bed and is fluidized by steam to prevent the contamination of the flue gas between the two reactors. The performance of chemical looping combustion of coal is experimentally investigated with a NiO/Al{sub 2}O{sub 3} oxygen carrier in a 1 kW{sub th} prototype. The experimental results show that the configuration can minimize the amount of residual char entering into the air reactor from the fuel ...
Korea Atomic Energy Research Institute (KAERI) has been developing the integral reactor. The reactor head structure assembly (RHSA) is the structure installed over the reactor cover. Due to the characteristics of an integral reactor, there are many instrument cables and power cables coming out from the reactor cover and main components. The RHSA provides an interface location to connect these cables from Architecture Engineer (AE) and System Designer (SD). It also prevents a pipe whip and it prohibits instruments from becoming missiles. In this research, the axiomatic design approach for the RHSA is performed.
In this paper Particle Bed Reactor (PBR) designs are discussed which use /sup 233/U and /sup 242m/Am as fissile materials. A constant total power of 100MW is assumed for all reactors in this study. Three broad aspects of these reactors is discussed. First, possible reactor designs are developed, second physics calculations are outlined and discussed and third mass estimates of the various candidates reactors are made. It is concluded that reactors with a specific mass of 1 kg/MW can be envisioned of /sup 233/U is used and approximately a quarter of this value can be achieved if /sup 242m/Am is used. If this power level is increased by increasing the power density lower specific mass values are achievable. The limit will be determined by uncertainties in the thermal-hydraulic analysis. 5 refs., 5 figs., 6 tabs.
Four low activation alloy classes, two austenitic and two ferritic, have been incorporated into the MOTA-1B experiment in the FFTF reactor to provide an early assessment of the suitability of such alloys for reactor service.
The FFTF reactor is described. Procedures and equipment used to protect personnel from potential hazards of oxygen deficient environments are described.
The location of defective LMFBR fuel pins by the determination of gas tag isotopic ratios is discussed. The application of this method to the FFTF Reactor briefly described.
This document is the annual update of the FFTF and Advanced Reactors Transition Program Resource Loaded Schedule for FY 2002 using current project direction and authorized funding levels
Of some interest is the comparison between the actinide nuclide burning up (fission) rates such as americium 241, americium 242, curium 244, and neptunium 237, in the reactors with fast or thermal neutron spectra.
Of some interest is the comparison between the actinide nuclide burning up (fission) rates such as americium 241, americium 242, curium 244, and neptunium 237, in the reactors with fast or thermal neutron spectra.
The term 'Post-CHF' was generally used in the two-phase flow regime in tube flow occurring downstream of the CHF. It has various other names such as dispersed flow, liquid-deficient flow, mist flow and film boiling because the two-phase regime is characterized by a continuous vapor phase with discrete liquid drops and a non-wetted heated surface. The regime has been adopted in a lot of applications including nuclear power plants, fossil power plants, steam generators, refrigeration systems and spray cooling, In particular, this regime has a considerable importance in the areas of light water reactor(LWR) accident analysis (off-normal operating conditions) and design in heat exchangers operating in the once-through mode where subcooled liquid enters the exchanger and superheated vapor exits. Recently, innovative PWRs adopt very high power density increases and so require increased safety margins. For instance, advanced PWRs ...
The term 'Post-CHF' was generally used in the two-phase flow regime in tube flow occurring downstream of the CHF. It has various other names such as dispersed flow, liquid-deficient flow, mist flow and film boiling because the two-phase regime is characterized by a continuous vapor phase with discrete liquid drops and a non-wetted heated surface. The regime has been adopted in a lot of applications including nuclear power plants, fossil power plants, steam generators, refrigeration systems and spray cooling, In particular, this regime has a considerable importance in the areas of light water reactor(LWR) accident analysis (off-normal operating conditions) and design in heat exchangers operating in the once-through mode where subcooled liquid enters the exchanger and superheated vapor exits. Recently, innovative PWRs adopt very high power density increases and so require increased safety margins. For instance, advanced PWRs would be going to use ...
The sulfur-iodine water-splitting cycle is characterized by the following three reactions: 2H/sub 2/O + SO/sub 2/ + I/sub 2/ ..-->.. H/sub 2/SO/sub 4/ + 2HI; H/sub 2/SO/sub 4/ ..-->.. H/sub 2/O + SO/sub 2/ + 1/2 O/sub 2/; and 2HI ..-->.. H/sub 2/ + I/sub 2/. This cycle was developed at General Atomic after several critical features in the above reactions were discovered. These involved phase separations, catalytic reactions, etc. Estimates of the energy efficiency of this economically reasonable advanced state-of-the-art processing unit produced sufficiently high values (to approx.47%) to warrant cycle development effort. The DOE contract was largely directed toward the engineering development of this cycle, including a small demonstration unit (CLCD), a bench-scale unit, engineering design, and costing. The work has resulted in a design that is projected to produce H/sub 2/ at prices not yet generally competitive with fossil-fuel-produced H/sub 2/ but are ...
The authors have discovered chert xenoliths from green rocks in the Pippu area, central Hokkaido, Japan. Reports were given on the discovery with regard to the state of its production, chemical composition of the green rocks, and radiolarian fossils produced from the chert and their age. Considerations were given on the geological significance thereof. On 23 green rocks and five cherts out of the collected samples, rock slices were prepared, and petrographic statement was made by using a polarizing microscope. In addition, the whole petro-chemical composition analysis was performed on green rocks to discuss the radiolarian fossils and geological ages. The following conclusions were obtained as a result: green rocks may be identified as a product of igneous activities in a large plate in a certain period from the latter Callovian period of the middle age of the Jurassic period to the Barremian period of the Paleozoic era in the Cretaceous ...
This presentation describes a method for analyzing, quantifying, and minimizing the total cost of fossil, combined cycle, and pumped hydro power plant cycling operation. The method has been developed, refined, and applied during engineering studies at some 160 units in the United States and 8 units at the Irish Electric Supply Board (ESB) generating system. The basic premise of these studies was that utilities are underestimating the cost of cycling operation. The studies showed that the cost of cycling conventional boiler/turbine fossil power plants can range from between $2,500 and $500,000 per start-stop cycle. It was found that utilities typically estimate these costs by factors of 3 to 30 below actual costs and, thus, often significantly underestimate their true cycling costs. Knowledge of the actual, or total, cost of cycling will reduce power production costs by enabling utilities to more accurately dispatch their units to manage unit ...
The technical potentials of electric power generation from hydro power in Germany, the current harnessing of hydro power, its costs, and certain characteristic quantities reflecting its effects on the environment are described. These diverse characteristic quantities are compared with those of other renewable and fossil energy sources used to generate electricity. On this basis, opportunities for extending the use of hydro power in Germany and its limits are discussed. (orig.) [Deutsch] Das Ziel der folgenden Ausfuehrungen ist, die technischen Potentiale und deren derzeitige Nutzung, die Kosten und bestimmte die Umwelteffekte beschreibende Kenngroessen einer Stromerzeugung aus Wasserkraft in Deutschland darzustellen. Diese unterschiedlichen Kenngroessen werden anschliessend mit denen anderer regenerativer Energien und fossiler Energietraeger zur Stromerzeugung verglichen. Ausgehend davon werden die Moeglichkeiten und Grenzen einer ...
Cost is a key issue in the spreading of any technology. In this work, the cost of hydrogen is analyzed and determined, for hydrogen obtained by electrolysis. Different contributing partial costs are taken into account to calculate the hydrogen final cost, such as energy and electrolyzers taxes. Energy cost data is taken from official URLs, while electrolyzer costs are obtained from commercial companies. The analysis is accomplished under different hypothesis, and for different countries: Germany, France, Austria, Switzerland, Spain and the Canadian region of Ontario. Finally, the obtained costs are compared to those of the most used fossil fuels, both in the automotive industry (gasoline and diesel) and in the residential sector (butane, coal, town gas and wood), and the possibilities of hydrogen competing against fuels are discussed. According to this work, in the automotive industry, even neglecting subsidies, hydrogen can compete with fossil ...
The use of concentrated solar energy for co-producing Zn and synthesis gas from Zn O and natural gas upgrades the calorific value of the initial reactants by 39% and, when compared to the traditional carbothermic reduction of Zn O, has the potential of reducing CO{sub 2} emissions by up to 78%. An economic assessment for an industrial thermochemical plant, 30 to 51 MW solar input, indicates that the cost of solar production of zinc ranges between 89-133 $/t (excluding the cost of Zn O feed and credit for pollution abatement), and thus might be competitive with conventional fossil-fuel-based processes at current fuel prices. The cost of solar H{sub 2}, produced by splitting water with zinc, is estimated to be in the range 0.10-0.14 $/kWh, and it is a favorable long term prospect once the cost of energy will account for the environmental externalities from fossil fuel burning such as the costs for CO{sub 2} mitigation and pollution abatement. ...
This paper reported on a life cycle assessment (LCA) study that compared the environmental impacts of business-as-usual manure management with those of a manure management operation incorporating anaerobic digestion with combined heat and power generation. The case study was based on a medium sized dairy farm in northern New York State. The study identified the benefits resulting from the displacement of fossil fuels, and reduction of related emissions. Although anaerobic digestion of dairy manure with energy recovery through biogas combustion is viewed as a positive environmental approach to increase the use of renewable energy, there are potential negative impacts that can counteract the environmental benefits. The negative impacts are associated with emissions of methane and nitrogen species during digestion and after spreading of digester effluent. The environmental impacts and their causes should be evaluated in order to promote best management practices. ...
This article gives an account of the recent development of light water reactors new concepts in the world. Different projects are being studied. The CE80+ from Combustion Engineering (CE) is a 1350 MWe-PWR-type reactor whose primary circuit is confined in a spherical metallic containment. This reactor was certified by NRC (national regulatory commission) in mid-1996. The APWR (advanced pressurized water reactor) is developed by MHI (Mitsubishi heavy industries) in a collaboration with Westinghouse, this PWR-type reactor fitted with 4 loops derived from the SP90 model that was developed by Westinghouse during the eighties. 2 units of ABWR (advanced boiling water reactor) were commissioned in Japan in 1996 and 1997, ABWR was certified by NRC in mid-1996. The BWR90+ is developed by ABB-atom (Sweden) and it represents a cautious advanced version of the BWR75. ...
The paper describes transportation cost of the nuclear off-peak power for a hydrogen production based on water electrolysis in Japan. The power could be obtainable by substituting hydropower and/or fossil fueled power supplying peak and middle demands with nuclear power. The transportation cost of the off-peak power was evaluated to be 1.42 yen/kWh when an electrolyser receives the off-peak power from a 6kV distribution wire. Marked reduction of the cost was caused by the increase of the capacity factor. (author)
The article describes the energy in Lebanon. In 1995, 97% of the imported energy was based on hydrocarbons. Fuel and gas oil present 66% of the final energy. Air pollution is mainly caused by the transportation sector (vehicles and buses...) which presents 70% of the global atmospheric pollution. Renewable energy such as biomass, fossil energy, hydro-energy, solar energy... are also described. The solar energy was defined as a best solution that preserve health in Lebanon. The different applications of the solar for energy production is discussed: photovoltaic , thermal heating, sanitary hot water, electrical heaters, solar water heaters...In conclusion, solar heaters economize 80% of the annual energy expenses
If trends from the past continue into the future, the major increase in the use of energy will come from the developing nations. If the industrialization of the Third World continues to be based on the burning of fossil fuels, the impact on the global climate from these sources alone will be substantial. Statistical information supporting the above statements is presented. The conclusion is reached that improving the efficiency of energy use is not sufficient to avert climatic changes. The accelerated and worldwide use of nuclear power is essential and, if prudently used, can become, contrary to the recommendations of the Brundtland Commission, the basic energy source fuelling future sustainable developments of the world. (author).
The accuracy of the carbon 14 dating method is dependent on the fluctuations of carbon 14 in the atmosphere over long periods of time. Fossil corals that are dated by both carbon 14 and uranium-thorium methods allows the setting of calibration curves for the carbon 14 method for the last 50.000 years. The uranium-thorium method is based on the measurement of the ratio of 2 isotopes: thorium 230 and uranium 234 that are both present in the decay chain of uranium 238. (A.C.)
Polymeric waste materials should be considered resources for the manufacture of new products through recycling processes, with a similar status to virgin fossil-based plastics and biopolymers from renewable resources. Several efforts can be made to achieve this qualitative quantum leap in plastics recycling, and consequently introduce recycled products, with competitive performance, to the market. Scientific knowledge about the degradation processes during the life cycle and the development of fast and reliable analytical methods for the quality assessment of recycled plastics are fundamental to guarantee their performance in new applications. Different strategies-restabilisation, rebuilding, compatibilisation, and addition of elastomers and fillers-can be used to upgrade the structure and...
The section on environmental impacts covers global environmental concerns and air pollution. Energy systems includes the following: alternative fuels; co-generation; fossil fuels; mechanical thermal storage; fission/fusion; thermal management; electric and hybrid vehicles. The section on renewable energy sources includes biomass, hydrogen, and solar. This volume also contains separate sections for stirling cycles, policy issues, and new technologies for energy utilization. Separate abstracts were prepared for 150 papers of this volume.
The Oak Ridge National Laboratory (ORNL) is a multiprogram, multipurpose laboratory that conducts research in the physical, chemical, and life sciences; in fusion, fission, and fossil energy; and in energy conservation and other energy-related technologies. This review outlines some current endeavors of the lab. A state of the laboratory presentation is given by director, Alvin Trivelpiece. Research of single crystals for welding is described. The Science Alliance, a partnership between ORNL and the University of Tennessee, is chronicled. And several incites into distinguished personnel at the laboratory are given. (GHH)
The Uinta Basin is an important hydrocarbon producing area, with extensive resources of hydrocarbon, bitumen, and fossil fuels. Gilsonite, tar sands, oil shale and coal are found in abundance with the cretaceous and Tertiary sedimentary rocks. The 25 papers include discussion on: leasing; thermal maturity of rocks and hydrocarbon deposits; influence of source rock type, thermal maturity and migration on composition and distribution of the natural gas; drilling; geology; structural evolution of gilsonite dykes; reclamation of coal mines; oil shale resources; and uranium mining.
The tanning process and associated energy requirements are summarized. It appears that a significant economic impact may be possible if a shallow hydrothermal resource of approximately 150 to 170/sup 0/F (66 to 77/sup 0/C) were found, and the fluids were cascaded to produce the temperatures necessary for the various tanning operations. The hydrothermal energy would have to be cost competitive with the rapidly escalating fossil energy costs. Although one would need to thoroughly analyze the technical, environmental, and economic issues of such an application, this initial review indicates a good match between the process and potential hydrothermal resources.
The Federal Republic of German (FRG) had uniquely strict emission legislation for particulates SO_2 and NO_X from fossil-fired power plants. The 13th Regulation to the Federal Emission Control Act required that by 1 July 1988 all large furnaces fired with solid or liquid fuels that would not be decommissioned by 1993 be retrofitted with SO_2 control technology. The emission limits are 15 per cent of the sulphur introduced with the fuel (400 mg/m"3 maximum) at thermal capacities above 300 MW. 1 ref., 9 figs, 15 bibliographies.
The booklet presents general information and practical hints for the task of acquiring and evaluating the data describing investments and other expenditure and activities for pollution abatement measures taken by electric utilities. The information is intended as an aid for establishing standard criteria for assignment and evaluation, and for comparison and classification of pollution abatement measures. As a line of orientation, a catalogue of pollution control measures is given, arranged into the following sections: Fossil-fueled power plants; nuclear power plants (BWR and PWR); hydroelectric power plants; power transmission and distribution. (HSCH)
Decision making about possible investment options for energy supply technology is usually based on economic criteria reflecting primarily the unit cost of energy and the return on capital invested. This study attempts to reverse the process. The chosen starting point is a UK investment programme geared towards reliance on conservation, renewable energy systems and the more efficient use of our remaining fossil fuels (through combined heat and power and district heating systems). The number and type of jobs likely to be created is then estimated and compared with the jobs likely to be created by the currently proposed nuclear power programme. (author).
As a counter measure to protect against global warming, the development of CO{sub 2} recovery technology from fossil fuel power plant flue gas has continued. MEA processes are widely used for CO{sub 2} recovery from combustion flue gas in average use etc. However, if we consider power plant scale CO{sub 2} recovery, the biggest theme is the reduction of energy needed to recover CO{sub 2}. The paper focuses on sterically hindered amines and a new absorber packing. Also optimum steam system analysis results are indicated. 1 ref., 16 figs., 3 tabs.
Results of investigation of stress corrosion cracking of steam turbine materials in nuclear, fossil and geothermal power plants have been analysed. The role of factors that cause damage to rotor discs, mono block and welding rotors of steam turbines has been shown. These are yield stress and steel composition, stress intensity coefficient and crack growth rate, composition and temperature of the condensed steam and water, electrochemical conditions. The conclusion has been made about the state of stress corrosion cracking of the rotors materials, and main investigation trends which are necessary to solve this problem have been listed.
Papers are presented under 38 symposia. Subjects included reinforced concrete, protective coatings and linings, cathodic/anodic protection, chemical cleaning of boilers, managing corrosion with plastics, water treatment, HRSG boiler tube failure analysis, corrosion in oil and gas production, corrosion in petroleum refining and gas, processing, pipelines and tanks, high temperature materials, chemical process industry, aerospace equipment, materials technology developments for incinerators and waste fuel-fired processors, materials and corrosion in fossil-fuels conversion and combustion, corrosion in nuclear systems, marine corrosion, building systems, corrosion mechanisms, corrosion inhibitors and corrosion monitoring and measurement.
The manual presents the fundamentals of thermodynamics and fluid mechanics, the main components of steam power plants, and the power generation process. The following concepts and subjects are discussed at length: steam generator; steam turbines; turbogenerators; condensers; cooling technology; water/steam cycle and water treatment; design data of fossil-fuelled power plants; design and optimisation of nuclear power plant thermodynamics; pipelines and fittings; control systems in steam power plants; connection to the electricity grid and self-supply of thermal power plants; power plant transformer concepts and definitions. (HAG).
...it only highlights the different feedstocks used in the production of fiber-based packaging materials or fossil-fuel ones; what about the energy required to convert ...feedstock, is unacceptable in trying to quantify the overall burden a specific packaging material has on the environment. As an aside, the point ... Consequentially, it is difficult to speculate on how much packaging material a company diverts from the landfill by switching from one material to another ...without specifying what geographical region said packaging material resides in. In addition, there is a lot of interest in diverting PET thermoforms from ...
A historical background is first given in which the role of biomass is described in relation to its competition with fossil biomass for the production of chemicals and energy. Occurrences of reserves from both sources are then compared. Petrochemical and biomass routes are then analyzed in terms of their relative competitive advantages. The oleochemical and biotechnology cases are analyzed in more detail as examples of biomass utilization. Latin American examples of industrial manufacturing of biomass derived chemicals are then provided. Alcochemicals are analyzed in detail as well as essential oils and other chemicals. Finally, references are made to regional Latin American initiatives regarding biomass and the objectives, organization and nature of the initiative are presented.
In 1995, 25,8 % of the world electricity consumption was of nuclear origin, while in the EU this figure is increased up to 50,6 %. In order to maintain and even to increase its share in the electricity generation, Nuclear Energy needs to achieve a good economic performance as a base load source when compared with its competitors, basically coal and gas fired plants. Fossil-fired generation costs have declined over the past ten years, mainly due to lower fossil fuel prices. This factor together with the recently observed tendency of higher discount rates to be applied are challenging the attractiveness of the nuclear energy. Nuclear energy is a capital intensive option. Taken into account extensive standardization programs has been established aiming at cost reductions as well as to increase efficiency of nuclear energy utilization, among their main purposes. Externalities play an important role, as they are already internalized in nuclear ...
A guidance document on the instrumentation for monitoring and control of cycle chemistry for the steam-water circuits of fossil-fired and combined-cycle power plants was developed within the IAPWS Power Cycle Chemistry Working Group. This technical guidance document has been authorized by the International Association for the Properties of Water and Steam (IAPWS) at its meeting in Doorwerth, The Netherlands, 6-11 September, 2009, for issue by its Secretariat. The members of the IAPWS are: Britain and Ireland, Canada, the Czech Republic, Denmark, France, Germany, Greece, Japan, Russia, and the United States of America, and the associate members Argentina and Brazil, Italy, and Switzerland. In order to achieve suitable chemical conditions in steam-water circuits it is essential to establish reliable monitoring of key parameters on every plant. This enables the demonstration of operation within cycle chemistry targets, and alerts the operators to the need to take ...
The invention concerns a procedure for operating reactors in nuclear power plants. It aims at utilizing power reserves in nuclear power plants. This can be achieved by a steam-side connection of the steam generators of two reactors. The amount of steam exchanged between the units is chosen in such a way that power changes at the steam turbines feedback mainly to the corresponding reactor. In order to realize a high power transfer it is necessary to return the amount of condensate produced in the steam receiving unit and corresponding to the power transferred to the feedwater system of the steam donating unit.
The purpose of this paper is to describe instrumentation and control (I C) system improvements at Experimental Breeder Reactor 11 (EBR-11). The improvements are focused on three objectives; to keep the reactor and balance of plant (BOP) I C systems at a high level of reliability, to provide diagnostic systems that can provide accurate information needed for analysis of fuel performance, and to provide systems that will be prototypic of I C systems of the next generation of liquid metal reactor (LMR) plants.
The purpose of this paper is to describe instrumentation and control (I&C) system improvements at Experimental Breeder Reactor 11 (EBR-11). The improvements are focused on three objectives; to keep the reactor and balance of plant (BOP) I&C systems at a high level of reliability, to provide diagnostic systems that can provide accurate information needed for analysis of fuel performance, and to provide systems that will be prototypic of I&C systems of the next generation of liquid metal reactor (LMR) plants.
Results of tests on the 1 kg/h continuous reactor for the hydroliquefaction of coal are described. The reactor was operated at 415-435 C and 21 MPa using a continuous stirred reactor with a retention time of about 2 hours. All product oils were recovered by distillation. Sub-bituminous coal was found to give the best product yield. Tests using 5% red mud and 3% improved red mud showed significant increases in oil yield. (4 refs.)
A new reactor concept is described which would enable fission fragments to be continuously extracted from the reactor. Such a reactor has the potential of enabling extremely energetic and ambitious deep space missions. In this talk the basic physics issues involved in the operation of this type of reactor are outlined, and some possible applications to space exploration are described. 3 refs., 2 figs., 3 tabs.
The kinetic parameters, ..cap alpha.. the coupling coefficient and tau-bar the mean neutron transit time have been determined using a reactor oscillator on the coupled-core of the Queen Mary College research reactor. By using correlation techniques it has proved possible to use detectors small enough to be inserted in the fuel tanks. It is shown that the simplified Baldwin model with one-group diffusion theory is inadequate to describe the kinetic behaviour and the experimentally-determined parameters are dependent upon the positioning of the detectors.
An experimental plan for improving the problems of failed fuel location system in Wolsung Unit-2 reactors was established. It is not possible to make an experiment on the failed fuel monitoring nuclides in the cold laboratories because they have very short half life. Therefore, the experiments can be only carried out at the existing monitoring system under reactor operation. For that reason, an experimental plan was drawn up for installing the radiation detection system on reactor site.
Dr. Rudolf Schulten of West Germany and expert witnesses from national laboratories, utilities, and the nuclear industry testified on reactor safety issues as they relate to the Chernobyl accident and public concern that modern technology has not paid enough attention to public safety. Each of the witnesses contributed safety-related information based on what has been learned from the Soviet incident. Particular focus went to similarities and differences between the Chernobyl and US reactors in safety design and engineering and to the environmental effects of the accident. The N reactor near Richland and a commercial reactor at Fort St. Vrain, Colorado are the only two operating graphite reactors, but neither is a boiling water reactor.
Dr. Rudolf Schulten of West Germany and expert witnesses from national laboratories, utilities, and the nuclear industry testified on reactor safety issues as they relate to the Chernobyl accident and public concern that modern technology has not paid enough attention to public safety. Each of the witnesses contributed safety-related information based on what has been learned from the Soviet incident. Particular focus went to similarities and differences between the Chernobyl and US reactors in safety design and engineering and to the environmental effects of the accident. The N reactor near Richland and a commercial reactor at Fort St. Vrain, Colorado are the only two operating graphite reactors, but neither is a boiling water reactor.
Since the first round of conceptual fusion reactor designs in 1973 - 1974, there has been considerable progress in design improvement. Two recent tokamak designs of the Wisconsin and Culham groups, with increased plasma beta and wall loading (power density), lead to more compact reactors with easier maintenance. The Reference Theta-Pinch Reactor has undergone considerable upgrading in the design of the first wall insulator and blanket. In addition, a conceptual homopolar energy storage and transfer system has been designed. In the case of the mirror reactor, there are design changes toward improved modular construction and ease of handling, as well as improved direct converters. Conceptual designs of toroidal-multiple-mirror, liner-compression, and reverse-field pinch reactors are also discussed. A design is presented of a toroidal multiple-mirror reactor that ...
This paper presents the results of a series of experiments performed to study the effect of initial pressure vessel conditions on the extent of melt dispersal from scaled reactor cavities and describes progress in development of a mathematical model which is designed to predict the melt mass dispersed from reactor cavities as a function of reactor vessel initial conditions and on the vessel breach area. The model, which is being developed to also characterize the heat transfer and chemical reaction phenomena which would take place within the reactor cavity, is designed to be incorporated into a lumped-parameter containment analysis computer code.
The invention concerns an integrated nuclear reactor comprising natural convection cooling of the supporting skirt on which rests the shield closing the reactor vessel. Cooling is achieved by making the air circulate from the bottom to the top around the skirt and removing this air by a stack. The air can be atmospheric air or air taken from the low parts of the reactor. In the latter case, the stack emerges near a metal roof releasing its heat to the atmosphere by radiation, the air then dropping to the low parts. Application to fast nuclear reactors.
This paper discusses the remote plugging of leaks in inaccessible pipework, with main reference to small leaks which frequently appear in ancillary cooling water circuits of nuclear reactors. Initially developed to cure problems of the pre-stressed concrete pressure vessels of UK reactors, the ZORIC sealant has been used to repair leaking biological shield pipework on six CANDU reactors. ZORIC is based on a water-soluble epoxy resin and an aqueous suspension of a refined mineral clay. This paper describes the evolution of the sealant, the qualification and testing program, and their application to CANDU reactor systems. 2 refs., 6 figs.
The most important and difficult part of materials research for fusion reactor is realized to be irradiation studies of fusion reactor materials. Irradiation studies of fusion reactor materials utilizing FFTF/MOTA, as one of Japan/U.S.A. Fusion Collaboration Programs, have important role to establish fundamental understanding of heavy irradiation effects on materials behavior and properties and to develop methods and technologies for advanced irradiation studies under fusion reactor environment. This paper briefly reviews the history, the state of the art, and the future of the FFTF/MOTA program. (author).
RELAP5 (Reactor Excursion and Leak Analysis Program) is a system code developed at the Idaho National Environmental and Engineering Laboratory for thermal hydraulic analysis of nuclear reactors. The code RELAP5 is widely used for safety analysis studies of commercial nuclear power plants. However, recent released version of RELAP5/3.2 and over present significant capabilities for analysis of nuclear reactor research systems. As a contribution to the assessment of RELAP5/3.3 for research reactor safety analysis, experimental data from the University of Massachusetts Lowell Research Reactor UMLRR are used. The UMLRR is a 1 MW, light water moderated and cooled, graphite-reflected, open-pool type research reactor. This paper presents the development and the validation of a UMLRR-RELAP model using experimental data. For this purpose, a series of experiments were ...
The United State Domestic Research Reactor Infrastructure Program at the Idaho National Laboratory manages and provides project management, technical, quality engineering, quality inspection and nuclear material support for the United States Department of Energy sponsored University Reactor Fuels Program. This program provides fresh, unirradiated nuclear fuel to Domestic University Research Reactor Facilities and is responsible for the return of the DOE-owned, irradiated nuclear fuel over the life of the program. This presentation will introduce the program management team, the universities supported by the program, the status of the program and focus on the return process of irradiated nuclear fuel for long term storage at DOE managed receipt facilities. It will include lessons learned from research reactor facilities that have successfully shipped spent fuel elements to DOE receipt facilities.
The operation of a nuclear power reactor necessarily implies the consumption or burnup of reactor fuel by fission and capture, which gives rise to a decrease in the reactivity of the reactor. The effect of americium formation on the criticality of a thermal power reactor using two types of fuel is studied. The three-dimensional core calculation is used to calculate the production of the transuranium isotopes and their effect on the effective multiplication factor (K[sub eff]). This effect cannot be neglected for thermal power reactors with UO[sub 2]-PuO[sub 2] fuel (3.11% after 70 weeks of operation). The effect of the transuranium isotopes on the K[sub eff] for a thermal power reactor with UO[sub 2] fuel is about 0.0018% and can be ignored. (author).
The operation of a nuclear power reactor necessarily implies the consumption or burnup of reactor fuel by fission and capture, which gives rise to a decrease in the reactivity of the reactor. The effect of americium formation on the criticality of a thermal power reactor using two types of fuel is studied. The three-dimensional core calculation is used to calculate the production of the transuranium isotopes and their effect on the effective multiplication factor (K_e_f_f). This effect cannot be neglected for thermal power reactors with UO_2-PuO_2 fuel (3.11% after 70 weeks of operation). The effect of the transuranium isotopes on the K_e_f_f for a thermal power reactor with UO_2 fuel is about 0.0018% and can be ignored. (author).
In allusion to the explosion of a urea reactor took place in a fertilizer plant at Pingyin, Shandong, China, a series of evidence collection and inspection jobs which includes collecting operation condition and parameters, sampling the explosion fracture, reactor body apart from explosion fracture, and leak detection medium and its hangover, etc., had been carried out firstly. Based on these jobs, farther analysis and computation work has been done to the structural and materials characteristics and the operation condition of the urea reactor, including compositions, metallographic phases, tensile properties, impact energy, strain ageing characteristics, and fracture toughness of the urea reactor steels, the compositions of leak detection medium and its hangover in the urea reactor, and ex...
High-flux neutron sources are continuing to be of interest both in Canada and internationally to support materials testing for advanced power reactors, new developments in extracted-neutron-beam applications, and commercial production of selected radioisotopes. The advanced MAPLE reactor concept has been developed to meet these needs. The advanced MAPLE reactor is a new tank-type D_2O reactor that uses rodded low-enrichment uranium fuel in a compact annular core to generate peak thermal-neutron fluxes of 1 x 10"1"9 n#centre dot#s"-"1 in a central irradiation rig with a thermal power output of 50 MW. Capital and incremental development costs are minimized by using MAPLE reactor technology to the greatest extent practicable.
The rationale for hybrid fusion-fission reactors is the production of fissile fuel for fission reactors. A new class of reactor, the fission-suppressed hybrid promises unusually good safety features as well as the ability to support 25 light-water reactors of the same nuclear power rating, or even more high-conversion-ratio reactors such as the heavy-water type. One 4000-MW nuclear hybrid can produce 7200 kg of /sup 233/U per year. To obtain good economics, injector efficiency times plasma gain (eta/sub i/Q) should be greater than 2, the wall load should be greater than 1 MW m/sup -2/, and the hybrid should cost less than 6 times the cost of a light-water reactor. Introduction rates for the fission-suppressed hybrid are unusually rapid.
The testing of candidate fuel elements at prototypic operating conditions with respect to temperature, power density, hydrogen coolant flow rate, etc., a crucial component in the development and qualification of nuclear rocket engines based on the Particle Bed Reactor (PBR), NERVA-derivative, and other concepts. Such testing may be performed at existing reactors, or at new facilities. A scoping study has been performed to assess the feasibility of testing PBR based fuel elements at the TREAT reactor. initial results suggest that full-scale PBR, elements could be tested at an average energy deposition of {approximately}60--80 MW-s/L in the current TREAT reactor. If the TREAT reactor was upgraded to include fuel elements with a higher temperature limit, average energy deposition of {approximately}100 MW/L may be achievable.
SCDAP/RELAP5 code has been developed in US for best-estimate simulation of light water reactors transients during nuclear accidents. The code models the coupled behaviour of the cooling system, reactor core and fission products release during the accident. It is the result of the coupling between RELAP5, modelling thermal hydraulic, control system, reactor kinetics and the transport of noncondensable gases, and SCDAP code modelling the behaviour of the reactor core during severe accidents. The paper briefly presents the application of SCDAP/RELAP5 code to CANDU severe accident analysis. Also, the paper proposes a summary of the needs for development that could enhance the quality of the severe accidents related predictions in CANDU reactors. (authors)
The objective of the study is to improve the volume of nuclear power plant which adopts passive safety system concept. The passive safety system reactor is characterized by excellent safety and reliability. But the volume of NSSS (Nuclear Steam Supply System) of the passive safety system reactor is so small that it should be upgraded for commercial operation. For volume upgrade, detailed analyses are performed as follows; core design, hydraulics, design and mechnical structures, and safety analysis. In addition to above analysis, some investigations must be supplied as follows: power density vs. DNB margin decrease, outlet temperature vs. EPRI-URD, additional tests for upgraded reactor, dynamic analysis of mechanical vibration according to expanded reactor vessel and expanded in-core structures, and Merit loss of passive safety system reactor according to design margin decrease. ...
The calculated radioactive waste inventories of the Turkey Point pressurized water fission reactor (PWR) and the Starfire conceptual fusion tokamak are compared as a function of time from initial start-up to 10,000 years after decommissioning. Only material out of reactor at least one year is considered. The total activity in Ci/W(th) of the Starfire tokamak is slightly greater than that of the PWR during the active lifetimes of the two reactors and beyond 1000 years. However, using reduced activation materials in Starfire can result in about 1/2000 as much long-lived radioactivity as in the fission reactor. It is stressed that comparison of wastes on this basis is not straightforward, since the radioisotopes and methods required for their disposal are different for fusion and fission reactors. 2 refs., 1 fig., 2 tabs.
Today TBP and TBAs are the compounds which have the highest potential to replace the hydrides arsine and phosphine in the MOVPE process. The authors have demonstrated the entire material system Ga-In-As-P can be grown without any loss of quality using TBP and TBAs not only in one reactor, but in a complete family of reactors. These reactors range from small-scale single wafer R and D reactors to multiwafer Planetary Reactor systems. Both InP based and GaAs based materials could be grown with an excellent quality. Thus all growth processes for III-V devices--long and short wavelength lasers, LEDs, high speed transistors, etc.--can be switched to TBP and TBAs. This will drastically reduce safety hazards and lead to processes that have advantages both from the ecological and economical point of view.
Two sodium cooled reactors are currently being operated in the United States of America for the US Department of Energy. These are Experimental Breeder Reactor 11, EBR-11, and the Fast Flux Test Facility, FFTF. EBR-11 is located near Idaho Falls, Idaho, and the FFTF is near Richland, Washington. These reactors are currently engaged in a wide range of testing including fuels and materials tests, and plant system performance and safety development. The US DOE program also includes designs of a next generation sodium cooled power reactor. The FFTF and EBR-11 communities are providing input to these designs. This paper discusses the efforts to develop and operate cover gas systems for the sodium cooled nuclear reactor program in the USA.
Encapsulation of a unique isotopic blend of krypton and xenon gas employs a special application of laser technology. The encapsulated gas is then used as the primary medium for detection and identification of failed nuclear fuel rods. The use of gas tagging as a means of detecting and identifying failed nuclear fuel rods has been successfully demonstrated and used by the Argonne National Laboratory, Experimental Breeder Reactor (EBR-2) Project, and the Westinghouse Hanford Company (WHC), Fast Flux Test Facility (FFTF) Fast Breeder Reactor Program. The Power Reactor and Nuclear Fuel Development Corporation (PNC) of Japan has selected this leak detection system for use in their MONJU Prototype Reactor fuel assemblies. The MONJU reactor is almost identical in design to the highly successful FFTF reactor, which is currently in standby status.
The Fast Flux Test Facility (FFTF) is a 400 Mw(t), loop-type, sodium-cooled, fast neutron reactor. It is operated by the Westinghouse Hanford Company for the United States Department of Energy at Richland, Washington. The FFTF is a multipurpose test reactor used to irradiate fuels and materials for programs such as Liquid Metal Reactor (LMR) research, fusion research, space power systems, isotope production and international research. FFTF is also used for testing concepts to be used in Advanced Reactors which will be designed to maximize passive safety features and not require complex shutdown systems to assure safe shutdown and heat removal. The FFTF also provides experience in the operation and maintenance of a reactor having prototypic components and systems typical of large LMR (LMFBR) power plants. The 5 year operational performance of the FFTF reactor is ...
The Fast Flux Test Facility (FFTF) is a 400 Mw(t), loop-type, sodium-cooled, fast neutron reactor. It is operated by the Westinghouse Hanford Company for the United States Department of Energy at Richland, Washington. The FFTF is a multipurpose test reactor used to irradiate fuels and materials for programs such as Liquid Metal Reactor (LMR) research, fusion research, space power systems, isotope production and international research. FFTF is also used for testing concepts to be used in Advanced Reactors which will be designed to maximize passive safety features and not require complex shutdown systems to assure safe shutdown and heat removal. The FFTF also provides experience in the operation and maintenance of a reactor having prototypic components and systems typical of large LMR (LMFBR) power plants. The 5 year operational performance of the FFTF reactor is ...
The activation aspects of pure fusion and hybrid fusion technology is studied to assess the radioactive safety of various fusion concepts including tokamak pure fusion, fissile fuel producing hybrid and radio waste transmuting hybrid. The activation properties of breeding, coolant and structural materials in fusion reactors might be quite different from those in fission reactors because of the high energy D-T fusion neutrons from the fusion cores. A study on the involved activation reactions and the uncertainties of the associated nuclear cross-sections is carried. The activation properties of various first wall concepts and blanket concepts are discussed. The radioactive inventory during the operation lifetime and the potential hazard of the radioactive nuclides with respect to near term (reprocessing) and long term (waste disposal) aspects are calculated, with reference to ITER/NET (International Thermonuclear Experiment ...
The activation aspects of pure fusion and hybrid fusion technology is studied to assess the radioactive safety of various fusion concepts including tokamak pure fusion, fissile fuel producing hybrid and radio waste transmuting hybrid. The activation properties of breeding, coolant and structural materials in fusion reactors might be quite different from those in fission reactors because of the high energy D-T fusion neutrons from the fusion cores. A study on the involved activation reactions and the uncertainties of the associated nuclear cross-sections is carried. The activation properties of various first wall concepts and blanket concepts are discussed. The radioactive inventory during the operation lifetime and the potential hazard of the radioactive nuclides with respect to near term (reprocessing) and long term (waste disposal) aspects are calculated, with reference to ITER/NET (International Thermonuclear Experiment ...
Total EU (and Norway) emissions of CO_2 from thermal power generation were some 950 million tonnes in 1990, the Kyoto agreement reference level. An ongoing research project, the GESTCO project, will provide the first documentation that, for the emission sources within the selected key areas, sufficient geological storage capacity is available for at least 30 years and possibly much longer. Cost of energy will obviously increase, but it is anticipated that electricity production cost price will be comparable to that of renewables. It would further have major implications for the European power generating industry which today is totally dominated by fossil fuel combustion with enormous emissions problems. The identification and siting of subsurface CO_2 storage capability can be expected to have considerable effect on the planning for and future siting of fossil fuel plants. In Norway there are plans to build several major, coastally sited, ...
The purpose of the conversion process is to convert the {sup 233}U fluoride compounds that are being extracted from the Molten Salt Reactor Experiment (MSRE) equipment to a stable oxide for long-term storage at Bldg. 3019.
In order to reduce the air concentration of (sup 3)H in the reactor buiIding of Wolsung Heavy Water Reactor, a computer code for estimation of adsorption behavior was programmed based on an equation derived for analysis of water vapor adsorption, and a ba...
The main aspects of the present WWER-440 reactors spent fuel management are described in the paper. Experimental results of fuel integrity studies which are carried out under conditions of a long-term storage are also presented. (author). 5 refs, 5 figs.
Starting from the Molten Salt Breeder Reactor project of Oak-Ridge, we have performed parametric studies in terms of safety coefficients, reprocessing requirements and breeding capabilities. In the frame of this major re-evaluation of the molten salt reactor (MSR), we have developed a new concept called Molten Salt Fast Reactor or MSFR, based on the Thorium fuel cycle and a fast neutron spectrum. This concept has been selected for further studies by the MSR steering committee of the Generation IV International Forum in 2009. Our reactor's studies of the MSFR concept rely on numerical simulations making use of the MCNP neutron transport code coupled with a code for materials evolution which resolves the Bateman's equations giving the population of each nucleus inside each part of the reactor at each moment. Because of MSR's fundamental characteristics compared to classical ...
This report is the final report on the seismic testing of reactor components conducted since 1977 with opening of the vibration laboratory at KAERI. In 1979, forced vibration testing of Wolsung-1 steam generator model using sine dwell and white nosie rand...
The calculated radioactive waste inventories of the Turkey Point pressurized water fission reactor (PWR) and the Starfire conceptual fusion tokamak are compared as a function of time from initial start-up to 10,000 years after decommissioning. Only materi...
The paper briefly describes the nuclear reactor facilities at Sandia Laboratories which are used for simulating nuclear weapon produced neutron environments. These reactor facilities are used principally in support of continuing R and D programs for the Department of Energy/Office of Military Application (DOE/OMA) in studying the effects of radiation on nuclear weapon systems and components. As such, the reactors are available to DOE and DOD agencies and their contractors responsible for the radiation hardening of advanced nuclear weapon systems. Emphasis is placed upon two new reactor simulation sources; the Sandia Pulse Reactor-III (SPR-III) Facility which enhances the neutron exposure volume capabilities over those presently available with the existing SPR-II Facility, and the Upgraded Annular Core Pulse Reactor (ACPR) Facility which enhances the neutron ...
Based on a generalized theory of perturbations and on non-linear programming an approach to the quantitative determination of necessary accuracies for nuclear data is described. It is used to calculate transactinide isotope build-up in reactors.
A reactor was proposed in which the breeder mantel would consist of a charge of homogeneous cast breeder elements, so that the breeder element has the same shape as the fuel elements. By this method it would be possible to use the breeder element after its irradiation immediately for the charging of the fuel elements.
The Sp-100 reactor is a lithium-cooled high-temperature fast-spectrum reactor. The fuel is UN. The cladding is fabricated from PWC-11, a Nb alloy, as are all the primary structural components. A reactor lifetime of up to ten years with an operating temperature of 1370 K is required. The accumulated fluence is expected to be 6 x10"2"2 n/cm"2. The damage, which could result in swelling or embrittlement, anneals out as fast as it occurs for the majority of the structure. This has been confirmed by earlier radiation testing. A number of components, however, are exposed to lower temperatures and the reactor design and materials selection for these components must take this into consideration. Radiation effects must also be considered for the UN fuel, bearing materials, etc. To data an instrumented experiment, MOTO 1000A, has been conducted in the FFTF reactor and as uninstrumented ...
The Fast Flux Test Facility (FFTF) reactor, which started operating in 1982, is a 400 MWt sodium-cooled fast neutron reactor located in Hanford, Washington State, and operated by Westinghouse Hanford Co. under contract with U.S. Department of Energy. The reactor has a wide variety of functions for irradiation tests and special tests, and its major purpose is the irradiation of fuel and material for liquid metal reactor, nuclear reactor and space reactor projects. The review first describes major technical specifications and current conditions of the FFTF reactor. Then the plan for irradiation testing is outlined focusing on general features, fuel pin/assembly irradiation tests, and absorber irradiation tests. Assemblies for special tests include the material open test assembly (MOTA), fuel open test assembly (FOTA), closed loop ...
The Fast Flux Test Facility (FFTF) reactor, which started operating in 1982, is a 400 MWt sodium-cooled fast neutron reactor located in Hanford, Washington State, and operated by Westinghouse Hanford Co. under contract with U.S. Department of Energy. The reactor has a wide variety of functions for irradiation tests and special tests, and its major purpose is the irradiation of fuel and material for liquid metal reactor, nuclear reactor and space reactor projects. The review first describes major technical specifications and current conditions of the FFTF reactor. Then the plan for irradiation testing is outlined focusing on general features, fuel pin/assembly irradiation tests, and absorber irradiation tests. Assemblies for special tests include the material open test assembly (MOTA), fuel open test assembly (FOTA), closed loop ...
This is the final Report for the technical ''on-the-job traning'' for the Wolsung CANDU nuclear power plant which is the first Pressurized Heavy Water Reactor setting up in Korea. The technical ''on-the-job traning'' was established to increase the capabi...
Coke consumption may be cut as much as fifty percent using a coal reactor to furnish carbon monoxide for ore reduction in a blast furnace while lowering the sulfur content of pig iron accompanied by a smaller slag volume.
The primary scope of this study is to establish the analysis technology for the advanced reactor designed on the basis of the passive and inherent safety concepts. This study is extended to the application of these technology to the safety analysis of the passive reactor. The study was performed for the small and medium sized reactor and the large sized reactor by focusing on the development of the analysis technology for the passive components. Among the identified concepts the once-through steam generator, the natural circulation of the integral reactor, heat pipe for containment cooling, and hydraulic valve were selected as the high priority items to be developed and the related studies are being performed for these items. For the large sized passive reactor, the study plans to extend the applicability of the best estimate computer code RELAP5/MOD3 which is ...
To propose a new design concept of a nuclear reactor used in the space, research has been conducted on the conceptual design of a new nuclear reactor on the basis of the following three main concepts: (1) Thermionic generation by thermionic fuel elements (TFE), (2) reactivity control by rotary reflector, and (3) reactor cooling by liquid metal. The outcomes of the research are: (1) A calculation algorithm was derived for obtaining convergent conditions by repeating nuclear characteristic calculation and thermal flow characteristic calculation for the space nuclear reactor. (2) Use of this algorithm and the parametric study established that a space nuclear reactor using 97% enriched uranium nitride as the fuel and lithium as the coolant and having a core with a radius of about 25 cm, a height of about 50 cm and a generation efficiency of about 7% can probably be operated continuously ...
Renewable energy systems, such as photovoltaic and wind-turbine energy systems, are considered to be environmentally sound from the viewpoint of carbon-dioxide emissions and resource depletion. The cost of energy supplied from renewable energy systems is higher than that of conventional fossil-fuel systems, and this hinders the wider spread of renewable energy systems. Global environmental problems, however, are becoming more obvious. There is a movement to defray the additional cost of electricity generated in environmentally-sound processes. In this paper, we report the results of a survey using the contingent valuation method (CVM) of the willingness of Japanese households to pay more, in the form of a flat monthly surcharge, for renewable energy. The median value of willingness to pay for renewable energy by Japanese households is estimated at about 2000 yen (around 17 US$ with the exchange rate 115 yen/US$) per month per household. (Author)
This user's guide describes BNW-III, a computer code developed by the Pacific Northwest Laboratory (PNL) as part of the Dry Cooling Enhancement Program sponsored by the US Department of Energy (DOE). The BNW-III code models a modular dry/wet cooling system for a nuclear or fossil fuel power plant. The purpose of this guide is to give the code user a brief description of what the BNW-III code is and how to use it. It describes the cooling system being modeled and the various models used. A detailed description of code input and code output is also included. The BNW-III code was developed to analyze a specific cooling system layout. However, there is a large degree of freedom in the type of cooling modules that can be selected and in the performance of those modules. The costs of the modules are input to the code, giving the user a great deal of flexibility.
The objective of the three-phase Holly Sugar Geothermal Project was to replace fossil fuels with geothermal energy for sugar beet processing at the Holly Sugar plant located in Brawley, California, in a technically straightforward, economically sound and environmentally acceptable manner. The first phase of the project, discussed in this final report, encompassed the design and analysis of a geothermal industrial heat system for Holly Sugar and addresses: (1) assessment of the geothermal resource; (2) development of a preliminary system design; (3) analysis and publication of an environmental analysis and monitoring report; (4) preliminary economic analyses; (5) dissemination of project related information; and (6) the development of a proposal for the follow-on phases.
This quarterly report covers activities of the Two-Stage, Close- Coupled Catalytic Liquefaction of Coal program during the period January 1,--March 31,1992, at Hydrocarbon Research, Inc. in Lawrenceville and Princeton, New Jersey. This DOE contract period is from October 1, 1988 to September 30, 1992. The overall purpose of the program is to achieve higher yields of better quality transportation and turbine fuels and to lower the capital and production costs in order to make the products from direct coal liquefaction competitive with other fossil fuel products. The quarterly report covers work on Laboratory Testing, PDU Activities and Administration.
The need for alternative energy increases steadily???especially due to the climate change and the limited availability of fossil fuels. Geothermal power uses the intrinsic heat which is stored in the accessible part of the Earth???s crust. Its importance among the renewable energy resources originates from the almost unlimited energy supply of the Earth and its independence from external influences such as seasonal or even daily climatic variability. Nevertheless, there are risks which have to be assessed. From a mathematical point of view there are four building blocks of the characterization of deep geothermal systems: seismic exploration, gravimetry, modeling transport processes, and modeling the stress field. In particular, local depletion poses a significant risk during the industrial...
The fossil fuel consumption and pollutant emissions in a coal fired fluidized bed boiler could be reduced by biomass pyrolysis gas reburning. The influence of three kinds of biomass pyrolysis gases on the emission of N2O in a laboratory scale fluidized bed was investigated using the mechanism of GRI3.0 in this paper. The results showed that: the effect of sawdust pyrolysis gas reburning on N2O was more significant than that of rice husk and orange peel under the same conditions; the increase of initial oxygen content from 1% to 8% in flue gas would restrain the decomposition of N2O; the N2O decomposition was enhanced by increasing reaction temperature from 1073.15 K to 1323.15 K, and the decomposition rate may reach 99% at 1223.15 K.
Some aspects of the PSO scheme for natural gas are examined critically. Two central arguments used for justifying the PSO subsidy scheme of natural gas and its distribution are reviewed; these include the 'smallholder argument' and the 'environmental argument'. The 'smallholder argument' claims that since Norway has the natural gas resources, it should also make use of the natural gas in the country, and not simply send the raw material to other countries. The 'environmental argument' states that natural gas compared to other fossil fuels such as coal and fuel oil, is a far cleaner alternative, thus an environmental-friendly alternative entitled to financial support. The arguments are critically examined by the author (ml)
Storage of thermal energy in aquifers has obvious benefits of saving energy and decreasing the consumption of fossil fuels. However, aquifer thermal energy storage (ATES), which involves groundwater aquifers as the storage medium for heat or chill, impinges on the environment. A literature review of pertinent microbiology publications (Hicks and Stewart, 1988) identified the potential for the interaction of ATES systems and microbiological processes to create a source of infectious diseases and the potential for damage to the environment. In addition, the review identified a potential for microbiological processes to develop conditions that would interfere with the operation of an ATES system. As a result of this research effort, investigators from Finland, Germany, Switzerland, and the United States have examined several ATES systems in operation and have observed that the ATES systems studied do not contribute to infectious disease transmission, do not adversely ...
Storage of thermal energy in aquifers has obvious benefits of saving energy and decreasing the consumption of fossil fuels. However, aquifer thermal energy storage (ATES), which involves groundwater aquifers as the storage medium for heat or chill, impinges on the environment. A literature review of pertinent microbiology publications (Hicks and Stewart, 1988) identified the potential for the interaction of ATES systems and microbiological processes to create a source of infectious diseases and the potential for damage to the environment. In addition, the review identified a potential for microbiological processes to develop conditions that would interfere with the operation of an ATES system. As a result of this research effort, investigators from Finland, Germany, Switzerland, and the United States have examined several ATES systems in operation and have observed that the ATES systems studied do not contribute to infectious disease transmission, do not adversely ...
The ever increasing fossil fuel usage and cost, environmental concern has forced the world to look for alternatives. Straight vegetable oils in compression ignition engine are a ready solution available, however, with certain limitations and with some advantages as reported by many researchers. A comprehensive and critical review is presented specifically pertaining to straight vegetable oils usage in diesel engine. A detailed record of historical events described. Research carried out specifically under Indian conditions and international research work on the usage of straight vegetable oils in the diesel engine is separately reviewed. Many researchers have reported that straight vegetable oils in small percentage blends with diesel when used lower capacity diesel engines have shown great...
This third Missouri River Basin Commission report on Status of Electric Power in the Missouri River Basin provides information on the status of electric power generation, future needs, and potentials for meeting these needs. Information for this 1980 update is based upon available published information up to and including December 31, 1979. State and federal members of the Missouri River Basin Commission provided information for sections of the report and on legislative activities. Information is included on the planning and projected costs of hydro, nuclear and fossil-fuel power plants, pumped-storage plants, transmission systems, projected power demands, the environmental, socio-economic-cultural impacts of electric power generation, and regulations affecting energy development. (LCL)
In order to promote uniformity between jurisdictions, the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) has developed the National Directory for Radiation Protection, which is a regulatory framework that all Australian governments have agreed to adopt. There is a large and diverse range of industries involved in mining or mineral processing, and the production of fossil fuels in Australia. Enhanced levels of naturally occurring radionuclides can be associated with mineral extraction and processing, other industries (e.g. metal recycling) and some products (e.g. plasterboard). ARPANSA, in conjunction with industry and State regulators, has undertaken a review and assessment of naturally occurring radioactive material (NORM) management in Australian industries. This rev...
Research facilities and personnel in high efficiency separation processes for carbon dioxide removal from industrial sources, such as fossil fuel fired power stations, goal gasification plants, and hydrogen production units for enhanced oil recovery applications at the University of Regina were described. A brief summary of current projects, such as the determination of CO{sub 2} absorption capacity of sterically hindered amines, the formulation of high CO{sub 2} absorption capacity solvents, the search for high performance absorbers and regenerators, studies on material corrosion, and optimization and cost studies of co-production of CO{sub 2} and electricity, was also provided.
Role of microelements in coal in connection with their combustion in power stations, gasification and hydrogenation is discussed from the standpoint of environmental pollution and effects on technological parameters. In the wastes from fossil-fuel power stations there are biogenic and toxic elements (Be, B, Pb, etc.) present, which eventually go into the soil. Analyses showed that coal from the Kuznetsk, Donetsk, Ehkibastuz and Kansk-Achinsk basins which are used for power, have a relatively low level of biogenic and toxic microelements, e.g. Ba, B, Mn, Pb, Co, Ni, V, Cu, Y. Coal reactivity in gasification and hydrogenation is discussed. The catalytic effect of several microelements in coal gasification and hydrogenation is established. A geochemical multiplicative indicator is presented which makes quantitative evaluation of the suitability of coals for hydrogenation possible. 17 references.
The PAH (polycyclic aromatic hydrocarbons) concentration in coastal zones in the Arctic were studied. Assessment in remote areas is difficult because PAHs contamination from fossil fuel discharges and combustion can be masked by PAHs from natural sources, such as oil seeps, bitumens and forest fires. It is believed that the most important source of anthropogenic PAHs in the Arctic is the long range transport of combustion emissions. A comparison study of PAH distribution between the Beaufort Sea and the Barents Sea led to the interpretation of PAH distributions in terms of potential sources and their geochemistry. PAH concentrations in the Barents Sea sediments were found to be 2 to 20 times lower than in the Beaufort Sea sediments; they are believed to be from anthropogenic sources. In the Beaufort Sea the sediments were found to have been derived from natural sources. 7 refs., 2 figs.
The production of atmospheric pollutants in combustion processes depends on plant characteristic, combustion conditions and fuel quality. The influence of fuel quality on the emission of sulphur oxides, nitrogen oxides, carbon monoxide, dust and carbon dioxide and on the emission of some toxic pollutants, such as heavy metals and polycyclic aromatic hydrocarbons, is analysed. The comparison between the emission limits, fixed by the Italian legislation, and the uncontrolled pollutant emissions, produced by fossil fuel combustion in power plants and industrial use, shows that, in order to comply with the limits, a reduction of pollutant emissions is required through the use of abatement systems and cleaner fuels where natural gas has a primary role. The use of cleaner fuels is particularly required in heating plants and appliances for the residential sector, where the development of new gas technologies further increases the environmental advantages of natural gas in ...
Introduction Alternative ways and means of transportation are necessary in order to reduce the environmental impacts of mobility. In the recent years, biofuels were first seen as a main option and then LCA showed also possible hazards of this development. Recently, public interest is rapidly shifting towards electromobility. Therefore it is necessary to also gain better knowledge about the environmental impacts of this technology. This includes a modelling of the pathways of the necessary increase in electricity supply and an appropriate modelling of battery manufacture. Summary of data presented At this forum most recent results of life cycle assessment studies of electric car driving compared to driving fossil- and agro-fuelled cars were presented. The environmental performance of indivi...
A process and apparatus for the production of coke, asphalt and jet fuel m a feed of fossil fuels containing volatile carbon compounds therein is disclosed. The process includes the steps of pyrolyzing the feed in an entrained bed pyrolyzing means, separating the volatile pyrolysis products from the solid pyrolysis products removing at least one coke from the solid pyrolysis products, fractionating the volatile pyrolysis products to produce an overhead stream and a bottom stream which is useful as asphalt for road pavement, condensing the overhead stream to produce a condensed liquid fraction and a noncondensable, gaseous fraction, and removing water from the condensed liquid fraction to produce a jet fuel-containing product. The disclosed apparatus is useful for practicing the foregoing process. the process provides a useful method of mass producing and jet fuels from materials such as coal, oil shale and tar sands.
Beaked whales (Ziphiidae) often show highly specialized features, involving bone morphology or structure, in the rostral region of their skulls. Previous studies revealed an extremely derived and peculiar histological structure in the rostrum of the extant Mesoplodon densirostris. In order to assess if this structure is a general feature of ziphiids, the swollen premaxillae of Aporotus recurvirostris, a Miocene species from the North Sea, were studied histologically. These bones are pachyostotic and strongly osteosclerotic. However, their structural organization is entirely different from that of M. densirostris rostrum: they are basically made of a non-remodeled, laminar tissue that was cyclically deposited by the periosteum. As compared to the generalized structure of the premaxillae of ...
The global interest in renewable energy is attributed to the decline in fossil fuel sources and the need for technical, economic, social and environmental sustainability. This study focused on the new techniques that have been developed for the use of biomass for energy from wood wastes from the forest-based industry. As an energy source, wood waste contributes positively to the environment by reducing environmental problems related to contamination of soil, air and water through improper disposal of waste. Biomass gasification has the advantage of converting biomass into a combustible gas that can be used for heat generation, electricity and synthesis of chemicals. Syngas produced from gasification of eucalyptus residues has significant potential, with an average High Heating Value of 6.60 MJ/m{sup 3}, and regular composition during the process, with predominance of carbon monoxide, followed by hydrogen, carbon dioxide and methane.
The primary objective of this study was to evaluate the potential environmental effects (both adverse and beneficials) of aquifer thermal energy storage (ATES) technology pertaining to microbial communities indigenous to subsurface environments (i.e., aquifers) and the propagation, movement, and potential release of pathogenic microorganisms (specifically, Legionella) within ATES systems. Seasonal storage of thermal energy in aquifers shows great promise to reduce peak demand; reduce electric utility load problems; contribute to establishing favorable economics for district heating and cooling systems; and reduce pollution from extraction, refining, and combustion of fossil fuels. However, concerns that the widespread implementation of this technology may have adverse effects on biological systems indigeneous to aquifers, as well as help to propagate and release pathogenic organisms that enter thee environments need to be resolved. 101 refs., 2 tabs.
2-methylpropan-1-ol (isobutanol) is a leading candidate biofuel for the replacement or supplementation of current fossil fuels. Recent work has demonstrated glucose to isobutanol conversion through a modified amino acid pathway in a recombinant organism. Although anaerobic conditions are required for an economically competitive process, only aerobic isobutanol production has been feasible due to an imbalance in cofactor utilization. Two of the pathway enzymes, ketol-acid reductoisomerase and alcohol dehydrogenase, require nicotinamide dinucleotide phosphate (NADPH); glycolysis, however, produces only nicotinamide dinucleotide (NADH). Here, we compare two solutions to this imbalance problem: (1) over-expression of pyridine nucleotide transhydrogenase PntAB and (2) construction of an NADH-de...
Biodiesel from non-grain feedstock has been considered as one of the proper substitutes for fossil fuels associated with a series of activities emerging in China in order to meet the resource shortage and develop the energy crops. This paper presents an ecological accounting framework based on embodied energy, emergy, and CO2 emission for the whole production chain of biodiesel made from Jatropha curcas L. (JCL) oil. The energy and materials invested in and CO2 emission from the whole process, including cropping, transportation, extraction, and production, are accounted and calculated. Also, EmCO2, the ratio of real CO2 released to the emergy-based sustainability indicator per joule biodiesel, is proposed in this paper to present a new goal function for low-carbon system optimization. Fina...
The analysis of bagasse use indicates that the production of exportable electricity from sugar cane factories in Mauritius can be increased from the current level of between 10 and 20 kWh to around 60 kWh per tonne cane crushed. If the bagasse is dried and pelletized, and cane tops and leaves (CT and L) also used, electricity production can be further increased to around 100-110 kWh per tonne of cane crushed. An economic analysis of the process shows that the cost of electricity generated within the sugar industry in Mauritius is competitive with that of electricity produced from fossil fuels. In addition, it is shown that almost twice the current annual electricity consumption, or the postulated annual electricity consumption for the year 2000, of the island can be provided by the Mauritian Sugar Industry. 10 references.
Recently it is strongly required to reduce energy consumption to cope with the global warming. Since energy consumption in commercial and residential sectors are increasing while industrial sector is almost constant in Japan, policies to lead energy conservation in urban areas is quite important. This study aims at investigating the performance of urban energy systems which install combined heat and power (CHP) as a district heating and cooling (DHC) plant and the influence of CHP on the structure of electric power systems of utilities. The behavior of energy technologies and the possibility of energy conservation are evaluated based on an optimization model with respect to total system cost. Sensitivity analysis of population allocation into urban areas indicates that fossil fuel consumption varies in the range of 10--20% compared with conventional systems.
Current decisions on greenhouse gas emissions may have effects on human well being for centuries. This project has aimed to extend the economic models designed for analyzing this particular issue. A closely related topic follows from the fact that emitting CO{sub 2} can be interpreted as a utilization of a free access resource, i.e., when countries gain from utilizing cheap fossil fuels (relative to noncarbon energy sources), the possible loss any country suffers from climate change is only a negligible fraction of the total loss of all countries. Thus, from a global point of view, the incentives for an individual country to abate emissions is low. Economic understanding of these problems calls for dynamic game-theoretical models
Thermophotovoltaic energy conversion achieves direct conversion of thermal energy to electricity without the need for complex dynamic machinery operating in one of several possible thermodynamic cycles. This paper presents an analysis of a hybrid solar thermophotovoltaic (STPV) energy conversion system in which a receiver/photovoltaic (PV) array subsystem is powered by either a solar concentrator or a fossil fuel combustion source. The overall TPV system efficiency is calculated using an appropriate selective emitter and a spectrally tuned solar cell designed to achieve maximum conversion efficiency in the narrow band emitted by the selective emitter. Two limiting cases are examined to place upper and lower bounds on system performance. The estimates of system performance are based on actual experimental data from PV cells and selective emitters.
The economy of medicinal plant production is burdened considerably by the energy costs of drying. To substitute fossil energy, a solar heated dryer was developed, taking a plastic film greenhouse as superstructure to lower the initial costs. The solar air heaters, being incorporated into the roof, consist of a black absorber tissue, which is placed between the transparent cover of the greenhouse and an insulating air-bubble foil. To obtain a modular design, the system is structured along the ridge into segments of 2 m width. Each segment forms an independent solar air heater/batch dryer unit and is operated by a fan with a power consumption of 500 W. A prototype was tested in Yugoslavia, drying mint, sage and hops. (author).
The Consortium for Fossil Fuel Liquefaction Science (CFFLS) is a research consortium that includes five universities and a state energy laboratory. The membership is comprised of Auburn University, the University of Kentucky, the University of Pittsburgh, the University of Utah, West Virginia University, and the Kentucky Energy Cabinet Laboratory. The Consortium was formed in 1984 in response to the concern of the faculty and scientists at these institutions over the decline of coal liquefaction research in the United States, particularly long-range, basic research. Significant progress towards these goals was made in the current contract period. Major research accomplishments are presented on coal desulfurization, coprocessing, pyrolysis, enhanced reactivity, characterization, resource evaluation and database development. 108 refs., 90 figs., 38 tabs.
For the conversion of thermal energy into electric energy in modern condenser power plants, according to the way of steam generation, two different types of power stations are built: power stations for fossile fuels and nuclear power stations. Also two classes of steam turbines were developed, corresponding to the two power station types, whose steam conditions, by experience and extensive calculations of economy, were determined so that a minimum of power generating cost will result. The two classes, the HMN and the SN series, are composed according to the modular system and designed in such a manner that with a small number of standard components, steam turbines for the power range between 100 and 2,500 MW can be built. (orig.).
This article reports on the operation of Fibrowatt's third chicken waste-fuelled power plant at Thetford in Norfolk, UK. Details are given of the plant which started operation in October 1998, the chicken litter fuel, the spiral screw fuel feeders, the Detroit Stoker grate and spreader stokers which ensure the fuel is burnt mid-air, the production of fertiliser from the ash, and fluegas emission control using cyclones, a baghouse and lime addition to neutralise acid gas. The economics of the project, and the support for the renewable electricity generation under the UK government's Non-Fossil Fuel Obligation are discussed. A site plan of the Thetford plant and a flow diagram of the process are provided.
In certain regions of the sea floor, water and methane from organic depositions have turned into a burnable form of ice, i.e. methane hydrates which contain more stored energy than all fossil fuel reserves. If they should desintegrate as a result of global heating, methane will be released and will contribute to further global heating. [Deutsch] Im Boden bestimmter Meeresregionen haben sich Wasser und Methan aus organischen Ablagerungen zu einer brennbaren Form von Eis vereinigt. Diese Methanhydrate speichern mehr Energie als alle fossilen Brennstoffvorraete. Wenn sie sich bei einer globalen Erwaermung zersetzen, koennte das entweichende Methan als Treibhausgas die Erde noch mehr aufheizen. (orig.)
Determination of the radiocarbon (14C) content of airborne particulate matter yields insight into the proportion of the carbonaceous material derived from fossil and contemporary carbon sources. Daily samples of PM2.5 were collected by high-volume sampler at an urban background site in Birmingham, UK, and the fraction of 14C in both the total carbon, and in the organic and elemental carbon fractions, determined by two-stage combustion to CO2, graphitisation and quantification by accelerator mass spectrometry. OC and EC content was also determined by Sunset Analyzer. The mean fraction contemporary TC in the PM2.5 samples was 0.50 (range 0.27-0.66, n=26). There was no seasonality to the data, but there was a positive trend between fraction contemporary TC and magnitude of SOC/TC ratio and fo...
As coal becomes more and more important as a power plant fuel in this time of energy shortage and the combustion of high-sulfur coals that would impair air quality, efforts have been made to devise efficient processes to control sulfur dioxide emission. Besides desulfurization before combustion, flue gas desulfurization is considered the most promising method that could also be applicable to all other fossil fuels. In this article, the flue gas desulfurization processes are briefly reviewed, and processes with highest use and with high potential for future use are compared from technical and economical points of view. In the selection of a desulfurization process, it is very important to consider the capacity of the plant, fuel type and fuel-to-sulfur ratio, availability and price of the reagent to be used, type, price, and market of side products, disposal problems of wastes, and environmental factors.
Progress made during the first phase effort of the Solar-Thermal Full-System Experiment is summarized. This is one of a number of projects in the Solar-Thermal Subprogram involved with the development of solar central receiver hardware and systems for future use by utilities. The main emphasis is on systems that use Brayton-Cycle (gas turbine) equipment. The project summarized involves the planning and design of a complete Brayton-Cycle solar central receiver experimental system that would include all components of a commercial-size electric utility solar power plant. The objective of the overall project is to demonstrate the technical feasibility of a complete Brayton-Cycle, solar-fossil hybrid central receiver system. Major objectives of the Phase I effort summarized are to plan and design the experiment in detail and to organize a utility Test and Operating Group that would be directly involved in the development and operation of the experiment. (LEW)
To estimate the waste management needs of a fusion power reactor, a scheme for handling radioactive waste from a fusion plant has been devised. The handling scheme proceeds with radioactive waste, primarily from blanket replacement, being stored on-site; waste in cooled and shielded casks is then isolated off-site; finally, the materials are recycled. Using activities and component lifetimes supplied by designers, several conceptual fusion power reactors have been analyzed and their waste streams compared to fission reactors with regard to total activity, specific activity, and lifetimes of activity.
To estimate the waste management needs of a fusion power reactor, a scheme for handling radioactive waste from a fusion plant has been devised. The handling scheme proceeds with radioactive waste, primarily from blanket replacement, being stored on-site; waste in cooled and shielded casks is then isolated off-site; finally, the materials are recycled. Using activities and component lifetimes supplied by designers, several conceptual fusion power reactors have been analyzed and their waste streams compared to fission reactors with regard to total activity, specific activity, and lifetimes of activity.
Comments are made on the Public Inquiry into CEGB's proposal to construct a pressurized water reactor (PWR) at Sizewell, UK. Aspects discussed include: time elapsed and its possible effect on the result; economics of nuclear power plants compared with coal-fired power plants; changes in real sterling/dollar exchange rates; effect of mineworkers' strike; the UK electric power generating system; AGR reactors compared with PWR reactors; extension of Magnox reactor life; radioactive waste management; political decisions.
Utility interest has recently increased in potential future nuclear units that combine the characteristics of smaller size, greater simplicity, and more passive safety features. In response to such interest, General Electric (GE) began development in 1982 of a 600-MW(electric) reactor with simplified power generation and safety systems. This paper provides an overview of the simplified boiling water reactor (SBWR) design, with emphasis on the thermal-hydraulic aspects of the design. The SBWR is a natural circulation reactor requiring no pumps to circulate the water through the core.
Nuclear physics parameters of the Wolsung CANDU-PHW reactor are computed by use of the PHWCELL computer code that is an improved version of LATREP. The PHWCELL code mainly computes cell parameters of heavy water moderated reactors, and modeling scheme of heavy water reactor cell calculations has been developed with the PHWCELL computer code. The reactor operating conditions considered in the study are cold zero power (CZP) and hot full power (HFP) with equilibrium poison. The cell parameters are also computed as a function of fuel burnup and the numerical results are compared with the results in PSR of the Wolsung unit and in the previous study. (author).
The risk analysis was carried out in consideration of conditions prevailing at the Kalkar site analogous to the investigations in phase A of DRS (German Reactor Study). Earthquake design loads include the probabilities of upper deviations of the site intensities to be expected. The calculations of dynamic loads for select buildings are made using models and computational methods. Component analyses were performed analogous to DRS for the supports of large components, supports of the roof construction of the reactor building taking into account support reserves due to plastic work capacity, wall disks in steam generator buildings and switchboard plant buildings. (DG).
Object: To limit the discharge amount of reactor water in a primary system at the time of scram to prevent excessive outflow of reactor water outside the system. Structure: A signal from an upper limit position indicator detects the fact that control rods are completely inserted when the reactor is urgently stopped and the detection signal causes a valve in an outflow line of the discharge water from a control rod driving mechanism to be closed to limit the amount of discharge flown into the scram discharge vessel, thus preventing outflow of reactor water in the primary system after the scram has been initiated. (Kamimura, M.).
Modelling the behaviour of fission product (FP) in a nuclear reactor coolant system (RCS) undergoing a hypothetical severe accident is an important step in the evaluation of radioactive release outside a nuclear power plant. This paper scrutinize Small Break LOCA sequence for WWER1000 reactor in order to investigate the possible paths for release of FP from fuel pallets to the reactor containment. Contemporaneous computer code for simulation of RCS will be use for the analysis. The results from analysis of fuel damage and release of FP trough the break of cold leg are present. (author)
... in the design of such devices as fusion reactors, magnetohydrodynamic generators, magnetically levitated vehicles, magnetic forming devices, and ...
Since January, 1981, the project of development of nuclear fuel fabrication technology for Wolsung reactor (CANDU type) was undertaken by KAERI(Korea Advanced Energy Research Institute) and successfully fulfilled with loading 24 fuel bundles made by KAERI in Wolsung reactor in September, 1984. On the basis of this accumulated technology and experience, mass production plan to supply all the nuclear fuels for Wolsung reactor is under way. In this presentation, the Korean experience in the development of the nuclear fuel fabrication technology, safety and performance evaluation of KAERI fuel and the results of irradiation of KAERI fuels in Wolsung reactor will be described.
Since January, 1981, the project of development of nuclear fuel fabrication technology for Wolsung reactor (CANDU type) was undertaken by KAERI(Korea Advanced Energy Research Institute) and successfully fulfilled with loading 24 fuel bundles made by KAERI in Wolsung reactor in September, 1984. On the basis of this accumulated technology and experience, mass production plan to supply all the nuclear fuels for Wolsung reactor is under way. In this presentation, the Korean experience in the development of the nuclear fuel fabrication technology, safety and performance evaluation of KAERI fuel and the results of irradiation of KAERI fuels in Wolsung reactor will be described.
In this paper the diffusion of tritiated water vapor into concrete walls is studied to evaluate tritiated water retention capacity of a fusion reactor concrete building. Using a model of the tritiated water diffusion determined form experimental results, depth profiles of tritiated water in concrete are calculated in the case of being exposed to air containing tritiated water vapor during the normal operational condition of a fusion reactor. A 0.5-m-thick concrete is sufficient for reactor hall walls from a viewpoint of the tritium containment.
In this paper the diffusion of tritiated water vapor into concrete walls is studied to evaluate tritiated water retention capacity of a fusion reactor concrete building. Using a model of the tritiated water diffusion determined form experimental results, depth profiles of tritiated water in concrete are calculated in the case of being exposed to air containing tritiated water vapor during the normal operational condition of a fusion reactor. A 0.5-m-thick concrete is sufficient for reactor hall walls from a viewpoint of the tritium containment.
Purpose : To obtain an emergency core cooling device in a FBR type reactor by utilizing heat pipes which are not actuated at usual operation condition but actuated reliably upon emergency. Constitution : A system for injecting heat medium into heat pipes is provided. By injecting the heat medium into the heat pipes upon emergency to actuate the heat pipes, the reactor core is cooled. During normal reactor operation, the inside of the heat pipes is evacuated from a vacuum pump and no heat medium is filled therein, whereby unnecessary heat loss during the normal operation can be prevented. (Ikeda, J.).
Conceptual fusion reactor studies over the past 10 to 15 years have projected systems that may be too large, complex, and costly to be of commercial interest. One main direction for improved fusion reactors points towards smaller, higher-power-density approaches. First-order economic issues (i.e., unit direct cost and cost of electricity) are used to support the need for more compact fusion reactors. A generic fusion physics/engineering/costing model is used to provide a quantiative basis for these arguments for specific fusion concepts.
In 1980 Sasol completed its very large coal conversion complex, Sasol Two and Three in South Africa. This complex, the largest coal-to-liquids facility in the world, utilizes Sasol's proprietary Fischer-Tropsch technology, the Synthol Process. The two key elements of the Synthol Process are its catalyst and its unique fluidized bed reactor, the Synthol Circulating Fluidized Bed Reactor. Details on the catalytic aspects and reaction mechanism have been given elsewhere. In this paper, the history of the development of the reactor is discussed.
The addition of ZnO, depleted in the Zn-64 isotope, to the water of boiling water nuclear reactors lessens the accumulation of Co-60 on the reactor interior surfaces, reduces radioactive wastes and increases the reactor service-life because of the inhibitory action of zinc on inter-granular stress corrosion cracking. To the same effect depleted zinc in the form of acetate dihydrate is used in pressurized water reactors. Gas centrifuge isotope separation method is applied for production of depleted zinc on the industrial scale. More than 20 years of depleted zinc application history demonstrates its benefits for reduction of NPP personnel radiation exposure and combating construction materials corrosion.
This paper reports that, to obtain better simulation results for a Canada deuterium uranium (CANDU) reactor operation, a new simulation method is developed that uses actual detector readings as a correction factor. Detector readings from a CANDU reactor are used to correct the calculated flux distribution during core calculation iterations. A suitable function is found to describe the relationship between the detector flux and the fluxes of mesh points around the detector. The new simulation method is tested by performing numerical calculations for the Wolsung reactor (a CANDU-600). The results show that the new method predicts the core state more accurately with fewer iterations.
The Fast Flux Test Facility near Richland, Washington, utilizes computer control for reactor refueling and other related core component handling and processing tasks. The computer controlled tasks described in this paper include core component transfers within the reactor vessel, core component transfers into and out of the reactor vessel, remote duct measurements of irradiated core components, remote duct cutting, and finally, transferring irradiated components out of the reactor containment building for off-site shipments or to long term storage. 3 refs., 16 figs.
Progress in the construction of Candu reactors at home and abroad is surveyed. Some A.E.C.L. research projects are also mentioned. During 1979, Candu reactors again showed their superior capacity factors, four of them being among the ten most reliable reactors in the world. Progress in construction at Pickering B, Bruce B, Point Lepreau, Gentilly-2, Darlington, Wolsung (Korea), Cordoba (Argentina), and Cernavoda (Romania) is recounted. In 1979, it was unfortunately necessary to replace installed steam generators at Pickering B, Bruce B, Point Lepreau and Gentilly-2. At Wolsung, the reactor was pre-assembled before installation, which is a new technique. (N.D.H.).
... be easily replaceable, and its compartment or container ... in a simple, efficient manner for storage or disposal. ... and enters the reactor at approximatel ...
Various schemes of cooling have been investigated for the purpose of assessing potential benefits on the operational characteristics of the Syrian MNSR reactor. A detailed thermal hydraulic model for the analysis of MNSR has been developed. The analysis shows that an auxiliary cooling system, installed in the pool which surrounds the lower section of the reactor vessel, will significantly offset the consumption of excess reactivity due to the negative reactivity temperature coefficient, Hence, the maximum operating time of the reactor is extended. Compared with experimental data, the suggested model proves to be valid for the analysis of MNSR behavior under both steady state and transient conditions. (author)
A novel device called the gas expansion model (GEM) is being developed at the Hanford Engineering Development Laboratory for testing in the 400-MW(th) fast flux test facility (FFTF) reactor. Incorporation of the GEM into liquid-metal reactor designs is intended to measurably contribute to the achievement of inherent safety, by allowing the reactor to passively shut down even in the extremely remote (hypothetical) event of an unprotected (no scram) loss-of-flow accident. The purpose of this paper is to describe the GEM and present predictive analyses of the effectiveness of the device during unprotected loss-of-flow experiments in the FFTF.
A novel device called the gas expansion model (GEM) is being developed at the Hanford Engineering Development Laboratory for testing in the 400-MW(th) fast flux test facility (FFTF) reactor. Incorporation of the GEM into liquid-metal reactor designs is intended to measurably contribute to the achievement of inherent safety, by allowing the reactor to passively shut down even in the extremely remote (hypothetical) event of an unprotected (no scram) loss-of-flow accident. The purpose of this paper is to describe the GEM and present predictive analyses of the effectiveness of the device during unprotected loss-of-flow experiments in the FFTF.
This is the sixth book on reactor materials published under sponsorship of the Naval Reactors Office of the United States Department of Energy, formerly the United States Atomic Energy Commission. This book presents a comprehensive compilation of the most significant properties of thorium dioxide, much like the book Uranium Dioxide: Properties and Nuclear Applications presented information on the fuel material used in the Shippingport Pressurized Water Reactor core.
This document presents the integrated reactors concepts by a presentation of four reactors: PIUS, SIR, IRIS and CAREM. The core conception, the operating, the safety, the economical aspects and the possible users are detailed. From the performance of the classical integrated PWR, the necessity of new innovative fuels utilization, the research of a simplified design to make easier the safety and the KWh cost decrease, a new integrated reactor is presented: SCAR 600. (A.L.B.)
The heavy water reactor such as Wolsung No.1 and No.2 has a purification system to purify the reactor coolant. The control system regulates the coolant temperature to protect the ion exchanger. After the fuel exchanges of operating plant, the increase of the coolant pressure makes the purification temperature control difficult. In this paper, the controllability of the control dynamics of the purification system was analysed and the optimal parameters were proposed. To reduce the effects of the flow disturbance, the feedforward control structure was proposed and analysed.
The status of neutron activation cross sections for some threshold reactions important for reactor materials dosimetry is reviewed. An attempt is made to understand and explain discrepancies between integral and differential data, using recent available experimental results. The importance of standard and benchmark neutron fields for testing differential data for reactor dosimetry is emphasized and the Interlaboratory Reaction Rate (ILRR) program, as well as a similar program pursued by the IAEA, are briefly described.
The availability of reactor-produced radioisotopes in the United States for use in medical research and nuclear medicine has traditionally depended on facilities which are an integral part of the US national laboratories and a few reactors at universities. One exception is the reactor in Sterling Forest, New York, originally operated as part of the Cintichem (Union Carbide) system, which is currently in the process of permanent shutdown. Since there are no industry-run reactors in the US, the national laboratories and universities thus play a critical role in providing reactor-produced radioisotopes for medical research and clinical use. The goal of this survey is to provide a comprehensive summary of these production capabilities. With the temporary shutdown of the Oak Ridge National Laboratory (ORNL) High Flux Isotope Reactor (HFIR) in November 1986, the ...
Field reversed configuration (FRC) is a prospective high ? magnetic system for high efficiency D- 3He fusion reactor. Self-consistent FRC plasma profiles and static electric field for reactor calculations are discussed in framework of the model including flow equilibrium and collisionless transport equations. The extrapolations to reactor regimes of plasma confinement scaling laws are considered.
As part of a handbook on the efficient use of energy a chapter is included which is intended to give an appreciation of the principles and problems involved in the generation of nuclear power. The subject is discussed under the following headings: introductory nuclear physics; basic reactor physics; thermal reactors; fast reactors; fuel reserves and utilization; environmental considerations; nuclear fusion. (U.K.).
High pressure experiments in a jet-stirred reactor have been performed to study the NO{sub x} formation in lean premixed combustion of methane/air mixtures. The experimental results are compared with numerical predictions using four well known reaction mechanisms and a model which consists of a series of two perfectly stirred reactors and a plug flow reactor. (author) 2 figs., 7 refs.
The European Research and Development Program on decay heat removal by natural convection for the European Fast Reactor (EFR) covers the calculational methods and the model experiments performed for code validation. The studies concentrate on important physical effects of the cooling modes within the primary system and the direct reactor cooling circuits and include fundamental tests as well as reactor experiments. (author)
Wolsung nuclear power plant has experienced four occasions of reactor shutdown owing to heavy water leaks since its commercial operation. Among these heavy water leaks, only one case was acute and brought about reactor shutdown but the other cases listed below were chronic and repaired after manual reactor shutdown. (author). 4 tabs., 10 figs.
To seek for a promising concept of a heavy liquid metal coolant (HLMC) fast reactor plant, Japan Nuclear Cycle Development Institute (JNC) and the electric utilities conducted conceptual design study on various types of plant concepts and compared these concepts based on technical feasibility and economical perspective. The Pb-Bi cooled complete natural circulation reactor concept may attain high safety level and construction cost goal (Yen 200,000/kWe) (authors)
The Department of Energy Office of Fissile Materials Disposition (DOE/MD) initiated a detailed analysis activity to evaluate each of ten plutonium disposition alternatives that survived an initial screening process. This document, Volume 2 of a four volume report, summarizes the results of these analyses for the CANDU reactor based plutonium disposition alternative.
The concept of preliminary transmutation of minor actinides before placement to the long-term storage is considered. The purpose of such preliminary transmutation before ultimate storage is to incinerate a part of actinides and to transform another part into new actinides providing low level of radiotoxicity accumulated in the storage. Modes of transmutation in reactors of PWR, PHWR (CANDU), and Superfenix types are compared. Among power reactors, heavy-water PHWR type reactor is most acceptable for preliminary transmutation. (author)
The Fast Flux Test Facility (FFTF) bottom-loading transfer cask (BLTC) system is designed to provide ex-vessel fuel transfers of irradiated reactor components between the reactor containment building and the LMFBR shipping cask in the reactor service building. This system is being procured from National Lead Industries, Wilmington, Delaware, under management of Aerojet Manufacturing Company.
Afterheat represents an important consideration in design of conceptual fusion power reactors, particularly during normal or unplanned shutdown. Afterheat calculations have been undertaken for various generic designs, but with special reference to the Culham DEMO reactor. These calculations have included the redistribution of heating by gamma ray transport. Selected temperature response calculations have been undertaken. (author).
The Integral Fast Reactor is an innovative liquid metal reactor concept that is being developed by Argonne National Laboratory. It takes advantage of the properties of metallic fuel and liquid metal cooling to offer significant improvements in reactor safety, operation, fuel cycle economics, environmental protection, and safeguards. The plans for demonstrating the IFR fuel cycle, including its waste processing options, by processing irradiated fuel from the Experimental Breeder Reactor-II fuel in its associated Fuel Cycle Facility have been developed for the first refining series. This series has been designed to provide the data needed for the further development of the IFR program. An important piece of the data needed is the recovery of TRU material during the reprocessing and waste operations.
The Integral Fast Reactor is an innovative liquid metal reactor concept that is being developed by Argonne National Laboratory. It takes advantage of the properties of metallic fuel and liquid metal cooling to offer significant improvements in reactor safety, operation, fuel cycle economics, environmental protection, and safeguards. The plans for demonstrating the IFR fuel cycle, including its waste processing options, by processing irradiated fuel from the Experimental Breeder Reactor-II fuel in its associated Fuel Cycle Facility have been developed for the first refining series. This series has been designed to provide the data needed for the further development of the IFR program. An important piece of the data needed is the recovery of TRU material during the reprocessing and waste operations.
One of the characteristic safety features of a pool type research reactor is a safety flapper valve. The valve enables natural convection cooling mechanism in one of the following events. (a) Opening flapper valve promote decay heat removal following reactor's shutdown. (b) Also the valve is gravity driven. There is a possibility that the valve fails to open when it is required to do so. In the present paper the cooling characteristics of the core are analyzed for this event. A steady state study was performed for 5 MW power and 18 FE following a reactor shutdown. It is shown that enough margin exists to assure adequate reactor core cooling should the safety flapper valve fails to open. (authors)
Conceptual fusion reactor studies over the past 10-15 yr have projected systems that may be too large, complex, and costly to be of commercial interest. One main direction for improved fusion reactors points toward smaller, higher-power-density approaches. First-order economic issues (i.e., unit direct cost and cost of electricity) are used to support the need for more compact fusion reactors. The results of a number of recent conceptual designs of reversed-field pinch, spheromak, and tokamak fusion reactors are summarized as examples of more compact approaches. While a focus has been placed on increasing the fusion-power-core mass power density beyond the minimum economic threshold of 100-200 kWe/tonne, other means by which the overall attractiveness of fusion as a long-term energy source are also addressed.
This paper discusses how the U.S. Liquid Metal Reactor Development Program has been restructured to carry out R and D on advanced reactor technology. The program gives particular emphasis to improvements to reactor safety. The new directions are based on the technology of the integral fast reactor (IFR). Much of the basis for superior safety performance using IFR technology has been experimentally verified and aggressive programs continue in EBR-II and TREAT. Progress has been made in demonstrating both the metallic fuel and the new electrochemical processes of the IFR. The FFTF facility is converting to metallic fuel; however, FFTF also maintains a considerable U.S. program in oxide fuels. In addition, generic programs are continuing in steam generator testing, materials development, and with international cooperation, aqueous reprocessing.
The Advanced MAPLE is a research reactor design under development as a high-flux neutron source. The main performance goals for the reactor are a high peak thermal neutron flux in a heavy-water reflector tank, and a high average fast neutron flux in a central irradiation facility, with a maximum linear fuel rod rating of less than 120 kW/m. This study investigated the neutronic and reactor design consequences of the use of H_2O coolant as opposed to D_2O. The neutronics results, and several other considerations, indicate that H_2O coolant has a number of advantages. It is suggested that the H_2O coolant option be considered in the design of the Advanced MAPLE reactor. (L.L.) 9 refs., 4 figs., tab.
A new chemical reactor, the Open Plate Reactor, is being developed by Alfa Laval AB. It combines good mixing with high heat transfer capacity into one operation. With the new concept, highly exothermic reactions can be produced using more concentrated reactants. A nonlinear model of the reactor is derived and a control system is developed. For temperature control a cooling system is designed and experimentally verified, which uses a mid-ranging control structure to increase the operating range of the hydraulic equipment. A Model Predictive Controller is proposed to maximize the conversion under hard input and state constraints. An extended Kalman filter is designed to estimate unmeasured concentrations and parameters. Simulations show that the designed control system gives high conversion ...
The PERMCAT is a membrane reactor proposed for processing fusion reactor plasma exhaust gas: tritium removal is obtained by isotopic swamping operating in counter-current mode. In this work, a membrane reactor using a permeator tube of length about 500 mm produced via diffusion welding of Pd-Ag thin foils is described. An appropriate mechanical design of the membrane module has been developed in order to avoid any significant compressive and bending stresses on the very long and thin wall permeator tube: two expanded bellows have been applied to the Pd-Ag tube, so that it has been pre-tensioned before operating. The elongation of the metal permeator under hydrogenation has been theoretically estimated and experimentally verified for properly designing the membrane reactor.
SMART (System-Integrated Modular Advanced Reactor) is a first-of-the-kind integral reactor with 330 MW thermal power under active development by Korea Atomic Energy Research Institute (KAERI) for power generation and seawater desalination. SMART employs various design features that are not typically found in other nuclear power plants. Examples include a unique passive residual heat removal system (PRHRS), and enclosure of a pressurizer, eight helical steam generators, and eight canned reactor coolant pumps inside the reactor pressure vessel. This paper presents risk insights on the SMART reactor gained during the development of a regulatory PSA model by Korea Institute of Nuclear Safety (KINS)
Purpose: To stably control the reactor water level so as not to cause excess water feeding in a BWR type reactor. Constitution: A flow control valve is disposed to the exit of a feedwater pump for a nuclear reactor and the valve is controlled by a flow regulator to maintain the water level constant in the reactor. A signal from a water level controller is inputted to the flow regulator to thereby control the flow rate control valve. In this case, the flow regulator remains in a saturated state just after the starting of the feedwater pump, in which the pump flowrate is at 100% to result in an excess water feeding condition. In view of the above, a feedback circuit is provided to the flow regulator so that the saturated state is eliminated and the water feeding can be controlled directly from the water level controller. (Kamimura, M.).
As an integral part of the Fast Test Reactor Vibration Program for Reactor Internals, the flow-induced vibrational characteristics of scaled Fast Test Reactor core internal and peripheral components were assessed under scaled and simulated prototype flow conditions in the Hydraulic Core Mockup. The Hydraulic Core Mockup, a 0.285 geometric scale model, was designed to model the vibrational and hydraulic characteristics of the Fast Test Reactor. Model component vibrational characteristics were measured and determined over a range of 36 percent to 111 percent of the scaled prototype design flow. Selected model and prototype components were shaker tested to establish modal characteristics. The dynamic response of the Hydraulic Core Mockup components exhibited no anomalous flow-rate dependent or modal characteristics, and prototype response predictions were adjudged acceptable.
A series of experiments is to be made during the acceptance test program of the Fast Flux Test Facility (FFTF) to measure the gamma ray characteristics of the Fast Test Reactor (FTR) and to establish the performance characteristics of the reactor shield. These measurements are a part of the FFTF Reactor Characterization Program (RCP). Detailed plans have been developed for these experiments. During the initial phase of the Characteristics Program, which will be carried out in the In-Reactor Thimble (IRT), both active and passive measurement methods will be employed to obtain as much information concerning the gamma ray environment as is practical. More limited active gamma ray measurements also will be made in the Vibration Open Test Assembly (VOTA).
Preparations are under way for the initial startup and testing of the Fast Flux Test Facility (FFTF). The FFTF Reactor Characterization Program is that part of the startup test plan that deals with the determination of the neutron, gamma ray and thermal hydraulic characteristics of the reactor. This program encompasses measurements and calculations of: neutron spectra, flux and fluence; gamma-ray spectra, dose and heating; fission rate distributions; capture rate distributions; other reaction rates of interest; fission product yields; and thermal hydraulic data. Measurements of these parameters will be made in the reactor core and reflectors, will extend vertically downward to the vicinity of the core support structure and upward to the top of the sodium pool, and will extend radially outward to include in-vessel fuel storage locations and the cavity between the reactor vessel and the concrete wall.
The deliveration by the Nuclear Safety Commission was commenced on the alteration in reactor installation, as it had been inquired by the Ministry of International Trade and Industry. The alteration is the additional installation of the reactor No. 2 in the Sendai Nuclear Power Station, Kyushu Electric Power Co., Inc. It is a PWR power plant with thermal output of about 2,660 MW (electric output of 890 MW), to be installed, adjoining to the reactor No. 1 of the same type and capacity under construction. In the examination by MITI, it was confirmed that the technological capabilities for its construction and operation and the radiation protection measures in power generation are both sufficient. The contents of the examination include the siting conditions, the location and construction of reactor facilities, etc. (J.P.N.).
The deliberation by the Nuclear Safety Commission was initiated on the alteration in reactor installation, as was required by the Ministry of International Trade and Industry. The alteration is the additional installation of the reactor No. 2 in the Sendai Nuclear Power Station, Kyushu Electric Power Co., Inc. It is a PWR power plant with thermal output of about 2,660 MW (electric output of 890 MW), to be installed, adjoining to the reactor No. 1 of the same type and capacity under construction. In the examination by MITI, it was confirmed that the technological capabilities for its construction and operation and the radiation protection measures in power generation are both sufficient. The contents of the examination include the siting conditions, the location and construction of reactor facilities, etc.
The swelling and in-reactor creep behaviors of the PCA alloy have been determined from the irradiation of pressurized tube specimens in the FFTF reactor. These data have been obtained to a peak neutron fluence corresponding to approximately 80 dpa in the FFTF reactor for irradiation temperatures between 400 and 750/sup 0/C. Diametral measurements performed on the unstressed specimens indicate the possible onset of swelling in the PCA alloy for irradiation temperatures between 400 and 550/sup 0/C and at a neutron fluence corresponding to approx.50 dpa. The creep data suggest a non-linear fluence dependence and linear stress dependence (for hoop stresses less than 100 MPa) which is consistent with the in-reactor creep behavior of many cold worked austenitic stainless steels. These PCA creep data are compared to available 316 SS in-reactor creep data. The ...
The swelling and in-reactor creep behaviors of the PCA alloy have been determined from the irradiation of pressurized tube specimens in the FFTF reactor. These data have been obtained to a peak neutron fluence corresponding to approximately 80 dpa in the FFTF reactor for irradiation temperatures between 400 and 750"0C. Diametral measurements performed on the unstressed specimens indicate the possible onset of swelling in the PCA alloy for irradiation temperatures between 400 and 550"0C and at a neutron fluence corresponding to #approx#50 dpa. The creep data suggest a non-linear fluence dependence and linear stress dependence (for hoop stresses less than 100 MPa) which is consistent with the in-reactor creep behavior of many cold worked austenitic stainless steels. These PCA creep data are compared to available 316 SS in-reactor creep data. The in-reactor creep ...
SMART (System integrated Modular Advanced ReacTor) , is under development at the Korea Atomic Energy Research Institute (KAERI). SMART is an integral type pressurized water reactor which contains a pressurizer, 4 reactor coolant pumps (RCPs), and 8 steam generator cassettes(S/Gs) in a single reactor vessel. This reactor has substantially enhanced its safety with an integral layout of its major components, 4 trains of safety injection system (SIS), and an adoption of 4 trains of passive residual heat removal system (PRHRS) instead of an active auxiliary feedwater system . The thermal power is 330 MWth. During the conceptual design stage, a preliminary PSA was performed. PSA results identified that a steam generator tube rupture (SGTR) is one of the most important initiating events which results in a high core damage frequency. Clear understanding of accident progression with various ...
The long operating cycle simplified boiling water reactor is a reactor concept that pursues both safety and the economy by employing a natural circulation reactor core without a refueling, a passive decay heat removal, and an integrated building for the reactor and turbine. Throughout the entire spectrum of the design basis accident, the reactor core is kept covered by the passive emergency core cooling system. The decay heat is removed by the conventional active low-pressure residual heat removal system. As for a postulated severe accident, the suppression pool water floods the lower part of the reactor pressure vessel (RPV) in the case when core damage occurs, and the in-vessel retention that keeps the melt inside the RPV is achieved by supplying the coolant. The containment adopts a parallel-double-steel-plate structure similar to a hull structure, which ...
A study has been made of the reactor blockages occurring in the course of direct hydroliquefaction of Miike coal, Taiheiyo coal and Yallourn coal briquets in a tubular reactor. The liquefaction tests were carried out at 450 C under 24.6 MPa hydrogen pressure, with red mud and sulfur catalyst. From the observed balances for catalyst and coal ash, it was inferred that reactor blockages are due to sedimentation of catalyst and ash. The conditions for catalyst and coal ash run-off were determined after solvent and slurry flow rates had been altered to suit the type of coal being tested. It was found that ash run-off occurred more readily as the difference between the slurry flow velocity and the natural sedimentation velocity of red mud in the coal liquids increased. Even when ash run-off was occurring, however, the ash concentration of the slurry in the reactor was higher than the concentration in the feed ...
One of the key features of ANL's Integral Fast Reactor (IFR) concept is a close-coupled fuel cycle. The proposed fuel cycle is similar to that demonstrated over the first five to six years of operation of EBR-II, when a fuel cycle facility adjacent to EBR-II was operated to reprocess and refabricate rapidly fuel discharged from the EBR-II. Locating the IFR and its fuel cycle facility on the same site makes the IFR a self-contained system. Because the reactor fuel and the uranium blanket are metals, pyrometallurgical processes (shortned to ''pyroprocesses'') have been chosen. The objectives of the IFR processes for the reactor fuel and blanket materials are to (1) recover fissionable materials in high yield; (2) remove fission products adequately from the reactor fuel, e.g., a decontamination factor of 10 to 100; and (3) upgrade the concentration of plutonium ...
Calculations have been made to determine the production of "1"8"8W from "1"8"6W in several US fission reactor systems, e.g., Fast Flux Test Facility (FFTF), the High Flux Isotope Reactor (HFIR), and the Advanced Test Reactor (ATR). Important input to these calculations are the cross-section parameters for "1"8"6W, "1"8"7W, and "1"8"8W. Only two values have been measured for "1"8"7W and none for "1"8"8W. Consequently, results from integral measurements play a crucial role in determining the "1"8"7W and "1"8"8W values. This has been studied for irradiations in the FFTF and the Oregon State Univ. (OSU) research reactor. Short irradiation of enriched "1"8"6W in both the FFTF and the OSU reactors have produced #mu#Ci/g quantities of "1"8"8W/"1"8"8Re. Measurements were made of the "1"8"8W gamma ray emission. These results were incorporated with other available data to provide more ...
With the objective to improve the reactor physics calculation on a 2D and 3D nuclear reactor via the Diffusion Equation, an adaptive automatic finite element remeshing method, based on the elementary area (2D) or volume (3D) constraints, has been developed. The adaptive remeshing technique, guided by a posteriori error estimator, makes use of two external mesh generator programs: Triangle and TetGen. The use of these free external finite element mesh generators and an adaptive remeshing technique based on the current field continuity show that they are powerful tools to improve the neutron flux distribution calculation and by consequence the power solution of the reactor core even though they have a minor influence on the critical coefficient of the calculated reactor core examples. Two numerical examples are presented: the 2D IAEA reactor core numerical benchmark and the 3D model ...
The steam generator low water level trip setpoint of KORI NPP units 3 and 4(KNU 3 and 4), three-loop Westinghouse pressurized water reactor, is higher than that of OPR1000. In addition, steam generator downcomer water level in KNU 3 and 4 could fluctuate easily during a transient because of smaller downcomer water inventory, compared to the total water inventory in the steam generator. Due to these reasons, there is a higher possibility of unnecessary reactor trips caused by the steam generator low-low water level in KNU 3 and 4. Its operating history shows that most of reactor trips were caused by steam generator low-low level reactor trip signal. Such reactor trips, especially unnecessary ones, result in time and economic losses. In this paper, a feasibility study was performed to reduce unnecessary reactor trip by changing steam generator low-low water level ...
The steam generator low water level trip setpoint of KORI NPP units 3 and 4(KNU 3 and 4), three-loop Westinghouse pressurized water reactor, is higher than that of OPR1000. In addition, steam generator downcomer water level in KNU 3 and 4 could fluctuate easily during a transient because of smaller downcomer water inventory, compared to the total water inventory in the steam generator. Due to these reasons, there is a higher possibility of unnecessary reactor trips caused by the steam generator low-low water level in KNU 3 and 4. Its operating history shows that most of reactor trips were caused by steam generator low-low level reactor trip signal. Such reactor trips, especially unnecessary ones, result in time and economic losses. In this paper, a feasibility study was performed to reduce unnecessary reactor trip by changing steam generator low-low water level ...
Discussions regarding the use of wood fuels for commercial energy production in the Netherlands began in the 1990's. The main reasons for using wood fuel are: the political demand for using renewable energy, the need to reduce CO_2 emissions, and the lack of markets for surplus timber. Only 10 % of the area of Holland is forested. Therefore, early thinning and cleaning are important management tools for improving growth and producing better quality timber. The energy potential from early thinning and plantation cleaning could be between 400 000 and 570 000 dry tons annually. The Netherlands has not experience in harvesting energy wood. However, through the International Energy Agency/Bioenergy Agreement, knowledge gained in other countries, especially Denmark, Sweden and Finland, is being transferred to Holland. In 1996, there have been made field tests with Danish equipment. Although there are few technical barriers to wood fuel in the Netherlands, the economics of wood fuels ...
The abatement of CO{sub 2} emissions is a huge technical and economical challenge. Fossil fuels, which represent 88% of the world primary energy consumption, are the main source of the 25 billions of CO{sub 2} released each year in the atmosphere. The mastery of CO{sub 2} emissions cannot come from a single technology but must result from the simultaneous implementation of several means, like the development of carbon-free energies and the mastery of fossil fuel emissions. The opportunities of progress are numerous and compatible with the economic development. This document presents, first, the different greenhouse gases, the CO{sub 2} emissions per country and the main sources of CO{sub 2} emissions (power and heat generation, transports). Then it presents different ways of abatement of CO{sub 2} emissions: clean coal technologies, gas combined cycles, CO{sub 2} sequestration, reduction of fuel consumption in transports, development of ...
Cereal straw, a by-product in the production of agricultural crops, is considered as a potentially large source of energy supply with an estimated value of 47 x 10{sup 18} J worldwide. However, there is some debate regarding the actual amounts of straw which could be removed from arable soils without jeopardizing their quality, as well as the potential trade-offs in the overall straw-to-energy chain compared to the use of fossil energy sources. Here, we used a deterministic model of C and N dynamics in soil-crop systems to simulate the effect of straw removal under various sets of soil, climate and crop management conditions in northeastern France. Model results in terms of nitrate leaching, soil C variations, nitrous oxide and ammonia emissions were subsequently inputted into the life-cycle assessment (LCA) of a particular bio-energy chain in which straw was used to generate heat and power in a plant producing bio-ethanol from wheat grains. Straw removal had ...
Based on the IAPWS technical guidance on ''Instrumentation for Monitoring and Control of Cycle Chemistry for Steam-Water Circuits of Fossil-Fired and Combined Cycle Power Plants,'' the latest situation regarding instrumentation for nuclear power plants is discussed. As a result of the discussion, it is concluded that: (1) Reliable and safe operation of plants is established by the application of suitable chemical conditions in plant cooling systems, which should be supported by the selection of suitable control targets for monitoring and by the application of reliable instruments. (2) The minimum level of key instrumentation consists of on-line as well as off-line instruments for monitoring the key parameters: - on-line: pH, conductivity, cation conductivity, O{sub 2} and H{sub 2} concentrations, electrochemical corrosion potential; - off-line: radioactive nuclides ({sup 60}Co, {sup 58}Co, {sup 131}I, etc.), and the ...
At COP3 in 1997, an agreement was made to the innovative technical development/promotion by international cooperation, and the promotion of transfer of environmental technology to developing countries. Under the agreement, a feasibility study of international cooperation was made, and especially a study was conducted of the utilization/development of solar energy by the innovative solar thermochemical process. The main reason for global warming is emissions of a large amount of CO2 caused by the direct combustion of fossil fuels. Therefore, a CO2 recycle system taken up in the study enables a more substantial decline in CO2 emission (kg/kWh) per unit generation than the conventional thermal power system by composing solar methanol or solar dimethyl ether using fossil fuels including coal, water, CO2, etc. as raw materials and using solar energy as heat source, and by using this as fuel (solar fuel). CO2 can be reduced by 13% to 14% by ...
The method for calculating emissions to air has been revised, which has led to adjustments. Because of this, emissions in 1999 cannot yet be compared with previous years. Emissions in 1990 - 1998 are being recalculated now using the new method and are expected to be ready during 2001. Emissions to air of carbon dioxide (CO_2) in Sweden was 56.58 million tonnes in 1999, not including emissions from biofuels and international bunkers. The major sources of CO_2 emissions are the combustion of fossil fuels and the use of fuels for mobile sources. Total emissions to air of sulphur dioxide (SO_2) and nitrogen oxides (NO_x, counted as NO_2) in Sweden was 66 000 and 263 000 tonnes respectively in 1999. International bunkers are not included. The major source of SO_2 emissions is combustion of fossil fuels. Road traffic is the major source of NO_x emissions. Emissions to air of methane (CH_4), nitrous oxide (N_2O), carbon monoxide (CO) and volatile ...
Due to depletion of fossil fuel, bio-fuels have generated a significant interest as an alternative fuel for the future. The use of bio-fuels to fuel gas turbine seems a viable solution for the problems of decreasing fossil-fuel reserves and environmental concerns. Bio-fuels are alternative fuels, made from renewable sources and having environmental benefit. In recent years, the desire for energy independence, foreseen depletion of nonrenewable fuel resources, fluctuating petroleum fuel costs, the necessity of stimulating agriculture based economy, and the reality of climate change have created an interest in the development of bio-fuels. The application of bio-fuels in automobiles and heating applications is increasing day by day. Therefore the use of these fuels in gas turbines would extend this application to aviation field. The impact of costly petroleum-based aviation fuel on the environment is harmful. So the development of alternative ...
Geological carbon dioxide capture and storage (CCS) is currently seriously considered for addressing, in the near term, the problem of climate change. CCS technology is available today and is expected to become an increasingly affordable CO2 abatement alternative. Whereas the rapidly growing scientific literature on CCS as well as experimental and commercial practice demonstrate the technological and economic feasibility of implementing this clean fossil fuel option on a large scale, relatively little attention has been paid so far to the risks and environmental externalities of geological storage of CO2. This paper assesses the effects of including CCS damage costs in a long-term energy scenario analysis for Europe. An external cost sensitivity analysis is performed with a bottom-up energy technology model that accounts not only for CCS technologies but also for their external costs. Our main conclusion is that in a business-as-usual scenario (i.e. without climate ...
The experience base regarding fission product behavior developed during the Rover program, the nuclear rocket development program of 1955--1972, will be useful in planning a renewed nuclear rocket program. During the Rover program, 20 reactors were tested at the Nuclear Rocket Development Station in Nevada. Nineteen of these discharged effluent directly into the atmosphere; the last reactor tested, a non-flight-prototypic, fuel-element-testing reactor called the Nuclear Furnace (NF-1) was connected to an effluent cleanup system that removed fission products before the hydrogen coolant (propellant) was discharged to the atmosphere. In general, we are able to increase both test duration and fuel temperature during the test series. Therefore fission product data from the later part of the program are more interesting and more applicable to future reactors. We have collected fission product retention (and ...
This report discusses Test Campaign TC07 of the Kellogg Brown & Root, Inc. (KBR) Transport Reactor train with a Siemens Westinghouse Power Corporation (Siemens Westinghouse) particle filter system at the Power Systems Development Facility (PSDF) located in Wilsonville, Alabama. The Transport Reactor is an advanced circulating fluidized-bed reactor designed to operate as either a combustor or a gasifier using a particulate control device (PCD). The Transport Reactor was operated as a pressurized gasifier during TC07. Prior to TC07, the Transport Reactor was modified to allow operations as an oxygen-blown gasifier. Test Run TC07 was started on December 11, 2001, and the sand circulation tests (TC07A) were completed on December 14, 2001. The coal-feed tests (TC07B-D) were started on January 17, 2002 and completed on April 5, 2002. Due to operational difficulties with the ...
The liquefaction reaction system of an NEDOL process coal liquefaction 1t/d PSU was opened and checked to investigate the cause of the rise of differential pressure between liquefaction reactors of the PSU. The liquefaction test at a coal concentration of 50 wt% using Tanito Harum coal was conducted, and it was found that the differential pressure between reactors was on the increase. By the two-phase flow pressure loss method, deposition thickness of deposit in pipelines was estimated at 4.4mm at the time of end operation, which agreed with a measuring value obtained from a {gamma} ray. The rise of differential pressure was caused by deposit formation in pipelines connecting reactors. The main component of the deposit is calcite (CaCO3 60-70%) and is the same as the usual one. It is also the same type as the deposit on the reactor wall. Ca in coal ash is concerned with this. To withdraw solid matters ...
The neutron data required to completely analyze fission reactors includes many isotopes and covers a broad energy range. In both fast and thermal reactors, the neutron inventory is a fine balance determined by the fission properties of "2"3"5U, "2"3"9Pu and "2"3"8U and by the capture cross sections of "2"3"8U, fuel materials, structural materials and coolant materials. In fast reactors, the spectrum of neutrons ranges from 1 keV to 3 MeV and is influenced by the elastic and inelastic scattering properties of "2"3"8U and the structural and coolant materials. For neutron shielding applications, the important neutron data include the total cross sections of structural and coolant materials in the MeV range. The impact of these basic nuclear data in fission reactor applications is most suitably described by sensitivity analysis. For example, sensitivity coefficients computed for a typical large plutonium ...
The Fixed Bed Nuclear Reactor (FBNR) is a small 40 MWe reactor based on the Pressurized Water Reactor (PWR) technology. FBNR is an integrated primary circuit and simple in design. It has the characteristics of being small, modular, proliferation resistant, inherently safe and passively cooled reactor with reduced adverse environmental impact. It utilizes the fuel designed for high temperature reactors operating in a relatively low temperature of PWR environment The 15 mm diameter spherical fuel elements are made of TRISO type microspheres embedded in graphite and cladded by SiC. The coolant flow transfers them from the fuel chamber into the core and become fixed forming a suspended core. Any accident signal will cut off the power to the coolant pump causing a stop in the flow. This results in making the fuel elements fall out of the reactor core by the force of ...
In March 2007 in-pile testing of LEU U-Mo full-size IRT type fuel elements was started in the MIR reactor. Four prototype fuel elements for Uzbekistan WWR SM reactor are being tested simultaneously - two of tube type design and two of pin type design. The dismountable irradiation devices were constructed for intermediate reloading and inspection of fuel elements during reactor testing. The objective of the test is to obtain the experimental results for determination of more reliable design and licensing fuel elements for conversion of the WWR SM reactor. The heat power of fuel elements is measured on-line by thermal balance method. The distribution of fission density and burn-up of uranium in the volume of elements are calculated by using the MIR reactor MCU code (Monte-Carlo) model. In this paper the design of fuel elements, the technique, main parameters and preliminary results ...
Decay heat removal analyses for lead-bismuth cooled natural circulation reactors are described in this paper. A combined multi-dimensional plant dynamics code (MSG-COPD) has been developed to conduct the system analysis for the natural circulation reactors. For the preliminary study, transient analysis has been performed for a 100 MWe lead-bismuth-cooled reactor designed by Argonne National Laboratory (ANL). In addition, decay heat removal characteristics of a 400 MWe lead-bismuth-cooled natural circulation reactor designed by Japan Nuclear Cycle Development Institute (JNC) has been evaluated by using MSG-COPD. PRACS (Primary Reactor Auxiliary Cooling System) is prepared for the JNC's concept to get sufficient heat removal capacity. During 2000 sec after the transient, the outlet temperature shows increasing tendency up to the maximum temperature of 430 Centigrade, because ...
Validation of nuclear power reactor signals is often performed by comparing signal prototypes with the actual reactor signals. The signal prototypes are often computed based on empirical data. The implementation of an estimation algorithm which can make predictions on limited data is an important issue. A new machine learning algorithm called support vector machines (SVMS) recently developed by Vladimir Vapnik and his coworkers enables a high level of generalization with finite high-dimensional data. The improved generalization in comparison with standard methods like neural networks is due mainly to the following characteristics of the method. The input data space is transformed into a high-dimensional feature space using a kernel function, and the learning problem is formulated as a convex quadratic programming problem with a unique solution. In this paper the authors have applied the SVM method for data-based state estimation in nuclear ...
Tarapur Atomic Power Station Unit-3 and 4 (TAPS -3 and 4) are the 540 MWe reactors. Unit-4 attained first criticality on 06th March 2005 and operated for about 230 effective full power days (EFPD). Unit-3 attained first criticality on 21st May 2006 and operated for about 20 EFPD. With the reactor operation radiation field increases on the Primary Heat Transport system equipments, Moderator system equipments and auxiliary system equipments due to deposition of fission products and activation products in different reactor systems. These dose rates significantly contributes to the external exposure and stations collective dose during reactor operation, refueling operation and maintenance activities. A study was undertaken at TAPS 3 and 4 to identify the system equipments showing the significant dose rates and identify the radionuclides present in the primary heat transport system, Moderator systems, cover ...
A review of the status of integral measurements is presented for "2"4"0Pu, "2"4"1Pu, "2"4"2Pu, "2"4"1Am and "2"4"3Am. This review includes integral measurements pertinent to thermal reactor systems, i.e., thermal cross sections and resonance integrals, as well as measurements for fast reactor systems. It appears that for these nuclides the data for thermal reactors are in good shape; however, more work is recommended in defining the branching ratio of the capture cross section of "2"4"1Am to the isomeric and ground states of "2"4"2Am. Also, benchmark irradiation data are needed for cross section data testing using depletion/production codes. For fast reactors, experiments are in progress, in the UK, in France, and also in the US, with partial results available at this time. Fast integral data obtained from these measurements will be very beneficial. The recommendation pertaining to "2"4"1Am and proper ...
Atomic Energy Regulatory Board carries out the regulatory review of the reactor physics design, commissioning and operational aspects through Project Design Safety Committee and Specialist Group of reactor physicists with wide experience in the design, commissioning and operational safety review of NPPs. TAPP-3 and 4 PHWRs, being the first indigenous design of 540 MWe Units, are quite different than the standard 220 MWe PHWRs. The safety review of reactor physics design was quite complex, as majority of the systems were new. The Reactor Physics Specialist Group carried out extensive safety review of 540 MWe PHWR reactor physics design and made significant contributions of design modifications and improvements in the operational procedures. Some salient contributions include: Monitoring the core during bulk addition of moderator without the availability of shutdown systems. Logics ...
This study describes the mechanical compatibility of the direct use of spent pressurized water reactor (PWR) fuel in Canada deuterium uranium (CANDU) reactors (DUPIC) fuel, when it is loaded into a CANDU reactor. The mechanical compatibility can be assessed for the fuel management, primary heat transport system, fuel channel, and the fuel handling system in the reactor core by both the experimental and analytic methods. Because the physical dimensions of the DUPIC fuel bundle adopt the CANDU flexible (CANFLEX) fuel bundle design which has already been demonstrated for a commercial use in CANDU reactors, the experimental compatibility analyses focused on the generation of material property data and the irradiation tests of the DUPIC fuel, which are used for the computational analysis. The intermediate results of the mechanical compatibility analysis have shown that the integrity of ...
This report has reviewed the construction of a cooling tower for the K reactor at the DOE Savannah River Site in Aiken, South Carolina. It has been found that the cooling tower would prevent further destruction of cypress and tupelo trees, would maintain a more consistent flow from site streams, and would allow earlier recovery of stream corridors inside a portion of the site. About 630 acres of wetlands have already been affected by the hot water discharged by the K reactor during the past 35 years. GAO believes that about 10 to 12 acres of additional damage would be prevented by the tower for every year the reactor is operated, and if current plans for re-start and retirement of the reactor are followed, less than 100 acres would be preserved. As requested, GAO also identified an example of a project that could be funded as compensation to the public for the damage the K reactor ...
Since the 1970's, global efforts have been going on to replace the high-enriched (>90% "2"3"5U), low-density UAlx research reactor fuel with high-density, low enriched (<20% "2"3"5U) replacements. This search is driven by the attempt to reduce the civil use of high-enriched material because of proliferation risks and terrorist threats. American initiatives, such as the Global Threat Reduction Initiative (GTRI) and the Reduced Enrichment for Research and Test Reactors (RERTR) program have triggered the development of reliable low-enriched fuel types for these reactors, which can replace the high enriched ones without loss of performance. Most success has presently been obtained with U_3Si_2 dispersion fuel, which is currently used in many research reactors in the world. However, efforts to search for a replacement with even higher density, which will also allow the conversion of some high flux ...
The Fast Flux Test Facility (FFTF) was designed to test fast-reactor fuels and other nonfuel materials. In its 37 reactor cycles of operations, the FFTF reactor has performed very well and successfully completed all the irradiation testings with an operating efficiency factor as high as 98%. Since FFTF is an experimental reactor, its core loading changed from cycle to cycle. Depending on the number of test assemblies in the core and their location, the core loading can change significantly from an essentially homogeneous core loading to a relatively nonhomogeneous or even highly localized heterogeneous loading. Consequently, the core reload design and initial criticality analyses were required for each operating cycle. The zero power initial critical control rod bank height was predicted before each reactor startup. The initial critical prediction depends on the reactivity ...
This report summarizes work performed by Argonne National Laboratory on fatigue and environmentally assisted cracking (EAC) in light water reactors from January 1997 to June 1997. Topics that have been investigated include (a) fatigue of carbon, low-alloy, and austenitic stainless steels (SSs) used in reactor piping and pressure vessels, (b) irradiation-assisted stress corrosion cracking of Types 304 and 304L SS, and (c) EAC of Alloys 600 and 690. Fatigue tests were conducted on ferritic and austenitic SSs in water that contained various concentrations of dissolved oxygen (DO) to determine whether a slow strain rate applied during various portions of a tensile-loading cycle is equally effective in decreasing fatigue life. Slow-strain-rate-tensile tests were conducted in simulated boiling water reactor (BWR) water at 288 C on SS specimens irradiated to a low fluence in the Halden reactor and the results ...
In an existent emergency reactor core cooling device, if a ruptures should occure in a pipeline of a gravitational dropping type reactor core cooling system pool (GDCS) due to some or other causes, a portion of GDCS pool water was flown out of the ruptured port and could not be used for reactor core cooling. Then, a difference pressure detector is disposed to a GDCS pipeline at the inlet of a reactor pressure vessel. When it is judged by the detector, that coolants flow to the outside of the injection pipeline, an injection value disposed to the GDCS pipeline is closed by the difference pressure signal. Even if a rupture should occur on the side of the pressure vessel at downstream to the check value of the GDCS pipeline, since backflow is caused at the pressure container inlet of the GDCS pipeline with the rupture port, the rupture is detected by the difference pressure detector to close the injection ...
A highly reliable control rod drive mechanism (CRDM) installed inside the reactor vessel has developed for use of an advanced marine reactor. This CRDM contributes to compactness and simplicity of the reactor system, and it can eliminate the possibility of a rod ejection accident. The CRDM works in the high temperature and high pressure water - 310degC and 12 MPa, the same atmosphere as the primary loop. Driving force is produced by a synchronous motor with the rotor of a permanent magnet, which has been developed. An innovative latch mechanism using separable ball nuts can latch driving shaft connecting the control rod and de-latch it for scram. The rod position detector using a magnetostrictive wire type sensor on the principle of Wiedeman effect has been developed, accuracy of which is verified to have a detecting error within 1.2 mm. Ball bearings for thrust and radial supports in rotation have been developed to be ...
Korea Atomic Energy Research Institute(KAERI) launched a project to develop an integral reactor in 1996. The reactor called as System Integrated Modular Advanced Reactor(SMART) which is a kind of small modular reactors (SMRs). Since the early 1990s, there has been renewed interest in the development and application of small and medium sized integral reactors. 2009 assessment by the IAEA under its Innovative Nuclear Power Reactor and Fuel Cycle (INPRO) program concluded that there could be 96 SMRs in operation around the world by 2030 in its 'high' case, and 43 units in the 'low' case, none of them in the USA. The reason of the increased demand mostly comes from the fact that SMRs are thought to be more suitable for developing countries with small electrical grid capacity, insufficient infrastructure and limited investment capability than developed ones. However, ...
A novel scheme is proposed to drive a low-power subcritical fuel assembly by means of a long Cylindrical Radially-convergent Inertial Electrostatic Confinement (CRIEC) used as a neutron source. The concept is inherently safe in the sense that the fuel assembly remains subcritical at all times. Previous work has been done for the possible implementation of CRIEC as a subcritical assembly driver for power reactors. However, it has been found that the present technology and stage of development of IEC-based neutron sources can not meet the neutron flux requirements to drive a system as big as a power reactor. Nevertheless, smaller systems, such as research and training reactors, could be successfully driven with levels of neutron flux that seem more reasonable to be achieved in the near future by IEC devices. The need for custom-made expensive nuclear fission fuel, as in the case of the TRIGA reactors, is ...
Beach rocks are observed frequently on the tropical and subtropical sandy beaches where they express thin beds dipping seaward at less than 15 degrees. They consist of beach sediments including fossil shells, fragments of corals, diatoms and other biocarbonates, and are well cemented within the inter-tidal zone with calcium carbonate originated in sea water. Therefore, they are not only good indicators which show the past sea level, but also provide good sample material for radiocarbon dating. The locations of beach rocks give us an optimum condition studying a carbon cycle between land and marine environment by analyzing their isotope fractionations. In order to estimate the origin of calcium carbonate which worked as an adhesive when beach rocks were formed and to estimate the formative ages of beach rocks, a total of 330 fossil corals, fossil shells and calcarenite or calcirdite samples were collected from 128 sites of ...
Two US DOE projects in the Pacific Northwest offer unique on-the-scene training opportunities at sodium-cooled fast-reactor plants: the Fast Flux Test Facility (FFTF) near Richland, Washington, which has operated successfully in a wide range of irradiation test programs since 1980; and the Experimental Breeder Reactor II (EBR-II) near Idaho Falls, Idaho, which has been in operation for approximately 20 years. Training programs have been especially designed to take advantage of this plant experience. Available courses are described.
There is growing interest in using {sup 242m}Am as a nuclear fuel for space reactors and nuclear batteries. In this paper, we discuss different {sup 242m}Am enrichments, as well as fuel weight requirements, to produce a critical reactor. It was found that relatively low enrichments of {sup 242m}Am, about 10 w/o, are enough to guarantee criticality. Such low enrichments might eliminate the need for a {sup 242m}Am enrichment process. It was also found that the best results for low {sup 242m}Am requirements are obtained with a moderator to fuel volume ratio of 10,000.
Tritium dose management is an important aspect of the radiation protection program at CANDU type reactor sites. This paper describes the bioassay and dosimetry of tritium at CANDU reactor sites, especially for Wolsung Nuclear Power Plant. It presents a compilation of information drawn from published papers, technical reports, international and national guidelines as well as practical experience both in Korean and Canadian CANDU Nuclear Power Plants. The implementation of this program would provide a technical basis for calculations and records should be of acceptable quality and should meet overall radiation protection program objectives.
Search for the value of ?13 mixing angle is of importance in understanding the lepton flavor mixing matrix, and in motivating future experiments to probe CP violation in the lepton sector. Among the present experimental approaches, reactor experiment can provide a clean laboratory for the ?13-measurement. The Daya Bay experiment will start civil construction this year at Daya Bay, Guangdong, China. The goal of this experiment is to reach a sensitivity in sin2 2?13 of < 0.01 at 90% C.L. by precisely measuring the disappearance and spectral distortion of reactor electron anti-neutrinos with multiple identical detectors at different baselines. The talk will present the current status and prospects of the experiment.
A review of the performance of steam generator tubes in 116 water-cooled nuclear power reactors showed that tubes were plugged at 54 (46 percent) of the reactors. The number of tubes removed from service decreased from 4 692 (0.30 percent) in 1981 to 3 222 (0.20 percent) in 1982. The leading causes of tube failures were stress corrosion cracking from the primary side, stress corrosion cracking (or intergranular attack) from the secondary side and pitting corrosion. The lowest incidence of corrosion-induced defects from the secondary side occurred in reactors that have used only volatile treatment, with or without condensate demineralization.
Criticality was first achieved with the Fast Flux Test Facility (FFTF) a little more than 10 yr ago on February 9, 1980. Although the FFTF was designed and built primarily for testing fuels, materials, and components for the liquid-metal fast breeder reactor program, it has, over its first 10 yr of operation, provided valuable information in many other areas. This paper provides a summary of the contributions to the physics of liquid-metal reactors (LMRs) obtained from operation of and testing in the FFTF, with emphasis on some of the more significant and interesting accomplishments.
Precisely measuring $\\theta_{13}$ is one of the highest priority in neutrino oscillation study. Reactor experiments can cleanly determine $\\theta_{13}$. Past reactor neutrino experiments are reviewed and status of next precision $\\theta_{13}$ experiments are presented. Daya Bay is designed to measure $\\sin^22\\theta_{13}$ to better than 0.01 and Double Chooz and RENO are designed to measure it to 0.02-0.03. All are heading to full operation in 2010. Recent improvements in neutrino moment measurement are also briefed.
The reactor fuel cycle based on uranium is described. The various stages in the cycle include mining of uranium ores followed by crushing and grinding, leaching and purification of leach liquor by ion exchange resin process or solvent extraction process, refining of uranium concentrate (yellow cake) by digesting with HNO_3 and then solvent extracting uranyl nitrate with TBP, conversion of uranyl nitrate to uranium hexafluoride, production of uranium metal, uranium enrichment, fabrication of reactor fuel elements and reprocessing of the spent fuel. Chemical reactions wherever they are involved are explained. (M.G.B.).
A non-linear mathematical model of dynamics of horizontal steam generator for nuclear power unit with WWER type reactor is presented. To realize this model the GEMMA-120 simulation language for computer Odra-1204 has been used. Necessity of taking into account disposited thermal storage capacities along tubulation of a primary cycle is demonstrated. A number of lumped elements of reactor division against a required static accuracy of calculations has been determined. (author).
We study non-standard interactions (NSIs) at reactor neutrino experiments, and in particular, the mimicking effects on \\theta_13. We present generic formulas for oscillation probabilities including NSIs from sources and detectors. Instructive mappings between the fundamental leptonic mixing parameters and the effective leptonic mixing parameters are established. In addition, NSI corrections to the mixing angles \\theta_13 and \\theta_12 are discussed in detailed. Finally, we show that, even for a vanishing \\theta_13, an oscillation phenomenon may still be observed in future short baseline reactor neutrino experiments, such as Double Chooz and Daya Bay, due to the existences of NSIs.
A nonlinear dynamic transient analysis merging hand calculations and the NASTRAN structural analysis computer code was conducted for a Fast Flux Test Facility in-reactor test assembly during an extremely unlikely design basis accidental event which is considered a Hypothetical Core Disruptive Accident (HCDA). The finite element modeling of the problem took advantage of NASTRAN's versatility to create loads and nonlinear elements not previously found in NASTRAN's library. The structural criteria for the test assembly to withstand an HCDA stipulates that the test assembly and its spoolpiece shall remain integral with the reactor head such that missiles are not generated.
Norwegian authorities regard with some disquiet the possibility of a criticality accident in a ship propulsion reactor core at the Kola coast. Along this coast, in land storages, floating storages and in submarines taken out of service, the total number of spent fuel reactor cores amount to two hundred. The total Cs-137 radioactivity in spent ship propulsion reactor fuel at the Kola peninsula can be assessed to 600,000 TBq. A worst case release may amount to more than 5,000 TBq Cs-137, a quantity which under unfavourable conditions might cause serious contamination locally and even across the border to Norway.
This report presents a general investigation of the transport requirements associated with the construction and operation of conceptual fusion reactors. Projections of amounts of construction and operating materials requiring transportation are presented for several proposed designs. The material to be shipped is described along with the shipping containers that might be used, the transport modes and the expected impact of transporting these materials. Transportation of both radioactive and nonradioactive materials will be required. Most of these materials are routinely shipped by the transportation industry. Transportation requirements of a representative fusion reactor are also compared with Liquid Metal Fast Breeder Reactor (LMFBR) requirements.
The Fast Flux Test Facility (FFTF) is a 400 MWt sodium-cooled fast reactor operated by Westinghouse Hanford Company for the US Department of Energy to conduct fuels and materials testing in support of the US Liquid Metal Fast Breeder Reactor programme. Early in 1982, the FFTF began its first 100 day irradiation cycle. Since that time the plant has operated very well, achieving a cycle capacity factor of 94 per cent in the most recent irradiation cycle. The authors describe the results achieved in the first three cycles of operation and carrying through to the fourth reactor cycle which began in January 1984. (author).
The report presents a summary of the work of the Department of Nuclear Safety Research and Nuclear Facilities in 1995. The department`s research and development activities are organized in three research programmes: Radiation Protection, Reactor Safety, and Radioanalytical Chemistry. The nuclear facilities operated by the department include the Research Reactor DR3, the Isotope Laboratory, the Waste Treatment Plant, and the Educational Reactor DR1. Lists of staff and publications are included together with a summary of the staff`s participation in national and international committees. (au) 5 tabs., 21 ills.
The Daya Bay Reactor Anti-Neutrino Experiment is a neutrino oscillation experiment designed to observe and measure the neutrino mixing angle ?13. The sensitivity goal is 0.01 in sin 22?13 at the 90% confidence level, a significant improvement over the current limit. This will be accomplished by measuring the relative rates and energy spectra of reactor electron antineutrinos with multiple detectors positioned at different baselines. Civil construction is currently under-way as detector designs and planning near completion. Commissioning activities should be completed by the end of 2010, followed by a three-year run.
The paper provides a brief description of the fuel characterization for Fast Breeder Test Reactor (FBTR) and Prototype Fast Breeder Reactor (PFBR). The development and characterization of mechanical properties of Alloy D9 clad and wrapper tubes are discussed. The problems associated with fusion welding of Alloy D9 are outlined. Non-destructive characterization of cladding tubes by optimum encircling eddy current probes, on-line and off-line neural network methods is presented. Both the on-line and off-line neural network methods could readily detect and size defects specified by the designers
Existing applications of Alloy 800 are summarized, with particular reference to its use in various types of reactor. The need for a co-ordinated research and development programme is stressed, and the variables to be explored are outlined. The papers relating to the problem of corrosion and cracking in water and steam are considered. the strength and ductility of Alloy 800 is considered. Finally, sections of the summary deal with the use of Alloy 800 for (a) sodium cooled fast reactor boiler tubes; (b) the high temperature gas cooled reactor; and (c) PWR steam generator tubes. (U.K.).
A numerical and experimental investigation is carried out in a solar thermochemical reactor for the thermal dissociation of ZnO at 2000 K using concentrated solar energy. The reactor consists of a cavity-receiver lined with ZnO particles and directly exposed to high-flux irradiation. A transient heat transfer model is formulated to link the rate of radiation, convection, and conduction heat transfer to the reaction kinetics. The radiosity and Monte Carlo methods are applied to obtain the distribution of net radiative fluxes at the internal surfaces of the reactor cavity and at the surface of the ZnO bed. Validation is accomplished in terms of the calculated and measured transient temperature profiles and chemical reaction rates.
Reactor Power Measurement is an essential part of the Reactor Power Control Loop in PHWRs. None of the available power measuring sensor offers characteristics which allow their direct use in the Reactor Power Control Loop. Thermal power, which is considered as relatively accurate, suffers from measurement delays and is used only as reference. Neutronic power sensors like Ion Chambers and Self Powered Neutron Detectors (SPNDs) which sense instantaneous power suffer from inaccuracies. A technique is required which makes use of both types-reference power and instantaneous power to extract real power information from the signals. This paper describes techniques to calibrate (correct) neutronic power that with the thermal reference power signals. The paper also brings out limitation of the calibration technique. (author)
Tarapur Atomic Power Station unit-4 is first 540 MWe pressurized heavy water reactor. Heavy water is used as the coolant and moderator. With reactor operation tritium is formed by absorption of neutron by Deuterium atoms. Experience in the 220 MWe indicates that tritium is main contributor to the internal dose of radiation workers. Study on Tritium build up in Primary Heat Transport (PHT) and Moderator (MOD) system was carried out at the initial stage of the operation of the unit-3 and 4. This paper brings out tritium activity buildup in the PHT and MOD systems and its comparison with 220 MWe reactors. This paper helps in estimation of the internal dose contribution to the radiation workers at TAPS 3 and 4. (author)
Tarapur Atomic Power Station unit-4 is first 540 MWe pressurized heavy water reactor. Heavy water is used as the coolant and moderator. With reactor operation tritium is formed by absorption of neutron by deuterium atoms. Experience in the 220 MWe indicates that tritium is main contributor to the internal dose of radiation workers. Study on tritium build up in Primary Heat Transport (PHT) and Moderator (MOD) system was carried out at the initial stage of the operation of the unit-4. This paper brings out tritium activity buildup in the PHT and MOD systems and its comparison with 220 MWe reactors. This paper helps in estimation of the internal dose contribution to the radiation workers at TAPS 3 and 4. (author)
An experimental investigation on the thermal decomposition of CH4 into C and H2 was carried out using a 5kW particle-flow solar chemical reactor tested in a solar furnace in the 1300-1600K range. The reactor features a continuous flow of CH4 laden with mm-sized carbon black particles, confined to a cavity receiver and directly exposed to concentrated solar irradiation of up to 1720 suns. The reactor performance was examined for varying operational parameters, namely the solar power input, seed particle volume fraction, gas volume flow rate, and CH4 molar concentration. Methane conversion and hydrogen yield exceeding 95% were obtained at residence times of less than 2.0s. A solar-to-chemical energy conversion efficiency of 16% was experimentally reached, and a maximum value of 31% was numer...
A new kind of receiver-reactor for high-temperature solar furnaces is proposed. The main body of the receiver component is an ellipsoid of revolution with specularly reflecting inner walls. The reactor component, a crucible, is placed at one focal point and the aperture at the other. With this arrangement, substantially all of the incident radiation from the concentrator should reach the reactor directly or after one reflection from the cavity walls. An analysis of the radiative exchange among the surfaces is presented. The analysis provides a tool for a parametric study and optimization of the design. It is found that, in contrast to that of conventional well-insulated cavity receivers, its collection efficiency is not very sensitive to the size of its aperture.
Two neutrino mixing angles have been measured, and much of the neutrino community is turning its attention to the unmeasured mixing angle, $\\quq$, whose best limit comes from the reactor neutrino experiment CHOOZ.\\cite{bib:chooz} New two detector reactor neutrino experiments are being planned, along with more ambitious accelerator experiments, to measure or further limit $\\quq$. Here I will overview how to measure $\\quq$ using reactor neutrinos, mention some experiments that were considered and are not going forward, and review the current status of four projects: Double Chooz in France, Daya Bay in China, RENO in South Korea and Angra in Brazil. Finally I will mention how the neutrino observer can gauge progress in these projects two years from now as we approach the times corresponding to early estimates for new results.
This document details monthly activities at the Savannah River Laboratory. Topics addressed are reactor operation; tritium facilities and production; separation operations; environmental concerns; and waste management. (FI)
This document details monthly activities at the Savannah River Laboratory. Topics addressed are reactor operation; tritium facilities and production; separation operations; environmental concerns; and waste management. (FI)
A total of 86 experimental fuel pins with various fuel, liner, and cladding candidate materials have been irradiated in the Experimental Breeder Reactor-II (EBR-II) and the Fast Flux Test Facility (FFTF) reactor as part of the SP-100 fuel pin irradiation testing program. Postirradiation examination results from these fuel pin are key in establishing performance correlations and demonstrating the lifetime and safety of the reactor fuel system. This paper provides a brief description of the in-reactor fuel pin tests and presents the most recent irradiation data on the performance of wrought rhenium (Re) liner material and high density UN fuel at goal burnup of 6 atom percent (at. %). It also provides an overview of the significant variety of other fuel/liner/cladding combinations which were irradiated as part of this program and which may be of interest to more advanced efforts.
A series of tests was recently completed at the 400-MW (thermal) Fast Flux Test Facility (FFTF) to further demonstrate the passive safety characteristics of liquid-metal-cooled fast reactors. Earlier FFTF testing of decay heat removal by sodium natural circulation was reported in 1981. The main purpose of the 1986 test series was to demonstrate passive reactor shutdown during a loss-of-flow event when several inherent shutdown devices called gas expansion modules (GEMs) were installed in the reactor. However, these tests also provide further data on the natural circulation performance of the primary system, in particular the reactor core, and thus add to the data base available for checking the validity of available analytical tools.
The removal phenol and 2-chlorophenol using soybean seed-hulls in the presence of hydrogen peroxide was demonstrated. The performance of a stirred membrane reactor containing soluble purified SEP was compared with a batch stirred reactor containing raw soybean seed-hulls. The purified enzyme reactor proved to be ineffective while good results were obtained with the crude seed-hulls for the removal of phenol and 2-chlorophenol. A single batch reactor containing raw seed-hulls was effective in removing more than 98.5% of 2-chlorophenol (initially at 10000 ppm) in less than 15 min. The performance of these rectors is comparable to existing HRP-based technology. The stability of the soybean peroxidase (SBP) enzyme was also examined in the presence of detergents (SDS, Tween 20 and Triton X-100).
Radiological and environmental protection experience associated with the reactor cover gas processing system at the Fast Flux Test Facility (FFTF) has been excellent. Personnel radiation exposures received from operating and maintaining the reactor cover gas processing system have been very low, the system has remained free of radioactive particulate contamination through the first seven operating cycles (cesium contamination was detected at the end of Cycle 8A), and releases of radioactivity to the environment have been very low, well below environmental standards. This report discusses these three aspects of fast reactor cover gas purification over the first eight operating cycles of the FFTF (a duration of a little more than four years, from April 1982 through July 1986).
The hydraulic characteristics of flow control multiorifice plate assemblies designed for the FFTF reactor were investigated. The pressure drop flowrate characteristics determined in the test are presented. (JWR)
The ability of the /sup 252/Cf-source-driven neutron noise analysis method to measure subcriticality has been demonstrated in a variety of experimental configurations of fissile materials. Calculations for an approximately 4-m-dia configuration of light water reactor (LWR) fuel elements indicated the feasibility of measuring the subcriticality of large, loosely coupled arrays of LWR fuel elements by this same method. These analysis suggested application to the initial loading of both pressurized and boiling water reactors, zero-power testing of reactors (such as shutdown margin measurements after initial loading), light water reactor refueling, and safe storage of LWR spent fuel. In the fuel storage application, direct measurement of subcriticality in the actual fuel storage facilities provides the parameter which is directly related to criticality safety.
A dense Pd-Ag membrane reactor (MR) with 100% hydrogen selectivity packed with either Rh/La2O3 or Rh/La2O3-SiO2 as catalysts was used to carry out the dry reforming of methane. The membrane reactor simulation was performed using a well-known reactor model. For this purpose, we employed the equations derived from complete kinetic studies of the dry reforming of methane reaction in connection with both catalysts. In addition, we developed the kinetic equation for the reverse water gas shift reaction (RWGS). The combination of detailed kinetic studies with the measured permeation flux for the Pd-Ag membrane allowed a complete comparison between experimental and simulated operation variables. The variables studied for both catalysts were methane conversion and hydrogen permeation as a function...
Development of Scientific Foundations of the Technology of the Metal Matrix Packing of Leaky Unreprocessible Spent Nuclear Fuel of Different Purpose Reactors for a Long-term Environmentally Safe Storage.
Theoretical models of the decontamination process are developed and combined with an existing model of "6"0Co production in CANDU PHW reactors to predict the effects of decontamination on long term "6"0Co build-up in reactor primary heat transport systems. The effects of decontamination interval, decontamination factor, and post-decontamination corrosion release are calculated. An optimum decontamination strategy for a Pickering G.S. type reactor is developed on the basis of a cost-benefit analysis. This study indicates that the optimum decontamination interval is approximately six years. This optimum interval is relatively insensitive to variations in the costs of personnel exposure, the cost of a decontamination, the decontamination factor, and the post-decontamination corrosion model used. (author).
An optimal deployment pattern of flux mapping detectors for a Canada uranium-deuterium (CANDU)-600 pressurized heavy water reactor (PHWR) is determined by obtaining an optimal feedback relationship between flux measurements and zone controllers. The reactor core is modeled with a time-dependent two-group, two-dimensional diffusion equation, and flux perturbation are expressed by model expansions. The modal expansion coefficients are used as elements of the state vector representing the system dynamics. An optimal feedback matrix connecting the flux measurement vector to the control vector is derived by minimizing a quadratic performance index involving both the state and control vectors. We obtain the detector effectiveness in terms of the optimal feedback matrix and determine optimal detector locations for the Wolsung Unit 1 reactor in Korea. We have tested the methodology through evaluation of flux maps generated through ...
The ORR operated at an average power level of 29.7 MW for 85.3% of the time during this period. The reactor was shut down on fifteen occasions, nine of which were unscheduled. Reactor downtime needed for refueling and checks was normal. The reactor remained available for operation 88.3% of the time. Special tests completed during the quarter included: (1) transfer of LEU fuel elements CLE-202 and NLE-201 from core positions B-9 and B-2 to core positions C-5 and C-6 for continued operation; and (2) calculation of maximum heat flux in LEU elements CLE-201 and NLE-202 in core positions A-2 and A-8. In-service inspections included inspections of ORR decay tank, primary heat exchanger No. 4, and the 24-in. strainer.
An emergency shutdown system for high-temperature gas-cooled pebble-bed reactors is proposed in addition to the common absorber rod shutdown system. This system is based on the strongly absorbing effect of small boronated graphite spheres (called KLAK), which trickle in case of emergency by gravity from the top reflector into the reactor core. The inner reflector of the Siemens-Argonaut reactor was substituted by an assembly of spherical Arbeitsgemeinschaft Versuchsreaktor fuel elements, and the shutdown effect was examined by installing well-defined KLAK nests inside this assembly. The purpose was to develop and prove a calculational procedure for determining criticality values for assemblies of large fuel spheres and small absorbing spheres.
Monte Carlo neutron transport methods can be used to verify the applicability of point kinetics for safety analysis of nuclear reactors. KENO-NR was used to obtain the transfer function of the Advanced Neutron Source reactor and the time delay between the core power production and the external detectors, a parameter of interest to the safety systems design. The good agreement between the Monte Carlo generated transfer function and the point kinetics transfer function validates that the uncommon ANS geometry does not preclude the use of point kinetics in the frequency range that was investigated. Various features of the power spectral densities also demonstrated the applicability of point kinetics. The time delay was obtained from the cross-power spectral density (CPSD) and is {approximately}15 ms. These analyses show that frequency analysis can be used experimentally to investigate the validity of the use of point kinetics models in critical ...
The operational limits of the Tower Shielding Reactor-2 (TSR-2) have been revised to account for placing the reactor in a beam shield, which reduces convection cooling during a loss-of-coolant accident (LOCA). A detailed heat transfer analysis was performed to set operating time limits which preclude fuel damage during a LOCA. Since a LOCA is survivable, the pressure boundary need not be safety related, minimizing seismic and inspection requirements. Measurements of reactor component emittance for this analysis revealed that aluminum oxidized in water may have emittance much higher than accepted values, allowing higher operating limits than were originally expected. These limits could be increased further with analytical or hardware improvements. 5 refs., 7 figs.
The results obtained from experimental investigations and mathematical simulation of horizontal steam generators are considered. Recommendations for continuing these works are given.
This is a presentation on Human Factors in reactor operations. It discusses issues that deal with power plant operations, training and design, operational effectiveness and safety, supporting people to achieve effective and error free performance.
Purpose: To eliminate the water level deviation due to the recycling flowrate, as well as enable a stable control to a reference value even upon changes in the recycling flowrate caused by the variation in the opening degree of a minimum flow valve. Constitution: Reactor recycling system comprises a feedwater pump, a flowrate control valve, a reactor water level detector, and a minimum flow line and a minimum flow valve for preventing the overheating of the feedwater pump at a low flowrate. A flowrate compensator is further disposed, in which a recycling flowrate signal is subtracted from a pump flow rate signal and the result is fedback as a compensated pump flowrate signal. This enables the control system to operate at a rapid response for suppressing the effect of the recycling flowrate as external disturbance, whereby the water level in the reactor can be controlled stably to the reference level and the possibility ...
The document presented defines the plan to be used to coordinate the preparation, review, approval, and issuance of the operating procedure documents required to ensure safe and efficient operation of FFTF.
The document presented defines the plan to be used to coordinate the preparation, review, approval, and issuance of the operating procedure documents required to ensure safe and efficient operation of FFTF.
Tricking filters are a very promising alternative for the post treatment of effluents from UASB reactors treating domestic sewage,especially in developing countries. Although a fair amount of information is already available regarding organic mater removal in this combined system, very little is known in relation to nitrogen and surfactant removal in trickling filters post-UASB reactors. Therefore, the purpose of this study was to evaluate and compare the effect evaluate and compare the effect of different application rates and packing media types on trickling filters applied to the post-treatment of effluents from UASB reactors, regarding the removal of ammonia nitrogen and surfactants. (Author)
The CO laser is superior in the absorption characteristic to materials to the CO2 laser due to its shorter wavelength. In consideration of this characteristic Nuclear Power Engineering Corporation is studying this applicability sponsored by the Ministry of International Trade Industry of Japan to cutting of reactor core internals of commercial nuclear power plant. In decommissioning of reactor core internals it is necessary to cut stainless steel plates of 305 mm thick. The authors cut stainless steel plates of up to 310mm thick in air and those of up to 150 mm thick underwater with a 20kW class laser. Further, models simulating key structural elements of PWR core internals were cut and secondary products to clarify the applicability of the CO laser cutting to reactor core internals were evaluated. (author)
The current work continues a project completed in 1999 by ReMaxCo Technologies in which a novel, microwave based, VLS Silicon Carbide Fibrils concept was verified. This project continues the process development of a pilot scale commercial reactor. Success will lead to sufficient quantities of fibrils to expand work by ORNL and others on heat exchanger tube development. A semicontinuous, microwave heated, vacuum reactor was designed, fabricated and tested in these experiments. Cylindrical aluminum oxide reaction boats are coated, on the inner surface, with a catalyst and placed into the reactor under a light vacuum. A series of reaction boats are then moved, one at a time, through the reactor. Each boat is first preheated with resistance heaters to 850 C to 900 C. Each reaction boat is then moved, in turn, to the microwave heated section. The catalyst is heated to the required temperature of 1200 C to ...
The development of an electrolytic reduction technology for spent fuels in the form of oxide is of essence to introduce LWR SFs to a pyroprocessing. In this research, the technology was investigated to scale a reactor up, the electrochemical behaviors of FPs were studied to understand the process and a reaction rate data by using U{sub 3}O{sub 8} was obtained with a bench scale reactor. In a scale of 20 kgHM/batch reactor, U{sub 3}O{sub 8} and Simfuel were successfully reduced into metals. Electrochemical characteristics of LiBr, LiI and Li{sub 2}Se were measured in a bench scale reactor and an electrolytic reduction cell was modeled by a computational tool.
This paper explores the current trends in development of technology-neutral safety requirements to be used in the regulation of future nuclear power reactors and the role of the quantitative safety goals in the design of reactor safety systems. Establishing the requirements concerning the reliability of safety functions rather than on particular systems employed to achieve the functions, as well as the use of the recommendations of the International Commission on Radiological Protection (ICRP) on protection against potential exposure could form the basis of a technology-neutral framework for safety requirements on new reactor designs. Also it could contribute to international harmonisation of nuclear safety assessment practices as part of the licensing processes for future nuclear power plants. (author)
The Reactor Head Structure Assembly(RHSA) is the structure located on the reactor assembly. The purpose of the assembly is providing interface location for cables, preventing pipe whips, prohibiting instruments from becoming missiles, and restraining CEDMs' horizontal motion. On the RHSA, Reactor Disconnect Panels(RDP) are installed. The installation location of RDP is to be decided to minimize the geometric interface with other components. Since the neighborhood of RHSA is crowded due to many connectors and cables, it is necessary to find the good design of RHSA to make an intricate situation attenuated and the required function maintained. The geometric shape and overall configuration of RHSA are determined by axiomatic design approach. The FRs of RHSA are specified and the corresponding DPs are found to satisfy FRs in sequence. The finite element analysis is carried out based on the result of the axiomatic ...
Purpose: To secure the reactor operation safety by the provision of a fluid pressure detecting section for control rod driving fluid and a control rod interlock at the midway of the flow pass for supplying driving fluid to the control rod drives. Constitution: Between a driving line and a direction control valve are provided a pressure detecting portion, an alarm generating device, and a control rod inhibition interlock. The driving fluid from a driving fluid source is discharged by way of a pump and a manual valve into the reactor in which the control rods and reactor fuels are contained. In addition, when the direction control valve is switched and the control rods are inserted and extracted by the control rod drives, the pressure in the driving line is always detected by the pressure detection section, whereby if abnormal pressure is resulted, the alarm generating device is actuated to warn the abnormality and the ...
Analyses were performed of the safety-related performance of the reactor protection system (RPS) at U.S. Westinghouse and General Electric commercial reactors during the period 1984 through 1995. RPS operational data from these reactors were collected from the Nuclear Plant Reliability Data System (NPRDS) and Licensee Event Reports (LER). The common-cause failure (CCF) modeling in the fault trees developed for these studies and the analysis and use of common-cause failure data were sophisticated, state-of-the-art efforts. The overall CCF effort helped to test and expand the limits of the U.S. Nuclear Regulatory Commission's CCF methodology.
Recommendations of the Advisory Committee on Reactor Safeguards are presented to the Commissioners for their consideration for FY 82 budget for the NRC safety research program.
Recommendations of the Advisory Committee on Reactor Safeguards are presented to the Commissioners for their consideration for FY 83 budget for the NRC safety research program.
Progress reports are presented for the following two areas: catalytic cracking studies with water-wet silica-alumina catalysts; and Fischer-Tropsch reactor studies where similarities and differences between fixed bed and slurry type reactors are investigated and further experiments conducted to measure mass transfer coefficients and reaction kinetics which are to be used in a model slurry reactor. The following are some of the conclusions. (1) The premise that the presence of liquid water might increase catalytic cracking activity was found to be invalid. It was demonstrated that cracking can occur at previously unobserved low temperatures (though at low conversions) and that an anomaly exists in that one of the catalysts tested shows an entirely different cracking behavior and probably follows a different cracking mechanism. (2) the diameter of a fixed-bed Fischer-Tropsch reactor critically affected ...
In this work, long-term operation of a pilot scale mixed anaerobic reactor processing crude glycerol and rapeseed meal is discussed. These materials are generated as by-products of biodiesel production. Mixed reactor was operated under mesophilic conditions for the period of 654 days. Total cumulative production of biogas reached 379 m3 (at atmospheric pressure and ambient temperature). Maximum volumetric loading achieved during the operation was 2.17 kg m?3 d?1 for the crude glycerol dose of 2 L. When dosing crude glycerol as a single substrate, average specific production of biogas of 0.76 m3 per L of the g-phase was achieved. The lack of nutrients in the g-phase had to be compensated by an addition of ammonium nitrogen in the form of urea into the reactor. Long term processing of crude ...
The Advanced Neutron Source will be a new world-class facility for research using hot, thermal, cold, and ultra-cold neutrons. The heart of the facility will be a 330-MW (fission), heavy-water cooled and heavy-water moderated reactor. The reactor will be housed in a central reactor building, with supporting equipment located in an adjoining reactor support building. An array of cold neutron guides will fan out into a large guide hall, housing about 30 neutron research stations. Appropriate office, laboratory, and shop facilities will be included to provide a complete facility for users. The ANS is scheduled to begin operation at the Oak Ridge National Laboratory early in the next decade. This PDR document defines the plant-level requirements for the design, construction, and operation of ANS. It also defines and provides input to the individual System Design Description (SDD) documents. Together, this ...
An analytical method was proposed for calculating radiative fluxes incident on a planar circular detector from a volume multiple point chemi- or bio-luminescent source inside a coaxial cylindrical reactor. The method was designed for a cylindrical reactor when the surface reflections were neglected and when chemi- or bio-luminescence reaches a detector embedded in the same homogeneous optical medium as the point emitters of the volume multiple point source model. The radiative fluxes from arbitrarily distributed point emitters were expressed by one generalized quadruple-integral formula. Then some double- and single-integral formulas were obtained for calculating radiative fluxes from identically radiating point emitters uniformly distributed within the reactor. Selected results were compu...
Human errors have been reported as one of the most significant causes of major events in nuclear power plants (NPPs). For example, Kim and Park found that about 23% of the major events that occurred at NPPs in Republic of Korea from 1986 to 2006 were caused by human errors. For this reason, a detailed analysis on human errors is an important task for increasing the safety of NPPs. Kim and Choi?2 analyzed 100 human-related unplanned reactor trip events in the Republic of Korea from 1986 to 2006 to consider the type of human errors based on the simple path model for human-induced unplanned reactor trips developed by Kim and Park. In this paper, we will investigate and perform a detailed analysis of the data to identify human-related unplanned reactor trip trends
Today, as a result of increase in oil prices, limited fossil fuel resources, environmental consideration and global warming, the methyl ester fuels have been focused on alternative fuels. Methyl ester fuels can be used more efficiently in low heat rejection engines (LHR), in which the temperature of combustion chamber is increased by creating a thermal barrier. In this study, the piston, cylinder head, exhaust and inlet valves of a diesel engine were coated with the ceramic material Al{sub 2}O{sub 3}-TiO{sub 2} by the plasma spray method. Thus, a thermal barrier was provided for the parts of the combustion chamber with these coatings. The effects of corn oil methyl ester that produced by the transesterification method, and No. D2 fuels' performance and exhaust emissions' rate were studied by using equal in every respect coated and uncoated engines. Tests were performed on the uncoated engine, and then repeated on the coated engine and the results ...
In this study the greenhouse impact of the total Finnish forest sector was considered, which means that the estimated emissions and sink effects from exported forest products were also included. The forest biomass is and seems to be in the next decades the most important factor in the carbon balance of the total forest sector. The development alternatives of forest industries and waste management practices has still a remarkable influence on the greenhouse impact of the Finnish forest sector. The waste management practices in the future has an important influence on the emissions but the exact net greenhouse impact of the landfills is still uncertain. However, the methane emissions from existing landfills can be reduced essentially by gas recovery. Increased incineration and energy recovery of wood waste (and replacing fossil fuel use by it) is also a future alternative for reducing the greenhouse effects in the forest sector. The sequestration of carbon by ...
This dissertation reports on the application of numerical optimization techniques as applied to fuel cell simulation and design. Due to the "multi-physics" inherent in a fuel cell, which results in a highly coupled and non-linear behavior, an experimental program to analyze and improve the performance of fuel cells is extremely difficult. This program applies new optimization techniques with computational methods from the field of aerospace engineering to the fuel cell design problem. After an overview of fuel cell history, importance, and classification, a mathematical model of solid oxide fuel cells (SOFC) is presented. The governing equations are discretized and solved with computational fluid dynamics (CFD) techniques including unstructured meshes, non-linear solution methods, numerical derivatives with complex variables, and sensitivity analysis with adjoint methods. Following the validation of the fuel cell model in 2-D and 3-D, the results of the sensitivity analysis are ...
Research and development activities sponsored by countries within the International Energy Agency`s solar thermal working group. SolarPACES, have helped reduce the cost of solar thermal systems to one-fifth that of the early pilot plants. Continued technological improvements are currently being proven in next-generation demonstration plants. These advances, along with cost reductions made possible by scale-up to larger production and construction of a succession of power plants, have made solar thermal systems the lowest-cost solar energy in the world and promise cost-competitiveness with fossil-fuel plants in the future. Solar thermal technologies are appropriate for a wide range of applications, including dispatchable central-station power plants where they can meet peak-load to near-base-load needs of a utility, and distributed, modular power plants for both remote and grid-connected applications. In this paper, the authors present the collective position of the ...
This work, carried out by the parliamentary office for the evaluation of scientific and technological choices on request of the French National Assembly and Senate, takes stock of the present day situation and technical perspectives of development of renewable energy sources and of research needs of the French industry in this domain: 1 - renewable energies: key-technologies for the energy supply of developing countries and for a rational consumption in transportation systems and accommodations of developed countries (energies technically different from fossil or nuclear energies; fundamental energy sources for a developing world; different national goals in Europe depending on the available natural resources and on the political realities; a minor interest in France for the domestic power generation but a major interest for transports, residential and tertiary sectors and export); 2 - priority choices given to the French renewable energy resources: renewable ...
The present article describes the features of the fully-fired combined cycles and the outline of the plant. Hitachi has optimized fully-fired combined cycle systems by executing a heat recovery type combined cycle. For the fully-fired combined cycles, it is possible to raise plant efficiency through the selection of adequate gas turbine types and cycles. It is possible to apply existing boiler facilities, fuel combustion systems, and stacks. It is possible to execute civil and architectural works on existing plants in-service as well as modification works during routine inspections. The NOx increment by gas turbine unit installations can be reduced by denitration plant modifications. Examples of the fully-fired combined cycles under planning are also introduced. Furthermore, the relational technique and operational characteristics are mentioned, as for combustion characteristics under low oxygen concentration in the wind box, NOx emissions on combined cycle operations, and ...
Heat exchangers for high and ultrahigh temperatures are a need and a precondition to realise high efficient fossil fired power plants based on the so-called Externally Fired Combined Cycle (EFCC) or the Indirect Fired Gas Turbines (IFGT). The main target of both processes is to increase the thermal efficiency of existing power plants by approximately 25% resulting in the same decrease in fuel consumption and, therefore, in the same reduction of CO{sub 2} formation. The main activities of the MPA University of Stuttgart in this project is focused on the characterisation and qualification of the structural material of the ultrahigh temperature heat exchanger (UHTHE) necessary in the above mentioned processes. The influence of the temperature and load on the material behaviour have been analysed by means of tensile tests and creep tests. The effectiveness of different coating systems and the interaction between coating system and basic material was also investigated. ...
The proceedings include the following lectures: Facing the challenges - new structures for electricity production. Renewable energies in Europe - chances and challenges. Nuclear outlook in the UK. Sustainable energy for Europe. Requirements of the market and the grid operator at the electricity production companies. Perspectives for the future energy production. Pumped storage plants - status and perspectives. Nuclear power/renewable energies -partners or opponents? New fossil fired power stations in Europe - status and perspectives. Nuclear energy: outlook for new build and lifetime extension in Europe. Biomass in the future European energy market - experiences for dong energy. Meeting the EU 20:20 renewable energy targets: the offshore challenges. DESERTEC: sustainable electricity for Europe, Middle East and North Africa. New power plants in Europe - a challenge for project and quality management. Consideration of safely in new build activities of power plants. ...
Biogas, produced from anaerobic digestion of organic matter in domestic, industrial and rural wastewaters and residuals, represent an alternative and renewable source of energy, with growing use worldwide. In Brazil, high population and its spatial concentration and expressive agricultural and agricultural-industrial production indicate a substantial potential of biogas production. The results presented in this work show a potential of biogas production of almost 2 billion cubic feet a day of CH{sub 4}. Viability of biogas production and use depends substantially on project scale. Generally, biogas projects are viable from landfills and domestic wastewater treatment for populations higher than 50,000 inhabitants and swine and dairy farms with at least 5,000 and 1,000 animals, respectively. Biogas is also competitive when compared to fossil fuels used in industry and transport. Despite incentive mechanisms for biogas production and use, like Clean Development ...
The US Department of Energy is carrying out a program of research and development to establish the capability to produce synthetic liquid fuels from coal. According to the National Energy Policy Plan IV, the Assistant Secretary of Fossil Energy is charged with carrying out a program to foster an adequate supply of energy at reasonable cost through innovative, long-term R and D. The payoff for this kind of research is potentially high if the country should need the capability on short notice. However, the research is also high risk in terms of the expectation of process for synthetic fuels to turn a profit for a private sector company. As the date when commercial quantities of synfuels will be needed has retreated before lower real prices of petroleum, the US DOE program for coal liquefaction has evolved to give increasing support to longer range, more exploratory technologies, rather than those nearly developed to the point where commercialization is possible. ...
The ability to monitor the corrosion degradation of key components in fossil fuel power plants is of utmost importance for Futuregen and ultra-supercritical power plants. Fireside corrosion occurs in the high temperature sections of energy production facilities due to a number of factors: ash deposition, coal composition, thermal gradients, and low NOx conditions, among others. Problems occur when equipment designed for either oxidizing or reducing conditions is exposed to alternating oxidizing and reducing conditions. This can happen especially near the burners. The use of low NOx burners is becoming more commonplace and can produce reducing environments that accelerate corrosion. One method of addressing corrosion of these surfaces is the use of corrosion probes to monitor when process changes cause corrosive conditions. In such a case, corrosion rate could become a process control variable that directs the operation of a coal combustion or coal gasification ...
The mining and energy industry is under assault today for reasons that have less to do with alleged technical failures and much more to do with ethical complaints about a rate of growth in population that industrial products from mining resources have made possible. The political agendas of Western industrialized nations have been driven during the past quarter century by those whose social philosophy advocates a new ethic of biocentric equality, whereby humans must be forced to being `living as if Nature mattered`. A Green ethic requires that `a violent, plundering humankind` must abandon its alleged rape of the earth and derive its ethical norms from pre-existing ecosystemic harmonies to preserve a fragile and precarious balance existing in Nature. From the perspective of history, there is nothing new about such complaints, current complaints about the use of fossil fuels and pollution from mining, echo similar complaints in past periods. Current Green thinking ...
In recent years, the influences of acid rain such as the acidification of lake water, on bio-system by the heavy metals from effluent of soils with acid rain and also on the structural materials of buildings are seriously discussed. Sulfur and nitrogen that are contained in fossil fuels are released into the atmosphere by the fuel combustion as their oxides dissolve in rain drops as sulfite and nitrous ions, where they are further oxidized into sulfate and nitrate ions These ions lower the pH of rain water resulting so-called acid rain. Therefore, it is important to accurately determine these ions in rain water for the investigation of reality of acid rain. However, it is not easy to accurately determine these ions, especially for sulfite ions in rain water, since they are quickly oxidized by the catalytic action of metallic ions such as ferric and manganous ions. And light, temperature, pH of solution and also species and concentrations of dissolved metallic ions ...
Metallic components within or immediately adjacent to gasifiers, such as gas distributors, thermowells, transfer lines, and cyclones, are subjected to severe of temperature, pressure, and hostile multicomponent gas environments. Metallic heat exchangers/waste-heat boilers resistant to sulfidation, corrosion. and erosion in low- and medium-Btu gas environments are essential components in large-scale gasification schemes, in both dry ash and slogging type gasifiers. Components, in general. must be resistant to corrosion, erosion, and high-temperature creep. A substantial data base is needed on the mechanical properties of materials exposed to complex gas environments to provide a more viable basis for establishing long-term reliability of components. This work examines high-temperature creep of Alloy 800, a high-chromium alloy widely used in coal conversion systems, after exposure to oxygen and oxygen/sulfur mixed-gas environments over a wide temperature range. In addition, the data on ...
The processes controlling total carbon (C) storage and release from the terrestrial biosphere are still poorly quantified. We conclude from analysis of paleodata and climatebiome model output that terrestrial C exchanges since the last glacial maximum (LGM) were dominated by slow processes of C sequestration in soils, possibly modified by C starvation and reduced water use efficiency of trees during the LGM. In contrast, future C cycling will be dominated by human activities, not only from increasing C release with burning of fossil fuels, and but also from indirect effects which increase C storage in the terrestrial biosphere and decrease C storage in the biosphere. Comparison of the positive and negative C flux processes involved suggests that if the C sequestration processes are important, they likely will be so during the next few decades, gradually being counteracted by the C release processes. (Copyright (c) l993 Kluwer Academic Publishers.)
This report deals with the renewable energies and the local development called the territory intelligence in action. Taking into account the place of the electricity in the french energy accounting and the part of the nuclear in its production, the local authorities have to act in the heat domain, which is the first energy need in France, far in front of the specific electricity (those which cannot be replace by other type of energy). But 80% of the heat is today covered by fossil energies. No actions to change this situation will be done without a real implication of the local government. The authors preconize an ambitious objective: cover 50% of the heat needs from renewable energies in the next generat This objective must rely on a program called ''alternative energies''. In this framework the authors provide recommendations on the implementation of the renewable energies as an essential challenge for the local authorities. ...
A statistical survey is conducted of air pollution in the city of Rome (Italy) due to conventional building space heating systems burning fossil fuels. The survey identifies the annual consumption of the different fuels and the relative amounts of the various pollutants released into the atmosphere by the heating plants, e.g., sulfur and nitrogen oxides, carbon monoxide, etc. Comparisons are then made between the ratios of urban heating plant air pollutants produced per tonne of fuel employed and those for ENEL (Italian National Electricity Board) coal, oil and natural gas fired power plants, in order to demonstrate the better environmental performances of the utility operated energy plants. The building space heating system energy consumption and pollution data are then used in a cost benefit analysis favouring the retrofitting of conventional heating systems with heat pump systems to obtain substantial reductions in energy consumption, heating bills and urban air ...
A life cycle assessment was performed to quantify the non-renewable (fossil) energy use and global warming potential (GWP) in electricity generation from a typical gas fired combined cycle power plant in Singapore. The cost of electricity generation was estimated using a life cycle cost analysis (LCCA) tool. The life cycle assessment (LCA) of a 367.5 MW gas fired combined cycle power plant operating in Singapore revealed that hidden processes consume about 8% additional energy in addition to the fuel embedded energy, and the hidden GWP is about 18%. The natural gas consumed during the operational phase accounted for 82% of the life cycle cost of electricity generation. An empirical relation between plant efficiency and life cycle energy use and GWP in addition to a scenario for electricity cost with varying gas prices and plant efficiency have been established.
A life cycle assessment was performed to quantify the non-renewable (fossil) energy use and global warming potential (GWP) in electricity generation from a typical gas fired combined cycle power plant in Singapore. The cost of electricity generation was estimated using a life cycle cost analysis (LCCA) tool. The life cycle assessment (LCA) of a 367.5 MW gas fired combined cycle power plant operating in Singapore revealed that hidden processes consume about 8% additional energy in addition to the fuel embedded energy, and the hidden GWP is about 18%. The natural gas consumed during the operational phase accounted for 82% of the life cycle cost of electricity generation. An empirical relation between plant efficiency and life cycle energy use and GWP in addition to a scenario for electricity cost with varying gas prices and plant efficiency have been established.
Fully-fired combined cycle plants utilizing the high temperature gas turbine discharge as gas intake for a coal-fired steam generator were developed in the 1960's. Long-term experience and the excellent reliability statistics of the gas turbines of these plants have proven that the thermodynamic, economical and ecological advantages of combined cycle units over conventional units strongly suggest such plants for fossil-fuel applications. This paper describes the design and operation of these plants. Topics are Gersteinwerk Unit K combined-cycle power plant, plant design concept, design criteria and performance, gas turbines, steam generators, steam turbines, various modes of operation, typical plant start-up, environmental considerations, prototype plants and topping old steam turbine plants. It concludes that combined-cycle plants provide efficiencies over 45% with low NO/sub x/ emission and a low emission rate. 15 refs.
A wider use of renewable energy sources is considered to be the solution to fossil fuel depletion and environmental pollution. This paper discusses various design considerations for line focussing technology to achieve high efficiency and the possibility of generating power in the megawatt range based on solar thermal technologies. The impacts on the environment of conventional thermal power plants is outlined and an estimate made of the cost of pollution abatement measures. A cost benefit analysis is made using a typical 200 megawatt solar thermal plant, 500 km from the load centre, compared with a 220 megawatt coal fired and a similar capacity gas fired power plant, as examples. The results indicated that the energy from the solar thermal power plant is almost twice as expensive compared to conventionally generated electricity. If, however, impacts on the environment and notional cost associated with are considered, electricity from coal plants becomes either ...
A wider use of renewable energy sources is considered to be the solution to fossil fuel depletion and environmental pollution. This paper discusses various design considerations for line focussing technology to achieve high efficiency and the possibility of generating power in the megawatt range based on solar thermal technologies. The impacts on the environment of conventional thermal power plants is outlined and an estimate made of the cost of pollution abatement measures. A cost benefit analysis is made using a typical 200 megawatt solar thermal plant, 500 km from the load centre, compared with a 220 megawatt coal fired and a similar capacity gas fired power plant, as examples. The results indicated that the energy from the solar thermal power plant is almost twice as expensive compared to conventionally generated electricity. If, however, impacts on the environment and notional cost associated with are considered, electricity from coal plants becomes either ...
The French nuclear power program was pushed through in order to reduce the country's dependence on imported fossil sources of energy. Nuclear power and hydro power have achieved a level of self-sufficiency in the energy sector of more than 50%. It should be emphasized that the French nuclear power program was largely self-financed. Electricite de France (EdF) considers itself well prepared for the European market, provided the creation of the single market implies that electricity rates are taken as a yardstick of competitiveness. Negotiations about a European directive on deregulating the electricity market were for the government to hold. EdF pleaded in favor of preserving for each country a certain leeway for shaping its own policy. The road to deregulation was to be opened, but the specific situation of each country was to be taken electricity to be passed through imposes narrow constraints upon an expansion of exchanges of electricity, and public acceptance is ...
Polycyclic aromatic hydrocarbons (PAH`s) are ubiquitous hydrophobic organic pollutants in the marine environment. Many of the PAM`s are classified as possible carcinogens or mutagens, therefore they are of considerable concern to human and environmental health. The highest concentrations are found in coastal regions due to anthropogenic activities including oil spills, tanker operations, incomplete fossil fuel combustion and runoff. The sources and distribution of PAM`s in sediments are fairly well known, while the fate and transport of PAH`s in the marine environment are less known. Desorption is an important factor influencing the fate and transport of hydrophobic molecules at the seawater/sediment interface. The desorption of PAH`s from contaminated marine sediments to the water column/pore water affects the availability of the pollutant to biota. The sorption of PAH`s is determined in part by the organic carbon content of the sediments. The presence of ...
Ontario's Countdown Acid Rain program was formulated in 1985 and placed an annual SO{sub 2} emissions cap of 885 kilotonnes over the province from 1994. Caps were placed on emissions from the Inco nickel/copper smelter in Sudbury, the Falconbridge nickel/copper smelter in Sudbury, the Algoma iron ore sintering plant in Wawa, and Ontario Hydro fossil-fuel plants province-wide. Semi-annual reports are required of the companies, with the 6th report outlining the final planning phase and the 7th and later reports outlining implementation progress. This document summarizes the contents of the 7th set of reports and the responses of the government review team to each company's efforts. All companies have begun implementing abatement plans outlined in the final planning phase reports of December 1988 at a rapid pace and are generally on track in controlling emissions. However, all 4 company reports lack the necessary detail for a complete review of the ...
Combustion scientists are primarily concerned with the fuels most often burned as energy sources (coal, petroleum products, and natural gas), with the goal of learning to burn them as efficiently, intensely, and cleanly as possible. Discovering those slight rearrangements of chemical bonds that together account for the net chemical transformation is the key to understanding how combustion proceeds. Once these reactions have been defined, the chemist can determine the rate coefficient of each reaction as a function of temperature and assemble the information into flame models. The computer programs that use these models to predict experimental results combine two sets of equations describing (1) the diffusive and reactive rates of change in concentration of all the molecules in the flame and (2) the flow of the reacting gases. Although the details of hydrocarbon-flame models are still disputed, many of their general features are clear and the basic reactions well-known; computer models ...
Renewable energy sources have been attracting the attention of a sensitized public since general pollution abatement measures have been taken, since efforts have been going into the protection of the earth atmosphere, the preservation of the vital ozone layer, and the conservation of fossil energy sources, and since nuclear power risks have been recognized and discussed. In addition to wind power and solar energy solid biomass, e.g. wood, wood wastes, vegetable residues and plants cultivated for the purpose of energy production, is among the topical alternatives. Agriculture and silviculture are important end-users of potential decentralized energy supplies and are cut out for supplying biomass for energy utilization. Additional income sources will open up for farmers. Based on these facts this KTBL working paper describes the biomass energy potential and feasible harvesting and solid-fuel processing and combustion techniques. Energy cost prices are compared and ...
In the future fossil fuelled power plants are realised/laid down as combined cycle power plants with high current generation efficiencies. The method of pressure fluidized-bed combustion with downstream hot gas cleaning is going to compete with methods combined with a pressure coal gasification or a pressure dust combustion. The advantages of the pressure fluidized bed combustion are the simpler method set-up and consequently lower investment costs. (orig./CD) [Deutsch] Kohlegefeuerte Kraftwerke werden zukuenftig als kombinierte Gas/Dampfturbinen-Kraftwerke mit hohen Stromerzeugungswirkungsgraden ausgefuehrt werden. Das Verfahren der Druckwirbelschichtverbrennung mit nachgeschalteter Heissgasreinigung und Rauchgasturbine wird dabei mit Verfahren mit einer vorgeschalteten Kohledruckvergasung oder mit einer Druckstaubfeuerung konkurrieren. Die Vorteile der Druckwirbelschichtverbrennung liegen dabei auf dem insgesamt einfacheren Verfahrensaufbau und damit wohl auch ...
Limestone-based sorbents are used extensively in utility boilers and tail-gas desulfurization units to remove sulfur oxides formed during the combustion of fossil fuels. Such units generate {approximately}20 million tons of flue-gas desulfurization (FGD) wastes in the U.S. annually, the bulk of which ({approximately}95%) are discarded in landfills or holding ponds. However, a significant portion of the Ca in these materials is not sulfated (remains as CaO or Ca(OH){sub 2}), particularly in units that generate dry wastes. When hydrated, such wastes exhibit a strong affinity to absorb acid gases at ambient temperature. This study represents a continuation of previously reported CO{sub 2}-absorption studies and includes more recent work on the absorption of H{sub 2}S and NO. Ten FGD-waste samples along with a control fly ash were examined. Absorption capacities, the role of available calcium and particle size, and mineralogic changes in the wastes following exposure ...