Case studies of application of nuclear forensics to analyze nuclear trafficking activities

International Nuclear Information System (INIS)

Hrnecek, E.; Mayer, K.; Schubert, A.; Wallenius, M.

2010-01-01

Discuses the use of nuclear forensics to identify the source of 14 uranium pellets found in Germany. The pellets were found to be homogeneous typical of western european PWR pellets. Based on geometry Siemens , Germany was identified as the only possible manufacturer. The other case study considered was on a metal can containing of 18 grams of uranium dioxide powder found at ulm together with a lead foil containing 1.8 kilograms of uranium dioxide powder plus pellets of Uranium. Four other case studies are considered. the case studies demonstrates the use of nuclear forensics as a key element in combating illicit trafficking of nuclear materials.

Combustion systems and power plants incorporating parallel carbon dioxide capture and sweep-based membrane separation units to remove carbon dioxide from combustion gases

Science.gov (United States)

Wijmans, Johannes G [Menlo Park, CA; Merkel, Timothy C [Menlo Park, CA; Baker, Richard W [Palo Alto, CA

2011-10-11

Disclosed herein are combustion systems and power plants that incorporate sweep-based membrane separation units to remove carbon dioxide from combustion gases. In its most basic embodiment, the invention is a combustion system that includes three discrete units: a combustion unit, a carbon dioxide capture unit, and a sweep-based membrane separation unit. In a preferred embodiment, the invention is a power plant including a combustion unit, a power generation system, a carbon dioxide capture unit, and a sweep-based membrane separation unit. In both of these embodiments, the carbon dioxide capture unit and the sweep-based membrane separation unit are configured to be operated in parallel, by which we mean that each unit is adapted to receive exhaust gases from the combustion unit without such gases first passing through the other unit.

Carbon dioxide blasting as a nondestructive method for nuclear material decontamination

International Nuclear Information System (INIS)

Norton, C.J.; Campbell, R.A.

1991-01-01

Many traditional methods of decontamination use chemicals that are inherently harmful and can be direct environmental hazards. These methods may generate large volumes of mixed waste and high disposal costs. Sandblasting grit disposal costs have dramatically increased. Also, the additional volume of contaminated waste generated by sandblasting affects facilities disposal quotas. Water blasting now requires expensive processing procedures. State and federal governments are developing regulations that restrict the use of these methods; therefore, alternative technologies are becoming increasingly important. Carbon dioxide (CO 2 ) blasting is an important break-through for nuclear decontamination because of its superior environmental characteristics. The CO 2 blasting method is waterless, waste free, noncorrosive, and nonreactive. Commercial CO 2 is primarily produced as a salvaged waste gas from the production of other industrial gases. In the blasting operation, the frozen CO 2 pellet is transformed into its gaseous state, which is a normal component of the earth's atmosphere. The CO 2 blasting system can solve many of the environmental and cost problems now facing managers responsible for nuclear contamination

Classification of titanium dioxide

International Nuclear Information System (INIS)

Macias B, L.R.; Garcia C, R.M.; Maya M, M.E.; Ita T, A. De; Palacios G, J.

2002-01-01

In this work the X-ray diffraction (XRD), Scanning Electron Microscopy (Sem) and the X-ray Dispersive Energy Spectroscopy techniques are used with the purpose to achieve a complete identification of phases and mixture of phases of a crystalline material as titanium dioxide. The problem for solving consists of being able to distinguish a sample of titanium dioxide being different than a titanium dioxide pigment. A standard sample of titanium dioxide with NIST certificate is used, which indicates a purity of 99.74% for the TiO 2 . The following way is recommended to proceed: a)To make an analysis by means of X-ray diffraction technique to the sample of titanium dioxide pigment and on the standard of titanium dioxide waiting not find differences. b) To make a chemical analysis by the X-ray Dispersive Energy Spectroscopy via in a microscope, taking advantage of the high vacuum since it is oxygen which is analysed and if it is concluded that the aluminium oxide appears in a greater proportion to 1% it is established that is a titanium dioxide pigment, but if it is lesser then it will be only titanium dioxide. This type of analysis is an application of the nuclear techniques useful for the tariff classification of merchandise which is considered as of difficult recognition. (Author)

In situ titanium dioxide nanoparticles quantitative microscopy in cells and in C. elegans using nuclear microprobe analysis

Energy Technology Data Exchange (ETDEWEB)

Le Trequesser, Quentin [Université de Bordeaux, CENBG, Chemin du solarium, 33175 Gradignan (France); CNRS, UMR 5797, CENBG, Chemin du solarium, 33175 Gradignan (France); CNRS, Université de Bordeaux, ICMCB, 87 avenue du Dr. A. Schweitzer, Pessac F-33608 (France); Saez, Gladys; Devès, Guillaume; Michelet, Claire; Barberet, Philippe [Université de Bordeaux, CENBG, Chemin du solarium, 33175 Gradignan (France); CNRS, UMR 5797, CENBG, Chemin du solarium, 33175 Gradignan (France); Delville, Marie-Hélène [CNRS, Université de Bordeaux, ICMCB, 87 avenue du Dr. A. Schweitzer, Pessac F-33608 (France); Seznec, Hervé, E-mail: herve.seznec@cenbg.in2p3.fr [Université de Bordeaux, CENBG, Chemin du solarium, 33175 Gradignan (France); CNRS, UMR 5797, CENBG, Chemin du solarium, 33175 Gradignan (France)

2014-12-15

Detecting and tracking nanomaterials in biological systems is challenging and essential to understand the possible interactions with the living. In this context, in situ analyses were conducted on human skin cells and a multicellular organism (Caenorhabditiselegans) exposed to titanium dioxide nanoparticles (TiO{sub 2} NPs) using nuclear microprobe. Coupled to conventional methods, nuclear microprobe was found to be suitable for accurate description of chemical structure of biological systems and also for detection of native TiO{sub 2} NPs. The method presented herein opens the field to NPs exposure effects analyses and more generally to toxicological analyses assisted by nuclear microprobe. This method will show applications in key research areas where in situ imaging of chemical elements is essential.

Process for sequestering carbon dioxide and sulfur dioxide

Science.gov (United States)

Maroto-Valer, M Mercedes [State College, PA; Zhang, Yinzhi [State College, PA; Kuchta, Matthew E [State College, PA; Andresen, John M [State College, PA; Fauth, Dan J [Pittsburgh, PA

2009-10-20

A process for sequestering carbon dioxide, which includes reacting a silicate based material with an acid to form a suspension, and combining the suspension with carbon dioxide to create active carbonation of the silicate-based material, and thereafter producing a metal salt, silica and regenerating the acid in the liquid phase of the suspension.

Carbon dioxide and climate: too much heat clouds debate

Energy Technology Data Exchange (ETDEWEB)

Gribben, J

1978-12-01

Technical feature:The possibility of a significant global warming as a result of increased atmospheric carbon dioxide from the burning of fossil fuels (the greenhouse effect) has recently received attention from climatologists and energy policy planners. The greenhouse effect has been used by the pro-nuclear lobby as an argument in favor of a massive commitment to nuclear power generation. While the CO2 problem is real, the solution does not lie in an energy strategy based on nuclear power, which involves as yet unsolved problems of radioactive waste disposal. The economic feasibility of processes for removing CO2 from waste gases should be investigated. (4 graphs, 10 references)

Evaluation of possible use of disinfectant based on chlorine dioxide in dairy plant

Directory of Open Access Journals (Sweden)

Rakić-Martinez Mira

2009-01-01

Full Text Available Poor sanitation of food contact surfaces has been a contributing factor in food borne disease outbreaks, especially those involving Listeria monocytogenes, Salmonella spp., Escherichia coli, Staphylococcus aureus etc. The objectives of this study were therefore to: 1. Determine the efficiency of a disinfectant based on chlorine dioxide in suspension in a closed system in a dairy plant. 2. Evaluate the possibility of disinfection of working surfaces with a disinfectant based on chlorine dioxide. In order to determine the germicidal effect of the disinfectant based on chlorine dioxide by suspension test (BSEN 1276:1997; the following test organisms were used: Listeria monocytogenes, Proteus mirabilis, Escherichia coli, Bacillus cereus, Staphylococcus aureus and Pseudomonas aeruginosa clinical isolate. The corrosive properties of the disinfectant based on chlorine dioxide were tested by IDF 077:1977 standard. The efficacy of this disinfectant was investigated in a closed system in a dairy plant. Results indicated a 100% reduction of >108 cfu/ml L. monocytogenes, E. coli, Proteus mirabilis, Pseudomonas aeruginosa, S. aureus, viable count after 1 minute of exposure to 100 ppm of the disinfectant based on chlorine dioxide and 400 ppm for Bacillus cereus. In the presence of 2% skim milk and 4 % skim milk concentrations of 200 and 250 ppm resulted in 100% reduction in numbers of the five of six test microorganisms, respectively. The spore former, Bacillus cereus is less susceptible to the disinfectant. Therefore, the efficient concentration for 100% reduction in viable count after 1 minute exposure was 500 ppm. The corrosive properties of the disinfectant were not determined. In the case of closed system disinfection in a dairy plant, reduction in viable count after 15 minute exposure to 100 ppm of disinfectant based on chlorine dioxide ranged from 80 to 100%.

Thermodynamics of a post combustion hydrate-based carbon dioxide capture process

International Nuclear Information System (INIS)

Ben Attouche Sfaxi, I.

2011-07-01

Hydrates selectivity towards carbon dioxide is offering a promising route for carbon dioxide removal from flue gases. Hydrate-based CO 2 capture process could substitute amine facilities widely implemented in gas treatment plants but suffering from oxidative degradation problems and high energy demand. In the framework of this thesis, we focus on phase equilibria that are involved in such process. Experimental dissociation conditions for clathrate hydrates of carbon dioxide and nitrogen, in the presence of some promoting molecules (Tetrahydrofuran, Tetrabutyl ammonium bromide and Tetrabutyl ammonium Fluoride ) are reported in the experimental section of this work. The data generated in this work along with literature data are compared to the model predictions. The developed model is based on the Cubic Plus Association (CPA) equation of state (EoS) for fluid phases combined to the van der Waals and Platteeuw's theory for the hydrate phase. (author)

World warms to nuclear power

International Nuclear Information System (INIS)

Mortimer, N.

1989-01-01

The greenhouse effect and global warming is a major environmental issue. The nuclear industry has taken this opportunity to promote itself as providing clean energy without implication in either the greenhouse effect or acid rain. However, it is acknowledged that nuclear power does have its own environment concerns. Two questions are posed -does nuclear power contribute to carbon dioxide emissions and can nuclear power provide a realistic long-term solution to global warming? Although nuclear power stations do not emit carbon dioxide, emissions occur during the manufacture of reactor components, the operation of the nuclear fuel cycle and especially, during the mining and processing of the uranium ore. It is estimated that the supply of high grade ores will last only 23 years, beyond that the carbon dioxide emitted during the processing is estimated to be as great as the carbon dioxide emitted from an coal-fired reactor. Fast breeder reactors are dismissed as unable to provide an answer, so it is concluded that nuclear technology has only a very limited role to play in countering global warming.(UK)

Minimization of the fission product waste by using thorium based fuel instead of uranium dioxide

Energy Technology Data Exchange (ETDEWEB)

Galahom, A. Abdelghafar, E-mail: Agalahom@yahoo.com

2017-04-01

This research discusses the neutronic characteristics of VVER-1200 assembly fueled with five different fuel types based on thorium. These types of fuel based on mixing thorium as a fertile material with different fissile materials. The neutronic characteristics of these fuels are investigated by comparing their neutronic characteristics with the conventional uranium dioxide fuel using the MCNPX code. The objective of this study is to reduce the production of long-lived actinides, get rid of plutonium component and to improve the fuel cycle economy while maintaining acceptable values of the neutronic safety parameters such as moderator temperature coefficient, Doppler coefficient and effective delayed neutrons (β). The thorium based fuel has a more negative Doppler coefficient than uranium dioxide fuel. The moderator temperature coefficient (MTC) has been calculated for the different proposed fuels. Also, the fissile inventory ratio has been calculated at different burnup step. The use of Th-232 as a fertile material instead of U-238 in a nuclear fuel is the most promising fuel in VVER-1200 as it is the ideal solution to avoid the production of more plutonium components and long-lived minor actinides. The reactor grade plutonium accumulated in light water reactor with burnup can be recycled by mixing it with Th-232 to fuel the VVER-1200 assembly. The concentrations of Xe-135 and Sm-151 have been investigated, due to their high thermal neutron absorption cross section.

Assessment of industrial energy options based on coal and nuclear systems

International Nuclear Information System (INIS)

Anderson, T.D.; Bowers, H.I.; Bryan, R.H.; Delene, J.G.; Hise, E.C.; Jones, J.E. Jr.; Klepper, O.H.; Reed, S.A.; Spiewak, I.

1975-07-01

Industry consumes about 40 percent of the total primary energy used in the United States. Natural gas and oil, the major industrial fuels, are becoming scarce and expensive; therefore, there is a critical national need to develop alternative sources of industrial energy based on the more plentiful domestic fuels--coal and nuclear. This report gives the results of a comparative assessment of nuclear- and coal-based industrial energy systems which includes technical, environmental, economic, and resource aspects of industrial energy supply. The nuclear options examined were large commercial nuclear power plants (light-water reactors or high-temperature gas-cooled reactors) and a small [approximately 300-MW(t)] special-purpose pressurized-water reactor for industrial applications. Coal-based systems selected for study were those that appear capable of meeting environmental standards, especially with respect to sulfur dioxide; these are (1) conventional firing using either low- or high-sulfur coal with stack-gas scrubbing equipment, (2) fluidized-bed combustion using high-sulfur coal, (3) low- and intermediate-Btu gas, (4) high-Btu pipeline-quality gas, (5) solvent-refined coal, (6) liquid boiler fuels, and (7) methanol from coal. Results of the study indicated that both nuclear and coal fuel can alleviate the industrial energy deficit resulting from the decline in availability of natural gas and oil. However, because of its broader range of application and relative ease of implementation, coal is expected to be the more important substitute industrial fuel over the next 15 years. In the longer term, nuclear fuels could assume a major role for supplying industrial steam. (U.S.)

Report of the Carbon Dioxide Committee II

International Nuclear Information System (INIS)

1994-01-01

The Carbon Dioxide Committee was given the task of preparing a suggestion of the acts aimed at reducing the greenhouse gas emissions and increasing the sinks of carbon in Finland. Emissions of all greenhouse gases were in 1990 80 million tons. calculated as carbon dioxide. The carbon dioxide emissions were about 58 million tons of the total. The increase of forest resources binds carbon from the atmosphere and reduces thereby net emissions of Finland at present by nearly 30 million tons of carbon dioxide. Carbon dioxide emissions will grow during the next decades, unless strong measures to control them will not be taken. As a result of the Commissions examination, acts will be needed both in the production of energy and in its consumption. Emissions can be reduced by replacing fossil fuels with nuclear energy, bioenergy and other renewable energy sources. Saving of energy and improvement of energy efficiency will limit carbon dioxide emissions. The Commission has made suggestions both to change the structure of energy production and to control the consumption of energy. (orig.)

Incentives of carbon dioxide regulation for investment in low-carbon electricity technologies in Texas

International Nuclear Information System (INIS)

Castillo, Anya; Linn, Joshua

2011-01-01

This paper compares the incentives a carbon dioxide emissions price creates for investment in low carbon dioxide-emitting technologies in the electricity sector. We consider the extent to which operational differences across generation technologies - particularly, nuclear, wind and solar photovoltaic - create differences in the incentives for new investment, which is measured by the operating profits of a potential entrant. First, astylized model of an electricity system demonstrates that the composition of the existing generation system may cause electricity prices to increase by different amounts over time when a carbon dioxide price is imposed. Differences in operation across technologies therefore translate to differences in the operating profits of a potential entrant. Then, a detailed simulation model is used to consider a hypothetical carbon dioxide price of $10-$50 per metric ton for the Electric Reliability Council of Texas (ERCOT) market. The simulations show that, for the range of prices considered, the increase in electricity prices is positively correlated with output from a typical wind unit, but the correlation is much weaker for nuclear and photovoltaic. Consequently, a carbon dioxide price creates much stronger investment incentives for wind than for nuclear or photovoltaic technologies in the Texas market. - Highlights: → Compare incentives for new investment in low-emission electricity technologies created by carbon dioxide price. → Focus on ERCOT power system using stochastic unit commitment model. →Find a greater incentive for wind than solar or nuclear because of correlation between wind generation and increase in electricity prices.

Tropospheric nitrogen dioxide inversions based on spectral measurements of scattered sunlight

NARCIS (Netherlands)

Vlemmix, T.

2011-01-01

This thesis describes the development of inversion methods for tropospheric nitrogen dioxide (NO2), based on ground based observations of scattered sunlight with themulti-axis differential optical absorption spectroscopy (MAX-DOAS) technique. NO2 is an atmospheric trace gas which, when present near

Performance analysis of a novel energy storage system based on liquid carbon dioxide

International Nuclear Information System (INIS)

Wang, Mingkun; Zhao, Pan; Wu, Yi; Dai, Yiping

2015-01-01

Due to the intermittence and fluctuation of wind resource, the increasing penetration level of wind power will bring huge challenges to maintain the stability of power system. Integrating compressed air energy storage (CAES) system with wind farms can weaken this negative effect. However CAES system needs large caverns or mines to store compressed air, which is restricted in application. In this paper, a novel energy storage system based on liquid carbon dioxide is presented. The mathematical models of compressed liquid-carbon dioxide energy storage system are developed. The parametric analysis is conducted to examine the effect of some key thermodynamic parameters on the system performance. Compared with AA-CAES, the liquid carbon dioxide energy storage system has advantages such as a high energy density, high EVR. Moreover, the round trip efficiency of this system can reach about 56.64%, which is acceptable in consideration of the storage volume. Therefore, this proposed system has a good potential for storing wind power in large scale and offers an attractive solution to the challenges of the increasing penetration level of wind power. - Highlights: • A novel energy storage system based on liquid carbon dioxide is presented. • The effects of some key parameters on the system performance are studied. • The operation optimization is conducted by genetic algorithm. • Comparative analysis of AA-CAES and liquid carbon dioxide system is studied.

A high-temperature, short-duration method of fabricating surrogate fuel microkernels for carbide-based TRISO nuclear fuels

International Nuclear Information System (INIS)

Vasudevamurthy, G.; Radecka, A.; Massey, C.

2015-01-01

High-temperature gas-cooled reactor technology is a frontrunner among generation IV nuclear reactor designs. Among the advanced nuclear fuel forms proposed for these reactors, dispersion-type fuel consisting of microencapsulated uranium di-oxide kernels, popularly known as tri-structural isotropic (TRISO) fuel, has emerged as the fuel form of choice. Generation IV gas-cooled fast reactors offer the benefit of recycling nuclear waste with increased burn-ups in addition to producing the required power and hydrogen. Uranium carbide has shown great potential to replace uranium di-oxide for use in these fast spectrum reactors. Uranium carbide microkernels for fast reactor TRISO fuel have traditionally been fabricated by long-duration carbothermic reduction and sintering of precursor uranium dioxide microkernels produced using sol-gel techniques. These long-duration conversion processes are often plagued by issues such as final product purity and process parameters that are detrimental to minor actinide retention. In this context a relatively simple, high-temperature but relatively quick-rotating electrode arc melting method to fabricate microkernels directly from a feedstock electrode was investigated. The process was demonstrated using surrogate tungsten carbide on account of its easy availability, accessibility and the similarity of its melting point relative to uranium carbide and uranium di-oxide.

A high-temperature, short-duration method of fabricating surrogate fuel microkernels for carbide-based TRISO nuclear fuels

Energy Technology Data Exchange (ETDEWEB)

Vasudevamurthy, G.; Radecka, A.; Massey, C. [Virginia Commonwealth Univ., Richmond, VA (United States). High Temperature Materials Lab.

2015-07-01

High-temperature gas-cooled reactor technology is a frontrunner among generation IV nuclear reactor designs. Among the advanced nuclear fuel forms proposed for these reactors, dispersion-type fuel consisting of microencapsulated uranium di-oxide kernels, popularly known as tri-structural isotropic (TRISO) fuel, has emerged as the fuel form of choice. Generation IV gas-cooled fast reactors offer the benefit of recycling nuclear waste with increased burn-ups in addition to producing the required power and hydrogen. Uranium carbide has shown great potential to replace uranium di-oxide for use in these fast spectrum reactors. Uranium carbide microkernels for fast reactor TRISO fuel have traditionally been fabricated by long-duration carbothermic reduction and sintering of precursor uranium dioxide microkernels produced using sol-gel techniques. These long-duration conversion processes are often plagued by issues such as final product purity and process parameters that are detrimental to minor actinide retention. In this context a relatively simple, high-temperature but relatively quick-rotating electrode arc melting method to fabricate microkernels directly from a feedstock electrode was investigated. The process was demonstrated using surrogate tungsten carbide on account of its easy availability, accessibility and the similarity of its melting point relative to uranium carbide and uranium di-oxide.

Determination of trace metals in nuclear-grade uranium dioxide by X-ray fluorescence spectrometry

International Nuclear Information System (INIS)

Salvador, V.L.R.; Imakuma, K.

1988-04-01

A method is described for the simultaneous determination of low concentrations of Ca, Cr, Cu, Fe, Mn and Ni in nuclear-grade uranium dioxide by X-ray fluorescence spectrometry, without the use of chemical treatment. The lower limits of detection range from 2 μg g -1 for nickel and manganese to 5 μg g -1 for copper. Samples are prepared in the form of double-layer pellets with boric acid as a binding agent. Standards are prepared in a U 3 O 8 matrix, which is more chemically stable than UO 2 and has similar matrix behaviour. The correlation coefficients for calibration curves are better than 0.999. Erros range from 2.4 % for chromium to 6.8 % for nickel. (author) [pt

Titanium-based zeolitic imidazolate framework for chemical fixation of carbon dioxide

Science.gov (United States)

A titanium-based zeolitic imidazolate framework (Ti-ZIF) with high surface area and porous morphology was synthesized and itsefficacy was demonstrated in the synthesis of cyclic carbonates from epoxides and carbon dioxide.

Assessment of current atomic scale modelling methods for the investigation of nuclear fuels under irradiation: Example of uranium dioxide

International Nuclear Information System (INIS)

Bertolus, M.; Freyss, M.; Krack, M.; Devanathan, R.

2015-01-01

We focus here on the assessment of the description of interatomic interactions in uranium dioxide using, on the one hand, electronic structure methods, in particular in the Density Functional Theory (DFT) framework, and on the other hand, empirical potential methods. These two types of methods are complementary, the former enabling results to be obtained from a minimal amount of input data and further insight into the electronic and magnetic properties to be achieved, while the latter are irreplaceable for studies where a large number of atoms need to be considered. We consider basic properties as well as specific ones, which are important for the description of nuclear fuel under irradiation. These are especially energies, which are the main data passed on to higher scale models. For this exercise, we limit ourselves to uranium dioxide (UO 2 ) because of the extensive amount of studies available on this system. (authors)

Micromechanical approach of behavior of uranium dioxide nuclear fuel

International Nuclear Information System (INIS)

Soulacroix, Julian

2014-01-01

Uranium dioxide (UO 2 ) is the reference fuel for pressurized water nuclear reactors. Our study deals with understanding and modeling of mechanical behavior at the microstructure scale at low temperatures (brittle fracture) and high temperature (viscoplastic strain). We have first studied the geometrical properties of polycrystals at large and of UO 2 polycrystal more specifically. As of now, knowledge of this behavior in the brittle fracture range is limited. Consequently, we developed an experimental method which allows better understanding of brittle fracture phenomenon at grain scale. We show that fracture is fully intra-granular and {100} planes seem to be the most preferential cleavage planes. Experimental results are directly used to deduce constitutive equations of intra-granular brittle fracture at crystal scale. This behavior is then used in 3D polycrystal simulation of brittle fracture. The full field calculation gives access to the initiation of fracture and propagation of the crack through the grains. Finally, we developed a mechanical behavior model of UO 2 in the viscoplastic range. We first present constitutive equations at macroscopic scale which accounts for an ageing process caused by migration of defects towards dislocations. Secondly, we have developed a crystal plasticity model which was fitted to UO 2 . This model includes the rotation of the crystal lattice. We present examples of polycrystalline simulations. (author) [fr

Evolution of spent nuclear fuel in dry storage conditions for millennia and beyond

Energy Technology Data Exchange (ETDEWEB)

Wiss, Thierry, E-mail: thierry.wiss@ec.europa.eu [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, 76125 Karlsruhe (Germany); Hiernaut, Jean-Pol [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, 76125 Karlsruhe (Germany); Roudil, Danièle [Commissariat à l’Energie Atomique et aux Energie Alternatives, Centre de Marcoule, BP 30207 Bagnols-sur-Cèze (France); Colle, Jean-Yves; Maugeri, Emilio; Talip, Zeynep; Janssen, Arne; Rondinella, Vincenzo; Konings, Rudy J.M.; Matzke, Hans-Joachim [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, 76125 Karlsruhe (Germany); Weber, William J. [Department of Materials Science and Engineering, The University of Tennessee, Knoxville, TN 37996 (United States); Division of Materials Science and Technology, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States)

2014-08-01

Significant amounts of spent uranium dioxide nuclear fuel are accumulating worldwide from decades of commercial nuclear power production. While such spent fuel is intended to be reprocessed or disposed in geologic repositories, out-of-reactor radiation damage from alpha decay can be detrimental to its structural stability. Here we report on an experimental study in which radiation damage in plutonium dioxide, uranium dioxide samples doped with short-lived alpha-emitters and urano-thorianite minerals have been characterized by XRD, transmission electron microscopy, thermal desorption spectrometry and hardness measurements to assess the long-term stability of spent nuclear fuel to substantial alpha-decay doses. Defect accumulation is predicted to result in swelling of the atomic structure and decrease in fracture toughness; whereas, the accumulation of helium will produce bubbles that result in much larger gaseous-induced swelling that substantially increases the stresses in the constrained spent fuel. Based on these results, the radiation-ageing of highly-aged spent nuclear fuel over more than 10,000 years is predicted.

Aspect of nuclear power

International Nuclear Information System (INIS)

Haghighi Oskoei, R.; Raeis Hosseiny, N.

2004-01-01

Over the next 50 years, unless patterns change dramatically, energy production and use will contribute to global warming through large-scale greenhouse gas emissions-hundreds of billions of tonnes of carbon in the form of carbon dioxide. Nuclear power would be one option for reducing carbon emissions. At present, however, this is unlikely: nuclear power faces stagnation and decline. We decided to study the future of nuclear power because we believe this technology , despite the changes it faces, is an important option for the world to meet future energy needs without emitting carbon dioxide and other atmospheric pollutants. Other options include increased efficiency, renewable and sequestration. We believe that all options should be preserved as nations develop strategies at provide energy while meeting important environmental challenges. The nuclear power option will only be exercised, however if the technology demonstrates better economics, improved safety, successful waste management, and low proliferation risk, and if public policies place a significant value on electricity production that does not produce carbon dioxide

Aqueous Synthesis of Technetium-Doped Titanium Dioxide by Direct Oxidation of Titanium Powder, a Precursor for Ceramic Nuclear Waste Forms

Energy Technology Data Exchange (ETDEWEB)

Lukens, Wayne W. [Chemical; Saslow, Sarah A. [Earth

2017-11-17

Technetium-99 (Tc) is a problematic fission product that complicates the long-term disposal of nuclear waste due to its long half-life, high fission yield, and the environmental mobility of pertechnetate, its stable form in aerobic environments. One approach to preventing Tc contamination is through incorporation into durable waste forms based on weathering-resistant minerals such as rutile (titanium dioxide). Here, the incorporation of technetium into titanium dioxide by means of simple, aqueous chemistry is presented. X-ray absorption fine structure spectroscopy and diffuse reflectance spectroscopy indicate that Tc(IV) replaces Ti(IV) within the structure. Rather than being incorporated as isolated Tc(IV) ions, Tc is present as pairs of edge-sharing Tc(IV) octahedra similar to molecular Tc(IV) complexes such as [(H2EDTA)TcIV](u-O)2. Technetium-doped TiO2 was suspended in deionized water under aerobic conditions, and the Tc leached under these conditions was followed for 8 months. The normalized release rate of Tc (LRTc) from the TiO2 particles is low (3×10-6 g m-2 d-1), which illustrates the potential utility of TiO2 as waste form. However, the small size of the as-prepared TiO2 nanoparticles results in estimated retention of Tc for 104 years, which is only a fraction of the half-life of Tc (2×10-5 years).

Cost Evaluation with G4-ECONS Program for SI based Nuclear Hydrogen Production Plant

International Nuclear Information System (INIS)

Kim, Jong-ho; Lee, Ki-young; Kim, Yong-wan

2014-01-01

Contemporary hydrogen is production is primarily based on fossil fuels, which is not considered as environments friendly and economically efficient. To achieve the hydrogen economy, it is very important to produce a massive amount of hydrogen in a clean, safe and efficient way. Nuclear production of hydrogen would allow massive production of hydrogen at economic prices while avoiding environments pollution reducing the release of carbon dioxide. Nuclear production of hydrogen could thus become the enabling technology for the hydrogen economy. The economic assessment was performed for nuclear hydrogen production plant consisting of VHTR coupled with SI cycle. For the study, G4-ECONS developed by EMWG of GIF was appropriately modified to calculate the LUHC, assuming 36 months of plant construction time, 5 % of annual interest rate and 12.6 % of fixed charge rate. In G4-ECONS program, LUHC is calculated by the following formula; LUHC = (Annualized TCIC + Annualized O-M Cost + Annualized Fuel Cycle Cost + Annualized D-D Cost) / Annual Hydrogen Production Rate

Thermal and Physical Properties of Plutonium Dioxide Produced from the Oxidation of Metal: a Data Summary

Energy Technology Data Exchange (ETDEWEB)

Wayne, David M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2014-01-13

The ARIES Program at the Los Alamos National Laboratory removes plutonium metal from decommissioned nuclear weapons, and converts it to plutonium dioxide in a specially-designed Direct Metal Oxidation furnace. The plutonium dioxide is analyzed for specific surface area, particle size distribution, and moisture content. The purpose of these analyses is to certify that the plutonium dioxide powder meets or exceeds the specifications of the end-user, and the specifications for the packaging and transport of nuclear materials. Analytical results from plutonium dioxide from ARIES development activities, from ARIES production activities, from muffle furnace oxidation of metal, and from metal that was oxidized over a lengthy time interval in air at room temperature, are presented. The processes studied produce plutonium dioxide powder with distinct differences in measured properties, indicating the significant influence of oxidation conditions on physical properties.

Uranium dioxide electrolysis

Science.gov (United States)

Willit, James L [Batavia, IL; Ackerman, John P [Prescott, AZ; Williamson, Mark A [Naperville, IL

2009-12-29

This is a single stage process for treating spent nuclear fuel from light water reactors. The spent nuclear fuel, uranium oxide, UO.sub.2, is added to a solution of UCl.sub.4 dissolved in molten LiCl. A carbon anode and a metallic cathode is positioned in the molten salt bath. A power source is connected to the electrodes and a voltage greater than or equal to 1.3 volts is applied to the bath. At the anode, the carbon is oxidized to form carbon dioxide and uranium chloride. At the cathode, uranium is electroplated. The uranium chloride at the cathode reacts with more uranium oxide to continue the reaction. The process may also be used with other transuranic oxides and rare earth metal oxides.

Electronic structure of the actinides and their dioxides. Application to the defect formation energy and krypton solubility in uranium dioxide

International Nuclear Information System (INIS)

Petit, T.; CEA Centre d'Etudes de Grenoble, 38

1996-01-01

Uranium dioxide is the standard nuclear fuel used in French h power plants. During irradiation, fission products such as krypton and xenon are created inside fuel pellets. So, gas release could become, at very high burnup, a limiting factor in the reactor exploitation. To study this subject, we have realised calculations using the Density Functional Theory (DFT) into the Local Density Approximation (LDA) and the Atomic Sphere Approximation (ASA). First, we have validated our approach by calculating cohesive properties of thorium, protactinium and uranium metals. The good agreement between our results and experimental values implies that 5f electrons are itinerant. Calculated lattice parameter, cohesive energy and bulk modulus for uranium and thorium dioxides are in very good agreement with experiment. We show that binding between uranium and oxygen atoms is not completely ionic but partially covalent. The question of the electrical conductivity still remains an open problem. We have been able to calculate punctual defect formation energies in uranium dioxide. Accordingly to experimental observations, we find that it is easier to create a defect in the oxygen sublattice than in the uranium sublattice. Finally, we have been able to predict a probable site of krypton atoms in nuclear fuel: the Schottky trio. Experiences of Extended X-ray Absorption Fine structure Spectroscopy (EXAFS) and X-ray Photoelectron Spectroscopy (XPS) on uranium dioxide doped by ionic implantation will help us in the comprehension of the studied phenomena and the interpretation of our calculations. (author)

Designing photobioreactors based on living cells immobilized in silica gel for carbon dioxide mitigation.

Science.gov (United States)

Rooke, Joanna C; Léonard, Alexandre; Meunier, Christophe F; Su, Bao-Lian

2011-09-19

Atmospheric carbon dioxide levels have been rising since the industrial revolution, with the most dramatic increase occurring since the end of World War II. Carbon dioxide is widely regarded as one of the major factors contributing to the greenhouse effect, which is of major concern in today's society because it leads to global warming. Photosynthesis is Nature's tool for combating elevated carbon dioxide levels. In essence, photosynthesis allows a cell to harvest solar energy and convert it into chemical energy through the assimilation of carbon dioxide and water. Therefore photosynthesis is regarded as an ideal way to harness the abundance of solar energy that reaches Earth and convert anthropologically generated carbon dioxide into useful carbohydrates, providing a much more sustainable energy source. This Minireview aims to tackle the idea of immobilizing photosynthetic unicellular organisms within inert silica frameworks, providing protection both to the fragile cells and to the external ecosystem, and to use this resultant living hybrid material in a photobioreactor. The viability and activity of various unicellular organisms are summarized alongside design issues of a photobioreactor based on living hybrid materials. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Method for preparing a sinterable uranium dioxide powder

International Nuclear Information System (INIS)

Thornton, T.A.; Holaday, V.D. Jr.

1985-01-01

This invention provides an improved method for preparing a sinterable uranium dioxide powder for the preparation of nuclear fuel, using microwave radiation in a microwave induction furnace. The starting compound may be uranyl nitrate hexahydrate, ammonium diuranate or ammonium uranyl carbonate. The starting compound is heated in a microwave induction furnace for a period of time sufficient for compound decomposition. The decomposed compound is heated in a microwave induction furnace in a reducing atmosphere for a period of time sufficient to reduce the decomposed compound to uranium dioxide powder

Greenhouse gas emissions from the nuclear fuel cycle

International Nuclear Information System (INIS)

Taylor, M.

1996-01-01

Emissions of carbon dioxide and methane from the whole fuel-cycle of nuclear power generation are discussed. The low-cost, and therefore low-energy-using, uranium resources suffice to provide a large worldwide nuclear programme with fuel without producing substantial carbon dioxide. Very lower emissions of carbon dioxide can be achieved if uranium enrichment is carried out by centrifuging. Methane emissions from uranium mining are negligible or in almost any case virtually zero. (author). 9 refs, 1 tab

Semiconductor-Based Photoelectrochemical Conversion of Carbon Dioxide: Stepping Towards Artificial Photosynthesis.

Science.gov (United States)

Pang, Hong; Masuda, Takuya; Ye, Jinhua

2018-01-18

The photoelectrochemical (PEC) carbon dioxide reduction process stands out as a promising avenue for the conversion of solar energy into chemical feedstocks, among various methods available for carbon dioxide mitigation. Semiconductors derived from cheap and abundant elements are interesting candidates for catalysis. Whether employed as intrinsic semiconductors or hybridized with metallic cocatalysts, biocatalysts, and metal molecular complexes, semiconductor photocathodes exhibit good performance and low overpotential during carbon dioxide reduction. Apart from focusing on carbon dioxide reduction materials and chemistry, PEC cells towards standalone devices that use photohybrid electrodes or solar cells have also been a hot topic in recent research. An overview of the state-of-the-art progress in PEC carbon dioxide reduction is presented and a deep understanding of the catalysts of carbon dioxide reduction is also given. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Classification of titanium dioxide; Clasificacion del dioxido de titanio

Energy Technology Data Exchange (ETDEWEB)

Macias B, L.R. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Garcia C, R.M.; Maya M, M.E. [Secretaria de Hacienda y Credito Publico de Mexico, Mexico (Mexico); Ita T, A. De [Universidad Autonoma Metropolitana Azcapotzalco, Mexico (Mexico); Palacios G, J. [Instituto Politecnico Nacional (Mexico)

2002-07-01

In this work the X-ray diffraction (XRD), Scanning Electron Microscopy (Sem) and the X-ray Dispersive Energy Spectroscopy techniques are used with the purpose to achieve a complete identification of phases and mixture of phases of a crystalline material as titanium dioxide. The problem for solving consists of being able to distinguish a sample of titanium dioxide being different than a titanium dioxide pigment. A standard sample of titanium dioxide with NIST certificate is used, which indicates a purity of 99.74% for the TiO{sub 2}. The following way is recommended to proceed: a)To make an analysis by means of X-ray diffraction technique to the sample of titanium dioxide pigment and on the standard of titanium dioxide waiting not find differences. b) To make a chemical analysis by the X-ray Dispersive Energy Spectroscopy via in a microscope, taking advantage of the high vacuum since it is oxygen which is analysed and if it is concluded that the aluminium oxide appears in a greater proportion to 1% it is established that is a titanium dioxide pigment, but if it is lesser then it will be only titanium dioxide. This type of analysis is an application of the nuclear techniques useful for the tariff classification of merchandise which is considered as of difficult recognition. (Author)

Base isolation for nuclear power and nuclear material facilities

International Nuclear Information System (INIS)

Eidinger, J.M.; Kircher, C.A.; Vaidya, N.; Constantinou, M.; Kelly, J.M.; Seidensticker, R.; Tajirian, F.F.; Ovadia, D.

1989-01-01

This report serves to document the status of the practice for the use of base isolation systems in the design and construction of nuclear power and nuclear material facilities. The report first describes past and current (1989) applications of base isolation in nuclear facilities. The report then provides a brief discussion of non-nuclear applications. Finally, the report summarizes the status of known base-isolation codes and standards

Production of nuclear ceramic fuel for nuclear power plants at 'Ulba metallurgical plant' OSC

International Nuclear Information System (INIS)

Khadeev, V.G.

2000-01-01

The paper describes the flow-sheet of production of uranium dioxide powders and nuclear ceramic fuel pellets of them existing at the facility. 'UMP' OSC applies ADU extraction process of UO2 powders production. An indisputable success of the process is the possibility of use of the wide range of raw materials. Uranium hexafluoride, uranium oxides, uranium metal, uranium tetrafluoride, uranyl salts, uranium ore concentrates, all possible types of uranium-containing materials the processing of which by routine methods is difficult (ashes, scraps, etc.) are used as the raw materials. In addition, a reprocessed nuclear fuel can be used for fuel production. The quality of uranium dioxide powder produced does not depend on the type of uranium raw material used. High selectivity of extraction refining makes possible to obtain material with rather low impurities content that meets practically all specifications for uranium dioxide known to us. Ceramic and process features of uranium dioxide powders, namely, specific surface, bulk density, grain size and sinterability make possible to produce nuclear ceramic fuel with specified features. Quality of uranium dioxide powders produced by 'UMP' OSC was highly rated by General Electric company that is one of the leading companies from fuel manufactures in the USA market . It has certified 'UMP' OSC as its supplier. Currently, our company makes great efforts on establishing production of uranium dioxide powders with natural isotopes content for production of fuel for CANDU reactors. Trial lots of such powders are under tests at some companies manufacturing fuel for this type reactors in Canada, USA and Corea

Criticality characteristics of mixtures of plutonium, silicon dioxide, Nevada tuff, and water

International Nuclear Information System (INIS)

Sanchez, R.; Myers, W.; Hayes, D.

1997-01-01

The nuclear criticality characteristics of mixtures of plutonium, silicon dioxide, and water (Part A) or plutonium, silicon dioxide, Nevada Yucca Mountain tuff, and water (Part B) have become of interest because of the appearance of recent papers on the subject. These papers postulate that if excess weapons plutonium is vitrified into a silicate log and buried underground, a self-sustaining neutron chain reaction may develop given sufficient time and interaction with the burial medium. Moreover, given specific geologic actions resulting in postulated configurations, the referenced papers state that nuclear explosions could occur with multi-kiloton yields or yields equivalent to hundreds of tons of TNT

An Enhanced Soft Vibrotactile Actuator Based on ePVC Gel with Silicon Dioxide Nanoparticles.

Science.gov (United States)

Park, Won-Hyeong; Shin, Eun-Jae; Yun, Sungryul; Kim, Sang-Youn

2018-01-01

In this paper, we propose a soft vibrotactile actuator made by mixing silicon dioxide nanoparticles and plasticized PVC gel. The effect of the silicon dioxide nanoparticles in the plasticized PVC gel for the haptic performance is investigated in terms of electric, dielectric, and mechanical properties. Furthermore, eight soft vibrotactile actuators are prepared as a function of the content. Experiments are conducted to examine the haptic performance of the prepared eight soft vibrotactile actuators and to find the best weight ratio of the plasticized PVC gel to the nanoparticles. The experiments should show that the plasticized PVC gel with silicon dioxide nanoparticles improves the haptic performance of the plasticized PVC gel-based vibrotactile actuator, and the proposed vibrotactile actuator can create a variety of haptic sensations in a wide frequency range.

Study of Soil Decontamination Method Using Supercritical Carbon Dioxide and TBP

International Nuclear Information System (INIS)

Park, Jihye; Park, Kwangheon; Jung, Wonyoung

2014-01-01

The result of this study means that we have a possible new method for cheap and less wasteful nuclear waste decontamination. When severe accidents such as the incident at the Fukushima nuclear site occur, the soil near the power plant is contaminated with fission products or the activation metal structure of the power plant. The soil pollution form depends on the environment and soil characteristics of the contaminated areas. Thus, a- single-decontamination method is not effective for site cleanup. In addition, some soil decontamination methods are expensive and large amounts of secondary waste are generated. Therefore, we need new soil decontamination methods. In this study, instead of using a conventional solvent method that generates secondary waste, supercritical carbon dioxide was used to remove metal ions from the soil. Supercritical carbon dioxide is known for good permeation characteristics. We expect that we will reduce the cost of soil pollution management. Supercritical carbon dioxide can decontaminate soil easily, as it has the ability to penetrate even narrow gaps with very good moisture permeability. We used TBP, which is a known for extractant of actinium metal. TBP is usually used for uranium and strontium extraction. Using TBP-HNO 3 complex and supercritical carbon dioxide, we did extraction experiments for several heavy metals in contaminated soil

Study of Soil Decontamination Method Using Supercritical Carbon Dioxide and TBP

Energy Technology Data Exchange (ETDEWEB)

Park, Jihye; Park, Kwangheon; Jung, Wonyoung [Kyunghee Univ., Yongin (Korea, Republic of)

2014-05-15

The result of this study means that we have a possible new method for cheap and less wasteful nuclear waste decontamination. When severe accidents such as the incident at the Fukushima nuclear site occur, the soil near the power plant is contaminated with fission products or the activation metal structure of the power plant. The soil pollution form depends on the environment and soil characteristics of the contaminated areas. Thus, a- single-decontamination method is not effective for site cleanup. In addition, some soil decontamination methods are expensive and large amounts of secondary waste are generated. Therefore, we need new soil decontamination methods. In this study, instead of using a conventional solvent method that generates secondary waste, supercritical carbon dioxide was used to remove metal ions from the soil. Supercritical carbon dioxide is known for good permeation characteristics. We expect that we will reduce the cost of soil pollution management. Supercritical carbon dioxide can decontaminate soil easily, as it has the ability to penetrate even narrow gaps with very good moisture permeability. We used TBP, which is a known for extractant of actinium metal. TBP is usually used for uranium and strontium extraction. Using TBP-HNO{sub 3} complex and supercritical carbon dioxide, we did extraction experiments for several heavy metals in contaminated soil.

Dissolution of nuclear fuel samples for analytical purposes. I

International Nuclear Information System (INIS)

Krtil, J.

1983-01-01

Main attention is devoted to procedures for dissolving fuels based on uranium metal and its alloys, uranium oxides and carbides, plutonium metal, plutonium dioxide, plutonium carbides, mixed PuC-UC carbides and mixed oxides (PuU)O 2 . Data from the literature and experience gained with the dissolution of nuclear fuel samples at the Central Control Laboratory of the Nuclear Research Institute at Rez are given. (B.S.)

Can nuclear energy support civilized society in the 21st century? From a civilization based on chemical reactions to a civilization based on nuclear reactions

International Nuclear Information System (INIS)

Fuji-Ie, Yoichi

2006-01-01

The United Nations passed and adopted 'Principles of Sustainable Development' in 1992, as a resolution on the sustainable development of mankind. It advocates maintaining the ecological system to support the earth, while presenting the ethical issue of 'impartiality within a generation', the reduction of absolute poverty and also 'impartiality between generations', in particular 'not leaving a negative legacy to the next generation'. The issue of the appropriate handling of waste is by nature an issue of safety and resources, but is also an ethical issue. Nuclear power generation is more likely to conserve the environment, if the comparison between radioactive waste and carbon dioxide is considered. The creation of hydrogen by nuclear energy resembles the ecological relationship between the sun and the earth in that it consists of the conversion of nuclear energy into chemical energy. Nuclear fission, nuclear fusion, particle acceleration and lasers can all be found in the universe. It will be possible to find a future for nuclear energy by learning from and imitating nature. If the future of nuclear energy is seen from the viewpoint of sustainability, it can be expected that energy resources will be secured and the environment will be conserved by a system of nuclear energy, which will hopefully grow into a comprehensive nuclear science and technology that supports the civilization at its roots. (orig.)

Pyrochemical reduction of uranium dioxide and plutonium dioxide by lithium metal

International Nuclear Information System (INIS)

Usami, T.; Kurata, M.; Inoue, T.; Sims, H.E.; Beetham, S.A.; Jenkins, J.A.

2002-01-01

The lithium reduction process has been developed to apply a pyrochemical recycle process for oxide fuels. This process uses lithium metal as a reductant to convert oxides of actinide elements to metal. Lithium oxide generated in the reduction would be dissolved in a molten lithium chloride bath to enhance reduction. In this work, the solubility of Li 2 O in LiCl was measured to be 8.8 wt% at 650 deg. C. Uranium dioxide was reduced by Li with no intermediate products and formed porous metal. Plutonium dioxide including 3% of americium dioxide was also reduced and formed molten metal. Reduction of PuO 2 to metal also occurred even when the concentration of lithium oxide was just under saturation. This result indicates that the reduction proceeds more easily than the prediction based on the Gibbs free energy of formation. Americium dioxide was also reduced at 1.8 wt% lithium oxide, but was hardly reduced at 8.8 wt%

Automatic Carbon Dioxide-Methane Gas Sensor Based on the Solubility of Gases in Water

Directory of Open Access Journals (Sweden)

Raúl O. Cadena-Pereda

2012-08-01

Full Text Available Biogas methane content is a relevant variable in anaerobic digestion processing where knowledge of process kinetics or an early indicator of digester failure is needed. The contribution of this work is the development of a novel, simple and low cost automatic carbon dioxide-methane gas sensor based on the solubility of gases in water as the precursor of a sensor for biogas quality monitoring. The device described in this work was used for determining the composition of binary mixtures, such as carbon dioxide-methane, in the range of 0–100%. The design and implementation of a digital signal processor and control system into a low-cost Field Programmable Gate Array (FPGA platform has permitted the successful application of data acquisition, data distribution and digital data processing, making the construction of a standalone carbon dioxide-methane gas sensor possible.

Automatic carbon dioxide-methane gas sensor based on the solubility of gases in water.

Science.gov (United States)

Cadena-Pereda, Raúl O; Rivera-Muñoz, Eric M; Herrera-Ruiz, Gilberto; Gomez-Melendez, Domingo J; Anaya-Rivera, Ely K

2012-01-01

Biogas methane content is a relevant variable in anaerobic digestion processing where knowledge of process kinetics or an early indicator of digester failure is needed. The contribution of this work is the development of a novel, simple and low cost automatic carbon dioxide-methane gas sensor based on the solubility of gases in water as the precursor of a sensor for biogas quality monitoring. The device described in this work was used for determining the composition of binary mixtures, such as carbon dioxide-methane, in the range of 0-100%. The design and implementation of a digital signal processor and control system into a low-cost Field Programmable Gate Array (FPGA) platform has permitted the successful application of data acquisition, data distribution and digital data processing, making the construction of a standalone carbon dioxide-methane gas sensor possible.

MOLECULAR COMPLEXES OF SULPHUR DIOXIDE WITH N,O-CONTAINING ORGANIC BASES (REVIEW

Directory of Open Access Journals (Sweden)

R. E. Khoma

2016-10-01

Full Text Available The literature data on the synthesis, stoichiometry, structure and relative stability of molecular  complexes of sulphur dioxide with N,O-containing organic bases have been systematized and  generalized. It was shown that the yield of the reaction product of sulfur dioxide with organic  bases (such as amines are strongly influenced by the conditions of synthesis: the nature of  the solvent (basicity, polarity, the temperature and SO2:L ratio in the reaction medium. The stoichiometry of SO2*nL molecular complexes depends on ligand denticity, as well as its  ability to H-bonding. The reaction of the sulfur oxide (IV with organic bases can give S←N and S←O complexes. With the increase of the value of base proton affinity the decrease ΔrSN values has been marked. Characteristic parameter Δr SN = r SN – a1(rS+ rN (where rSNis the S←N donor-acceptor bond length has been determined by microwave spectroscopy and X-ray analysis, rSand rNwere the tabulated values of the homopolar covalent radii of sulphur and nitrogen heteroatoms. The dependence of formation enthalpy of molecular complexes of basic amines and spectral characteristics has been noted; enthalpy-entropy compensation for S←N and S←O complex-es has been stated. Despite the limited experimental data on the thermodynamics of complex formation and the lengths of donor-acceptor bonds for the same compounds it has been found bond S←N strength in SO2 molecular complexes to depend on the intrinsic value of ΔrSN. The contribution of van der Waals forces and charge transfer forces to the formation of molecular complexes of sulphur dioxide has been stated.

Synergistic production of hydrogen using fossil fuels and nuclear energy application of nuclear-heated membrane reformer

International Nuclear Information System (INIS)

Hori, M.; Matsui, K.; Tashimo, M.; Yasuda, I.

2004-01-01

Processes and technologies to produce hydrogen synergistically by the steam reforming reaction using fossil fuels and nuclear heat are reviewed. Formulas of chemical reactions, required heats for reactions, saving of fuel consumption or reduction of carbon dioxide emission, possible processes and other prospects are examined for such fossil fuels as natural gas, petroleum and coal. The 'membrane reformer' steam reforming with recirculation of reaction products in a closed loop configuration is considered to be the most advantageous among various synergistic hydrogen production methods. Typical merits of this method are: nuclear heat supply at medium temperature below 600 deg. C, compact plant size and membrane area for hydrogen production, efficient conversion of feed fuel, appreciable reduction of carbon dioxide emission, high purity hydrogen without any additional process, and ease of separating carbon dioxide for future sequestration requirements. With all these benefits, the synergistic production of hydrogen by membrane reformer using fossil fuels and nuclear energy can be an effective solution in this century for the world which has to use. fossil fuels any way to some extent while reducing carbon dioxide emission. For both the fossil fuels industry and the nuclear industry, which are under constraint of resource, environment and economy, this production method will be a viable symbiosis strategy for the coming hydrogen economy era. (author)

Computational Fluid Dynamics Analysis of Supercritical Carbon Dioxide Turbine

International Nuclear Information System (INIS)

Kim, Tae W.; Kim, Nam H.; Suh, Kune Y.; Kim, Seung O.

2006-01-01

The supercritical carbon dioxide (SCO 2 ) gas turbine Brayton cycle has been not only adopted in the secondary loop of the Generation IV nuclear energy systems but also planned to be installed in the high efficiency power conversion cycles of the nuclear fusion reactors. The potential beneficiaries include the Korea Advanced Liquid Metal Reactor (KALIMER), Korea Superconducting Tokamak Advanced Research (KSTAR) and International Thermonuclear Experimental Reactor (ITER). The reason for these welcomed applications is that the cycle can achieve the overall energy conversion efficiency as high as 45%. The SCO 2 turbine efficiency is one of the major parameters affecting the overall Brayton cycle efficiency. Thus, optimal turbine design determines the economics of the Generation IV as well as the future nuclear fission and fusion energy industry. Seoul National University has recently been working on the SCO 2 based Modular Optimized Brayton Integral System (MOBIS). MOBIS includes the Gas Advanced Turbine Operation Study (GATOS), the Loop Operating Brayton Optimization Study (LOBOS), the Nonsteady Operation Multidimensional Online Simulator (NOMOS), and the Turbine Advanced Compressor Operation Study (TACOS). This paper presents first results from GATOS

Generation of neutron scattering cross sections for silicon dioxide

International Nuclear Information System (INIS)

Ramos, R; Marquez Damian, J.I; Granada, J.R.; Cantargi, F

2009-01-01

A set of neutron scattering cross sections for silicon and oxygen bound in silicon dioxide were generated and validated. The cross sections were generated in the ACE format for MCNP using the nuclear data processing system NJOY, and the validation was done with published experimental data. This cross section library was applied to the calculation of five critical configurations published in the benchmark Critical Experiments with Heterogeneous Compositions of Highly Enriched Uranium, Silicon Dioxide and Polyethylene. The original calculations did not use the thermal scattering libraries generated in this work and presented significant differences with the experimental results. For this reason, the newly generated library was added to the input and the multiplication factor for each configuration was recomputed. The utilization of the thermal scattering libraries did not result in an improvement of the computational results. Based on this we conclude that integral experiments to validate this type of thermal cross sections need to be designed with a higher influence of thermal scattering in the measured result, and the experiments have to be performed under more controlled conditions. [es

The global environment effects of fossil and nuclear fuels

International Nuclear Information System (INIS)

Kemeny, L.G.

1981-01-01

The relative risks and environmental impacts of coal and uranium fueled power plants are dicussed. Fossil-fuel power plants are associated with a build-up of carbon dioxide levels and consequent climatic changes, release of sulphur dioxide and resultant acid rains and radioactive emissions. In comparing the discharges per megawatt year of sulphur dioxide, nitrogen dioxide and radioactive Ra-226 and Ra-225 in fly ash from coal and other fossil plants with Kr-85 and I-131 from nuclear plants, the fossil plants have a much poorer performance. Estimates indicate that nuclear energy can be adopted on a large scale as an alternative to coal without any increase in hazards and with a probability of a substantial reduction

Nuclear Energy and Synthetic Liquid Transportation Fuels

Science.gov (United States)

McDonald, Richard

2012-10-01

This talk will propose a plan to combine nuclear reactors with the Fischer-Tropsch (F-T) process to produce synthetic carbon-neutral liquid transportation fuels from sea water. These fuels can be formed from the hydrogen and carbon dioxide in sea water and will burn to water and carbon dioxide in a cycle powered by nuclear reactors. The F-T process was developed nearly 100 years ago as a method of synthesizing liquid fuels from coal. This process presently provides commercial liquid fuels in South Africa, Malaysia, and Qatar, mainly using natural gas as a feedstock. Nuclear energy can be used to separate water into hydrogen and oxygen as well as to extract carbon dioxide from sea water using ion exchange technology. The carbon dioxide and hydrogen react to form synthesis gas, the mixture needed at the beginning of the F-T process. Following further refining, the products, typically diesel and Jet-A, can use existing infrastructure and can power conventional engines with little or no modification. We can then use these carbon-neutral liquid fuels conveniently long into the future with few adverse environmental impacts.

Production of uranium dioxide

International Nuclear Information System (INIS)

Hart, J.E.; Shuck, D.L.; Lyon, W.L.

1977-01-01

A continuous, four stage fluidized bed process for converting uranium hexafluoride (UF 6 ) to ceramic-grade uranium dioxide (UO 2 ) powder suitable for use in the manufacture of fuel pellets for nuclear reactors is disclosed. The process comprises the steps of first reacting UF 6 with steam in a first fluidized bed, preferably at about 550 0 C, to form solid intermediate reaction products UO 2 F 2 , U 3 O 8 and an off-gas including hydrogen fluoride (HF). The solid intermediate reaction products are conveyed to a second fluidized bed reactor at which the mol fraction of HF is controlled at low levels in order to prevent the formation of uranium tetrafluoride (UF 4 ). The first intermediate reaction products are reacted in the second fluidized bed with steam and hydrogen at a temperature of about 630 0 C. The second intermediate reaction product including uranium dioxide (UO 2 ) is conveyed to a third fluidized bed reactor and reacted with additional steam and hydrogen at a temperature of about 650 0 C producing a reaction product consisting essentially of uranium dioxide having an oxygen-uranium ratio of about 2 and a low residual fluoride content. This product is then conveyed to a fourth fluidized bed wherein a mixture of air and preheated nitrogen is introduced in order to further reduce the fluoride content of the UO 2 and increase the oxygen-uranium ratio to about 2.25

Nuclear Research Institute Rez view

International Nuclear Information System (INIS)

Biza, K.; Pazdera, F.; Vasa, I.; Zdarek, J.

2004-01-01

In this presentation author deals with the present state and perspectives of nuclear energy in the Czech Republic and in the Slovak Republic. It is concluded that lifetime extension and finalization of Mochovce NPP Units 3 and 4 is the cheapest solution for base load production of electricity and is in line with the European union energy challenges: - decrease of carbon dioxide emissions; dependence on energy sources from politically unstable regions; decrease import dependence on energy sources. Nuclear energy is one of important sources for long term sustainability in energy. GEN IV is successful with meet the new requirements after 2025. We should participate on this long term development effort

The future of nuclear power

International Nuclear Information System (INIS)

Corak, Z.

2004-01-01

Energy production and use will contribute to global warming through greenhouse gas emissions in the next 50 years. Although nuclear power is faced with a lot of problems to be accepted by the public, it is still a significant option for the world to meet future needs without emitting carbon dioxide (CO 2 ) and other atmospheric pollutants. In 2002, nuclear power provided approximately 17% of world energy consumption. There is belief that worldwide electricity consumption will increase in the next few years, especially in the developing countries followed by economic growth and social progress. Official forecasts shows that there will be a mere increase of 5% in nuclear electricity worldwide by 2020. There are also predictions that electricity use may increase at 75%. These predictions require a necessity for construction of new nuclear power plants. There are only a few realistic options for reducing carbon dioxide emissions from electricity generation: Increase efficiency in electricity generation and use; Expand use of renewable energy sources such as wind, solar, biomass and geothermal; Capture carbon dioxide emissions at fossil-fuelled electric generating plants and permanently sequester the carbon; Increase use of nuclear power. In spite of the advantages that nuclear power has, it is faced with stagnation and decline today. Nuclear power is faced with four critical problems that must be successfully defeat for the large expansion of nuclear power to succeed. Those problems are cost, safety, waste and proliferation. Disapproval of nuclear power is strengthened by accidents that occurred at Three Mile Island in 1979, at Chernobyl in 1986 and by accidents at fuel cycle facilities in Japan, Russia and in the United States of America. There is also great concern about the safety and security of transportation of nuclear materials and the security of nuclear facilities from terrorist attack. The paper will provide summarized review regarding cost, safety, waste and

Computational Fluid Dynamics Analysis of Supercritical Carbon Dioxide Turbine

Energy Technology Data Exchange (ETDEWEB)

Kim, Tae W.; Kim, Nam H.; Suh, Kune Y. [Seoul National University, Seoul (Korea, Republic of); Kim, Seung O. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

2006-07-01

The supercritical carbon dioxide (SCO{sub 2}) gas turbine Brayton cycle has been not only adopted in the secondary loop of the Generation IV nuclear energy systems but also planned to be installed in the high efficiency power conversion cycles of the nuclear fusion reactors. The potential beneficiaries include the Korea Advanced Liquid Metal Reactor (KALIMER), Korea Superconducting Tokamak Advanced Research (KSTAR) and International Thermonuclear Experimental Reactor (ITER). The reason for these welcomed applications is that the cycle can achieve the overall energy conversion efficiency as high as 45%. The SCO{sub 2} turbine efficiency is one of the major parameters affecting the overall Brayton cycle efficiency. Thus, optimal turbine design determines the economics of the Generation IV as well as the future nuclear fission and fusion energy industry. Seoul National University has recently been working on the SCO{sub 2} based Modular Optimized Brayton Integral System (MOBIS). MOBIS includes the Gas Advanced Turbine Operation Study (GATOS), the Loop Operating Brayton Optimization Study (LOBOS), the Nonsteady Operation Multidimensional Online Simulator (NOMOS), and the Turbine Advanced Compressor Operation Study (TACOS). This paper presents first results from GATOS.

Computational Fluid Dynamics Analysis of Supercritical Carbon Dioxide Turbine

Energy Technology Data Exchange (ETDEWEB)

Kim, Tae W.; Kim, Nam H.; Suh, Kune Y. [Seoul National University, Seoul (Korea, Republic of); Kim, Seung O. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2007-07-01

The supercritical carbon dioxide (SCO{sub 2}) gas turbine Brayton cycle has been not only adopted in the secondary loop of the Generation IV nuclear energy systems but also planned to be installed in the high efficiency power conversion cycles of the nuclear fusion reactors. The potential beneficiaries include the Korea Advanced Liquid Metal Reactor (KALIMER), the Korea Superconducting Tokamak Advanced Research (KSTAR) as well as the International Thermonuclear Experimental Reactor (ITER). The reason for these welcomed applications is that the cycle can achieve the overall energy conversion efficiency as high as 45%. The SCO{sub 2} turbine efficiency is one of the major parameters affecting the overall Brayton cycle efficiency. Thus, optimal turbine design determines the economics of the Generation IV as well as the future nuclear fission and fusion energy industry. Seoul National University has recently been working on the SCO{sub 2} based Modular Optimized Brayton Integral System (MOBIS). MOBIS includes the Gas Advanced Turbine Operation Study (GATOS), the Loop Operating Brayton Optimization Study (LOBOS), the Nonsteady Operation Multidimensional Online Simulator (NOMOS), and the Turbine Advanced Compressor Operation Study (TACOS). This paper presents results from GATOS.

Measures for carbon dioxide problem and utilization of energy

International Nuclear Information System (INIS)

Kojima, Toshinori

1992-01-01

As global environment problems, there are water, expansion of deserts, weather, tropical forests, wild animals, ocean pollution, nuclear waste contamination, acid rain, ozone layer and so on, and population, foods, energy, and resources are the problems surrounding them. It is clear that these origins are attributed to the development and consumption largely dependent on the intention of developed countries and the population problem of developing countries. In this report, the discharge of carbon dioxide that causes greenhouse effect and its relation with energy are discussed. The increase of carbon dioxide concentration, its release from fossil fuel, the destruction of forests, the balance of carbon on the earth, the development of new energy such as solar energy, the transport of new energy, secondary energy system and the role of carbon dioxide, the transfer to low carbon fuel and the carbon reduction treatment of fuel, the utilization of unused energy and energy price, the efficiency of energy utilization, the heightening of efficiency of energy conversion, energy conservation and the breakaway from energy wasteful use culture, and the recovery, preservation and use of discharged carbon dioxide are described. (K.I.)

Nuclear reactions video (knowledge base on low energy nuclear physics)

International Nuclear Information System (INIS)

Zagrebaev, V.; Kozhin, A.

1999-01-01

The NRV (nuclear reactions video) is an open and permanently extended global system of management and graphical representation of nuclear data and video-graphic computer simulation of low energy nuclear dynamics. It consists of a complete and renewed nuclear database and well known theoretical models of low energy nuclear reactions altogether forming the 'low energy nuclear knowledge base'. The NRV solves two main problems: 1) fast and visualized obtaining and processing experimental data on nuclear structure and nuclear reactions; 2) possibility for any inexperienced user to analyze experimental data within reliable commonly used models of nuclear dynamics. The system is based on the realization of the following principal things: the net and code compatibility with the main existing nuclear databases; maximal simplicity in handling: extended menu, friendly graphical interface, hypertext description of the models, and so on; maximal visualization of input data, dynamics of studied processes and final results by means of real three-dimensional images, plots, tables and formulas and a three-dimensional animation. All the codes are composed as the real Windows applications and work under Windows 95/NT

Carbon Dioxide Detection and Indoor Air Quality Control.

Science.gov (United States)

Bonino, Steve

2016-04-01

When building ventilation is reduced, energy is saved because it is not necessary to heat or cool as much outside air. Reduced ventilation can result in higher levels of carbon dioxide, which may cause building occupants to experience symptoms. Heating or cooling for ventilation air can be enhanced by a DCV system, which can save energy while providing a comfortable environment. Carbon dioxide concentrations within a building are often used to indicate whether adequate fresh air is being supplied to the building. These DCV systems use carbon dioxide sensors in each space or in the return air and adjust the ventilation based on carbon dioxide concentration; the higher the concentration, the more people occupy the space relative to the ventilation rate. With a carbon dioxide sensor DCV system, the fresh air ventilation rate varies based on the number ofpeople in the space, saving energy while maintaining a safe and comfortable environment.

Carbon dioxide production in animal houses

DEFF Research Database (Denmark)

Pedersen, Søren; Blanes-Vidal, Victoria; Joergensen, H.

2008-01-01

cellars are emptied regularly in a four weeks interval. Due to a high and variable carbon dioxide production in deep straw litter houses and houses with indoor storage of manure longer than four weeks, we do not recommend to calculate the ventilation flow based on the carbon dioxide concentration......This article deals with carbon dioxide production from farm animals; more specifically, it addresses the possibilities of using the measured carbon dioxide concentration in animal houses as basis for estimation of ventilation flow (as the ventilation flow is a key parameter of aerial emissions from...... animal houses). The investigations include measurements in respiration chambers and in animal houses, mainly for growing pigs and broilers. Over the last decade a fixed carbon dioxide production of 185 litres per hour per heat production unit, hpu (i.e. 1000 W of the total animal heat production at 20o...

Physical bases of nuclear medicine

International Nuclear Information System (INIS)

Isabelle, D.B.; Ducassou, D.

1975-01-01

The physical bases of nuclear medicine are outlined in several chapters devoted successively to: atomic and nuclear structures; nuclear reactions; radioactiity laws; a study of different types of disintegration; the interactions of radiations with matter [fr

Supercritical Carbon Dioxide–Based Sterilization of Decellularized Heart Valves

Directory of Open Access Journals (Sweden)

Ryan S. Hennessy, MD

2017-02-01

Full Text Available Summary: Sterilization of grafts is essential. Supercritical carbon dioxide, electrolyzed water, gamma radiation, ethanol-peracetic acid, and hydrogen peroxide techniques were compared for impact on sterility and mechanical integrity of porcine decellularized aortic valves. Ethanol-peracetic acid– and supercritical carbon dioxide–treated valves were found to be sterile using histology, microbe culture, and electron microscopy assays. The cusp tensile properties of supercritical carbon dioxide–treated valves were higher compared with valves treated with other techniques. Superior sterility and integrity was found in the decellularized valves treated with supercritical carbon dioxide sterilization. This sterilization technique may hold promise for other decellularized soft tissues. Key Words: decellularized, decontamination, heart valve, tensile properties, tissue engineering

Science communication from women in nuclear fuel development

International Nuclear Information System (INIS)

Roy, S.B.

2013-01-01

In India, nuclear fuel is required for operating both nuclear research reactors and power reactors. Indian women are extensively involved in nuclear fuel research and production activities. However, the nature and extent of their involvement differs based only on the job required and not on any gender basis. Excluding a few specific safety and security issues, therefore, science and technology communication really does not change according to the gender of the scientist or technologist. Presently in India, nuclear grade uranium metal is required for fuelling research reactors and nuclear grade uranium oxide is being utilized as fuel for power reactors. Hydrometallurgical operations using specific solvents are being used for achieving 'nuclear grade' in both sectors. For production of uranium oxide, purified uranium compounds need to get calcined and reduced for obtaining uranium dioxide of various qualities

French experience in the field of internal dosimetry assessment at a nuclear workplace. Methods and results on industrial uranium dioxide

International Nuclear Information System (INIS)

Ansoborlo, E.; Henge-Napoli, M.H.; Rannou, A.; Pihet, P.; Dewez, P.

1995-01-01

The implementation of the new ICRP recommendations and the diversity of industrial exposure materials make it necessary to modify our approach of assessing internal dosimetry. This paper describes a methodology developed to asses different parameters such as activity concentration and particle size distribution at the workplace; physico-chemical characteristics of industrial dust handled; and in vitro and in vivo solubility in order to determine the absorption rate blood. The determination of such specific parameters will lead to dose calculation in terms of committed effective Dose Per Unit of Intake (DPUI). Results obtained for an industrial uranium dioxide, UO 2 , at a French nuclear facility are presented. (author). 21 refs., 2 figs., 4 tabs

Hydrogen energy based on nuclear energy

International Nuclear Information System (INIS)

2002-06-01

A concept to produce hydrogen of an energy carrier using nuclear energy was proposed since 1970s, and a number of process based on thermochemical method has been investigated after petroleum shock. As this method is used high temperature based on nuclear reactors, these researches are mainly carried out as a part of application of high temperature reactors, which has been carried out at an aim of the high temperature reactor application in the Japan Atomic Energy Research Institute. On October, 2000, the 'First International Conference for Information Exchange on Hydrogen Production based on Nuclear Energy' was held by auspice of OECD/NEA, where hydrogen energy at energy view in the 21st Century, technology on hydrogen production using nuclear energy, and so on, were published. This commentary was summarized surveys and researches on hydrogen production using nuclear energy carried out by the Nuclear Hydrogen Research Group established on January, 2001 for one year. They contains, views on energy and hydrogen/nuclear energy, hydrogen production using nuclear energy and already finished researches, methods of hydrogen production using nuclear energy and their present conditions, concepts on production plants of nuclear hydrogen, resources on nuclear hydrogen production and effect on global environment, requests from market and acceptability of society, and its future process. (G.K.)

Nuclear fuel rod with burnable plate and pellet-clad interaction fix

International Nuclear Information System (INIS)

Boyle, R.F.

1987-01-01

This patent describes a nuclear fuel rod comprising a metallic tubular cladding containing nuclear fuel pellets, the pellets containing enriched uranium-235. The improvement described here comprises: ceramic wafers, each wafter comprising a sintered mixture of gadolinium oxide and uranium dioxide, the uranium oxide having no more uranium-235 than is present in natural uranium dioxide. Each of the wafers is axially disposed between a major portion of adjacent the nuclear fuel pellets, whereby the wafers freeze out volatile fission products produced by the nuclear fuel and prevent interaction of the fission products with the metallic tubing cladding

Oxygen partial pressure control during in-situ high temperature X-ray diffraction on cerium dioxide

International Nuclear Information System (INIS)

Strach, M.; Belin, R.C.; Richaud, J-C.; Rogez, J.

2014-01-01

Cerium dioxide is widely used as a surrogate for plutonium dioxide in the studies of MOX type nuclear fuel. Thus, obtaining an accurate description of the structures present in this system in a range of temperatures is of importance to the development of fuel for the IV. generation of nuclear reactors. However, such a study requires appropriate scientific tools, in particular regarding the control and monitoring of the oxygen partial pressure (pO 2 ). Here we discuss several in-situ X-ray diffraction experiments performed to determine the phases present in the hypo-stoichiometric CeO 2-x region of the phase diagram and clearly demonstrate the need for controlling the pO 2 . (authors)

Emanation of /sup 232/U daughter products from submicrometer particles of uranium oxide and thorium dioxide by nuclear recoil and inert gas diffusion

Energy Technology Data Exchange (ETDEWEB)

Coombs, M.A.; Cuddihy, R.G. (Lovelace Biomedical and Environmental Research Inst., Albuquerque, NM (USA). Inhalation Toxicology Research Inst.)

1983-01-01

Emanation of /sup 232/U daughter products by nuclear recoil and inert gas diffusion from spherical, submicrometer particles of uranium oxide and thorium dioxide was studied. Monodisperse samples of particles containing 1% /sup 232/U and having physical diameters between 0.1 and 1 ..mu..m were used for the emanation measurements. Thorium-228 ions recoiling from the particles after alpha-decay of /sup 232/U were collected electrostatically on a recoil cathode. Radon-220 diffusing from the particles was swept by an airstream into a 4 l. chamber where the /sup 220/Rn daughters were collected on a second cathode. Mathematical models of radionuclide emanation from spherical particles were used to calculate the recoil range of /sup 228/Th and the diffusion coefficient of /sup 220/Rn in the particle matrix. A /sup 228/Th recoil range of 0.02 ..mu..m and a /sup 220/Rn diffusion coefficient of 3 x 10/sup -14/ cm/sup 2//sec were obtained in both uranium oxide and thorium dioxide particles.

Nuclear carrier business volume projections, 1980-2000

International Nuclear Information System (INIS)

Lebo, R.G.; McKeown, M.S.; Rhyne, W.R.

1980-05-01

The expected number of shipments of commodities in the nuclear fuel cycle are projected for the years 1980 thru 2000. Projections are made for: yellowcake (U 3 O 8 ); natural, enriched and reprocessed uranium hexafluoride (UF 6 ); uranium dioxide powder (UO 2 ); plutonium dioxide powder (PuO 2 ); fresh UO 2 and mixed oxide (MOX) fuel; spent UO 2 fuel; low-level waste (LLW); transuranic (TRU) waste; high-activity TRU waste; high-level waste (HLW), and cladding hulls. Projections are also made for non-fuel cycle commodities such as defense TRU wastes and institutional wastes, since they also are shipped by the commercial transportation industry. Projections of waste shipments from LWRs are based on the continuation of current volume reduction and solidification techniques now used by the utility industry. Projections are also made based on a 5% per year reduction in LWR waste volume shipped which is assumed to occur as a result of increased implementation of currently available volume reduction systems. This assumption results in a net 64% decrease in the total waste shipped by the year 2000. LWR waste shipment projections, and essentially all other projections for fuel cycle commodities covered in this report, are normalized to BWR and PWR generating capacity projections set forth by the Department of Energy (DOE) in their low-growth projection of April, 1979. Therefore these commodity shipment projections may be altered to comply with future changes in generating capacity projections. Projected shipments of waste from the reprocessing of spent UO 2 fuel are based on waste generation rates proposed by Nuclear Fuels Services, Allied-General Nuclear Services, Exxon Nuclear, and the DOE. Reprocessing is assumed to begin again in 1990, with mixed oxide fresh fuel available for shipment by 1991

Does nuclear energy save global environment?

International Nuclear Information System (INIS)

Matsui, Kazuaki

2006-01-01

Since the ecological footprint analysis in 1970s suggested changing consumption patterns and overpopulation concerns, energy policy such as energy conservation and use of renewable energy has become of prime importance. Several results of the long-term energy demand and supply analysis in 2050 or 2100 to reduce drastically carbon dioxide emission as a measure against global warming, showed the necessity of nuclear power deployment as well as maximum efforts to save energy, exploitation of the separation and disposal of carbon dioxide, and shifting energy sources to fuels that emit less greenhouse gases or non-fossil fuels. As a promising means to contribute to long-term energy supply, nuclear power generation is expected with improving safety, economic efficiency, environmental adaptability, and nuclear proliferation resistance of the technologies. (T.Tanaka)

Enantioselective small molecule synthesis by carbon dioxide fixation using a dual Brønsted acid/base organocatalyst.

Science.gov (United States)

Vara, Brandon A; Struble, Thomas J; Wang, Weiwei; Dobish, Mark C; Johnston, Jeffrey N

2015-06-17

Carbon dioxide exhibits many of the qualities of an ideal reagent: it is nontoxic, plentiful, and inexpensive. Unlike other gaseous reagents, however, it has found limited use in enantioselective synthesis. Moreover, unprecedented is a tool that merges one of the simplest biological approaches to catalysis-Brønsted acid/base activation-with this abundant reagent. We describe a metal-free small molecule catalyst that achieves the three component reaction between a homoallylic alcohol, carbon dioxide, and an electrophilic source of iodine. Cyclic carbonates are formed enantioselectively.

Analysis of burnup of Angra 2 PWR nuclear with addition of thorium dioxide fuel using ORIGEN-ARP

Energy Technology Data Exchange (ETDEWEB)

Goncalves, Isadora C.; Wichrowski, Caio C.; Oliveira, Claudio L. de; Vellozo, Sergio O.; Baptista, Camila O., E-mail: isadora.goncalves@ime.eb.br, E-mail: wichrowski@ime.eb.br, E-mail: d7luiz@yahoo.com.br, E-mail: vellozo@ime.eb.br, E-mail: camila.oliv.baptista@gmail.com [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil). Secao de Engenharia Nuclear

2017-11-01

It is known that isotope {sup 232}thorium is a fertile nuclide with the ability to convert into {sup 233}uranium, a potentially fissile isotope, after absorbing a neutron. As there is a large stock of available thorium in the world, this element shows great promise in mitigate the world energy crisis, more particularly in the problem of uranium scarcity, besides being an alternative nuclear fuel for those currently used in reactors, and yet presenting advantages as an option for the non-proliferation movement, among others. In this study, the analysis of the remaining nuclides of burnup was carried out for the core configuration of a PWR (pressurized water reactor) reactor, specifically the Angra 2 reactor, using only uranium dioxide, its current configuration, and in different configurations including a mixed oxide of uranium and thorium in three concentrations, allowing a preliminary assessment of the feasibility of the modification of the fuel, the resulting production of {sup 233}uranium, the emergence of {sup 231}protactinium (an isotope that only occurs as a fission product of {sup 232}Th) resulting from burning. The study was carried out using data obtained from FSAR (Final Safety Analysis Report) of Angra 2, using the SCALE 6.1, a modeling and simulation nuclear code, especially its ORIGEN-ARP module, which analyzes the depletion of isotopes presents in a reactor. (author)

Analysis of burnup of Angra 2 PWR nuclear with addition of thorium dioxide fuel using ORIGEN-ARP

International Nuclear Information System (INIS)

Goncalves, Isadora C.; Wichrowski, Caio C.; Oliveira, Claudio L. de; Vellozo, Sergio O.; Baptista, Camila O.

2017-01-01

It is known that isotope "2"3"2thorium is a fertile nuclide with the ability to convert into "2"3"3uranium, a potentially fissile isotope, after absorbing a neutron. As there is a large stock of available thorium in the world, this element shows great promise in mitigate the world energy crisis, more particularly in the problem of uranium scarcity, besides being an alternative nuclear fuel for those currently used in reactors, and yet presenting advantages as an option for the non-proliferation movement, among others. In this study, the analysis of the remaining nuclides of burnup was carried out for the core configuration of a PWR (pressurized water reactor) reactor, specifically the Angra 2 reactor, using only uranium dioxide, its current configuration, and in different configurations including a mixed oxide of uranium and thorium in three concentrations, allowing a preliminary assessment of the feasibility of the modification of the fuel, the resulting production of "2"3"3uranium, the emergence of "2"3"1protactinium (an isotope that only occurs as a fission product of "2"3"2Th) resulting from burning. The study was carried out using data obtained from FSAR (Final Safety Analysis Report) of Angra 2, using the SCALE 6.1, a modeling and simulation nuclear code, especially its ORIGEN-ARP module, which analyzes the depletion of isotopes presents in a reactor. (author)

Nuclear power and other thermal power

International Nuclear Information System (INIS)

Bakke, J.

1978-01-01

Some philosophical aspects of mortality statistics are first briefly mentioued, then the environmental problems of, first, nuclear power plants, then fossil fuelled power plants are summarised. The effects of releases of carbon dioxide, sulphur dioxide and nitrogen oxides are briefly discussed. The possible health effects of radiation from nuclear power plants and those of gaseous and particulate effluents from fossil fuel plants are also discussed. It is pointed out that in choosing between alternative evils the worst course is to make no choice at all, that is, failure to install thermal power plants will lead to isolated domestic burning of fossil fuels which is clearly the worst situation regarding pollution. (JIW)

Risk assessment and nuclear power

International Nuclear Information System (INIS)

Bodansky, D.

1982-01-01

The range of risk perceptions involving nuclear power is so great that there is little hope of bridging extreme positions, but a consensus based upon reasoned discussion among uncommitted people could determine a sensible path. Our concerns over the uncertainties of risk assessment have made it increasingly difficult to make responsible decisions fast enough to deal with modern needs. The result is an immobility in energy matters that can point to a 2% reduction in oil use as its only triumph. The risk of nuclear war as a result of military action over energy issues suggests to some that the solution is to abolish nuclear power (however impractical) and to others that a rapid spread of nuclear power will eliminate energy as an incentive for war. If nuclear war is the major risk to consider, risk assessments need to include the risks of war, as well as those of carbon dioxide buildup and socio-economic disruptions, all of which loom larger than the risks of nuclear-plant accidents. Energy choices should be aimed at diminishing these major risks, even if they include the use of nuclear power. 26 references

Requirements for controlling a repository's releases of carbon-14 dioxide; the high costs and negligible benefits

International Nuclear Information System (INIS)

Park, U Sun; Pflum, C.G.

1990-01-01

A repository excavated within the unsaturated zone may release carbon (C)-14 dioxide in amounts that exceed limits imposed by the Environmental Protection Agency (EPA) and the Nuclear Regulatory Commission (NRC). The release would not threaten the general population, but may expose some hypothetical maximally exposed individual to 0.0005 millirems/year. Yet a repository's releases of C-14 dioxide are strictly regulated, perhaps unintentionally. The EPA and NRC regulations could force the Department of Energy to design and fabricate an expensive 10,000-year waste package solely for the sake of controlling releases of C-14 dioxide. This paper argues that the repository regulations should exempt releases of C-14 dioxide or at least impose more equitable limits. 21 refs., 1 tab

NARCISS critical stand experiments for studying the nuclear safety in accident water immersion of highly enriched uranium dioxide fuel elements

International Nuclear Information System (INIS)

Ponomarev-Stepnoj, N.N.; Glushkov, E.S.; Bubelev, V.G.

2005-01-01

A brief description of the Topaz-2 SNPS designed under scientific supervision of RRC KI in Russia, and of the NARCISS critical facility, is given. At the NARCISS critical facility, neutronic peculiarities and nuclear safety issues of the Topaz-2 system reactor were studied experimentally. This work is devoted to a detailed description of experiments on investigation of criticality safety in accident water immersion og highly enriched uranium dioxide fuel elements, performed at the NARCISS facility. The experiments were carried out at water-moderated critical assemblies with varying height, number, and spacing of fuel elements. The results obtained in the critical experiments, computational models of the investigated critical configurations, and comparison of the computational and experimental results are given [ru

Proprietary, standard, and government-supported nuclear data bases

International Nuclear Information System (INIS)

Poncelet, C.G.; Ozer, O.; Harris, D.R.

1975-07-01

This study presents an assessment of the complex situation surrounding nuclear data bases for nuclear power technology. Requirements for nuclear data bases are identified as regards engineering functions and system applications for the many and various user groups that rely on nuclear data bases. Current practices in the development and generation of nuclear data sets are described, and the competitive aspect of design nuclear data set development is noted. The past and current role of the federal government in nuclear data base development is reviewed, and the relative merits of continued government involvement are explored. National policies of the United States and other industrial countries regarding the availability of nationally supported nuclear data information are reviewed. Current proprietary policies of reactor vendors regarding design library data sets are discussed along with the basis for such proprietary policies. The legal aspects of protective policies are explored as are their impacts on the nuclear power industry as a whole. The effect of the regulatory process on the availability and documentation of nuclear data bases is examined. Current nuclear data standard developments are reviewed, including a discussion of the standard preparation process. Standards currently proposed or in preparation that directly relate to nuclear data bases are discussed in some detail. (auth)

Nuclear energy supports sustainable development

International Nuclear Information System (INIS)

Koprda, V.

2005-01-01

The article is aimed at acceptability, compatibility and sustainability of nuclear energy as non-dispensable part of energy sources with vast innovation potential. The safety of nuclear energy , radioactive waste deposition, and prevention of risk from misuse of nuclear material have to be very seriously abjudged and solved. Nuclear energy is one of the ways how to decrease the contamination of atmosphere with carbon dioxide and it solves partially also the problem of global increase of temperature and climate changes. Given are the main factors responsible for the renaissance of nuclear energy. (author)

Evaluation of a membrane based carbon dioxide absorber for spacecraft ECLS applications

NARCIS (Netherlands)

Feron, P.H.M.; Eckhard, F.; Witt, J.

1996-01-01

In an on-going harmonized ESA/NIVR project, performed by Stork Comprimo and TNO-MEP, the removal of the carbon dioxide with membranes is studied. The use of membrane gas absorption for carbon dioxide removal is currently hampered by the fact that the commonly used alkanolamines result in leakage

Metal corrosion in a supercritical carbon dioxide - liquid sodium power cycle.

Energy Technology Data Exchange (ETDEWEB)

Moore, Robert Charles; Conboy, Thomas M.

2012-02-01

A liquid sodium cooled fast reactor coupled to a supercritical carbon dioxide Brayton power cycle is a promising combination for the next generation nuclear power production process. For optimum efficiency, a microchannel heat exchanger, constructed by diffusion bonding, can be used for heat transfer from the liquid sodium reactor coolant to the supercritical carbon dioxide. In this work, we have reviewed the literature on corrosion of metals in liquid sodium and carbon dioxide. The main conclusions are (1) pure, dry CO{sub 2} is virtually inert but can be highly corrosive in the presence of even ppm concentrations of water, (2) carburization and decarburization are very significant mechanism for corrosion in liquid sodium especially at high temperature and the mechanism is not well understood, and (3) very little information could be located on corrosion of diffusion bonded metals. Significantly more research is needed in all of these areas.

The cohesive energy of uranium dioxide and thorium dioxide

International Nuclear Information System (INIS)

Childs, B.G.

1958-08-01

Theoretical values have been calculated of the heats of formation of uranium dioxide and thorium dioxide on the assumption that the atomic binding forces in these solids are predominantly ionic in character. The good agreement found between the theoretical and observed values shows that the ionic model may, with care, be used in calculating the energies of defects in the uranium and thorium dioxide crystal structures. (author)

Standard test methods for chemical, mass spectrometric, and spectrochemical analysis of nuclear-grade plutonium dioxide powders and pellets

CERN Document Server

American Society for Testing and Materials. Philadelphia

2010-01-01

1.1 These test methods cover procedures for the chemical, mass spectrometric, and spectrochemical analysis of nuclear-grade plutonium dioxide powders and pellets to determine compliance with specifications. 1.2 The analytical procedures appear in the following order: Sections Plutonium Sample Handling 8 to 10 Plutonium by Controlled-Potential Coulometry Plutonium by Ceric Sulfate Titration Plutonium by Amperometric Titration with Iron(II) Plutonium by Diode Array Spectrophotometry Nitrogen by Distillation Spectrophotometry Using Nessler Reagent 11 to 18 Carbon (Total) by Direct Combustion–Thermal Conductivity 19 to 30 Total Chlorine and Fluorine by Pyrohydrolysis 31 to 38 Sulfur by Distillation Spectrophotometry 39 to 47 Plutonium Isotopic Analysis by Mass Spectrometry Rare Earth Elements by Spectroscopy 48 to 55 Trace Elements by Carrier–Distillation Spectroscopy 56 to 63 Impurities by ICP-AES Impurity Elements by Spark-Source Mass Spectrography 64 to 70 Moisture by the Coulomet...

Design of a supercritical carbon dioxide cooled reactor for marine applications

International Nuclear Information System (INIS)

Bollardiere, T. Paris de; Verchere, T.; Wilson, M.; O'Sullivan, P.; Heap, S.; Thompson, A.; Jewer, S.; Beeley, P.A.

2009-01-01

The reactor physics and thermal hydraulics aspects of a feasibility study conducted to assess the potential of a supercritical carbon dioxide (sCO2) cooled nuclear reactor for marine propulsion are presented. Supercritical carbon dioxide cycles have been proposed for next generation nuclear plants as such cycles take advantage of sCO2 property changes near the critical point which leads to improved plant efficiency over existing nuclear plant cycles at the same temperatures and pressures. Selecting two 192 MWth cores and a recompression Brayton cycle it was determined that a maximum power conversion efficiency of 47.5 % could be achieved. The core design employs TRISO particles in a graphite matrix forming a fuelled annulus in a prismatic graphite moderating block. The design of this plant has been modeled using WIMS/MONK (neutronics) and Flownex (plant thermal hydraulics and power conversion). Plant modeling found that the core remains within thermal safety limits in the event of a LOCA. The major limitation of the design was found to be the high xenon levels produced as a result of the high neutron flux required of a gas cooled reactor and the effect it has on the versatility of the plant to cope with changes in power demand. (author)

Nuclear energy and environment

Energy Technology Data Exchange (ETDEWEB)

NONE

1991-12-31

The film stresses that a drastic reduction in carbon dioxide emissions, mainly from the burning of fossil fuels, must be achieved to limit a dangerous concentration of greenhouse gases in the atmosphere. It compares the environmental costs of different energy sources, in particular the wastes of a coal-fired versus a nuclear plant, and mentions the measures taken to reinforce protection against the risk of nuclear accidents

Basic study for development of nuclear heat application systems

Energy Technology Data Exchange (ETDEWEB)

Inaba, Yoshitomo; Fumizawa, Motoo; Hishida, Makoto [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment] [and others

1996-05-01

We need to intensely investigate real possibilities of nuclear heat application systems which exploit high potential of nuclear energy as a promising candidate of the future energy resource in the world. In this report, special interest was placed on coal reforming systems because we thought a compact heat source of nuclear power with a very high energy density might compensate the environmental problem caused by burning a great amount of coal. First, we reviewed state-of-the-art technologies for coal reforming technology with a special attention on coal gasification technologies. Based on these basic data, we proposed several nuclear coal reforming systems and discussed advantages and disadvantages of the systems. We also explored a model with which we could analyze nuclear heat application systems all together. In addition, we investigated possibility and effects of nuclear heat utilization systems producing chemical materials from carbon dioxide in flue gas of fossil fuel power plant. As a result, we showed nuclear heat application systems were useful. (author).

BILP-19-An Ultramicroporous Organic Network with Exceptional Carbon Dioxide Uptake.

Science.gov (United States)

Klumpen, Christoph; Radakovitsch, Florian; Jess, Andreas; Senker, Jürgen

2017-08-12

Porous benzimidazole-based polymers (BILPs) have proven to be promising for carbon dioxide capture and storage. The polarity of their chemical structure in combination with an inherent porosity allows for adsorbing large amounts of carbon dioxide in combination with high selectivities over unpolar guest molecules such as methane and nitrogen. For this reason, among purely organic polymers, BILPs contain some of the most effective networks to date. Nevertheless, they are still outperformed by competitive materials such as metal-organic frameworks (MOFs) or metal doped porous polymers. Here, we report the synthesis of BILP-19 and its exceptional carbon dioxide uptake of up to 6 mmol•g-1 at 273 K, making the network comparable to state-of-the-art materials. BILP-19 precipitates in a particulate structure with a strongly anisotropic growth into platelets, indicating a sheet-like structure for the network. It exhibits only a small microporous but a remarkable ultra-microporous surface area of 144 m2•g-1 and 1325 m2•g-1, respectively. We attribute the exceptional uptake of small guest molecules such as carbon dioxide and water to the distinct ultra-microporosity. Additionally, a pronounced hysteresis for both guests is observed, which in combination with the platelet character is probably caused by an expansion of the interparticle space, creating additional accessible ultra-microporous pore volume. For nitrogen and methane, this effect does not occur which explains their low affinity. In consequence, Henry selectivities of 123 for CO2/N2 at 298 K and 12 for CO2/CH4 at 273 K were determined. The network was carefully characterized with solid-state nuclear magnetic resonance (NMR) and infrared (IR) spectroscopy, thermal gravimetry (TG) and elemental analyses as well as physisorption experiments with Ar, N2, CO2, CH4 and water.

Scenario-based roadmapping assessing nuclear technology development paths for future nuclear energy system scenarios

International Nuclear Information System (INIS)

Van Den Durpel, Luc; Roelofs, Ferry; Yacout, Abdellatif

2009-01-01

Nuclear energy may play a significant role in a future sustainable energy mix. The transition from today's nuclear energy system towards a future more sustainable nuclear energy system will be dictated by technology availability, energy market competitiveness and capability to achieve sustainability through the nuclear fuel cycle. Various scenarios have been investigated worldwide each with a diverse set of assumptions on the timing and characteristics of new nuclear energy systems. Scenario-based roadmapping combines the dynamic scenario-analysis of nuclear energy systems' futures with the technology roadmap information published and analysed in various technology assessment reports though integrated within the nuclear technology roadmap Nuclear-Roadmap.net. The advantages of this combination is to allow mutual improvement of scenario analysis and nuclear technology roadmapping providing a higher degree of confidence in the assessment of nuclear energy system futures. This paper provides a description of scenario-based roadmapping based on DANESS and Nuclear-Roadmap.net. (author)

Carbon dioxide fluid-flow modeling and injectivity calculations

Science.gov (United States)

Burke, Lauri

2011-01-01

At present, the literature lacks a geologic-based assessment methodology for numerically estimating injectivity, lateral migration, and subsequent long-term containment of supercritical carbon dioxide that has undergone geologic sequestration into subsurface formations. This study provides a method for and quantification of first-order approximations for the time scale of supercritical carbon dioxide lateral migration over a one-kilometer distance through a representative volume of rock. These calculations provide a quantified foundation for estimating injectivity and geologic storage of carbon dioxide.

Climate change and the competitiveness of nuclear power

International Nuclear Information System (INIS)

Han, Seung Hyuk; Oh, Jin Ho

2007-01-01

Global atmospheric concentrations of carbon dioxide have increased remarkably as a result of human activities since the Industrial Revolution. According to the 4th Assessment Report of the IPCC (Intergovernmental Panel on Climate Change), dated February 2007, many scientific and technical facts show that the primary source of the increased atmospheric concentration of carbon dioxide results from 'fossil fuel use'. with land use change providing another significant but smaller contribution. And the report says that the global average temperature will rise 1.8∼4.deg.C in the 21st century, which has the probability of above 90%. Also there was an important announcement in COP12 meeting which was held in Kenya on November 2006, where the Stern Review revealed that the overall costs and risks of Climate Change would be equivalent to loss at least 5% of global GDP each year, now and after. These are risks of major disruption to economic and social activity, on a scale similar to those associated with the great wars and the economic depression of the first half of the 20th century. Natural gas dispute of Russia Ukraine in 2006 and oil pipeline dispute of Russia Belarus in the beginning of 2007 provided the important message to the world as well as European countries with respect to energy security which means the stability of energy supply. Annex I nations have duties to cut GHG emissions about 5.2% according to the Kyoto Protocol. As worldwide energy environment is changing, nuclear power industries have met the new situation after TMI accident in 1979 and Chernovyl accident in 1986 which made the nuclear power industries frozen for 30 years. There also have been technical developments and cost saving efforts to strengthen competitiveness of the nuclear power industries. However, nuclear power did not acquire its validity in cost based competitiveness compared to fossil fuels but just keeps its advantage of stability in fuel supply. This study describes GHG emission

Carbon dioxide utilization in a microalga-based biorefinery: Efficiency of carbon removal and economic performance under carbon taxation.

Science.gov (United States)

Wiesberg, Igor Lapenda; Brigagão, George Victor; de Medeiros, José Luiz; de Queiroz Fernandes Araújo, Ofélia

2017-12-01

Coal-fired power plants are major stationary sources of carbon dioxide and environmental constraints demand technologies for abatement. Although Carbon Capture and Storage is the most mature route, it poses severe economic penalty to power generation. Alternatively, this penalty is potentially reduced by Carbon Capture and Utilization, which converts carbon dioxide to valuable products, monetizing it. This work evaluates a route consisting of carbon dioxide bio-capture by Chlorella pyrenoidosa and use of the resulting biomass as feedstock to a microalgae-based biorefinery; Carbon Capture and Storage route is evaluated as a reference technology. The integrated arrangement comprises: (a) carbon dioxide biocapture in a photobioreactor, (b) oil extraction from part of the produced biomass, (b) gasification of remaining biomass to obtain bio-syngas, and (c) conversion of bio-syngas to methanol. Calculation of capital and operational expenditures are estimated based on mass and energy balances obtained by process simulation for both routes (Carbon Capture and Storage and the biorefinery). Capital expenditure for the biorefinery is higher by a factor of 6.7, while operational expenditure is lower by a factor of 0.45 and revenues occur only for this route, with a ratio revenue/operational expenditure of 1.6. The photobioreactor is responsible for one fifth of the biorefinery capital expenditure, with footprint of about 1000 ha, posing the most significant barrier for technical and economic feasibility of the proposed biorefinery. The Biorefinery and Carbon Capture and Storage routes show carbon dioxide capture efficiency of 73% and 48%, respectively, with capture cost of 139$/t and 304$/t. Additionally, the biorefinery has superior performance in all evaluated metrics of environmental impacts. Copyright © 2017 Elsevier Ltd. All rights reserved.

Nuclear power after Copenhagen

International Nuclear Information System (INIS)

Adam, G.

2010-01-01

The presentation discusses the problems of carbon dioxide emissions and advantages of nuclear technology as the only non-carbon technology with a proven track record that can make a significant contribution on the scale that will be required. The nuclear technology also has the potential to produce carbon free heat, and a further potential to produce hydrogen for the transport sector and possibly also for desalination projects. Nuclear energy also helps to reduce the serious health effects resulting from fossil fuel combustion which particularly affects women

Energy supplies in view of the climatic problem with carbon dioxide

International Nuclear Information System (INIS)

Voigt, H.

1988-01-01

Climatic changes can be expected with increasing and even with stagnating carbon dioxide emissions. If they are to be restricted to an apparently bearable level, the consumption of fossil energy carriers must be reduced. This can be attained through a reduction in requirement and through increased use of non-fossil primary energy forms. Amongst these, nuclear energy and hydroelectricity are already available. Both nuclear energy and solar energy are by human standards adequate and inexhaustible sources of energy, if thorium 232 and uranium 238 are used in high temperature and breeder reactors and if the new techniques for the extensive use of solar energy are successfully developed. A possible structure for the future energy supply industry with a third of present-day carbon dioxide emissions is presented for the example of the Federal Republic of Germany and for a global model. The change in structure must begin now, because later the rates of change needed would be unrealistically high from a technical and economic point of view. Some apparently necessary and possible steps towards this objective are indicated. (orig.) [de

Investigation of the dissolution of uranium dioxide in nitric media: a new approach aiming at understanding interface mechanisms

International Nuclear Information System (INIS)

Delwaulle, Celine

2011-01-01

This research thesis deals with the back-end cycle of the nuclear fuel by improving, modernizing and optimizing the processes used for all types of fuels which are to be re-processed. After a presentation of the industrial context and of the state of the art concerning dissolution kinetic data for uranium dioxide and mixed oxide, the author proposes a model which couples dissolution kinetics and hydrodynamics of a solid in presence of auto-catalytic species, in order to better understand phenomena occurring at the solid-liquid-gas interface. The next part reports dissolution experiments on a non-radioactive material (copper) and out of a nuclear environment. Then, the author identifies steps which are required to transpose this experiment within a nuclear environment. The first results obtained on uranium dioxide are discussed. Recommendations for further studies conclude the report

Ion implantation to improve mechanical and electrical properties of resistive materials based on ruthenium dioxide

International Nuclear Information System (INIS)

Byeli, A.V.; Shykh, S.K.; Beresina, V.P.

1996-01-01

This paper reports the influence of ion implantation, using different chemical species, on the surface micromorphology, wear resistance, coefficient of friction and electrical resistivity, and its variation during friction for resistive materials based on ruthenium dioxide. It is demonstrated that nitrogen and hydrogen ions are the most effective for modifying surface properties. (Author)

Amperometric sensor for carbon dioxide: design, characteristics, and perforance

International Nuclear Information System (INIS)

Evans, J.; Pletcher, D.; Warburton, P.R.G.; Gibbs, T.K.

1989-01-01

A new sensor for atmospheric carbon dioxide is described. It is an amperometric device based on a porous electrode in a three-electrode cell and the electrolyte is a copper diamine complex in aqueous potassium chloride. The platinum cathode, held at constant potential, is used to detect the formation of Cu 2+ following the change in the pH of the solution when the sensor is exposed to an atmosphere containing carbon dioxide. The sensor described is designed to monitor carbon dioxide concentrations in the range 0-5%, although with some modifications, other ranges would be possible. The response to a change in the carbon dioxide content of the atmosphere is rapid (about 10s) while the monitored current is strongly (but nonlinearly) dependent on carbon dioxide concentration. Unlike other amperometric devices for carbon dioxide, there is no interference from oxygen although other acid gases would lead to an interfering response

Combined effect of sulfur dioxide and carbon dioxide gases on mold fungi

Energy Technology Data Exchange (ETDEWEB)

Kochurova, A.I.; Karpova, T.N.

1974-01-01

Sulfur dioxide at 0.08% killed Penicillium expansum, Stemphylium macrosporium, and Botrytis cinerea within 24 hours. At 0.2%, it killed P. citrinum, Alternaria tenuis, and Fusarium moniliforme. Sulfur dioxide (at 0.04%) and Sulfur dioxide-carbon dioxide mixtures (at 0.02 and 5% respectively) completely suppressed the growth of P. citrinum, P. expansum, P. rubrum, A. tenuis, S. macrosporium, B. cinerea, and F. moniliforme in laboratory experiments. 1 table.

Surface Characterization and Electrochemical Oxidation of Metal Doped Uranium Dioxide

Energy Technology Data Exchange (ETDEWEB)

Lee, Jeongmook; Kim, Jandee; Youn, Young-Sang; Kim, Jong-Goo; Ha, Yeong-Keong; Kim, Jong-Yun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-10-15

Trivalent element in UO{sub 2} matrix makes the oxygen vacancy from loss of oxygen for charge compensation. Tetravalent element alters lattice parameter of UO{sub 2} due to diameter difference between the tetravalent element and replaced U. These structural changes have significant effect on not only relevant fuel performance but also the kinetics of fuel oxidation. Park and Olander explained the stabilization of Ln (III)-doped UO{sub 2} against oxidation based on oxygen potential calculations. In this work, we have been investigated the effect of Gd{sup 3+} and Th{sup 4+} doping on the UO{sub 2} structure with Raman spectroscopy and X-ray diffraction to characterize the surface structure of nuclear fuel material. For Gd doped UO{sub 2}, its electrochemical oxidation behaviors are also investigated. The Gd and Th doped uranium dioxide solid solution pellets with various doping level were investigated by XRD, Raman spectroscopy, SEM, electrochemical experiments to investigate surface structure and electro chemical oxidation behaviors. The lattice parameter evaluated from XRD spectra indicated the formation of solid solutions. Raman spectra showed the existence of the oxygen vacancy. SEM images showed the grain structure on the surface of Gd doped uranium dioxide depending on doping level and oxygen-to-metal ratio.

Determination of the stoichiometric ratio uranium dioxide samples

International Nuclear Information System (INIS)

Moura, Sergio Carvalho

1999-01-01

The determination of the O/U stoichiometric ratio in uranium dioxide is an important parameter in order to qualify nuclear fuels. The excess oxygen in the crystallographic structure can cause changes in the physico-chemical properties of this compound such as variation of the thermal conductivity alterations, fuel plasticity and others, affecting the efficiency of this material when it is utilized as nuclear fuel in the reactor core. The purpose of this work is to evaluate methods for the determination of uranium oxide samples from two different production processes, using gravimetric, voltammetric and X-ray diffraction techniques. After the evaluation of these techniques, the main aspect of this work is to define a reliable methodology in order to characterize the behavior of uranium oxide. The methodology used in this work consisted of two different steps: utilization of gravimetric and volumetric methods in order to determine the ratio in uranium dioxide samples; utilization of X-ray diffraction technique in order to determine the lattice parameters using patterns and application of the Rietveld method during refining of the structural data. As a result of the experimental part of this work it was found that the X-ray diffraction analysis performs better and detects the presence of more phases than gravimetric and voltammetric techniques, not sensitive enough in this detection. (author)

Capacitor-based detection of nuclear magnetization: nuclear quadrupole resonance of surfaces.

Science.gov (United States)

Gregorovič, Alan; Apih, Tomaž; Kvasić, Ivan; Lužnik, Janko; Pirnat, Janez; Trontelj, Zvonko; Strle, Drago; Muševič, Igor

2011-03-01

We demonstrate excitation and detection of nuclear magnetization in a nuclear quadrupole resonance (NQR) experiment with a parallel plate capacitor, where the sample is located between the two capacitor plates and not in a coil as usually. While the sensitivity of this capacitor-based detection is found lower compared to an optimal coil-based detection of the same amount of sample, it becomes comparable in the case of very thin samples and even advantageous in the proximity of conducting bodies. This capacitor-based setup may find its application in acquisition of NQR signals from the surface layers on conducting bodies or in a portable tightly integrated nuclear magnetic resonance sensor. Copyright © 2010 Elsevier Inc. All rights reserved.

Carbon dioxide as chemical feedstock

National Research Council Canada - National Science Library

Aresta, M

2010-01-01

... Dioxide as an Inert Solvent for Chemical Syntheses 15 Alessandro Galia and Giuseppe Filardo Introduction 15 Dense Carbon Dioxide as Solvent Medium for Chemical Processes 15 Enzymatic Catalysis in Dense Carbon Dioxide 18 Other Reactions in Dense Carbon Dioxide 19 Polymer Synthesis in Supercritical Carbon Dioxide 20 Chain Polymerizations: Synt...

Fixation of carbon dioxide into dimethyl carbonate over ...

Science.gov (United States)

A titanium-based zeolitic thiophene-benzimidazolate framework has been designed for the direct synthesis of dimethyl carbonate (DMC) from methanol and carbon dioxide. The developed catalyst activates carbon dioxide and delivers over 16% yield of DMC without the use of any dehydrating agent or requirement for azeotropic distillation. Prepared for submission to Nature Scientific reports.

The nuclear energy outlook--a new book from the OECD nuclear energy agency.

Science.gov (United States)

Yoshimura, Uichiro

2011-01-01

This paper summarizes the key points of a report titled Nuclear Energy Outlook, published in 2008 by the Nuclear Energy Agency of the Organization for Economic Cooperation and Development, which has 30 member nations. The report discusses the commitment of many nations to increase nuclear power generating capacity and the potential rate of building new electricity-generating nuclear plants by 2030 to 2050. The resulting decrease in carbon dioxide emissions from fossil fuel combustion resulting from an increase in nuclear power sources is described. Other topics that are discussed include the need to develop non-proliferative nuclear fuels, the importance of developing geological disposal facilities or reprocessing capabilities for spent nuclear fuel and high-level radioactive waste materials, and the requirements for a larger nuclear workforce and greater cost competitiveness for nuclear power generation. Copyright © 2010 Health Physics Society

The basic discussion on nuclear power safety improvement based on nuclear equipment design

International Nuclear Information System (INIS)

Zhao Feiyun; Yao Yangui; Yu Hao; He Yinbiao; Gao Lei; Yao Weida

2013-01-01

The safety of strengthening nuclear power design was described based on nuclear equipment design after Fukushima nuclear accident. From these aspects, such as advanced standard system, advanced design method, suitable test means, consideration of beyond design basis event, and nuclear safety culture construction, the importance of nuclear safety improvement was emphatically presented. The enlightenment was given to nuclear power designer. (authors)

Nuclear power

International Nuclear Information System (INIS)

King, P.

1990-01-01

Written from the basis of neutrality, neither for nor against nuclear power this book considers whether there are special features of nuclear power which mean that its development should be either promoted or restrained by the State. The author makes it dear that there are no easy answers to the questions raised by the intervention of nuclear power but calls for openness in the nuclear decision making process. First, the need for energy is considered; most people agree that energy is the power to progress. Then the historicalzed background to the current position of nuclear power is given. Further chapters consider the fuel cycle, environmental impacts including carbon dioxide emission and the greenhouse effect, the costs, safety and risks and waste disposal. No conclusion either for or against nuclear power is made. The various shades of opinion are outlined and the arguments presented so that readers can come to their own conclusions. (UK)

Carbon dioxide stripping in aquaculture. part 1: terminology and reporting

Science.gov (United States)

Colt, John; Watten, Barnaby; Pfeiffer, Tim

2012-01-01

The removal of carbon dioxide gas in aquacultural systems is much more complex than for oxygen or nitrogen gas because of liquid reactions of carbon dioxide and their kinetics. Almost all published carbon dioxide removal information for aquaculture is based on the apparent removal value after the CO2(aq) + HOH ⇔ H2CO3 reaction has reached equilibrium. The true carbon dioxide removal is larger than the apparent value, especially for high alkalinities and seawater. For low alkalinity freshwaters (<2000 μeq/kg), the difference between the true and apparent removal is small and can be ignored for many applications. Analytical and reporting standards are recommended to improve our understanding of carbon dioxide removal.

Experience with a uranyl nitrate/uranium dioxide conversion pilot plant

International Nuclear Information System (INIS)

Arcuri, L.; Pietrelli, L.

1984-01-01

A plant for the precipitation of sinterable nuclear grade UO 2 powders is described in this report. The plant has been designed, built and set up by SNIA TECHINT. ENEA has been involved in the job as nuclear consultant. Main process steps are: dissolution of UO 2 powder or sintered UO 2 pellets, adjustment of uranyl nitrate solutions, precipitation of uranium peroxide by means of hydrogen peroxide, centrifugation of the precipitate, drying, calcination and reduction to uranium dioxide. The report is divided in two main section: the process description and the ''hot test'' report. Some laboratory data on precipitation of ammonium diuranate by means of NH 4 OH, are also reported

Ground-based Nuclear Detonation Detection (GNDD) Technology Roadmap

International Nuclear Information System (INIS)

Casey, Leslie A.

2014-01-01

This GNDD Technology Roadmap is intended to provide guidance to potential researchers and help management define research priorities to achieve technology advancements for ground-based nuclear explosion monitoring science being pursued by the Ground-based Nuclear Detonation Detection (GNDD) Team within the Office of Nuclear Detonation Detection in the National Nuclear Security Administration (NNSA) of the U.S. Department of Energy (DOE). Four science-based elements were selected to encompass the entire scope of nuclear monitoring research and development (R&D) necessary to facilitate breakthrough scientific results, as well as deliver impactful products. Promising future R&D is delineated including dual use associated with the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Important research themes as well as associated metrics are identified along with a progression of accomplishments, represented by a selected bibliography, that are precursors to major improvements to nuclear explosion monitoring.

Ground-based Nuclear Detonation Detection (GNDD) Technology Roadmap

Energy Technology Data Exchange (ETDEWEB)

Casey, Leslie A.

2014-01-13

This GNDD Technology Roadmap is intended to provide guidance to potential researchers and help management define research priorities to achieve technology advancements for ground-based nuclear explosion monitoring science being pursued by the Ground-based Nuclear Detonation Detection (GNDD) Team within the Office of Nuclear Detonation Detection in the National Nuclear Security Administration (NNSA) of the U.S. Department of Energy (DOE). Four science-based elements were selected to encompass the entire scope of nuclear monitoring research and development (R&D) necessary to facilitate breakthrough scientific results, as well as deliver impactful products. Promising future R&D is delineated including dual use associated with the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Important research themes as well as associated metrics are identified along with a progression of accomplishments, represented by a selected bibliography, that are precursors to major improvements to nuclear explosion monitoring.

Application of a systematic methodology for sustainable carbon dioxide utilization process design

DEFF Research Database (Denmark)

Plaza, Cristina Calvera; Frauzem, Rebecca; Gani, Rafiqul

than carbon capture and storage. To achieve this a methodology is developed to design sustainable carbon dioxide utilization processes. First, the information on the possible utilization alternatives is collected, including the economic potential of the process and the carbon dioxide emissions...... emission are desired in order to reduce the carbon dioxide emissions. Using this estimated preliminary evaluation, the top processes, with the most negative carbon dioxide emission are investigated by rigorous detailed simulation to evaluate the net carbon dioxide emissions. Once the base case design...

Fugitive binder for nuclear fuel materials

International Nuclear Information System (INIS)

Gallivan, T.J.

1980-01-01

A compound consisting of ammonium cations and carbonate, bicarbonate, or carbamate anions, or a mixture of such compounds, is useful as a binder for uranium dioxide fuel pellets for which it is desired to maintain a certain degree of porosity, uniformity of pore size, a lack of interconnections between the pores, and the shape or configuration of the base material particles in the final article after sintering. Upon heating, these binders decompose into gases and leave substantially no impurities. A process for sintering green nuclear fuel pellets using these binders is provided. (LL)

Electrocatalytic reduction of carbon dioxide on electrodeposited tin-based surfaces

Science.gov (United States)

Alba, Bianca Christina S.; Camayang, John Carl A.; Mopon, Marlon L.; del Rosario, Julie Anne D.

2017-08-01

The electrocatalytic reduction of carbon dioxide to small organic molecular compounds provides a means of generating alternative fuel source while suppressing climate change. Suitable catalysts, however, are necessary to optimize its reaction kinetics towards more valuable products. Consequently, in this study, electrodeposited Sn electrodes have been developed as catalysts for CO2 electroreduction. Deposition potential was varied to produce different Sn catalysts. SEM showed varying morphologies and increasing amount as the applied potential becomes more negative. Cyclic voltammetry and chronoamperometry showed that the activity and stability of the catalysts towards CO2 reduction depend on the morphology and presence of tin oxides. These results provide a better understanding on the performance of electrodeposited Sn-based surfaces as catalysts for CO2 reduction.

The greenhouse effect and nuclear energy

International Nuclear Information System (INIS)

Coulter, J.

1988-01-01

The author argues that nuclear power will do little to mitigate the problem of the greenhouse effect and is likely to exacerbate it. Changes since the mid 1970s illustrate the close linking of nuclear and economic growth with the associated growth of fossil fill consumption, the inability of nuclear power to substitute for fossil either technically or economically, and the greater contribution that can be made to energy availability and to reduction of carbon dioxide release by conservation

International nuclear safety center database on material properties

International Nuclear Information System (INIS)

Fink, J.K.

1996-01-01

International nuclear safety center database on the following material properties is described: fuel, cladding,absorbers, moderators, structural materials, coolants, concretes, liquid mixtures, uranium dioxide

Modeling and calculation of open carbon dioxide refrigeration system

International Nuclear Information System (INIS)

Cai, Yufei; Zhu, Chunling; Jiang, Yanlong; Shi, Hong

2015-01-01

Highlights: • A model of open refrigeration system is developed. • The state of CO 2 has great effect on Refrigeration capacity loss by heat transfer. • Refrigeration capacity loss by remaining CO 2 has little relation to the state of CO 2 . • Calculation results are in agreement with the test results. - Abstract: Based on the analysis of the properties of carbon dioxide, an open carbon dioxide refrigeration system is proposed, which is responsible for the situation without external electricity unit. A model of open refrigeration system is developed, and the relationship between the storage environment of carbon dioxide and refrigeration capacity is conducted. Meanwhile, a test platform is developed to simulation the performance of the open carbon dioxide refrigeration system. By comparing the theoretical calculations and the experimental results, several conclusions are obtained as follows: refrigeration capacity loss by heat transfer in supercritical state is much more than that in two-phase region and the refrigeration capacity loss by remaining carbon dioxide has little relation to the state of carbon dioxide. The results will be helpful to the use of open carbon dioxide refrigeration

France without nuclear power

International Nuclear Information System (INIS)

Charmant, A.; Devezeaux, J.G.; Ladoux, N.; Vielle, M.

1991-01-01

As coal production declined and France found herself in a condition of energy dependency, the country decided to turn to nuclear power and a major construction program was undertaken in 1970. The consequences of this step are examined in this article, by imagining where France would be without its nuclear power. At the end of the sixties, fuel-oil incontestably offered the cheapest way of producing electricity; but the first petroleum crisis was to upset the order of economic performance, and coal then became the more attractive fuel. The first part of this article therefore presents coal as an alternative to nuclear power, describing the coal scenario first and then comparing the relative costs of nuclear and coal investment strategies and operating costs (the item that differs most is the price of the fuel). The second part of the article analyzes the consequences this would have on the electrical power market, from the supply and demand point of view, and in terms of prices. The third part of the article discusses the macro-economic consequences of such a step: the drop in the level of energy dependency, increased costs and the disappearance of electricity exports. The article ends with an analysis of the environmental consequences, which are of greater and greater concern today. The advantage here falls very much in favor of nuclear power, if we judge by the lesser emissions of sulfur dioxide, nitrogen oxides and especially carbon dioxide. 22 refs.; 13 figs.; 10 tabs

Carbon-Based Regenerable Sorbents for the Combined Carbon Dioxide and Ammonia Removal for the Primary Life Support System (PLSS)

Science.gov (United States)

Wojtowicz, Marek A.; Cosgrove, Joseph E.; Serio, Michael A.; Manthina, Venkata; Singh, Prabhakar; Chullen, Cinda

2014-01-01

Results are presented on the development of reversible sorbents for the combined carbon dioxide and trace-contaminant (TC) removal for use in Extravehicular Activities (EVAs). Since ammonia is the most important TC to be captured, data on TC sorption presented in this paper are limited to ammonia, with results relevant to other TCs to be reported at a later time. The currently available life support systems use separate units for carbon dioxide, trace contaminants, and moisture control, and the long-term objective is to replace the above three modules with a single one. Furthermore, the current TC-control technology involves the use of a packed bed of acid-impregnated granular charcoal, which is non-regenerable, and the carbon-based sorbent under development in this project can be regenerated by exposure to vacuum at room temperature. The objective of this study was to demonstrate the feasibility of using carbon sorbents for the reversible, concurrent sorption of carbon dioxide and ammonia. Several carbon sorbents were fabricated and tested, and multiple adsorption/vacuum-regeneration cycles were demonstrated at room temperature, and also a carbon surface conditioning technique that enhances the combined carbon dioxide and ammonia sorption without impairing sorbent regeneration.

Steam generators for nuclear power plants

International Nuclear Information System (INIS)

Tillequin, Jean

1975-01-01

The role and the general characteristics of steam generators in nuclear power plants are indicated, and particular types are described according to the coolant nature (carbon dioxide, helium, light water, heavy water, sodium) [fr

Theoretical study using electronic structure calculations of uranium and cerium dioxides containing defects and impurities

International Nuclear Information System (INIS)

Shi, Lei

2016-01-01

Uranium dioxide (UO_2) is the most widely used nuclear fuel in existing nuclear reactors around the world. While in service for energy supply, UO_2 is submitted to the neutron flux and undergoes nuclear fission chain reactions, which create large number of fission products and point defects. The study of the behavior of the fission products and point defects is important to understand the fuel properties under irradiation. We conduct electronic structure calculations based on the density functional theory (DFT) to model this radiation damage at the atomic scale. The DFT+U method is used to describe the strong correlation of the 4f electrons of cerium and 5f electrons of uranium in the materials studied (UO_2, CeO_2 and (U, Ce)O_2). (U, Ce)O_2 is studied because it is considered as a low radioactive model material of mixed actinide oxides such as the MOX fuel (U, Pu)O_2 used in light water reactors and fast neutron reactors. Cerium dioxide (CeO_2) is studied to provide reference data of (U, Ce)O_2. We perform a DFT+U study of point defects and gaseous fission products (Xe and Kr) in CeO_2 and compare our results to the existing ones of UO_2. We study the bulk properties as well as the behavior of defects for (U, Ce)O_2, and compare our results to the ones of (U, Pu)O_2. Furthermore, for the study of defects in UO_2, methodological improvements are explored considering the spin-orbit coupling effect and the finite-size effect of the simulation supercell. (author) [fr

Diastereoisomeric diversity dictates reactivity of epoxy groups in limonene dioxide polymerization

Directory of Open Access Journals (Sweden)

M. Soto

2018-06-01

Full Text Available Limonene dioxide (LDO has the potential to find a wide application as a bio-based epoxy resin. Its polymerizations by catalyzed ring-opening, and by polyaddition with diamines were compared with the polymerizations of the commercial epoxy resins bisphenol-A diglycidyl ether (BADGE, and 3,4-epoxycyclohexylmethyl-3′,4′-epoxycyclohexane carboxylate (ECC. Differential scanning calorimetry (DSC studies showed that LDO polymerizations suffer in all cases studied from incomplete conversions. Nuclear magnetic resonance (NMR studies revealed that in cis-isomers of LDO the internal epoxide rings were not reacting. The low reactivity of this epoxide group was explained by mechanistic considerations making use of the Fürst-Plattner rule, or trans-diaxial effect. Due to diastereomeric diversity approximately one-fourth of epoxide groups present in LDO could not react. Therefore, a diastereoselective epoxidation of limonene could provide a fully reactive bio-based epoxy resin.

Effects of sulfur dioxide on vegetation

Energy Technology Data Exchange (ETDEWEB)

Whitby, G S

1939-11-11

A discussion is presented on the effects of sulfur dioxide on vegetation as observed at Trail, British Columbia. The investigation was carried out over a period of eight years, 1929 to 1937. The concentration of sulfur dioxide at the United States border was carefully determined throughout the crop season at a point 16 miles from the source of sulfur dioxide. Maximum and average concentrations in part per million are given. The sulfur content of vegetation was determined and was found to diminish as the distance from the smelter increased. It was determined that the sulfur content may rise to four times the normal amount without injurious effect. This is particularly so with prolonged low concentration. The effect on the soil was determined by measuring soluble sulfate, pH and exchangeable bases. The soil near the plant was affected, but this fell off rapidly with increase in distance so that eight miles from the smelter the soil was substantially normal. No effect on water supplies was found. An appreciable retardation in growth, as determined by annular rings, was noted for trees exposed to the sulfur dioxide. This effect was lost following installation of sulfur dioxide control at Trail. Conifers were found more susceptible during periods of active growth than when dormant. Also, transplanted conifers were more severly affected than native trees. Seedlings were less resistant that older trees.

Study of non stoichiometric uranium dioxide samples (UO2)

International Nuclear Information System (INIS)

Moura, Sergio C.; Lima, Nelson B. de; Bustillos, Jose O.V.

1999-01-01

The gravimetric and voltammetric methods for determination of non-stoichiometric O/U ratio in uranium dioxide used as nuclear fuel are discussed in this work. The oxidation of uranium oxide is very complex due to many phase changes. gravimetric and voltammetric methods do not detect phase changes. The results of this work shown that, to evaluate both methods is requiring to be done Rietveld methods by x-ray diffraction data to identify the uranium oxide phase changes. (author)

Space nuclear power systems for extraterrestrial basing

International Nuclear Information System (INIS)

Lance, J.R.; Chi, J.W.H.

1989-01-01

Previous studies of nuclear and non-nuclear power systems for lunar bases are compared with recent studies by others. Power levels from tens of kW e for early base operation up to 2000 kW e for a self-sustaining base with a Closed Environment Life Support System (CELSS) are considered. Permanent lunar or Martian bases will require the use of multiple nuclear units connected to loads with a power transmission and distribution system analogous to earth-based electric utility systems. A methodology used for such systems is applied to the lunar base system to examine the effects of adding 100 kW e SP-100 class and/or larger nuclear units when a reliability criterion is imposed. The results show that resource and logistic burdens can be reduced by using 1000 kW e units early in the base growth scenario without compromising system reliability. Therefore, both technologies being developed in two current programs (SP-100 and NERVA Derivative Reactor (NDR) technology for space power) can be used effectively for extraterrestrial base power systems. Recent developments in NDR design that result in major reductions in reactor mass are also described. (author)

Carbon Cycling with Nuclear Power

Science.gov (United States)

Lackner, Klaus S.

2011-11-01

Liquid hydrocarbon fuels like gasoline, diesel or jet fuel are the most efficient ways of delivering energy to the transportation sector, in particular cars, ships and airplanes. Unfortunately, their use nearly unavoidably leads to the emission of carbon dioxide into the atmosphere. Unless an equivalent amount is removed from the air, the carbon dioxide will accumulate and significantly contribute to the man-made greenhouse effect. If fuels are made from biomass, the capture of carbon dioxide is a natural part of the cycle. Here, we discuss technical options for capturing carbon dioxide at much faster rates. We outline the basic concepts, discuss how such capture technologies could be made affordable and show how they could be integrated into a larger system approach. In the short term, the likely source of the hydrocarbon fuels is oil or gas; in the longer term, technologies that can provide energy to remove oxygen from carbon dioxide and water molecules and combine the remaining components into liquid fuels make it possible to recycle carbon between fuels and carbon dioxide in an entirely abiotic process. Here we focus on renewable and nuclear energy options for producing liquid fuels and show how air capture combined with fuel synthesis could be more economic than a transition to electric cars or hydrogen-fueled cars.

An introduction to serious nuclear accident chemistry

Directory of Open Access Journals (Sweden)

Mark Russell St. John Foreman

2015-12-01

Full Text Available A review of the chemistry occurring inside a nuclear power plant during a serious reactor accident is presented. This includes some aspects of the behavior of nuclear fuel, its cladding, cesium and iodine. This review concentrates on the chemistry of an accident in a water-cooled reactor loaded with uranium dioxide or mixed metal oxide fuel.

Environment and nuclear power

International Nuclear Information System (INIS)

Anon.

1994-01-01

Aimed at the general public this leaflet, one of a series prepared by AEA Technology, on behalf of the British Nuclear Industry Forum, seeks to put the case for generating electricity to meet United Kingdom and world demand using nuclear power. It examines the environmental problems linked to the use of fossil-fuels in power stations and other uses, such as the Greenhouse Effect. Problems associated with excess carbon dioxide emissions are also discussed, such as acid rain, the effects of deforestation and lead in petrol. The role of renewable energy sources is mentioned briefly. The leaflet also seeks to reassure on issues such as nuclear waste managements and the likelihood and effects of nuclear accidents. (UK)

Flexible substrates as basis for photocatalytic reduction of carbon dioxide

DEFF Research Database (Denmark)

Jensen, Jacob; Mikkelsen, Mette; Krebs, Frederik C

2011-01-01

A photocatalytic system for converting carbon dioxide into carbon monoxide was designed and constructed. The system relies on thin films of the photocatalyst prepared at low temperature using spray coating. We formulated inks based on the well-known photocatalyst titanium dioxide and characterized...

Radioactivity around naval nuclear bases

International Nuclear Information System (INIS)

1989-02-01

Between 12th July and 2nd August 1988, Greenpeace took sediment samples from around four Royal Navy bases in the United Kingdom. Faslane, where nuclear powered submarines are berthed; Devonport and Rosyth where refit work is carried out and Portsmouth where US and UK nuclear submarines often visit. Samples were also taken from the US Navy base at Holy Loch, Scotland, where nuclear powered ballistic missile submarines are based. The samples were analysed at St Bartholomew Hospital Medical School, London. Identical samples were provided to the MoD personnel at Faslane and Devonport on the date taken. The purpose of carrying out the sampling programme was to highlight the fact that publicly available statistics from Ministry of Agriculture Fisheries and Food (MAFF) are too limited in range, concentrating as they do merely on radioactive levels found between tides. The findings point to the necessity of monitoring subtidal as well as intertidal areas since levels of radioactivity found in the samples at Faslane and Holy Loch were four to nine times the figures published by MAFF. Until such time as nuclear power is no longer used at sea, it is the contention of Greenpeace that a more independent and comprehensive picture of the nature of radioactive contamination from around UK naval establishments must be obtained, than that presently available from MAFF. (author)

Conflict nuclear power. Theses for current supply with and without nuclear power

International Nuclear Information System (INIS)

Schwarz, E.

2007-01-01

In the context of a lecture at the 2nd Internationally Renewable Energy Storage Conference at 19th to 21st November, 2007, in Bonn (Federal Republic of Germany), the author of the contribution under consideration reports on theses for current supply with and without nuclear power. (1) Theses for current supply with nuclear energy: Due to a relative amount of 17 % of nuclear energy in the world-wide energy production and due to the present reactor technology, the supplies of uranium amount nearly 50 to 70 years. The security of the nuclear power stations is controversially judged in the public and policy. In a catastrophic accident in a nuclear power station, an amount of nearly 2.5 billion Euro is available for adjustment of damages (cover note). The disposal of radioactive wastes is not solved anywhere in the world. The politically demanded separation between military and civilian use of the nuclear energy technology is not possible. The exit from the nuclear energy is fixed in the atomic law. By any means, the Federal Republic of Germany is not insulated in the European Union according to its politics of nuclear exit. After legal adjustment of the exit from the nuclear energy the Federal Republic of Germany should unfold appropriate activities for the re-orientation of Euratom, Nuclear Energy Agency and the International Atomic Energy Agency. The consideration of the use of nuclear energy in relation to the risks has to result that its current kind of use is not acceptable and to be terminated as fast as possible. (2) Theses for current supply without nuclear energy: The scenario technology enables a transparency of energy future being deliverable for political decisions. In accordance with this scenario, the initial extra costs of the development of the renewable energies and the combined heat and power generation amount approximately 4 billion Euro per year. The conversion of the power generation to renewable energies and combined heat and power generation

Communication: Photoinduced carbon dioxide binding with surface-functionalized silicon quantum dots

Science.gov (United States)

Douglas-Gallardo, Oscar A.; Sánchez, Cristián Gabriel; Vöhringer-Martinez, Esteban

2018-04-01

Nowadays, the search for efficient methods able to reduce the high atmospheric carbon dioxide concentration has turned into a very dynamic research area. Several environmental problems have been closely associated with the high atmospheric level of this greenhouse gas. Here, a novel system based on the use of surface-functionalized silicon quantum dots (sf-SiQDs) is theoretically proposed as a versatile device to bind carbon dioxide. Within this approach, carbon dioxide trapping is modulated by a photoinduced charge redistribution between the capping molecule and the silicon quantum dots (SiQDs). The chemical and electronic properties of the proposed SiQDs have been studied with a Density Functional Theory and Density Functional Tight-Binding (DFTB) approach along with a time-dependent model based on the DFTB framework. To the best of our knowledge, this is the first report that proposes and explores the potential application of a versatile and friendly device based on the use of sf-SiQDs for photochemically activated carbon dioxide fixation.

Nuclear safety based on nuclear knowledge - A Romanian approach

International Nuclear Information System (INIS)

Valeca, S.C.; Popescu, D.

2007-01-01

Full text: The recognized 'father' of the nuclear field, the scientist A. Einstein inherited us with a CONTRADICTION. On one hand he was the supporter of researches in the nuclear field, but on the other hand, when he saw the first devastating results of the atomic explosions he suddenly became a fervent opponent. In such conditions, the nuclear field made its first step in the conscience of humanity. Unfortunately it was a left first step. For this reason and also because of the nuclear incidents passed over the history of the field and due to yet unclear strategies regarding the final disposal of radioactive waste, a part of public opinion 'embraced' the concept 'NIMBY - Not In My Back Yard'. At present and for the future we have to fight against this concept in order to transform it in 'PIMY - Please In My Yard'. As a consequence, alongside numerous activities well-known by the specialists in the field, regulated and authorized by the regulatory body in the nuclear field, associated programmes for the CONTINUOUS qualification and education of human resources are needed. The Concept of Nuclear Security covers all the activities resulted from the nuclear fuel cycle. Taking into consideration the international experience in this field in our country's case, these activities were estimated for periods of approximately 70 years, as following: 10 years: the characterization and selection of the site, the design, construction and the commission of a nuclear power plant; 40 years: the operation, maintenance and modernization of a nuclear power plant; 20 years: the preservation for the decommissioning and the decommissioning of the nuclear power plant. In all these stages until present Romania based a lot on the indigene component regarding the activities of research and development, design, construction - assembling, exploitation and maintenance (both for NPP Unit 1 and Unit 2, where this component was approximately of 50%). In such conditions, it was needed the

Use of a Nuclear High Temperature Gas Reactor in a Coal-To-Liquids Process

International Nuclear Information System (INIS)

Robert S. Cherry; Richard A. Wood

2006-01-01

AREVA's High Temperature Gas Reactor (HTGR) can potentially provide nuclear-generated, high-level heat to chemical process applications. The use of nuclear heat to help convert coal to liquid fuels is particularly attractive because of concerns about the future availability of petroleum for vehicle fuels. This report was commissioned to review the technical and economic aspects of how well this integration might actually work. The objective was to review coal liquefaction processes and propose one or more ways that nuclear process heat could be used to improve the overall process economics and performance. Shell's SCGP process was selected as the gasifier for the base case system. It operates in the range of 1250 to 1600 C to minimize the formation of tars, oil, and methane, while also maximizing the conversion of the coal's carbon to gas. Synthesis gas from this system is cooled, cleaned, reacted to produce the proper ratio of hydrogen to carbon monoxide and fed to a Fischer-Tropsch (FT) reaction and product upgrading system. The design coal-feed rate of 18,800 ton/day produces 26.000 barrels/day of FT products. Thermal energy at approximately 850 C from a HTGR does not directly integrate into this gasification process efficiently. However, it can be used to electrolyze water to make hydrogen and oxygen, both of which can be beneficially used in the gasification/FT process. These additions then allow carbon-containing streams of carbon dioxide and FT tail-gas to be recycled in the gasifier, greatly improving the overall carbon recovery and thereby producing more FT fuel for the same coal input. The final process configuration, scaled to make the same amount of product as the base case, requires only 5,800 ton/day of coal feed. Because it has a carbon utilization of 96.9%, the process produces almost no carbon dioxide byproduct Because the nuclear-assisted process requires six AREVA reactors to supply the heat, the capital cost is high. The conventional plant is

Carbon Dioxide Mitigation Benefit of High-Speed Railway in Terms of Carbon Tax

Directory of Open Access Journals (Sweden)

Fu Yanbing

2013-01-01

Full Text Available This paper calculates the carbon dioxide mitigation benefit of high-speed railway based on the carbon dioxide tax policy. We define the carbon dioxide emission system boundary for high-speed railway in its whole life cycle and estimate the life cycle carbon dioxide inventories during its construction, application, and recovery stages. And then we establish a theoretical model to calculate the life cycle carbon dioxide mitigation quantity for high-speed railway when compared with road transport and then calculate its carbon dioxide mitigation benefit. The numerical example shows that the carbon dioxide mitigation benefit of high-speed railway is better than that of road transport from the whole life cycle perspective.

Test and evaluation of computerized nuclear material accounting methods. Final report

International Nuclear Information System (INIS)

1995-01-01

In accordance with the definition of a Material Balance Area (MBA) as a well-defined geographical area involving an Integral operation, the building housing the BFS-1 and BFS-1 critical facilities is considered to consist of one MBA. The BFS materials are in the form of small disks clad in stainless steel and each disk with nuclear material has its own serial number. Fissile material disks in the BFS MBA can be located at three key monitoring points: BFS-1 facility, BFS-2 facility and main storage of BFS fissile materials (storage 1). When used in the BFS-1 or BFS-2 critical facilities, the fissile material disks are loaded in tubes (fuel rods) forming critical assembly cores. The following specific features of the BFS MBA should be taken into account for the purpose of computerized accounting of nuclear material: (1) very large number of nuclear material items (about 70,000 fissile material items); and (2) periodically very intensive shuffling of nuclear material items. Requirements for the computerized system are determined by basic objectives of nuclear material accounting: (1) providing accurate information on the identity and location of all items in the BFS material balance area; (2) providing accurate information on location and identity of tamper-indicating devices; (3) tracking nuclear material inventories; (4) issuing periodic reports; (5) assisting with the detection of material gains or losses; (6) providing a history of nuclear material transactions; (7) preventing unauthorized access to the system and data falsification. In August 1995, the prototype computerized accounting system was installed on the BFS facility for trial operation. Information on two nuclear material types was entered into the data base: weapon-grade plutonium metal and 36% enriched uranium dioxide. The total number of the weapon-grade plutonium disks is 12,690 and the total number of the uranium dioxide disks is 1,700

Radiation induced sulfur dioxide removal

International Nuclear Information System (INIS)

Chmielewski, A.G.

2000-01-01

The biggest source of air pollution is the combustion of fossil fuels, were pollutants such as particulate, sulfur dioxide (SO 2 ), nitrogen oxides (NO x ), and volatile organic compounds (VOC) are emitted. Among these pollutants, sulfur dioxide plays the main role in acidification of the environment. The mechanism of sulfur dioxide transformation in the environment is partly photochemical. This is not direct photooxidation, however, but oxidation through formed radicals. Heterogenic reactions play an important role in this transformation as well; therefore, observations from environmental chemistry can be used in air pollution control engineering. One of the most promising technologies for desulfurization of the flue gases (and simultaneous denitrification) is radiation technology with an electron accelerator application. Contrary to the nitrogen oxides (NO x ) removal processes, which is based on pure radiation induced reactions, sulfur dioxide removal depends on two pathways: a thermochemical reaction in the presence of ammonia/water vapor and a radiation set of radiochemical reactions. The mechanism of these reactions and the consequent technological parameters of the process are discussed in this paper. The industrial application of this radiation technology is being implemented in an industrial pilot plant operated by INCT at EPS Kaweczyn. A full-scale industrial plant is currently in operation in China, and two others are under development in Japan and Poland. (author)

Gas Gain Measurement Of GEM-Foil In Argon-Carbon Dioxide Mixture

International Nuclear Information System (INIS)

Nguyen Ngoc Duy; Vuong Huu Tan; Le Hong Khiem

2011-01-01

Nuclear reaction measurement with radioactive beam at low energy plays an important role in nuclear astrophysics and nuclear structure. The trajectory of particle beams can be obtained by using an active gas target, multiple-sampling and tracking proportional chamber (MSTPC), as a proportional counter. Because of intensity of low energy radioactive beam, in the stellar reaction such as (α, p), (p, α), it is necessary to increase the gain for the counter. In this case, a gas electrons multiplier (GEM) foil will be used, so the proportional counter is called GEM-MSTPC. The efficient gas gain of GEM foils which relates to foil thickness and operating pressure was investigated with two type of the foils, 400 μm and 200 μm, in Argon (70%) + Carbon dioxide (30%) mixture. (author)

Hydrogen from nuclear energy and the impact on climate change

International Nuclear Information System (INIS)

Duffey, R.B.; Miller, A.I.; Poehnell, T.G.

2001-01-01

The two major candidates for hydrogen production include nuclear power and other renewable energy sources. However, hydrogen produced by steam reforming of natural gas offers little advantage in total cycle greenhouse gas (GHG) emissions over hybrid internal combustion engine (ICE) technology. Only nuclear power offers the possibility of cutting GHG emissions significantly and to economically provide electricity for traditional applications and by producing hydrogen for its widespread use in the transportation sector. Using nuclear energy to produce hydrogen for transportation fuel, doubles or triples nuclear's capacity to reduce GHG emissions. An analysis at the Atomic Energy of Canada shows that a combination of hydrogen fuel and nuclear energy can stabilize GHG emissions and climate change for a wide range of the latest scenarios presented by the Intergovernmental Panel on Climate Change. The technology for replacing hydrocarbon fuels with non-polluting hydrogen exists with nuclear power, electrolysis and fuel cells, using electric power grids for distribution. It was emphasized that a move toward total emissions-free transportation will be a move towards solving the negative effects of climate change. This paper illustrated the trends between global economic and atmospheric carbon dioxide concentrations. Low carbon dioxide emission energy alternatives were discussed along with the sources of hydrogen and the full cycle assessment results in reduced emissions. It was shown that deploying 20 CANDU NPPs (of 690 MW (e) net each) would fuel 13 million vehicles with the effect of levelling of carbon dioxide emissions from transportation between 2020 to 2030. 13 refs., 2 tabs., 3 figs

The current state of development works for manufacturing and methods of controlling the nuclear fuel for NPPs of Ukraine

International Nuclear Information System (INIS)

Odeychuk, N.P.; Levenets, V.V.; Krasnorutsky, V.S.

2000-01-01

The paper presents the results of NSC KIPT researches on manufacturing the fuel microspheres and pellets based on uranium dioxide. The data on fuel characteristics for different manufacturing stages are given. The problems of improving the fuel quality with changing the structure characteristics of pellets are considered. Demonstrated is the hardware for pellet controlling and presented are the new ways for developing the methods of controlling the nuclear fuel: X-ray fluorescent analysis; complex of nuclear-physical methods on the base of accelerators; laser-excitation energy-mass-spectrometer. (author)

Method and aparatus for flue gas cleaning by separation and liquefaction of sulfur dioxide and carbon dioxide

International Nuclear Information System (INIS)

Abdelmalek, F.T.

1992-01-01

This patent describes a method for recovering sulfur dioxide, carbon dioxide, and cleaning flue gases emitted from power plants. It comprises: electronically treating the flue gases to neutralize its electrostatic charges and to enhance the coagulation of its molecules and particles; exchanging sensible and latent heat of the neutralized flue gases to lower its temperature down to a temperature approaching the ambient temperature while recovering its separating the flue gas in a first stage; cooling the separated enriched carbon dioxide gas fraction, after each separation stage, while removing its vapor condensate, then compressing the enriched carbon dioxide gas fraction and simultaneously cooling the compressed gas to liquefy the sulfur dioxide gas then; allowing the sulfur dioxide gas to condense, and continuously removing the liquefied sulfur dioxide; compressing he desulfurized enriched carbon dioxide fraction to further increase its pressure, and simultaneously cooling he compressed gas to liquefy the carbon dioxide gas, then; allowing the carbon dioxide gas to condense and continuously removing the liquefied carbon dioxide; allowing the light components of the flue gas to be released in a cooling tower discharge plume

Nuclear power company activity based costing management analysis

International Nuclear Information System (INIS)

Xu Dan

2012-01-01

With Nuclear Energy Industry development, Nuclear Power Company has the continual promoting stress of inner management to the sustainable marketing operation development. In view of this, it is very imminence that Nuclear Power Company should promote the cost management levels and built the nuclear safety based lower cost competitive advantage. Activity based costing management (ABCM) transfer the cost management emphases from the 'product' to the 'activity' using the value chain analysis methods, cost driver analysis methods and so on. According to the analysis of the detail activities and the value chains, cancel the unnecessary activity, low down the resource consuming of the necessary activity, and manage the cost from the source, achieve the purpose of reducing cost, boosting efficiency and realizing the management value. It gets the conclusion from the detail analysis with the nuclear power company procedure and activity, and also with the selection to 'pieces analysis' of the important cost related project in the nuclear power company. The conclusion is that the activities of the nuclear power company has the obviously performance. It can use the management of ABC method. And with the management of the procedure and activity, it is helpful to realize the nuclear safety based low cost competitive advantage in the nuclear power company. (author)

The financing of nuclear power plants

International Nuclear Information System (INIS)

Taylor, M.

2009-01-01

Existing nuclear generating capacity plays an important role in providing secure, economic and low-carbon electricity supplies in many OECD countries. At the same time, there is increasing recognition that an expansion of nuclear power could play a valuable role in reducing future carbon dioxide emissions. However, in recent years only a handful of new nuclear power plants (NPPs) have been built in just a few OECD countries. An important reason for this is the challenges associated with financing the construction of new NPPs

Predictor of regulation of uranium dioxide powder pressing process

International Nuclear Information System (INIS)

Motta, Eduardo Souza; Araujo, Victor Hugo Leal de; Bernardelli, Sergio Henrique

2007-01-01

One of the most important steps of the uranium dioxide pellets fabrication used in the nuclear fuel elements is the green pellets pressing. The target density of the pellets after the sintering process determines the density of the green pellet. To meet the same sintered target density the green density may vary according to the powder characteristics. These variations implies in changing the regulation of the press for different powder's patches. The regulation done empirically imply in productivity loss and necessity of reprocessing the pellets pressed during the press regulation and also depends on the operator experience. At this work, was developed an artificial neural network feed forward back propagation to predict the press regulation, depending on the powder characteristics and the green pellet's target density. The results obtained at INB - Industrias Nucleares do Brasil S. A. during the fabrication of the fifth recharge of Angra II nuclear power plant are presented. (author)

Standard test method for the determination of uranium by ignition and the oxygen to uranium (O/U) atomic ratio of nuclear grade uranium dioxide powders and pellets

CERN Document Server

American Society for Testing and Materials. Philadelphia

2000-01-01

1.1 This test method covers the determination of uranium and the oxygen to uranium atomic ratio in nuclear grade uranium dioxide powder and pellets. 1.2 This test method does not include provisions for preventing criticality accidents or requirements for health and safety. Observance of this test method does not relieve the user of the obligation to be aware of and conform to all international, national, or federal, state and local regulations pertaining to possessing, shipping, processing, or using source or special nuclear material. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 1.4 This test method also is applicable to UO3 and U3O8 powder.

U.S. Forward Operating Base Applications of Nuclear Power

International Nuclear Information System (INIS)

Griffith, George W.

2015-01-01

This paper provides a high level overview of current nuclear power technology and the potential use of nuclear power at military bases. The size, power ranges, and applicability of nuclear power units for military base power are reviewed. Previous and current reactor projects are described to further define the potential for nuclear power for military power.

The future of nuclear energy in Europe

International Nuclear Information System (INIS)

Schmidt-Kuester, W.J.

2000-01-01

Are concerns about global warming of the Earth's atmosphere going to rekindle interest in nuclear power and in building new nuclear power plants in Europe? As a consequence of the discussions about the climate, the use of nuclear power as an important energy source is currently being re-evaluated, finds Dr. Wolf-J. Schmidt-Kuester, Secretary General of FORATOM, the European Atomic Forum, headquartered in Brussels. In his article, he argues that a renaissance of nuclear power will be possible also in Europe once politics supports resuming an unbiased discussion of all topics associated with the energy problem. Europe must face two problems in the energy sector for which solutions must be found: the growing dependence on fossil energy resources, and the need to curb greenhouse gas emissions, especially those of carbon dioxide. Nuclear power is already making a sizable contribution towards the solution of these problems, but its future potential has hardly been tapped. Public acceptance of nuclear power shows that the intention to opt out of the peaceful uses of nuclear power is not based on an identical attitude of the public, but is motivated politically, finding only little public support, as in the cases of Sweden and Germany. (orig.) [de

Optimization of screen-printed ruthenium dioxide electrodes for pH measurements

International Nuclear Information System (INIS)

Wyzkiewicz, I.

2002-01-01

Optimization of disposable, screen-printed pH-sensors based on ruthenium dioxide is described in this paper. The electrodes were prepared with the use of thick-film technology. The pH-sensitive layers were deposited onto polyester foil. Polymer graphite paste containing ruthenium dioxide from 0% to 90% has been investigated. The dependence of the pH-sensitive layers related to ruthenium dioxide content is presented. The investigation proved that the electrodes containing 40-60% ruthenium dioxide exhibit linear high sensitivity (∼ 50 mV/pH) in the wide range of pH (2 - 11) as well as very good reproducibility. (author)

A DICOM based PACS for nuclear medicine

International Nuclear Information System (INIS)

Lassmann, M.; Reiners, C.

2002-01-01

The installation of a radiology information system (RIS) connected to a hospital information system (HIS) and a picture archiving and communications system (PACS) seems mandatory for a nuclear medicine department in order to guarantee a high patient throughput. With these systems a fast transmission of reports, images to the in- and out-patients' wards and private practitioners is realized. Therefore, since April 2000, at the department of nuclear medicine of the university of Wuerzburg a completely DICOM based PACS has been implemented in addition to the RIS. With this system a DICOM based workflow is realized throughout the department of nuclear medicine for reporting and archiving. The PACS is connected to six gamma-cameras, a PET scanner, a bone densitometry system and an ultrasound device. The volume of image data archived per month is 4 GByte. Patient demographics are provided to the modalities via DICOM-Worklist. With these PACS components a department specific archive purely based on DICOM can be realized. During the installation process problems occurred mainly because of the complex DICOM standard for nuclear medicine. Related to that is the problem that most of the software implementations still contain bugs or are not adapted to the needs of a nuclear medicine department (particularly for PET). A communication software for the distribution of nuclear medicine reports and images based on techniques used for the worldwide web is currently tested. (orig.) [de

Thermodynamics Properties of Binary Gas Mixtures for Brayton Space Nuclear Power System

International Nuclear Information System (INIS)

You Ersheng; Shi Lei; Zhang Zuoyi

2014-01-01

Space nuclear power system with closed Brayton cycle has the potential advantages of high cycle efficiency. It can be achieved to limit the specific mass of the system with a competitive design scheme, so as to strengthen the advantage of the nuclear energy applying in space propulsion and electric generating compared to solar or chemical propellant. Whereby, the thermodynamic properties of working fluids have a significant influence on the performance of the plant. Therefore, two binary mixtures helium-nitrogen and helium-carbon dioxide are introduced to analysis the variation in the transport and heat transfer capacity of working fluids. Based on the parameters of pure gases, the heat transfer coefficient, pressure losses and aerodynamic loading are calculated as a function of mole fraction at the temperature of 400 K and 1200 K, as well as the typical operating pressure of 2 MPa. Results indicated that the mixture of helium-carbon dioxide with a mole fraction of 0.4 is a more attractive choice for the high heat transfer coefficient, low aerodynamic loading and acceptable pressure losses in contrast to helium-nitrogen and other mixing ratios of helium-carbon dioxide. Its heat transfer coefficient is almost 20% more than that of pure helium and the normalized aerodynamic loading is less than 34% at 1200 K. However; the pressure losses are a little higher with ~3.5 times those of pure helium. (author)

Carbon Dioxide Capture and Separation Techniques for Gasification-based Power Generation Point Sources

Energy Technology Data Exchange (ETDEWEB)

Pennline, H.W.; Luebke, D.R.; Jones, K.L.; Morsi, B.I. (Univ. of Pittsburgh, PA); Heintz, Y.J. (Univ. of Pittsburgh, PA); Ilconich, J.B. (Parsons)

2007-06-01

The capture/separation step for carbon dioxide (CO2) from large-point sources is a critical one with respect to the technical feasibility and cost of the overall carbon sequestration scenario. For large-point sources, such as those found in power generation, the carbon dioxide capture techniques being investigated by the in-house research area of the National Energy Technology Laboratory possess the potential for improved efficiency and reduced costs as compared to more conventional technologies. The investigated techniques can have wide applications, but the research has focused on capture/separation of carbon dioxide from flue gas (post-combustion from fossil fuel-fired combustors) and from fuel gas (precombustion, such as integrated gasification combined cycle or IGCC). With respect to fuel gas applications, novel concepts are being developed in wet scrubbing with physical absorption; chemical absorption with solid sorbents; and separation by membranes. In one concept, a wet scrubbing technique is being investigated that uses a physical solvent process to remove CO2 from fuel gas of an IGCC system at elevated temperature and pressure. The need to define an ideal solvent has led to the study of the solubility and mass transfer properties of various solvents. Pertaining to another separation technology, fabrication techniques and mechanistic studies for membranes separating CO2 from the fuel gas produced by coal gasification are also being performed. Membranes that consist of CO2-philic ionic liquids encapsulated into a polymeric substrate have been investigated for permeability and selectivity. Finally, dry, regenerable processes based on sorbents are additional techniques for CO2 capture from fuel gas. An overview of these novel techniques is presented along with a research progress status of technologies related to membranes and physical solvents.

Why do they think nuclear power is origin of global warming effect?

International Nuclear Information System (INIS)

Fukae, Chiyokazu

2005-01-01

A questionnaire on nuclear power was conducted on 1500 adults in Kansai area, Japan, from October 9 to November 9, 2003. The recovery ratio was 71.0%. The results showed that 34% of them thought the nuclear power was protection of the global warming effect and 35% it was origin of the effect. It was analyzed by the logistic regression analysis method on whether the nuclear power was protection of global warming effect or not. About 43% of them recognized the nuclear power contributed to control carbon dioxide emission, and the mechanism of global warming effect. However, 35% of them did not recognize the mechanism and thought radioactive materials emission gave bad effects on the global environment. To make recognize the nuclear power is a good power source for protection of the global warming effect, the amount of reduction of carbon dioxide emission by nuclear power had to be shown. It is the shortest way for solution of the global warming problem to prove worthy of nuclear power's trust by safety and stable operation. (S.Y.)

Mechanochemically Activated, Calcium Oxide-Based, Magnesium Oxide-Stabilized Carbon Dioxide Sorbents.

Science.gov (United States)

Kurlov, Alexey; Broda, Marcin; Hosseini, Davood; Mitchell, Sharon J; Pérez-Ramírez, Javier; Müller, Christoph R

2016-09-08

Carbon dioxide capture and storage (CCS) is a promising approach to reduce anthropogenic CO2 emissions and mitigate climate change. However, the costs associated with the capture of CO2 using the currently available technology, that is, amine scrubbing, are considered prohibitive. In this context, the so-called calcium looping process, which relies on the reversible carbonation of CaO, is an attractive alternative. The main disadvantage of naturally occurring CaO-based CO2 sorbents, such as limestone, is their rapid deactivation caused by thermal sintering. Here, we report a scalable route based on wet mechanochemical activation to prepare MgO-stabilized, CaO-based CO2 sorbents. We optimized the synthesis conditions through a fundamental understanding of the underlying stabilization mechanism, and the quantity of MgO required to stabilize CaO could be reduced to as little as 15 wt %. This allowed the preparation of CO2 sorbents that exceed the CO2 uptake of the reference limestone by 200 %. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Titanium dioxide-based DGT technique for in situ measurement of dissolved reactive phosphorus in fresh and marine waters

DEFF Research Database (Denmark)

Panther, Jared G.; Teasdale, Peter R.; Bennett, William W.

2010-01-01

A new diffusive gradients in a thin film (DGT) technique for measuring dissolved reactive phosphorus (DRP) in fresh and marine waters is reported. The new method, which uses a commercially available titanium dioxide based adsorbent (Metsorb), was evaluated and compared to the well-established fer...

Evaluation of a titanium dioxide-based DGT technique for measuring inorganic uranium species in fresh and marine waters

DEFF Research Database (Denmark)

Hutchins, Colin M.; Panther, Jared G.; Teasdale, Peter R.

2012-01-01

A new diffusive gradients in a thin film (DGT) technique for measuring dissolved uranium (U) in freshwater is reported. The new method utilises a previously described binding phase, Metsorb (a titanium dioxide based adsorbent). This binding phase was evaluated and compared to the well-established...

Selection of materials in nuclear fuel: present and future

International Nuclear Information System (INIS)

Munoz-Reja, C.; Fuentes, L.; Garcia de la Infanta, J. M.; Munoz Sicilia, A.

2013-01-01

One of the main aspects of the nuclear fuel is the selection of materials for the components. The operating conditions of the fuel elements impose a major challenge to materials: high temperature, corrosive aqueous environment, high mechanical properties, long periods of time under these extreme conditions and what is the differentiating factor; the effect of irradiation. The materials are selected to fulfill these severe requirements and also to be able to control and to predict its behavior in the working conditions. Their development, in terms of composition and processing, is based on the continuous follow-up of the operation behavior. Many of these materials are specific of the nuclear industry, such as the uranium dioxide and the zirconium alloys. This article presents the selection and development of the nuclear fuel materials as a function of the services requirements. It also includes a view of the new nuclear fuels materials that are being raised after Fukushima accident. (Author)

Kinetics of aging of metastable, zirconium-dioxide-based solid electrolytes

International Nuclear Information System (INIS)

Vlasov, A.N.; Inozemtsev, M.V.

1985-01-01

The kinetics of aging of zirconium-dioxide-based metastable solid oxide electrolytes stabilized with 8 to 10 mole % of yttrium, holmium, or scandium oxide were studied over the temperature range from 1200 to 1373 0 K. Kinetic equations were proposed which describe the conduction behavior of two-phase solid electrolytes in a wide time range. The processes were found to occur independently at the initial stage of aging in the cubic solution, viz., an increase in the number of nuclei of the new phase, and a growth in volume of nuclei of the new phase. After a long time the former process ceases, and the kinetics of aging of the electrolyte only are determined by the kinetics of volume growth of the inclusions of new phase. The time-dependent behavior of two-phase solid solutions is discussed theoretically and examined experimentally

Carbon dioxide dangers demonstration model

Science.gov (United States)

Venezky, Dina; Wessells, Stephen

2010-01-01

Carbon dioxide is a dangerous volcanic gas. When carbon dioxide seeps from the ground, it normally mixes with the air and dissipates rapidly. However, because carbon dioxide gas is heavier than air, it can collect in snowbanks, depressions, and poorly ventilated enclosures posing a potential danger to people and other living things. In this experiment we show how carbon dioxide gas displaces oxygen as it collects in low-lying areas. When carbon dioxide, created by mixing vinegar and baking soda, is added to a bowl with candles of different heights, the flames are extinguished as if by magic.

Microbial-induced remediation of Zn2+ pollution based on the capture and utilization of carbon dioxide

Directory of Open Access Journals (Sweden)

Qiwei Zhan

2016-01-01

Conclusions: The TG-DSC results showed that weight loss of the precipitates occurred around 253°C. The FTIR and TG-DSC results were in accord with the XRD and EDS results and proved again that the precipitates were basic zinc carbonate. This work thus demonstrates a new method for processing Zn2+ pollution based on the utilization of carbon dioxide.

Contribution to the study of uranium dioxide aqueous corrosion mechanisms

International Nuclear Information System (INIS)

Gallien, J.-P.

1994-01-01

The corrosion of uranium dioxide by a synthetical ground water has been studied in order to understand the behaviour of nuclear fuels in the hypothesis of a direct storage. An original leaching unit has been carried out in order to control the parameters occurring in the oxidation-dissolution of the uranium dioxide and to condition the leachate (in particular the temperature and the partial pressure of the carbon dioxide). A ground water in equilibrium with the geological enveloping site has been reconstituted from data acquired on the site. The influence of two parameters has been followed: the carbon dioxide carbon pressure and the redox potential. Each experiment has been carried out at 96 C during one month and the time-history of the solutions and of the solids has been studied. In oxidizing conditions, the uranium concentration in solution has been controlled by an U(VI) complex (one oxide, one hydroxide or a carbonate). The possibility of a control by an U(IV) complex (as coffinite, uraninite or uraninite B) has been confirmed in the case of reducing leaching. An original interpretation of the Rutherford backscattering spectra has allowed to describe the decomposition of the samples in a succession of layers of different densities. A very good agreement between the analyses of the solids and those of the solutions has been obtained in the experiments occurring in reducing conditions. Complementary leaching involving solutions containing stable isotopes (deuterium, O 18 ) have revealed the formation of an hydrated layer and the contribution of grain boundaries to the corrosion phenomenon of uranium dioxide. The results of the current hydro-geochemistry study on the uranium Oklo deposit prove the realism of the experiments that have been carried out in the laboratory. (O.M.)

Space-Based Detection of Missing Sulfur Dioxide Sources of Global Air Pollution

Science.gov (United States)

McLinden, Chris A.; Fioletov, Vitali; Shephard, Mark W.; Krotkov, Nick; Li, Can; Martin, Randall V.; Moran, Michael D.; Joiner, Joanna

2016-01-01

Sulfur dioxide is designated a criteria air contaminant (or equivalent) by virtually all developed nations. When released into the atmosphere, sulfur dioxide forms sulfuric acid and fine particulate matter, secondary pollutants that have significant adverse effects on human health, the environment and the economy. The conventional, bottom-up emissions inventories used to assess impacts, however, are often incomplete or outdated, particularly for developing nations that lack comprehensive emission reporting requirements and infrastructure. Here we present a satellite-based, global emission inventory for SO2 that is derived through a simultaneous detection, mapping and emission-quantifying procedure, and thereby independent of conventional information sources. We find that of the 500 or so large sources in our inventory, nearly 40 are not captured in leading conventional inventories. These missing sources are scattered throughout the developing world-over a third are clustered around the Persian Gulf-and add up to 7 to 14 Tg of SO2 yr(exp -1), or roughly 6-12% of the global anthropogenic source. Our estimates of national total emissions are generally in line with conventional numbers, but for some regions, and for SO2 emissions from volcanoes, discrepancies can be as large as a factor of three or more. We anticipate that our inventory will help eliminate gaps in bottom-up inventories, independent of geopolitical borders and source types.

Design of a Uranium Dioxide Spheroidization System

Science.gov (United States)

Cavender, Daniel P.; Mireles, Omar R.; Frendi, Abdelkader

2013-01-01

The plasma spheroidization system (PSS) is the first process in the development of tungsten-uranium dioxide (W-UO2) fuel cermets. The PSS process improves particle spherocity and surface morphology for coating by chemical vapor deposition (CVD) process. Angular fully dense particles melt in an argon-hydrogen plasma jet at between 32-36 kW, and become spherical due to surface tension. Surrogate CeO2 powder was used in place of UO2 for system and process parameter development. Particles range in size from 100 - 50 microns in diameter. Student s t-test and hypothesis testing of two proportions statistical methods were applied to characterize and compare the spherocity of pre and post process powders. Particle spherocity was determined by irregularity parameter. Processed powders show great than 800% increase in the number of spherical particles over the stock powder with the mean spherocity only mildly improved. It is recommended that powders be processed two-three times in order to reach the desired spherocity, and that process parameters be optimized for a more narrow particles size range. Keywords: spherocity, spheroidization, plasma, uranium-dioxide, cermet, nuclear, propulsion

Using Demonstrations Involving Combustion and Acid-Base Chemistry to Show Hydration of Carbon Dioxide, Sulfur Dioxide, and Magnesium Oxide and Their Relevance for Environmental Climate Science

Science.gov (United States)

Shaw, C. Frank, III; Webb, James W.; Rothenberger, Otis

2016-01-01

The nature of acidic and basic (alkaline) oxides can be easily illustrated via a series of three straightforward classroom demonstrations for high school and general chemistry courses. Properties of carbon dioxide, sulfur dioxide, and magnesium oxide are revealed inexpensively and safely. Additionally, the very different kinetics of hydration of…

Kinetics of aging of metastable solid electrolytes based on zirconium dioxide

International Nuclear Information System (INIS)

Vlasov, A.N.; Inozemtsev, M.V.

1985-01-01

Kinetics of aging of metastable solid electrolytes on the base of zirconium dioxide stabilized with 8-10 mol.%of yttrium, holmium, and scandium oxides has been studied within the 1200-1373 K temperature range. Kinetic equations describibg behaviour of electric conductivity of two-phase solid electrolytes within a wide temperature interval have been suggested. It has been established that at the initial stage of ageing in cubic solid solution two processes proceed independently of one another: growth of a number of new phase centres and of a volume of new phase centres. At large times growth of a number of new phase centres stops, and kinetics of electrolyte aging is defined only by the growth kinetics of a volume of new phase inclusions

Tungsten - Yttrium Based Nuclear Structural Materials

Science.gov (United States)

Ramana, Chintalapalle; Chessa, Jack; Martinenz, Gustavo

2013-04-01

The challenging problem currently facing the nuclear science community in this 21st century is design and development of novel structural materials, which will have an impact on the next-generation nuclear reactors. The materials available at present include reduced activation ferritic/martensitic steels, dispersion strengthened reduced activation ferritic steels, and vanadium- or tungsten-based alloys. These materials exhibit one or more specific problems, which are either intrinsic or caused by reactors. This work is focussed towards tungsten-yttrium (W-Y) based alloys and oxide ceramics, which can be utilized in nuclear applications. The goal is to derive a fundamental scientific understanding of W-Y-based materials. In collaboration with University of Califonia -- Davis, the project is designated to demonstrate the W-Y based alloys, ceramics and composites with enhanced physical, mechanical, thermo-chemical properties and higher radiation resistance. Efforts are focussed on understanding the microstructure, manipulating materials behavior under charged-particle and neutron irradiation, and create a knowledge database of defects, elemental diffusion/segregation, and defect trapping along grain boundaries and interfaces. Preliminary results will be discussed.

Carbon Dioxide Embolism during Laparoscopic Surgery

Science.gov (United States)

Park, Eun Young; Kwon, Ja-Young

2012-01-01

Clinically significant carbon dioxide embolism is a rare but potentially fatal complication of anesthesia administered during laparoscopic surgery. Its most common cause is inadvertent injection of carbon dioxide into a large vein, artery or solid organ. This error usually occurs during or shortly after insufflation of carbon dioxide into the body cavity, but may result from direct intravascular insufflation of carbon dioxide during surgery. Clinical presentation of carbon dioxide embolism ranges from asymptomatic to neurologic injury, cardiovascular collapse or even death, which is dependent on the rate and volume of carbon dioxide entrapment and the patient's condition. We reviewed extensive literature regarding carbon dioxide embolism in detail and set out to describe the complication from background to treatment. We hope that the present work will improve our understanding of carbon dioxide embolism during laparoscopic surgery. PMID:22476987

Carbon dioxide sensor

Science.gov (United States)

Dutta, Prabir K [Worthington, OH; Lee, Inhee [Columbus, OH; Akbar, Sheikh A [Hilliard, OH

2011-11-15

The present invention generally relates to carbon dioxide (CO.sub.2) sensors. In one embodiment, the present invention relates to a carbon dioxide (CO.sub.2) sensor that incorporates lithium phosphate (Li.sub.3PO.sub.4) as an electrolyte and sensing electrode comprising a combination of lithium carbonate (Li.sub.2CO.sub.3) and barium carbonate (BaCO.sub.3). In another embodiment, the present invention relates to a carbon dioxide (CO.sub.2) sensor has a reduced sensitivity to humidity due to a sensing electrode with a layered structure of lithium carbonate and barium carbonate. In still another embodiment, the present invention relates to a method of producing carbon dioxide (CO.sub.2) sensors having lithium phosphate (Li.sub.3PO.sub.4) as an electrolyte and sensing electrode comprising a combination of lithium carbonate (Li.sub.2CO.sub.3) and barium carbonate (BaCO.sub.3).

Embodied carbon dioxide flow in international trade: A comparative analysis based on China and Japan.

Science.gov (United States)

Long, Ruyin; Li, Jinqiu; Chen, Hong; Zhang, Linling; Li, Qianwen

2018-03-01

Carbon dioxide embodied flow in international trade has become an important factor in defining global carbon emission responsibility and climate policy. We conducted an empirical analysis for China and Japan for the years 2000-2014, using a multi-region input-output model and considering the rest of the world as a comparison group. We compared the two countries' direct and complete carbon dioxide emissions intensity and bilateral economic activities such as imports and exports, production and consumption to analyze the difference between China and Japan. The results showed that the intensities of carbon emissions in all sectors of China were higher than that in Japan and that China's annual production-based emissions were greater than consumption-based emissions, the opposite of these relationships in Japan. China was a typical net carbon export country, and carbon embodied in its imports and exports continued to increase throughout the study period. In contrast, Japan's volume and growth rate of embodied carbon emissions were far less than China's and Japan was a typical net carbon import country. Finally, the conclusions of this study support recommendations for the formulation of international carbon emission responsibility allocation, domestic abatement policy as well as China's trade policy. Copyright © 2018 Elsevier Ltd. All rights reserved.

Nanoparticulate cerium dioxide and cerium dioxide-titanium dioxide composite thin films on glass by aerosol assisted chemical vapour deposition

International Nuclear Information System (INIS)

Qureshi, Uzma; Dunnill, Charles W.; Parkin, Ivan P.

2009-01-01

Two series of composite thin films were deposited on glass by aerosol assisted chemical vapour deposition (AACVD)-nanoparticulate cerium dioxide and nanoparticulate cerium dioxide embedded in a titanium dioxide matrix. The films were analysed by a range of techniques including UV-visible absorption spectroscopy, X-ray diffraction, scanning electron microscopy and energy dispersive analysis by X-rays. The AACVD prepared films showed the functional properties of photocatalysis and super-hydrophilicity. The CeO 2 nanoparticle thin films displaying photocatalysis and photo-induced hydrophilicity almost comparable to that of anatase titania.

Beryllium Project: developing in CDTN of uranium dioxide fuel pellets with addition of beryllium oxide to increase the thermal conductivity

International Nuclear Information System (INIS)

Ferreira, Ricardo Alberto Neto; Camarano, Denise das Merces; Miranda, Odair; Grossi, Pablo Andrade; Andrade, Antonio Santos; Queiroz, Carolinne Mol; Gonzaga, Mariana de Carvalho Leal

2013-01-01

Although the nuclear fuel currently based on pellets of uranium dioxide be very safe and stable, the biggest problem is that this material is not a good conductor of heat. This results in an elevated temperature gradient between the center and its lateral surface, which leads to a premature degradation of the fuel, which restricts the performance of the reactor, being necessary to change the fuel before its full utilization. An increase of only 5 to 10 percent in its thermal conductivity, would be a significant increase. An increase of 50 percent would be a great improvement. A project entitled 'Beryllium Project' was developed in CDTN - Centro de Desenvolvimento da Tecnologia Nuclear, which aimed to develop fuel pellets made from a mixture of uranium dioxide microspheres and beryllium oxide powder to obtain a better heat conductor phase, filling the voids between the microspheres to increase the thermal conductivity of the pellet. Increases in the thermal conductivity in the range of 8.6% to 125%, depending on the level of addition employed in the range of 1% to 14% by weight of beryllium oxide, were obtained. This type of fuel promises to be safer than current fuels, improving the performance of the reactor, in addition to last longer, resulting in great savings. (author)

It is time to put carbon dioxide to work

Energy Technology Data Exchange (ETDEWEB)

Lipinsky, E.S. [Battelle, Columbus, OH (United States)

1993-12-31

The need to control emissions of carbon dioxide into the atmosphere is the subject of vigorous debate at this time. There is growing evidence that rising levels of carbon dioxide increase global warming, with perhaps highly adverse impacts for the human economy. There are calls for carbon taxes and other harsh measures. Japan has established a national goal of holding carbon dioxide emissions in the year 2000 to 1990 levels. I hope that this conference will be a turning point in the United States position on this issue. The current major end uses for CO{sub 2} include refrigeration, beverage carbonation, soda ash production, fire fighting, and urea fertilizer production. They are all based on chemistry that would not surprise a good chemist of the 19th century. Consumption of carbon dioxide in synthesis of industrial chemicals is limited. Usually one explains low production of chemicals from a candidate feedstock in terms of poor availability, price, purity, or reactivity. We can eliminate the first three as the causes of the underutilization of carbon dioxide.

Nuclear data transmission based on zigbee

International Nuclear Information System (INIS)

Cui Yan; Fang Fang; Chen Wei; Jiang Zancheng

2007-01-01

Zigbee, a new wireless communication protocol, which is an important technology supporting wireless sensor networks. We introduce a solution of nuclear data transmission based on zigbee, the cc2420 build up the core of the data acquisition module and the wireless transceive module, and realized remote monitor and nuclear data quickly analysis. (authors)

Reactors physics. Bases of nuclear physics

International Nuclear Information System (INIS)

Diop, Ch.M.

2006-01-01

The aim of nuclear reactor physics is to quantify the relevant macroscopic data for the characterization of the neutronic state of a reactor core and to evaluate the effects of radiations (neutrons and gamma radiations) on organic matter and on inorganic materials. This first article presents the bases of nuclear physics in the context of nuclear reactors: 1 - reactor physics and nuclear physics; 2 - atomic nucleus - basic definitions: nucleus constituents, dimensions and mass of the atomic nucleus, mass defect, binding energy and stability of the nucleus, strong interaction, nuclear momentums of nucleons and nucleus; 3 - nucleus stability and radioactivity: equation of evolution with time - radioactive decay law; alpha decay, stability limit of spontaneous fission, beta decay, electronic capture, gamma emission, internal conversion, radioactivity, two-body problem and notion of radioactive equilibrium. (J.S.)

Manufacturing sector carbon dioxide emissions in nine OECD countries 1973--87: A Divisia index decomposition to changes in fuel mix, emission coefficients, industry structure, energy intensities, and international structure

International Nuclear Information System (INIS)

Torvanger, A.

1990-11-01

In this paper the reduction in energy-related manufacturing carbon dioxide emissions for nine OECD countries in the period 1973 to 1987 is analyzed. Carbon dioxide emissions are estimated from energy use data. The emphasis is on carbon dioxide intensities, defined as emissions divided by value added. The overall manufacturing carbon dioxide intensity for the nine OECD countries was reduced by 42% in the period 1973--1987. Five fuels are specified together with six subsectors of manufacturing. Carbon dioxide emissions are estimated from fossil fuel consumption, employing emissions coefficients for gas, oil and solids. In addition, electricity consumption is specified. For electricity use an emission coefficient index is calculated from the shares of fossil fuels, nuclear power and hydro power used to generate electricity, and the efficiency in electricity generation from these energy sources. A Divisia index approach is used to sort out the contribution to reduced carbon dioxide intensity from different components. The major finding is that the main contribution to reduced carbon dioxide intensity is from the general reduction in manufacturing energy intensity, most likely driven by economic growth and increased energy prices, giving incentives to invest in new technology and new industrial processes. There is also a significant contribution from reduced production in the most carbon dioxide intensive subsectors, and a contribution from higher efficiency in electricity generation together with a larger nuclear power share at the expense of oil. 19 refs., 5 figs., 11 tabs

Preliminary Design and Computational Fluid Dynamics Analysis of Supercritical Carbon Dioxide Turbine Blade

International Nuclear Information System (INIS)

Jeong, Wi S.; Kim, Tae W.; Suh, Kune Y.

2007-01-01

The supercritical gas turbine Brayton cycle has been adopted in the secondary loop of the Generation IV Nuclear Energy Systems, and planned to be installed in power conversion cycles of the nuclear fusion reactors as well. The supercritical carbon dioxide (SCO 2 ) is one of widely considered fluids for this concept. The potential beneficiaries include the Secure Transportable Autonomous Reactor- Liquid Metal (STAR-LM), the Korea Advanced Liquid Metal Reactor (KALIMER) and Battery Omnibus Reactor Integral System (BORIS) which is being developed at the Seoul National University. The reason for these welcomed applications is that the SCO 2 Brayton cycle can achieve higher overall energy conversion efficiency than the steam turbine Rankine cycle. Seoul National University has recently been working on the SCO 2 based Modular Optimized Brayton Integral System (MOBIS). The MOBIS design power conversion efficiency is about 45%. Gas turbine design is crucial part in achieving this high efficiency. In this paper, the preliminary analysis on first stage of gas turbine was performed using CFX as a solver

Nuclear energy in France : Assessing its impacts on the economy and the environment

International Nuclear Information System (INIS)

Charmant, A.; Devezeaux de Lavergne, J-G.; Ladoux, N.; Vielle, M.

1994-01-01

It is argued that an environmental assessment of the French nuclear industry is meaningless without an economic assessment, such as is provided here, using the Micro-Melodie macro-economic model. Nuclear power has led to cheap electricity, and price stability resulting from increasing energy self-sufficiency (from 22% in 1973 to 47% in 1989). Moreover, nuclear exports have had a significant favourable effect on France's balance of payments. The only feasible alternative to nuclear is coal, with all its disadvantages. The most spectacular effect of the nuclear program has been the reduction of carbon dioxide emissions from 530 million tonnes per annum in 1973 to 387 at the time of the conference. Although forecasts have shown that a resumption of nuclear programs would cause world-wide annual carbon dioxide emissions to be reduced by only 4% by the year 2020, nevertheless, nuclear has a part to play in environmental amelioration, particularly in the developed countries, which use most of the world's energy production. 9 refs., 13 tabs., 13 figs

Nuclear fuel element

International Nuclear Information System (INIS)

Iwano, Yoshihiko.

1993-01-01

Microfine cracks having a depth of less than 10% of a pipe thickness are disposed radially from a central axis each at an interval of less than 100 micron over the entire inner circumferential surface of a zirconium alloy fuel cladding tube. For manufacturing such a nuclear fuel element, the inside of the cladding tube is at first filled with an electrolyte solution of potassium chloride. Then, electrolysis is conducted using the cladding tube as an anode and the electrolyte solution as a cathode, and the inner surface of the cladding tube with a zirconium dioxide layer having a predetermined thickness. Subsequently, the cladding tube is laid on a smooth steel plate and lightly compressed by other smooth steel plate to form microfine cracks in the zirconium dioxide layer on the inner surface of the cladding tube. Such a compressing operation is continuously applied to the cladding tube while rotating the cladding tube. This can inhibit progress of cracks on the inner surface of the cladding tube, thereby enabling to prevent failure of the cladding tube even if a pellet/cladding tube mechanical interaction is applied. Accordingly, reliability of the nuclear fuel elements is improved. (I.N.)

Development of a Supercritical Carbon Dioxide Brayton Cycle: Improving VHTR Efficiency and Testing Material Compatibility - Final Report

International Nuclear Information System (INIS)

Chang H. Oh

2006-01-01

Generation IV reactors will need to be intrinsically safe, having a proliferation-resistant fuel cycle and several advantages relative to existing light water reactor (LWR). They, however, must still overcome certain technical issues and the cost barrier before it can be built in the U.S. The establishment of a nuclear power cost goal of 3.3 cents/kWh is desirable in order to compete with fossil combined-cycle, gas turbine power generation. This goal requires approximately a 30 percent reduction in power cost for state-of-the-art nuclear plants. It has been demonstrated that this large cost differential can be overcome only by technology improvements that lead to a combination of better efficiency and more compatible reactor materials. The objectives of this research are (1) to develop a supercritical carbon dioxide Brayton cycle in the secondary power conversion side that can be applied to the Very-High-Temperature Gas-Cooled Reactor (VHTR), (2) to improve the plant net efficiency by using the carbon dioxide Brayton cycle, and (3) to test material compatibility at high temperatures and pressures. The reduced volumetric flow rate of carbon dioxide due to higher density compared to helium will reduce compression work, which eventually increase plant net efficiency

There are countries increasing the number of nuclear power plants instead of running campaigns for a nuclear power phase-out. For example Japan, France, China

International Nuclear Information System (INIS)

Jopp, K.

1997-01-01

Public debates in Germany about the role of nuclear power generation create the impression that nuclear power is heading towards its end, quite contrary to the way nuclear power is perceived in the majority of countries. This particularly applies to countries in Asia, but also to France, for example, or Slovakia, countries which unambigiously favor the option not burdened by carbon dioxide emissions.(orig.) [de

Does Carbon Dioxide Predict Temperature?

OpenAIRE

Mytty, Tuukka

2013-01-01

Does carbon dioxide predict temperature? No it does not, in the time period of 1880-2004 with the carbon dioxide and temperature data used in this thesis. According to the Inter Governmental Panel on Climate Change(IPCC) carbon dioxide is the most important factor in raising the global temperature. Therefore, it is reasonable to assume that carbon dioxide truly predicts temperature. Because this paper uses observational data it has to be kept in mind that no causality interpretation can be ma...

Molybdenum dioxide-molybdenite roasting

International Nuclear Information System (INIS)

Sabacky, B.J.; Hepworth, M.T.

1984-01-01

A process is disclosed for roasting molybdenite concentrates directly to molybdenum dioxide. The process comprises establishing a roasting zone having a temperature of about 700 0 C. to about 800 0 C., introducing into the roasting zone particulate molybdenum dioxide and molybdenite in a weight ratio of at least about 2:1 along with an oxygen-containing gas in amount sufficient to oxidize the sulfur content of the molybdenite to molybdenum dioxide

Nuclear Power Reactor simulator - based training program

International Nuclear Information System (INIS)

Abdelwahab, S.A.S.

2009-01-01

nuclear power stations will continue playing a major role as an energy source for electric generation and heat production in the world. in this paper, a nuclear power reactor simulator- based training program will be presented . this program is designed to aid in training of the reactor operators about the principles of operation of the plant. also it could help the researchers and the designers to analyze and to estimate the performance of the nuclear reactors and facilitate further studies for selection of the proper controller and its optimization process as it is difficult and time consuming to do all experiments in the real nuclear environment.this program is written in MATLAB code as MATLAB software provides sophisticated tools comparable to those in other software such as visual basic for the creation of graphical user interface (GUI). moreover MATLAB is available for all major operating systems. the used SIMULINK reactor model for the nuclear reactor can be used to model different types by adopting appropriate parameters. the model of each component of the reactor is based on physical laws rather than the use of look up tables or curve fitting.this simulation based training program will improve acquisition and retention knowledge also trainee will learn faster and will have better attitude

Carbon materials-functionalized tin dioxide nanoparticles toward robust, high-performance nitrogen dioxide gas sensor.

Science.gov (United States)

Zhang, Rui; Liu, Xiupeng; Zhou, Tingting; Wang, Lili; Zhang, Tong

2018-08-15

Carbon (C) materials, which process excellent electrical conductivity and high carrier mobility, are promising sensing materials as active units for gas sensors. However, structural agglomeration caused by chemical processes results in a small resistance change and low sensing response. To address the above issues, structure-derived carbon-coated tin dioxide (SnO 2 ) nanoparticles having distinct core-shell morphology with a 3D net-like structure and highly uniform size are prepared by careful synthesis and fine structural design. The optimum carbon-coated SnO 2 nanoparticles (SnO 2 /C)-based gas sensor exhibits a low working temperature, excellent selectivity and fast response-recovery properties. In addition, the SnO 2 /C-based gas sensor can maintain a sensitivity to nitrogen dioxide (NO 2 ) of 3 after being cycled 4 times at 140 °C for, suggesting its good long-term stability. The structural integrity, good synergistic properties, and high gas-sensing performance of SnO 2 /C render it a promising sensing material for advanced gas sensors. Copyright © 2018 Elsevier Inc. All rights reserved.

Establishment of THERPRO Database and Estimation of the Effect of Fuel Burn-up on the Thermal Conductivity of Uranium Dioxide

International Nuclear Information System (INIS)

Lee, Hyun Seon

2005-02-01

Materials property data are an essential part of major disciplines in many engineering fields. To nuclear engineering, fundamental understanding of thermo-physical chemical mechanical properties of nuclear materials is very important. THERPRO data base that is re-designed and re-constructed through this study is a web-based on-line nuclear materials properties data base. For the future upgrade of the data base contemporary information technologies have been incorporated during the construction. Basically THERPRO data base has a hierarchical structure consisting of several levels: home page, element, compound, property, author, report, and bibliography level. All of data sets in each level are interconnected using network structure and thus every data can be easily retrieved including the bibliographical information by an appropriate query action. As a part of THERPRO DB utilization, the effect of fuel burn-up on the thermal conductivity of irradiated uranium dioxide is analyzed with the data contained in the data base as well as recent data published in the relevant journals. Their data are comparatively studied and the effect is estimated using FRAPCON-3 code with two in-pile data sets, BR-3 111i5 and Oconee rod 15309. The results show that the fuel center line temperature can differ 200 .deg. C∼400 .deg. C from thermal conductivity models depending on burn-up, which can significantly influence high burn-up fuel performance. In conclusion, it is demonstrated through this study that THERPRO data base can be a great utility for nuclear engineers and researchers, if appropriately utilized

Evaluation of uranium dioxide thermal conductivity using molecular dynamics simulations

International Nuclear Information System (INIS)

Kim, Woongkee; Kaviany, Massoud; Shim, J. H.

2014-01-01

It can be extended to larger space, time scale and even real reactor situation with fission product as multi-scale formalism. Uranium dioxide is a fluorite structure with Fm3m space group. Since it is insulator, dominant heat carrier is phonon, rather than electrons. So, using equilibrium molecular dynamics (MD) simulation, we present the appropriate calculation parameters in MD simulation by calculating thermal conductivity and application of it to the thermal conductivity of polycrystal. In this work, we investigate thermal conductivity of uranium dioxide and optimize the parameters related to its process. In this process, called Green Kubo formula, there are two parameters i.e correlation length and sampling interval, which effect on ensemble integration in order to obtain thermal conductivity. Through several comparisons, long correlation length and short sampling interval give better results. Using this strategy, thermal conductivity of poly crystal is obtained and comparison with that of pure crystal is made. Thermal conductivity of poly crystal show lower value that that of pure crystal. In further study, we broaden the study to transport coefficient of radiation damaged structures using molecular dynamics. Although molecular dynamics is tools for treating microscopic scale, most macroscopic issues related to nuclear materials such as voids in fuel materials and weakened mechanical properties by radiation are based on microscopic basis. Thus, research on microscopic scale would be expanded in this field and many hidden mechanism in atomic scales will be revealed via both atomic scale simulations and experiments

Uranium dioxide thermal characterization by the flash laser method from 23 Celsius to 175 Celsius

International Nuclear Information System (INIS)

Faeda, K.C.M.; Lameiras, F.S.; Carneiro, L.S.S.; Camarano, D.M.; Ferreira, R.A.N.

2010-01-01

The Laser Flash Method has become one of the most common techniques for measuring thermal diffusivity and conductivity in solids and liquids. This method is recognized by INMETRO as standard to be used in Brazil for measuring thermophysical properties of materials, such as metals, carbon composites, ceramics, and also nuclear materials. This article describes the experimental bench of the LMPT-Laboratorio de Medicao de Propriedades Termofisicas de Combustiveis Nucleares e Materiais of the CDTN-Centro de Desenvolvimento da Tecnologia Nuclear, (LMPT), as well as the mathematical model developed based on this method. The obtained results for the thermal diffusivity and for the thermal conductivity of uranium dioxide (U0 2 ) pellets in the temperature range from 25 deg to 175 deg C, are discussed and compared with the literature data. The estimative of the input quantities uncertainty of the mathematical model was determined according to ISO - BIPM-Guide to the Expression of Uncertainty in Measurement and the Monte Carlo Method was used to estimate of the output quantities uncertainty (thermal diffusivity and thermal conductivity). Additionally the results of the x-rays of these pellets are presented. (author)

Coal and carbon dioxide reduction: What does it mean for our power production future?

International Nuclear Information System (INIS)

Weinstein, R.E.

1994-01-01

Carbon dioxide (CO 2 ) is not a pollutant. It is a limiting nutrient, like water and oxygen, necessary for life to exist on earth. It helps retain heat from the sun keeping the earth comfortably warm. Though scientifically controversial, some segments of the public are nonetheless concerned that increasing amounts of carbon dioxide (and other gases) emitted by mankind's activity may contribute to what they perceive as mankind-induced global warming trend, the so-called open-quotes greenhouse effect.close quotes The 1992 Earth Summit in Rio De Janeiro addressed this, and in response, the U.S. signed agreements to roll back its greenhouse gas emissions to 1990 levels. Carbon dioxide is of concern as a greenhouse gas because of the quantity produced by the combustion of fossil fuels. Because coal is mostly carbon, when burned, it produces more carbon dioxide per Btu of energy released of any of the common fossil fuels. With 54 percent of our electricity generated by coal, capping carbon dioxide emissions without disrupting the economy will be no mean feat for the United States. The U.S. also relies on its huge reserves for its energy independence, so altering policies that affect coal use must be carefully assessed. A growing population and economy demand more energy. One can use other fuels than coal: natural gas releases only 56 percent the carbon dioxide coal does, and nuclear energy produces none. One can also employ higher efficiency coal plants to reduce the amount of carbon dioxide produced for a given power output. The highest efficiency coal units projected are magnetohydrodynamics (MHD) plants the focus of this conference which are projected to produce electricity at 60 percent energy efficiency, extraordinary by today's standards. Does this mean that the Rio de Janeiro agreement then encourages the earlier introduction of MHD and other emerging high efficiency coal technologies?

Non-catalytic plasma-arc reforming of natural gas with carbon dioxide as the oxidizing agent for the production of synthesis gas or hydrogen

OpenAIRE

Blom, P.W.E.; Basson, G.W.

2013-01-01

The world’s energy consumption is increasing constantly due to the growing population of the world. The increasing energy consumption has a negative effect on the fossil fuel reserves of the world. Hydrogen has the potential to provide energy for all our needs by making use of fossil fuel such as natural gas and nuclear-based electricity. Hydrogen can be produced by reforming methane with carbon dioxide as the oxidizing agent. Hydrogen can be produced in a Plasma-arc reforming ...

Carbon dioxide and future climate

Energy Technology Data Exchange (ETDEWEB)

Mitchell, J M

1977-03-01

The addition of carbon dioxide to the atmosphere due to burning fossil fuel is discussed. The release rate of carbon dioxide has been growing since at least 1950 at an average rate of 4.3% per year. If all known fossil fuel reserves in the world are consumed, a total of between 5 and 14 times the present amount of carbon dioxide in the atmosphere will be released. The oceans would then be unlikely to withdraw the proportion of perhaps 40% which they are believed to have withdrawn up to the present. The increase in the atmosphere would be in excess of 3 times or conceivably ten times the present amount. If the reserves are used up within a few hundred years, more than half the excess carbon dioxide would remain in the atmosphere after a thousand years. The ''greenhouse'' effect of carbon dioxide is explained. The simulation with numerical models of the effects of carbon dioxide on atmospheric radiation fluxes is discussed. An estimated increase in the average annual temperature of the earth of 2.4 to 2.9C is given for doubling the carbon dioxide content; also a 7% increase in global average precipitation. The effect of increasing carbon dioxide on global mean temperature is viewed in the perspective of the glacial-interglacial cycles. The warming effect of carbon dioxide may induce a ''super-interglacial'' on the present interglacial which is expected to decline toward a new ice age in the next several thousand years. Finally it is proposed that it may be necessary to phase out the use of fossil fuels before all the knowledge is acquired which would necessitate such an action.

Interaction of titanium and vanadium with carbon dioxide under heating

International Nuclear Information System (INIS)

Vlasyuk, R.Z.; Kurovskij, V.Ya.; Lyapunov, V.P.; Radomysel'skij, I.D.

1986-01-01

The methods of gravitmetric and X-ray phase analysis as well as analysis of composition of gases in the heating chamber have been used to investigate the mechanism of titanium and vanadium interaction with carbon dioxide in the 300-1000 deg C temperature range. The analogy of mechanisms of the interaction of titanium and vanadium with carbon dioxide in oxides production on the metal surface with subsequent carbidizing treatment at temperatures above 800 deg C is shown. Temperature limits of material operation on the base of titanium or vanadium in carbon dioxide must not exceed 400 or 600 deg C, respectively

Nuclear Renaissance in an Era of Anthropogenic Climate Change

International Nuclear Information System (INIS)

Bird, John

2008-01-01

This paper substantiates the anthropogenic origin of climate change, demonstrates the resulting consequences, and thereby establishes the need for a nuclear renaissance over the next thirty years. First, the mechanisms behind the natural cycles in global warming, specifically, cycles of precession and eccentricity in Earth's orbit, as measured in ice cores, are compared to the mechanisms of anthropogenic warming, revealing the scientific basis for the observed correlation between carbon dioxide and temperature. Second, the resulting climate change is exemplified by key results from experiments performed by the author in the Arctic and at the South Geographic Pole, and the author's experience of Switzerland's costliest natural catastrophe - the flash flood of 2005. Third, although facing barriers such as research and development requirements, political will and public acceptance, the potential for nuclear power to triple to 1,000 GWe by 2050 would mitigate climate change by holding carbon dioxide concentration below 500 ppm, thereby challenging the younger nuclear generation to contribute to the most important issue facing humanity. (authors)

Recent activities of the nuclear fuel technology department of Cekmece Nuclear Research and Training Center

International Nuclear Information System (INIS)

Can, S.; Aybers, T.; Kopuz, B.

1997-01-01

The Nuclear Fuel Technology Department (NFTD) in CNRTC is a unique unit in Turkey in charge of performing all activities in nuclear fuel field. It has a pilot plant on uranium refining and conversion to UO 2 since 1986. Presently, its R and D activities are focused on pellet manufacturing and characterization: UO 2 , ThO 2 and (Th,U)O 2 . The studies on thorium dioxide fuel include to obtain ThO 2 pellets from thorium nitrate and mixed (Th,U)O 2 pellets. A study on evaluation of different fuel cycle options in accordance with nuclear energy planning in Turkey is also going on. (author)

Statement of nuclear incidents (1st. Qtr. 1990)

International Nuclear Information System (INIS)

1990-06-01

Only one incident was reported; at Bradwell nuclear power station, where there was a leak of carbon dioxide gas. No radioactive contamination was detected and the amount of gas released was well within operating levels. (UK)

Sequestering carbon dioxide in industrial polymers: Building materials for the 21st century

Energy Technology Data Exchange (ETDEWEB)

Molton, P.M.; Nelson, D.A.

1993-06-01

This study was undertaken to determine the possibility of developing beneficial uses for carbon dioxide as a key component for a large-volume building product. Such a use may provide an alternative to storing the gas in oceanic sinks or clathrates as a way to slow the rate of global warming. The authors investigated the concept that carbon dioxide might be used with other chemicals to make carbon-dioxide-based polymers which would be lightweight, strong, and economical alternatives to some types of wood and silica-based building materials. As a construction-grade material, carbon dioxide would be fixed in a solid, useful form where it would not contribute to global warming. With the probable imposition of a fuel carbon tax in industrialized countries, this alternative would allow beneficial use of the carbon dioxide and could remove it from the tax basis if legislation were structured appropriately. Hence, there would be an economic driver towards the use of carbon-dioxide-based polymers which would enhance their future applications. Information was obtained through literature searches and personal contacts on carbon dioxide polymers which showed that the concept (1) is technically feasible, (2) is economically defensible, and (3) has an existing industrial infrastructure which could logically develop it. The technology exists for production of building materials which are strong enough for use by industry and which contain up to 90% by weight of carbon dioxide, both chemically and physically bound. A significant side-benefit of using this material would be that it is self-extinguishing in case of fire. This report is the first stage in the investigation. Further work being proposed will provide details on costs, specific applications and volumes, and potential impacts of this technology.

Uranium dioxide pellets

International Nuclear Information System (INIS)

Zawidzki, T.W.

1979-01-01

Sintered uranium dioxide pellets composed of particles of size > 50 microns suitable for power reactor use are made by incorporating a small amount of sulphur into the uranium dioxide before sintering. The increase in grain size achieved results in an improvement in overall efficiency when such pellets are used in a power reactor. (author)

Sintered nuclear fuel and method of preparing same

International Nuclear Information System (INIS)

Abate-Daga, G.; Amato, I.

1975-01-01

A description is given of a method of preparing a nuclear fuel containing a consumable nuclear poison uniformly distributed therein in the form of coated micro-spheres of between 10 and 2,000 microns diameter, consisting in preparing sintered micro-spheres of the consumable poison, covering those micro-spheres with a protective coating and incorporating the coated micro-spheres into uranium dioxide powder, followed by sintering

Mass transfer and thermodynamic modeling of carbon dioxide absorption into MEA aqueous solution

Directory of Open Access Journals (Sweden)

Ghaemi Ahad

2017-09-01

Full Text Available In this research, thermodynamic and absorption rate of carbon dioxide in monoethanolamine (MEA solution was investigated. A correlation based on both liquid and a gas phase variable for carbon dioxide absorption rate was presented using the π-Buckingham theorem. The correlation was constructed based on dimensionless numbers, including carbon dioxide loading, carbon dioxide partial pressure, film parameter and the ratio of liquid phase film thickness and gas phase film thickness. The film parameter is used to apply the effect of chemical reactions on absorption rate. A thermodynamic model based on the extended-UNIQUAC equations for the activity coefficients coupled with the Virial equation of state for representing the non-ideality of the vapor phase was used to predict the CO2 solubility in the CO2-MEA-H2O system. The average absolute error of the results for the correlation was 6.4%, which indicates the accuracy of the proposed correlation.

Interaction of titanium and vanadium with carbon dioxide in heating

International Nuclear Information System (INIS)

Vlasyuk, R.Z.; Kurovskii, V.Y.; Lyapunov, A.P.; Radomysel'skii, I.D.

1986-01-01

To obtain prediction data on the change in properties of titaniumand vanadium-base powder metallurgy materials operating in a carbon dioxide atmosphere, and also to clarify the mechanism of their interaction with the gas in this work, gravimetric investigations of specimens heated at temperatures of 300-1000 C and an x-ray diffraction analysis of their surface were made and the composition of the gas in the heating chamber was studied. The results of the investigations indicate a similarity between the mechanisms of interaction of titanium and vanadium with carbon dioxide including the formation of oxides on the surface of the metal with subsequent carbidization at temperatures above 800 C. On the basis of the data obtained, it may be concluded that the operating temperature limits of titanium- or vanadium-base materials in carbon dioxide must not exceed 400 and 600 C, respectively

Operating conditions of T.B.P. line uranium purification plant, for uranium dioxide production

International Nuclear Information System (INIS)

Vardich, R.N.; La Gamma, A.M.; Anasco, R.; Soler, S.M.G. de; Isnardi, E.; Gea, V.; Chiaraviglio, R.; Matyjasczyk, E.; Aramayo, R.

1992-01-01

In this contribution are presented the operative conditions and the results obtained step of the Uranium dioxide production plant of Argentina. The refining step involve the Uranium concentrate dissolution, the silica ageing, the filtration and liquid - liquid extraction with n-tributyl phosphate solution in kerosene. The established operative conditions allow to obtain Uranyl nitrate solutions of nuclear purity in industrial scale. (author)

Dye-sensitized solar cell architecture based on indium-tin oxide nanowires coated with titanium dioxide

International Nuclear Information System (INIS)

Joanni, Ednan; Savu, Raluca; Sousa Goes, Marcio de; Bueno, Paulo Roberto; Nei de Freitas, Jilian; Nogueira, Ana Flavia; Longo, Elson; Varela, Jose Arana

2007-01-01

A new architecture for dye-sensitized solar cells is employed, based on a nanostructured transparent conducting oxide protruding from the substrate, covered with a separate active oxide layer. The objective is to decrease electron-hole recombination. The concept was tested by growing branched indium-tin oxide nanowires on glass using pulsed laser deposition followed by deposition of a sputtered titanium dioxide layer covering the wires. The separation of charge generation and charge transport functions opens many possibilities for dye-sensitized solar cell optimization

Nuclear energy - Determination of chlorine and fluorine in uranium dioxide powder and sintered pellets

International Nuclear Information System (INIS)

2008-01-01

This International Standard describes a method for determining the chlorine and fluorine concentrations in uranium dioxide and in sintered fuel pellets by pyrohydrolysis of samples, followed either by liquid ion-exchange chromatography or by selective electrode measurement of chlorine and fluorine ions. Many ion-exchange chromatography systems and ion-selective electrode measurement systems are available

Natural language interface for nuclear data bases

International Nuclear Information System (INIS)

Heger, A.S.; Koen, B.V.

1987-01-01

A natural language interface has been developed for access to information from a data base, simulating a nuclear plant reliability data system (NPRDS), one of the several existing data bases serving the nuclear industry. In the last decade, the importance of information has been demonstrated by the impressive diffusion of data base management systems. The present methods that are employed to access data bases fall into two main categories of menu-driven systems and use of data base manipulation languages. Both of these methods are currently used by NPRDS. These methods have proven to be tedious, however, and require extensive training by the user for effective utilization of the data base. Artificial intelligence techniques have been used in the development of several intelligent front ends for data bases in nonnuclear domains. Lunar is a natural language program for interface to a data base describing moon rock samples brought back by Apollo. Intellect is one of the first data base question-answering systems that was commercially available in the financial area. Ladder is an intelligent data base interface that was developed as a management aid to Navy decision makers. A natural language interface for nuclear data bases that can be used by nonprogrammers with little or no training provides a means for achieving this goal for this industry

Comparison of the antifungal activity of titanium dioxide based nanosilver packaging and conventional polyethylene packaging in consumed bread

Directory of Open Access Journals (Sweden)

H Mohammadi

2014-12-01

Full Text Available Using titanium dioxide nanosilver packaging which is antibacterial and resistance to the diffusion of gases such as oxygen is increasing in food industry. Therefore we compared the effect of titanium dioxide based nanosilver packaging and conventional polyethylene packaging - on fungal flora of consuming bread in order to increase the shelf life storage of  consuming bread. One hundred forty four samples of 6 different types of loaf of bread randomly obtained from 12 bakeries in District 2 of Tehran. The samples were packaged with 3%, 5% and 10% nano coatings and also conventional polyethylene coatings as control group. The bacterial examination and monitoring of samples, according to the national standards of Iran was carried out 3 times, on days 1, 3, 7, 14 and 28, of study period.This study showed that the film type and storage period, were main factors which significantly influenced fungal flora of bread. The lowest rate of various fungi growth (%14 was observed in 10% Nano film, while the highest rate of various fungi growth (47% was observed in conventional polyethylene coating (P<0.001. With increasing storage periods,  the number of various fungi increased, however this correlation was not similar in most of breads and fungi types. There were significant difference between them (P = 0.001. According to the results of the present study, due to increasing population growth and in order to improve food security, using packages with nanosilver particles which are based on titanium dioxide, prevails over the polyethylene packages. Therefore using such packages are highly recommended in bakery industry.

Certification of a uranium-238 dioxide reference material for neutron dosimetry (EC nuclear reference material 501)

International Nuclear Information System (INIS)

Pauwels, J.; Lievens, F.; Ingelbrecht, C.

1989-01-01

Uranium-238 oxide of 99.999% isotopic and 99.98% chemical purity was transformed into dioxide spheres of nominal 0.5 and 1.0 mm diameter by gel precipitation and subsequent calcination under carbon dioxide and under argon containing 5% hydrogen at 1 125 K. The spheres were analysed by thermal ionization mass spectrometry, including isotope dilution, by gravimetry and by potentiometric titration. On the basis of these analyses, the uranium mass fraction was certified at 879.4 ± 2.8 g.kg -1 , and the 235 U/U - and 238 U/U abundances at 10.4 ± 0.5 mg.kg -1 and 999.9896 ± 0.0005 g.kg -1 , respectively. The material is intended to be used as a reference material in neutron metrology

CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS

Energy Technology Data Exchange (ETDEWEB)

David A. Green; Brian S. Turk; Raghubir P. Gupta; Alejandro Lopez-Ortiz; Douglas P. Harrison; Ya Liang

2001-07-01

Sodium based sorbents including sodium carbonate may be used to capture carbon dioxide from flue gas. A relatively concentrated carbon dioxide stream may be recoverable for sequestration when the sorbent is regenerated. Electrobalance tests indicated that sodium carbonate monohydrate was formed in a mixture of helium and water vapor at temperatures below 65 C. Additional compounds may also form, but this could not be confirmed. In the presence of carbon dioxide and water vapor, both the initial reaction rate of sodium carbonate with carbon dioxide and water and the sorbent capacity decreased with increasing temperature, consistent with the results from the previous quarter. Increasing the carbon dioxide concentration at constant temperature and water vapor concentration produced a measurable increase in rate, as did increasing the water vapor concentration at constant carbon dioxide concentration and temperature. Runs conducted with a flatter TGA pan resulted in a higher initial reaction rate, presumably due to improved gas-solid contact, but after a short time, there was no significant difference in the rates measured with the different pans. Analyses of kinetic data suggest that the surface of the sodium carbonate particles may be much hotter than the bulk gas due to the highly exothermic reaction with carbon dioxide and water, and that the rate of heat removal from the particle may control the reaction rate. A material and energy balance was developed for a cyclic carbonation/calcination process which captures about 26 percent of the carbon dioxide present in flue gas available at 250 C.

Carbon dioxide emissions due to Swedish imports and consumption: estimates using different methods

International Nuclear Information System (INIS)

Carlsson-Kanyama, Annika; Assefa, Getachew; Wadeskog, Anders

2007-04-01

Global trade of products and services challenges the traditional way in which emissions of carbon dioxide are declared and accounted for. Instead of only considering territorial emissions there are now strong reasons to determine how the carbon dioxide emitted in the production of imports are partitioned around the world and how the total emissions change for a country's final consumption compared to final production. In this report results from four different methods of calculating the total carbon dioxide emissions from Sweden's overall consumption are presented. Total carbon dioxide emissions for Sweden's final consumption vary from 57 to 109 M tons during one year depending on the methodology. The four methods used for estimating these emissions give results of 57, 61, 68 and 109 Mton of carbon dioxide. Two methods are based on information concerning Sweden's imports and our national production of goods and services excluding production that is exported while two methods are based on final consumer expenditures. Three of the methods use mainly emission data from Sweden while one method depends entirely upon emission data from Sweden's trading partners. The last method also gives the highest emissions level, 109 Mton of carbon dioxide. The calculations performed here can be compared to the emissions reported by Sweden, 54 Mton of carbon dioxide per year. Our estimates give per capita emission levels of between 6,3 and 12 tons of carbon dioxide per year. The estimate of 12 tons per capita is a result of using emissions data from Sweden's trading partners. The total emissions as a result of Sweden's imports are 26 or 74 M tons of carbon dioxide depending on how they are calculated. The lower figure is based upon the imports of today but with emissions as if everything was produced as in Sweden. The higher level is based upon using existing but partly inadequate international emission statistics. These levels can be compared to the about 35 M tons of carbon dioxide

Statement on nuclear incidents at nuclear installations -third quarter 1987

International Nuclear Information System (INIS)

1988-01-01

Four incidents are reported. Carbon dioxide containing a small amount of radioactive material was released at the Chapelcross works of British Nuclear Fuels. However, air monitoring showed the contamination to be small. Surfaces contaminated were cleaned and the reactor was allowed to restart as scheduled. Refurbishment work at the Berkeley Nuclear Power Station sewage plant revealed five radioactive particles. The sludge has been isolated until a disposal method is found. Contamination on a coverall was found at the Sellafield reprocessing plant. Both the operators who may have worn the coverall may have received excess doses. Improvements in the possible source of contamination have been made. A leak of gas from the Hunterston B nuclear power station was found to be from a failed joint on a bolted flange on the bypass circuit heat exchanger. The joint has been repaired. (U.K.)

Titanium dioxide modified with various amines used as sorbents of carbon dioxide

International Nuclear Information System (INIS)

Kapica-Kozar, Joanna; Pirog, Ewa; Kusiak-Nejman, Ewelina; Wrobel, Rafal J.; Gesikiewicz-Puchalska, Andzelika; Morawski, Antoni W.; Narkiewicz, Urszula; Michalkiewicz, Beata

2017-01-01

In this study, titanium dioxide was modified with various amines through hydrothermal treatment for adsorption of CO_2. The carbon dioxide adsorption performance of the prepared samples was measured using an STA 449 C thermo-balance (Netzsch Company, Germany). The morphological structures, functional groups and elemental compositions of the unmodified and amine-modified titanium dioxide sorbents were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR/DR) and scanning electron microscopy (SEM), respectively. The results showed that modification of TiO_2 with amines through hydrothermal treatment is a simple method to prepare CO_2 sorbents with high adsorption capacities. Moreover, the results revealed that TEPA-modified titanium dioxide shoved the highest adsorption capacity, enabling an increase in CO_2 uptake from 0.45 mmol CO_2 g"-"1 in the case of raw TiO_2 to 1.63 mmol CO_2 g"-"1. This result could be indirectly related to the fact that TEPA has the highest amino group content among the three amines used in our research. Additionally, durability tests performed by cyclic adsorption-desorption revealed that TEPA modified titanium dioxide also possesses excellent stability, despite a slight decrease in adsorption capacity over time. (authors)

Nuclear energy - Uranium dioxide powder and sintered pellets - Determination of oxygen/uranium atomic ratio by the amperometric method. 2. ed.

International Nuclear Information System (INIS)

2007-01-01

This International Standard specifies an analytical method for the determination of the oxygen/uranium atomic ratio in uranium dioxide powder and sintered pellets. The method is applicable to reactor grade samples of hyper-stoichiometric uranium dioxide powder and pellets. The presence of reducing agents or residual organic additives invalidates the procedure. The test sample is dissolved in orthophosphoric acid, which does not oxidize the uranium(IV) from UO 2 molecules. Thus, the uranium(VI) that is present in the dissolved solution is from UO 3 and/or U 3 O 8 molecules only, and is proportional to the excess oxygen in these molecules. The uranium(VI) content of the solution is determined by titration with a previously standardized solution of ammonium iron(II) sulfate hexahydrate in orthophosphoric acid. The end-point of the titration is determined amperometrically using a pair of polarized platinum electrodes. The oxygen/uranium ratio is calculated from the uranium(VI) content. A portion, weighing about 1 g, of the test sample is dissolved in orthophosphoric acid. The dissolution is performed in an atmosphere of nitrogen or carbon dioxide when sintered material is being analysed. When highly sintered material is being analysed, the dissolution is performed at a higher temperature in purified phosphoric acid from which the water has been partly removed. The cooled solution is titrated with an orthophosphoric acid solution of ammonium iron(II) sulfate, which has previously been standardized against potassium dichromate. The end-point of the titration is detected by the sudden increase of current between a pair of polarized platinum electrodes on the addition of an excess of ammonium iron(II) sulfate solution. The paper provides information about scope, principle, reactions, reagents, apparatus, preparation of test sample, procedure (uranium dioxide powder, sintered pellets of uranium dioxide, highly sintered pellets of uranium dioxide and determination

Experience-based innovations in management of nuclear power plant technology

International Nuclear Information System (INIS)

Wagner, R.L.; Bradbury, R.B.; Freeman, D.V.; Jacobs, S.B.

1987-01-01

During 45 years of nuclear technology development and experience, Stone and Webster (S and W) has developed and successfully applied various innovative techniques to numerous nuclear projects. These techniques, developed primarily in response to the increasing scope and complexity of nuclear power plants, have been used and refined to provide efficient management of the two major nuclear project acticities-design and construction. For this paper, these techniques have been divided into: 1) engineering-based innovations, 2) construction-based innovations, and 3) management-based innovations. (author)

Experience-based innovations in management of nuclear power plant technology

International Nuclear Information System (INIS)

Wagner, R.L.; Bradbury, R.B.; Freeman, D.V.; Jacobs, S.B.

1988-01-01

During 45 years of nuclear technology development and experience, Stone and Webster (S and W) has developed and successfully applied various innovative techniques to numerous nuclear projects. These techniques, developed primarily in response to the increasing scope and complexity of nuclear power plants, have been used and refined to provide efficient management of the two major nuclear project activities - design and construction. For this paper, these techniques have been divided into: (1) engineering-based innovations, (2) construction-based innovations, and (3) management-based innovations

Carbon dioxide elimination and regeneration of resources in a microwave plasma torch

International Nuclear Information System (INIS)

Uhm, Han S.; Kwak, Hyoung S.; Hong, Yong C.

2016-01-01

Carbon dioxide gas as a working gas produces a stable plasma-torch by making use of 2.45 GHz microwaves. The temperature of the torch flame is measured by making use of optical spectroscopy and a thermocouple device. Two distinctive regions are exhibited, a bright, whitish region of a high-temperature zone and a bluish, dimmer region of a relatively low-temperature zone. The bright, whitish region is a typical torch based on plasma species where an analytical investigation indicates dissociation of a substantial fraction of carbon dioxide molecules, forming carbon monoxides and oxygen atoms. The emission profiles of the oxygen atoms and the carbon monoxide molecules confirm the theoretical predictions of carbon dioxide disintegration in the torch. Various hydrocarbon materials may be introduced into the carbon dioxide torch, regenerating new resources and reducing carbon dioxide concentration in the torch. As an example, coal powders in the carbon dioxide torch are converted into carbon monoxide according to the reaction of CO_2 + C → 2CO, reducing a substantial amount of carbon dioxide concentration in the torch. In this regards, the microwave plasma torch may be one of the best ways of converting the carbon dioxides into useful new materials. - Highlights: • Carbon dioxide gas produces a plasma-torch by making use of 2.45 GHz microwaves. • The temperature measurement of torch flame by optical spectroscopy. • Disintegration of carbon dioxide into carbon monoxide and oxygen atom. • Emission profiles of carbon monoxide confirm disintegration theory. • Conversion of carbon dioxide into carbon monoxide in the plasma torch. - This article presents carbon-dioxide plasma torch operated by microwaves and its applications to regeneration of new resources, eliminating carbon dioxide molecules.

Electronic structure of the actinides and their dioxides. Application to the defect formation energy and krypton solubility in uranium dioxide; Etude de la structure electronique des actinides et de leurs dioxydes. Application aux defauts ponctuels et aux gaz de fission dans le dioxyde d`uranium

Energy Technology Data Exchange (ETDEWEB)

Petit, T. [CEA Centre d`Etudes Nucleaires de Grenoble, 38 (France)]|[CEA Centre d`Etudes de Grenoble, 38 (France). Dept. de Thermohydraulique et de Physique

1996-09-28

Uranium dioxide is the standard nuclear fuel used in French h power plants. During irradiation, fission products such as krypton and xenon are created inside fuel pellets. So, gas release could become, at very high burnup, a limiting factor in the reactor exploitation. To study this subject, we have realised calculations using the Density Functional Theory (DFT) into the Local Density Approximation (LDA) and the Atomic Sphere Approximation (ASA). First, we have validated our approach by calculating cohesive properties of thorium, protactinium and uranium metals. The good agreement between our results and experimental values implies that 5f electrons are itinerant. Calculated lattice parameter, cohesive energy and bulk modulus for uranium and thorium dioxides are in very good agreement with experiment. We show that binding between uranium and oxygen atoms is not completely ionic but partially covalent. The question of the electrical conductivity still remains an open problem. We have been able to calculate punctual defect formation energies in uranium dioxide. Accordingly to experimental observations, we find that it is easier to create a defect in the oxygen sublattice than in the uranium sublattice. Finally, we have been able to predict a probable site of krypton atoms in nuclear fuel: the Schottky trio. Experiences of Extended X-ray Absorption Fine structure Spectroscopy (EXAFS) and X-ray Photoelectron Spectroscopy (XPS) on uranium dioxide doped by ionic implantation will help us in the comprehension of the studied phenomena and the interpretation of our calculations. (author). 256 refs.

Users' guide for a personal-computer-based nuclear power plant fire data base

International Nuclear Information System (INIS)

Wheelis, W.T.

1986-08-01

The Nuclear Power Plant Fire Data Base has been developed for use with an IBM XT (or with a compatible system). Nuclear power plant fire data is located in many diverse references, making it both costly and time-consuming to obtain. The purpose of this Fire Data Base is to collect and to make easily accessible nuclear power plant fire data. This users' guide discusses in depth the specific features and capabilities of the various options found in the data base. Capabilities include the ability to search several database fields simultaneously to meet user-defined conditions, display basic plant information, and determine the operating experience (in years) for several nuclear power plant locations. Step-by-step examples are included for each option to allow the user to learn how to access the data

Climatic change and nuclear energy

International Nuclear Information System (INIS)

Schneider, M.

2000-08-01

The data presented in the different chapters lead to show that nuclear energy ids not a sustainable energy sources for the following reasons: investments in nuclear energy account financing that lacks to energy efficiency programmes. The nuclear programmes have negative effects such the need of great electric network, the need of highly qualified personnel, the freezing of innovation in the fields of supply and demand, development of small performing units. The countries resort to nuclear energy are among the biggest carbon dioxide emitters, because big size nuclear power plants lead to stimulate electric power consumption instead of inducing its rational use. Nuclear energy produces only electric power then a part of needs concerns heat (or cold) and when it is taken into account nuclear energy loses its advantages to the profit of cogeneration installations. Finally nuclear energy is a dangerous energy source, difficult to control as the accident occurring at Tokai MURA showed it in 1998. The problem of radioactive wastes is not still solved and the nuclear proliferation constitutes one of the most important threat at the international level. (N.C.)

Carbon dioxide elimination and regeneration of resources in a microwave plasma torch.

Science.gov (United States)

Uhm, Han S; Kwak, Hyoung S; Hong, Yong C

2016-04-01

Carbon dioxide gas as a working gas produces a stable plasma-torch by making use of 2.45 GHz microwaves. The temperature of the torch flame is measured by making use of optical spectroscopy and a thermocouple device. Two distinctive regions are exhibited, a bright, whitish region of a high-temperature zone and a bluish, dimmer region of a relatively low-temperature zone. The bright, whitish region is a typical torch based on plasma species where an analytical investigation indicates dissociation of a substantial fraction of carbon dioxide molecules, forming carbon monoxides and oxygen atoms. The emission profiles of the oxygen atoms and the carbon monoxide molecules confirm the theoretical predictions of carbon dioxide disintegration in the torch. Various hydrocarbon materials may be introduced into the carbon dioxide torch, regenerating new resources and reducing carbon dioxide concentration in the torch. As an example, coal powders in the carbon dioxide torch are converted into carbon monoxide according to the reaction of CO2 + C → 2CO, reducing a substantial amount of carbon dioxide concentration in the torch. In this regards, the microwave plasma torch may be one of the best ways of converting the carbon dioxides into useful new materials. Copyright © 2015 Elsevier Ltd. All rights reserved.

Data base of nuclear information and its practical usage

International Nuclear Information System (INIS)

Anon

2005-01-01

It is reported on the development and using in Japan the nuclear data base NUCIA (Nuclear Information Archives). The NUCIA consists of the Web site for presentation of general data and the system for recording the data on the accidents and failures in the field of nuclear power. Possibility of data loading and processing in the XML format is ensured. The data base was putting into operation in October 2003 [ru

Computational analysis of supercritical carbon dioxide flow around a turbine and compressor BLADE

International Nuclear Information System (INIS)

Kim, Tae W.; Kim, Nam H.; Suh, Kune Y.; Kim, Seung O.

2007-01-01

The turbine and compressor isentropic efficiencies are one of the major parameters affecting the overall Brayton cycle efficiency. Thus, the optimal turbine and compressor design should contribute to the economics of future nuclear fission and fusion energy systems. A computation analysis was performed utilizing CFX for the supercritical carbon dioxide (SCO 2 ) flow around a turbine and compressor blade to check on the potential efficiency of the turbine and compressor which determine such basic design values as the blade (or impeller) and nozzle (or diffuser) types, blade height, and minimum and maximum radii of the hub and tip. Basic design values of the turbine and compressor blades based on the Argonne National Laboratory (ANL) design code was generated by ANSYS BladeGen TM . The boundary conditions were based on the KALIMER-600 secondary loop. Optimal SCO 2 turbine and compressor blades were developed for high efficiency of 90% by the computational analysis. (author)

Competitiveness of nuclear power in Belgium

International Nuclear Information System (INIS)

Frederick, G.; Gillon, J.P.; Delvoye, J.

1995-01-01

In Belgium, the power utilities have to draw up periodically, for the Belgium Government, a national equipment plan so as to substantiate the investments planned for the ten year period that follows the publication of the plan. The justification of this plan is mainly based on the cost of the kilowatt-hour produced by the different types of power units. The most recently published plan covers the period 1988-1998. The three power generation means considered in Belgium for comparison are nuclear, coal and gas. Taking into account the official calculation criteria (discount rate of 8.6% and book-keeping life of 20 years), nuclear generation is clearly situated between the low and high hypotheses for gas, while coal is more costly. By using more realistic values of the book-keeping life, nuclear and gas are at the same level. Nuclear power generation can be an economic option for base load generation, especially if gas prices go up. This may be the case in the coming years, since 'a dash for gas' is currently being experienced and since the nuclear fuel costs are lower than the conservative price level adopted in the equipment plant in 1988. Despite the advantages of nuclear energy (economic advantages as a result of price stability, ecological advantages with respect to the greenhouse effect and carbon dioxide production, political advantages in terms of energy independence, and industrial advantages in terms of benefits to the domestic economy), it can only be developed in a favourable context if it is accepted by the citizens. This is the reason why the utilities are waiting for a national political consensus before introducing officially new nuclear plants in their planning proposals. (author). 7 figs, 4 tabs

The financing of nuclear power plants

International Nuclear Information System (INIS)

2009-01-01

Many countries have recognised that greater use of nuclear power could play a valuable role in reducing carbon dioxide emissions. However, given the high capital cost and complexity of nuclear power plants, financing their construction often remains a challenge. This is especially true where such financing is left to the private sector in the context of competitive electricity markets. This study examines the financial risks involved in investing in a new nuclear power plant, how these can be mitigated, and how projects can be structured so that residual risks are taken by those best able to manage them. Given that expansion of nuclear power programmes will require strong and sustained government support, the study highlights the role of governments in facilitating and encouraging investment in new nuclear generating capacity

Conventional and nuclear energy conversionenvironmental impacts

Energy Technology Data Exchange (ETDEWEB)

Schikarski, W

1978-11-01

Nuclear power plants and reprocessing plants add, on the average, only 1% to natural radiation levels. Levels of atmospheric pollution caused by coal-fired power plants are compared with those made by nuclear plants. Three means of comparison are performed: calculations of relative pollutant levels, which results in a ratio of 1:100 in favor of nuclear power; calculations of the volume of pure air necessary to dilute the pollutant to applicable limit levels, which produce a ratio of 1:1000 in favor of nuclear; and ratio of pollutant levels to natural background levels, which shows that coal plants roughly double the natural carbon dioxide level while nuclear plants contribute only a few percent to the natural background radiation level. (in German) (5 diagrams, 17 references, 13 tables)

What is nuclear power in Japan?

Science.gov (United States)

Suzuki, Toshikazu

2011-03-01

The aggressive use of such non-fossil energy as the atomic energy with high power density and energy production efficiency is an indispensable choice aiming at the low-carbon society. There is a trial calculation that the carbon dioxide emission of 40000 ton can be suppressed by nuclear power generation by one ton of uranium. The basis of nuclear research after the Second World War in Japan was established by the researchers learnt in Argonne National Laboratory. In 2010, NPPs under operation are 54 units and the total electric generating power is 48.85GW. The amount of nuclear power generation per person of the people is 0.38kW in Japan, and it is near 0.34kW of the United States. However, the TMI accident and the Chernobyl disaster should have greatly stagnated the nuclear industry of Japan although it is not more serious than the United States. A lot of Japanese unconsciously associate a nuclear accident with the atomic bomb. According to the investigation which Science and Technology Agency carried out to the specialist in 1999, ``What will be the field where talent should be emphatically sent in the future?'' the rank of nuclear technology was the lowest in 32 fields. The influence of the nuclear industry stagnation was remarkable in the education. The subject related to the atomic energy of a university existed 19 in 1985 that was the previous year of the Chernobyl disaster decreased to 7 in 2003. In such a situation, we have to rely on the atomic energy because Japan depends for 96% of energy resources on import. The development of the fuel reprocessing and the fast breeder reactor has been continued in spite of a heavy failure. That is the only means left behind for Japan to be released from both fossil fuel and carbon dioxide.

Synthesis of uranium and thorium dioxides by Complex Sol-Gel Processes (CSGP). Synthesis of uranium oxides by Complex Sol-Gel Processes (CSGP)

International Nuclear Information System (INIS)

Deptula, A.; Brykala, M.; Lada, W.; Olczak, T.; Wawszczak, D.; Chmielewski, A.G.; Modolo, G.; Daniels, H.

2010-01-01

In the Institute of Nuclear Chemistry and Technology (INCT), a new method of synthesis of uranium and thorium dioxides by original variant of sol-gel method - Complex Sol-Gel Process (CSGP), has been elaborated. The main modification step is the formation of nitrate-ascorbate sols from components alkalized by aqueous ammonia. Those sols were gelled into: - irregularly agglomerates by evaporation of water; - medium sized microspheres (diameter <150) by IChTJ variant of sol-gel processes by water extraction from drops of emulsion sols in 2-ethylhexanol-1 by this solvent. Uranium dioxide was obtained by a reduction of gels with hydrogen at temperatures >700 deg. C, while thorium dioxide by a simple calcination in the air atmosphere. (authors)

Liquid carbon dioxide absorbents, methods of using the same, and related system

Science.gov (United States)

Perry, Robert James; Soloveichik, Grigorii Lev; Rubinsztajn, Malgorzata Iwona; O'Brien, Michael Joseph; Lewis, Larry Neil; Lam, Tunchiao Hubert; Kniajanski, Sergei; Hancu, Dan

2018-05-01

A carbon dioxide absorbent composition is described, including (i) a liquid, nonaqueous silicon-based material, functionalized with one or more groups that either reversibly react with CO2 or have a high-affinity for CO2, and (ii) a hydroxy-containing solvent that is capable of dissolving both the silicon-based material and a reaction product of the silicon-based material and CO2. The absorbent may be utilized in methods to reduce carbon dioxide in an exhaust gas, and finds particular utility in power plants.

Effect of sulfur dioxide partial pressure on the reaction of iodine, sulfur dioxide and water

International Nuclear Information System (INIS)

Nakajima, Hayato; Imai, Yoshiyuki; Kasahara, Seiji; Kubo, Shinji; Onuki, Kaoru

2007-01-01

Effect of sulfur dioxide partial pressure on the reaction of iodine, sulfur dioxide and water, which is a unit reaction in the IS process for thermochemical hydrogen production, was studied experimentally at 323 K under iodine saturation. Quasi-equilibrium state was observed in the presence of sulfur dioxide gas at constant pressure. The composition of the poly-hydriodic acid solution formed was discussed assuming an ideal desulfurization by the reverse reaction of the Bunsen reaction. The value of HI/(HI+H 2 O) of the desulfurized solution was large at high sulfur dioxide pressure and reached the maximum of 15.7 ± 0.3 mol%. (author)

Microscopically Based Nuclear Energy Functionals

International Nuclear Information System (INIS)

Bogner, S. K.

2009-01-01

A major goal of the SciDAC project 'Building a Universal Nuclear Energy Density Functional' is to develop next-generation nuclear energy density functionals that give controlled extrapolations away from stability with improved performance across the mass table. One strategy is to identify missing physics in phenomenological Skyrme functionals based on our understanding of the underlying internucleon interactions and microscopic many-body theory. In this contribution, I describe ongoing efforts to use the density matrix expansion of Negele and Vautherin to incorporate missing finite-range effects from the underlying two- and three-nucleon interactions into phenomenological Skyrme functionals.

Systematic framework for carbon dioxide capture and utilization processes to reduce the global carbon dioxide emissions

DEFF Research Database (Denmark)

Frauzem, Rebecca; Plaza, Cristina Calvera; Gani, Rafiqul

information-data on various carbon dioxide emission sources and available capture-utilization technologies; the model and solution libraries [2]; and the generic 3-stage approach for determining more sustainable solutions [3] through superstructure (processing networks) based optimization – adopted for global...... need to provide, amongst other options: useful data from in-house databases on carbon dioxide emission sources; mathematical models from a library of process-property models; numerical solvers from library of implemented solvers; and, work-flows and data-flows for different benefit scenarios...... to be investigated. It is useful to start by developing a prototype framework and then augmenting its application range by increasing the contents of its databases, libraries and work-flows and data-flows. The objective is to present such a prototype framework with its implemented database containing collected...

Long-Term, Autonomous Measurement of Atmospheric Carbon Dioxide Using an Ormosil Nanocomposite-Based Optical Sensor

Energy Technology Data Exchange (ETDEWEB)

Kisholoy Goswami

2005-10-11

The goal of this project is to construct a prototype carbon dioxide sensor that can be commercialized to offer a low-cost, autonomous instrument for long-term, unattended measurements. Currently, a cost-effective CO2 sensor system is not available that can perform cross-platform measurements (ground-based or airborne platforms such as balloon and unmanned aerial vehicle (UAV)) for understanding the carbon sequestration phenomenon. The CO2 sensor would support the research objectives of DOE-sponsored programs such as AmeriFlux and the North American Carbon Program (NACP). Global energy consumption is projected to rise 60% over the next 20 years and use of oil is projected to increase by approximately 40%. The combustion of coal, oil, and natural gas has increased carbon emissions globally from 1.6 billion tons in 1950 to 6.3 billion tons in 2000. This figure is expected to reach 10 billon tons by 2020. It is important to understand the fate of this excess CO2 in the global carbon cycle. The overall goal of the project is to develop an accurate and reliable optical sensor for monitoring carbon dioxide autonomously at least for one year at a point remote from the actual CO2 release site. In Phase I of this project, InnoSense LLC (ISL) demonstrated the feasibility of an ormosil-monolith based Autonomous Sensor for Atmospheric CO2 (ASAC) device. All of the Phase I objectives were successfully met.

Relationship between Sampling Distance and Carbon Dioxide Emission under Oil Palm Plantation

Directory of Open Access Journals (Sweden)

Ai Dariah

2013-05-01

Full Text Available A carbon dioxide emission on peatland under oil palm plantation was highly varied due to many factors involved. The objectives of the research were to evaluate the effect of sampling distance from center of oil palm tree on Carbon dioxide flux, and to study the factors that cause variability of carbon dioxide flux on peatland under oil palm plantation. The study was conducted on peatland at Arang-Arang Village, Kumpek Ulu Sub-District, Muaro Jambi District, Jambi Province, on six-years old oil palm plantation. The study was conducted in the form of observational exploratory. Emission measurements were performed on 5 selected oil palm trees at points within 100, 150, 200, 250, 300, 350, and 400 cm from the center of trunk. Carbon dioxide flux was measured using (IRGA, Li-COR 820. The results showed that there was significant correlation between the distance of sampling from center of oil palm tree and Carbon dioxide flux. The farther distance from the tree, the more decreased of Carbon dioxide flux . Before applying fertilizer, variability of soil fertility was not significantly correlated with the flux of Carbon dioxide, so the difference of Carbon dioxide flux based on distance sampling can be caused by root distribution factor. After fertilizer application, variability of Carbon dioxide flux under the oil palm tree were not only affected by differences in root distribution but also greatly influenced by fertilization.

46 CFR 169.732 - Carbon dioxide alarm.

Science.gov (United States)

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Carbon dioxide alarm. 169.732 Section 169.732 Shipping... Control, Miscellaneous Systems, and Equipment Markings § 169.732 Carbon dioxide alarm. Each carbon dioxide alarm must be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED.” ...

40 CFR 180.1195 - Titanium dioxide.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Titanium dioxide. 180.1195 Section 180.1195 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS... Titanium dioxide. Titanium dioxide is exempted from the requirement of a tolerance for residues in or on...

Behaviour of magnesium and two magnesium alloys heated in a carbon dioxide flow

International Nuclear Information System (INIS)

Boussion, M.-L.; Darras, R.; Leclercq, D.

1959-01-01

Magnesium is a particularly attractive material for sheathing uranium fuel elements in nuclear reactors in order to avoid uranium hot temperature oxidation by the cooling fluid. As this cooling fluid will be carbon dioxide at the (future) Marcoule plants, a thorough study of magnesium and magnesium alloys behaviour when heated by carbon dioxide at a 400 C temperature, have been completed. Tests on three materials (Mg, Mg-Zr and Mg-Zr-Zn) have been performed with CO 2 up to a temperature of 550 C, at atmospheric pressure in the presence of a certain amount of oxygen and nitrogen (in order to study the influence of these impurities), and at a pressure of 15 kg / cm 2 . Oxidation results are detailed. Reprint of a paper published in 'Revue de Metallurgie', LVI, n. 1, 1959, p. 61-67

DOUBLE-SHELL TANK (DST) HYDROXIDE DEPLETION MODEL FOR CARBON DIOXIDE ABSORPTION

International Nuclear Information System (INIS)

OGDEN DM; KIRCH NW

2007-01-01

This document generates a supernatant hydroxide ion depletion model based on mechanistic principles. The carbon dioxide absorption mechanistic model is developed in this report. The report also benchmarks the model against historical tank supernatant hydroxide data and vapor space carbon dioxide data. A comparison of the newly generated mechanistic model with previously applied empirical hydroxide depletion equations is also performed

46 CFR 108.627 - Carbon dioxide alarm.

Science.gov (United States)

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Carbon dioxide alarm. 108.627 Section 108.627 Shipping... EQUIPMENT Equipment Markings and Instructions § 108.627 Carbon dioxide alarm. Each carbon dioxide alarm must be identified by marking: “WHEN ALARM SOUNDS VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED” next to...

High-temperature, Knudsen cell-mass spectroscopic studies on lanthanum oxide/uranium dioxide solid solutions

International Nuclear Information System (INIS)

Sunder, S.; McEachern, R.; LeBlanc, J.C.

2001-01-01

Knudsen cell-mass spectroscopic experiments were carried out with lanthanum oxide/uranium oxide solid solutions (1%, 2% and 5% (metal at.% basis)) to assess the volatilization characteristics of rare earths present in irradiated nuclear fuel. The oxidation state of each sample used was conditioned to the 'uranium dioxide stage' by heating in the Knudsen cell under an atmosphere of 10% CO 2 in CO. The mass spectra were analyzed to obtain the vapour pressures of the lanthanum and uranium species. It was found that the vapour pressure of lanthanum oxide follows Henry's law, i.e., its value is directly proportional to its concentration in the solid phase. Also, the vapour pressure of lanthanum oxide over the solid solution, after correction for its concentration in the solid phase, is similar to that of uranium dioxide. (authors)

Competence-based and integrity-based trust as predictors of acceptance of carbon dioxide capture and storage (CCS).

Science.gov (United States)

Terwel, Bart W; Harinck, Fieke; Ellemers, Naomi; Daamen, Dancker D L

2009-08-01

Public trust in organizations that are involved in the management and use of new technologies affects lay judgments about the risks and benefits associated with these technologies. In turn, judgments about risks and benefits influence lay attitudes toward these technologies. The validity of this (indirect) effect of trust on lay attitudes toward new technologies, which is referred to as the causal chain account of trust, has up till now only been examined in correlational research. The two studies reported in this article used an experimental approach to more specifically test the causal chain account of trust in the context of carbon dioxide capture and storage technology (CCS). Complementing existing literature, the current studies explicitly distinguished between two different types of trust in organizations: competence-based trust (Study 1) and integrity-based trust (Study 2). In line with predictions, results showed that the organizational position regarding CCS implementation (pro versus con) more strongly affected people's risk and benefit perceptions and their subsequent acceptance of CCS when competence-based trust was high rather than low. In contrast, the organizational position had a greater impact on people's level of CCS acceptance when integrity-based trust was low rather than high.

Operation of Nuclear Fuel Based on Reprocessed Uranium for VVER-type Reactors in Competitive Nuclear Fuel Cycles

Energy Technology Data Exchange (ETDEWEB)

Troyanov, V.; Molchanov, V.; Tuzov, A. [TVEL Corporation, 49 Kashirskoe shosse, Moscow 115409 (Russian Federation); Semchenkov, Yu.; Lizorkin, M. [RRC ' Kurchatov Institute' (Russian Federation); Vasilchenko, I.; Lushin, V. [OKB ' Gidropress' (Russian Federation)

2009-06-15

Current nuclear fuel cycle of Russian nuclear power involves reprocessed low-enriched uranium in nuclear fuel production for some NPP units with VVER-type LWR. This paper discusses design and performance characteristics of commercial nuclear fuel based on natural and reprocessed uranium. It presents the review of results of commercial operation of nuclear fuel based on reprocessed uranium on Russian NPPs-unit No.2 of Kola NPP and unit No.2 of Kalinin NPP. The results of calculation and experimental validation of safe fuel operation including necessary isotope composition conformed to regulation requirements and results of pilot fuel operation are also considered. Meeting the customer requirements the possibility of high burn-up achieving was demonstrated. In addition the paper compares the characteristics of nuclear fuel cycles with maximum length based on reprocessed and natural uranium considering relevant 5% enrichment limitation and necessity of {sup 236}U compensation. The expedience of uranium-235 enrichment increasing over 5% is discussed with the aim to implement longer fuel cycles. (authors)

Thermodynamic and transport properties of uranium dioxide and related phases

International Nuclear Information System (INIS)

1965-01-01

The high melting point of uranium dioxide and its stability under irradiation have led to its use as a fuel in a variety of types of nuclear reactors. A wide range of chemical and physical studies has been stimulated by this circumstances and by the complex nature of the uranium dioxide phase itself. The boundaries of this phase widen as the temperature is increased; at 2000 deg. K a single, homogeneous phase exists from U 2.27 to a hypostoichiometric (UO 2-x ) composition, depending on the oxygen potential of the surroundings. Since there is often an incentive to operate a reactor at the maximum practicable heat rating and, therefore, maximum thermal gradient in the fuel, the determination of the physical properties of the UO 2-x phase becomes a matter of great technological importance. In addition a complex sequence of U-O phases may be formed during the preparation of powder feed material or during the sintering process; these affect the microstructure and properties of the final product and have also received much attention. 184 refs, 33 figs, 15 tabs

Carbon dioxide enhances fragility of ice crystals

International Nuclear Information System (INIS)

Qin Zhao; Buehler, Markus J

2012-01-01

Ice caps and glaciers cover 7% of the Earth, greater than the land area of Europe and North America combined, and play an important role in global climate. The small-scale failure mechanisms of ice fracture, however, remain largely elusive. In particular, little understanding exists about how the presence and concentration of carbon dioxide molecules, a significant component in the atmosphere, affects the propensity of ice to fracture. Here we use atomic simulations with the first-principles based ReaxFF force field capable of describing the details of chemical reactions at the tip of a crack, applied to investigate the effects of the presence of carbon dioxide molecules on ice fracture. Our result shows that increasing concentrations of carbon dioxide molecules significantly decrease the fracture toughness of the ice crystal, making it more fragile. Using enhanced molecular sampling with metadynamics we reconstruct the free energy landscape in varied chemical microenvironments and find that carbon dioxide molecules affect the bonds between water molecules at the crack tip and decrease their strength by altering the dissociation energy of hydrogen bonds. In the context of glacier dynamics our findings may provide a novel viewpoint that could aid in understanding the breakdown and melting of glaciers, suggesting that the chemical composition of the atmosphere can be critical to mediate the large-scale motion of large volumes of ice.

Extended-length fiber optic carbon dioxide monitoring

Science.gov (United States)

Delgado-Alonso, Jesus; Lieberman, Robert A.

2013-05-01

This paper discusses the design and performance of fiber optic distributed intrinsic sensors for dissolved carbon dioxide, based on the use optical fibers fabricated so that their entire lengths are chemically sensitive. These fibers use a polymer-clad, silica-core structure where the cladding undergoes a large, reversible, change in optical absorbance in the presence of CO2. The local "cladding loss" induced by this change is thus a direct indication of the carbon dioxide concentration in any section of the fiber. To create these fibers, have developed a carbon dioxide-permeable polymer material that adheres well to glass, is physically robust, has a refractive index lower than fused silica, and acts as excellent hosts for a unique colorimetric indicator system that respond to CO2. We have used this proprietary material to produce carbon-dioxide sensitive fibers up to 50 meters long, using commercial optical fiber fabrication techniques. The sensors have shown a measurement range of dissolved CO2 of 0 to 1,450 mg/l (0 to 100% CO2 saturation), limit of detection of 0.3 mg/l and precision of 1.0 mg/l in the 0 to 50 mg/l dissolved CO2 range, when a 5 meter-long sensor fiber segment is used. Maximum fiber length, minimum detectable concentration, and spatial resolution can be adjusted by adjusting indicator concentration and fiber design.

Effect of additives on enhanced sintering and grain growth in uranium dioxide

International Nuclear Information System (INIS)

Bourgeois, L.

1992-06-01

The use of sintering additives has been the most effective way of promoting grain growth of uranium dioxide. We have established a same mechanism for additives which belongs to corundum structure: chromium, aluminium, vanadium and titanium sesquioxides. Study of thermodynamical stabilities of dopants has lead to define suitable sintering atmospheres in order to enhance grain growth. Low solubility limits have been defined at T=1700 deg C for four additives, from variations of final grain size versus initial dopant concentration Identification of second phase after cooling has been done from electronic diffraction patterns. It appears that these solubilities decrease sharply as positive deviation from stoichiometry of uranium dioxide increases. Dilatometric analysis of sintering of doped uranium dioxide has shown in certain cases some enhancement in densification rates, at the point of onset of abnormal grain growth, which is believed to be the source. Nevertheless, the following growth is accompanied with pores coalescence mechanisms and pores entrapment inside grains. Increased thermal stability, during standard annealing, is expected, limiting thereby redensification of nuclear fuel in reactors. Finally, from investigations of additives vaporizations, Al 2 O 3 and Cr 2 O 3 , oxygen exchanges between additives and matrix are believed to occur, which should lead to enhance pore mobility. (Author)., refs., figs., tabs

Liquid carbon dioxide absorbents, methods of using the same, and related systems

Energy Technology Data Exchange (ETDEWEB)

O' Brien, Michael Joseph; Perry, Robert James; Lam, Tunchiao Hubert; Soloveichik, Grigorii Lev; Kniajanski, Sergei; Lewis, Larry Neil; Rubinsztajn, Malgorzata Iwona; Hancu, Dan

2016-09-13

A carbon dioxide absorbent composition is described, including (i) a liquid, nonaqueous silicon-based material, functionalized with one or more groups that either reversibly react with CO.sub.2 or have a high-affinity for CO.sub.2; and (ii) a hydroxy-containing solvent that is capable of dissolving both the silicon-based material and a reaction product of the silicon-based material and CO.sub.2. The absorbent may be utilized in methods to reduce carbon dioxide in an exhaust gas, and finds particular utility in power plants.

15 years after Chernobyl. Nuclear plus greenhouse effect?

International Nuclear Information System (INIS)

Schneider, M.; Rosen, M.

2001-04-01

Today, the argument in favour of nuclear energy is not an economical one nor linked to energy resources but is at the level of climatic change. Nuclear energy is seen as the only energy source without carbon dioxide emissions. A more detailed analysis of greenhouse gases on the life cycle shows that nuclear energy gives as greenhouse gases as big hydroelectric power plants or wind power plants, these emissions are more important than for biogas installations with cogeneration. The strategy of energy efficiency is certainly more competitive than the new reactors in other terms it is more efficiency to reduce the consumption than to increase the nuclear production. (N.C.)

Hydrothermal synthesis for fabrication and reprocessing of MOX nuclear fuel

International Nuclear Information System (INIS)

Ohta, Suguru; Yamamura, Tomoo; Shirasaki, Kenji; Satoh, Isamu; Shikama, Tatsuo

2011-01-01

To improve the nuclear proliferation resistance and to minimize use of chemicals, a new reprocessing and fabrication process of 'mixed oxide' (MOX) fuel was proposed and studied by using simulated spent fuel solutions. The process is consisting of the two steps, i.e. the removal of fission product (FP) from dissolved spent fuel by using carbonate solutions (Step-1), and hydrothermal synthesis of uranium dioxides (Step-2). In Step-1, rare earth (the precipitation ratio: 90%) and alkaline earth (10-50% for Sr) as FP were removed based on their low solubility of hydroxides and carbonate salts, with uranium kept dissolved for the certain carbonate solutions of weak base (Type 2) or mixtures of relatively strong base and weak base (Type 3). In Step-2, the features of uranium dioxides UO 2+x particles, i.e. stoichiometry (x=0.05-0.2), size (0.2-3 μm) and shape (cubic, spherical, rectangular parallelpiped, etc.), were controlled, and the cesium was removed down to 40 ppm by an addition of organic additives. The decontamination factors (DF) for cesium exceeds 10 5 , whereas the total DF of all the simulated FP were as low as the order of 10 which requires future studies for removal of alkaline earth, Re and Tc etc. (author)

Nuclear Renaissance in an Era of Anthropogenic Climate Change

Energy Technology Data Exchange (ETDEWEB)

Bird, John [Bruce Power, Box 3000 B06, Tiverton, Ontario N0G 2T0 (Canada)

2008-07-01

This paper substantiates the anthropogenic origin of climate change, demonstrates the resulting consequences, and thereby establishes the need for a nuclear renaissance over the next thirty years. First, the mechanisms behind the natural cycles in global warming, specifically, cycles of precession and eccentricity in Earth's orbit, as measured in ice cores, are compared to the mechanisms of anthropogenic warming, revealing the scientific basis for the observed correlation between carbon dioxide and temperature. Second, the resulting climate change is exemplified by key results from experiments performed by the author in the Arctic and at the South Geographic Pole, and the author's experience of Switzerland's costliest natural catastrophe - the flash flood of 2005. Third, although facing barriers such as research and development requirements, political will and public acceptance, the potential for nuclear power to triple to 1,000 GWe by 2050 would mitigate climate change by holding carbon dioxide concentration below 500 ppm, thereby challenging the younger nuclear generation to contribute to the most important issue facing humanity. (authors)

Recognition of people with an opinion that nuclear power generation causes global warming

International Nuclear Information System (INIS)

Fukue, Chiyokazu

2004-01-01

Almost a half of the people are thinking that nuclear power generation causes global warming. We conducted a survey in order to explore the recognition and background for the thinking of people. Consequently, the existence of the right knowledge ''nuclear power generation does not discharge carbon dioxide at the time of power generation'' influenced most the idea which nuclear power generation prevents global warming. On the other hand, the misunderstanding as ''the radioactive material produced from a nuclear power plant advances global warming'' has influenced the idea considered as a cause, and it is though that this misunderstanding depend on the negative image to nuclear power generation. Moreover, many people do not recognize the mechanism of global warming, and it is thought that they confuse global warming with the other global environment problems, such as acid rain or ozone layer destruction. Therefore, it is required to spread the knowledge that nuclear power generation does not discharge carbon dioxide, and to promote the understanding that a radioactive material is not related to global warming. Furthermore, it is required to distinguish global warming from the other global environment problems, and to explain them intelligibly. (author)

21 CFR 73.2575 - Titanium dioxide.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Titanium dioxide. 73.2575 Section 73.2575 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2575 Titanium dioxide. (a) Identity and specifications. The color additive titanium dioxide shall conform in identity and specifications to the requirements...

Environmental release of carbon-14 gas from a hypothetical nuclear waste repository

International Nuclear Information System (INIS)

Lehto, M.A.; Merrell, G.B.

1994-01-01

Radioisotopes may form gases in a spent nuclear fuel waste package due to elevated temperatures or degradation of the fuel rods. Radioactive carbon-14, as gaseous carbon dioxide, is one of the gaseous radioisotopes of concern at an underground disposal facility for spent nuclear fuel and high-level radioactive waste. Carbon-14 dioxide may accumulate inside an intact waste container. Upon breach of the container, a potentially large pulse of carbon-14 dioxide gas may be released to the surrounding environment, followed by a lower, long-term continuous release. If the waste were disposed of in an unsaturated geologic environment, the carbon-14 gas would begin to move through the unsaturated zone to the accessible environment. This study investigates the transport of radioactive carbon-14 gas in geologic porous media using a one-dimensional analytical solution. Spent nuclear fuel emplaced in a deep geologic repository located at a generic unsaturated tuff site is analyzed. The source term for the carbon-14 gas and geologic parameters was obtained from previously published materials. The one-dimensional analytical solution includes diffusion, advection, radionuclide retardation, and radioactive decay terms. Two hypothetical sites are analyzed. One is dominated by advective transport, and the other is dominated by diffusive transport. The dominant transport mechanism at an actual site depends on the site characteristics. Results from the simulations include carbon-14 dioxide travel times to the accessible environment and the total release to the environment over a 10,000-year period. The results are compared to regulatory criteria

Knowledge Based Help desk System in Nuclear Malaysia

International Nuclear Information System (INIS)

Mohamad Safuan Sulaiman; Abdul Muin Abdul Rahman; Norzalina Nasirudin; Khairiel Adyani Abdul Ghani; Abdul Aziz Mhd Ramli; Mohd Ashhar Khalid

2012-01-01

Knowledge based (K-based) Help desk system is a knowledge oriented web based system that provides support to business process of the technical service providers. It is a multi-centric system which focuses on end-users, technical workers and higher level management through utilization of knowledge which resides and grows within the system. The objectives of the system are to be a user-friendly, capture technical knowledge for efficient performance and educating users for self reliance. These were achieved through the improvement of the help desk business process and better management of technical knowledge. This system has been tested and implemented in Information Technology Center (IT), Engineering Division (BKJ) and Instrumentation and Automation Center (IAC) at the Malaysian Nuclear Agency (Nuclear Malaysia). Higher levels of user satisfaction and faster growth in technical knowledge repository have been recorded in the system. This paper describes the help desk system in the perspective of management of its technical knowledge contributing to strengthening organizational knowledge asset of Nuclear Malaysia as national nuclear research institution. (Author)

An endohedral fullerene-based nuclear spin quantum computer

International Nuclear Information System (INIS)

Ju Chenyong; Suter, Dieter; Du Jiangfeng

2011-01-01

We propose a new scalable quantum computer architecture based on endohedral fullerene molecules. Qubits are encoded in the nuclear spins of the endohedral atoms, which posses even longer coherence times than the electron spins which are used as the qubits in previous proposals. To address the individual qubits, we use the hyperfine interaction, which distinguishes two modes (active and passive) of the nuclear spin. Two-qubit quantum gates are effectively implemented by employing the electronic dipolar interaction between adjacent molecules. The electron spins also assist in the qubit initialization and readout. Our architecture should be significantly easier to implement than earlier proposals for spin-based quantum computers, such as the concept of Kane [B.E. Kane, Nature 393 (1998) 133]. - Research highlights: → We propose an endohedral fullerene-based scalable quantum computer architecture. → Qubits are encoded on nuclear spins, while electron spins serve as auxiliaries. → Nuclear spins are individually addressed using the hyperfine interaction. → Two-qubit gates are implemented through the medium of electron spins.

Life cycle study. Carbon dioxide emissions lower in electric heating than in oil heating

Energy Technology Data Exchange (ETDEWEB)

Heikkinen, A.; Jaervinen, P.; Nikula, A.

1996-11-01

A primary objective of energy conservation is to cut carbon dioxide emissions. A comparative study on the various heating forms, based on the life cycle approach, showed that the carbon dioxide emissions resulting form heating are appreciably lower now that electric heating has become more common. The level of carbon dioxide emissions in Finland would have been millions of tonnes higher had oil heating been chosen instead of electric heating. (orig.)

Carbon dioxide-krypton separation and radon removal from nuclear-fuel-reprocessing off-gas streams

International Nuclear Information System (INIS)

Hirsch, P.M.; Higuchi, K.Y.; Abraham, L.

1982-07-01

General Atomic Company (GA) is conducting pilot-plant-scale tests that simulate the treatment of radioactive and other noxious volatile and gaseous constituents of off-gas streams from nuclear reprocessing plants. This paper reports the results of engineering-scale tests performed on the CO 2 /krypton separation and radon holdup/decay subsystems of the GA integrated off-gas treatment system. Separation of CO 2 from krypton-containing gas streams is necessary to facilitate subsequent waste processing and krypton storage. Molecular sieve 5A achieved this separation in dissolver off-gas streams containing relatively low krypton and CO 2 concentrations and in krypton-rich product streams from processes such as the krypton absorption in liquid carbon dioxide (KALC) process. The CO 2 /krypton separation unit is a 30.5-cm-diameter x 1.8-m-long column containing molecular sieve 5A. The loading capacity for CO 2 was determined for gas mixtures containing 250 ppM to 2.2% CO 2 and 170 to 750 ppM krypton in either N 2 or air. Gas streams rich in CO 2 were diluted with N 2 to reduce the temperature rise from the heat of adsorption, which would otherwise affect loading capacity. The effluent CO 2 concentration prior to breakthrough was less than 10 ppM, and the adsorption capacity for krypton was negligible. Krypton was monitored on-line with a time-of-flight mass spectrometer and its concentration determined quantitatively by a method of continuous analysis, i.e., selected-ion monitoring. Radon-220 was treated by holdup and decay on a column of synthetic H-mordenite. The Rn-220 concentration was monitored on-line with flow-through diffused-junction alpha detectors. Single-channel analyzers were utilized to isolate the 6.287-MeV alpha energy band characteristic of Rn-220 decay from energy bands due to daughter products

Progress on High-Energy 2-micron Solid State Laser for NASA Space-Based Wind and Carbon Dioxide Measurements

Science.gov (United States)

Singh, Upendra N.

2011-01-01

Sustained research efforts at NASA Langley Research Center during last fifteen years have resulted in significant advancement of a 2-micron diode-pumped, solid-state laser transmitter for wind and carbon dioxide measurements from ground, air and space-borne platforms. Solid-state 2-micron laser is a key subsystem for a coherent Doppler lidar that measures the horizontal and vertical wind velocities with high precision and resolution. The same laser, after a few modifications, can also be used in a Differential Absorption Lidar system for measuring atmospheric CO2 concentration profiles. Researchers at NASA Langley Research Center have developed a compact, flight capable, high energy, injection seeded, 2-micron laser transmitter for ground and airborne wind and carbon dioxide measurements. It is capable of producing 250 mJ at 10 Hz by an oscillator and one amplifier. This compact laser transmitter was integrated into a mobile trailer based coherent Doppler wind and CO2 DIAL system and was deployed during field measurement campaigns. This paper will give an overview of 2-micron solid-state laser technology development and discuss results from recent ground-based field measurements.

Carbon Dioxide Removal via Passive Thermal Approaches

Science.gov (United States)

Lawson, Michael; Hanford, Anthony; Conger, Bruce; Anderson, Molly

2011-01-01

A paper describes a regenerable approach to separate carbon dioxide from other cabin gases by means of cooling until the carbon dioxide forms carbon dioxide ice on the walls of the physical device. Currently, NASA space vehicles remove carbon dioxide by reaction with lithium hydroxide (LiOH) or by adsorption to an amine, a zeolite, or other sorbent. Use of lithium hydroxide, though reliable and well-understood, requires significant mass for all but the shortest missions in the form of lithium hydroxide pellets, because the reaction of carbon dioxide with lithium hydroxide is essentially irreversible. This approach is regenerable, uses less power than other historical approaches, and it is almost entirely passive, so it is more economical to operate and potentially maintenance- free for long-duration missions. In carbon dioxide removal mode, this approach passes a bone-dry stream of crew cabin atmospheric gas through a metal channel in thermal contact with a radiator. The radiator is pointed to reject thermal loads only to space. Within the channel, the working stream is cooled to the sublimation temperature of carbon dioxide at the prevailing cabin pressure, leading to formation of carbon dioxide ice on the channel walls. After a prescribed time or accumulation of carbon dioxide ice, for regeneration of the device, the channel is closed off from the crew cabin and the carbon dioxide ice is sublimed and either vented to the environment or accumulated for recovery of oxygen in a fully regenerative life support system.

21 CFR 582.1240 - Carbon dioxide.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Carbon dioxide. 582.1240 Section 582.1240 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1240 Carbon dioxide. (a) Product. Carbon dioxide. (b) Conditions of use. This substance is generally...

21 CFR 73.1575 - Titanium dioxide.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Titanium dioxide. 73.1575 Section 73.1575 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1575 Titanium dioxide. (a) Identity and specifications. (1) The color additive titanium dioxide shall conform in identity and specifications to the requirements...

Titanium Dioxide-Based 64∘ YX LiNbO3 Surface Acoustic Wave Hydrogen Gas Sensors

Directory of Open Access Journals (Sweden)

A. Z. Sadek

2008-01-01

Full Text Available Amorphous titanium dioxide (TiO2 and gold (Au doped TiO2-based surface acoustic wave (SAW sensors have been investigated as hydrogen gas detectors. The nanocrystal-doped TiO2 films were synthesized through a sol-gel route, mixing a Ti-butoxide-based solution with diluted colloidal gold nanoparticles. The films were deposited via spin coating onto 64∘ YX LiNbO3 SAW transducers in a helium atmosphere. The SAW gas sensors were operated at various temperatures between 150 and 310∘C. It was found that gold doping on TiO2 increased the device sensitivity and reduced the optimum operating temperature.

Carbon dioxide and climate

Energy Technology Data Exchange (ETDEWEB)

1990-10-01

Scientific and public interest in greenhouse gases, climate warming, and global change virtually exploded in 1988. The Department's focused research on atmospheric CO{sub 2} contributed sound and timely scientific information to the many questions produced by the groundswell of interest and concern. Research projects summarized in this document provided the data base that made timely responses possible, and the contributions from participating scientists are genuinely appreciated. In the past year, the core CO{sub 2} research has continued to improve the scientific knowledge needed to project future atmospheric CO{sub 2} concentrations, to estimate climate sensitivity, and to assess the responses of vegetation to rising concentrations of CO{sub 2} and to climate change. The Carbon Dioxide Research Program's goal is to develop sound scientific information for policy formulation and governmental action in response to changes of atmospheric CO{sub 2}. The Program Summary describes projects funded by the Carbon Dioxide Research Program during FY 1990 and gives a brief overview of objectives, organization, and accomplishments.

Carbon dioxide stripping in aquaculture -- part II: development of gas transfer models

Science.gov (United States)

Colt, John; Watten, Barnaby; Pfeiffer, Tim

2012-01-01

The basic mass transfer equation for gases such as oxygen and carbon dioxide can be derived from integration of the driving force equation. Because of the physical characteristics of the gas transfer processes, slightly different models are used for aerators tested under the non steady-state procedures, than for packed columns, or weirs. It is suggested that the standard condition for carbon dioxide should be 20 °C, 1 atm, CCO2=20 mg/kg, and XCO2=0.000285. The selection of the standard condition for carbon dioxide based on a fixed mole fraction ensures that standardized carbon dioxide transfer rates will be comparable even though the value of C*CO2 in the atmosphere is increasing with time. The computation of mass transfer for carbon dioxide is complicated by the impact of water depth and gas phase enrichment on the saturation concentration within the unit, although the importance of either factor depends strongly on the specific type of aerator. For some types of aerators, the most accurate gas phase model remains to be determined for carbon dioxide. The assumption that carbon dioxide can be treated as a non-reactive gas in packed columns may apply for cold acidic waters but not for warm alkaline waters.

Perspectives in the use of carbon dioxide

Directory of Open Access Journals (Sweden)

Aresta Michele

1999-01-01

Full Text Available The mitigation of carbon dioxide is one of the scientific and technological challenges of the 2000s. Among the technologies that are under assessment, the recovery of carbon dioxide from power plants or industrial flue gases plays a strategic role. Recovered carbon dioxide can be either disposed in natural fields or used. The availability of large amounts of carbon dioxide may open new routes to its utilisation in biological, chemical and innovative technological processes. In this paper, the potential of carbon dioxide utilisation in the short-, medium-term is reviewed.

Meeting world energy needs. The economic and environmental aspects of the nuclear option

International Nuclear Information System (INIS)

Ward, D.P.; Chalpin, D.M.

1994-01-01

Tabulated capital, operating, and overall production costs for nuclear, coal, and gas-fuelled power show that nuclear power is a viable option for meeting the world's energy needs. The advantage of nuclear, otherwise limited to certain markets, is seen to be much greater when credit is taken for environmental factors, namely emissions of carbon dioxide and acidic gases by fossil-fuelled plants. 5 figs

Nuclear power and climate change

International Nuclear Information System (INIS)

1998-04-01

In the Kyoto Protocol, agreed upon by the Parties to the United Nations Framework Convention on Climate Change (UNFCCC) in December 1997, Annex I countries committed to reduce their greenhouse gas (GHG) emissions. Also, the Protocol states that Annex I countries shall undertake promotion, research, development and increased use of new and renewable forms of energy, of carbon dioxide sequestration technologies and of advanced and innovative environmentally sound technologies. One important option that could be covered by the last phrase, and is not specifically mentioned, is nuclear energy which is essentially carbon-free. Nuclear Energy Agency (NEA) has investigated the role that nuclear power could play in alleviating the risk of global climate change. The main objective of the study is to provide a quantitative basis for assessing the consequences for the nuclear sector and for the reduction of GHG emissions of alternative nuclear development paths. The analysis covers the economic, financial, industrial and potential environmental effects of three alternative nuclear power development paths ('nuclear variants'). (K.A.)

21 CFR 73.575 - Titanium dioxide.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Titanium dioxide. 73.575 Section 73.575 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.575 Titanium dioxide. (a) Identity. (1) The color additive titanium dioxide is synthetically prepared TiO2, free from admixture with other substances. (2) Color...

21 CFR 73.3126 - Titanium dioxide.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Titanium dioxide. 73.3126 Section 73.3126 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Medical Devices § 73.3126 Titanium dioxide. (a) Identity and specifications. The color additive titanium dioxide (CAS Reg. No. 13463-67-7), Color Index No. 77891, shall...

Geologic map showing springs rich in carbon dioxide or or chloride in California

Science.gov (United States)

Barnes, Ivan; Irwin, William P.; Gibson, H.A.

1975-01-01

Carbon dioxide- and chloride-rich springs occur in all geologic provinces in California, but are most abundant in the Coast Ranges and the Great Valley. The carbon-dioxide-rich springs issue mainly from Franciscan terrane; they also are rich in boron and are of the metamorphic type (White, 1957). Based on isotopic data, either the carbon dioxide or the water, or both, may be of metamorphic origin. Because of high magnesium values, the water of many of the carbon-dioxide-rich springs is thought to have passed through serpentinite. The chloride-rich waters are most common in rocks of the Great Valley sequence. Nearly all are more dilute than present-day sea water. The similarity in isotopic compositions of the metamorphic carbon-dioxide-rich water and the chloride-rich water may indicate a similar extent of water-rock interaction.

Nuclear Energy Cost Data Base: A reference data base for nuclear and coal-fired powerplant power generation cost analysis

International Nuclear Information System (INIS)

Delene, J.G.; Bowers, H.I.

1986-12-01

A reference data base and standard methodology are needed for performing comparative nuclear and fossil power generation cost analyses for the Department of Energy, Office of Nuclear Energy. This report contains such a methodology together with reference assumptions and data to be used with the methodology. It is intended to provide basic guidelines or a starting point for analyses and to serve as a focal point in establishing parameters and methods to be used in economic comparisons of nuclear systems with alternatives. The data base is applicable for economic comparisons of new base load light-water reactors on either the current once-through cycle or self-generated recycle, high- and low-sulfur coal-fired plants, and oil- and natural gas-fired electric generating plants coming on line around the turn of the century. In additions to light-water reactors and fossil fuel-fired plants, preliminary cost information is also presented on liquid metal reactor plants. This report includes a data base containing proposed technical and economic assumptions to be used in analyses, discussions of recommended methodology to be used in calculating power generation costs, and a sample calculation for illustrative benchmark purposes

Nuclear Energy Cost Data Base: a reference data base for nuclear and coal-fired powerplant power generation cost analysis

International Nuclear Information System (INIS)

1985-06-01

A reference data base and standard methodology are needed for performing comparative nuclear and fossil power generation cost analyses for the Department of Energy, Office of Nuclear Energy. This report contains such a methodology together with reference assumptions and data to be used with the methodology. It is intended to provide basic guidelines or a starting point for analyses and to serve as a focal point in establishing parameters and methods to be used in economic comparisons of nuclear systems with alternatives. The data base is applicable for economic comparisons of new base load light-water reactors on either the current once-through cycle or self-generated recycle, high- and low-sulfur coal-fired plants, and oil- and natural gas-fired electric generating plants coming on line in the last decade of this century. In addition to light-water reactors and fossil fuel-fired plants, preliminary cost information is also presented on liquid metal reactor plants. This report includes a data base containing proposed technical and economic assumptions to be used in analyses, discussions of a recommended methodology to be used in calculating power generation costs, and a sample calculation for illustrative and benchmark purposes

ICT based training on nuclear technology applications in Tanzania

Energy Technology Data Exchange (ETDEWEB)

Mdoe, S.L. [Nuclear Technology Applications Directorate, Tanzania Atomic Energy Commission, P.O. Box 743, Arusha (Tanzania)]. E-mail: slcmdoe@yahoo.com; Kimaro, E. [Nuclear Technology Applications Directorate, Tanzania Atomic Energy Commission, P.O. Box 743, Arusha (Tanzania)]. E-mail: taec@habari.co.tz

2006-07-01

Peaceful application of nuclear technology has contributed to socio-economic resource development in Tanzania. The Tanzania Atomic Energy Commission has taken some active steps for the incorporation and or adoption of ICT-based training modules in nuclear science and technology and its applications. The overall objective of this programme is to establish a sustainable national capability for using the potential of information communication technologies (ICTs) for training and education in the field of nuclear science and technology. This paper reviews some of the experience which the authors gained in the area of ICT based training in nuclear technology applications, it describes some of the challenges experienced, and some proposals to address the issues involved. (author)

ICT based training on nuclear technology applications in Tanzania

International Nuclear Information System (INIS)

Mdoe, S.L.; Kimaro, E.

2006-01-01

Peaceful application of nuclear technology has contributed to socio-economic resource development in Tanzania. The Tanzania Atomic Energy Commission has taken some active steps for the incorporation and or adoption of ICT-based training modules in nuclear science and technology and its applications. The overall objective of this programme is to establish a sustainable national capability for using the potential of information communication technologies (ICTs) for training and education in the field of nuclear science and technology. This paper reviews some of the experience which the authors gained in the area of ICT based training in nuclear technology applications, it describes some of the challenges experienced, and some proposals to address the issues involved. (author)

ISLSCP II Air-Sea Carbon Dioxide Gas Exchange

Data.gov (United States)

National Aeronautics and Space Administration — This data set contains the calculated net ocean-air carbon dioxide (CO2) flux and sea-air CO2 partial pressure (pCO2) difference. The estimates are based on...

Process for producing nuclear reactor fuel oxides

International Nuclear Information System (INIS)

Goenrich, H.; Druckenbrodt, W.G.

1981-01-01

The waste gases of the calcination process furnace in the AVC or AV/PuC process (manufacture of nuclear reactor fuel dioxides) are returned to the furnace in a closed circuit. The NH 3 produced replaces the hydrogen which would otherwise be required for reduction in this process. (orig.) [de

Carbon dioxide and climate

International Nuclear Information System (INIS)

1991-10-01

Global climate change is a serious environmental concern, and the US has developed ''An Action Agenda'' to deal with it. At the heart of the US effort is the US Global Change Research Program (USGCRP), which has been developed by the Committee on Earth and Environmental Sciences (CEES) of the Federal Coordinating Council for Sciences, Engineering, and Technology (FCCSET). The USGCRP will provide the scientific basis for sound policy making on the climate-change issue. The DOE contribution to the USGCRP is the Carbon Dioxide Research Program, which now places particular emphasis on the rapid improvement of the capability to predict global and regional climate change. DOE's Carbon Dioxide Research Program has been addressing the carbon dioxide-climate change connection for more than twelve years and has provided a solid scientific foundation for the USGCRP. The expansion of the DOE effort reflects the increased attention that the Department has placed on the issue and is reflected in the National Energy Strategy (NES) that was released in 1991. This Program Summary describes projects funded by the Carbon Dioxide Research Program during FY 1991 and gives a brief overview of objectives, organization, and accomplishments. The Environmental Sciences Division of the Office of Health and Environmental Research, Office of Energy Research supports a Carbon Dioxide Research Program to determine the scientific linkage between the rise of greenhouse gases in the atmosphere, especially carbon dioxide, and climate and vegetation change. One facet is the Core CO 2 Program, a pioneering program that DOE established more than 10 years ago to understand and predict the ways that fossil-fuel burning could affect atmospheric CO 2 concentration, global climate, and the Earth's biosphere. Major research areas are: global carbon cycle; climate detection and models of climate change; vegetation research; resource analysis; and, information and integration

Antibotulinal efficacy of sulfur dioxide in meat.

Science.gov (United States)

Tompkin, R B; Christiansen, L N; Shaparis, A B

1980-01-01

The addition of sodium metabisulfite as a source of sulfur dioxide delayed botulinal outgrowth in perishable canned comminuted pork when it was temperature abused at 27 degree C. The degree of inhibition was directly related to the level of sulfur dioxide. Levels greater than 100 microgram of sulfur dioxide per g were necessary to achieve significant inhibition when a target level of 100 botulinal spores per g was used. Sodium nitrite partially reduced the efficacy of the sulfur dioxide. Sulfur dioxide offers a new option for the control of botulinal outgrowth in cured or noncured meat and poultry products. PMID:6996613

The effects of low level chlorination and chlorine dioxide on biofouling control in a once-through service water system

International Nuclear Information System (INIS)

Garrett, W.E. Jr.; Laylor, M.M.

1995-01-01

Continuous chlorination has been successfully used for the control of Corbicula at a nuclear power plant located on the Chattahoochee River in southeastern Alabama, since 1986. The purpose of this study was to investigate further minimization of chlorine usage and determine if chlorine dioxide is a feasible alternative. Four continuous biocide treatments were evaluated for macro and microfouling control effectiveness, operational feasibility, and environmental acceptability. One semi-continuous chlorination treatment was also evaluated for macrofouling control effectiveness. Higher treatment residuals were possible with chlorine dioxide than with chlorination due to the river discharge limitations. At the levels tested, continuous chlorine dioxide was significantly more effective in providing both macro and microfouling control. Semi-continuous chlorination was just as effective as continuous chlorination for controlling macrofouling. The Corbicula treatment programs that were tested should all provide sufficient control for zebra mussels. Chlorine dioxide was not as cost effective as chlorination for providing macrofouling control. The semi-continuous treatment save 50% on chemical usage and will allow for the simultaneous treatment of two service water systems. Chlorite levels produced during the chlorine dioxide treatments were found to be environmentally acceptable. Levels of trihalomethanes in the chlorinated service water were less than the maximum levels allowed in drinking water

Hodgkin's disease following thorium dioxide angiography

Energy Technology Data Exchange (ETDEWEB)

Gotlieb, A I; Kirk, M E [McGill Univ., Montreal, Quebec (Canada). Dept. of Pathology; Hutchison, J L [Montreal General Hospital, Quebec (Canada)

1976-09-04

Hodgkin's disease occurred in a 53-year-old man who, 25 years previously, had undergone cerebral angiography, for which thorium dioxide suspension (Thorotrast) was used. Deposits of thorium dioxide were noted in reticuloendothelial cells in various locations. An association between thorium dioxide administration and the subsequent development of malignant tumours and neoplastic hematologic disorders has previously been reported.

21 CFR 184.1240 - Carbon dioxide.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Carbon dioxide. 184.1240 Section 184.1240 Food and... Substances Affirmed as GRAS § 184.1240 Carbon dioxide. (a) Carbon dioxide (empirical formula CO2, CAS Reg. No.... The solid form, dry ice, sublimes under atmospheric pressure at a temperature of −78.5 °C. Carbon...

Balancing atmospheric carbon dioxide

Energy Technology Data Exchange (ETDEWEB)

Goreau, T.J. (Discovery Bay Marine Laboratory, Univ. of the West Indies (JM))

1990-01-01

Rising carbon dioxide and global temperatures are causing increasing worldwide concern, and pressure towards an international law of the atmosphere is rapidly escalating, yet widespread misconceptions about the greenhouse effect's inevitability, time scale, and causes have inhibited effective consensus and action. Observations from Antarctic ice cores, Amazonian rain forests, and Carribean coral reefs suggest that the biological effects of climate change may be more severe than climate models predict. Efforts to limit emissions from fossil-fuel combustion alone are incapable of stabilizing levels of carbon dioxide in the atmosphere. Stabilizing atmospheric carbon dioxide requires coupled measures to balance sources and sinks of the gas, and will only be viable with large-scale investments in increased sustainable productivity on degraded tropical soils, and in long-term research on renewable energy and biomass product development in the developing countries. A mechanism is outlined which directly links fossil-fuel combustion sources of carbon dioxide to removal via increasing biotic productivity and storage. A preliminary cost-benefit analysis suggests that such measures are very affordable, costing far less than inaction. (With 88 refs.).

Balancing atmospheric carbon dioxide

Energy Technology Data Exchange (ETDEWEB)

Goreau, T J [Discovery Bay Marine Laboratory, Univ. of the West Indies (JM)

1990-01-01

Rising carbon dioxide and global temperatures are causing increasing worldwide concern, and pressure towards an international law of the atmosphere is rapidly escalating, yet widespread misconceptions about the greenhouse effect's inevitability, time scale, and causes have inhibited effective consensus and action. Observations from Antarctic ice cores, Amazonian rain forests, and Carribean coral reefs suggest that the biological effects of climate change may be more severe than climate models predict. Efforts to limit emissions from fossil-fuel combustion alone are incapable of stabilizing levels of carbon dioxide in the atmosphere. Stabilizing atmospheric carbon dioxide requires coupled measures to balance sources and sinks of the gas, and will only be viable with large-scale investments in increased sustainable productivity on degraded tropical soils, and in long-term research on renewable energy and biomass product development in the developing countries. A mechanism is outlined which directly links fossil-fuel combustion sources of carbon dioxide to removal via increasing biotic productivity and storage. A preliminary cost-benefit analysis suggests that such measures are very affordable, costing far less than inaction. (With 88 refs.).

Certification of a uranium dioxide reference material for chemical analyses

International Nuclear Information System (INIS)

Le Duigou, Y.

1984-01-01

This report, issued by the Central Bureau for Nuclear Measurements (CBNM), describes the characterization of a uranium dioxide reference material with accurately determined uranium mass fraction for chemical analyses. The preparation, conditioning, homogeneity tests and the analyses performed on this material are described in Annex 1. The evaluation of the individual impurity results, total of impurities and uranium mass fraction are given in Annex 2. Information on a direct determination of uranium by titration is given in Annex 3. The uranium mass fraction (881.34+-0.13) g.kg -1 calculated in Annex 2 is given on the certificate

Experimental nitrogen dioxide poisoning in cattle

Energy Technology Data Exchange (ETDEWEB)

Cutlip, R C

1966-01-01

Experimental nitrogen dioxide inhalation has been reported to produce signs and lesions typical of field cases of bovine pulmonary adenomatosis (BPA) as described by Monlux et al, and Seaton. Similar lesions have been produced in mice and guinea pigs. These studies were conducted because of the similarities between silo-filler's disease of man, caused by nitrogen dioxide, and BPA. Since previous studies involved inadequate numbers of cattle, a more critical evaluation of the effects of nitrogen dioxide was needed. This project was designed to study the clinical and pathologic alterations induced in cattle by repeated exposure to nitrogen dioxide gas.

Trends and characteristics observed in nuclear events based on international nuclear event scale reports

International Nuclear Information System (INIS)

Watanabe, Norio

2001-01-01

The International Nuclear Event Scale (INES) is jointly operated by the IAEA and the OECD-NEA as a means designed for providing prompt, clear and consistent information related to nuclear events, that occurred at nuclear facilities, and facilitating communication between the nuclear community, the media and the public. Nuclear events are reported to the INES with the Scale', a consistent safety significance indicator, which runs from level 0, for events with no safety significance, to level 7 for a major accident with widespread health and environmental effects. Since the operation of INES was initiated in 1990, approximately 500 events have been reported and disseminated. The present paper discusses the trends observed in nuclear events, such as overall trends of the reported events and characteristics of safety significant events with level 2 or higher, based on the INES reports. (author)

Average Nuclear properties based on statistical model

International Nuclear Information System (INIS)

El-Jaick, L.J.

1974-01-01

The rough properties of nuclei were investigated by statistical model, in systems with the same and different number of protons and neutrons, separately, considering the Coulomb energy in the last system. Some average nuclear properties were calculated based on the energy density of nuclear matter, from Weizsscker-Beth mass semiempiric formulae, generalized for compressible nuclei. In the study of a s surface energy coefficient, the great influence exercised by Coulomb energy and nuclear compressibility was verified. For a good adjust of beta stability lines and mass excess, the surface symmetry energy were established. (M.C.K.) [pt

Template-Assisted Wet-Combustion Synthesis of Fibrous Nickel-Based Catalyst for Carbon Dioxide Methanation and Methane Steam Reforming.

Science.gov (United States)

Aghayan, M; Potemkin, D I; Rubio-Marcos, F; Uskov, S I; Snytnikov, P V; Hussainova, I

2017-12-20

Efficient capture and recycling of CO 2 enable not only prevention of global warming but also the supply of useful low-carbon fuels. The catalytic conversion of CO 2 into an organic compound is a promising recycling approach which opens new concepts and opportunities for catalytic and industrial development. Here we report about template-assisted wet-combustion synthesis of a one-dimensional nickel-based catalyst for carbon dioxide methanation and methane steam reforming. Because of a high temperature achieved in a short time during reaction and a large amount of evolved gases, the wet-combustion synthesis yields homogeneously precipitated nanoparticles of NiO with average particle size of 4 nm on alumina nanofibers covered with a NiAl 2 O 4 nanolayer. The as-synthesized core-shell structured fibers exhibit outstanding activity in steam reforming of methane and sufficient activity in carbon dioxide methanation with 100% selectivity toward methane formation. The as-synthesized catalyst shows stable operation under the reaction conditions for at least 50 h.

Modified surface of titanium dioxide nanoparticles-based biosensor for DNA detection

Science.gov (United States)

Nadzirah, Sh.; Hashim, U.; Rusop, M.

2018-05-01

A new technique was used to develop a simple and selective picoammeter DNA biosensor for identification of E. coli O157:H7. This biosensor was fabricated from titanium dioxide nanoparticles that was synthesized by sol-gel method and spin-coated on silicon dioxide substrate via spinner. 3-Aminopropyl triethoxy silane (APTES) was used to modify the surface of TiO2. Simple surface modification approach has been applied; which is single dropping of APTES onto the TiO2 nanoparticles surface. Carboxyl modified probe DNA has been bind onto the surface of APTES/TiO2 without any amplifier element. Electrical signal has been used as the indicator to differentiate each step (surface modification of TiO2 and probe DNA immobilization). The I-V measurements indicate extremely low current (pico-ampere) flow through the device which is 2.8138E-10 A for pure TiO2 nanoparticles, 2.8124E-10 A after APTES modification and 3.5949E-10 A after probe DNA immobilization.

Nanocomposites based on thermoplastic elastomers with functional basis of nano titanium dioxide

Energy Technology Data Exchange (ETDEWEB)

Yulovskaya, V. D.; Kuz’micheva, G. M., E-mail: galina-kuzmicheva@list.ru [Federal State Budget Educational Institution of Higher Education “Moscow Technological University” (Russian Federation); Klechkovskaya, V. V. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Orekhov, A. S.; Zubavichus, Ya. V. [National Research Centre “Kurchatov Institute” (Russian Federation); Domoroshchina, E. N.; Shegay, A. V. [Federal State Budget Educational Institution of Higher Education “Moscow Technological University” (Russian Federation)

2016-03-15

Nanocomposites based on a thermoplastic elastomer (TPE) (low-density polyethylene (LDPE) and 1,2-polybutadiene in a ratio of 60/40) with functional titanium dioxide nanoparticles of different nature, TiO{sub 2}/TPE, have been prepared and investigated by a complex of methods (X-ray diffraction analysis using X-ray and synchrotron radiation beams, scanning electron microscopy, transmission electron microscopy, and X-ray energy-dispersive spectroscopy). The morphology of the composites is found to be somewhat different, depending on the TiO{sub 2} characteristics. It is revealed that nanocomposites with cellular or porous structures containing nano-TiO{sub 2} aggregates with a large specific surface and large sizes of crystallites and nanoparticles exhibit the best deformation‒strength and fatigue properties and stability to the effect of active media under conditions of ozone and vapor‒air aging.

Conference/debate on nuclear power. Press file

International Nuclear Information System (INIS)

1998-01-01

This press dossier presents in a digest way the advantages of nuclear power with respect to other energy sources. After a presentation of the worldwide energy resources (electric power demand, fossil-fuel reserves, renewable energies, environmental constraints), the dossier describes the functioning principle of a PWR reactor as a presentation of the French nuclear program (historical aspects, policy, organization of activities, trade, EPR project). In the last part, the sociological aspects of nuclear power are approached: environmental aspects (natural radioactivity, reactors safety, radioactive wastes, environment protection, carbon dioxide and energy production), and public health aspects (principles of radioactivity, dose effects, industrial and scientific applications of radionuclides, nuclear controversy, reactor accidents, legal aspects of radioprotection, safety standards and controls). (J.S.)

Drying of supercritical carbon dioxide with membrane processes

NARCIS (Netherlands)

Lohaus, Theresa; Scholz, Marco; Koziara, Beata; Benes, Nieck Edwin; Wessling, Matthias

2015-01-01

In supercritical extraction processes regenerating the supercritical fluid represents the main cost constraint. Membrane technology has potential for cost efficient regeneration of water-loaded supercritical carbon dioxide. In this study we have designed membrane-based processes to dehydrate

Hydrogen production by nuclear heat

International Nuclear Information System (INIS)

Crosbie, Leanne M.; Chapin, Douglas

2003-01-01

A major shift in the way the world obtains energy is on the horizon. For a new energy carrier to enter the market, several objectives must be met. New energy carriers must meet increasing production needs, reduce global pollution emissions, be distributed for availability worldwide, be produced and used safely, and be economically sustainable during all phases of the carrier lifecycle. Many believe that hydrogen will overtake electricity as the preferred energy carrier. Hydrogen can be burned cleanly and may be used to produce electricity via fuel cells. Its use could drastically reduce global CO 2 emissions. However, as an energy carrier, hydrogen is produced with input energy from other sources. Conventional hydrogen production methods are costly and most produce carbon dioxide, therefore, negating many of the benefits of using hydrogen. With growing concerns about global pollution, alternatives to fossil-based hydrogen production are being developed around the world. Nuclear energy offers unique benefits for near-term and economically viable production of hydrogen. Three candidate technologies, all nuclear-based, are examined. These include: advanced electrolysis of water, steam reforming of methane, and the sulfur-iodine thermochemical water-splitting cycle. The underlying technology of each process, advantages and disadvantages, current status, and production cost estimates are given. (author)

Designing a nuclear data base prototype using Oracle and Prolog

International Nuclear Information System (INIS)

Paviotti-Corcuera, R.; Ford, C.E.; Perez, R.B.

1988-11-01

An ever-increasing demand exists for easily accessible nuclear data base systems. The purpose of this work is to analyze the feasibility of using artificial intelligence methods as tools to provide the necessary functionality to extract information from nuclear data files in a user-friendly manner. For the prototype of this work, a sample of data that can be later enlarged to a complete, evaluated nuclear data base has been used. To implement this prototype, two approaches have been followed: a conventional approach using the commercially available Oracle relational data base management system; and an artificial intelligence approach using the Prolog programming language. This prototypic work shows the feasibility of applying artificial intelligence methods to data bases, and represents a first step toward development of intelligent nuclear data base systems. The characteristics of the query language from both approaches make the second one preferable from a user's point of view. 23 refs., 7 tabs

Absorption of carbon dioxide in waste tanks

International Nuclear Information System (INIS)

Hobbs, D.T.

1987-01-01

Air flow rates and carbon dioxide concentrations of air entering and exiting eight H-Area waste tanks were monitored for a period of one year. The average instanteous concentration of carbon dioxide in air is within the range reported offsite, and therefore is not affect by operation of the coal-fired power plant adjacent to the tank farm. Waste solutions in each of the tanks were observed to be continuously absorbing carbon dioxide. The rate of absorption of carbon dioxide decreased linearly with the pH of the solution. Personnel exposure associated with the routine sampling and analysis of radioactive wastes stored at SRP to determine the levels of corrosion inhibitors in solution could be reduced by monitoring the absorption of carbon dioxide and using the relationship between pH and carbon dioxide absorption to determine the free hydroxide concentration in solution

Moderator for nuclear reactor

International Nuclear Information System (INIS)

Milgram, M.S.; Dunn, J.T.; Hart, R.S.

1995-01-01

This invention relates to a moderator for a nuclear reactor and more specifically, to a composite moderator. A moderator is designed to slow down, or thermalize, neutrons which are released during nuclear reactions in the reactor fuel. Pure or almost pure materials like light water, heavy water, beryllium or graphite are used singly as moderators at present. All these materials, are used widely. Graphite has a good mechanical strength at high temperatures encountered in the nuclear core and therefore is used as both the moderator and core structural material. It also exhibits a low neutron-capture cross section and high neutron scattering cross section. However, graphite is susceptible to attach by carbon dioxide and/or oxygen where applicable, and releases stress energy under certain circumstances, although under normal operating conditions these reactions can be controlled. (author). 1 tab

An internet-based teaching file on clinical nuclear medicine

International Nuclear Information System (INIS)

Jiang Zhong; Wu Jinchang

2001-01-01

Objective: The goal of this project was to develop an internet-based interactive digital teaching file on nuclide imaging in clinical nuclear medicine, with the capability of access to internet. Methods: On the basis of academic teaching contents in nuclear medicine textbook for undergraduates who major in nuclear medicine, Frontpage 2000, HTML language, and JavaScript language in some parts of the contents, were utilized in the internet-based teaching file developed in this study. Results: A practical and comprehensive teaching file was accomplished and may get access with acceptable speed to internet. Besides basic teaching contents of nuclide imagings, a large number of typical and rare clinical cases, questionnaire with answers and update data in the field of nuclear medicine were included in the file. Conclusion: This teaching file meets its goal of providing an easy-to-use and internet-based digital teaching file, characteristically with the contents instant and enriched, and with the modes diversified and colorful

Performance Based Failure Criteria of the Base Isolation System for Nuclear Power Plants

International Nuclear Information System (INIS)

Kim, Jung Han; Kim, Min Kyu; Choi, In Kil

2013-01-01

The realistic approach to evaluate the failure state of the base isolation system is necessary. From this point of view, several concerns are reviewed and discussed in this study. This is the preliminary study for the performance based risk assessment of a base isolated nuclear power plant. The items to evaluate the capacity and response of an individual base isolator and a base isolation system were briefly outlined. However, the methodology to evaluate the realistic fragility of a base isolation system still needs to be specified. For the quantification of the seismic risk for a nuclear power plant structure, the failure probabilities of the structural component for the various seismic intensity levels need to be calculated. The failure probability is evaluated as the probability when the seismic response of a structure exceeds the failure criteria. Accordingly, the failure mode of the structural system caused by an earthquake vibration should be defined first. The type of a base isolator appropriate for a nuclear power plant structure is regarded as an elastometric rubber bearing with a lead core. The failure limit of the lead-rubber bearing (LRB) is not easy to be predicted because of its high nonlinearity and a complex loading condition by an earthquake excitation. Furthermore, the failure mode of the LRB system installed below the nuclear island cannot be simply determined because the basemat can be sufficiently supported if the number of damaged isolator is not much

Nanocomposites based on titanium dioxide and polythiophene: structure and properties

Czech Academy of Sciences Publication Activity Database

Vu, Q. T.; Pavlík, Martin; Hebestreit, N.; Rammelt, U.; Plieth, W.; Pfleger, Jiří

2005-01-01

Roč. 65, 1-2 (2005), s. 69-77 ISSN 1381-5148. [International Conference on Polymers and Organic Chemistry /11./. Prague, 18.06.2004-23.06.2004] R&D Projects: GA AV ČR IAA4050406 Grant - others:European Graduate School: Advanced Polymeric Materials(XE) IGK720 Institutional research plan: CEZ:AV0Z40500505 Keywords : polythiophene * titanium dioxide * nanocomposites Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.565, year: 2005

The nuclear review

International Nuclear Information System (INIS)

Hawley, R.

1994-01-01

The United Kingdom Government's Review of the prospects for nuclear power, which commenced in May 1994, has terms of reference in which four key issues are identified. These are: whether privatisation is possible and on what timescale; the most cost-effective management of the public sector's liabilities; whether new nuclear stations can be built on a commercial basis and with private finance; and what particular benefits or disadvantages nuclear power has with respect to diversity, security of supply and environmental impacts. The response of Nuclear Electric to these issues is summarized. The Company believes that the financial obstacles to privatisation which existed when it was established in 1989 have been largely overcome and that privatisation now provides it with the best competitive opportunity in today's electricity market. Significant progress has been made in reducing and quantifying the financial liabilities associated with waste management and reactor decommissioning. To secure its future, Nuclear Electric must be allowed to build new plants to replace the 2500 MW(e) of Magnox capacity which will retire by the end of the century. Longer term wider policy objectives should also take account of the fact that during the last twelve months alone, Nuclear Electric has saved the emission of 60 million tonnes of carbon dioxide. (UK)

JANIS: NEA JAva-based Nuclear Data Information System

Science.gov (United States)

Soppera, Nicolas; Bossant, Manuel; Cabellos, Oscar; Dupont, Emmeric; Díez, Carlos J.

2017-09-01

JANIS (JAva-based Nuclear Data Information System) software is developed by the OECD Nuclear Energy Agency (NEA) Data Bank to facilitate the visualization and manipulation of nuclear data, giving access to evaluated nuclear data libraries, such as ENDF, JEFF, JENDL, TENDL etc., and also to experimental nuclear data (EXFOR) and bibliographical references (CINDA). It is available as a standalone Java program, downloadable and distributed on DVD and also a web application available on the NEA website. One of the main new features in JANIS is the scripting capability via command line, which notably automatizes plots generation and permits automatically extracting data from the JANIS database. Recent NEA software developments rely on these JANIS features to access nuclear data, for example the Nuclear Data Sensitivity Tool (NDaST) makes use of covariance data in BOXER and COVERX formats, which are retrieved from the JANIS database. New features added in this version of the JANIS software are described along this paper with some examples.

Sub-Critical Nuclear Reactor Based on FFAG-Accelerator

Energy Technology Data Exchange (ETDEWEB)

Lee, Hee Seok; Kang, Hung Sik; Lee, Tae Yeon [Pohang Accelerator Laboratory, Pohang (Korea, Republic of)

2011-10-15

After the East-Japan earthquake and the subsequent nuclear disaster, the anti-nuclear mood has been wide spread. It is very unfortunate both for nuclear science community and for the future of mankind, which is threatened by two serious challenges, the global warming caused by the greenhouse effect and the shortage of energy cause by the petroleum exhaustion. While the nuclear energy seemed to be the only solution to these problems, it is clear that it has its own problems, one of which broke out so strikingly in Japan. There are also other problems such as the radiotoxic nuclear wastes that survive up to even tens of thousands years and the limited reserves of Uranium. To solve these problems of nuclear fission energy, accelerator-based sub-critical nuclear reactor was once proposed. (Its details will be explained below.) First of all, it is safe in a disaster such as an earthquake, because the deriving accelerator stops immediately by the earthquake. It also minimizes the nuclear waste problem by reducing the amount of the toxic waste and shortening their half lifetime to only a few hundred years. Finally, it solves the Uranium reserve problem because it can use Thorium as its fuel. The Thorium reserve is much larger than that of Uranium. Although the idea of the accelerator-driven nuclear reactor was proposed long time ago, it has not been utilized yet first by technical difficulty and economical reasons. The accelerator-based system needs 1 GeV, 10 MW power proton accelerator. A conventional linear accelerator would need several hundred m length, which is highly costly particularly in Korea because of the high land cost. However, recent technologies make it possible to realize that scale accelerator by a reasonable size. That is the fixed-field alternating gradient (FFAG) accelerator that is described in this article

Sub-Critical Nuclear Reactor Based on FFAG-Accelerator

International Nuclear Information System (INIS)

Lee, Hee Seok; Kang, Hung Sik; Lee, Tae Yeon

2011-01-01

After the East-Japan earthquake and the subsequent nuclear disaster, the anti-nuclear mood has been wide spread. It is very unfortunate both for nuclear science community and for the future of mankind, which is threatened by two serious challenges, the global warming caused by the greenhouse effect and the shortage of energy cause by the petroleum exhaustion. While the nuclear energy seemed to be the only solution to these problems, it is clear that it has its own problems, one of which broke out so strikingly in Japan. There are also other problems such as the radiotoxic nuclear wastes that survive up to even tens of thousands years and the limited reserves of Uranium. To solve these problems of nuclear fission energy, accelerator-based sub-critical nuclear reactor was once proposed. (Its details will be explained below.) First of all, it is safe in a disaster such as an earthquake, because the deriving accelerator stops immediately by the earthquake. It also minimizes the nuclear waste problem by reducing the amount of the toxic waste and shortening their half lifetime to only a few hundred years. Finally, it solves the Uranium reserve problem because it can use Thorium as its fuel. The Thorium reserve is much larger than that of Uranium. Although the idea of the accelerator-driven nuclear reactor was proposed long time ago, it has not been utilized yet first by technical difficulty and economical reasons. The accelerator-based system needs 1 GeV, 10 MW power proton accelerator. A conventional linear accelerator would need several hundred m length, which is highly costly particularly in Korea because of the high land cost. However, recent technologies make it possible to realize that scale accelerator by a reasonable size. That is the fixed-field alternating gradient (FFAG) accelerator that is described in this article

The nuclear power alternative

International Nuclear Information System (INIS)

Blix, H.

1989-04-01

The Director General of the IAEA stressed the need for energy policies and other measures which would help to slow and eventually halt the present build-up of carbon dioxide, methane and other so-called greenhouse gases, which are held to cause global warming. He urged that nuclear power and various other sources of energy, none of which contribute to global warming, should not be seen as alternatives, but should all be used to counteract the greenhouse effect. He pointed out that the commercially used renewable energies, apart from hydropower, currently represent only 0.3% of the world's energy consumption and, by contrast, the 5% of the world's energy consumption coming from nuclear power is not insignificant. Dr. Blix noted that opposition for nuclear power stems from fear of accidents and concern about the nuclear wastes. But no generation of electricity, whether by coal, hydro, gas or nuclear power, is without some risk. He emphasized that safety can never be a static concept, and that many new measures are being taken by governments and by the IAEA to further strengthen the safety of nuclear power

Residential carbon dioxide emissions in Canada. Impact of efficiency improvements and fuel substitution

International Nuclear Information System (INIS)

Ugursal, V.I.; FUng, A.S.

1998-01-01

The effect of improving house envelope, heating system and appliance efficiencies, and fuel substitution on the atmospheric emissions of carbon dioxide in the Canadian residential sector is studied based on simulation studies. The findings clearly indicate that improving appliance efficiency reduces the overall end-use energy consumption in the residential sector as well as the associated carbon dioxide emissions. However, the magnitude of the reduction in carbon dioxide emissions as a result of improving only appliance efficiencies is quite small. Significantly larger reductions can be obtained by improving house envelopes and heating/cooling systems in addition to improving appliance efficiencies. Fuel substitution for space and domestic hot water heating can also present a potential to reduce carbon dioxide emissions depending on the fuel substitution scenario adopted. (author)

Facile hydrothermal preparation of titanium dioxide decorated reduced graphene oxide nanocomposite

Science.gov (United States)

Chang, Betty Yea Sze; Huang, Nay Ming; An’amt, Mohd Nor; Marlinda, Abdul Rahman; Norazriena, Yusoff; Muhamad, Muhamad Rasat; Harrison, Ian; Lim, Hong Ngee; Chia, Chin Hua

2012-01-01

A simple single-stage approach, based on the hydrothermal technique, has been introduced to synthesize reduced graphene oxide/titanium dioxide nanocomposites. The titanium dioxide nanoparticles are formed at the same time as the graphene oxide is reduced to graphene. The triethanolamine used in the process has two roles. It acts as a reducing agent for the graphene oxide as well as a capping agent, allowing the formation of titanium dioxide nanoparticles with a narrow size distribution (~20 nm). Transmission electron micrographs show that the nanoparticles are uniformly distributed on the reduced graphene oxide nanosheet. Thermogravimetric analysis shows the nanocomposites have an enhanced thermal stability over the original components. The potential applications for this technology were demonstrated by the use of a reduced graphene oxide/titanium dioxide nanocomposite-modified glassy carbon electrode, which enhanced the electrochemical performance compared to a conventional glassy carbon electrode when interacting with mercury(II) ions in potassium chloride electrolyte. PMID:22848166

Adjustement of Dancoff factor for calculating the cell of fluidized bed nuclear reactor

International Nuclear Information System (INIS)

Borges, V.; Sefidvash, F.

1988-01-01

A new nuclear reactor design based on the fluidized bed concept is under reserch and development. It utilized spherical fuel of slightly enriched zircaloy-clad uranium dioxide fluidized by light water under pressure since the Leopard code has been developed for light water reactor analysis, it was necessary to develop a method to determine the dimensions of the hypothetical fuel rod lattice, which are neutronically equivalent to the spherical fuel pellet lattice. This method is shown to calculate the Dancoff factor correctly. (author) [pt

Future perspective of thorium based nuclear fuels and thorium potential of Turkey

International Nuclear Information System (INIS)

Unak, T.; Yildirim, Y.

2001-01-01

Today's nuclear technology has principally been based on the use of fissile U-235 and Pu-239. he existence of thorium in the nature and its potential use in the nuclear technology were not unfortunately into account with a sufficient importance. The global distributions of thorium and uranium reserves indicate that in general some developed countries such as the USA, Canada, Australia, France have considerable uranium reserves, and contrarily only some developing countries such as Turkey, Brazil, India, Egypt have considerable thorium reserves. The studies carried out on the thorium during the last 50 years have clearly showed that the thorium based nuclear fuels have the potential easily use in most of reactor types actually operated with the classical uranium based nuclear fuels without any considerable modification. In the case of the use of thorium based nuclear fuels in future nuclear energy production systems, the serious problems such as the excess of Pu-239, the proliferation potential of nuclear weapons, and also the anxious of nuclear terrorism will probably be resolved, and sustainable nuclear energy production will be realized in the next new century. (authors)

Future perspective of thorium based nuclear fuels and thorium potential of Turkey

International Nuclear Information System (INIS)

Unak, T.; Yildirim, Y.

2000-01-01

Today's nuclear technology has principally been based on the use of fissile U-235 and Pu-239. The existence of thorium in the nature and its potential use in the nuclear technology were not unfortunately into account with a sufficient importance. The global distributions of thorium and uranium reserves indicate that in general some developed countries such as the USA, Canada, Australia, France have considerable uranium reserves, and contrarily only some developing countries such as Turkey, Brazil, India, Egypt have considerable thorium reserves. The studies carried out on the thorium during the last 50 years have clearly showed that the thorium based nuclear fuels have the potential easily use in most of reactor types actually operated with the classical uranium based nuclear fuels without any considerable modification. In the case of the use of thorium based nuclear fuels in future nuclear energy production systems, the serious problems such as the excess of Pu-239, the proliferation potential of nuclear weapons, and also the anxious of nuclear terrorism will probably be resolved, and sustainable nuclear energy production will be realized in the next new century. (authors)

Supercritical fluid carbon dioxide extraction of actinides

International Nuclear Information System (INIS)

Rao, Ankita; Tomar, B.S.

2016-01-01

Supercritical fluid extraction (SFE) is a process akin to liquid-liquid or solvent extraction where a Supercritical fluid (SCF) is contacted with a solid/ liquid matrix for the purpose of separating the component of interest from the original matrix. Carbon dioxide is a preferred choice as supercritical fluid (SCF) owing to its moderate critical parameter (P c = 7.38 MPa and T c = 304.1K) coupled with radiation and chemical stability, non toxic nature and low cost. Despite widespread applications for extraction of organic compounds and associated advantages especially liquid waste minimization, the SFE of metal ions was left unexplored for quite some time, as direct metal ion extraction is inefficient due charge neutralization requirement and weak solute-solvent interaction. Neutral SCF soluble metal-ligand complexation is imperative and SFE of actinides was reported only in 1994. Several studies have been carried out on SFE of uranium, thorium and plutonium from nitric acid medium employing different sets of ligands (organophosphorus, diketones, amides). Especially attractive is the possibility of direct dissolution and extraction of actinides employing ligand-acid adducts (like TBP.HNO 3 adduct) from solid matrices of different stages of nuclear fuel cycle viz. ores, spent nuclear fuels and radioactive wastes. Also, partitioning of actinides from fission products has been explored in spent nuclear fuel. These studies on supercritical fluid extraction of actinides indicate a more efficient and environmentally sustainable technology. (author)

Social networking-based simulations for nuclear security: Strategy assessment following nuclear cyber terror on South Korean nuclear power plants (NPPs)

International Nuclear Information System (INIS)

Woo, Tae Ho; Kwak, Sang Man

2015-01-01

Highlights: • The cyber terror modeling is made by the social networking algorithm. • This is applicable by the social networking service (SNS). • Security of nuclear industry could be controlled by the network theory. • Newly developed complex algorithm can be introduced. • Simplified graphics show the operator easily. - Abstract: Nuclear energy has been studied for the secure power productions, which is based on the simulation study following the incident of nuclear cyber terror attack on South Korean nuclear power plants (NPPs). The social networking is used for the terror incident modeling and its prevention strategies. The nuclear industry could be investigated in the aspect of minimizing the dangerous situations caused by possible terror attacks which are considered by the society oriented connectivity among the related people or groups. The social networking circle by system dynamics diagram (SNCSD) is constructed, where the configuration of a model social networking example by system dynamics (SD) is applied. From A to H regions, the values are obtained by the random numbers incorporated with the designed algorithms. The results show the comparative values of terror possibilities which are based on the proposed social networking algorithm. It is possible to prepare for potential terrorism in the nuclear industry

A Nuclear Scale System Based on LabVIEW

International Nuclear Information System (INIS)

Liu Shixing; Gu Qindong

2009-01-01

Nuclear mass scales measure the weight of materials which absorb and attenuate the nuclear radiation when the low energy γ-ray through it and is a non-contact continuous measurement device with simple structure and reliable operation. LabVIEW as a graphical programming language is a standard data acquisition and instrument control software. Based on the principle of nuclear mass scale measuring system, monitoring software for nuclear scale system is designed using LabVIEW programming environment. Software architecture mainly composed of three basic modules which include the monitoring software, databases and Web services. It achieves measurement data acquisition, status monitoring, and data management and has networking functions. (authors)

Reducing carbon dioxide to products

Science.gov (United States)

Cole, Emily Barton; Sivasankar, Narayanappa; Parajuli, Rishi; Keets, Kate A

2014-09-30

A method reducing carbon dioxide to one or more products may include steps (A) to (C). Step (A) may bubble said carbon dioxide into a solution of an electrolyte and a catalyst in a divided electrochemical cell. The divided electrochemical cell may include an anode in a first cell compartment and a cathode in a second cell compartment. The cathode may reduce said carbon dioxide into said products. Step (B) may adjust one or more of (a) a cathode material, (b) a surface morphology of said cathode, (c) said electrolyte, (d) a manner in which said carbon dioxide is bubbled, (e), a pH level of said solution, and (f) an electrical potential of said divided electrochemical cell, to vary at least one of (i) which of said products is produced and (ii) a faradaic yield of said products. Step (C) may separate said products from said solution.

2D-Titanium dioxide nanosheets modified with Nd, Ag and Au: Preparation, characterization and photocatalytic activity

Czech Academy of Sciences Publication Activity Database

Pližingrová, Eva; Klementová, Mariana; Bezdička, Petr; Boháček, Jaroslav; Barbieriková, Z.; Dvoranová, D.; Mazúr, M.; Krýsa, J.; Šubrt, Jan; Brezová, V.

2017-01-01

Roč. 281, MAR (2017), s. 165-180 ISSN 0920-5861 R&D Projects: GA ČR(CZ) GA14-20744S; GA MŠk(CZ) 7AMB14SK178 Institutional support: RVO:61388980 Keywords : Modified titanium dioxide * Photocatalysis * Plasmonic effect * EPR spectroscopy * Lyophilization * Spin trapping Subject RIV: CA - Inorganic Chemistry OBOR OECD: Inorganic and nuclear chemistry Impact factor: 4.636, year: 2016

Computer-based control of nuclear power information systems at international level

International Nuclear Information System (INIS)

Boniface, Ekechukwu; Okonkwo, Obi

2011-01-01

In most highly industrialized countries of the world information plays major role in anti-nuclear campaign. Information and discussions on nuclear power need critical and objective analysis before the structured information presentation to the public to avoid bias anti-nuclear information on one side and neglect of great risk in nuclear power. This research is developing a computer-based information system for the control of nuclear power at international level. The system is to provide easy and fast information highways for the followings: (1) Low Regulatory dose and activity limit as level of high danger for individuals and public. (2) Provision of relevant technical or scientific education among the information carriers in the nuclear power countries. The research is on fact oriented investigation about radioactivity. It also deals with fact oriented education about nuclear accidents and safety. A standard procedure for dissemination of latest findings using technical and scientific experts in nuclear technology is developed. The information highway clearly analyzes the factual information about radiation risk and nuclear energy. Radiation cannot be removed from our environment. The necessity of radiation utilizations defines nuclear energy as two-edge sword. It is therefore, possible to use computer-based information system in projecting and dissemination of expert knowledge about nuclear technology positively and also to use it in directing the public on the safety and control of the nuclear energy. The computer-based information highway for nuclear energy technology is to assist in scientific research and technological development at international level. (author)

Oil sand synfuel production using nuclear energy

International Nuclear Information System (INIS)

Barnert, H.

1984-10-01

The importance of oil sand as a primary energy carrier is illustrated. The oil sand mining project 'synfuel' in Fort McMurray, Alberta, Canada, is described. On the basis of a layout of an In-situ-process different possibilities of introducing nuclear energy to the process are described. This leads to an increase of the product yield, leading finally to a doubling of the energy output compared to the reference layout. The introduction of nuclear energy contributes to the reduction of emissions, in particular to the emission of carbon dioxide in the conversion process. (orig.)

Modeling carbon dioxide sequestration in saline aquifers: Significance of elevated pressures and salinities

International Nuclear Information System (INIS)

Allen, D.E.; Strazisar, B.R.; Soong, Y.; Hedges, S.W.

2005-01-01

The ultimate capacity of saline formations to sequester carbon dioxide by solubility and mineral trapping must be determined by simulating sequestration with geochemical models. These models, however, are only as reliable as the data and reaction scheme on which they are based. Several models have been used to make estimates of carbon dioxide solubility and mineral formation as a function of pressure and fluid composition. Intercomparison of modeling results indicates that failure to adjust all equilibrium constants to account for elevated carbon dioxide pressures results in significant errors in both solubility and mineral formation estimates. Absence of experimental data at high carbon dioxide pressures and high salinities make verification of model results difficult. Results indicate standalone solubility models that do not take mineral reactions into account will underestimate the total capacity of aquifers to sequester carbon dioxide in the long term through enhanced solubility and mineral trapping mechanisms. Overall, it is difficult to confidently predict the ultimate sequestration capacity of deep saline aquifers using geochemical models. (author)

Reliability research to nuclear power plant operators based on several methods

International Nuclear Information System (INIS)

Fang Xiang; Li Fu; Zhao Bingquan

2009-01-01

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

Development of data base system for nuclear material accountancy data at PNC

International Nuclear Information System (INIS)

Hirosawa, N.; Akiba, Mitsunori; Nakagima, Kiyoshi; Usui, Shinichi; Tosa, Kiyofumi; Hashimoto, Kazuyuki.

1993-01-01

PNC is developing a wide area of nuclear fuel cycle. Therefore, much nuclear material with a various form exists at each facility in the Works, and the controls of the inventory changes and the physical inventories of nuclear material are important. Nuclear material accountancy is a basic measure in safeguards system based on Non-Proliferation Treaty(NPT). In the light of such importance of material accountancy, the data base of nuclear material control and the material accountancy report system for all facilities has been developed by using the computer. By this system, accountancy report to STA is being presented certainly and timely. Property management and rapid corresponding to inquiries from STA can be carried out by the data base system which has free item searching procedure. The present paper introduces 'Development of Data Base System for Nuclear Material Accountancy Data at PNC'. (author)

A METHOD OF PREPARING URANIUM DIOXIDE

Science.gov (United States)

Scott, F.A.; Mudge, L.K.

1963-12-17

A process of purifying raw, in particular plutonium- and fission- products-containing, uranium dioxide is described. The uranium dioxide is dissolved in a molten chloride mixture containing potassium chloride plus sodium, lithium, magnesium, or lead chloride under anhydrous conditions; an electric current and a chlorinating gas are passed through the mixture whereby pure uranium dioxide is deposited on and at the same time partially redissolved from the cathode. (AEC)

Experience with performance based training of nuclear criticality safety engineers

International Nuclear Information System (INIS)

Taylor, R.G.

1993-01-01

For non-reactor nuclear facilities, the U.S. Department of Energy (DOE) does not require that nuclear criticality safety engineers demonstrate qualification for their job. It is likely, however, that more formalism will be required in the future. Current DOE requirements for those positions which do have to demonstrate qualification indicate that qualification should be achieved by using a systematic approach such as performance based training (PBT). Assuming that PBT would be an acceptable mechanism for nuclear criticality safety engineer training in a more formal environment, a site-specific analysis of the nuclear criticality safety engineer job was performed. Based on this analysis, classes are being developed and delivered to a target audience of newer nuclear criticality safety engineers. Because current interest is in developing training for selected aspects of the nuclear criticality safety engineer job, the analysis is incompletely developed in some areas

46 CFR 97.37-9 - Carbon dioxide alarm.

Science.gov (United States)

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Carbon dioxide alarm. 97.37-9 Section 97.37-9 Shipping... Markings for Fire and Emergency Equipment, Etc. § 97.37-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING...

46 CFR 78.47-9 - Carbon dioxide alarm.

Science.gov (United States)

2010-10-01

... 46 Shipping 3 2010-10-01 2010-10-01 false Carbon dioxide alarm. 78.47-9 Section 78.47-9 Shipping... and Emergency Equipment, Etc. § 78.47-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED.” (b) [Reserved] ...

46 CFR 196.37-9 - Carbon dioxide alarm.

Science.gov (United States)

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Carbon dioxide alarm. 196.37-9 Section 196.37-9 Shipping... Markings for Fire and Emergency Equipment, etc. § 196.37-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING...

Research-based approaches to nuclear education

Energy Technology Data Exchange (ETDEWEB)

Donev, J.M.K.C., E-mail: jason.donev@ucalgary.ca [Univ. of Calgary, Calgary, AB (Canada); Carpenter, Y., E-mail: ycarpenter@gmail.com [Univ.ty of Colorado at Boulder, Boulder, CO (United States)

2014-07-01

Teaching nuclear power requires an expert to communicate a significant number of abstract concepts from diverse disciplines, and assemble these into a larger intellectual framework for the students. Scholarly education research, particularly in individual science disciplines, has provided significant advances in teaching core subject material by breaking away from traditional lecturing. Thus far, however,little work has applied these results to introductory nuclear power classes. This paper explores a method of engaging introductory nuclear students deeply by using a combination of Socratic and mastery methods of teaching. Students develop conceptual understanding of the material through the group work and the use of diverse resources, including textbooks, online references, and computer models that encourage free exploration of these concepts. Marks have improved considerably, and students engage with the material at a significantly deeper level than in previous lecture-based iterations of this course. (author)

Research-based approaches to nuclear education

International Nuclear Information System (INIS)

Donev, J.M.K.C.; Carpenter, Y.

2014-01-01

Teaching nuclear power requires an expert to communicate a significant number of abstract concepts from diverse disciplines, and assemble these into a larger intellectual framework for the students. Scholarly education research, particularly in individual science disciplines, has provided significant advances in teaching core subject material by breaking away from traditional lecturing. Thus far, however,little work has applied these results to introductory nuclear power classes. This paper explores a method of engaging introductory nuclear students deeply by using a combination of Socratic and mastery methods of teaching. Students develop conceptual understanding of the material through the group work and the use of diverse resources, including textbooks, online references, and computer models that encourage free exploration of these concepts. Marks have improved considerably, and students engage with the material at a significantly deeper level than in previous lecture-based iterations of this course. (author)

Development and application of a luminol-based nitrogen dioxide detector

International Nuclear Information System (INIS)

Wendel, G.J.

1985-01-01

An instrument for the continuous measurement of nitrogen dioxide (NO 2 ) at all atmospheric concentration ranges and conditions was developed. The detector is based on the chemiluminescent reaction between 5-amino-2,3-dihydro-1,4-phthalazinedione (luminol) and NO 2 in alkaline aqueous solution. Development included the optimization of the cell design and the solution composition. Sodium sulfite (Na 2 SO 3 ) and methanol (CH 3 OH) were added to the solution to improve sensitivity and specificity. The detector was favorably compared to two different instruments measuring NO 2 by NO + O 3 chemiluminescent and by a tunable diode laser absorption spectrometry system. The detector has demonstrated a detection limit of 30 parts-per-trillion by volume (ppt) and a frequency response of 0.3 Hz. The instrument was operated for two one-month periods on Bermuda. The purpose was to study air masses from the East Coast of the United States after transport over the ocean. Average daily values were 400 ppt with values as low as 100 ppt measured. Other field experiments involved monitoring of NO 2 in ambient air in the range of 1 to 60 parts-per-billion by volume

Risk-based inspection in the context of nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Soares, Wellington A.; Vasconcelos, Vanderley de; Rabello, Emerson G., E-mail: soaresw@cdtn.br, E-mail: vasconv@cdtn.br, E-mail: egr@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2015-07-01

Nuclear power plant owners have to consider several aspects like safety, availability, costs and radiation exposure during operation of nuclear power plants. They also need to demonstrate to regulatory bodies that risk assessment and inspection planning processes are being implemented in effective and appropriate manner. Risk-Based Inspection (RBI) is a methodology that, unlike time-based inspection, involves a quantitative assessment of both failure probability and consequence associated with each safety-related item. A correctly implemented RBI program classifies individual equipment by its risks and prioritizes inspection efforts based on this classification. While in traditional deterministic approach, the inspection frequencies are constant, in the RBI approach the inspection interval for each item depends on the risk level. Regularly, inspection intervals from RBI result in risk levels lower or equal than deterministic inspection intervals. According to the literature, RBI solutions improve integrity and reduce costs through a more effective inspection. Risk-Informed In-service Inspection (RI-ISI) is the equivalent term used in the nuclear area. Its use in nuclear power plants around world is briefly reviewed in this paper. Identification of practice methodologies for performing risk-based analyses presented in this paper can help both Brazilian nuclear power plant operator and regulatory body in evaluating the RI-ISI technique feasibility as a tool for optimizing inspections within nuclear plants. (author)

Risk-based inspection in the context of nuclear power plants

International Nuclear Information System (INIS)

Soares, Wellington A.; Vasconcelos, Vanderley de; Rabello, Emerson G.

2015-01-01

Nuclear power plant owners have to consider several aspects like safety, availability, costs and radiation exposure during operation of nuclear power plants. They also need to demonstrate to regulatory bodies that risk assessment and inspection planning processes are being implemented in effective and appropriate manner. Risk-Based Inspection (RBI) is a methodology that, unlike time-based inspection, involves a quantitative assessment of both failure probability and consequence associated with each safety-related item. A correctly implemented RBI program classifies individual equipment by its risks and prioritizes inspection efforts based on this classification. While in traditional deterministic approach, the inspection frequencies are constant, in the RBI approach the inspection interval for each item depends on the risk level. Regularly, inspection intervals from RBI result in risk levels lower or equal than deterministic inspection intervals. According to the literature, RBI solutions improve integrity and reduce costs through a more effective inspection. Risk-Informed In-service Inspection (RI-ISI) is the equivalent term used in the nuclear area. Its use in nuclear power plants around world is briefly reviewed in this paper. Identification of practice methodologies for performing risk-based analyses presented in this paper can help both Brazilian nuclear power plant operator and regulatory body in evaluating the RI-ISI technique feasibility as a tool for optimizing inspections within nuclear plants. (author)

Beneficial Use of Carbon Dioxide in Precast Concrete Production

Energy Technology Data Exchange (ETDEWEB)

Shao, Yixin [McGill Univ., Montreal, QC (Canada)

2014-06-26

The feasibility of using carbon dioxide as feedstock in precast concrete production is studied. Carbon dioxide reacts with calcium compounds in concrete, producing solid calcium carbonates in binding matrix. Two typical precast products are examined for their capacity to store carbon dioxide during the production. They are concrete blocks and fiber-cement panels. The two products are currently mass produced and cured by steam. Carbon dioxide can be used to replace steam in curing process to accelerate early strength, improve the long-term durability and reduce energy and emission. For a reaction within a 24-hour process window, the theoretical maximum possible carbon uptake in concrete is found to be 29% based on cement mass in the product. To reach the maximum uptake, a special process is developed to promote the reaction efficiency to 60-80% in 4-hour carbon dioxide curing and improve the resistance to freeze-thaw cycling and sulfate ion attack. The process is also optimized to meet the project target of $10/tCO₂ in carbon utilization. By the use of self-concentrating absorption technology, high purity CO₂ can be produced at a price below $40/t. With low cost CO₂ capture and utilization technologies, it is feasible to establish a network for carbon capture and utilization at the vicinity of carbon sources. If all block produces and panel producers in United States could adopt carbon dioxide process in their production in place of steam, carbon utilization in these two markets alone could consume more than 2 Mt CO₂/year. This capture and utilization process can be extended to more precast products and will continue for years to come.

Nuclear power: the future reassessed

Energy Technology Data Exchange (ETDEWEB)

Roberts, L [East Anglia Univ., Norwich (UK). Environmental Risk Assessment Unit (ERAU)

1991-02-01

In recommending that consent be given for the construction of a further Pressurized Water Reactor at Hinkley Point in Somerset, UK, the Inspector at the Public Inquiry underlined two major benefits: (i) the contribution an additional large nuclear plant would make to the strategic objective of diversity of supply, and (ii) the environmental benefits of nuclear power compared to many alternative forms of electricity generation. The major environmental advantages of nuclear power over fossil fuel combustion arise both because of the small amounts of fuel required - 1/18,000 compared to coal - thus minimizing transport needs and land use, and because of the virtual absence of atmospheric emissions from nuclear stations. Nuclear reactors emit no acid gases and the nuclear fuel cycle gives rise to only small amounts of carbon dioxide. An expansion of the nuclear option is often opposed on three grounds; the need to dispose of radioactive waste; the danger of the proliferation of nuclear weapons and the risk of a large scale accident. However all these doubts can be answered and the arguments supporting nuclear safety are summarized. It is argued that the contribution to primary energy demand in Europe could be doubled or trebled by 2020 with considerable benefits in overall safety environmental impacts at no extra cost. (author).

Nuclear power: the future reassessed

International Nuclear Information System (INIS)

Roberts, L.

1991-01-01

In recommending that consent be given for the construction of a further Pressurized Water Reactor at Hinkley Point in Somerset, UK, the Inspector at the Public Inquiry underlined two major benefits: (i) the contribution an additional large nuclear plant would make to the strategic objective of diversity of supply, and (ii) the environmental benefits of nuclear power compared to many alternative forms of electricity generation. The major environmental advantages of nuclear power over fossil fuel combustion arise both because of the small amounts of fuel required - 1/18,000 compared to coal - thus minimizing transport needs and land use, and because of the virtual absence of atmospheric emissions from nuclear stations. Nuclear reactors emit no acid gases and the nuclear fuel cycle gives rise to only small amounts of carbon dioxide. An expansion of the nuclear option is often opposed on three grounds; the need to dispose of radioactive waste; the danger of the proliferation of nuclear weapons and the risk of a large scale accident. However all these doubts can be answered and the arguments supporting nuclear safety are summarized. It is argued that the contribution to primary energy demand in Europe could be doubled or trebled by 2020 with considerable benefits in overall safety environmental impacts at no extra cost. (author)

NO global warming = YES nuclear energy. The International Nuclear Forum and the United Nations Framework Convention on Climate Change

International Nuclear Information System (INIS)

Cornish, Emma

2000-01-01

The nuclear industry sits along side the renewable energy sector in its role as a non carbon emitting technology. But persuading international political leaders of this fact presents a challenge. Generating electricity from nuclear fuel avoids at least 2 billion tonnes of carbon dioxide every year through its 16% share of world wide electricity generation. Nuclear energy is essential to minimising greenhouse gas emissions. This presentation highlights the main issues resulting from the climate change negotiations that are highly relevant to the industry; explains the activities of the International Nuclear Forum and our interaction with the delegates to the process; outlines future activities. The International Nuclear Forum (INF) was formed to provide a collective voice lobbying for nuclear at the climate change negotiations. It's internationally representative of the industry and comprises of: the Uranium Institute; the Nuclear Energy Institute; the Japan Atomic Industry Forum; the Canadian Nuclear Association; the European Nuclear Society, and Foratom. All are accredited non governmental observers to the negotiations of the United Nations Framework Convention on Climate Change

Integrated strategy for N-methylformanilide production from carbon dioxide of flue gas in coal-fired power plant

International Nuclear Information System (INIS)

Han, Jeehoon

2017-01-01

Highlights: • A ‘green’ N-methylformanilide production process based new carbon dioxide conversion technologies is developed. • Monoethanolamine-based system for capturing carbon dioxide from the flue gas of a coal-fired power plant is deployed. • Gamma-valerolactone is used a solvent and catalyst for converting carbon dioxide to N-methylformanilide. • New separations for recovery of N-methylformanilide and gamma-valerolactone are developed. • Economic evaluation of the proposed process is performed. - Abstract: In this work, an integrated strategy is developed for producing N-methylformanilide from the carbon dioxide of flue gas in a coal-fired power plant. Based on lab-scale experimental studies presenting maximum yields (96%) with low reaction concentrations (below 25 wt% reactants) using large volumes of gamma-valerolactone as a solvent and catalyst, the integrated strategy focuses on the development of commercial-scale processes that consist of a monoethanolamine-based carbon dioxide separation subsystem and a catalytic conversion subsystem of N-Methylaniline with carbon dioxide to N-methylformanilide. Moreover, a heat exchanger network is designed to minimize the total energy requirements by transferring the heat between subsystems. In the proposed integrated strategy, the energy efficiency after heat integration (77.5%) is higher than that before heat integration (74.5%). Economic analysis results show that the minimum selling price of N-methylformanilide ($1592.1 Mt"−"1 using the best possible parameters) for use in this integrated strategy is cost-competitive with the current market price ($2984 Mt"−"1).

CQUESTRA, a risk and performance assessment code for geological sequestration of carbon dioxide

International Nuclear Information System (INIS)

LeNeveu, D.M.

2008-01-01

A computationally efficient semi-analytical code, CQUESTRA, has been developed for probabilistic risk assessment and rapid screening of potential sites for geological sequestration of carbon dioxide. The rate of dissolution and leakage from a trapped underground pool of carbon dioxide is determined. The trapped carbon dioxide could be mixed with hydrocarbons and other components to form a buoyant phase. The program considers potential mechanisms for escape from the geological formations such as the movement of the buoyant phase through failed seals in wellbores, the annulus around wellbores and through open fractures in the caprock. Plume animations of dissolved carbon dioxide in formation water around the wellbores are provided. Solubility, density and viscosity of the buoyant phase are determined by equations of state. Advection, dispersion, diffusion, buoyancy, aquifer flow rates and local formation fluid pressure are taken into account in the modeling of the carbon dioxide movement. Results from a hypothetical example simulation based on data from the Williston basin near Weyburn, Saskatchewan, indicate that this site is potentially a viable candidate for carbon dioxide sequestration. Sensitivity analysis of CQUESTRA indicates that criteria such as siting below aquifers with large flow rates and siting in reservoirs having fluid pressure below the pressure of the formations above can promote complete dissolution of the carbon dioxide during movement toward the surface, thereby preventing release to the biosphere. Formation of very small carbon dioxide bubbles within the fluid in the wellbores can also lead to complete dissolution

Delignification of softwood kraft pulp by chlorine dioxide in a laboratory bleaching liquor displacement reactor

International Nuclear Information System (INIS)

Hamzeh, Y.; Izadyar, S.

2008-01-01

The chlorine dioxide delignification efficiency of softwood kraft pulp in the laboratory liquor displacement reactor (fixed bed reactor) was investigated and compared with conventional batch reactor. The comparison of two reactors was made based on the effective efficiency and overall efficiency of chlorine dioxide. Effective efficiency corresponds to the oxidizing capacity of chlorine dioxide which consumed by organic materials. Comparison of two reactors based on the effective efficiency showed that the selectivity of delignification significantly enhanced in the displacement reactor in which the primary reaction products are eliminated from reaction zone by displacing flow. On the other hand, the formation of high amounts of chlorate in the reaction zone of displacement reactor reduces the overall efficiency of chlorine dioxide delignification stage. Thus, in spite of significant decrease in useless secondary reactions, this type of reactor would not be cost effective in the industrial scale

Once-through hybrid sulfur process for nuclear hydrogen production

International Nuclear Information System (INIS)

Jeong, Y. H.

2008-01-01

Increasing concern about the global climate change spurs the development of low- or zero-carbon energy system. Nuclear hydrogen production by water electrolysis would be the one of the short-term solutions, but low efficiency and high production cost (high energy consumption) is the technical hurdle to be removed. In this paper the once-through sulfur process composed of the desulfurization and the water electrolysis systems is proposed. Electrode potential for the conventional water electrolysis (∼2.0 V) can be reduced significantly by the anode depolarization using sulfur dioxide: down to 0.6 V depending on the current density This depolarized electrolysis is the electrolysis step of the hybrid sulfur process originally proposed by the Westinghouse. However; recycling of sulfur dioxide requires a high temperature heat source and thus put another technical hurdle on the way to nuclear hydrogen production: the development of high temperature nuclear reactors and corresponding sulfuric acid decomposition system. By the once-through use of sulfur dioxide rather than the closed recycle, the hurdle can be removed. For the sulfur feed, the desulfurization system is integrated into the water electrolysis system. Fossil fuels include a few percent of sulfur by weight. During the refinement or energy conversion, most of the sulfur should be separated The separated sulfur can be fed to the water electrolysis system and the final product would be hydrogen and sulfuric acid, which is number one chemical in the world by volume. Lowered electrode potential and additional byproduct, the sulfuric acid, can provide economically affordable hydrogen. In this study, the once-through hybrid sulfur process for hydrogen production was proposed and the process was optimized considering energy consumption in electrolysis and sulfuric acid concentration. Economic feasibility of the proposed process was also discussed. Based on currently available experimental data for the electrode

Exact Solution of Fractional Diffusion Model with Source Term used in Study of Concentration of Fission Product in Uranium Dioxide Particle

International Nuclear Information System (INIS)

Fang Chao; Cao Jianzhu; Sun Lifeng

2011-01-01

The exact solution of fractional diffusion model with a location-independent source term used in the study of the concentration of fission product in spherical uranium dioxide (UO 2 ) particle is built. The adsorption effect of the fission product on the surface of the UO 2 particle and the delayed decay effect are also considered. The solution is given in terms of Mittag-Leffler function with finite Hankel integral transformation and Laplace transformation. At last, the reduced forms of the solution under some special physical conditions, which is used in nuclear engineering, are obtained and corresponding remarks are given to provide significant exact results to the concentration analysis of nuclear fission products in nuclear reactor. (nuclear physics)

Task Order 20: Supercritical Carbon Dioxide Brayton Cycle Energy Conversion Study

Energy Technology Data Exchange (ETDEWEB)

Murray, Paul [AREVA Federal Services, LLC, Charlotte, NC (United States); Lindsay, Edward [AREVA Federal Services, LLC, Charlotte, NC (United States); McDowell, Michael [AREVA Federal Services, LLC, Charlotte, NC (United States); Huang, Megan [AREVA Federal Services, LLC, Charlotte, NC (United States)

2015-04-23

AREVA Inc. developed this study for the US Department of Energy (DOE) office of Nuclear Energy (NE) in accordance with Task Order 20 Statement of Work (SOW) covering research and development activities for the Supercritical Carbon Dioxide (sCO2) Brayton Cycle energy conversion. The study addresses the conversion of sCO2 heat energy to electrical output by use of a Brayton Cycle system and focuses on the potential of a net efficiency increase via cycle recuperation and recompression stages. The study also addresses issues and study needed to advance development and implementation of a 10 MWe sCO2 demonstration project.

Nuclear energy cost data base: A reference data base for nuclear and coal-fired powerplant power generation cost analysis

International Nuclear Information System (INIS)

1988-09-01

A reference data base and standard methodology are needed for performing comparative nuclear and fossil power generation cost analyses for the Department of Energy, Office of Nuclear Energy. This report contains such a methodology together with reference assumptions and data to be used with the methodology. It is intended to provide basic guidelines or a starting point for analyses and to serve as a focal point in establishing parameters and methods to be used in economic comparisons of nuclear systems with alternatives. The data base is applicable for economic comparisons of new base load light-water reactors on a once-through cycle, and high- and low-sulfur coal-fired plants, and oil- and natural gas-fired electric generating plants coming on line around the turn of the century. In addition to current generation light-water reactors and fossil fuel-fired plants, preliminary cost information is also presented on improved and advanced light-water reactors, liquid metal reactor plants and fuel cycle facilities. This report includes an updated data base containing proposed technical and economic assumptions to be used in analyses, discussions of a recommended methodology to be used in calculating power generation costs, a sample calculation for illustrative and benchmark purposes and projected power generation costs for fission and coal-fired alternatives. Effects of the 1986 Tax Reform Act are included. 126 refs., 17 figs., 47 tabs

Our response to climate change requires nuclear power

International Nuclear Information System (INIS)

Kemeny, L.

2007-01-01

Australian politicians and environmental activists who reject nuclear power as the pivotal technology to combat climate change stand compromised before the court of international scientific opinion and informed global realism. The content of their rhetoric on nuclear matters comprises pseudo-science, innuendo and ideological prejudice communicated through the politics of fear and risk. The recent report of the United Nations Intergovernmental Panel on Climate Change (IPCC) calls for urgent major reductions in greenhouse gas emissions, without which the natural feedback mechanisms that control global temperatures might be overwhelmed. It points out that presently human activity produces around 23.6 billion tonnes of carbon dioxide per annum, about one half of which can be absorbed by soil and ocean. However this capacity is being rapidly destroyed by rising soil and ocean surface temperatures. The report points out that if global warming cannot be kept between manageable limits, it could lead to the destruction of the Great Barrier Reef and the Amazon rainforest, and lead to the forced migration of hundreds of millions of people from equatorial regions and the loss of vast tracts of land as ice caps melt and sea levels rise. For many scientists and engineers concerned with energy and environmental issues it is a matter of deep regret that, the IPCC meetings at Kyoto and Paris have not explicitly endorsed the central role, which could be played by nuclear energy in combating greenhouse gas production and climate change. The environmental benefits from switching to nuclear fuels are striking. The IPCC delegates attending Kyoto in 1997 must have known that light and air-conditioning for the modern International Convention Centre were obtained from an electricity grid supplied partly from a network of 54 nuclear power stations. The greenhouse gas emissions saved by the use of this network and the uranium fuel cycle is around 287 million tonnes of carbon dioxide per

Establishment of nuclear knowledge and information infrastructure; establishment of web-based database system for nuclear events

Energy Technology Data Exchange (ETDEWEB)

Park, W. J.; Kim, K. J. [Korea Atomic Energy Research Institute , Taejeon (Korea); Lee, S. H. [Korea Institute of Nuclear Safety, Taejeon (Korea)

2001-05-01

Nuclear events data reported by nuclear power plants are useful to prevent nuclear accidents at the power plant by examine the cause of initiating events and removal of weak points in the aspects of operational safety, and to improve nuclear safety in design and operation stages by backfitting operational experiences and practices 'Nuclear Event Evaluation Database : NEED' system distributed by CD-ROM media are upgraded to the NEED-Web (Web-based Nuclear Event Evaluation Database) version to manage event data using database system on network basis and the event data and the statistics are provided to the authorized users in the Nuclear Portal Site and publics through Internet Web services. The efforts to establish the NEED-Web system will improve the integrity of events data occurred in Korean nuclear power plant and the usability of data services, and enhance the confidence building and the transparency to the public in nuclear safety. 11 refs., 27 figs. (Author)

27 CFR 24.319 - Carbon dioxide record.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Carbon dioxide record. 24..., DEPARTMENT OF THE TREASURY LIQUORS WINE Records and Reports § 24.319 Carbon dioxide record. A proprietor who uses carbon dioxide in still wine shall maintain a record of the laboratory tests conducted to...

Development of a low cost unmanned aircraft system for atmospheric carbon dioxide leak detection

Science.gov (United States)

Mitchell, Taylor Austin

Carbon sequestration, the storage of carbon dioxide gas underground, has the potential to reduce global warming by removing a greenhouse gas from the atmosphere. These storage sites, however, must first be monitored to detect if carbon dioxide is leaking back out to the atmosphere. As an alternative to traditional large ground-based sensor networks to monitor CO2 levels for leaks, unmanned aircraft offer the potential to perform in-situ atmospheric leak detection over large areas for a fraction of the cost. This project developed a proof-of-concept sensor system to map relative carbon dioxide levels to detect potential leaks. The sensor system included a Sensair K-30 FR CO2 sensor, GPS, and altimeter connected an Arduino microcontroller which logged data to an onboard SD card. Ground tests were performed to verify and calibrate the system including wind tunnel tests to determine the optimal configuration of the system for the quickest response time (4-8 seconds based upon flowrate). Tests were then conducted over a controlled release of CO 2 in addition to over controlled rangeland fires which released carbon dioxide over a large area as would be expected from a carbon sequestration source. 3D maps of carbon dioxide were developed from the system telemetry that clearly illustrated increased CO2 levels from the fires. These tests demonstrated the system's ability to detect increased carbon dioxide concentrations in the atmosphere.

Development of an Integrated Education/Training based Nuclear Outreach Model

International Nuclear Information System (INIS)

Han, Kyongwon; Nam, Youngmi; Hwang, Ina; Lee, Jisuk; Ko, Hansuk; Lee, Taejoon

2013-01-01

The Korean nuclear community also recognizes the importance of outreach from its experience with rad waste and nuclear power programs. Accordingly, nationwide programs dealing with public information, support for local community development, and HRD are implemented continuously involving a number of organizations concerned. The Nuclear Training and Education Center (NTC) of the Korea Atomic Energy Research Institute (KAERI), with its unique function and capability as a national research organization, has needs for the enhancement of public acceptance for KAERI programs, a better contribution to the national effort, and addressing the emerging needs for international education/training on nuclear outreach. This paper presents an integrated education/training based nuclear outreach model with a set of reference program, which is developed for NTC. An integrated education/training based nuclear outreach model for NTC is developed addressing the increasing needs for public acceptance on the peaceful use of nuclear energy, in terms of supporting KAERI activities, contributing to the national nuclear outreach efforts, and promoting international education and training on nuclear outreach. The model, harmonized with the national nuclear outreach system, consists of objectives, target audiences, a set of reference program supported by infrastructure and networking, and an evaluation system. The program is further specified into sub-programs with detailed design for the respective audiences. The developed model with a reference program is characterized by its integrity in terms of encompassing the whole outreach process cycle, and setting up of a target audience based total program structure with existing and new sub-programs. Also, it intends to be sustainable by addressing future generations' needs as well as innovative in the program delivery. The model will be continuously upgraded and applied addressing respective needs of the audiences

Development of an Integrated Education/Training based Nuclear Outreach Model

Energy Technology Data Exchange (ETDEWEB)

Han, Kyongwon; Nam, Youngmi; Hwang, Ina; Lee, Jisuk; Ko, Hansuk; Lee, Taejoon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2013-05-15

The Korean nuclear community also recognizes the importance of outreach from its experience with rad waste and nuclear power programs. Accordingly, nationwide programs dealing with public information, support for local community development, and HRD are implemented continuously involving a number of organizations concerned. The Nuclear Training and Education Center (NTC) of the Korea Atomic Energy Research Institute (KAERI), with its unique function and capability as a national research organization, has needs for the enhancement of public acceptance for KAERI programs, a better contribution to the national effort, and addressing the emerging needs for international education/training on nuclear outreach. This paper presents an integrated education/training based nuclear outreach model with a set of reference program, which is developed for NTC. An integrated education/training based nuclear outreach model for NTC is developed addressing the increasing needs for public acceptance on the peaceful use of nuclear energy, in terms of supporting KAERI activities, contributing to the national nuclear outreach efforts, and promoting international education and training on nuclear outreach. The model, harmonized with the national nuclear outreach system, consists of objectives, target audiences, a set of reference program supported by infrastructure and networking, and an evaluation system. The program is further specified into sub-programs with detailed design for the respective audiences. The developed model with a reference program is characterized by its integrity in terms of encompassing the whole outreach process cycle, and setting up of a target audience based total program structure with existing and new sub-programs. Also, it intends to be sustainable by addressing future generations' needs as well as innovative in the program delivery. The model will be continuously upgraded and applied addressing respective needs of the audiences.

Epiphytic lichens as indicators of air pollution by sulfur dioxide

Energy Technology Data Exchange (ETDEWEB)

Goodman, G; Rose, F

1973-01-01

Epiphytic lichens show specific differential responses to sulfur dioxide in the air, and it has been possible to construct a scale of SO/sub 2/ pollution based upon lichen communities present upon trees. Maps of pollution zones have now been prepared for England, Wales and Northern France. It has proved possible to correlate these zones with mean winter levels of sulfur dioxide measured instrumentally. Laboratory studies indicate the essential validity of this approach. An interesting correlation between air pollution and topography can be demonstrated in much of south-east England.

Conversion of no-carrier-added [11C]carbon dioxide to [11C]carbon monoxide on molybdenum for the synthesis of 11C-labelled aromatic ketones

International Nuclear Information System (INIS)

Zeisler, S.K.; Nader, M.; Theobald, A.; Oberdorfer, F.

1997-01-01

A new method for the efficient conversion of no-carrier-added [ 11 C]carbon dioxide into [ 11 C]carbon monoxide is described. [ 11 C]Carbon dioxide produced by proton bombardment of ultra high purity nitrogen is pre-concentrated in a cryo trap and then passed through a quartz tube filled with a mesh of thin molybdenum wire heated to 850 o C. [ 11 C]Carbon dioxide readily reacts with molybdenum to form [ 11 C]carbon monoxide and molybdenum(IV) oxide. The latter also reduces carbon dioxide to carbon monoxide and helps improve the performance of the converter. [ 11 C]Carbon monoxide is purified from remaining [ 11 C]carbon dioxide and collected in a small silica trap from which it is eluted into a reaction mixture for the palladium-mediated synthesis of a 11 C-labelled aromatic ketone. Radiochemical yields of up to 81% (decay-corrected) for [ 11 C]carbon monoxide were obtained. Radiochemical purity and specific radioactivity of both [ 11 C]carbon monoxide and the 11 C-labelled ketone are sufficient for nuclear medical studies with PET. (Author)

A simple dynamic rising nuclear cloud based model of ground radioactive fallout for atmospheric nuclear explosion

International Nuclear Information System (INIS)

Zheng Yi

2008-01-01

A simple dynamic rising nuclear cloud based model for atmospheric nuclear explosion radioactive prediction was presented. The deposition of particles and initial cloud radius changing with time before the cloud stabilization was considered. Large-scale relative diffusion theory was used after cloud stabilization. The model was considered reasonable and dependable in comparison with four U.S. nuclear test cases and DELFIC model results. (authors)

Sol-gel growth of vanadium dioxide

International Nuclear Information System (INIS)

Speck, K.R.

1990-01-01

This thesis examines the chemical reactivity of vanadium (IV) tetrakis(t-butoxide) as a precursor for the sol-gel synthesis of vanadium dioxide. Hydrolysis and condensation of the alkoxide was studied by FTIR spectroscopy. Chemical modification of the vanadium tetraalkoxide by alcohol interchange was studied using 51 V NMR and FTIR. Vanadium dioxide thin films and powders were made from vanadium tetrakis(t-butoxide) by standard sol-gel techniques. Post-deposition heating under nitrogen was necessary to transform amorphous gels into vanadium dioxide. Crystallization of films and powders was studied by FTIR, DSC, TGA, and XRD. Gel-derived vanadium dioxide films undergo a reversible semiconductor-to-metal phase transition near 68C, exhibiting characteristic resistive and spectral changes. The electrical resistance decreased by two to three orders of magnitude and the infrared transmission sharply dropped as the material was cycled through this thermally induced phase transition. The sol-gel method was also used to make doped vanadium dioxide films. Films were doped with tungsten and molybdenum ions to effectively lower the temperature at which the transition occurs

Computer-based control systems of nuclear power plants

International Nuclear Information System (INIS)

Kalashnikov, V.K.; Shugam, R.A.; Ol'shevsky, Yu.N.

1975-01-01

Computer-based control systems of nuclear power plants may be classified into those using computers for data acquisition only, those using computers for data acquisition and data processing, and those using computers for process control. In the present paper a brief review is given of the functions the systems above mentioned perform, their applications in different nuclear power plants, and some of their characteristics. The trend towards hierarchic systems using control computers with reserves already becomes clear when consideration is made of the control systems applied in the Canadian nuclear power plants that pertain to the first ones equipped with process computers. The control system being now under development for the large Soviet reactors of WWER type will also be based on the use of control computers. That part of the system concerned with controlling the reactor assembly is described in detail

Nuclear energy and the greenhouse problem

International Nuclear Information System (INIS)

Kemeny, L.G.

2001-01-01

Last November - almost in parallel with the Hague Meeting on Climate Change - more than 1,500 of the world's top nuclear scientists and energy technologists met in Washington DC, at the Joint Conference of the American Nuclear Society, the European Nuclear Society, the Nuclear Energy Institute and the International Nuclear Energy Academy. Unlike the United Nations follow up to the Kyoto protocol, which ended in disarray, a note of high optimism and informed realism pervaded the nuclear conference which, among its multiple streams of subject material and papers by international experts, carried the two main themes of Long Term Globally Sustainable Energy Options and Nuclear Energy and the Greenhouse Problem. This paper considers the immense contribution to Greenhouse gas emission minimisation made by nuclear energy in 1999. In that year the global electricity production by the world's 435 nuclear power stations was 2,398 TWh or 16% of total electricity generation or 5% of total primary energy production. The amount of avoided carbon dioxide emission because of the use of nuclear energy in 1999 was 2.4 billion tonnes. This is 10% of total emissions. Japan's 54 nuclear power stations alone save the equivalent of Australia's total Greenhouse emissions. The secret of this success is Australia's uranium fuel

Some aspects of a technology of processing weapons grade plutonium to nuclear fuel

International Nuclear Information System (INIS)

Bibilashvili, Y.; Glagovsky, E.M.; Zakharkin, B.S.; Orlov, V.K.; Reshetnikov, F.G.; Rogozkin, B.G.; Soloni-N, M.I.

2000-01-01

The concept by Russia to use fissile weapons-grade materials, which are being recovered from nuclear pits in the process of disarmament, is based on an assessment of weapons-grade plutonium as an important energy source intended for use in nuclear power plants. However, in the path of involving plutonium excessive from the purposes of national safety into industrial power engineering there are a lot of problems, from which effectiveness and terms of its disposition are being dependent upon. Those problems have political, economical, financial and environmental character. This report outlines several technology problems of processing weapons-grade metallic plutonium into MOX-fuel for reactors based on thermal and fast neutrons, in particular, the issue of conversion of the metal into dioxide from the viewpoint of fabrication of pelletized MOX-fuel. The processing of metallic weapons-grade plutonium into nuclear fuel is a rather complicated and multi-stage process, every stage of which is its own production. Some of the stages are absent in production of MOX-fuel, for instance the stage of the conversion, i.e. transferring of metallic plutonium into dioxide of the ceramic quality. At this stage of plutonium utilization some tasks must be resolved as follows: I. As a result of the conversion, a material purified from ballast and radiogenic admixtures has to be obtained. This one will be applied to fabricate pelletized MOX-fuel going from morphological, physico-mechanical and technological properties. II. It is well known that metallic gallium, which is used as an alloying addition in weapons-grade plutonium, actively reacts with multiple metals. Therefore, an important issue is to study the effect of gallium on the technology of MOX-fuel production, quality of the pellets, as well as the interaction of gallium oxide with zirconium and steel shells of fuel elements depending upon the content of gallium in the fuel. The rate of the interaction of gallium oxide

Long-term outlook of energy demand and supply in Japan. Estimation of energy demand and supply for 'Nuclear Energy Vision 2100' of JAEA

International Nuclear Information System (INIS)

Tatematsu, Kenji; Kawasaki, Hirotsugu; Nemoto, Masahiro; Murakami, Masakazu

2009-06-01

In this study, we showed an energy demand and supply scenario toward the year 2100 in Japan, which underlies JAEA's 'Nuclear Energy Vision 2100' published in October 2008. This energy demand and supply scenario aimed at the coexistence of the reduction of the carbon dioxide emission and the energy security through reduction of the fossil fuel usage, positive electrification and the nuclear energy usage. We reduced the ratio of the fossil fuel in the primary energy supply to about 1/3 and extend the share of renewable and nuclear energy to 70% from current 15%. As a result, the carbon dioxide emission was reduced to current 10%, and it developed that the half was the contribution of the nuclear energy. (author)

Nuclear component design ontology building based on ASME codes

International Nuclear Information System (INIS)

Bao Shiyi; Zhou Yu; He Shuyan

2005-01-01

The adoption of ontology analysis in the study of concept knowledge acquisition and representation for the nuclear component design process based on computer-supported cooperative work (CSCW) makes it possible to share and reuse numerous concept knowledge of multi-disciplinary domains. A practical ontology building method is accordingly proposed based on Protege knowledge model in combination with both top-down and bottom-up approaches together with Formal Concept Analysis (FCA). FCA exhibits its advantages in the way it helps establish and improve taxonomic hierarchy of concepts and resolve concept conflict occurred in modeling multi-disciplinary domains. With Protege-3.0 as the ontology building tool, a nuclear component design ontology based ASME codes is developed by utilizing the ontology building method. The ontology serves as the basis to realize concept knowledge sharing and reusing of nuclear component design. (authors)

Evaluation and Optimization of a Supercritical Carbon Dioxide Power Conversion Cycle for Nuclear Applications

International Nuclear Information System (INIS)

Harvego, Edwin A.; McKellar, Michael G.

2011-01-01

There have been a number of studies involving the use of gases operating in the supercritical mode for power production and process heat applications. Supercritical carbon dioxide (CO2) is particularly attractive because it is capable of achieving relatively high power conversion cycle efficiencies in the temperature range between 550 C and 750 C. Therefore, it has the potential for use with any type of high-temperature nuclear reactor concept, assuming reactor core outlet temperatures of at least 550 C. The particular power cycle investigated in this paper is a supercritical CO2 Recompression Brayton Cycle. The CO2 Recompression Brayton Cycle can be used as either a direct or indirect power conversion cycle, depending on the reactor type and reactor outlet temperature. The advantage of this cycle when compared to the helium Brayton Cycle is the lower required operating temperature; 550 C versus 850 C. However, the supercritical CO2 Recompression Brayton Cycle requires an operating pressure in the range of 20 MPa, which is considerably higher than the required helium Brayton cycle operating pressure of 8 MPa. This paper presents results of analyses performed using the UniSim process analyses software to evaluate the performance of the supercritical CO2 Brayton Recompression Cycle for different reactor outlet temperatures. The UniSim model assumed a 600 MWt reactor power source, which provides heat to the power cycle at a maximum temperature of between 550 C and 750 C. The UniSim model used realistic component parameters and operating conditions to model the complete power conversion system. CO2 properties were evaluated, and the operating range for the cycle was adjusted to take advantage of the rapidly changing conditions near the critical point. The UniSim model was then optimized to maximize the power cycle thermal efficiency at the different maximum power cycle operating temperatures. The results of the analyses showed that power cycle thermal efficiencies in

Chemoselective alternating copolymerization of limonene dioxide and carbon dioxide : a new highly functional aliphatic epoxy polycarbonate

NARCIS (Netherlands)

Li, C.; Sablong, R.J.; Koning, C.E.

The alternating copolymerization of biorenewable limonene dioxide with carbon dioxide (CO2) catalyzed by a zinc β-diiminate complex is reported. The chemoselective reaction results in linear amorphous polycarbonates that carry pendent methyloxiranes and exhibit glass transition temperatures (Tg) up

Nitrogen-Rich Porous Polymers for Carbon Dioxide and Iodine Sequestration for Environmental Remediation.

Science.gov (United States)

Abdelmoaty, Yomna H; Tessema, Tsemre-Dingel; Choudhury, Fatema Akthar; El-Kadri, Oussama M; El-Kaderi, Hani M

2018-05-09

The use of fossil fuels for energy production is accompanied by carbon dioxide release into the environment causing catastrophic climate changes. Meanwhile, replacing fossil fuels with carbon-free nuclear energy has the potential to release radioactive iodine during nuclear waste processing and in case of a nuclear accident. Therefore, developing efficient adsorbents for carbon dioxide and iodine capture is of great importance. Two nitrogen-rich porous polymers (NRPPs) derived from 4-bis-(2,4-diamino-1,3,5-triazine)-benzene building block were prepared and tested for use in CO 2 and I 2 capture. Copolymerization of 1,4-bis-(2,4-diamino-1,3,5-triazine)-benzene with terephthalaldehyde and 1,3,5-tris(4-formylphenyl)benzene in dimethyl sulfoxide at 180 °C afforded highly porous NRPP-1 (SA BET = 1579 m 2 g -1 ) and NRPP-2 (SA BET = 1028 m 2 g -1 ), respectively. The combination of high nitrogen content, π-electron conjugated structure, and microporosity makes NRPPs very effective in CO 2 uptake and I 2 capture. NRPPs exhibit high CO 2 uptakes (NRPP-1, 6.1 mmol g -1 and NRPP-2, 7.06 mmol g -1 ) at 273 K and 1.0 bar. The 7.06 mmol g -1 CO 2 uptake by NRPP-2 is the second highest value reported to date for porous organic polymers. According to vapor iodine uptake studies, the polymers display high capacity and rapid reversible uptake release for I 2 (NRPP-1, 192 wt % and NRPP-2, 222 wt %). Our studies show that the green nature (metal-free) of NRPPs and their effective capture of CO 2 and I 2 make this class of porous materials promising for environmental remediation.

Modelling interactions of carbon dioxide, forests, and climate

International Nuclear Information System (INIS)

Luxmoore, R.J.; Baldocchi, D.D.

1994-01-01

Atmospheric carbon dioxide is rising and forests and climate is changing exclamation point This combination of fact and premise may be evaluated at a range of temporal and spatial scales with the aid of computer simulators describing the interrelationships between forest vegetation, litter and soil characteristics, and appropriate meteorological variables. Some insights on the effects of climate on the transfers of carbon and the converse effect of carbon transfer on climate are discussed as a basis for assessing the significance of feedbacks between vegetation and climate under conditions of rising atmospheric carbon dioxide. Three main classes of forest models are reviewed. These are physiologically-based models, forest succession simulators based on the JABOWA model, and ecosystem-carbon budget models that use compartment transfer rates with empirically estimated coefficients. Some regression modeling approaches are also outlined. Energy budget models applied to forests and grasslands are also reviewed. This review presents examples of forest models; a comprehensive discussion of all available models is not undertaken

Conceptual Design of On-line Based Licensing Review and Assesment System of Nuclear Installations and Nuclear Materials ('PRIBEN')

International Nuclear Information System (INIS)

Melani, Ai; Chang, Soon Heung

2008-01-01

At the present Indonesia has no nuclear power plant in operation yet, although it is expected that the first nuclear power plant will be operated and commercially available in around the year of 2016 to 2017 in Muria Peninsula. There are only three research reactors, one nuclear fuel fabrication plant for research reactors, and one experimental fuel fabrication plant for nuclear power, one isotope production facility and some other research facilities. All the facility is under Nuclear Energy Regulatory Agency (BAPETEN) controlling through regulation, licensing and inspection. The organizations operation submits licensing application to BAPETEN before utilizing the facility. According to the regulation before BAPETEN give license they perform review and assessment for the utility application. Based on the review and assessment result, BAPETEN may stipulate, reject, delay or terminate the license. In anticipation of expansion of the nuclear program in Indonesia, BAPETEN should have an integrated and updated system for review and asses the licensing application. For this reason, an expert system for the review and asses the licensing application, so-called PRIBEN (Perizinan Reaktor, Instalasi dan Bahan Nuklir/Licensing of Reactor, Nuclear Installations and Nuclear Materials), is developed which runs on the online-based reality environment

Feedback mechanisms in the climate system affecting future levels of carbon dioxide

International Nuclear Information System (INIS)

Kellogg, W.W.

1983-01-01

The rate of increase of concentration of atmospheric carbon dioxide depends on the consumption of fossil fuels (the major source of 'new' carbon dioxide) and the natural sinks for this trace constituent, primarily the oceans and the biosphere. (It is now fairly well established that the biosphere cannot be a major source, as has been claimed.) The rate of operation of these sinks depends on several factors determined by the state of the climate system, and they will therefore presumably change as the greenhouse effect of increasing carbon dioxide warms the earth. Five specific feedback loops are discussed, two of which are positive (amplifying the rate of increase), two are weakly negative (damping the rate of increase), and one is indeterminate but probably positive. It is concluded that it would be well to be prepared for the possibility that carbon dioxide may increase faster than predicted by models based on the current or past state of the climate system

Applications of computer based safety systems in Korea nuclear power plants

International Nuclear Information System (INIS)

Won Young Yun

1998-01-01

With the progress of computer technology, the applications of computer based safety systems in Korea nuclear power plants have increased rapidly in recent decades. The main purpose of this movement is to take advantage of modern computer technology so as to improve the operability and maintainability of the plants. However, in fact there have been a lot of controversies on computer based systems' safety between the regulatory body and nuclear utility in Korea. The Korea Institute of Nuclear Safety (KINS), technical support organization for nuclear plant licensing, is currently confronted with the pressure to set up well defined domestic regulatory requirements from this aspect. This paper presents the current status and the regulatory activities related to the applications of computer based safety systems in Korea. (author)

A metal-free electrocatalyst for carbon dioxide reduction to multi-carbon hydrocarbons and oxygenates

Science.gov (United States)

Wu, Jingjie; Ma, Sichao; Sun, Jing; Gold, Jake I.; Tiwary, Chandrasekhar; Kim, Byoungsu; Zhu, Lingyang; Chopra, Nitin; Odeh, Ihab N.; Vajtai, Robert; Yu, Aaron Z.; Luo, Raymond; Lou, Jun; Ding, Guqiao; Kenis, Paul J. A.; Ajayan, Pulickel M.

2016-12-01

Electroreduction of carbon dioxide into higher-energy liquid fuels and chemicals is a promising but challenging renewable energy conversion technology. Among the electrocatalysts screened so far for carbon dioxide reduction, which includes metals, alloys, organometallics, layered materials and carbon nanostructures, only copper exhibits selectivity towards formation of hydrocarbons and multi-carbon oxygenates at fairly high efficiencies, whereas most others favour production of carbon monoxide or formate. Here we report that nanometre-size N-doped graphene quantum dots (NGQDs) catalyse the electrochemical reduction of carbon dioxide into multi-carbon hydrocarbons and oxygenates at high Faradaic efficiencies, high current densities and low overpotentials. The NGQDs show a high total Faradaic efficiency of carbon dioxide reduction of up to 90%, with selectivity for ethylene and ethanol conversions reaching 45%. The C2 and C3 product distribution and production rate for NGQD-catalysed carbon dioxide reduction is comparable to those obtained with copper nanoparticle-based electrocatalysts.

A metal-free electrocatalyst for carbon dioxide reduction to multi-carbon hydrocarbons and oxygenates

Science.gov (United States)

Wu, Jingjie; Ma, Sichao; Sun, Jing; Gold, Jake I.; Tiwary, ChandraSekhar; Kim, Byoungsu; Zhu, Lingyang; Chopra, Nitin; Odeh, Ihab N.; Vajtai, Robert; Yu, Aaron Z.; Luo, Raymond; Lou, Jun; Ding, Guqiao; Kenis, Paul J. A.; Ajayan, Pulickel M.

2016-01-01

Electroreduction of carbon dioxide into higher-energy liquid fuels and chemicals is a promising but challenging renewable energy conversion technology. Among the electrocatalysts screened so far for carbon dioxide reduction, which includes metals, alloys, organometallics, layered materials and carbon nanostructures, only copper exhibits selectivity towards formation of hydrocarbons and multi-carbon oxygenates at fairly high efficiencies, whereas most others favour production of carbon monoxide or formate. Here we report that nanometre-size N-doped graphene quantum dots (NGQDs) catalyse the electrochemical reduction of carbon dioxide into multi-carbon hydrocarbons and oxygenates at high Faradaic efficiencies, high current densities and low overpotentials. The NGQDs show a high total Faradaic efficiency of carbon dioxide reduction of up to 90%, with selectivity for ethylene and ethanol conversions reaching 45%. The C2 and C3 product distribution and production rate for NGQD-catalysed carbon dioxide reduction is comparable to those obtained with copper nanoparticle-based electrocatalysts. PMID:27958290

Carbon dioxide: emissions and effects

Energy Technology Data Exchange (ETDEWEB)

Smith, I M

1982-01-01

This review provides a comprehensive guide to work carried out since 1978 in the many disciplines involved in this complex issue. Possible scenarios for carbon dioxide emissions, sources and sinks in the carbon cycle and for climatic changes are examined. The current concensus (by no means unanimous) of specialists on this issue appears to be that a continuation of reduced trends in energy consumption since 1973 is likely to double the atmospheric carbon dioxide concentration to 600 ppmv during the latter part of the next century. However, a higher demand scenario, requiring an upper limit of coal production, would bring forward the doubling to about the middle of the next century. Current climatic models predict that such a concentration of carbon dioxide would cause an average global warming of from 1.0 to 4.5/sup 0/C which might be delayed by the thermal inertia of the oceans. A warming due to estimated increases in carbon dioxide should, if the model results are correct, become apparent at the end of this century. Regional climatic changes are likely to vary considerably and prove disadvantageous to some regions and beneficial to others. Different strategies for dealing with the carbon dioxide issue are considered: no response, alleviation, countermeasures and prevention. It is concluded that uncertainties do not justify either the use of carbon dioxide disposal and other technical fixes at present or a policy of no further growth in fossil fuel consumption. On the other hand, major efforts to conserve energy would give more time to adapt to changes. The alleviation of climatic impacts and other desirable dual-benefit measures are advocated in addition to continuing international, interdisciplinary research on all aspects.

Forecasting carbon dioxide emissions based on a hybrid of mixed data sampling regression model and back propagation neural network in the USA.

Science.gov (United States)

Zhao, Xin; Han, Meng; Ding, Lili; Calin, Adrian Cantemir

2018-01-01

The accurate forecast of carbon dioxide emissions is critical for policy makers to take proper measures to establish a low carbon society. This paper discusses a hybrid of the mixed data sampling (MIDAS) regression model and BP (back propagation) neural network (MIDAS-BP model) to forecast carbon dioxide emissions. Such analysis uses mixed frequency data to study the effects of quarterly economic growth on annual carbon dioxide emissions. The forecasting ability of MIDAS-BP is remarkably better than MIDAS, ordinary least square (OLS), polynomial distributed lags (PDL), autoregressive distributed lags (ADL), and auto-regressive moving average (ARMA) models. The MIDAS-BP model is suitable for forecasting carbon dioxide emissions for both the short and longer term. This research is expected to influence the methodology for forecasting carbon dioxide emissions by improving the forecast accuracy. Empirical results show that economic growth has both negative and positive effects on carbon dioxide emissions that last 15 quarters. Carbon dioxide emissions are also affected by their own change within 3 years. Therefore, there is a need for policy makers to explore an alternative way to develop the economy, especially applying new energy policies to establish a low carbon society.

NMR-based metabonomic study of the sub-acute toxicity of titanium dioxide nanoparticles in rats after oral administration

Science.gov (United States)

Bu, Qian; Yan, Guangyan; Deng, Pengchi; Peng, Feng; Lin, Hongjun; Xu, Youzhi; Cao, Zhixing; Zhou, Tian; Xue, Aiqin; Wang, Yanli; Cen, Xiaobo; Zhao, Ying-Lan

2010-03-01

As titanium dioxide nanoparticles (TiO2 NPs) are widely used commercially, their potential toxicity on human health has attracted particular attention. In the present study, the oral toxicological effects of TiO2 NPs (dosed at 0.16, 0.4 and 1 g kg - 1, respectively) were investigated using conventional approaches and metabonomic analysis in Wistar rats. Serum chemistry, hematology and histopathology examinations were performed. The urine and serum were investigated by 1H nuclear magnetic resonance (NMR) using principal components and partial least squares discriminant analysis. The metabolic signature of urinalysis in TiO2 NP-treated rats showed increases in the levels of taurine, citrate, hippurate, histidine, trimethylamine-N-oxide (TMAO), citrulline, α-ketoglutarate, phenylacetylglycine (PAG) and acetate; moreover, decreases in the levels of lactate, betaine, methionine, threonine, pyruvate, 3-D-hydroxybutyrate (3-D-HB), choline and leucine were observed. The metabonomics analysis of serum showed increases in TMAO, choline, creatine, phosphocholine and 3-D-HB as well as decreases in glutamine, pyruvate, glutamate, acetoacetate, glutathione and methionine after TiO2 NP treatment. Aspartate aminotransferase (AST), creatine kinase (CK) and lactate dehydrogenase (LDH) were elevated and mitochondrial swelling in heart tissue was observed in TiO2 NP-treated rats. These findings indicate that disturbances in energy and amino acid metabolism and the gut microflora environment may be attributable to the slight injury to the liver and heart caused by TiO2 NPs. Moreover, the NMR-based metabolomic approach is a reliable and sensitive method to study the biochemical effects of nanomaterials.

NMR-based metabonomic study of the sub-acute toxicity of titanium dioxide nanoparticles in rats after oral administration

International Nuclear Information System (INIS)

Bu Qian; Lin Hongjun; Xu Youzhi; Cao Zhixing; Zhou Tian; Zhao Yinglan; Yan Guangyan; Cen Xiaobo; Deng Pengchi; Peng Feng; Xue Aiqin; Wang Yanli

2010-01-01

As titanium dioxide nanoparticles (TiO 2 NPs) are widely used commercially, their potential toxicity on human health has attracted particular attention. In the present study, the oral toxicological effects of TiO 2 NPs (dosed at 0.16, 0.4 and 1 g kg -1 , respectively) were investigated using conventional approaches and metabonomic analysis in Wistar rats. Serum chemistry, hematology and histopathology examinations were performed. The urine and serum were investigated by 1 H nuclear magnetic resonance (NMR) using principal components and partial least squares discriminant analysis. The metabolic signature of urinalysis in TiO 2 NP-treated rats showed increases in the levels of taurine, citrate, hippurate, histidine, trimethylamine-N-oxide (TMAO), citrulline, α-ketoglutarate, phenylacetylglycine (PAG) and acetate; moreover, decreases in the levels of lactate, betaine, methionine, threonine, pyruvate, 3-D-hydroxybutyrate (3-D-HB), choline and leucine were observed. The metabonomics analysis of serum showed increases in TMAO, choline, creatine, phosphocholine and 3-D-HB as well as decreases in glutamine, pyruvate, glutamate, acetoacetate, glutathione and methionine after TiO 2 NP treatment. Aspartate aminotransferase (AST), creatine kinase (CK) and lactate dehydrogenase (LDH) were elevated and mitochondrial swelling in heart tissue was observed in TiO 2 NP-treated rats. These findings indicate that disturbances in energy and amino acid metabolism and the gut microflora environment may be attributable to the slight injury to the liver and heart caused by TiO 2 NPs. Moreover, the NMR-based metabolomic approach is a reliable and sensitive method to study the biochemical effects of nanomaterials.

Analysis of energy consumption and carbon dioxide emissions in ceramic tile manufacture

International Nuclear Information System (INIS)

Monfort, E.; Mezquita, A.; Granel, R.; Vaquer, E.; Escrig, A.; Miralles, A.; Zaera, V.

2010-01-01

The ceramic tile manufacturing process is energy intensive since it contains several stages in which the product is subject to thermal treatment. The thermal energy used in the process is usually obtained by combustion of natural gas, which is a fossil fuel whose oxidation produces emissions of carbon dioxide, a greenhouse gas. Energy costs account for 15% of the average direct manufacturing costs, and are strongly influenced by the price of natural gas, which has increased significantly in the last few years. Carbon dioxide emissions are internationally monitored and controlled in the frame of the Kyoto Protocol. Applicable Spanish law is based on the European Directive on emissions trading, and the assignment of emissions rights is based on historical values in the sectors involved. Legislation is scheduled to change in 2013, and the resulting changes will directly affect the Spanish ceramic tile manufacturing industry, since many facilities will become part of the emissions trading system. The purpose of this study is to determine current thermal energy consumption and carbon dioxide emissions in the ceramic tile manufacturing process. A comprehensive sectoral study has been carried out for this purpose on several levels: the first analyses energy consumption and carbon dioxide emissions in the entire industry; the second determines energy consumption and carbon dioxide emissions in industrial facilities over a long period of time (several months); while the third level breaks down these values, determining energy consumption and emissions in terms of the product made and the manufacturing stage. (Author) 8 refs.

Reducing regulatory and economic uncertainty in the next generation of U.S. nuclear power plants

International Nuclear Information System (INIS)

Simard, R.L.; Bell, R.J.

1998-01-01

Nuclear Power Plants have accounted for 40% of all new electricity supplied in the last 25 years. Nuclear energy and coal fired plants together account for approximately three quarters of the current electricity supply.In addition to assuring reliability and diversity of energy supply, U.S. nuclear plants proved their value in another critical area of the national energy policy-managing environmental impacts.Since 1973, the use of nuclear energy in lieu of fossil fuels has prevented the emission of more than 2 billion tons of carbon in the form of carbon dioxide, 80 million tons of sulfur dioxide and 35 million tons of nitrogen oxides. Now looking ahead to the next 25 years, the challenge is to maintain reliability of energy supply, while meeting increasingly urgent needs to minimize environmental impacts from the electricity sector. Fossil fired power plants face increasing regulatory requirements and constraints on emissions.The response to the challenges of the future must include aggressive development of renewable energy sources and increased reliance on nuclear energy-the only non-emitting sources of electricity available for deployment in the near term.(DM)

Nuclear based diagnostics in high-power laser applications

Energy Technology Data Exchange (ETDEWEB)

Guenther, Marc; Sonnabend, Kerstin; Harres, Knut; Otten, Anke; Roth, Markus [TU Darmstadt, Institut fuer Kernphysik, Darmstadt (Germany); Vogt, Karsten; Bagnoud, Vincent [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany)

2010-07-01

High-power lasers allow focused intensities of >10{sup 18} W/cm{sup 2}. During the laser-solid interaction, an intense relativistic electron current is injected from the plasma into the target. One challenge is to characterize the electron dynamic close to the interaction region. Moreover, next generation high-power laser proton acceleration leads to high proton fluxes, which require novel, nuclear diagnostic techniques. We present an activation-based nuclear pyrometry for the investigation of electrons generated in relativistic laser-solid interactions. We use novel activation targets consisting of several isotopes with different photo-neutron disintegration thresholds. The electrons are decelerated inside the target via bremsstrahlung processes. The high-energy bremsstrahlung induces photo-nuclear reactions. In this energy range no disturbing low energy effects are important. Via the pyrometry the Reconstruction of the absolute yield, spectral and spatial distribution of the electrons is possible. For the characterization of proton beams we present a nuclear activation imaging spectroscopy (NAIS). The diagnostic is based on proton-neutron disintegration reactions of copper stacked in consecutive layers. An autoradiography of copper layers leads to spectrally and spatially reconstruction of the beam profile.

Nuclear power and the greenhouse effect

International Nuclear Information System (INIS)

Donaldson, D; Tolland, H.; Grimston, M.

1990-01-01

The greenhouse effect is first explained. The evidence is shown in global warming and changing weather patterns which are generally believed to be due to the emission of greenhouse gases, including carbon dioxide. Serious consequences are predicted if emission of the greenhouse gases is not reduced. Sources of these gases are identified - agriculture, carbon fluorocarbons, coal-fired power stations, vehicle exhausts. The need is to use energy more efficiently but such measures as combined heat and power stations, more fuel efficient cars and better thermal insulation in homes is advocated. The expansion of renewable energy sources such as wind and water power is also suggested. Nuclear power is promoted as it reduces the carbon dioxide emissions and in both the short and long-term will reduce the emission of greenhouse gases. (author)

Modeling of carbon dioxide absorption by aqueous ammonia solutions using the Extended UNIQUAC model

DEFF Research Database (Denmark)

Darde, Victor Camille Alfred; van Well, Willy J. M.; Stenby, Erling Halfdan

2010-01-01

An upgraded version of the Extended UNIQUAC thermodynamic model for the carbon dioxide-ammonia-water system has been developed, based on the original version proposed by Thomsen and Rasmussen. The original model was valid in the temperature range 0-110°C, the pressure range 0-10 MPa...... properties of carbon dioxide and ammonia to supercritical conditions....

Polymorph-dependent titanium dioxide nanoparticle dissolution in acidic and alkali digestions

Science.gov (United States)

Multiple polymorphs (anatase, brookite and rutile) of titanium dioxide nanoparticles (TiO2-NPs) with variable structures were quantified in environmental matrices via microwave-based hydrofluoric (HF) and nitric (HNO3) mixed acid digestion and muffle furnace (MF)-based potassium ...

Nuclear fuel supply view in Argentina

International Nuclear Information System (INIS)

Cirimello, R.O.

1997-01-01

The Argentine Atomic Energy Commission promoted and participated in a unique achievement in the R and D system in Argentina: the integration of science technology and production based on a central core of knowledge for the control and management of the nuclear fuel cycle technology. CONUAR SA, as a fuel manufacturer, FAE SA, the manufacturer of Zircaloy tubes, CNEA and now DIOXITEC SA producer of Uranium Dioxide, have been supply, in the last ten years, the amount of products required for about 1300 Tn of equivalent U content in fuels. The most promising changes for the fuel cycle economy is the Slight Enriched Uranium project which begun in Atucha I reactor. In 1997 seventy five fuel assemblies, equivalent to 900 Candu fuel bundles, will complete its irradiation. (author)

A new fluidized bed nuclear reactor

International Nuclear Information System (INIS)

Sefidvash, F.

1986-01-01

A new nuclear reactor design based on the fluidized bed concept is proposed. A current design utilizes spherical fuel of slightly enriched Zircaloy-clad uranium dioxide fluidized by light water under pressure. The reactor is modular in system; therefore, any size reactor can be constructed from the basic standard modul. The reactor physics calculations show that reactivity increases with porosity to a maximum value and thereafter decreases. This produces inherent safety and eliminates the need for control rods and burnable poisons. The heat transfer calculations show that the maximum power extracted from the reactor core is not limited to the material temperature limits but to the maximum mass flow of coolant, which corresponds to the desired operating porosity. Design simplicity and inherent safety make it an attractive small reactor design. (Author) [pt

Global warming---The role for nuclear power

International Nuclear Information System (INIS)

Jones, J.E. Jr.; Fulkerson, W.

1989-01-01

Nuclear power is currently making an important contribution to our energy requirements. It provides 17% of the world's electricity today --- almost 20% in the US. Reducing the emissions of carbon dioxide over the next 30 to 50 years sufficiently to address the issue of global warming can only be accomplished by a combination of much improved energy efficiency, substantial growth in use of nuclear power, and substantial growth in use of renewable energy. This paper discusses new initiatives in the major nuclear technologies (LWR, HTGR, LMR) which are emerging from a fundamental reexamination of nuclear power in response to the challenges and opportunities in the 21st century. To fulfill its role, nuclear power must gain worldwide acceptance as a viable energy option. The use of modern technology and ''passive'' safety features in next-generation nuclear power plants offers the potential to simplify their design and operation, enhance their safety, and reduce the cost of electricity. With such improvements, we believe nuclear power can regain public confidence and make a significant contribution to our energy future. 24 refs., 2 figs., 1 tab

Data base on nuclear power plant dose reduction research projects

Energy Technology Data Exchange (ETDEWEB)

Khan, T.A.; Baum, J.W.

1986-10-01

Staff at the ALARA Center of Brookhaven National Laboratory have established a data base of information about current research that is likely to result in lower radiation doses to workers. The data base, concerned primarily with nuclear power generation, is part of a project that the ALARA Center is carrying out for the Nuclear Regulatory Commission. This report describes its current status. A substantial amount of research on reducing occupational exposure is being done in the US and abroad. This research is beginning to have an impact on the collective dose expenditures at nuclear power plants. The collective radiation doses in Europe, Japan, and North America all show downward trends. A large part of the research in the US is either sponsored by the nuclear industry through joint industry organizations such as EPRI and ESEERCO or is done by individual corporations. There is also significant participation by smaller companies. The main emphasis of the research on dose reduction is on engineering approaches aimed at reducing radiation fields or keeping people out of high-exposure areas by using robotics. Effective ALARA programs are also underway at a large number of nuclear plants. Additional attention should be given to non-engineering approaches to dose reduction, which are potentially very useful and cost effective but require quantitative study and analysis based on data from nuclear power plants. 9 refs., 1 fig.

Extraction of cobalt ion from textile using a complexing macromolecular surfactant in supercritical carbon dioxide

International Nuclear Information System (INIS)

Chirat, Mathieu; Ribaut, Tiphaine; Clerc, Sebastien; Lacroix-Desmazes, Patrick; Charton, Frederic; Fournel, Bruno

2013-01-01

Cobalt ion under the form of cobalt nitrate is removed from a textile lab coat using supercritical carbon dioxide extraction. The process involves a macromolecular additive of well-defined architecture, acting both as a surfactant and a complexing agent. The extraction efficiency of cobalt reaches 66% when using a poly(1,1,2,2-tetrahydroperfluoro-decyl-acrylate-co-vinyl-benzylphosphonic diacid) gradient copolymer in the presence of water at 160 bar and 40 C. The synergy of the two additives, namely the copolymer and water which are useless if used separately, is pointed out. The potential of the supercritical carbon dioxide process using complexing macromolecular surfactant lies in the ability to modulate the complexing unit as a function of the metal as well as the architecture of the surface-active agent for applications ranging for instance from nuclear decontamination to the recovery of strategic metals. (authors)

Fixation of carbon dioxide by coral reef. Sangosho ni yoru CO2 no kotei

Energy Technology Data Exchange (ETDEWEB)

Yamamuro, M [Geological Survey of Japan, Tsukuba, Ibaraki (Japan)

1993-08-01

The methods for fixation of carbon dioxide in the atmosphere in order to control the greenhouse effect, are groped. Carbon is fixed through two ways such as the production of organic compounds by photosynthesis and formation of calcium carbonate by calcification. Among them, the photosynthesis fixes carbon dioxide in the air, and calcification, on thinking of only chemical equilibrium in the sea water, is a process to exhaust carbon dioxide from ocean to the atmosphere. It is, therefore, uneven in opinions of researchers if the coral reef is an absorbing source or an exhausting one of carbon dioxide. A conventional discussion on this theme, did not carry out based on the actual search or measurement, but preceded on modelling. In order, therefore, to introduce a scientific decision on a play of the coral reef for the global carbon circulation, it seems to take more time. In this paper, an opinion that the coral reef is an absorbing source of carbon dioxide in the air according to some measuring results of carbon dioxide fixation velocity and organic compounds volume in sediments in the coral reefs, are described. 11 refs., 4 figs.

The role of nuclear power in the option zero emission technologies for fossil fuels

International Nuclear Information System (INIS)

Corak, Z.

2006-01-01

The energy sector is one of the main sources of greenhouse gas (GHG) emissions particularly carbon dioxide (CO2) increasing concerns due to their potential risk to induce global warming and climate change. The Parties having signed the Kyoto Protocol in December 1997, committed to decrease their GHG emissions. The Protocol states that countries shall undertake promotion, research, development and increased use of new and renewable forms of energy, of carbon dioxide sequestration technologies and of advanced and innovative environmentally sound technologies. The one significant option that is not specifically mentioned is nuclear energy which is essentially carbon-free. There are a number of technical options that could help reducing, or at least slowing the increase of, GHG emissions from the energy sector. The list of options includes: improving the efficiency of energy conversion and end-use processes; shifting to less carbon intensive energy sources (e.g. shifting from coal to natural gas); developing carbon-free or low-carbon energy sources; and carbon sequestration (e.g. planting forests or capturing and storing carbon dioxide). It must be pointed out that nuclear power is one of the few options that are currently available on the market, competitive in a number of countries, especially if global costs to society of alternative options are considered; practically carbon-free; and sustainable at large-scale deployment. The nuclear power could play significant role in alleviating the risk of global climate change. The main objective of the article is to present sequestration options, their cost evaluation as well as comparation with alternative possibilities of nuclear energy production. (author)

A web-based course in nuclear and radiochemistry

International Nuclear Information System (INIS)

Landsberger, S.; Plionis, A.

2009-01-01

Over the last six years through a Department of Energy Radiochemistry Education Award Program (REAP) we have developed a completely webbased course in nuclear and radiochemistry given at the University of Texas at Austin. This course has had nuclear and radiation engineering and chemistry graduate students. While the course also has an extensive laboratory component only the lectures are web based. The lectures begin with a historical introduction of radiochemistry followed by two movies on Madame Curie. This is followed by the usual lectures on radioactivity, fundamental properties, radioactive decay, decay modes, and nuclear reactions. As section on radioactive waste management and nuclear fuel cycle is also presented. Lectures in neutron activation analysis, geo- and cosmochemistry, and plutonium chemistry have also been developed. All lectures are in power point with many animations and a significant number of solved problems. All students are required to make a short oral presentation on some aspect of nuclear and radiochemistry in their research or a chosen topic. (author)

Uranium Dioxide Powder Flow ability Improvement Using Sol-Gel

International Nuclear Information System (INIS)

Juanda, D.; Sambodo Daru, G.

1998-01-01

The improvement of flow ability characteristics of uranium dioxide powder has been done using sol-gel process. To anticipate a pellet mass production with uniform pellet dimension, the uranium dioxide powder must be have a spherical form. Uranium dioxide spherical powder has been diluted in acid transformed into sol colloidal solution. To obtain uranium dioxide spherical form, the uranium sol-colloidal solution has been dropped in a hot paraffin ( at the temperature of 90 0 C) to form gelatinous colloid and then dried at 800 0 C, and sintered at the temperature of 1700 0 C. The flow ability of spherical uranium dioxide powder has been examined by using Flowmeter Hall (ASTM. B. 213-46T). The measurement result reveals that the spherical uranium dioxide powder has a flow ability twice than that of unprocessed uranium dioxide powder

CFD study on the supercritical carbon dioxide cooled pebble bed reactor

Energy Technology Data Exchange (ETDEWEB)

Yu, Dali, E-mail: ydlmitd@outlook.com; Peng, Minjun; Wang, Zhongyi

2015-01-15

Highlights: • An innovation concept of supercritical carbon dioxide cooled pebble bed reactor is proposed. • Body-centered cuboid (BCCa) arrangement is adopted for the pebbles. • S-CO{sub 2} would be a good candidate coolant for using in pebble bed reactor. - Abstract: The thermal hydraulic study of using supercritical carbon dioxide (S-CO{sub 2}), a superior fluid state brayton cycle medium, in pebble bed type nuclear reactor is assessed through computational fluid dynamics (CFD) methodology. Preliminary concept design of this S-CO{sub 2} cooled pebble bed reactor (PBR) is implemented by the well-known KTA heat transfer correlation and Ergun pressure drop equation. Eddy viscosity transport turbulence model is adopted and verified by KTA calculated results. Distributions of the temperature, velocity, pressure and Nusselt (Nu) number of the coolant near the surface of the middle spherical fuel element are obtained and analyzed. The conclusion of the assessment is that S-CO{sub 2} would be a good candidate coolant for using in pebble bed reactor due primarily to its good heat transfer characteristic and large mass density, which could lead to achieve lower pressure drop and higher power density.

Nuclear engineering education: A competence based approach to curricula development

International Nuclear Information System (INIS)

2014-01-01

Maintaining nuclear competencies in the nuclear industry is a one of the most critical challenges in the near future. With the development of a number of nuclear engineering educational programmes in several States, this publication provides guidance to decision makers in Member States on a competence based approach to curricula development, presenting the established practices and associated requirements for educational programmes in this field. It is a consolidation of best practices that will ensure sustainable, effective nuclear engineering programmes, contributing to the safe, efficient and economic operation of nuclear power plants. The information presented is drawn from a variety of recognized nuclear engineering programmes around the world and contributes to the main areas that are needed to ensure a viable and robust nuclear industry

Historical civilian nuclear accident based Nuclear Reactor Condition Analyzer

Science.gov (United States)

McCoy, Kaylyn Marie

There are significant challenges to successfully monitoring multiple processes within a nuclear reactor facility. The evidence for this observation can be seen in the historical civilian nuclear incidents that have occurred with similar initiating conditions and sequences of events. Because there is a current lack within the nuclear industry, with regards to the monitoring of internal sensors across multiple processes for patterns of failure, this study has developed a program that is directed at accomplishing that charge through an innovation that monitors these systems simultaneously. The inclusion of digital sensor technology within the nuclear industry has appreciably increased computer systems' capabilities to manipulate sensor signals, thus making the satisfaction of these monitoring challenges possible. One such manipulation to signal data has been explored in this study. The Nuclear Reactor Condition Analyzer (NRCA) program that has been developed for this research, with the assistance of the Nuclear Regulatory Commission's Graduate Fellowship, utilizes one-norm distance and kernel weighting equations to normalize all nuclear reactor parameters under the program's analysis. This normalization allows the program to set more consistent parameter value thresholds for a more simplified approach to analyzing the condition of the nuclear reactor under its scrutiny. The product of this research provides a means for the nuclear industry to implement a safety and monitoring program that can oversee the system parameters of a nuclear power reactor facility, like that of a nuclear power plant.

Method of production of granulates of ceramic nuclear fuels

International Nuclear Information System (INIS)

Wilkinson, W.L.

1975-01-01

To obtain a classified granulate of ceramic nuclear fuels with narrow grain size spectrum, the nuclear fuel powder is made into a slurry in a non-aqueous solvent with a water content as low as possible (e.g. chlorated hydrocarbon), a binder added to it, and spray-dried. The dry granulate desired is already obtained by this working stage. Polybutyl methacrylate in dibutylphthalate is proposed as binder. An example in which uranium dioxide powder is slurried in trichloro-ethylene is described in detail. (UWI/LH) [de

A review on the status of development in thorium-based nuclear fuels

International Nuclear Information System (INIS)

Lee, Young Woo; Na, S. H.; Lee, Y. W.; Kim, H. S.; Kim, S. H.; Joung, C.Y.

2000-02-01

Thorium as an alternative nuclear energy source had been widely investigated in the 1950s-1960s because it is more abundant than uranium, but the studies of thorium nuclear fuel cycle were discontinued by political and economic reasons in the 1970s. Recently, however, renewed interest was vested in thorium-based nuclear fuel cycle because it may generate less long-lived minor actinides and has a lower radiotoxicity of high level wastes after reprocessing compared with the thorium fuel cycle. In this state-of the art report, thorium-based nuclear cycle. In this state-of the art report, thorium-based nuclear fuel cycle and fuel fabrication processes developed so far with different reactor types are reviewed and analyzed to establish basic technologies of thorium fuel fabrication which could meet our situation. (author)

The roles and functions of a lunar base Nuclear Technology Center

International Nuclear Information System (INIS)

Buden, D.; Angelo, J.A. Jr.

1991-01-01

This paper describes the roles and functions of a special Nuclear Technology Center which is developed as an integral part of a permanent lunar base. Numerous contemporary studies clearly point out that nuclear energy technology will play a major role in any successful lunar/Mars initiative program and in the overall establishment of humanity's solar system civilization. The key role of nuclear energy in the providing power has been recognized. A Nuclear Technology Center developed as part of of a permanent lunar base can also help bring about many other nuclear technology applications, such as producing radioisotopes for self-illumination, food preservation, waste sterilization, and medical treatment; providing thermal energy for mining, materials processing and agricultural; and as a source of emergency habitat power. Designing such a center will involve the deployment, operation, servicing and waste product management and disposal of megawatt class reactor power plants. This challenge must be met with a minimum of direct human support at the facility. Furthermore, to support the timely, efficient integration of this Nuclear Technology Center in the evolving lunar base infrastructure, an analog of such a facility will be needed here on Earth. 12 refs., 4 figs., 1 tab

Dissolution of uranium dioxide in supercritical carbon dioxide modified with tri-n-butyl phosphate-hydrogen peroxide

International Nuclear Information System (INIS)

Kanekar, A.S.; Pathak, P.N.; Mohapatra, P.K.; Manchanda, V.K.

2009-01-01

Direct dissolution of uranium dioxide in supercritical carbon dioxide modified with tri-n-butyl phosphate (TBP) has been attempted. The effects of TBP concentration and pressure on the extraction of uranium have been studied. Addition of hydrogen peroxide in the modifier enhances the dissolution/extraction of uranium. (author)

Piping support load data base for nuclear plants

International Nuclear Information System (INIS)

Childress, G.G.

1991-01-01

Nuclear Station Modifications are continuous through the life of a Nuclear Power Plant. The NSM often impacts an existing piping system and its supports. Prior to implementation of the NSM, the modified piping system is qualified and the qualification documented. This manual review process is tedious and an obvious bottleneck to engineering productivity. Collectively, over 100,000 piping supports exist at Duke Power Company's Nuclear Stations. Engineering support must maintain proper documentation of all data for each support. Duke Power Company has designed and developed a mainframe based system that: directly uses Support Load Summary data generated by a piping analysis computer program; streamlines the pipe support evaluation process; easily retrieves As-Built and NSM information for any pipe support from an NSM or AS-BUILT data base; and generated documentation for easy traceability of data to the information source. This paper discusses the design considerations for development of Support Loads Database System (SLDB) and reviews the program functionality through the user menus

Nitrogen dioxide exposures inside ice skating rinks.

Science.gov (United States)

Brauer, M; Spengler, J D

1994-01-01

OBJECTIVES. The common operation of fuel-powered resurfacing equipment in enclosed ice skating rinks has the potential for producing high concentrations of carbon monoxide and nitrogen dioxide. Exposures to these gaseous combustion products may adversely affect the health of those inside the rink. Little information is available on pollutant concentrations under normal operating conditions. METHODS. One-week average nitrogen dioxide concentrations in 70 northeastern US rinks were measured with passive samplers during normal winter season conditions. RESULTS. The median nitrogen dioxide level inside rinks was 180 ppb, more than 10 times higher than the median outdoor concentration. One-week average nitrogen dioxide concentrations above 1000 ppb were measured in 10% of the rinks. CONCLUSIONS. Considering that short-term peak concentrations were likely to have reached two to five times the measured 1-week averages, our results suggest that nitrogen dioxide levels were well above short-term air quality guidelines and constitute a public health concern of considerable magnitude. PMID:8129060

Capacitance-Assisted Sustainable Electrochemical Carbon Dioxide Mineralisation.

Science.gov (United States)

Lamb, Katie J; Dowsett, Mark R; Chatzipanagis, Konstantinos; Scullion, Zhan Wei; Kröger, Roland; Lee, James D; Aguiar, Pedro M; North, Michael; Parkin, Alison

2018-01-10

An electrochemical cell comprising a novel dual-component graphite and Earth-crust abundant metal anode, a hydrogen producing cathode and an aqueous sodium chloride electrolyte was constructed and used for carbon dioxide mineralisation. Under an atmosphere of 5 % carbon dioxide in nitrogen, the cell exhibited both capacitive and oxidative electrochemistry at the anode. The graphite acted as a supercapacitive reagent concentrator, pumping carbon dioxide into aqueous solution as hydrogen carbonate. Simultaneous oxidation of the anodic metal generated cations, which reacted with the hydrogen carbonate to give mineralised carbon dioxide. Whilst conventional electrochemical carbon dioxide reduction requires hydrogen, this cell generates hydrogen at the cathode. Carbon capture can be achieved in a highly sustainable manner using scrap metal within the anode, seawater as the electrolyte, an industrially relevant gas stream and a solar panel as an effective zero-carbon energy source. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

A framework for AI-based nuclear design support system

International Nuclear Information System (INIS)

Furuta, Kazuo; Kondo, Shunsuke

1991-01-01

Nowadays many computer programs are being developed and used for the analytic tasks in nuclear reactor design, but experienced designers are still responsible for most of the synthetic tasks which are not amenable to algorithmic computer processes. Artificial intelligence (AI) is a promising technology to deal with these intractable tasks in design. In development of AI-based design support systems, it is desirable to choose a comprehensive framework based on the scientific theory of design. In this work a framework for AI-based design support systems for nuclear reactor design will be proposed based on an exploration model of design. The fundamental architectures of this framework will be described especially on knowledge representation, context management and design planning. (author)

Research Progress in Carbon Dioxide Storage and Enhanced Oil Recovery

Science.gov (United States)

Wang, Keliang; Wang, Gang; Lu, Chunjing

2018-02-01

With the rapid development of global economy, human beings have become highly dependent upon fossil fuel such as coal and petroleum. Much fossil fuel is consumed in industrial production and human life. As a result, carbon dioxide emissions have been increasing, and the greenhouse effects thereby generated are posing serious threats to environment of the earth. These years, increasing average global temperature, frequent extreme weather events and climatic changes cause material disasters to the world. After scientists’ long-term research, ample evidences have proven that emissions of greenhouse gas like carbon dioxide have brought about tremendous changes to global climate. To really reduce carbon dioxide emissions, governments of different countries and international organizations have invested much money and human resources in performing research related to carbon dioxide emissions. Manual underground carbon dioxide storage and carbon dioxide-enhanced oil recovery are schemes with great potential and prospect for reducing carbon dioxide emissions. Compared with other schemes for reducing carbon dioxide emissions, aforementioned two schemes exhibit high storage capacity and yield considerable economic benefits, so they have become research focuses for reducing carbon dioxide emissions. This paper introduces the research progress in underground carbon dioxide storage and enhanced oil recovery, pointing out the significance and necessity of carbon dioxide-driven enhanced oil recovery.

Adsorption of acids and bases from aqueous solutions onto silicon dioxide particles.

Science.gov (United States)

Zengin, Huseyin; Erkan, Belgin

2009-12-30

The adsorption of acids and bases onto the surface of silicon dioxide (SiO(2)) particles was systematically studied as a function of several variables, including activation conditions, contact time, specific surface area, particle size, concentration and temperature. The physical properties of SiO(2) particles were investigated, where characterizations were carried out by FT-IR spectroscopy, and morphology was examined by scanning electron microscopy (SEM). The SEM of samples showed good dispersion and uniform SiO(2) particles with an average diameter of about 1-1.5 microm. The adsorption results revealed that SiO(2) surfaces possessed effective interactions with acids and bases, and greatest adsorption capacity was achieved with NaOH, where the best fit isotherm model was the Freundlich adsorption model. The adsorption properties of raw SiO(2) particles were further improved by ultrasonication. Langmuir monolayer adsorption capacity of NaOH adsorbate at 25 degrees C on sonicated SiO(2) (182.6 mg/g) was found to be greater than that of the unsonicated SiO(2) (154.3mg/g). The spontaneity of the adsorption process was established by decreases in DeltaG(ads)(0), which varied from -10.5 to -13.6 kJ mol(-1), in the temperature range 283-338K.

The Probability of Tax Charges for Industrial Emission of Carbon Dioxide

International Nuclear Information System (INIS)

Arief-Goeritno

2000-01-01

Generally, although all industrial by product can be toxic and non-toxic pollutant that have potential hazard for human being and environmental. One of these pollutants is carbon dioxide that has potential contribution for greenhouse effect. Although carbon dioxide can be absorbed by plants at the forest but quantity of this emission more higher than quantity of forest area. For this reason rehabilitation of the forest and diversifications and energy saving can be used for decreasing of greenhouse effect. The synergy action such as economical instrumentation (specially microeconomics) can be implemented base on regulators, taxing and incentive and effluent charge by deeper assessment on environmental economics. By identification of quality and quantity fossil fuels that was burned in the industrial process so with stoichiometry calculation will be found quantity of carbon dioxide emission and the taxes can be estimated. (author)

Energy efficient solvent regeneration process for carbon dioxide capture

Science.gov (United States)

Zhou, Shaojun; Meyer, Howard S.; Li, Shiguang

2018-02-27

A process for removing carbon dioxide from a carbon dioxide-loaded solvent uses two stages of flash apparatus. Carbon dioxide is flashed from the solvent at a higher temperature and pressure in the first stage, and a lower temperature and pressure in the second stage, and is fed to a multi-stage compression train for high pressure liquefaction. Because some of the carbon dioxide fed to the compression train is already under pressure, less energy is required to further compress the carbon dioxide to a liquid state, compared to conventional processes.

Nuclear energy cost data base. A reference data base for nuclear and coal-fired powerplant power-generation cost analysis

International Nuclear Information System (INIS)

1982-10-01

A reference data base and standard methodology are needed for performing comparative nuclear and fossil power generation cost analyses for DOE/NE. Proposals are presented for such a methodology and for reference assumptions and data to be used with the methodology. This report is intended to provide basic guidelines or a starting point for analysis and to serve as a focal point in establishing parameters and methods to be used in economic comparisons of nuclear systems with alternatives. The data base is applicable for economic comparisons of new base-load light water reactors on either a current once-through cycle or self-generated recycle, high- and low-sulfur coal-fired plants, and oil and natural gas-fired electric generating plant coming on line in the last decade of this century. This paper includes a data base containing proposed technical and economic assumptions to be used in analyses, discussions of a recommended methodology to be used in calculating power generation costs, and a sample calculation for illustrative and benchmark purposes

[Sulfur dioxide limit standard and residues in Chinese medicinal materials].

Science.gov (United States)

Kang, Chuan-Zhi; Yang, Wan-Zhen; Mo, Ge; Zhou, Li; Jiang, Jing-Yi; Lv, Chao-Geng; Wang, Sheng; Zhou, Tao; Yang, Ye; Guo, Lan-Ping

2018-01-01

The traditional sulfur fumigation processing method has been widely used in the initial processing and storage of traditional Chinese medicinal materials due to its economy, efficiency, convenience, high operability and effect on mold and insect prevention. However, excessive sulfur fumigation of traditional Chinese medicinal materials would lead to the changes in chemical compositions, and even endanger human health. This study showed that traditional Chinese medicinal materials were sulfur fumigated directly after being harvested for quick drying, or fumigated after being weted in the storage process for preventing mold and insects. We found that the sulfur dioxide limits for traditional Chinese medicinal materials were stricter than those for foods. Based on the existing limit standards, we obtained the data of sulfur dioxide residues for 35 types of traditional Chinese medicinal materials in a total of 862 batches. According to the limit standard in the Chinese Pharmacopoeia (150， 400 mg·kg⁻¹), the average over-standard rate of sulfur dioxide was as high as 52.43%, but it was reduced to 29.47% if calculated based on the limit for vegetable additive standard (500 mg·kg⁻¹). Sulfur fumigation issue shall be considered correctly: sulfur dioxide is a type of low toxic substance and less dangerous than aflatoxin and other highly toxic substances, and a small amount of residue would not increase the toxicity of traditional Chinese medicinal materials. However, sulfur fumigation might change the content of chemical substances and affect the quality of traditional Chinese medicinal materials. Furthermore, the exposure hazards of toxic substances are comprehensively correlated with exposure cycle, exposure frequency, and application method. In conclusion, it is suggested to strengthen the studies on the limit standard of traditional Chinese medicinal materials, formulate practical and feasible limit standard for sulfur dioxide residues in traditional Chinese

Deposition of carbon dioxide

International Nuclear Information System (INIS)

2001-01-01

In Norway, there is currently a debate about whether or not to build gas power stations. To meet the possibility of reduced emission quotas for carbon dioxide in the future, current interest focuses on the incorporation of large-scale separation and deposition of carbon dioxide when such plants are planned. A group of experts concludes that this technology will become self-financing by means of environmental taxes. From the environmental point of view, taxes upon production are to be preferred over taxes on consumption

A Nuclear Safety System based on Industrial Computer

International Nuclear Information System (INIS)

Kim, Ji Hyeon; Oh, Do Young; Lee, Nam Hoon; Kim, Chang Ho; Kim, Jae Hack

2011-01-01

The Plant Protection System(PPS), a nuclear safety Instrumentation and Control (I and C) system for Nuclear Power Plants(NPPs), generates reactor trip on abnormal reactor condition. The Core Protection Calculator System (CPCS) is a safety system that generates and transmits the channel trip signal to the PPS on an abnormal condition. Currently, these systems are designed on the Programmable Logic Controller(PLC) based system and it is necessary to consider a new system platform to adapt simpler system configuration and improved software development process. The CPCS was the first implementation using a micro computer in a nuclear power plant safety protection system in 1980 which have been deployed in Ulchin units 3,4,5,6 and Younggwang units 3,4,5,6. The CPCS software was developed in the Concurrent Micro5 minicomputer using assembly language and embedded into the Concurrent 3205 computer. Following the micro computer based CPCS, PLC based Common-Q platform has been used for the ShinKori/ShinWolsong units 1,2 PPS and CPCS, and the POSAFE-Q PLC platform is used for the ShinUlchin units 1,2 PPS and CPCS. In developing the next generation safety system platform, several factors (e.g., hardware/software reliability, flexibility, licensibility and industrial support) can be considered. This paper suggests an Industrial Computer(IC) based protection system that can be developed with improved flexibility without losing system reliability. The IC based system has the advantage of a simple system configuration with optimized processor boards because of improved processor performance and unlimited interoperability between the target system and development system that use commercial CASE tools. This paper presents the background to selecting the IC based system with a case study design of the CPCS. Eventually, this kind of platform can be used for nuclear power plant safety systems like the PPS, CPCS, Qualified Indication and Alarm . Pami(QIAS-P), and Engineering Safety

A Nuclear Safety System based on Industrial Computer

Energy Technology Data Exchange (ETDEWEB)

Kim, Ji Hyeon; Oh, Do Young; Lee, Nam Hoon; Kim, Chang Ho; Kim, Jae Hack [Korea Electric Power Corporation Engineering and Construction, Daejeon (Korea, Republic of)

2011-05-15

The Plant Protection System(PPS), a nuclear safety Instrumentation and Control (I and C) system for Nuclear Power Plants(NPPs), generates reactor trip on abnormal reactor condition. The Core Protection Calculator System (CPCS) is a safety system that generates and transmits the channel trip signal to the PPS on an abnormal condition. Currently, these systems are designed on the Programmable Logic Controller(PLC) based system and it is necessary to consider a new system platform to adapt simpler system configuration and improved software development process. The CPCS was the first implementation using a micro computer in a nuclear power plant safety protection system in 1980 which have been deployed in Ulchin units 3,4,5,6 and Younggwang units 3,4,5,6. The CPCS software was developed in the Concurrent Micro5 minicomputer using assembly language and embedded into the Concurrent 3205 computer. Following the micro computer based CPCS, PLC based Common-Q platform has been used for the ShinKori/ShinWolsong units 1,2 PPS and CPCS, and the POSAFE-Q PLC platform is used for the ShinUlchin units 1,2 PPS and CPCS. In developing the next generation safety system platform, several factors (e.g., hardware/software reliability, flexibility, licensibility and industrial support) can be considered. This paper suggests an Industrial Computer(IC) based protection system that can be developed with improved flexibility without losing system reliability. The IC based system has the advantage of a simple system configuration with optimized processor boards because of improved processor performance and unlimited interoperability between the target system and development system that use commercial CASE tools. This paper presents the background to selecting the IC based system with a case study design of the CPCS. Eventually, this kind of platform can be used for nuclear power plant safety systems like the PPS, CPCS, Qualified Indication and Alarm . Pami(QIAS-P), and Engineering Safety

Nuclear winter - a calculative experiment

International Nuclear Information System (INIS)

Aleksandrov, V.B.; Stenchikov, G.L.

1985-01-01

Using a hydrodynamic model of the Earth climate the climatic consequences following carbon dioxide concentration augmentation in the Earth atmosphere, effects of aerosol contamination and solar constant variation due to the use of nuclear weapon are studied. Results of studying the sensitivity of average annual climatic regime of the atmosphere and ocean general circulation to a sudde extremely strong, long-term change in optical properties of the air in the short-wave portion of the spectrum are discussed. These changes could be caused by contamination of the atmosphere with dust during a nuclear conflict and soot resulting from fires. It is shown, that after nuclear war according to practically any scenario, people who would survive the first blow will find themselves in conditions of a severe cold, darkness, absence of water, food and fuel under the effect of a powerful radiation, contaminants, diseases and under extreme pycological stress

Philosophy and safety requirements for land-based nuclear installations

International Nuclear Information System (INIS)

Kellermann, Otto

1978-01-01

The main ideas of safety philosophy for land-based nuclear installations are presented together with their background of protection goals. Today's requirements for design and quality assurance are deductively shown. Finally a proposition is made for a new balancing of safety philosophy according to the high safety level that nuclear installations have reached

Experience with performance based training of nuclear criticality safety engineers

International Nuclear Information System (INIS)

Taylor, R.G.

1993-01-01

Historically, new entrants to the practice of nuclear criticality safety have learned their job primarily by on-the-job training (OJT) often by association with an experienced nuclear criticality safety engineer who probably also learned their job by OJT. Typically, the new entrant learned what he/she needed to know to solve a particular problem and accumulated experience as more problems were solved. It is likely that more formalism will be required in the future. Current US Department of Energy requirements for those positions which have to demonstrate qualification indicate that it should be achieved by using a systematic approach such as performance based training (PBT). Assuming that PBT would be an acceptable mechanism for nuclear criticality safety engineer training in a more formal environment, a site-specific analysis of the nuclear criticality safety engineer job was performed. Based on this analysis, classes are being developed and delivered to a target audience of newer nuclear criticality safety engineers. Because current interest is in developing training for selected aspects of the nuclear criticality safety engineer job, the analysis i's incompletely developed in some areas. Details of this analysis are provided in this report

Tropospheric nitrogen dioxide column retrieval based on ground-based zenith-sky DOAS observations

Science.gov (United States)

Tack, F. M.; Hendrick, F.; Pinardi, G.; Fayt, C.; Van Roozendael, M.

2013-12-01

A retrieval approach has been developed to derive tropospheric NO2 vertical column amounts from ground-based zenith-sky measurements of scattered sunlight. Zenith radiance spectra are observed in the visible range by the BIRA-IASB Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) instrument and analyzed by the DOAS technique, based on a least-squares spectral fitting. In recent years, this technique has shown to be a well-suited remote sensing tool for monitoring atmospheric trace gases. The retrieval algorithm is developed and validated based on a two month dataset acquired from June to July 2009 in the framework of the Cabauw (51.97° N, 4.93° E) Intercomparison campaign for Nitrogen Dioxide measuring Instruments (CINDI). Once fully operational, the retrieval approach can be applied to observations from stations of the Network for the Detection of Atmospheric Composition Change (NDACC). The obtained tropospheric vertical column amounts are compared with the multi-axis retrieval from the BIRA-IASB MAX-DOAS instrument and the retrieval from a zenith-viewing only SAOZ instrument (Système d'Analyse par Observations Zénithales), owned by Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS). First results show a good agreement for the whole time series with the multi-axis retrieval (R = 0.82; y = 0.88x + 0.30) as well as with the SAOZ retrieval (R = 0.85; y = 0.76x + 0.28 ). Main error sources arise from the uncertainties in the determination of tropospheric and stratospheric air mass factors, the stratospheric NO2 abundances and the residual amount in the reference spectrum. However zenith-sky measurements have been commonly used over the last decades for stratospheric monitoring, this study also illustrates the suitability for retrieval of tropospheric column amounts. As there are long time series of zenith-sky acquisitions available, the developed approach offers new perspectives with regard to the use of observations from the NDACC

World-Economy Centrality and Carbon Dioxide Emissions: A New Look at the Position in the Capitalist World-System and Environmental Pollution

Directory of Open Access Journals (Sweden)

Paul Prew

2015-08-01

Full Text Available With the ever-growing concern of climate change, much attention has been paid to the factors driving carbon dioxide emissions. Previous research in the World-Systems perspective has identified a relationship between carbon dioxide emissions and position in the world-economy. This study intends to build on the previous research by developing a new, more parsimonious indicator of World-System position based on Immanuel Wallerstein’s theoretical concepts of incorporation and core-periphery processes. The new World-System indicator is derived from the centrality measure in network analysis based on import data from the International Monetary Fund’s Direction of Trade Statistics. Based on the theoretical concepts of core-periphery processes, carbon dioxide emissions are predicted to rise based on the predominance of energy-intensive, high-technology, core processes within the nation. The results tend to demonstrate a strong relationship between carbon dioxide emissions and position in the world-economy, and the new World-System position indicator is more strongly related with carbon dioxide emissions than Gross Domestic Product per capita.

Economic Evaluations for the Carbon Dioxide-involved Production of High-value Chemicals

Energy Technology Data Exchange (ETDEWEB)

Lee, Ji Hyun; Lee, Dong Woog; Jang, Se Gyu; Kwak, No-Sang; Lee, In Young; Jang, Kyung Ryoung; Shim, Jae-Goo [KEPCO Research Institute, Daejon (Korea, Republic of); Choi, Jong Shin [Korea East-West Power Co. LTD, Seoul (Korea, Republic of)

2014-06-15

Economic evaluation of the manufacturing technology of high-value chemicals through the carbonation reaction of carbon dioxide contained in the flue gas was performed, and analysis of the IRR (Internal Rate of Return) and whole profit along the production plan of the final product was conducted. Through a carbonation reaction with sodium hydroxide that is generated from electrolysis and by using carbon dioxide in the combustion gas that is generated in the power plant, it is possible to get a high value products such as sodium bicarbonate compound and also to reduce the carbon dioxide emission simultaneously. The IRR (Internal Rate of Return) and NPV (Net Present Value) methods were used for the economic evaluation of the process which could handle carbon dioxide of 100 tons per day in the period of the 20 years of plant operation. The results of economic evaluation showed that the IRR of baseline case of technology was 67.2% and the profit that obtained during the whole operation period (20 years) was 346,922 million won based on NPV value. When considering ETS due to the emissions trading enforcement that will be activated in 2015, the NPV was improved to a 6,000 million won. Based on this results, it could be concluded that this CO2 carbonation technology is an cost-effective technology option for the reduction of greenhouse gas.

Economic Evaluations for the Carbon Dioxide-involved Production of High-value Chemicals

International Nuclear Information System (INIS)

Lee, Ji Hyun; Lee, Dong Woog; Jang, Se Gyu; Kwak, No-Sang; Lee, In Young; Jang, Kyung Ryoung; Shim, Jae-Goo; Choi, Jong Shin

2014-01-01

Economic evaluation of the manufacturing technology of high-value chemicals through the carbonation reaction of carbon dioxide contained in the flue gas was performed, and analysis of the IRR (Internal Rate of Return) and whole profit along the production plan of the final product was conducted. Through a carbonation reaction with sodium hydroxide that is generated from electrolysis and by using carbon dioxide in the combustion gas that is generated in the power plant, it is possible to get a high value products such as sodium bicarbonate compound and also to reduce the carbon dioxide emission simultaneously. The IRR (Internal Rate of Return) and NPV (Net Present Value) methods were used for the economic evaluation of the process which could handle carbon dioxide of 100 tons per day in the period of the 20 years of plant operation. The results of economic evaluation showed that the IRR of baseline case of technology was 67.2% and the profit that obtained during the whole operation period (20 years) was 346,922 million won based on NPV value. When considering ETS due to the emissions trading enforcement that will be activated in 2015, the NPV was improved to a 6,000 million won. Based on this results, it could be concluded that this CO2 carbonation technology is an cost-effective technology option for the reduction of greenhouse gas

Materials for nuclear diffusion-bonded compact heat exchangers

International Nuclear Information System (INIS)

Li, Xiuqing; Smith, Tim; Kininmont, David; Dewson, Stephen John

2009-01-01

This paper discusses the characteristics of materials used in the manufacture of diffusion bonded compact heat exchangers. Heatric have successfully developed a wide range of alloys tailored to meet process and customer requirements. This paper will focus on two materials of interest to the nuclear industry: dual certified SS316/316L stainless steel and nickel-based alloy Inconel 617. Dual certified SS316/316L is the alloy used most widely in the manufacture of Heatric's compact heat exchangers. Its excellent mechanical and corrosion resistance properties make it a good choice for use with many heat transfer media, including water, carbon dioxide, liquid sodium, and helium. As part of Heatric's continuing product development programme, work has been done to investigate strengthening mechanisms of the alloy; this paper will focus in particular on the effects of nitrogen addition. Another area of Heatric's programme is Alloy 617. This alloy has recently been developed for diffusion bonded compact heat exchanger for high temperature nuclear applications, such as the intermediate heat exchanger (IHX) for the very high temperature nuclear reactors for production of electricity, hydrogen and process heat. This paper will focus on the effects of diffusion bonding process and cooling rate on the properties of alloy 617. This paper also compares the properties and discusses the applications of these two alloys to compact heat exchangers for various nuclear processes. (author)

Carbon Dioxide for pH Control

Energy Technology Data Exchange (ETDEWEB)

Wagonner, R.C.

2001-08-16

Cardox, the major supplier of carbon dioxide, has developed a diffuser to introduce carbon dioxide into a water volume as small bubbles to minimize reagent loss to the atmosphere. This unit is integral to several configurations suggested for treatment to control alkalinity in water streams.

Carbon dioxide sequestration by mineral carbonation

NARCIS (Netherlands)

Huijgen, W.J.J.

2007-01-01

The increasing atmospheric carbon dioxide (CO2) concentration, mainly caused by fossil fuel combustion, has lead to concerns about global warming. A possible technology that can contribute to the reduction of carbon dioxide emissions is CO2 sequestration by mineral carbonation. The basic concept

Application of condition based maintenance to nuclear power plants

International Nuclear Information System (INIS)

Sonoda, Yukio; Nakano, Tomohito; Shimizu, Shunichi; Iida, Jun; Atomura, Masakazu; Abe, Masahiro

2002-01-01

Device Karte management system which supports application of condition based maintenance to nuclear power plants has been developed. The purpose of this system is to support maintenance personnel in device inspection scheduling based on operating condition monitoring and maintenance histories. There are four functions: field database, degradation estimation, inspection time decision and maintenance planning. The authors have been applying this system to dozens of devices of Onagawa Nuclear Power Station Unit No. 1 for one year. This paper represents the system concept and its application experiences. (author)

Economics of nuclear power in Finland

International Nuclear Information System (INIS)

Tarjanne, Risto; Luostarinen, Kari

2002-01-01

The nuclear power generation fits perfectly with the long duration load profile of the Finnish power system. The good performance of the Finnish nuclear power has yielded benefits also to the consumers through its contribution to decreasing the electricity price. Furthermore, the introduction of nuclear power has resulted in a clear drop in carbon dioxide emissions from electricity generation in the shift of 1970's and 1980's. In the year 2001 the four Finnish nuclear power units at Loviisa and Olkiluoto generated 22.8 TWh electricity, equivalent to 28 per cent of the total consumption. Loviisa power station has a net output capacity of 2 x 488 MW, and Olkiluoto 2 x 840 MW. The capacity factors of the four nuclear units have been above 90 per cent, which are among the highest in the world. The energy-intensive process industries in particular have strong belief in nuclear power. In November 2000, Teollisuuden Voima company (TVO) submitted to the Finnish Government an application for decision in principle concerning the construction of a new nuclear power plant unit. The arguments were among other things to guarantee for the Finnish industry the availability of cheap electric energy and to meet the future growth of electricity consumption in Finland. The carbon-free nuclear power also represents the most efficient means to meet the Greenhouse Gas abatement quota of Finland. Simultaneously, the energy policy of the Government includes intensive R and D and investment support for the renewable energy sources and energy conservation, and the objective is also to replace coal with natural gas as much as reasonably possible. The fifth nuclear unit would be located in one of the existing Finnish nuclear sites, i.e. Olkiluoto or Loviisa. The size of the new nuclear unit would be in the range of 1000 to 1600 MW electric. The ready infrastructure of the existing site could be utilised resulting in lower investment cost for the new unit. The Finnish Government accepted the

Process for the preparation of uranium dioxide

International Nuclear Information System (INIS)

Watt, G.W.; Baugh, D.W. Jr.

1977-01-01

An actinide dioxide, e.g., uranium dioxide, plutonium dioxide, neptunium dioxide, etc., is prepared by reacting the actinide nitrate hexahydrate with sodium dithionite as a first step; the reaction product from this first step is a novel composition of matter comprising the actinide sulfite tetrahydrate. The reaction product resulting from this first step is then converted to the actinide dioxide by heating it in the absence of an oxygen-containing atmosphere (e.g., nitrogen) to a temperature of about 500 0 to about 950 0 C for about 15 to about 135 minutes. If the reaction product resulting from the first step is, prior to carrying out the second heating step, exposed to an oxygen-containing atmosphere such as air, the resultant product is a novel composition of matter comprising the actinide oxysulfite tetrahydrate which can also be readily converted to the actinide dioxide by heating it in the absence of an oxygen-containing atmosphere (e.g., nitrogen) at a temperature of about 400 0 to about 900 0 C for about 30 to about 150 minutes. Further, the actinide oxysulfite tetrahydrate can be partially dehydrated at reduced pressures (and in the presence of a suitable dehydrating agent such as phosphorus pentoxide). The partially dehydrated product may be readily converted to the dioxide form by heating it in the absence of an oxygen-containing atmosphere (e.g., nitrogen) at a temperature of about 500 0 to about 900 0 C for about 30 to about 150 minutes. 16 claims

Carbon dioxide in Arctic and subarctic regions

Energy Technology Data Exchange (ETDEWEB)

Gosink, T. A.; Kelley, J. J.

1981-03-01

A three year research project was presented that would define the role of the Arctic ocean, sea ice, tundra, taiga, high latitude ponds and lakes and polar anthropogenic activity on the carbon dioxide content of the atmosphere. Due to the large physical and geographical differences between the two polar regions, a comparison of CO/sub 2/ source and sink strengths of the two areas was proposed. Research opportunities during the first year, particularly those aboard the Swedish icebreaker, YMER, provided additional confirmatory data about the natural source and sink strengths for carbon dioxide in the Arctic regions. As a result, the hypothesis that these natural sources and sinks are strong enough to significantly affect global atmospheric carbon dioxide levels is considerably strengthened. Based on the available data we calculate that the whole Arctic region is a net annual sink for about 1.1 x 10/sup 15/ g of CO/sub 2/, or the equivalent of about 5% of the annual anthropogenic input into the atmosphere. For the second year of this research effort, research on the seasonal sources and sinks of CO/sub 2/ in the Arctic will be continued. Particular attention will be paid to the seasonal sea ice zones during the freeze and thaw periods, and the tundra-taiga regions, also during the freeze and thaw periods.

Triple-Pulse Integrated Path Differential Absorption Lidar for Carbon Dioxide Measurement - Novel Lidar Technologies and Techniques with Path to Space

Science.gov (United States)

Singh, Upendra N.; Refaat, Tamer F.; Petros, Mulugeta

2017-01-01

The societal benefits of understanding climate change through identification of global carbon dioxide sources and sinks led to the desired NASA's active sensing of carbon dioxide emissions over nights, days, and seasons (ASCENDS) space-based missions of global carbon dioxide measurements. For more than 15 years, NASA Langley Research Center (LaRC) have developed several carbon dioxide active remote sensors using the differential absorption lidar (DIAL) technique operating at the two-micron wavelength. Currently, an airborne two-micron triple-pulse integrated path differential absorption (IPDA) lidar is under development. This IPDA lidar measures carbon dioxide as well as water vapor, the dominant interfering molecule on carbon dioxide remote sensing. Advancement of this triple-pulse IPDA lidar development is presented.

Uncertainties in neural network model based on carbon dioxide concentration for occupancy estimation

Energy Technology Data Exchange (ETDEWEB)

Alam, Azimil Gani; Rahman, Haolia; Kim, Jung-Kyung; Han, Hwataik [Kookmin University, Seoul (Korea, Republic of)

2017-05-15

Demand control ventilation is employed to save energy by adjusting airflow rate according to the ventilation load of a building. This paper investigates a method for occupancy estimation by using a dynamic neural network model based on carbon dioxide concentration in an occupied zone. The method can be applied to most commercial and residential buildings where human effluents to be ventilated. An indoor simulation program CONTAMW is used to generate indoor CO{sub 2} data corresponding to various occupancy schedules and airflow patterns to train neural network models. Coefficients of variation are obtained depending on the complexities of the physical parameters as well as the system parameters of neural networks, such as the numbers of hidden neurons and tapped delay lines. We intend to identify the uncertainties caused by the model parameters themselves, by excluding uncertainties in input data inherent in measurement. Our results show estimation accuracy is highly influenced by the frequency of occupancy variation but not significantly influenced by fluctuation in the airflow rate. Furthermore, we discuss the applicability and validity of the present method based on passive environmental conditions for estimating occupancy in a room from the viewpoint of demand control ventilation applications.

Investigation of high burnup structures in uranium dioxide applying cellular automata: algorithms and codes

International Nuclear Information System (INIS)

Akishina, E.P.; Kostenko, B.F.; Ivanov, V.V.

2003-01-01

A new method of research in spatial structures that result from uranium dioxide burning in nuclear reactors of modern atomic plants is suggested. The method is based on the presentation of images of the mentioned structures in the form of the working field of a cellular automaton (CA). First, it has allowed one to extract some important quantitative characteristics of the structures directly from the micrographs of the uranium fuel surface. Secondly, the CA has been found out to allow one to formulate easily the dynamics of the evolution of the studied structures in terms of such micrograph elements as spots, spots' boundaries, cracks, etc. Relation has been found between the dynamics and some exactly solvable models of the theory of cellular automata, in particular, the Ising model and the vote model. This investigation gives a detailed description of some CA algorithms which allow one to perform the fuel surface image processing and to model its evolution caused by burnup or chemical etching. (author)

A new Finnish nuclear power unit

International Nuclear Information System (INIS)

2004-01-01

In Finland, nuclear power is considered a natural part of a sustainable energy system. The Finnish Parliament has decided that development of nuclear power is consistent with the overall interests of society when climate issues, environmental targets, supply security and stable and competitive prices of electric power are considered as a whole. In 2002, the Finnish Parliament approved the Government's decision in principle to build a fifth nuclear power plant. The new project is the most advanced energy project in the Nordic countries with respect to the availability of energy free of carbon dioxide. The decision is also welcomed by the EU. The new reactor will be of the EPR (European Pressurized Water Reactor) type. In addition to supplying power to the Finnish industries, the plant is considered necessary if Finland is to comply with international conventions on CO 2 emissions

60 years controlled nuclear fission: CP-1

International Nuclear Information System (INIS)

Anon.

2002-01-01

On December 2, 1942, the Chicago Pile 1 (CP-1) went critical for the first time. In this way, the scientists and engineers involved in the project under the leadership of Enrico Fermi succeeded in demonstrating that a self-sustaining nuclear reaction with nuclear fission processes was technically feasible. Only four years after the discovery and proof of nuclear fission by Otto Hahn, Fritz Strassmann, and Lise Meitner, the experiment consisting of graphite blocks as the moderator and uranium dioxide pellets as the fuel, as well as instrumentation and control devices, had been set up in the former squash court of the field and track stadium of the University of Chicago. Precisely at 3.36 a.m. Chicago time, after control rods had been withdrawn, the instruments showed the chain reaction by the neutron flux they indicated. An important cornerstone in the use of nuclear power had thus been laid. (orig.)

Framework for AI-based nuclear reactor design support system

International Nuclear Information System (INIS)

Furuta, Kazuo; Kondo, Shunsuke

1992-01-01

Nowadays many computer programs are being developed and used for the analytic tasks in nuclear reactor design, but experienced designers are still responsible for most of the synthetic tasks which are not amenable to algorithmic computer processes. Artificial intelligence (AI) is a promising technology to deal with these intractable tasks in design. In development of AI-based design support systems, it is desirable to choose a comprehensive framework based on the scientific theory of design. In this work a framework for AI-based design support systems for nuclear reactor design will be proposed based on an explorative abduction model of design. The fundamental architectures of this framework will be described especially on knowledge representation, context management and design planning. (author)

Nuclear Energy Today - Second edition

International Nuclear Information System (INIS)

Alonso, Agustin; Nakoski, John; Lamarre, Greg; Vasquez-Maignan, Ximena; Dale, Beverly; Keppler, Jan; Taylor, Martin; Paillere, Henri; Cameron, Ron; Dujardin, Thierry; Gannon-Picot, Cynthia; Grandrieux, Delphine; Dery, Helene; Anglade-Constantin, Sylvia; Vuillaume, Fabienne

2012-01-01

Meeting the growing demand for energy, and electricity in particular, while addressing the need to curb greenhouse gas emissions and to ensure security of energy supply, is one of the most difficult challenges facing the world's economies. No single technology can respond to this challenge, and the solution which policy-makers are seeking lies in the diversification of energy sources. Although nuclear energy currently provides over 20% of electricity in the OECD area and does not emit any carbon dioxide during production, it continues to be seen by many as a controversial technology. Public concern remains over its safety and the management of radioactive waste, and financing such a capital-intensive technology is a complex issue. The role that nuclear power will play in the future depends on the answers to these questions, several of which are provided in this up-to-date review of the status of nuclear energy, as well as on the outcome of research and development on the nuclear fuel cycle and reactor technologies

Cadmium Telluride-Titanium Dioxide Nanocomposite for Photodegradation of Organic Substance.

Science.gov (United States)

Ontam, Areeporn; Khaorapapong, Nithima; Ogawa, Makoto

2015-12-01

Cadmium telluride-titanium dioxide nanocomposite was prepared by hydrothermal reaction of sol-gel derived titanium dioxide and organically modified cadmium telluride. The crystallinity of titanium dioxide in the nanocomposite was higher than that of pure titanium dioxide obtained by the reaction under the same temperature and pressure conditions, showing that cadmium telluride induced the crystallization of titanium dioxide. Diffuse reflectance spectrum of the nanocomposite showed the higher absorption efficiency in the UV-visible region due to band-gap excitation of titanium dioxide. The nanocomposite significantly showed the improvement of photocatalytic activity for 4-chlorophenol with UV light.

Lidar detection of carbon dioxide in volcanic plumes

Science.gov (United States)

Fiorani, Luca; Santoro, Simone; Parracino, Stefano; Maio, Giovanni; Del Franco, Mario; Aiuppa, Alessandro

2015-06-01

Volcanic gases give information on magmatic processes. In particular, anomalous releases of carbon dioxide precede volcanic eruptions. Up to now, this gas has been measured in volcanic plumes with conventional measurements that imply the severe risks of local sampling and can last many hours. For these reasons and for the great advantages of laser sensing, the thorough development of volcanic lidar has been undertaken at the Diagnostics and Metrology Laboratory (UTAPRAD-DIM) of the Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA). In fact, lidar profiling allows one to scan remotely volcanic plumes in a fast and continuous way, and with high spatial and temporal resolution. Two differential absorption lidar instruments will be presented in this paper: BILLI (BrIdge voLcanic LIdar), based on injection seeded Nd:YAG laser, double grating dye laser, difference frequency mixing (DFM) and optical parametric amplifier (OPA), and VULLI (VULcamed Lidar), based on injection seeded Nd:YAG laser and optical parametric oscillator (OPO). The first one is funded by the ERC (European Research Council) project BRIDGE and the second one by the ERDF (European Regional Development Fund) project VULCAMED. While VULLI has not yet been tested in a volcanic site, BILLI scanned the gas emitted by Pozzuoli Solfatara (Campi Flegrei volcanic area, Naples, Italy) during a field campaign carried out from 13 to 17 October 2014. Carbon dioxide concentration maps were retrieved remotely in few minutes in the crater area. Lidar measurements were in good agreement with well-established techniques, based on different operating principles. To our knowledge, it is the first time that carbon dioxide in a volcanic plume is retrieved by lidar, representing the first direct measurement of this kind ever performed on an active volcano and showing the high potential of laser remote sensing in geophysical research.

Studies on the extraction of nuclear pure magnesium from sea bittern

International Nuclear Information System (INIS)

Isaack, S.L.

1979-01-01

This investigation is devoted to the extraction of nuclear grade magnesium from sea bittern. It comprises three main parts: The first is pertaining to examine the effect of bittern evaporation on both its physical and chemical properties. It a second part , a brief comparative study on magnesium extraction from bittern by use of lime, dolime, solvent extraction and precipitation with ammonia solution and gas as also with ammonia carbon dioxide gas mixture, has been attempted. The precipitation approach by ammonia-carbon dioxide mixture was the mean adopted. A careful systematic examination of various parameters affecting precipitation was undertaken on economic basis. Recovery and purity of magnesium hydroxide, have been taken into account by the study of magnesium concentration in the bittern, its temperature, flow rate of precipitant, ... etc. Since the produced magnesium compound contained 100 ppm of boron, it has to be minimized to less than 1 ppm to agree with the nuclear specifications