The Experts below are selected from a list of 18084 Experts worldwide ranked by ideXlab platform
Tadashi Inoue - One of the best experts on this subject based on the ideXlab platform.
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development of pyroprocessing and its future direction
Nuclear Engineering and Technology, 2008Co-Authors: Tadashi Inoue, Lothar KochAbstract:Pyroprocessing is the optimal means of treating spent Metal Fuels from Metal fast fuel reactors and is proposed as a potential option for GNEP in order to meet the requirements of the next generation fuel cycle. Currently, efforts for research and development are being made not only in the U.S., but also in Asian countries. Electrorefining, cathode processing by distillation, injection casting for fuel fabrication, and waste treatment must be verified by the use of genuine materials, and the engineering scale model of each device must be developed for commercial deployment. Pyroprocessing can be effectively extended to treat oxide Fuels by applying an electrochemical reduction, for which various kinds of oxides are examined. A typical morphology change was observed following the electrochemical reduction, while the product composition was estimated through the process flow diagram. The products include much stronger radiation emitter than pure typical LWR Pu or weapon-grade Pu. Nevertheless, institutional measures are unavoidable to ensure proliferation-proof plant operations. The safeguard concept of a pyroprocessing plant was compared with that of a PUREX plant. The pyroprocessing is better adapted for a collocation system positioned with some reactors and a single processing facility rather than for a centralized reprocessing unit with a large scale throughput.
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actinide recycling by pyro process with Metal fuel fbr for future nuclear fuel cycle system
Progress in Nuclear Energy, 2002Co-Authors: Tadashi InoueAbstract:Pyro-Metallurgical technology is one of potential devices for future nuclear fuel cycle. Not only economic advantage but also environmental safety and strong resistance for proliferation are required for the fuel cycle. In order to satisfy the requirement, actinides recycling applicable to LWR and FBR cycles by pyro-process has been developed since more than ten years in CRIEPI. The main technology is electrorefining for U and Pu separation and reductive-extraction for TRU separation, which can be applied on oxide Fuels through reduction process as well as Metal Fuels. The application of this technology on separation of TRU in HLLW through chlorination could contribute to the improvement of public acceptance on the geologic disposal. The main achievements are summarized as follows: • -|The elemental technologies, such as electrorefining, reductive extraction, injection casting and salt waste treatment and solidification, have been developed successfully with lots of experiments • -|The fuel dissolution into molten salt and uranium recovery on solid cathode for electrorefining have been demonstrated by engineering scale facility in Argonne National Laboratory by using spent Fuels and in CRIEPI by uranium tests. • -|Single element tests, using actinides, showed the Li reduction to be technically feasible, remaining the subjects of technical feasibility on multi-elements system and on effective recycle of Li by electrolysis of Li2O. • -|Concerning on the treatment of HLLW for actinide separation, the conversion to chlorides through oxides has been also established through uranium tests. • -|It is confirmed that more than 99% of TRU nuclides can be recovered from the high level liquid waste by TRU tests • -|Through these studies, the process flow sheets for reprocessing of Metal and oxide Fuels and for partitioning of TRU separation have been established. The subjects to be emphasized for further development are classified into three categories, that is, process development (demonstration), technology for engineering development, and supplemental technology. The Metal fuel FBR has a high potential for recycling actinides by integration with pyro-reprocessing. Alloys of U-Pu-Zr with minor actinides are investigated from points of fuel properties. The miscibility and other characteristics suggest that the maximum content up to ca. 5 wt% of minor actinides is allowable in the matrix. Nine pins of Metal fuel including minor actinides are ready for irradiation at Phenix fast reactor.
Edward L Dreizin - One of the best experts on this subject based on the ideXlab platform.
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Metal based reactive nanomaterials
Progress in Energy and Combustion Science, 2009Co-Authors: Edward L DreizinAbstract:Recent developments in materials processing and characterization resulted in the discovery of a new type of reactive materials containing nanoscaled Metal components. The well-known high oxidation energies of Metallic Fuels can now be released very rapidly because of the very high reactive interface areas in such Metal-based reactive nanomaterials. Consequently, these materials are currently being examined for an entire range of applications in energetic formulations inappropriate for conventional, micron-sized Metal Fuels having relatively low reaction rates. New application areas, such as reactive structural materials, are also being explored. Research remains active in manufacturing and characterization of Metal-based reactive nanomaterials including elemental Metal nanopowders and various nanocomposite material systems. Because of the nanometer scale of the individual particles, or phase domains, and because of the very high enthalpy of reaction between components of the nanocomposite materials, the final phase compositions, morphology, and thermodynamic properties of the reactive nanocomposite materials may be different from those of their micron-scaled counterparts. Ignition mechanisms in such materials can be governed by heterogeneous reactions that are insignificant for materials with less developed reactive interface areas. New combustion regimes are being observed that are affected by very short ignition delays combined with very high Metal combustion temperatures. Current progress in this rapidly growing research area is reviewed and some potential directions for the future research are discussed.
D J Jarvis - One of the best experts on this subject based on the ideXlab platform.
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direct combustion of recyclable Metal Fuels for zero carbon heat and power
Applied Energy, 2015Co-Authors: Jeffrey M Bergthorson, Samuel Goroshin, Michael Soo, Philippe Julien, Jan Palecka, David L Frost, D J JarvisAbstract:Abstract It is becoming widely recognized that our society must transition to low-carbon energy systems to combat global climate change, and renewable energy sources are needed to provide energy security in a world with limited fossil-fuel resources. While many clean power-generation solutions have been proposed and are being developed, our ability to transition to a low-carbon society is prevented by the present lack of clean and renewable energy carriers that can replace the crucial roles that fossil Fuels play, due to their abundance, convenience and performance, in global energy trade and transportation. Any future low-carbon energy carriers that aim to displace or supplement fossil Fuels must have high energy densities for convenient trade and storage, and should be consumable within efficient high-power-density engines for transportation, heavy machinery, and other off-grid energy applications. Hydrogen and batteries have been widely studied but they are not suitable for use as international energy-trading commodities and they cannot provide the energy density and safety demanded by society. Metal Fuels, produced using low-carbon recycling systems powered by clean primary energy, such as solar and wind, promise energy densities that are competitive to fossil Fuels with low, or even negative, net carbon dioxide emissions. To date, however, few practical high-power-density end-use devices for generating heat or power from Metal Fuels have been proposed. This paper proposes a novel concept for power generation in which Metal Fuels are burned with air in a combustor to provide clean, high-grade heat. The Metal-fuel combustion heat can be used directly for industrial or residential heating and can also power external-combustion engines, operating on the Rankine or Stirling cycles, or thermo-electric generators over a wide range of power levels. A design concept is proposed for a Metal-fuelled combustor that is based upon extensive experimental and theoretical studies of stabilized and propagating Metal flames performed at McGill University. This paper also reviews the fundamental and applied aspects of Metal-fuel combustion in order to provide the framework needed to assess any potential Metal engine technologies. The energy and power densities of the proposed Metal-fuelled zero-carbon heat engines are predicted to be close to current fossil-fuelled internal-combustion engines, making them an attractive technology for a future low-carbon society.
Steven F Son - One of the best experts on this subject based on the ideXlab platform.
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a mechanism for shattering microexplosions and dispersive boiling phenomena in aluminum lithium alloy based solid propellant
Proceedings of the Combustion Institute, 2017Co-Authors: Brandon C Terry, Travis R Sippel, I E Gunduz, Mark A Pfeil, Steven F SonAbstract:Abstract The microexplosive nature of multicomponent liquid Fuels has been both studied and fielded to decrease droplet residence times and increase completeness of combustion. However, little work has focused on investigating microexplosive Metal Fuels to enhance the Metal fuel combustion efficiency in traditional energetic material formulations. Microscopic surface videography was performed on two solid propellant formulations, one using aluminum (baseline) and the other with 80/20 wt% Al–Li alloy as fuel additives. It was observed that the propellant combustion with neat aluminum formed large molten droplets at the surface as aluminum particles agglomerate, which is a well-known problem with aluminized propellants. In contrast, the Al–Li propellant formed an Al–Li melt-layer on the propellant surface during combustion. Droplets were ejected from the surface melt-layer through dispersive boiling. Above the surface, further dispersive boiling is observed from the ejected droplets and droplet-shattering microexplosions are also observed. These dynamics are thought to be a result of a large disparity in volatility (i.e., boiling points) between the Metals in the molten alloy and the large Lewis number in the droplet, so that superheating occurs before the more volatile component (here Li) can diffuse to the surface. A Lewis number of 7440 was estimated for molten 80/20 wt% Al–Li alloy, which is nearly three orders of magnitude larger than typical multicomponent liquid hydrocarbon droplets that microexplode, suggesting a higher propensity for molten droplet microexplosions. This would also indicate that a smaller amount of the volatile component might be necessary for microexplosions and dispersive boiling than observed for liquid hydrocarbon Fuels. These dynamics are important for Metal fuel applications, because injectors cannot be used to decrease droplet size in a Metallized energetic material formulation.
Hosam E Mostafa - One of the best experts on this subject based on the ideXlab platform.
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combustion characteristics of extruded double base propellant based on ammonium perchlorate aluminum binary mixture
Fuel, 2017Co-Authors: Sherif Elbasuney, Ahmed Fahd, Hosam E MostafaAbstract:Abstract Much attention has been directed toward the development of modified double base (MDB) propellant as it can offer high specific impulse as well as wide range of burning rate. One of the main approaches for the development of MDB propellant is the integration of potential oxidizers and Metal Fuels. This study reports on, the impact of potential oxidizers including potassium perchlorate (KP) and ammonium perchlorate (AP) on combustion characteristics of double base (DB) propellant. The impact of these energetic additives on burning rate and the characteristic exhaust velocity of gaseous product (C ∗ ) were evaluated using small-scale ballistic evaluation test motor. The two potential oxidizers KP and AP exhibited controversy effects; whereas KP positively impact the burning rate, AP positively impact C ∗ . The partial replacement of AP with aluminum Metal fuel demonstrated a positive impact on both the burning rate and C ∗ . Aluminum Metal fuel offered an increase the combustion temperature, and propellant thermal conductivity. Consequently, it could alter the combustion mechanism, by thinning the induction zone, allowing the luminous flame zone to be more adjacent to the burning surface. Accordingly, the combustion reaction could proceed faster. While, MDB based on AP/Al were found to be more energetic with an increase in calorific value to reference formulation using bomb calorimetery; they exhibited good thermal stability in terms of ignition temperature using cook off test, and accepted thermal behavior using DSC.