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Sample records for simulated metallic spent

  1. Development of advanced spent fuel management process. The fabrication and oxidation behavior of simulated metallized spent fuel

    Energy Technology Data Exchange (ETDEWEB)

    Ro, Seung Gy; Shin, Y.J.; You, G.S.; Joo, J.S.; Min, D.K.; Chun, Y.B.; Lee, E.P.; Seo, H.S.; Ahn, S.B

    1999-03-01

    The simulated metallized spent fuel ingots were fabricated and evaluated the oxidation rates and the activation energies under several temperature conditions to develop an advanced spent fuel management process. It was also checked the alloying characteristics of the some elements with metal uranium. (Author). 3 refs., 1 tab., 36 figs.

  2. Casting technology for manufacturing metal rods from simulated metallic spent fuels

    Science.gov (United States)

    Leeand, Y. S.; Lee, D. B.; Kim, C. K.; Shin, Y. J.; Lee, J. H.

    2000-09-01

    A uranium metal rod 13.5 mm in diameter and 1,150 mm long was produced from simulated metallic spent fuels with advanced casting equipment using the directional-solidification method. A vacuum casting furnace equipped with a four-zone heater to prevent surface oxidation and the formation of surface shrinkage holes was designed. By controlling the axial temperature gradient of the casting furnace, deformation by the surface shrinkage phenomena was diminished, and a sound rod was manufactured. The cooling behavior of the molten uranium was analyzed using the computer software package MAGMAsoft.

  3. The miscibility and oxidation study of the simulated metallic spent fuel for the development of an advanced spent fuel management process

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Y. J.; You, G. S.; Ju, J. S.; Lee, E. P.; Seo, H. S.; Ahn, S. B. [Korea Atomic Energy Research Institute, Taejeon (Korea)

    1999-03-01

    The simulated metallic spent fuel ingots were fabricated and evaluated the oxidation rates and the activation energies under several temperature conditions to develop an advanced spent fuel management process. It was also checked the immiscibility of the some elements with metal uranium. 2 refs., 45 figs. (Author)

  4. Oxidation kinetics of simulated metallic spent fuel in air at 200∼300 .deg. C

    International Nuclear Information System (INIS)

    Joo, J. S.; Yoo, K. S.; Jo, I. J.; Kook, D. H.; Lee, E. P.; Lee, J. C.; Bang, K. S.; Kim, H. D.

    2003-01-01

    In order to evaluate the long term storage safety study of the metallic spent fuel, U-5Zr, U-5Ti, U-5Ni, U-5Nb, and U-5Hf simulated metallic uranium alloys, known as corrosion resistant alloys, were fabricated and oxidized in oxygen gas at 200 .deg. C ∼ 300 .deg. C. All simulated metallic uranium alloys were more corrosion resistant than pure uranium metal, and corrosion resistance increases Nb, Ni, Ti, Zr, Hf in that order. The oxidation rates of uranium alloys determined and activation energy was calculated for each alloy. The matrix microstructure of the test specimens were analyzed using OM, SEM, and EPMA. It was concluded that Nb was the best acceptable alloying elements for reducing corrosion of uranium metal, and Ni, Ti were also considered to suitable as candidate

  5. Numerical simulation of minor actinide recovery behaviour in batch processing of spent metallic fuel by electrorefining

    Energy Technology Data Exchange (ETDEWEB)

    Nawada, H P; Bhat, N P [Metallurgy Division, Indira Gandhi Centre for Atomic Research, Kalpakkam (India); Balasubramanian, G R [Atomic Energy Commission, Mumbai (India)

    1994-06-01

    Numerical simulation of electro-transport of fuel actinides (FAs), minor actinides (MAs) and rare earths (REs) in the electro-refiner (ER) for pyrochemical reprocessing of a typical spent IFR metallic fuel has been attempted based on improved thermo-chemical model developed for application to multi-component system in the ER. Optimization of MA recovery and decontamination factors (DFs) for MAs and REs in batch processing is presented. (author). 7 refs., 4 figs., 1 tab.

  6. Development of casting technology for manufacturing metal rods with simulated metallic spent fuels

    International Nuclear Information System (INIS)

    Lee, D. B.; Lee, Y. S.; Woo, Y. M.; Jang, S. J.; Kim, J. D; Kim, C. K.; Shin, Y. J.; Lee, J. H.

    1999-01-01

    The advanced casting equipment based on the directional solidification method was developed for manufacturing the uranium metal rod having 13.5 mm diameter and 1,200 mm length. In order to prevent surface-shrunk holes revealed easily in course of casting the small diameter and long rods, the vacuum casting furnace has the four pre-heaters equipped with temperature controller. On the other hand, the computer simulation to estimate the defective location and to analyze the solidus behavior of molten uranium in the mold were also performed by using MAGMA Code. As a result of the experimental and theoretical study, the sound rod has successfully been manufactured

  7. Recovery of metals from simulant spent lithium-ion battery as organophosphonate coordination polymers in aqueous media

    Energy Technology Data Exchange (ETDEWEB)

    Perez, Emilie; Andre, Marie-Laure; Navarro Amador, Ricardo [ICSM, Institut de Chimie Séparative de Marcoule, UMR 5257, CEA/CNRS/ENSCM/UM, Bât 426, BP 17171, 30207 Bagnols-sur-Cèze cedex (France); Hyvrard, François; Borrini, Julien [SARPI VEOLIA, Direction Technique et Innovations, Zone portuaire de Limay-Porcheville, 427 route du Hazay, 78520 Limay (France); Carboni, Michaël, E-mail: michael.carboni@cea.fr [ICSM, Institut de Chimie Séparative de Marcoule, UMR 5257, CEA/CNRS/ENSCM/UM, Bât 426, BP 17171, 30207 Bagnols-sur-Cèze cedex (France); Meyer, Daniel [ICSM, Institut de Chimie Séparative de Marcoule, UMR 5257, CEA/CNRS/ENSCM/UM, Bât 426, BP 17171, 30207 Bagnols-sur-Cèze cedex (France)

    2016-11-05

    Highlights: • Original waste disposal strategies for battery. • Precipitation of metals as coordination polymers. • Organo-phosphonate coordination polymers. • Selective extraction of manganese or co-precipitation of manganese/cobalt. • The recycling process give a promising application on any waste solution. - Abstract: An innovative approach is proposed for the recycling of metals from a simulant lithium-ion battery (LIBs) waste aqueous solution. Phosphonate organic linkers are introduced as precipitating agents to selectively react with the metals to form coordination polymers from an aqueous solution containing Ni, Mn and Co in a hydrothermal process. The supernatant is analyzed by ICP-AES to quantify the efficiency and the selectivity of the precipitation and the materials are characterized by Scanning Electron Microscopy (SEM), Powder X-Ray Diffraction (PXRD), Thermogravimetric Analyses (TGA) and nitrogen gas sorption (BET). Conditions have been achieved to selectively precipitate Manganese or Manganese/Cobalt from this solution with a high efficiency. This work describes a novel method to obtain potentially valuable coordination polymers from a waste metal solution that can be generalized on any waste solution.

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

    International Nuclear Information System (INIS)

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

    1993-01-01

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

  9. Production of metal waste forms from spent fuel treatment

    International Nuclear Information System (INIS)

    Westphal, B.R.; Keiser, D.D.; Rigg, R.H.; Laug, D.V.

    1995-01-01

    Treatment of spent nuclear fuel at Argonne National Laboratory consists of a pyroprocessing scheme in which the development of suitable waste forms is being advanced. Of the two waste forms being proposed, metal and mineral, the production of the metal waste form utilizes induction melting to stabilize the waste product. Alloying of metallic nuclear materials by induction melting has long been an Argonne strength and thus, the transition to metallic waste processing seems compatible. A test program is being initiated to coalesce the production of the metal waste forms with current induction melting capabilities

  10. Dissolution of Metal Supported Spent Auto Catalysts in Acids

    Directory of Open Access Journals (Sweden)

    Fornalczyk A.

    2016-03-01

    Full Text Available Metal supported auto catalysts, have been used in sports and racing cars initially, but nowadays their application systematically increases. In Metal Substrate (supported Converters (MSC, catalytic functions are performed by the Platinum Group Metals (PGM: Pt, Pd, Rh, similarly to the catalysts on ceramic carriers. The contents of these metals make that spent catalytic converters are valuable source of precious metals. All over the world there are many methods for the metals recovery from the ceramic carriers, however, the issue of platinum recovery from metal supported catalysts has not been studied sufficiently yet. The paper presents preliminary results of dissolution of spent automotive catalyst on a metal carrier by means of acids: H2SO4, HCl, HNO3, H3PO4. The main assumption of the research was the dissolution of base metals (Fe, Cr, Al from metallic carrier of catalyst, avoiding dissolution of PGMs. Dissolution was the most effective when concentrated hydrochloric acid, and 2M sulfuric acid (VI was used. It was observed that the dust, remaining after leaching, contained platinum in the level of 0.8% and 0.7%, respectively.

  11. Development of metal cask for nuclear spent fuel

    International Nuclear Information System (INIS)

    Matsuoka, T.; Kuri, S.; Ohsono, K.; Hode, S.

    2001-01-01

    It is one of the realistic solutions against increasing demand on interim storage of spent fuel assemblies arising from nuclear power plants in Japan to apply dual purpose (transport and storage) metal casks. Since 1980's Mitsubishi Heavy Industries, Ltd. (MHI) has been contributing to develop metal cask technologies for utilities, etc. in Japan, and have established transport and storage cask design ''MSF series'' which realizes higher payload and reliability for long term storage. MSF series transport and storage casks use various new design concepts and materials to improve thermal performance of the cask, structural integrity of the basket, durability of the neutron shielding material and so on. This paper summarizes an outline of the cask design that can accommodate BWR spent fuel assemblies as well as the new technologies applied to the design and fabrication. (author)

  12. Recovering metal values hydrometallurgically from spent dry battery cells

    Science.gov (United States)

    Rabah, M. A.; Barakat, M. A.; Mahrous, Y. Sh.

    1999-12-01

    A hydro-pyrometallurgical method was used to recover metal values from spent dry battery cells. Water-soluble ingredients were filtered, and solid residue was sorted by magnetic separation and water flotation. Parameters affecting the recovery efficiency were also studied. Results revealed that metallic parts, carbon rods, and paper were safely recovered; pure NH4Cl, MnO2, and ZnCl2 salts were obtained. Maximum recovery efficiencies reached 93 percent for manganese and 99.5 percent for zinc and NH4.

  13. Metals recovery of spent household batteries using a hydrometallurgical process

    International Nuclear Information System (INIS)

    Souza, K.P.; Tenorio, J.A.S.

    2010-01-01

    The objective of the work is to study a method for metals recovery from a sample composed by a mixture of the main types of spent household batteries. Segregation of the main metals is investigated using a treatment route consisting of the following steps: manual identified and dismantling, grinding, electric furnace reduction, acid leaching and selective precipitation with sodium hydroxide with and without hydrogen peroxide. Before and after precipitations the solutions had been analyzed by Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP/OES) and the precipitated analyzed by Scanning Electron Microscopy (SEM) with Spectrometry of Energy Dispersion Spectroscopy (EDS). The results had indicated that the great majority of metals had been precipitated in pHs studied, also had co-precipitation or simultaneous precipitation of metals in some pHs. (author)

  14. Spent fuel metal storage cask performance testing and future spent fuel concrete module performance testing

    International Nuclear Information System (INIS)

    McKinnon, M.A.; Creer, J.M.

    1988-10-01

    REA-2023 Gesellshaft fur Nuklear Service (GNS) CASTOR-V/21, Transnuclear TN-24P, and Westinghouse MC-10 metal storage casks, have been performance tested under the guidance of the Pacific Northwest Laboratory to determine their thermal and shielding performance. The REA-2023 cask was tested under Department of Energy (DOE) sponsorship at General Electric's facilities in Morris, Illinois, using BWR spent fuel from the Cooper Reactor. The other three casks were tested under a cooperative agreement between Virginia Power Company and DOE at the Idaho National Engineering Laboratory (INEL) by EGandG Idaho, Inc., using intact spent PWR fuel from the Surry reactors. The Electric Power Research Institute (EPRI) made contributions to both programs. A summary of the various cask designs and the results of the performance tests is presented. The cask designs include: solid and liquid neutron shields; lead, steel, and nodular cast iron gamma shields; stainless steel, aluminum, and copper baskets; and borated materials for criticality control. 4 refs., 8 figs., 6 tabs

  15. Electrometallurgical treatment of metallic spent nuclear fuel stored at the Hanford Site

    International Nuclear Information System (INIS)

    Laidler, J.J.; Gay, E.C.

    1996-01-01

    The major component of the DOE spent nuclear fuel inventory is the metallic fuel stored at the Hanford site in the southeastern part of the state of Washington. Most of this fuel was discharged from the N-Reactor; a small part of the inventory is fuel from the early Hanford production reactors. The U.S. Department of Energy (DOE) plans to remove these fuels from the spent fuel storage pools in which they are presently stored, dry them, and place them in interim storage at a location at the Hanford site that is far removed from the Columbia River. It is not yet certain that these fuels will be acceptable for disposal in a mined geologic repository without further treatment, due to their potential pyrophoric character. A practical method for treatment of the Hanford metallic spent fuel, based on an electrorefining process, has been developed and has been demonstrated with unirradiated N-Reactor fuel and with simulated single-pass reactor (SPR) spent fuel. The process can be operated with any desired throughput rates; being a batch process, it is simply a matter of setting the size of the electrorefiner modules and the number of such modules. A single module, prototypic of a production-scale module, has been fabricated and testing is in progress at a throughput rate of 150 kg (heavy metal) per day. The envisioned production version would incorporate additional anode baskets and cathode tubes and provide a throughput rate of 333 kgHM/day. A system with four of these modules would permit treatment of Hanford metallic fuels at a rate of at least 250 metric tons per year

  16. Hydrometallurgical Recovery of Metal Values From Spent Dry Battery Cells

    International Nuclear Information System (INIS)

    Rabah, M.A.; Barakat, M.A.; Mahrous, Y.Sh.

    1999-01-01

    This study focuses on the recovery of metal values from spent dry battery cells (DBC) applying a hydro-pyrometallurgical method. A process flow sheet was followed up starting with cutting the DBC with toothed cutter disc followed by water soaking and rinsing. Water soluble ingredients were filtered. Solid residue was assorted with the help of magnetic separation and water flotation.The method utilizes hydrogen peroxide to enhance dissolution of these metals in acidic or alkaline leachants. Parameters affecting the recovery efficiency such as stoichiometric ratio, solid: liquid ratio, temperature, time and ph of the system were investigated. In this concern, experiments were executed with a battery sample weighing up to 15 kg. Atomic absorption analysis showed that the input DBC contain appreciable amounts of metal zinc, zinc chloride and manganese that are recoverable.Results obtained revealed that metallic parts, carbon rods and paper were safely separated for recycling. From the water-soluble salts, pure NH 4 CI, MnO 2 and ZnCI 2 salts are obtained meeting the standard specifications. Temperature up to 55 degree enhances the recovery process. Under the optimum conditions, maximum recovery efficiency obtained amounts to 93% for Mn, and 99.5% for Zn and NH 4 CI. A model for explaining the obtained results was also given. Dissolution of metals concerned increases in the order nitric> hydrochloric acid. Results were explained in the premise of the kinetic and thermodynamic properties of the reactions involved. Cost estimate of the products shows that the prices of the products are competitive to those of the market prices

  17. Possibilities Of Metals Extracton From Spent Metallic Automotive Catalytic Converters By Using Biometallurgical Method

    Directory of Open Access Journals (Sweden)

    Willner J.

    2015-09-01

    Full Text Available The main task of automotive catalytic converters is reducing the amount of harmful components of exhaust gases. Metallic catalytic converters are an alternative to standard ceramic catalytic converters. Metallic carriers are usually made from FeCrAl steel, which is covered by a layer of Precious Group Metals (PGMs acting as a catalyst. There are many methods used for recovery of platinum from ceramic carriers in the world, but the issue of platinum and other metals recovery from metallic carriers is poorly described. The article presents results of preliminary experiments of metals biooxidation (Fe, Cr and Al from spent catalytic converters with metallic carrier, using bacteria of the Acidithiobacillus genus.

  18. A study on the thermal expansion characteristics of simulated spent fuel and simulated DUPIC fuel

    International Nuclear Information System (INIS)

    Kang, Kweon Ho; Ryu, H. J.; Kim, H. S.; Song, K. C.; Yang, M. S.

    2001-10-01

    Thermal expansions of simulated spent PWR fuel and simulated DUPIC fuel were studied using a dilatometer in the temperature range from 298 to 1900 K. The densities of simulated spent PWR fuel and simulated DUPIC fuel used in the measurement were 10.28 g/cm3 (95.35 % of TD) and 10.26 g/cm3 (95.14 % of TD), respectively. Their linear thermal expansions of simulated fuels are higher than that of UO2, and the difference between these fuels and UO2 increases progressively as temperature increases. However, the difference between simulated spent PWR fuel and simulated DUPIC fuel can hardly be observed. For the temperature range from 298 to 1900 K, the values of the average linear thermal expansion coefficients for simulated spent PWR fuel and simulated DUPIC fuel are 1.391 10-5 and 1.393 10-5 K-1, respectively. As temperature increases to 1900 K, the relative densities of simulated spent PWR fuel and simulated DUPIC fuel decrease to 93.81 and 93.76 % of initial densities at 298 K, respectively

  19. Development of advanced spent fuel management process / criticality safety analysis for integrated mockup and metallized spent fuel storage

    International Nuclear Information System (INIS)

    Ro, Seong Gy; Shin, Hee Sung; Shin, Young Joon; Bae, Kang Mok

    1999-02-01

    Benchmark calculation for SCALE4.3 CSAS6 module and burnup credit criticality analysis performed by CSAS6 module are described in this report. Calculation biases by the SCALE4.3 CSAS6 module for PWR spent fuel, metallized spent fuel and aqueous nuclear materials have been determined on the basis of the benchmark to be 0.011, 0.023 and 0.010, respectively. The maximum allowable multiplication factor for an integrated mockup and metallized spent fuel storage is conservatively determined to be 0.927. With the aid of this code system, K eff values as a function of metallization ratio for the integrated mockup have been calculated. The maximum values of K eff for normal and hypothetical accident conditions are 0.346 and 0.598, respectively, much less than the maximum allowable multiplication factor of 0.927. Besides, burnup credit criticality analysis has been performed for infinite arrays of square and hexagonal canisters containing metallized spent fuel rods with different canister wall thickness, canister surface-to-surface distance and water content. It is revealed that the effective multiplication factor for canister arrays as mentioned above is well below the subcritical limit regardless of external conditions when its wall thickness is over 9 mm. (Author). 37 refs., 27 tabs., 64 figs

  20. Metal waste forms from treatment of EBR-II spent fuel

    International Nuclear Information System (INIS)

    Abraham, D. P.

    1998-01-01

    Demonstration of Argonne National Laboratory's electrometallurgical treatment of spent nuclear fuel is currently being conducted on irradiated, metallic driver fuel and blanket fuel elements from the Experimental Breeder Reactor-II (EBR-II) in Idaho. The residual metallic material from the electrometallurgical treatment process is consolidated into an ingot, the metal waste form (MWF), by employing an induction furnace in a hot cell. Scanning electron microscopy (SEM) and chemical analyses have been performed on irradiated cladding hulls from the driver fuel, and on samples from the alloy ingots. This paper presents the microstructures of the radioactive ingots and compares them with observations on simulated waste forms prepared using non-irradiated material. These simulated waste forms have the baseline composition of stainless steel - 15 wt % zirconium (SS-15Zr). Additions of noble metal elements, which serve as surrogates for fission products, and actinides are made to that baseline composition. The partitioning of noble metal and actinide elements into alloy phases and the role of zirconium for incorporating these elements is discussed in this paper

  1. Literature survey on metal waste form for metallic waste from electrorefiners for the electrometallurgical treatment of spent metallic fuels

    International Nuclear Information System (INIS)

    Nishimura, Tomohiro

    2003-01-01

    This report summarizes the recent results of the metal waste form development activities at the Argonne National Laboratory in the USA for high-level radioactive metallic waste (stainless-steel (SS) cladding hulls, zirconium (Zr), noble-metal fission products (NMFPs), etc.) from electrorefiners for the electrometallurgical treatment of spent metallic fuels. Their main results are as follows: (1) SS- 15 wt.% Zr- ∼4 wt.% NMFPs alloy was selected as the metal waste form, (2) metallurgical data, properties, long-term corrosion data, etc. of the alloy have been collected, (3) 10-kg ingots have been produced in hot tests and a 60-kg production machine is under development. The following research should be made to show the feasibility of the metal waste form in Japan: (1) degradation assessment of the metal waste form in Japanese geological repository environments, and (2) clarification of the maximum allowable contents of NMFPs. (author)

  2. Metal recovery from spent refinery catalysts by means of biotechnological strategies

    International Nuclear Information System (INIS)

    Beolchini, F.; Fonti, V.; Ferella, F.; Veglio, F.

    2010-01-01

    A bioleaching study aimed at recovering metals from hazardous spent hydroprocessing catalysts was carried out. The exhaust catalyst was rich in nickel (4.5 mg/g), vanadium (9.4 mg/g) and molybdenum (4.4 mg/g). Involved microorganisms were iron/sulphur oxidizing bacteria. Investigated factors were elemental sulphur addition, ferrous iron addition and actions contrasting a possible metal toxicity (either adding powdered activated charcoal or simulating a cross current process by means of periodical filtration). Ferrous iron resulted to be essential for metal extraction: nickel and vanadium extraction yields were 83% and 90%, respectively, while about 50% with no iron. The observed values for molybdenum extraction yields were not as high as Ni and V ones (the highest values were around 30-40%). The investigated actions aimed at contrasting a possible metal toxicity resulted not to be effective; in contrast, sequential filtration of the liquor leach had a significant negative effect on metals extraction. Nickel and vanadium dissolution kinetics resulted to be significantly faster than molybdenum dissolution ones. Furthermore, a simple first order kinetic model was successfully fitted to experimental data. All the observed results supported the important role of the indirect mechanism in bioleaching of LC-Finer catalysts.

  3. Metal recovery from spent refinery catalysts by means of biotechnological strategies

    Energy Technology Data Exchange (ETDEWEB)

    Beolchini, F., E-mail: f.beolchini@univpm.it [Department of Marine Sciences, Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona (Italy); Fonti, V. [Department of Marine Sciences, Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona (Italy); Ferella, F.; Veglio, F. [Department of Chemistry, Chemical Engineering and Materials, University of L' Aquila, Monteluco di Roio, 67040 L' Aquila (Italy)

    2010-06-15

    A bioleaching study aimed at recovering metals from hazardous spent hydroprocessing catalysts was carried out. The exhaust catalyst was rich in nickel (4.5 mg/g), vanadium (9.4 mg/g) and molybdenum (4.4 mg/g). Involved microorganisms were iron/sulphur oxidizing bacteria. Investigated factors were elemental sulphur addition, ferrous iron addition and actions contrasting a possible metal toxicity (either adding powdered activated charcoal or simulating a cross current process by means of periodical filtration). Ferrous iron resulted to be essential for metal extraction: nickel and vanadium extraction yields were 83% and 90%, respectively, while about 50% with no iron. The observed values for molybdenum extraction yields were not as high as Ni and V ones (the highest values were around 30-40%). The investigated actions aimed at contrasting a possible metal toxicity resulted not to be effective; in contrast, sequential filtration of the liquor leach had a significant negative effect on metals extraction. Nickel and vanadium dissolution kinetics resulted to be significantly faster than molybdenum dissolution ones. Furthermore, a simple first order kinetic model was successfully fitted to experimental data. All the observed results supported the important role of the indirect mechanism in bioleaching of LC-Finer catalysts.

  4. Recovery of Platinum Group Metals from Spent Catalysts Using Iron Chloride Vapor Treatment

    Science.gov (United States)

    Taninouchi, Yu-ki; Okabe, Toru H.

    2018-05-01

    The recovery of platinum group metals (PGMs) from spent automobile catalysts is a difficult process because of their relatively low contents in the scrap. In this study, to improve the efficiency of the existing recycling techniques, a novel physical concentration method involving treatment with FeCl2 vapor has been examined. The reactions occurring between typical catalyst components and FeCl2 vapor are discussed from the thermodynamic point of view, and the validity of the proposed technique was experimentally verified. The obtained results indicate that the vapor treatment at around 1200 K (927 °C) can effectively alloy PGMs (Pt, Pd, and Rh) with Fe, resulting in the formation of a ferromagnetic alloy. It was also confirmed that cordierite and alumina (the major catalyst components) remained unreacted after the vapor treatment, while ceria species were converted into oxychlorides. The samples simulating the automobile catalyst were also subjected to magnetic separation after the treatment with FeCl2 vapor; as a result, PGMs were successfully extracted and concentrated in the form of a magnetic powder. Thus, the FeCl2 vapor treatment followed by magnetic separation can be utilized for recovering PGMs directly from spent catalysts as an effective pretreatment for the currently used recycling methods.

  5. Separation of Metals From Spent Catalysts Waste by Bioleaching Process

    OpenAIRE

    Sirin Fairus, Tria Liliandini, M.Febrian, Ronny Kurniawan

    2010-01-01

    A kind of waste that hard to be treated is a metal containing solid waste. Leaching method is one thealternative waste treatment. But there still left an obstacle on this method, it is the difficulty to find theselective solvent for the type of certain metal that will separated. Bioleaching is one of the carry ablealternative waste treatments to overcome that obstacle. Bioleaching is a metal dissolving process orextraction from a sediment become dissolve form using microorganisms. On this met...

  6. Collision simulations of an exclusive ship of spent nuclear fuels

    International Nuclear Information System (INIS)

    Kitamura, Ou; Endo, Hisayoshi

    2000-01-01

    Exclusive ships for sea transport of irradiated nuclear fuels operating in Japanese territorial waters are required to be built with the special hull structure against collision. To comply with the official notice 'KAISA No. 520' issued by the Ministry of Transport, the side structure of any such exclusive ship must be designed to secure the specified energy absorption capability based on Minorsky's ship collision model. The Shipbuilding Research Association of Japan (JSRA) has studied the safety in sea transport of nuclear fuels intermittently for these several decades. Recently, the adoption of finite element method has made detailed collision analyses practicable. Since 1998, the regulation research panel No. 46 of JSRA has carried out a series of finite element collision simulations in order to estimate the realistic damage to a typical exclusive ship of spent nuclear fuels. The expected structural responses, global motions and energy absorption capabilities of both colliding and struck ships during collision were investigated. The results of the investigations have shown that the ship is very likely to withstand the collision even with one of the world's largest ship. This is due mainly to her hull structure specially strengthened beyond the crushing strength of the colliding bow structures. (author)

  7. Bioremediation of {sup 60}Co from simulated spent decontamination solutions

    Energy Technology Data Exchange (ETDEWEB)

    Rashmi, K.; Naga Sowjanya, T.; Maruthi Mohan, P.; Balaji, V.; Venkateswaran, G

    2004-07-26

    Bioremediation of {sup 60}Co from simulated spent decontamination solutions by utilizing different biomass of (Neurospora crassa, Trichoderma viridae, Mucor recemosus, Rhizopus chinensis, Penicillium citrinum, Aspergillus niger and, Aspergillus flavus) fungi is reported. Various fungal species were screened to evaluate their potential for removing cobalt from very low concentrations (0.03-0.16 {mu}M) in presence of a high background of iron (9.33 mM) and nickel (0.93 mM) complexed with EDTA (10.3 mM). The different fungal isolates employed in this study showed a pickup of cobalt in the range 8-500 ng/g of dry biomass. The [Fe]/[Co] and [Ni]/[Co] ratios in the solutions before and after exposure to the fungi were also determined. At micromolar level the cobalt pickup by many fungi especially the mutants of N. crassa is seen to be proportional to the initial cobalt concentration taken in the solution. However, R. chinensis exhibits a low but iron concentration dependent cobalt pickup. Prior saturating the fungi with excess of iron during their growth showed the presence of selective cobalt pickup sites. The existence of cobalt specific sorption sites is shown by a model experiment with R. chinensis wherein at a constant cobalt concentration (0.034 {mu}M) and varying iron concentrations so as to yield [Fe/Co]{sub initial} ratios in solution of 10, 100, 1000 and 287 000 have all yielded a definite Co pickup capacity in the range 8-47 ng/g. The presence of Cr(III)EDTA (3 mM) in solution along with complexed Fe and Ni has not influenced the cobalt removal. The significant feature of this study is that even when cobalt is present in trace level (sub-micromolar) in a matrix of high concentration (millimolar levels) of iron, nickel and chromium, a situation typically encountered in spent decontamination solutions arising from stainless steel based primary systems of nuclear reactors, a number of fungi studied in this work showed a good sensitivity for cobalt pickup.

  8. Bioremediation of 60Co from simulated spent decontamination solutions

    International Nuclear Information System (INIS)

    Rashmi, K.; Naga Sowjanya, T.; Maruthi Mohan, P.; Balaji, V.; Venkateswaran, G.

    2004-01-01

    Bioremediation of 60 Co from simulated spent decontamination solutions by utilizing different biomass of (Neurospora crassa, Trichoderma viridae, Mucor recemosus, Rhizopus chinensis, Penicillium citrinum, Aspergillus niger and, Aspergillus flavus) fungi is reported. Various fungal species were screened to evaluate their potential for removing cobalt from very low concentrations (0.03-0.16 μM) in presence of a high background of iron (9.33 mM) and nickel (0.93 mM) complexed with EDTA (10.3 mM). The different fungal isolates employed in this study showed a pickup of cobalt in the range 8-500 ng/g of dry biomass. The [Fe]/[Co] and [Ni]/[Co] ratios in the solutions before and after exposure to the fungi were also determined. At micromolar level the cobalt pickup by many fungi especially the mutants of N. crassa is seen to be proportional to the initial cobalt concentration taken in the solution. However, R. chinensis exhibits a low but iron concentration dependent cobalt pickup. Prior saturating the fungi with excess of iron during their growth showed the presence of selective cobalt pickup sites. The existence of cobalt specific sorption sites is shown by a model experiment with R. chinensis wherein at a constant cobalt concentration (0.034 μM) and varying iron concentrations so as to yield [Fe/Co] initial ratios in solution of 10, 100, 1000 and 287 000 have all yielded a definite Co pickup capacity in the range 8-47 ng/g. The presence of Cr(III)EDTA (3 mM) in solution along with complexed Fe and Ni has not influenced the cobalt removal. The significant feature of this study is that even when cobalt is present in trace level (sub-micromolar) in a matrix of high concentration (millimolar levels) of iron, nickel and chromium, a situation typically encountered in spent decontamination solutions arising from stainless steel based primary systems of nuclear reactors, a number of fungi studied in this work showed a good sensitivity for cobalt pickup

  9. Bioleaching of metals from spent refinery petroleum catalyst using moderately thermophilic bacteria: effect of particle size.

    Science.gov (United States)

    Srichandan, Haragobinda; Singh, Sradhanjali; Pathak, Ashish; Kim, Dong-Jin; Lee, Seoung-Won; Heyes, Graeme

    2014-01-01

    The present work investigated the leaching potential of moderately thermophilic bacteria in the recovery of metals from spent petroleum catalyst of varying particle sizes. The batch bioleaching experiments were conducted by employing a mixed consortium of moderate thermophilic bacteria at 45°C and by using five different particle sizes (from 45 to >2000 μm) of acetone-washed spent catalyst. The elemental mapping by FESEM confirmed the presence of Al, Ni, V and Mo along with sulfur in the spent catalyst. During bioleaching, Ni (92-97%) and V (81-91%) were leached in higher concentrations, whereas leaching yields of Al (23-38%) were found to be lowest in all particle sizes investigated. Decreasing the particle size from >2000 μm to 45-106 μm caused an increase in leaching yields of metals during initial hours. However, the final metals leaching yields were almost independent of particle sizes of catalyst. Leaching kinetics was observed to follow the diffusion-controlled model showing the linearity more close than the chemical control. The results of the present study suggested that bioleaching using moderate thermophilic bacteria was highly effective in removing the metals from spent catalyst. Moreover, bioleaching can be conducted using spent catalyst of higher particle size (>2000 μm), thus saving the grinding cost and making process attractive for larger scale application.

  10. Comprehensive evaluation on effective leaching of critical metals from spent lithium-ion batteries.

    Science.gov (United States)

    Gao, Wenfang; Liu, Chenming; Cao, Hongbin; Zheng, Xiaohong; Lin, Xiao; Wang, Haijuan; Zhang, Yi; Sun, Zhi

    2018-05-01

    Recovery of metals from spent lithium-ion batteries (LIBs) has attracted worldwide attention because of issues from both environmental impacts and resource supply. Leaching, for instance using an acidic solution, is a critical step for effective recovery of metals from spent LIBs. To achieve both high leaching efficiency and selectivity of the targeted metals, improved understanding on the interactive features of the materials and leaching solutions is highly required. However, such understanding is still limited at least caused by the variation on physiochemical properties of different leaching solutions. In this research, a comprehensive investigation and evaluation on the leaching process using acidic solutions to recycle spent LIBs is carried out. Through analyzing two important parameters, i.e. leaching speed and recovery rate of the corresponding metals, the effects of hydrogen ion concentration, acid species and concentration on these two parameters were evaluated. It was found that a leachant with organic acids may leach Co and Li from the cathode scrap and leave Al foil as metallic form with high leaching selectivity, while that with inorganic acids typically leach all metals into the solution. Inconsistency between the leaching selectivity and efficiency during spent LIBs recycling is frequently noticed. In order to achieve an optimal status with both high leaching selectivity and efficiency (especially at high solid-to-liquid ratios), it is important to manipulate the average leaching speed and recovery rate of metals to optimize the leaching conditions. Subsequently, it is found that the leaching speed is significantly dependent on the hydrogen ion concentration and the capability of releasing hydrogen ions of the acidic leachant during leaching. With this research, it is expected to improve understanding on controlling the physiochemical properties of a leaching solution and to potentially design processes for spent LIBs recycling with high industrial

  11. Simulation of the mechanical behavior of a spent fuel shipping cask in a rail accident environment

    International Nuclear Information System (INIS)

    Fields, S.R.

    1977-02-01

    A preliminary mathematical model has been developed to simulate the dynamic mechanical response of a large spent fuel shipping cask to the impact experienced in a hypothetical rail accident. The report was written to record the status of the development of the mechanical response model and to supplement an earlier report on spent fuel shipping cask accident evaluation

  12. Simulations of Recrystallization in Metals

    DEFF Research Database (Denmark)

    Godiksen, Rasmus Brauner

    2007-01-01

    structures in the deformed metal due to local effects: Inhomogeneous boundary morphologies and dislocation-structure-dependent migration rates are observed. The effects that the dislocation structures have must be taken into account in order to create realistic recrystallization models, and through......The growth of new near-perfect grains during recrystallization of deformed metals is governed by the migration of the grain boundaries surrounding the new grains. The grain boundaries migrate through the deformed metal driven by the excess energy of the dislocation structures created during...... deformation. Recently, it has been found that recrystallization is far more inhomogeneous than previously thought. The purpose of this PhD-project is to study recrystallization by computer simulations with special focus on inhomogeneous growth. Two types of simulations have been employed: geometric...

  13. Development of simulation code for FBR spent fuel dissolution with rotary drum type continuous dissolver

    International Nuclear Information System (INIS)

    Sano, Yuichi; Katsurai, Kiyomichi; Washiya, Tadahiro; Koizumi, Tsutomu; Matsumoto, Satoshi

    2011-01-01

    Japan Atomic Energy Agency (JAEA) has been studying rotary drum type continuous dissolver for FBR spent fuel dissolution. For estimating the fuel dissolution behavior under several operational conditions in this dissolver, we have been developing the simulation code, PLUM, which mainly consists of 3 modules for calculating chemical reaction, mass transfer and thermal balance in the rotary drum type continuous dissolver. Under the various conditions where dissolution experiments were carried out with the batch-wise dissolver for FBR spent fuel and with the rotary drum type continuous dissolver for UO 2 fuel, it was confirmed that the fuel dissolution behaviors calculated by the PLUM code showed good agreement with the experimental ones. Based on this result, the condition for obtaining the dissolver solution with high HM (heavy metal : U and Pu) concentration (∼500g/L), which is required for the next step, i.e. crystallization process, was also analyzed by this code and appropriate operational conditions with the rotary drum type continuous dissolver, such as feedrate, concentration and temperature of nitric acid, could be clarified. (author)

  14. The role of fission products (noble metal particles) in spent fuel corrosion process in a failed container

    Energy Technology Data Exchange (ETDEWEB)

    Wu, L., E-mail: lwu59@uwo.ca [Univ. of Western Ontario, Dept. of Chemistry, London, Ontario (Canada); Shoesmith, D.W. [Univ. of Western Ontario, Dept. of Chemistry, London, Ontario (Canada); Univ. of Western Ontario, Surface Science Western, London, Ontario (Canada)

    2013-07-01

    The corrosion/dissolution of simulated spent fuel has been studied electrochemically. Fission products within the UO{sub 2} matrix are found to have significant effect on the anodic dissolution behaviour of the fuel. It is observed that H{sub 2}O{sub 2}oxidation is accelerated on the surfaces of doped noble metal (ε) particles existing in the fuel matrix. It is concluded that H{sub 2}O{sub 2} decomposition rather than UO{sub 2} corrosion should be the dominant reaction under high H{sub 2}O{sub 2} concentrations. (author)

  15. Recovery of metals from a mixture of various spent batteries by a hydrometallurgical process.

    Science.gov (United States)

    Tanong, Kulchaya; Coudert, Lucie; Mercier, Guy; Blais, Jean-Francois

    2016-10-01

    Spent batteries contain hazardous materials, including numerous metals (cadmium, lead, nickel, zinc, etc.) that are present at high concentrations. Therefore, proper treatment of these wastes is necessary to prevent their harmful effects on human health and the environment. Current recycling processes are mainly applied to treat each type of spent battery separately. In this laboratory study, a hydrometallurgical process has been developed to simultaneously and efficiently solubilize metals from spent batteries. Among the various chemical leaching agents tested, sulfuric acid was found to be the most efficient and cheapest reagent. A Box-Behnken design was used to identify the influence of several parameters (acid concentration, solid/liquid ratio, retention time and number of leaching steps) on the removal of metals from spent batteries. According to the results, the solid/liquid ratio and acid concentration seemed to be the main parameters influencing the solubilization of zinc, manganese, nickel, cadmium and cobalt from spent batteries. According to the results, the highest metal leaching removals were obtained under the optimal leaching conditions (pulp density = 180 g/L (w/v), [H2SO4] = 1 M, number of leaching step = 3 and leaching time = 30 min). Under such optimum conditions, the removal yields obtained were estimated to be 65% for Mn, 99.9% for Cd, 100% for Zn, 74% for Co and 68% for Ni. Further studies will be performed to improve the solubilization of Mn and to selectively recover the metals. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Recovery Of Electrodic Powder From Spent Nickel-Metal Hydride Batteries (NiMH

    Directory of Open Access Journals (Sweden)

    Shin S.M.

    2015-06-01

    Full Text Available This study was focused on recycling process newly proposed to recover electrodic powder enriched in nickel (Ni and rare earth elements (La and Ce from spent nickel-metal hydride batteries (NiMH. In addition, this new process was designed to prevent explosion of batteries during thermal treatment under inert atmosphere. Spent nickel metal hydride batteries were heated over range of 300°C to 600°C for 2 hours and each component was completely separated inside reactor after experiment. Electrodic powder was successfully recovered from bulk components containing several pieces of metals through sieving operation. The electrodic powder obtained was examined by X-ray diffraction (XRD and energy dispersive X-ray spectroscopy (EDX and image of the powder was taken by scanning electron microscopy (SEM. It was finally found that nickel and rare earth elements were mainly recovered to about 45 wt.% and 12 wt.% in electrodic powder, respectively.

  17. Bioleaching of valuable metals from spent lithium-ion mobile phone batteries using Aspergillus niger

    Science.gov (United States)

    Horeh, N. Bahaloo; Mousavi, S. M.; Shojaosadati, S. A.

    2016-07-01

    In this paper, a bio-hydrometallurgical route based on fungal activity of Aspergillus niger was evaluated for the detoxification and recovery of Cu, Li, Mn, Al, Co and Ni metals from spent lithium-ion phone mobile batteries under various conditions (one-step, two-step and spent medium bioleaching). The maximum recovery efficiency of 100% for Cu, 95% for Li, 70% for Mn, 65% for Al, 45% for Co, and 38% for Ni was obtained at a pulp density of 1% in spent medium bioleaching. The HPLC results indicated that citric acid in comparison with other detected organic acids (gluconic, oxalic and malic acid) had an important role in the effectiveness of bioleaching using A. niger. The results of FTIR, XRD and FE-SEM analysis of battery powder before and after bioleaching process confirmed that the fungal activities were quite effective. In addition, bioleaching achieved higher removal efficiency for heavy metals than the chemical leaching. This research demonstrated the great potential of bio-hydrometallurgical route to recover heavy metals from spent lithium-ion mobile phone batteries.

  18. Technology development program for safe shipment of spent fuel from liquid metal fast breeder reactor

    International Nuclear Information System (INIS)

    Freedman, J.M.; Humphreys, J.R.

    1975-10-01

    A comprehensive plan to develop shipping cask technology is described. Technical programs in the disciplines of heat transfer, structures and containment, spent fuel characterization, hot laboratory verification, shielding, and hazards analysis are discussed. Both short- and long-term goals in each discipline are delineated and how the disciplines interrelate is shown. The technologies developed will be used in the design, fabrication, and testing of truck-mounted and rail-car casks. These casks will be used for safely transporting short-cooled, high-burnup Liquid Metal Fast Breeder Reactor (LMFBR) spent fuel from reactors to reprocessing plants

  19. Study on uranium metallization yield of spent Pressurized Water Reactor fuels and oxidation behavior of fission products in uranium metals

    International Nuclear Information System (INIS)

    Choi, Ke Chon; Lee, Chang Heon; Kim, Won Ho

    2003-01-01

    Metallization yield of uranium oxide to uranium metal from lithium reduction process of spent Pressurized Water Reactor (PWR) fuels was measured using thermogravimetric analyzer. A reduced metal produced in the process was divided into a solid and a powder part, and each metallization yield was measured. Metallization yield of the solid part was 90.7∼95.9 wt%, and the powder being 77.8∼71.5 wt% individually. Oxidation behaviour of the quarternary alloy was investigated to take data on the thermal oxidation stability necessary for the study on dry storage of the reduced metal. At 600∼700 .deg. C, weight increments of allow of No, Ru, Rh and Pd was 0.40∼0.55 wt%. Phase change on the surface of the allow was started at 750 .deg. C. In particular, Mo was rapidly oxidized and then the alloy lost 0.76∼25.22 wt% in weight

  20. Process optimization and kinetics for leaching of rare earth metals from the spent Ni-metal hydride batteries.

    Science.gov (United States)

    Meshram, Pratima; Pandey, B D; Mankhand, T R

    2016-05-01

    Nickel-metal hydride batteries (Ni-MH) contain not only the base metals, but valuable rare earth metals (REMs) viz. La, Sm, Nd, Pr and Ce as well. In view of the importance of resource recycling and assured supply of the contained metals in such wastes, the present study has focussed on the leaching of the rare earth metals from the spent Ni-MH batteries. The conditions for the leaching of REMs from the spent batteries were optimized as: 2M H2SO4, 348K temperature and 120min of time at a pulp density (PD) of 100g/L. Under this condition, the leaching of 98.1% Nd, 98.4% Sm, 95.5% Pr and 89.4% Ce was achieved. Besides the rare earth metals, more than 90% of base metals (Ni, Co, Mn and Zn) were also leached out in this condition. Kinetic data for the dissolution of all the rare earth metals showed the best fit to the chemical control shrinking core model. The leaching of metals followed the mechanism involving the chemical reaction proceeding on the surface of particles by the lixiviant, which was corroborated by the XRD phase analysis and SEM-EDS studies. The activation energy of 7.6, 6.3, 11.3 and 13.5kJ/mol was acquired for the leaching of neodymium, samarium, praseodymium and cerium, respectively in the temperature range 305-348K. From the leach liquor, the mixed rare earth metals were precipitated at pH∼1.8 and the precipitated REMs was analyzed by XRD and SEM studies to determine the phases and the morphological features. Copyright © 2015. Published by Elsevier Ltd.

  1. Metal waste forms from the electrometallurgical treatment of spent nuclear fuel

    International Nuclear Information System (INIS)

    Abraham, D.P.; McDeavitt, S.M.; Park, J.

    1996-01-01

    Stainless steel-zirconium alloys are being developed for the disposal of radioactive metal isotopes isolated using an electrometallurgical treatment technique to treat spent nuclear fuel. The nominal waste forms are stainless steel-15 wt% zirconium alloy and zirconium-8 wt% stainless steel alloy. These alloys are generated in yttria crucibles by melting the starting materials at 1,600 C under an argon atmosphere. This paper discusses the microstructures, corrosion and mechanical test results, and thermophysical properties of the metal waste form alloys

  2. Spent fuel reprocessing system availability definition by process simulation

    International Nuclear Information System (INIS)

    Holder, N.; Haldy, B.B.; Jonzen, M.

    1978-05-01

    To examine nuclear fuel reprocessing plant operating parameters such as maintainability, reliability, availability, equipment redundancy, and surge storage requirements and their effect on plant throughput, a computer simulation model of integrated HTGR fuel reprocessing plant operations is being developed at General Atomic Company (GA). The simulation methodology and the status of the computer programming completed on reprocessing head end systems is reported

  3. Cation immobilization in pyrolyzed simulated spent ion exchange resins

    International Nuclear Information System (INIS)

    Luca, Vittorio; Bianchi, Hugo L.; Manzini, Alberto C.

    2012-01-01

    Significant quantities of spent ion exchange resins that are contaminated by an assortment of radioactive elements are produced by the nuclear industry each year. The baseline technology for the conditioning of these spent resins is encapsulation in ordinary Portland cement which has various shortcomings none the least of which is the relatively low loading of resin in the cement and the poor immobilization of highly mobile elements such as cesium. The present study was conducted with cationic resin samples (Lewatit S100) loaded with Cs + , Sr 2+ , Co 2+ , Ni 2+ in roughly equimolar proportions at levels at or below 30% of the total cation exchange capacity. Low temperature thermal treatment of the resins was conducted in inert (Ar), or reducing (CH 4 ) gas atmospheres, or supercritical ethanol to convert the hydrated polymeric resin beads into carbonaceous materials that contained no water. This pyrolytic treatment resulted in at least a 50% volume reduction to give mechanically robust spherical materials. Scanning electron microscope investigations of cross-sections of the beads combined with energy dispersive analysis showed that initially all elements were uniformly distributed through the resin matrix but that at higher temperatures the distribution of Cs became inhomogeneous. Although Cs was found in the entire cross-section, a significant proportion of the Cs occurred within internal rings while a proportion migrated toward the outer surfaces to form a crustal deposit. Leaching experiments conducted in water at 25 °C showed that the divalent contaminant elements were very difficult to leach from the beads heated in inert atmospheres in the range 200–600 °C. Cumulative fractional loses of the order of 0.001 were observed for these divalent elements for temperatures below 500 °C. Regardless of the processing temperature, the cumulative fractional loss of Cs in water at 25 °C reached a plateau or steady-state within the first 24 h increasing only

  4. Recycling of spent noble metal catalysts with emphasis on pyrometallurgical processing

    Energy Technology Data Exchange (ETDEWEB)

    Hagelueken, C. [Degussa Huels AG, Hanau (Germany)

    1999-09-01

    Precious metal catalysts for catalytic Naphta Reforming, Isomerization, Hydrogenation and other chemical and petrochemical processes are valuable assets for oil refineries and chemical companies. At the end of the service life of a reactor load of catalyst, the efficient and reliable recovery of the precious metals contained in the catalyst is of paramount importance. More than 150 years of technological advances at Degussa-Huels have resulted in refining methods for all kinds of precious metal containing materials which guarantee an optimum technical yield of the precious metals included. The refining of catalysts today is one of the important activities in the precious metals business unit. In the state-of-the-art precious metal refinery at Hanau in the centre of Germany, a wide variety of processes for the recovery of all precious metals is offered. These processes include accurate preparation, sampling and analysis as well as both wet-chemical and pyrometallurgical recovery techniques. Special emphasis in this presentation is laid on the advantages of pyrometallurgical processes for certain kinds of catalysts. To avoid any risks during transport, sampling and treatment of the spent catalyst, all parties involved in the recycling chain strictly have to follow the relevant safety regulations. Under its commitment to 'Responsible Care' standard procedures have been developed which include pre-shipment samples, safety data sheets/questionnaires and inspection of spent catalysts. These measures not only support a safe and environmentally sound catalyst recycling but also enable to determine the most suitable and economic recovery process - for the benefit of the customer. (orig.)

  5. Hydrometallurgical recovery of metal values from sulfuric acid leaching liquor of spent lithium-ion batteries.

    Science.gov (United States)

    Chen, Xiangping; Chen, Yongbin; Zhou, Tao; Liu, Depei; Hu, Hang; Fan, Shaoyun

    2015-04-01

    Environmentally hazardous substances contained in spent Li-ion batteries, such as heavy metals and nocuous organics, will pose a threat to the environment and human health. On the other hand, the sustainable recycling of spent lithium-ion batteries may bring about environmental and economic benefits. In this study, a hydrometallurgical process was adopted for the comprehensive recovery of nickel, manganese, cobalt and lithium from sulfuric acid leaching liquor from waste cathode materials of spent lithium-ion batteries. First, nickel ions were selectively precipitated and recovered using dimethylglyoxime reagent. Recycled dimethylglyoxime could be re-used as precipitant for nickel and revealed similar precipitation performance compared with fresh dimethylglyoxime. Then the separation of manganese and cobalt was conducted by solvent extraction method using cobalt loaded D2EHPA. And McCabe-Thiele isotherm was employed for the prediction of the degree of separation and the number of extraction stages needed at specific experimental conditions. Finally, cobalt and lithium were sequentially precipitated and recovered as CoC2O4 ⋅ 2H2O and Li2CO3 using ammonium oxalate solution and saturated sodium carbonate solution, respectively. Recovery efficiencies could be attained as follows: 98.7% for Ni; 97.1% for Mn, 98.2% for Co and 81.0% for Li under optimized experimental conditions. This hydrometallurgical process may promise a candidate for the effective separation and recovery of metal values from the sulfuric acid leaching liquor. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Process and equipment qualification of the ceramic and metal waste forms for spent fuel treatment

    International Nuclear Information System (INIS)

    Marsden, Ken; Knight, Collin; Bateman, Kenneth; Westphal, Brian; Lind, Paul

    2005-01-01

    The electrometallurgical process for treating sodium-bonded spent metallic fuel at the Materials and Fuels Complex of the Idaho National Laboratory separates actinides and partitions fission products into two waste forms. The first is the metal waste form, which is primarily composed of stainless steel from the fuel cladding. This stainless steel is alloyed with 15w% zirconium to produce a very corrosion-resistant metal which binds noble metal fission products and residual actinides. The second is the ceramic waste form which stabilizes fission product-loaded chloride salts in a sodalite and glass composite. These two waste forms will be packaged together for disposal at the Yucca Mountain repository. Two production-scale metal waste furnaces have been constructed. The first is in a large argon-atmosphere glovebox and has been used for equipment qualification, process development, and process qualification - the demonstration of process reliability for production of the DOE-qualified metal waste form. The second furnace will be transferred into a hot cell for production of metal waste. Prototype production-scale ceramic waste equipment has been constructed or procured; some equipment has been qualified with fission product-loaded salt in the hot cell. Qualification of the remaining equipment with surrogate materials is underway. (author)

  7. Method for calculating the duration of vacuum drying of a metal-concrete container for spent nuclear fuel

    Science.gov (United States)

    Karyakin, Yu. E.; Nekhozhin, M. A.; Pletnev, A. A.

    2013-07-01

    A method for calculating the quantity of moisture in a metal-concrete container in the process of its charging with spent nuclear fuel is proposed. A computing method and results obtained by it for conservative estimation of the time of vacuum drying of a container charged with spent nuclear fuel by technologies with quantization and without quantization of the lower fuel element cluster are presented. It has been shown that the absence of quantization in loading spent fuel increases several times the time of vacuum drying of the metal-concrete container.

  8. Hydrometallurgical recovery of metal values from sulfuric acid leaching liquor of spent lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xiangping; Chen, Yongbin; Zhou, Tao, E-mail: zhoutao@csu.edu.cn; Liu, Depei; Hu, Hang; Fan, Shaoyun

    2015-04-15

    Highlights: • Selective precipitation and solvent extraction were adopted. • Nickel, cobalt and lithium were selectively precipitated. • Co-D2EHPA was employed as high-efficiency extraction reagent for manganese. • High recovery percentages could be achieved for all metal values. - Abstract: Environmentally hazardous substances contained in spent Li-ion batteries, such as heavy metals and nocuous organics, will pose a threat to the environment and human health. On the other hand, the sustainable recycling of spent lithium-ion batteries may bring about environmental and economic benefits. In this study, a hydrometallurgical process was adopted for the comprehensive recovery of nickel, manganese, cobalt and lithium from sulfuric acid leaching liquor from waste cathode materials of spent lithium-ion batteries. First, nickel ions were selectively precipitated and recovered using dimethylglyoxime reagent. Recycled dimethylglyoxime could be re-used as precipitant for nickel and revealed similar precipitation performance compared with fresh dimethylglyoxime. Then the separation of manganese and cobalt was conducted by solvent extraction method using cobalt loaded D2EHPA. And McCabe–Thiele isotherm was employed for the prediction of the degree of separation and the number of extraction stages needed at specific experimental conditions. Finally, cobalt and lithium were sequentially precipitated and recovered as CoC{sub 2}O{sub 4}⋅2H{sub 2}O and Li{sub 2}CO{sub 3} using ammonium oxalate solution and saturated sodium carbonate solution, respectively. Recovery efficiencies could be attained as follows: 98.7% for Ni; 97.1% for Mn, 98.2% for Co and 81.0% for Li under optimized experimental conditions. This hydrometallurgical process may promise a candidate for the effective separation and recovery of metal values from the sulfuric acid leaching liquor.

  9. Hydrometallurgical recovery of metal values from sulfuric acid leaching liquor of spent lithium-ion batteries

    International Nuclear Information System (INIS)

    Chen, Xiangping; Chen, Yongbin; Zhou, Tao; Liu, Depei; Hu, Hang; Fan, Shaoyun

    2015-01-01

    Highlights: • Selective precipitation and solvent extraction were adopted. • Nickel, cobalt and lithium were selectively precipitated. • Co-D2EHPA was employed as high-efficiency extraction reagent for manganese. • High recovery percentages could be achieved for all metal values. - Abstract: Environmentally hazardous substances contained in spent Li-ion batteries, such as heavy metals and nocuous organics, will pose a threat to the environment and human health. On the other hand, the sustainable recycling of spent lithium-ion batteries may bring about environmental and economic benefits. In this study, a hydrometallurgical process was adopted for the comprehensive recovery of nickel, manganese, cobalt and lithium from sulfuric acid leaching liquor from waste cathode materials of spent lithium-ion batteries. First, nickel ions were selectively precipitated and recovered using dimethylglyoxime reagent. Recycled dimethylglyoxime could be re-used as precipitant for nickel and revealed similar precipitation performance compared with fresh dimethylglyoxime. Then the separation of manganese and cobalt was conducted by solvent extraction method using cobalt loaded D2EHPA. And McCabe–Thiele isotherm was employed for the prediction of the degree of separation and the number of extraction stages needed at specific experimental conditions. Finally, cobalt and lithium were sequentially precipitated and recovered as CoC 2 O 4 ⋅2H 2 O and Li 2 CO 3 using ammonium oxalate solution and saturated sodium carbonate solution, respectively. Recovery efficiencies could be attained as follows: 98.7% for Ni; 97.1% for Mn, 98.2% for Co and 81.0% for Li under optimized experimental conditions. This hydrometallurgical process may promise a candidate for the effective separation and recovery of metal values from the sulfuric acid leaching liquor

  10. Measuring the noble metal and iodine composition of extracted noble metal phase from spent nuclear fuel using instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Palomares, R.I.; Dayman, K.J.; Landsberger, S.; Biegalski, S.R.; Soderquist, C.Z.; Casella, A.J.; Brady Raap, M.C.; Schwantes, J.M.

    2015-01-01

    Masses of noble metal and iodine nuclides in the metallic noble metal phase extracted from spent fuel are measured using instrumental neutron activation analysis. Nuclide presence is predicted using fission yield analysis, and radionuclides are identified and the masses quantified using neutron activation analysis. The nuclide compositions of noble metal phase derived from two dissolution methods, UO 2 fuel dissolved in nitric acid and UO 2 fuel dissolved in ammonium-carbonate and hydrogen-peroxide solution, are compared. - Highlights: • The noble metal phase was chemically extracted from spent nuclear fuel and analyzed non-destructively. • Noble metal phase nuclides and long-lived iodine were identified and quantified using neutron activation analysis. • Activation to shorter-lived radionuclides allowed rapid analysis of long-lived fission products in spent fuel using gamma spectrometry

  11. Recovery and Separation of Valuable Metals from Spent Nickel-Metal Hydride Batteries using some Organophosphorus Extractants

    International Nuclear Information System (INIS)

    Aly, M.I.; Daoud, J.A.; ALy, H.F.

    2012-01-01

    The separation of cobalt, nickel, and rare earth elements from NiMH battery residues is evaluated in this paper. A hydrometallurgical process is developed for the recovery of metals from spent batteries and a selective separation of RE by precipitation of sodium RE double sulfate is performed. The methodology used benefits the solubility of the battery electrode materials in sulfuric or hydrochloric acids. The results obtained show that sulfuric acid is slightly less powerful in leaching (NiMH) compared to HCl acid. However, sulfuric acid was used on economic basis. Leaching solution was obtained by using 3 M H 2 SO 4 at 70 +1 degree C + 3% wt. H 2 O 2 for 5 hours. It has been shown that it is possible to recover about 98 % of the RE contained in spent NiMH batteries. The maximum recovery of nickel and cobalt metals was 99.9% and 99.4%, respectively. The effects of the main operating variables of both leaching and solvent extraction steps of nickel (II) and cobalt (II) from the leach solution using HDEHP (di-2-ethylhexyl phosphoric acid) and CYANEX 272 (di-(2,4,4 trimethyl pentyl) phosphinic acid) in kerosene were investigated aiming to maximize metal separation for recycling purposes. The developed process for the recovery and separation of nickel (II) , cobalt (II), and rare earth from spent NiMH batteries is tested and the obtained sulfate salts CoSO 4 and NiSO 4 have a high purity, suggesting that these recovered products could be used as chemical materials without further purification

  12. Recycling of spent adsorbents for oxyanions and heavy metal ions in the production of ceramics.

    Science.gov (United States)

    Verbinnen, Bram; Block, Chantal; Van Caneghem, Jo; Vandecasteele, Carlo

    2015-11-01

    Spent adsorbents for oxyanion forming elements and heavy metals are classified as hazardous materials and they are typically treated by stabilization/solidification before landfilling. The use of lime or cement for stabilization/solidification entails a high environmental impact and landfilling costs are high. This paper shows that mixing spent adsorbents in the raw material for the production of ceramic materials is a valuable alternative to stabilize oxyanion forming elements and heavy metals. The produced ceramics can be used as construction material, avoiding the high economic and environmental impact of stabilization/solidification followed by landfilling. To study the stabilization of oxyanion forming elements and heavy metals during the production process, two series of experiments were performed. In the first series of experiments, the main pollutant, Mo was adsorbed onto iron-based adsorbents, which were then mixed with industrial sludge (3 w/w%) and heated at 1100°C for 30 min. Mo was chosen, as this element is easily adsorbed onto iron-based adsorbents and it is the element that is the most difficult to stabilize (i.e. the highest temperatures need to be reached before the concentrations in the leachate are reduced). Leaching concentration from the 97/3 sludge/adsorbent mixture before heating ranged between 85 and 154 mg/kg; after the heating process they were reduced to 0.42-1.48 mg/kg. Mo was actually stabilized, as the total Mo concentration after addition was not affected by the heat treatment. In the second series of experiments, the sludge was spiked with other heavy metals and oxyanion forming elements (Cr, Ni, Cu, Zn, As, Cd and Pb) in concentrations 5 times higher than the initial concentrations; after heat treatment the leachate concentrations were below the regulatory limit values. The incorporation of spent adsorbents in ceramic materials is a valuable and sustainable alternative to the existing treatment methods, saving raw materials in the

  13. Simulating thermal behavior of AECL's spent fuel dry storage system with CATHENA

    International Nuclear Information System (INIS)

    Sabourin, G.

    1998-01-01

    This paper documents the comparisons between CATHENA predictions and temperature measurements taken at the Gentilly-2 NPP spent fuel dry storage facility and in a mock--up of a storage basket placed inside a storage cylinder. It also presents CATHENA temperature predictions related to the storage of spent fuel in MACSTOR modules as planned for Ignalina NPP, Lithuania. CATHENA has been chosen because it can simulate many noncondensable gases including air and helium, and because of its great flexibility in the representation of the MACSTOR module geometry. The results of the simulations show good agreement with the experimental measurements. The two comparisons indicate that CATHENA can be used to simulate heat transfer from the fuel to the external air circuit of the spent fuel dry storage system. For the Ignalina MACSTOR module, containing RBMK fuel having higher heat release than typical CANDU fuel, CATHENA predicts that the maximum fuel temperature is expected to be around 240 deg C, giving an acceptable margin below the maximum allowed temperature of 300 deg C. In conclusion, this paper shows that the thermalhydraulic code CATHENA can accurately predict the thermal behavior AECL's air cooled spent fuel dry storage system. (author)

  14. Simulating thermal behavior of AECL's spent fuel dry storage system with CATHENA

    Energy Technology Data Exchange (ETDEWEB)

    Sabourin, G. [Atomic Energy of Canada Limited, Montreal, PQ (Canada)

    1998-07-01

    This paper documents the comparisons between CATHENA predictions and temperature measurements taken at the Gentilly-2 NPP spent fuel dry storage facility and in a mock--up of a storage basket placed inside a storage cylinder. It also presents CATHENA temperature predictions related to the storage of spent fuel in MACSTOR modules as planned for Ignalina NPP, Lithuania. CATHENA has been chosen because it can simulate many noncondensable gases including air and helium, and because of its great flexibility in the representation of the MACSTOR module geometry. The results of the simulations show good agreement with the experimental measurements. The two comparisons indicate that CATHENA can be used to simulate heat transfer from the fuel to the external air circuit of the spent fuel dry storage system. For the Ignalina MACSTOR module, containing RBMK fuel having higher heat release than typical CANDU fuel, CATHENA predicts that the maximum fuel temperature is expected to be around 240 deg C, giving an acceptable margin below the maximum allowed temperature of 300 deg C. In conclusion, this paper shows that the thermalhydraulic code CATHENA can accurately predict the thermal behavior AECL's air cooled spent fuel dry storage system. (author)

  15. The evaluation of minimum cooling period for loading of PWR spent nuclear fuel of a dual purpose metal cask

    Energy Technology Data Exchange (ETDEWEB)

    Dho, Ho Seog; Kim, Tae Man; Cho, Chun Hyung [Korea Radioactive Waste Agency, Daejeon (Korea, Republic of)

    2016-12-15

    Recently, because the wet pool storage facilities of NPPs in Korea has become saturated, there has been much active R and D on an interim dry storage system using a transportation and storage cask. Generally, the shielding evaluation for the design of a spent fuel transportation and storage cask is performed by the design basis fuel, which selects the most conservative fuel among the fuels to be loaded into the cask. However, the loading of actual spent fuel into the transportation metal cask is not limited to the design basis fuel used in the shielding evaluation; the loading feasibility of actual spent fuel is determined by the shielding evaluation that considers the characteristics of the initial enrichment, the maximum burnup and the minimum cooling period. This study describes a shielding analysis method for determining the minimum cooling period of spent fuel that meets the domestic transportation standard of the dual purpose metal cask. In particular, the spent fuel of 3.0-4.5wt% initial enrichment, which has a large amount of release, was evaluated by segmented shielding calculations for efficient improvement of the results. The shielding evaluation revealed that about 81% of generated spent fuel from the domestic nuclear power plants until 2008 could be transported by the dual purpose metal cask. The results of this study will be helpful in establishing a technical basis for developing operating procedures for transportation of the dual purpose metal cask.

  16. The evaluation of minimum cooling period for loading of PWR spent nuclear fuel of a dual purpose metal cask

    International Nuclear Information System (INIS)

    Dho, Ho Seog; Kim, Tae Man; Cho, Chun Hyung

    2016-01-01

    Recently, because the wet pool storage facilities of NPPs in Korea has become saturated, there has been much active R and D on an interim dry storage system using a transportation and storage cask. Generally, the shielding evaluation for the design of a spent fuel transportation and storage cask is performed by the design basis fuel, which selects the most conservative fuel among the fuels to be loaded into the cask. However, the loading of actual spent fuel into the transportation metal cask is not limited to the design basis fuel used in the shielding evaluation; the loading feasibility of actual spent fuel is determined by the shielding evaluation that considers the characteristics of the initial enrichment, the maximum burnup and the minimum cooling period. This study describes a shielding analysis method for determining the minimum cooling period of spent fuel that meets the domestic transportation standard of the dual purpose metal cask. In particular, the spent fuel of 3.0-4.5wt% initial enrichment, which has a large amount of release, was evaluated by segmented shielding calculations for efficient improvement of the results. The shielding evaluation revealed that about 81% of generated spent fuel from the domestic nuclear power plants until 2008 could be transported by the dual purpose metal cask. The results of this study will be helpful in establishing a technical basis for developing operating procedures for transportation of the dual purpose metal cask

  17. Separation and Recovery of Precious Metals from Leach Liquors of Spent Electronic Wastes by Solvent Extraction

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Thi Hong; Wang, Lingyun; Lee, Man Seung [Mokpo National University, Mokpo (Korea, Republic of)

    2017-04-15

    Solvent extraction was employed to recover precious metals (Au (III), Pd (II) and Pt (IV)) from the leach solution of spent electronic wastes containing Cu (II), Cr (III) and Fe (III). First, pure Fe (III) and Au (III) were recovered by simultaneous extraction with Cyanex 923 followed by selective stripping with HCl and Na{sub 2}S{sub 2}O{sub 3}. Second, Pt (IV), Pd (II) and Cu (II) were extracted by Alamine 336 from the raffinate. After the removal of Cu (II) by stripping with weak HCl, Pd (II) and Pt (IV) were separately stripped by controlling the concentration of thiourea in the mixture with HCl. A process flow sheet for the separation of precious metals was proposed.

  18. CFD Simulation of Heat and Fluid Flow for Spent Fuel in a Dry Storage

    International Nuclear Information System (INIS)

    In, Wangkee; Kwack, Youngkyun; Kook, Donghak; Koo, Yanghyun

    2014-01-01

    A dry storage system is used for the interim storage of spent fuel prior to permanent depository and/or recycling. The spent fuel is initially stored in a water pool for more than 5 years at least after dispatch from the reactor core and is transported to dry storage. The dry cask contains a multiple number of spent fuel assemblies, which are cooled down in the spent fuel pool. The dry cask is usually filled up with helium gas for increasing the heat transfer to the environment outside the cask. The dry storage system has been used for more than a decade in United States of America (USA) and the European Union (EU). Korea is also developing a dry storage system since its spent fuel pool is anticipated to be full within 10 years. The spent fuel will be stored in a dry cask for more than 40 years. The integrity and safety of spent fuel are important for long-term dry storage. The long-term storage will experience the degradation of spent fuel such as the embrittlement of fuel cladding, thermal creep and hydride reorientation. High burn-up fuel may expedite the material degradation. It is known that the cladding temperature has a strong influence on the material degradation. Hence, it is necessary to accurately predict the local distribution of the cladding temperature using the Computational Fluid Dynamics (CFD) approach. The objective of this study is to apply the CFD method for predicting the three-dimensional distribution of fuel temperature in a dry cask. This CFD study simulated the dry cask for containing the 21 fuel assemblies under development in Korea. This paper presents the fluid velocity and temperature distribution as well as the fuel temperature. A two-step CFD approach was applied to simulate the heat and fluid flow in a dry storage of 21 spent fuel assemblies. The first CFD analysis predicted the helium flow and temperature in a dry cask by a assuming porous body of the spent fuel. The second CFD analysis was to simulate a spent fuel assembly in the

  19. Technique for recovering rare-earth metals from spent sintered Nd-Fe-B magnets without external heating

    Directory of Open Access Journals (Sweden)

    Ryo Sasai

    2016-06-01

    Full Text Available To selectively recover rare-earth metals with higher purity from spent sintered Nd-Fe-B magnets without external heating, we investigated the mechano-chemical treatment of spent sintered Nd-Fe-B magnet powder with a reaction solution of HCl and (COOH2 at room temperature. The results of various experiments showed that the mechano-chemical treatment with HCl and (COOH2 is very effective for recovering the rare-earth metals contained in spent sintered Nd-Fe-B magnet powder; the recovery rate and purity of the rare-earth metals were 95.3 and 95.0 mass%, respectively, under optimal conditions ([HCl] = 0.2 mol/dm3 and [(COOH2] = 0.25 mol/dm3.

  20. Recovery of Ni Metal from Spent Catalyst with Emulsion Liquid Membrane Using Cyanex 272 as Extractant

    Science.gov (United States)

    Yuliusman; Huda, M.; Ramadhan, I. T.; Farry, A. R.; Wulandari, P. T.; Alfia, R.

    2018-03-01

    In this study was conducted to recover nickel metal from spent nickel catalyst resulting from hydrotreating process in petroleum industry. The nickel extraction study with the emulsion liquid membrane using Cyanex 272 as an extractant to extract and separate nickel from the feed phase solution. Feed phase solution was preapred from spent catalyst using sulphuric acid. Liquid membrane consists of a kerosene as diluent, a Span 80 as surfactant, a Cyanex 272 as carrier and sulphuric acid solutions have been used as the stripping solution. The important parameters governing the permeation of nickel and their effect on the separation process have been studied. These parameters are surfactant concentration, extractant concentration feed phase pH. The optimum conditions of the emulsion membrane making process is using 0.06 M Cyanex 272, 8% w/v SPAN 80, 0.05 M H2SO4, internal phase extractant / phase volume ratio: 1/1, and stirring speed 1150 rpm for 60 Minute that can produce emulsion membrane with stability level above 90% after 4 hours. In the extraction process with optimum condition pH 6 for feed phase, ratio of phase emulsion/phase of feed: 1/2, and stirring speed 175 rpm for 15 minutes with result 81.51% nickel was extracted.

  1. The importance of pre-treatment of spent hydrotreating catalysts on metals recovery

    Directory of Open Access Journals (Sweden)

    Alexandre Luiz de Souza Pereira

    2011-01-01

    Full Text Available This work describes a three-step pre-treatment route for processing spent commercial NiMo/Al2O3 catalysts. Extraction of soluble coke with n-hexane and/or leaching of foulant elements with oxalic acid were performed before burning insoluble coke under air. Oxidized catalysts were leached with 9 mol L-1 sulfuric acid. Iron was the only foulant element partially leached by oxalic acid. The amount of insoluble matter in sulfuric acid was drastically reduced when iron and/or soluble coke were previously removed. Losses of active phase metals (Ni, Mo during leaching with oxalic acid were compensated by the increase of their recovery in the sulfuric acid leachate.

  2. The importance of pre-treatment of spent hydrotreating catalysts on metals recovery

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Alexandre Luiz de Souza; Silva, Cristiano Nunes da; Afonso, Julio Carlos, E-mail: julio@iq.ufrj.b [Universidade Federal do Rio de Janeiro (IQ/UFRJ), RJ (Brazil). Inst. de Quimica. Dept. de Quimica Analitica; Mantovano, Jose Luiz [Instituto de Engenharia Nuclear (CNEN/IEN-RJ), Rio de Janeiro, RJ (Brazil). Dept. de Quimica e Materiais Nucleares

    2011-07-01

    This work describes a three-step pre-treatment route for processing spent commercial Ni Mo/Al{sub 2}O{sub 3} catalysts. Extraction of soluble coke with n-hexane and/or leaching of foulant elements with oxalic acid were performed before burning insoluble coke under air. Oxidized catalysts were leached with 9 mol L{sup -1} sulfuric acid. Iron was the only foulant element partially leached by oxalic acid. The amount of insoluble matter in sulfuric acid was drastically reduced when iron and/or soluble coke were previously removed. Losses of active phase metals (Ni, Mo) during leaching with oxalic acid were compensated by the increase of their recovery in the sulfuric acid leachate. (author)

  3. Improvement of numerical simulation methods on safety assessment of the spent fuel storage facility

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-08-15

    Improvement of numerical simulation methods on safety assessment of the spent fuel storage facility is one of main objectives of JNES activities. For the thermal and structural analyses, the radiative heat transfer analysis code S-FOKS has been developed to reduce computing time and to avoid using large memory area. In order to simulate the specular reflection, a new model (called 'model-2') is planned to install to S-FOKS code. The theoretical values with the specular reflection in simple geometry were lead to verify S-FOKS model-2. (author)

  4. Calculation of the process of vacuum drying of a metal-concrete container with spent nuclear fuel

    Science.gov (United States)

    Karyakin, Yu. E.; Lavrent'ev, S. A.; Pavlyukevich, N. V.; Pletnev, A. A.; Fedorovich, E. D.

    2012-01-01

    An algorithm and results of calculation of the process of vacuum drying of a metal-concrete container intended for long-term "dry" storage of spent nuclear fuel are presented. A calculated substantiation of the initial amount of moisture in the container is given.

  5. A review of metal recovery from spent petroleum catalysts and ash.

    Science.gov (United States)

    Akcil, Ata; Vegliò, Francesco; Ferella, Francesco; Okudan, Mediha Demet; Tuncuk, Aysenur

    2015-11-01

    With the increase in environmental awareness, the disposal of any form of hazardous waste has become a great concern for the industrial sector. Spent catalysts contribute to a significant amount of the solid waste generated by the petrochemical and petroleum refining industry. Hydro-cracking and hydrodesulfurization (HDS) catalysts are extensively used in the petroleum refining and petrochemical industries. The catalysts used in the refining processes lose their effectiveness over time. When the activity of catalysts decline below the acceptable level, they are usually regenerated and reused but regeneration is not possible every time. Recycling of some industrial waste containing base metals (such as V, Ni, Co, Mo) is estimated as an economical opportunity in the exploitation of these wastes. Alkali roasted catalysts can be leached in water to get the Mo and V in solution (in which temperature plays an important role during leaching). Several techniques are possible to separate the different metals, among those selective precipitation and solvent extraction are the most used. Pyrometallurgical treatment and bio-hydrometallurgical leaching were also proposed in the scientific literature but up to now they did not have any industrial application. An overview on patented and commercial processes was also presented. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Separation and Recovery of Uranium Metal from Spent Light Water Reactor Fuel via Electrolytic Reduction and Electrorefining

    International Nuclear Information System (INIS)

    Herrmann, S.D.; Li, S.X.

    2010-01-01

    A series of bench-scale experiments was performed in a hot cell at Idaho National Laboratory to demonstrate the separation and recovery of uranium metal from spent light water reactor (LWR) oxide fuel. The experiments involved crushing spent LWR fuel to particulate and separating it from its cladding. Oxide fuel particulate was then converted to metal in a series of six electrolytic reduction runs that were performed in succession with a single salt loading of molten LiCl - 1 wt% Li2O at 650 C. Analysis of salt samples following the series of electrolytic reduction runs identified the diffusion of select fission products from the spent fuel to the molten salt electrolyte. The extents of metal oxide conversion in the post-test fuel were also quantified, including a nominal 99.7% conversion of uranium oxide to metal. Uranium metal was then separated from the reduced LWR fuel in a series of six electrorefining runs that were performed in succession with a single salt loading of molten LiCl-KCl-UCl3 at 500 C. Analysis of salt samples following the series of electrorefining runs identified additional partitioning of fission products into the molten salt electrolyte. Analyses of the separated uranium metal were performed, and its decontamination factors were determined.

  7. Standard guide for pyrophoricity/combustibility testing in support of pyrophoricity analyses of metallic uranium spent nuclear fuel

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 This guide covers testing protocols for testing the pyrophoricity/combustibility characteristics of metallic uranium-based spent nuclear fuel (SNF). The testing will provide basic data for input into more detailed computer codes or analyses of thermal, chemical, and mechanical SNF responses. These analyses would support the engineered barrier system (EBS) design bases and safety assessment of extended interim storage facilities and final disposal in a geologic repository. The testing also could provide data related to licensing requirements for the design and operation of a monitored retrievable storage facility (MRS) or independent spent fuel storage installation (ISFSI). 1.2 This guide describes testing of metallic uranium and metallic uranium-based SNF in support of transportation (in accordance with the requirements of 10CFR71), interim storage (in accordance with the requirements of 10CFR72), and geologic repository disposal (in accordance with the requirements of 10CFR60/63). The testing described ...

  8. The GC computer code for flow sheet simulation of pyrochemical processing of spent nuclear fuels

    International Nuclear Information System (INIS)

    Ahluwalia, R.K.; Geyer, H.K.

    1996-01-01

    The GC computer code has been developed for flow sheet simulation of pyrochemical processing of spent nuclear fuel. It utilizes a robust algorithm SLG for analyzing simultaneous chemical reactions between species distributed across many phases. Models have been developed for analysis of the oxide fuel reduction process, salt recovery by electrochemical decomposition of lithium oxide, uranium separation from the reduced fuel by electrorefining, and extraction of fission products into liquid cadmium. The versatility of GC is demonstrated by applying the code to a flow sheet of current interest

  9. Simulation of differential die-away instrument’s response to asymmetrically burned spent nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Martinik, Tomas, E-mail: tomas.martinik@physics.uu.se [Department of Physics and Astronomy, Uppsala University, Box 516 Sweden, SE-75120 Uppsala (Sweden); Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM, 87545 (United States); Henzl, Vladimir [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM, 87545 (United States); Grape, Sophie; Svärd, Staffan Jacobsson; Jansson, Peter [Department of Physics and Astronomy, Uppsala University, Box 516 Sweden, SE-75120 Uppsala (Sweden); Swinhoe, Martyn T. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM, 87545 (United States); Tobin, Stephen J. [Department of Physics and Astronomy, Uppsala University, Box 516 Sweden, SE-75120 Uppsala (Sweden); Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM, 87545 (United States); Swedish Nuclear Fuel and Waste Management Company, Blekholmstorget 30, Box 250, SE-101 24 Stockholm (Sweden)

    2015-07-11

    Previous simulation studies of Differential Die‐Away (DDA) instrument’s response to active interrogation of spent nuclear fuel from a pressurized water reactor (PWR) yielded promising results in terms of its capability to accurately measure or estimate basic spent fuel assembly (SFA) characteristics, such as multiplication, initial enrichment (IE) and burn-up (BU) as well as the total plutonium content. These studies were however performed only for a subset of idealized SFAs with a symmetric BU with respect to its longitudinal axis. Therefore, to complement the previous results, additional simulations have been performed of the DDA instrument’s response to interrogation of asymmetrically burned spent nuclear fuel in order to determine whether detailed assay of SFAs from all 4 sides will be necessary in real life applications or whether a cost and time saving single sided assay could be used to achieve results of similar quality as previously reported in case of symmetrically burned SFAs. The results of this study suggest that DDA instrument response depends on the position of the individual neutron detectors and in fact can be split in two modes. The first mode, measured by the back detectors, is not significantly sensitive to the spatial distribution of fissile isotopes and neutron absorbers, but rather reflects the total amount of both contributors as in the cases of symmetrically burned SFAs. In contrary, the second mode, measured by the front detectors, yields certain sensitivity to the orientation of the asymmetrically burned SFA inside the assaying instrument. This study thus provides evidence that the DDA instrument can potentially be utilized as necessary in both ways, i.e. a quick determination of the average SFA characteristics in a single assay, as well as a more detailed characterization involving several DDA observables through assay of the SFA from all of its four sides that can possibly map the burn-up distribution and/or identify diversion or

  10. Leaching of the simulated borosilicate waste glasses and spent nuclear fuel under a repository condition

    International Nuclear Information System (INIS)

    Kim, Seung Soo; Chun, Kwan Sik; Kang, Chul Hyung; Suh, Hang Suk

    2002-12-01

    Leaching behaviors of simulated waste glass and spent fuel, contacted on bentonite blocks, in synthetic granitic groundwater were investigated in this study. The leach rate of boron from borosilicate waste glass between the compacted bentonite blocks reached about 0.03 gm-2day-1 at 1500 days, like as that of molybdenum. However, the concentration of uranium in leachate pass through bentonite blocks was less than their detection limits of 2 μg/L and whose yellow amorphous compound was found on the surface of glass contacted with the bentonite blocks. The leaching mechanism of waste glasses differed with their composition. The release rate of cesium from PWR spent fuel in the simulated granitic water without bentonite was leas than $1.0x10 -5 fraction/day after 300 days. The retardation factor of cesium by a 10 -mm thickness of bentonite block was more than 100 for 4-years leaching time. The cumulative release fraction of uranium for 954 days was 0.016% (1.7x10 -7 fraction/day) in granitic water without bentonite. The gap inventory of cesium for spent fuel G23-J11 was 0.15∼0.2%. However, the release of cesium from C15-I08 was 0.9% until 60 days and has being continued after that. Gap inventories of strontium and iodine in G23-J11 were 0.033% and below 0.2%, respectively. The sum of fraction of cesium in gap and grain boundary of G23-J11 was suggested below 3% and less

  11. Simulation of differential die-away instrument’s response to asymmetrically burned spent nuclear fuel

    International Nuclear Information System (INIS)

    Martinik, Tomas; Henzl, Vladimir; Grape, Sophie; Svärd, Staffan Jacobsson; Jansson, Peter; Swinhoe, Martyn T.; Tobin, Stephen J.

    2015-01-01

    Previous simulation studies of Differential Die‐Away (DDA) instrument’s response to active interrogation of spent nuclear fuel from a pressurized water reactor (PWR) yielded promising results in terms of its capability to accurately measure or estimate basic spent fuel assembly (SFA) characteristics, such as multiplication, initial enrichment (IE) and burn-up (BU) as well as the total plutonium content. These studies were however performed only for a subset of idealized SFAs with a symmetric BU with respect to its longitudinal axis. Therefore, to complement the previous results, additional simulations have been performed of the DDA instrument’s response to interrogation of asymmetrically burned spent nuclear fuel in order to determine whether detailed assay of SFAs from all 4 sides will be necessary in real life applications or whether a cost and time saving single sided assay could be used to achieve results of similar quality as previously reported in case of symmetrically burned SFAs. The results of this study suggest that DDA instrument response depends on the position of the individual neutron detectors and in fact can be split in two modes. The first mode, measured by the back detectors, is not significantly sensitive to the spatial distribution of fissile isotopes and neutron absorbers, but rather reflects the total amount of both contributors as in the cases of symmetrically burned SFAs. In contrary, the second mode, measured by the front detectors, yields certain sensitivity to the orientation of the asymmetrically burned SFA inside the assaying instrument. This study thus provides evidence that the DDA instrument can potentially be utilized as necessary in both ways, i.e. a quick determination of the average SFA characteristics in a single assay, as well as a more detailed characterization involving several DDA observables through assay of the SFA from all of its four sides that can possibly map the burn-up distribution and/or identify diversion or

  12. Bituminization of simulated waste, spent resins, evaporator concentrates and animal ashes by extrusion process

    International Nuclear Information System (INIS)

    Grosche Filho, C.E.; Chandra, U.

    1986-01-01

    The results of the study of simulated radwaste, spent ion-exchange resins, borates/evaporator-concentrates and animal ashes, in bituminized form, are presented and discussed. Distilled and oxidized bitumen were used for characterizing the crude material and simulated wastes-bitumen mixtures of varying weight composition 30, 40, 50, 60% by weight the dry waste material. The asphaltine and parafin contents in the bitumens were determined. Some additives and clays were used aiming best characteristics of solidified wastes. For leaching studies, granular ion-exchange resins were loaded with Cs 134 and mixtures of resins-bitumens were prepared. The leaching studies were executed using the IAEA recommendation and the ISO method. It was used a conventional screw-extruder, used in plastic industry, to determine operational conditions and process difficulties. Mixtures resins-bitumen and concentrate-bitumen in differents operational condition were prepared and analysed. (Author) [pt

  13. Simulation of interim spent fuel storage system with discrete event model

    International Nuclear Information System (INIS)

    Yoon, Wan Ki; Song, Ki Chan; Lee, Jae Sol; Park, Hyun Soo

    1989-01-01

    This paper describes dynamic simulation of the spent fuel storage system which is described by statistical discrete event models. It visualizes flow and queue of system over time, assesses the operational performance of the system activities and establishes the system components and streams. It gives information on system organization and operation policy with reference to the design. System was tested and analyzed over a number of critical parameters to establish the optimal system. Workforce schedule and resources with long processing time dominate process. A combination of two workforce shifts a day and two cooling pits gives the optimal solution of storage system. Discrete system simulation is an useful tool to get information on optimal design and operation of the storage system. (Author)

  14. Review and evaluation of long-term integrity on metal casks and spent fuels stored in overseas countries

    International Nuclear Information System (INIS)

    Sasahara, Akihiro; Saegusa, Toshiari

    2009-01-01

    Inspection and experimental results on the metal cask and PWR-UO 2 spent fuels practically stored for fifteen years in Idaho National Laboratory (INL) are reviewed. Experimental results on PWR-UO 2 and BWR-MOX spent fuels stored for twenty years under wet or dry condition obtained by Central Research Institute of Electric Power Industry (CRIEPI) are also reviewed. These results show that the integrity of the metal cask and PWR-spent fuels are maintained at least during dry storage for fifteen years and that Japanese electric utilities may start their self-inspection on casks and spent fuels after fifteen-year storage. The gas sampling carrying out in INL can be applied to licensing for interim dry storage facilities in Japan. New program for the fuel integrity for high burn-up fuels (>45 GWd/MTU) at transportation after dry storage has been launched by Nuclear Regulation Commission (NRC), Department of Energy (DOE) and Electric Power Research Institute (EPRI) in USA. (author)

  15. Spent lithium-ion battery recycling - Reductive ammonia leaching of metals from cathode scrap by sodium sulphite.

    Science.gov (United States)

    Zheng, Xiaohong; Gao, Wenfang; Zhang, Xihua; He, Mingming; Lin, Xiao; Cao, Hongbin; Zhang, Yi; Sun, Zhi

    2017-02-01

    Recycling of spent lithium-ion batteries has attracted wide attention because of their high content of valuable and hazardous metals. One of the difficulties for effective metal recovery is the separation of different metals from the solution after leaching. In this research, a full hydrometallurgical process is developed to selectively recover valuable metals (Ni, Co and Li) from cathode scrap of spent lithium ion batteries. By introducing ammonia-ammonium sulphate as the leaching solution and sodium sulphite as the reductant, the total selectivity of Ni, Co and Li in the first-step leaching solution is more than 98.6% while it for Mn is only 1.36%. In detail understanding of the selective leaching process is carried out by investigating the effects of parameters such as leaching reagent composition, leaching time (0-480min), agitation speed (200-700rpm), pulp density (10-50g/L) and temperature (323-353K). It was found that Mn is primarily reduced from Mn 4+ into Mn 2+ into the solution as [Formula: see text] while it subsequently precipitates out into the residue in the form of (NH 4 ) 2 Mn(SO 3 ) 2 ·H 2 O. Ni, Co and Li are leached and remain in the solution either as metallic ion or amine complexes. The optimised leaching conditions can be further obtained and the leaching kinetics is found to be chemical reaction control under current leaching conditions. As a result, this research is potentially beneficial for further optimisation of the spent lithium ion battery recycling process after incorporating with metal extraction from the leaching solution. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Simulation of spent sulfite liquor fermentation using the object oriented knowledge based shell G2

    Energy Technology Data Exchange (ETDEWEB)

    Polakovic, M; Hoernsten, E G; Mandenius, C F

    1992-10-01

    This report demonstrates that simulation is a valuable tool, which can provide useful information for industrial fermentor operation and design. The key to good simulation is reliable fermentation kinetics. Starting point is the kinetics found in literature or obtained in laboratory experiments. This need not necessarily give a correct description of full-scale plant behaviour for several reasons, like population distribution (different characteristics of recycled biomass), natural selection of microorganism and metabolic behaviour modification during long-term operation, etc. Therefore, it is highly recommended to verify the kinetics on real plant data obtained either from permanent monitoring or especially designed plant measurements. We wanted to use the unique design of the MoDo ethanol plant in order to obtain sufficient information concerning the fermentation kinetics formulation based on normal steady-state operation. Unfortunately, this was not possible from the data obtained, because we could only estimate the fermentation rates in the first fermentor. The rest of the cascades was only flown through by the mash. A solution worth to try is to increase the flow rate of spent sulfite liquor, or to decrease the fermentor medium volume and then make new measurements. If this would help to formulate the process kinetics, simulation could then be used more efficiently for improving the current process or in design of the new one. (21 refs., 2 figs., 5 tabs.).

  17. Simulation of the metallic powders compaction process

    International Nuclear Information System (INIS)

    Prado, J.M.; Riera, M.D.

    1998-01-01

    The simulation by means of finite elements of the forming processes of mechanical components is a very useful tool for their design and validation. In this work, the simulation of the compaction of a metal powder is presented. The finite element software ABAQUS is used together with the modified CAM-clay plasticity model in order to represent the elastoplastic behaviour of the material. Density distributions are obtained and therefore the motion of the compaction punches which improve this distribution can be found. Stress distribution in the different parts of the mould can also be determined. (Author) 9 refs

  18. Development of dual-purpose metal cask for interim storage of spent nuclear fuel (1). Outline of cask structure

    International Nuclear Information System (INIS)

    Shimizu, Masashi; Hayashi, Makoto; Kashiwakura, Jun

    2003-01-01

    Spent fuels discharged from nuclear power plants in Japan are planed to be reprocessed at the nuclear fuel recycle plant under construction at Rokkasho-mura. Since the amount of the spent fuels exceeds that of recycled fuel, the spent fuels have to be properly stored and maintained as recycle fuel resource until the beginning of the reprocessing. For that sake, interim storage installations are being constructed outside the nuclear power plants by 2010. The storage dry casks have been practically used as the interim storage in the nuclear power plants. From this reason, the storage system using the storage dry casks is promising as the interim storage installations away form the reactors, which are under discussion. In the interim storage facilities, the storage using the dry cask of the storage metal cask with business showings, having the function of transportation is now under discussion. By employing transportation and storage dual-purpose cask, the repack equipments can be exhausted, and the reliability of the interim storage installations can be increased. Hitachi, Ltd. has been developing the high reliable and economical transportation and storage dry metal cask. In this report, the outline of our developing transportation and storage dry cask is described. (author)

  19. Development of the graphic design and control system based on a graphic simulator for the spent fuel dismantling equipment

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J. Y.; Kim, S. H.; Song, T. G.; Yoon, J. S

    2000-06-01

    In this study, the graphic design system is developed for designing the spent fuel rod consolidation and the dismantling processes. This system is used throughout the design stages from the conceptual design to the motion analysis. Also, the real-time control system of the rod extracting equipment is developed. This system utilizes the graphic simulator which simulates the motion of the equipment in real time by synchronously connecting the control PC with the graphic server through the TCP/IP network. The developed system is expected to be used as an effective tool in designing the process equipment for the spent fuel management. And the real-time graphic control system can be effectively used to enhance the reliability and safety of the spent fuel handling process by providing the remote monitoring function of the process.

  20. Development of the graphic design and control system based on a graphic simulator for the spent fuel dismantling equipment

    International Nuclear Information System (INIS)

    Lee, J. Y.; Kim, S. H.; Song, T. G.; Yoon, J. S.

    2000-06-01

    In this study, the graphic design system is developed for designing the spent fuel rod consolidation and the dismantling processes. This system is used throughout the design stages from the conceptual design to the motion analysis. Also, the real-time control system of the rod extracting equipment is developed. This system utilizes the graphic simulator which simulates the motion of the equipment in real time by synchronously connecting the control PC with the graphic server through the TCP/IP network. The developed system is expected to be used as an effective tool in designing the process equipment for the spent fuel management. And the real-time graphic control system can be effectively used to enhance the reliability and safety of the spent fuel handling process by providing the remote monitoring function of the process

  1. Metal release from simulated fixed orthodontic appliances.

    Science.gov (United States)

    Hwang, C J; Shin, J S; Cha, J Y

    2001-10-01

    Most orthodontic appliances and archwires are stainless steel or nickel-titanium (NiTi) alloys that can release metal ions, with saliva as the medium. To measure metal released from the fixed orthodontic appliances currently in use, we fabricated simulated fixed orthodontic appliances that corresponded to half of the maxillary arch and soaked them in 50 mL of artificial saliva (pH 6.75 +/- 0.15, 37 degrees C) for 3 months. We used brackets, tubes, and bands made by Tomy (Tokyo, Japan). Four groups were established according to the appliance manufacturer and the type of metal in the .016 x .022-in archwires. Groups A and B were stainless steel archwires from Ormco (Glendora, Calif) and Dentaurum (Ispringen, Germany), respectively, and groups C and D were both NiTi archwires with Ormco's copper NiTi and Tomy's Bioforce sentalloy, respectively. Stainless steel archwires were heat treated in an electric furnace at 500 degrees C for 1 minute and quenched in water. We measured the amount of metal released from each group by immersion time. Our conclusions were as follows: (1) there was no increase in the amount of chromium released after 4 weeks in group A, 2 weeks in group B, 3 weeks in group C, and 8 weeks in group D; (2) there was no increase in the amount of nickel released after 2 weeks in group A, 3 days in group B, 7 days in group C, and 3 weeks in group D; and (3) there was no increase in the amount of iron released after 2 weeks in group A, 3 days in group B, and 1 day in groups C and D. In our 3-month-long investigation, we saw a decrease in metal released as immersion time increased.

  2. Organic oxalate as leachant and precipitant for the recovery of valuable metals from spent lithium-ion batteries

    International Nuclear Information System (INIS)

    Sun Liang; Qiu Keqiang

    2012-01-01

    Graphical abstract: Display Omitted Highlights: ► Vacuum pyrolysis as a pretreatment was used to separate cathode material from aluminum foils. ► Cobalt and lithium can be leached using oxalate while cobalt can be directly precipitated as cobalt oxalate. ► Cobalt and lithium can be separated efficiently from each other only in the oxalate leaching process. ► High reaction efficiency of LiCoO 2 was obtained with oxalate. - Abstract: Spent lithium-ion batteries containing lots of strategic resources such as cobalt and lithium are considered as an attractive secondary resource. In this work, an environmentally compatible process based on vacuum pyrolysis, oxalate leaching and precipitation is applied to recover cobalt and lithium from spent lithium-ion batteries. Oxalate is introduced as leaching reagent meanwhile as precipitant which leaches and precipitates cobalt from LiCoO 2 and CoO directly as CoC 2 O 4 ·2H 2 O with 1.0 M oxalate solution at 80 °C and solid/liquid ratio of 50 g L −1 for 120 min. The reaction efficiency of more than 98% of LiCoO 2 can be achieved and cobalt and lithium can also be separated efficiently during the hydrometallurgical process. The combined process is simple and adequate for the recovery of valuable metals from spent lithium-ion batteries.

  3. An analysis of harmful factors to storage stability of the reduced metallic spent fuel

    International Nuclear Information System (INIS)

    Joo, Z. S.; Yoo, K. S.; Cho, I. J.; Kook, D. H.; Lee, J. C.; Lee, E. P.

    2002-01-01

    To analyze harmful factors for the reduced uranium metal, which was mainly composed of uranium, several basic properties such as microstructure, immiscibility, thermal, fission product effects were surveyed. And the oxidation properties of metal uranium and uranium alloys were also studied to select alloying elements for producing a stable uranium metal

  4. Simulation of Thermal, Neutronic and Radiation Characteristics in Spent Nuclear Fuel and Radwaste Facilities

    International Nuclear Information System (INIS)

    Poskas, P.; Bartkus, G.

    1999-01-01

    The overview of the activities in the Division of Thermo hydro-mechanics related with the assessment of thermal, neutronic and radiation characteristics in spent nuclear fuel and radwaste facilities are performed. Also some new data about radiation characteristics of the RBMK-1500 spent nuclear fuel are presented. (author)

  5. EQ6 Calculations for Chemical Degradation Of N Reactor (U-Metal) Spent Nuclear Fuel Waste Packages

    International Nuclear Information System (INIS)

    P. Bernot

    2001-01-01

    The Monitored Geologic Repository (MGR) Waste Package Department of the Civilian Radioactive Waste Management System Management and Operating Contractor (CRWMS M and O) performed calculations to provide input for disposal of spent nuclear fuel (SNF) from the N Reactor, a graphite moderated reactor at the Department of Energy's (DOE) Hanford Site (ref. 1). The N Reactor core was fueled with slightly enriched (0.947 wt% and 0.947 to 1.25 wt% 235 U in Mark IV and Mark IA fuels, respectively) U-metal clad in Zircaloy-2 (Ref. 1, Sec. 3). Both types of N Reactor SNF have been considered for disposal at the proposed Yucca Mountain site. For some WPs, the outer shell and inner shell may breach (Ref. 3) allowing the influx of water. Water in the WP will moderate neutrons, increasing the likelihood of a criticality event within the WP; and the water may, in time, gradually leach the fissile components from the WP, further affecting the neutronics of the system. This study presents calculations of the long-term geochemical behavior of WPs containing two multi-canister overpacks (MCO) with either six baskets of Mark IA or five baskets of Mark IV intact N Reactor SNF rods (Ref. 1, Sec. 4) and two high-level waste (HLW) glass pour canisters (GPCs) arranged according to the codisposal concept (Ref. 4). The specific study objectives were to determine: (1) The extent to which fissile uranium will remain in the WP after corrosion/dissolution of the initial WP configuration (2) The extent to which fissile uranium will be carried out of the degraded WP by infiltrating water (such that internal criticality is no longer possible, but the possibility of external criticality may be enhanced); and (3) The nominal chemical composition for the criticality evaluations of the WP design, and to suggest the range of parametric variations for additional evaluations. The scope of this calculation, the chemical compositions (and subsequent criticality evaluations) of the simulations, is limited to

  6. EQ6 Calculations for Chemical Degradation Of N Reactor (U-Metal) Spent Nuclear Fuel Waste Packages

    Energy Technology Data Exchange (ETDEWEB)

    P. Bernot

    2001-02-27

    The Monitored Geologic Repository (MGR) Waste Package Department of the Civilian Radioactive Waste Management System Management & Operating Contractor (CRWMS M&O) performed calculations to provide input for disposal of spent nuclear fuel (SNF) from the N Reactor, a graphite moderated reactor at the Department of Energy's (DOE) Hanford Site (ref. 1). The N Reactor core was fueled with slightly enriched (0.947 wt% and 0.947 to 1.25 wt% {sup 235}U in Mark IV and Mark IA fuels, respectively) U-metal clad in Zircaloy-2 (Ref. 1, Sec. 3). Both types of N Reactor SNF have been considered for disposal at the proposed Yucca Mountain site. For some WPs, the outer shell and inner shell may breach (Ref. 3) allowing the influx of water. Water in the WP will moderate neutrons, increasing the likelihood of a criticality event within the WP; and the water may, in time, gradually leach the fissile components from the WP, further affecting the neutronics of the system. This study presents calculations of the long-term geochemical behavior of WPs containing two multi-canister overpacks (MCO) with either six baskets of Mark IA or five baskets of Mark IV intact N Reactor SNF rods (Ref. 1, Sec. 4) and two high-level waste (HLW) glass pour canisters (GPCs) arranged according to the codisposal concept (Ref. 4). The specific study objectives were to determine: (1) The extent to which fissile uranium will remain in the WP after corrosion/dissolution of the initial WP configuration (2) The extent to which fissile uranium will be carried out of the degraded WP by infiltrating water (such that internal criticality is no longer possible, but the possibility of external criticality may be enhanced); and (3) The nominal chemical composition for the criticality evaluations of the WP design, and to suggest the range of parametric variations for additional evaluations. The scope of this calculation, the chemical compositions (and subsequent criticality evaluations) of the simulations, is limited

  7. Residual salt separation from simulated spent nuclear fuel reduced in a LiCl-Li2O salt

    International Nuclear Information System (INIS)

    Hur, Jin-Mok; Hong, Sun-Seok; Seo, Chung-Seok

    2006-01-01

    The electrochemical reduction of spent nuclear fuel in LiCl-Li 2 O molten salt for the conditioning of spent nuclear fuel requires the separation of the residual salts from a reduced metal product after the reduction process. Considering the behavior of spent nuclear fuel during the electrochemical reduction process, a surrogate material matrix was constructed and inactive tests on a salt separation were carried out to produce the data required for active tests. Fresh uranium metal prepared from the electrochemical reduction of U 3 O 8 powder was used as the surrogates of the spent nuclear fuel Atomic Energy Society of Japan, Tokyo, Japan, All rights reservedopyriprocess. LiCl, Li 2 O, Y 2 O 3 and SrCl 2 were selected as the components of the residual salts. Interactions between the salts and their influence on the separation of the residual salts were analyzed by differential scanning calorimetry (DSC) and thermogravimetry (TG). Eutectic melting of LiCl-Li 2 O and LiCl-SrCl 2 led to a melting point which was lower than that of the LiCl molten salt was observed. Residual salts were separated by a vaporization method. Co-vaporization of LiCl-Li 2 O and LiCl-SrCl 2 was achieved below the temperatures which could make the uranium metal oxidation by Li 2 O possible. The salt vaporization rates at 950degC were measured as follows: LiCl-8 wt% Li 2 O>LiCl>LiCl-8 wt% SrCl 2 >SrCl 2 . (author)

  8. Electrolytic reduction of a simulated oxide spent fuel and the fates of representative elements in a Li{sub 2}O-LiCl molten salt

    Energy Technology Data Exchange (ETDEWEB)

    Park, Wooshin, E-mail: wooshin@kaeri.re.kr; Choi, Eun-Young; Kim, Sung-Wook; Jeon, Sang-Chae; Cho, Young-Hwan; Hur, Jin-Mok

    2016-08-15

    A series of electrolytic reduction experiments were carried out using a simulated oxide spent fuel to investigate the reduction behavior of elements in a mixed oxide condition and the fates of elements in the reduction process with 1.0 wt% Li{sub 2}O-LiCl. It was found out that 155% of the theoretical charge was enough to reduce the simulated. Te and Eu were expected to possibly exist in the precipitate and on the anode surface, whereas Ba and Sr showed apparent dissolution behaviors. Rare earths showed relatively low metal fractions from 28.2 to 34.0% except for Y. And the solubility of rare earths was observed to be low due to the low concentration of Li{sub 2}O. The reduction of U was successful as expected showing 99.8% of a metal fraction. Also it was shown that the reduction of ZrO{sub 2} would be effective when a relatively small amount was included in a metal oxide mixture.

  9. Simulation-based Investigation of Electric Power Generation by Using Gamma Radiation from Spent Nuclear Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Haneol; Yim, Mansung [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2014-05-15

    This study investigates the feasibility of using gamma radiation energy from spent nuclear fuels to produce electricity as emergency power source. The proposed electric power system includes electricity generation and storage. Electricity generation was based on conversion of gamma energy to light energy using a scintillator and then to electric energy using a solar cell. Generated electricity was to be stored in a battery as a power source. The efficiency of energy conversion and the extent of the resulting electric power source capability were examined by computer model-based simulation. Main factors which affect to total electric power generated include thermal power of nuclear power plant, average burn-up period for fuel rod, battery charging time, and scintillator thickness. The estimated total power generation and its possible application is discussed. Although the output power increases as scintillator becomes thicker, thick scintillator can be problem because of its high price. There are two ways to solve this problem. The first one is to use thin scintillator to whole fuel assembly area. The second one is to use thick scintillator to limited region. But the current per fuel assembly for the first case for 4000MWth, 72 month burnup is about several to tens of microampere scale, which is too small to charge. Because of this the system is supposed to have thick scintillator system with limited region. Based on the results, the generated electricity is expected to be insufficient to operate the safety injection pumps even at the maximum power output. This may be important for security purposes. Based on the current design, the solar cell efficiency is estimated to be around 1.5-4%. As the efficiency is a strong function of scintillation wavelength, improving the efficiency may be possible by broadening the wavelength through the use of multiple scintillators. Future work will also include validation of the results through experiments, and material reliability

  10. Simulation-based Investigation of Electric Power Generation by Using Gamma Radiation from Spent Nuclear Fuel

    International Nuclear Information System (INIS)

    Lee, Haneol; Yim, Mansung

    2014-01-01

    This study investigates the feasibility of using gamma radiation energy from spent nuclear fuels to produce electricity as emergency power source. The proposed electric power system includes electricity generation and storage. Electricity generation was based on conversion of gamma energy to light energy using a scintillator and then to electric energy using a solar cell. Generated electricity was to be stored in a battery as a power source. The efficiency of energy conversion and the extent of the resulting electric power source capability were examined by computer model-based simulation. Main factors which affect to total electric power generated include thermal power of nuclear power plant, average burn-up period for fuel rod, battery charging time, and scintillator thickness. The estimated total power generation and its possible application is discussed. Although the output power increases as scintillator becomes thicker, thick scintillator can be problem because of its high price. There are two ways to solve this problem. The first one is to use thin scintillator to whole fuel assembly area. The second one is to use thick scintillator to limited region. But the current per fuel assembly for the first case for 4000MWth, 72 month burnup is about several to tens of microampere scale, which is too small to charge. Because of this the system is supposed to have thick scintillator system with limited region. Based on the results, the generated electricity is expected to be insufficient to operate the safety injection pumps even at the maximum power output. This may be important for security purposes. Based on the current design, the solar cell efficiency is estimated to be around 1.5-4%. As the efficiency is a strong function of scintillation wavelength, improving the efficiency may be possible by broadening the wavelength through the use of multiple scintillators. Future work will also include validation of the results through experiments, and material reliability

  11. Analysis experiment in the mechanical non-oxidization decladding of the simulated spent fuel

    International Nuclear Information System (INIS)

    Jung, Jae Hoo; Yoon, Ji Sup; Hong, Dong Hee; Kim, Young Hwan; Lee, Jong Youl; Park, Gee Yung; Kim, Do Woo

    2000-11-01

    A decladding process, the first process of the fuel recycling, is accomplished by two different methods, chemical(wet type) method and mechanical(dry type) method. The chemical method is widely used in the existing commercial reprocessing plants because of its high efficiency, however, this process generates a lot of liquid radioactive wastes. To deal with this problem, the mechanical decladding process using the pressing mechanism is considered in this research. The pressing type decladding process is to extract the fuel pellet by inserting the pin into the fuel clad and by pressing out the fuel pellet. The pressing type decladding device equipped with two manually driven handles had been developed in the first step, and the performance of this device had been tested by using the simulated fuel rods filled with the plaster instead of spent fuel pellet. The experimental result showed that the best fuel extraction and recovery rate can be obtaind with the pellet size of 30 mm. In the second step, the manually driven handle had been replaced with the motor drive machanism. Also, the design of the device had been modified in consideration of the remote operation, in consideration of the hot cell operation. Several problems had been revealed such as the dust generation, difficulty in quantification of fuel mass, contamination of a spring module, difficulty in remote disassembly of the servo motor, and inaccurate positioning of the rotary plate. Considering these problems, the design has been again modified, at this year, by installing a dust collection device, a brushing mechanism, a countermeter, a pellet recognization sensor; by modifying the positioning mechanism of the rotary plate; and by modularizing the press pin mechanism. Also, in this modification, the 3 dimensional graphic design method has been adopted. with this modifications, the improved mechanical decladding device has been developed and its performance is investigated through a series of experiments

  12. Organic reductants based leaching: A sustainable process for the recovery of valuable metals from spent lithium ion batteries.

    Science.gov (United States)

    Chen, Xiangping; Guo, Chunxiu; Ma, Hongrui; Li, Jiazhu; Zhou, Tao; Cao, Ling; Kang, Duozhi

    2018-05-01

    It is significant to recover metal values from spent lithium ion batteries (LIBs) for the alleviation or prevention of potential risks towards environmental pollution and public health, as well as for the conservation of valuable metals. Herein a hydrometallurgical process was proposed to explore the possibility for the leaching of different metals from waste cathodic materials (LiCoO 2 ) of spent LIBs using organics as reductant in sulfuric acid medium. According to the leaching results, about 98% Co and 96% Li can be leached under the optimal experimental conditions of reaction temperature - 95 °C, reaction time - 120 min, reductive agent dosage - 0.4 g/g, slurry density - 25 g/L, concentration of sulfuric acid-3 mol/L in H 2 SO 4  + glucose leaching system. Similar results (96% Co and 100% Li) can be obtained in H 2 SO 4  + sucrose leaching system under optimized leaching conditions. Despite a complete leaching of Li (∼100%), only 54% Co can be dissolved in the H 2 SO 4  + cellulose leaching system under optimized leaching conditions. Finally, different characterization methods, including UV-Vis, FT-IR, SEM and XRD, were employed for the tentative exploration of reductive leaching reactions using organic as reductant in sulfuric acid medium. All the leaching and characterization results confirm that both glucose and sucrose are effective reductants during leaching, while cellulose should be further degraded to organics with low molecular weights to achieve a satisfactory leaching performance. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Using contraband simulators for portal metal detector testing

    Energy Technology Data Exchange (ETDEWEB)

    Murray, D.W.

    1992-08-01

    Because contraband materials or items are either too dangerous or too expensive, contraband simulators have been widely used to test contraband detection equipment. Very realistic bomb simulators have been used to test x-ray scanners, and common radioactive sources have been used successfully to test the operation of special nuclear material (SNM) radiation detectors. The simulators used to test early metal detectors were also reasonably successful; however, these simulators were rapidly outdated by the introduction of modern active field metal detectors. This paper describes some of the earlier attempts to develop metal detector test simulators. A successful highly enriched uranium (HEU) simulator for metal detector testing is described that has duplicated all the characteristics modern equipment is capable of detecting. The paper also describes the development needed to produce handgun simulators that could be used effectively for metal detector performance testing.

  14. Using contraband simulators for portal metal detector testing

    Energy Technology Data Exchange (ETDEWEB)

    Murray, D.W.

    1992-01-01

    Because contraband materials or items are either too dangerous or too expensive, contraband simulators have been widely used to test contraband detection equipment. Very realistic bomb simulators have been used to test x-ray scanners, and common radioactive sources have been used successfully to test the operation of special nuclear material (SNM) radiation detectors. The simulators used to test early metal detectors were also reasonably successful; however, these simulators were rapidly outdated by the introduction of modern active field metal detectors. This paper describes some of the earlier attempts to develop metal detector test simulators. A successful highly enriched uranium (HEU) simulator for metal detector testing is described that has duplicated all the characteristics modern equipment is capable of detecting. The paper also describes the development needed to produce handgun simulators that could be used effectively for metal detector performance testing.

  15. Simulation codes of chemical separation process of spent fuel reprocessing. Tool for process development and safety research

    International Nuclear Information System (INIS)

    Asakura, Toshihide; Sato, Makoto; Matsumura, Masakazu; Morita, Yasuji

    2005-01-01

    This paper reviews the succeeding development and utilization of Extraction System Simulation Code for Advanced Reprocessing (ESSCAR). From the viewpoint of development, more tests with spent fuel and calculations should be performed with better understanding of the physico-chemical phenomena in a separation process. From the viewpoint of process safety research on fuel cycle facilities, it is important to know the process behavior of a key substance; being highly reactive but existing only trace amount. (author)

  16. Seal performance of thermal aged metal gasket of dual purpose metal cask for interim spent fuel storage after external impact load

    International Nuclear Information System (INIS)

    Takeshi Yokoyama; Masami Kato; Satoshi Itooka

    2005-01-01

    As for interim storage for spent nuclear fuels using dual purpose dry metal cask in Japan, we recognize one of the important technical issues that there is a possibility for the cask with degraded metal gasket during storage to apply to transportation. In our study until 2003 focused on degradation of important components for the cask safety performance during storage and application to transportation, for metal gasket, we conducted property tests for degradation and influence of lid movement on seal performance, and furthermore verification tests. From the results, we developed the method to evaluate leak rate from lid with degraded metal gasket at accidents during transportation and in addition, we found as follows: Lid would hardly move and leak rate would not increase seriously during fire event. Leak rate from lid with degraded metal gasket could be evaluated by using results of leak rate trend depending on horizontal displacement of lid by external impact load. So, with regard to influence of lid movement on seal performance, we conducted additional test for extending horizontal displacement in lid moving in 2004. In addition, seal performance was discussed from the results, both previous and latest test. (authors)

  17. Determining heavy metals in spent compact fluorescent lamps (CFLs) and their waste management challenges: Some strategies for improving current conditions

    International Nuclear Information System (INIS)

    Taghipour, Hassan; Amjad, Zahra; Jafarabadi, Mohamad Asghari; Gholampour, Akbar; Norouz, Prviz

    2014-01-01

    Highlights: • Heavy metals in spent compact fluorescent lamps (CFLs) determined. • Current waste management condition of CFLs in Iran assessed. • Currently, waste of CFLs is disposed by municipal waste stream in waste landfills. • We propose extended producer responsibility (EPR) for CFLs waste management. - Abstract: From environmental viewpoint, the most important advantage of compact fluorescent lamps (CFLs) is reduction of green house gas emissions. But their significant disadvantage is disposal of spent lamps because of containing a few milligrams of toxic metals, especially mercury and lead. For a successful implementation of any waste management plan, availability of sufficient and accurate information on quantities and compositions of the generated waste and current management conditions is a fundamental prerequisite. In this study, CFLs were selected among 20 different brands in Iran. Content of heavy metals including mercury, lead, nickel, arsenic and chromium was determined by inductive coupled plasma (ICP). Two cities, Tehran and Tabriz, were selected for assessing the current waste management condition of CFLs. The study found that waste generation amount of CFLs in the country was about 159.80, 183.82 and 153.75 million per year in 2010, 2011 and 2012, respectively. Waste generation rate of CFLs in Iran was determined to be 2.05 per person in 2012. The average amount of mercury, lead, nickel, arsenic and chromium was 0.417, 2.33, 0.064, 0.056 and 0.012 mg per lamp, respectively. Currently, waste of CFLs is disposed by municipal waste stream in waste landfills. For improving the current conditions, we propose by considering the successful experience of extended producer responsibility (EPR) in other electronic waste management. The EPR program with advanced recycling fee (ARF) is implemented for collecting and then recycling CFLs. For encouraging consumers to take the spent CFLs back at the end of the products’ useful life, a proportion of

  18. Determining heavy metals in spent compact fluorescent lamps (CFLs) and their waste management challenges: Some strategies for improving current conditions

    Energy Technology Data Exchange (ETDEWEB)

    Taghipour, Hassan, E-mail: hteir@yahoo.com [Department of Environmental Health Engineering, Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of); Amjad, Zahra [Student Research Committee, Department of Environmental Health Engineering, Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of); Jafarabadi, Mohamad Asghari [Medical Education Research Center, Department of Statistics and Epidemiology, Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of); Gholampour, Akbar [Department of Environmental Health Engineering, Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of); Norouz, Prviz [Environmental Health Engineering, Shahid Beheshti University of Medical Sciences, Tehran (Iran, Islamic Republic of)

    2014-07-15

    Highlights: • Heavy metals in spent compact fluorescent lamps (CFLs) determined. • Current waste management condition of CFLs in Iran assessed. • Currently, waste of CFLs is disposed by municipal waste stream in waste landfills. • We propose extended producer responsibility (EPR) for CFLs waste management. - Abstract: From environmental viewpoint, the most important advantage of compact fluorescent lamps (CFLs) is reduction of green house gas emissions. But their significant disadvantage is disposal of spent lamps because of containing a few milligrams of toxic metals, especially mercury and lead. For a successful implementation of any waste management plan, availability of sufficient and accurate information on quantities and compositions of the generated waste and current management conditions is a fundamental prerequisite. In this study, CFLs were selected among 20 different brands in Iran. Content of heavy metals including mercury, lead, nickel, arsenic and chromium was determined by inductive coupled plasma (ICP). Two cities, Tehran and Tabriz, were selected for assessing the current waste management condition of CFLs. The study found that waste generation amount of CFLs in the country was about 159.80, 183.82 and 153.75 million per year in 2010, 2011 and 2012, respectively. Waste generation rate of CFLs in Iran was determined to be 2.05 per person in 2012. The average amount of mercury, lead, nickel, arsenic and chromium was 0.417, 2.33, 0.064, 0.056 and 0.012 mg per lamp, respectively. Currently, waste of CFLs is disposed by municipal waste stream in waste landfills. For improving the current conditions, we propose by considering the successful experience of extended producer responsibility (EPR) in other electronic waste management. The EPR program with advanced recycling fee (ARF) is implemented for collecting and then recycling CFLs. For encouraging consumers to take the spent CFLs back at the end of the products’ useful life, a proportion of

  19. Atomistic simulation of nanoformed metallic glass

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Cheng-Da, E-mail: nanowu@cycu.edu.tw

    2015-07-15

    Highlights: • STZ forms at substrate surface underneath punch. • Atoms underneath punch have higher speeds at larger mold displacement. • Stick-slip phenomenon becomes more obvious with increasing imprint speed. • Great pattern transfer is obtained with unloading at low temperatures. - Abstract: The effects of forming speed and temperature on the forming mechanism and mechanics of Cu{sub 50}Zr{sub 25}Ti{sub 25} metallic glass are studied using molecular dynamics simulations based on the second-moment approximation of the many-body tight-binding potential. These effects are investigated in terms of atomic trajectories, flow field, slip vectors, internal energy, radial distribution function, and elastic recovery of nanoimprint lithography (NIL) patterns. The simulation results show that a shear transformation zone (STZ) forms at the substrate surface underneath the mold during the forming process. The STZ area increases with mold displacement (D). The movement speed of substrate atoms underneath the mold increases with increasing D value. The movement directions of substrate atoms underneath the mold are more agreeable for a larger D value. The stick-slip phenomenon becomes more obvious with increasing D value and imprint speed. The substrate energy increases with increasing imprint speed and temperature. Great NIL pattern transfer is obtained with unloading at low temperatures (e.g., room temperature)

  20. Burnup simulations and spent fuel characteristics of ZrO{sub 2} based inert matrix fuels

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, E.A. [Department of Mechanical Engineering, University of Texas, Austin, TX (United States); Deinert, M.R. [Department of Theoretical and Applied Mechanics, Cornell University, Ithaca, NY (United States)]. E-mail: mrd6@cornell.edu; Herring, S.T. [Idaho National Laboratory, Idaho Falls, ID (United States); Cady, K.B. [Department of Theoretical and Applied Mechanics, Cornell University, Ithaca, NY (United States)

    2007-03-31

    Reducing the inventory of long lived isotopes that are contained in spent nuclear fuel is essential for maximizing repository capacity and extending the lifetime of related storage. Because of their non-fertile matrices, inert matrix fuels (IMF's) could be an ideal vehicle for using light-water reactors to help decrease the inventory of plutonium and other transuranics (neptunium, americium, curium) that are contained within spent uranium oxide fuel (UOX). Quantifying the characteristics of spent IMF is therefore of fundamental importance to determining its effect on repository design and capacity. We consider six ZrO{sub 2} based IMF formulations with different transuranic loadings in a 1-8 IMF to UOX pin-cell arrangement. Burnup calculations are performed using a collision probability model where transport of neutrons through space is modeled using fuel to moderator transport and escape probabilities. The lethargy dependent neutron flux is treated with a high resolution multigroup thermalization method. The results of the reactor physics model are compared to a benchmark case performed with Montebruns and indicate that the approach yields reliable results applicable to high-level analyses of spent fuel isotopics. The data generated show that a fourfold reduction in the radiological and integrated thermal output is achievable in single recycle using IMF, as compared to direct disposal of an energy equivalent spent UOX.

  1. Acquisition of Co metal from spent lithium-ion battery using emulsion liquid membrane technology and emulsion stability test

    Science.gov (United States)

    Yuliusman; Wulandari, P. T.; Amiliana, R. A.; Huda, M.; Kusumadewi, F. A.

    2018-03-01

    Lithium-ion batteries are the most common type to be used as energy source in mobile phone. The amount of lithium-ion battery wastes is approximated by 200 – 500 ton/year. In one lithium-ion battery, there are 5 – 20% of cobalt metal, depend on the manufacturer. One of the way to recover a valuable metal from waste is leaching process then continued with extraction, which is the aim of this study. Spent lithium-ion batteries will be characterized with EDX and AAS, the result will show the amount of cobalt metal with form of LiCoO2 in the cathode. Hydrochloric acid concentration used is 4 M, temperature 80°C, and reaction time 1 hour. This study will discuss the emulsion stability test on emulsion liquid membrane. The purpose of emulsion stability test in this study was to determine optimum concentration of surfactant and extractant to produce a stable emulsion. Surfactant and extractant used were SPAN 80 and Cyanex 272 respectively with both concentrations varied. Membrane and feed phase ratios used in this experiment was 1 : 2. The optimum results of this study were SPAN 80 concentrations of 10% w/v and Cyanex 272 0.7 M.

  2. Hydrometallurgical process for the recovery of metal values from spent lithium-ion batteries in citric acid media.

    Science.gov (United States)

    Chen, Xiangping; Zhou, Tao

    2014-11-01

    In this paper, a hydrometallurgical process has been proposed to recover valuable metals from spent lithium-ion batteries in citric acid media. Leaching efficiencies as high as 97%, 95%, 94%, and 99% of Ni, Co, Mn, and Li were achieved under the optimal leaching experimental conditions of citric acid concentration of 2 mol L(-1), leaching temperature of 80 °C, leaching time of 90 min, liquid-solid ratio of 30 ml g(-1), and 2 vol. % H2O2. For the metals recovery process, nickel and cobalt were selectively precipitated by dimethylglyoxime reagent and ammonium oxalate sequentially. Then manganese was extracted by Na-D2EHPA and the manganese-loaded D2EHPA was stripped with sulfuric acid. The manganese was recovered as MnSO4 in aqueous phase and D2EHPA could be reused after saponification. Finally, lithium was precipitated by 0.5 mol L(-1) sodium phosphate. Under their optimal conditions, the recovery percentages of Ni, Co, Mn, and Li can reach 98%, 97%, 98%, and 89%, respectively. This is a relatively simple route in which all metal values could be effectively leached and recovered in citric acid media. © The Author(s) 2014.

  3. Loss of cooling accident simulation of nuclear power station spent-fuel pool

    Energy Technology Data Exchange (ETDEWEB)

    Lee, M.; Liang, K-S., E-mail: mlee@ess.nthu.edu.tw, E-mail: ksliang_1@hotmail.com [National Tsing Hua Univ., Hsinchu, Taiwan (China); Lin, K-Y., E-mail: syrup760914@gmail.com [Taiwan Power Company, Taiwan (China)

    2014-07-01

    The core melt down accident of Fukushima Nuclear Power Station on March 11th, 2011 alerted nuclear industry that the long term loss of cooling of spent fuel pool may need some attention. The target plant analyzed is the Chinshan Nuclear Power Station of Taiwan Power Company. The 3-Dimensional RELAP5 input deck of the spent fuel pool of the station is built. The results indicate that spent fuel of Chinshan Nuclear Power Station is uncovered at 6.75 days after an accident of loss cooling takes place and cladding temperature rises above 2,200{sup o}F around 8 days. The time is about 13 hours earlier than the results predicted using simple energy balance method. The results also show that the impact of Counter Current Flow Limitation (CCFL) and radiation heat transfer model is marginal. (author)

  4. Determining heavy metals in spent compact fluorescent lamps (CFLs) and their waste management challenges: some strategies for improving current conditions.

    Science.gov (United States)

    Taghipour, Hassan; Amjad, Zahra; Jafarabadi, Mohamad Asghari; Gholampour, Akbar; Norouz, Prviz

    2014-07-01

    From environmental viewpoint, the most important advantage of compact fluorescent lamps (CFLs) is reduction of green house gas emissions. But their significant disadvantage is disposal of spent lamps because of containing a few milligrams of toxic metals, especially mercury and lead. For a successful implementation of any waste management plan, availability of sufficient and accurate information on quantities and compositions of the generated waste and current management conditions is a fundamental prerequisite. In this study, CFLs were selected among 20 different brands in Iran. Content of heavy metals including mercury, lead, nickel, arsenic and chromium was determined by inductive coupled plasma (ICP). Two cities, Tehran and Tabriz, were selected for assessing the current waste management condition of CFLs. The study found that waste generation amount of CFLs in the country was about 159.80, 183.82 and 153.75 million per year in 2010, 2011 and 2012, respectively. Waste generation rate of CFLs in Iran was determined to be 2.05 per person in 2012. The average amount of mercury, lead, nickel, arsenic and chromium was 0.417, 2.33, 0.064, 0.056 and 0.012 mg per lamp, respectively. Currently, waste of CFLs is disposed by municipal waste stream in waste landfills. For improving the current conditions, we propose by considering the successful experience of extended producer responsibility (EPR) in other electronic waste management. The EPR program with advanced recycling fee (ARF) is implemented for collecting and then recycling CFLs. For encouraging consumers to take the spent CFLs back at the end of the products' useful life, a proportion of ARF (for example, 50%) can be refunded. On the other hand, the government and Environmental Protection Agency should support and encourage recycling companies of CFLs both technically and financially in the first place. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Numerical simulations of the metallicity distribution in dwarf spheroidal galaxies

    NARCIS (Netherlands)

    Ripamonti, E.; Tolstoy, E.; Helmi, A.; Battaglia, G.; Abel, T.

    2006-01-01

    Abstract: Recent observations show that the number of stars with very low metallicities in the dwarf spheroidal satellites of the Milky Way is low, despite the low average metallicities of stars in these systems. We undertake numerical simulations of star formation and metal enrichment of dwarf

  6. Monte Carlo Simulation of Quantitative Electron Probe Microanalysis of the PWR Spent Fuel with a Pt Coating

    International Nuclear Information System (INIS)

    Kwon, Hyoung Mun; Lee, Hyung Kwon; Son, Young Zoon; Chun, Yong Bum

    2012-01-01

    The PWR spent fuel sample should be coated with conducting material in order to provide a path for electrons and to prevent charging. Generally, the ZAF method has been used for quantitative electron probe microanalysis of conducting samples. However, the coated samples are not applicable for the ZAF method. Probe current, primary electron energy and x-ray produced by the primary beam are attenuated within the coating films. The electron and X-ray depth distributions for a quantitative electron probe micro analysis were simulated by the CASINO Monte Carlo program [2] to evaluate the x-ray attenuation within the Pt coating films. The target samples are the PWR spent fuels with 50 GWd/tU of burnup , 6 years of cooling time and a Pt coating film (3, 5, 7, 10 and 15 nm thickness)

  7. Monte Carlo Simulation of Quantitative Electron Probe Microanalysis of the PWR Spent Fuel with a Pt Coating

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Hyoung Mun; Lee, Hyung Kwon; Son, Young Zoon; Chun, Yong Bum [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-05-15

    The PWR spent fuel sample should be coated with conducting material in order to provide a path for electrons and to prevent charging. Generally, the ZAF method has been used for quantitative electron probe microanalysis of conducting samples. However, the coated samples are not applicable for the ZAF method. Probe current, primary electron energy and x-ray produced by the primary beam are attenuated within the coating films. The electron and X-ray depth distributions for a quantitative electron probe micro analysis were simulated by the CASINO Monte Carlo program [2] to evaluate the x-ray attenuation within the Pt coating films. The target samples are the PWR spent fuels with 50 GWd/tU of burnup , 6 years of cooling time and a Pt coating film (3, 5, 7, 10 and 15 nm thickness)

  8. Status of radiation shield design for liquid metal fast breeder reactor spent fuel shipping cask application

    International Nuclear Information System (INIS)

    Dupree, S.A.; Rack, H.J.

    1976-09-01

    Neutron and gamma-ray transport calculations in one-dimensional cylindrical geometry have been performed on a trial reference LMFBR spent-fuel shipping cask that could transport one CRBR subassembly. In the study it was assumed that a layer of depleted U and a layer of neutron shielding materials were sandwiched between 5.08-cm-thick (2-in.) layers of stainless steel. The thicknesses of the internal layers were adjusted until a balanced dose rate (50 percent neuton and 50 percent gamma-ray) of 5 mrem/hr was achieved at a point 1.83 m (6 ft) from the cask surface. Neutron-shield materials considered were LiH, Be, B 4 C, DiH 2 . 5 , and C (graphite). Of these materials, LiH provided the smallest, lightest, and least expensive cask; however, its use would be contigent on expansion of production facilities for LiH and development of a canning or cladding procedure. The B 4 C shielded cask would offer the best alternative if the designs were limited to those using currently available materials

  9. Opportunities in the certification of metal storage casks for spent fuel transport

    International Nuclear Information System (INIS)

    Teer, B.R.

    1988-01-01

    The current regulatory climate in the Transportation Certification Branch of the Nuclear Regulatory Commission is such that the applicant for a Certificate of Compliance must submit a well prepared, comprehensive Safety Analysis Report which meets all requirements of Regulatory Guide. All methods and procedures for structural, nuclear and thermal analyses must be qualified and benchmarked. The materials used for the containment boundary, impact limiters, neutron and gamma shields and internal structures must have documented and reproducible properties and, ideally, be referred in a recognized national standard. And, finally, in most cases, the analyses must be supplemented by model or full scale test results. The paper discusses some recent Transnuclear experiences with the NRC Transportation Certification Branch in attempting to get the TN-BRP and TN-REG casks certified for the transport of spent fuel. The authors have utilized non-standard materials for the baskets and a modified material for the containment. The impact limiters are not of a conventional design. Some of the analytical procedures are proprietary codes which are not used by others in the industry

  10. Standard review plan for reviewing safety analysis reports for dry metallic spent fuel storage casks

    International Nuclear Information System (INIS)

    1988-01-01

    The Cask Standard Review Plan (CSRP) has been prepared as guidance to be used in the review of Cask Safety Analysis Reports (CSARs) for storage packages. The principal purpose of the CSRP is to assure the quality and uniformity of storage cask reviews and to present a well-defined base from which to evaluate proposed changes in the scope and requirements of reviews. The CSRP also sets forth solutions and approaches determined to be acceptable in the past by the NRC staff in dealing with a specific safety issue or safety-related design area. These solutions and approaches are presented in this form so that reviewers can take consistent and well-understood positions as the same safety issues arise in future cases. An applicant submitting a CSAR does not have to follow the solutions or approaches presented in the CSRP. However, applicants should recognize that the NRC staff has spent substantial time and effort in reviewing and developing their positions for the issues. A corresponding amount of time and effort will probably be required to review and accept new or different solutions and approaches

  11. Recovery of valuable metals from spent HEV NiMH battery leach solutions

    OpenAIRE

    Ricknell, Jonas

    2017-01-01

    As the demand on resources is increasing worldwide, the process of recycling material has become more important. The specific recycling of metals used in car batteries, and more specifically in the large batteries used in hybrid electric vehicles, is a rising concern where the industrially implemented recycling processes concerning these batteries that exist today are often highly pollutant and energy consuming. In the present study, an alternative hydrometallurgical recycling process of the ...

  12. Metals, heavy metals and microorganism removal from spent filter backwash water by hybrid coagulation-UF processes

    Directory of Open Access Journals (Sweden)

    Mokhtar Mahdavi

    2018-04-01

    Full Text Available Spent filter backwash water (SFBW reuse has attracted particular attention, especially in countries that experience water scarcity. It can act as a permanent water source until the water treatment plant is working. In this study, the concentrations of Fe, Al, Pb, As, and Cd with total and fecal coliform (TC/FC were investigated in raw and treated SFBW by hybrid coagulation-UF processes. The pilot plant consisted of pre-sedimentation, coagulation, flocculation, clarification, and ultrafiltration (UF units. Poly-aluminum ferric chloride (PAFCL and ferric chloride (FeCl3 were used as pretreatment. The results showed that, at the optimum dose of PAFCl, the average removal of TC and FC was 88 and 79% and with PAFCl-UF process, it reached 100 and 100%, respectively. For FeCl3, removal efficiency of TC and FC were 81 and 72% and by applying FeCl3-UF process, it reached 100 and 100%, respectively. In comparison with FeCl3, PAFCl showed better removal efficiency for Fe, Pb, As, and Cd, except residual Al concentration. Coagulation-UF process could treat SFBW efficiently and treated SFBW could meet the US-EPA drinking water standard. Health risk index values of Fe, AL, Pb, AS, and Cd in treated SFBW indicate no risk of exposure to the use of this water.

  13. Multistage leaching of metals from spent lithium ion battery waste using electrochemically generated acidic lixiviant.

    Science.gov (United States)

    Boxall, N J; Adamek, N; Cheng, K Y; Haque, N; Bruckard, W; Kaksonen, A H

    2018-04-01

    Lithium ion battery (LIB) waste contains significant valuable resources that could be recovered and reused to manufacture new products. This study aimed to develop an alternative process for extracting metals from LIB waste using acidic solutions generated by electrolysis for leaching. Results showed that solutions generated by electrolysis of 0.5 M NaCl at 8 V with graphite or mixed metal oxide (MMO) electrodes were weakly acidic and leach yields obtained under single stage (batch) leaching were poor (leaching with the graphite electrolyte solution improved leach yields overall, but the electrodes corroded over time. Though yields obtained with both electrolyte leach solutions were low when compared to the 4 M HCl control, there still remains potential to optimise the conditions for the generation of the acidic anolyte solution and the solubilisation of valuable metals from the LIB waste. A preliminary value proposition indicated that the process has the potential to be economically feasible if leach yields can be improved, especially based on the value of recoverable cobalt and lithium. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Export control guide: Spent nuclear fuel reprocessing and preparation of plutonium metal

    International Nuclear Information System (INIS)

    1993-10-01

    The international Treaty on the Non-Proliferation of Nuclear Weapons, also referred to as the Non-Proliferation Treaty (NPT), states in Article III, paragraph 2(b) that open-quotes Each State Party to the Treaty undertakes not to provide . . . equipment or material especially designed or prepared for the processing, use or production of special fissionable material to any non-nuclear-weapon State for peaceful purposes, unless the source or special fissionable material shall be subject to the safeguards required by this Article.close quotes This guide was prepared to assist export control officials in the interpretation, understanding, and implementation of export laws and controls relating to the international Trigger List for irradiated nuclear fuel reprocessing equipment, components, and materials. The guide also contains information related to the production of plutonium metal. Reprocessing and its place in the nuclear fuel cycle are described briefly; the standard procedure to prepare metallic plutonium is discussed; steps used to prepare Trigger List controls are cited; descriptions of controlled items are given; and special materials of construction are noted. This is followed by a comprehensive description of especially designed or prepared equipment, materials, and components of reprocessing and plutonium metal processes and includes photographs and/or pictorial representations. The nomenclature of the Trigger List has been retained in the numbered sections of this document for clarity

  15. Recovery of valuable metals from waste cathode materials of spent lithium-ion batteries using mild phosphoric acid

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xiangping, E-mail: chenxiangping101@163.com [School of Environmental Science and Engineering, Shaanxi University of Science & Technology, Xi’an 710021 (China); College of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Ma, Hongrui, E-mail: mahr@sust.edu.cn [School of Environmental Science and Engineering, Shaanxi University of Science & Technology, Xi’an 710021 (China); Luo, Chuanbao; Zhou, Tao [College of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China)

    2017-03-15

    Graphical abstract: Cobalt can be directly recovered as Co{sub 3}(PO{sub 4}){sub 2} from waste LiCoO{sub 2} using H{sub 3}PO{sub 4} as leaching and precipitating agent. - Highlights: • Phosphoric acid was innovatively used as leaching and precipitating agent. • Over 99% Co and Li can be separated and recovered in a single leaching step. • Co and Li can be separated under mild conditions of 40 °C and 0.7 M H{sub 3}PO{sub 4}. • Activation energy values for Co and Li are 7.3 and 10.168 kJ/mol. • Cobalt phosphate (97.1% in purity) can be obtained as the leaching product. - Abstract: Sustainable recycling of valuable metals from spent lithium-ion batteries (LIBs) may be necessary to alleviate the depletion of strategic metal resources and potential risk of environmental pollution. Herein a hydrometallurgical process was proposed to explore the possibility for the recovery of valuable metals from the cathode materials (LiCoO{sub 2}) of spent LIBs using phosphoric acid as both leaching and precipitating agent under mild leaching conditions. According to the leaching results, over 99% Co can be separated and recovered as Co{sub 3}(PO{sub 4}){sub 2} in a short-cut process involved merely with leaching and filtrating, under the optimized leaching conditions of 40 °C (T), 60 min (t), 4 vol.% H{sub 2}O{sub 2}, 20 mL g{sup −1} (L/S) and 0.7 mol/L H{sub 3}PO{sub 4}. Then leaching kinetics was investigated based on the logarithmic rate kinetics model and the obtained results indicate that the leaching of Co and Li fits well with this model and the activation energies (Ea) for Co and Li are 7.3 and 10.2 kJ/mol, respectively. Finally, it can be discovered from characterization results that the obtained product is 97.1% pure cobalt phosphate (Co{sub 3}(PO{sub 4}){sub 2}).

  16. Full scale simulations of accidents on spent-nuclear-fuel shipping systems

    International Nuclear Information System (INIS)

    Yoshimura, H.R.

    1978-01-01

    In 1977 and 1978, five first-of-a-kind full scale tests of spent-nuclear-fuel shipping systems were conducted at Sandia Laboratories. The objectives of this broad test program were (1) to assess and demonstrate the validity of current analytical and scale modeling techniques for predicting damage in accident conditions by comparing predicted results with actual test results, and (2) to gain quantitative knowledge of extreme accident environments by assessing the response of full scale hardware under actual test conditions. The tests were not intended to validate the present regulatory standards. The spent fuel cask tests fell into the following configurations: crashes of a truck-transport system into a massive concrete barrier (100 and 130 km/h); a grade crossing impact test (130 km/h) involving a locomotive and a stalled tractor-trailer; and a railcar shipping system impact into a massive concrete barrier (130 km/h) followed by fire. In addition to collecting much data on the response of cask transport systems, the program has demonstrated thus far that current analytical and scale modeling techniques are valid approaches for predicting vehicular and cask damage in accident environments. The tests have also shown that the spent casks tested are extremely rugged devices capable of retaining their radioactive contents in very severe accidents

  17. A system automatic study for the spent fuel rod cutting and simulated fuel pellet extraction device

    International Nuclear Information System (INIS)

    Jeong, J. H.; Yun, J. S.; Hong, D. H.; Kim, Y. H.; Park, K. Y.

    2001-01-01

    A fuel pellet extraction device of the spent fuel rods is described. The device consists of a cutting device of the spent fuel rods and the decladding device of the fuel pellets. The cutting device is to cut a spent fuel rod to n optimal size for fast decladding operation. To design the device, the fuel rod properties are investigated including the dimension and material of fuel rod tubes and pellets. Also, various methods of existing cutting method are investigated. The design concepts accommodate remote operability for the Hot-Cell(radioactive ) area operation. Also, the modularization of the device structure is considered for the easy maintenance. The decladding device is to extract the fuel pellet from the rod cut. To design this device, the existing method is investigated including the chemical and mechanical decladding methods. From the view point of fuel recovery and feasibility of implementation. it is concluded that the chemical decladding method is not appropriate due to the mass production of radioactive liquid wastes, in spite of its high fuel recovery characteristics. Hence, in this paper, the mechanical decladding method is adopted and the device is designed so as to be applicable to various lengths of rod-cuts. As like the cutting device,the concepts of remote operability and maintainability is considered. Both devices are fabricated and the performance is investigated through a series of experiments. From the experimental result, the optimal operational condition of the devices is established

  18. Microcomputer simulation model for facility performance assessment: a case study of nuclear spent fuel handling facility operations

    International Nuclear Information System (INIS)

    Chockie, A.D.; Hostick, C.J.; Otis, P.T.

    1985-10-01

    A microcomputer based simulation model was recently developed at the Pacific Northwest Laboratory (PNL) to assist in the evaluation of design alternatives for a proposed facility to receive, consolidate and store nuclear spent fuel from US commercial power plants. Previous performance assessments were limited to deterministic calculations and Gantt chart representations of the facility operations. To insure that the design of the facility will be adequate to meet the specified throughput requirements, the simulation model was used to analyze such factors as material flow, equipment capability and the interface between the MRS facility and the nuclear waste transportation system. The simulation analysis model was based on commercially available software and application programs designed to represent the MRS waste handling facility operations. The results of the evaluation were used by the design review team at PNL to identify areas where design modifications should be considered. 4 figs

  19. Sustainable recovery of valuable metals from spent lithium-ion batteries using DL-malic acid: Leaching and kinetics aspect.

    Science.gov (United States)

    Sun, Conghao; Xu, Liping; Chen, Xiangping; Qiu, Tianyun; Zhou, Tao

    2018-02-01

    An eco-friendly and benign process has been investigated for the dissolution of Li, Co, Ni, and Mn from the cathode materials of spent LiNi 1/3 Co 1/3 Mn 1/3 O 2 batteries, using DL-malic acid as the leaching agent in this study. The leaching efficiencies of Li, Co, Ni, and Mn can reach about 98.9%, 94.3%, 95.1%, and 96.4%, respectively, under the leaching conditions of DL-malic acid concentration of 1.2 M, hydrogen peroxide content of 1.5 vol.%, solid-to-liquid ratio of 40 g l -1 , leaching temperature of 80°C, and leaching time of 30 min. In addition, the leaching kinetic was investigated based on the shrinking model and the results reveal that the leaching reaction is controlled by chemical reactions within 10 min with activation energies (Ea) of 21.3 kJ·mol -1 , 30.4 kJ·mol -1 , 27.9 kJ·mol -1 , and 26.2 kJ·mol -1 for Li, Co, Ni, and Mn, respectively. Diffusion process becomes the controlled step with a prolonged leaching time from 15 to 30 min, and the activation energies (Ea) are 20.2 kJ·mol -1 , 28.9 kJ·mol -1 , 26.3 kJ·mol -1 , and 25.0 kJ·mol -1 for Li, Co, Ni, and Mn, respectively. This hydrometallurgical route was found to be effective and environmentally friendly for leaching metals from spent lithium batteries.

  20. Hydrometallurgical separation of rare earth elements, cobalt and nickel from spent nickel-metal-hydride batteries

    Science.gov (United States)

    Rodrigues, Luiz Eduardo Oliveira Carmo; Mansur, Marcelo Borges

    The separation of rare earth elements, cobalt and nickel from NiMH battery residues is evaluated in this paper. Analysis of the internal content of the NiMH batteries shows that nickel is the main metal present in the residue (around 50% in weight), as well as potassium (2.2-10.9%), cobalt (5.1-5.5%), rare earth elements (15.3-29.0%) and cadmium (2.8%). The presence of cadmium reveals that some Ni-Cd batteries are possibly labeled as NiMH ones. The leaching of nickel and cobalt from the NiMH battery powder with sulfuric acid is efficient; operating variables temperature and concentration of H 2O 2 has no significant effect for the conditions studied. A mixture of rare earth elements is separated by precipitation with NaOH. Finally, solvent extraction with D2EHPA (di-2-ethylhexyl phosphoric acid) followed by Cyanex 272 (bis-2,4,4-trimethylpentyl phosphinic acid) can separate cadmium, cobalt and nickel from the leach liquor. The effect of the main operating variables of both leaching and solvent extraction steps are discussed aiming to maximize metal separation for recycling purposes.

  1. Operational analysis and improvement of a spent nuclear fuel handling and treatment facility using discrete event simulation

    International Nuclear Information System (INIS)

    Garcia, H.E.

    2000-01-01

    Spent nuclear fuel handling and treatment often require facilities with a high level of operational complexity. Simulation models can reveal undesirable characteristics and production problems before they become readily apparent during system operations. The value of this approach is illustrated here through an operational study, using discrete event modeling techniques, to analyze the Fuel Conditioning Facility at Argonne National Laboratory and to identify enhanced nuclear waste treatment configurations. The modeling approach and results of what-if studies are discussed. An example on how to improve productivity is presented.

  2. Simulated BRDF based on measured surface topography of metal

    Science.gov (United States)

    Yang, Haiyue; Haist, Tobias; Gronle, Marc; Osten, Wolfgang

    2017-06-01

    The radiative reflective properties of a calibration standard rough surface were simulated by ray tracing and the Finite-difference time-domain (FDTD) method. The simulation results have been used to compute the reflectance distribution functions (BRDF) of metal surfaces and have been compared with experimental measurements. The experimental and simulated results are in good agreement.

  3. Oil removal of spent hydrotreating catalyst CoMo/Al{sub 2}O{sub 3} via a facile method with enhanced metal recovery

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yue [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Xu, Shengming, E-mail: smxu@tsinghua.edu.cn [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Beijing Key Lab of Radioactive Wastes Treatment, Tsinghua University, Beijing 100084 (China); Li, Zhen [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Wang, Jianlong [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Beijing Key Lab of Radioactive Wastes Treatment, Tsinghua University, Beijing 100084 (China); Zhao, Zhongwei [School of Metallurgy and Environment, Central South University, Changsha 410083, Hunan (China); Xu, Zhenghe, E-mail: zhenghe.xu@ualberta.ca [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Department of Chemical and Material Engineering, University of Alberta, Edmonton, Alberta T6G 1H9 (Canada)

    2016-11-15

    Highlights: • A novel approach for oil removal from spent hydrotreating catalysts has been developed. • Oil removal possibility is analyzed through surface characteristics. • Oil is successfully removed from spent catalysts via aqueous surfactant solution. • Over 98% Mo can be leached after oil removal and thermal treatment. • The proposed deoiling method helps to avoid detrimental impurity generation (CoMoO{sub 4}) and enhance metal recovery. - Abstract: Deoiling process is a key issue for recovering metal values from spent hydrotreating catalysts. The oils can be removed with organic solvents, but the industrialized application of this method is greatly hampered by the high cost and complex processes. Despite the roasting method is simple and low-cost, it generates hardest-to-recycle impurities (CoMoO{sub 4} or NiMoO{sub 4}) and enormous toxic gases. In this study, a novel and facile approach to remove oils from the spent hydrotreating catalysts is developed. Firstly, surface properties of spent catalysts are characterized to reveal the possibility of oil removal. And then, oils are removed with water solution under the conditions of 90 °C, 0.1 wt% SDS, 2.0 wt% NaOH and 10 ml/g L/S ratio for 4 h. Finally, thermal treatment and leaching tests are carried out to further explore the advantages of oil removal. The results show that no hardest-to-recycle impurity CoMoO{sub 4} is found in XPS spectra of thermally treated samples after deoiling and molybdenum is leached completely with sodium carbonate solution. It means that the proposed deoiling method can not only remove oils simply and without enormous harmful gases generating, but also avoid the generation of detrimental impurity and promote recycling of valuable metals from spent hydrotreating catalysts.

  4. Spent fuel storage and isolation

    International Nuclear Information System (INIS)

    Bensky, M.S.; Kurzeka, W.J.; Bauer, A.A.; Carr, J.A.; Matthews, S.C.

    1979-02-01

    The principal spent fuel activities conducted within the commercial waste and spent fuel within the Commercial Waste and Spent Fuel Packaging Program are: simulated near-surface (drywell) storage demonstrations at Hanford and the Nevada Test Site; surface (sealed storage cask) and drywell demonstrations at the Nevada Test Site; and spent fuel receiving and packaging facility conceptual design. These investigations are described

  5. Modelling Methods of Magnetohydrodynamic Phenomena Occurring in a Channel of the Device Used to Wash Out the Spent Automotive Catalyst by a Liquid Metal

    Directory of Open Access Journals (Sweden)

    Fornalczyk A.

    2016-06-01

    Full Text Available The recovery of precious metals is necessary for environmental and economic reasons. Spent catalysts from automotive industry containing precious metals are very attractive recyclable material as the devices have to be periodically renovated and eventually replaced. This paper presents the method of removing platinum from the spent catalytic converters applying lead as a collector metal in a device used to wash out by using mangetohydrodynamic stirrer. The article includes the description of the methods used for modeling of magnetohydrodynamic phenomena (coupled analysis of the electromagnetic, temperature and flow fields occurring in this particular device. The paper describes the general phenomena and ways of coupling the various physical fields for this type of calculation. The basic computational techniques with a discussion of their advantages and disadvantages are presented.

  6. Numerical simulation of ambient flow and thermal distributions in a spent fuel storage cask array

    International Nuclear Information System (INIS)

    Michener, T.; Trent, D.S.; Guttmann, J.; Bajwa, C.

    2001-01-01

    At the request of the U.S. Nuclear Regulatory Commission (USNRC), the staff at the Pacific Northwest National Laboratory (PNNL) analyzed the thermal performance of the Utah Private Fuel Storage (PFS) using the TEMPEST computational fluid dynamics software. A three-dimensional section of the PFS with a total of 20 casks was modeled to estimate the ambient flow and temperature distributions surrounding the casks. The purpose of this analysis was to compute the cask inlet vent air temperature to be used for boundary conditions in a detailed analysis of an individual Holtec Hi-Storm 100 cask using the COBRA-SFS (Spent Fuel Storage) thermal hydraulic computer software. (author)

  7. Mono- and di-n-butyl phosphates of some metals in spent nuclear fuel reprocessing

    Energy Technology Data Exchange (ETDEWEB)

    Solovkin, A.S.

    1982-01-01

    Results of investigations which have been carried out in the Soviet Union for the last 10 years on the determination of the composition, structure, conditions of the formation and solubility of mono- and di-n-butyl phosphates of metals (U/sup 6 +/, Pu/sup 4 +/, Pu/sup 3 +/, Th, Zr, Fe/sup 3 +/, Am, Al, rare-earth elements), which are important for the processes of irradiated nuclear fuel reprocessing, are presented. A conclusion is made that zirconium mono- and di-n-butyl phosphates are the least soluble in aqueous and organic solvents of all investigated compounds. FeA/sub 3/ and AmA/sub 3/ are weakly soluble in aqueous solutions. The other compounds are sufficiently soluble in moderately acidic aqueous solutions or in DBP and TBP with dilutents. The obtained results indicate at the similarity of zirconium and plutonium (4) chemical properties; thorium, in this respect, is not an analogue of plutonium (4). Possible structural formulas of the investigated compounds are considered.

  8. CFD simulations on the dynamics of liquid sloshing and its control in a storage tank for spent fuel applications

    International Nuclear Information System (INIS)

    Sanapala, V.S.; Velusamy, K.; Patnaik, B.S.V.

    2016-01-01

    Highlights: • Dynamics of sloshing in partially filled spent fuel storage tanks is numerically simulated. • Two type of baffle plates were examined towards the control of slosh suppression. • An optimum baffles configuration was obtained, after carrying out systematic investigations. • This vertical baffle design was effective, when tested for a seismic excitation (El centro). - Abstract: Spent nuclear liquid waste is often kept in partially filled storage tanks. When such storage tanks are subjected to wind and/or earthquake induced excitations, this could lead to detrimental conditions. Therefore, storage tank designers should ensure safe design margins and develop methodologies to overcome a wide range of possible scenarios. In the present study, systematic numerical simulations are carried out to investigate the sloshing dynamics of liquid in a storage tank, subjected to seismic excitation. As a precursor, the influence of resonant harmonic excitation on the free surface displacement, pressure distribution, slosh forces etc. is studied. To suppress the free surface fluctuations and the associated slosh force, two types of baffles viz., ring and vertical baffle are examined. Based on the response to an imposed harmonic excitation, the vertical baffle plate in the middle of the tank, was found to be effective and its dimensions are systematically optimized. This baffle geometry was tested for a well known seismic excitation (El Centro) and it was observed to effectively suppress free surface fluctuations and the slosh forces.

  9. Thermal simulations and tests in the development of a helmet transport spent fuel elements Research Reactor

    International Nuclear Information System (INIS)

    Saliba, R.; Quintana, F.; Márquez Turiello, R.; Furnari, J.C.; Pimenta Mourão, R.

    2013-01-01

    A packaging for the transport of irradiated fuel from research reactors was designed by a group of researchers to improve the capability in the management of spent fuel elements from the reactors operated in the region. Two half-scale models for MTR fuel were constructed and tested so far and a third one for both MTR and TRIGA fuels will be constructed and tested next. Four test campaigns have been carried out, covering both normal and hypothetical accident conditions of transportation. The thermal test is part of the requirements for the qualification of transportation packages for nuclear reactors spent fuel elements. In this paper both the numerical modelling and experimental thermal tests performed are presented and discussed. The cask is briefly described as well as the finite element model developed and the main adopted hypotheses for the thermal phenomena. The results of both numerical runs and experimental tests are discussed as a tool to validate the thermal modelling. The impact limiters, attached to the cask for protection, were not modelled. (author) [es

  10. Leaching of spent fuel in simulated disposal condition and separation of plutonium species as a function of oxidation state

    International Nuclear Information System (INIS)

    Kim, Seung Soo; Chun, Kwan Sik; Kang, Chul Hyung

    2000-11-01

    The influences of compacted bentonite on the leaching of spent fuel in bentonite-saturated ground water at room temperature were investigated by analyzing the components of leachates as well as the alterated surface of them. And the plutonium species was separated by ion exchangers. The amounts of Cs, Sb, Sr, Am, Ru, Pu and U released from spent fuel by bentonite-saturated solution for the initial 165 days were 2.0, 0.2, 0.2, 0.02, 0.005, 5x10 - 4, 0.05 % of inventory, respectively. These values correspond to several ∼ several tens times as much as those through bentonite block which were compacted to 1.4 g/cm 3 . The comparison of the cesium released in groundwater and bentonite-saturated solution through bentonite block is simular values, whose lower concentration in leachant indicates that most of radionuclides are retained by compacted bentonite, even though alkali metal such as Cs. The separation of plutonium species as a function of oxidation state by ion exchanger was succeed by two columns' method with packing materials as SiO - , SiO-SO 3 -

  11. Spent NiMH batteries-The role of selective precipitation in the recovery of valuable metals

    Science.gov (United States)

    Bertuol, Daniel Assumpção; Bernardes, Andréa Moura; Tenório, Jorge Alberto Soares

    The production of electronic equipment, such as computers and cell phones, and, consequently, batteries, has increased dramatically. One of the types of batteries whose production and consumption has increased in recent times is the nickel metal hydride (NiMH) battery. This study evaluated a hydrometallurgical method of recovery of rare earths and a simple method to obtain a solution rich in Ni-Co from spent NiMH batteries. The active materials from both electrodes were manually removed from the accumulators and leached. Several acid and basic solutions for the recovery of rare earths were evaluated. Results showed that more than 98 wt.% of the rare earths were recovered as sulfate salts by dissolution with sulfuric acid, followed by selective precipitation at pH 1.2 using sodium hydroxide. The complete process, precipitation at pH 1.2 followed by precipitation at pH 7, removed about 100 wt.% of iron and 70 wt.% of zinc from the leaching solution. Results were similar to those found in studies that used solvent extraction. This method is easy, economic, and does not pose environmental threats of solvent extraction.

  12. Simulating cosmic metal enrichment by the first galaxies

    NARCIS (Netherlands)

    Pallottini, A.; Ferrara, A.; Gallerani, S.; Salvadori, S.; D'Odorico, V.

    We study cosmic metal enrichment via adaptive mesh refinement hydrodynamical simulations in a (10 Mpc h-1)3 volume following the Population III (PopIII)-PopII transition and for different PopIII initial mass function (IMFs). We have analysed the joint evolution of metal enrichment on galactic and

  13. Simulation of the ductile damage under the metal forming

    International Nuclear Information System (INIS)

    Bogatov, A. A.

    2003-01-01

    Potentiality of metal forming is limited by ductile damage. The damage degree is estimated by the scalar value ω, that is equal to 0(ω=0) before plastic strain and is equal to 1(ω=1) at the macro cracks moment. There are two criteria that describe micro damage. The value ω=ω * corresponds to the generation of micro voids that couldn't be recovered by recrystallization but do not reduce the metal strength. The value ω=ω ** corresponds to the generation of micro voids that reduce the metal strength and material long life. The models of metal damage accumulation under pure and alternate strain also the model of metal damage recovery under the recrystallization are developed. The specimen testing at high loading parameters gives the basic equations of the ductile damage mechanics. All of that gives the method to study ductile damage under the metal forming. The methodology damage nucleation and growing is shown on various examples: the void and crack development in the areas ductile damage and unlimited ductility; mathematical simulation of the metal damage under the sheet and wire drawing and others. The problems of physical simulating at the ductile damage under metal forming are shown too in this paper. The method and equipment of metal damage physical simulation are proposed. (Original)

  14. Large scale experiments simulating hydrogen distribution in a spent fuel pool building during a hypothetical fuel uncovery accident scenario

    Energy Technology Data Exchange (ETDEWEB)

    Mignot, Guillaume; Paranjape, Sidharth; Paladino, Domenico; Jaeckel, Bernd; Rydl, Adolf [Paul Scherrer Institute, Villigen (Switzerland)

    2016-08-15

    Following the Fukushima accident and its extended station blackout, attention was brought to the importance of the spent fuel pools' (SFPs) behavior in case of a prolonged loss of the cooling system. Since then, many analytical works have been performed to estimate the timing of hypothetical fuel uncovery for various SFP types. Experimentally, however, little was done to investigate issues related to the formation of a flammable gas mixture, distribution, and stratification in the SFP building itself and to some extent assess the capability for the code to correctly predict it. This paper presents the main outcomes of the Experiments on Spent Fuel Pool (ESFP) project carried out under the auspices of Swissnuclear (Framework 2012–2013) in the PANDA facility at the Paul Scherrer Institut in Switzerland. It consists of an experimental investigation focused on hydrogen concentration build-up into a SFP building during a predefined scaled scenario for different venting positions. Tests follow a two-phase scenario. Initially steam is released to mimic the boiling of the pool followed by a helium/steam mixture release to simulate the deterioration of the oxidizing spent fuel. Results shows that while the SFP building would mainly be inerted by the presence of a high concentration of steam, the volume located below the level of the pool in adjacent rooms would maintain a high air content. The interface of the two-gas mixture presents the highest risk of flammability. Additionally, it was observed that the gas mixture could become stagnant leading locally to high hydrogen concentration while steam condenses. Overall, the experiments provide relevant information for the potentially hazardous gas distribution formed in the SFP building and hints on accident management and on eventual retrofitting measures to be implemented in the SFP building.

  15. Metallic ions catalysis for improving bioleaching yield of Zn and Mn from spent Zn-Mn batteries at high pulp density of 10.

    Science.gov (United States)

    Niu, Zhirui; Huang, Qifei; Wang, Jia; Yang, Yiran; Xin, Baoping; Chen, Shi

    2015-11-15

    Bioleaching of spent batteries was often conducted at pulp density of 1.0% or lower. In this work, metallic ions catalytic bioleaching was used for release Zn and Mn from spent ZMBs at 10% of pulp density. The results showed only Cu(2+) improved mobilization of Zn and Mn from the spent batteries among tested four metallic ions. When Cu(2+) content increased from 0 to 0.8 g/L, the maximum release efficiency elevated from 47.7% to 62.5% for Zn and from 30.9% to 62.4% for Mn, respectively. The Cu(2+) catalysis boosted bioleaching of resistant hetaerolite through forming a possible intermediate CuMn2O4 which was subject to be attacked by Fe(3+) based on a cycle of Fe(3+)/Fe(2+). However, poor growth of cells, formation of KFe3(SO4)2(OH)6 and its possible blockage between cells and energy matters destroyed the cycle of Fe(3+)/Fe(2+), stopping bioleaching of hetaerolite. The chemical reaction controlled model fitted best for describing Cu(2+) catalytic bioleaching of spent ZMBs. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Oil removal of spent hydrotreating catalyst CoMo/Al2O3 via a facile method with enhanced metal recovery.

    Science.gov (United States)

    Yang, Yue; Xu, Shengming; Li, Zhen; Wang, Jianlong; Zhao, Zhongwei; Xu, Zhenghe

    2016-11-15

    Deoiling process is a key issue for recovering metal values from spent hydrotreating catalysts. The oils can be removed with organic solvents, but the industrialized application of this method is greatly hampered by the high cost and complex processes. Despite the roasting method is simple and low-cost, it generates hardest-to-recycle impurities (CoMoO4 or NiMoO4) and enormous toxic gases. In this study, a novel and facile approach to remove oils from the spent hydrotreating catalysts is developed. Firstly, surface properties of spent catalysts are characterized to reveal the possibility of oil removal. And then, oils are removed with water solution under the conditions of 90°C, 0.1wt% SDS, 2.0wt% NaOH and 10ml/gL/S ratio for 4h. Finally, thermal treatment and leaching tests are carried out to further explore the advantages of oil removal. The results show that no hardest-to-recycle impurity CoMoO4 is found in XPS spectra of thermally treated samples after deoiling and molybdenum is leached completely with sodium carbonate solution. It means that the proposed deoiling method can not only remove oils simply and without enormous harmful gases generating, but also avoid the generation of detrimental impurity and promote recycling of valuable metals from spent hydrotreating catalysts. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Atomistic simulations of Mg-Cu metallic glasses: Mechanical properties

    DEFF Research Database (Denmark)

    Bailey, Nicholas; Schiøtz, Jakob; Jacobsen, Karsten Wedel

    2004-01-01

    The atomistic mechanisms of plastic deformation in amorphous metals are far from being understood. We have derived potential parameters for molecular dynamics simulations of Mg-Cu amorphous alloys using the Effective Medium Theory. We have simulated the formation of alloys by cooling from the melt...

  18. Computer simulations of the mechanical properties of metals

    DEFF Research Database (Denmark)

    Schiøtz, Jakob; Vegge, Tejs

    1999-01-01

    Atomic-scale computer simulations can be used to gain a better understanding of the mechanical properties of materials. In this paper we demonstrate how this can be done in the case of nanocrystalline copper, and give a brief overview of how simulations may be extended to larger length scales....... Nanocrystline metals are metals with grain sizes in the nanometre range, they have a number of technologically interesting properties such as much increased hardness and yield strength. Our simulations show that the deformation mechanisms are different in these materials than in coarse-grained materials...

  19. A Qualitative Analysis of the Neutron Population in Fresh and Spent Fuel Assemblies during Simulated Interrogation using the Differential Die-Away Technique

    International Nuclear Information System (INIS)

    Lundkvista, Niklas; Goodsell, Alison V.; Grapea, Sophie; Hendricksb, John S.; Henzlb, Vladimir; Swinhoe, Martyn T.; Tobin, Stephen J.

    2015-01-01

    Monte Carlo simulations were performed for the differential die-away (DDA) technique to analyse the time-dependent behaviour of the neutron population in fresh and spent nuclear fuel assemblies as part of the Next Generation Safeguards Initiative Spent Fuel (NGSI-SF) Project. Simulations were performed to investigate both a possibly portable as well as a permanent DDA instrument. Taking advantage of a custom made modification to the MCNPX code, the variation in the neutron population, simultaneously in time and space, was examined. The motivation for this research was to improve the design of the DDA instrument, as it is being considered for possible deployment at the Central Storage of Spent Nuclear Fuel and Encapsulation Plant in Sweden (Clab), as well as to assist in the interpretation of the both simulated and measured signals.

  20. Thermal treatment and ammoniacal leaching for the recovery of valuable metals from spent lithium-ion batteries.

    Science.gov (United States)

    Chen, Yongming; Liu, Nannan; Hu, Fang; Ye, Longgang; Xi, Yan; Yang, Shenghai

    2018-05-01

    The recycling of spent commercial lithium-ion batteries (LIBs) generates numerous environmental and economic benefits. In this research, a thermal treatment-ammoniacal leaching process is proposed to recover valuable metals from cathode active powder. Based on the thermal behavior by TG-DSC analysis, the cathode active powder is calcined at 300 °C and 550 °C in air atmosphere, and the crystalline phase characterization indicates that a new phase of Co 3 O 4 appears in the cathode active powder calcined at 550 °C, which signifies that the layer structure of LiCoO 2 collapses. The valence of manganese increases to form Li 4 Mn 5 O 12 in spinel structure of LiMn 2 O 4 . Using calcined cathode powder as feed material, ammoniacal leaching is carried out in (NH 4 ) 2 SO 4 -(NH 4 ) 2 SO 3 solution. Under the optimum conditions, Ni, Co, Mn and Li can be completely leached out with efficiencies of 98%, 81%, 92% and 98%, respectively. However, with the increase of ammonia concentration, the leaching efficiency of Mn decreases dramatically to 4% due to the formation of double salts. It is found that Co and Mn can be precipitated into residues in the form of (NH 4 ) 2 Co(SO 4 ) 2 ·H 2 O, (NH 4 ) 2 Mn(SO 3 ) 2 ·H 2 O and (NH 4 ) 2 Mn(SO 4 ) 2 ·6H 2 O under different leaching parameters. Based on the corresponding relationship between the leaching efficiency and phase evolution of object element, selective leaching can be achieved by controlling the formation of double salts. Copyright © 2018 Elsevier Ltd. All rights reserved.

  1. Selection of dissolution process for spent fuels and preparation of corrosion test solution simulated to dissolver (contract research)

    International Nuclear Information System (INIS)

    Motooka, Takafumi; Terakado, Shogo; Koya, Toshio; Hamada, Shozo; Kiuchi, Kiyoshi

    2001-03-01

    In order to evaluate the reliability of reprocessing equipment materials used in the Rokkasho Reprocessing Plant, we have proceeded a mock-up test and laboratory tests for getting corrosion parameters. In a dissolver made of zirconium, the simulation of test solutions to the practical solution which includes the high concentration of radioactive elements such as FP and TRU is one of the important issues with respect to the life prediction. On this experiment, the dissolution process of spent fuels and the preparation of test solution for evaluating the corrosion resistance of dissolver materials were selected. These processes were tested in the No.3 cell of WASTEF. The test solution for corrosion tests was prepared by adjusting the uranium and nitric acid concentrations. (author)

  2. Metals recovery of spent household batteries using a hydrometallurgical process; Recuperacao de metais de sucatas de pilhas e baterias pos-consumo utilizando processamento hidrometalurgico

    Energy Technology Data Exchange (ETDEWEB)

    Souza, K.P.; Tenorio, J.A.S., E-mail: kprovazi@gmail.co [Universidade de Sao Paulo (USP), SP (Brazil). Dept. de Engenharia Metalurgica e de Materiais

    2010-07-01

    The objective of the work is to study a method for metals recovery from a sample composed by a mixture of the main types of spent household batteries. Segregation of the main metals is investigated using a treatment route consisting of the following steps: manual identified and dismantling, grinding, electric furnace reduction, acid leaching and selective precipitation with sodium hydroxide with and without hydrogen peroxide. Before and after precipitations the solutions had been analyzed by Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP/OES) and the precipitated analyzed by Scanning Electron Microscopy (SEM) with Spectrometry of Energy Dispersion Spectroscopy (EDS). The results had indicated that the great majority of metals had been precipitated in pHs studied, also had co-precipitation or simultaneous precipitation of metals in some pHs. (author)

  3. Ageing of metallic gaskets for spent fuel casks: Century-long life forecast from 25,000-h-long experiments

    International Nuclear Information System (INIS)

    Sassoulas, H.; Morice, L.; Caplain, P.; Rouaud, C.; Mirabel, L.; Beal, F.

    2006-01-01

    An experimental programme is being carried out that aims at quantifying the relaxation of four types of metallic HELICOFLEX[reg] seals during their use in spent nuclear fuel storage casks. Two types of lining are taken into account: aluminium and silver. Tests longer than 10,000 h are implemented only for silver. For each type of lining, two different section diameters are investigated. The work aims at evaluating the minimum residual linear load that can be guaranteed for a seal after a particular time of relaxation. This relaxation depends on the evolution of the seal temperature with time. Therefore, holds of seals tightened between two flanges have been performed at several constant temperatures, including 100 and 200 deg. C. Residual load and 'useful' recovery have been measured after the holds. Results are interpreted according to two methods: a time extrapolation, and a time-temperature equivalence parameter. Both methods are based on linear relationships and are assessed through a statistical analysis (calculation of scatter) which is also used to determine a minimum guaranteed residual load. Finite element simulations of the relaxation of a seal have also been performed in order to justify qualitatively that the time extrapolation method is safe. For silver lining seals, the use of a time-temperature equivalence parameter equal to T (11 + log 1 (t)) appears justified and this enables us to assess the maximum temperature at which seals can be 'safely' used 'up to a century'. Using the available ageing results (longest holds: 25,000 h), and the proposed prediction method, it can be proven that the two types of silver lining seals which are evaluated will retain a residual linear load of at least 100 N mm -1 of seal perimeter after one century of use in a cask, if the initial temperature of the seal after closing the cask is less than or equal to 100 deg. C

  4. Bituminization of simulated waste, spent resins, evaporator concentrates and animal ashes by extrusion process

    International Nuclear Information System (INIS)

    Grosche Filho, C.E.; Chandra, U.

    1987-01-01

    The results of the study of bituminization of simulated radwaste - spennt ion-exchange resins, borate evaporator/concentrates and animal ashes, are presented and discussed. Distilled and oxidizer bitumen were used. Characterization of the crude material and simulated wastes-bitumen mixtures of varying weigt composition (30, 40, 50, 60% by weight of dry waste material) was carried out. The asphaltene and parafin contents in the bitumens were also determined. Some additives and were used with an aim to improve the characteristcs of solidified wastes. For leaching studies, granular ion-exchange resins were with Cs - 134 and mixtures of resin-bitumen were prepared. The leaching studies were executed using the IAEA recommendation and the ISO method. A conventional screw-extruder, common in plastic industry, was used determine operational parameters and process difficulties. Mixtures of resin-bitumen and evaporator concentrate-bitumen obtained from differents operational conditions were characterized. (Author) [pt

  5. Phase 1 study of metallic cask systems for spent fuel management from reactor to repository. Volume I. Phase 1 study summary

    International Nuclear Information System (INIS)

    1986-02-01

    It was proposed to perform a systems evaluation of metallic cask systems in order to define and examine the use of various metallic cask concepts or combination of concepts for the overall inventory management of spent fuel starting with its discharge from reactors to its emplacement in geologic repositories. This systems evaluation occurs in three phases. This three phase systems evaluation leads to a definition and recommendation of a sound and practical metallic cask system to accomplish efficient and effective management of spent fuel in the back end of the nuclear fuel cycle. Phase 1 Study objectives: establish system-wide functional criteria and assumptions; perform the systems engineering needed to define the metallic cask concepts and their feasibility; perform a screening evaluation of the technical and economic merits of the concepts; and recommend those to be included for a more detailed systems evaluation in Phase 2. Phase 2 Study objectives: refine the system-wide functional criteria and assumptions; perform the design engineering needed to enhance the validity and workability of those concepts recommended in Phase 1; and perform a more detailed systems evaluation. Phase 3 Study objectives: conclude the systems evaluation and develop an implementation plan. Volume I presents an overview of the detailed systems evaluation presented in Volume II

  6. The effectiveness of spent coffee grounds and its biochar on the amelioration of heavy metals-contaminated water and soil using chemical and biological assessments.

    Science.gov (United States)

    Kim, Min-Suk; Min, Hyun-Gi; Koo, Namin; Park, Jeongsik; Lee, Sang-Hwan; Bak, Gwan-In; Kim, Jeong-Gyu

    2014-12-15

    Spent coffee grounds (SCG) and charred spent coffee grounds (SCG-char) have been widely used to adsorb or to amend heavy metals that contaminate water or soil and their success is usually assessed by chemical analysis. In this work, the effects of SCG and SCG-char on metal-contaminated water and soil were evaluated using chemical and biological assessments; a phytotoxicity test using bok choy (Brassica campestris L. ssp. chinensis Jusl.) was conducted for the biological assessment. When SCG and SCG-char were applied to acid mine drainage, the heavy metal concentrations were decreased and the pH was increased. However, for SCG, the phytotoxicity increased because a massive amount of dissolved organic carbon was released from SCG. In contrast, SCG-char did not exhibit this phenomenon because any easily released organic matter was removed during pyrolysis. While the bioavailable heavy metal content decreased in soils treated with SCG or SCG-char, the phytotoxicity only rose after SCG treatment. According to our statistical methodology, bioavailable Pb, Cu and As, as well as the electrical conductivity representing an increase in organic content, affected the phytotoxicity of soil. Therefore, applying SCG during environment remediation requires careful biological assessments and evaluations of the efficiency of this remediation technology. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Interatomic potentials and the simulation of lattice defects in metals

    International Nuclear Information System (INIS)

    Heugten, W.F.W.M. van.

    1979-01-01

    The computer simulation technique is applied to investigate the properties of point defects and line defects in metals. For that purpose crystallites are constructed in which these defects are simulated. In the case of line defects (dislocations) the initial positions of the atoms, surrounding the dislocations, are determined using the elastic theory of anisotropic media. Hereafter the atoms in such crystallites are allowed to relax to there minimum potential energy positions under the influence of the interatomic forces. These forces are derived from interatomic interaction potentials. These potentials are together with the boundary conditions of the simulated crystallite the main input data in these computer simulation models. The metals considered include molybdenum, tungsten and tantalum. (Auth.)

  8. Probing the limits of metal plasticity with molecular dynamics simulations

    Science.gov (United States)

    Zepeda-Ruiz, Luis A.; Stukowski, Alexander; Oppelstrup, Tomas; Bulatov, Vasily V.

    2017-10-01

    Ordinarily, the strength and plasticity properties of a metal are defined by dislocations--line defects in the crystal lattice whose motion results in material slippage along lattice planes. Dislocation dynamics models are usually used as mesoscale proxies for true atomistic dynamics, which are computationally expensive to perform routinely. However, atomistic simulations accurately capture every possible mechanism of material response, resolving every ``jiggle and wiggle'' of atomic motion, whereas dislocation dynamics models do not. Here we present fully dynamic atomistic simulations of bulk single-crystal plasticity in the body-centred-cubic metal tantalum. Our goal is to quantify the conditions under which the limits of dislocation-mediated plasticity are reached and to understand what happens to the metal beyond any such limit. In our simulations, the metal is compressed at ultrahigh strain rates along its [001] crystal axis under conditions of constant pressure, temperature and strain rate. To address the complexity of crystal plasticity processes on the length scales (85-340 nm) and timescales (1 ns-1μs) that we examine, we use recently developed methods of in situ computational microscopy to recast the enormous amount of transient trajectory data generated in our simulations into a form that can be analysed by a human. Our simulations predict that, on reaching certain limiting conditions of strain, dislocations alone can no longer relieve mechanical loads; instead, another mechanism, known as deformation twinning (the sudden re-orientation of the crystal lattice), takes over as the dominant mode of dynamic response. Below this limit, the metal assumes a strain-path-independent steady state of plastic flow in which the flow stress and the dislocation density remain constant as long as the conditions of straining thereafter remain unchanged. In this distinct state, tantalum flows like a viscous fluid while retaining its crystal lattice and remaining a strong

  9. Numerical Simulation of the Thermal Performance of a Dry Storage Cask for Spent Nuclear Fuel

    Directory of Open Access Journals (Sweden)

    Heui-Yung Chang

    2018-01-01

    Full Text Available In this study, the heat flow characteristics and thermal performance of a dry storage cask were investigated via thermal flow experiments and a computational fluid dynamics (CFD simulation. The results indicate that there are many inner circulations in the flow channel of the cask (the channel width is 10 cm. These circulations affect the channel airflow efficiency, which in turn affects the heat dissipation of the dry storage cask. The daily operating temperatures at the top concrete lid and the upper locations of the concrete cask are higher than those permitted by the design specification. The installation of the salt particle collection device has a limited negative effect on the thermal dissipation performance of the dry storage cask.

  10. Direct disposal of spent fuel. Simulation of shaft transport. Phase III. Final report

    International Nuclear Information System (INIS)

    Filbert, W.; Heda, M.; Khamis, M.; Neydek, J.; Niehues, N.; Rissel, J.; Schrimpf, C.; Weber, W.; Fuchs, D.; Gerlach, A.; Langebrake, F.; Sindern, W.; Gasch, A.; Leicht, R.; Schwab, B.; Hecke, R. van; Kipka, P.; Simmich, K.; Weber, H.

    1994-01-01

    The aim of these demonstration tests was to verify the technical feasibility of a shaft hoisting equipment with a payload of 85 t as well as the safe transport of POLLUX-casks. In phase III of the project the components and the test stand were built, their proper functioning and reliability were tested to demonstrate that they are state-of-the-art. The following additional investigations were carried out: - Tests to fix operational disturbances and simulation tests for the new components to demonstrate their licensibility -Selection and lifetime tests of ropes and investigation of the present state-of-the-art of rope slighting under the conditions of the conceptual design of the shaft hoisting facility - Execution of a probabilistic safety analysis e.g. the determination of the release of radioactive material (result: probability [de

  11. NEMD simulations for ductile metal sliding

    Energy Technology Data Exchange (ETDEWEB)

    Hammerberg, James E [Los Alamos National Laboratory; Germann, Timothy C [Los Alamos National Laboratory; Ravelo, Ramon J [Los Alamos National Laboratory; Holian, Brad L [Los Alamos National Laboratory

    2011-01-31

    We have studied the sliding behavior for a 19 M Al(110)/Al(110) defective crystal at 15 GPa as a function of relative sliding velocity. The general features are qualitatively similar to smaller scale (1.4 M) atom simulations for Al(111)/Al(110) nondefective single crystal sliding. The critical velocity, v{sub c}, is approximately the same for the defective crystal as the size scaled v{sub c}. The lower velocity tangential force is depressed relative to the perfect crystal. The critical temperature, T*, is depressed relative to the perfect crystal. These conclusions are consistent with a lower value for f{sub c} for the defective crystal. The detailed features of structural transformation and the high velocity regime remain to be mapped.

  12. Ab initio simulation of dislocation cores in metals

    International Nuclear Information System (INIS)

    Ventelon, L.

    2008-01-01

    In the framework of the multi scale simulation of metals and alloys plasticity, the aim of this study is to develop a methodology of ab initio dislocations study and to apply it to the [111] screw dislocation in the bc iron. (A.L.B.)

  13. Simulation of heavy metal contamination of fresh water bodies: toxic ...

    African Journals Online (AJOL)

    Michael Horsfall

    www.bioline.org.br/ja. Simulation of heavy metal contamination of fresh water bodies: toxic effects in the ... 96 hours (though sampling was done at the 48th hour). Biochemical markers of ... silver, while enhancing the bioavailability of mercury in Ceriodaphnia ..... Biochemical and molecular disorders of bilirubin metabolism.

  14. Process optimization and leaching kinetics of zinc and manganese metals from zinc-carbon and alkaline spent batteries using citric acid reagent

    Science.gov (United States)

    Yuliusman; Amiliana, R. A.; Wulandari, P. T.; Huda, M.; Kusumadewi, F. A.

    2018-03-01

    Zn-Carbon and Alkaline spent batteries contains heavy metals, such as zinc and manganese, which can causes environmental problem if not handled properly. Usually the recovery of these metals were done by leaching method using strong acid, but the use of strong acids as leaching reagents can be harmful to the environment. This paper concerns the recovery of Zn and Mn metals from Zn-C and alkaline spent batteries with leaching method using citric acid as the environmental friendly leaching reagent. The leaching conditions using citric acid were optimized and the leaching kinetics of Zn and Mn in citric acid solution was investigated. The leaching of 89.62% Zn and 63.26% Mn was achieved with 1.5 M citric acid, 90°C temperature, and 90 minutes stirring time. Kinetics data for the dissolution of Zn showed the best fit to chemical control shrinking core model, while the diffusion controlled model was suitable for the dissolution of Mn kinetics data. The activation energy of 6.12 and 1.73 kcal/mol was acquired for the leaching of Zn and Mn in the temperature range 60°C-90°C.

  15. 2D and 3D thermal simulations for storage systems with internal natural convection for canistered spent fuel

    International Nuclear Information System (INIS)

    Yaksh, M.; Wang, C.

    2004-01-01

    In the US, the number of nuclear plants expected to implement on-site dry storage is increasing each year. As reactors burn advanced fuel assemblies to higher burnups, the dry storage systems will be required to accommodate higher heat loads. This is due to the increasing capacity of the systems and the need to store higher burnup fuel with reasonable cooling periods (i.e., five to six years). As the storage systems heat rejection design must be passive, natural convection is an efficient means for rejection of heat from the spent fuel to the surface of the canister boundary. The design presented in this paper is a canistered system that employs conduction, radiation and convection to reject heat from the canister, which is stored in a vertical concrete cask. The canister containing the spent fuel in this design is a right circular stainless steel vessel capable of storing 37 PWR fuel assemblies with a total canister heat load of 40 kW. Accompanying any design effort is the use of a numerical methodology that can accurately predict the peak-clad temperatures of the fuel and the structural components of the system. The main challenge to any analysis employing internal natural convection may be perceived as a practical limitation due to the size of the model. Since canisters are typically cylindrical, a two-dimensional model can be used to represent the canister. The fuel basket structure, which maintains the configuration of the spent fuel, is an array of square tubes, and is non-axisymmetric. Flow up through the fuel region in the basket encounters a complex cross section due to the fuel assembly rod array (up to 17 x 17). The flow region of the heated gas down the outside of the basket in the annulus between the canister shell and the basket assembly (downcomer) is also an irregular shaped area. To confirm that a two-dimensional (2D) modelling methodology is appropriate, a benchmark using results from a thermal test is required. The thermal test focuses on the

  16. Thermal simulation of the magnesium thermal of metallic uranium reduction

    International Nuclear Information System (INIS)

    Borges, W.A.; Saliba-Silva, A.M.

    2008-01-01

    Metallic uranium production is vital to fabricate fuel elements for nuclear research reactors and to produce radioisotopes and radiopharmaceuticals. Metallic uranium is got via magnesiothermal reduction of UF 4 . This reaction is carried out inside a closed graphite crucible inserted in a metallic reactor adequately sealed without any outside contact. The assembled set is gradually heated up inside a pit furnace up to reach the reaction ignition temperature (between 600-650 deg C). The optimization of the reactive system depends on the mathematical modeling using simulation by finite elements and computational calculation with specialized programs. In this way, the reactants' thermal behavior is forecast until they reach the ignition temperature. The optimization of the uranium production reaction is based on minimization of thermal losses using better the exo thermal reaction heat. As lower the thermal losses, as higher would be the heat amount to raise the temperature of reaction products. This promotes the adequate melting of uranium and slag, so allowing better metal/slag separation with higher metallic yield. This work shows how the mathematical simulation is made and supplies some preliminary results. (author)

  17. Simulation of the injection casting of metallic fuels

    International Nuclear Information System (INIS)

    Nakagawa, Tomokazu; Ogata, Takanari; Tokiwai, Moriyasu.

    1989-01-01

    For the fabrication of metallic fuel pins, injection casting is a preferable process because the simplicity of the process is suitable for remote operation. In this process, the molten metal in the crucible is injected into evacuated molds (suspended above the crucible) by pressurizing the casting furnace. Argonne National Laboratory has already adopted this process in the Integral Fast Reactor program. To obtain fuel pins with good quality, the casting parameters, such as the molten metal temperature, the magnitude of the pressure applied, the pressurizing rate, the cooling time, etc., must be optimized. Otherwise, bad-quality castings (short castings, rough surfaces, shrinkage cavities, mold fracture) may result. Therefore, it is very important in designing the casting equipment and optimizing the operation conditions to be able to predict the fluid and thermal behavior of the castings. This paper describes methods to simulate the heat and mass transfer in the molds and molten metallic fuel during injection casting. The results obtained by simulation are compared with experimental ones. Also, appropriate casting conditions for the uranium-plutonium-zirconium alloy are discussed based on the simulated results

  18. Vacuum pyrolysis and hydrometallurgical process for the recovery of valuable metals from spent lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Liang [College of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Key Laboratory of Resources Chemistry of Nonferrous Metals, Central South University, Ministry of Education of the People' s Republic of China (China); Qiu, Keqiang, E-mail: qiuwhs@sohu.com [College of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Key Laboratory of Resources Chemistry of Nonferrous Metals, Central South University, Ministry of Education of the People' s Republic of China (China)

    2011-10-30

    Highlights: {yields} The cathode active materials LiCoO{sub 2} from spent lithium-ion batteries peeled completely from aluminum foils by vacuum pyrolysis and hydrometallurgical process. {yields} The aluminum foils were excellent without damage after vacuum pyrolysis. {yields} The pyrolysis products organic fluorine compounds from organic electrolyte and binder were collected and enriched. {yields} High leaching efficiencies of cobalt and lithium were obtained with H{sub 2}SO{sub 4} and H{sub 2}O{sub 2}. - Abstract: Spent lithium-ion batteries contain lots of strategic resources such as cobalt and lithium together with other hazardous materials, which are considered as an attractive secondary resource and environmental contaminant. In this work, a novel process involving vacuum pyrolysis and hydrometallurgical technique was developed for the combined recovery of cobalt and lithium from spent lithium-ion batteries. The results of vacuum pyrolysis of cathode material showed that the cathode powder composing of LiCoO{sub 2} and CoO peeled completely from aluminum foils under the following experimental conditions: temperature of 600 {sup o}C, vacuum evaporation time of 30 min, and residual gas pressure of 1.0 kPa. Over 99% of cobalt and lithium could be recovered from peeled cobalt lithium oxides with 2 M sulfuric acid leaching solution at 80 {sup o}C and solid/liquid ratio of 50 g L{sup -1} for 60 min. This technology offers an efficient way to recycle valuable materials from spent lithium-ion batteries, and it is feasible to scale up and help to reduce the environmental pollution of spent lithium-ion batteries.

  19. Vacuum pyrolysis and hydrometallurgical process for the recovery of valuable metals from spent lithium-ion batteries

    International Nuclear Information System (INIS)

    Sun, Liang; Qiu, Keqiang

    2011-01-01

    Highlights: → The cathode active materials LiCoO 2 from spent lithium-ion batteries peeled completely from aluminum foils by vacuum pyrolysis and hydrometallurgical process. → The aluminum foils were excellent without damage after vacuum pyrolysis. → The pyrolysis products organic fluorine compounds from organic electrolyte and binder were collected and enriched. → High leaching efficiencies of cobalt and lithium were obtained with H 2 SO 4 and H 2 O 2 . - Abstract: Spent lithium-ion batteries contain lots of strategic resources such as cobalt and lithium together with other hazardous materials, which are considered as an attractive secondary resource and environmental contaminant. In this work, a novel process involving vacuum pyrolysis and hydrometallurgical technique was developed for the combined recovery of cobalt and lithium from spent lithium-ion batteries. The results of vacuum pyrolysis of cathode material showed that the cathode powder composing of LiCoO 2 and CoO peeled completely from aluminum foils under the following experimental conditions: temperature of 600 o C, vacuum evaporation time of 30 min, and residual gas pressure of 1.0 kPa. Over 99% of cobalt and lithium could be recovered from peeled cobalt lithium oxides with 2 M sulfuric acid leaching solution at 80 o C and solid/liquid ratio of 50 g L -1 for 60 min. This technology offers an efficient way to recycle valuable materials from spent lithium-ion batteries, and it is feasible to scale up and help to reduce the environmental pollution of spent lithium-ion batteries.

  20. Study of plasticity in metals by numerical simulations

    International Nuclear Information System (INIS)

    Clouet, E.

    2013-01-01

    We present a study of the plastic behaviour in metals based on the modelling of dislocation properties. Different simulation tools have been used and developed to study plasticity in structural materials, in particular metals used in the nuclear industry. In iron or zirconium alloys, plasticity is controlled at low temperature by the glide of screw dislocations. Atomistic simulations can be used to model dislocation core properties and thus to obtain a better knowledge of the mechanisms controlling dislocation glide. Such atomistic simulations need nevertheless some special care because of the long range elastic field induced by the dislocations. We have therefore developed a modelling approach relying both on atomistic simulations, using either empirical interatomic potentials or ab initio calculations, and on elasticity theory. Such an approach has been used to obtain dislocation intrinsic core properties. These simulations allowed us to describe, in iron, the variations of these core properties with the dislocation character. In zirconium, we could identity the origin of the high lattice friction and obtain a better understanding of the competition between the different glide systems. At high temperature, dislocations do not only glide but can also cross-slip or climb. This leads to a motion of the dislocations out of their glide plane which needs to be considered when modelling the plastic flow. We performed a study of dislocation climb at different scales, leading to the implementation of a dislocation climb model in dislocation dynamics simulations. (author) [fr

  1. Two-step process of regeneration of acid(s) from ZrF{sub 4} containing spent pickle liquor and recovery of zirconium metal

    Energy Technology Data Exchange (ETDEWEB)

    Nersisyan, Hayk [Graduate School of Department of Materials Science & Engineering, Chungnam National University, 99 Daehakro, Yuseong-gu, Daejeon (Korea, Republic of); RASOM, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon (Korea, Republic of); Han, Seul Ki; Choi, Jeong Hun [Graduate School of Department of Materials Science & Engineering, Chungnam National University, 99 Daehakro, Yuseong-gu, Daejeon (Korea, Republic of); Graduate School of Energy Science & Technology, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon (Korea, Republic of); Lee, Young-Jun; Yoo, Bung Uk [Graduate School of Energy Science & Technology, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon (Korea, Republic of); Ri, Vladislav E. [Graduate School of Department of Materials Science & Engineering, Chungnam National University, 99 Daehakro, Yuseong-gu, Daejeon (Korea, Republic of); Lee, Jong Hyeon, E-mail: jonglee@cnu.ac.kr [Graduate School of Department of Materials Science & Engineering, Chungnam National University, 99 Daehakro, Yuseong-gu, Daejeon (Korea, Republic of); Graduate School of Energy Science & Technology, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon (Korea, Republic of); RASOM, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon (Korea, Republic of)

    2017-04-01

    In this paper we describe a progressive two-step process that allows zirconium fluoride (ZrF{sub 4}) contained in spent baths for etched zirconium alloys to be effectively recycled on a pilot scale and produce a high purity regenerated pickling acid. In the first step, a spent pickling liquor is treated by a BaF{sub 2} suspension to produce water insoluble Ba{sub 2}ZrF{sub 8}. After filtration of Ba{sub 2}ZrF{sub 8} more than 99.9 wt % purity pickling acid is regenerated. The precipitation mechanism of Ba{sub 2}ZrF{sub 8} is discussed and the role of BaF{sub 2} particles size on the precipitation process is demonstrated. In the second step the as-precipitated Ba{sub 2}ZrF{sub 8} is mixed with Mg and Cu metal powders and heat-treated at 1200 °C (or above) to produce CuZr alloy ingot. The characteristics of the ingot are discussed in regard to Cu concentration and the heating temperature. - Highlights: •Two-step process for recycling ZrF{sub 4} containing pickling acid on a pilot scale is developed. •Water insoluble Ba{sub 2}ZrF{sub 8} is precipitated by mixing spent pickling liquor with BaF{sub 2}. •The recycled pickling acid demonstrates more than 99.9 wt % purity. •The processing of Ba{sub 2}ZrF{sub 8} with Cu and Mg metals at 1200 °C yielded CuZr alloy. •The recovery depth of Zr was more than 95 wt%.

  2. Optical properties of metallic nanoparticles basic principles and simulation

    CERN Document Server

    Trügler, Andreas

    2016-01-01

    This book introduces the fascinating world of plasmonics and physics at the nanoscale, with a focus on simulations and the theoretical aspects of optics and nanotechnology. A research field with numerous applications, plasmonics bridges the gap between the micrometer length scale of light and the secrets of the nanoworld. This is achieved by binding light to charge density oscillations of metallic nanostructures, so-called surface plasmons, which allow electromagnetic radiation to be focussed down to spots as small as a few nanometers. The book is a snapshot of recent and ongoing research and at the same time outlines our present understanding of the optical properties of metallic nanoparticles, ranging from the tunability of plasmonic resonances to the ultrafast dynamics of light-matter interaction. Beginning with a gentle introduction that highlights the basics of plasmonic interactions and plasmon imaging, the author then presents a suitable theoretical framework for the description of metallic nanostructu...

  3. Quantum-based Atomistic Simulation of Transition Metals

    International Nuclear Information System (INIS)

    Moriarty, J A; Benedict, L X; Glosli, J N; Hood, R Q; Orlikowski, D A; Patel, M V; Soderlind, P; Streitz, F H; Tang, M; Yang, L H

    2005-01-01

    First-principles generalized pseudopotential theory (GPT) provides a fundamental basis for transferable multi-ion interatomic potentials in d-electron transition metals within density-functional quantum mechanics. In mid-period bcc metals, where multi-ion angular forces are important to structural properties, simplified model GPT or MGPT potentials have been developed based on canonical d bands to allow analytic forms and large-scale atomistic simulations. Robust, advanced-generation MGPT potentials have now been obtained for Ta and Mo and successfully applied to a wide range of structural, thermodynamic, defect and mechanical properties at both ambient and extreme conditions of pressure and temperature. Recent algorithm improvements have also led to a more general matrix representation of MGPT beyond canonical bands allowing increased accuracy and extension to f-electron actinide metals, an order of magnitude increase in computational speed, and the current development of temperature-dependent potentials

  4. Pyrolysis of marine biomass to produce bio-oil and its upgrading using a novel multi-metal catalyst prepared from the spent car catalytic converter.

    Science.gov (United States)

    Sabegh, Mahzad Yaghmaei; Norouzi, Omid; Jafarian, Sajedeh; Khosh, Akram Ghanbari; Tavasoli, Ahmad

    2018-02-01

    In order to reduce the economic and environmental consequences caused by spent car catalyst, we herein report for the first time a novel promising multi-metal catalyst prepared from spent car catalytic converters to upgrade the pyrolysis bio-oils. The physico-chemical properties of prepared catalyst were characterized by XRD, EDS, FESEM, and FT-IR analyses. The thermal stability of the multi-metal catalyst was studied with TGA. To investigate the activity of the catalyst, Conversion of Cladophora glomerata (C. glomerata) into bio-products was carried out via a fixed bed reactor with and without catalyst at the temperature of 500°C. Although the catalyst didn't catalyze the gasification reaction, bio-oil was upgraded over the catalyst. The main effect of the catalyst on the bio-oil components is deoxygenating of nitrogen compounds and promotion the ketonization reaction, which converts acid to ketone and declines the corrosive nature of bio-oil. Copyright © 2017. Published by Elsevier Ltd.

  5. Molecular Dynamics Simulations of displacement cascades in metallic systems

    International Nuclear Information System (INIS)

    Doan, N.V.; Tietze, H.

    1995-01-01

    We use Molecular Dynamics Computer Simulations to investigate defect production induced by energetic displacement cascades up to 10 keV in pure metals (Cu, Ni) and in ordered intermetallic alloys NiAl, Ni 3 Al. Various model potentials were employed to describe the many-body nature of the interactions: the RGL (Rosato-Guillope-Legrand) model was used in pure Cu and Ni simulations; the modified version of the Vitek, Ackland and Cserti potentials (due to Gao, Bacon and Ackland) in Ni 3 Al and the EAM potentials of Foiles and Daw modified by Rubini and Ballone in NiAl, Ni 3 Al were used in alloy simulations. Atomic mixing and disordering were studied into details owing to imaging techniques and determined at different phases of the cascades. Some mixing mechanisms were identified. Our results were compared with existing data and those obtained by similar Molecular Dynamics Simulations available in the literature. (orig.)

  6. Spent fuel pyroprocessing demonstration

    International Nuclear Information System (INIS)

    McFarlane, L.F.; Lineberry, M.J.

    1995-01-01

    A major element of the shutdown of the US liquid metal reactor development program is managing the sodium-bonded spent metallic fuel from the Experimental Breeder Reactor-II to meet US environmental laws. Argonne National Laboratory has refurbished and equipped an existing hot cell facility for treating the spent fuel by a high-temperature electrochemical process commonly called pyroprocessing. Four products will be produced for storage and disposal. Two high-level waste forms will be produced and qualified for disposal of the fission and activation products. Uranium and transuranium alloys will be produced for storage pending a decision by the US Department of Energy on the fate of its plutonium and enriched uranium. Together these activities will demonstrate a unique electrochemical treatment technology for spent nuclear fuel. This technology potentially has significant economic and technical advantages over either conventional reprocessing or direct disposal as a high-level waste option

  7. Molecular Models for DSMC Simulations of Metal Vapor Deposition

    OpenAIRE

    Venkattraman, A; Alexeenko, Alina A

    2010-01-01

    The direct simulation Monte Carlo (DSMC) method is applied here to model the electron‐beam (e‐beam) physical vapor deposition of copper thin films. A suitable molecular model for copper‐copper interactions have been determined based on comparisons with experiments for a 2D slit source. The model for atomic copper vapor is then used in axi‐symmetric DSMC simulations for analysis of a typical e‐beam metal deposition system with a cup crucible. The dimensional and non‐dimensional mass fluxes obt...

  8. High Antioxidant Action and Prebiotic Activity of Hydrolyzed Spent Coffee Grounds (HSCG) in a Simulated Digestion-Fermentation Model: Toward the Development of a Novel Food Supplement.

    Science.gov (United States)

    Panzella, Lucia; Pérez-Burillo, Sergio; Pastoriza, Silvia; Martín, María Ángeles; Cerruti, Pierfrancesco; Goya, Luis; Ramos, Sonia; Rufián-Henares, José Ángel; Napolitano, Alessandra; d'Ischia, Marco

    2017-08-09

    Spent coffee grounds are a byproduct with a large production all over the world. The aim of this study was to explore the effects of a simulated digestion-fermentation treatment on hydrolyzed spent coffee grounds (HSCG) and to investigate the antioxidant properties of the digestion and fermentation products in the human hepatocellular carcinoma HepG2 cell line. The potentially bioaccessible (soluble) fractions exhibited high chemoprotective activity in HepG2 cells against oxidative stress. Structural analysis of both the indigestible (insoluble) and soluble material revealed partial hydrolysis and release of the lignin components in the potentially bioaccessible fraction following simulated digestion-fermentation. A high prebiotic activity as determined from the increase in Lactobacillus spp. and Bifidobacterium spp. and the production of short-chain fatty acids (SCFAs) following microbial fermentation of HSCG was also observed. These results pave the way toward the use of HSCG as a food supplement.

  9. Design and Test of Advanced Thermal Simulators for an Alkali Metal-Cooled Reactor Simulator

    Science.gov (United States)

    Garber, Anne E.; Dickens, Ricky E.

    2011-01-01

    The Early Flight Fission Test Facility (EFF-TF) at NASA Marshall Space Flight Center (MSFC) has as one of its primary missions the development and testing of fission reactor simulators for space applications. A key component in these simulated reactors is the thermal simulator, designed to closely mimic the form and function of a nuclear fuel pin using electric heating. Continuing effort has been made to design simple, robust, inexpensive thermal simulators that closely match the steady-state and transient performance of a nuclear fuel pin. A series of these simulators have been designed, developed, fabricated and tested individually and in a number of simulated reactor systems at the EFF-TF. The purpose of the thermal simulators developed under the Fission Surface Power (FSP) task is to ensure that non-nuclear testing can be performed at sufficiently high fidelity to allow a cost-effective qualification and acceptance strategy to be used. Prototype thermal simulator design is founded on the baseline Fission Surface Power reactor design. Recent efforts have been focused on the design, fabrication and test of a prototype thermal simulator appropriate for use in the Technology Demonstration Unit (TDU). While designing the thermal simulators described in this paper, effort were made to improve the axial power profile matching of the thermal simulators. Simultaneously, a search was conducted for graphite materials with higher resistivities than had been employed in the past. The combination of these two efforts resulted in the creation of thermal simulators with power capacities of 2300-3300 W per unit. Six of these elements were installed in a simulated core and tested in the alkali metal-cooled Fission Surface Power Primary Test Circuit (FSP-PTC) at a variety of liquid metal flow rates and temperatures. This paper documents the design of the thermal simulators, test program, and test results.

  10. Knowledge Based Cloud FE Simulation of Sheet Metal Forming Processes.

    Science.gov (United States)

    Zhou, Du; Yuan, Xi; Gao, Haoxiang; Wang, Ailing; Liu, Jun; El Fakir, Omer; Politis, Denis J; Wang, Liliang; Lin, Jianguo

    2016-12-13

    The use of Finite Element (FE) simulation software to adequately predict the outcome of sheet metal forming processes is crucial to enhancing the efficiency and lowering the development time of such processes, whilst reducing costs involved in trial-and-error prototyping. Recent focus on the substitution of steel components with aluminum alloy alternatives in the automotive and aerospace sectors has increased the need to simulate the forming behavior of such alloys for ever more complex component geometries. However these alloys, and in particular their high strength variants, exhibit limited formability at room temperature, and high temperature manufacturing technologies have been developed to form them. Consequently, advanced constitutive models are required to reflect the associated temperature and strain rate effects. Simulating such behavior is computationally very expensive using conventional FE simulation techniques. This paper presents a novel Knowledge Based Cloud FE (KBC-FE) simulation technique that combines advanced material and friction models with conventional FE simulations in an efficient manner thus enhancing the capability of commercial simulation software packages. The application of these methods is demonstrated through two example case studies, namely: the prediction of a material's forming limit under hot stamping conditions, and the tool life prediction under multi-cycle loading conditions.

  11. Simulating the production of free defects in irradiated metals

    International Nuclear Information System (INIS)

    Heinisch, H.L.

    1995-01-01

    Under cascade-producing irradiation by high energy neutrons or charged particles, only a small fraction of the initially displaced atoms contribute to the population of free defects that are available to migrate throughout the metal and cause microstructural changes. Although, in principle, computer simulations of free defect production could best be done using molecular dynamics, in practice, the wide ranges of time and distance scales involved can be done only by a combination of atomistic models that employ various levels of approximation. An atomic-scale, multi-model approach has been developed that combines molecular dynamics, binary collision models and stochastic annealing simulation. The annealing simulation is utilized in calibrating binary collision simulations to the results of molecular dynamics calculations, as well as to model the subsequent migration of the defects on more macroscopic time and size scales. The annealing simulation and the method of calibrating the multi-model approach are discussed, and the results of simulations of cascades in copper are presented. The temperature dependence of free defect production following simulated annealing of isolated cascades in copper shows a differential in the fractions of free vacancies and interstitial defects escaping from the cascade above stage V. This differential, a consequence of the direct formation of interstitial clusters in cascades and the relative thermal stability of vacancy and interstitial clusters during subsequent annealing, is the basis for the production bias mechanism of void swelling. (orig.)

  12. Sequential separation of transuranic elements and fission products from uranium metal ingots in electrolytic reduction process of spent PWR fuels

    International Nuclear Information System (INIS)

    Chang Heon Lee; Kih Soo Joe; Won Ho Kim; Euo Chang Jung; Kwang Yong Jee

    2009-01-01

    A sequential separation procedure has been developed for the determination of transuranic elements and fission products in uranium metal ingot samples from an electrolytic reduction process for a metallization of uranium dioxide to uranium metal in a medium of LiCl-Li 2 O molten salt at 650 deg C. Pu, Np and U were separated using anion-exchange and tri-n-butylphosphate (TBP) extraction chromatography. Cs, Sr, Ba, Ce, Pr, Nd, Sm, Eu, Gd, Zr and Mo were separated in several groups from Am and Cm using TBP and di(2-ethylhexyl)phosphoric acid (HDEHP) extraction chromatography. Effect of Fe, Ni, Cr and Mg, which were corrosion products formed through the process, on the separation of the analytes was investigated in detail. The validity of the separation procedure was evaluated by measuring the recovery of the stable metals and 239 Pu, 237 Np, 241 Am and 244 Cm added to a synthetic uranium metal ingot dissolved solution. (author)

  13. Metallic Fuel Casting Development and Parameter Optimization Simulations

    International Nuclear Information System (INIS)

    Fielding, Randall S.; Kennedy, J.R.; Crapps, J.; Unal, C.

    2013-01-01

    Conclusions: • Gravity casting is a feasible process for casting of metallic fuels: – May not be as robust as CGIC, more parameter dependent to find right “sweet spot” for high quality castings; – Fluid flow is very important and is affected by mold design, vent size, super heat, etc.; – Pressure differential assist was found to be detrimental. • Simulation found that vent location was important to allow adequate filling of mold; • Surface tension plays an important role in determining casting quality; • Casting and simulations high light the need for better characterized fluid physical and thermal properties; • Results from simulations will be incorporated in GACS design such as vent location and physical property characterization

  14. Numerical Simulations of Particle Deposition in Metal Foam Heat Exchangers

    Science.gov (United States)

    Sauret, Emilie; Saha, Suvash C.; Gu, Yuantong

    2013-01-01

    Australia is a high-potential country for geothermal power with reserves currently estimated in the tens of millions of petajoules, enough to power the nation for at least 1000 years at current usage. However, these resources are mainly located in isolated arid regions where water is scarce. Therefore, wet cooling systems for geothermal plants in Australia are the least attractive solution and thus air-cooled heat exchangers are preferred. In order to increase the efficiency of such heat exchangers, metal foams have been used. One issue raised by this solution is the fouling caused by dust deposition. In this case, the heat transfer characteristics of the metal foam heat exchanger can dramatically deteriorate. Exploring the particle deposition property in the metal foam exchanger becomes crucial. This paper is a numerical investigation aimed to address this issue. Two-dimensional (2D) numerical simulations of a standard one-row tube bundle wrapped with metal foam in cross-flow are performed and highlight preferential particle deposition areas.

  15. Spent fuel management

    International Nuclear Information System (INIS)

    2005-01-01

    The production of nuclear electricity results in the generation of spent fuel that requires safe, secure and efficient management. Appropriate management of the resulting spent fuel is a key issue for the steady and sustainable growth of nuclear energy. Currently about 10,000 tonnes heavy metal (HM) of spent fuel are unloaded every year from nuclear power reactors worldwide, of which 8,500 t HM need to be stored (after accounting for reprocessed fuel). This is the largest continuous source of civil radioactive material generated, and needs to be managed appropriately. Member States have referred to storage periods of 100 years and even beyond, and as storage quantities and durations extend, new challenges arise in the institutional as well as in the technical area. The IAEA gives high priority to safe and effective spent fuel management. As an example of continuing efforts, the 2003 International Conference on Storage of Spent Fuel from Power Reactors gathered 125 participants from 35 member states to exchange information on this important subject. With its large number of Member States, the IAEA is well-positioned to gather and share information useful in addressing Member State priorities. IAEA activities on this topic include plans to produce technical documents as resources for a range of priority topics: spent fuel performance assessment and research, burnup credit applications, cask maintenance, cask loading optimization, long term storage requirements including records maintenance, economics, spent fuel treatment, remote technology, and influence of fuel design on spent fuel storage. In addition to broader topics, the IAEA supports coordinated research projects and technical cooperation projects focused on specific needs

  16. Containing method for spent fuel and spent fuel containing vessel

    International Nuclear Information System (INIS)

    Maekawa, Hiromichi; Hanada, Yoshine.

    1996-01-01

    Upon containing spent fuels, a metal vessel main body and a support spacer having fuel containing holes are provided. The support spacer is disposed in the inside of the metal vessel main body, and spent fuel assemblies are loaded in the fuel containing holes. Then, a lid is welded at the opening of the metal vessel main body to provide a sealing state. In this state, heat released from the spent fuel assemblies is transferred to the wall of the metal vessel main body via the support spacer. Since the support spacer has a greater heat conductivity than gases, heat of the spent fuel assemblies tends to be released to the outside, thereby capable of removing heat of the spent fuel assemblies effectively. In addition, since the surfaces of the spent fuel assemblies are in contact with the inner surface of the fuel containing holes of the support spacer, impact-resistance and earthquake-resistance are ensured, and radiation from the spent fuel assemblies is decayed by passing through the layer of the support spacer. (T.M.)

  17. Simulations of rapid pressure-induced solidification in molten metals

    International Nuclear Information System (INIS)

    Patel, Mehul V.; Streitz, Frederick H.

    2004-01-01

    The process of interest in this study is the solidification of a molten metal subjected to rapid pressurization. Most details about solidification occurring when the liquid-solid coexistence line is suddenly transversed along the pressure axis remain unknown. We present preliminary results from an ongoing study of this process for both simple models of metals (Cu) and more sophisticated material models (MGPT potentials for Ta). Atomistic (molecular dynamics) simulations are used to extract details such as the time and length scales that govern these processes. Starting with relatively simple potential models, we demonstrate how molecular dynamics can be used to study solidification. Local and global order parameters that aid in characterizing the phase have been identified, and the dependence of the solidification time on the phase space distance between the final (P,T) state and the coexistence line has been characterized

  18. Advanced Wear Simulation for Bulk Metal Forming Processes

    Directory of Open Access Journals (Sweden)

    Behrens Bernd-Arno

    2016-01-01

    Full Text Available In the recent decades the finite element method has become an essential tool for the cost-efficient virtual process design in the metal forming sector in order to counter the constantly increasing quality standards, particularly from the automotive industry as well as intensified international competition in the forging industry. An optimized process design taking precise tool wear prediction into account is a way to increase the cost-efficiency of the bulk metal forming processes. The main objective of the work presented in this paper is a modelling algorithm, which allows predicting die wear with respect to a geometry update during the forming simulation. Changes in the contact area caused by geometry update lead to the different die wear distribution. It primarily concerns the die areas, which undergo high thermal and mechanical loads.

  19. Structural evaluation of spent nuclear fuel storage facilities under aircraft crash impact (2). Horizontal impact test onto reduced scale metal cask due to aircraft engine missile

    International Nuclear Information System (INIS)

    Namba, Kosuke; Shirai, Koji; Saegusa, Toshiari

    2009-01-01

    In this study, to confirm the sealing performance of a metal cask subjected to impact force due to possible commercial aircraft crash against a spent fuel storage facility, the horizontal impact test was carried out. In the test, an aircraft engine missile with a speed of 57.3 m/s attacked the reduced scale metal cask containing helium gas, which stands vertically. Then the leak rate and sliding displacement of the lid were measured. The leak rate increased rapidly and reached to 4.0 x 10 -6 Pa·m 3 /sec. After that, the leak rate decreased slowly and converged to 1.0x10 -6 Pa·m 3 /sec after 20 hours from the impact test. The leak rate of a full scale cask was evaluated using that of reduced scale cask obtained by the test. Then the leak rate of the full scale cask was 3.5x10 -5 Pa·m 3 /sec. This result showed that the sealing performance of the full scale metal cask would not be affected immediately by the horizontal impact of the aircraft engine with a speed of 57.3 m/s. (author)

  20. Quantum dynamical simulations of local field enhancement in metal nanoparticles.

    Science.gov (United States)

    Negre, Christian F A; Perassi, Eduardo M; Coronado, Eduardo A; Sánchez, Cristián G

    2013-03-27

    Field enhancements (Γ) around small Ag nanoparticles (NPs) are calculated using a quantum dynamical simulation formalism and the results are compared with electrodynamic simulations using the discrete dipole approximation (DDA) in order to address the important issue of the intrinsic atomistic structure of NPs. Quite remarkably, in both quantum and classical approaches the highest values of Γ are located in the same regions around single NPs. However, by introducing a complete atomistic description of the metallic NPs in optical simulations, a different pattern of the Γ distribution is obtained. Knowing the correct pattern of the Γ distribution around NPs is crucial for understanding the spectroscopic features of molecules inside hot spots. The enhancement produced by surface plasmon coupling is studied by using both approaches in NP dimers for different inter-particle distances. The results show that the trend of the variation of Γ versus inter-particle distance is different for classical and quantum simulations. This difference is explained in terms of a charge transfer mechanism that cannot be obtained with classical electrodynamics. Finally, time dependent distribution of the enhancement factor is simulated by introducing a time dependent field perturbation into the Hamiltonian, allowing an assessment of the localized surface plasmon resonance quantum dynamics.

  1. Hydrometallurgical method for recycling rare earth metals, cobalt, nickel, iron, and manganese from negative electrodes of spent Ni-MH mobile phone batteries

    International Nuclear Information System (INIS)

    Santos, Vinicius Emmanuel de Oliveira dos; Lelis, Maria de Fatima Fontes; Freitas, Marcos Benedito Jose Geraldo de

    2014-01-01

    A hydrometallurgical method for the recovery of rare earth metals, cobalt, nickel, iron, and manganese from the negative electrodes of spent Ni-MH mobile phone batteries was developed. The rare earth compounds were obtained by chemical precipitation at pH 1.5, with sodium cerium sulfate (NaCe(SO 4 ) 2 .H 2 O) and lanthanum sulfate (La 2 (SO 4 ) 3 .H 2 O) as the major recovered components. Iron was recovered as Fe(OH) 3 and FeO. Manganese was obtained as Mn 3 O 4 .The recovered Ni(OH) 2 and Co(OH) 2 were subsequently used to synthesize LiCoO 2 , LiNiO 2 and CoO, for use as cathodes in ion-Li batteries. The anodes and recycled materials were characterized by analytical techniques. (author)

  2. First Principles Simulation of a Ceramic/ Metal Interface with Misfit

    International Nuclear Information System (INIS)

    Benedek, R.; Alavi, A.; Seidman, D. N.; Yang, L. H.; Muller, D. A.; Woodward, C.

    2000-01-01

    The relaxed atomic structure of a model ceramic/metal interface, {222}MgO/Cu , is simulated, including lattice constant mismatch, using first principles local-density functional theory plane wave pseudopotential methods. The 399-atom computational unit cell contains 36 O and 49 Cu atoms per layer in accordance with the 7/6 ratio of MgO to Cu lattice constants. The atomic layers on both sides of the interface warp to optimize the local bonding. The interface adhesive energy is calculated. The interface electronic structure is found to vary appreciably with the local environment. (c) 2000 The American Physical Society

  3. Simulation of Cu-Mg metallic glass: Thermodynamics and structure

    DEFF Research Database (Denmark)

    Bailey, Nicholas; Schiøtz, Jakob; Jacobsen, Karsten Wedel

    2004-01-01

    We have obtained effective medium theory interatomic potential parameters suitable for studying Cu-Mg metallic glasses. We present thermodynamic and structural results from simulations of such glasses over a range of compositions. We have produced low-temperature configurations by cooling from...... the melt at as slow a rate as practical, using constant temperature and pressure molecular dynamics. During the cooling process we have carried out thermodynamic analyses based on the temperature dependence of the enthalpy and its derivative, the specific heat, from which the glass transition temperature...

  4. Development of spent fuel remote handling technology

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Ji Sup; Park, B S; Park, Y S; Oh, S C; Kim, S H; Cho, M W; Hong, D H

    1997-12-01

    Since the nation`s policy on spent fuel management is not finalized, the technical items commonly required for safe management and recycling of spent fuel - remote technologies of transportation, inspection, maintenance, and disassembly of spent fuel - are selected and pursued. In this regards, the following R and D activities are carried out : collision free transportation of spent fuel assembly, mechanical disassembly of spent nuclear fuel and graphical simulation of fuel handling / disassembly process. (author). 36 refs., 16 tabs., 77 figs

  5. Development of spent fuel remote handling technology

    International Nuclear Information System (INIS)

    Yoon, Ji Sup; Park, B. S.; Park, Y. S.; Oh, S. C.; Kim, S. H.; Cho, M. W.; Hong, D. H.

    1997-12-01

    Since the nation's policy on spent fuel management is not finalized, the technical items commonly required for safe management and recycling of spent fuel - remote technologies of transportation, inspection, maintenance, and disassembly of spent fuel - are selected and pursued. In this regards, the following R and D activities are carried out : collision free transportation of spent fuel assembly, mechanical disassembly of spent nuclear fuel and graphical simulation of fuel handling / disassembly process. (author). 36 refs., 16 tabs., 77 figs

  6. Simulated Tip Rub Testing of Low-Density Metal Foam

    Science.gov (United States)

    Bowman, Cheryl L.; Jones, Michael G.

    2009-01-01

    Preliminary acoustic studies have indicated that low-density, open-cell, metal foams may be suitable acoustic liner material for noise suppression in high by-pass engines. Metal foam response under simulated tip rub conditions was studied to assess whether its durability would be sufficient for the foam to serve both as a rub strip above the rotor as well as an acoustic treatment. Samples represented four metal alloys, nominal cell dimensions ranging from 60 to 120 cells per inch (cpi), and relative densities ranging from 3.4 to 10 percent. The resulting rubbed surfaces were relatively smooth and the open cell structure of the foam was not adversely affected. Sample relative density appeared to have significant influence on the forces induced by the rub event. Acoustic responses of various surface preparations were measured using a normal incidence tube. The results of this study indicate that the foam s open-cell structure was retained after rubbing and that the acoustic absorption spectra variation was minimal.

  7. A simulator study of adverse wear with metal and cement debris contamination in metal-on-metal hip bearings.

    Science.gov (United States)

    Halim, T; Clarke, I C; Burgett-Moreno, M D; Donaldson, T K; Savisaar, C; Bowsher, J G

    2014-03-01

    Third-body wear is believed to be one trigger for adverse results with metal-on-metal (MOM) bearings. Impingement and subluxation may release metal particles from MOM replacements. We therefore challenged MOM bearings with relevant debris types of cobalt-chrome alloy (CoCr), titanium alloy (Ti6Al4V) and polymethylmethacrylate bone cement (PMMA). Cement flakes (PMMA), CoCr and Ti6Al4V particles (size range 5 µm to 400 µm) were run in a MOM wear simulation. Debris allotments (5 mg) were inserted at ten intervals during the five million cycle (5 Mc) test. In a clean test phase (0 Mc to 0.8 Mc), lubricants retained their yellow colour. Addition of metal particles at 0.8 Mc turned lubricants black within the first hour of the test and remained so for the duration, while PMMA particles did not change the colour of the lubricant. Rates of wear with PMMA, CoCr and Ti6Al4V debris averaged 0.3 mm(3)/Mc, 4.1 mm(3)/Mc and 6.4 mm(3)/Mc, respectively. Metal particles turned simulator lubricants black with rates of wear of MOM bearings an order of magnitude higher than with control PMMA particles. This appeared to model the findings of black, periarticular joint tissues and high CoCr wear in failed MOM replacements. The amount of wear debris produced during a 500 000-cycle interval of gait was 30 to 50 times greater than the weight of triggering particle allotment, indicating that MOM bearings were extremely sensitive to third-body wear. Cite this article: Bone Joint Res 2015;4:29-37. ©2015 The British Editorial Society of Bone & Joint Surgery.

  8. Numerical simulation of heat transfer in metal foams

    Science.gov (United States)

    Gangapatnam, Priyatham; Kurian, Renju; Venkateshan, S. P.

    2018-02-01

    This paper reports a numerical study of forced convection heat transfer in high porosity aluminum foams. Numerical modeling is done considering both local thermal equilibrium and non local thermal equilibrium conditions in ANSYS-Fluent. The results of the numerical model were validated with experimental results, where air was forced through aluminum foams in a vertical duct at different heat fluxes and velocities. It is observed that while the LTE model highly under predicts the heat transfer in these foams, LTNE model predicts the Nusselt number accurately. The novelty of this study is that once hydrodynamic experiments are conducted the permeability and porosity values obtained experimentally can be used to numerically simulate heat transfer in metal foams. The simulation of heat transfer in foams is further extended to find the effect of foam thickness on heat transfer in metal foams. The numerical results indicate that though larger foam thicknesses resulted in higher heat transfer coefficient, this effect weakens with thickness and is negligible in thick foams.

  9. Novel Experimental Simulations of the Atmospheric Injection of Meteoric Metals

    Energy Technology Data Exchange (ETDEWEB)

    Gómez Martín, J. C.; Bones, D. L.; Carrillo-Sánchez, J. D.; James, A. D.; Plane, J. M. C. [School of Chemistry, University of Leeds, Woodhouse Lane, Leeds LS2 9JT (United Kingdom); Trigo-Rodríguez, J. M. [Meteorites, Minor Bodies and Planetary Science Group, Institute of Space Sciences (CSIC-IEEC). Campus UAB, C/Can Magrans s/n, E-08193 Cerdanyola del Vallés (Barcelona) (Spain); Fegley, B. Jr., E-mail: J.M.C.Plane@leeds.ac.uk [Washington University, St. Louis, MO (United States)

    2017-02-20

    A newly developed laboratory, Meteoric Ablation Simulator (MASI), is used to test model predictions of the atmospheric ablation of interplanetary dust particles (IDPs) with experimental Na, Fe, and Ca vaporization profiles. MASI is the first laboratory setup capable of performing time-resolved atmospheric ablation simulations, by means of precision resistive heating and atomic laser-induced fluorescence detection. Experiments using meteoritic IDP analogues show that at least three mineral phases (Na-rich plagioclase, metal sulfide, and Mg-rich silicate) are required to explain the observed appearance temperatures of the vaporized elements. Low melting temperatures of Na-rich plagioclase and metal sulfide, compared to silicate grains, preclude equilibration of all the elemental constituents in a single melt. The phase-change process of distinct mineral components determines the way in which Na and Fe evaporate. Ca evaporation is dependent on particle size and on the initial composition of the molten silicate. Measured vaporized fractions of Na, Fe, and Ca as a function of particle size and speed confirm differential ablation (i.e., the most volatile elements such as Na ablate first, followed by the main constituents Fe, Mg, and Si, and finally the most refractory elements such as Ca). The Chemical Ablation Model (CABMOD) provides a reasonable approximation to this effect based on chemical fractionation of a molten silicate in thermodynamic equilibrium, even though the compositional and geometric description of IDPs is simplistic. Improvements in the model are required in order to better reproduce the specific shape of the elemental ablation profiles.

  10. Heat transfer enhancement for spent nuclear fuel assembly disposal packages using metallic void fillers: A prevention technique for solidification shrinkage-induced interfacial gaps

    Energy Technology Data Exchange (ETDEWEB)

    Park, Yongsoo, E-mail: yspark@alum.mit.edu; McKrell, Thomas J.; Driscoll, Michael J.

    2017-06-15

    This study considers replacing the externally accessible void spaces inside a disposal package containing a spent nuclear fuel assembly (SNFA) with high heat conducting metal to increase the effective thermal conductivity of the package and simplify the heat transfer mechanism inside the package by reducing it to a conduction dominant problem. The focus of the study is on preventing the gaps adjacent to the walls of the package components, produced by solidification shrinkage of poured liquid metal. We approached the problem by providing a temporary coating layer on the components to avoid direct build-up of thick metal oxides on their surface to promote metallic bonding at the interfaces under a non-inert environment. Laboratory scale experiments without SNFA were performed with Zn coated low carbon steel canisters and Zamak-3 void filler under two different filling temperature conditions – below and above the melting point of Zn (designated BMP and AMP respectively). Gap formation was successfully prevented in both cases while we confirmed an open gap in a control experiment, which used an uncoated canister. Minor growth of Al-Fe intermetallic phases was observed at the canister/filler interface of the sample produced under the BMP condition while their growth was significant and showed irregularly distributed morphology in the sample produced under the AMP condition, which has a potential to mitigate excessive residual stresses caused by shrinkage prevention. A procedure for the full-scale application was specified based on the results. - Highlights: •A void filling technique is introduced to enhance SNFA package heat transfer. •The technique is demonstrated via experiments using the Fe-Al-Zn system. •A procedure for the full scale application is proposed based on the results.

  11. Disposal of spent fuel

    International Nuclear Information System (INIS)

    Blomeke, J.O.; Ferguson, D.E.; Croff, A.G.

    1978-01-01

    Based on preliminary analyses, spent fuel assemblies are an acceptable form for waste disposal. The following studies appear necessary to bring our knowledge of spent fuel as a final disposal form to a level comparable with that of the solidified wastes from reprocessing: 1. A complete systems analysis is needed of spent fuel disposition from reactor discharge to final isolation in a repository. 2. Since it appears desirable to encase the spent fuel assembly in a metal canister, candidate materials for this container need to be studied. 3. It is highly likely that some ''filler'' material will be needed between the fuel elements and the can. 4. Leachability, stability, and waste-rock interaction studies should be carried out on the fuels. The major disadvantages of spent fuel as a disposal form are the lower maximum heat loading, 60 kW/acre versus 150 kW/acre for high-level waste from a reprocessing plant; the greater long-term potential hazard due to the larger quantities of plutonium and uranium introduced into a repository; and the possibility of criticality in case the repository is breached. The major advantages are the lower cost and increased near-term safety resulting from eliminating reprocessing and the treatment and handling of the wastes therefrom

  12. Numerical simulation of gas metal arc welding parametrical study

    International Nuclear Information System (INIS)

    Szanto, M.; Gilad, I.; Shai, I.; Quinn, T.P.

    2002-01-01

    The Gas Metal Arc Welding (GMAW) is a widely used welding process in the industry. The process variables are usually determined through extensive experiments. Numerical simulation, reduce the cost and extends the understanding of the process. In the present work, a versatile model for numerical simulation of GMAW is presented. The model provides the basis for fundamental understanding of the process. The model solves the magneto-hydrodynamic equations for the flow and temperature fields of the molten electrode and the plasma simultaneously, to form a fully coupled model. A commercial CFD code was extended to include the effects of radiation, Lorentz forces, Joule heating and thermoelectric effects. The geometry of the numerical model assembled to fit an experimental apparatus. To demonstrate the method, an aluminum electrode was modeled in a pure argon arc. Material properties and welding parameters are the input variables in the numerical model. In a typical process, the temperature distribution of the plasma is over 15000 K, resulting high non-linearity of the material properties. Moreover, there is high uncertainty in the available property data, at that range of temperatures. Therefore, correction factors were derived for the material properties to adjust between the numerical and the experimental results. Using the compensated properties, parametric study was performed. The effects of the welding parameters on the process, such the working voltage, electrode feed rate and shielding gas flow, were derived. The principal result of the present work is the ability to predict, by numerical simulation, the mode, size and frequency of the metal transferred from the electrode, which is the main material and energy source for the welding pool in GMAW

  13. Encapsulating spent nuclear fuel

    International Nuclear Information System (INIS)

    Fleischer, L.R.; Gunasekaran, M.

    1979-01-01

    A system is described for encapsulating spent nuclear fuel discharged from nuclear reactors in the form of rods or multi-rod assemblies. The rods are completely and contiguously enclosed in concrete in which metallic fibres are incorporated to increase thermal conductivity and polymers to decrease fluid permeability. This technique provides the advantage of acceptable long-term stability for storage over the conventional underwater storage method. Examples are given of suitable concrete compositions. (UK)

  14. Monte Carlo simulation of the electron and X-ray depth distribution for quantitative electron probe microanalysis of PWR spent fuels

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Hyoung Mun; Lee, Hyung Kwon; Son, Young Zoon; Chun, Yong Bum [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2011-10-15

    Electron probe microanalysis requires several corrections to quantify an element of a specimen. The X-rays produced by the primary beam are created at some depth in the specimen. This distribution is usually represented as the function {Phi}(pz), and it is possible to calculate the correction factors for atomic number and absorption effects. The electron and X-ray depth distributions for a quantitative electron probe micro analysis were simulated by the CASINO Monte Carlo program to quantify some elements of the PWR spent fuel with 50 GWd/tU of burnup and 2 years of cooling time

  15. Monte Carlo simulation of the electron and X-ray depth distribution for quantitative electron probe microanalysis of PWR spent fuels

    International Nuclear Information System (INIS)

    Kwon, Hyoung Mun; Lee, Hyung Kwon; Son, Young Zoon; Chun, Yong Bum

    2011-01-01

    Electron probe microanalysis requires several corrections to quantify an element of a specimen. The X-rays produced by the primary beam are created at some depth in the specimen. This distribution is usually represented as the function Φ(pz), and it is possible to calculate the correction factors for atomic number and absorption effects. The electron and X-ray depth distributions for a quantitative electron probe micro analysis were simulated by the CASINO Monte Carlo program to quantify some elements of the PWR spent fuel with 50 GWd/tU of burnup and 2 years of cooling time

  16. Mathematical simulation of the behaviour of the spent organic extractive solution near the injection well area in the case of underground disposal

    International Nuclear Information System (INIS)

    Istomin, A.D.; Noskov, M.D.; Balakhonov, V.G.; Zubkov, A.A.; Egorov, G.F.

    2005-01-01

    A mathematical model is presented of the processes in the collector seam under combined disposal of organic and radioactive wastes in porous geological strata of deep bedding. The model describes filtration, mass transfer, sorption and desorption of radionuclides, radioactive decay, decomposition of organic components and heat transfer. The computer software is developed. The results of simulating the thermal field dynamics, behaviour of the components of the spent organic extractive solution and water radioactive wastes in the collector seam of deep bedding are presented [ru

  17. Numerical simulation of metallic wire arc additive manufacturing (WAAM)

    Science.gov (United States)

    Graf, M.; Pradjadhiana, K. P.; Hälsig, A.; Manurung, Y. H. P.; Awiszus, B.

    2018-05-01

    Additive-manufacturing technologies have been gaining tremendously in popularity for some years in the production of single-part series with complex, close-to-final-contour geometries and the processing of special or hybrid materials. In principle, the processes can be subdivided into wire-based and powder-based processes in accordance with the Association of German Engineers (VDI) Guideline 3405. A further subdivision is made with respect to the smelting technology. In all of the processes, the base material is applied in layers at the points where it is needed in accordance with the final contour. The process that was investigated was wire-based, multi-pass welding by means of gas-metal arc welding. This was accomplished in the present study by determining the material parameters (thermo-mechanical and thermo-physical characteristics) of the welding filler G3Si1 (material number: 1.5125) that were necessary for the numerical simulation and implementing them in a commercial FE program (MSC Marc Mentat). The focus of this paper was on simulation and validation with respect to geometry and microstructural development in the welding passes. The resulting minimal deviation between reality and simulation was a result of the measurement inertia of the thermocouples. In general, however, the FE model can be used to make a very good predetermination of the cooling behaviour, which affects the microstructural development and thus the mechanical properties of the joining zone, as well as the geometric design of the component (distortion, etc.).

  18. Spent fuel reprocessing method

    International Nuclear Information System (INIS)

    Shoji, Hirokazu; Mizuguchi, Koji; Kobayashi, Tsuguyuki.

    1996-01-01

    Spent oxide fuels containing oxides of uranium and transuranium elements are dismantled and sheared, then oxide fuels are reduced into metals of uranium and transuranium elements in a molten salt with or without mechanical removal of coatings. The reduced metals of uranium and transuranium elements and the molten salts are subjected to phase separation. From the metals of uranium and transuranium elements subjected to phase separation, uranium is separated to a solid cathode and transuranium elements are separated to a cadmium cathode by an electrolytic method. Molten salts deposited together with uranium to the solid cathode, and uranium and transuranium elements deposited to the cadmium cathode are distilled to remove deposited molten salts and cadmium. As a result, TRU oxides (solid) such as UO 2 , Pu 2 in spent fuels can be reduced to U and TRU by a high temperature metallurgical method not using an aqueous solution to separate them in the form of metal from other ingredients, and further, metal fuels can be obtained through an injection molding step depending on the purpose. (N.H.)

  19. Standard Guide for Simulation of Helium Effects in Irradiated Metals

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1996-01-01

    1.1 This guide provides advice for conducting experiments to investigate the effects of helium on the properties of metals where the technique for introducing the helium differs in some way from the actual mechanism of introduction of helium in service. Simulation techniques considered for introducing helium shall include charged particle implantation, exposure to α-emitting radioisotopes, and tritium decay techniques. Procedures for the analysis of helium content and helium distribution within the specimen are also recommended. 1.2 Two other methods for introducing helium into irradiated materials are not covered in this guide. They are the enhancement of helium production in nickel-bearing alloys by spectral tailoring in mixed-spectrum fission reactors, and isotopic tailoring in both fast and mixed-spectrum fission reactors. These techniques are described in Refs (1-5). Dual ion beam techniques (6) for simultaneously implanting helium and generating displacement damage are also not included here. This lat...

  20. Alternatives for recovering metals from spent catalysts for hydrotreating of heavy hydrocarbons: a case study; Alternativas para la recuperacion de metales a partir de catalizadores gastados del hidrotratamiento de hidrocarburos pesados: un caso de estudio

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, Fernando; Ramirez, Sergio; Ancheyta, Jorge; Mavil, Martha [Instituto Mexicano del Petroleo, Mexico, D.F. (Mexico)]. E-mail: jancheyt@imp.mx

    2008-05-15

    The increasing production of spent hydrotreating catalysts used for processing heavy hydrocarbons and the problems related to their disposal are described in this work. These catalysts contain important amounts of heavy metals such as molybdenum (Mo), nickel (Ni), cobalt (Co) and vanadium (V), which can be recovered and hence an economical benefit may be obtained. The results of experimental tests for alkaline leaching (NaOH) to recover V and Mo, and the effect of operating conditions on metal recovery are also presented. The results show that, in general, the highest recovery of Mo is obtained at pH 8.5 and leaching time of 12 hours, while in the case of V, the highest recovery is observed at pH 9.0 and 8 hours. In both cases, the leaching solution contained 10 wt % alkaline. Based on the experimental information and data from a commercial plant, a preliminary economy study was developed, in which the expected economical benefits of metals recovery from spent catalysts used for hydrotreating heavy hydrocarbon are estimated. [Spanish] En el presente trabajo se describe la problematica de la creciente produccion de catalizadores gastados de los procesos de hidrotratamiento de hidrocarburos pesados. Estos catalizadores contienen cantidades importantes de metales pesados como molibdeno (Mo), niquel (Ni), cobalto (Co) y vanadio (V), que son susceptibles de recuperarse y obtener con ello un beneficio economico. Tambien se presentan resultados de pruebas experimentales de lixiviacion alcalina (NaOH) para la recuperacion de V y Mo, y el efecto de las variables de operacion sobre la recuperacion de metales. En general, se encontro que las mejores recuperaciones de Mo fueron a pH de 8.5 y 12 h, mientras que para el V fueron a pH de 9.0 y 8 h, ambos a una concentracion del agente lixiviante de 10% en peso. Con base en la informacion experimental obtenida y datos de una planta industrial se presenta un estudio economico preliminar, en el que se estiman los beneficios

  1. Simulation of Cu-Mg metallic glass: Thermodynamics and structure

    International Nuclear Information System (INIS)

    Bailey, Nicholas P.; Schioetz, Jakob; Jacobsen, Karsten W.

    2004-01-01

    We have obtained effective medium theory interatomic potential parameters suitable for studying Cu-Mg metallic glasses. We present thermodynamic and structural results from simulations of such glasses over a range of compositions. We have produced low-temperature configurations by cooling from the melt at as slow a rate as practical, using constant temperature and pressure molecular dynamics. During the cooling process we have carried out thermodynamic analyses based on the temperature dependence of the enthalpy and its derivative, the specific heat, from which the glass transition temperature may be determined. We have also carried out structural analyses using the radial distribution function (RDF) and common neighbor analysis (CNA). Our analysis suggests that the splitting of the second peak, commonly associated with metallic glasses, in fact, has little to do with the glass transition itself, but is simply a consequence of the narrowing of peaks associated with structural features present in the liquid state. In fact, the splitting temperature for the Cu-Cu RDF is well above T g . The CNA also highlights a strong similarity between the structure of the intermetallic alloys and the amorphous alloys of similar composition. We have also investigated the diffusivity in the supercooled regime. Its temperature dependence indicates fragile-liquid behavior, typical of binary metallic glasses. On the other hand, the relatively low specific-heat jump of around 1.5k B /atom indicates apparent strong-liquid behavior, but this can be explained by the width of the transition due to the high cooling rates

  2. Computer simulation of plastic deformation in irradiated metals

    International Nuclear Information System (INIS)

    Colak, U.

    1989-01-01

    A computer-based model is developed for the localized plastic deformation in irradiated metals by dislocation channeling, and it is applied to irradiated single crystals of niobium. In the model, the concentrated plastic deformation in the dislocation channels is postulated to occur by virtue of the motion of dislocations in a series of pile-tips on closely spaced parallel slip planes. The dynamics of this dislocation motion is governed by an experimentally determined dependence of dislocation velocity on shear stress. This leads to a set of coupled differential equations for the positions of the individual dislocations in the pile-up as a function of time. Shear displacement in the channel region is calculated from the total distance traveled by the dislocations. The macroscopic shape change in single crystal metal sheet samples is determined by the axial displacement produced by the shear displacements in the dislocation channels. Computer simulations are performed for the plastic deformation up to 20% engineering strain at a constant strain rate. Results of the computer calculations are compared with experimental observations of the shear stress-engineering strain curve obtained in tensile tests described in the literature. Agreement between the calculated and experimental stress-strain curves is obtained for shear displacement of 1.20-1.25 μm and 1000 active slip planes per channel, which is reasonable in the view of experimental observations

  3. Atomistic simulation of fatigue in face centred cubic metals

    International Nuclear Information System (INIS)

    Fan, Zhengxuan

    2016-01-01

    Fatigue is one of the major damage mechanisms of metals. It is characterized by strong environmental effects and wide lifetime dispersions which must be better understood. Different face centred cubic metals, al, Cu, Ni, and Ag are analyzed. The mechanical behaviour of surface steps naturally created by the glide of dislocations subjected to cyclic loading is examined using molecular dynamics simulations in vacuum and in air for Cu and Ni. an atomistic reconstruction phenomenon is observed at these surface steps which can induce strong irreversibility. Three different mechanisms of reconstruction are defined. Surface slip irreversibility under cyclic loading is analyzed. all surface steps are intrinsically irreversible under usual fatigue laboratory loading amplitude without the arrival of opposite sign dislocations on direct neighbor plane.With opposite sign dislocations on non direct neighbour planes, irreversibility cumulates cycle by cycle and a micro-notch is produced whose depth gradually increases.Oxygen environment affects the surface (first stage of oxidation) but does not lead to higher irreversibility as it has no major influence on the different mechanisms linked to surface relief evolution.a rough estimation of surface irreversibility is carried out for pure edge dislocations in persistent slip bands in so-called wavy materials. It gives an irreversibility fraction between 0.5 and 0.75 in copper in vacuum and in air, in agreement with recent atomic force microscopy measurements.Crack propagation mechanisms are simulated in inert environment. Cracks can propagate owing to the irreversibility of generated dislocations because of their mutual interactions up to the formation of dislocation junctions. (author) [fr

  4. A liquid-metal reactor for burning minor actinides of spent light water reactor fuel. 1: Neutronics design study

    International Nuclear Information System (INIS)

    Choi, H.; Downar, T.J.

    1999-01-01

    A liquid-metal reactor was designed for the primary purpose of burning the minor actinide waste from commercial light water reactors (LWRs). The design was constrained to maintain acceptable safety performance as measured by the burnup reactivity swing, the Doppler constant, and the sodium void worth. Sensitivity studies were performed for homogeneous and decoupled core designs, and a minor actinide burner design was determined to maximize actinide consumption and satisfy safety constraints. One of the principal innovations was the use of two core regions, with a fissile plutonium outer core and an inner core consisting only of minor actinides. The physics studies performed here indicate that a 1200-MW(thermal) core is able to consume the annual minor actinide inventory of about 16 LWRs and still exhibit reasonable safety characteristics

  5. Simulated electron affinity tuning in metal-insulator-metal (MIM) diodes

    Science.gov (United States)

    Mistry, Kissan; Yavuz, Mustafa; Musselman, Kevin P.

    2017-05-01

    Metal-insulator-metal diodes for rectification applications must exhibit high asymmetry, nonlinearity, and responsivity. Traditional methods of improving these figures of merit have consisted of increasing insulator thickness, adding multiple insulator layers, and utilizing a variety of metal contact combinations. However, these methods have come with the price of increasing the diode resistance and ultimately limiting the operating frequency to well below the terahertz regime. In this work, an Airy Function Transfer Matrix simulation method was used to observe the effect of tuning the electron affinity of the insulator as a technique to decrease the diode resistance. It was shown that a small increase in electron affinity can result in a resistance decrease in upwards of five orders of magnitude, corresponding to an increase in operating frequency on the same order. Electron affinity tuning has a minimal effect on the diode figures of merit, where asymmetry improves or remains unaffected and slight decreases in nonlinearity and responsivity are likely to be greatly outweighed by the improved operating frequency of the diode.

  6. Parallel Object Oriented MD Simulation Program for Long Time Simulations of Metallic Glasses and Undercooled Liquids

    Science.gov (United States)

    Böddeker, B.; Teichler, H.

    The MD simulation program TABB is motivated by the need of long time simulations for the investigation of slow processes near the glass transition of glass forming alloys. TABB is written in C++ with a high degree of flexibility: TABB allows the use of any short ranged pair potentials or EAM potentials, by generating and using a spline representation of all functions and their derivatives. TABB supports several numerical integration algorithms like the Runge-Kotta or the modified Gear-predictor-corrector algorithm of order five. The boundary conditions can be chosen to resemble the geometry of bulk materials or films. The simulation box length or the pressure can be fixed for each dimension separately. TABB may be used in isokinetic, isoenergeric or canonic (with random forces) mode. TABB contains a simple instruction interpreter to easily control the parameters and options during the simulation. The same source code can be compiled either for workstations or for parallel computers. The main optimization goal of TABB is to allow long time simulations of medium or small sized systems. To make this possible, much attention is spent on the optimized communication between the nodes. TABB uses a domain decomposition procedure. To use many nodes with a small system, the domain size has to be small compared to the range of particle interactions. In the limit of many nodes for only few atoms, the bottle neck of communication is the latency time. TABB minimizes the number of pairs of domains containing atoms that interact between these domains. This procedure minimizes the need of communication calls between pairs of nodes. TABB decides automatically, to how many, and to which directions the decomposition shall be applied. E.g., in the case of one dimensional domain decomposition, the simulation box is only split into "slabs" along a selected direction. The three dimensional domain decomposition is best with respect to the number of interacting domains only for simulations

  7. Variation simulation for compliant sheet metal assemblies with applications

    Science.gov (United States)

    Long, Yufeng

    Sheet metals are widely used in discrete products, such as automobiles, aircraft, furniture and electronics appliances, due to their good manufacturability and low cost. A typical automotive body assembly consists of more than 300 parts welded together in more than 200 assembly fixture stations. Such an assembly system is usually quite complex, and takes a long time to develop. As the automotive customer demands products of increasing quality in a shorter time, engineers in automotive industry turn to computer-aided engineering (CAE) tools for help. Computers are an invaluable resource for engineers, not only to simplify and automate the design process, but also to share design specifications with manufacturing groups so that production systems can be tooled up quickly and efficiently. Therefore, it is beneficial to develop computerized simulation and evaluation tools for development of automotive body assembly systems. It is a well-known fact that assembly architectures (joints, fixtures, and assembly lines) have a profound impact on dimensional quality of compliant sheet metal assemblies. To evaluate sheet metal assembly architectures, a special dimensional analysis tool need be developed for predicting dimensional variation of the assembly. Then, the corresponding systematic tools can be established to help engineers select the assembly architectures. In this dissertation, a unified variation model is developed to predict variation in compliant sheet metal assemblies by considering fixture-induced rigid-body motion, deformation and springback. Based on the unified variation model, variation propagation models in multiple assembly stations with various configurations are established. To evaluate the dimensional capability of assembly architectures, quantitative indices are proposed based on the sensitivity matrix, which are independent of the variation level of the process. Examples are given to demonstrate their applications in selecting robust assembly

  8. Solving optimisation problems in metal forming using Finite Element simulation and metamodelling techniques

    NARCIS (Netherlands)

    Bonte, M.H.A.; van den Boogaard, Antonius H.; Huetink, Han

    2005-01-01

    During the last decades, Finite Element (FEM) simulations of metal forming processes have become important tools for designing feasible production processes. In more recent years, several authors recognised the potential of coupling FEM simulations to mathematical optimisation algorithms to design

  9. Survival of encapsulated potentially probiotic Lactobacillus plantarum D6SM3 with bioemulsifier derived from spent yeast in simulated gastrointestinal conditions

    Directory of Open Access Journals (Sweden)

    Paweena Dikit

    2015-08-01

    Full Text Available The effect of encapsulation with three kinds of emulsifier (Tween 80, gum arabic and bioemulsifier extracted from spent yeast on the survival of Lactobacillus plantarum D6SM3 in simulated gastrointestinal tract during storage at 4°C and room temperature was investigated. The survival of all encapsulated cells treated in simulated gastric juice was higher than free cells at both pH 2.5 and 3.0. The viability of the free and encapsulated cells showed a gradual decline throughout the storage period at 4°C. However, the viability rapidly declined at room temperature. In addition, the droplet size distribution of encapsulated cells was compared between those with and without an emulsifier by using the laser diffraction method. The particle size and polydispersity value of encapsulated cells were controlled better in emulsion with emulsifier added. The surface of encapsulated cells with emulsifier exhibited smoother characteristics than those without emulsifier.

  10. Micromechanical simulation of frictional behaviour in metal forming

    International Nuclear Information System (INIS)

    Zhang, S.; Hodgson, P.D.; Cardew-Hall, M.J.; Kalyanasundaram, S.

    2000-01-01

    Friction is a critical factor for Sheet Metal Forming (SMF). The Coulomb friction model is usually used in most Finite Element (FE) simulation for SMF. However, friction is a function of the local contact deformation conditions, such as local pressure, roughness and relative velocity. This paper will present a micromechanical model that accounts for the local frictional behaviour through finite element simulations performed at the micromechanical level. Frictional behaviour between contact surfaces can be based on three cases: boundary, hydrodynamic and mixed lubrication. In our microscopic friction model based on FEM, the case of boundary lubrication contact between sheet and tool has been considered. In the view of microscopic geometry, roughness depends upon amplitude and wavelength of surface asperities of sheet and tool. The mean pressure applied on the surface differs from the pressure over the actual contact area. The effect of roughness (microscopic geometric condition) and relative speed of contact surfaces on friction coefficient was examined in the FE model for the microscopic friction behaviour. The analysis was performed using an explicit finite element formulation. In this study, it was found that the roughness of deformable sheet decreases during sliding and the coefficient of friction increases with increasing roughness of contact surfaces. The coefficient of friction increases with the increase of relative velocity and adhesive friction coefficient between contact surfaces. (author)

  11. Structural analysis of a metal spent-fuel storage cask in an aircraft crash for risk assessment

    International Nuclear Information System (INIS)

    Almomani, Belal; Lee, Sanghoon; Kang, Hyun Gook

    2016-01-01

    Highlights: • Several engine-applied loads with different locations of impact on the storage cask body were implemented. • Cask structural responses due to the influence of engine impact loadings were analyzed. • Leakage path areas from lid closure openings were numerically calculated. • Release fractions that depend on the generated seal opening areas and fuel damage ratios were estimated. - Abstract: Evaluations of the impact resistance of a dry storage cask under mechanical impact loadings resulting from a large commercial aircraft crash have become an important issue for designers and evaluators, in order to promote interim dry storage activities and to evaluate design safety margins. This study presents a method to evaluate the structural integrity of a generic metal cask subjected to various mechanical loading conditions, which represent aircraft engine impacts, on different locations of the cask body. Thirty representative impact conditions are analyzed to provide a comprehensive evaluation of cask damage response. The applied engine impact load–time functions were carefully re-derived by utilizing CRIEPI’s proposed curve through Riera’s approach for six impact velocities, and applied to five locations on a freestanding cask: lateral impacts on the lower half, center of gravity, and upper half of the cask body, corner impact on the lid closure, and vertical impact on the center of the lid closure. A nonlinear dynamic finite element analysis is performed to evaluate the dynamic response of the cask lid closure system and to calculate the lid gaps. The release fractions from the cask to the environment for each impact condition are preliminarily estimated by referring to a proposed methodology from literature. It is believed that this paper presents a systematic process to connect the mechanical analysis of a cask response at the moment of aircraft engine impact with its radiological consequence analysis.

  12. Structural analysis of a metal spent-fuel storage cask in an aircraft crash for risk assessment

    Energy Technology Data Exchange (ETDEWEB)

    Almomani, Belal, E-mail: balmomani@kaist.ac.kr [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Lee, Sanghoon, E-mail: shlee1222@kmu.ac.kr [Department of Mechanical and Automotive Engineering, Keimyung University, Dalgubeol-daero 1095, Dalseo-gu, Daegu (Korea, Republic of); Kang, Hyun Gook, E-mail: hyungook@kaist.ac.kr [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)

    2016-11-15

    Highlights: • Several engine-applied loads with different locations of impact on the storage cask body were implemented. • Cask structural responses due to the influence of engine impact loadings were analyzed. • Leakage path areas from lid closure openings were numerically calculated. • Release fractions that depend on the generated seal opening areas and fuel damage ratios were estimated. - Abstract: Evaluations of the impact resistance of a dry storage cask under mechanical impact loadings resulting from a large commercial aircraft crash have become an important issue for designers and evaluators, in order to promote interim dry storage activities and to evaluate design safety margins. This study presents a method to evaluate the structural integrity of a generic metal cask subjected to various mechanical loading conditions, which represent aircraft engine impacts, on different locations of the cask body. Thirty representative impact conditions are analyzed to provide a comprehensive evaluation of cask damage response. The applied engine impact load–time functions were carefully re-derived by utilizing CRIEPI’s proposed curve through Riera’s approach for six impact velocities, and applied to five locations on a freestanding cask: lateral impacts on the lower half, center of gravity, and upper half of the cask body, corner impact on the lid closure, and vertical impact on the center of the lid closure. A nonlinear dynamic finite element analysis is performed to evaluate the dynamic response of the cask lid closure system and to calculate the lid gaps. The release fractions from the cask to the environment for each impact condition are preliminarily estimated by referring to a proposed methodology from literature. It is believed that this paper presents a systematic process to connect the mechanical analysis of a cask response at the moment of aircraft engine impact with its radiological consequence analysis.

  13. Hydrometallurgical process for the recovery of high value metals from spent lithium nickel cobalt aluminum oxide based lithium-ion batteries

    Science.gov (United States)

    Joulié, M.; Laucournet, R.; Billy, E.

    2014-02-01

    A hydrometallurgical process is developed to recover valuable metals of the lithium nickel cobalt aluminum oxide (NCA) cathodes from spent lithium-ion batteries (LIBs). Effect of parameters such as type of acid (H2SO4, HNO3 and HCl), acid concentration (1-4 mol L-1), leaching time (3-18 h) and leaching temperature (25-90 °C) with a solid to liquid ratio fixed at 5% (w/v) are investigated to determine the most efficient conditions of dissolution. The preliminary results indicate that HCl provides higher leaching efficiency. In optimum conditions, a complete dissolution is performed for Li, Ni, Co and Al. In the nickel and cobalt recovery process, at first the Co(II) in the leaching liquor is selectively oxidized in Co(III) with NaClO reagent to recover Co2O3, 3H2O by a selective precipitation at pH = 3. Then, the nickel hydroxide is precipitated by a base addition at pH = 11. The recovery efficiency of cobalt and nickel are respectively 100% and 99.99%.

  14. Numerical simulation of turbulent forced convection in liquid metals

    International Nuclear Information System (INIS)

    Vodret, S; Di Maio, D Vitale; Caruso, G

    2014-01-01

    In the frame of the future generation of nuclear reactors, liquid metals are foreseen to be used as a primary coolant. Liquid metals are characterized by a very low Prandtl number due to their very high heat diffusivity. As such, they do not meet the so-called Reynolds analogy which assumes a complete similarity between the momentum and the thermal boundary layers via the use of the turbulent Prandtl number. Particularly, in the case of industrial fluid-dynamic calculations where a resolved computation near walls could be extremely time consuming and could need very large computational resources, the use of the classical wall function approach could lead to an inaccurate description of the temperature profile close to the wall. The first aim of the present study is to investigate the ability of a well- established commercial code (ANSYS FLUENT v.14) to deal with this issue, validating a suitable expression for the turbulent Prandtl number. Moreover, a thermal wall-function developed at Universite Catholique de Louvain has been implemented in FLUENT and validated, overcoming the limits of the solver to define it directly. Both the resolved and unresolved approaches have been carried out for a channel flow case and assessed against available direct numerical and large eddy simulations. A comparison between the numerically evaluated Nusselt number and the main correlations available in the literature has been also carried out. Finally, an application of the proposed methodology to a typical sub-channel case has been performed, comparing the results with literature correlations for tube banks

  15. Oxidation of elemental mercury by modified spent TiO2-based SCR-DeNOx catalysts in simulated coal-fired flue gas.

    Science.gov (United States)

    Zhao, Lingkui; Li, Caiting; Zhang, Xunan; Zeng, Guangming; Zhang, Jie; Xie, Yin'e

    2016-01-01

    In order to reduce the costs, the recycle of spent TiO2-based SCR-DeNOx catalysts were employed as a potential catalytic support material for elemental mercury (Hg(0)) oxidation in simulated coal-fired flue gas. The catalytic mechanism for simultaneous removal of Hg(0) and NO was also investigated. The catalysts were characterized by Brunauer-Emmett-Teller (BET), scanning electron microscope (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) method. Results indicated that spent TiO2-based SCR-DeNOx catalyst supported Ce-Mn mixed oxides catalyst (CeMn/SCR1) was highly active for Hg(0) oxidation at low temperatures. The Ce1.00Mn/SCR1 performed the best catalytic activities, and approximately 92.80% mercury oxidation efficiency was obtained at 150 °C. The inhibition effect of NH3 on Hg(0) oxidation was confirmed in that NH3 consumed the surface oxygen. Moreover, H2O inhibited Hg(0) oxidation while SO2 had a promotional effect with the aid of O2. The XPS results illustrated that the surface oxygen was responsible for Hg(0) oxidation and NO conversion. Besides, the Hg(0) oxidation and NO conversion were thought to be aided by synergistic effect between the manganese and cerium oxides.

  16. Experience Of Using Metal-and-Concrete Cask TUK-108/1 For Storage And Transportation Of Spent Nuclear Fuel Of Decommissioned NPS

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, E.; Dyer, R. [Environmental Protection Agency, Ronald Reagan Bldg. 3rd Floor 1200 Pennsylvania Av., NW Washington, D.C. 20024 (United States); Snipes, R. [Oak Ridge National Laboratories, VA (United States); Dolbenkov, V.G.; Guskov, V.D.; Korotkov, G.V. [Joint Stock Company ' KBSM' , 64 Lesnoy Av., St.Petersburg 194100 (Russian Federation); Makarchuk, T.F. [Joint Stock Company ' Atomstroyexport' , Potapovskiy str. 5, bld. 4, Moscow, 101990 (Russian Federation); Zakharchev, A.A. [State Corporation ' Rosatom' , 24-26 Ordinka St., Moscow, 100000 (Russian Federation)

    2009-06-15

    In past 10 years in Russia an intensive development of a new technology of management of spent nuclear fuel (SNF) has taken place. This technology is based on the concept of using a shielded cask which provides safety of its content (SNF) and meeting all other safety requirements to storage and transportation of SNF. Radiation protection against emission and non-propagation of activity outside the cask is ensured by the physical barriers such as all-metal or composite body, face work, inner structures to accommodate spent fuel assemblies (SFA), lids with sealing systems. Residual heat buildup is off-taken to the environment by natural way: emission and convection of surrounding air. The necessity in development of the cask technology of SNF management was conditioned by the situation at hand with defueling of Russian decommissioned nuclear-powered submarines (NPS) as the existed transport infrastructure and enterprises involved in fuel processing could not meet the demand for transportation and processing of SNF neither from reactors of all dismantled NPS, nor from reactors of NPS waiting for decommissioning. The US and Norway actively participated in the trilateral joint project with the Russian Federation aimed at creation of a cask prototype for interim storage and transportation of SNF of dismantled NPS. The 1.1 Project is a part of the Arctic Military Environmental Cooperation (AMEC) Program. In December 2000 the project was successfully completed by issuance of the certificate-permit for design and transportation of NP Submarine SNF. It was a first certified dual-purpose TUK from the MMC family. In these years 106 TUK-108/1 casks have been manufactured and supplied to PO Mayak, JSC CS Zvezda, JSC CS Zvezdochka and FSUE DalRAO. The storage pads for interim storage of TUK-108/1 have been built and currently are in operation on sites of SNF unloading from submarine reactors and SNF cask-loading such as JSC CS Zvezda, JSC CS Zvezdochka and FSUE DalRAO. In

  17. Dry refabrication technology development of spent nuclear fuel

    International Nuclear Information System (INIS)

    Park, Geun Il; Lee, J. W.; Song, K. C.

    2012-04-01

    Key technologies highly applicable to the development of advanced nuclear fuel cycle for the spent fuel recycling were developed using spent fuel and simulated spent fuel (SIMFUEL). In the frame work of dry process oxide products fabrication and the property characteristics of dry process products, hot cell experimental data for decladding, powdering and oxide product fabrication from low and high burnup spent fuel have been produced, basic technology for fabrication of spent fuel standard material has been developed, and remotely modulated welding equipment has been designed and fabricated. Also, fabrication technology of simulated dry process products was established and property models were developed based on reproducible property measurement data. In the development of head-end technology for dry refabrication of spent nuclear fuel and key technologies for volume reduction of head-end process waste which are essential in back-end fuel cycle field including pyro-processing, advanced head-end unit process technology development includes the establishment of experimental conditions for synthesis of porous fuel particles using a granulating furnace and for preparation of UO2 pellets, and fabrication and performance demonstration of engineering scale equipment for off-gas treatment of semi-volatile nuclides, and development of phosphate ceramic technology for immobilization of used filters. Radioactivation characterization and treatment equipment design of metal wastes from pretreatment process was conducted, and preliminary experiments of chlorination/electrorefining techniques for the treatment of hull wastes were performed. Based on the verification of the key technologies for head-end process via the hot-cell tests using spent nuclear fuel, pre-conceptual design for the head-end equipments was performed

  18. Dry refabrication technology development of spent nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Park, Geun Il; Lee, J. W.; Song, K. C.; and others

    2012-04-15

    Key technologies highly applicable to the development of advanced nuclear fuel cycle for the spent fuel recycling were developed using spent fuel and simulated spent fuel (SIMFUEL). In the frame work of dry process oxide products fabrication and the property characteristics of dry process products, hot cell experimental data for decladding, powdering and oxide product fabrication from low and high burnup spent fuel have been produced, basic technology for fabrication of spent fuel standard material has been developed, and remotely modulated welding equipment has been designed and fabricated. Also, fabrication technology of simulated dry process products was established and property models were developed based on reproducible property measurement data. In the development of head-end technology for dry refabrication of spent nuclear fuel and key technologies for volume reduction of head-end process waste which are essential in back-end fuel cycle field including pyro-processing, advanced head-end unit process technology development includes the establishment of experimental conditions for synthesis of porous fuel particles using a granulating furnace and for preparation of UO2 pellets, and fabrication and performance demonstration of engineering scale equipment for off-gas treatment of semi-volatile nuclides, and development of phosphate ceramic technology for immobilization of used filters. Radioactivation characterization and treatment equipment design of metal wastes from pretreatment process was conducted, and preliminary experiments of chlorination/electrorefining techniques for the treatment of hull wastes were performed. Based on the verification of the key technologies for head-end process via the hot-cell tests using spent nuclear fuel, pre-conceptual design for the head-end equipments was performed.

  19. CFD simulating the transient thermal–hydraulic characteristics in a 17 × 17 bundle for a spent fuel pool under the loss of external cooling system accident

    International Nuclear Information System (INIS)

    Chen, S.R.; Lin, W.C.; Ferng, Y.M.; Chieng, C.C.; Pei, B.S.

    2014-01-01

    Highlights: • A 3-D CFD is adopted to simulate transient behaviors in an SFP under the accident. • This model realistically simulates a 17 × 17 bundle, rid of porous media approach. • The loss of external cooling system accident for an SFP is assumed in this paper. • Thermal–hydraulic characteristics in a bundle are strongly influenced by grids. • The results confirm temperature rising rate used in Maanshan NPP is conservative. - Abstract: This paper develops a three-dimensional (3-D) transient computational fluid dynamics (CFD) model to simulate the thermal–hydraulic characteristics in a fuel bundle located in a spent fuel pool (SFP) under the loss of external cooling system accident. The SFP located in the Maanshan nuclear power plant (NPP) is selected herein. Without adopting the porous media approach usually used in the previous CFD works, this model uses a real-geometry simulation of a 17 × 17 fuel bundle, which can obtain the localized distributions of the flow and heat transfer during the accident. These distribution characteristics include several peaks in the axial distributions of flow, pressure, temperature, and Nusselt number (Nu) near the support grids, the non-uniform distribution of secondary flow, and the non-uniform temperature distribution due to flow mixing between rods, etc. According to the conditions adopted in the Procedure 597.1 (MNPP Plant Procedure 597.1, 2010) for the management of the loss-of-cooling event of the spent fuel pool in the Maanshan NPP, the temperature rising rate predicted by the present model can be equivalent to 1.26 K/h, which is the same order as that of 3.5 K/h in the this procedure. This result also confirms that the temperature rising rate used in the Procedure 597.1 for the Maanshan NPP is conservative. In addition, after the loss of external cooling system, there are about 44 h for the operator to repair the malfunctioning system or provide the alternative water source for the pool inventory to

  20. Development of spent fuel dry storage technology

    International Nuclear Information System (INIS)

    Maruoka, Kunio; Matsunaga, Kenichi; Kunishima, Shigeru

    2000-01-01

    The spent fuels are the recycle fuel resources, and it is very important to store the spent fuels in safety. There are two types of the spent fuel interim storage system. One is wet storage system and another is dry storage system. In this study, the dry storage technology, dual purpose metal cask storage and canister storage, has been developed. For the dual purpose metal cask storage, boronated aluminum basket cell, rational cask body shape and shaping process have been developed, and new type dual purpose metal cask has been designed. For the canister storage, new type concrete cask and high density vault storage technology have been developed. The results of this study will be useful for the spent fuel interim storage. Safety and economical spent fuel interim storage will be realized in the near future. (author)

  1. Preparation and Heat-Treatment of DWPF Simulants With and Without Co-Precipitated Noble Metals

    International Nuclear Information System (INIS)

    Koopman, David C.:Eibling, Russel E

    2005-01-01

    The Savannah River National Laboratory is in the process of investigating factors suspected of impacting catalytic hydrogen generation in the Chemical Process Cell of the Defense Waste Processing Facility, DWPF. Noble metal catalyzed hydrogen generation in simulation work constrains the allowable acid addition operating window in DWPF. This constraint potentially impacts washing strategies during sludge batch preparation. It can also influence decisions related to the addition of secondary waste streams to a sludge batch. Noble metals have historically been added as trim chemicals to process simulations. The present study investigated the potential conservatism that might be present from adding the catalytic species as trim chemicals to the final sludge simulant versus co-precipitating the noble metals into the insoluble sludge solids matrix. Parallel preparations of two sludge simulants targeting the composition of Sludge Batch 3 were performed in order to evaluate the impact of the form of noble metals. Identical steps were used except that one simulant had dissolved palladium, rhodium, and ruthenium present during the precipitation of the insoluble solids. Noble metals were trimmed into the other stimulant prior to process tests. Portions of both sludge simulants were held at 97 C for about eight hours to qualitatively simulate the effects of long term storage on particle morphology and speciation. The simulants were used as feeds for Sludge Receipt and Adjustment Tank, SRAT, process simulations. The following conclusions were drawn from the simulant preparation work: (1) The first preparation of a waste slurry simulant with co-precipitated noble metals was successful, based on the data obtained. It appears that 99+% of the noble metals were retained in the simulant. (2) Better control of carbonate, hydroxide, and post-wash trim chemical additions is needed before the new method of simulant preparation will be as reproducible as the old method. (3) The two new

  2. Critical and subcritical parameters of the system simulating plutonium metal dissolution

    International Nuclear Information System (INIS)

    Vasilev, Yury Yu.; Ryazanov, Boris G.; Sviridov, Victor I.; Mozhayeva, Lubov I.

    2003-01-01

    Dissolution of plutonium metal was simulated using the Monte Carlo computer code to calculate criticality safety limits for the process. Calculations were made for the constant masses of plutonium charged to the dissolving vessel considering distribution of plutonium in metal and solution phases. Critical parameters and limits were calculated as a function of dissolving vessel volume and plutonium metal mass. 240 Pu content was assumed to be from 0% to 10% (mass). Critical parameters were evaluated for the system with a water reflector. Results of this paper may be used in the designing process equipment for plutonium metal dissolution. (author)

  3. Numerical simulation on the explosive boiling phenomena on the surface of molten metal

    International Nuclear Information System (INIS)

    Chen Deqi; Peng Cheng; Wang Qinghua; Pan Liangming

    2014-01-01

    In this paper, numerical simulation was carried out to investigate the explosive boiling phenomenon on high temperature surface also the influence of vapor growth rate during explosive boiling, vapor condensation in sub-cooled water and the subsequent effect on flowing and heat transfer. The simulation result indicates that the steam on the molten metal surface grows with very high speed, and it pushes away the sub-cooled water around and causes severe flowing. The steam clusters which block the sub-cooled water to rewet the molten metal surface are appearing at the same time. During the growth, lifting off as well as condensation of the steam clusters, the sub-cooled water around is strongly disturbed, and obvious vortexes appear. Conversely, the vortex will influence the steam cluster detachment and cub-cooled water rewetting the metal surface. This simulation visually displays the complex explosive boiling phenomena on the molten metal surface with high temperature. (authors)

  4. Spent fuel shipping cask accident evaluation

    International Nuclear Information System (INIS)

    Fields, S.R.

    1975-12-01

    Mathematical models have been developed to simulate the dynamic behavior, following a hypothetical accident and fire, of typical casks designed for the rail shipment of spent fuel from nuclear reactors, and to determine the extent of radioactive releases under postulated conditions. The casks modeled were the IF-300, designed by the General Electric Company for the shipment of spent LWR fuel, and a cask designed by the Aerojet Manufacturing Company for the shipment of spent LMFBR fuel

  5. Bioremediation of trace cobalt from simulated spent decontamination solutions of nuclear power reactors using E. coli expressing NiCoT genes

    International Nuclear Information System (INIS)

    Raghu, G.; Maruthi Mohan, P.; Balaji, V.; Venkateswaran, G.; Rodrigue, A.; Lyon 1 Univ., 69

    2008-01-01

    Removal of radioactive cobalt at trace levels (∼nM) in the presence of large excess (10 6 -fold) of corrosion product ions of complexed Fe, Cr, and Ni in spent chemical decontamination formulations (simulated effluent) of nuclear reactors is currently done by using synthetic organic ion exchangers. A large volume of solid waste is generated due to the nonspecific nature of ion sorption. Our earlier work using various fungi and bacteria, with the aim of nuclear waste volume reduction, realized up to 30% of Co removal with specific capacities calculated up to 1 μg/g in 6-24 h. In the present study using engineered Escherichia coli expressing NiCoT genes from Rhodopseudomonas palustris CGA009 (RP) and Novosphingobium aromaticivorans F-199 (NA), we report a significant increase in the specific capacity for Co removal (12 μg/g) in 1-h exposure to simulated effluent. About 85% of Co removal was achieved in a two-cycle treatment with the cloned bacteria. Expression of NiCoT genes in the E. coli knockout mutant of NiCoT efflux gene (rcnA) was more efficient as compared to expression in wild-type E. coli MC4100, JM109 and BL21 (DE3) hosts. The viability of the E. coli strains in the formulation as well as at different doses of gamma rays exposure and the effect of gamma dose on their cobalt removal capacity are determined. The potential application scheme of the above process of bioremediation of cobalt from nuclear power reactor chemical decontamination effluents is discussed. (orig.)

  6. Geochemical simulation of the evolution of granitic rocks and clay minerals submitted to a temperature increase in the vicinity of a repository for spent nuclear fuel

    International Nuclear Information System (INIS)

    Fritz, B.; Kam, M.; Tardy, Y.

    1984-07-01

    The alteration of a granitic rock around a repository for spent nuclear fuel has been simulated considering the effect of an increase of temperature due to this kind of induced geothermal system. The results of the simulation have been interpreted in terms of mass transfer and volumic consequences. The alteration proceeds by dissolution of minerals (with an increase of the volumes of fissures and cracks) and precipitation of secondary miminerals as calcite and clay minerals particularly (with a decrease of the porosity). The increase of the temperature from 10 degrees C to about 100 degrees C will favour the alteration of the granitic rock around the repository by the solution filling the porosity. The rock is characterized by a very low fissure porosity and a consequent very low water velocity. This too, favours intense water rock interactions and production of secondary clays and the total possible mass transfer will decrease the porosity. A combination of these thermodynamic mass balance calculations with a kinetic approach of mineral dissolutions gives a first attempt to calibrate the modelling in the time scale: the decrease of porosity can be roughly estimated between 2 and 20% for 100,000 years. The particular problem of Na-bentonites behaviour in the proximate vicinity of the repository has been studied too. One must distinguish between two types of clay-water interactions: -within the rock around the repository, Na-bentonites should evolute with illitization in slighltly open system with low clay/water ratios, -within the repository itself, the clay reacts in a closed system for a long time with high clay/water ratios and a self-buffering effect should maintain the bentonite type. This chemical buffering effect is a positive point for the use of this clay as chemical barrier. (Author)

  7. Computer simulations of nanoindentation in Mg-Cu and Cu-Zr metallic glasses

    DEFF Research Database (Denmark)

    Paduraru, Anca; Andersen, Ulrik Grønbjerg; Thyssen, Anders

    2010-01-01

    The formation of shear bands during plastic deformation of Cu0.50Zr0.50 and Mg0.85Cu0.15 metallic glasses is studied using atomic-scale computer simulations. The atomic interactions are described using realistic many-body potentials within the effective medium theory, and are compared with similar...... simulations using a Lennard-Jones description of the material. The metallic glasses are deformed both in simple shear and in a simulated nanoindentation experiment. Plastic shear localizes into shear bands with a width of approximately 5 nm in CuZr and 8 nm in MgCu. In simple shear, the shear band formation...... is very clear, whereas only incipient shear bands are seen in nanoindentation. The shear band formation during nanoindentation is sensitive to the indentation velocity, indenter radius and the cooling rate during the formation of the metallic glass. For comparison, a similar nanoindentation simulation...

  8. Reuse of Hydrotreating Spent Catalyst

    International Nuclear Information System (INIS)

    Habib, A.M.; Menoufy, M.F.; Amhed, S.H.

    2004-01-01

    All hydro treating catalysts used in petroleum refining processes gradually lose activity through coking, poisoning by metal, sulfur or halides or lose surface area from sintering at high process temperatures. Waste hydrotreating catalyst, which have been used in re-refining of waste lube oil at Alexandria Petroleum Company (after 5 years lifetime) compared with the same fresh catalyst were used in the present work. Studies are conducted on partial extraction of the active metals of spent catalyst (Mo and Ni) using three leaching solvents,4% oxidized oxalic acid, 10% aqueous sodium hydroxide and 10% citric acid. The leaching experiments are conducting on the de coked extrude [un crushed] spent catalyst samples. These steps are carried out in order to rejuvenate the spent catalyst to be reused in other reactions. The results indicated that 4% oxidized oxalic acid leaching solution gave total metal removal 45.6 for de coked catalyst samples while NaOH gave 35% and citric acid gave 31.9 % The oxidized leaching agent was the most efficient leaching solvent to facilitate the metal removal, and the rejuvenated catalyst was characterized by the unchanged crystalline phase The rejuvenated catalyst was applied for hydrodesulfurization (HDS) of vacuum gas oil as a feedstock, under different hydrogen pressure 20-80 bar in order to compare its HDS activity

  9. Performance simulation of serpentine type metallic and non-metallic solar collector

    International Nuclear Information System (INIS)

    Al-Sageer, A. A. M.; Alowa, M. I.; Saad, M.

    2006-01-01

    This paper presents a theoretical investigation of metallic and non-metalic solar water collector models for evaluating its performane parameters. The determined parameters include heat removal factor , overall heat loss coefficients, heat gain, daily and hourly efficiencies. The present study reports that, under forced circulation lest, the non-metallic collector has an inferior performance parameters when compared to that of the metallic one. It was also revealed that the overall heat loss coefficients of both collectors show weak dependence on the flow rate variations. It was also noticed that the heat removal factor forboth models is more sensitive to the flow rate variations. Also noticed that the heat removal factor for both models is more sensitive to the flow rate variations. Also, a comparision of performance parameters of the theoretical and experimental studies showed good agreements for most hours of the day, except the results obtained at the early morning and late after noon hours.(Author)

  10. Platinum group metal nitrides and carbides: synthesis, properties and simulation

    International Nuclear Information System (INIS)

    Ivanovskii, Alexander L

    2009-01-01

    Experimental and theoretical data on new compounds, nitrides and carbides of the platinum group 4d and 5d metals (ruthenium, rhodium, palladium, osmium, iridium, platinum), published over the past five years are summarized. The extreme mechanical properties of platinoid nitrides and carbides, i.e., their high strength and low compressibility, are noted. The prospects of further studies and the scope of application of these compounds are discussed.

  11. Simulating the long-term chemistry of an upland UK catchment: Heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    Tipping, E. [Centre for Ecology and Hydrology (Lancaster), Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom)]. E-mail: et@ceh.ac.uk; Lawlor, A.J. [Centre for Ecology and Hydrology (Lancaster), Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom); Lofts, S. [Centre for Ecology and Hydrology (Lancaster), Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom); Shotbolt, L. [Environment Department, University of York, Heslington, York YO10 5DD (United Kingdom)

    2006-05-15

    CHUM-AM was used to investigate the behaviours of atmospherically-deposited heavy metals (Ni, Cu, Zn, Cd and Pb) in three moorland sub-catchments in Cumbria UK. The principal processes controlling cationic metals are competitive partitioning to soil organic matter, chemical interactions in solution, and chemical weathering. Metal deposition histories were generated by combining measured data for the last 30 years with local lake sediment records. For Ni, Cu, Zn and Cd, default parameters for the interactions with organic matter provided reasonable agreement between simulated and observed present-day soil metal pools and average streamwater concentrations. However, for Pb, the soil binding affinity in the model had to be increased to match the observations. Simulations suggest that weakly-sorbing metals (Ni, Zn, Cd) will respond on timescales of decades to centuries to changes in metal inputs or acidification status. More strongly-sorbing metals (Cu, Pb) will respond over centuries to millennia. - Catchment turnover times for the strongly-retained metals Cu and Pb are of the order of centuries, whereas those for the more mobile Ni, Zn and Cd are appreciably shorter.

  12. A new simulation model for electrochemical metal deposition

    International Nuclear Information System (INIS)

    Schmickler, W.; Poetting, K.; Mariscal, M.

    2006-01-01

    A new atomistic simulation model for electrochemical systems is presented. It combines microcanonical molecular dynamics for the electrode with stochastic dynamics for the solution, and allows the simulation of electrochemical deposition and dissolution for specific electrode potentials. As first applications the deposition of silver and platinum on Au(1 1 1) have been studied; both flat surfaces and surfaces with islands have been considered. The two systems behave quite differently: Ag on Au(1 1 1) grows layer by layer, while Pt forms a surface alloy on Au(1 1 1), which is followed by three-dimensional growth

  13. Spent fuel's behavior under dynamic drip tests

    International Nuclear Information System (INIS)

    Finn, P.A.; Buck, E.C.; Hoh, J.C.; Bates, J.K.

    1995-01-01

    In the potential repository at Yucca Mountain, failure of the waste package container and the cladding of the spent nuclear fuel would expose the fuel to water under oxidizing conditions. To simulate the release behavior of radionuclides from spent fuel, dynamic drip and vapor tests with spent nuclear fuel have been ongoing for 2.5 years. Rapid alteration of the spent fuel has been noted with concurrent release of radionuclides. Colloidal species containing americium and plutonium have been found in the leachate. This observation suggests that colloidal transport of radionuclides should be included in the performance assessment of a potential repository

  14. Potential for preparation of hot gas cleanup sorbents from spent hydroprocessing catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Furimsky, E.; Biagini, M. [Canada Centre for Mineral and Energy Technology, Ottawa, ON (Canada). Energy Research Labs.

    1996-01-01

    Three spent-decoked hydroprocessing catalysts and two corresponding fresh catalysts were tested as hot gas clean-up sorbents and compared with the zinc ferrite using a simulated coal gasification gas mixture. The catalysts deposited only by coke exhibited relatively good cleaning efficiency. The catalyst deposited by coke and metals such as vanadium and nickel was less efficient. The useful life of the spent hydroprocessing catalysts may be extended if utilized as hot gas clean-up sorbents. 12 refs., 3 figs., 4 tabs.

  15. Computer simulations of small semiconductor and metal clusters

    International Nuclear Information System (INIS)

    Andreoni, W.

    1991-01-01

    A brief survey is presented of recent simulations of small clusters, made with both ab-initio and classical approaches, with particular emphasis on the application of the Car-Parrinello method. The discussion mainly focusses on the structural properties of a variety of materials and on the effects of temperature. (orig.)

  16. Efficient implicit FEM simulation of sheet metal forming

    NARCIS (Netherlands)

    van den Boogaard, Antonius H.; Meinders, Vincent T.; Huetink, Han

    2003-01-01

    For the simulation of industrial sheet forming processes, the time discretisation is one of the important factors that determine the accuracy and efficiency of the algorithm. For relatively small models, the implicit time integration method is preferred, because of its inherent equilibrium check.

  17. Development of parallel benchmark code by sheet metal forming simulator 'ITAS'

    International Nuclear Information System (INIS)

    Watanabe, Hiroshi; Suzuki, Shintaro; Minami, Kazuo

    1999-03-01

    This report describes the development of parallel benchmark code by sheet metal forming simulator 'ITAS'. ITAS is a nonlinear elasto-plastic analysis program by the finite element method for the purpose of the simulation of sheet metal forming. ITAS adopts the dynamic analysis method that computes displacement of sheet metal at every time unit and utilizes the implicit method with the direct linear equation solver. Therefore the simulator is very robust. However, it requires a lot of computational time and memory capacity. In the development of the parallel benchmark code, we designed the code by MPI programming to reduce the computational time. In numerical experiments on the five kinds of parallel super computers at CCSE JAERI, i.e., SP2, SR2201, SX-4, T94 and VPP300, good performances are observed. The result will be shown to the public through WWW so that the benchmark results may become a guideline of research and development of the parallel program. (author)

  18. [Using sequential indicator simulation method to define risk areas of soil heavy metals in farmland.

    Science.gov (United States)

    Yang, Hao; Song, Ying Qiang; Hu, Yue Ming; Chen, Fei Xiang; Zhang, Rui

    2018-05-01

    The heavy metals in soil have serious impacts on safety, ecological environment and human health due to their toxicity and accumulation. It is necessary to efficiently identify the risk area of heavy metals in farmland soil, which is of important significance for environment protection, pollution warning and farmland risk control. We collected 204 samples and analyzed the contents of seven kinds of heavy metals (Cu, Zn, Pb, Cd, Cr, As, Hg) in Zengcheng District of Guangzhou, China. In order to overcame the problems of the data, including the limitation of abnormal values and skewness distribution and the smooth effect with the traditional kriging methods, we used sequential indicator simulation method (SISIM) to define the spatial distribution of heavy metals, and combined Hakanson index method to identify potential ecological risk area of heavy metals in farmland. The results showed that: (1) Based on the similar accuracy of spatial prediction of soil heavy metals, the SISIM had a better expression of detail rebuild than ordinary kriging in small scale area. Compared to indicator kriging, the SISIM had less error rate (4.9%-17.1%) in uncertainty evaluation of heavy-metal risk identification. The SISIM had less smooth effect and was more applicable to simulate the spatial uncertainty assessment of soil heavy metals and risk identification. (2) There was no pollution in Zengcheng's farmland. Moderate potential ecological risk was found in the southern part of study area due to enterprise production, human activities, and river sediments. This study combined the sequential indicator simulation with Hakanson risk index method, and effectively overcame the outlier information loss and smooth effect of traditional kriging method. It provided a new way to identify the soil heavy metal risk area of farmland in uneven sampling.

  19. The DSNP simulation language and its application to liquid-metal fast breeder reactor transient analyses

    International Nuclear Information System (INIS)

    Saphier, D.; Madell, J.T.

    1982-01-01

    A new, special purpose block-oriented simulation language, the Dynamic Simulator for Nuclear Power Plants (DSNP), was used to perform a dynamic analysis of several conceptual design studies of liquid metal fast breeder reactors. The DSNP being a high level language enables the user to transform a power plant flow chart directly into a simulation program using a small number of DSNP statements. In addition to the language statements, the DSNP system has its own precompiler and an extensive library containing models of power plant components, algorithms of physical processes, material property functions, and various auxiliary functions. The comparative analysis covered oxide-fueled versus metal-fueled core designs and loop- versus pool-type reactors. The question of interest was the rate of change of the temperatures in the components in the upper plenum and the primary loop, in particular the reactor outlet nozzle and the intermediate heat exchanger inlet nozzle during different types of transients. From the simulations performed it can be concluded that metal-fueled cores will have much faster temperature transients than oxide-fueled cores due mainly to the much higher thermal diffusivity of the metal fuel. The transients in the pool-type design (either with oxide fuel or metal fuel) will be much slower than in the loop-type design due to the large heat capacity of the sodium pool. The DSNP language was demonstrated to be well suited to perform many types of transient analysis in nuclear power plants

  20. Simulation of Metal Particulates in High Energetic Materials

    Science.gov (United States)

    2015-05-28

    temperatures and pressures disintegrate the carbon- fiber casing, thus not producing any fragments. These carbon-fiber casing warheads are a solution...Polymer-Bonded Explosive (PBX) and Livermore’s High-Energy Explosive (LX) are examples of ex- plosives that use “ plastic ” as a binder material. Other...simulation data to empirical data does not provide any benefit to this research due to the complexity of plastically bonded explosives like PBX9501. The

  1. Atomic-scale simulations of the mechanical deformation of nanocrystalline metals

    DEFF Research Database (Denmark)

    Schiøtz, Jakob; Vegge, Tejs; Di Tolla, Francesco

    1999-01-01

    that the main deformation mode is sliding in the grain boundaries through a large number of uncorrelated events, where a few atoms (or a few tens of atoms) slide with respect to each other. Little dislocation activity is seen in the grain interiors. The localization of the deformation to the grain boundaries......Nanocrystalline metals, i.e., metals in which the grain size is in the nanometer range, have a range of technologically interesting properties including increased hardness and yield strength. We present atomic-scale simulations of the plastic behavior of nanocrystalline copper. The simulations show...

  2. Ion bombardment induced smoothing of amorphous metallic surfaces: Experiments versus computer simulations

    International Nuclear Information System (INIS)

    Vauth, Sebastian; Mayr, S. G.

    2008-01-01

    Smoothing of rough amorphous metallic surfaces by bombardment with heavy ions in the low keV regime is investigated by a combined experimental-simulational study. Vapor deposited rough amorphous Zr 65 Al 7.5 Cu 27.5 films are the basis for systematic in situ scanning tunneling microscopy measurements on the smoothing reaction due to 3 keV Kr + ion bombardment. The experimental results are directly compared to the predictions of a multiscale simulation approach, which incorporates stochastic rate equations of the Langevin type in combination with previously reported classical molecular dynamics simulations [Phys. Rev. B 75, 224107 (2007)] to model surface smoothing across length and time scales. The combined approach of experiments and simulations clearly corroborates a key role of ion induced viscous flow and ballistic effects in low keV heavy ion induced smoothing of amorphous metallic surfaces at ambient temperatures

  3. Stress analysis and deformation prediction of sheet metal workpieces based on finite element simulation

    OpenAIRE

    Ren Penghao; Wang Aimin; Wang Xiaolong; Zhang Yanlin

    2017-01-01

    After aluminum alloy sheet metal parts machining, the residual stress release will cause a large deformation. To solve this problem, this paper takes a aluminum alloy sheet aerospace workpiece as an example, establishes the theoretical model of elastic deformation and the finite element model, and places quantitative initial stress in each element of machining area, analyses stress release simulation and deformation. Through different initial stress release simulative analysis of deformation ...

  4. Advanced solid elements for sheet metal forming simulation

    Science.gov (United States)

    Mataix, Vicente; Rossi, Riccardo; Oñate, Eugenio; Flores, Fernando G.

    2016-08-01

    The solid-shells are an attractive kind of element for the simulation of forming processes, due to the fact that any kind of generic 3D constitutive law can be employed without any additional hypothesis. The present work consists in the improvement of a triangular prism solid-shell originally developed by Flores[2, 3]. The solid-shell can be used in the analysis of thin/thick shell, undergoing large deformations. The element is formulated in total Lagrangian formulation, and employs the neighbour (adjacent) elements to perform a local patch to enrich the displacement field. In the original formulation a modified right Cauchy-Green deformation tensor (C) is obtained; in the present work a modified deformation gradient (F) is obtained, which allows to generalise the methodology and allows to employ the Pull-Back and Push-Forwards operations. The element is based in three modifications: (a) a classical assumed strain approach for transverse shear strains (b) an assumed strain approach for the in-plane components using information from neighbour elements and (c) an averaging of the volumetric strain over the element. The objective is to use this type of elements for the simulation of shells avoiding transverse shear locking, improving the membrane behaviour of the in-plane triangle and to handle quasi-incompressible materials or materials with isochoric plastic flow.

  5. Nanometric mechanical cutting of metallic glass investigated using atomistic simulation

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Cheng-Da, E-mail: nanowu@cycu.edu.tw [Department of Mechanical Engineering, Chung Yuan Christian University, 200, Chung Pei Rd., Chung Li District, Taoyuan City 32023, Taiwan (China); Fang, Te-Hua, E-mail: fang.tehua@msa.hinet.net [Department of Mechanical Engineering, National Kaohsiung University of Applied Sciences, Kaohsiung 807, Taiwan (China); Su, Jih-Kai, E-mail: yummy_2468@yahoo.com.tw [Department of Mechanical Engineering, National Kaohsiung University of Applied Sciences, Kaohsiung 807, Taiwan (China)

    2017-02-28

    Highlights: • A nanoscale chip with a shear plane of 135° is extruded by the tool. • Tangential force and normal force increase with increasing tool nose radius. • Resistance factor increases with increasing cutting depth and temperature. - Abstract: The effects of cutting depth, tool nose radius, and temperature on the cutting mechanism and mechanics of amorphous NiAl workpieces are studied using molecular dynamics simulations based on the second-moment approximation of the many-body tight-binding potential. These effects are investigated in terms of atomic trajectories and flow field, shear strain, cutting force, resistance factor, cutting ratio, and pile-up characteristics. The simulation results show that a nanoscale chip with a shear plane of 135° is extruded by the tool from a workpiece surface during the cutting process. The workpiece atoms underneath the tool flow upward due to the adhesion force and elastic recovery. The required tangential force and normal force increase with increasing cutting depth and tool nose radius; both forces also increase with decreasing temperature. The resistance factor increases with increasing cutting depth and temperature, and decreases with increasing tool nose radius.

  6. The metallicity distribution of H I systems in the EAGLE cosmological simulations

    Science.gov (United States)

    Rahmati, Alireza; Oppenheimer, Benjamin D.

    2018-06-01

    The metallicity of strong H I systems, spanning from damped Lyman α absorbers (DLAs) to Lyman-limit systems (LLSs), is explored between z = 5 → 0 using the EAGLE high-resolution cosmological hydrodynamic simulation of galaxy formation. The metallicities of LLSs and DLAs steadily increase with time in agreement with observations. DLAs are more metal rich than LLSs, although the metallicities in the LLS column density range (N_{H I }≈ 10^{17}-10^{20} cm^{-2}) are relatively flat, evolving from a median H I-weighted metallicity of {Z}≲ 10^{-2} Z_{⊙} at z = 3 to ≈10-0.5 Z⊙ by z = 0. The metal content of H I systems tracks the increasing stellar content of the Universe, holding ≈ 5 {per cent} of the integrated total metals released from stars at z = 0. We also consider partial LLS (pLLS, N_{H I}≈ 10^{16}-10^{17} cm^{-2}) metallicities, and find good agreement with Wotta et al. for the fraction of systems above (37 per cent) and below (63 per cent) 0.1 Z⊙. We also find a large dispersion of pLLS metallicities, although we do not reproduce the observed metallicity bimodality and instead we make the prediction that a larger sample will yield more pLLSs around 0.1 Z⊙. We underpredict the median metallicity of strong LLSs, and predict a population of Z 3 that are not observed, which may indicate more widespread early enrichment in the real Universe compared to EAGLE.

  7. METAL STRUCTURES SURVIVABILITY ASSESSMENT WHEN SIMULATING SERVICE CONDITIONS

    Directory of Open Access Journals (Sweden)

    O. M. Gibalenko

    2016-04-01

    Full Text Available Purpose. The research is aimed at improving the quality and reliability of measures of primary and secondary protection of metal structures at manufacturing companies, to prolong the service life of cyclically loaded structures of production facilities taking into account the corrosion level of danger. Methodology. Authors proposed to use the principles of process approach for statement and realization of management problems of operational service life in corrosion environments. The principles of ensuring reliability on the level of corrosion danger include justification of stages sequence for survivability assessment of a structural metalwork based on the strategy of DMAIC (define, measure, analyze, improve, control: definitions, measurements, analysis, improvement and monitoring of measures of primary and secondary corrosion protection. Findings. Providing control measures from corrosion according to the criterion of corrosion danger allows providing requirements of reliability of structural metalwork based on calculated provisions of the limiting conditions method and solving the problems of management in technological safety during the expected service life of structural objects. Originality. The developed strategy of maintenance of the industrial facilities on an actual state includes the process approach to resource management by creation of system for the account and the functional controlling, risk analysis and regulation of technological safety in production facilities of the enterprises. Realization of the principles of process approach to management of technological safety at the object level is directed to perfecting of tools and methods of anticorrosive protection, extension of a resource taking into account indexes of survivability (, and justification of program measures to ensure the reliability of enterprises(PER. Practical value. On the basis of process approach to quality and reliability management, generalizations of the

  8. Friction modelling in sheet metal forming simulations: application and validation on an U-Bend product

    NARCIS (Netherlands)

    Sigvant, Mats; Hol, Johan; Chezan, Toni; van den Boogaard, Ton; Hora, P.

    2015-01-01

    The accuracy of sheet metal forming simulations strongly depends on, amongst others, friction modelling. The industrial standard is to use the Coulomb friction model with a constant coefficient of friction. However, it is known that the true friction conditions are dependent on the tribology system,

  9. Determination of the bioaccessible fraction of metals in urban aerosol using simulated lung fluids

    Czech Academy of Sciences Publication Activity Database

    Coufalík, Pavel; Mikuška, Pavel; Matoušek, Tomáš; Večeřa, Zbyněk

    2016-01-01

    Roč. 140, SEP (2016), s. 469-475 ISSN 1352-2310 R&D Projects: GA ČR(CZ) GA14-25558S; GA ČR(CZ) GA13-01438S Institutional support: RVO:68081715 Keywords : metal * aerosol * simulated lung fluid Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.629, year: 2016

  10. Kinematic and dynamic simulation of the functioning of torsionally flexible metal coupling

    Directory of Open Access Journals (Sweden)

    Krzysztof FILIPOWICZ

    2010-01-01

    Full Text Available The article presents the process of visualization and the accuracy of performance of the prototype of bidirectional torsionally flexible metal coupling using Autodesk® Inventor® Professional 2009. Selected figures from the simulations are presented and discussed on the basis of a virtual model of the coupling.

  11. Characteristics of spent nuclear fuel

    International Nuclear Information System (INIS)

    Notz, K.J.

    1988-04-01

    The Office of Civilian Radioactive Waste Management (OCRWM) is responsible for the spent fuels and other wastes that will, or may, eventually be disposed of in a geological repository. The two major sources of these materials are commercial light-water reactor (LWR) spent fuel and immobilized high-level waste (HLW). Other wastes that may require long-term isolation include non-LWR spent fuels and miscellaneous sources such as activated metals. This report deals with spent fuels, but for completeness, the other sources are described briefly. Detailed characterizations are required for all of these potential repository wastes. These characteristics include physical, chemical, and radiological properties. The latter must take into account decay as a function of time. In addition, the present inventories and projected quantities of the various wastes are needed. This information has been assembled in a Characteristics Data Base which provides data in four formats: hard copy standard reports, menu-driven personal computer (PC) data bases, program-level PC data bases, and mainframe computer files. 5 refs., 3 figs., 4 tabs

  12. Numerical and experimental validation of a particle Galerkin method for metal grinding simulation

    Science.gov (United States)

    Wu, C. T.; Bui, Tinh Quoc; Wu, Youcai; Luo, Tzui-Liang; Wang, Morris; Liao, Chien-Chih; Chen, Pei-Yin; Lai, Yu-Sheng

    2018-03-01

    In this paper, a numerical approach with an experimental validation is introduced for modelling high-speed metal grinding processes in 6061-T6 aluminum alloys. The derivation of the present numerical method starts with an establishment of a stabilized particle Galerkin approximation. A non-residual penalty term from strain smoothing is introduced as a means of stabilizing the particle Galerkin method. Additionally, second-order strain gradients are introduced to the penalized functional for the regularization of damage-induced strain localization problem. To handle the severe deformation in metal grinding simulation, an adaptive anisotropic Lagrangian kernel is employed. Finally, the formulation incorporates a bond-based failure criterion to bypass the prospective spurious damage growth issues in material failure and cutting debris simulation. A three-dimensional metal grinding problem is analyzed and compared with the experimental results to demonstrate the effectiveness and accuracy of the proposed numerical approach.

  13. Development of an expert system for the simulation model for casting metal substructure of a metal-ceramic crown design.

    Science.gov (United States)

    Matin, Ivan; Hadzistevic, Miodrag; Vukelic, Djordje; Potran, Michal; Brajlih, Tomaz

    2017-07-01

    Nowadays, the integrated CAD/CAE systems are favored solutions for the design of simulation models for casting metal substructures of metal-ceramic crowns. The worldwide authors have used different approaches to solve the problems using an expert system. Despite substantial research progress in the design of experts systems for the simulation model design and manufacturing have insufficiently considered the specifics of casting in dentistry, especially the need for further CAD, RE, CAE for the estimation of casting parameters and the control of the casting machine. The novel expert system performs the following: CAD modeling of the simulation model for casting, fast modeling of gate design, CAD eligibility and cast ability check of the model, estimation and running of the program code for the casting machine, as well as manufacturing time reduction of the metal substructure. The authors propose an integration method using common data model approach, blackboard architecture, rule-based reasoning and iterative redesign method. Arithmetic mean roughness values was determinated with constant Gauss low-pass filter (cut-off length of 2.5mm) according to ISO 4287 using Mahr MARSURF PS1. Dimensional deviation between the designed model and manufactured cast was determined using the coordinate measuring machine Zeiss Contura G2 and GOM Inspect software. The ES allows for obtaining the castings derived roughness grade number N7. The dimensional deviation between the simulation model of the metal substructure and the manufactured cast is 0.018mm. The arithmetic mean roughness values measured on the casting substructure are from 1.935µm to 2.778µm. The realized developed expert system with the integrated database is fully applicable for the observed hardware and software. Values of the arithmetic mean roughness and dimensional deviation indicate that casting substructures are surface quality, which is more than enough and useful for direct porcelain veneering. The

  14. Impact of trace metal concentrations on coccolithophore growth and morphology: laboratory simulations of Cretaceous stress

    Science.gov (United States)

    Faucher, Giulia; Hoffmann, Linn; Bach, Lennart T.; Bottini, Cinzia; Erba, Elisabetta; Riebesell, Ulf

    2017-07-01

    The Cretaceous ocean witnessed intervals of profound perturbations such as volcanic input of large amounts of CO2, anoxia, eutrophication and introduction of biologically relevant metals. Some of these extreme events were characterized by size reduction and/or morphological changes of a few calcareous nannofossil species. The correspondence between intervals of high trace metal concentrations and coccolith dwarfism suggests a negative effect of these elements on nannoplankton biocalcification processes in past oceans. In order to test this hypothesis, we explored the potential effect of a mixture of trace metals on growth and morphology of four living coccolithophore species, namely Emiliania huxleyi, Gephyrocapsa oceanica, Pleurochrysis carterae and Coccolithus pelagicus. The phylogenetic history of coccolithophores shows that the selected living species are linked to Mesozoic species showing dwarfism under excess metal concentrations. The trace metals tested were chosen to simulate the environmental stress identified in the geological record and upon known trace metal interactions with living coccolithophore algae.Our laboratory experiments demonstrated that elevated trace metal concentrations, similarly to the fossil record, affect coccolithophore algae size and/or weight. Smaller coccoliths were detected in E. huxleyi and C. pelagicus, while coccoliths of G. oceanica showed a decrease in size only at the highest trace metal concentrations. P. carterae coccolith size was unresponsive to changing trace metal concentrations. These differences among species allow discriminating the most- (P. carterae), intermediate- (E. huxleyi and G. oceanica) and least-tolerant (C. pelagicus) taxa. The fossil record and the experimental results converge on a selective response of coccolithophores to metal availability.These species-specific differences must be considered before morphological features of coccoliths are used to reconstruct paleo-chemical conditions.

  15. Impact of trace metal concentrations on coccolithophore growth and morphology: laboratory simulations of Cretaceous stress

    Directory of Open Access Journals (Sweden)

    G. Faucher

    2017-07-01

    Full Text Available The Cretaceous ocean witnessed intervals of profound perturbations such as volcanic input of large amounts of CO2, anoxia, eutrophication and introduction of biologically relevant metals. Some of these extreme events were characterized by size reduction and/or morphological changes of a few calcareous nannofossil species. The correspondence between intervals of high trace metal concentrations and coccolith dwarfism suggests a negative effect of these elements on nannoplankton biocalcification processes in past oceans. In order to test this hypothesis, we explored the potential effect of a mixture of trace metals on growth and morphology of four living coccolithophore species, namely Emiliania huxleyi, Gephyrocapsa oceanica, Pleurochrysis carterae and Coccolithus pelagicus. The phylogenetic history of coccolithophores shows that the selected living species are linked to Mesozoic species showing dwarfism under excess metal concentrations. The trace metals tested were chosen to simulate the environmental stress identified in the geological record and upon known trace metal interactions with living coccolithophore algae.Our laboratory experiments demonstrated that elevated trace metal concentrations, similarly to the fossil record, affect coccolithophore algae size and/or weight. Smaller coccoliths were detected in E. huxleyi and C. pelagicus, while coccoliths of G. oceanica showed a decrease in size only at the highest trace metal concentrations. P. carterae coccolith size was unresponsive to changing trace metal concentrations. These differences among species allow discriminating the most- (P. carterae, intermediate- (E. huxleyi and G. oceanica and least-tolerant (C. pelagicus taxa. The fossil record and the experimental results converge on a selective response of coccolithophores to metal availability.These species-specific differences must be considered before morphological features of coccoliths are used to reconstruct paleo-chemical conditions.

  16. Modelling Sawing of Metal Tubes Through FEM Simulation

    International Nuclear Information System (INIS)

    Bort, C. M. Giorgio; Bosetti, P.; Bruschi, S.

    2011-01-01

    The paper presents the development of a numerical model of the sawing process of AISI 304 thin tubes, which is cut through a circular blade with alternating roughing and finishing teeth. The numerical simulation environment is the three-dimensional FEM software Deform v.10.1. The teeth actual trajectories were determined by a blade kinematics analysis developed in Matlab. Due to the manufacturing rolling steps and subsequent welding stage, the tube material is characterized by a gradient of properties along its thickness. Consequently, a simplified cutting test was set up and carried out in order to identify the values of relevant material parameters to be used in the numerical model. The dedicated test was the Orthogonal Tube Cutting test (OTC), which was performed on an instrumented lathe. The proposed numerical model was validated by comparing numerical results and experimental data obtained from sawing tests carried out on an industrial machine. The following outputs were compared: the cutting force, the chip thickness, and the chip contact area.

  17. Modelling Sawing of Metal Tubes Through FEM Simulation

    Science.gov (United States)

    Bort, C. M. Giorgio; Bosetti, P.; Bruschi, S.

    2011-05-01

    The paper presents the development of a numerical model of the sawing process of AISI 304 thin tubes, which is cut through a circular blade with alternating roughing and finishing teeth. The numerical simulation environment is the three-dimensional FEM software Deform™ v.10.1. The teeth actual trajectories were determined by a blade kinematics analysis developed in Matlab™. Due to the manufacturing rolling steps and subsequent welding stage, the tube material is characterized by a gradient of properties along its thickness. Consequently, a simplified cutting test was set up and carried out in order to identify the values of relevant material parameters to be used in the numerical model. The dedicated test was the Orthogonal Tube Cutting test (OTC), which was performed on an instrumented lathe. The proposed numerical model was validated by comparing numerical results and experimental data obtained from sawing tests carried out on an industrial machine. The following outputs were compared: the cutting force, the chip thickness, and the chip contact area.

  18. Simulation of short-term annealing of displacement cascades in FCC metals

    International Nuclear Information System (INIS)

    Heinisch, H.L.; Doran, D.G.; Schwartz, D.M.

    1980-01-01

    Computer models have been developed for the simulation of high energy displacement cascades. The objective is the generation of defect production functions for use in correlation analysis of radiation effects in fusion reactor materials. In particular, the stochastic cascade annealing simulation code SCAS has been developed and used to model the short-term annealing behavior of simulated cascades in FCC metals. The code is fast enough to make annealing of high energy cascades practical. Sets of cascades from 5 keV to 100 keV in copper were generated by the binary collision code MARLOWE

  19. NOBLE METAL CHEMISTRY AND HYDROGEN GENERATION DURING SIMULATED DWPF MELTER FEED PREPARATION

    Energy Technology Data Exchange (ETDEWEB)

    Koopman, D

    2008-06-25

    Simulations of the Defense Waste Processing Facility (DWPF) Chemical Processing Cell vessels were performed with the primary purpose of producing melter feeds for the beaded frit program plus obtaining samples of simulated slurries containing high concentrations of noble metals for off-site analytical studies for the hydrogen program. Eight pairs of 22-L simulations were performed of the Sludge Receipt and Adjustment Tank (SRAT) and Slurry Mix Evaporator (SME) cycles. These sixteen simulations did not contain mercury. Six pairs were trimmed with a single noble metal (Ag, Pd, Rh, or Ru). One pair had all four noble metals, and one pair had no noble metals. One supporting 4-L simulation was completed with Ru and Hg. Several other 4-L supporting tests with mercury have not yet been performed. This report covers the calculations performed on SRNL analytical and process data related to the noble metals and hydrogen generation. It was originally envisioned as a supporting document for the off-site analytical studies. Significant new findings were made, and many previous hypotheses and findings were given additional support as summarized below. The timing of hydrogen generation events was reproduced very well within each of the eight pairs of runs, e.g. the onset of hydrogen, peak in hydrogen, etc. occurred at nearly identical times. Peak generation rates and total SRAT masses of CO{sub 2} and oxides of nitrogen were reproduced well. Comparable measures for hydrogen were reproduced with more variability, but still reasonably well. The extent of the reproducibility of the results validates the conclusions that were drawn from the data.

  20. Finite element simulation and Experimental verification of Incremental Sheet metal Forming

    Science.gov (United States)

    Kaushik Yanamundra, Krishna; Karthikeyan, R., Dr.; Naranje, Vishal, Dr

    2018-04-01

    Incremental sheet metal forming is now a proven manufacturing technique that can be employed to obtain application specific, customized, symmetric or asymmetric shapes that are required by automobile or biomedical industries for specific purposes like car body parts, dental implants or knee implants. Finite element simulation of metal forming process is being performed successfully using explicit dynamics analysis of commercial FE software. The simulation is mainly useful in optimization of the process as well design of the final product. This paper focuses on simulating the incremental sheet metal forming process in ABAQUS, and validating the results using experimental methods. The shapes generated for testing are of trapezoid, dome and elliptical shapes whose G codes are written and fed into the CNC milling machine with an attached forming tool with a hemispherical bottom. The same pre-generated coordinates are used to simulate a similar machining conditions in ABAQUS and the tool forces, stresses and strains in the workpiece while machining are obtained as the output data. The forces experimentally were recorded using a dynamometer. The experimental and simulated results were then compared and thus conclusions were drawn.

  1. Spent Fuel Ratio Estimates from Numerical Models in ALE3D

    Energy Technology Data Exchange (ETDEWEB)

    Margraf, J. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Dunn, T. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-08-02

    Potential threat of intentional sabotage of spent nuclear fuel storage facilities is of significant importance to national security. Paramount is the study of focused energy attacks on these materials and the potential release of aerosolized hazardous particulates into the environment. Depleted uranium oxide (DUO2) is often chosen as a surrogate material for testing due to the unreasonable cost and safety demands for conducting full-scale tests with real spent nuclear fuel. To account for differences in mechanical response resulting in changes to particle distribution it is necessary to scale the DUO2 results to get a proper measure for spent fuel. This is accomplished with the spent fuel ratio (SFR), the ratio of respirable aerosol mass released due to identical damage conditions between a spent fuel and a surrogate material like depleted uranium oxide (DUO2). A very limited number of full-scale experiments have been carried out to capture this data, and the oft-questioned validity of the results typically leads to overly-conservative risk estimates. In the present work, the ALE3D hydrocode is used to simulate DUO2 and spent nuclear fuel pellets impacted by metal jets. The results demonstrate an alternative approach to estimate the respirable release fraction of fragmented nuclear fuel.

  2. Molecular dynamics simulation of self-diffusion coefficients for liquid metals

    International Nuclear Information System (INIS)

    Ju Yuan-Yuan; Zhang Qing-Ming; Gong Zi-Zheng; Ji Guang-Fu

    2013-01-01

    The temperature-dependent coefficients of self-diffusion for liquid metals are simulated by molecular dynamics methods based on the embedded-atom-method (EAM) potential function. The simulated results show that a good inverse linear relation exists between the natural logarithm of self-diffusion coefficients and temperature, though the results in the literature vary somewhat, due to the employment of different potential functions. The estimated activation energy of liquid metals obtained by fitting the Arrhenius formula is close to the experimental data. The temperature-dependent shear-viscosities obtained from the Stokes—Einstein relation in conjunction with the results of molecular dynamics simulation are generally consistent with other values in the literature. (atomic and molecular physics)

  3. Rejuvenation of residual oil hydrotreating catalysts by leaching of foulant metals. Modelling of the metal leaching process

    Energy Technology Data Exchange (ETDEWEB)

    Marafi, M.; Kam, E.K.T.; Stanislaus, A.; Absi-Halabi, M. [Petroleum Technology Department, Petroleum, Petrochemicals and Materials Division, Kuwait Institute for Scientific Research, Safat (Kuwait)

    1996-11-19

    Increasing emphasis has been paid in recent years on the development of processes for the rejuvenation of spent residual oil hydroprocessing catalysts, which are deactivated by deposition of metals (e.g. vanadium) and coke. As part of a research program on this subject, we have investigated selective removal of the major metal foulant from the spent catalyst by chemical leaching. In the present paper, we report the development of a model for foulant metals leaching from the spent catalyst. The leaching process is considered to involve two consecutive operations: (1) removal of metal foulants along the main mass transfer channels connected to the narrow pores until the pore structure begins to develop and (2) removal of metal foulants from the pore structure. Both kinetic and mass transfer aspects were considered in the model development, and a good agreement was noticed between experimental and simulated results

  4. Reprocessing method for spent fuel

    International Nuclear Information System (INIS)

    Fujie, Makoto; Shoji, Yuichi; Kobayashi, Tsuguyuki.

    1997-01-01

    After reducing oxides of uranium (U), plutonium (Pu) and miner actinides in spent fuels by magnesium (Mg) in a molten salt, rear earth element oxides and salts of alkali metals and alkaline earth metals contained in the molten salt phase are separated and removed. Further, the Mg phase containing the reduced metals is evaporated to separate and remove Mg, thereby recovering U, Pu and minor actinides. In a lithium (Li) process, Li 2 O also generated in the reduction step is regenerated to Li simultaneously, and the reduction is conducted while suppressing the Li 2 O concentration in the molten salt low. This can improve the reduction rate of oxides of U, Pu and minor actinides compared with conventional cases. Since Li 2 O is regenerated into Li in the reduction step of the Li process, deposited Li 2 O is not carried to an electrolysis purification step, and recovering rate of U, Pu and minor actinides is not lowered. (T.M.)

  5. A preliminary assessment of system cost impacts of using transportable storage casks and other shippable metal casks in the utility/DOE spent fuel management system

    International Nuclear Information System (INIS)

    Johnson, E.R.

    1988-01-01

    In view of the foregoing, a study was conducted by E.R. Johnson Associates, Inc. and H and R Technical Associates, Inc. to determine the prospective viability of the use of TSCs and shippable SOCs in the combined utility/DOE system. This study considered costs, ALARA considerations and the logistics of the use and delivery of casks to the DOE system by utilities. It was intended that this study would result in a technical and cost resource base that could be used for evaluating various strategies and scenarios for deploying TSCs or SOCs in the combined utility/DOE spent fuel management system with respect to the prospective economic advantage that could be realized

  6. Baseline metal enrichment from Population III star formation in cosmological volume simulations

    Science.gov (United States)

    Jaacks, Jason; Thompson, Robert; Finkelstein, Steven L.; Bromm, Volker

    2018-04-01

    We utilize the hydrodynamic and N-body code GIZMO coupled with our newly developed sub-grid Population III (Pop III) Legacy model, designed specifically for cosmological volume simulations, to study the baseline metal enrichment from Pop III star formation at z > 7. In this idealized numerical experiment, we only consider Pop III star formation. We find that our model Pop III star formation rate density (SFRD), which peaks at ˜ 10- 3 M⊙ yr- 1 Mpc- 1 near z ˜ 10, agrees well with previous numerical studies and is consistent with the observed estimates for Pop II SFRDs. The mean Pop III metallicity rises smoothly from z = 25 to 7, but does not reach the critical metallicity value, Zcrit = 10-4 Z⊙, required for the Pop III to Pop II transition in star formation mode until z ≃ 7. This suggests that, while individual haloes can suppress in situ Pop III star formation, the external enrichment is insufficient to globally terminate Pop III star formation. The maximum enrichment from Pop III star formation in star-forming dark matter haloes is Z ˜ 10-2 Z⊙, whereas the minimum found in externally enriched haloes is Z ≳ 10-7 Z⊙. Finally, mock observations of our simulated IGM enriched with Pop III metals produce equivalent widths similar to observations of an extremely metal-poor damped Lyman alpha system at z = 7.04, which is thought to be enriched by Pop III star formation only.

  7. Simulation studies of current transport in metal-insulator-semiconductor Schottky barrier diodes

    International Nuclear Information System (INIS)

    Chand, Subhash; Bala, Saroj

    2007-01-01

    The current-voltage characteristics of Schottky diodes with an interfacial insulator layer are analysed by numerical simulation. The current-voltage data of the metal-insulator-semiconductor Schottky diode are simulated using thermionic emission diffusion (TED) equation taking into account an interfacial layer parameter. The calculated current-voltage data are fitted into ideal TED equation to see the apparent effect of interfacial layer parameters on current transport. Results obtained from the simulation studies shows that with mere presence of an interfacial layer at the metal-semiconductor interface the Schottky contact behave as an ideal diode of apparently high barrier height (BH), but with same ideality factor and series resistance as considered for a pure Schottky contact without an interfacial layer. This apparent BH decreases linearly with decreasing temperature. The effects giving rise to high ideality factor in metal-insulator-semiconductor diode are analysed. Reasons for observed temperature dependence of ideality factor in experimentally fabricated metal-insulator-semiconductor diodes are analysed and possible mechanisms are discussed

  8. Residual salts separation from metal reduced electrolytically in a LiCl-Li2O molten salt

    International Nuclear Information System (INIS)

    Hur, Jin Mok; Oh, Seung Chul; Hong, Sun Seok; Seo, Chung Seok; Park, Seong Won

    2005-01-01

    The PWR spent oxide fuel can be reduced electrolytically in a hot molten salt for the conditioning and the preparation of a metallic fuel. Then the metal product is smelted into an ingot to be treated in the post process. Incidentally, the residual salt which originated from the molten salt and spent fuel elements should be separated from the metal product during the smelting. In this work, we constructed a surrogate material system to simulate the salt separation from the reduced spent fuel and studied the vaporization behaviors of the salts

  9. Spent fuels program

    International Nuclear Information System (INIS)

    Shappert, L.B.

    1983-01-01

    The goal of this task is to support the Domestic Spent Fuel Storage Program through studies involving the transport of spent fuel. A catalog was developed to provide authoritative, timely, and accessible transportation information for persons involved in the transport of irradiated reactor fuel. The catalog, drafted and submitted to the Transportation Technology Center, Sandia National Laboratories, for their review and approval, covers such topics as federal, state, and local regulations, spent fuel characteristics, cask characteristics, transportation costs, and emergency response information

  10. Structural evaluation of spent nuclear fuel storage facilities under aircraft crash impact. Numerical study on evaluation of sealing performance of metal cask subjected to impact force

    International Nuclear Information System (INIS)

    Namba, Kosuke; Shirai, Koji; Saegusa, Toshiari

    2008-01-01

    A lot of safety evaluations on the important nuclear facilities against the aircraft crash have been reported in other countries. But the condition and the evaluation method to define impact force of aircraft crash have not been described clearly in the reports. In Japan, public concern with the safety evaluation against aircraft crash is increasing. It is important to make clear the behavior of the storage facilities installing the metal casks on impact loading due to aircraft crash. In this study, concerning crash between commercial aircraft and storage facility, impact analysis using dynamic analysis code LS-DYNA has been executed. The results showed that the storage facility was not completely destroyed. But the rigid aircraft engine may penetrate into the storage facility with local failure. Thus, we assumed the engine hit a metal cask in the storage facility and evaluated sealing performance of the metal cask under the impact loading. If the engine with 90m/s crashed the storage facility having concrete wall of 85cm in thickness, the remaining velocity became 60m/s after penetration. We calculated impact force of the engine with 60m/s crashing into the metal cask. Concerning the metal cask loaded the impact force, impact analysis was executed. We assumed two directions of impact force. One is vertical load and another is horizontal load against the cask. The result showed that plastic strain was not generated on flanges of the 1st lid and the sealing performance of the cask was maintained in each impact case. (author)

  11. Simulated optical properties of noble metallic nanopolyhedra with different shapes and structures

    Science.gov (United States)

    Zhang, An-Qi; Qian, Dong-Jin; Chen, Meng

    2013-11-01

    The optical properties of nanostructured architectures are highly sensitive to their compositions, structures, dimensions, geometries and embedding mediums. Nanopolyhedra, including homogeneous metal nanoparticles and core-shell structures, have unique optical properties. In the beginning of this study, Discrete Dipole Approximation (DDA) method has been introduced. Then the simulated extinction spectra of single-component metal nanoparticles and Au@Ag polyhedra were calculated using both Mie and DDA methods. The influence of morphology and components on the optical response is discussed and well-supported by previously published experimental results. It is observed that the Localized Surface Plasmon Resonance peaks are mainly decided by sharp vertexes and symmetry of noble metallic polyhedra, as well as the structure of the Au@Ag core-shell nanoparticles.

  12. Quantum mechanical ab initio simulation of the electron screening effect in metal deuteride crystals

    Energy Technology Data Exchange (ETDEWEB)

    Huke, A.; Chun, S.M.; Biller, A.; Heide, P. [Technische Universitaet Berlin, Institut fuer Optik und Atomare Physik, Berlin (Germany); Czerski, K. [Technische Universitaet Berlin, Institut fuer Optik und Atomare Physik, Berlin (Germany); University of Szczecin, Institute of Physics, Szczecin (Poland)

    2008-02-15

    In antecedent experiments the electron screening energies of the d+d reactions in metallic environments have been determined to be enhanced by an order of magnitude in comparison to the case of gaseous deuterium targets. The analytical models describing averaged material properties have not been able to explain the experimental results so far. Therefore, a first effort has been undertaken to simulate the dynamics of reacting deuterons in a metallic lattice by means of an ab initio Hartree-Fock calculation of the total electrostatic force between the lattice and the successively approaching deuterons via path integration. The calculations have been performed for Li and Ta, clearly showing a migration of electrons from host metallic to the deuterium atoms. However, in order to avoid more of the necessary simplifications in the model the utilization of a massive parallel supercomputer would be required. (orig.) 3.

  13. Noble metal behavior during melting of simulated high-level nuclear waste glass feeds

    International Nuclear Information System (INIS)

    Anderson, L.D.; Dennis, T.; Elliott, M.L.; Hrma, P.

    1993-04-01

    Noble metals and their oxides can settle in waste glass melters and cause electrical shorting. Simulated waste feeds from Hanford, Savannah River, and Germany were heat treated for 1 hour in a gradient furnace at temperatures ranging from approximately 600 degrees C--1000 degrees C and examined by electron microscopy to determine shapes, sizes, and distribution of noble metal particles as a function of temperature. Individual noble metal particles and agglomerates of rhodium (Rh), ruthenium (RuO 2 ), and palladium (Pd), as well as their alloys, were seen. the majority of particles and agglomerates were generally less than 10 microns; however, large agglomerations (up to 1 mm) were found in the German feed. Detailed particle distribution and characterization was performed for a Hanford waste to provide input to computer modeling of particle settling in the melter

  14. Noble metal behavior during melting of simulated high-level nuclear waste glass feeds

    International Nuclear Information System (INIS)

    Anderson, L.D.; Dennis, T.; Elliott, M.L.; Hrma, P.

    1994-01-01

    Noble metals and their oxides can settle in waste glass melters and cause electrical shorting. Simulate waste feeds from Hanford, Savannah River, and Kernforschungszentrum Karlsruhe were heat treated for 1 hour in a gradient furnace at temperatures ranging from approximately 600 degrees C to 1000 degrees C and examined by electron microscopy to determine shapes, sizes, and distribution of noble metal particles as a function of temperature. Individual noble metal particles and agglomerates of rhodium (Rh), ruthenium (RuO 2 ), and palladium (Pd), as well as their alloys, were seen. The majority of particles and agglomerates were generally less than 10 μm; however, large agglomerations (up to 1 mm) were found in the German feed. 5 refs., 6 figs., 2 tabs

  15. Three-dimensional phase-field simulation on the deformation of metallic glass nanowires

    International Nuclear Information System (INIS)

    Zhang, H.Y.; Zheng, G.P.

    2014-01-01

    Highlights: • 3D phase-field modeling is developed to investigate the deformation of MG nanowires. • The surface defects significantly affect the mechanical properties of nanowires. • Multiple shear bands are initiated from the surfaces of nanowires with D < 50 nm. - Abstract: It is very challenging to investigate the deformation mechanisms in micro- and nano-scale metallic glasses with diameters below several hundred nanometers using the atomistic simulation or the experimental approaches. In this work, we develop the fully three-dimensional phase-field model to bridge this gap and investigate the sample size effects on the deformation behaviors of metallic glass nanowires. The initial deformation defects on the surface are found to significantly affect the mechanical strength and deformation mode of nanowires. The improved ductility of metallic glass nanowires could be related with the multiple shear bands initiated from the nanowire surfaces

  16. Developing Spent Fuel Assembly for Advanced NDA Instrument Calibration - NGSI Spent Fuel Project

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Jianwei [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gauld, Ian C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Banfield, James [GE Hitachi Nuclear Energy, Wilmington, NC (United States); Skutnik, Steven [Univ. of Tennessee, Knoxville, TN (United States)

    2014-02-01

    This report summarizes the work by Oak Ridge National Laboratory to investigate the application of modeling and simulation to support the performance assessment and calibration of the advanced nondestructive assay (NDA) instruments developed under the Next Generation Safeguards Initiative Spent Fuel (NGSI-SF) Project. Advanced NDA instrument calibration will likely require reference spent fuel assemblies with well-characterized nuclide compositions that can serve as working standards. Because no reference spent fuel standard currently exists, and the practical ability to obtain direct measurement of nuclide compositions using destructive assay (DA) measurements of an entire fuel assembly is prohibitive in the near term due to the complexity and cost of spent fuel experiments, modeling and simulation will be required to construct such reference fuel assemblies. These calculations will be used to support instrument field tests at the Swedish Interim Storage Facility (Clab) for Spent Nuclear Fuel.

  17. Numerical modelling of adsorption of metallic particles on graphite substrate via molecular dynamics simulation

    International Nuclear Information System (INIS)

    Rafii-Tabar, H.

    1998-01-01

    A computer-based numerical modelling of the adsorption process of gas phase metallic particles on the surface of a graphite substrate has been performed via the application of molecular dynamics simulation method. The simulation related to an extensive STM-based experiment performed in this field, and reproduces part of the experimental results. Both two-body and many-body inter-atomic potentials have been employed. A Morse-type potential describing the metal-carbon interactions at the interface was specially formulated for this modelling. Intercalation of silver in graphite has been observed as well as the correct alignments of monomers, dimers and two-dimensional islands on the surface. (author)

  18. Numerical simulation of a metal corrosion for a point defect for a organic protection layer

    International Nuclear Information System (INIS)

    Vautrin-Ul, Ch.; Chausse, A.; Stafiej, J.; Badiali, J.P.

    2005-01-01

    The safety of radioactive wastes disposal requires a big knowledge on their aging facing a corrosive environment. The corrosion is a complex phenomenon which implies many processes bound to the physic and the chemistry of the system. This approach proposes, from a little number of simple processes, numerical simulation which will define theses complex phenomenon. The presented model is a 2 dimension model at a mesoscopic scale and based on cellular automates. It allows the simulation of a metal evolution, protected by a polymer layer and in contact at one point with a corrosive media at a defect of the layer. (A.L.B.)

  19. Vitrification of noble metals containing NCAW simulant with an engineering scale melter (ESM): Campaign report

    Energy Technology Data Exchange (ETDEWEB)

    Grunewald, W.; Roth, G.; Tobie, W.; Weisenburger, S.; Weiss, K.; Elliott, M.; Eyler, L.L.

    1996-03-01

    ESM has been designed as a 10th-scale model of the DWPF-type melter, currently the reference melter for nitrification of Hanford double shell tankwaste. ESM and related equipment have been integrated to the existing mockup vitrification plant VA-WAK at KfK. On June 2-July 10, 1992, a shakedown test using 2.61 m{sup 3} of NCAW (neutralized current acid waste) simulant without noble metals was performed. On July 11-Aug. 30, 1992, 14.23 m{sup 3} of the same simulant with nominal concentrations of Ru, Rh, and Pd were vitrified. Objective was to investigate the behavior of such a melter with respect to discharge of noble metals with routine glass pouring via glass overflow. Results indicate an accumulation of noble metals in the bottom area of the flat-bottomed ESM. About 65 wt% of the noble metals fed to the melter could be drained out, whereas 35 wt% accumulated in the melter, based on analysis of glass samples from glass pouring stream in to the canisters. After the melter was drained at the end of the campaign through a bottom drain valve, glass samples were taken from the residual bottom layer. The samples had significantly increased noble metals content (factor of 20-45 to target loading). They showed also a significant decrease of the specific electric resistance compared to bulk glass (factor of 10). A decrease of 10- 15% of the resistance between he power electrodes could be seen at the run end, but the total amount of noble metals accumulated was not yet sufficient enough to disturb the Joule heating of the glass tank severely.

  20. Spent fuel interim management: 1995 update

    International Nuclear Information System (INIS)

    Anderson, C.K.

    1995-01-01

    The problems of interim away-from-reactor spent fuel storage and storage in spent fuel pools at the reactor site are discussed. An overview of the state-of-the-art in the USA, Europe, and Japan is presented. The technical facilities for away-from-reactor storage are briefly described, including wet storage pools, interactive concrete systems, metallic containers, and passive concrete systems. Reprocessing technologies are mostly at the design stage only. It is predicted that during the 20 years to come, about 50 000 tonnes of spent fuel will be stored at reactor sites regardless of the advance of spent fuel reprocessing or interim storage projects. (J.B.). 4 tabs., 2 figs

  1. Choosing a spent fuel interim storage system

    International Nuclear Information System (INIS)

    Roland, V.; Hunter, I.

    2001-01-01

    The Transnucleaire Group has developed different modular solutions to address spent fuel interim storage needs of NPP. These solutions, that are present in Europe, USA and Asia are metal casks (dual purpose or storage only) of the TN 24 family and the NUHOMS canister based system. It is not always simple for an operator to sort out relevant choice criteria. After explaining the basic designs involved on the examples of the TN 120 WWER dual purpose cask and the NUHOMS 56 WWER for WWER 440 spent fuel, we shall discuss the criteria that govern the choice of a given spent fuel interim storage system from the stand point of the operator. In conclusion, choosing and implementing an interim storage system is a complex process, whose implications can be far reaching for the long-term success of a spent fuel management policy. (author)

  2. Computational simulation studies of the reduction process of UF4 to metallic uranium

    International Nuclear Information System (INIS)

    Borges, Wesden de Almeida

    2011-01-01

    The production of metallic uranium is essential for production of fuel elements for using in nuclear reactors manufacturing of radioisotopes and radiopharmaceuticals. In IPEN, metallic uranium is produced by magnesiothermical reduction of UF 4 . This reaction is performed in a closed graphite crucible inserted in a sealed metal reactor and no contact with the outside environment. The set is gradually heated in an oven pit, until it reaches the ignition temperature of the reaction (between 600-650 degree C). The modeling of the heating profile of the system can be made using simulation programs by finite element method. Through the thermal profiles in the load, we can have a notion of heating period required for the reaction to occur, allowing the identification of the same group in a greater or smaller yield in metallic uranium production. Thermal properties of UF 4 are estimated, obtaining thermal conductivity and heat capacity using the Flash Laser Method, and for the load UF 4 + Mg, either. The results are compared to laboratory tests to simulate the primary production process. (author)

  3. Molecular dynamics simulations of the DNA interaction with metallic nanoparticles and TiO2 surfaces

    International Nuclear Information System (INIS)

    Kholmurodov, Kh.T.; Krasavin, E.A.; Dushanov, E.B.; Hassan, H.K.; Galal, A.; ElHabashy, H.A.; Sweilam, N.H.; Yasuoka, K.

    2013-01-01

    The understanding of the mechanism of DNA interactions and binding with metallic nanoparticles (NPs) and surfaces represents a great interest in today's medicine applications due to diagnostic and treatment of oncology diseases. Recent experimental and simulation studies involve the DNA interaction with highly localized proton beams or metallic NPs (such as Ag, Au, etc.), aimed at targeted cancer therapy through the injection of metal micro- or nanoparticles into the tumor tissue with consequent local microwave or laser heating. The effects of mutational structure changes in DNA and protein structures could result in destroying of native chemical (hydrogen) bonds or, on the contrary, creating of new bonds that do not normally exist there. The cause of such changes might be the alteration of one or several nucleotides (in DNA) or the substitution of specific amino acid residues (in proteins) that can lead to the essential structural destabilization or unfolding. At the atomic or molecular level, the replacement of one nucleotide by another (in DNA double helices) or replacement of one amino acid residue by another (in proteins) cause essential modifications of the molecular force fields of the environment that break locally important hydrogen bonds underlying the structural stability of the biological molecules. In this work, the molecular dynamics(MD) simulations were performed for four DNA models and the flexibilities of the purine and pyrimidine nucleotides during the interaction process with the metallic NPs and TiO 2 surface were clarified

  4. Simulation of the accumulation kinetics for radiation point defects in a metals with impurity

    International Nuclear Information System (INIS)

    Iskakov, B.M.; Nurova, A.B.

    2001-01-01

    In the work a kinetics of vacancies (V) and interstitial atoms (IA) accumulation for cases when the V and IA are recombining with each other, absorbing by drain and capturing by impurity atoms has been simulated. The differential equations system numerical solution was carried out by the Runge-Kutta method. The dynamical equilibrium time achievement for the point radiation defects accumulation process in the metal with impurity is considered

  5. Development of JSTAMP-Works/NV and HYSTAMP for Multipurpose Multistage Sheet Metal Forming Simulation

    International Nuclear Information System (INIS)

    Umezu, Yasuyoshi; Watanabe, Yuko; Ma, Ninshu

    2005-01-01

    Since 1996, Japan Research Institute Limited (JRI) has been providing a sheet metal forming simulation system called JSTAMP-Works packaged the FEM solvers of LS-DYNA and JOH/NIKE, which might be the first multistage system at that time and has been enjoying good reputation among users in Japan. To match the recent needs, 'faster, more accurate and easier', of process designers and CAE engineers, a new metal forming simulation system JSTAMP-Works/NV is developed. The JSTAMP-Works/NV packaged the automatic healing function of CAD and had much more new capabilities such as prediction of 3D trimming lines for flanging or hemming, remote control of solver execution for multi-stage forming processes and shape evaluation between FEM and CAD.On the other way, a multi-stage multi-purpose inverse FEM solver HYSTAMP is developed and will be soon put into market, which is approved to be very fast, quite accurate and robust.Lastly, authors will give some application examples of user defined ductile damage subroutine in LS-DYNA for the estimation of material failure and springback in metal forming simulation

  6. Development of JSTAMP-Works/NV and HYSTAMP for Multipurpose Multistage Sheet Metal Forming Simulation

    Science.gov (United States)

    Umezu, Yasuyoshi; Watanabe, Yuko; Ma, Ninshu

    2005-08-01

    Since 1996, Japan Research Institute Limited (JRI) has been providing a sheet metal forming simulation system called JSTAMP-Works packaged the FEM solvers of LS-DYNA and JOH/NIKE, which might be the first multistage system at that time and has been enjoying good reputation among users in Japan. To match the recent needs, "faster, more accurate and easier", of process designers and CAE engineers, a new metal forming simulation system JSTAMP-Works/NV is developed. The JSTAMP-Works/NV packaged the automatic healing function of CAD and had much more new capabilities such as prediction of 3D trimming lines for flanging or hemming, remote control of solver execution for multi-stage forming processes and shape evaluation between FEM and CAD. On the other way, a multi-stage multi-purpose inverse FEM solver HYSTAMP is developed and will be soon put into market, which is approved to be very fast, quite accurate and robust. Lastly, authors will give some application examples of user defined ductile damage subroutine in LS-DYNA for the estimation of material failure and springback in metal forming simulation.

  7. Process Simulation of Aluminium Sheet Metal Deep Drawing at Elevated Temperatures

    International Nuclear Information System (INIS)

    Winklhofer, Johannes; Trattnig, Gernot; Lind, Christoph; Sommitsch, Christof; Feuerhuber, Hannes

    2010-01-01

    Lightweight design is essential for an economic and environmentally friendly vehicle. Aluminium sheet metal is well known for its ability to improve the strength to weight ratio of lightweight structures. One disadvantage of aluminium is that it is less formable than steel. Therefore complex part geometries can only be realized by expensive multi-step production processes. One method for overcoming this disadvantage is deep drawing at elevated temperatures. In this way the formability of aluminium sheet metal can be improved significantly, and the number of necessary production steps can thereby be reduced. This paper introduces deep drawing of aluminium sheet metal at elevated temperatures, a corresponding simulation method, a characteristic process and its optimization. The temperature and strain rate dependent material properties of a 5xxx series alloy and their modelling are discussed. A three dimensional thermomechanically coupled finite element deep drawing simulation model and its validation are presented. Based on the validated simulation model an optimised process strategy regarding formability, time and cost is introduced.

  8. An FSI Simulation of the Metal Panel Deflection in a Shock Tube Using Illinois Rocstar Simulation Suite

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Jung Hun; Sa, Jeong Hwan; Kim, Han Gi; Cho, Keum Won [Korea Institute of Science and Technology Information, Daejeon (Korea, Republic of)

    2017-05-15

    As the recent development of computing architecture and application software technology, real world simulation, which is the ultimate destination of computer simulation, is emerging as a practical issue in several research sectors. In this paper, metal plate motion in a square shock tube for small time interval was calculated using a supercomputing-based fluid-structure-combustion multi-physics simulation tool called Illinois Rocstar, developed in a US national R and D program at the University of Illinois. Afterwards, the simulation results were compared with those from experiments. The coupled solvers for unsteady compressible fluid dynamics and for structural analysis were based on the finite volume structured grid system and the large deformation linear elastic model, respectively. In addition, a strong correlation between calculation and experiment was shown, probably because of the predictor corrector time-integration scheme framework. In the future, additional validation studies and code improvements for higher accuracy will be conducted to obtain a reliable open-source software research tool.

  9. Hydroprocessing using regenerated spent heavy hydrocarbon catalyst

    International Nuclear Information System (INIS)

    Clark, F.T.; Hensley, A.L. Jr.

    1992-01-01

    This patent describes a process for hydroprocessing a hydrocarbon feedstock. It comprises: contacting the feedstock with hydrogen under hydroprocessing conditions with a hydroprocessing catalyst wherein the hydroprocessing catalyst contains a total contaminant metals build-up of greater than about 4 wt. % nickel plus vanadium, a hydrogenation component selected from the group consisting of Group VIB metals and Group VIII metals and is regenerated spent hydroprocessing catalyst regenerated by a process comprising the steps: partially decoking the spent catalyst in an initial coke-burning step; impregnating the partially decoked catalyst with a Group IIA metal-containing impregnation solution; and decoking the impregnated catalyst in a final coke-burning step wherein the impregnated catalyst is contacted with an oxygen-containing gas at a temperature of about 600 degrees F to about 1400 degrees F

  10. Implementation of virtual models from sheet metal forming simulation into physical 3D colour models using 3D printing

    Science.gov (United States)

    Junk, S.

    2016-08-01

    Today the methods of numerical simulation of sheet metal forming offer a great diversity of possibilities for optimization in product development and in process design. However, the results from simulation are only available as virtual models. Because there are any forming tools available during the early stages of product development, physical models that could serve to represent the virtual results are therefore lacking. Physical 3D-models can be created using 3D-printing and serve as an illustration and present a better understanding of the simulation results. In this way, the results from the simulation can be made more “comprehensible” within a development team. This paper presents the possibilities of 3D-colour printing with particular consideration of the requirements regarding the implementation of sheet metal forming simulation. Using concrete examples of sheet metal forming, the manufacturing of 3D colour models will be expounded upon on the basis of simulation results.

  11. Study and full-scale test of a high-velocity grade-crossing simulated accident of a locomotive and a nuclear-spent-fuel shipping cask

    International Nuclear Information System (INIS)

    Huerta, M.; Yoshimura, H.R.

    1983-02-01

    This report described structural analyses of a high-speed impact between a locomotive and a tractor-trailer system carrying a nuclear-spent-fuel shipping cask. The analyses included both mathematical and physical scale-modeling of the system. The report then describes the full-scale test conducted as part of the program. The system response is described in detail, and a comparison is made between the analyses and the actual hardware response as observed in the full-scale test. 34 figures

  12. Multi-scale simulation of single crystal hollow turbine blade manufactured by liquid metal cooling process

    Directory of Open Access Journals (Sweden)

    Xuewei Yan

    2018-02-01

    Full Text Available Liquid metal cooling (LMC process as a powerful directional solidification (DS technique is prospectively used to manufacture single crystal (SC turbine blades. An understanding of the temperature distribution and microstructure evolution in LMC process is required in order to improve the properties of the blades. For this reason, a multi-scale model coupling with the temperature field, grain growth and solute diffusion was established. The temperature distribution and mushy zone evolution of the hollow blade was simulated and discussed. According to the simulation results, the mushy zone might be convex and ahead of the ceramic beads at a lower withdrawal rate, while it will be concave and laggard at a higher withdrawal rate, and a uniform and horizontal mushy zone will be formed at a medium withdrawal rate. Grain growth of the blade at different withdrawal rates was also investigated. Single crystal structures were all selected out at three different withdrawal rates. Moreover, mis-orientation of the grains at 8 mm/min reached ~30°, while it was ~5° and ~15° at 10 mm/min and 12 mm/min, respectively. The model for predicting dendritic morphology was verified by corresponding experiment. Large scale for 2D dendritic distribution in the whole sections was investigated by experiment and simulation, and they presented a well agreement with each other. Keywords: Hollow blade, Single crystal, Multi-scale simulation, Liquid metal cooling

  13. Separation and preconcentration of platinum-group metals from spent autocatalysts solutions using a hetero-polymeric S, N-containing sorbent and determination by high-resolution continuum source graphite furnace atomic absorption spectrometry.

    Science.gov (United States)

    Eskina, Vasilina V; Dalnova, Olga A; Filatova, Daria G; Baranovskaya, Vasilisa B; Karpov, Yuri A

    2016-10-01

    This paper describes the potential of high-resolution continuum source graphite furnace atomic absorption spectrometry for determination of Pt, Pd and Rh after separation and concentration by original in-house developed heterochain polymer S, N-containing sorbent. The methods of sample preparation of spent ceramic-based autocatalysts were considered, two of which were used: autoclave decomposition in mixture of acids HCl:HNO3 (3:1) and high-temperature melting with K2S2O7. Both methods anyway limit the direct determination of analytes by HR CS GFAAS. Using the first method it is an incomplete digestion of spent autocatalysts samples, since the precipitate is Si, and the rhodium metal dissolves with difficulty and partially passes into solution. In contrast to the first method, the second method allow to completely transfer analytes into solution, however, the background signal produced by the chemical composition of the flux, overlaps the analytical zone. It was found, that Pt, Pd and Rh contained in the spent ceramic automotive catalysts could be effectively separated and concentrated by heterochain polymer S, N-containing sorbent, which has high sorption capacity, selectivity and resistant to dilute acids. The chosen HR CS GFAAS analysis conditions enable us to determine Pt, Pd and Rh with good metrological characteristics. The concentrations of Pt, Pd and Rh in two samples of automobile exhaust catalysts were found in range of 0.00015-0.00050; 0.170-0.189; 0.0180-0.0210wt%, respectively. The relative standard deviation obtained by HR CS GFAAS was not more than 5%. Limits of detection by HR CS GFAAS achieved were 6.2·10(-6)wt% for Pt, 1.8·10(-6)wt% for Pd, and 3.4·10(-6)wt% for Rh. Limits of determination achieved by HR CS GFAAS were 1.1·10(-5)wt% for Pt, 6.9·10(-5)wt% for Pd, and 8.3·10(-5)wt% for Rh. To control the accuracy of PGM in sorption concentrates by HR CS GFAAS method, it was appropriate to conduct an inter-method comparative experiment. The

  14. Stress analysis and deformation prediction of sheet metal workpieces based on finite element simulation

    Directory of Open Access Journals (Sweden)

    Ren Penghao

    2017-01-01

    Full Text Available After aluminum alloy sheet metal parts machining, the residual stress release will cause a large deformation. To solve this problem, this paper takes a aluminum alloy sheet aerospace workpiece as an example, establishes the theoretical model of elastic deformation and the finite element model, and places quantitative initial stress in each element of machining area, analyses stress release simulation and deformation. Through different initial stress release simulative analysis of deformation of the workpiece, a linear relationship between initial stress and deformation is found; Through simulative analysis of coupling direction-stress release, the superposing relationship between the deformation caused by coupling direction-stress and the deformation caused by single direction stress is found. The research results provide important theoretical support for the stress threshold setting and deformation controlling of the workpieces in the production practice.

  15. Extension technology of store ability of spent fuel

    International Nuclear Information System (INIS)

    1991-05-01

    It is the introduction of the extension technology of store ability of spent fuel including metal store cask, transport and store cask, concrete cask, NUHOMS and MVDS. It explains of technology of recombination of spent fuel including the purpose and real application, demonstration, presumption of expense, major interesting issue and the present condition of relevant licences permit and approvals.

  16. Spent nuclear fuel storage

    International Nuclear Information System (INIS)

    Romanato, Luiz Sergio

    2005-01-01

    When a country becomes self-sufficient in part of the nuclear cycle, as production of fuel that will be used in nuclear power plants for energy generation, it is necessary to pay attention for the best method of storing the spent fuel. Temporary storage of spent nuclear fuel is a necessary practice and is applied nowadays all over the world, so much in countries that have not been defined their plan for a definitive repository, as well for those that already put in practice such storage form. There are two main aspects that involve the spent fuels: one regarding the spent nuclear fuel storage intended to reprocessing and the other in which the spent fuel will be sent for final deposition when the definitive place is defined, correctly located, appropriately characterized as to several technical aspects, and licentiate. This last aspect can involve decades of studies because of the technical and normative definitions at a given country. In Brazil, the interest is linked with the storage of spent fuels that will not be reprocessed. This work analyses possible types of storage, the international panorama and a proposal for future construction of a spent nuclear fuel temporary storage place in the country. (author)

  17. Simulated Performance of the Integrated Passive Neutron Albedo Reactivity and Self-Interrogation Neutron Resonance Densitometry Detector Designed for Spent Fuel Measurement at the Fugen Reactor in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Ulrich, Timothy J. II [Los Alamos National Laboratory; Lafleur, Adrienne M. [Los Alamos National Laboratory; Menlove, Howard O. [Los Alamos National Laboratory; Swinhoe, Martyn T. [Los Alamos National Laboratory; Tobin, Stephen J. [Los Alamos National Laboratory; Seya, Michio [Los Alamos National Laboratory; Bolind, Alan M. [Los Alamos National Laboratory

    2012-07-16

    An integrated nondestructive assay instrument, which combined the Passive Neutron Albedo Reactivity (PNAR) and the Self-Interrogation Neutron Resonance Densitometry (SINRD) techniques, is the research focus for a collaborative effort between Los Alamos National Laboratory (LANL) and the Japanese Atomic Energy Agency as part of the Next Generation Safeguard Initiative. We will quantify the anticipated performance of this experimental system in two physical environments: (1) At LANL we will measure fresh Low Enriched Uranium (LEU) assemblies for which the average enrichment can be varied from 0.2% to 3.2% and for which Gd laced rods will be included. (2) At Fugen we will measure spent Mixed Oxide (MOX-B) and LEU spent fuel assemblies from the heavy water moderated Fugen reactor. The MOX-B assemblies will vary in burnup from {approx}3 GWd/tHM to {approx}20 GWd/tHM while the LEU assemblies ({approx}1.9% initial enrichment) will vary from {approx}2 GWd/tHM to {approx}7 GWd/tHM. The estimated count rates will be calculated using MCNPX. These preliminary results will help the finalization of the hardware design and also serve a guide for the experiment. The hardware of the detector is expected to be fabricated in 2012 with measurements expected to take place in 2012 and 2013. This work is supported by the Next Generation Safeguards Initiative, Office of Nuclear Safeguards and Security, National Nuclear Security Administration.

  18. Integrated simulation of continuous-scale and discrete-scale radiative transfer in metal foams

    Science.gov (United States)

    Xia, Xin-Lin; Li, Yang; Sun, Chuang; Ai, Qing; Tan, He-Ping

    2018-06-01

    A novel integrated simulation of radiative transfer in metal foams is presented. It integrates the continuous-scale simulation with the direct discrete-scale simulation in a single computational domain. It relies on the coupling of the real discrete-scale foam geometry with the equivalent continuous-scale medium through a specially defined scale-coupled zone. This zone holds continuous but nonhomogeneous volumetric radiative properties. The scale-coupled approach is compared to the traditional continuous-scale approach using volumetric radiative properties in the equivalent participating medium and to the direct discrete-scale approach employing the real 3D foam geometry obtained by computed tomography. All the analyses are based on geometrical optics. The Monte Carlo ray-tracing procedure is used for computations of the absorbed radiative fluxes and the apparent radiative behaviors of metal foams. The results obtained by the three approaches are in tenable agreement. The scale-coupled approach is fully validated in calculating the apparent radiative behaviors of metal foams composed of very absorbing to very reflective struts and that composed of very rough to very smooth struts. This new approach leads to a reduction in computational time by approximately one order of magnitude compared to the direct discrete-scale approach. Meanwhile, it can offer information on the local geometry-dependent feature and at the same time the equivalent feature in an integrated simulation. This new approach is promising to combine the advantages of the continuous-scale approach (rapid calculations) and direct discrete-scale approach (accurate prediction of local radiative quantities).

  19. Physical properties of Pd and Al transition metals and Pd-Al binary metal alloy investigated by using molecular dynamics simulation

    International Nuclear Information System (INIS)

    Coruh, A.; Uludogan, M.; Tomak, M.; Cagin, T.

    2002-01-01

    In this study, physical properties, such as Pair Distribution Function g(r), Structure Factor S(k)''1'',''4, Diffusion Coefficient D''2''.''4, Intermediate Scattering function S(k,t)''3'',''4 and Dynamical Structure Factor S(k,w)''3'',''4 of some transition metals and metal alloys are investigated by using molecular dynamics simulation method. The simulation is specified for Pd, Al transition metals and Pd-Al binary metal alloys in the liquid form for different concentrations and at various temperatures by using Quantum Sutton-Chen (Q-SC) inter atomic potential. Intermediate scattering function and dynamical structure factor are calculated for various values of wave vector k. Results are in good agreement with published data''1'',''3'',''4

  20. Benchmark measurements and simulations of dose perturbations due to metallic spheres in proton beams

    International Nuclear Information System (INIS)

    Newhauser, Wayne D.; Rechner, Laura; Mirkovic, Dragan; Yepes, Pablo; Koch, Nicholas C.; Titt, Uwe; Fontenot, Jonas D.; Zhang, Rui

    2013-01-01

    Monte Carlo simulations are increasingly used for dose calculations in proton therapy due to its inherent accuracy. However, dosimetric deviations have been found using Monte Carlo code when high density materials are present in the proton beamline. The purpose of this work was to quantify the magnitude of dose perturbation caused by metal objects. We did this by comparing measurements and Monte Carlo predictions of dose perturbations caused by the presence of small metal spheres in several clinical proton therapy beams as functions of proton beam range and drift space. Monte Carlo codes MCNPX, GEANT4 and Fast Dose Calculator (FDC) were used. Generally good agreement was found between measurements and Monte Carlo predictions, with the average difference within 5% and maximum difference within 17%. The modification of multiple Coulomb scattering model in MCNPX code yielded improvement in accuracy and provided the best overall agreement with measurements. Our results confirmed that Monte Carlo codes are well suited for predicting multiple Coulomb scattering in proton therapy beams when short drift spaces are involved. - Highlights: • We compared measurements and Monte Carlo predictions of dose perturbations caused by the metal objects in proton beams. • Different Monte Carlo codes were used, including MCNPX, GEANT4 and Fast Dose Calculator. • Good agreement was found between measurements and Monte Carlo simulations. • The modification of multiple Coulomb scattering model in MCNPX code yielded improved accuracy. • Our results confirmed that Monte Carlo codes are well suited for predicting multiple Coulomb scattering in proton therapy

  1. A guide for validation of FE-Simulations in bulk metal forming

    International Nuclear Information System (INIS)

    Tekkaya, A. Erman

    2005-01-01

    Numerical analysis of metal forming processes is an everyday practice in industry. Forming loads, material flow, forming defects such as underfills, laps and even cracks, stresses in dies and punches, as well as product properties like new hardness distribution, dimensional accuracies and residual stresses are predicted by numerical analysis and used for technology generation. Most of the numerical analysis is done by the finite element method made available for engineers and technicians by numerous by powerful commercial software packages. These software packages act as black-boxes and usually hide the complicated numerical procedures and even their crucial parameters from the applier. Therefore, the question arises during the industrial applications: how accurate is the simulation and how can the results can be assessed? The aim of this paper is to provide a guideline to assess the results of metal forming simulations. Although some ideas are valid for any metal forming process, bulk forming is the process concern. The paper will address firstly the possible sources of error in a finite element analysis of bulk forming processes. Then, some useful elementary knowledge will be summarized. Various levels of validation such as result and ability validation and assessment will be discussed. Finally, interpretation of results will be treated. In this content also some suggestions will be given. (author)

  2. Numerical simulation of systems of shear bands in ductile metal with inclusions

    Energy Technology Data Exchange (ETDEWEB)

    Plohr, JeeYeon N., E-mail: jplohr@lanl.gov; Plohr, Bradley J. [Los Alamos National Laboratory, Theoretical Division, Los Alamos, NM 87545 (United States)

    2016-02-15

    We develop a method for numerical simulations of high strain-rate loading of mesoscale samples of ductile metal with inclusions. Because of its small-scale inhomogeneity, the composite material is prone to localized shear deformation (adiabatic shear bands). This method employs the Generalized Method of Cells of Paley and Aboudi [Mech. Materials, vol. 14, pp. 127–139, 1992] to ensure that the micro mechanical behavior of the metal and inclusions is reflected properly in the behavior of the composite at the mesoscale. To find the effective plastic strain rate when shear bands are present, we extend and apply the analytic and numerical analysis of shear bands of Glimm, Plohr, and Sharp [Mech. Materials, vol. 24, pp. 31–41, 1996]. Our tests of the method focus on the stress/strain response in uniaxial-strain flow, both compressive and tensile, of depleted uranium metal containing silicon carbide inclusions. We use the Preston-Tonks-Wallace viscoplasticity model [J. Appl. Phys., vol. 93, pp. 211–220, 2003], which applies to the high strain-rate regime of an isotropic viscoplastic solid. In results, we verify the elevated temperature and thermal softening at shear bands in our simulations of pure DU and DU/SiC composites. We also note that in composites, due the asymmetry caused by the inclusions, shear band form at different times in different subcells. In particular, in the subcells near inclusions, shear band form much earlier than they do in pure DU.

  3. Numerical simulation of systems of shear bands in ductile metal with inclusions

    Directory of Open Access Journals (Sweden)

    JeeYeon N. Plohr

    2016-02-01

    Full Text Available We develop a method for numerical simulations of high strain-rate loading of mesoscale samples of ductile metal with inclusions. Because of its small-scale inhomogeneity, the composite material is prone to localized shear deformation (adiabatic shear bands. This method employs the Generalized Method of Cells of Paley and Aboudi [Mech. Materials, vol. 14, pp. 127–139, 1992] to ensure that the micro mechanical behavior of the metal and inclusions is reflected properly in the behavior of the composite at the mesoscale. To find the effective plastic strain rate when shear bands are present, we extend and apply the analytic and numerical analysis of shear bands of Glimm, Plohr, and Sharp [Mech. Materials, vol. 24, pp. 31–41, 1996]. Our tests of the method focus on the stress/strain response in uniaxial-strain flow, both compressive and tensile, of depleted uranium metal containing silicon carbide inclusions. We use the Preston-Tonks-Wallace viscoplasticity model [J. Appl. Phys., vol. 93, pp. 211–220, 2003], which applies to the high strain-rate regime of an isotropic viscoplastic solid. In results, we verify the elevated temperature and thermal softening at shear bands in our simulations of pure DU and DU/SiC composites. We also note that in composites, due the asymmetry caused by the inclusions, shear band form at different times in different subcells. In particular, in the subcells near inclusions, shear band form much earlier than they do in pure DU.

  4. Numerical simulation of systems of shear bands in ductile metal with inclusions

    Science.gov (United States)

    Plohr, Jeeyeon

    2017-06-01

    We develop a method for numerical simulations of high strain-rate loading of mesoscale samples of ductile metal with inclusions. Because of its small-scale inhomogeneity, the composite material is prone to localized shear deformation. This method employs the Generalized Method of Cells to ensure that the micro mechanical behavior of the metal and inclusions is reflected properly in the behavior of the composite at the mesoscale. To find the effective plastic strain rate when shear bands are present, we extend and apply the analytic and numerical analysis of shear bands of Glimm, Plohr, and Sharp. Our tests of the method focus on the stress/strain response in uniaxial-strain flow, both compressive and tensile, of depleted uranium metal containing silicon carbide inclusions. In results, we verify the elevated temperature and thermal softening at shear bands in our simulations of pure DU and DU/SiC composites. We also note that in composites, due the asymmetry caused by the inclusions, shear band form at different times in different subcells. In particular, in the subcells near inclusions, shear band form much earlier than they do in pure DU.

  5. Heaters to simulate fuel pins for heat transfer tests in single-phase liquid-metal-flow

    International Nuclear Information System (INIS)

    Casal, V.; Graf, E.; Hartmann, W.

    1976-09-01

    The development of heaters for thermal simulation of the fuel elements of liquid metal cooled fast breeder reactors (SNR) is reported. Beginning with the experimental demands various heating methods are discussed for thermodynamic investigations of the heat transfer in liquid metals. Then a preferred heater rod is derived to simulate the fuel pins of a SNR. Finally it is reported on the fabrication and the operation practice. (orig.) [de

  6. Leaching of copper and zinc from spent antifouling paint particles

    International Nuclear Information System (INIS)

    Singh, Nimisha; Turner, Andrew

    2009-01-01

    Leaching of Cu and Zn from a composite of spent antifouling paint particles, containing about 300 mg g -1 and 110 mg g -1 of the respective metals, was studied in batch experiments. For a given set of simulated environmental conditions, release of Cu was independent of paint particle concentration due to attainment of pseudo-saturation, but Zn was less constrained by solubility effects and release increased with increasing particle concentration. Leaching of Cu increased but Zn decreased with increasing salinity, consistent with mechanisms governing the dissolution of Cu 2 O in the presence of chloride and Zn acrylates in the presence of seawater cations. Because of complex reaction kinetics and the presence of calcium carbonate in the paint matrix, metal leaching appeared to be greater at 4 deg. C than 19 deg. C under many conditions. These findings have important environmental and biological implications regarding the deliberate or inadvertent disposal of antifouling paint residues. - Copper and zinc are readily leached from particles of spent antifouling paint under a range of environmental conditions

  7. Leaching of copper and zinc from spent antifouling paint particles

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Nimisha [School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom); Turner, Andrew [School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom)], E-mail: aturner@plymouth.ac.uk

    2009-02-15

    Leaching of Cu and Zn from a composite of spent antifouling paint particles, containing about 300 mg g{sup -1} and 110 mg g{sup -1} of the respective metals, was studied in batch experiments. For a given set of simulated environmental conditions, release of Cu was independent of paint particle concentration due to attainment of pseudo-saturation, but Zn was less constrained by solubility effects and release increased with increasing particle concentration. Leaching of Cu increased but Zn decreased with increasing salinity, consistent with mechanisms governing the dissolution of Cu{sub 2}O in the presence of chloride and Zn acrylates in the presence of seawater cations. Because of complex reaction kinetics and the presence of calcium carbonate in the paint matrix, metal leaching appeared to be greater at 4 deg. C than 19 deg. C under many conditions. These findings have important environmental and biological implications regarding the deliberate or inadvertent disposal of antifouling paint residues. - Copper and zinc are readily leached from particles of spent antifouling paint under a range of environmental conditions.

  8. Electrodialytic decontamination of spent ion exchange resins

    International Nuclear Information System (INIS)

    Nott, B.R.

    1982-01-01

    Development of a novel electrodialytic decontamination process for the selective removal of radioactive Cs from spent ion exchange resins containing large amounts of Li is described. The process involves passage of a dc electric current through a bed of the spent ion exchange resin in a specially designed electrodialytic cell. The radiocesium so removed from a volume of the spent resin is concentrated onto a much smaller volume of a Cs selective sorbent to achieve a significant radioactive waste volume reduction. Technical feasibility of the electrodialytic resin decontamination process has been demonstrated on a bench scale with a batch of simulated spent ion exchange resin and using potassium cobalt ferrocyanide as the Cs selective sorbent. A volume reduction factor between 10 and 17 has been estimated. The process appears to be economically attractive. Improvements in process economics can be expected from optimization of the process. Other possible applications of the EDRD process have been identified

  9. Pyrochemical processing of DOE spent nuclear fuel

    International Nuclear Information System (INIS)

    Laidler, J.J.

    1995-01-01

    A compact, efficient method for conditioning spent nuclear fuel is under development. This method, known as pyrochemical processing, or open-quotes pyroprocessing,close quotes provides a separation of fission products from the actinide elements present in spent fuel and further separates pure uranium from the transuranic elements. The process can facilitate the timely and environmentally-sound treatment of the highly diverse collection of spent fuel currently in the inventory of the United States Department of Energy (DOE). The pyroprocess utilizes elevated-temperature processes to prepare spent fuel for fission product separation; that separation is accomplished by a molten salt electrorefining step that provides efficient (>99.9%) separation of transuranics. The resultant waste forms from the pyroprocess, are stable under envisioned repository environment conditions and highly leach-resistant. Treatment of any spent fuel type produces a set of common high-level waste forms, one a mineral and the other a metal alloy, that can be readily qualified for repository disposal and avoid the substantial costs that would be associated with the qualification of the numerous spent fuel types included in the DOE inventory

  10. Development of advanced spent fuel management process

    International Nuclear Information System (INIS)

    Park, Seong Won; Shin, Y. J.; Cho, S. H.

    2004-03-01

    The research on spent fuel management focuses on the maximization of the disposal efficiency by a volume reduction, the improvement of the environmental friendliness by the partitioning and transmutation of the long lived nuclides, and the recycling of the spent fuel for an efficient utilization of the uranium source. In the second phase which started in 2001, the performance test of the advanced spent fuel management process consisting of voloxidation, reduction of spent fuel and the lithium recovery process has been completed successfully on a laboratory scale. The world-premier spent fuel reduction hot test of a 5 kgHM/batch has been performed successfully by joint research with Russia and the valuable data on the actinides and FPs material balance and the characteristics of the metal product were obtained with experience to help design an engineering scale reduction system. The electrolytic reduction technology which integrates uranium oxide reduction in a molten LiCl-Li 2 O system and Li 2 O electrolysis is developed and a unique reaction system is also devised. Design data such as the treatment capacity, current density and mass transfer behavior obtained from the performance test of a 5 kgU/batch electrolytic reduction system pave the way for the third phase of the hot cell demonstration of the advanced spent fuel management technology

  11. Computer Simulation of the Formation of Non-Metallic Precipitates During a Continuous Casting of Steel

    Directory of Open Access Journals (Sweden)

    Kalisz D.

    2016-03-01

    Full Text Available The authors own computer software, based on the Ueshima mathematical model with taking into account the back diffusion, determined from the Wołczyński equation, was developed for simulation calculations. The applied calculation procedure allowed to determine the chemical composition of the non-metallic phase in steel deoxidised by means of Mn, Si and Al, at the given cooling rate. The calculation results were confirmed by the analysis of samples taken from the determined areas of the cast ingot. This indicates that the developed computer software can be applied for designing the steel casting process of the strictly determined chemical composition and for obtaining the required non-metallic precipitates.

  12. Molecular dynamics simulations of the structure evolutions of Cu-Zr metallic glasses under irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Lang, Lin [College of Materials Science and Engineering, Hunan University, Changsha 410082 (China); Department of Applied Physics, School of Physics and Electronics, Hunan University, Changsha 410082 (China); Tian, Zean; Xiao, Shifang [Department of Applied Physics, School of Physics and Electronics, Hunan University, Changsha 410082 (China); Deng, Huiqiu, E-mail: hqdeng@hnu.edu.cn [Department of Applied Physics, School of Physics and Electronics, Hunan University, Changsha 410082 (China); Ao, Bingyun [Science and Technology on Surface Physics and Chemistry Laboratory, Mianyang 621907 (China); Chen, Piheng, E-mail: chenpiheng@caep.cn [Science and Technology on Surface Physics and Chemistry Laboratory, Mianyang 621907 (China); Hu, Wangyu [College of Materials Science and Engineering, Hunan University, Changsha 410082 (China)

    2017-02-15

    Highlights: • The structural evolution of Cu{sub 64.5}Zr{sub 35.5} MG under irradiation was studied. • The structure clusters were analyzed using the LSCA method. • Most of these radiation damages have been self-recovered quickly. - Abstract: Molecular dynamics simulations have been performed to investigate the structural evolution of Cu{sub 64.5}Zr{sub 35.5} metallic glasses under irradiation. The largest standard cluster analysis (LSCA) method was used to quantify the microstructure within the collision cascade regions. It is found that the majority of clusters within the collision cascade regions are full and defective icosahedrons. Not only the smaller structures (common neighbor subcluster) but also primary clusters greatly changed during the collision cascades; while most of these radiation damages self-recover quickly in the following quench states. These findings indicate the Cu-Zr metallic glasses have excellent irradiation-resistance properties.

  13. Simulating solidification in metals at high pressure: The drive to petascale computing

    International Nuclear Information System (INIS)

    Streitz, Frederick H; Glosli, James N; Patel, Mehul V; Chan, Bor; Yates, Robert K; Supinski, Bronis R de; Sexton, James; Gunnels, John A

    2006-01-01

    We investigate solidification in metal systems ranging in size from 64,000 to 524,288,000 atoms on the IBM BlueGene/L computer at LLNL. Using the newly developed ddcMD code, we achieve performance rates as high as 103 TFlops, with a performance of 101.7 TFlop sustained over a 7 hour run on 131,072 cpus. We demonstrate superb strong and weak scaling. Our calculations are significant as they represent the first atomic-scale model of metal solidification to proceed, without finite size effects, from spontaneous nucleation and growth of solid out of the liquid, through the coalescence phase, and into the onset of coarsening. Thus, our simulations represent the first step towards an atomistic model of nucleation and growth that can directly link atomistic to mesoscopic length scales

  14. Evaluation of Package Stress during Temperature Cycling using Metal Deformation Measurement and FEM Simulation

    International Nuclear Information System (INIS)

    Hoeglauer, J.; Bohm, C.; Otremba, R.; Maerz, J.; Nelle, P.; Stecher, M.; Alpern, P.

    2006-01-01

    Plastic encapsulated devices that are exposed to Temperature Cycling (TC) tests undergo an excessive mechanical stress due to different Coefficients of Thermal Expansion (CTE) of the various materials used in the system. Especially in the corners of the die, passivation cracks and shifted metal lines can be observed, which demonstrates an increasing mechanical stress from chip center to the corners of the die. This effect has been known for a long time. This paper presents a simple measurement technique to quantify the mechanical shear stress at the chip-Mold Compound (MC) interface by measuring the deformation of a periodical metal structure. Based on this deformation measurement, we evaluated the stress distribution within the package, and the influence of different parameters such as number of cycles and chip size. Furthermore, these experimental results were compared with FEM simulation, and showed good agreement but could not account in all cases for the total amount of observed shift

  15. Compaction simulation of nano-crystalline metals with molecular dynamics analysis

    Directory of Open Access Journals (Sweden)

    Khoei A.R.

    2016-01-01

    Full Text Available The molecular-dynamics analysis is presented for 3D compaction simulation of nano-crystalline metals under uniaxial compaction process. The nano-crystalline metals consist of nickel and aluminum nano-particles, which are mixed with specified proportions. The EAM pair-potential is employed to model the formation of nano-particles at different temperatures, number of nano-particles, and mixing ratio of Ni and Al nano-particles to form the component into the shape of a die. The die-walls are modeled using the Lennard-Jones inter-atomic potential between the atoms of nano-particles and die-walls. The forming process is model in uniaxial compression, which is simulated until the full-dense condition is attained at constant temperature. Numerical simulations are performed by presenting the densification of nano-particles at different deformations and distribution of dislocations. Finally, the evolutions of relative density with the pressure as well as the stress-strain curves are depicted during the compaction process.

  16. Spent sulfite liquor developments

    Energy Technology Data Exchange (ETDEWEB)

    Black, H H

    1958-01-01

    A review of methods of utilizing spent sulfite liquor, including evaporation and burning, fermentation to produce yeast or alcohol, production of vanillin and lignosulfonates, and use as a roadbinder.

  17. Spent fuel workshop'2002

    International Nuclear Information System (INIS)

    Poinssot, Ch.

    2002-01-01

    This document gathers the transparencies of the presentations given at the 2002 spent fuel workshop: Session 1 - Research Projects: Overview on the IN CAN PROCESSES European project (M. Cowper), Overview on the SPENT FUEL STABILITY European project (C. Poinssot), Overview on the French R and D project on spent fuel long term evolution, PRECCI (C. Poinssot); Session 2 - Spent Fuel Oxidation: Oxidation of uranium dioxide single crystals (F. Garrido), Experimental results on SF oxidation and new modeling approach (L. Desgranges), LWR spent fuel oxidation - effects of burn-up and humidity (B. Hanson), An approach to modeling CANDU fuel oxidation under dry storage conditions (P. Taylor); Session 3 - Spent Fuel Dissolution Experiments: Overview on high burnup spent fuel dissolution studies at FZK/INE (A. Loida), Results on the influence of hydrogen on spent fuel leaching (K. Spahiu), Leaching of spent UO 2 fuel under inert and reducing conditions (Y. Albinsson), Fuel corrosion investigation by electrochemical techniques (D. Wegen), A reanalysis of LWR spent fuel flow through dissolution tests (B. Hanson), U-bearing secondary phases formed during fuel corrosion (R. Finch), The near-field chemical conditions and spent fuel leaching (D. Cui), The release of radionuclides from spent fuel in bentonite block (S.S. Kim), Trace actinide behavior in altered spent fuel (E. Buck, B. Hanson); Session 4 - Radiolysis Issues: The effect of radiolysis on UO 2 dissolution determined from electrochemical experiments with 238 Pu doped UO 2 M. Stroess-Gascoyne (F. King, J.S. Betteridge, F. Garisto), doped UO 2 studies (V. Rondinella), Preliminary results of static and dynamic dissolution tests with α doped UO 2 in Boom clay conditions (K. Lemmens), Studies of the behavior of UO 2 / water interfaces under He 2+ beam (C. Corbel), Alpha and gamma radiolysis effects on UO 2 alteration in water (C. Jegou), Behavior of Pu-doped pellets in brines (M. Kelm), On the potential catalytic behavior of

  18. Spent fuel and high level waste: Chemical durability and performance under simulated repository conditions. Results of a coordinated research project 1998-2004

    International Nuclear Information System (INIS)

    2007-10-01

    This publication contains the results of an IAEA Coordinated Research Project (CRP). It provides a basis for understanding the potential interactions of waste form and repository environment, which is necessary for the development of the design and safety case for deep disposal. Types of high level waste matrices investigated include spent fuel, glasses and ceramics. Of particular interest are the experimental results pertaining to ceramic forms such as SYNROC. This publication also outlines important areas for future work, namely, standardized, collaborative experimental protocols for package-release studies, structured development and calibration of predictive models linking the performance of packaged waste and the repository environment, and studies of the long term behaviour of the wastes, including active waste samples

  19. Development of advanced spent fuel management process

    International Nuclear Information System (INIS)

    Shin, Young Joon; Cho, S. H.; You, G. S.

    2001-04-01

    Currently, the economic advantage of any known approach to the back end fuel cycle of a nuclear power reactor has not been well established. Thus the long term storage of the spent fuel in a safe manner is one of the important issues to be resolved in countries where the nuclear power has a relatively heavy weight in power production of that country. At KAERI, as a solution to this particular issue midterm storage of the spent fuel, an alternative approach has been developed. This approach includes the decladding and pulverization process of the spent PWR fuel rod, the reducing process from the uranium oxide to a metallic uranium powder using Li metal in a LiCl salt, the continuous casting process of the reduced metal, and the recovery process of Li from mixed salts by the electrolysis. We conducted the laboratory scale tests of each processes for the technical feasibility and determination for the operational conditions for this approach. Also, we performed the theoretical safety analysis and conducted integral tests for the equipment integration through the Mock-up facility with non-radioactive samples. There were no major issues in the approach, however, material incompatibility of the alkaline metal and oxide in a salt at a high temperature and the reactor that contains the salt became a show stopper of the process. Also the difficulty of the clear separation of the salt with metals reduced from the oxide became a major issue

  20. Experimental and Monte Carlo simulated spectra of a liquid-metal-jet x-ray source

    International Nuclear Information System (INIS)

    Marziani, M.; Gambaccini, M.; Di Domenico, G.; Taibi, A.; Cardarelli, P.

    2014-01-01

    A prototype x-ray system based on a liquid-metal-jet anode was evaluated within the framework of the LABSYNC project. The generated spectrum was measured using a CZT-based spectrometer and was compared with spectra simulated by three Monte Carlo codes: MCNPX, PENELOPE and EGS5. Notable differences in the simulated spectra were found. These are mainly attributable to differences in the models adopted for the electron-impact ionization cross section. The simulation that more closely reproduces the experimentally measured spectrum was provided by PENELOPE. - Highlights: • The x-ray spectrum of a liquid-jet x-ray anode was measured with a CZT spectrometer. • Results were compared with Monte Carlo simulations using MCNPX, PENELOPE, EGS5. • Notable differences were found among the Monte Carlo simulated spectra. • The key role was played by the electron-impact ionization cross-section model used. • The experimentally measured spectrum was closely reproduced by the PENELOPE code

  1. Conditioning of spent mercury by amalgamation

    International Nuclear Information System (INIS)

    Yim, S. P.; Shon, J. S.; An, B. G.; Lee, H. J.; Lee, J. W.; Ji, C. G.; Kim, S. H.; Yoon, J. H.; Yang, M. S.

    2002-01-01

    Solidification by amalgamation was performed to immobilize and stabilize the liquid spent mercury. First, the appropriate metal and alloy which can convert liquid mercury into a solid form of amalgam were selected through initial tests. The amalgam form, formulated in optimum composition, was characterized and subjected to performance tests including compressive strength, water immersion, leachability and initial vaporization rate to evaluate mechanical integrity, durability and leaching properties. Finally, bench scale amalgamation trial was conducted with about 1 kg of spent mercury to verify the feasibility of amalgamation method

  2. Near-ideal strength in metal nanotubes revealed by atomistic simulations

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Mingfei; Xiao, Fei [Department of Materials Science, Fudan University, 220 Handan Road, Shanghai 200433 (China); Deng, Chuang, E-mail: dengc@ad.umanitoba.ca [Department of Mechanical and Manufacturing Engineering, The University of Manitoba, 15Gillson Street, Winnipeg, Manitoba R3T 5V6 (Canada)

    2013-12-02

    Here we report extraordinary mechanical properties revealed by atomistic simulations in metal nanotubes with hollow interior that have been long overlooked. Particularly, the yield strength in [1 1 1] Au nanotubes is found to be up to 60% higher than the corresponding solid Au nanowire, which approaches the theoretical ideal strength in Au. Furthermore, a remarkable transition from sharp to smooth yielding is observed in Au nanotubes with decreasing wall thickness. The ultrahigh tensile strength in [1 1 1] Au nanotube might originate from the repulsive image force exerted by the interior surface against dislocation nucleation from the outer surface.

  3. Optimal fabrication processes for unidirectional metal-matrix composites: A computational simulation

    Science.gov (United States)

    Saravanos, D. A.; Murthy, P. L. N.; Morel, M.

    1990-01-01

    A method is proposed for optimizing the fabrication process of unidirectional metal matrix composites. The temperature and pressure histories are optimized such that the residual microstresses of the composite at the end of the fabrication process are minimized and the material integrity throughout the process is ensured. The response of the composite during the fabrication is simulated based on a nonlinear micromechanics theory. The optimal fabrication problem is formulated and solved with non-linear programming. Application cases regarding the optimization of the fabrication cool-down phases of unidirectional ultra-high modulus graphite/copper and silicon carbide/titanium composites are presented.

  4. Optimal fabrication processes for unidirectional metal-matrix composites - A computational simulation

    Science.gov (United States)

    Saravanos, D. A.; Murthy, P. L. N.; Morel, M.

    1990-01-01

    A method is proposed for optimizing the fabrication process of unidirectional metal matrix composites. The temperature and pressure histories are optimized such that the residual microstresses of the composite at the end of the fabrication process are minimized and the material integrity throughout the process is ensured. The response of the composite during the fabrication is simulated based on a nonlinear micromechanics theory. The optimal fabrication problem is formulated and solved with nonlinear programming. Application cases regarding the optimization of the fabrication cool-down phases of unidirectional ultra-high modulus graphite/copper and silicon carbide/titanium composites are presented.

  5. Multiscale simulations in face-centered cubic metals: A method coupling quantum mechanics and molecular mechanics

    International Nuclear Information System (INIS)

    Yu Xiao-Xiang; Wang Chong-Yu

    2013-01-01

    An effective multiscale simulation which concurrently couples the quantum-mechanical and molecular-mechanical calculations based on the position continuity of atoms is presented. By an iterative procedure, the structure of the dislocation core in face-centered cubic metal is obtained by first-principles calculation and the long-range stress is released by molecular dynamics relaxation. Compared to earlier multiscale methods, the present work couples the long-range strain to the local displacements of the dislocation core in a simpler way with the same accuracy. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  6. Detecting Structural Features in Metallic Glass via Synchrotron Radiation Experiments Combined with Simulations

    Directory of Open Access Journals (Sweden)

    Gu-Qing Guo

    2015-11-01

    Full Text Available Revealing the essential structural features of metallic glasses (MGs will enhance the understanding of glass-forming mechanisms. In this work, a feasible scheme is provided where we performed the state-of-the-art synchrotron-radiation based experiments combined with simulations to investigate the microstructures of ZrCu amorphous compositions. It is revealed that in order to stabilize the amorphous state and optimize the topological and chemical distribution, besides the icosahedral or icosahedral-like clusters, other types of clusters also participate in the formation of the microstructure in MGs. This cluster-level co-existing feature may be popular in this class of glassy materials.

  7. Advanced numerical simulation based on a non-local micromorphic model for metal forming processes

    Directory of Open Access Journals (Sweden)

    Diamantopoulou Evangelia

    2016-01-01

    Full Text Available An advanced numerical methodology is developed for metal forming simulation based on thermodynamically-consistent nonlocal constitutive equations accounting for various fully coupled mechanical phenomena under finite strain in the framework of micromorphic continua. The numerical implementation into ABAQUS/Explicit is made for 2D quadrangular elements thanks to the VUEL users’ subroutine. Simple examples with presence of a damaged area are made in order to show the ability of the proposed methodology to describe the independence of the solution from the space discretization.

  8. Numerical simulation on single bubble rising behavior in liquid metal using moving particle semi-implicit method

    International Nuclear Information System (INIS)

    Zuo Juanli; Tian Wenxi; Qiu Suizheng; Chen Ronghua; Su Guanghui

    2011-01-01

    The gas-lift pump in liquid metal cooling fast reactor (LMFR) is an innovational conceptual design to enhance the natural circulation ability of reactor core. The two-phase flow character of gas-liquid metal makes significant improvement of the natural circulation capacity and reactor safety. In present basic study, the rising behavior of a single nitrogen bubble in five kinds of liquid metals (lead bismuth alloy, liquid kalium, sodium, potassium sodium alloy and lithium lead alloy) was numerically simulated using moving particle semi-implicit (MPS) method. The whole growing process of single nitrogen bubble in liquid metal was captured. The bubble shape and rising speed of single nitrogen bubble in each liquid metal were compared. The comparison between simulation results using MPS method and Grace graphical correlation shows a good agreement. (authors)

  9. Some consistency requirements on thermophysicsal properties used in metal processing simulations

    International Nuclear Information System (INIS)

    Bertran, L.A.

    1992-01-01

    Stresses and deformations during metal processing are being simulated from room temperature to melting. This requires that thermophysical data be obtained at high temperature, an expensive task even when the sampling of elevated temperatures is quite sparse. Use of constitutive models with complex inelastic responses along with sparsely sampled data increases uncertainties as to physical meaning of simulation results. Identification of dependences among the physical parameters as a function of temperature offer increased confidence and lower experimental costs. In this paper examples for bilinear stress-strain materials are given (e.g., yield strain, the ratio of yield stress to Young's modulus, should be continuous where the coefficient of thermal expansion is continuous in T) and similar constraints are discussed for more complex constitutive responses

  10. Fully-Coupled Thermo-Electrical Modeling and Simulation of Transition Metal Oxide Memristors

    Energy Technology Data Exchange (ETDEWEB)

    Mamaluy, Denis [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Gao, Xujiao [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Tierney, Brian David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Marinella, Matthew [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Mickel, Patrick [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Tierney, Brian D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-11-01

    Transition metal oxide (TMO) memristors have recently attracted special attention from the semiconductor industry and academia. Memristors are one of the strongest candidates to replace flash memory, and possibly DRAM and SRAM in the near future. Moreover, memristors have a high potential to enable beyond-CMOS technology advances in novel architectures for high performance computing (HPC). The utility of memristors has been demonstrated in reprogrammable logic (cross-bar switches), brain-inspired computing and in non-CMOS complementary logic. Indeed, the potential use of memristors as logic devices is especially important considering the inevitable end of CMOS technology scaling that is anticipated by 2025. In order to aid the on-going Sandia memristor fabrication effort with a memristor design tool and establish a clear physical picture of resistance switching in TMO memristors, we have created and validated with experimental data a simulation tool we name the Memristor Charge Transport (MCT) Simulator.

  11. Atomistic simulation study of the shear-band deformation mechanism in Mg-Cu metallic glasses

    DEFF Research Database (Denmark)

    Bailey, Nicholas; Schiøtz, Jakob; Jacobsen, Karsten Wedel

    2006-01-01

    We have simulated plastic deformation of a model Mg-Cu metallic glass in order to study shear banding. In uniaxial tension, we find a necking instability occurs rather than shear banding. We can force the latter to occur by deforming in plane strain, forbidding the change of length in one...... of the transverse directions. Furthermore, in most of the simulations a notch is used to initiate shear bands, which lie at a 45 degrees angle to the tensile loading direction. The shear bands are characterized by the Falk and Langer local measure of plastic deformation D-min(2), averaged here over volumes...... observe a slight decrease in density, up to 1%, within the shear band, which is consistent with notions of increased free volume or disorder within a plastically deforming amorphous material....

  12. Safe transport of spent fuels after long-term storage

    International Nuclear Information System (INIS)

    Aritomi, M.; Takeda, T.; Ozaki, S.

    2004-01-01

    Considering the scarcity of energy resources in Japan, a nuclear energy policy pertaining to the spent fuel storage has been adopted. The nuclear energy policy sets the rules that spent fuels generated from LWRs shall be reprocessed and that plutonium and unburnt uranium shall be recovered and reused. For this purpose, a reprocessing plant, which has a reprocessing capability of 800 ton/yr, is under construction at Rokkasho Village. However, it is anticipated that the start of its operation will be delayed. In addition, the amount of spent fuels generated from nuclear power plants exceeds its reprocessing capability. Therefore, the establishment of storage technology for spent fuels becomes an urgent problem in Japan in order to continue smoothly the LWR operations. In this paper, the background of nuclear power generation in Japan is introduced at first. Next, the policy of spent fuel storage in Japan and circumstances surrounding the spent fuels in Japan are mentioned. Furthermore, the major subjects for discussions to settle and improve 'Standard for Safety Design and Inspection of Metal Casks for Spent Fuel Interim Storage Facility' in Atomic Energy Society of Japan are discussed, such as the integrity of fuel cladding, basket, shielding material and metal gasket for the long term storage for achieving safe transport of spent fuels after the storage. Finally, solutions to the unsolved subject in establishing the spent fuel interim storage technologies ase introduced accordingly

  13. Advances in model-based software for simulating ultrasonic immersion inspections of metal components

    Science.gov (United States)

    Chiou, Chien-Ping; Margetan, Frank J.; Taylor, Jared L.; Engle, Brady J.; Roberts, Ronald A.

    2018-04-01

    Under the sponsorship of the National Science Foundation's Industry/University Cooperative Research Center at ISU, an effort was initiated in 2015 to repackage existing research-grade software into user-friendly tools for the rapid estimation of signal-to-noise ratio (SNR) for ultrasonic inspections of metals. The software combines: (1) a Python-based graphical user interface for specifying an inspection scenario and displaying results; and (2) a Fortran-based engine for computing defect signals and backscattered grain noise characteristics. The later makes use the Thompson-Gray measurement model for the response from an internal defect, and the Thompson-Margetan independent scatterer model for backscattered grain noise. This paper, the third in the series [1-2], provides an overview of the ongoing modeling effort with emphasis on recent developments. These include the ability to: (1) treat microstructures where grain size, shape and tilt relative to the incident sound direction can all vary with depth; and (2) simulate C-scans of defect signals in the presence of backscattered grain noise. The simulation software can now treat both normal and oblique-incidence immersion inspections of curved metal components. Both longitudinal and shear-wave inspections are treated. The model transducer can either be planar, spherically-focused, or bi-cylindrically-focused. A calibration (or reference) signal is required and is used to deduce the measurement system efficiency function. This can be "invented" by the software using center frequency and bandwidth information specified by the user, or, alternatively, a measured calibration signal can be used. Defect types include flat-bottomed-hole reference reflectors, and spherical pores and inclusions. Simulation outputs include estimated defect signal amplitudes, root-mean-square values of grain noise amplitudes, and SNR as functions of the depth of the defect within the metal component. At any particular depth, the user can view

  14. Modelling and Simulation of Tensile Fracture in High Velocity Compacted Metal Powder

    International Nuclear Information System (INIS)

    Jonsen, P.; Haeggblad, H.-A.

    2007-01-01

    In cold uniaxial powder compaction, powder is formed into a desired shape with rigid tools and a die. After pressing, but before sintering, the compacted powder is called green body. A critical property in the metal powder pressing process is the mechanical properties of the green body. Beyond a green body free from defects, desired properties are high strength and uniform density. High velocity compaction (HVC) using a hydraulic operated hammer is a production method to form powder utilizing a shock wave. Pre-alloyed water atomised iron powder has been HVC-formed into circular discs with high densities. The diametral compression test also called the Brazilian disc test is an established method to measure tensile strength in low strength material like e.g. rock, concrete, polymers and ceramics. During the test a thin disc is compressed across the diameter to failure. The compression induces a tensile stress perpendicular to the compressed diameter. In this study the test have been used to study crack initiation and the tensile fracture process of HVC-formed metal powder discs with a relative density of 99%. A fictitious crack model controlled by a stress versus crack-width relationship is utilized to model green body cracking. Tensile strength is used as a failure condition and limits the stress in the fracture interface. The softening rate of the model is obtained from the corresponding rate of the dissipated energy. The deformation of the powder material is modelled with an elastic-plastic Cap model. The characteristics of the tensile fracture development of the central crack in a diametrically loaded specimen is numerically studied with a three dimensional finite element simulation. Results from the finite element simulation of the diametral compression test shows that it is possible to simulate fracturing of HVC-formed powder. Results from the simulation agree reasonably with experiments

  15. Investigation of the condition of spent-fuel pool components

    International Nuclear Information System (INIS)

    Kustas, F.M.; Bates, S.O.; Opitz, B.E.; Johnson, A.B. Jr.; Perez, J.M. Jr.; Farnsworth, R.K.

    1981-09-01

    It is currently projected that spent nuclear fuel, which is discharged from the reactor and then stored in water pools, may remain in those pools for several decades. Other studies have addressed the expected integrity of the spent fuel during extended water storage; this study assesses the integrity of metallic spent fuel pool components. Results from metallurgical examinations of specimens taken from stainless steel and aluminum components exposed in spent fuel pools are presented. Licensee Event Reports (LERs) relating to problems with spent fuel components were assessed and are summarized to define the types of operational problems that have occurred. The major conclusions of this study are: aluminum and stainless steel spent fuel pool components have a good history of performance in both deionized and borated water pools. Although some operational problems involving pool components have occurred, these problems have had minimal impacts

  16. Investigation of the condition of spent-fuel pool components

    Energy Technology Data Exchange (ETDEWEB)

    Kustas, F.M.; Bates, S.O.; Opitz, B.E.; Johnson, A.B. Jr.; Perez, J.M. Jr.; Farnsworth, R.K.

    1981-09-01

    It is currently projected that spent nuclear fuel, which is discharged from the reactor and then stored in water pools, may remain in those pools for several decades. Other studies have addressed the expected integrity of the spent fuel during extended water storage; this study assesses the integrity of metallic spent fuel pool components. Results from metallurgical examinations of specimens taken from stainless steel and aluminum components exposed in spent fuel pools are presented. Licensee Event Reports (LERs) relating to problems with spent fuel components were assessed and are summarized to define the types of operational problems that have occurred. The major conclusions of this study are: aluminum and stainless steel spent fuel pool components have a good history of performance in both deionized and borated water pools. Although some operational problems involving pool components have occurred, these problems have had minimal impacts.

  17. High-Throughput Molecular Simulations of Metal Organic Frameworks for CO2 Separation: Opportunities and Challenges

    Directory of Open Access Journals (Sweden)

    Ilknur Erucar

    2018-02-01

    Full Text Available Metal organic frameworks (MOFs have emerged as great alternatives to traditional nanoporous materials for CO2 separation applications. MOFs are porous materials that are formed by self-assembly of transition metals and organic ligands. The most important advantage of MOFs over well-known porous materials is the possibility to generate multiple materials with varying structural properties and chemical functionalities by changing the combination of metal centers and organic linkers during the synthesis. This leads to a large diversity of materials with various pore sizes and shapes that can be efficiently used for CO2 separations. Since the number of synthesized MOFs has already reached to several thousand, experimental investigation of each MOF at the lab-scale is not practical. High-throughput computational screening of MOFs is a great opportunity to identify the best materials for CO2 separation and to gain molecular-level insights into the structure–performance relationships. This type of knowledge can be used to design new materials with the desired structural features that can lead to extraordinarily high CO2 selectivities. In this mini-review, we focused on developments in high-throughput molecular simulations of MOFs for CO2 separations. After reviewing the current studies on this topic, we discussed the opportunities and challenges in the field and addressed the potential future developments.

  18. Simulation of Nanowires on Metal Vicinal Surfaces: Effect of Growth Parameters and Energetic Barriers

    Science.gov (United States)

    Hamouda, Ajmi B. H.; Blel, Sonia; Einstein, T. L.

    2012-02-01

    Growing one-dimensional metal structures is an important task in the investigation of the electronic and magnetic properties of new devices. We used kinetic Monte-Carlo (kMC) method to simulate the formation of nanowires of several metallic and non-metallic adatoms on Cu and Pt vicinal surfaces. We found that mono-atomic chains form on step-edges due to energetic barriers (the so-called Ehrlich-shwoebel and exchange barriers) on step-edge. Creation of perfect wires is found to depend on growth parameters and binding energies. We measure the filling ratio of nanowires for different chemical species in a wide range of temperature and flux. Perfect wires were obtained at lower deposition rate for all tested adatoms, however we notice different temperature ranges. Our results were compared with experimental ones [Gambardella et al., Surf. Sci.449, 93-103 (2000), PRB 61, 2254-2262, (2000)]. We review the role of impurities in nanostructuring of surfaces [Hamouda et al., Phys. Rev. B 83, 035423, (2011)] and discuss the effect of their energetic barriers on the obtained quality of nanowires. Our work provides experimentalists with optimum growth parameters for the creation of a uniform distribution of wires on surfaces.

  19. NUMERICAL SIMULATION OF METAL MELT FLOWS IN MOLD CAVITY WITH CERAMIC POROUS MEDIA

    Directory of Open Access Journals (Sweden)

    Changchun Dong

    2016-05-01

    Full Text Available Process modeling of metal melt flow in porous media plays an important role in casting of metal matrix composites. In this work, a mathematical model of the metal melt flow in preform ceramic particles was used to simulate the flow behavior in a mold cavity. The effects of fluid viscosity and permeability (mainly affected by porosity of ceramic preforms on the flow behavior were analyzed. The results indicate that ceramic porous media have a significant effect on the flow behavior by contributing to a low filling velocity and sharp pressure drop in the cavity. The pressure drop has a linear relationship with the fluid velocity, and a nonlinear relationship with porosity. When the porosity is relatively small, the pressure drop is extremely large. When porosity exceeds a certain value, the pressure drop is independent of porosity. The relationship between viscosity and porosity is described, and it is shown that the critical porosity changes when the viscosity of the melt changes. However, due to the limited viscosity change, the critical porosity changes by less than 0.043.

  20. Spent fuel storage facility, Kalpakkam

    International Nuclear Information System (INIS)

    Shreekumar, B.; Anthony, S.

    2017-01-01

    Spent Fuel Storage Facility (SFSF), Kalpakkam is designed to store spent fuel arising from PHWRs. Spent fuel is transported in AERB qualified/authorized shipping cask by NPCIL to SFSF by road or rail route. The spent fuel storage facility at Kalpakkam was hot commissioned in December 2006. All systems, structures and components (SSCs) related to safety are designed to meet the operational requirements

  1. Metals and polybrominated diphenyl ethers leaching from electronic waste in simulated landfills

    Energy Technology Data Exchange (ETDEWEB)

    Kiddee, Peeranart [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes Campus, Adelaide, 5095 (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of the Environment, Mawson Lakes Campus, Adelaide, 5095 (Australia); Naidu, Ravi, E-mail: ravi.naidu@crccare.com [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes Campus, Adelaide, 5095 (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of the Environment, Mawson Lakes Campus, Adelaide, 5095 (Australia); Wong, Ming H. [Croucher Institute for Environmental Sciences, and Department of Biology, Hong Kong Baptist University, Kowloon Tong (China)

    2013-05-15

    Highlights: • Simulated landfill columns provided realistic results than lab based column study. • Column leachates showed significant seasonal effect on toxic substances. • Toxic substances in the landfill leachates pose environmental and health hazards. • A better management of e-waste is urgently needed. -- Abstract: Landfills established prior to the recognition of potential impacts from the leaching of heavy metals and toxic organic compounds often lack appropriate barriers and pose significant risks of contamination of groundwater. In this study, bioavailable metal(oids) and polybrominated diphenyl ethers (PBDEs) in leachates from landfill columns that contained intact or broken e-waste were studied under conditions that simulate landfills in terms of waste components and methods of disposal of e-wastes, and with realistic rainfall. Fourteen elements and PBDEs were analysed in leachates over a period of 21 months. The results demonstrate that the average concentrations of Al, Ba, Be, Cd, Co, Cr, Cu, Ni, Pb, Sb and V in leachates from the column that contained broken e-waste items were significantly higher than the column without e-waste. BDE-153 was the highest average PBDEs congener in all columns but the average of ∑PBDEs levels in columns that contained intact e-waste were (3.7 ng/l) and were not significantly higher than that in the leachates from the control column.

  2. Numerical simulation of turbulent liquid metal flows in plane channels and annuli

    International Nuclear Information System (INIS)

    Groetzbach, G.

    1980-06-01

    The method of direct numerical simulation is used to study heat transfer and statistical data for fully developed turbulent liquid metal flows in plane channels and annuli. Subgrid scale models using one transport equation account for the high wave-number turbulence not resolved by the finite difference grid. A special subgrid-scale heat flux model is deduced together with an approximative theory to calculate all model coefficients. This model can be applied on the total Peclet number range of technical liquid metal flows. Especially it can be used for very small Peclet numbers, where the results are independent on model parameters. A verification of the numerical results for liquid sodium and mercury flows is undertaken by the Nusselt number in plane channels and radial temperature and eddy conductivity profiles for annuli. The numerically determined Nusselt numbers for annuli indicate that many empirical correlations overestimate the influence of the ratio of radii. The numerical results for the eddy conductivity profiles may be used to remove these problems. The statistical properties of the simulated temperature fluctuations are within the wide scatter-band of experimental data. The numerical results give reasonable heat flux correlation coefficients which depend only weakly on the problem marking parameters. (orig.) [de

  3. Process simulation and experimental validation of Hot Metal Gas Forming with new press hardening steels

    Science.gov (United States)

    Paul, A.; Reuther, F.; Neumann, S.; Albert, A.; Landgrebe, D.

    2017-09-01

    One field in the work of the Fraunhofer Institute for Machine Tools and Forming Technology IWU in Chemnitz is industry applied research in Hot Metal Gas Forming, combined with press hardening in one process step. In this paper the results of investigations on new press hardening steels from SSAB AB (Docol®1800 Bor and Docol®2000 Bor) are presented. Hot tensile tests recorded by the project partner (University of West Bohemia, Faculty of Mechanical Engineering) were used to create a material model for thermo-mechanical forming simulations. For this purpose the provided raw data were converted into flow curve approximations of the real stress-real strain-curves for both materials and afterwards integrated in a LS-DYNA simulation model of Hot Metal Gas Forming with all relevant boundary conditions and sub-stages. Preliminary experimental tests were carried out using a tool at room temperature to permit evaluation of the forming behaviour of Docol 1800 Bor and Docol 2000 Bor tubes as well as validation of the simulation model. Using this demonstrator geometry (outer diameter 57 mm, tube length 300 mm, wall thickness 1.5 mm), the intention was to perform a series of tests with different furnace temperatures (from 870 °C to 1035 °C), maximum internal pressures (up to 67 MPa) and pressure build-up rates (up to 40 MPa/s) to evaluate the formability of Docol 1800 Bor and Docol 2000 Bor. Selected demonstrator parts produced in that way were subsequently analysed by wall thickness and hardness measurements. The tests were carried out using the completely modernized Dunkes/AP&T HS3-1500 hydroforming press at the Fraunhofer IWU. In summary, creating a consistent simulation model with all relevant sub-stages was successfully established in LS-DYNA. The computation results show a high correlation with the experimental data regarding the thinning behaviour. The Hot Metal Gas Forming of the demonstrator geometry was successfully established as well. Different hardness values

  4. Numerical Simulation of Multiphase Magnetohydrodynamic Flow and Deformation of Electrolyte-Metal Interface in Aluminum Electrolysis Cells

    Science.gov (United States)

    Hua, Jinsong; Rudshaug, Magne; Droste, Christian; Jorgensen, Robert; Giskeodegard, Nils-Haavard

    2018-06-01

    A computational fluid dynamics based multiphase magnetohydrodynamic (MHD) flow model for simulating the melt flow and bath-metal interface deformation in realistic aluminum reduction cells is presented. The model accounts for the complex physics of the MHD problem in aluminum reduction cells by coupling two immiscible fluids, electromagnetic field, Lorentz force, flow turbulence, and complex cell geometry with large length scale. Especially, the deformation of bath-metal interface is tracked directly in the simulation, and the condition of constant anode-cathode distance (ACD) is maintained by moving anode bottom dynamically with the deforming bath-metal interface. The metal pad deformation and melt flow predicted by the current model are compared to the predictions using a simplified model where the bath-metal interface is assumed flat. The effects of the induced electric current due to fluid flow and the magnetic field due to the interior cell current on the metal pad deformation and melt flow are investigated. The presented model extends the conventional simplified box model by including detailed cell geometry such as the ledge profile and all channels (side, central, and cross-channels). The simulations show the model sensitivity to different side ledge profiles and the cross-channel width by comparing the predicted melt flow and metal pad heaving. In addition, the model dependencies upon the reduction cell operation conditions such as ACD, current distribution on cathode surface and open/closed channel top, are discussed.

  5. Pacific Northwest Laboratory (PNL) spent fuel transportation and handling facility models

    International Nuclear Information System (INIS)

    Andrews, W.B.; Bower, J.C.; Burnett, R.A.; Engel, R.L.; Rolland, C.W.

    1979-09-01

    A spent fuel logistics study was conducted in support of the US DOE program to develop facilities for preparing spent unreprocessed fuel from commercial LWRs for geological storage. Two computerized logistics models were developed. The first one was the site evaluation model. Two studies of spent fuel handling facility and spent fuel disposal facility siting were completed; the first postulates a single spent fuel handling facility located at any of six DOE laboratory sites, while the second study examined siting strategies with the spent fuel repository relative to the spent fuel handling facility. A second model to conduct storage/handling facility simulations was developed

  6. Pacific Northwest Laboratory (PNL) spent fuel transportation and handling facility models

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, W.B.; Bower, J.C.; Burnett, R.A.; Engel, R.L.; Rolland, C.W.

    1979-09-01

    A spent fuel logistics study was conducted in support of the US DOE program to develop facilities for preparing spent unreprocessed fuel from commercial LWRs for geological storage. Two computerized logistics models were developed. The first one was the site evaluation model. Two studies of spent fuel handling facility and spent fuel disposal facility siting were completed; the first postulates a single spent fuel handling facility located at any of six DOE laboratory sites, while the second study examined siting strategies with the spent fuel repository relative to the spent fuel handling facility. A second model to conduct storage/handling facility simulations was developed. (DLC)

  7. Thermochemical treatment of spent ion exchange resins

    International Nuclear Information System (INIS)

    Ojovan, M.I.; Petrov, G.A.; Dmitriev, S.A.; Trusov, B.G.; Semenov, K.N.; Klimov, V.L.

    2001-01-01

    Spent ion exchange resins (IER) is a principal type of radioactive waste constantly generated by nuclear plants of various functions. The reduction of volume of this waste and its treatment to the forms suitable for long-term disposal is an urgent problem facing the present-day atomic energetics. Nowadays the technological process THOR (Studsvik, Sweden) based on the thermodestruction of IER is the best developed and realized on the industrial scale. Unfortunately, this process requires expensive equipment and great energy consumption for the moisture to be evaporated and thereafter IER to be destroyed by heat. Meanwhile the capability of some elements (Mg, Al, Si, Ti etc.) has long been known and practical use found for active interaction with water in combustion regime. This property of the metals has been used in the development of new technology of treatment of IERs in SIA ''Radon''. Wet IER is mixed with powder metal fuel (PMF) which represents a mixture of metal powder, a quantity of burning activator and some technological additives. On initiation, the mixture of IER with PMF burns without extra energy supply to generate enough heat for the moisture to be evaporated and products of IER decomposition to be destroyed and evaporated. To burn out the products of IER evaporation the air is used. The thermodynamic simulation data and the results of experiments using a pilot plant show that radionuclides contained in IER are chemically bound in ash residue consisting of metal oxides, spinel, silicates, etc. According to the experimental data, radionuclides in amounts of 90% or more of Cs-137 and up to 95% of Sr-90 and Co-60 are fixed in the ash residue. The residue volume is several times less than the initial volume of IER. Concentrations of hazard gases in off-gases do not exceed maximum permissible ones accepted in different countries. The technological process is easy to perform, it does not require sophisticated equipment and great energy consumption which

  8. Guidebook on spent fuel storage

    International Nuclear Information System (INIS)

    1984-01-01

    The Guidebook summarizes the experience and information in various areas related to spent fuel storage: technological aspects, the transport of spent fuel, economical, regulatory and institutional aspects, international safeguards, evaluation criteria for the selection of a specific spent fuel storage concept, international cooperation on spent fuel storage. The last part of the Guidebook presents specific problems on the spent fuel storage in the United Kingdom, Sweden, USSR, USA, Federal Republic of Germany and Switzerland

  9. Spent Fuel in Chile

    International Nuclear Information System (INIS)

    López Lizana, F.

    2015-01-01

    The government has made a complete and serious study of many different aspects and possible road maps for nuclear electric power with strong emphasis on safety and energy independence. In the study, the chapter of SFM has not been a relevant issue at this early stage due to the fact that it has been left for later implementation stage. This paper deals with the options Chile might consider in managing its Spent Fuel taking into account foreign experience and factors related to safety, economics, public acceptance and possible novel approaches in spent fuel treatment. The country’s distinctiveness and past experience in this area taking into account that Chile has two research reactors which will have an influence in the design of the Spent Fuel option. (author)

  10. Spent fuel reprocessing options

    International Nuclear Information System (INIS)

    2008-08-01

    The objective of this publication is to provide an update on the latest developments in nuclear reprocessing technologies in the light of new developments on the global nuclear scene. The background information on spent fuel reprocessing is provided in Section One. Substantial global growth of nuclear electricity generation is expected to occur during this century, in response to environmental issues and to assure the sustainability of the electrical energy supply in both industrial and less-developed countries. This growth carries with it an increasing responsibility to ensure that nuclear fuel cycle technologies are used only for peaceful purposes. In Section Two, an overview of the options for spent fuel reprocessing and their level of development are provided. A number of options exist for the treatment of spent fuel. Some, including those that avoid separation of a pure plutonium stream, are at an advanced level of technological maturity. These could be deployed in the next generation of industrial-scale reprocessing plants, while others (such as dry methods) are at a pilot scale, laboratory scale or conceptual stage of development. In Section Three, research and development in support of advanced reprocessing options is described. Next-generation spent fuel reprocessing plants are likely to be based on aqueous extraction processes that can be designed to a country specific set of spent fuel partitioning criteria for recycling of fissile materials to advanced light water reactors or fast spectrum reactors. The physical design of these plants must incorporate effective means for materials accountancy, safeguards and physical protection. Section four deals with issues and challenges related to spent fuel reprocessing. The spent fuel reprocessing options assessment of economics, proliferation resistance, and environmental impact are discussed. The importance of public acceptance for a reprocessing strategy is discussed. A review of modelling tools to support the

  11. Clinical evaluation of a commercial orthopedic metal artifact reduction tool for CT simulations in radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Li Hua; Noel, Camille; Chen, Haijian; Harold Li, H.; Low, Daniel; Moore, Kevin; Klahr, Paul; Michalski, Jeff; Gay, Hiram A.; Thorstad, Wade; Mutic, Sasa [Department of Radiation Oncology, Washington University, St. Louis, Missouri 63110 (United States); Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California 90095 (United States); Department of Radiation Oncology, University of California San Diego, San Diego, California 92093 (United States); Philips Healthcare System, Cleveland, Ohio 44143 (United States); Department of Radiation Oncology, Washington University, St. Louis, Missouri 63110 (United States)

    2012-12-15

    Purpose: Severe artifacts in kilovoltage-CT simulation images caused by large metallic implants can significantly degrade the conspicuity and apparent CT Hounsfield number of targets and anatomic structures, jeopardize the confidence of anatomical segmentation, and introduce inaccuracies into the radiation therapy treatment planning process. This study evaluated the performance of the first commercial orthopedic metal artifact reduction function (O-MAR) for radiation therapy, and investigated its clinical applications in treatment planning. Methods: Both phantom and clinical data were used for the evaluation. The CIRS electron density phantom with known physical (and electron) density plugs and removable titanium implants was scanned on a Philips Brilliance Big Bore 16-slice CT simulator. The CT Hounsfield numbers of density plugs on both uncorrected and O-MAR corrected images were compared. Treatment planning accuracy was evaluated by comparing simulated dose distributions computed using the true density images, uncorrected images, and O-MAR corrected images. Ten CT image sets of patients with large hip implants were processed with the O-MAR function and evaluated by two radiation oncologists using a five-point score for overall image quality, anatomical conspicuity, and CT Hounsfield number accuracy. By utilizing the same structure contours delineated from the O-MAR corrected images, clinical IMRT treatment plans for five patients were computed on the uncorrected and O-MAR corrected images, respectively, and compared. Results: Results of the phantom study indicated that CT Hounsfield number accuracy and noise were improved on the O-MAR corrected images, especially for images with bilateral metal implants. The {gamma} pass rates of the simulated dose distributions computed on the uncorrected and O-MAR corrected images referenced to those of the true densities were higher than 99.9% (even when using 1% and 3 mm distance-to-agreement criterion), suggesting that dose

  12. Structure of Cu64.5Zr35.5 metallic glass by reverse Monte Carlo simulations

    International Nuclear Information System (INIS)

    Fang, X. W.; Huang, Li; Wang, C. Z.; Ho, K. M.; Ding, Z. J.

    2014-01-01

    Reverse Monte Carlo simulations (RMC) have been widely used to generate three dimensional (3D) atomistic models for glass systems. To examine the reliability of the method for metallic glass, we use RMC to predict the atomic configurations of a “known” structure from molecular dynamics (MD) simulations, and then compare the structure obtained from the RMC with the target structure from MD. We show that when the structure factors and partial pair correlation functions from the MD simulations are used as inputs for RMC simulations, the 3D atomistic structure of the glass obtained from the RMC gives the short- and medium-range order in good agreement with those from the target structure by the MD simulation. These results suggest that 3D atomistic structure model of the metallic glass alloys can be reasonably well reproduced by RMC method with a proper choice of input constraints

  13. Springback Simulation and Tool Surface Compensation Algorithm for Sheet Metal Forming

    International Nuclear Information System (INIS)

    Shen Guozhe; Hu Ping; Zhang Xiangkui; Chen Xiaobin; Li Xiaoda

    2005-01-01

    Springback is an unquenchable forming defect in the sheet metal forming process. How to calculate springback accurately is a big challenge for a lot of FEA software. Springback compensation makes the stamped final part accordant with the designed part shape by modifying tool surface, which depends on the accurate springback amount. How ever, the meshing data based on numerical simulation is expressed by nodes and elements, such data can not be supplied directly to tool surface CAD data. In this paper, a tool surface compensation algorithm based on numerical simulation technique of springback process is proposed in which the independently developed dynamic explicit springback algorithm (DESA) is used to simulate springback amount. When doing the tool surface compensation, the springback amount of the projected point can be obtained by interpolation of the springback amount of the projected element nodes. So the modified values of tool surface can be calculated reversely. After repeating the springback and compensation calculations for 1∼3 times, the reasonable tool surface mesh is gained. Finally, the FEM data on the compensated tool surface is fitted into the surface by CAD modeling software. The examination of a real industrial part shows the validity of the present method

  14. Theories, Methods and Numerical Technology of Sheet Metal Cold and Hot Forming Analysis, Simulation and Engineering Applications

    CERN Document Server

    Hu, Ping; Liu, Li-zhong; Zhu, Yi-guo

    2013-01-01

    Over the last 15 years, the application of innovative steel concepts in the automotive industry has increased steadily. Numerical simulation technology of hot forming of high-strength steel allows engineers to modify the formability of hot forming steel metals and to optimize die design schemes. Theories, Methods and Numerical Technology of Sheet Metal Cold and Hot Forming focuses on hot and cold forming theories, numerical methods, relative simulation and experiment techniques for high-strength steel forming and die design in the automobile industry. Theories, Methods and Numerical Technology of Sheet Metal Cold and Hot Forming introduces the general theories of cold forming, then expands upon advanced hot forming theories and simulation methods, including: • the forming process, • constitutive equations, • hot boundary constraint treatment, and • hot forming equipment and experiments. Various calculation methods of cold and hot forming, based on the authors’ experience in commercial CAE software f...

  15. Reprocessing of spent plasma

    International Nuclear Information System (INIS)

    Pierini, G.

    1981-01-01

    This invention relates to a process for removing helium and other impurities from a mixture containing deuterium and tritium, a deuterium/tritium mixture when purified in accordance with such a process and, more particularly, to a process for the reprocessing of spent plasma removed from a thermofusion reactor. (U.K.)

  16. Statistical analysis of dimer formation in supersaturated metal vapor based on molecular dynamics simulation

    Science.gov (United States)

    Korenchenko, Anna E.; Vorontsov, Alexander G.; Gelchinski, Boris R.; Sannikov, Grigorii P.

    2018-04-01

    We discuss the problem of dimer formation during the homogeneous nucleation of atomic metal vapor in an inert gas environment. We simulated nucleation with molecular dynamics and carried out the statistical analysis of double- and triple-atomic collisions as the two ways of long-lived diatomic complex formation. Close pair of atoms with lifetime greater than the mean time interval between atom-atom collisions is called a long-lived diatomic complex. We found that double- and triple-atomic collisions gave approximately the same probabilities of long-lived diatomic complex formation, but internal energy of the resulted state was essentially lower in the second case. Some diatomic complexes formed in three-particle collisions are stable enough to be a critical nucleus.

  17. Nonequilibrium Molecular Simulations of New Ionic Lubricants at Metallic Surfaces: Prediction of the Friction.

    Science.gov (United States)

    Mendonça, Ana C F; Pádua, Agílio A H; Malfreyt, Patrice

    2013-03-12

    We report nonequilibrium molecular dynamics of ionic liquids interacting with metallic surfaces. A specific set of interaction parameters for ionic liquids composed of alkylammonium cations and alkylsulfonate anions with an iron surface, which has been previously developed (J. Chem. Theory Comput.2012, 8, 3348) is used here. We develop a procedure for a quantitative prediction of the friction coefficient at different loads and shear rates. The simulated friction coefficient agrees very well with the available experimental ones. The dependence of friction on the load, shear velocity, surface topology, and length of alkyl side chains in the ionic liquid is also investigated. The changes in the frictional forces are explained in terms of the specific arrangements and orientations of groups forming the ionic liquid at the vicinity of the surface.

  18. Simulation of grain boundary effects on electronic transport in metals, and detailed causes of scattering

    Energy Technology Data Exchange (ETDEWEB)

    Feldman, Baruch [Process Technology Modeling, Design and Technology Solutions, Technology and Manufacturing Group, Intel Corporation, Santa Clara, CA 95052 (United States); Department of Physics, University of Washington, Seattle, WA 98195 (United States); Park, Seongjun; Haverty, Michael; Shankar, Sadasivan [Process Technology Modeling, Design and Technology Solutions, Technology and Manufacturing Group, Intel Corporation, Santa Clara, CA 95052 (United States); Dunham, Scott T. [Department of Physics, University of Washington, Seattle, WA 98195 (United States); Department of Electrical Engineering, University of Washington, Seattle, WA 98195 (United States)

    2010-07-15

    We present first-principles simulations of single grain boundary reflectivity of electrons in noble metals, Cu and Ag. We examine twin and non-twin grain boundaries using non-equilibrium Green's function and first principles methods. We also investigate the determinants of reflectivity in grain boundaries by modeling atomic vacancies, disorder, and orientation and find that both the change in grain orientation and disorder in the boundary itself contribute significantly to reflectivity. We find that grain boundary reflectivity may vary widely depending on the grain boundary structure, consistent with published experimental results. Finally, we examine the reflectivity from multiple grain boundaries and find that grain boundary reflectivity may depend on neighboring grain boundaries. This study raises some potential limitations in the independent grain boundary assumptions of the Mayadas-Shatzkes (MS) model. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  19. Evaluation of the reconstruction of image acquired from CT simulator to reduce metal artifact

    International Nuclear Information System (INIS)

    Choi, Ji Hun; Park, Jin Hong; Choi, Byung Don; Won, Hui Su; Chang, Nam Jun; Goo, Jang Hyun; Hong, Joo Wan

    2014-01-01

    This study presents the usefulness assessment of metal artifact reduction for orthopedic implants(O-MAR) to decrease metal artifacts from materials with high density when acquired CT images. By CT simulator, original CT images were acquired from Gammex and Rando phantom and those phantoms inserted with high density materials were scanned for other CT images with metal artifacts and then O-MAR was applied to those images, respectively. To evaluate CT images using Gammex phantom, 5 regions of interest(ROIs) were placed at 5 organs and 3 ROIs were set up at points affected by artifacts. The averages of standard deviation(SD) and CT numbers were compared with a plan using original image. For assessment of variations in dose of tissue around materials with high density, the volume of a cylindrical shape was designed at 3 places in images acquired from Rando phantom by Eclipse. With 6 MV, 7-fields, 15x15cm 2 and 100 cGy per fraction, treatment planning was created and the mean dose were compared with a plan using original image. In the test with the Gammex phantom, CT numbers had a few difference at established points and especially 3 points affected by artifacts had most of the same figures. In the case of O-MAR image, the more reduction in SD appeared at all of 8 points than non O-MAR image. In the test using the Rando Phantom, the variations in dose of tissue around high density materials had a few difference between original CT image and CT image with O-MAR. The CT images using O-MAR were acquired clearly at the boundary of tissue around high density materials and applying O-MAR was useful for correcting CT numbers

  20. Development of spent fuel remote handling technology

    International Nuclear Information System (INIS)

    Yoon, J. S.; Hong, H. D.; Kim, S. H.

    2004-02-01

    In this research, the remote handling technology is developed for the advanced spent fuel conditioning process which gives a possible solution to deal with the rapidly increasing spent fuels. In detail, a fuel rod slitting device is developed for the decladding of the spent fuel. A series of experiments has been performed to find out the optimal condition of the spent fuel voloxidation which converts the UO 2 pellet into U 3 O 8 powder. The design requirements of the ACP equipment for hot test is established by analysing the modular requirement, radiation hardening and thermal protection of the process equipment, etc. The prototype of the servo manipulator is developed. The manipulator has an excellent performance in terms of the payload to weight ratio that is 30 % higher than that of existing manipulators. To provide reliability and safety of the ACP, the 3 dimensional graphic simulator is developed. Using the simulator the remote handling operation is simulated and as a result, the optimal layout of ACP is obtained. The supervisory control system is designed to control and monitor the several different unit processes. Also the failure monitoring system is developed to detect the possible accidents of the reduction reactor

  1. Molecular Dynamics Simulations of Grain Boundary and Bulk Diffusion in Metals.

    Science.gov (United States)

    Plimpton, Steven James

    Diffusion is a microscopic mass transport mechanism that underlies many important macroscopic phenomena affecting the structural, electrical, and mechanical properties of metals. This thesis presents results from atomistic simulation studies of diffusion both in bulk and in the fast diffusion paths known as grain boundaries. Using the principles of molecular dynamics single boundaries are studied and their structure and dynamic properties characterized. In particular, tilt boundary bicrystal and bulk models of fcc Al and bcc alpha-Fe are simulated. Diffusion coefficients and activation energies for atomic motion are calculated for both models and compared to experimental data. The influence of the interatomic pair potential on the diffusion is studied in detail. A universal relation between the melting temperature that a pair potential induces in a simulated bulk model and the potential energy barrier height for atomic hopping is derived and used to correlate results for a wide variety of pair potentials. Using these techniques grain boundary and bulk diffusion coefficients for any fcc material can be estimated from simple static calculations without the need to perform more time-consuming dynamic simulations. The influences of two other factors on grain boundary diffusion are also studied because of the interest of the microelectronics industry in the diffusion related reliability problem known as electromigration. The first factor, known to affect the self diffusion rate of Al, is the presence of Cu impurity atoms in Al tilt boundaries. The bicrystal model for Al is seeded randomly with Cu atoms and a simple hybrid Morse potential used to model the Al-Cu interaction. While some effect due to the Cu is noted, it is concluded that pair potentials are likely an inadequate approximation for the alloy system. The second factor studied is the effect of the boundary orientation angle on the diffusion rate. Symmetric bcc Fe boundaries are relaxed to find optimal

  2. Process and system to encapsulate spent nuclear fuel

    International Nuclear Information System (INIS)

    Gunasekaran, Muthian; Fleischer, L.R.

    1980-01-01

    System for encapsulating spent nuclear fuel containing active fission matter and comprised in a metal casing, where concrete covers this casing in a contiguous, uniform and complete manner. It is characterized in that this concrete contains metal fibres to raise the thermal conductivity and polymers for increasing impermeability and that convection facilities are provided for cooling the outer surface of the concrete [fr

  3. German Spent Nuclear Fuel Legacy: Characteristics and High-Level Waste Management Issues

    Directory of Open Access Journals (Sweden)

    A. Schwenk-Ferrero

    2013-01-01

    Full Text Available Germany is phasing-out the utilization of nuclear energy until 2022. Currently, nine light water reactors of originally nineteen are still connected to the grid. All power plants generate high-level nuclear waste like spent uranium or mixed uranium-plutonium dioxide fuel which has to be properly managed. Moreover, vitrified high-level waste containing minor actinides, fission products, and traces of plutonium reprocessing loses produced by reprocessing facilities has to be disposed of. In the paper, the assessments of German spent fuel legacy (heavy metal content and the nuclide composition of this inventory have been done. The methodology used applies advanced nuclear fuel cycle simulation techniques in order to reproduce the operation of the German nuclear power plants from 1969 till 2022. NFCSim code developed by LANL was adopted for this purpose. It was estimated that ~10,300 tonnes of unreprocessed nuclear spent fuel will be generated until the shut-down of the ultimate German reactor. This inventory will contain ~131 tonnes of plutonium, ~21 tonnes of minor actinides, and 440 tonnes of fission products. Apart from this, ca.215 tonnes of vitrified HLW will be present. As fission products and transuranium elements remain radioactive from 104 to 106 years, the characteristics of spent fuel legacy over this period are estimated, and their impacts on decay storage and final repository are discussed.

  4. Performance Evaluation of the Neutron Coincidence Counter for the Advanced Spent Fuel Conditioning Process

    International Nuclear Information System (INIS)

    Lee, S.Y.; Li, T.K.; Menlove, Howard O.; Kim, H.D.; Ko, W.I.; Park, S.W.

    2005-01-01

    The Advanced Spent Fuel Conditioning Process (ACP) is a pyrochemical dry reprocessing technique to convert oxide-type spent nuclear fuel into a metallic form. The Korea Atomic Energy Research Institute (KAERI) has been developing this technology for the purpose of spent fuel management and is planning to perform a lab-scale demonstration in 2006. With this technology, a significant reduction of the volume and heat load of spent fuel is expected, which could decrease the burden of safety and economics. In this study, MCNPX code calculations were carried out to estimate the performance of a neutron coincidence counter designed for measruement of the process materials in the pilot-scale ACP facility. To verify the design requirement, the singles and doubles counting rates of the detectors were simulated with the latest coincidence capability of the MCNPX code. Then, the precision of the coincidence measurements were evaluated on various process materials from the ACP. It was verified that the performance of the neutron coincidence counter could meet the design criteria for all samples in the ACP, and the material accounting system for the pilot-scale ACP facility could meet the IAEA safeguards goals.

  5. Molecular dynamics for near melting temperatures simulations of metals using modified embedded-atom method

    Science.gov (United States)

    Etesami, S. Alireza; Asadi, Ebrahim

    2018-01-01

    Availability of a reliable interatomic potential is one of the major challenges in utilizing molecular dynamics (MD) for simulations of metals at near the melting temperatures and melting point (MP). Here, we propose a novel approach to address this challenge in the concept of modified-embedded-atom (MEAM) interatomic potential; also, we apply the approach on iron, nickel, copper, and aluminum as case studies. We propose adding experimentally available high temperature elastic constants and MP of the element to the list of typical low temperature properties used for the development of MD interatomic potential parameters. We show that the proposed approach results in a reasonable agreement between the MD calculations of melting properties such as latent heat, expansion in melting, liquid structure factor, and solid-liquid interface stiffness and their experimental/computational counterparts. Then, we present the physical properties of mentioned elements near melting temperatures using the new MEAM parameters. We observe that the behavior of elastic constants, heat capacity and thermal linear expansion coefficient at room temperature compared to MP follows an empirical linear relation (α±β × MP) for transition metals. Furthermore, a linear relation between the tetragonal shear modulus and the enthalpy change from room temperature to MP is observed for face-centered cubic materials.

  6. Computer simulation of void formation in residual gas atom free metals by dual beam irradiation experiments

    International Nuclear Information System (INIS)

    Shimomura, Y.; Nishiguchi, R.; La Rubia, T.D. de; Guinan, M.W.

    1992-01-01

    In our recent experiments (1), we found that voids nucleate at vacancy clusters which trap gas atoms such as hydrogen and helium in ion- and neutron-irradiated copper. A molecular dynamics computer simulation, which implements an empirical embedded atom method to calculate forces that act on atoms in metals, suggests that a void nucleation occurs in pure copper at six and seven vacancy clusters. The structure of six and seven vacancy clusters in copper fluctuates between a stacking fault tetrahedron and a void. When a hydrogen is trapped at voids of six and seven vacancy, a void can keep their structure for appreciably long time; that is, the void do not relax to a stacking fault tetrahedron and grows to a large void. In order to explore the detailed atomics of void formation, it is emphasized that dual-beam irradiation experiments that utilize beams of gas atoms and self-ions should be carried out with residual gas atom free metal specimens. (author)

  7. Simulated body-fluid tests and electrochemical investigations on biocompatibility of metallic glasses

    International Nuclear Information System (INIS)

    Lin, C.H.; Huang, C.H.; Chuang, J.F.; Lee, H.C.; Liu, M.C.; Du, X.H.; Huang, J.C.; Jang, J.S.C.; Chen, C.H.

    2012-01-01

    This paper presents the in-vitro and electrochemical investigations of four metallic glasses (MGs) for finding potential MG-based bio-materials. The simulation body-fluid Hanks solution is utilized for testing the corrosion resistance of MGs, and microorganisms of Escherichia coli are used in testing the bio-toxicity. In addition, a simple cyclic voltammetry method is used for rapid verification of the potential electrochemical responses. It is found that the Zr-based MG can sustain in the body-fluid, exhibiting the best corrosion resistance and electrochemical stability. The microbiologic test shows that E. coli can grow on the surface of the Zr-based metallic glass, confirming the low cell toxicity of this Zr-based MG. Highlights: ► Vanadium is added in Cu–Zr–Al alloy to induce B2-CuZr formation. ► The more induced B2-CuZr phase can improve compressive plasticity. ► The plasticity improvement might be caused by B2 phase dynamic coarsening.

  8. The molecular dynamics simulation of structure and transport properties of sheared super-cooled liquid metal

    International Nuclear Information System (INIS)

    Wang Li; Liu Xiangfa; Zhang Yanning; Yang Hua; Chen Ying; Bian Xiufang

    2003-01-01

    Much more attention has been paid to the microstructure of liquid metal under non-ordinary condition recently. In this Letter, the pair correlation function (PCF), together with internal energy of sheared super-cooled liquid Co as a function of temperature has been calculated by molecular dynamics simulation based upon the embedded atom method (EAM) and analyzed compared to that under normal condition. The finding indicates that there exist three obvious peaks of PCF for liquid Co; while as the shear stress is applied to the liquid, the first and second peaks of PCF become lower, the third peak disappeared. The concentric shell structure representing short-range order of liquid still exists, however, it is weakened by the addition of shear stress, leading to the increases of disordering degree of liquid metal. The curves of energy versus temperature suggest the higher crystalline temperature compared to that under normal condition at the same cooling rate. In addition, the viscosity of super-liquid Co is calculated by non-equilibrium molecular dynamics (NEMD)

  9. Direct Numerical Simulations of Microstructure Effects During High-Rate Loading of Additively Manufactured Metals

    Science.gov (United States)

    Battaile, Corbett; Owen, Steven; Moore, Nathan

    2017-06-01

    The properties of most engineering materials depend on the characteristics of internal microstructures and defects. In additively manufactured (AM) metals, these can include polycrystalline grains, impurities, phases, and significant porosity that qualitatively differ from conventional engineering materials. The microscopic details of the interactions between these internal defects, and the propagation of applied loads through the body, act in concert to dictate macro-observable properties like strength and compressibility. In this work, we used Sandia's ALEGRA finite element software to simulate the high-strain-rate loading of AM metals from laser engineered net shaping (LENS) and thermal spraying. The microstructural details of the material were represented explicitly, such that internal features like second phases and pores are captured and meshed as individual entities in the computational domain. We will discuss the dependence of the high-strain-rate mechanical properties on microstructural characteristics such as the shapes, sizes, and volume fractions of second phases and pores. In addition, we will examine how the details of the microstructural representation affect the microscopic material response to dynamic loads, and the effects of using ``stair-step'' versus conformal interfaces smoothed via the SCULPT tool in Sandia's CUBIT software. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the US DOE NNSA under contract DE-AC04-94AL85000.

  10. Conformable liquid metal printed epidermal electronics for smart physiological monitoring and simulation treatment

    Science.gov (United States)

    Wang, Xuelin; Zhang, Yuxin; Guo, Rui; Wang, Hongzhang; Yuan, Bo; Liu, Jing

    2018-03-01

    Conformable epidermal printed electronics enabled from gallium-based liquid metals (LMs), highly conductive and low-melting-point alloys, are proposed as the core to achieving immediate contact between skin surface and electrodes, which can avoid the skin deformation often caused by conventional rigid electrodes. When measuring signals, LMs can eliminate resonance problems with shorter time to reach steady state than Pt and gelled Pt electrodes. By comparing the contact resistance under different working conditions, it is demonstrated that both ex vivo and in vivo LM electrode-skin models have the virtues of direct and immediate contact with skin surface without the deformation encountered with conventional rigid electrodes. In addition, electrocardio electrodes composed of conformable LM printed epidermal electronics are adopted as smart devices to monitor electrocardiogram signals of rabbits. Furthermore, simulation treatment for smart defibrillation offers a feasible way to demonstrate the effect of liquid metal electrodes (LMEs) on the human body with less energy loss. The remarkable features of soft epidermal LMEs such as high conformability, good conductivity, better signal stability, and fine biocompatibility represent a critical step towards accurate medical monitoring and future smart treatments.

  11. Metal release from sandstones under experimentally and numerically simulated CO2 leakage conditions.

    Science.gov (United States)

    Kirsch, Katie; Navarre-Sitchler, Alexis K; Wunsch, Assaf; McCray, John E

    2014-01-01

    Leakage of CO2 from a deep storage formation into an overlying potable aquifer may adversely impact water quality and human health. Understanding CO2-water-rock interactions is therefore an important step toward the safe implementation of geologic carbon sequestration. This study targeted the geochemical response of siliclastic rock, specifically three sandstones of the Mesaverde Group in northwestern Colorado. To test the hypothesis that carbonate minerals, even when present in very low levels, would be the primary source of metals released into a CO2-impacted aquifer, two batch experiments were conducted. Samples were reacted for 27 days with water and CO2 at partial pressures of 0.01 and 1 bar, representing natural background levels and levels expected in an aquifer impacted by a small leakage, respectively. Concentrations of major (e.g., Ca, Mg) and trace (e.g., As, Ba, Cd, Fe, Mn, Pb, Sr, U) elements increased rapidly after CO2 was introduced into the system, but did not exceed primary Maximum Contaminant Levels set by the U.S. Environmental Protection Agency. Results of sequential extraction suggest that carbonate minerals, although volumetrically insignificant in the sandstone samples, are the dominant source of mobile metals. This interpretation is supported by a simple geochemical model, which could simulate observed changes in fluid composition through CO2-induced calcite and dolomite dissolution.

  12. Electrometallurgical treatment of oxide spent fuels

    International Nuclear Information System (INIS)

    Karell, E. J.

    1999-01-01

    The Department of Energy (DOE) inventory of spent nuclear fuel contains a wide variety of oxide fuel types that may be unsuitable for direct repository disposal in their current form. The molten-salt electrometallurgical treatment technique developed by Argonne National Laboratory (ANL) has the potential to simplify preparing and qualifying these fuels for disposal by converting them into three uniform product streams: uranium metal, a metal waste form, and a ceramic waste form. This paper describes the major steps in the electrometallurgical treatment process for oxide fuels and provides the results of recent experiments performed to develop and scale up the process

  13. Laser surveillance system for spent fuel

    International Nuclear Information System (INIS)

    Fiarman, S.; Zucker, M.S.; Bieber, A.M. Jr.

    1980-01-01

    A laser surveillance system installed at spent fuel storage pools will provide the safeguard inspector with specific knowledge of spent fuel movement that cannot be obtained with current surveillance systems. The laser system will allow for the division of the pool's spent fuel inventory into two populations - those assemblies which have been moved and those which haven't - which is essential for maximizing the efficiency and effectiveness of the inspection effort. We have designed, constructed, and tested a laser system and have used it with a simulated BWR assembly. The reflected signal from the zircaloy rods depends on the position of the assembly, but in all cases is easily discernable from the reference scan of background with no assembly

  14. Laser surveillance system for spent fuel

    International Nuclear Information System (INIS)

    Fiarman, S.; Zucker, M.S.; Bieber, A.M. Jr.

    1980-01-01

    A laser surveillance system installed at spent fuel storage pools (SFSP's) will provide the safeguard inspector with specific knowledge of spent fuel movement that cannot be obtained with current surveillance systems. The laser system will allow for the division of the pool's spent fuel inventory into two populations - those assemblies which have been moved and those which haven't - which is essential for maximizing the efficiency and effectiveness of the inspection effort. We have designed, constructed, and tested a full size laser system operating in air and have used an array of 6 zircaloy BWR tubes to simulate an assembly. The reflective signal from the zircaloy rods is a strong function of position of the assembly, but in all cases is easily discernable from the reference scan of the background with no assembly. A design for a SFSP laser surveillance system incorporating laser ranging is discussed. 10 figures

  15. Advanced waste forms from spent nuclear fuel

    International Nuclear Information System (INIS)

    Ackerman, J.P.; McPheeters, C.C.

    1995-01-01

    More than one hundred spent nuclear fuel types, having an aggregate mass of more than 5000 metric tons (2700 metric tons of heavy metal), are stored by the United States Department of Energy. This paper proposes a method for converting this wide variety of fuel types into two waste forms for geologic disposal. The method is based on a molten salt electrorefining technique that was developed for conditioning the sodium-bonded, metallic fuel from the Experimental Breeder Reactor-II (EBR-II) for geologic disposal. The electrorefining method produces two stable, optionally actinide-free, high-level waste forms: an alloy formed from stainless steel, zirconium, and noble metal fission products, and a ceramic waste form containing the reactive metal fission products. Electrorefining and its accompanying head-end process are briefly described, and methods for isolating fission products and fabricating waste forms are discussed

  16. Molecular dynamics simulation of nanotribology properties of CuZr metallic glasses

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Cheng-Da [Chung Yuan Christian University, Department of Mechanical Engineering, Taoyuan City (China)

    2016-04-15

    The effects of scratch depth, scratch speed, and alloy composition on the mechanical deformation and nanotribology properties of CuZr metallic glasses are studied using molecular dynamics simulations based on the second-moment approximation of the many-body tight-binding potential. These effects are investigated in terms of atomic trajectories, slip vectors, friction force, normal force, and friction coefficient. The simulation results show that a few shear transformation zones independently develop at the contact area between the probe tip and the film. Pileup occurs in the nanoscratch process but not during nanoindentation at a depth of 2.4 nm. There are two areas on the surface where the atoms have high slip vector values during nanoscratching. These areas form due to the removal of atoms that piled up around the probe tip and those behind the probe tip, respectively. Both the friction force and the normal force increase with increasing scratch depth and scratch speed. Friction coefficients decrease with increasing scratch depth, scratch speed, and Zr content in films. (orig.)

  17. Stress Analysis of Non-Ferrous Metals Welds by Numerical Simulation

    Directory of Open Access Journals (Sweden)

    Kravarikova Helena

    2017-01-01

    Full Text Available Thermal energy welded material unevenly heated and thus supports the creation of tension. During the fusing process welding transient tensions generated in the welded material. Generation of the transient tensions depends on the thermal expansion and fixed permanently welded parts. Tensions are the result of the interaction of material particles. For welded parts and constructions it is necessary to know the size and direction of application of tensions. The emerging tensions can cause local change or a total deformation of welded materials. Deformations and residual stresses impair the performance of a welded construction, reduces the stability of the parts. To reduce or eliminate of action or a screening direction stresses and strains it is necessary to know the mechanism of their emergence. It is now possible to examine the emergence of tensions numerical experiments on any model using numerical simulation using FEM. Results of numerical experiment is the analysis of stress and deformation course. In the plane the tension it divided into normal σ and τ tangential folders. Decomposition stress on components simplifies the stress analysis. The results obtained from numerical analysis are correct to predict the stress distribution and size. The paper presents the results of numerical experiments stress analysis solutions fillet welds using FEM numerical simulation of welding of non-ferrous metals.

  18. In vitro analysis of nanotoxicity of metallic nanoparticles in simulated intracorporeal bio-environment

    International Nuclear Information System (INIS)

    Meng Huan; Chen Zhen; Zhang Chengcheng; Zhao Yuliang; Xing Gengmei; Yuan Hui; Chen Chunying; Zhao Feng; Ye Chang; Jia Guang; Wang Xiang

    2005-01-01

    The wildly uses of copper in the various aspects of the life and industry have proved that microsized copper is a substance of very low toxicity. However, the recent experimental results indicate that the acute toxicity of nanosized particles in mice is dramatically different from the microsized particles of copper. The biological toxicity of copper showed increasing feature with the decrease of the particle size. To further study these observations, chemical oxidation-reduction titration analysis was carried out to study the kinetics of nano copper particles in simulated gastric juice. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) (Thermo Elemental X7) was used to detect the content of copper in the organs of mice exposed to a wide range of doses. These in vitro studies of chemical reactivity suggest that the nano-sized copper is extremely reactive in simulated intracorporeal environment. The nano copper particles can be converted into ionic form much easier than micro particles of the identical quantity under the same conditions in vitro. The hydrogen ion consumed by nano-sized copper in stomach is dramatically quicker than by micro copper particles. At the presentation, we will discuss the analyzed results for the different distribution of nanoparticles, the different mortality in nano copper treated animal groups between male and female mice, and show evidences demonstrating that the huge surface area as well the ultrahigh chemical reactivity would be the main causes dominating the biological activity/toxicity of metallic nanoparticles in vivo.

  19. The cavitation erosion of ultrasonic sonotrode during large-scale metallic casting: Experiment and simulation.

    Science.gov (United States)

    Tian, Yang; Liu, Zhilin; Li, Xiaoqian; Zhang, Lihua; Li, Ruiqing; Jiang, Ripeng; Dong, Fang

    2018-05-01

    Ultrasonic sonotrodes play an essential role in transmitting power ultrasound into the large-scale metallic casting. However, cavitation erosion considerably impairs the in-service performance of ultrasonic sonotrodes, leading to marginal microstructural refinement. In this work, the cavitation erosion behaviour of ultrasonic sonotrodes in large-scale castings was explored using the industry-level experiments of Al alloy cylindrical ingots (i.e. 630 mm in diameter and 6000 mm in length). When introducing power ultrasound, severe cavitation erosion was found to reproducibly occur at some specific positions on ultrasonic sonotrodes. However, there is no cavitation erosion present on the ultrasonic sonotrodes that were not driven by electric generator. Vibratory examination showed cavitation erosion depended on the vibration state of ultrasonic sonotrodes. Moreover, a finite element (FE) model was developed to simulate the evolution and distribution of acoustic pressure in 3-D solidification volume. FE simulation results confirmed that significant dynamic interaction between sonotrodes and melts only happened at some specific positions corresponding to severe cavitation erosion. This work will allow for developing more advanced ultrasonic sonotrodes with better cavitation erosion-resistance, in particular for large-scale castings, from the perspectives of ultrasonic physics and mechanical design. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. Electronic excitations and their effect on the interionic forces in simulations of radiation damage in metals

    International Nuclear Information System (INIS)

    Race, C P; Mason, D R; Sutton, A P

    2009-01-01

    Using time-dependent tight-binding simulations of radiation damage cascades in a model metal we directly investigate the nature of the excitations of a system of quantum mechanical electrons in response to the motion of a set of classical ions. We furthermore investigate the effect of these excitations on the attractive electronic forces between the ions. We find that the electronic excitations are well described by a Fermi-Dirac distribution at some elevated temperature, even in the absence of the direct electron-electron interactions that would be required in order to thermalize a non-equilibrium distribution. We explain this result in terms of the spectrum of characteristic frequencies of the ionic motion. Decomposing the electronic force into four well-defined components within the basis of instantaneous electronic eigenstates, we find that the effect of accumulated excitations in weakening the interionic bonds is mostly (95%) accounted for by a thermal model for the electronic excitations. This result justifies the use of the simplifying assumption of a thermalized electron system in simulations of radiation damage with an electronic temperature dependence and in the development of temperature-dependent classical potentials.

  1. Dose perturbation in the presence of metallic implants: treatment planning system versus Monte Carlo simulations

    International Nuclear Information System (INIS)

    Wieslander, Elinore; Knoeoes, Tommy

    2003-01-01

    An increasing number of patients receiving radiation therapy have metallic implants such as hip prostheses. Therefore, beams are normally set up to avoid irradiation through the implant; however, this cannot always be accomplished. In such situations, knowledge of the accuracy of the used treatment planning system (TPS) is required. Two algorithms, the pencil beam (PB) and the collapsed cone (CC), are implemented in the studied TPS. Comparisons are made with Monte Carlo simulations for 6 and 18 MV. The studied materials are steel, CoCrMo, Orthinox(a stainless steel alloy and registered trademark of Stryker Corporation), TiAlV and Ti. Monte Carlo simulated depth dose curves and dose profiles are compared to CC and PB calculated data. The CC algorithm shows overall a better agreement with Monte Carlo than the PB algorithm. Thus, it is recommended to use the CC algorithm to get the most accurate dose calculation both for the planning target volume and for tissues adjacent to the implants when beams are set up to pass through implants

  2. Electronic excitations and their effect on the interionic forces in simulations of radiation damage in metals.

    Science.gov (United States)

    Race, C P; Mason, D R; Sutton, A P

    2009-03-18

    Using time-dependent tight-binding simulations of radiation damage cascades in a model metal we directly investigate the nature of the excitations of a system of quantum mechanical electrons in response to the motion of a set of classical ions. We furthermore investigate the effect of these excitations on the attractive electronic forces between the ions. We find that the electronic excitations are well described by a Fermi-Dirac distribution at some elevated temperature, even in the absence of the direct electron-electron interactions that would be required in order to thermalize a non-equilibrium distribution. We explain this result in terms of the spectrum of characteristic frequencies of the ionic motion. Decomposing the electronic force into four well-defined components within the basis of instantaneous electronic eigenstates, we find that the effect of accumulated excitations in weakening the interionic bonds is mostly (95%) accounted for by a thermal model for the electronic excitations. This result justifies the use of the simplifying assumption of a thermalized electron system in simulations of radiation damage with an electronic temperature dependence and in the development of temperature-dependent classical potentials.

  3. Noble metal catalyzed hydrogen generation from formic acid in nitrite-containing simulated nuclear waste media

    International Nuclear Information System (INIS)

    King, R.B.; Bhattacharyya, N.K.; Wiemers, K.D.

    1994-08-01

    Simulants for the Hanford Waste Vitrification Plant (HWVP) feed containing the major non-radioactive components Al, Cd, Fe, Mn, Nd, Ni, Si, Zr, Na, CO 3 2- , NO 3 -, and NO 2 - were used as media to evaluate the stability of formic acid towards hydrogen evolution by the reaction HCO 2 H → H 2 + CO 2 catalyzed by the noble metals Ru, Rh, and/or Pd found in significant quantities in uranium fission products. Small scale experiments using 40-50 mL of feed simulant in closed glass reactors (250-550 mL total volume) at 80-100 degree C were used to study the effect of nitrite and nitrate ion on the catalytic activities of the noble metals for formic acid decomposition. Reactions were monitored using gas chromatography to analyze the CO 2 , H 2 , NO, and N 2 O in the gas phase as a function of time. Rhodium, which was introduced as soluble RhCl 3 ·3H 2 O, was found to be the most active catalyst for hydrogen generation from formic acid above ∼80 degree C in the presence of nitrite ion in accord with earlier observations. The inherent homogeneous nature of the nitrite-promoted Rh-catalyzed formic acid decomposition is suggested by the approximate pseudo first-order dependence of the hydrogen production rate on Rh concentration. Titration of the typical feed simulants containing carbonate and nitrite with formic acid in the presence of rhodium at the reaction temperature (∼90 degree C) indicates that the nitrite-promoted Rh-catalyzed decomposition of formic acid occurs only after formic acid has reacted with all of the carbonate and nitrite present to form CO 2 and NO/N 2 O, respectively. The catalytic activities of Ru and Pd towards hydrogen generation from formic acid are quite different than those of Rh in that they are inhibited rather than promoted by the presence of nitrite ion

  4. Options and processes for spent catalyst handling and utilization.

    Science.gov (United States)

    Marafi, M; Stanislaus, A

    2003-07-18

    The quantity of spent hydroprocessing catalysts discarded as solid wastes in the petroleum refining industries has increased remarkably in recent years due to a rapid growth in the hydroprocessing capacity to meet the rising demand for low-sulfur fuels. Due to their toxic nature, spent hydroprocessing catalysts have been branded as hazardous wastes, and the refiners are experiencing pressure from environmental authorities to handle them safely. Several alternative methods such as reclamation of metals, rejuvenation and reuse, disposal in landfills and preparation of useful materials using spent catalysts as raw materials are available to deal with the spent catalyst problem. The technical feasibility as well as the environmental and economic aspects of these options are reviewed. In addition, details of two bench-scale processes, one for rejuvenation of spent hydroprocessing catalysts, and the other for producing non-leachable synthetic aggregate materials that were developed in this laboratory, are presented in this paper.

  5. Spent fuel dissolution mechanisms

    International Nuclear Information System (INIS)

    Ollila, K.

    1993-11-01

    This study is a literature survey on the dissolution mechanisms of spent fuel under disposal conditions. First, the effects of radiolysis products on the oxidative dissolution mechanisms and rates of UO 2 are discussed. These effects have mainly been investigated by using electrochemical methods. Then the release mechanisms of soluble radionuclides and the dissolution of the UO 2 matrix including the actinides, are treated. Experimental methods have been developed for measuring the grain-boundary inventories of radionuclides. The behaviour of cesium, strontium and technetium in leaching tests shows different trends. Comparison of spent fuel leaching data strongly suggests that the release of 90 Sr into the leachant can be used as a measure of the oxidation/dissolution of the fuel matrix. Approaches to the modelling UO 2 , dissolution are briefly discussed in the next chapter. Lastly, the use of natural material, uraninite, in the evaluation of the long-term performance of spent fuel is discussed. (orig.). (81 ref., 37 figs., 8 tabs.)

  6. Finite Element Method Simulations of the Near-Field Enhancement at the Vicinity of Fractal Rough Metallic Surfaces

    International Nuclear Information System (INIS)

    Micic, Miodrag; Klymyshyn, Nicholas A.; Lu, H Peter

    2004-01-01

    Near-field optical enhancement at metal surfaces and methods such as surface plasmon resonance (SPR), surface-enhanced Raman scattering (SERS), fluorescent quenching and enhancement, and various near-field scanning microscopies (NSOM) all depend on a metals surface properties, mainly on its morphology and SPR resonant frequency. We report on simulations of the influence of different surface morphologies on electromagnetic field enhancements at the rough surfaces of noble metals and also evaluate the optimal conditions for the generation of a surface-enhanced Raman signal of absorbed species on a metallic substrate. All simulations were performed with a classical electrodynamics approach using the full set of Maxwells equations, which were solved with the three-dimensional finite element method (FEM). Two different classes of surfaces where modeled using fractals, representing diffusion limited aggregation growth dendritic structures, such as one on the surface of electrodes, and second one representing the sponge-like structure used to model surfaces of particles with high porosity, such as metal coated catalyst supports. The simulations depict the high inhomogeneity of an enhanced electromagnetic field as both a field enhancement and field attenuation near the surface. While the diffusion limited aggregation dendritical fractals enhanced the near-field electromagnetic field, the sponge fractals significantly reduced the local electromagnetic field intensity. Moreover, the fractal orders of the fractal objects did not significantly alter the total enhancement, and the distribution of a near-field enhancement was essentially invariant to the changes in the angle of an incoming laser beam

  7. Impact of simulated acid rain on trace metals and aluminum leaching in latosol from Guangdong Province, China

    Science.gov (United States)

    Jia-En Zhang; Jiayu Yu; Ying Ouyang; Huaqin. Xu

    2014-01-01

    Acid rain is one of the most serious ecological and environmental problems worldwide. This study investigated the impacts of simulated acid rain (SAR) upon leaching of trace metals and aluminum (Al) from a soil. Soil pot leaching experiments were performed to investigate the impacts of SAR at five different pH levels (or treatments) over a 34-day period upon the...

  8. CO 2 adsorption in mono-, di- and trivalent cation-exchanged metal-organic frameworks: A molecular simulation study

    KAUST Repository

    Chen, Yifei; Nalaparaju, Anjaiah; Eddaoudi, Mohamed; JIANG, Jianwen

    2012-01-01

    A molecular simulation study is reported for CO 2 adsorption in rho zeolite-like metal-organic framework (rho-ZMOF) exchanged with a series of cations (Na +, K +, Rb +, Cs +, Mg 2+, Ca 2+, and Al 3+). The isosteric heat and Henry's constant

  9. Development of spent fuel remote handling technology

    International Nuclear Information System (INIS)

    Yoon, J. S.; Hong, H. D.; Kim, Y. H.

    2001-03-01

    Since the amount of the spent fuel rapidly increases, the current R and D activities are focused on the technology development related with the storage and utilization of the spent fuel. In this research, to provide such a technology, the mechanical head-end process has been developed. In detail, the swing and shock-free crane and the RCGLUD(Remote Cask Grappling and Lid Unbolting Device) were developed for the safe transportation of the spent fuel assembly, the LLW drum and the transportation cask. Also, the disassembly devices required for the head-end process were developed. This process consists of an assembly downender, a rod extractor, a rod cutter, a fuel decladding device, a skeleton compactor, a force-rectifiable manipulator for the abnormal spent fuel disassembly, and the gantry type telescopic transporter, etc. To provide reliability and safety of these devices, the 3 dimensional graphic design system is developed. In this system, the mechanical devices are modelled and their operation is simulated in the virtual environment using the graphic simulation tools. So that the performance and the operational mal-function can be investigated prior to the fabrication of the devices. All the devices are tested and verified by using the fuel prototype at the mockup facility

  10. Fabrication of simulated DUPIC fuel

    Science.gov (United States)

    Kang, Kweon Ho; Song, Ki Chan; Park, Hee Sung; Moon, Je Sun; Yang, Myung Seung

    2000-12-01

    Simulated DUPIC fuel provides a convenient way to investigate the DUPIC fuel properties and behavior such as thermal conductivity, thermal expansion, fission gas release, leaching, and so on without the complications of handling radioactive materials. Several pellets simulating the composition and microstructure of DUPIC fuel are fabricated by resintering the powder, which was treated through OREOX process of simulated spent PWR fuel pellets, which had been prepared from a mixture of UO2 and stable forms of constituent nuclides. The key issues for producing simulated pellets that replicate the phases and microstructure of irradiated fuel are to achieve a submicrometre dispersion during mixing and diffusional homogeneity during sintering. This study describes the powder treatment, OREOX, compaction and sintering to fabricate simulated DUPIC fuel using the simulated spent PWR fuel. The homogeneity of additives in the powder was observed after attrition milling. The microstructure of the simulated spent PWR fuel agrees well with the other studies. The leading structural features observed are as follows: rare earth and other oxides dissolved in the UO2 matrix, small metallic precipitates distributed throughout the matrix, and a perovskite phase finely dispersed on grain boundaries.

  11. Safeguardability of advanced spent fuel conditioning process

    Energy Technology Data Exchange (ETDEWEB)

    Li, T. K. (Tien K.); Lee, S. Y. (Sang Yoon); Burr, Tom; Russo, P. A. (Phyllis A.); Menlove, Howard O.; Kim, H. D.; Ko, W. I. (Won Il); Park, S. W.; Park, H. S.

    2004-01-01

    The Advanced Spent Fuel Conditioning Process (ACP) is an electro-metallurgical treatment technique to convert oxide-type spent nuclear fuel into a metallic form. The Korea Atomic Energy Research Institute (KAERI) has been developing this technology since 1977 for the purpose of spent fuel management and is planning to perform a lab-scale demonstration in 2006. By using of this technology, a significant reduction of the volume and heat load of spent fuel is expected, which would lighten the burden of final disposal in terms of disposal size, safety and economics. In the framework of collaboration agreement to develop the safeguards system for the ACP, a joint study on the safeguardability of the ACP technology has been performed by the Los Alamos National Laboratory (LANL) and the KAERI since 2002. In this study, the safeguardability of the ACP technology was examined for the pilot-scale facility. The process and material flows were conceptually designed, and the uncertainties in material accounting were estimated with international target values.

  12. Geotechnical and large numeric studies on direct ultimate disposal of spent fuel elements. Project part 1: Thermal simulation of gallery storage. Final report (8th report)

    International Nuclear Information System (INIS)

    Heusermann, S.; Liedtke, L.; Soennke, J.; Sprado, K.H.; Gloeggler, W.

    1995-01-01

    Short-term tension measurements show that a reduced rock tension level exists in the Thermal Storage Simulation field (TSS). This tension level is markedly lower than the lithostatic rock pressure to be expected in the salt rock. The long-term tension measurements show that tension maxima will develop until early in 1993 in the close-in area of the experimental fields, for instance in the pillar between the galleries A and B. Creep tests with salt rock specimens from the TSS field show that the creep performance at room temperature of the Na2β rock salt to be considered in the experimental fields can be sufficiently accurately described by the reference creep law for stationary creep used by the BGR (Bundesanstalt f. Geowissenschaften und Rohstoffe).The experimental in-situ results on the permeability of the salt rock in the experimental fields indicate i.a. very low permeabilities, except for a restricted, local area within the loosening zone below gallery B. This exhibits relatively high permeabilities. The experimental in-situ results on the permeability of the backfilling in the experimental galleries show that during the experimental measuring period, an only small change in permeability due to compaction of the backfilling material was observed. This result agrees with results of compaction tests performed by the GSF. The measured results show a difference in permeabilities between backfilling material subject to heating up, and colder material. (orig.) [de

  13. Analysis and simulation of non-metallic inclusions in spheroidal graphite iron

    International Nuclear Information System (INIS)

    Pustal, B; Schelnberger, B; Bührig-Polaczek, A

    2016-01-01

    Non-metallic inclusions in spheroidal cast iron (SGI) reduce fatigue strength and yield strength. This type of inclusion usually accumulates at grain boundaries. Papers addressing this topic show the overall impact of both the fraction of so-called white (carbides) and black (non-metallic) inclusions on mechanical properties. In the present work we focus on the origin and the formation conditions of black Mg-bearing inclusions, further distinguishing between Si-bearing and non-Si-bearing Mg inclusions. The formation was simulated applying thermodynamic approaches. Moreover, appropriate experiments have been carried out and a large number of particles have been studied applying innovative feature analysis with regard to shape, size, and composition. Magnesium silicates are predicted at elevated oxygen concentrations, whereas at low levels of oxygen sulphides and carbides appear at a late stage of solidification. Experiments with three consecutive flow obstacles show that the amount of magnesium silicates decrease after each of the three obstacles, whereas the fraction of non-Si-bearing inclusions remains approximately constant. The size of inclusions divides in halves over the flow path and the number of particles increases accordingly. We point out that based on feature analysis Mg-O-C bearing inclusion show disadvantageous form factors for which reason this kind of inclusions may be extremely harmful in terms of crack initiation. All results obtained indicate that magnesium silicates are entrapped on mould filling, whereas Mg-(O, C, S, P, N) bearing particles are precipitates at late stages of solidification. Consequently, the only avoidance strategy is setting up optimum retained magnesium content. (paper)

  14. ENVI Model Development for Korean Nuclear Spent Fuel Options Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Sunyoung; Jeong, Yon Hong; Han, Jae-Jun; Lee, Aeri; Hwang, Yong-Soo [Korea Institute of Nuclear Nonproliferation and Control, Daejeon (Korea, Republic of)

    2015-10-15

    The disposal facility of the spent nuclear fuel will be operated from 2051. This paper presents the ENVI code developed by GoldSim Software to simulate options for managing spent nuclear fuel (SNF) in South Korea. The ENVI is a simulator to allow decision-makers to assist to evaluate the performance for spent nuclear fuel management. The multiple options for managing the spent nuclear fuel including the storage and transportation are investigated into interim storage, permanent disposal in geological repositories and overseas and domestic reprocessing. The ENVI code uses the GoldSim software to simulate the logistics of the associated activities. The result by the ENVI model not only produces the total cost to compare among the multiple options but also predict the sizes and timings of different facilities required. In order to decide the policy for spent nuclear management this purpose of this paper is to draw the optimum management plan to solve the nuclear spent fuel issue in the economical aspects. This paper is focused on the development of the ENVI's logic and calculations to simulate four options(No Reprocessing, Overseas Reprocessing, Domestic Reprocessing, and Overseas and Domestic Reprocessing) for managing the spent nuclear fuel in South Korea. The time history of the spent nuclear fuel produced from both the existing and future NPP's can be predicted, based on the Goldsim software made available very user friendly model. The simulation result will be used to suggest the strategic plans for the spent nuclear fuel management.

  15. ENVI Model Development for Korean Nuclear Spent Fuel Options Analysis

    International Nuclear Information System (INIS)

    Chang, Sunyoung; Jeong, Yon Hong; Han, Jae-Jun; Lee, Aeri; Hwang, Yong-Soo

    2015-01-01

    The disposal facility of the spent nuclear fuel will be operated from 2051. This paper presents the ENVI code developed by GoldSim Software to simulate options for managing spent nuclear fuel (SNF) in South Korea. The ENVI is a simulator to allow decision-makers to assist to evaluate the performance for spent nuclear fuel management. The multiple options for managing the spent nuclear fuel including the storage and transportation are investigated into interim storage, permanent disposal in geological repositories and overseas and domestic reprocessing. The ENVI code uses the GoldSim software to simulate the logistics of the associated activities. The result by the ENVI model not only produces the total cost to compare among the multiple options but also predict the sizes and timings of different facilities required. In order to decide the policy for spent nuclear management this purpose of this paper is to draw the optimum management plan to solve the nuclear spent fuel issue in the economical aspects. This paper is focused on the development of the ENVI's logic and calculations to simulate four options(No Reprocessing, Overseas Reprocessing, Domestic Reprocessing, and Overseas and Domestic Reprocessing) for managing the spent nuclear fuel in South Korea. The time history of the spent nuclear fuel produced from both the existing and future NPP's can be predicted, based on the Goldsim software made available very user friendly model. The simulation result will be used to suggest the strategic plans for the spent nuclear fuel management

  16. Analysis of material flow in metal forming processes by using computer simulation and experiment with model material

    International Nuclear Information System (INIS)

    Kim, Heon Young; Kim, Dong Won

    1993-01-01

    The objective of the present study is to analyze material flow in the metal forming processes by using computer simulation and experiment with model material, plasticine. A UBET program is developed to analyze the bulk flow behaviour of various metal forming problems. The elemental strain-hardening effect is considered in an incremental manner and the element system is automatically regenerated at every deforming step in the program. The material flow behaviour in closed-die forging process with rib-web type cavity are analyzed by UBET and elastic-plastic finite element method, and verified by experiments with plasticine. There were good agreements between simulation and experiment. The effect of corner rounding on material flow behavior is investigated in the analysis of backward extrusion with square die. Flat punch indentation process is simulated by UBET, and the results are compared with that of elastic-plastic finite element method. (Author)

  17. Spent fuel storage requirements

    International Nuclear Information System (INIS)

    Fletcher, J.

    1982-06-01

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

  18. Spent fuel transportation problems

    International Nuclear Information System (INIS)

    Kondrat'ev, A.N.; Kosarev, Yu.A.; Yulikov, E.A.

    1977-01-01

    In this paper, problems of transportation of nuclear spent fuel to reprocessing plants are discussed. The solutions proposed are directed toward the achievement of the transportation as economic and safe as possible. The increase of the nuclear power plants number in the USSR and the great distances between these plants and the reprocessing plants involve an intensification of the spent fuel transportation. Higher burnup and holdup time reduction cause the necessity of more bulky casks. In this connection, the economic problems become still more important. One of the ways of the problem solution is the development of rational and cheap cask designs. Also, the enforcement in the world of the environmental and personnel health protection requires to increase the transportation reliability and safety. The paper summarizes safe transportation rules with clarifying the following questions: the increase of the transport unit quantity of the spent fuel; rational shipment organization that minimizes vehicle turnover cycle duration; development of the reliable calculation methods to determine strength, thermal conditions and nuclear safety of transport packaging as applied to the vehicles of high capacity; maximum unification of vehicles, calculation methods and documents; and cask testing on models and in pilot scale on specific test rigs to assure that they meet the international safe fuel shipment rules. Besides, some considerations on the choice and use of structural materials for casks are given, and problems of manufacturing such casks from uranium and lead are considered, as well as problems of the development of fireproof shells, control instrumentation, vehicles decontamination, etc. All the problems are considered from the point of view of normal and accidental shipment conditions. Conclusions are presented [ru

  19. Noble metal (NM) behavior during simulated HLLW vitrification in induction melter with cold crucible

    International Nuclear Information System (INIS)

    Demin, A.V.; Matyunin, Y.I.; Fedorova, M.I.

    1995-01-01

    The investigation of noble metal (Ru, Rh, Pd) properties in, glass melts are connected with their specific behaviors during HLLW vitrification. Ruthenium, rhodium and palladium volatilities and heterogeneous platinoid phases forming on melts are investigated in reasonable details conformably to Joule's heating ceramic melters. The vitrification conditions in melters with induction heating of melts are differ from the vitrification ones in ceramic melters on some numbers of parameters (the availability of significant temperature gradients and convection flows in melts, short time of molten mass updating in melter and probability of definite interaction between high-frequency field and melt inhomogeneities). The results of simulated HLLW solidification modelling of the vitrification process in induction melter with cold crucible to produce phosphate and boron-silicate materials are presented. The properties of received glasses and behavior of platinoids are shown to have analogies and distinctions in comparison with compounds, synthesized in ceramic melter. The structures of dispersed particles of NM heterogeneous phases forming in glass melts prepared in induction melter with cold crucible are identified. The results of investigations show, that the marked distinctions between two processes can influence (in definite degree) as on property of synthesized materials, as on behavior of platinoid during vitrifications

  20. Simulation Based Investigation of Focusing Phased Array Ultrasound in Dissimilar Metal Welds

    Directory of Open Access Journals (Sweden)

    Hun-Hee Kim

    2016-02-01

    Full Text Available Flaws at dissimilar metal welds (DMWs, such as reactor coolant systems components, Control Rod Drive Mechanism (CRDM, Bottom Mounted Instrumentation (BMI etc., in nuclear power plants have been found. Notably, primary water stress corrosion cracking (PWSCC in the DMWs could cause significant reliability problems at nuclear power plants. Therefore, phased array ultrasound is widely used for inspecting surface break cracks and stress corrosion cracks in DMWs. However, inspection of DMWs using phased array ultrasound has a relatively low probability of detection of cracks, because the crystalline structure of welds causes distortion and splitting of the ultrasonic beams which propagates anisotropic medium. Therefore, advanced evaluation techniques of phased array ultrasound are needed for improvement in the probability of detection of flaws in DMWs. Thus, in this study, an investigation of focusing and steering phased array ultrasound in DMWs was carried out using a time reversal technique, and an adaptive focusing technique based on finite element method (FEM simulation. Also, evaluation of focusing performance of three different focusing techniques was performed by comparing amplitude of phased array ultrasonic signals scattered from the targeted flaw with three different time delays.

  1. A numerical simulation of metallic cylindrical sandwich shells subjected to air blast loading

    Directory of Open Access Journals (Sweden)

    Lin Jing

    Full Text Available The dynamic response of cylindrical sandwich shells with aluminum foam cores subjected to air blast loading was investigated numerically in this paper. According to KNR theory, the nonlinear compressibility of the air and finite shock conditions were taken into account in the finite element model. Numerical simulation results show that the compression strain, which plays a key role on energy absorption, increases approximately linearly with normalized impulse, and reduces with increasing relative density or the ratio of face-sheet thickness and core thickness. An increase of the impulse will delay the equalization of top and bottom face-sheet velocities of sandwich shell, but there is a maximum value in the studied bound. A limited study of weight optimization was carried out for sandwich shells with respect to the respective geometric parameters, including face-sheet thickness, core thickness and core relative density. These numerical results are of worth to theoretical prediction and engineering application of cellular metal sandwich structures.

  2. Performance of hybrid nano-micro reinforced mg metal matrix composites brake calliper: simulation approach

    Science.gov (United States)

    Fatchurrohman, N.; Chia, S. T.

    2017-10-01

    Most commercial vehicles use brake calliper made of grey cast iron (GCI) which possesses heavy weight. This contributes to the total weight of the vehicle which can lead to higher fuel consumption. Another major problem is GCI calliper tends to deflect during clamping action, known as “bending of bridge”. This will result in extended pedal travel. Magnesium metal matrix composites (Mg-MMC) has a potential application in the automotive industry since it having a lower density, higher strength and very good modulus of elasticity as compared to GCI. This paper proposed initial development of hybrid Mg-MMC brake calliper. This was achieved by analyzing the performance of hybrid nano-micro reinforced Mg-MMC and comparing with the conventional GCI brake calliper. It was performed using simulation in ANSYS, a finite element analysis (FEA) software. The results show that hybrid Mg-MMC has better performance in terms of reduction the weight of the brake calliper, reduction in total deformation/deflection and better ability to withstand equivalent elastic strain.

  3. Experimental and analytical investigation on metal damage suffered from simulated lightning currents

    Science.gov (United States)

    Yakun, LIU; Zhengcai, FU; Quanzhen, LIU; Baoquan, LIU; Anirban, GUHA

    2017-12-01

    The damage of two typical metal materials, Al alloy 3003 and steel alloy Q235B, subjected to four representative lightning current components are investigated by laboratory and analytical studies to provide fundamental data for lightning protection. The four lightning components simulating the natural lightning consist of the first return stroke, the continuing current of interval stroke, the long continuing current, and the subsequent stroke, with amplitudes 200 kA, 8 kA, 400 A, and 100 kA, respectively. The damage depth and area suffered from different lightning components are measured by the ultrasonic scanning system. And the temperature rise is measured by the thermal imaging camera. The results show that, for both Al 3003 and steel Q235B, the first return stroke component results in the largest damage area with damage depth 0.02 mm uttermost. The long continuing current component leads to the deepest damage depth of 3.3 mm for Al 3003 and much higher temperature rise than other components. The correlation analysis between damage results and lightning parameters indicates that the damage depth has a positive correlation with charge transfer. The damage area is mainly determined by the current amplitude and the temperature rise increases linearly with the charge transfer larger.

  4. Studies on the finite element simulation in sheet metal stamping processes

    Science.gov (United States)

    Huang, Ying

    The sheet metal stamping process plays an important role in modern industry. With the ever-increasing demand for shape complexity, product quality and new materials, the traditional trial and error method for setting up a sheet metal stamping process is no longer efficient. As a result, the Finite Element Modeling (FEM) method has now been widely used. From a physical point of view, the formability and the quality of a product are influenced by several factors. The design of the product in the initial stage and the motion of the press during the production stage are two of these crucial factors. This thesis focuses on the numerical simulation for these two factors using FEM. Currently, there are a number of commercial FEM software systems available in the market. These software systems are based on an incremental FEM process that models the sheet metal stamping process in small incremental steps. Even though the incremental FEM is accurate, it is not suitable for the initial conceptual design for its needing of detailed design parameters and enormous calculation times. As a result, another type of FEM, called the inverse FEM method or one-step FEM method, has been proposed. While it is less accurate than that of the incremental method, this method requires much less computation and hence, has a great potential. However, it also faces a number of unsolved problems, which limits its application. This motivates the presented research. After the review of the basic theory of the inverse method, a new modified arc-length search method is proposed to find better initial solution. The methods to deal with the vertical walls are also discussed and presented. Then, a generalized multi-step inverse FEM method is proposed. It solves two key obstacles: the first one is to determine the initial solution of the intermediate three-dimensional configurations and the other is to control the movement of nodes so they could only slide on constraint surfaces during the search by

  5. Development of advanced spent fuel management process

    International Nuclear Information System (INIS)

    Ro, Seung Gy; Shin, Y. J.; Do, J. B.; You, G. S.; Seo, J. S.; Lee, H. G.

    1998-03-01

    This study is to develop an advanced spent fuel management process for countries which have not yet decided a back-end nuclear fuel cycle policy. The aims of this process development based on the pyroreduction technology of PWR spent fuels with molten lithium, are to reduce the storage volume by a quarter and to reduce the storage cooling load in half by the preferential removal of highly radioactive decay-heat elements such as Cs-137 and Sr-90 only. From the experimental results which confirm the feasibility of metallization technology, it is concluded that there are no problems in aspects of reaction kinetics and equilibrium. However, the operating performance test of each equipment on an engineering scale still remain and will be conducted in 1999. (author). 21 refs., 45 tabs., 119 figs

  6. Evaluation of solubility in simulated lung fluid of metals present in the slag from a metallurgical industry to produce metallic zinc.

    Science.gov (United States)

    Lima, Rosilda M G; Carneiro, Luana G; Afonso, Júlio C; Cunha, Kenya M D

    2013-01-01

    The objective of this study was to determine the solubility parameters (rapid and slow dissolution rates, rapid and slow dissolution fractions) for nickel, cadmium, zinc and manganese compounds present in a pile of slag accumulated under exposure to weathering. This slag was generated by a metallurgical industry that produced zinc and zinc alloys from hemimorphite (Zn(4)(OH)(2)Si(2)O(7).H(2)O) and willemite (Zn(2)SiO(4)) minerals. A static dissolution test in vitro was used to determine the solubility parameters and Gamble's solution was used as the simulated lung fluid (SLF), on a time basis ranging from 10 min to 1 year. The metal concentrations in the slag samples and in the SLF were determined using Particle Induced X-rays Emission (PIXE). There are significant differences in terms of solubility parameters among the metals. The results indicated that the zinc, nickel, cadmium and manganese compounds present in the slag were moderately soluble in the SLF. The rapid dissolution fractions of these metals are associated with their sulfates. In conclusion, this study confirms the harmful effects on the neighboring population of the airborne particles containing these metals that came from the slag.

  7. Survey of wet and dry spent fuel storage

    International Nuclear Information System (INIS)

    1999-07-01

    Spent fuel storage is one of the important stages in the nuclear fuel cycle and stands among the most vital challenges for countries operating nuclear power plants. Continuous attention is being given by the IAEA to the collection, analysis and exchange of information on spent fuel management. Its role in this area is to provide a forum for exchanging information and for coordinating and encouraging closer co-operation among Member States. Spent fuel management is recognized as a high priority IAEA activity. In 1997, the annual spent fuel arising from all types of power reactors worldwide amounted to about 10,500 tonnes heavy metal (t HM). The total amount of spent fuel accumulated worldwide at the end of 1997 was about 200,000 t HM of which about 130,000 t HM of spent fuel is presently being stored in at-reactor (AR) or away-from-reactor (AFR) storage facilities awaiting either reprocessing or final disposal and 70,000 t HM has been reprocessed. Projections indicate that the cumulative amount generated by 2010 may surpass 340,000 t HM and by the year 2015 395,000 t HM. Part of the spent fuel will be reprocessed and some countries took the option to dispose their spent fuel in a repository. Most countries with nuclear programmes are using the deferral of a decision approach, a 'wait and see' strategy with interim storage, which provides the ability to monitor the storage continuously and to retrieve the spent fuel later for either direct disposal or reprocessing. Some countries use different approaches for different types of fuel. Today the worldwide reprocessing capacity is only a fraction of the total spent fuel arising and since no final repository has yet been constructed, there will be an increasing demand for interim storage. The present survey contains information on the basic storage technologies and facility types, experience with wet and dry storage of spent fuel and international experience in spent fuel transport. The main aim is to provide spent fuel

  8. Time-domain simulations for metallic nano-structures - a Krylov-subspace approach beyond the limitations of FDTD

    Energy Technology Data Exchange (ETDEWEB)

    Koenig, Michael [Institut fuer Theoretische Festkoerperphysik, Universitaet Karlsruhe (Germany); Karlsruhe School of Optics and Photonics (KSOP), Universitaet Karlsruhe (Germany); Niegemann, Jens; Tkeshelashvili, Lasha; Busch, Kurt [Institut fuer Theoretische Festkoerperphysik, Universitaet Karlsruhe (Germany); DFG Forschungszentrum Center for Functional Nanostructures (CFN), Universitaet Karlsruhe (Germany); Karlsruhe School of Optics and Photonics (KSOP), Universitaet Karlsruhe (Germany)

    2008-07-01

    Numerical simulations of metallic nano-structures are crucial for the efficient design of plasmonic devices. Conventional time-domain solvers such as FDTD introduce large numerical errors especially at metallic surfaces. Our approach combines a discontinuous Galerkin method on an adaptive mesh for the spatial discretisation with a Krylov-subspace technique for the time-stepping procedure. Thus, the higher-order accuracy in both time and space is supported by unconditional stability. As illustrative examples, we compare numerical results obtained with our method against analytical reference solutions and results from FDTD calculations.

  9. Spent fuel interim storage

    International Nuclear Information System (INIS)

    Bilegan, Iosif C.

    2003-01-01

    The official inauguration of the spent fuel interim storage took place on Monday July 28, 2003 at Cernavoda NNP. The inaugural event was attended by local and central public authority representatives, a Canadian Government delegation as well as newsmen from local and central mass media and numerous specialists from Cernavoda NPP compound. Mr Andrei Grigorescu, State Secretary with the Economy and Commerce Ministry, underlined in his talk the importance of this objective for the continuous development of nuclear power in Romania as well as for Romania's complying with the EU practice in this field. Also the excellent collaboration between the Canadian contractor AECL and the Romanian partners Nuclear Montaj, CITON, UTI, General Concret in the accomplishment of this unit at the planned terms and costs. On behalf of Canadian delegation, spoke Minister Don Boudria. He underlined the importance which the Canadian Government affords to the cooperation with Romania aiming at specific objectives in the field of nuclear power such as the Cernavoda NPP Unit 2 and spent fuel interim storage. After traditional cutting of the inaugural ribbon by the two Ministers the festivities continued on the Cernavoda NPP Compound with undersigning the documents regarding the project completion and a press conference

  10. Spent fuel storage rack

    International Nuclear Information System (INIS)

    Kurokawa, Hideaki; Kumagaya, Naomi; Oda, Masashi; Matsuda, Masami; Maruyama, Hiromi; Yamanaka, Tsuneyasu.

    1997-01-01

    The structure of a spent fuel storage rack is determined by the material, thickness, size of square cylindrical tubes (the gap between spent fuel assemblies and the square cylindrical tubes) and pitch of the arrangement (the gap between each of the square cylindrical tubes). In the present invention, the thickness and the pitch of the arrangement of the square tubes are optimized while evaluating subcriticality. Namely, when the sum of the thickness of the water gap at the outer side (the pitch of arrangement of the cylindrical tubes) and the thickness of the cylindrical tubes is made constant, the storage rack is formed by determining the thickness of the cylindrical tubes which is smaller than the optimum value among the combination of the thickness of the water gap at the outer side and that of the cylindrical tube under the effective multiplication factor to be performed. Then, the weight of the rack can be reduced, and the burden of the load on the bottom of the pool can be reduced. Further, the amount of the constitutional materials of the rack itself can be reduced thereby capable of reducing the cost for the materials of the rack. (T.M.)

  11. Apparatus and method for reprocessing and separating spent nuclear fuels

    International Nuclear Information System (INIS)

    Krikorian, O.H.; Grens, J.Z.; Parrish, W.H.; Coops, M.S.

    1983-01-01

    A method and apparatus for separating and reprocessing spent nuclear fuels includes a separation vessel housing a molten metal solvent in a reaction region, a reflux region positioned above and adjacent to the reaction region, and a porous filter member defining the bottom of the separation vessel in a supporting relationship with the metal solvent. Spent fuels are added to the metal solvent. A non-oxidizing nitrogen-containing gas is introduced into the separation vessel, forming solid actinide nitrides in the metal solvent from actinide fuels, while leaving other fission products in solution. A pressure of about 1.1 to 1.2 atm is applied in the reflux region, forcing the molten metal solvent and soluble fission products out of the vessel, while leaving the solid actinide nitrides in the separation vessel. (author)

  12. Investigating H₂ Sorption in a Fluorinated Metal-Organic Framework with Small Pores Through Molecular Simulation and Inelastic Neutron Scattering.

    Science.gov (United States)

    Forrest, Katherine A; Pham, Tony; Georgiev, Peter A; Pinzan, Florian; Cioce, Christian R; Unruh, Tobias; Eckert, Juergen; Space, Brian

    2015-07-07

    Simulations of H2 sorption were performed in a metal-organic framework (MOF) consisting of Zn(2+) ions coordinated to 1,2,4-triazole and tetrafluoroterephthalate ligands (denoted [Zn(trz)(tftph)] in this work). The simulated H2 sorption isotherms reported in this work are consistent with the experimental data for the state points considered. The experimental H2 isosteric heat of adsorption (Qst) values for this MOF are approximately 8.0 kJ mol(-1) for the considered loading range, which is in the proximity of those determined from simulation. The experimental inelastic neutron scattering (INS) spectra for H2 in [Zn(trz)(tftph)] reveal at least two peaks that occur at low energies, which corresponds to high barriers to rotation for the respective sites. The most favorable sorption site in the MOF was identified from the simulations as sorption in the vicinity of a metal-coordinated H2O molecule, an exposed fluorine atom, and a carboxylate oxygen atom in a confined region in the framework. Secondary sorption was observed between the fluorine atoms of adjacent tetrafluoroterephthalate ligands. The H2 molecule at the primary sorption site in [Zn(trz)(tftph)] exhibits a rotational barrier that exceeds that for most neutral MOFs with open-metal sites according to an empirical phenomenological model, and this was further validated by calculating the rotational potential energy surface for H2 at this site.

  13. A sheet metal forming simulation of automotive outer panels considering the behavior of air in die cavity

    Science.gov (United States)

    Choi, Kwang Yong; Kim, Yun Chang; Choi, Hee Kwan; Kang, Chul Ho; Kim, Heon Young

    2013-12-01

    During a sheet metal forming process of automotive outer panels, the air trapped between a blank sheet and a die tool can become highly compressed, ultimately influencing the blank deformation and the press force. To prevent this problem, vent holes are drilled into die tools and needs several tens to hundreds according to the model size. The design and the drilling of vent holes are based on expert's experience and try-out result and thus the process can be one of reasons increasing development cycle. Therefore the study on the size, the number, and the position of vent holes is demanded for reducing development cycle, but there is no simulation technology for analyzing forming defects, making numerical sheet metal forming process simulations that incorporate the fluid dynamics of air. This study presents a sheet metal forming simulation of automotive outer panels (a roof and a body side outer) that simultaneously simulates the behavior of air in a die cavity. Through CAE results, the effect of air behavior and vent holes to blank deformation was analyzed. For this study, the commercial software PAM-STAMP{trade mark, serif} and PAM-SAFE{trade mark, serif} was used.

  14. Using sequential indicator simulation to assess the uncertainty of delineating heavy-metal contaminated soils

    International Nuclear Information System (INIS)

    Juang, Kai-Wei; Chen, Yue-Shin; Lee, Dar-Yuan

    2004-01-01

    Mapping the spatial distribution of soil pollutants is essential for delineating contaminated areas. Currently, geostatistical interpolation, kriging, is increasingly used to estimate pollutant concentrations in soils. The kriging-based approach, indicator kriging (IK), may be used to model the uncertainty of mapping. However, a smoothing effect is usually produced when using kriging in pollutant mapping. The detailed spatial patterns of pollutants could, therefore, be lost. The local uncertainty of mapping pollutants derived by the IK technique is referred to as the conditional cumulative distribution function (ccdf) for one specific location (i.e. single-location uncertainty). The local uncertainty information obtained by IK is not sufficient as the uncertainty of mapping at several locations simultaneously (i.e. multi-location uncertainty or spatial uncertainty) is required to assess the reliability of the delineation of contaminated areas. The simulation approach, sequential indicator simulation (SIS), which has the ability to model not only single, but also multi-location uncertainties, was used, in this study, to assess the uncertainty of the delineation of heavy metal contaminated soils. To illustrate this, a data set of Cu concentrations in soil from Taiwan was used. The results show that contour maps of Cu concentrations generated by the SIS realizations exhausted all the spatial patterns of Cu concentrations without the smoothing effect found when using the kriging method. Based on the SIS realizations, the local uncertainty of Cu concentrations at a specific location of x', refers to the probability of the Cu concentration z(x') being higher than the defined threshold level of contamination (z c ). This can be written as Prob SIS [z(x')>z c ], representing the probability of contamination. The probability map of Prob SIS [z(x')>z c ] can then be used for delineating contaminated areas. In addition, the multi-location uncertainty of an area A

  15. European workshop on spent catalysts. Book of abstracts

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    In 1999 and 2002 two well attended workshops on recycling, regeneration, reuse and disposal of spent catalysts took place in Frankfurt. This series has been continued in Berlin. The workshop was organized in collaboration with DGMK, the German Society for Petroleum and Coal Science and Technology. Contributions were in the following areas of catalyst deactivation: recycling of spent catalysts in chemical and petrochemical industry, recycling of precious metal catalysts and heterogenous base metal catalysts, legal aspects of transboundary movements, catalyst regeneration, quality control, slurry catalysts, commercial reactivation of hydrotreating catalysts. (uke)

  16. Spent fuel management in India

    International Nuclear Information System (INIS)

    Balu, K.

    1998-01-01

    From Indian point of view, the spent fuel management by the reprocessing and plutonium recycle option is considered to be a superior and an inevitable option. The nuclear energy programme in Indian envisages three stages of implementation involving installation of thermal reactors in the first phase followed by recycling of plutonium from reprocessed fuel in fast breeder reactors and in the third phase utilization of its large thorium reserves in reactor system based on U-233-Th cycle. The Indian programme for Waste Management envisages disposal of low and intermediate level radioactive waste in near surface disposal facilities and deep geological disposal for high level and alpha bearing wastes. A Waste Immobilization Plant (WHIP), employing metallic melter for HLW vitrification is operational at Tarapur. Two more WIPs are being set up at Kalpakkam and Tarapur. A Solid waste Storage Surveillance Facility (SSSF) is also set up for interim storage of vitrified HLW. Site investigations are in progress for selecting site for ultimate disposal in igneous rock formations. R and D works is taken up on partitioning of HLW. Solvent extraction and extraction chromatographic studies are in progress. Presently emphasis is on separation of heat generating short lived nuclides like strontium and alpha emitters. (author)

  17. The spent fuel safety experiment

    International Nuclear Information System (INIS)

    Harmms, G.A.; Davis, F.J.; Ford, J.T.

    1995-01-01

    The Department of Energy is conducting an ongoing investigation of the consequences of taking fuel burnup into account in the design of spent fuel transportation packages. A series of experiments, collectively called the Spent Fuel Safety Experiment (SFSX), has been devised to provide integral benchmarks for testing computer-generated predictions of spent fuel behavior. A set of experiments is planned in which sections of unirradiated fuel rods are interchanged with similar sections of spent PWR fuel rods in a critical assembly. By determining the critical size of the arrays, one can obtain benchmark data for comparison with criticality safety calculations. The integral reactivity worth of the spent fuel can be assessed by comparing the measured delayed critical fuel loading with and without spent fuel. An analytical effort to model the experiments and anticipate the core loadings required to yield the delayed critical conditions runs in parallel with the experimental effort

  18. Fuel Rod Melt Progression Simulation Using Low-Temperature Melting Metal Alloy

    International Nuclear Information System (INIS)

    Seung Dong Lee; Suh, Kune Y.; GoonCherl Park; Un Chul Lee

    2002-01-01

    The TMI-2 accident and various severe fuel damage experiments have shown that core damage is likely to proceed through various states before the core slumps into the lower head. Numerous experiments were conducted to address when and how the core can lose its original geometry, what geometries are formed, and in what processes the core materials are transported to the lower plenum of the reactor pressure vessel. Core degradation progresses along the line of clad ballooning, clad oxidation, material interaction, metallic blockage, molten pool formation, melt progression, and relocation to the lower head. Relocation into the lower plenum may occur from the lateral periphery or from the bottom of the core depending upon the thermal and physical states of the pool. Determining the quantities and rate of molten material transfer to the lower head is important since significant amounts of molten material relocated to the lower head can threaten the vessel integrity by steam explosion and thermal and mechanical attack of the melt. In this paper the focus is placed on the melt flow regime on a cylindrical fuel rod utilizing the LAMDA (Lumped Analysis of Melting in Degrading Assemblies) facility at the Seoul National University. The downward relocation of the molten material is a combination of the external film flow and the internal pipe flow. The heater rods are 0.8 m long and are coated by a low-temperature melting metal alloy. The electrical internal heating method is employed during the test. External heating is adopted to simulate the exothermic Zircaloy-steam reaction. Tests are conducted in several quasi-steady-state conditions. Given the variable boundary conditions including the heat flux and the water level, observation is made for the melting location, progression, and the mass of molten material. Finally, the core melt progression model is developed from the visual inspection and quantitative analysis of the experimental data. As the core material relocates

  19. Spent fuel: prediction model development

    International Nuclear Information System (INIS)

    Almassy, M.Y.; Bosi, D.M.; Cantley, D.A.

    1979-07-01

    The need for spent fuel disposal performance modeling stems from a requirement to assess the risks involved with deep geologic disposal of spent fuel, and to support licensing and public acceptance of spent fuel repositories. Through the balanced program of analysis, diagnostic testing, and disposal demonstration tests, highlighted in this presentation, the goal of defining risks and of quantifying fuel performance during long-term disposal can be attained

  20. Thermal transport across metal silicide-silicon interfaces: First-principles calculations and Green's function transport simulations

    Science.gov (United States)

    Sadasivam, Sridhar; Ye, Ning; Feser, Joseph P.; Charles, James; Miao, Kai; Kubis, Tillmann; Fisher, Timothy S.

    2017-02-01

    Heat transfer across metal-semiconductor interfaces involves multiple fundamental transport mechanisms such as elastic and inelastic phonon scattering, and electron-phonon coupling within the metal and across the interface. The relative contributions of these different transport mechanisms to the interface conductance remains unclear in the current literature. In this work, we use a combination of first-principles calculations under the density functional theory framework and heat transport simulations using the atomistic Green's function (AGF) method to quantitatively predict the contribution of the different scattering mechanisms to the thermal interface conductance of epitaxial CoSi2-Si interfaces. An important development in the present work is the direct computation of interfacial bonding from density functional perturbation theory (DFPT) and hence the avoidance of commonly used "mixing rules" to obtain the cross-interface force constants from bulk material force constants. Another important algorithmic development is the integration of the recursive Green's function (RGF) method with Büttiker probe scattering that enables computationally efficient simulations of inelastic phonon scattering and its contribution to the thermal interface conductance. First-principles calculations of electron-phonon coupling reveal that cross-interface energy transfer between metal electrons and atomic vibrations in the semiconductor is mediated by delocalized acoustic phonon modes that extend on both sides of the interface, and phonon modes that are localized inside the semiconductor region of the interface exhibit negligible coupling with electrons in the metal. We also provide a direct comparison between simulation predictions and experimental measurements of thermal interface conductance of epitaxial CoSi2-Si interfaces using the time-domain thermoreflectance technique. Importantly, the experimental results, performed across a wide temperature range, only agree well with

  1. Probing adsorption sites of carbon dioxide in metal organic framework of [Zn(bdc)(dpds)]n: A molecular simulation study

    Science.gov (United States)

    Lu, Shih-I.; Liao, Jian-Min; Huang, Xiao-Zhuang; Lin, Chia-Hsun; Ke, Szu-Yu; Wang, Chih-Chieh

    2017-11-01

    We used force-field based grand-canonical Monte Carlo simulation method and density functional theory to study adsorption characteristics of carbon dioxide (CO2) molecules in a metal-organic framework (MOF) compound, [Zn(bdc)(dpds)]n. The studied MOF include a metal ion (Zn(II)), an anion organic linker (dianion of benzene dicarboxylicacid, bdc2-) and a neutral organic linker (4,4‧-dipyridyldisulfide, dpds). Results from calculated adsorption isotherms and enthalpies of adsorption agree with the experimental data. The interactions between the adsorbed CO2 and the organic linkers were examined in simulations. Calculated results show available absorption sites are surrounded by two dpds ligands in which an S-S bond as an N-N‧ spacer connect two pyridines. In contrast, the bdc2- ligand does not give a significant contribution to the substantial adsorption amount even though it contains the carboxylate group that provides available bonding site to CO2.

  2. Simulation study ε-Caprolactam monomer and metallic elements migration from irradiated polymeric packaging into food stimulants

    International Nuclear Information System (INIS)

    Rosa, Faena Machado Leite

    2008-01-01

    For decades migration study of chemical compounds from packaging into food, such as metals, residual monomers and additives, is a very important issue, concerning public health and minimize chemical contamination. In this work, it was done irradiations of packagings taken in contact with food simulant, and it was studied this migration through a mathematical model of the diffusion process, compiled in a computational simulation method in order to study the microscopic behavior of migration of metallic elements cadmium, chromium, antimony and cobalt, present in metallic plastics from dairy product packagings, and also the migration of - caprolactam monomer, present in nylon polymeric plastics used for package meat stuffs, to the food simulant acetic acid 3%. The results from simulations of the migration of -caprolactam monomer were compared with experimental results obtained from high resolution gas chromatography (HRGC) measurements, and the simulation of metallic elements migration were compared with the neutron activation analysis measurements (NAA). These experimental results were performed and kindly informed by another research groups, partners in this project. The food packaging system was discretized in one-dimension space and in time and the partial differential equation that defines the diffusive process, the second 'Fick's law', together with an equation of Arrhenius type dealing with the thermal influence, were solved using finite differences. The final step of the resolution was a tridiagonal linear system, solved using the Thomas algorithm. It was studied, and in some cases even foreseen, experimental quantities, like the diffusion coefficient, activation energy and concentration profile of migrant compounds, allowing the understanding of the diffusion process and the quantitative estimate of the migration of such compounds under ionizing radiation influence. Variation on the initial concentration levels (C 0 ) of the monomer inside the packaging

  3. Development and computational simulation of thermoelectric electromagnetic pumps for controlling the fluid flow in liquid metal cooled space nuclear reactors

    International Nuclear Information System (INIS)

    Borges, E.M.

    1991-01-01

    Thermoelectric Electromagnetic (TEEM) Pumps can be used for controlling the fluid flow in the primary and secondary circuits of liquid metal cooled space nuclear reactor. In order to simulate and to evaluate the pumps performance, in steady-state, the computer program BEMTE has been developed to study the main operational parameters and to determine the system actuation point, for a given reactor operating power. The results for each stage of the program were satisfactory, compared to experimental data. The program shows to be adequate for the design and simulating of direct current electromagnetic pumps. (author)

  4. Accelerating solidification process simulation for large-sized system of liquid metal atoms using GPU with CUDA

    Energy Technology Data Exchange (ETDEWEB)

    Jie, Liang [School of Information Science and Engineering, Hunan University, Changshang, 410082 (China); Li, KenLi, E-mail: lkl@hnu.edu.cn [School of Information Science and Engineering, Hunan University, Changshang, 410082 (China); National Supercomputing Center in Changsha, 410082 (China); Shi, Lin [School of Information Science and Engineering, Hunan University, Changshang, 410082 (China); Liu, RangSu [School of Physics and Micro Electronic, Hunan University, Changshang, 410082 (China); Mei, Jing [School of Information Science and Engineering, Hunan University, Changshang, 410082 (China)

    2014-01-15

    Molecular dynamics simulation is a powerful tool to simulate and analyze complex physical processes and phenomena at atomic characteristic for predicting the natural time-evolution of a system of atoms. Precise simulation of physical processes has strong requirements both in the simulation size and computing timescale. Therefore, finding available computing resources is crucial to accelerate computation. However, a tremendous computational resource (GPGPU) are recently being utilized for general purpose computing due to its high performance of floating-point arithmetic operation, wide memory bandwidth and enhanced programmability. As for the most time-consuming component in MD simulation calculation during the case of studying liquid metal solidification processes, this paper presents a fine-grained spatial decomposition method to accelerate the computation of update of neighbor lists and interaction force calculation by take advantage of modern graphics processors units (GPU), enlarging the scale of the simulation system to a simulation system involving 10 000 000 atoms. In addition, a number of evaluations and tests, ranging from executions on different precision enabled-CUDA versions, over various types of GPU (NVIDIA 480GTX, 580GTX and M2050) to CPU clusters with different number of CPU cores are discussed. The experimental results demonstrate that GPU-based calculations are typically 9∼11 times faster than the corresponding sequential execution and approximately 1.5∼2 times faster than 16 CPU cores clusters implementations. On the basis of the simulated results, the comparisons between the theoretical results and the experimental ones are executed, and the good agreement between the two and more complete and larger cluster structures in the actual macroscopic materials are observed. Moreover, different nucleation and evolution mechanism of nano-clusters and nano-crystals formed in the processes of metal solidification is observed with large

  5. Ab initio STM and STS simulations on magnetic and nonmagnetic metallic surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Dick, Alexey

    2008-04-14

    The aim of this work was to provide an in-depth understanding of a new generation of scan- ning tunneling microscopy experiments, performed employing different regimes of the STM: the spectroscopy-mode (the so-called Fourier Transformed STM, FT-STM), and the spin-sensitive mode (the so-called spin-polarized STM, SP-STM). In the present thesis ab initio tools are proposed that are based on DFT calculations to theoretically predict and analyze such types of the STM. The first part of this thesis focusses on the simulation of FT-STM, the mode that allows to probe local dispersion properties of the electrons at the surface. In order to provide the theoretical counterpart of the experimental FT-STM spectra we have introduced a new implicit approach that is derived from Tersoff-Hamann theory of the STM. The importance of an accurate description of surface wavefunctions at 5-15 A above the surface as well as the spurious quantum- size effects have been discussed in detail together with approaches to obtain converged FT-STM images. We applied our method to FT-STM experiments performed on Ag(110) surfaces. In the second part of the thesis we discuss the modeling of the spin-resolved STM, the mode that allows to characterize the magnetic structure of a surface. As a case system we studied here the magnetically-ordered transition-metal nitride surface Mn{sub 3}N{sub 2}(010). Because SP-STM experiments did not allow a conclusive understanding of the surface structure, we have first employed ab initio thermodynamics to figure out the most stable magnetic and atomic configuration of the surface that are consistent with experiments. To simulate SP-STM images on the most stable Mn{sub 3}N{sub 2}(010) surface we have employed the spin-generalized transfer-Hamiltonian formalism, assuming that the tip wavefunctions have dominant radial symmetry (s-like tip). (orig.)

  6. Corrosion of dissimilar metal crevices in simulated concentrated ground water solutions at elevated temperature

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, B.M.; Quinn, M.J

    2003-01-01

    The disposal of high-level nuclear waste in the Yucca Mountain, Nevada is under consideration by the US Department of Energy. The proposed facility will be located in the unsaturated zone approximately 300 m below the surface and 300 m above the water table. The proposed waste container consists of an outer corrosion-resistant Alloy 22 shell surrounding a 316 NG stainless steel structural inner container that encapsulates the used nuclear fuel waste. A titanium drip shield is proposed to protect the waste container from ground water seepage arid rock-fail. A cycle of dripping/evaporation could result in the generation of concentrated aggressive solutions, which could contact the waste container. The waste container material could be susceptible to crevice corrosion from such solutions. The experiments described in this report support the modeling of waste package degradation processes. The intent was to provide parameter values that are required to model crevice corrosion chemistry, as it relates to hydrogen pick-up, and stress corrosion cracking for selected candidate waste package materials. The purpose of the experiments was to study the crevice corrosion behavior of various candidate materials under near freely corroding conditions and to determine the pH developed in crevice solutions. Experimental results of crevice corrosion of dissimilar metal pairs (Alloy 22, Grade-7 and -16 titanium and 316 stainless steel) immersed in a simulated concentrated ground water at {approx}90{sup o}C are reported. The corrosion potential was measured during exposure periods of between 330 and 630 h. Following the experiments, the pH of the crevice solution was measured. The results indicate that a limited degree of crevice acidification occurred during the experiment. The values for corrosion potential suggest that crevice corrosion may have initiated. The total corrosion was limited, with little visible evidence for crevice corrosion being observed on the sample coupon faces

  7. Corrosion of dissimilar metal crevices in simulated concentrated ground water solutions at elevated temperature

    International Nuclear Information System (INIS)

    Ikeda, B.M.; Quinn, M.J.

    2003-01-01

    The disposal of high-level nuclear waste in the Yucca Mountain, Nevada is under consideration by the US Department of Energy. The proposed facility will be located in the unsaturated zone approximately 300 m below the surface and 300 m above the water table. The proposed waste container consists of an outer corrosion-resistant Alloy 22 shell surrounding a 316 NG stainless steel structural inner container that encapsulates the used nuclear fuel waste. A titanium drip shield is proposed to protect the waste container from ground water seepage arid rock-fail. A cycle of dripping/evaporation could result in the generation of concentrated aggressive solutions, which could contact the waste container. The waste container material could be susceptible to crevice corrosion from such solutions. The experiments described in this report support the modeling of waste package degradation processes. The intent was to provide parameter values that are required to model crevice corrosion chemistry, as it relates to hydrogen pick-up, and stress corrosion cracking for selected candidate waste package materials. The purpose of the experiments was to study the crevice corrosion behavior of various candidate materials under near freely corroding conditions and to determine the pH developed in crevice solutions. Experimental results of crevice corrosion of dissimilar metal pairs (Alloy 22, Grade-7 and -16 titanium and 316 stainless steel) immersed in a simulated concentrated ground water at ∼90 o C are reported. The corrosion potential was measured during exposure periods of between 330 and 630 h. Following the experiments, the pH of the crevice solution was measured. The results indicate that a limited degree of crevice acidification occurred during the experiment. The values for corrosion potential suggest that crevice corrosion may have initiated. The total corrosion was limited, with little visible evidence for crevice corrosion being observed on the sample coupon faces. The

  8. Design and simulation of an activated sludge unit associated to a continuous reactor to remove heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    D`Avila, J.S.; Nascimento, R.R. [Ambientec Consultoria Ltda., Aracaju, SE (Brazil)

    1993-12-31

    A software was developed to design and simulate an activated sludge unit associated to a new technology to remove heavy metals from wastewater. In this process, a continuous high efficiency biphasic reactor operates by using particles of activated peat in conjugation with the sludge unit. The results obtained may be useful to increase the efficiency or to reduce the design and operational costs involved in a activated sludge unit. (author). 5 refs., 2 tabs.

  9. Magnetic response from a composite of metal-dielectric particles in the visible range: T-matrix simulation

    Directory of Open Access Journals (Sweden)

    O. Zhuromskyy

    2011-09-01

    Full Text Available The optical response of a particle composed of a dielectric core surrounded by a densely packed shell of small metal spheres is simulated with the superposition Tmatrix method for realistic material parameters. In order to compute the electric and magnetic particle polarizabilities a single expansion T-matrix is derived from a particle centered T-matrix. Finally the permeability of a medium comprising such particles is found to deviate considerable from unity resulting in a noticeable optical response.

  10. Design and simulation of an activated sludge unit associated to a continuous reactor to remove heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    D` Avila, J S; Nascimento, R R [Ambientec Consultoria Ltda., Aracaju, SE (Brazil)

    1994-12-31

    A software was developed to design and simulate an activated sludge unit associated to a new technology to remove heavy metals from wastewater. In this process, a continuous high efficiency biphasic reactor operates by using particles of activated peat in conjugation with the sludge unit. The results obtained may be useful to increase the efficiency or to reduce the design and operational costs involved in a activated sludge unit. (author). 5 refs., 2 tabs.

  11. Parallel assembling and equation solving via graph algorithms with an application to the FE simulation of metal extrusion processes

    CERN Document Server

    Unterkircher, A

    2005-01-01

    We propose methods for parallel assembling and iterative equation solving based on graph algorithms. The assembling technique is independent of dimension, element type and model shape. As a parallel solving technique we construct a multiplicative symmetric Schwarz preconditioner for the conjugate gradient method. Both methods have been incorporated into a non-linear FE code to simulate 3D metal extrusion processes. We illustrate the efficiency of these methods on shared memory computers by realistic examples.

  12. Numerical simulation of the alloying process during impulse induction heating of the metal substrate

    Science.gov (United States)

    Popov, V. N.

    2017-10-01

    2D numerical modeling of the processes during the alloying of the substrate surface metal layer is carried out. Heating, phase transition, heat and mass transfer in the molten metal, solidification of the melt are considered with the aid the proposed mathematical model. Under study is the applicability of the high-frequency electromagnetic field impulse for metal heating and melting. The distribution of the electromagnetic energy in the metal is described by empirical formulas. According to the results of numerical experiments, the flow structure in the melt and distribution of the alloying substances is evaluated.

  13. Spent fuel treatment at ANL-West

    International Nuclear Information System (INIS)

    Goff, K.M.; Benedict, R.W.; Levinskas, D.

    1994-01-01

    At Argonne National Laboratory-West (ANL-West) there are several thousand kilograms of metallic spent nuclear fuel containing bond sodium. This fuel will be treated in the Fuel Cycle Facility at ANL-West to produce stable waste forms for storage and disposal. The treatment operations will employ a pyrochemical process that also has applications for treating most of the fuel types within the Department of Energy complex. The treatment equipment is in its last stage of readiness, and operations will begin in the Fall of 1994

  14. An advanced constitutive model in the sheet metal forming simulation: the Teodosiu microstructural model and the Cazacu Barlat yield criterion

    International Nuclear Information System (INIS)

    Alves, J.L.; Oliveira, M.C.; Menezes, L.F.

    2004-01-01

    Two constitutive models used to describe the plastic behavior of sheet metals in the numerical simulation of sheet metal forming process are studied: a recently proposed advanced constitutive model based on the Teodosiu microstructural model and the Cazacu Barlat yield criterion is compared with a more classical one, based on the Swift law and the Hill 1948 yield criterion. These constitutive models are implemented into DD3IMP, a finite element home code specifically developed to simulate sheet metal forming processes, which generically is a 3-D elastoplastic finite element code with an updated Lagrangian formulation, following a fully implicit time integration scheme, large elastoplastic strains and rotations. Solid finite elements and parametric surfaces are used to model the blank sheet and tool surfaces, respectively. Some details of the numerical implementation of the constitutive models are given. Finally, the theory is illustrated with the numerical simulation of the deep drawing of a cylindrical cup. The results show that the proposed advanced constitutive model predicts with more exactness the final shape (medium height and ears profile) of the formed part, as one can conclude from the comparison with the experimental results

  15. Comparison of Metal-on-Metal Hip Simulator Wear Measured by Gravimetric, CMM and Optical Profiling Methods

    OpenAIRE

    Alberts, Larry Russell; Martinez-Nogues, Vanesa; Cook, Richard; Maul, Christian; Bills, Paul J.; Racasan, Radu; Stolz, Martin; Wood, Robert J. K.

    2018-01-01

    Simulation of wear in artificial joint implants is critical for evaluating implant designs and materials. Traditional protocols employ the gravimetric method to determine the loss of material by measuring the weight of the implant components before and after various test intervals and after the completed test. However, the gravimetric method cannot identify the location, area coverage or maximum depth of the wear and it has difficulties with proportionally small weight changes in relatively h...

  16. Processes and Technologies for the Recycling of Spent Fluorescent Lamps

    Directory of Open Access Journals (Sweden)

    Kujawski Wojciech

    2014-09-01

    Full Text Available The growing industrial application of rare earth metals led to great interest in the new technologies for the recycling and recovery of REEs from diverse sources. This work reviews the various methods for the recycling of spent fluorescent lamps. The spent fluorescent lamps are potential source of important rare earth elements (REEs such as: yttrium, terbium, europium, lanthanum and cerium. The characteristics of REEs properties and construction of typical fl uorescent lamps is described. The work compares also current technologies which can be utilized for an efficient recovery of REEs from phosphors powders coming from spent fluorescent lamps. The work is especially focused on the hydrometallurgical and pyrometallurgical processes. It was concluded that hydrometallurgical processes are especially useful for the recovery of REEs from spent fluorescent lamps. Moreover, the methods used for recycling of REEs are identical or very similar to those utilized for the raw ores processing.

  17. Safety analysis of spent fuel transport and storage casks under extreme impact conditions

    International Nuclear Information System (INIS)

    Wolff, D.; Wieser, G.; Ballheimer, V.; Voelzke, H.; Droste, B.

    2005-01-01

    following impact of building structures of a nuclear storage facility. In this context we present methods to calculate the deformation of cask components and relative displacements between the metallic seals and their counterparts with respect to the preservation of the leak tightness. In this paper we also discuss examples of potential explosion impacts from dangerous goods on CASTOR spent fuel casks during transportation: experimental investigation of an LPG rail tank explosion next to a cask and numerical simulation of a detonation blast wave due to 21 Mg explosives in a distance of 25 m to a cask. The presented examples demonstrate the wide safety margins of the investigated monolithic cast iron transport and storage casks. (author)

  18. Production of ceramic-metal joints for high-vacuum applications and development of simulation program for discharge tube

    Energy Technology Data Exchange (ETDEWEB)

    Kang, S. H.; Chung, K. H. [Seoul National University, Seoul (Korea)

    2000-04-01

    To develop a ceramic-metal jointed tube for high-vacuum applications, metalizing process and active metal brazing were investigated. Active metal brazing was adopted as a joining process to produce a high-vacuum tube which had high joint strength and reliability. A possibility for the development of new composition of Mo-Mn paste was studied. Also, to improve the strength and reliability of active metal brazed joint, TiN coating was introduced as a diffusion barrier. It was revealed that TiN coating could improve the joint strength and reliability. 100mm {phi} tube joint was produced using incusil ABA brazing alloy. The strength and reliability of manufactured tube showed higher value than commercial one. The electric field distribution in ceramic tube under high voltage was analyzed. Two dimensional electric field distribution was investigated under the existence of charged particles. From this result, electric field distribution at the surface of ceramic tube and the location of high electric field was predicted. Finally, Arc discharge was simulated to analyze the effect of arc discharge on the discharge tube wall. The maximum temperature of arc was 12000-13000K. The wall temperature was increased 100-170K by the arc discharge. 45 refs., 57 figs., 4 tabs. (Author)

  19. Influence of heavy metals on the formation and the distribution behavior of PAH and PCDD/F during simulated fires.

    Science.gov (United States)

    Wobst, M; Wichmann, H; Bahadir, M

    2003-04-01

    Combustion experiments were performed with an artificial fire load (polystyrene and quartz powder) in a laboratory scale incinerator in the presence of gaseous HCl to simulate accidental fire conditions. The aim of this investigation was to trace back the alterations of the formation and the distribution behavior of PAH and PCDD/PCDF to the presence of CuO or a mixture of metal oxides (CdO, CuO, Fe(2)O(3), PbO, MoO(3), ZnO). The total amount of the 16 PAH target compounds was reduced by the factor of 5-9 when the mixture of metal oxides was present rather than merely CuO. PAH patterns as well as their distribution behavior were significantly influenced by these oxides. In general, transportation inside the installation was enhanced for most of the 16 analyzed PAH. Only fluorene and dibenzo[a,h]anthracene were transported to a smaller extent. In contrast to PAH, total concentrations of PCDD were increased by factor 9 and of PCDF by factor 10, respectively, when CuO was present. Adding the mixture of metal oxides resulted in an increase of PCDD by factor 14 and of PCDF by factor 7. CuO and the mixture of metal oxides had a different influence on the PCDD/F homologue patterns. For instance, the HxCDF to OCDF ratio after incineration without any metal oxide was 1 to 6, whereas addition of CuO or the mixture of the metal oxides shifted the HxCDF to OCDF ratios towards 1 to 40 or 1 to 17, respectively. Combustion along with CuO increased transportation of higher chlorinated PCDF congeners, whereas the mixture of the metal oxides caused a strong decrease of PCDF distribution throughout the system.

  20. Simulation of trace metals and PAH atmospheric pollution over Greater Paris: Concentrations and deposition on urban surfaces

    Science.gov (United States)

    Thouron, L.; Seigneur, C.; Kim, Y.; Legorgeu, C.; Roustan, Y.; Bruge, B.

    2017-10-01

    Urban areas can be subject not only to poor air quality, but also to contamination of other environmental media by air pollutants. Here, we address the potential transfer of selected air pollutants (two metals and three PAH) to urban surfaces. To that end, we simulate meteorology and air pollution from Europe to a Paris suburban neighborhood, using a four-level one-way nesting approach. The meteorological and air quality simulations use urban canopy sub-models in order to better represent the effect of the urban morphology on the air flow, atmospheric dispersion, and deposition of air pollutants to urban surfaces. This modeling approach allows us to distinguish air pollutant deposition among various urban surfaces (roofs, roads, and walls). Meteorological model performance is satisfactory, showing improved results compared to earlier simulations, although precipitation amounts are underestimated. Concentration simulation results are also satisfactory for both metals, with a fractional bias Paris region. The model simulation results suggest that both wet and dry deposition processes need to be considered when estimating the transfer of air pollutants to other environmental media. Dry deposition fluxes to various urban surfaces are mostly uniform for PAH, which are entirely present in fine particles. However, there is significantly less wall deposition compared to deposition to roofs and roads for trace metals, due to their coarse fraction. Meteorology, particle size distribution, and urban morphology are all important factors affecting air pollutant deposition. Future work should focus on the collection of data suitable to evaluate the performance of atmospheric models for both wet and dry deposition with fine spatial resolution.

  1. Enhanced Thermal Management System for Spent Nuclear Fuel Dry Storage Canister with Hybrid Heat Pipes

    International Nuclear Information System (INIS)

    Jeong, Yeong Shin; Bang, In Cheol

    2016-01-01

    Dry storage uses the gas or air as coolant within sealed canister with neutron shielding materials. Dry storage system for spent fuel is regarded as relatively safe and emits little radioactive waste for the storage, but it showed that the storage capacity and overall safety of dry cask needs to be enhanced for the dry storage cask for LWR in Korea. For safety enhancement of dry cask, previous studies of our group firstly suggested the passive cooling system with heat pipes for LWR spent fuel dry storage metal cask. As an extension, enhanced thermal management systems for the spent fuel dry storage cask for LWR was suggested with hybrid heat pipe concept, and their performances were analyzed in thermal-hydraulic viewpoint in this paper. In this paper, hybrid heat pipe concept for dry storage cask is suggested for thermal management to enhance safety margin. Although current design of dry cask satisfies the design criteria, it cannot be assured to have long term storage period and designed lifetime. Introducing hybrid heat pipe concept to dry storage cask designed without disrupting structural integrity, it can enhance the overall safety characteristics with adequate thermal management to reduce overall temperature as well as criticality control. To evaluate thermal performance of hybrid heat pipe according to its design, CFD simulation was conducted and previous and revised design of hybrid heat pipe was compared in terms of temperature inside canister

  2. Laser-Induced Breakdown Spectroscopy for Qualitative Analysis of Metals in Simulated Martian Soils

    Science.gov (United States)

    Mowry, Curtis; Milofsky, Rob; Collins, William; Pimentel, Adam S.

    2017-01-01

    This laboratory introduces students to laser-induced breakdown spectroscopy (LIBS) for the analysis of metals in soil and rock samples. LIBS employs a laser-initiated spark to induce electronic excitation of metal atoms. Ensuing atomic emission allows for qualitative and semiquantitative analysis. The students use LIBS to analyze a series of…

  3. Molecular dynamics simulations with electronic stopping can reproduce experimental sputtering yields of metals impacted by large cluster ions

    Science.gov (United States)

    Tian, Jiting; Zhou, Wei; Feng, Qijie; Zheng, Jian

    2018-03-01

    An unsolved problem in research of sputtering from metals induced by energetic large cluster ions is that molecular dynamics (MD) simulations often produce sputtering yields much higher than experimental results. Different from the previous simulations considering only elastic atomic interactions (nuclear stopping), here we incorporate inelastic electrons-atoms interactions (electronic stopping, ES) into MD simulations using a friction model. In this way we have simulated continuous 45° impacts of 10-20 keV C60 on a Ag(111) surface, and found that the calculated sputtering yields can be very close to the experimental results when the model parameter is appropriately assigned. Conversely, when we ignore the effect of ES, the yields are much higher, just like the previous studies. We further expand our research to the sputtering of Au induced by continuous keV C60 or Ar100 bombardments, and obtain quite similar results. Our study indicates that the gap between the experimental and the simulated sputtering yields is probably induced by the ignorance of ES in the simulations, and that a careful treatment of this issue is important for simulations of cluster-ion-induced sputtering, especially for those aiming to compare with experiments.

  4. Spent fuel management in Japan

    International Nuclear Information System (INIS)

    Mineo, H.; Nomura, Y.; Sakamoto, K.

    1998-01-01

    In Japan 52 commercial nuclear power units are now operated, and the total power generation capacity is about 45 GWe. The cumulative amount of spent fuel arising is about 13,500 tU as of March 1997. Spent fuel is reprocessed, and recovered nuclear materials are to be recycled in LWRs and FBRs. In February 1997 short-term policy measures were announced by the Atomic Energy Commission, which addressed promotion of reprocessing programme in Rokkasho, plutonium utilization in LWRs, spent fuel management, backend measures and FBR development. With regard to the spent fuel management, the policy measures included expansion of spent fuel storage capacity at reactor sites and a study on spent fuel storage away from reactor sites, considering the increasing amount of spent fuel arising. Research and development on spent fuel storage has been carried out, particularly on dry storage technology. Fundamental studies are also conducted to implement the burnup credit into the criticality safety design of storage and transportation casks. Rokkasho reprocessing plant is being constructed towards its commencement in 2003, and Pu utilization in LWRs will be started in 1999. Research and development of future recycling technology are also continued for the establishment of nuclear fuel cycle based on FBRs and LWRs. (author)

  5. Novel bioactive materials developed by simulated body fluid evaluation: Surface-modified Ti metal and its alloys.

    Science.gov (United States)

    Kokubo, Tadashi; Yamaguchi, Seiji

    2016-10-15

    Until the discovery of the bone-bonding activity of Bioglass by Hench et al. in the early 1970s, it had not been demonstrated that a synthetic material could bond to living bone without eliciting a foreign body reaction. Since then, various kinds of materials based on calcium phosphate, such as sintered hydroxyapatite and β-tricalcium phosphate have also been shown to bond to living bone. Until the discovery of the bone-bonding activity of Ti metal formed with a sodium titanate surface layer by the present authors in 1996, it had not been shown that a metallic material could bond to living bone. Since then, various kinds of surface-modified Ti metal and its alloys have been found to bond to living bone. Until the discovery of the osteoinduction of porous hydroxyapatite by Yamasaki in 1990, it was unknown whether a synthetic material could induce bone formation even in muscle tissue. Since then, various kinds of porous calcium phosphate ceramics have been shown to induce osteoinduction. Until the discovery of osteoinduction induced by a porous Ti metal formed with a titanium oxide surface layer by Fujibayashi et al. in 2004, it had been unclear whether porous metals would be able to induce osteoinduction. These novel bioactive materials have been developed by systematic research into the apatite formation that occurs on surface-modified Ti metal and its related materials in an acellular simulated body fluid (SBF) having ion concentrations almost equal to those of human blood plasma. Some of the novel bioactive materials based on Ti metal are already in clinical use or clinical trials, such as artificial hip joints and spinal fusion devices. In the present paper, we review how these novel bioactive materials based on Ti metal have been developed based on an evaluation of apatite formation in SBF. Without the SBF evaluation, these novel bioactive materials would most likely never have been developed. On the basis of systematic study of apatite formation on a material

  6. Process Development And Simulation For Cold Fabrication Of Doubly Curved Metal Plate By Using Line Array Roll Set

    International Nuclear Information System (INIS)

    Shim, D. S.; Jung, C. G.; Seong, D. Y.; Yang, D. Y.; Han, J. M.; Han, M. S.

    2007-01-01

    For effective manufacturing of a doubly curved sheet metal, a novel sheet metal forming process is proposed. The suggested process uses a Line Array Roll Set (LARS) composed of a pair of upper and lower roll assemblies in a symmetric manner. The process offers flexibility as compared with the conventional manufacturing processes, because it does not require any complex-shaped die and loss of material by blank-holding is minimized. LARS allows flexibility of the incremental forming process and adopts the principle of bending deformation, resulting in a slight deformation in thickness. Rolls composed of line array roll sets are divided into a driving roll row and two idle roll rows. The arrayed rolls in the central lines of the upper and lower roll assemblies are motor-driven so that they deform and transfer the sheet metal using friction between the rolls and the sheet metal. The remaining rolls are idle rolls, generating bending deformation with driving rolls. Furthermore, all the rolls are movable in any direction so that they are adaptable to any size or shape of the desired three-dimensional configuration. In the process, the sheet is deformed incrementally as deformation proceeds simultaneously in rolling and transverse directions step by step. Consequently, it can be applied to the fabrication of doubly curved ship hull plates by undergoing several passes. In this work, FEM simulations are carried out for verification of the proposed incremental forming system using the chosen design parameters. Based on the results of the simulation, the relationship between the roll set configuration and the curvature of a sheet metal is determined. The process information such as the forming loads and torques acting on every roll is analyzed as important data for the design and development of the manufacturing system

  7. Development of spent fuel remote handling technology

    Energy Technology Data Exchange (ETDEWEB)

    Park, B. S.; Yoon, J. S.; Hong, H. D. (and others)

    2007-02-15

    In this research, the remote handling technology was developed for the ACP application. The ACP gives a possible solution to reduce the rapidly cumulative amount of spent fuels generated from the nuclear power plants in Korea. The remote technologies developed in this work are a slitting device, a voloxidizer, a modified telescopic servo manipulator and a digital mock-up. A slitting device was developed to declad the spent fuel rod-cuts and collect the spent fuel UO{sub 2} pellets. A voloxidizer was developed to convert the spent fuel UO{sub 2} pellets obtained from the slitting process in to U{sub 3}O{sub 8} powder. Experiments were performed to test the capabilities and remote operation of the developed slitting device and voloxidizer by using simulated rod-cuts and fuel in the ACP hot cell. A telescopic servo manipulator was redesigned and manufactured improving the structure of the prototype. This servo manipulator was installed in the ACP hot cell, and the target module for maintenance of the process equipment was selected. The optimal procedures for remote operation were made through the maintenance tests by using the servo manipulator. The ACP digital mockup in a virtual environment was established to secure a reliability and safety of remote operation and maintenance. The simulation for the remote operation and maintenance was implemented and the operability was analyzed. A digital mockup about the preliminary conceptual design of an enginnering-scale ACP was established, and an analysis about a scale of facility and remote handling was accomplished. The real-time diagnostic technique was developed to detect the possible fault accidents of the slitting device. An assessment of radiation effect for various sensors was also conducted in the radiation environment.

  8. Yugoslav spent nuclear fuel management program and international perspectives

    International Nuclear Information System (INIS)

    Pesic, M.; Subotic, K.; Sotic, O.; Plecas, I.; Ljubenov, V.; Peric, A.; Milosevic, M.

    2002-01-01

    Spent nuclear fuel stored in the Vinca Institute of Nuclear Sciences, Yugoslavia, consists of about 2.5 tons of metal uranium (initial enrichment 2%) and about 20 kg uranium dioxide (dispersed in aluminum matrix, initial fuel uranium enrichment 80%). This spent nuclear fuel is generated in operation of the RA heavy water research reactor during 1959-1984 period. Both types of fuel are of ex-USSR origin, have the same shape and dimensions and approximately the same initial mass of 235 nuclide. They are known as the TVR-S type of fuel elements. The total of 8030 spent fuel elements are stored at the RA research reactor premises, almost all in the spent fuel pool filled by ordinary water. The last used 480 high-enriched uranium spent fuel elements are kept in the drained RA reactor core since 1984. Fuel layer of both enrichments is covered with thin aluminium cladding. Due to non-suitable chemical parameters of water in the spent fuel storage pool, the corrosion processes penetrated aluminium cladding and aluminium walls od storage containers during storage period long from 20 to 40 years. Activity of fission products ( 137 Cs) is detected in water samples during water inspection in 1996 and experts of the lAEA Russia and USA were invited to help. By end of 2001, some remediation of the water transparency of the storage pool and inspections of water samples taken from the storage containers with the spent fuel elements were carried out by the Vinca Institute staff and with the help of experts from the Russia and the IAEA. Following new initiatives on international perspective on spent fuel management, a proposal was set by the IAEA, and was supported by the governments of the USA and the Russian Federation to ship the spent fuel elements of the RA research reactor to Mayak spent fuel processing plant in Russia. This paper describes current status of the reactor RA spent fuel elements, initiative for new Yugoslav spent fuel management program speculates on some of the

  9. WWER spent fuel storage

    Energy Technology Data Exchange (ETDEWEB)

    Bower, C C; Lettington, C [GEC Alsthom Engineering Systems Ltd., Whetstone (United Kingdom)

    1994-12-31

    Selection criteria for PAKS NPP dry storage system are outlined. They include the following: fuel temperature in storage; sub-criticality assurance (avoidance of criticality for fuel in the unirradiated condition without having to take credit for burn-up); assurance of decay heat removal; dose uptake to the operators and public; protection of environment; volume of waste produced during operation and decommissioning; physical protection of stored irradiated fuel assemblies; IAEA safeguards assurance; storage system versus final disposal route; cost of construction and extent of technology transfer to Hungarian industry. Several available systems are evaluated against these criteria, and as a result the GEC ALSTHOM Modular Vault Dry Store (MVDS) system has been selected. The MVDS is a passively cooled dry storage facility. Its most important technical, safety, licensing and technology transfer characteristics are outlined. On the basis of the experience gained some key questions and considerations related to the East European perspective in the field of spent fuel storage are discussed. 8 figs.

  10. WWER spent fuel storage

    International Nuclear Information System (INIS)

    Bower, C.C.; Lettington, C.

    1994-01-01

    Selection criteria for PAKS NPP dry storage system are outlined. They include the following: fuel temperature in storage; sub-criticality assurance (avoidance of criticality for fuel in the unirradiated condition without having to take credit for burn-up); assurance of decay heat removal; dose uptake to the operators and public; protection of environment; volume of waste produced during operation and decommissioning; physical protection of stored irradiated fuel assemblies; IAEA safeguards assurance; storage system versus final disposal route; cost of construction and extent of technology transfer to Hungarian industry. Several available systems are evaluated against these criteria, and as a result the GEC ALSTHOM Modular Vault Dry Store (MVDS) system has been selected. The MVDS is a passively cooled dry storage facility. Its most important technical, safety, licensing and technology transfer characteristics are outlined. On the basis of the experience gained some key questions and considerations related to the East European perspective in the field of spent fuel storage are discussed. 8 figs

  11. Methods for expanding the capacity of spent fuel storage facilities

    International Nuclear Information System (INIS)

    1990-06-01

    At the beginning of 1989 more than 55,000 metric tonnes of heavy metal (MTHM) of spent Light Water Reactor (LWR) and Heavy Water Reactor (HWR) fuel had been discharged worldwide from nuclear power plants. Only a small fraction of this fuel has been reprocessed. The majority of the spent fuel assemblies are currently held at-reactor (AR) or away-from-reactor (AFR) in storage awaiting either chemical processing or final disposal depending on the fuel concept chosen by individual countries. Studies made by NEA and IAEA have projected that annual spent fuel arising will reach about 10,000 t HM in the year 2000 and cumulative arising will be more than 200,000 t HM. Taking into account the large quantity of spent fuel discharged from NPP and that the first demonstrations of the direct disposal of spent fuel or HLW are expected only after the year 2020, long-term storage will be the primary option for management of spent fuel until well into the next century. There are several options to expand storage capacity: (1) to construct new away-from-reactor storage facilities, (2) to transport spent fuel from a full at-reactor pool to another site for storage in a pool that has sufficient space to accommodate it, (3) to expand the capacity of existing AR pools by using compact racks, double-tierce, rod consolidation and by increasing the dimensions of existing pools. The purpose of the meeting was: to exchange new information on the international level on the subject connected with the expansion of storage capacities for spent fuel; to elaborate the state-of-the-art of this problem; to define the most important areas for future activity; on the basis of the above information to give recommendations to potential users for selection and application of the most suitable methods for expanding spent fuel facilities taking into account the relevant country's conditions. Refs, figs and tabs

  12. Spent fuel management overview: a global perspective

    International Nuclear Information System (INIS)

    Bonne, A.; Crijns, M.J.; Dyck, P.H.; Fukuda, K.; Mourogov, V.M.

    1999-01-01

    The paper defines the main spent fuel management strategies and options, highlights the challenges for spent fuel storage and gives an overview of the regional balances of spent fuel storage capacity and spent fuel arising. The relevant IAEA activities in the area of spent fuel management are summarised. (author)

  13. Absorption column working study for iodine formed in spent fuel reprocessing plant gaseous effluents: hydrodynamic and mass transfer

    International Nuclear Information System (INIS)

    Vignau, B.

    1986-09-01

    The hydrodynamic and matter transfer parameters has been studied on absorption columns destined to trap iodine issued of spent fuel reprocessing plants. These columns have different packing - Raschig rings (glass, ceramic, PVC, steel) - Berl saddles (ceramic) - Weaved metallic thread (steel). The effect of dimension and of packing structure on gas pressure drop and on liquid holdup has been evaluated. The partial transfer coefficients of I 2 -Air-NaOH system has been the object of an experimental study. This system can be simulated by CO 2 -Air-NaOH system [fr

  14. Technical note: Comparison of metal-on-metal hip simulator wear measured by gravimetric, CMM and optical profiling methods

    Science.gov (United States)

    Alberts, L. Russell; Martinez-Nogues, Vanesa; Baker Cook, Richard; Maul, Christian; Bills, Paul; Racasan, R.; Stolz, Martin; Wood, Robert J. K.

    2018-03-01

    Simulation of wear in artificial joint implants is critical for evaluating implant designs and materials. Traditional protocols employ the gravimetric method to determine the loss of material by measuring the weight of the implant components before and after various test intervals and after the completed test. However, the gravimetric method cannot identify the location, area coverage or maximum depth of the wear and it has difficulties with proportionally small weight changes in relatively heavy implants. In this study, we compare the gravimetric method with two geometric surface methods; an optical light method (RedLux) and a coordinate measuring method (CMM). We tested ten Adept hips in a simulator for 2 million cycles (MC). Gravimetric and optical methods were performed at 0.33, 0.66, 1.00, 1.33 and 2 MC. CMM measurements were done before and after the test. A high correlation was found between the gravimetric and optical methods for both heads (R 2  =  0.997) and for cups (R 2  =  0.96). Both geometric methods (optical and CMM) measured more volume loss than the gravimetric method (for the heads, p  =  0.004 (optical) and p  =  0.08 (CMM); for the cups p  =  0.01 (optical) and p  =  0.003 (CMM)). Two cups recorded negative wear at 2 MC by the gravimetric method but none did by either the optical method or by CMM. The geometric methods were prone to confounding factors such as surface deformation and the gravimetric method could be confounded by protein absorption and backside wear. Both of the geometric methods were able to show the location, area covered and depth of the wear on the bearing surfaces, and track their changes during the test run; providing significant advantages to solely using the gravimetric method.

  15. Simulation of Molten Core-Concrete Interaction in oxide/metal stratified configuration with the TOLBIAC-ICB code

    International Nuclear Information System (INIS)

    Tourniaire, B.; Spindler, B.

    2005-01-01

    The frame of this work is the validation of the TOLBIAC-ICB code which is devoted to the simulation of Molten Core-Concrete Interaction (MCCI) for reactor safety analysis. Attention focuses here on the validation of TOLBIAC-ICB in configurations expected to be representative of the long term phase of MCCI i.e. during an interaction between an oxide/metal stratified corium melt and a concrete structure. Up to now the BETA tests performed at the Forschungszentrum Karlsruhe (FzK) are the only tests available to study such kind of interaction. The BETA tests are first described and the operating conditions are reminded. The TOLBIAC-ICB code is then briefly described, with emphasis on the models used for stratified configurations. The results of the simulations are discussed. A sensitivity study is also performed with the power generated in the oxide layer instead of the metal layer as in the test. This last calculation shows that the large axial ablation observed in the tests is probably due to the peculiar configuration of the test with input power in the bottom metal layer. Since in the reactor case the residual power would be mainly concentrated in the upper oxide layer, the conclusions of the BETA tests for the reactor applications, in term of axial ablation, must be derived with caution. (author)

  16. On the use of atomistic simulations to aid bulk metallic glasses structural elucidation with solid-state NMR.

    Science.gov (United States)

    Ferreira, Ary R; Rino, José P

    2017-08-24

    Solid-state nuclear magnetic resonance (ssNMR) experimental 27 Al metallic shifts reported in the literature for bulk metallic glasses (BMGs) were revisited in the light of state-of-the-art atomistic simulations. In a consistent way, the Gauge-Including Projector Augmented-Wave (GIPAW) method was applied in conjunction with classical molecular dynamics (CMD). A series of Zr-Cu-Al alloys with low Al concentrations were selected as case study systems, for which realistic CMD derived structural models were used for a short- and medium-range order mining. That initial procedure allowed the detection of trends describing changes on the microstructure of the material upon Al alloying, which in turn were used to guide GIPAW calculations with a set of abstract systems in the context of ssNMR. With essential precision and accuracy, the ab initio simulations also yielded valuable trends from the electronic structure point of view, which enabled an overview of the bonding nature of Al-centered clusters as well as its influence on the experimental ssNMR outcomes. The approach described in this work might promote the use of ssNMR spectroscopy in research on glassy metals. Moreover, the results presented demonstrate the possibility to expand the applications of this technique, with deeper insight into nuclear interactions and less speculative assignments.

  17. Possible origin of the discrepancy in Peierls stresses of fcc metals: First-principles simulations of dislocation mobility in aluminum

    Science.gov (United States)

    Shin, Ilgyou; Carter, Emily A.

    2013-08-01

    Dislocation motion governs the strength and ductility of metals, and the Peierls stress (σp) quantifies dislocation mobility. σp measurements carry substantial uncertainty in face-centered cubic (fcc) metals, and σp values can differ by up to two orders of magnitude. We perform first-principles simulations based on orbital-free density functional theory (OFDFT) to calculate the most accurate currently possible σp for the motion of (1)/(2)111 dislocations in fcc Al. We predict the σps of screw and edge dislocations (dissociated in their equilibrium state) to be 1.9×10-4G and 4.9×10-5G, respectively (G is the shear modulus). These values fall within the range of measurements from mechanical deformation tests (10-4-10-5G). OFDFT also finds a new metastable structure for a screw dislocation not seen in earlier simulations, in which a dislocation core on the glide plane does not dissociate into partials. The corresponding σp for this undissociated dislocation is predicted to be 1.1×10-2G, which agrees with typical Bordoni peak measurements (10-2-10-3G). The calculated σps for dissociated and undissociated screw dislocations differ by two orders of magnitude. The presence of undissociated, as well as dissociated, screw dislocations may resolve the decades-long mystery in fcc metals regarding the two orders of magnitude discrepancy in σp measurements.

  18. Spent fuel treatment in Japan

    International Nuclear Information System (INIS)

    Takahashi, K.

    1999-01-01

    In Japan, 52 nuclear power reactors are operating with a total power generation capacity of 45 GWe. The cumulative amount of spent fuel arising, as of March 1998, is about 14,700 W. Spent fuel is reprocessed and recovered nuclear materials are to be recycled in LWRs and FBRs. Pu utilization in LWRs will commence in 1999. In January 1997, short-term policy measures were announced by the Atomic Energy Commission, which addressed promotion of the reprocessing programme in Rokkasho, plutonium utilization in LWRs, spent fuel management, back-end measures and FBR development. With regard to the spent fuel management, the policy measures included expansion of spent fuel storage capacity at reactor sites and a study on spent fuel storage away-from-reactor sites, considering the increasing amount of spent fuel arising. Valuable experience was been accumulated at the Tokai Reprocessing Plant (TRP), from the start of hot operation in 1977 up to now. The role of the TRP will be changed from an operation-oriented to a more R and D oriented facility, when PNC is reorganized into the new organization JNC. The Rokkasho reprocessing plant is under construction and is expected to commence operation in 2003. R and D of future recycling technologies is also continued for the establishment of a nuclear fuel cycle based on FBRs and LWRs. (author)

  19. Disposal of spent nuclear fuel

    International Nuclear Information System (INIS)

    1979-12-01

    This report addresses the topic of the mined geologic disposal of spent nuclear fuel from Pressurized Water Reactors (PWR) and Boiling Water Reactors (BWR). Although some fuel processing options are identified, most of the information in this report relates to the isolation of spent fuel in the form it is removed from the reactor. The characteristics of the waste management system and research which relate to spent fuel isolation are discussed. The differences between spent fuel and processed HLW which impact the waste isolation system are defined and evaluated for the nature and extent of that impact. What is known and what needs to be determined about spent fuel as a waste form to design a viable waste isolation system is presented. Other waste forms and programs such as geologic exploration, site characterization and licensing which are generic to all waste forms are also discussed. R and D is being carried out to establish the technical information to develop the methods used for disposal of spent fuel. All evidence to date indicates that there is no reason, based on safety considerations, that spent fuel should not be disposed of as a waste

  20. Dry spent fuel storage licensing

    International Nuclear Information System (INIS)

    Sturz, F.C.

    1995-01-01

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

  1. MD simulation of atomic displacements in metals and metallic bilayers under low energy ion bombardment at 300 K

    International Nuclear Information System (INIS)

    Kornich, G.V.; Betz, G.; Bazhin, A.I.

    1999-01-01

    MD simulations of 100 eV Ar ion bombardment of (1 0 0) Ni and Al as well as Al/Ni bilayer crystals at 300 K have been performed and compared to previous calculations at 0 K. The Al/Ni bilayer crystal consisted of one Al layer on a (1 0 0) Ni substrate. Sputtering yields for Ni and Al/Ni show no temperature dependence, while for Al a pronounced increase with temperature was observed. The contributions of different mechanisms to the production of surface and bulk defects are discussed. The mean square displacement (MSD) of atoms is in all cases larger at 300 K as compared to 0 K. The larger MSD at 300 K is mainly due to an increase in lateral (perpendicular to the ion beam) motion of displaced atoms. Similar the number of atomic jumps, in which an atom leaves its original Wigner-Seitz cell, increases in all cases with temperature. For the pure elements the production of bulk vacancies and interstitials decreases with temperature, but the number of surface vacancies and ad-atoms increases with temperature. For the bilayer system practically no temperature dependence for defects was observed

  2. Assessment of spent fuel cooling

    International Nuclear Information System (INIS)

    Ibarra, J.G.; Jones, W.R.; Lanik, G.F.

    1997-01-01

    The paper presents the methodology, the findings, and the conclusions of a study that was done by the Nuclear Regulatory Commission's Office for Analysis and Evaluation of Operational Data (AEOD) on loss of spent fuel pool cooling. The study involved an examination of spent fuel pool designs, operating experience, operating practices, and procedures. AEOD's work was augmented in the area of statistics and probabilistic risk assessment by experts from the Idaho Nuclear Engineering Laboratory. Operating experience was integrated into a probabilistic risk assessment to gain insight on the risks from spent fuel pools

  3. Thermal Analysis of Surrogate Simulated Molten Salts with Metal Chloride Impurities for Electrorefining Used Nuclear Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Toni Y. Gutknecht; Guy L. Fredrickson; Vivek Utgikar

    2012-04-01

    This project is a fundamental study to measure thermal properties (liquidus, solidus, phase transformation, and enthalpy) of molten salt systems of interest to electrorefining operations, which are used in both the fuel cycle research & development mission and the spent fuel treatment mission of the Department of Energy. During electrorefining operations the electrolyte accumulates elements more active than uranium (transuranics, fission products and bond sodium). The accumulation needs to be closely monitored because the thermal properties of the electrolyte will change as the concentration of the impurities increases. During electrorefining (processing techniques used at the Idaho National Laboratory to separate uranium from spent nuclear fuel) it is important for the electrolyte to remain in a homogeneous liquid phase for operational safeguard and criticality reasons. The phase stability of molten salts in an electrorefiner may be adversely affected by the buildup of fission products in the electrolyte. Potential situations that need to be avoided are: (i) build up of fissile elements in the salt approaching the criticality limits specified for the vessel (ii) freezing of the salts due to change in the liquidus temperature and (iii) phase separation (non-homogenous solution) of elements. The stability (and homogeneity) of the phases can potentially be monitored through the thermal characterization of the salts, which can be a function of impurity concentration. This work describes the experimental results of typical salts compositions, consisting of chlorides of strontium, samarium, praseodymium, lanthanum, barium, cerium, cesium, neodymium, sodium and gadolinium (as a surrogate for both uranium and plutonium), used in the processing of used nuclear fuels. Differential scanning calorimetry was used to analyze numerous salt samples providing results on the thermal properties. The property of most interest to pyroprocessing is the liquidus temperature. It was

  4. The atomic-scale nucleation mechanism of NiTi metallic glasses upon isothermal annealing studied via molecular dynamics simulations.

    Science.gov (United States)

    Li, Yang; Li, JiaHao; Liu, BaiXin

    2015-10-28

    Nucleation is one of the most essential transformation paths in phase transition and exerts a significant influence on the crystallization process. Molecular dynamics simulations were performed to investigate the atomic-scale nucleation mechanisms of NiTi metallic glasses upon devitrification at various temperatures (700 K, 750 K, 800 K, and 850 K). Our simulations reveal that at 700 K and 750 K, nucleation is polynuclear with high nucleation density, while at 800 K it is mononuclear. The underlying nucleation mechanisms have been clarified, manifesting that nucleation can be induced either by the initial ordered clusters (IOCs) or by the other precursors of nuclei evolved directly from the supercooled liquid. IOCs and other precursors stem from the thermal fluctuations of bond orientational order in supercooled liquids during the quenching process and during the annealing process, respectively. The simulation results not only elucidate the underlying nucleation mechanisms varied with temperature, but also unveil the origin of nucleation. These discoveries offer new insights into the devitrification mechanism of metallic glasses.

  5. Dislocations and elementary processes of plasticity in FCC metals: atomic scale simulations

    International Nuclear Information System (INIS)

    Rodney, D.

    2000-01-01

    We present atomic-scale simulations of two elementary processes of FCC crystal plasticity. The first study consists in the simulation by molecular dynamics, in a nickel crystal, of the interactions between an edge dislocation and glissile interstitial loops of the type that form under irradiation in displacement cascades. The simulations show various atomic-scale interaction processes leading to the absorption and drag of the loops by the dislocation. These reactions certainly contribute to the formation of the 'clear bands' observed in deformed irradiated materials. The simulations also allow to study quantitatively the role of the glissile loops in irradiation hardening. In particular, dislocation unpinning stresses for certain pinning mechanisms are evaluated from the simulations. The second study consists first in the generalization in three dimensions of the quasi-continuum method (QCM), a multi-scale simulation method which couples atomistic techniques and the finite element method. In the QCM, regions close to dislocation cores are simulated at the atomic-scale while the rest of the crystal is simulated with a lower resolution by means of a discretization of the displacement fields using the finite element method. The QCM is then tested on the simulation of the formation and breaking of dislocation junctions in an aluminum crystal. Comparison of the simulations with an elastic model of dislocation junctions shows that the structure and strength of the junctions are dominated by elastic line tension effects, as is assumed in classical theories. (author)

  6. Conditioning of spent nuclear fuel for permanent disposal

    International Nuclear Information System (INIS)

    Laidler, J.J.

    1994-01-01

    A compact, efficient method for conditioning spent nuclear fuel is under development This method, known as pyrochemical processing, or open-quotes pyroprocessing,close quotes provides a separation of fission products from the actinide elements present in spent fuel and further separates pure uranium from the transuranic elements. The process can facilitate the timely and environmentally-sound treatment of the highly diverse collection of spent fuel currently in the inventory of the United States Department of Energy (DOE). The pyroprocess utilizes elevated-temperature processes to prepare spent fuel for fission product separation; that separation is accomplished by a molten salt electrorefining step that provides efficient (99.9%) separation of transuranics. The resultant waste forms from the pyroprocess are stable under envisioned repository environment conditions and highly leach-resistant. Treatment of any spent fuel type produces a set of common high-level waste forms, one a mineral and the other a metal alloy, that can be readily qualified for repository disposal and preclude the substantial costs that would be associated with the qualification of the numerous spent fuel types included in the DOE inventory

  7. Conditioning of spent nuclear fuel for permanent disposal

    International Nuclear Information System (INIS)

    Laidler, J.J.

    1994-01-01

    A compact, efficient method for conditioning spent nuclear fuel is under development. This method, known as pyrochemical processing, or pyroprocessing, provides a separation of fission products from the actinide elements present in spent fuel and further separates pure uranium from the transuranic elements. The process can facilitate the timely and environmentally-sound treatment of the highly diverse collection of spent fuel currently in the inventory of the US Department of Energy (DOE). The pyroprocess utilizes elevated-temperature processes to prepare spent fuel for fission product separation; that separation is accomplished by a molten salt electrorefining step that provides efficient (> 99.9%) separation of transuranics. The resultant waste forms from the pyroprocess are stable under envisioned repository environment conditions and highly leach-resistant. Treatment of any spent fuel type produces a set of common high-level waste forms, one a mineral and the other a metal alloy, that can be readily qualified for repository disposal and that avoid the substantial costs that would be associated with the qualification of the numerous spent fuel types included in the DOE inventory

  8. Spent fuel element storage facility

    International Nuclear Information System (INIS)

    Ukaji, Hideo; Yamashita, Rikuo.

    1981-01-01

    Purpose: To always keep water level of a spent fuel cask pit equal with water level of spent fuel storage pool by means of syphon principle. Constitution: The pool water of a spent fuel storage pool is airtightly communicated through a pipe with the pool water of a spent fuel cask, and a gate is provided between the pool and the cask. Since cask is conveyed into the cask pit as the gate close while conveying, the pool water level is raised an amount corresponding to the volume of the cask, and water flow through scattering pipe and the communication pipe to the storage pool. When the fuel is conveyed out of the cask, the water level is lowered in the amount corresponding to the volume in the cask pit, and the water in the pool flow through the communication pipe to the cask pit. (Sekiya, K.)

  9. Spent fuel management in Spain

    International Nuclear Information System (INIS)

    Gonzalez, J.L.

    2002-01-01

    The spent fuel management strategy in Spain is presented. The strategy includes temporary solutions and plans for final disposal. The need for R and D including partitioning and transmutation, as well as the financial constraints are also addressed. (author)

  10. Spent fuel management in Canada

    International Nuclear Information System (INIS)

    Khan, A.; Pattantyus, P.

    1999-01-01

    The current status of the Canadian spent fuel storage is presented. This includes wet and dry interim storage. Extension of wet interim storage facilities is nor planned, as dry technologies have found wide acceptance. The Canadian nuclear program is sustained by commercial Ontario Hydro CANDU type reactors, since 1971, representing 13600 MW(e) of installed capacity, able to produce 9200 spent fuel bundles (1800 tU) every year, and Hydro Quebec and New Brunswick CANDU reactors each producing 685 MW(e) and about 100 tU of spent fuel annually. The implementation of various interim (wt and dry) storage technologies resulted in simple, dense and low cost systems. Economical factors determined that the open cycle option be adopted for the CANDU type reactors rather that recycling the spent fuel. Research and development activities for immobilization and final disposal of nuclear waste are being undertaken in the Canadian Nuclear Fuel Waste Management Program

  11. Intermodal transportation of spent fuel

    International Nuclear Information System (INIS)

    Elder, H.K.

    1983-09-01

    Concepts for transportation of spent fuel in rail casks from nuclear power plant sites with no rail service are under consideration by the US Department of Energy in the Commercial Spent Fuel Management program at the Pacific Northwest Laboratory. This report identifies and evaluates three alternative systems for intermodal transfer of spent fuel: heavy-haul truck to rail, barge to rail, and barge to heavy-haul truck. This report concludes that, with some modifications and provisions for new equipment, existing rail and marine systems can provide a transportation base for the intermodal transfer of spent fuel to federal interim storage facilities. Some needed land transportation support and loading and unloading equipment does not currently exist. There are insufficient shipping casks available at this time, but the industrial capability to meet projected needs appears adequate

  12. Transportation of spent MTR fuels

    International Nuclear Information System (INIS)

    Raisonnier, D.

    1997-01-01

    This paper gives an overview of the various aspects of MTR spent fuel transportation and provides in particular information about the on-going shipment of 4 spent fuel casks to the United States. Transnucleaire is a transport and Engineering Company created in 1963 at the request of the French Atomic Energy Commission. The company followed the growth of the world nuclear industry and has now six subsidiaries and affiliated companies established in countries with major nuclear programs

  13. Transportation of spent MTR fuels

    Energy Technology Data Exchange (ETDEWEB)

    Raisonnier, D.

    1997-08-01

    This paper gives an overview of the various aspects of MTR spent fuel transportation and provides in particular information about the on-going shipment of 4 spent fuel casks to the United States. Transnucleaire is a transport and Engineering Company created in 1963 at the request of the French Atomic Energy Commission. The company followed the growth of the world nuclear industry and has now six subsidiaries and affiliated companies established in countries with major nuclear programs.

  14. Spent-fuel-storage alternatives

    International Nuclear Information System (INIS)

    1980-01-01

    The Spent Fuel Storage Alternatives meeting was a technical forum in which 37 experts from 12 states discussed storage alternatives that are available or are under development. The subject matter was divided into the following five areas: techniques for increasing fuel storage density; dry storage of spent fuel; fuel characterization and conditioning; fuel storage operating experience; and storage and transport economics. Nineteen of the 21 papers which were presented at this meeting are included in this Proceedings. These have been abstracted and indexed

  15. Electrochemical Corrosion Studies for Modeling Metallic Waste Form Release Rates

    International Nuclear Information System (INIS)

    Poineau, Frederic; Tamalis, Dimitri

    2016-01-01

    The isotope 99 Tc is an important fission product generated from nuclear power production. Because of its long half-life (t 1/2 = 2.13 ∙ 105 years) and beta-radiotoxicity (β - = 292 keV), it is a major concern in the long-term management of spent nuclear fuel. In the spent nuclear fuel, Tc is present as an alloy with Mo, Ru, Rh, and Pd called the epsilon-phase, the relative amount of which increases with fuel burn-up. In some separation schemes for spent nuclear fuel, Tc would be separated from the spent fuel and disposed of in a durable waste form. Technetium waste forms under consideration include metallic alloys, oxide ceramics and borosilicate glass. In the development of a metallic waste form, after separation from the spent fuel, Tc would be converted to the metal, incorporated into an alloy and the resulting waste form stored in a repository. Metallic alloys under consideration include Tc–Zr alloys, Tc–stainless steel alloys and Tc–Inconel alloys (Inconel is an alloy of Ni, Cr and iron which is resistant to corrosion). To predict the long-term behavior of the metallic Tc waste form, understanding the corrosion properties of Tc metal and Tc alloys in various chemical environments is needed, but efforts to model the behavior of Tc metallic alloys are limited. One parameter that should also be considered in predicting the long-term behavior of the Tc waste form is the ingrowth of stable Ru that occurs from the radioactive decay of 99 Tc ( 99 Tc → 99 Ru + β - ). After a geological period of time, significant amounts of Ru will be present in the Tc and may affect its corrosion properties. Studying the effect of Ru on the corrosion behavior of Tc is also of importance. In this context, we studied the electrochemical behavior of Tc metal, Tc-Ni alloys (to model Tc-Inconel alloy) and Tc-Ru alloys in acidic media. The study of Tc-U alloys has also been performed in order to better understand the nature of Tc in metallic spent fuel. Computational modeling

  16. Electrochemical Corrosion Studies for Modeling Metallic Waste Form Release Rates

    Energy Technology Data Exchange (ETDEWEB)

    Poineau, Frederic [Univ. of Nevada, Las Vegas, NV (United States); Tamalis, Dimitri [Florida Memorial Univ., Miami Gardens, FL (United States)

    2016-08-01

    nature of Tc in metallic spent fuel. Computational modeling and simulations were performed to shed light on experimental results and explain structural and kinetics trends.

  17. Leaching Behavior of Heavy Metals and Transformation of Their Speciation in Polluted Soil Receiving Simulated Acid Rain

    Science.gov (United States)

    Zheng, Shun-an; Zheng, Xiangqun; Chen, Chun

    2012-01-01

    Heavy metals that leach from contaminated soils under acid rain are of increasing concern. In this study, simulated acid rain (SAR) was pumped through columns of artificially contaminated purple soil. Column leaching tests and sequential extraction were conducted for the heavy metals Cu, Pb, Cd, and Zn to determine the extent of their leaching as well as to examine the transformation of their speciation in the artificially contaminated soil columns. Results showed that the maximum leachate concentrations of Cu, Pb, Cd, and Zn were less than those specified in the Chinese Quality Standards for Groundwater (Grade IV), thereby suggesting that the heavy metals that leached from the polluted purple soil receiving acid rain may not pose as risks to water quality. Most of the Pb and Cd leachate concentrations were below their detection limits. By contrast, higher Cu and Zn leachate concentrations were found because they were released by the soil in larger amounts as compared with those of Pb and Cd. The differences in the Cu and Zn leachate concentrations between the controls (SAR at pH 5.6) and the treatments (SAR at pH 3.0 and 4.5) were significant. Similar trends were observed in the total leached amounts of Cu and Zn. The proportions of Cu, Pb, Cd, and Zn in the EXC and OX fractions were generally increased after the leaching experiment at three pH levels, whereas those of the RES, OM, and CAR fractions were slightly decreased. Acid rain favors the leaching of heavy metals from the contaminated purple soil and makes the heavy metal fractions become more labile. Moreover, a pH decrease from 5.6 to 3.0 significantly enhanced such effects. PMID:23185399

  18. Effect of thermal and mechanical parameter’s damage numerical simulation cycling effects on defects in hot metal forming processes

    Science.gov (United States)

    El Amri, Abdelouahid; el yakhloufi Haddou, Mounir; Khamlichi, Abdellatif

    2017-10-01

    Damage mechanisms in hot metal forming processes are accelerated by mechanical stresses arising during Thermal and mechanical properties variations, because it consists of the materials with different thermal and mechanical loadings and swelling coefficients. In this work, 3D finite element models (FEM) are developed to simulate the effect of Temperature and the stresses on the model development, using a general purpose FE software ABAQUS. Explicit dynamic analysis with coupled Temperature displacement procedure is used for a model. The purpose of this research was to study the thermomechanical damage mechanics in hot forming processes. The important process variables and the main characteristics of various hot forming processes will also be discussed.

  19. Desorption of metals from Cetraria islandica (L. Ach. Lichen using solutions simulating acid rain

    Directory of Open Access Journals (Sweden)

    Čučulović Ana A.

    2014-01-01

    Full Text Available Desorption of metals K, Al, Ca, Mg, Fe, Ba, Zn, Mn, Cu and Sr from Cetraria islandica (L. with solutions whose composition was similar to that of acid rain, was investigated. Desorption of metals from the lichen was performed by five successive desorption processes. Solution mixtures containing H2SO4, HNO3 and H2SO4-HNO3 were used for desorption. Each solution had three different pH values: 4.61, 5.15 and 5.75, so that the desorptions were performed with nine different solutions successively five times, always using the same solution volume. The investigated metals can be divided into two groups. One group was comprised of K, Ca and Mg, which were desorbed in each of the five desorption processes at all pH values used. The second group included Al, Fe, Zn, Ba, Mn and Sr; these were not desorbed in each individual desorption and not at all pH values, whereas Cu was not desorbed at all under any circumstances. Using the logarithmic dependence of the metal content as a function of the desorption number, it was found that potassium builds two types of links and is connected with weaker links in lichen. Potassium is completely desorbed, 80% in the first desorption, and then gradually in the following desorptions. Other metals are linked with one weaker link (desorption 1-38% and with one very strong link (desorption below the metal detection limit. [Projekat Ministarstva nauke Republike Srbije, br. III43009 i br. ON 172019

  20. HFIR spent fuel management alternatives

    International Nuclear Information System (INIS)

    Begovich, J.M.; Green, V.M.; Shappert, L.B.; Lotts, A.L.

    1992-01-01

    The High Flux Isotope Reactor (HFIR) at Martin Marietta Energy Systems' Oak Ridge National Laboratory (ORNL) has been unable to ship its spent fuel to Savannah River Site (SRS) for reprocessing since 1985. The HFIR storage pools are expected to fill up in the February 1994 to February 1995 time frame. If a management altemative to existing HFIR pool storage is not identified and implemented before the HFIR pools are full, the HFIR will be forced to shut down. This study investigated several alternatives for managing the HFIR spent fuel, attempting to identify options that could be implemented before the HFIR pools are full. The options investigated were: installing a dedicated dry cask storage facility at ORNL, increasing HFIR pool storage capacity by clearing the HFIR pools of debris and either close-packing or stacking the spent fuel elements, storing the spent fuel at another ORNL pool, storing the spent fuel in one or more hot cells at ORNL, and shipping the spent fuel offsite for reprocessing or storage elsewhere

  1. EBR-II spent fuel treatment demonstration project

    International Nuclear Information System (INIS)

    Benedict, R.W.; Henslee, S.P.

    1997-01-01

    For approximately 10 years, Argonne National Laboratory was developed a fast reactor fuel cycle based on dry processing. When the US fast reactor program was canceled in 1994, the fuel processing technology, called the electrometallurgical technique, was adapted for treating unstable spent nuclear fuel for disposal. While this technique, which involves electrorefining fuel in a molten salt bath, is being developed for several different fuel categories, its initial application is for sodium-bonded metallic spent fuel. In June 1996, the Department of Energy (DOE) approved a radiation demonstration program in which 100 spent driver assemblies and 25 spent blanket assemblies from the Experimental Breeder Reactor-II (EBR-II) will be treated over a three-year period. This demonstrated will provide data that address issues in the National Research Council's evaluation of the technology. The planned operations will neutralize the reactive component (elemental sodium) in the fuel and produce a low enriched uranium product, a ceramic waste and a metal waste. The fission products and transuranium elements, which accumulate in the electrorefining salt, will be stabilized in the glass-bonded ceramic waste form. The stainless steel cladding hulls, noble metal fission products, and insoluble residues from the process will be stabilized in a stainless steel/zirconium alloy. Upon completion of a successful demonstration and additional environmental evaluation, the current plans are to process the remainder of the DOE sodium bonded fuel

  2. Experimental simulation techniques for the evaluation of structural changes in metals and alloys

    International Nuclear Information System (INIS)

    Lucki, Georgi

    1992-01-01

    In this work, high-doses irradiation in nuclear reactor were simulated using a cyclotron in order to study mechanical, electric, magnetic and structural changes in materials. Results of such simulations for portland cement, binary alloys and stainless steels are presented and discussed. 15 refs., 11 figs., 1 tab

  3. Evaluation of solubility in simulated lung fluid of metals present in the sludge from a metallurgical industry to produce metallic zinc

    International Nuclear Information System (INIS)

    Lima, Rosilda Maria Gomes de

    2012-01-01

    The objective of this study was to determine the solubility parameters (rapid and slow dissolution rates, rapid and slow dissolution fractions) metal particles present in a pile of sludge accumulated under exposure to weathering from the Cia Mercantil Inga, located at the Ilha da Madeira, Sepetiba Bay, Rio de Janeiro. Plant samples collected in the neighboring of the pile and bioindicators placed in the region and collected after some months indicated that the inhabitants of Ilha da Madeira have been exposed to trace elements such zinc, cadmium, mercury and lead, produced during the processing of zinc minerals (hemimorphite - Zn 4 (OH) 2 Si 2 O 7 .H 2 O, and willemite - Zn 2 SiO 4 ). A static dissolution test in vitro was used to determine the solubility parameters using a simulated lung fluid (SLF), on a time basis ranging from 10 min to 1 year. The metal concentrations in the sludge samples and in the SLF were determined using Particle Induced X-rays Emission (PIXE). In conclusion, this study confirms the harmful effects on the neighboring population of the airborne particles containing these metals that came from the sludge. The solubility parameters obtained for Zn, Cd, Cr, Ni and Mn present in the rapid dissolution fraction in SLF were 0.945; 0.473; 0.226; 0.300 and 0.497, respectively, and the corresponding times for half life of dissolution of the rapid fraction were f r = 2.082 days; f r = 0.09 days; f r = 0.37 days; f r = 0.332 days ad f r = 0.99 days; for the slow dissolution fraction times were f r = 146.95 days; f r = 63 days; f r = 86.64 days; f r = 79.66 days and f r = 59.84 days. These values indicate that these metals present a moderate absorption level in SLF, and may be classified as M type, according to the International Commission on Radiological Protection (ICRP). The use of solubility parameters allowed a better description of the kinetic behaviour of the sludge in the human body and, therefore, a better evaluation of the worker’s risk to

  4. Development of aircraft brake materials. [evaluation of metal and ceramic materials in sliding tests simulation of aircraft braking

    Science.gov (United States)

    Ho, T. L.; Peterson, M. B.

    1974-01-01

    The requirements of brake materials were outlined and a survey made to select materials to meet the needs of high temperature brakes. A number of metals and ceramic materials were selected and evaluated in sliding tests which simulated aircraft braking. Nickel, molybdenum tungsten, Zr02, high temperature cements and carbons were tested. Additives were then incorporated into these materials to optimize their wear or strength behavior with particular emphasis on nickel and molybdenum base materials and a high temperature potassium silicate cement. Optimum materials were developed which improved wear behavior over conventional brake materials in the simulated test. The best materials are a nickel, aluminum oxide, lead tungstate composition containing graphite or molybdenum disulphite; a molybdenum base material containing LPA100 (an intermetallic compound of cobalt, molybdenum, and silicon); and a carbon material (P5).

  5. Dual-Function Metal-Organic Framework as a Versatile Catalyst for Detoxifying Chemical Warfare Agent Simulants.

    Science.gov (United States)

    Liu, Yangyang; Moon, Su-Young; Hupp, Joseph T; Farha, Omar K

    2015-12-22

    The nanocrystals of a porphyrin-based zirconium(IV) metal-organic framework (MOF) are used as a dual-function catalyst for the simultaneous detoxification of two chemical warfare agent simulants at room temperature. Simulants of nerve agent (such as GD, VX) and mustard gas, dimethyl 4-nitrophenyl phosphate and 2-chloroethyl ethyl sulfide, have been hydrolyzed and oxidized, respectively, to nontoxic products via a pair of pathways catalyzed by the same MOF. Phosphotriesterase-like activity of the Zr6-containing node combined with photoactivity of the porphyrin linker gives rise to a versatile MOF catalyst. In addition, bringing the MOF crystals down to the nanoregime leads to acceleration of the catalysis.

  6. Use of a commercial heat transfer code to predict horizontally oriented spent fuel rod temperatures

    International Nuclear Information System (INIS)

    Wix, S.D.; Koski, J.A.

    1992-01-01

    Radioactive spent fuel assemblies are a source of hazardous waste that will have to be dealt with in the near future. It is anticipated that the spent fuel assemblies will be transported to disposal sites in spent fuel transportation casks. In order to design a reliable and safe transportation cask, the maximum cladding temperature of the spent fuel rod arrays must be calculated. The maximum rod temperature is a limiting factor in the amount of spent fuel that can be loaded in a transportation cask. The scope of this work is to demonstrate that reasonable and conservative spent fuel rod temperature predictions can be made using commercially available thermal analysis codes. The demonstration is accomplished by a comparison between numerical temperature predictions, with a commercially available thermal analysis code, and experimental temperature data for electrical rod heaters simulating a horizontally oriented spent fuel rod bundle

  7. Optimal Performance Simulation of a Metal Fiber Filter for Capturing Radioactive Aerosols

    International Nuclear Information System (INIS)

    Lee, Seung Uk; Lee, Chan Hyun; Park, Min Chan; Lee, Jaek Eun

    2016-01-01

    In this study, the metal fiber filter used for removing radioactive aerosol is systematically dissected and studied in order to figure out the optimal design which can be applied to the actual operation conditions in nuclear heating, ventilation and air conditioning (HVAC) systems for particle collection. In order to derive the optimal design for metal fiber HEPA filter, a numerical model is developed and its results are compared to experimental data to test reliability. Moreover, sensitivity analysis is performed using important parameters to determine which parameters have large influence on the filter performance. Using the model developed in this study, optimal design parameters for pleated metal fiber filters are derived which include fiber diameter less than 4 μm, solidity larger than 0.2, filter thickness larger than 1 mm, and face velocity lower than 5 cm/s. With these conditions, the metal filter qualified for the HEPA filter standard which specified 99.97% efficiency in the 0.3 μm particle size range.

  8. Simplified computational simulation of liquid metal behaviour in turbulent flow with heat transfer

    International Nuclear Information System (INIS)

    Costa, E.B. da.

    1992-09-01

    The present work selected the available bibliography equations and empirical relationships to the development of a computer code to obtain the turbulent velocity and temperature profiles in liquid metal tube flow with heat generation. The computer code is applied to a standard problem and the results are considered satisfactory, at least from the viewpoint of qualitative behaviour. (author). 50 refs, 21 figs, 3 tabs

  9. Modelling and numerical simulation of Supercritical CO2 debinding of Inconel 718 components elaborated by Metal Injection Molding

    Directory of Open Access Journals (Sweden)

    Aboubakry Agne

    2017-10-01

    Full Text Available A debinding step using the supercritical state of a fluid has been increasingly investigated for extracting organic binders from components obtained by metal-injection molding. It consists of placing the component in an enclosure subjected to pressure and temperatures higher than the critical point to perform polymer extraction of the Metal-injection molding (MIM component. It is an alternative to conventional solvent debinding. The topic of this study is to model and simulate the supercritical debinding stage to elucidate the mechanism of polymer degradation and stabilization with a three-dimensional model. Modelling this extraction process would optimize the process on an industrial scale. It can be physically described by Fick’s law of diffusion. The model’s main parameter is the diffusion coefficient, which is identified by using linear regression based on the least-squares method. In the model, an effective length scale is specially developed to take into account the diffusion in all directions. The tests were performed for extracting polyethylene glycol, an organic additive, using supercritical CO2 in injected components. The feedstock is composed of polypropylene, polyethylene glycol, and stearic-acid as binder mixed with Inconel 718 super-alloy powders. The identified parameters were used to calculate the diffusion coefficient and simulate the supercritical debinding step on the Comsol Multiphysics® finite-element software platform to predict the remaining binder. The obtained numerical simulation results are in good agreement with the experimental data. The proposed numerical simulations allow for the determination of the remaining polyethylene glycol (PEG binder distribution with respect to processing parameters for components during the supercritical debinding process at any time. Moreover, this approach can be used in other formulation, powder, and binder systems.

  10. First-principles simulations on the new hybrid phases of germanene with alkali metal atoms coverage

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Jianmei [Hunan Key Laboratory for Computation and Simulation in Science and Engineering, School of Mathematics and Computational Science, Xiangtan University, Hunan 411105 (China); Tang, Chan; Zhong, Jianxin [Hunan Key Laboratory for Micro-Nano Energy Materials and Devices, School of Physics and Optoelectronic Engineering, Xiangtan University, Hunan 411105 (China); Mao, Yuliang, E-mail: ylmao@xtu.edu.cn [Hunan Key Laboratory for Micro-Nano Energy Materials and Devices, School of Physics and Optoelectronic Engineering, Xiangtan University, Hunan 411105 (China)

    2016-01-01

    Graphical abstract: - Highlights: • The predicted new phase of complete lithiated germanene is more favorable to form than germanane. • Besides ionic interactions, covalent component in some extent leads the complete lithiated germanene into a semiconductor. • 2D phases of Ge{sub 2}X{sub 1} (X = Li, Na, K) are metallic with weak polarization. • Half-lithiated germanene exhibits local magnetic moments on the Ge atoms neighbored with Li adatoms. - Abstract: We present first-principles calculations of a new type hybrid phases composed by buckled germanene with saturated or half-saturated alkali metal atoms adsorption. Our energetics and electronic structure analysis suggests that adsorbed alkali metal atoms (Li, Na, K) can be used as covered adatoms to synthesize germanene-based new phases in two dimensional. The predicted new phases of Ge{sub 2}X{sub 2} and Ge{sub 2}X{sub 1} (X = Li, Na, K) relative to the single germanene sheet could exist at room temperature. The formation energy of Ge{sub 2}Li{sub 2} configuration obtained from complete lithiation is even more favorable than that of germanane. Charge transfer is significant between the alkali metal atoms and Ge, indicating the ionic interactions between them. Furthermore, our charge density analysis indicates that covalent component in some extent exists in Ge{sub 2}X{sub 2} and Ge{sub 2}X{sub 1} (X = Li, Na, K) 2D phases, which even leads the complete lithiated germanene into a semiconductor with an energy gap of 0.14 eV. We report that 2D phases of Ge{sub 2}X{sub 1} (X = Li, Na, K) are metallic with weak polarization on the Fermi level and in unoccupied states. It is found that half-lithiated germanene exhibits local magnetic moments of 0.48 μ{sub B} on the Ge atoms neighbored with Li adatoms.

  11. A new method to estimate heat source parameters in gas metal arc welding simulation process

    International Nuclear Information System (INIS)

    Jia, Xiaolei; Xu, Jie; Liu, Zhaoheng; Huang, Shaojie; Fan, Yu; Sun, Zhi

    2014-01-01

    Highlights: •A new method for accurate simulation of heat source parameters was presented. •The partial least-squares regression analysis was recommended in the method. •The welding experiment results verified accuracy of the proposed method. -- Abstract: Heat source parameters were usually recommended by experience in welding simulation process, which induced error in simulation results (e.g. temperature distribution and residual stress). In this paper, a new method was developed to accurately estimate heat source parameters in welding simulation. In order to reduce the simulation complexity, a sensitivity analysis of heat source parameters was carried out. The relationships between heat source parameters and welding pool characteristics (fusion width (W), penetration depth (D) and peak temperature (T p )) were obtained with both the multiple regression analysis (MRA) and the partial least-squares regression analysis (PLSRA). Different regression models were employed in each regression method. Comparisons of both methods were performed. A welding experiment was carried out to verify the method. The results showed that both the MRA and the PLSRA were feasible and accurate for prediction of heat source parameters in welding simulation. However, the PLSRA was recommended for its advantages of requiring less simulation data

  12. Simulation of Zr content in TiZrCuNi brazing filler metal for Ti6Al4V alloy

    International Nuclear Information System (INIS)

    Yue, Xishan; Xie, Zonghong; Jing, Yongjuan

    2017-01-01

    To optimize the Zr content in Ti-based filler metal, the covalent electron on the nearest atoms bond in unit cell (n_A"u"-"v) with Ti-based BCC structure was calculated, in which the brazing temperature was considered due to its influence on the lattice parameter. Based on EET theory (The Empirical Electron Theory for solid and molecules), n_A"u"-"v represents the strength of the unit cell with defined element composition and structure, which reflects the effect from solid solution strengthening on the strength of the unit cell. For Ti-Zr-15Cu-10Ni wt% filler metal, it kept constant as 0.3476 with Zr as 37.5 ∝ 45 wt% and decreased to 0.333 with Zr decreasing from 37.5 to 25 wt%. Finally, it increased up to 0.3406 with Zr as 2 ∝ 10 wt%. Thus, Ti-based filler metal with Zr content being 2 ∝ 10 wt% is suggested based on the simulation results. Moreover, the calculated covalent electron of n_A"u"-"v showed good agreement with the hardness of the joint by filler 37.5Zr and 10Zr. The composition of Ti-10Zr-15Cu-10Ni wt% was verified in this study with higher tensile strength of the brazing joint and uniform microstructure of the interface. (orig.)

  13. Simulation of Zr content in TiZrCuNi brazing filler metal for Ti6Al4V alloy

    Energy Technology Data Exchange (ETDEWEB)

    Yue, Xishan [Northwestern Polytechnical University, School of Astronautics, Xi' an (China); AVIC Beijing Aeronautical Manufacturing Technology Research Institute, Aeronautical Key Laboratory for Welding and Joining Technology, Beijing (China); Xie, Zonghong [Northwestern Polytechnical University, School of Astronautics, Xi' an (China); Jing, Yongjuan [AVIC Beijing Aeronautical Manufacturing Technology Research Institute, Aeronautical Key Laboratory for Welding and Joining Technology, Beijing (China)

    2017-07-15

    To optimize the Zr content in Ti-based filler metal, the covalent electron on the nearest atoms bond in unit cell (n{sub A}{sup u-v}) with Ti-based BCC structure was calculated, in which the brazing temperature was considered due to its influence on the lattice parameter. Based on EET theory (The Empirical Electron Theory for solid and molecules), n{sub A}{sup u-v} represents the strength of the unit cell with defined element composition and structure, which reflects the effect from solid solution strengthening on the strength of the unit cell. For Ti-Zr-15Cu-10Ni wt% filler metal, it kept constant as 0.3476 with Zr as 37.5 ∝ 45 wt% and decreased to 0.333 with Zr decreasing from 37.5 to 25 wt%. Finally, it increased up to 0.3406 with Zr as 2 ∝ 10 wt%. Thus, Ti-based filler metal with Zr content being 2 ∝ 10 wt% is suggested based on the simulation results. Moreover, the calculated covalent electron of n{sub A}{sup u-v} showed good agreement with the hardness of the joint by filler 37.5Zr and 10Zr. The composition of Ti-10Zr-15Cu-10Ni wt% was verified in this study with higher tensile strength of the brazing joint and uniform microstructure of the interface. (orig.)

  14. Finite element modeling simulation-assisted design of integrated microfluidic chips for heavy metal ion stripping analysis

    International Nuclear Information System (INIS)

    Hong, Ying; Zou, Jianhua; Ge, Gang; Xiao, Wanyue; Shao, Jinjun; Dong, Xiaochen; Gao, Ling

    2017-01-01

    In this article, a transparent integrated microfluidic device composed of a 3D-printed thin-layer flow cell (3D-PTLFC) and an S-shaped screen-printed electrode (SPE) has been designed and fabricated for heavy metal ion stripping analysis. A finite element modeling (FEM) simulation is employed to optimize the shape of the electrode, the direction of the inlet pipeline, the thin-layer channel height and the sample flow rate to enhance the electron-enrichment efficiency for stripping analysis. The results demonstrate that the S-shaped SPE configuration matches the channel in 3D-PTLFC perfectly for the anodic stripping behavior of the heavy metal ions. Under optimized conditions, a wide linear range of 1–80 µ g l −1 is achieved for Pb 2+ detection with a limit of 0.3 µ g l −1 for the microfluidic device. Thus, the obtained integrated microfluidic device proves to be a promising approach for heavy metal ions stripping analysis with low cost and high performance. (paper)