Removal of alkaline-earth elements by a carbonate precipitation in a chloride molten salt

International Nuclear Information System (INIS)

Yung-Zun Cho; In-Tae Kim; Hee-Chui Yang; Hee-Chui Eun; Hwan-Seo Park; Eung-Ho Kim

2007-01-01

Separation of some alkaline-earth chlorides (Sr, Ba) was investigated by using carbonate injection method in LiCl-KCl eutectic and LiCl molten salts. The effects of the injected molar ratio of carbonate([K 2 (or Li 2 )CO 3 /Sr(or Ba)Cl 2 ]) and the temperature(450-750 deg.) on the conversion ratio of the Sr or Ba carbonate were determined. In addition, the form of the Sr and Ba carbonate resulting from the carbonation reaction with carbonates was identified via XRD and SEM-EDS analysis. In these experiments, the carbonate injection method can remove Sr and Ba chlorides effectively over 99% in both LiCl-KCl eutectic and LiCl molten salt conditions. When Sr and Ba were co-presented in the eutectic molten salt, they were carbonated in a form of Ba 0.5 Sr 0.3 CO 3 . And when Sr was present in LiCl molten salt, it was carbonated in the form of SrCO 3 . Carbonation ratio increased with a decreasing temperature and it was more favorable in the case of a K 2 CO 3 injection than that of Li 2 CO 3 . Based on this experiment, it is postulated that carbonate precipitation method has the potential for removing alkali-earth chlorides from LiCl-KCl eutectic and LiCl molten salts. (authors)

Electrochemical reduction of lanthanum trichloride in a molten equimolar mixture of sodium and potassium chlorides

Energy Technology Data Exchange (ETDEWEB)

Glagolevskaya, A.L.; Kuznetsov, S.A.; Polyakov, E.G.; Stangrit, P.T.

1987-09-20

The authors used linear voltamperometry for the investigation of the mechanism for the cathodic reduction of lanthanum. The mechanism for the cathodic reduction of lanthanum chloride in molten equimolar NaCl-KCl may be seen as consisting of a slow irreversible electrode reaction with a subsequent rapid irreversible chemical reaction. Lanthanum ions in a lower oxidation state were not found upon the prolonged maintenance of metallic lanthanum in molten NaCl-KCl-LaCl/sub 3/. Only an increase in the concentration of lanthanum(III) chloride in the melt was noted. The appearance of oxygen anions in the melt does not lead to a change in the mechanism of the cathodic reduction of lanthanum chloride but reduces the concentration of this chloride due to the formation of lanthanum oxochloride which is insoluble in the melt.

Anodic and cathodic reactions in molten calcium chloride

International Nuclear Information System (INIS)

Fray, D.J.

2002-01-01

Calcium chloride is a very interesting electrolyte in that it is available, virtually free, in high purity form as a waste product from the chemical industry. It has a very large solubility for oxide ions, far greater than many alkali halides and other divalent halides and has the same toxicity as sodium chloride and also a very high solubility in water. Intuitively, on the passage of current, it is expected that calcium would be deposited at the cathode and chlorine would evolve at the anode. However, if calcium oxide is added to the melt, it is possible to deposit calcium and evolve oxygen containing gases at the anode, making the process far less polluting than when chlorine is evolved. This process is discussed in terms of the addition of calcium to molten lead. Furthermore, these reactions can be altered dramatically depending upon the electrode materials and the other ions dissolved in the calcium chloride. As calcium is only deposited at very negative cathodic potentials, there are several interesting cathodic reactions that can occur and these include the decomposition of the carbonate ion and the ionization of oxygen, sulphur, selenium and tellurium. For example, if an oxide is used as the cathode in molten calcium chloride, the favoured reaction is shown to be the ionization of oxygen O + 2e - → O 2- rather than Ca 2+ + 2 e- → Ca. The oxygen ions dissolve in the salt leaving the metal behind, and this leads to the interesting hypothesis that metal oxides can be reduced directly to the metal purely by the use of electrons. Examples are given for the reduction of titanium dioxide, zirconium dioxide, chromium oxide and niobium oxide and by mixing oxide powders together and reducing the mixed compact, alloys and intermetallic compounds are formed. Preliminary calculations indicate that this new process should be much cheaper than conventional metallothermic reduction for these elements. (author)

Wetting of a Charged Surface of Glassy Carbon by Molten Alkali-Metal Chlorides

Science.gov (United States)

Stepanov, V. P.

2018-03-01

Values of the contact angle of wetting of a surface of glassy carbon by molten chlorides of lithium, sodium, potassium, and cesium are measured by the meniscus weight method to determine the common factors of wettability of solid surfaces by ionic melts upon a change in the salt phase composition and a jump in electric potential. It is found that with a potential shift in the positive direction the shape of the curve of the contact angle's dependence on the potential varies upon substitution of one salt by another: the angle of wetting shrinks monotonously in lithium chloride but remains constant in molten cesium chloride. This phenomenon is explained by the hypothesis that the nature of the halide anion adsorption on the positively charged surface of an electrode is chemical and not electrostatic. It is shown that the adsorption process is accompanied by charge transfer through the interface, with covalent bonding between the adsorbent and adsorbate.

Electrolytic production of light lanthanides from molten chloride alloys on a large laboratory scale

International Nuclear Information System (INIS)

Szklarski, W.; Bogacz, A.; Strzyzewska, M.

1979-01-01

Literature data relating to electrolytic production of rare earth metals are presented. Conditions and results are given of own investigations into the electrolytic process of light lanthanide chloride solutions (LA-Nd) in molten potassium and sodium chlorides conducted on a large laboratory scale using molybdenic, iron, cobaltic and zinc cathodes. Design schemes of employed electrolysers are enclosed. (author)

Preliminary treatment of chlorinated streams containing fission products: mechanisms leading to crystalline phases in molten chloride media; Pretraitement pyrochimique de flux charges en produits de fission: mecanismes conduisant a l'obtention de phases cristallines en milieux chlorures fondus

Energy Technology Data Exchange (ETDEWEB)

Hudry, D

2008-10-15

The world of the nuclear power gets ready for profound modifications so that 'the atom' can aspire in conformance with long-lasting energy: it is what we call the development of generation IV nuclear systems. So, the new pyrochemical separation processes for the spent fuel reprocessing are currently being investigated. Techniques in molten chloride media generate an ultimate flow (with high chlorine content) which cannot be incorporated in conventional glass matrices. This flow is entirely water-soluble and must be conditioned in a chemical form which is compatible with a long-term disposal. This work of thesis consists in studying new ways for the management of the chlorinated streams loaded with fission products (FP). To do it, a strategy of selective FP extraction via the in situ formation of crystalline phases was retained. The possibility of extracting rare earths in the eutectic LiCl-KCl was demonstrated via the development of a new way of synthesis of rare earth phosphates (TRPO{sub 4}). As regards alkaline earths, the conversion of strontium and barium chlorides to the corresponding tungstates or molybdates was studied in different solvents. Mechanisms leading to the crystalline phases in molten chloride media were studied via the coupling of NMR and XRD techniques. First of all, it has been shown that these mechanisms are dependent on the stability of the used precursors. So in the case of the formation of rare earth phosphates the solvent is chemically active. On the other hand, in the case of the formation of alkaline earth tungstates it would seem that the solvent plays the role of structuring agent which can control the ability to react of chlorides. (author)

Evidence for many-body interactions in the structure of molten alkali chlorides

International Nuclear Information System (INIS)

Malescio, G.P.; Tosi, M.P.

1985-02-01

An inversion of the measured partial structure factors of molten sodium chloride is attempted in order to assess some qualitative features of interionic forces in the melt. We start from a calculation of liquid structure and thermodynamic properties by means of a refined theory based on interionic pair potentials determined from properties of the solid phase. This yields very good agreement with the measured values of the internal energy and the compressibility of the liquid, whereas discrepancies with the observed structure are mainly localized in the region of interionic distances outside the minimum of the cation-anion potential. These discrepancies, when interpreted in terms of effective pair potentials in the melt through inversion of the structural data, strongly suggest the presence of many-body effects, insofar as such effective pair potentials oscillate with the local liquid structure and are inconsistent with the measured thermodynamic quantities. A similar analysis of data on molten rubidium and cesium chloride, though harder to carry out quantitatively, supports the above conclusion. (author)

Development of pyrometallurgical partitioning technology of long-lived nuclides. Recovery of volatile chlorides for chlorination process using molten salt trap. 1

International Nuclear Information System (INIS)

Hijikata, Takatoshi; Nakamura, Kyosei; Kurata, Masateru; Konagaya, Hideaki

1997-01-01

The dry process for partitioning of long-lived nuclides from high level radioactive waste has been developed. One of the subjects for development of this process is the recovering of the volatilization of chlorides for the chlorination process. We proposed that the volatile chlorides were recovered by the molten salt trap. We researched the behavior of volatile chlorides (ferric chloride, zirconium tetra-chloride and molybdenum pent-chloride) in LiCl-KCl eutectic salt. In this result, the volatile rate of these chlorides was slower than the volatile rate of undissolved chlorides in LiCl-KCl eutectic salt. Also, we make a prototype of molten salt trap for recovering the volatile chlorides and tested the performance of this experimental apparatus and recovering ratio of volatile chlorides. This trap has a good performance of recovering volatile chlorides. (author)

Separation of hafnium from zirconium in their tetrachloride solution in molten alkali metal chlorides

Energy Technology Data Exchange (ETDEWEB)

Salyulev, A B; Kudyakov, V Ya; Smirnov, M V; Moskalenko, N I [AN SSSR, Sverdlovsk. Inst. Ehlektrokhimii

1984-08-01

The coefficient of HfCl/sub 4/ and ZrCl/sub 4/ separation in the process of vapour sublimation from their solutions in molten NaCl, KCl, CsCl, NaCl-KCl and NaCl-CsCl equimolar mixtures is found to vary in the series from approximately 1.10 to approximately 1.22 and practically not to depend on the temperature (in the 600-910 deg) range and concentration (2-25 mol.% ZrCl/sub 4/+HfCl/sub 4/). HfCl/sub 4/ and ZrCl/sub 4/ are shown to form almost perfect solutions with each other, which in their turn form imperfect solutions with molten alkali metal chlorides, with the strength of hafnium complex chloride anions increasing higher than that of zirconium in the series from NaCl to CsCl.

Separation of hafnium from zirconium in their tetrachloride solution in molten alkali metal chlorides

International Nuclear Information System (INIS)

Salyulev, A.B.; Kudyakov, V.Ya.; Smirnov, M.V.; Moskalenko, N.I.

1984-01-01

The coefficient of HfCl 4 and ZrCl 4 separation in the process of vapour sublimation from their solutions in molten NaCl, KCl, CsCl, NaCl-KCl and NaCl-CsCl equimolar mixtures is found to vary in the series from approximately 1.10 to approximately 1.22 and practically not to depend on the temperature (in the 600-910 deg) range and concentration (2-25 mol.% ZrCl 4 +HfCl 4 ). HfCl 4 and ZrCl 4 are shown to form almost perfect solutions with each other, which in their turn form imperfect solutions with molten alkali metal chlorides, with the strength of hafnium complex chloride anions increasing higher than that of zirconium in the series from NaCl to CsCl

Structure and thermodynamic properties of molten rare earth-alkali chloride mixtures

International Nuclear Information System (INIS)

Okamoto, Y.; Ogawa, T.

1999-01-01

The dependence of the enthalpy of mixing on the structure of molten rare earth-alkali chloride mixtures has been investigated by molecular dynamics simulation. The experimental enthalpy of the mixing with its negative and its dependence on the cation size was qualitatively reproduced. It became clear that the enthalpy of mixing depends on the structural features of short and medium range. (orig.)

Redox reactions in rare earth chloride molten electrolytes

International Nuclear Information System (INIS)

Khokhlov, V.A.; Novoselova, A.V.; Nikolaeva, E.V.; Tkacheva, O.Yu.; Salyulev, A.B.

2007-01-01

Rare earth (REM, Ln) solutions in chloride melts including MCI+LnCl 3 mixtures, where M - alkali metals, were investigated by potentiometry, voltammetry, conductometry in wide concentration and temperature intervals. Findings present complete and trusty information on the valent state of rare earths, structure and composition of complex ions affecting essentially on properties of electrolytes. It is demonstrated that the coexistence of rare earth ions with different oxidation level formed as a result of possible redox reactions: 2Ln 3+ + Ln ↔3Ln 2+ , Ln 2+ + Ln↔2Ln + and nM + + Ln↔nM + Ln n+ appears sharply in thermodynamic and transport properties of molten Ln-LnCl 3 and Ln-LnCl 3 -MCl systems [ru

Molten Chloride Salts for Heat Transfer in Nuclear Systems

Science.gov (United States)

Ambrosek, James Wallace

2011-12-01

A forced convection loop was designed and constructed to examine the thermal-hydraulic performance of molten KCl-MgCl2 (68-32 at %) salt for use in nuclear co-generation facilities. As part of this research, methods for prediction of the thermo-physical properties of salt mixtures for selection of the coolant salt were studied. In addition, corrosion studies of 10 different alloys were exposed to the KCl-MgCl2 to determine a suitable construction material for the loop. Using experimental data found in literature for unary and binary salt systems, models were found, or developed to extrapolate the available experimental data to unstudied salt systems. These property models were then used to investigate the thermo-physical properties of the LINO3-NaNO3-KNO 3-Ca(NO3), system used in solar energy applications. Using these models, the density, viscosity, adiabatic compressibility, thermal conductivity, heat capacity, and melting temperatures of higher order systems can be approximated. These models may be applied to other molten salt systems. Coupons of 10 different alloys were exposed to the chloride salt for 100 hours at 850°C was undertaken to help determine with which alloy to construct the loop. Of the alloys exposed, Haynes 230 had the least amount of weight loss per area. Nickel and Hastelloy N performed best based on maximum depth of attack. Inconel 625 and 718 had a nearly uniform depletion of Cr from the surface of the sample. All other alloys tested had depletion of Cr along the grain boundaries. The Nb in Inconel 625 and 718 changed the way the Cr is depleted in these alloys. Grain-boundary engineering (GBE) of Incoloy 800H improved the corrosion resistance (weight loss and maximum depth of attack) by nearly 50% as compared to the as-received Incoloy 800H sample. A high temperature pump, thermal flow meter, and pressure differential device was designed, constructed and tested for use in the loop, The heat transfer of the molten chloride salt was found to

Molten salt scrubbing of zirconium or hafnium tetrachloride

International Nuclear Information System (INIS)

Lee, E.D.; McLaughlin, D.F.

1990-01-01

This patent describes a continuous process for removing impurities of iron or aluminum chloride or both from vaporous zirconium or hafnium chloride or both. It comprises: introducing impure zirconium or hafnium chloride vapor or both into a middle portion of an absorbing column containing a molten salt phase, the molten salt phase absorbing the impurities of iron or aluminum chloride or both to produce chloride vapor stripped of zirconium or hafnium chloride; introducing sodium or potassium chloride or both into a top portion of the column; controlling the top portion of the column to between 300--375 degrees C.; heating a bottom portion of the column to 450--550 degrees C. To vaporize zirconium chloride or hafnium chloride or hafnium and zirconium chloride from the molten salt; withdrawing molten salt substantially free of zirconium and hafnium chloride from the bottom portion of the column; and withdrawing zirconium chloride or hafnium chloride or hafnium and zirconium chloride vapor substantially free of impurities of iron and aluminum chloride from the top of the column

Environmental and energy gains from using molten magnesium–sodium–potassium chlorides for electro-metallisation of refractory metal oxides

Directory of Open Access Journals (Sweden)

Wei Li

2015-12-01

Full Text Available The molten eutectic mixture of magnesium, sodium and potassium chlorides (MgCl2–NaCl–KCl has inappreciable solubility for oxide ions, and can help disengage a carbon anode from the oxide ions generated at a metal oxide cathode, and effectively avoid carbon dioxide formation. This “disengaging strategy” was successfully demonstrated in electro-reduction of solid oxides of zirconium and tantalum. It has led to significantly higher current efficiency (93%, and lower energy consumption (1.4 kW h kg−1 in electrolysis of tantalum oxide to tantalum metal compared to the conventional electrolysis in molten calcium chloride (e.g. 78% and 2.4 kW h/kg-Ta.

Highly selective oxidative dehydrogenation of ethane with supported molten chloride catalysts

Energy Technology Data Exchange (ETDEWEB)

Gaertner, C.A.; Veen, A.C. van; Lercher, J.A. [Technische Univ. Muenchen (Germany). Catalysis Research Center

2011-07-01

Ethene production is one of the most important transformations in chemical industry, given that C{sub 2}H{sub 4} serves as building block for many mass-market products. Besides conventional thermal processes like steam cracking of ethane, ethane can be produced selectively by catalytic processes. One of the classes of catalysts that have been reported in literature as active and highly selective for the oxidative dehydrogenation of ethane is that of supported molten chloride catalysts, containing an alkali chloride overlayer on a solid support. This work deals with fundamental aspects of the catalytic action in latter class of catalysts. Results from kinetic reaction studies are related to observations in detailed characterization and lead to a comprehensive mechanistic understanding. Of fundamental importance towards mechanistic insights is the oxygen storage capacity of the catalysts that has been determined by transient step experiments. (orig.)

Corrosion potentials of hafnium in molten alkaline-earth metal chlorides

International Nuclear Information System (INIS)

Kovalik, O.Yu.; Tkhaj, V.D.

2000-01-01

Corrosion potentials of hafnium in molten calcium, strontium and barium chlorides are measured and their temperature dependences are determined. It is stated that the corrosion potential of hafnium becomes more electropositive with an increase of the environment temperature. If the temperature is the same the potential shifts to the interval of more electronegative values in the row of CaCl 2 , SrCl 2 , BaCl 2 which corresponds to a lesser corrosion rate in environments positioned from left to right. the comparison of hafnium corrosion potentials with previously measured values for titanium and zirconium shows that a metal activity decrease results in a more electronegative corrosion potential [ru

Development of electrolytic process in molten salt media for light rare-earth metals production. The metallic cerium electrodeposition

International Nuclear Information System (INIS)

Restivo, T.A.G.

1994-01-01

The development of molten salt process and the respective equipment aiming rare-earth metals recovery was described. In the present case, the liquid cerium metal electrodeposition in a molten electrolytes of cerium chloride and an equimolar mixture of sodium and potassium chlorides in temperatures near 800 C was studied. Due the high chemical reactivity of the rare-earth metals in the liquid state and their molten halides, an electrolytic cell was constructed with controlled atmosphere, graphite crucibles and anodes and a tungsten cathode. The electrolytic process variables and characteristics were evaluated upon the current efficiency and metallic product purity. Based on this evaluations, were suggested some alterations on the electrolytic reactor design and upon the process parameters. (author). 90 refs, 37 figs, 20 tabs

Molten salt extractive distillation process for zirconium-hafnium separation

International Nuclear Information System (INIS)

McLaughlin, D.F.; Stoltz, R.A.

1989-01-01

This patent describes an improvement in a process for zirconium-hafnium separation. It utilizes an extractive distillation column with a mixture of zirconium and hafnium tetrachlorides introduced into a distillation column having a top and bottom with hafnium enriched overheads taken from the top of the column and a molten salt solvent circulated through the column to provide a liquid phase, and with molten salt solvent containing zirconium chloride being taken from the bottom of the distillation column. The improvements comprising: utilizing a molten salt solvent consisting principally of lithium chloride and at least one of sodium, potassium, magnesium and calcium chlorides; stripping of the zirconium chloride taken from the bottom of the distillation column by electrochemically reducing zirconium from the molten salt solvent; and utilizing a pressurized reflux condenser on the top of the column to add the hafnium chloride enriched overheads to the molten salt solvent previously stripped of zirconium chloride

In situ spectroscopy and spectroelectrochemistry of uranium in high-temperature alkali chloride molten salts.

Science.gov (United States)

Polovov, Ilya B; Volkovich, Vladimir A; Charnock, John M; Kralj, Brett; Lewin, Robert G; Kinoshita, Hajime; May, Iain; Sharrad, Clint A

2008-09-01

Soluble uranium chloride species, in the oxidation states of III+, IV+, V+, and VI+, have been chemically generated in high-temperature alkali chloride melts. These reactions were monitored by in situ electronic absorption spectroscopy. In situ X-ray absorption spectroscopy of uranium(VI) in a molten LiCl-KCl eutectic was used to determine the immediate coordination environment about the uranium. The dominant species in the melt was [UO 2Cl 4] (2-). Further analysis of the extended X-ray absorption fine structure data and Raman spectroscopy of the melts quenched back to room temperature indicated the possibility of ordering beyond the first coordination sphere of [UO 2Cl 4] (2-). The electrolytic generation of uranium(III) in a molten LiCl-KCl eutectic was also investigated. Anodic dissolution of uranium metal was found to be more efficient at producing uranium(III) in high-temperature melts than the cathodic reduction of uranium(IV). These high-temperature electrolytic processes were studied by in situ electronic absorption spectroelectrochemistry, and we have also developed in situ X-ray absorption spectroelectrochemistry techniques to probe both the uranium oxidation state and the uranium coordination environment in these melts.

Thermogravimetric method of estimation of uranyl cation state in melts of alkali metal chlorides and their mixtures

International Nuclear Information System (INIS)

Vorobej, M.P.; Desyatnik, V.N.

1979-01-01

The thermogravimetric method was used to study the chloridizing of uranium oxides in molten media. The study of the uranium oxide chloridizing served as a basis for evaluating comparatively, using the DTA method, the uranyl-cation state in a melt. Using the alkali metals as example, it was shown that the decomposition of the frozen uranium oxychlorides proceeds with the formation of intermediate chlorouranates. The final product of the thermolysis are uranates Me 2 U 2 O 7 (Me-Li, Na, K, Rb, Cs). The time and the conditions of the change of uranium oxides to the oxyanion [UO 2 Cl 4 ] 2- were determined as a function of the chloridizing agent. The method can be employed for evaluating uranyl-ions in molten media where they are used as electrolytes in the extraction of uranium dioxide

Electrodeposition behavior of nickel and nickel-zinc alloys from the zinc chloride-1-ethyl-3-methylimidazolium chloride low temperature molten salt

International Nuclear Information System (INIS)

Gou Shiping; Sun, I.-W.

2008-01-01

The electrodeposition of nickel and nickel-zinc alloys was investigated at polycrystalline tungsten electrode in the zinc chloride-1-ethyl-3-methylimidazolium chloride molten salt. Although nickel(II) chloride dissolved easily into the pure chloride-rich 1-ethyl-3-methylimidazolium chloride ionic melt, metallic nickel could not be obtained by electrochemical reduction of this solution. The addition of zinc chloride to this solution shifted the reduction of nickel(II) to more positive potential making the electrodeposition of nickel possible. The electrodeposition of nickel, however, requires an overpotential driven nucleation process. Dense and compact nickel deposits with good adherence could be prepared by controlling the deposition potential. X-ray powder diffraction measurements indicated the presence of crystalline nickel deposits. Non-anomalous electrodeposition of nickel-zinc alloys was achieved through the underpotential deposition of zinc on the deposited nickel at a potential more negative than that of the deposition of nickel. X-ray powder diffraction and energy-dispersive spectrometry measurements of the electrodeposits indicated that the composition and the phase types of the nickel-zinc alloys are dependent on the deposition potential. For the Ni-Zn alloy deposits prepared by underpotential deposition of Zn on Ni, the Zn content in the Ni-Zn was always less than 50 atom%

Process for recovering tritium from molten lithium metal

Science.gov (United States)

Maroni, Victor A.

1976-01-01

Lithium tritide (LiT) is extracted from molten lithium metal that has been exposed to neutron irradiation for breeding tritium within a thermonuclear or fission reactor. The extraction is performed by intimately contacting the molten lithium metal with a molten lithium salt, for instance, lithium chloride - potassium chloride eutectic to distribute LiT between the salt and metal phases. The extracted tritium is recovered in gaseous form from the molten salt phase by a subsequent electrolytic or oxidation step.

NMR study of thallium(I) ions in molten binary mixtures of nitrates and chlorides

International Nuclear Information System (INIS)

Nakamura, Yoshio; Kitazawa, Yukiharu; Shimoji, Mitsuo; Shimokawa, Shigezo.

1983-01-01

The chemical shifts of 205 Tl NMR in molten binary mixtures of nitrates and those of chlorides have been measured as a function of composition and temperature. The shifts increase in the diamagnetic direction with decreasing the size of foreign cations and increase in the paramagnetic direction with increasing temperature. These results are interpreted by changes in the overlap of orbitals of the Tl + ion and the anion, which depend upon composition and temperature. (author)

Continuous extraction of molten chloride salts with liquid cadmium alloys

International Nuclear Information System (INIS)

Chow, L.S.; Basco, J.K.; Ackerman, J.P.; Johnson, T.R.

1993-01-01

A pyrochemical method is being developed at Argonne National Laboratory (ANL) to provide contnuous multistage extractions between molten chloride salts and liquid cadmium alloys at 500 degrees C. The extraction method will be used to recover transuranic (TRU) elements from the process salt in the electroretiner used in the pyrochemical reprocessing of spent fuel from the Integral Fast Reactor (IFR). The IFR is one of the Department of Energy's advanced power reactor concepts. The recovered TRU elements are returned to the electrorefiner. The extracted salt undergoes further processing to remove rare earths and other fission products so that most of the purified salt can also be returned to the electrorefiner, thereby extending the useful life of the process salt many times

Electrochemical-metallothermic reduction of zirconium in molten salt solutions

International Nuclear Information System (INIS)

McLaughlin, D.F.; Talko, F.

1990-01-01

This patent describes a method for separating hafnium from zirconium of the type wherein a feed containing zirconium and hafnium chlorides is prepared from zirconium-hafnium chloride and the feed is introduced into a distillation column, which distillation column has a reboiler connected at the bottom and a reflux condenser connected at the top and wherein a hafnium chloride enriched stream is taken from the top of the column and a zirconium enriched chloride stream is taken from the bottom of the column. It comprises: reducing the zirconium enriched chloride stream taken from the distillation column to metal by electrochemically reducing an alkaline earth metal in a molten salt bath with the molten salt in the molten salt bath consisting essentially of a mixture of at least one alkali metal chloride and at least one alkaline earth metal chloride and zirconium chloride, with the reduced alkaline earth metal reacting with the zirconium chloride to produce zirconium metal and alkaline earth metal chloride

Actinide oxides synthesis in molten chloride. Structural studies and reaction mechanisms

International Nuclear Information System (INIS)

Vigier, J.F.

2012-01-01

Pyrochemical processes are studied as potential alternatives to hydrochemical processes for spent nuclear fuel treatment. The CEA pyrochemical process led to a molten LiCl-CaCl 2 (30-70% mol) salt at 700 C with solubilized actinides at the oxidation state (III). The study developed in this thesis concerns actinide oxides synthesis in this media for nuclear fuel re-fabrication. This synthesis was done by wet argon sparging. First, this conversion method is described for neodymium (III) and cerium (III) co-conversion. The conversion rates are around 99.9%. The obtained powders contain mixed oxychloride Ce 1-x Nd x OCl as main component, with a small amount of mixed oxide Ce 1-x Nd x O 2-0,5x for the high cerium ratio. A second oxychloride CeIV(Nd 0.7 Ce 0.3 ) III O 3 Cl is obtained in specific conditions and in very low quantity. The structure of this oxychloride is described in this study. The partially oxidative property of the conversion method induces the oxidation of a part of cerium (III) to oxidation state (IV). In the case of uranium (III) conversion by wet argon sparging, all the uranium is oxidized and give the oxide UO 2 as single compound. The conversion rate for this element is over 99.9% in the molten chloride, but significant amount of uranium is lost by volatilization during the conversion. The study shows the oxygen sensitivity of uranium during the conversion, inducing oxidation over the oxidation state (IV), and giving UO 2+x or uranate CaUO 4 . As a consequence, oxygen led to calcium pollution in the precipitate. Finally, the U(III) and Pu(III) co-conversion study shows the highest precipitation sensitivity of uranium (III) in comparison with plutonium (III), responsible of a successive conversion of the two elements, giving an oxide mixture of UO 2 et PuO 2 with quantitative conversion rate. Surprisingly, the conversion of Pu(III) in the same conditions led to a mixture of PuO 2 and PuOCl, characteristic of a partial oxidation from Pu (III) to Pu

On barium oxide solubility in barium-containing chloride melts

International Nuclear Information System (INIS)

Nikolaeva, Elena V.; Zakiryanova, Irina D.; Bovet, Andrey L.; Korzun, Iraida V.

2016-01-01

Oxide solubility in chloride melts depends on temperature and composition of molten solvent. The solubility of barium oxide in the solvents with barium chloride content is essentially higher than that in molten alkali chlorides. Spectral data demonstrate the existence of oxychloride ionic groupings in such melts. This work presents the results of the BaO solubility in two molten BaCl 2 -NaCl systems with different barium chloride content. The received data together with earlier published results revealed the main regularities of BaO solubility in molten BaO-BaCl 2 -MCl systems.

Study of Reaction of Curium Oxy-Compound Formation in Molten Chlorides

Energy Technology Data Exchange (ETDEWEB)

Osipenko, A.G.; Mayorshin, A.A.; Bychkov, A.V. [Dimitrovgrad-10, Ulyanovsk region, 433510 (Russian Federation)

2008-07-01

The method of potentiometric titration using oxygen sensors with solid electrolyte membrane was applied for the study of the interaction of curium cations with oxygen anions in the molten alkali metal chlorides in the temperature range of 450-850 C degrees depending on oxy-acidity of the environment. Assumptions were made concerning ion and phase composition of the obtained high-temperature compounds and chemical reactions taking place in the melts. This scheme assumes that as the basicity of the melt increases, initially the formation of soluble curium oxychlorides takes place in the melt (presumably CmO{sup -}) that is followed by formation of solid CmOCl and finally sesquioxide Cm{sub 2}O{sub 3}. Basic thermodynamic values were calculated for the resultant curium oxy-compounds.

Immobilization of fission products arising from pyrometallurgical reprocessing in chloride media

Science.gov (United States)

Leturcq, G.; Grandjean, A.; Rigaud, D.; Perouty, P.; Charlot, M.

2005-12-01

Spent nuclear fuel reprocessing to recover energy-producing elements such as uranium or plutonium can be performed by a pyrochemical process. In such method, the actinides and fission products are extracted by electrodeposition in a molten chloride medium. These processes generate chlorinated alkali salt flows contaminated by fission products, mainly Cs, Ba, Sr and rare earth elements constituting high-level waste. Two possible alternatives are investigated for managing this wasteform; a protocol is described for dechlorinating the fission products to allow vitrification, and mineral phases capable of immobilizing chlorides are listed to allow specification of a dedicated ceramic matrix suitable for containment of these chlorinated waste streams. The results of tests to synthesize chlorosilicate phases are also discussed.

The measurement of metallic uranium solubility in lithium chloride molten salt

International Nuclear Information System (INIS)

Park, K. K.; Choi, I. K.; Yeon, J. W.; Choi, K. S.; Park, Y. J.

2002-01-01

For the purpose of more precise solubility measurement of metallic uranium in lithium chloride melt, the effect of lithium chloride on uranium determination and and the change of oxidation state of metallic uranium in the media were investigated. Uranium of higher than 10 μg/g could be directly determined by ICP-AES. In the case of the lower concentration, the separation and concentration of uranium by anion exchanger was followed by ICP-AES, thereby extending the measurable concentration to 0.1 μg/g. The effects of lithium oxide, uranium oxides(UO 2 or U 3 O 8 ) and metallic lithium on the solubility of metallic uranium were individually investigated in glassy carbon or stainless steel crucibles under argon gas atmosphere. Since metallic uranium is oxidized to uranium(III) in the absence of metallic lithium, causing an increase in the solubility, metallic lithium as reducing agent should be present in the reaction media to obtain the more precise solubility. The metallic uranium solubilities measured at 660 and 690 .deg. C were both lower than 10 μg/g

Pourbaix diagrams of actinides in molten chlorides using an indicating electrode for oxide ion activity; Etablissement de diagrammes de Pourbaix des actinides dans les chlorures fondus au moyen d'une electrode indicatrice de l'activite des ions oxyde

Energy Technology Data Exchange (ETDEWEB)

Lambertin, D.; Lacquement, J. [CEA Valrho, (DCC/DRRV/SPHA), 30 - Marcoule (France)

2000-07-01

Pyrochemical separation methods using high temperature molten salt media could emerge as promising and valuable routes compared with aqueous methods for separation and transmutation strategies for long-lived radionuclides. A good knowledge of the molten salt chemistry is essential for controlling these separations, and elementary data are required for molten halide salts, which can be readily provided by electrochemical methods. Applying the chemical principles of aqueous solutions to the molten salt media, Pourbaix diagrams - called in this case potential-oxo-acidity (pO{sup 2-}) - can be plotted. They offer a rapid and comprehensive view of the thermodynamic properties of selected elements in a solvent of interest. Two methods are available for preparing these diagrams. The first is based on available thermodynamic data on pure element oxide (and oxychloride) compounds and on element chloride activity coefficients in melt (which can be electrochemically determined). In this method, we consider the oxide anion exchange reactions between the pure compounds, water and hydrogen chloride. The second method is a direct and experimental determination of the oxo-acidic properties of the studied element chlorides in melts. Use of an Yttria-Stabilised Zirconia Membrane (YSZM) electrode (oxide anion selective electrode) helps determine the nature of the stable oxide compounds in melts as well as their stabilities. The YSZM is used with a silver/silver chloride reference system, and was developed 25 years ago. Two examples of Potential-acidity diagrams. Employing the first method and the determination of the standard potential of plutonium in LiCl-KCl and NaCl-KCl eutectic mixtures, potential-oxo-acidity diagrams were plotted for these melts at various temperatures. It was found that the stability domain for plutonium chloride depends on the melt composition (influence of oxide anion solvation). We also used the Omega acidity function - based on reaction (1) - which is a

Cerium concentrate and mixed rare earth chloride by the oxidative decomposition of bastnaesite in molten sodium hydroxide

International Nuclear Information System (INIS)

Iijima, Toshio; Kato, Kazuhiro; Kuno, Toyohiko; Okuwaki, Akitsugu; Umetsu, Yoshiaki; Okabe, Taijiro

1993-01-01

Bastnaesite was treated in molten NaOH at 623-777 K for 10-60 min under atmosphere. Cerium-(III) in the ore was easily oxidized 95% or more within 30 min to give an oxidation product composed of solid solutions of CeO 2 -rich and CeO 2 -lean phases and Ce-free rare earth oxide phase. Simultaneously fluoride ion was removed 97% or more. Cerium concentrate was prepared from the oxidation product by leaching with 0.1-3 M HCl solution. The yield of cerium concentrate and the CeO 2 content reached 55-57% and 70-72%, respectively. Mixed rare earth chloride is composed of about 90% rare earth chloride and 10% alkaline earth chloride, and the contents of CeCl 3 , LaCl 3 , NdCl 3 , and PrCl 3 are 11.5, 58.5, 14.4, and 5.4%, respectively. The particle size of resulting cerium concentrate was fairly uniform and about 0.1 μm

Electrical conductivity of molten carbonate and carbonate-chloride systems coexisting with aluminium oxide powder

Energy Technology Data Exchange (ETDEWEB)

Nikolaeva, Elena V. [Institute of High Temperature Electrochemistry, Yekaterinburg (Russian Federation); Ural Federal Univ., Yekaterinburg (Russian Federation); Ural State Economic Univ., Yekaterinburg (Russian Federation); Bovet, Andrey L.; Zakiryanova, Irina D. [Institute of High Temperature Electrochemistry, Yekaterinburg (Russian Federation); Ural Federal Univ., Yekaterinburg (Russian Federation)

2018-04-01

The electrical properties of composite electrolytes (suspensions) composed of α-Al{sub 2}O{sub 3} powder and molten carbonate eutectic (Li{sub 2}CO{sub 3}-Na{sub 2}CO{sub 3}-K{sub 2}CO{sub 3}){sub eut} or molten carbonate-chloride mixture 0.72(Li{sub 2}CO{sub 3}-Na{sub 2}CO{sub 3}-K{sub 2}CO{sub 3}){sub eut}-0.28NaCl have been investigated by AC impedance method. This system shows a dependence of the electrical conductivity upon the temperature and the α-Al{sub 2}O{sub 3} content. The specific electrical conductivity of the α-Al{sub 2}O{sub 3}/(Li{sub 2}CO{sub 3}-Na{sub 2}CO{sub 3}-K{sub 2}CO{sub 3}){sub eut} system can be adequately described by the Maxwell equation for two-phase heterogeneous materials. The regression equation for the dependence of the specific conductivity of the α-Al{sub 2}O{sub 3}/(Li{sub 2}CO{sub 3}-Na{sub 2}CO{sub 3}-K{sub 2}CO{sub 3}){sub eut} composite on the aluminium oxide concentration and temperature was obtained.

Detection and removal of molten salts from molten aluminum alloys

Energy Technology Data Exchange (ETDEWEB)

K. Butcher; D. Smith; C. L. Lin; L. Aubrey

1999-08-02

Molten salts are one source of inclusions and defects in aluminum ingots and cast shapes. A selective adsorption media was used to remove these inclusions and a device for detection of molten salts was tested. This set of experiments is described and the results are presented and analyzed.

A study on conductivity, density, and viscosity of molten salt systems

International Nuclear Information System (INIS)

Cho, Kangjo

1976-01-01

A relation between the equivalent conductivity and density for molten salts is deduced with the aid of significant structures theory, and the solid state density at melting point is evaluated approximately for some rare-earth metal chlorides and the other chlorides. Furthermore, the relation among the equivalent conductivity, density, and viscosity for some molten salts is discussed. (auth.)

Mechanism of growth, composition and structure of oxide films formed on ferrous alloys in molten salt electrolytes - a review

International Nuclear Information System (INIS)

Tzvetkoff, Tz.; Kolchakov, J.

2004-01-01

The growth kinetics, chemical composition and structure of scales formed during corrosion of Fe and its alloys in molten salts are reviewed. Special attention is paid to the effect of the composition of the molten salt mixture and the gas atmosphere on the stability and protective ability of corrosion layers. First, the thermodynamical background of the corrosion and oxidation of Fe-base engineering materials in molten salt media is briefly commented. A concise review of the growth kinetics of passivating oxide films is also presented. These two introductory chapters serve as a guide for the extensive survey of the growth mechanism, nature and properties of oxide and related scales on ferrous alloys in a range of molten electrolytes - chlorides, nitrates, sulphates, carbonates, hydroxides and mixtures thereof in gas atmospheres containing O 2 , CO 2 , SO 2 , SO 3 and HCl

Evaluation of chloride-ion-specific electrodes as in situ chemical sensors for monitoring total chloride concentration in aqueous solutions generated during the recovery of plutonium from molten salts used in plutonium electrorefining operations

International Nuclear Information System (INIS)

Smith, W.H.

1992-10-01

Two commercially available chloride-ion-specific electrodes (CLISEs), a solid-state type and a membrane type, were evaluated as potential in situ chemical sensors for determining total chloride ion concentration in mixed sodium chloride/potassium chloride/hydrochloric acid solutions generated during the recovery of plutonium from molten salts used in plutonium electrorefining operations. Because the response of the solid-state CLISE was closer than was the response of the membrane-type CLISE to the theoretical response predicted by the Nernst equation, the solid-state CLISE was selected for further evaluation. A detailed investigation of the characteristics of the chloride system and the corresponding CLISE response to concentration changes suggested four methods by which the CLISE could be used either as a direct, in situ sensor or as an indirect sensor through which an analysis could be performed on-line with a sample extracted from the process solution

Deposition of niobium plate on niobium-titanium from molten salts

International Nuclear Information System (INIS)

Matychenko, Eh.S.; Shevyrev, A.A.; Stolyarova, L.A.; Sukhorzhevskaya, S.L.

1993-01-01

A possibility of using Nb-Ti alloys (50 and 34 mas.% of Ti) as substrates for deposition of niobium coating of chloride-fluoride and fluoride molten salts is studied. Corrosion behaviour of alloys indicates in the electrolytic bath within 970-1070 K interval, coating structure and state of coating-substrate boundary are investigated. Chloride-fluoride molten salt usefullness for making products with niobium coatings is shown

Saturated steams pressure of HfCl4-KCl molten mixtures

International Nuclear Information System (INIS)

Salyulev, A.B.; Smirnov, M.V.; Kudyakov, V.Ya.

1980-01-01

A bellows null pressure gauge and the dynamic method were used to measure the total and partial pressures of saturated vapors of individual components of molten HfCl 4 -KCl mixtures, as a function of temperature (260 to 1000 deg C) and composition (1.9 to 64.3 mol.% HfCl 4 ). Empirical equations expressing the relationship between pressure and temperature are presented. It is shown that in molten mixtures of hafnium tetrachloride with chlorides of alkaline metals its partial pressure dramatically increases when potassium chloride substitutes for cesium chloride

Boric Ester-Type Molten Salt via Dehydrocoupling Reaction

Directory of Open Access Journals (Sweden)

Noriyoshi Matsumi

2014-11-01

Full Text Available Novel boric ester-type molten salt was prepared using 1-(2-hydroxyethyl-3-methylimidazolium chloride as a key starting material. After an ion exchange reaction of 1-(2-hydroxyethyl-3-methylimidazolium chloride with lithium (bis-(trifluoromethanesulfonyl imide (LiNTf2, the resulting 1-(2-hydroxyethyl-3-methylimidazolium NTf2 was reacted with 9-borabicyclo[3.3.1]nonane (9-BBN to give the desired boric ester-type molten salt in a moderate yield. The structure of the boric ester-type molten salt was supported by 1H-, 13C-, 11B- and 19F-NMR spectra. In the presence of two different kinds of lithium salts, the matrices showed an ionic conductivity in the range of 1.1 × 10−4–1.6 × 10−5 S cm−1 at 51 °C. This was higher than other organoboron molten salts ever reported.

Preparation of uranium coatings by electro deposition in molten chloride media

International Nuclear Information System (INIS)

Taxil, P.; Serrano, K.; Dugne, O.

2001-01-01

The electrodeposition of uranium is now a relevant topic for two kinds of applications: the preparation of this metal with compounds extracted from the mineral ores; the separation from lanthanides in the nuclear waste. This paper concerns the process of preparation of uranium metal on various substrates, using the electro deposition process in molten salts. The electrolyte consists of an eutectic mixture NaCl-KCl as solvent (fusion point 650 deg C) and a tetravalent uranium compound, UCl 4 as solute. We present the results, theoretical and practical, necessary to manage the process. So, the following points will be considered stepwise in this paper: the electrochemical behaviour of uranium III ions in the electrolyte, since it is now clearly established that uranium metal can be prepared by electrochemical reduction of UCl 3 in a NaCl-KCl mixture in a single step process: U III + 3 e → U 0 ; the crystallisation mode of uranium on the cathodic material; the preparation of uranium coatings with variables conditions: temperature, electrolyte concentration, current density and cathodic substrate; the observation of the crystal growth on the substrates, by using SEM micrographies. (authors)

Electrochemistry of vanadium(II and the electrodeposition of aluminum-vanadium alloys in the aluminum chloride-1-ethyl-3-methylimidazolium chloride molten salt

Directory of Open Access Journals (Sweden)

Tsuda T.

2003-01-01

Full Text Available The electrochemical behavior of vanadium(II was examined in the 66.7-33.3 mole percent aluminum chloride-1-ethyl-3-methylimidazolium chloride molten salt containing dissolved VCl2 at 353 K. Voltammetry experiments revealed that V(II could be electrochemically oxidized to V(III and V(IV. However at slow scan rates the V(II/V(III electrode reaction is complicated by the rapid precipitation of V(III as VCl3. The reduction of V(II occurs at potentials considerably negative of the Al(III/Al electrode reaction, and Al-V alloys cannot be electrodeposited from this melt. However electrodeposition experiments conducted in VCl2-saturated melt containing the additive, 1-ethyl-3-methylimidazolium tetrafluoroborate, resulted in Al-V alloys. The vanadium content of these alloys increased with increasing cathodic current density or more negative applied potentials. X-ray analysis of Al-V alloys that were electrodeposited on a rotating copper wire substrate indicated that these alloys did not form or contain an intermetallic compound, but were non-equilibrium or metastable solid solutions. The chloride-pitting corrosion properties of these alloys were examined in aqueous NaCl by using potentiodynamic polarization techniques. Alloys containing ~10 a/o vanadium exhibited a pitting potential that was 0.3 V positive of that for pure aluminum.

Saturated steams pressure of HfCl/sub 4/-KCl molten mixtures

Energy Technology Data Exchange (ETDEWEB)

Salyulev, A B; Smirnov, M V; Kudyakov, V Ya [AN SSSR, Sverdlovsk. Inst. Ehlektrokhimii

1980-02-01

A bellows null pressure gauge and the dynamic method were used to measure the total and partial pressures of saturated vapors of individual components of molten HfCl/sub 4/-KCl mixtures, as a function of temperature (260 to 1000 deg C) and composition (1.9 to 64.3 mol.% HfCl/sub 4/). Empirical equations expressing the relationship between pressure and temperature are presented. It is shown that in molten mixtures of hafnium tetrachloride with chlorides of alkaline metals its partial pressure dramatically increases when potassium chloride substitutes for cesium chloride.

Behaviour of metals and alloys in molten fluoride media

International Nuclear Information System (INIS)

Fabre, St.

2009-01-01

Fluoride salts are contemplated for Generation IV nuclear systems which structural materials need to resist corrosion at high temperatures. Corrosion of metals in molten fluorides has been investigated in support of the Molten Salt Reactor's development and led to an optimized alloy, Hastelloy-N, but it lacked fundamentals data for the comprehension of materials' degradation mechanisms. The main objective of this work is then to help with the understanding of the corrosion behaviour of nickel and its alloys in fluoride salts. An experimental method was built up using electrochemical techniques and enabled to investigate the thermochemical conditions of the media and the influence of different parameters (media, temperature and quantity of impurities) on the behaviour of the materials. Most tests were performed in LiF-NaF mixtures between 800 and 1000 C. Pure metals can be classified as follows: Cr ≤ Fe ≤ Ni ≤ Mo ≤ W in increasing stability order and two specific behaviours were evidenced: Cr and Fe corrode in the melt, whereas Ni, Mo and W are stable, underlining the significance level of the redox couple controlling the reactions in the mixture. Moreover, corrosion current densities increase with temperature, fluoro-acidity and the quantity of dissolved oxide in the melt. Binary Ni-Cr alloys were also tested; selective attack of Cr is first observed before both elements are oxidized. Combining thermochemical calculations and experimental results enables to propose an approach to establish an optimized composition for a stable alloy. Immersion tests were finally achieved in addition to the electrochemical tests: interpretations of both methods were compared and completed. (author)

Stabilization of molten salt materials using metal chlorides for solar thermal storage.

Science.gov (United States)

Dunlop, T O; Jarvis, D J; Voice, W E; Sullivan, J H

2018-05-29

The effect of a variety of metal-chlorides additions on the melting behavior and thermal stability of commercially available salts was investigated. Ternary salts comprised of KNO 3, NaNO 2, and NaNO 3 were produced with additions of a variety of chlorides (KCl, LiCl, CaCl 2 , ZnCl 2 , NaCl and MgCl 2 ). Thermogravimetric analysis and weight loss experiments showed that the quaternary salt containing a 5 wt% addition of LiCl and KCl led to an increase in short term thermal stability compared to the ternary control salts. These additions allowed the salts to remain stable up to a temperature of 630 °C. Long term weight loss experiments showed an upper stability increase of 50 °C. A 5 wt% LiCl addition resulted in a weight loss of only 25% after 30 hours in comparison to a 61% loss for control ternary salts. Calorimetry showed that LiCl additions allow partial melting at 80 °C, in comparison to the 142 °C of ternary salts. This drop in melting point, combined with increased stability, provided a molten working range increase of almost 100 °C in total, in comparison to the control ternary salts. XRD analysis showed the oxidation effect of decomposing salts and the additional phase created with LiCl additions to allow melting point changes to occur.

46 CFR 151.50-55 - Sulfur (molten).

Science.gov (United States)

2010-10-01

... BULK LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-55 Sulfur (molten). (a.... Heat transfer media shall be steam, and alternate media will require specific approval of the... 46 Shipping 5 2010-10-01 2010-10-01 false Sulfur (molten). 151.50-55 Section 151.50-55 Shipping...

High temperature corrosion of nickel alloys by molten calcium chloride in an oxidising environment

International Nuclear Information System (INIS)

Barnett, Roger; Gittos, Mike

2012-09-01

A series of nickel alloys was submerged in molten calcium chloride (a molten salt proposed for and used in the nuclear industry for a variety of applications), at 850 deg. C for 72 hours under an oxidising environment. The samples were analysed in detail, in order to determine their corrosion behaviour and suitability for use under these conditions. 310 stainless steel was used as a reference material. Extensive corrosion occurred and the observed attack on the metal substrates was general and massive with corrosion rates ranging from 1.17 mm/year, for Haynes 214, to 13.3 mm/year, for 310 stainless steel. All materials showed selective leaching of chromium from the samples but the oxide layer formed was not protective, spalling away easily. The severity of the attack was not immediately visible from the corrosion rate alone: samples showed a friable scale on the surface and deep penetration of the attack beneath, up to 0.63 mm for 310 stainless steel. In some cases, the attack was clearly intergranular with chromium being depleted along the grain boundaries, whereas in others, the attack was more general. No simple correlation between alloying elements and corrosion rate was apparent, with additions of aluminium and silicon appearing to have little or no protective effect. Alloys 600 and Haynes HR-160 showed promise, with relatively low corrosion rates and penetration depths. (authors)

Thermal Characterization of Molten Salt Systems

Energy Technology Data Exchange (ETDEWEB)

Toni Y. Gutknecht; Guy L. Fredrickson

2011-09-01

The phase stability of molten salts in an electrorefiner (ER) may be adversely affected by the buildup of sodium, fission products, and transuranics in the electrolyte. Potential situations that need to be avoided are the following: (1) salt freezing due to an unexpected change in the liquidus temperature, (2) phase separation or non-homogeneity of the molten salt due to the precipitation of solids or formation of immiscible liquids, and (3) any mechanism that can result in the separation and concentration of fissile elements from the molten salt. Any of these situations would result in an off-normal condition outside the established safety basis for electrorefiner (ER) operations. 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 report describes the experimental results of typical salts compositions, which consist of chlorides of potassium, lithium, strontium, samarium, praseodymium, lanthanum, barium, cerium, cesium, neodymium, sodium and gadolinium chlorides as a surrogate for both uranium and plutonium, used for the processing of used nuclear fuels.

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

Cation exchange process for molten salt extraction residues

International Nuclear Information System (INIS)

Proctor, S.G.

1975-01-01

A new method, utilizing a cation exchange technique, has been developed for processing molten salt extraction (MSE) chloride salt residues. The developed ion exchange procedure has been used to separate americium and plutonium from gross quantities of magnesium, potassium, and sodium chloride that are present in the residues. The recovered plutonium and americium contained only 20 percent of the original amounts of magnesium, potassium, and sodium and were completely free of any detectable amounts of chloride impurity. (U.S.)

Condensation mechanisms of tetravalent technetium in chloride media

International Nuclear Information System (INIS)

Poineau, F.

2004-10-01

In deep storage technetium can exist in degree IV or III. Recent studies on Tc(IV) have shown that Tc n O y (4n-2y)+ , Tc IV (μ-O) 2 Tc IV structure, is a precursor for precipitation of TcO 2 . Few data are available on Tc n O y (4n-2y)+ Subject of this thesis is the mechanism of condensation of Tc(IV) leading to this form. Kinetic studies have shown that the condensation of Tc IV Cl 5 (H 2 O) - in chloride media leads to a dimer. XAS studies resulted in a linear structure Tc IV -O-Tc IV . This compound, formulated as Tc 2 OCl 10 4- , is stable at pH = 0.3, it undergoes cyclization to Tc n O y (4n-2y)+ at pH =1.5 and is oxidized to TcO 4 - under α radiation. In 3 M chloride media, TcO 2 lead to formation Tc 2 OCl 10 4- at pH = 0.3 and to Tc n O y (4n-2y)+ at pH = 1.5. An electrochemical cell permitting 'in situ' XAS measurement was developed. XANES studies have shown that the reduction of Tc(VII) lead to a Tc(IV)/Tc(III) mixture. (author)

Investigation of molten salt fast reactor

International Nuclear Information System (INIS)

Kubota, Kenichi; Konomura, Mamoru

2002-01-01

On survey research for practicability strategy of fast reactor (FR) (phase 1), to extract future practicability image candidates of FR from wide options, in addition to their survey and investigation objects of not only solid fuel reactors of conventional research object but also molten salt reactor as a flowing fuel reactor, investigation on concept of molten salt FR plant was carried out. As a part of the first step of the survey research for practicability strategy, a basic concept on plant centered at nuclear reactor facility using chloride molten salt reactor capable of carrying out U-Pu cycle was examined, to perform a base construction to evaluate economical potential for a practical FBR. As a result, a result could be obtained that because of inferior fuel inventory and heat transmission to those in Na cooling reactor in present knowledge, mass of reactor vessel and intermediate heat exchanger were to widely increased to expect reduction of power generation unit price even on considering cheapness of its fuel cycle cost. Therefore, at present step further investigation on concept design of the chloride molten salt reactor plant system is too early in time, and it is at a condition where basic and elementary researches aiming at upgrading of economical efficiency such as wide reduction of fuel inventory, a measure expectable for remarkable rationalization effect of reprocessing system integrating a reactor to a processing facility, and so on. (G.K.)

Molten salt combustion of radioactive wastes

International Nuclear Information System (INIS)

Grantham, L.F.; McKenzie, D.E.; Richards, W.L.; Oldenkamp, R.D.

1976-01-01

The Atomics International Molten Salt Combustion Process reduces the weight and volume of combustible β-γ contaminated transuranic waste by utilizing air in a molten salt medium to combust organic materials, to trap particulates, and to react chemically with any acidic gases produced during combustion. Typically, incomplete combustion products such as hydrocarbons and carbon monoxide are below detection limits (i.e., 3 ) is directly related to the sodium chloride vapor pressure of the melt; >80% of the particulate is sodium chloride. Essentially all metal oxides (combustion ash) are retained in the melt, e.g., >99.9% of the plutonium, >99.6% of the europium, and >99.9% of the ruthenium are retained in the melt. Both bench-scale radioactive and pilot scale (50 kg/hr) nonradioactive combustion tests have been completed with essentially the same results. Design of three combustors for industrial applications are underway

Thermochemical properties of media for pyrometallurgical nuclear fuel reprocessing

International Nuclear Information System (INIS)

Hosoya, Yuji; Terai, Takayuki

1998-01-01

Molten chloride/cadmium system is considered to be applied to a solvent in pyrochemical reprocessing of spent nuclear fuel. In this work, phase diagrams for molten chloride systems were constructed, using NdCl 3 as an imitative substance in place of UCl 3 or PuCl 3 . Hastelloy-X (Ni/Cr21/Fe18/Mo9/W) was examined as a structural material for the corrosion-resistance against molten chloride baths containing NdCl 3 . The process of corrosion was thermochemically discussed and the form of the corrosion was illustrated. Rutherford backscattering spectroscopy was successfully applied to determine the elemental distribution profile of specimens tested on the compatibility with molten chloride mixture at elevated temperature. Ferritic steel was also examined as another candidate material for the compatibility with molten cadmium covered with LiCl-KCl eutectic salt. Variation of near-surface composition was observed by comparing the results of Rutherford backscattering spectroscopy obtained before and after the dipping. (author)

Titanium electroplating of copper in molten salt media

International Nuclear Information System (INIS)

Renaud, Denis

1985-01-01

After a bibliographical survey on electroplating in molten salt media and on the electrolytic production of titanium, the author explains the reasons for the choice of the LiF-NaF-KF eutectic mix as solvent. He recalls the main properties which are used, and describes the conventional and convolutional processing of data obtained by linear volt-amperometry. He presents the electrolyte preparation mode which takes into account the existence of titanium ions with intermediate oxidation degree, and the reactivity of titanium with oxygenated species. Experimental results are discussed. Then, after the study of the mechanism of reduction of trivalent titanium into titanium on molybdenum (intermetallic diffusion is here negligible), he reports the study of this mechanism on copper (it is a more complicated situation, due to combinations between titanium and copper). The effect of different parameters (electrolyte purity, current density, electrode potential and temperature) is interpreted in order to identify optimal conditions for titanium electroplating of copper [fr

Fission product removal from molten salt using zeolite

International Nuclear Information System (INIS)

Pereira, C.; Babcock, B.D.

1996-01-01

Spent nuclear fuel (SNF) can be treated in a molten salt electrorefiner for conversion into metal and mineral waste forms for geologic disposal. The fuel is dissolved in molten chloride salt. Non-transuranic fission products in the molten salt are ion-exchanged into zeolite A, which is subsequently mixed with glass and consolidated. Zeolite was found to be effective in removing fission product cations from the molten salt. Breakthrough of cesium and the alkaline earths occurred more rapidly than was observed for the rare earths. The effluent composition as a function of time is presented, as well as results for the distribution of fission products along the length of the column. Effects of temperature and salt flow rate are also discussed

Molten salts and nuclear energy production

International Nuclear Information System (INIS)

Le Brun, Christian

2007-01-01

Molten salts (fluorides or chlorides) were considered near the beginning of research into nuclear energy production. This was initially due to their advantageous physical and chemical properties: good heat transfer capacity, radiation insensitivity, high boiling point, wide range solubility for actinides. In addition it was realised that molten salts could be used in numerous situations: high temperature heat transfer, core coolants with solid fuels, liquid fuel in a molten salt reactor, solvents for spent nuclear solid fuel in the case of pyro-reprocessing and coolant and tritium production in the case of fusion. Molten salt reactors, one of the six innovative concepts chosen by the Generation IV international forum, are particularly interesting for use as either waste incinerators or thorium cycle systems. As the neutron balance in the thorium cycle is very tight, the possibility to perform online extraction of some fission product poisons from the salt is very attractive. In this article the most important questions that must be addressed to demonstrate the feasibility of molten salt reactor will be reviewed

Catalysis in Molten Ionic Media

DEFF Research Database (Denmark)

Boghosian, Soghomon; Fehrmann, Rasmus

2013-01-01

This chapter deals with catalysis in molten salts and ionic liquids, which are introduced and reviewed briefly, while an in-depth review of the oxidation catalyst used for the manufacturing of sulfuric acid and cleaning of flue gas from electrical power plants is the main topic of the chapter...

Selective Adsorption of Sodium Aluminum Fluoride Salts from Molten Aluminum

Energy Technology Data Exchange (ETDEWEB)

Leonard S. Aubrey; Christine A. Boyle; Eddie M. Williams; David H. DeYoung; Dawid D. Smith; Feng Chi

2007-08-16

Aluminum is produced in electrolytic reduction cells where alumina feedstock is dissolved in molten cryolite (sodium aluminum fluoride) along with aluminum and calcium fluorides. The dissolved alumina is then reduced by electrolysis and the molten aluminum separates to the bottom of the cell. The reduction cell is periodically tapped to remove the molten aluminum. During the tapping process, some of the molten electrolyte (commonly referred as “bath” in the aluminum industry) is carried over with the molten aluminum and into the transfer crucible. The carryover of molten bath into the holding furnace can create significant operational problems in aluminum cast houses. Bath carryover can result in several problems. The most troublesome problem is sodium and calcium pickup in magnesium-bearing alloys. Magnesium alloying additions can result in Mg-Na and Mg-Ca exchange reactions with the molten bath, which results in the undesirable pickup of elemental sodium and calcium. This final report presents the findings of a project to evaluate removal of molten bath using a new and novel micro-porous filter media. The theory of selective adsorption or removal is based on interfacial surface energy differences of molten aluminum and bath on the micro-porous filter structure. This report describes the theory of the selective adsorption-filtration process, the development of suitable micro-porous filter media, and the operational results obtained with a micro-porous bed filtration system. The micro-porous filter media was found to very effectively remove molten sodium aluminum fluoride bath by the selective adsorption-filtration mechanism.

Electrodeposition of antimony, tellurium and their alloys from molten acetamide mixtures

NARCIS (Netherlands)

Nguyen, H.P.; Peng, X.; Murugan, G.; Vullers, R.J.M.; Vereecken, P.M.; Fransaer, J.

2013-01-01

We examine the electrodeposition of antimony (Sb), tellurium (Te) and their alloys from molten mixtures of acetamide - antimony chloride and tellurium chloride. The binary mixtures of acetamide with SbCl3 and TeCl 4 exhibit eutectic formation with large depressions of freezing points to below room

Voltammetry of uranyl chloride in the LiCl - KCl eutectic

International Nuclear Information System (INIS)

Fondanaiche, J.C.

1965-01-01

Spent UO 2 - PuO 2 fuels can be reprocessed in a molten salt media. Uranium dioxide can easily be dissolved as UO 2 Cl 2 in a molten salt bath using chlorine gas. A study of quantitative analysis of an uranyl chloride solution in the LiCl-KCl eutectic at 400 C has been performed here using voltammetry (a large area-graphite indicator electrode has been employed). The precision which is obtained is around 6 per cent for concentrations below 10 -2 M. Precision decreases slightly for more concentrated solutions. The study of polarization curves allowed to give a reduction mechanism for the UO 2 ++ ion. For dilute solutions, this reduction proceeds through the UO 2 + ion. But interpretation of current-potential curves is made difficult by the dismutation reaction of the UO 2 ion and by the fact that the surface of the indicator electrode is not renewed. (author) [fr

Candidate molten salt investigation for an accelerator driven subcritical core

International Nuclear Information System (INIS)

Sooby, E.; Baty, A.; Beneš, O.; McIntyre, P.; Pogue, N.; Salanne, M.; Sattarov, A.

2013-01-01

Highlights: • Developing accelerator driven subcritical fission to destroy transuranics in SNF. • The core is a vessel containing a molten mixture of NaCl and transuranic chlorides. • Molecular dynamics used to calculate the thermophysical properties of the salt. • Density and molecular structure for actinide salts reported here. • The neutronics of ADS fission in molten salt are presented. -- Abstract: We report a design for accelerator-driven subcritical fission in a molten salt core (ADSMS) that utilizes a fuel salt composed of NaCl and transuranic (TRU) chlorides. The ADSMS core is designed for fast neutronics (28% of neutrons >1 MeV) to optimize TRU destruction. The choice of a NaCl-based salt offers benefits for corrosion, operating temperature, and actinide solubility as compared with LiF-based fuel salts. A molecular dynamics (MD) code has been used to estimate properties of the molten salt system which are important for ADSMS design but have never been measured experimentally. Results from the MD studies are reported. Experimental measurements of fuel salt properties and studies of corrosion and radiation damage on candidate metals for the core vessel are anticipated

Candidate molten salt investigation for an accelerator driven subcritical core

Energy Technology Data Exchange (ETDEWEB)

Sooby, E., E-mail: soobyes@tamu.edu [Texas A and M University, Accelerator Research Laboratory, 3380 University Dr. East, College Station, TX 77845 (United States); Baty, A. [Texas A and M University, Accelerator Research Laboratory, 3380 University Dr. East, College Station, TX 77845 (United States); Beneš, O. [European Commission, DG Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, 76125 Karlsruhe (Germany); McIntyre, P.; Pogue, N. [Texas A and M University, Accelerator Research Laboratory, 3380 University Dr. East, College Station, TX 77845 (United States); Salanne, M. [Université Pierre et Marie Curie, CNRS, Laboratoire PECSA, F-75005 Paris (France); Sattarov, A. [Texas A and M University, Accelerator Research Laboratory, 3380 University Dr. East, College Station, TX 77845 (United States)

2013-09-15

Highlights: • Developing accelerator driven subcritical fission to destroy transuranics in SNF. • The core is a vessel containing a molten mixture of NaCl and transuranic chlorides. • Molecular dynamics used to calculate the thermophysical properties of the salt. • Density and molecular structure for actinide salts reported here. • The neutronics of ADS fission in molten salt are presented. -- Abstract: We report a design for accelerator-driven subcritical fission in a molten salt core (ADSMS) that utilizes a fuel salt composed of NaCl and transuranic (TRU) chlorides. The ADSMS core is designed for fast neutronics (28% of neutrons >1 MeV) to optimize TRU destruction. The choice of a NaCl-based salt offers benefits for corrosion, operating temperature, and actinide solubility as compared with LiF-based fuel salts. A molecular dynamics (MD) code has been used to estimate properties of the molten salt system which are important for ADSMS design but have never been measured experimentally. Results from the MD studies are reported. Experimental measurements of fuel salt properties and studies of corrosion and radiation damage on candidate metals for the core vessel are anticipated.

Structure and thermodynamic properties of molten rubidium chloride

International Nuclear Information System (INIS)

Ballone, P.; Pastore, G.; Tosi, M.P.; Trieste Univ.

1984-02-01

Self-consistent calculations of partial pair distribution functions and thermodynamic properties are presented for molten RbCl in a non-polarizable-ion model and compared with computer simulation data. The theory, which is quantitatively very successful, hinges on an empirical evaluation of bridge diagrams including both excluded-volume effects and long-range Coulomb effects. (author)

Potentiometric Sensor for Real-Time Monitoring of Multivalent Ion Concentrations in Molten Salt

International Nuclear Information System (INIS)

Zink, Peter A.; Jue, Jan-Fong; Serrano, Brenda E.; Fredrickson, Guy L.; Cowan, Ben F.; Herrmann, Steven D.; Li, Shelly X.

2010-01-01

Electrorefining of spent metallic nuclear fuel in high temperature molten salt systems is a core technology in pyroprocessing, which in turn plays a critical role in the development of advanced fuel cycle technologies. In electrorefining, spent nuclear fuel is treated electrochemically in order to effect separations between uranium, noble metals, and active metals, which include the transuranics. The accumulation of active metals in a lithium chloride-potassium chloride (LiCl-KCl) eutectic molten salt electrolyte occurs at the expense of the UCl3-oxidant concentration in the electrolyte, which must be periodically replenished. Our interests lie with the accumulation of active metals in the molten salt electrolyte. The real-time monitoring of actinide concentrations in the molten salt electrolyte is highly desirable for controlling electrochemical operations and assuring materials control and accountancy. However, real-time monitoring is not possible with current methods for sampling and chemical analysis. A new solid-state electrochemical sensor is being developed for real-time monitoring of actinide ion concentrations in a molten salt electrorefiner. The ultimate function of the sensor is to monitor plutonium concentrations during electrorefining operations, but in this work gadolinium was employed as a surrogate material for plutonium. In a parametric study, polycrystalline sodium beta double-prime alumina (Na-β(double p rime)-alumina) discs and tubes were subject to vapor-phase exchange with gadolinium ions (Gd3+) using a gadolinium chloride salt (GdCl3) as a precursor to produce gadolinium beta double-prime alumina (Gd-β(double p rime)-alumina) samples. Electrochemical impedance spectroscopy and microstructural analysis were performed on the ion-exchanged discs to determine the relationship between ion exchange and Gd3+ ion conductivity. The ion-exchanged tubes were configured as potentiometric sensors in order to monitor real-time Gd3+ ion concentrations in

Electrochemical extraction of samarium from molten chlorides in pyrochemical processes

International Nuclear Information System (INIS)

Castrillejo, Y.; Fernandez, P.; Medina, J.; Hernandez, P.; Barrado, E.

2011-01-01

This work concerns the electrochemical extraction of samarium from molten chlorides. In this way, the electrochemical behaviour of samarium ions has been investigated in the eutectic LiCl-KCl at the surface of tungsten, aluminium and aluminium coated tungsten electrodes. On a W inert electrode the electro-reduction of Sm(III) takes place in only one soluble-soluble electrochemical step Sm(III)/Sm(II). The electrochemical system Sm(II)/Sm(0) has not been observed within the electrochemical window, because of the prior reduction of Li(I) ions from the solvent, which inhibits the electro-extraction of Sm species from the salt on such a substrate. Sm metal in contact with the melt react to give Li(0) according to the reaction: Sm(0) + 2Li(I) ↔ Sm(II) + 2Li(0). On the contrary, on reactive Al electrodes the electrochemical system Sm(II)/Sm(0) was observed within the electroactive range. The potential shift of the redox couple is caused by the decrease of Sm activity in the metal phase due to the formation of Sm-Al alloys at the interface. The formation mechanism of the intermetallic compounds was studied in a melt containing: (i) both Sm(III) and Al(III) ions, using W and Al coated tungsten electrodes, and (ii) Sm(III) ions using an Al electrode. Analysis of the samples after potentiostatic electrolysis by X-ray diffraction and scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS), allowed the identification of Al 3 Sm and Al 2 Sm.

Electrochemical extraction of samarium from molten chlorides in pyrochemical processes

Energy Technology Data Exchange (ETDEWEB)

Castrillejo, Y., E-mail: ycastril@qa.uva.es [QUIANE/Dept Quimica Analitica, F. de Ciencias, Universidad de Valladolid, Prado de la Magdalena s/n, 47005 Valladolid (Spain); Fernandez, P. [QUIANE/Dept Quimica Analitica, F. de Ciencias, Universidad de Valladolid, Prado de la Magdalena s/n, 47005 Valladolid (Spain); Medina, J. [Dept Fisica Materia Condensada Cristalografia y Mineralogia, F. de Ciencias, Universidad de Valladolid, Prado de la Magdalena s/n, 47005 Valladolid (Spain); Hernandez, P. [Centro de Investigaciones Quimicas, Universidad Autonoma del Estado de Hidalgo, Carr. Pachuca-Tulancingo Km. 4.5, C.P. 42076 Pachuca, Hidalgo (Mexico); Barrado, E. [QUIANE/Dept Quimica Analitica, F. de Ciencias, Universidad de Valladolid, Prado de la Magdalena s/n, 47005 Valladolid (Spain)

2011-10-01

This work concerns the electrochemical extraction of samarium from molten chlorides. In this way, the electrochemical behaviour of samarium ions has been investigated in the eutectic LiCl-KCl at the surface of tungsten, aluminium and aluminium coated tungsten electrodes. On a W inert electrode the electro-reduction of Sm(III) takes place in only one soluble-soluble electrochemical step Sm(III)/Sm(II). The electrochemical system Sm(II)/Sm(0) has not been observed within the electrochemical window, because of the prior reduction of Li(I) ions from the solvent, which inhibits the electro-extraction of Sm species from the salt on such a substrate. Sm metal in contact with the melt react to give Li(0) according to the reaction: Sm(0) + 2Li(I) {r_reversible} Sm(II) + 2Li(0). On the contrary, on reactive Al electrodes the electrochemical system Sm(II)/Sm(0) was observed within the electroactive range. The potential shift of the redox couple is caused by the decrease of Sm activity in the metal phase due to the formation of Sm-Al alloys at the interface. The formation mechanism of the intermetallic compounds was studied in a melt containing: (i) both Sm(III) and Al(III) ions, using W and Al coated tungsten electrodes, and (ii) Sm(III) ions using an Al electrode. Analysis of the samples after potentiostatic electrolysis by X-ray diffraction and scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS), allowed the identification of Al{sub 3}Sm and Al{sub 2}Sm.

Mixing of zeolite powders and molten salt

International Nuclear Information System (INIS)

Pereira, C.; Zyryanov, V.N.; Lewis, M.A.; Ackerman, J.P.

1996-01-01

Transuranics and fission products in a molten salt can be incorporated into zeolite A by an ion exchange process and by a batch mixing or blending process. The zeolite is then mixed with glass and consolidated into a monolithic waste form for geologic disposal. Both processes require mixing of zeolite powders with molten salt at elevated temperatures (>700 K). Complete occlusion of salt and a uniform distribution of chloride and fission products are desired for incorporation of the powders into the final waste form. The relative effectiveness of the blending process was studied over a series of temperature, time, and composition profiles. The major criteria for determining the effectiveness of the mixing operations were the level and uniformity of residual free salt in the mixtures. High operating temperatures (>775 K) improved salt occlusion. Reducing the chloride levels in the mixture to below 80% of the full salt capacity of the zeolite significantly reduced the free salt level in the final product

Chemical and electrochemical properties in the molten lithium chloride-potassium chloride eutectic

International Nuclear Information System (INIS)

Delarue, G.

1960-12-01

We have studied the behaviour of several chemical species in the molten LiCI-KCI eutectic. The solubility of certain oxides and sulphides has made it possible for us to show the existence of O 2- and S 2- ions. We have been able to show the existence of a certain number of chemical reactions: oxido-reduction precipitation, complex formation; we have studied, amongst others, the oxidation of O 2- and of S 2- . (author) [fr

Contribution to the study of the vertical molten zone process (1963)

International Nuclear Information System (INIS)

Lenzin, M.

1963-01-01

Construction and use of several molten zone apparatuses operating either vertically or horizontally. Efficient purification of uranyl nitrate hexahydrate but less successful in the case of other hydrated double salts and of zirconyl chloride in the hydrochloric gel form. Demonstration and study of the dissymmetry in the direction of the transport of the impurity during, the purification by a vertical molten zone process. (author) [fr

Electrochemical investigations of La, Nd and Am in molten chloride salts in view of Am/Ln partitioning

International Nuclear Information System (INIS)

Pernel, C.; Serp, J.; Ougier, M.; Malmbeck, R.; Glatz, J.P.

2001-01-01

The electrochemical behaviour of La, Nd and Am has been investigated in molten LiCl-KCl eutectic. La shows a reversible single reduction/oxidation step controlled by mass transfer. The electrochemical reduction of Nd and Am proceeds via a two steps process, i.e. the reduction of trivalent species (Nd(III) and Am(III)) leading to Nd(II) and Am(II) species which are reduced at more negative potentials to form metallic deposits. Diffusion coefficients of La, Nd and Am have been calculated and are in reasonable agreement with literature data. Electro-depositions of La and Nd have been carried out onto solid Ni and liquid Cd cathodes. Much higher deposition efficiency is obtained for La compared to Nd on a solid cathode. This is an effect of the multi-valent nature of Nd in the chloride melts. (author)

Electrochemical investigations of La, Nd and Am in molten chloride salts in view of Am/Ln partitioning

Energy Technology Data Exchange (ETDEWEB)

Pernel, C.; Serp, J.; Ougier, M.; Malmbeck, R.; Glatz, J.P. [European Commission, JRC, ITU, Karlsruhe (Germany)

2001-07-01

The electrochemical behaviour of La, Nd and Am has been investigated in molten LiCl-KCl eutectic. La shows a reversible single reduction/oxidation step controlled by mass transfer. The electrochemical reduction of Nd and Am proceeds via a two steps process, i.e. the reduction of trivalent species (Nd(III) and Am(III)) leading to Nd(II) and Am(II) species which are reduced at more negative potentials to form metallic deposits. Diffusion coefficients of La, Nd and Am have been calculated and are in reasonable agreement with literature data. Electro-depositions of La and Nd have been carried out onto solid Ni and liquid Cd cathodes. Much higher deposition efficiency is obtained for La compared to Nd on a solid cathode. This is an effect of the multi-valent nature of Nd in the chloride melts. (author)

Application of molten salts in pyrochemical processing of reactive metals

International Nuclear Information System (INIS)

Mishra, B.; Olson, D.L.; Averill, W.A.

1992-01-01

Various mixes of chloride and fluoride salts are used as the media for conducting pyrochemical processes in the production and purification of reactive metals. These processes generate a significant amount of contaminated waste that has to be treated for recycling or disposal. Molten calcium chloride based salt systems have been used in this work to electrolytically regenerate calcium metal from calcium oxide for the in situ reduction of reactive metal oxides. The recovery of calcium is characterized by the process efficiency to overcome back reactions in the electrowinning cell. A thermodynamic analysis, based on fundamental rate theory, has been performed to understand the process parameters controlling the metal deposition, rate, behavior of the ceramic anode-sheath and influence of the back-reactions. It has been observed that the deposition of calcium is dependent on the ionic diffusion through the sheath. It has also been evidenced that the recovered calcium is completely lost through the back-reactions in the absence of a sheath. A practical scenario has also been presented where the electrowon metal can be used in situ as a reductant to reduce another reactive metal oxide

Fabrication of aluminum nitride crucibles for molten salt and plutonium compatibility studies

International Nuclear Information System (INIS)

Phillips, J.A.

1991-01-01

The overall objective of this research was to fabricate a calcium oxide sinter-aided aluminum nitride crucible and determine the compatibility of this crucible with molten chloride salts and plutonium metal in the DOR process. Calcium oxide sinter-aided aluminum nitride was preferred over yttrium oxide sinter-aided aluminum nitride because of (1) the presence of calcium chloride, calcium oxide, and calcium metal in the molten salts utilized in the DOR process, and (2) the higher volatility of the secondary phases formed compared with phases resulting from the addition of yttrium oxide during the aluminum nitride sintering process. The calcium oxide system may yield a higher purity crystal structure with fewer secondary phases present than in the yttrium oxide system. The secondary phases that are present in the grain boundaries may be unreactive with the calcium chloride salt due to the presence of calcium in the secondary phases

Study of electrochemical processes for separation of the actinides and lanthanides in molten fluoride media

International Nuclear Information System (INIS)

Zvejskova, R.; Chuchvalcova Bimova, K.; Lisy, F.; Soucek, P.

2005-01-01

The technology of the Molten Salt Reactors (MSR) is developed for two possible applications: For one thing as the Molten Salt Transmutation Reactor (MSTR) incinerating plutonium and minor actinides within reprocessing of spent fuel from PWR or FBR and for another thing as electricity generating MSR working under thorium uranium fuel cycle. Electrochemical separation processes are one of promising pyrochemical techniques that should enable the on-line reprocessing of circulating fuel salt in MSR (fuel cycle back-end). The former application represents the Czech P and T concept, in which framework the electrolytic separation can be applied both in the front-end and back-end of the MSTR fuel cycle. Within the front-end electro separation should follow the Fluoride Volatility Method (FVM), which should separate 95 % of uranium from the spent fuel in the form of volatile uranium hexafluoride. The residual uranium and fission products (FP) are supposed to be separated among others also by electrochemical methods. The presented work comprises the results reached within development of electrochemical separation of the actinides and fission products from each other by electrolytic deposition method on solid cathode in molten fluoride media, that represent he carrier salts of MSR technology. The knowledge of electrochemical properties (red-ox potentials, mainly of deposition potentials) is necessary for determination of separation possibilities of individual components by electrolysis. (authors)

Contribution to the study of the redox reactions and the speciation of technetium in chloride and carbonate media

International Nuclear Information System (INIS)

Ben Said, K.

1999-11-01

Technetium is important as a long half-life multi-valent radioelement within the framework of the nuclear waste storage especially in underground geological sites. So, the safety studies require the knowledge of the redox and of the chemical properties of this element in order to model its geochemical behaviour in the environment. Our studies deal with the redox behaviour and the speciation of technetium in chloride and carbonate media. Similar natural systems possess redox potentials likely to reduce Tc(VII) into Tc(V), Tc(IV) and Tc(III). The question of the standard redox potential of the Tc(VII)Tc(IV) couple is settled in non complexing media where Tc(IV) exists as TcO 2 (s) but is still a matter of debate in complexing media. The formal potential of the Tc(VII)/Tc(IV couple has been determined by an indirect method in 1.0 M HCl media where Tc(IV) exists as chloride complexes. The species formed by dissolving K 2 TcCl 6 (s) in chloride media have been characterised by complementary techniques of speciation (UV-visible and Raman spectrometry, X-rays absorption spectroscopy and polarography). Two chemical formulae have been proposed for the chloride species of Tc(IV) in 1.0 M HCl media as hydrolyzed TcCl 6 2- : TcCl 5 (H 2 O) - or TcCl 4 (H 2 O) 2 . The chemical or electrochemical reduction of pertechnetate in carbonate media leads to amorphous oxides or carbonate complexes of Tc(IV) and/or of Tc(III). In carbonate media, the stability of the species under γ irradiation has been estimated by UV/VIS spectrophotometry: Tc(VII) is stable but reduced into Tc(IV) in the presence of formate when the carbonate complex of Tc(IV) is oxidised into Tc(VII). So the most mobile valency Tc(VII) seems to be the stable one in irradiated carbonate media. (author)

Development of electrolytic process in molten salt media for light rare-earth metals production. The metallic cerium electrodeposition; Desenvolvimento de processo de eletrolise em meio de sais fundidos para a producao de metais de terras-raras leves. A obtencao do cerio metalico

Energy Technology Data Exchange (ETDEWEB)

Restivo, T A.G.

1994-12-31

The development of molten salt process and the respective equipment aiming rare-earth metals recovery was described. In the present case, the liquid cerium metal electrodeposition in a molten electrolytes of cerium chloride and an equimolar mixture of sodium and potassium chlorides in temperatures near 800{sup C} was studied. Due the high chemical reactivity of the rare-earth metals in the liquid state and their molten halides, an electrolytic cell was constructed with controlled atmosphere, graphite crucibles and anodes and a tungsten cathode. The electrolytic process variables and characteristics were evaluated upon the current efficiency and metallic product purity. Based on this evaluations, were suggested some alterations on the electrolytic reactor design and upon the process parameters. (author). 90 refs, 37 figs, 20 tabs.

Electrochemistry of plutonium in molten halides

International Nuclear Information System (INIS)

McCurry, L.E.; Moy, G.M.M.; Bowersox, D.F.

1987-01-01

The electrochemistry of plutonium in molten halides is of technological importance as a method of purification of plutonium. Previous authors have reported that plutonium can be purified by electrorefining impure plutonium in various molten haldies. Work to eluciate the mechanism of the plutonium reduction in molten halides has been limited to a chronopotentiometric study in LiCl-KCl. Potentiometric studies have been carried out to determine the standard reduction potential for the plutonium (III) couple in various molten alkali metal halides. Initial cyclic voltammetric experiments were performed in molten KCL at 1100 K. A silver/silver chloride (10 mole %) in equimolar NaCl-KCl was used as a reference electrode. Working and counter electrodes were tungsten. The cell components and melt were contained in a quartz crucible. Background cyclic voltammograms of the KCl melt at the tungsten electrode showed no evidence of electroactive impurities in the melt. Plutonium was added to the melt as PuCl/sub 3/, which was prepared by chlorination of the oxide. At low concentrations of PuCl/sub 3/ in the melt (0.01-0.03 molar), no reduction wave due to the reduction of Pu(III) was observed in the voltammograms up to the potassium reduction limit of the melt. However on scan reversal after scanning into the potassium reduction limit a new oxidation wave was observed

Method of processing chloride waste

International Nuclear Information System (INIS)

Tokiwai, Moriyasu; Tsunashima, Mikiyasu; Horie, Masaaki; Koyama, Masafumi; Sudo, Minoru; Kitagawa, Masatoshi; Ogasawara, Tadashi.

1991-01-01

In a method of applying molten salt electrolysis to chloride wastes discharged from a electrolytic refining step of a dry reprocessing step for spent fuels, and removed with transuranium elements of long half-decaying time, metals capable of alloying with alkali and alkaline earth metals under melting by electrolysis are used as a cathode material, and an electrolytic temperature is made higher than the melting point of salts in a molten salt electrolysis bath, to recover Li, Ca and Na as alloys with the cathode material in a first electrolysis step. Then, the electrolytic temperature is made higher than the melting point of the chloride salts remained in the bath after the electrolysis step described above by using the cathode material, to recover Ba, Rb, Sr and Cs of nuclear fission products also as alloys with the cathode material in a second electrolysis step. Accordingly, the amount of wastes formed can be reduced, and the wastes contain no heat generating nuclear fission elements. (T.M.)

Investigation of residual anode material after electrorefining uranium in molten chloride salt

Energy Technology Data Exchange (ETDEWEB)

Rose, M.A., E-mail: marose@anl.gov [Department of Nuclear Engineering, Purdue University, West Lafayette, IN, 47907 (United States); Nuclear Engineering Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Williamson, M.A.; Willit, J. [Nuclear Engineering Division, Argonne National Laboratory, Argonne, IL 60439 (United States)

2015-12-15

A buildup of material at uranium anodes during uranium electrorefining in molten chloride salts has been observed. Potentiodynamic testing has been conducted using a three electrode cell, with a uranium working electrode in both LiCl/KCl eutectic and LiCl each containing ∼5 mol% UCl{sub 3}. The anodic current response was observed at 50° intervals between 450 °C and 650 °C in the eutectic salt. These tests revealed a buildup of material at the anode in LiCl/KCl salt, which was sampled at room temperature, and analyzed using ICP-MS, XRD and SEM techniques. Examination of the analytical data, current response curves and published phase diagrams has established that as the uranium anode dissolves, the U{sup 3+} ion concentration in the diffusion layer surrounding the electrode rises precipitously to levels, which may at low temperatures exceed the solubility limit for UCl{sub 3} or in the case of the eutectic salt for K{sub 2}UCl{sub 5}. The reduction in current response observed at low temperature in eutectic salt is eliminated at 650 °C, where K{sub 2}UCl{sub 5} is absent due to its congruent melting and only simple concentration polarization effects are seen. In LiCl similar concentration effects are seen though significantly longer time at applied potential is required to effect a reduction in the current response as compared to the eutectic salt.

Growth and Breakdown of Surface Films and Localized Corrosion of Aluminum in Concentrated Chloride Media

National Research Council Canada - National Science Library

Lee, Jiajing

1994-01-01

...) and mechanical stress for aluminum and titanium alloys in aggressive corrosion environments. This report presents results of some very preliminary experiments on aluminum alloys and titanium during anodic dissolution in chloride media...

Thorium valency in molten alkali halides in equilibrium with metallic thorium

International Nuclear Information System (INIS)

Smirnov, M.V.; Kudyakov, V.Ya.

1983-01-01

Metallic thorium is shown to corrode in molten alkali halides even in the absence of external oxidizing agents, alkali cations acting as oxidizing agents. Its corrosion rate grows in the series of alkali chlorides from LiCl to CsCl at constant temperature. Substituting halide anions for one another exerts a smaller influence, the rate rising slightly in going from chlorides to bromides and iodides, having the same alkali cations. Thorium valency is determined coulometrically, the metal being dissolved anodically in molten alkali halides and their mixtures. In fluoride melts it is equal to 4 but in chloride, bromide and iodide ones, as a rule, it has non-integral values between 4 and 2 which diminish as the temperature is raised, as the thorium concentration is lowered, as the radii of alkali cations decrease and those of halide anions increase. The emf of cells Th/N ThHlsub(n) + (1-N) MHl/MHl/C, Hlsub(2(g)) where Hl is Cl, Br or I, M is Li, Na, K, Cs or Na + K, and N < 0.05, is measured as a function of concentration at several temperatures. Expressions are obtained for its concentration dependence. The emf grows in the series of alkali chlorides from LiCl to CsCl, other conditions being equal. (author)

Thermodynamic properties of molten mixtures of lithium, rubidium, cesium and beryllium chlorides

International Nuclear Information System (INIS)

Zarubitskij, O.G.; Podafa, B.P.; Dubovoj, P.G.

1982-01-01

e. m. f. in binary systems of beryllium chloride with rubidium and cesium chlorides were measured. Concentration dependences of thermodynamic functions (mixing entropy Gibbs free energy) of beryllium chloride in the systems as well as with the participation of lithium chloride were analysed

Molten salt processes in special materials preparation

International Nuclear Information System (INIS)

Krishnamurthy, N.; Suri, A.K.

2013-01-01

As a class, molten salts are the largest collection of non aqueous inorganic solvents. On account of their stability at high temperature and compatibility to a number of process requirements, molten salts are considered indispensable to realize many of the numerous benefits of high temperature technology. They play a crucial role and form the basis for numerous elegant processes for the preparation of metals and materials. Molten salt are considered versatile heat transfer media and have led to the evolution of many interesting reactor concepts in fission and possibly in fusion. They also have been the basis of thinking for few novel processes for power generation. While focusing principally on the actual utilization of molten salts for a variety of materials preparation efforts in BARC, this lecture also covers a few of the other areas of technological applications together with the scientific basis for considering the molten salts in such situations. (author)

Uranium (III)-Plutonium (III) co-precipitation in molten chloride

Science.gov (United States)

Vigier, Jean-François; Laplace, Annabelle; Renard, Catherine; Miguirditchian, Manuel; Abraham, Francis

2018-02-01

Co-management of the actinides in an integrated closed fuel cycle by a pyrochemical process is studied at the laboratory scale in France in the CEA-ATALANTE facility. In this context the co-precipitation of U(III) and Pu(III) by wet argon sparging in LiCl-CaCl2 (30-70 mol%) molten salt at 705 °C is studied. Pu(III) is prepared in situ in the molten salt by carbochlorination of PuO2 and U(III) is then introduced as UCl3 after chlorine purge by argon to avoid any oxidation of uranium up to U(VI) by Cl2. The oxide conversion yield through wet argon sparging is quantitative. However, the preferential oxidation of U(III) in comparison to Pu(III) is responsible for a successive conversion of the two actinides, giving a mixture of UO2 and PuO2 oxides. Surprisingly, the conversion of sole Pu(III) in the same conditions leads to a mixture of PuO2 and PuOCl, characteristic of a partial oxidation of Pu(III) to Pu(IV). This is in contrast with coconversion of U(III)-Pu(III) mixtures but in agreement with the conversion of Ce(III).

Structure of partly quenched molten copper chloride

International Nuclear Information System (INIS)

Pastore, G.; Tosi, M.P.

1995-09-01

The structural modifications induced in a model of molten CuCl by quenching the chlorine component into a microporous disordered matrix are evaluated using the hypernetted-chain closure in Ornstein-Zernike relations for the pair distribution functions in random systems. Aside from obvious changes in the behaviour of long-wavelength density fluctuations, the main effect of partial quenching is an enhanced delocalization of the Cu + ions. The model suggests that the ionic mobility in a superionic glass is enhanced relative to the melt at the same temperature and density. Only very minor quantitative differences are found in the structural functions when the replica Ornstein-Zernike relations derived by Given and Stell for a partly quenched system are simplified to those given earlier by Madden and Glandt. (author). 19 refs, 6 figs

Chemical Reduction of SIM MOX in Molten Lithium Chloride Using Lithium Metal Reductant

Science.gov (United States)

Kato, Tetsuya; Usami, Tsuyoshi; Kurata, Masaki; Inoue, Tadashi; Sims, Howard E.; Jenkins, Jan A.

2007-09-01

A simulated spent oxide fuel in a sintered pellet form, which contained the twelve elements U, Pu, Am, Np, Cm, Ce, Nd, Sm, Ba, Zr,Mo, and Pd, was reduced with Li metal in a molten LiCl bath at 923 K. More than 90% of U and Pu were reduced to metal to form a porous alloy without significant change in the Pu/U ratio. Small fractions of Pu were also combined with Pd to form stable alloys. In the gap of the porous U-Pu alloy, the aggregation of the rare-earth (RE) oxide was observed. Some amount of the RE elements and the actinoides leached from the pellet. The leaching ratio of Am to the initially loaded amount was only several percent, which was far from about 80% obtained in the previous ones on simple MOX including U, Pu, and Am. The difference suggests that a large part of Am existed in the RE oxide rather than in the U-Pu alloy. The detection of the RE elements and actinoides in the molten LiCl bath seemed to indicate that they dissolved into the molten LiCl bath containing the oxide ion, which is the by-product of the reduction, as solubility of RE elements was measured in the molten LiCl-Li2O previously.

Thermal energy storage using chloride salts and their eutectics

International Nuclear Information System (INIS)

Myers, Philip D.; Goswami, D. Yogi

2016-01-01

Achieving the goals of the U.S. Department of Energy (DOE) Sunshot initiative requires (1) higher operating temperatures for concentrating solar power (CSP) plants to increase theoretical efficiency, and (2) effective thermal energy storage (TES) strategies to ensure dispatchability. Current inorganic salt-based TES systems in large-scale CSP plants generally employ molten nitrate salts for energy storage, but nitrate salts are limited in application to lower temperatures—generally, below 600 °C. These materials are sufficient for parabolic trough power plants, but they are inadequate for use at higher temperatures. At the higher operating temperatures achievable in solar power tower-type CSP plants, chloride salts are promising candidates for application as TES materials, owing to their thermal stability and generally lower cost compared to nitrate salts. In light of this, a recent study was conducted, which included a preliminary survey of chloride salts and binary eutectic systems that show promise as high temperature TES media. This study provided some basic information about the salts, including phase equilibria data and estimates of latent heat of fusion for some of the eutectics. Cost estimates were obtained through a review of bulk pricing for the pure salts among various vendors. This review paper updates that prior study, adding data for additional salt eutectic systems obtained from the literature. Where possible, data are obtained from the thermodynamic database software, FactSage. Radiative properties are presented, as well, since at higher temperatures, thermal radiation becomes a significant mode of heat transfer. Material compatibility for inorganic salts is another important consideration (e.g., with regard to piping and/or containment), so a summary of corrosion studies with various materials is also presented. Lastly, cost data for these systems are presented, allowing for meaningful comparison among these systems and other materials for TES

Laser-Induced Breakdown Spectroscopy (LIBS) in a Novel Molten Salt Aerosol System.

Science.gov (United States)

Williams, Ammon N; Phongikaroon, Supathorn

2017-04-01

In the pyrochemical separation of used nuclear fuel (UNF), fission product, rare earth, and actinide chlorides accumulate in the molten salt electrolyte over time. Measuring this salt composition in near real-time is advantageous for operational efficiency, material accountability, and nuclear safeguards. Laser-induced breakdown spectroscopy (LIBS) has been proposed and demonstrated as a potential analytical approach for molten LiCl-KCl salts. However, all the studies conducted to date have used a static surface approach which can lead to issues with splashing, low repeatability, and poor sample homogeneity. In this initial study, a novel molten salt aerosol approach has been developed and explored to measure the composition of the salt via LIBS. The functionality of the system has been demonstrated as well as a basic optimization of the laser energy and nebulizer gas pressure used. Initial results have shown that this molten salt aerosol-LIBS system has a great potential as an analytical technique for measuring the molten salt electrolyte used in this UNF reprocessing technology.

Structure of tungsten electrodeposited from oxide chloride-fluoride molten salts

International Nuclear Information System (INIS)

Pavlovskij, V.A.; Reznichenko, V.A.

1998-01-01

Investigation results on the influence of electrolysis parameters and electrolyte composition on tungsten cathode deposit structure are presented. The electrolysis was performed in NaCl-NaF-WO 3 molten salts using tungsten and tungsten coated molybdenum cathodes. Morphological and metallographic studies of tungsten crystals were carrier out. Tungsten deposits were obtained in the form of crystalline conglomerates, sponge and high dispersity powder

Experiments comparing the uptake of americium from chloride media using extraction chromatography

International Nuclear Information System (INIS)

FitzPatrick, J.R.; Schake, B.S.; Schulte, L.D.; Martinez, B.T.; Salazar, R.R.

1995-01-01

Clean-up of actinide effluent waste steams is of increasing importance at the Los Alamos Plutonium Facility, TA-55, and removing the actinide elements to very low levels allows less radioactivity to go the Los Alamos National Laboratory Water Treatment Facility, TA-50, thus reducing the number of drums of TRU waste. Americium (Am) is a difficult element to remove from chloride media because the +3 state is difficult to oxidize and chelating resins work better with elements such as plutonium which are more readily oxidized to the +4 and/or +6 state. Currently in hydrochloric acid (HC1) media, the acidic liquid waste is neutralized with potassium hydroxide to precipitate the metal hydroxides, before disposal to TA-50. This process is not very efficient. The removal of Am from chloride media was compared using a series of resins, some commercial and some made in our laboratory, using different percentages by weight of octyl(phenyl)-N,N-diiso- butylcarbamoyl-methylphosphine oxide (CMPO ) along with diamyl amylphosphonate (DAAP) or tributyl phosphate (TBP) as diluents. Resins were also made with no added diluent. Early comparisons using small-scale contact studies with 0.5 grams of resin in 0.1M-12M HC1, and subsequent small-scale flow experiments show a trend in which Am uptake is proportional to the amount of CMPO on the resins and the diluent plays a minor role in the uptake of Am from these solutions. Redox chemistry effects were also investigated. From these studies, it is possible to determine the best conditions for the removal of Am from HC1 media thus reducing the gross alpha content of the waste stream by a factor of 10-100 which reduces the number of barrels of waste produced at the Water Treatment Facility

Metallurgical electrochemistry: the interface between materials science and molten salt chemistry

International Nuclear Information System (INIS)

Sadoway, D.R.

1991-01-01

Even though molten salt electrolysis finds application in the primary extraction of metals (electrowinning), the purification and recycling of metals (electrorefining), and in the formation of metal coatings (electroplating), the technology remains in many respects underexploited. Electrolysis in molten salts as well as other nonaqueous media has enormous potential for materials processing. First, owing to the special attributes of nonaqueous electrolytes electrochemical processing in these media has an important role to play in the generation of advanced materials, i.e., materials with specialized chemistries or tailored microstructures (electrosynthesis). Secondly, as environmental quality standards rise beyond the capabilities of classical metals extraction technologies to comply, molten salt electrolysis may prove to be the only acceptable route from ore to metal. Growing public awareness of pollution from the metals industry could stimulate a renaissance in molten salt electrochemistry. Challenges facing metallurgical electrochemistry as relates to the environment fall into two categories: (1) improving existing electrochemical technology, and (2) developing clean electrochemical technology to displace current nonelectrochemical technology. In both instances success hinges upon the discovery of advanced materials and the ecologically sound extraction of metals, the close coupling between materials science and molten salt chemistry is manifest. (author) 6 refs

Redox reactions in rare earth chloride molten electrolytes; Okislitel'no-vosstanovitel'nye reaktsii v rasplavlennykh ehlektrolitakh, soderzhashchikh khloridy redkozemel'nykh metallov

Energy Technology Data Exchange (ETDEWEB)

Khokhlov, V A; Novoselova, A V; Nikolaeva, E V; Tkacheva, O Yu; Salyulev, A B [Inst. Vysokotemperaturnoj Ehlektrokhimii UrO RAN, Ekaterinburg (Russian Federation)

2007-08-15

Rare earth (REM, Ln) solutions in chloride melts including MCI+LnCl{sub 3} mixtures, where M - alkali metals, were investigated by potentiometry, voltammetry, conductometry in wide concentration and temperature intervals. Findings present complete and trusty information on the valent state of rare earths, structure and composition of complex ions affecting essentially on properties of electrolytes. It is demonstrated that the coexistence of rare earth ions with different oxidation level formed as a result of possible redox reactions: 2Ln{sup 3+} + Ln {r_reversible}3Ln{sup 2+}, Ln{sup 2+} + Ln{r_reversible}2Ln{sup +} and nM{sup +} + Ln{r_reversible}nM + Ln{sup n+} appears sharply in thermodynamic and transport properties of molten Ln-LnCl{sub 3} and Ln-LnCl{sub 3}-MCl systems.

Precipitation of metal nitrides from chloride melts

International Nuclear Information System (INIS)

Slater, S.A.; Miller, W.E.; Willit, J.L.

1996-01-01

Precipitation of actinides, lanthanides, and fission products as nitrides from molten chloride melts is being investigated for use as a final cleanup step in treating radioactive salt wastes generated by electrometallurgical processing of spent nuclear fuel. The radioactive components (eg, fission products) need to be removed to reduce the volume of high-level waste that requires disposal. To extract the fission products from the salt, a nitride precipitation process is being developed. The salt waste is first contacted with a molten metal; after equilibrium is reached, a nitride is added to the metal phase. The insoluble nitrides can be recovered and converted to a borosilicate glass after air oxidation. For a bench-scale experimental setup, a crucible was designed to contact the salt and metal phases. Solubility tests were performed with candidate nitrides and metal nitrides for which there are no solubility data. Experiments were performed to assess feasibility of precipitation of metal nitrides from chloride melts

Study of the Effect of Molten Copper Chloride Immersion Test on Alloys with High Nickel Content with and without Surface Coatings

Science.gov (United States)

Siantar, Edwin

The demand for hydrogen as a clean energy carrier has increased greatly. The Cu-Cl cycle is a promising thermochemical cycle that is currently being developed to be the large-scale method of hydrogen production. The lifetime of materials for the pipes transporting molten CuCl is an important parameter for an economic design of a commercial thermochemical Cu-Cl hydrogen plant. This research is an examination of candidate materials following an immersion test in molten CuCl at 500 °C for 100 h. Two alloys, Ni based super-alloy (Inconel 625) and super austenitic stainless steel (AL6XN) were selected as the base metal. There were two types of coating applied to improve the corrosion resistance of the base metals during molten CuCl exposure. A metallic of Diamalloy 4006 and two ceramic of yttria stabilized zirconia and alumina coatings were applied to the base metal using thermal spray methods. An immersion apparatus was designed and constructed to perform an immersion test that has a condition similar to those in a hydrogen plant. After the immersion test, the materials were evaluated using an electrochemical method in combination with ex-situ surface analysis. The surface condition including elemental composition, film structure and resistivity of the materials were examined and compared. The majority of the coatings were damaged and fell off. Cracks were found in the original coated specimens indicating the sample geometry may have affected the integrity of the sprayed coating. When the coating cracked, it provided a pathway for the molten CuCl to go under the coating and react with the surface underneath the coating. Copper deposits and iron chloride that were found on the sample surfaces suggest that there were corrosion reactions that involved the metal dissolution and reduction of copper during immersion test. The results also suggest that Inconel 625 performed better than stainless steel AL6XN. Both Diamalloy 4006 and YSZ (ZrO2 18TiO2 10Y2O3) coatings seemed to

Actinides-lanthanides (neodymium) separation by electrolytical extraction in molten fluoride media; Separation actinides-lanthanides (neodyne) par extraction electrolytique en milieux fluorures fondus

Energy Technology Data Exchange (ETDEWEB)

Hamel, C

2005-02-15

The aim of this thesis is to assess the potentialities of pyrochemical processes for futur nuclear fuels and Generation IV reactors (more particularly molten salt reactors). This study concerns the Actinides-Lanthanides and Lanthanides-Solvent separation by electrolytical extraction in molten fluoride media at high temperature. Three elements are selected for this study: neodymium (NdF{sub 3}), uranium (UF{sub 4}) and plutonium (PuF{sub 3}). Firstly, the electrochemical study of these three compounds in molten fluoride media is performed to evaluate the separations. Electrodeposition processes are studied and the values of formal potentials of U(III)/U(0), Pu(III)/Pu(0) and Nd(III)/Nd(0) are obtained in LiF-CaF{sub 2} eutectic mixture. Thermodynamically, the values of potentials differences are enough to separate U-Nd and Pu-Nd with a yield of extraction of 99.99%; this value is just sufficient for the Pu-Nd separation. Concerning the Nd-solvent separation this potential difference is too small. Next, the electrodeposition of solid metals on inert electrodes is performed. This study showed that the uranium and neodymium deposits are unstable in several fluoride media. In addition, the presence of salts in the dendritic metal is observed for the U solid deposits. Finally, a reactive cathode is used to improve these separation results and the shape of the deposits. The experimental results on nickel electrodes showed an improvement of the Pu-Nd separation and the Nd-solvent separation with the depolarisation phenomenon of the metal deposit on the nickel. Moreover, U and Nd metal are stabilized in the alloy which allows the elimination of reactions with the solvent as observed for the solid deposit. The formation of liquids alloys makes also easier the recovery of these three. (author)

Actinides-lanthanides (neodymium) separation by electrolytic extraction in molten fluoride media; Separation actinides-lanthanides (neodyne) par extraction electrolytique en milieux fluorures fondus

Energy Technology Data Exchange (ETDEWEB)

Hamel, C

2005-02-15

The aim of this thesis is to assess the potentialities of pyrochemical processes for future nuclear fuels and Generation IV reactors (more particularly molten salt reactors). This study concerns the Actinides-Lanthanides and Lanthanides-Solvent separation by electrolytic extraction in molten fluoride media at high temperature. Three elements are selected for this study: neodymium (NdF{sub 3}), uranium (UF{sub 4}) and plutonium (PuF{sub 3}). Firstly, the electrochemical study of these three compounds in molten fluoride media is performed to evaluate the separations. Electrodeposition processes are studied and the values of formal potentials of U(III)/U(0), Pu(III)/Pu(0) and Nd(III)/Nd(0) are obtained in LiF-CaF{sub 2} eutectic mixture. Thermodynamically, the values of potentials differences are enough to separate U-Nd and Pu-Nd with a yield of extraction of 99.99%; this value is just sufficient for the Pu-Nd separation. Concerning the Nd-solvent separation this potential difference is too small. Next, the electrodeposition of solid metals on inert electrodes is performed. This study showed that the uranium and neodymium deposits are unstable in several fluoride media. In addition, the presence of salts in the dendritic metal is observed for the U solid deposits. Finally, a reactive cathode is used to improve these separation results and the shape of the deposits. The experimental results on nickel electrodes showed an improvement of the Pu-Nd separation and the Nd-solvent separation with the depolarization phenomenon of the metal deposit on the nickel. Moreover, U and Nd metal are stabilized in the alloy which allows the elimination of reactions with the solvent as observed for the solid deposit. The formation of liquids alloys makes also easier the recovery of these three. (author)

Laminar iridium coating produced by pulse current electrodeposition from chloride molten salt

Energy Technology Data Exchange (ETDEWEB)

Zhu, Li’an, E-mail: mr_zla@163.com; Bai, Shuxin; Zhang, Hong; Ye, Yicong

2013-10-01

Due to the unique physical and chemical properties, Iridium (Ir) is one of the most promising oxidation-resistant coatings for refractory materials above 1800 °C in aerospace field. However, the Ir coatings prepared by traditional methods are composed of columnar grains throughout the coating thickness. The columnar structure of the coating is considered to do harm to its oxidation resistance. The laminar Ir coating is expected to have a better high-temperature oxidation resistance than the columnar Ir coating does. The pulse current electrodeposition, with three independent parameters: average current density (J{sub m}), duty cycle (R) and pulse frequency (f), is considered to be a promising method to fabricate layered Ir coating. In this study, laminar Ir coatings were prepared by pulse current electrodeposition in chloride molten salt. The morphology, roughness and texture of the coatings were determined by scanning electron microscope (SEM), profilometer and X-ray diffraction (XRD), respectively. The results showed that the laminar Ir coatings were composed of a nucleation layer with columnar structure and a growth layer with laminar structure. The top surfaces of the laminar Ir coatings consisted of cauliflower-like aggregates containing many fine grains, which were separated by deep grooves. The laminar Ir coating produced at the deposition condition of 20 mA/cm{sup 2} (J{sub m}), 10% (R) and 6 Hz (f) was quite smooth (R{sub a} 1.01 ± 0.09 μm) with extremely high degree of preferred orientation of 〈1 1 1〉, and its laminar structure was well developed with clear boundaries and uniform thickness of sub-layers.

Chemistry and technology of Molten Salt Reactors - history and perspectives

International Nuclear Information System (INIS)

Uhlir, Jan

2007-01-01

Molten Salt Reactors represent one of promising future nuclear reactor concept included also in the Generation IV reactors family. This reactor type is distinguished by an extraordinarily close connection between the reactor physics and chemical technology, which is given by the specific features of the chemical form of fuel, representing by molten fluoride salt and circulating through the reactor core and also by the requirements of continuous 'on-line' reprocessing of the spent fuel. The history of Molten Salt Reactors reaches the period of fifties and sixties, when the first experimental Molten Salt Reactors were constructed and tested in ORNL (US). Several molten salt techniques dedicated to fresh molten salt fuel processing and spent fuel reprocessing were studied and developed in those days. Today, after nearly thirty years of discontinuance, a renewed interest in the Molten Salt Reactor technology is observed. Current experimental R and D activities in the area of Molten Salt Reactor technology are realized by a relatively small number of research institutions mainly in the EU, Russia and USA. The main effort is directed primarily to the development of separation processes suitable for the molten salt fuel processing and reprocessing technology. The techniques under development are molten salt/liquid metal extraction processes, electrochemical separation processes from the molten salt media, fused salt volatilization techniques and gas extraction from the molten salt medium

Chemical properties of some elements in a molten lithium chloride, potassium chloride eutectic (1962); Proprietes chimiques de quelques elements dans l'eutectique chlorure de lithium-chlorure de potassium fondu (1962)

Energy Technology Data Exchange (ETDEWEB)

Molina, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1961-12-15

The increasing use of molten media especially in chemical preparations and for certain technological applications, has made it more necessary to have a knowledge of the chemical properties of elements in these solvents. Structural studies on molten solutions show the existence of certain species such as ions and complexes known to exist in aqueous solutions. This fact, together with certain experiments on chemical reactions in molten media has led us to establish a comparison between these media and aqueous solutions. We wish to show that the same fundamental phenomena occur in these media as are found in the chemistry of aqueous solutions and that this makes it possible to predict certain reactions. We have taken as examples the chemical properties of vanadium, uranium and sulphur in a LiCl-KCl eutectic melted at 480 deg. C. The first problem is to identify the various degrees of oxidation of these elements existing in the solvent chosen. We have tried to resolve it by comparing the absorption spectra obtained in aqueous solution and in the molten eutectic. We consider the possibilities of this method in a chapter on absorption spectrophotometry in the LiCl-KCl eutectic. During the study of the chemical properties we stress the various methods of displacing the equilibria: complex formation, variation of the oxidation-reduction properties with complex formation. The complexes of the O{sup 2-} ion are considered in particular. The study of the exchange of this particle is facilitated by the use of a classification of some of its complexes which we call the pO{sup 2-} scale by analogy with the pH scale; the value pO{sup 2-} is defined by the relationship: pO{sup 2-} = log O{sup 2-} Similarly, the use of apparent potential diagrams pO{sup 2-} makes it possible to predict and to interpret reactions involving the simultaneous exchange of electrons and O{sup 2-} ions between the various degrees of oxidation of the same element. It is possible, by studying some reactions

Catalytic cracking of slack wax with molten mixtures containing aluminum chloride and bromide. [Wax obtained in the process of dewaxing lubricating oils

Energy Technology Data Exchange (ETDEWEB)

Ohtsuka, Y; Oizumi, K; Tamai, Y

1983-09-01

The catalytic cracking of slack wax with molten mixtures of AlCl/sub 3/ (aluminum chloride) and AlBr/sub 3/ (aluminum bromide) was investigated in an atmospheric semi-batch reactor at low temperatures of 100 to 160/sup 0/C. The cracking rate was proportional to the amount of unreacted wax. The conversion at 135/sup 0/C reached 25 wt % under typical reaction conditions. About 95 wt % of the cracking products consisted of isobutane, 2-methylbutane, and methylpentanes, ca. 50% of these isoparaffins being isobutane. The difference in cracking activity between this catalyst and a solid acid catalyst is discussed based on the product distribution. Hardly any reaction took place without HCl, which shows that the presence of HCl is essential for this cracking. The cracking rate increased sharply with an increase in the amount of the catalyst. The rate did not depend on the composition of the AlCl/sub 3//sup -/ AlBr/sub 3/ catalyst, but the product distribution did depend on it and the content of the gasoline fraction in the products increased with an increase in the concentration of AlBr/sub 3/. The cracking residue was characterized by IR and NMR spectroscopy. The results show that the cracking reaction probably occurs heterogeneously at the interface between the liquid wax and the molten catalyst. 3 figures, 4 tables.

Molten salt reactors - safety options galore

International Nuclear Information System (INIS)

Gat, U.; Dodds, H.L.

1997-01-01

Safety features and attributes of molten salt reactors (MSR) are described. The unique features of fluid fuel reactors of on-line continuous processing and the ability for so-called external cooling result in simple and safe designs with low excess reactivity, low fission product inventory, and small source term. These, in turn, make a criticality accident unlikely and reduce the severity of a loss of coolant to where they are no longer severe accidents. A melt down is not an accident for a reactor that uses molten fuel. The molten salts are stable, non-reactive and efficient heat transfer media that operate at high temperatures at low pressures and are highly compatible with selected structural materials. All these features reduce the accident plethora. Freeze valves can be used for added safety. An ultimate safe reactor (U.S.R) is described with safety features that are passive, inherent and non-tamperable (PINT)

Atomic size effects on local coordination and medium range order in molten trivalent metal chlorides

International Nuclear Information System (INIS)

Tatlipinar, H.; Akdeniz, Z.; Pastore, G.

1992-08-01

Structural correlations in molten trivalent metal chlorides are evaluated as functions of the metal ion size R M across the range from LaCl 3 (R M approx. 1.4 A) to AlCl 3 (R M approx. 0.8 A), using a charged soft-sphere model and the hypernetted chain approximation. Main attention is given to trends in the local liquid structure (partial radial distribution functions, coordination numbers and bond lengths) and in the intermediate range order (first sharp diffraction peak in the number-number and partial structure factors). The trend towards fourfold local coordination of the metal ions, the stabilization of their first-neighbour chlorine cage and the growth of medium range order are found to proceed in parallel as the size of the metal ion is allowed to decrease at constant number density and temperature. A tendency to molecular-type local structure and liquid-vapour phase separation is found within the hypernetted chain scheme at small metal ion sizes corresponding to AlCl 3 and is emphasized by decreasing the number density of the fluid. The predicted molecular units are rather strongly distorted Al 2 Cl 6 dimers, in agreement with observation. The calculated structural trends for other trichlorides are compared with diffraction and transport data. (author). 17 refs, 8 figs, 1 tab

A analysis of molten salt separation system for nuclear wastes transmutation

Energy Technology Data Exchange (ETDEWEB)

Hwang, In Soon; Park, Byung Gi [Seoul National University, Seoul (Korea, Republic of); Kim, Kwang Bum; Kwon, Ou Sung [Yonsei University, Seoul (Korea, Republic of)

1997-07-01

Typical molten salt separation is ANL-IFR pyroprocessing and ORNL-MSRE pyroprocessing. IFR pyroprocessing is based on Chloride chemistry and electrorefining. MSRE pyroprocessing is base on fluoride chemistry and reductive extraction. Major technologies of molten salt separation are electrorefining, electrowining, reductive extraction, and oxide reduction. Common characteristics of this technologies is to utilize reduction-oxidation phenomena in molten salt. Electrorefining process is modeled on the basis of diffusion layer theory and Butler-Volmor relation. This model is numerically solved by LSODA package. To acquire the technology of electrorefining process, 3-electrode electrochemical cell is developed where electrolyte is 500 degree C LiCl-KCl eutectic molten salt, working electrodes are Ni and Au, and reference electrode is Ag/AgCl. We have investigated the stable potential range using cyclic voltammogram of Ni electrode. We have measured steady state polarization curve of Ni electrode. Then corrosion potential of Ni electrode is -0.38V{sub Ag/AgCl} and corrosion current is 1.23 x 10{sup -4} A/cm{sup 2}. 12 refs., 6 tabs., 24 figs. (author)

Determination of activity coefficient of lanthanum chloride in molten LiCl-KCl eutectic salt as a function of cesium chloride and lanthanum chloride concentrations using electromotive force measurements

Energy Technology Data Exchange (ETDEWEB)

Bagri, Prashant, E-mail: prashant.bagri@utah.edu; Simpson, Michael F.

2016-12-15

The thermodynamic behavior of lanthanides in molten salt systems is of significant scientific interest for the spent fuel reprocessing of Generation IV reactors. In this study, the apparent standard reduction potential (apparent potential) and activity coefficient of LaCl{sub 3} were determined in a molten salt solution of eutectic LiCl-KCl as a function of concentration of LaCl{sub 3}. The effect of adding up to 1.40 mol % CsCl was also investigated. These properties were determined by measuring the open circuit potential of the La—La(III) redox couple in a high temperature molten salt electrochemical cell. Both the apparent potential and activity coefficient exhibited a strong dependence on concentration. A low concentration (0.69 mol %) of CsCl had no significant effect on the measured properties, while a higher concentration (1.40 mol %) of CsCl caused an increase (become more positive) in the apparent potential and activity coefficient at the higher range of LaCl{sub 3} concentrations.

On some regularities of metal oxide solubility in molten CsI at T = 973 K

Energy Technology Data Exchange (ETDEWEB)

Cherginets, V.L., E-mail: v_cherginets@ukr.net [Institute for Scintillation Materials, National Academy of Sciences of Ukraine, Lenin Avenue, 60, Kharkov 61001 (Ukraine); National Technical University ' Kharkiv Polytechnical Institute' , 21 Frunze St., 61002 Kharkov (Ukraine); Rebrova, T.P.; Datsko, Yu.N.; Shtitelman, V.A. [Institute for Scintillation Materials, National Academy of Sciences of Ukraine, Lenin Avenue, 60, Kharkov 61001 (Ukraine); Bryleva, E.Yu. [State Scientific Organization STC ' Institute for Single Crystals' , National Academy of Sciences of Ukraine, Lenin Avenue, 60, Kharkov 61001 (Ukraine)

2011-08-15

Highlights: > CdO, ZnO, NiO, and EuO are insoluble in CsI melt at 973 K. > The oxide solubilities are lower than those in chloride melts. > The oxide solubilities reduce with the cation radius. > ZnO, NiO, and EuO are suitable for scavenging CsO from oxide ion traces. - Abstract: Solubility products of CdO (pK{sub s,CdO} = 6.80 {+-} 0.2), ZnO (pK{sub s,ZnO} = 10.0 {+-} 0.5), NiO (pK{sub s,NiO} = 11.2 {+-} 0.2) and EuO (pK{sub s,EuO} = 13.1 {+-} 0.2) in molten CsI at T = 973 K are determined by potentiometric titration of (0.02 to 0.03) mol . kg{sup -1} solutions of the corresponding metal chlorides by strong base (KOH) using a membrane oxygen electrode Pt(O{sub 2})|ZrO{sub 2}(Y{sub 2}O{sub 3}) as an indicator. On the basis of pK{sub s,MeO} values, all the oxides studied are referred to practically insoluble in molten CsI. The values of the oxide solubility in CsI melt are lower than the corresponding values in molten alkali metal chlorides. This can be explained by 'softer' basic properties of I{sup -} as compared with Cl{sup -} in the frames of the Pearson 'hard' and 'soft' acid-base concept. In the oxide samples studied, the values of the solubility fall with the decreasing cation radius. The correlation between pK{sub s,MeO} and the polarizing action by Goldshmidt (Zr{sub Me{sup 2+}}{sup -2}) of the cation is practically linear and may be proposed for estimation of the solubility of s- and d- element oxides in molten CsI on the basis of their cation radii.

Preview of DATACHOA Ver. 1.0: Database for Chemical and Physical Properties of Molten Chloride Salts Comprising Actinide and Lanthanide Chloride Salts

Energy Technology Data Exchange (ETDEWEB)

Kim, Jong-Yun; Lee, Jin-Hong; Park, Tae-Hong; Bae, Sang-Eun; Cho, Young Hwan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-10-15

International Atomic Energy Agency (IAEA) provides molten salt database based on a world-wide-web (WWW) server. However, many data useful for the pyroprocess under development in Korea are missing. We have developed various measurement techniques for obtaining the chemical and physical data of the molten salts over the last four years: absorption spectra, emission spectra, molar absorptivity, Gibbs free energy, apparent potential, activity coefficient, exchange current density, solubility, electrical conductivity, density, surface tension, viscosity, melting point, diffusion coefficient, etc, which have been of our current interests. Those property data are essential in the understanding and the operation of the pyrochemical system. Some properties are intercorrelated, and multi-component molten salt systems can be understood by using a multivariate chemometric data analysis. Our final goal is to establish the 'Expert System', which is defined as a system that emulates the decision-making ability of a human expert. Although expert systems have been successful in the artificial intelligence, they are not known to chemists or chemical engineers for many years. The DATACHOA is the first step forward to the 'Expert System', although the amount of our property data is not currently enough to build up the 'Expert System'. DATACHOA is our first attempt to collect extensive basic and fundamental properties of molten salts of interest to pyroprocess chemists and engineers in Korea. DATACHOA ver. 1.0 will be released to the pyroprocess engineers within a few months.

Corrosion resistance of metals and alloys in molten alkalies

International Nuclear Information System (INIS)

Zarubitskij, O.G.; Dmitruk, B.F.; Minets, L.A.

1979-01-01

Literature data on the corrosion of non-ferrous and noble metals, iron and steels in the molten alkalis and mixtures of their base are presented. It is shown that zirconium, niobium and tantalum are characterized by high corrosion stability in the molten NaOH. Additions of NaOH and KOH to the alkali chloride melts result in a 1000 time decrease of zirconium corrosion rate at 850 deg. The data testify to the characteristic passivating properties of OH - ions; Mo and W do not possess an ability to selfpassivation in hydroxide melts. Corrosion resistance of carbon and chromium-nickel steels in hydroxide melts depends considerably on the temperature, electrolyte composition and atmosphere over them. At the temperatures up to 600 deg C chromium-nickel steel is corrosion resistant in the molten alkali only in the inert atmosphere. Corrosion rate of chromium-nickel alloy is the lower the less chromium and the more nickel it contains. For the small installations the 4Kh18N25S2 and Kh23N28M3D3T steels can be recommended

Low-temperature synthesis of nanocrystalline ZrC coatings on flake graphite by molten salts

Energy Technology Data Exchange (ETDEWEB)

Ding, Jun, E-mail: dingjun@wust.edu.cn; Guo, Ding; Deng, Chengji; Zhu, Hongxi; Yu, Chao

2017-06-15

Highlights: • Uniform ZrC coatings are prepared on flake graphite at 900 °C. • ZrC coatings are composed of nanosized (30–50 nm) particles. • The template growth mechanism is believed to be dominant in the molten salt synthesis process. - Abstract: A novel molten salt synthetic route has been developed to prepare nanocrystalline zirconium carbide (ZrC) coatings on flake graphite at 900 °C, using Zr powder and flake graphite as the source materials in a static argon atmosphere, along with molten salts as the media. The effects of different molten salt media, the sintered temperature, and the heat preservation time on the phase and microstructure of the synthetic materials were investigated. The ZrC coatings formed on the flake graphite were uniform and composed of nanosized particles (30–50 nm). With an increase in the reaction temperature, the ZrC nanosized particles were more denser, and the heat preservation time and thickness of the ZrC coating also increased accordingly. Electron microscopy was used to observe the ZrC coatings on the flake graphite, indicating that a “template mechanism” played an important role during the molten salt synthesis.

Electrochemical properties of actinides in molten chlorides

International Nuclear Information System (INIS)

Lambertin, D.; Lacquement, J.; Sanchez, S.; Picard, G.

2000-01-01

The chemical properties of plutonium and cerium chlorides have been studied in the fused CaCl 2 -NaCl equimolar mixture at 550 deg. C using a tungsten working electrode and a pO 2- indicator electrode. The standard potential of Pu(III)/Pu was determined using cyclic voltammetry. The solubility product of Pu 2 O 3 was calculated by potentiometric titration. The standard potential of Ce(III)/Ce have been determined by a potentiometry method. Potentiometric titrations of Ce(III) have been shown the existence of a soluble cerium oxychloride. All these data allowed us to draw the potential-pO 2- diagram which summarises the properties of plutonium and cerium compounds in the melt. (authors)

Candidate molten salt investigation for an accelerator driven subcritical core

Science.gov (United States)

Sooby, E.; Baty, A.; Beneš, O.; McIntyre, P.; Pogue, N.; Salanne, M.; Sattarov, A.

2013-09-01

We report a design for accelerator-driven subcritical fission in a molten salt core (ADSMS) that utilizes a fuel salt composed of NaCl and transuranic (TRU) chlorides. The ADSMS core is designed for fast neutronics (28% of neutrons >1 MeV) to optimize TRU destruction. The choice of a NaCl-based salt offers benefits for corrosion, operating temperature, and actinide solubility as compared with LiF-based fuel salts. A molecular dynamics (MD) code has been used to estimate properties of the molten salt system which are important for ADSMS design but have never been measured experimentally. Results from the MD studies are reported. Experimental measurements of fuel salt properties and studies of corrosion and radiation damage on candidate metals for the core vessel are anticipated. A special thanks is due to Prof. Paul Madden for introducing the ADSMS group to the concept of using the molten salt as the spallation target, rather than a conventional heavy metal spallation target. This feature helps to optimize this core as a Pu/TRU burner.

AlN powder synthesis via nitriding reaction of aluminum sub-chloride

Energy Technology Data Exchange (ETDEWEB)

Ohashi, T.; Nishida, T.; Sugiura, M. (Waseda Univ., Tokyo (Japan). Graduate School); Fuwa, A. (Waseda Univ., Tokyo (Japan))

1993-06-01

In order to obtain the pertinent properties of aluminium nitride in its sintered form, it is desirable to have powders of finer sizes with narrower size distribution and higher purity, thereby making the sintering processing easier and the final body denser. Instead of using sublimated aluminum tri-chloride vapor (AlCl3) as an aluminum source in the vapor phase nitriding reaction, the mixed aluminum chloride vapor consisted of aluminum tri-chloride, bi-chloride and mono-chloride are used in the reaction with ammonia at temperatures of 1000 and 1200K. The mixed chloride vapors are produced by reacting chlorine with molten aluminum at 1000 or 1200K under atmospheric pressure. The reaction of this mixed chloride vapor with ammonia is then experimentally investigated to study the aluminum nitride powder morphology. The aluminum nitride powders synthesized under various ammonia concentrations are characterized for size distribution, mean particle size and particle morphology. 24 refs., 8 figs., 2 tabs.

Absorption media for irreversibly gettering thionyl chloride

Science.gov (United States)

Buffleben, George; Goods, Steven H.; Shepodd, Timothy; Wheeler, David R.; Whinnery, Jr., LeRoy

2002-01-01

Thionyl chloride is a hazardous and reactive chemical used as the liquid cathode in commercial primary batteries. Contrary to previous thinking, ASZM-TEDA.RTM. carbon (Calgon Corporation) reversibly absorbs thionyl chloride. Thus, several candidate materials were examined as irreversible getters for thionyl chloride. The capacity, rate and effect of temperature were also explored. A wide variety of likely materials were investigated through screening experiments focusing on the degree of heat generated by the reaction as well as the material absorption capacity and irreversibility, in order to help narrow the group of possible getter choices. More thorough, quantitative measurements were performed on promising materials. The best performing getter was a mixture of ZnO and ASZM-TEDA.RTM. carbon. In this example, the ZnO reacts with thionyl chloride to form ZnCl.sub.2 and SO.sub.2. The SO.sub.2 is then irreversibly gettered by ASZM-TEDA.RTM. carbon. This combination of ZnO and carbon has a high capacity, is irreversible and functions effectively above -20.degree. C.

Investigation of the evaporation of rare earth chlorides in a LiCl-KCl molten salt

International Nuclear Information System (INIS)

Sung Bin Park; Dong Wook Cho; Moon Sik Woo; Sung Chan Hwang; Young Ho Kang; Jeong Guk Kim; Hansoo Lee

2011-01-01

Uranium dendrites which were deposited at a solid cathode of an electrorefiner contained a certain amount of salts. These salts should be removed for the recovery of pure metal using a cathode processor. In the uranium deposits from the electrorefining process, there are actinide chlorides and rare earth chlorides in addition to uranium chloride in the LiCl-KCl eutectic salt. The evaporation behaviors of the actinides and rare earth chlorides in the salts should be investigated for the removal of salts in the deposits. Experiments on the salt evaporation of rare earth chlorides in a LiCl-KCl eutectic salt were carried out. Though the vapor pressures of the rare earth chlorides were lower than those of the LiCl and KCl, the rare earth chlorides were co-evaporized with the LiCl-KCl eutectic salt. The Hertz-Langmuir relation was applied for this evaporation, and also the evaporation rates of the salt were obtained. The co-evaporation of the rare earth chlorides and LiCl-KCl eutectic were also discussed. (author)

Reuse of spent fuel cladding Zr by molten salt toward advanced recycle society

International Nuclear Information System (INIS)

Amano, Osamu; Kobayashi, Hiroaki; Suzuki, Kazunori; Yasuike, Y.; Sato, Nobuaki

2003-01-01

Cladding tubes of zircaloy 95% generated from reprocessing process for spent nuclear fuels are to be chopped in about 3 cm length, compacted and solidified with cements. This paper reports the summary of investigation of the present possible techniques for zirconium recovery: (1) electrolysis of molten salts (Zr-chlorides and/or fluorides) and (2) separation as volatile zirconium chlorides (ZrCl 4 ) (chloride volatility process) followed by reaction with metallic magnesium at 900degC to produce sponged Zr (Kroll method). The feasibility are discussed from the point of view of reduction of secondary radioactive wastes, accumulation of such nuclides as Co-60 and Ni-63 in electrolytic basin, radioactivity estimation in the products, and also problems of cleaning and reducing chemicals. (S. Ohno)

Hydrodynamic simulation of a lithium chloride salt system

International Nuclear Information System (INIS)

Eberle, C. S.; Herrmann, S. D.; Knighton, G. C.

1999-01-01

A fused lithium chloride salt system's constitutive properties were evaluated and compared to a number of fluid properties, and water was shown to be an excellent simulant of lithium chloride salt. With a simple flow model, the principal scaling term was shown to be a function of the kinematic viscosity. A water mock-up of the molten salt was also shown to be within a ±3% error in the scaling analysis. This made it possible to consider developing water scaled tests of the molten salt system. Accurate flow velocity and pressure measurements were acquired by developing a directional velocity probe. The device was constructed and calibrated with a repeatable accuracy of ±15%. This was verified by a detailed evaluation of the probe. Extensive flow measurements of the engineering scale mockup were conducted, and the results were carefully compared to radial flow patterns of a straight blade stirrer. The flow measurements demonstrated an anti-symmetric nature of the stirring, and many additional effects were also identified. The basket design was shown to prevent fluid penetration into the fuel baskets when external stirring was the flow mechanism

Actinide-Lanthanide separation by an electrolytic method in molten salt media: feasibility assessment of a renewed liquid cathode

International Nuclear Information System (INIS)

Huguet, A.

2009-12-01

This study is part of a research program concerning the assessment of pyrochemical methods for the nuclear waste processing. The An-Ln partitioning could be achieved by an electrolytic selective extraction in molten salt media. It has been decided to focus on liquid reactive cathode which better suits to a group actinides co-recycling. The aim of the study is to propose, define and initiate the development of an electrolytic pyro-process dedicated to the quantitative and selective recovery of the actinides. Quantitativeness is related to technology, whereas selectivity is governed by chemistry. The first step consisted in selecting the adequate operating conditions, which enables a sufficient An-Ln separation. The first step consisted, by means of thermodynamic calculi and electrochemical investigations, in selecting a promising combination between molten electrolyte and cathodic material, regarding the process constraints. To improve the recovery yield, it is necessary to develop a disruptive technology: here comes the concept of a dynamic electrodeposition carried out onto liquid metallic drops. The next step consisted in designing and manufacturing a lab-scale device which enables dropping flow studies. Since interfacial phenomena are of primary meaning in such a concept, it has been decided to focus on high temperature liquid-liquid interfacial measurements. (author)

Precipitation of lamellar gold nanocrystals in molten polymers

International Nuclear Information System (INIS)

Palomba, M.; Carotenuto, G.

2016-01-01

Non-aggregated lamellar gold crystals with regular shape (triangles, squares, pentagons, etc.) have been produced by thermal decomposition of gold chloride (AuCl) molecules in molten amorphous polymers (polystyrene and poly(methyl methacrylate)). Such covalent inorganic gold salt is high soluble into non-polar polymers and it thermally decomposes at temperatures compatible with the polymer thermal stability, producing gold atoms and chlorine radicals. At the end of the gold precipitation process, the polymer matrix resulted chemically modified because of the partial cross-linking process due to the gold atom formation reaction.

Advanced heat exchanger development for molten salts

Energy Technology Data Exchange (ETDEWEB)

Sabharwall, Piyush, E-mail: Piyush.Sabharwall@inl.gov [Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Clark, Denis; Glazoff, Michael [Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Zheng, Guiqiu; Sridharan, Kumar; Anderson, Mark [University of Wisconsin, Madison (United States)

2014-12-15

Highlights: • Hastelloy N and 242, shows corrosion resistance to molten salt at nominal operating temperatures. • Both diffusion welds and sheet material in Hastelloy N were corrosion tested in at 650, 700, and 850 °C for 200, 500, and 1000 h. • Thermal gradients and galvanic couples in the molten salts enhance corrosion rates. • Corrosion rates found were typically <10 mils per year. - Abstract: This study addresses present work concerned with advanced heat exchanger development for molten salt in nuclear and non-nuclear thermal systems. The molten salt systems discussed herein use alloys, such as Hastelloy N and 242, that show good corrosion resistance in molten salt at nominal operating temperatures up to 700 °C. These alloys were diffusion welded, and the corresponding information is presented. Test specimens were prepared for exposing diffusion welds to molten salt environments. Hastelloy N and 242 were found to be weldable by diffusion welding, with ultimate tensile strengths about 90% of base metal values. Both diffusion welds and sheet material in Hastelloy N were corrosion tested in 58 mol% KF and 42 mol% ZrF{sub 4} at 650, 700, and 850 °C for 200, 500, and 1000 h. Corrosion rates were similar between welded and nonwelded materials, typically <100 μm per year after 1000 h of corrosion tests. No catastrophic corrosion was observed in the diffusion welded regions. For materials of construction, nickel-based alloys and alloys with dense nickel coatings are effectively inert to corrosion in fluorides, but not so in chlorides. Hence, additional testing of selected alloys for resistance to intergranular corrosion is needed, as is a determination of corrosion rate as a function of the type of salt impurity and alloy composition, with respect to chromium and carbon, to better define the best conditions for corrosion resistance. Also presented is the division of the nuclear reactor and high-temperature components per American Society of Mechanical

Effect of preparation temperature and cycling voltage range on molten salt method prepared SnO2

CSIR Research Space (South Africa)

Reddy, MV

2013-09-01

Full Text Available We prepared nano-sized tin (IV) oxide (SnO(sub2)) via molten-salt technique: heating a mixture of tin tetrachloride, lithium nitrate and lithium chloride at 280 °C in air. The powders are characterized by X-ray diffraction and transmission scanning...

Volume reduction of waste contaminated by fission product elements and plutonium using molten salt combustion

International Nuclear Information System (INIS)

McKenzie, D.E.; Grantham, L.F.; Paulson, R.B.

1979-01-01

In the Molten Salt Combustion Process, transuranic or β-γ organic waste and air are continuously introduced beneath the surface of a sodium carbonate-containing melt at a temperature of about 800 0 C. Complete combustion of the organic material to carbon dioxide and steam occurs without the conversion of nitrogen to nitrogen oxides. The noxious gases formed by combustion of the chloride, sulfur or phosphorus content of the waste instantly react with the melt to form the corresponding sodium compounds. These compounds as well as the ash and radionuclides are retained in the molten salt. The spent salt is either fused cast into an engineered disposal container or processed to recover salt and plutonium. Molten salt combustion reduces the waste to about 2% of its original volume. Many reactor or reprocessing wastes which cannot be incinerated without difficulty are readily combusted in the molten salt. A 50 kg/hr molten salt combustion system is being designed for the Radioactive Waste Management Complex at the Idaho National Engineering Laboratory. Construction of the combustor started during 1977, and combustor startup was scheduled for the spring of 1978

Stabilization/Solidification of radioactive molten salt waste by using xSiO2-yAl2O3-zP2O5 material

International Nuclear Information System (INIS)

Hwan-Seo Park; In-Tae Kim; Yong-Zun Cho; Seong-Won Park; Eung-Ho Kim

2008-01-01

Molten salt waste generated from the electro metallurgical process to recover uranium and transuranic elements is considered as one of problematic wastes to be difficult to immobilize into a durable for final disposal. As an alternative, this study suggested a new method performed at molten state, where dechlorination was achieved with a new inorganic material containing SiO 2 , Al 2 O 3 and P 2 O 5 (SAP). The SAP as a reactive material to molten salt was prepared by a conventional sol-gel process. The prepared SAPs were reacted with each metal chloride, LiCl, CsCl, SrCl 2 and CeCl 3 at 650 deg. C for 6 hours and also were reacted with simulated salt waste consisting of 90 wt% LiCl, 6.8 wt% CsCl and 3.2 wt% SrCl 2 at different waste loading. All the reactions were carried out in oxidative atmosphere and metal chlorides were effectively converted into stable products under a reasonable reaction ratio

Study on the phosphate reaction characteristics of lanthanide chlorides in molten salt with operating conditions

International Nuclear Information System (INIS)

Lee, Tae-Kyo; Hwang, Taek-Sung; Cho, Yung-Zun; Eun, Hee-Chul; Park, Hwan-Seo; Park, Geun-Il; Son, Sung-Mo

2013-01-01

A minimization of waste salt is one of the most important issues for the optimization of pyroprocessing. The separation of fission products in waste salts and the reuse of purified waste salt are promising strategies for minimizing the waste salt amounts. The phosphate precipitation of lanthanide is currently being considered for eutectic (LiCl–KCl) waste salt purification. In this research, the effects of molten salt temperature (400–550°C) and reaction time (max. 180 min) upon conversion into the phosphate of lanthanides was investigated using 1 and 3 kg of eutectic salt. The conversion efficiency of lanthanides to molten salt-insoluble precipitates and phosphates was increased with an increase in molten salt temperature and operating time until it attained a specific temperature and time. K 3 PO 4 as a precipitant was more favorable than Li 3 PO 4 in terms of reactivity. To obtain over a 99% overall conversion efficiency, about 30 min was required in the case of using K 3 PO 4 at 450°C, but about 120 min in the case of using Li 3 PO 4 at 550°C. The lanthanide precipitates formed by a reaction with phosphate were a mixture of monoclinic structures, usually representing a polyhedron structure, and a tetragonal structure, representing a platelet structure. (author)

Corrosion Study of Stainless Steels in Peracetic Acid Bleach Media With and Without Chloride and Chelant

Directory of Open Access Journals (Sweden)

Rohtash

2014-12-01

Full Text Available The paper industries are adopting non-chlorine containing chemicals e.g. peroxide, ozone, peracids etc. as alternate of chlorine based bleach chemicals e.g. chlorine and chlorine dioxide etc. with the aim of eco-friend atmospheres. Changeover to the new chemicals in the bleaching process is likely to affect the metallurgy of the existing bleach plants due to change in the corrosivity of the media. Accordingly, corrosion investigations were performed in a peracid namely peracetic acid to test the suitability of austenitic stainless steels 654SMO, 265SMO, 2205, 317L and 316L. The performance of above stainless steels was evaluated through long term immersion tests and Electrochemical polarization measurements in peracetic acid (PAA bleach media at pH value 4 maintaining concentration 0.2 % as active oxygen along with three chloride levels 0, 500 and 1000 ppm in pulp-free laboratory. To study the effect of corrosion inhibitors with extending limit of chloride in liquors, measurements were also made with two types of chelants- EDTA & MgSO4. The results showed that corrosivity of PAA reduced by addition of chelant while increased with concentration of Cl¯. The results also exhibited that EDTA is better inhibitor than MgSO4.

Corrosion-electrochemical behavior of zirconium in molten alkali metal carbonates

Science.gov (United States)

Nikitina, E. V.

2016-08-01

The corrosion and electrochemical characteristics of zirconium during its interaction with molten lithium, sodium, and potassium carbonates containing from 1 to 5 wt % additives to the salt phase are studied in a temperature range of 500-800°C using gravimetry, corrosion potential measurement, and anodic polarization. The substances decreasing the corrosion losses due to the strengthening and thickening of an oxide film (lithium, sodium, potassium hydroxides) are used as passivators. Sodium chloride, fluoride, and sulfate serve as corrosion stimulators (activators).

Density and electrical conductivity of NaCl-CoCl2 and NaCl-NiCl2 molten mixtures

International Nuclear Information System (INIS)

Red'kin, A.A.; Salyulev, A.B.; Smirnov, M.V.; Khokhlov, V.A.

1995-01-01

The density and electrical conductivity of cobalt and nickel dichlorides and their solutions in molten sodium chloride have been measured. The density was measured by a dilatometric method, and the electrical conductivity by an AC technique. The molar volume and equivalent conductance were calculated. (orig.)

Study of electrochemical behaviour of tantalum in molten alkali metal chlorides

International Nuclear Information System (INIS)

Bajmakov, A.N.; Ezrokhina, A.M.; Sashinina, O.A.; Shkol'nikov, S.N.

1985-01-01

Equilibrium potentials of metallic tantalum in the melt TaCl 5 +KCl-NaCl are studied. Are average degree of tantalum ion oxidation, which are in equilibrium with metallic tantalum, is determined. Anodic behaviour of tantalum in equimolar mixture of potassium and sodium chlorides with Ta and F ion additions is considered. An average degree of oxidation of Ta ions, which transfer into the melt, depending on current density, is determined. It is established that tantalum is dissolved in the regime of diffusional kinetics. It is shown that tantalum corrodes in equimolar mixture of potassium and sodiUm chlorides, at that, corrosion rate increases with introdUction of Ta and F ions into solution. The corrosion is of electrochemical nature and it proceeds in the regime of diffusional kinetics

Molten salt processing of mixed wastes with offgas condensation

International Nuclear Information System (INIS)

Cooper, J.F.; Brummond, W.; Celeste, J.; Farmer, J.; Hoenig, C.; Krikorian, O.H.; Upadhye, R.; Gay, R.L.; Stewart, A.; Yosim, S.

1991-01-01

We are developing an advanced process for treatment of mixed wastes in molten salt media at temperatures of 700--1000 degrees C. Waste destruction has been demonstrated in a single stage oxidation process, with destruction efficiencies above 99.9999% for many waste categories. The molten salt provides a heat transfer medium, prevents thermal surges, and functions as an in situ scrubber to transform the acid-gas forming components of the waste into neutral salts and immobilizes potentially fugitive materials by a combination of particle wetting, encapsulation and chemical dissolution and solvation. Because the offgas is collected and assayed before release, and wastes containing toxic and radioactive materials are treated while immobilized in a condensed phase, the process avoids the problems sometimes associated with incineration processes. We are studying a potentially improved modification of this process, which treats oxidizable wastes in two stages: pyrolysis followed by catalyzed molten salt oxidation of the pyrolysis gases at ca. 700 degrees C. 15 refs., 5 figs., 1 tab

Molten salt/metal extractions for recovery of transuranic elements

International Nuclear Information System (INIS)

Chow, L.S.; Basco, J.K.; Ackerman, J.P.; Johnson, T.R.

1992-01-01

The integral fast reactor (EFR) is an advanced reactor concept that incorporates metallic driver and blanket fuels, an inherently safe, liquid-sodium-cooled, pool-type, reactor design, and on-site pyrochemical reprocessing (including electrorefining) of spent fuels and wastes. This paper describes a pyrochemical method that is being developed at Argonne National Laboratory to recover transuranic elements from the EFR electrorefiner process salt. The method uses multistage extractions between molten chloride salts and cadmium metal at high temperatures. The chemical basis of the salt extraction method, the test equipment, and a test plan are discussed

Reaction of uranium oxides with chlorine and carbon or carbon monoxide to prepare uranium chlorides

Energy Technology Data Exchange (ETDEWEB)

Haas, P.A.; Lee, D.D.; Mailen, J.C.

1991-11-01

The preferred preparation concept of uranium metal for feed to an AVLIS uranium enrichment process requires preparation of uranium tetrachloride (UCI{sub 4}) by reacting uranium oxides (UO{sub 2}/UO{sub 3}) and chlorine (Cl{sub 2}) in a molten chloride salt medium. UO{sub 2} is a very stable metal oxide; thus, the chemical conversion requires both a chlorinating agent and a reducing agent that gives an oxide product which is much more stable than the corresponding chloride. Experimental studies in a quartz reactor of 4-cm ID have demonstrated the practically of some chemical flow sheets. Experimentation has illustrated a sequence of results concerning the chemical flow sheets. Tests with a graphite block at 850{degrees}C demonstrated rapid reactions of Cl{sub 2} and evolution of carbon dioxide (CO{sub 2}) as a product. Use of carbon monoxide (CO) as the reducing agent also gave rapid reactions of Cl{sub 2} and formation of CO{sub 2} at lower temperatures, but the reduction reactions were slower than the chlorinations. Carbon powder in the molten salt melt gave higher rates of reduction and better steady state utilization of Cl{sub 2}. Addition of UO{sub 2} feed while chlorination was in progress greatly improved the operation by avoiding the plugging effects from high UO{sub 2} concentrations and the poor Cl{sub 2} utilizations from low UO{sub 2} concentrations. An UO{sub 3} feed gave undesirable effects while a feed of UO{sub 2}-C spheres was excellent. The UO{sub 2}-C spheres also gave good rates of reaction as a fixed bed without any molten chloride salt. Results with a larger reactor and a bottom condenser for volatilized uranium show collection of condensed uranium chlorides as a loose powder and chlorine utilizations of 95--98% at high feed rates. 14 refs., 7 figs., 14 tabs.

Design, construction, establishment of proof of principle, and testing of a spectrometer to permit spectroelectrochemical investigations of actinides in a confined system

International Nuclear Information System (INIS)

Dasgupta, P.K.; Li, J.

1999-02-01

This study examines the design, construction, and performance of a spectrometer that was designed and built for UV-visible absorption spectroscopic studies in molten salt media. Contrary to previous designs in the literature, the authors found that furnace and chemical components can be located away from the instrument and electronics. In studying the performance of the spectrometer, they used a potassium chloride eutectic mixture as the molten salt medium. They found that UV-visible absorption spectroscopic studies can be conveniently created in a molten alkali halide media with inexpensive equipment coupled with good sensitivity and precision. Further research will focus on designing a suitable fiber optic probe that will allow the authors to monitor the molten salt process on-line

Rechargeable lithium and sodium anodes in chloroaluminate molten salts containing thionyl chloride

Energy Technology Data Exchange (ETDEWEB)

Fuller, J.; Osteryoung, R.A. [North Carolina State Univ., Raleigh, NC (United States). Dept. of Chemistry; Carlin, R.T.

1995-11-01

Lithium and sodium deposition-stripping studies were performed in room temperature buffered neutral chloroaluminate melts containing low concentrations of thionyl chloride (SOCl{sub 2}). The SOCl{sub 2} solute promotes high cycling efficiencies of the alkali metals in these electrolytes. Staircase cyclic voltammetry and chronopotentiometry show cycling efficiencies of approximately 90% for both lithium and sodium. High cycling efficiencies are maintained following extended exposure of the melt to the dry box atmosphere and after time delays at open circuit. The performance of the SOCl{sub 2}-promoted systems is substantially improved over previous studies in room temperature melts containing hydrogen chloride as the promoting solute.

Domestic Material Content in Molten-Salt Concentrating Solar Power Plants

Energy Technology Data Exchange (ETDEWEB)

Turchi, Craig [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kurup, Parthiv [National Renewable Energy Lab. (NREL), Golden, CO (United States); Akar, Sertac [National Renewable Energy Lab. (NREL), Golden, CO (United States); Flores, Francisco [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2015-08-26

This study lists material composition data for two concentrating solar power (CSP) plant designs: a molten-salt power tower and a hypothetical parabolic trough plant, both of which employ a molten salt for the heat transfer fluid (HTF) and thermal storage media. The two designs have equivalent generating and thermal energy storage capacities. The material content of the saltHTF trough plant was approximately 25% lower than a comparably sized conventional oil-HTF parabolic trough plant. The significant reduction in oil, salt, metal, and insulation mass by switching to a salt-HTF design is expected to reduce the capital cost and LCOE for the parabolic trough system.

Corrosion resistance of ceramic materials in pyrochemical reprocessing atmosphere by using molten salt for spent nuclear oxide fuel. Corrosion research under chlorine gas condition

International Nuclear Information System (INIS)

Takeuchi, Masayuki; Hanada, Keiji; Koizumi, Tsutomu; Aose, Shinichi; Kato, Toshihiro

2002-12-01

Pyrochemical reprocessing using molten salts (RIAR process) has been recently developed for spent nuclear oxide fuel and discussed in feasibility study. It is required to improve the corrosion resistance of equipments such as electrolyzer because the process is operated in severe corrosion environment. In this study, the corrosion resistance of ceramic materials was discussed through the thermodynamic calculation and corrosion test. The corrosion test was basically carried out in alkali molten salt under chlorine gas condition. And further consideration about the effects of oxygen, carbon and main fission product's chlorides were evaluated in molten salt. The result of thermodynamic calculation shows most of ceramic oxides have good chemical stability on chlorine, oxygen and uranyl chloride, however the standard Gibb's free energies with carbon have negative value. On the other hand, eleven kinds of ceramic materials were examined by corrosion test, then silicon nitride, mullite and cordierite have a good corrosion resistance less than 0.1 mm/y. Cracks were not observed on the materials and flexural strength did not reduce remarkably after 480 hours test in molten salt with Cl 2 -O 2 bubbling. In conclusion, these three ceramic materials are most applicable materials for the pyrochemical reprocessing process with chlorine gas condition. (author)

Electrochemical separation of cerium and yttrium in molten chlorides on liquid-metallic electrodes

International Nuclear Information System (INIS)

Yamshchikov, L.F.; Lebedev, V.A.; Nichkov, I.F.

1978-01-01

An estimating calculation of the coefficients of separation of cerium and yttrium in the process of electrolysis in molten salts on liquid electrodes of aluminium, gallium, indium, lead, tin, antimonium and zinc is carried out. The calculation of the separation coefficients was carried out according to the known values of activation coefficients of cerium and yttrium in fusible metals. The electrolysis was carried out at 973 K in the argon air in the cell with an eutectic mixture of NaCl and KCl as an elactrolyte. It is shown that the salten phase is concentrated by yttrium, and the melallic one- by cerium on all the electrodes. The value of the separation coefficient of Ce and Y is considerably high and continuously increases on the fusible metals in the Zn, In, Ga, Al, Pb, Sn, Sb series. The experimental values of the separation coefficients practically coincide with the theoretically calculated ones, testifying to the possibility of the effective separation of elements even in a single-staged possibility of the effective separation of elements even in a single-staged process. An electrolysis of molten salts is not inferior in its selectivity to the universally recognized methods of the fine purification of substances permitting to separate Ce and Y with the Ksub(sep) approximately equal to 10

Electrochemical studies on plutonium in molten salts

International Nuclear Information System (INIS)

Bourges, G.; Lambertin, D.; Rochefort, S.; Delpech, S.; Picard, G.

2007-01-01

Electrochemical studies on plutonium have been supporting the development of pyrochemical processes involving plutonium at CEA. The electrochemical properties of plutonium have been studied in molten salts - ternary eutectic mixture NaCl-KCl-BaCl 2 , equimolar mixture NaCl-KCl and pure CaCl 2 - and in liquid gallium at 1073 K. The formal, or apparent, standard potential of Pu(III)/Pu redox couple in eutectic mixture of NaCl-KCl-BaCl 2 at 1073 K determined by potentiometry is equal to -2.56 V (versus Cl 2 , 1 atm/Cl - reference electrode). In NaCl-KCl eutectic mixture and in pure CaCl 2 the formal standard potentials deduced from cyclic voltammetry are respectively -2.54 V and -2.51 V. These potentials led to the calculation of the activity coefficients of Pu(III) in the molten salts. Chronoamperometry on plutonium in liquid gallium using molten chlorides - CaCl 2 and equimolar NaCl/KCl - led to the determination of the activity coefficient of Pu in liquid Ga, log γ = -7.3. This new data is a key parameter to assess the thermodynamic feasibility of a process using gallium as solvent metal. By comparing gallium with other solvent metals - cadmium, bismuth, aluminum - gallium appears to be, with aluminum, more favorable for the selectivity of the separation at 1073 K of plutonium from cerium. In fact, compared with a solid tungsten electrode, none of these solvent liquid metals is a real asset for the selectivity of the separation. The role of a solvent liquid metal is mainly to trap the elements

Electrical Conductivity of Molten DyCl3-NaCl and DyCl3-KCl Systems: An Approach to Structural Interpretations of Rare Earth Chloride Melts

Science.gov (United States)

Iwadate, Yasuhiko; Ohkubo, Takahiro

2017-11-01

Electrical conductivities (κs) of molten DyCl3-NaCl and DyCl3-KCl systems were estimated by measuring the impedances of each mixture melt at any temperature and/or frequency. The molar volumes (Vms) were measured by dilatometry and represented as a polynomial empirical equation of temperature and composition. Due to both the properties, the molar conductivities (Λms) were calculated and their temperature and/or composition dependences were discussed from the standpoint of structural features as well. The κs increased curvilinearly with increasing temperature across the whole composition ranges. This trend was also applied to the Λms which was fitted by an Arrhenius-type equation. The relationship of Λms with melt composition was studied and the Λms were found to decrease with increasing composition of DyCl3. These findings were interpreted based on the results of structural science so far reported, and finally, the relationship between Λms and the structures of pure rare earth chloride melts was discussed.

Density and electrical conductivity of NaCl-CoCl{sub 2} and NaCl-NiCl{sub 2} molten mixtures

Energy Technology Data Exchange (ETDEWEB)

Red` kin, A A [Institute of High Temp. Electrochem., Ekaterinburg (Russian Federation); Salyulev, A B [Institute of High Temp. Electrochem., Ekaterinburg (Russian Federation); Smirnov, M V [Institute of High Temp. Electrochem., Ekaterinburg (Russian Federation); Khokhlov, V A [Institute of High Temp. Electrochem., Ekaterinburg (Russian Federation)

1995-11-01

The density and electrical conductivity of cobalt and nickel dichlorides and their solutions in molten sodium chloride have been measured. The density was measured by a dilatometric method, and the electrical conductivity by an AC technique. The molar volume and equivalent conductance were calculated. (orig.)

Molten salt electrorefining method

International Nuclear Information System (INIS)

Tanaka, Hiroshi; Nakamura, Hitoshi; Shoji, Yuichi; Matsumaru, Ken-ichi.

1994-01-01

A molten cadmium phase (lower side) and a molten salt phase (upper side) are filled in an electrolytic bath. A basket incorporating spent nuclear fuels is inserted/disposed in the molten cadmium phase. A rotatable solid cathode is inserted/disposed in the molten salt phase. The spent fuels, for example, natural uranium, incorporated in the basket is dissolved in the molten cadmium phase. In this case, the uranium concentration in the molten salt phase is determined as from 0.5 to 20wt%. Then, electrolysis is conducted while setting a stirring power for stirring at least the molten salt phase of from 2.5 x 10 2 to 1 x 10 4 based on a reynolds number. Crystalline nuclei of uranium are precipitated uniformly on the surface of the solid cathode, and they grow into fine dendrites. With such procedures, since short-circuit between the cathode precipitates and the molten cadmium phase (anode) is scarcely caused, to improve the recovering rate of uranium. (I.N.)

Electrochemical separation of actinides and fission products in molten salt electrolyte

Energy Technology Data Exchange (ETDEWEB)

Gay, R.L.; Grantham, L.F.; Fusselman, S.P. [Rockwell International/Rocketdyne Division, Canoga Park, CA (United States)] [and others

1995-10-01

Molten salt electrochemical separation may be applied to accelerator-based conversion (ABC) and transmutation systems by dissolving the fluoride transport salt in LiCl-KCl eutectic solvent. The resulting fluoride-chloride mixture will contain small concentrations of fission product rare earths (La, Nd, Gd, Pr, Ce, Eu, Sm, and Y) and actinides (U, Np, Pu, Am, and Cm). The Gibbs free energies of formation of the metal chlorides are grouped advantageously such that the actinides can be deposited on a solid cathode with the majority of the rare earths remaining in the electrolyte. Thus, the actinides are recycled for further transmutation. Rockwell and its partners have measured the thermodynamic properties of the metal chlorides of interest (rare earths and actinides) and demonstrated separation of actinides from rare earths in laboratory studies. A model is being developed to predict the performance of a commercial electrochemical cell for separations starting with PUREX compositions. This model predicts excellent separation of plutonium and other actinides from the rare earths in metal-salt systems.

Liquid-liquid reductive extraction in molten fluoride salt/liquid aluminium as a core of process for the An/Ln group separation

International Nuclear Information System (INIS)

Conocar, O.

2007-06-01

This report concerns a pyrochemical process based on liquid-liquid extraction in a molten fluoride/liquid aluminium system as a core process for actinide (An)/lanthanide (Ln) group separation, studied at CEA. The basic and demonstrative experiments have established the feasibility of the An/Ln group separation in the molten fluoride/liquid aluminium system (U, Pu, Np, Am, Cm traces from Nd, Ce, Eu, Sm, Eu, La - An/Ln separation factors over 1000 - An recovery yield over 98 % in one batch). The main experimental efforts must now be targeted on the recovery of actinides from the Al matrix. A thermodynamic and bibliographical survey has been done. It shows that back-extraction in a molten chloride melt could be a promising technique for this purpose

Liquid-liquid reductive extraction in molten fluoride salt/liquid aluminium as a core of process for the An/Ln group separation

Energy Technology Data Exchange (ETDEWEB)

Conocar, O

2007-06-15

This report concerns a pyrochemical process based on liquid-liquid extraction in a molten fluoride/liquid aluminium system as a core process for actinide (An)/lanthanide (Ln) group separation, studied at CEA. The basic and demonstrative experiments have established the feasibility of the An/Ln group separation in the molten fluoride/liquid aluminium system (U, Pu, Np, Am, Cm traces from Nd, Ce, Eu, Sm, Eu, La - An/Ln separation factors over 1000 - An recovery yield over 98 % in one batch). The main experimental efforts must now be targeted on the recovery of actinides from the Al matrix. A thermodynamic and bibliographical survey has been done. It shows that back-extraction in a molten chloride melt could be a promising technique for this purpose.

Melting in trivalent metal chlorides

International Nuclear Information System (INIS)

Saboungi, M.L.; Price, D.L.; Scamehorn, C.; Tosi, M.P.

1990-11-01

We report a neutron diffraction study of the liquid structure of YCl 3 and combine the structural data with macroscopic melting and transport data to contrast the behaviour of this molten salt with those of SrCl 2 , ZnCl 2 and AlCl 3 as prototypes of different melting mechanisms for ionic materials. A novel melting mechanism for trivalent metal chlorides, leading to a loose disordered network of edge-sharing octahedral units in the liquid phase, is thereby established. The various melting behaviours are related to bonding character with the help of Pettifor's phenomenological chemical scale. (author). 25 refs, 4 figs, 3 tabs

Accelerator molten-salt breeder reactor

International Nuclear Information System (INIS)

Furukawa, Kazuo; Kuroi, Hideo; Kato, Yoshio; Oomichi, Toshihiko.

1979-01-01

Purpose: To obtain fission products and to transmute transuranium elements and other radioactive wastes by the use of Accelerator Molten-Salt Breeder Reactor. Constitution: Beams from an accelerator pipe at one end of a target vessel is injected through a window into target molten salts filled inside of the target vessel. The target molten salts are subjected to pump recycling or spontaneous convection while forcively cooled by blanket molten salts in an outer vessel. Then, energy is recovered from the blanket molten salts or the target molten salts at high temperatures through electric power generation or the like. Those salts containing such as thorium 232 and uranium 238 are used as the blanket molten salts so that fission products may be produced by neutrons generated in the target molten salts. PbCl 2 -PbF 2 and LiF-BeF 2 -ThF 4 can be used as the target molten salts and as the blanket molten salts respectively. (Seki, T.)

Electrochemical reduction of cerium oxides in molten salts

International Nuclear Information System (INIS)

Claux, B.; Serp, J.; Fouletier, J.

2011-01-01

This brief article describes a pyrochemical process that is used by CEA to turn actinide oxides into metal actinides. This process is applied to Cerium oxides (CeO 2 ) that simulate actinide oxides well chemically as cerium belongs to the lanthanide family. The process is in fact an electrolysis of cerium oxide in a bath of molten calcium chloride salt whose temperature is between 800 and 900 Celsius degrees. At those temperatures calcium chloride becomes a ionic liquid (Ca 2+ and Cl - ) that is a good electrical conductor and is particularly well-adapted as solvent to an electrolytic process. The electrolysis current allows the transformation of solvent Ca 2+ ions into metal calcium which, in turn, can reduce cerium oxide into metal cerium through chromatically. Experimental data shows the reduction of up to 90% of 10 g samples of CeO 2 in a 6 hour long electrolysis while the best reduction rate ever known was 80% so far. This result is all the more promising that cerium oxides are more difficult to reduce than actinide oxides from the thermodynamical perspective

Study of the reaction between Uranium(III) and Lanthanide oxide by using the UV-VIS spectrophotometer

International Nuclear Information System (INIS)

Kim, Tack-Jin; Cho, Young-Hwan; Choi, In-Kyu; Choi, Kwang-Soon; Jee, Kwang-Yong

2006-01-01

Recently, ionic melts have become attractive reaction media in many fields. Molten salt based electrochemical processes have been proposed as a promising method for future nuclear programs and more specifically for spent fuel processing. Molten alkaline chloride based melts are considered as a promising reaction media. For this, it is interesting to understand the chemical nature of the actinides and lanthanides in high-temperature melt. Some spectroscopy provides essential information on the exact nature of f-block elements LiCl-KCl melt system. The knowledge on the basic chemical properties of these lanthanide oxides and U(III) in molten salt media is essential for developing suitable processes. However, few studies have been reported until now on the interaction between U metal and lanthanide oxides in LiCl-KCl melt. So, we studied the interaction between U(III) and Ln(III) by using the UV-VIS spectra. UV-vis spectrometry is a strong analytical technique for characterizing chemical species and their behavior in molten salt

Fundamental study on decontamination of wastes contaminated by uranium fluorides by using ionic liquids - dissolution and electrochemistry of uranium in 1-butyl-3-methylimidazolium chloride

International Nuclear Information System (INIS)

Noriko Asanuma; Yusuke Ohhashi; Yukio Wada; Masayuki Harada; Yasuhisa Ikeda

2008-01-01

Treatment method for wastes contaminated uranium fluorides by using ionic liquids as media of pyrochemical process instead of alkali metal chloride molten salts was proposed. In this method, uranium fluorides such as UF 4 or NaF adsorbing UF 6 are dissolved in 1-butyl-3-methylimidazolium chloride (BMICl) and dissolved uranium species are recovered as deposits by electrochemical reduction. Under the atmospheric condition, UF 4 was completely dissolved in BMICl at 100 deg. C. UV-vis absorption spectra of the sample solution indicated that main species of uranium are U(VI) and a part of uranium exists as U(IV). Chemical form of uranium in the NaF adsorbents is Na 3 UO 2 F 5 . Therefore, it was immediately dissolved to BMICl. However, complete dissolution was not achieved. Cyclic voltammetry of the solutions prepared by dissolution experiments was performed. Redox properties of uranium species in each sample were irreversible. It was assigned to reduction of U(VI) to U(IV). As a result of preliminary bulk electrolysis, it was expected that reduction products are deposited on the carbon cathode. (authors)

Study into complexing of anhydrous uranyl chloride with organic o-bases in nonaqueous media. Interaction with aliphatic sulfoxides

Energy Technology Data Exchange (ETDEWEB)

Kobets, L V; Buchikhin, E P; Klyshevich, R P; Belyachis, G F

1982-01-01

The methods of spectrophotometry, conductometry and calorimetry have been used to investigate interaction of uranyl chloride with dimethyl, diamil, dioctyl sulfoxides in the nonaqueous acetone media. Existence of complexes with 1:1, 1:2, 1:3 composition for dimethyl sulfoxide and with 1:1, 1:2 composition for diamil-, dioctyl sulfoxides is revealed. The constants of formation and dissociation of these complexes are calculated; the enthalpies of their formation in acetone are determined.

Study into complexing of anhydrous uranyl chloride with organic o-bases in nonaqueous media. Interaction with aliphatic sulfoxides

International Nuclear Information System (INIS)

Kobets, L.V.; Buchikhin, E.P.; Klyshevich, R.P.; Belyachis, G.F.

1982-01-01

The methods of spectrophotometry, conductometry and calorimetry have been used to investigate interaction of uranyl chloride with dimethyl, diamil, dioctyl sulfoxides in the nonaqueous acetone media. Existence of complexes with 1:1, 1:2, 1:3 composition for dimethyl sulfoxide and with 1:1, 1:2 composition for diamil-, dioctyl sulfoxides is revealed. The constants of formation and dissociation of these complexes are calculated; the enthalpies of their formation in acetone are determined

Electrochemistry of thulium on inert electrodes and electrochemical formation of a Tm-Al alloy from molten chlorides

International Nuclear Information System (INIS)

Castrillejo, Y.; Fernandez, P.; Bermejo, M.R.; Barrado, E.; Martinez, A.M.

2009-01-01

The electrochemical behaviour of TmCl 3 solutions was studied in the eutectic LiCl-KCl in the temperature range 673-823 K using inert and reactive electrodes, i.e. W and Al, respectively. On an inert electrode, Tm(III) ions are reduced to metallic thulium through two consecutive steps: Tm(III) + 1e ↔ Tm(II) and Tm(II) + 2e ↔ Tm(0) The electroreduction of Tm(III) to Tm(II) was found to be quasi-reversible. The intrinsic rate constant of charge transfer, k 0 , as well as of the charge transfer coefficient, α, have been calculated by simulation of the cyclic voltammograms and logarithmic analysis of the convoluted curves. Electrocrystallization of thulium plays an important role in the electrodeposition process, being the nucleation mode affected by temperature. The diffusion coefficients of Tm(III) and Tm(II) ions have been found to be equal. The validity of the Arrhenius law was verified by plotting the variation of the logarithm of the diffusion coefficients vs. 1/T. The electrode reactions of Tm(III) solutions at an Al electrode were also investigated. The results showed that for the extraction of thulium from molten chlorides, the use of a reactive electrode made of aluminium leading to Al-Tm alloys seems to be a pertinent route. Potentiometric titrations of Tm(III) solutions with oxide donors, using a ytria stabilized zirconia electrode 'YSZE' as a pO 2- indicator electrode, have shown the formation of thulium oxychloride and thulium oxide and their corresponding solubility products have been determined at 723 K (pk s (TmOCl) = 8.0 ± 0.3 pk s (Tm 2 O 3 ) = 18.8 ± 0.7).

Analysis of an HVAC system for the molten cuprous chloride pouring operation in an industrial hydrogen production facility

Energy Technology Data Exchange (ETDEWEB)

Ghandehariun, S.; Talimi, M.; Rosen, M.A.; Naterer, G.F. [University of Ontario Inst. of Technology, Oshawa, ON (Canada). Faculty of Engineering and Applied Science

2010-07-01

Hydrogen can be produced by thermochemical water decomposition from various heat sources. The copper-chlorine (Cu-Cl) cycle is a potential future cycle that could be linked with nuclear reactors to thermally decompose water into oxygen and hydrogen, through intermediate copper and chlorine compounds. Heat is transferred between various processes. Effective heat recovery from the molten CuCl within the cycle is important for achieving high efficiency. This paper described the fundamentals of a preliminary HVAC system design for the molten CuCl pouring operation in an industrial facility, and the use of air cleaning devices to remove contaminants before discharge to the outdoor air. Heat recovery from molten CuCl involves calculating duct diameters to provide the desired duct air velocity through the system. The fan size is determined by evaluating the static pressure. An adequate supply of make-up air must be provided to replace the air exhausted through the ventilation system. This paper described the economics of the ventilation system as well as ways to protect employee health and minimize the costs associated with exhaust ventilation. 20 refs., 1 tab., 5 figs.

R and D of On-line Reprocessing Technology for Molten-Salt Reactor Systems

International Nuclear Information System (INIS)

Uhlir, Jan; Tulackova, Radka; Chuchvalcova Bimova, Karolina

2006-01-01

The Molten Salt Reactor (MSR) represents one of promising future nuclear reactor concept included in the Generation IV reactors family. The reactor can be operated as the thorium breeder or as the actinide transmuter. However, the future deployment of Molten-Salt Reactors will be significantly dependent on the successful mastering of advanced reprocessing technologies dedicated to their fuel cycle. Here the on-line reprocessing technology connected with the fuel circuit of MSR is of special importance because the reactor cannot be operated for a long run without the fuel salt clean-up. Generally, main MSR reprocessing technologies are pyrochemical, majority of them are fluoride technologies. The proposed flow-sheets of MSR on-line reprocessing are based on a combination of molten-salt / liquid metal extraction and electro-separation processes, which can be added to the gas extraction process already verified during the MSRE project in ORNL. The crucial separation method proposed for partitioning of actinides from fission products is based on successive Anodic dissolution and Cathodic deposition processes in molten fluoride media. (authors)

Some Elements of Equilibrium Diagrams for Systems of Iron with Water above 100 deg C and with Simple Chloride, Carbonate and Sulfate Melts

Energy Technology Data Exchange (ETDEWEB)

Lewis, Derek

1971-05-15

Some aspects of molten salts relevant to the nuclear power industry are discussed briefly and an approach is presented to the theoretical description of the electrochemical thermodynamics of corrosion, mass-transport and deposition processes in power-plant working on the water-cycle, and in homogenous molten-salt reactors. Diagrams are introduced, based on the parameter pe instead of the usual redox potential, that are useful for illustrating equilibrium data for aqueous systems at elevated temperatures and for molten salts. Systems including iron in water and in the eutectic mixtures of lithium and sodium chloride, carbonate and sulfate, are taken as examples

Some Elements of Equilibrium Diagrams for Systems of Iron with Water above 100 deg C and with Simple Chloride, Carbonate and Sulfate Melts

International Nuclear Information System (INIS)

Lewis, Derek

1971-05-01

Some aspects of molten salts relevant to the nuclear power industry are discussed briefly and an approach is presented to the theoretical description of the electrochemical thermodynamics of corrosion, mass-transport and deposition processes in power-plant working on the water-cycle, and in homogenous molten-salt reactors. Diagrams are introduced, based on the parameter pe instead of the usual redox potential, that are useful for illustrating equilibrium data for aqueous systems at elevated temperatures and for molten salts. Systems including iron in water and in the eutectic mixtures of lithium and sodium chloride, carbonate and sulfate, are taken as examples

Wall heat transfer coefficient in a molten salt bubble column: testing the experimental setup

CSIR Research Space (South Africa)

Skosana, PJ

2014-10-01

Full Text Available reactors that are highly exothermic or endothermic. This paper presents the design and operation of experimental setup used for measurement of the heat transfer coefficient in molten salt media. The experimental setup was operated with tap water, heat...

Molten salt breeder reactor

International Nuclear Information System (INIS)

1977-01-01

MSBR Study Group formed in October 1974 has studied molten salt breeder reactor and its various aspects. Usage of a molten salt fuel, extremely interesting as reactor chemistry, is a great feature to MSBR; there is no need for separate fuel making, reprocessing, waste storage facilities. The group studied the following, and these results are presented: molten salt technology, molten salt fuel chemistry and reprocessing, reactor characteristics, economy, reactor structural materials, etc. (Mori, K.)

Determination of the Optimum Conditions for Leaching of Zinc Cathode Melting Furnace Slag in Ammonium Chloride Media

Science.gov (United States)

Behnajady, Bahram; Babaeidehkordi, Amin; Moghaddam, Javad

2014-04-01

This research is part of a continuing effort to leach zinc from zinc cathode melting furnace slags (ZCMFSs) to produce zinc oxide. The slag with an assay of 68.05 pct Zn was used in ammonium chloride leaching for zinc extraction. In this paper, the effects of influential factors on extraction efficiency of Zn from a ZCMFS were investigated. The Taguchi's method based on orthogonal array (OA) design has been used to arrange the experimental runs in order to maximize zinc extraction from a slag. The softwares named Excel and Design-Expert 7 have been used to design experiments and subsequent analysis. OA L 25 (55) consisting of five parameters, each with five levels, was employed to evaluate the effects of reaction time ( t = 10, 30, 50, 70, 90 minutes), reaction temperature [ T = 313, 323, 333, 343, 353 (40, 50, 60, 70, 80) K (°C)], pulp density ( S/ L = 20, 40, 60, 80, 100 g/L), stirring speed ( R = 300, 400, 500, 600, 700 rpm), and ammonium chloride concentration ( C = 10, 15, 20, 25, 30 pctwt), on zinc extraction percent. Statistical analysis, ANOVA, was also employed to determine the relationship between experimental conditions and yield levels. The results showed that the significant parameters affecting leaching of slag were ammonium chloride concentration and pulp density, and increasing pulp density reduced leaching efficiency of zinc. However, increasing ammonium chloride concentration promoted the extraction of zinc. The optimum conditions for this study were found to be t 4: 70 minutes, T 5: 353 K (80 °C), ( S/ L)2: 40 g/L, R 3: 500 rpm, and C 4: 25 pctwt. Under these conditions, the dissolution percentage of Zn in ammonium chloride media was 94.61 pct.

Reactions of metal oxides with molten NaPO3 + NaCl mixtures

International Nuclear Information System (INIS)

Kovarskaya, E.N.; Mityakhina, V.S.; Rodionov, Yu.I.; Silin, M.Yu.

1988-01-01

We consider the dissolution mechanism for iron (III), europium(III), and tin(IV) oxides in molten NaPO 3 + NaCl that are responsible for the peak solubilities. We chose Fe 2 O 3 as the basic material since this occurs in large amounts around damaged metal structures in rock salt mines in a proposed zone for storing vitrified radioactive wastes. Solubility measurement and paper chromatography show that Fe 2 O 3 dissolves in molten NaPO 3 + NaCl in air by reaction with the solvent to give double iron and sodium diphosphates and monophosphates in accordance with the initial solution-in-the-melt composition, the degree of equilibration, and the temperature. The elevated solubilities for initial NaCl contents close to 30 mole % are due to sodium triphosphates and tricyclophosphates present in these melts. Moessbauer spectroscopy confirms that double iron, europium and tin diphosphates and monophosphates containing sodium occur in these chloride-polyphosphate melts

Kinetic studies on the removal of fission products from molten salt using Zeolite-4A. Contributed Paper RD-15

International Nuclear Information System (INIS)

Shafi, Suheel; Prabhakara Reddy, B.; Perumal, S.V.; Nagarajan, K.

2014-01-01

Molten salt electrorefining process is one of the nonaqueous processes, being developed for reprocessing metallic spent fuel. This process uses liquid metals and molten salts and is operated at elevated temperatures. In the electro-refining process, the spent fuel is used as the anode of the electro-refiner and the actinide elements in the spent fuel are electrotransported from the anode through the molten salt electrolyte onto a suitable cathode where they are collected as metals in pure form. After some batches are processed, chlorides of fission products such as alkali, alkaline earth and rare earth metals accumulate in the electrolyte salt. The accumulated FPs in the salt will be removed by adsorption/ion-exchange by using zeolite columns. Hence, kinetic studies on the adsorption of Cs, Ba which are some of the major FP products in LiCI-KCI eutectic, have been carried out

Development of fuel cycle technology for molten-salt reactor systems

International Nuclear Information System (INIS)

Uhlir, J.

2006-01-01

Full text: Full text: The Molten-Salt Reactor (MSR) represents one of promising advanced reactor type assigned to the GEN IV reactor systems. It can be operated either as thorium breeder within the Th -133U fuel cycle or as actinide transmuter incinerating transuranium fuel. Essentially the main advantage of MSR comes out from the prerequisite, that this reactor type should be directly connected with the 'on-line' reprocessing of circulating liquid (molten-salt) fuel. This principle should allow very effective extraction of freshly constituted fissile material (233U). Besides, the on-line fuel salt clean up is necessary within a long run to keep the reactor in operation. As a matter of principle, it permits to clear away typical reactor poisons like xenon, krypton, lanthanides etc. and possibly also other products of burned plutonium and transmuted minor actinides. The fuel salt clean up technology should be linked with the fresh MSR fuel processing to continuously refill the new fuel (thorium or transuranics) into the reactor system. On the other hand, the technologies of fresh transuranium molten-salt fuel processing from the current LWR spent fuel and of the on-line reprocessing of MSR fuel represent two killing points of the whole MSR technology, which have to be successfully solved before MSR deployment in the future. There are three main pyrochemical partitioning techniques proposed for processing and/or reprocessing of MSR fuel: Fluoride volatilization processes, Molten salt / liquid metal extraction processes and Electrochemical separation processes. Two of them - Fluoride Volatility Method and Electrochemical separation process from fluoride media are under development in the Nuclear Research Institute Rez pic. R and D in the field of Fluoride Volatility Method is concentrated to the development and verification of experimental semi-pilot technology for LWR spent fuel reprocessing, which may result in a product the form and composition of which might be

Dechlorination and Stabilization of Molten Salt Waste by Using xSiO2-yAl2O3- zP2O5 at Melting Temperature

International Nuclear Information System (INIS)

Park, Hwanseo; Kim, Intae; Kim, Hwanyoung; Kim, Joonhyung

2007-01-01

Molten salt waste, which is generated from the pyroprocess to separate uranium and trans-uranium elements from spent nuclear fuel, has been interested to researchers in the radioactive waste management. For its final disposal, direct immobilization into a suitable host matrix or indirect solidification by other chemical routes requires the control of chlorides and its volatility since molten salt wastes mainly consist of volatile metal chlorides. Glass-bonded sodalite (Na 6 M 2 Al 6 Si 6 O 24 Cl 2 , 1-5) suggested by Argonne National Laboratory (ANL), to the present, could be a practical solution to the immobilization of this waste, where waste form can be fabricated at about 915 .deg., lower than the melting temperature of many borosilicate glasses ( -1150 .deg.). A wet dechlorination to oxides or a thermal conversion into borate glass was suggested to remove Cl from salt waste (6-7) and it seemed that the preference of radionuclides for the intended chemical conversions or immobilizations described above could be hardly accomplished or failed, except the phosphate precipitation method suggested by Volkovich and his co-workers (8). Our research group suggested a novel method to treat molten salt waste, named GRSS (Gel-Route Stabilization/Solidification) using Si-P-Al system as a gel-forming system. This showed little vaporization during high temperature process and good leach resistance on Cs and Sr. As another method, this study suggested a method to stabilize molten salt wastes by using xSiO 2 -yAl 2 O 3 - zP 2 O 5 material. GRSS method is considered as a 'reaction system' to completely convert salt waste into stable product while the inorganic material used in this study is a stabilizer for salt wastes. Using this material, this study investigated the reactivity on different metal chlorides, thermal stability, leach-resistance and etc

Stabilization/Solidification of radioactive molten salt waste by using xSiO{sub 2}-yAl{sub 2}O{sub 3}-zP{sub 2}O{sub 5} material

Energy Technology Data Exchange (ETDEWEB)

Hwan-Seo Park; In-Tae Kim; Yong-Zun Cho; Seong-Won Park; Eung-Ho Kim [Korea Atomic Energy Research Institute: 150 Deokjin-dong, Yuseong, Daejeon, 305-353 (Korea, Republic of)

2008-07-01

Molten salt waste generated from the electro metallurgical process to recover uranium and transuranic elements is considered as one of problematic wastes to be difficult to immobilize into a durable for final disposal. As an alternative, this study suggested a new method performed at molten state, where dechlorination was achieved with a new inorganic material containing SiO{sub 2}, Al{sub 2}O{sub 3} and P{sub 2}O{sub 5} (SAP). The SAP as a reactive material to molten salt was prepared by a conventional sol-gel process. The prepared SAPs were reacted with each metal chloride, LiCl, CsCl, SrCl{sub 2} and CeCl{sub 3} at 650 deg. C for 6 hours and also were reacted with simulated salt waste consisting of 90 wt% LiCl, 6.8 wt% CsCl and 3.2 wt% SrCl{sub 2} at different waste loading. All the reactions were carried out in oxidative atmosphere and metal chlorides were effectively converted into stable products under a reasonable reaction ratio.

Formation of titanium diboride coatings during the anodic polarization of titanium in a chloride melt with a low boron oxide content

Science.gov (United States)

Elshina, L. A.; Malkov, V. B.; Molchanova, N. G.

2015-02-01

The corrosion-electrochemical behavior of titanium in a molten eutectic mixture of cesium and sodium chlorides containing up to 1 wt % boron oxide is studied in the temperature range 810-870 K in an argon atmosphere. The potential, the current, and the rate of titanium corrosion are determined. The optimum conditions of forming a dense continuous titanium diboride coating on titanium with high adhesion to the metallic base are found for the anodic activation of titanium in the molten electrolyte under study.

Reinforcement corrosion in alkaline chloride media with reduced oxygen concentrations

International Nuclear Information System (INIS)

Andrade, C.; Fullea, J.; Toro, L.; Martinez, I.; Rebolledo, N.

2013-01-01

It is commonly considered that the corrosion of steel in concrete is controlled by the oxygen content of the pore solution and there are service life models that relate the corrosion rate to the amount of oxygen. It is also commonly believed that in water saturated conditions the oxygen content in the pores is negligible and that underwater there is no risk of depassivation and the corrosion rate is very low. However, the available data on corrosion rates in immersed conditions do not indicate such performance; on the contrary corrosion develops when sufficient chloride reaches the reinforcement. In the present paper, results are presented for tests performed in alkaline chloride solutions that were purged with nitrogen to reduce the oxygen content. The results indicate that at very low oxygen concentrations, corrosion may develop in the presence of chlorides. The presence or absence of corrosion is influenced by the amount of chloride, the corrosion potential and the steel surface condition. (authors)

The nonmetal-metal transition in solutions of metals in molten salts

International Nuclear Information System (INIS)

Tosi, M.P.

1997-04-01

Solutions of metals in molten salts present a rich phenomenology: localization of electrons in disordered ionic media, activated electron transport increasing with metal concentration towards a nonmetal-metal (NM-M) transition, and liquid-liquid phase separation. A brief review of progress in the study of these systems is given in this article, with main focus on the NM-M transition. After recalling the known NM-M behaviour of the component elements in the case of expanded fluid alkali metals and mercury and of solid halogens under pressure, the article focuses on liquid metal - molten salt solutions and traces the different NM-M behaviours of the alkalis in their halides and of metals added to polyvalent metal halides. (author). 51 refs, 2 figs

The Limiting Phenomena at the Anode of the Electrowinning of Zinc from Zinc Chloride in a Molten Chloride Electrolyte

NARCIS (Netherlands)

Lans, S.C.

2004-01-01

The objective of this research is to investigate the possibilities and technological viability for the electrowinning of zinc from zinc chloride. This research contributes to development of an alternative process, because it provides: ⢠A clear understanding and overview of the present zinc

Co-ordination of heterovalent cation impurities in molten salts

International Nuclear Information System (INIS)

Andreoni, W.; Rovere, M.; Tosi, M.P.

1982-01-01

The local liquid structure around heterovalent cation impurities in molten chlorides is discussed in relation to spectroscopic data on solutions of transition metal ions. A tightly packed, low co-ordination shell is shown to be favoured by Coulomb ionic interactions for physically reasonable values of the size of the impurity. A competition between these forces and ''crystal field'' interactions favouring octahedral co-ordination is thus to be expected for many transition metal ions, as suggested by Gruen and McBeth. The transition observed for some transition metal ions from higher to lower co-ordination with increasing temperature is attributed primarily to entropy differences, that are roughly estimated in a solid-like model. (author)

Fluorescence Resonance Energy Transfer of the Tb(III)-Nd(III) Binary System in Molten LiCl-KCl Eutectic Salt

Energy Technology Data Exchange (ETDEWEB)

Kim, B. Y. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Yun, J. I. [KAIST, Daejeon (Korea, Republic of)

2015-05-15

The lanthanides act as a neutron poison in nuclear reactor with large neutron absorption cross section. For that reason, very low amount of lanthanides is required in the recovered U/TRU ingot product from pyrochemical process. In view of that, the investigation of thermodynamic properties and chemical behaviors of lanthanides in molten chloride salt are necessary to estimate the performance efficiency of pyrochemical process. However, there are uncertainties about knowledge and understanding of basic mechanisms in pyrochemical process, such as chemical speciation and redox behaviors due to the lack of in-situ monitoring methods for high temperature molten salt. The spectroscopic analysis is one of the probable techniques for in-situ qualitative and quantitative analysis. Recently, a few fluorescence spectroscopic measurements on single lanthanide element in molten LiCl-KCl eutectic have been investigated. The fluorescence intensity and the fluorescence lifetime of Tb(III) were decreased as increasing the concentration of Nd(III), demonstrating collisional quenching between donor ions and acceptor ions. The Forster distance (..0) of Tb(III)-Nd(III) binary system in molten LiCl-KCl eutectic was determined in the specific range of .... (0.1-1.0) and .. (1.387-1.496)

Pitting morphologies of zirconium base alloys in aqueous and non aqueous chloride media

International Nuclear Information System (INIS)

Palit, G.C.; Gadiyar, H.S.

1988-01-01

Pitting morphology of zirconium and Zr-Cr alloys in aqueous chloride and nonaqueous methanol + 0.4 per cent HCl solution was investigated and observed to follow different modes in these two environments. While in aqueous chloride solution pitting was transgranular and randomly oriented, in methanol-chloride solution pits were observed to initiate and propagate along the grain boundaries. In aqueous chloride solution very irregular and sponge like zirconium metal was formed inside the pit while in methanol-chloride solution the pits were crystallographic in nature. Optical microscopy has revealed that pits preferentially initiate and propagate along scratch line in aqueous chloride solution, but such was not the case in nonaqueous methanol-chloride solution. The nature and the mechanism operating in the catastropic failure of these materials are investigated. (author). 10 refs., 11 figs

Molten material-containing vessel

International Nuclear Information System (INIS)

Akagawa, Katsuhiko

1998-01-01

The molten material-containing vessel of the present invention comprises a vessel main body having an entrance opened at the upper end, a lid for closing the entrance, an outer tube having an upper end disposed at the lower surface of the lid, extended downwardly and having an closed lower end and an inner tube disposed coaxially with the outer tube. When a molten material is charged from the entrance to the inside of the vessel main body of the molten material-containing vessel and the entrance is closed by the lid, the outer tube and the inner tube are buried in the molten material in the vessel main body, accordingly, a fluid having its temperature elevated by absorption of the heat of the molten material rises along the inner circumferential surface of the outer tube, abuts against the lower surface of the lid and cooled by exchanging heat with the lid and forms a circulating flow. Since the heat in the molten material is continuously absorbed by the fluid, transferred to the lid and released from the lid to the atmospheric air, heat releasing efficiency can be improved compared with conventional cases. (N.H.)

Interaction of steel, titanium and zirconium with melted chlorides containing copper and zinc

International Nuclear Information System (INIS)

Ozeryanaya, I.N.; Manukhina, T.I.; Shibanov, B.S.

1976-01-01

Cu and Zn coatings were obtained by contact displacement of their molten chlorides. Cu was deposited on Kh18N10T stainless steel, and Zn was deposited on Ti or Zr at 400-550 0 . Cu was displaced from the electrolyte by all components in the steel. A smooth coating exhibited high adhesion. According to metallography there was a transition layer of a Ni-Cr solid solution between the surface Cu layer and steel. With electronegetiol Ti and Zr, contact deposition of Zn or Cu from chloride melts was possible. The coatings were multilayer and exhibited adequate adhesion. The coating consisted of an intermetallic compound of Ti or Zr with Zn

Molten fluoride fuel salt chemistry

International Nuclear Information System (INIS)

Toth, L.M.; Del Cul, G.D.; Dai, S.; Metcalf, D.H.

1995-01-01

The chemistry of molten fluorides is traced from their development as fuels in the Molten Salt Reactor Experiment with important factors in their selection being discussed. Key chemical characteristics such as solubility, redox behavior, and chemical activity are explained as they relate to the behavior of molten fluoride fuel systems. Development requirements for fitting the current state of the chemistry to modern nuclear fuel system are described. It is concluded that while much is known about molten fluoride behavior which can be used effectively to reduce the amount of development required for future systems, some significant molten salt chemical questions must still be addressed. copyright American Institute of Physics 1995

Symbiotic molten-salt systems coupled with accelerator molten-salt breeder (AMSB) or inertial-confined fusion hybrid molten-salt breeder (IHMSB) and their comparison

International Nuclear Information System (INIS)

Furukawa, K.

1984-01-01

Two types of breeder systems are proposed. One is the combined system of Accelerator Molten-Salt Breeder (AMSB) and Molten-Salt Converter Reactor (MSCR), and the other is the combined system of Inertial-confined Fusion Hybrid Molten-Salt Breeder (IHMSB) and modified MSCR. Both apply the molten-fluorides and have technically deep relations. AMSB would be much simpler and have already high technical feasibility. This will become economical the Th breeder system having a doubling time shorter than ten years and distributing any size of power stations MSCR. (orig.) [de

Fundamental study on decontamination of wastes contaminated by uranium fluorides by using ionic liquids - dissolution and electrochemistry of uranium in 1-butyl-3-methylimidazolium chloride

Energy Technology Data Exchange (ETDEWEB)

Noriko Asanuma [Department of Energy Science and Engineering, School of Engineering, Tokai University 1117 Kitakaname, Hiratsuka-shi, Kanagawa 259-1292 (Japan); Yusuke Ohhashi; Yukio Wada [Ningyo-toge Environmental Engineering Center, Japan Atomic Energy Agency Kagamino-cho, Tomata-gun, Okayama 708-0698 (Japan); Masayuki Harada; Yasuhisa Ikeda [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology 2-12-1-N1-34 Ookayama, Meguro-ku, Tokyo 152-8550 (Japan)

2008-07-01

Treatment method for wastes contaminated uranium fluorides by using ionic liquids as media of pyrochemical process instead of alkali metal chloride molten salts was proposed. In this method, uranium fluorides such as UF{sub 4} or NaF adsorbing UF{sub 6} are dissolved in 1-butyl-3-methylimidazolium chloride (BMICl) and dissolved uranium species are recovered as deposits by electrochemical reduction. Under the atmospheric condition, UF{sub 4} was completely dissolved in BMICl at 100 deg. C. UV-vis absorption spectra of the sample solution indicated that main species of uranium are U(VI) and a part of uranium exists as U(IV). Chemical form of uranium in the NaF adsorbents is Na{sub 3}UO{sub 2}F{sub 5}. Therefore, it was immediately dissolved to BMICl. However, complete dissolution was not achieved. Cyclic voltammetry of the solutions prepared by dissolution experiments was performed. Redox properties of uranium species in each sample were irreversible. It was assigned to reduction of U(VI) to U(IV). As a result of preliminary bulk electrolysis, it was expected that reduction products are deposited on the carbon cathode. (authors)

Application of the rotating cylinder electrode in molten LiCl-KCl eutectic containing uranium(III)- and magnesium(II)-chloride

Energy Technology Data Exchange (ETDEWEB)

Rappleye, Devin, E-mail: rappleye1@llnl.gov; Simpson, Michael F.

2017-04-15

The application of the rotating cylinder electrode (RCE) to molten LiCl-KCl eutectic mixtures for electroanalytical measurements is presented. This enabled the measurement of the limiting current which was observed to follow a linear trend with the rotational rate raised to 0.64–0.65 power on average, which closely agrees with existing RCE mass-transfer correlations. This is the first publication of electroanalytical RCE measurements in LiCl-KCl eutectic based molten salt mixtures, to our knowledge. These measurements were made in mixtures of molten LiCl-KCl eutectic containing UCl{sub 3} and MgCl{sub 2}. Kinetic parameters were calculated for Mg{sup 2+} in LiCl-KCl eutectic. The exchange current density (i{sub o}) of Mg{sup 2+} deposition varied with mole fraction (x) according to i{sub o}(A cm{sup −2}) = 1.64x{sup 0.689}. The parameters from RCE measurements were also applied in an electrochemical co-deposition model entitled DREP to detect and predict the deposition rate of U and Mg. DREP succeeded in detecting the co-deposition of U and Mg, even when Mg constituted less than 0.5 wt% of the deposit.

Coulometric thermometric titration of halides in molten calcium nitrate tetrahydrate.

Science.gov (United States)

Zsigrai, I J; Bartusz, D B

1983-01-01

A method for coulometric thermometric precipitation titrations of chloride, bromide and iodide in molten calcium nitrate tetrahydrate at 55 degrees with coulometrically generated silver ions has been developed. The change in temperature during the titration is followed with the aid of a thermistor bridge coupled to a recorder. To minimize the temperature effect of the passage of current through the melt, two thermistors are connected in opposition in the bridge, with one in the anodic and the other in the cathodic cell compartment. Amounts of 62-80 mumole of halide have been determined with relative error below 0.4% and relative standard deviation less than 2.7%. The relative error in determination of 40 mumole of iodide was + 2%.

Partial structures in molten AgBr

Energy Technology Data Exchange (ETDEWEB)

Ueno, Hiroki [Department of Condensed Matter Chemistry and Physics, Faculty of Sciences, Kyushu University, 4-2-1 Ropponmatsu, Chuo-ku, Fukuoka 810-8560 (Japan)], E-mail: ueno@gemini.rc.kyushu-u.ac.jp; Tahara, Shuta [Faculty of Pharmacy, Niigata University of Pharmacy and Applied Life Science, Higashijima, Akiha-ku, Niigata 956-8603 (Japan); Kawakita, Yukinobu [Department of Physics, Faculty of Sciences, Kyushu University, 4-2-1 Ropponmatsu, Chuo-ku, Fukuoka 810-8560 (Japan); Kohara, Shinji [Research and Utilization Division, Japan Synchrotron Radiation Research Institute (JASRI, SPring-8), 1-1-1 Koto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Takeda, Shin' ichi [Department of Physics, Faculty of Sciences, Kyushu University, 4-2-1 Ropponmatsu, Chuo-ku, Fukuoka 810-8560 (Japan)

2009-02-21

The structure of molten AgBr has been studied by means of neutron and X-ray diffractions with the aid of structural modeling. It is confirmed that the Ag-Ag correlation has a small but well-defined first peak in the partial pair distribution function whose tail penetrates into the Ag-Br nearest neighbor distribution. This feature on the Ag-Ag correlation is intermediate between that of molten AgCl (non-superionic melt) and that of molten AgI (superionic melt). The analysis of Br-Ag-Br bond angle reveals that molten AgBr preserves a rocksalt type local ordering in the solid phase, suggesting that molten AgBr is clarified as non-superionic melt like molten AgCl.

Combined system of accelerator molten-salt breeder (AMSB) apd molten-salt converter reactor (MSCR)

International Nuclear Information System (INIS)

Furukawa, K.; Kato, Y.; Ohmichi, T.; Ohno, H.

1983-01-01

A design and research program is discUssed of the development of accelerator molten-salt breeder (AMSB) consisting of a proton accelerator and a molten fluoride target. The target simultaneously serves as a blanket for fissionable material prodUction. An addition of some amoUnt of fissile nuclides to a melt expands the AMSB potentialities as the fissionable material production increases and the energy generation also grows up to the level of self-provision. Besides the blanket salts may be used as nuclear fuel for molten-salt converter reactor (MSCR). The combined AM SB+MSCR system has better parameters as compared to other breeder reactors, molten-salt breeder reactors (MSBR) included

Fundamentals of molten-salt thermal technology

International Nuclear Information System (INIS)

1980-08-01

This book has been published by the Society of Molten-Salt Thermal Technology to publish a part of the achievement of its members. This book is composed of seven chapters. The chapter 1 is Introduction. The chapter 2 explains the physical properties of molten salts, such as thermal behavior, surface tension, viscosity, electrical conductivity and others. The chapter 3 presents the compatibility with construction materials. Corrosion in molten salts, the electrochemical behavior of fluoride ions on carbon electrodes in fluoride melts, the behaviors of hastelloy N and metals in melts are items of this chapter. The equipments and instruments for molten salts are described in chapter 4. The heat transfer in molten salts is discussed in chapter 5. The chapter 6 explains the application of molten salt technology. The molten salt technology can be applied not only to thermal engineering and energy engineering but also to chemical and nuclear engineerings, and the technical fundamentals, current development status, technical problems and the perspective for the future are outlined. The chapter 7 is the summary of this book. The commercialization of molten salt power reactors is discussed at the end of this book. (Kato, T.)

Gases in molten salts

CERN Document Server

Tomkins, RPT

1991-01-01

This volume contains tabulated collections and critical evaluations of original data for the solubility of gases in molten salts, gathered from chemical literature through to the end of 1989. Within the volume, material is arranged according to the individual gas. The gases include hydrogen halides, inert gases, oxygen, nitrogen, hydrogen, carbon dioxide, water vapor and halogens. The molten salts consist of single salts, binary mixtures and multicomponent systems. Included also, is a special section on the solubility of gases in molten silicate systems, focussing on slags and fluxes.

Fast Spectrum Molten Salt Reactor Options

Energy Technology Data Exchange (ETDEWEB)

Gehin, Jess C [ORNL; Holcomb, David Eugene [ORNL; Flanagan, George F [ORNL; Patton, Bruce W [ORNL; Howard, Rob L [ORNL; Harrison, Thomas J [ORNL

2011-07-01

During 2010, fast-spectrum molten-salt reactors (FS-MSRs) were selected as a transformational reactor concept for light-water reactor (LWR)-derived heavy actinide disposition by the Department of Energy-Nuclear Energy Advanced Reactor Concepts (ARC) program and were the subject of a preliminary scoping investigation. Much of the reactor description information presented in this report derives from the preliminary studies performed for the ARC project. This report, however, has a somewhat broader scope-providing a conceptual overview of the characteristics and design options for FS-MSRs. It does not present in-depth evaluation of any FS-MSR particular characteristic, but instead provides an overview of all of the major reactor system technologies and characteristics, including the technology developments since the end of major molten salt reactor (MSR) development efforts in the 1970s. This report first presents a historical overview of the FS-MSR technology and describes the innovative characteristics of an FS-MSR. Next, it provides an overview of possible reactor configurations. The following design features/options and performance considerations are described including: (1) reactor salt options-both chloride and fluoride salts; (2) the impact of changing the carrier salt and actinide concentration on conversion ratio; (3) the conversion ratio; (4) an overview of the fuel salt chemical processing; (5) potential power cycles and hydrogen production options; and (6) overview of the performance characteristics of FS-MSRs, including general comparative metrics with LWRs. The conceptual-level evaluation includes resource sustainability, proliferation resistance, economics, and safety. The report concludes with a description of the work necessary to begin more detailed evaluation of FS-MSRs as a realistic reactor and fuel cycle option.

Molten salt reactors

International Nuclear Information System (INIS)

Bouchter, J.C.; Dufour, P.; Guidez, J.; Simon, N.; Renault, C.

2014-01-01

Molten salt reactors are one of the 6 concepts retained for the 4. generation of nuclear reactors. The principle of this reactor is very innovative: the nuclear fuel is dissolved in the coolant which allows the online reprocessing of the fuel and the online recovery of the fission products. A small prototype: the Molten Salt Reactor Experiment (MSRE - 8 MWt) was operating a few years in the sixties in the USA. The passage towards a fast reactor by the suppression of the graphite moderator leads to the concept of Molten Salt Fast Reactor (MSFR) which is presently studied through different European projects such as MOST, ALISIA and EVOL. Worldwide the main topics of research are: the adequate materials resisting to the high level of corrosiveness of the molten salts, fuel salt reprocessing, the 3-side coupling between neutron transport, thermohydraulics and thermo-chemistry, the management of the changing chemical composition of the salt, the enrichment of lithium with Li 7 in the case of the use of lithium fluoride salt and the use of MSFR using U 233 fuel (thorium cycle). The last part of the article presents a preliminary safety analysis of the MSFR. (A.C.)

Molten salt synthesis of sodium lithium titanium oxide anode material for lithium ion batteries

Energy Technology Data Exchange (ETDEWEB)

Yin, S.Y., E-mail: yshy2004@hotmail.com [College of Environmental and Biological Engineering, Wuhan Technology and Business University, Wuhan 430065 (China); Feng, C.Q. [Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry of Education Key Laboratory for Synthesis and Applications of Organic Functional Molecules, Hubei University, Wuhan 430062 (China); Wu, S.J.; Liu, H.L.; Ke, B.Q. [College of Environmental and Biological Engineering, Wuhan Technology and Business University, Wuhan 430065 (China); Zhang, K.L. [College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China); Chen, D.H. [College of Environmental and Biological Engineering, Wuhan Technology and Business University, Wuhan 430065 (China); Hubei Key Laboratory for Catalysis and Material Science, College of Chemistry and Material Science, South Central University for Nationalities, Wuhan 430074, Hubei (China)

2015-09-05

Highlights: • Na{sub 2}Li{sub 2}Ti{sub 6}O{sub 12} has been successfully synthesized via a molten salt route. • Calcination temperature is an important effect on the component and microstructure of the product. • Pure phase Na{sub 2}Li{sub 2}Ti{sub 6}O{sub 12} could be obtained at 700 °C for 2 h. - Abstract: The sodium lithium titanium oxide with composition Na{sub 2}Li{sub 2}Ti{sub 6}O{sub 14} has been synthesized by a molten salt synthesis method using sodium chloride and potassium chloride mixture as a flux medium. Synthetic variables on the synthesis, such as sintering temperature, sintering time and the amount of lithium carbonate, were intensively investigated. Powder X-ray diffraction and scanning electron microscopy images of the reaction products indicates that pure phase sodium lithium titanium oxide has been obtained at 700 °C, and impure phase sodium hexatitanate with whiskers produced at higher temperature due to lithium evaporative losses. The results of cyclic voltammetry and discharge–charge tests demonstrate that the synthesized products prepared at various temperatures exhibited electrochemical diversities due to the difference of the components. And the sample obtained at 700 °C revealed highly reversible insertion and extraction of Li{sup +} and displayed a single potential plateau at around 1.3 V. The product obtained at 700 °C for 2 h exhibits good cycling properties and retains the specific capacity of 62 mAh g{sup −1} after 500 cycles.

Preparation of complexes of zirconium and hafnium tetrachlorides with phosphorus oxychloride

International Nuclear Information System (INIS)

Snyder, T.S.; Stoltz, R.A.

1989-01-01

This patent describes an improvement in a method for separating hafnium chloride from zirconium chloride using a distillation column, with a hafnium chloride enriched vapor stream taken from the top of the column and a zirconium enriched chloride stream taken from the bottom of the column. The improvement comprising: purifying the zirconium-hafnium chloride in a molten salt purification vessel prior to or after introduction into the distillation column to substantially eliminate iron chloride from the zirconium-hafnium chloride by at least periodically removing iron chloride from the molten salt purification vessel by electrochemically plating iron onto an electrode in the molten salt purification vessel. The molten salt in the molten salt purification vessel consisting essentially of a mixture of chlorides selected from the group consisting of alkali metals, alkaline earth metals, zirconium, hafnium, aluminum, manganese, and zinc

Molten fuel studies at Winfrith

International Nuclear Information System (INIS)

Edwards, A.J.; Knowles, J.B.; Tattersall, R.B.

1988-01-01

This report describes the experimental facilities available for molten fuel studies at Winfrith. These include a large facility capable of testing components at full LMFBR subassembly scale and also a high pressure facility for experiments at pressures up to 25 MPa, covering the whole range of temperatures and pressures of interest for the PWR. If the hypothetical accident conditions initiating the release of molten fuel do not produce an explosive transfer of thermal energy on contact of molten fuel with the reactor coolant, then an intermediate rate of heat transfer over several hundred milliseconds may occur. Theoretical work is described which is being carried out to predict the resulting pressurisation and the degree of mechanical loading on the reactor structure. Finally the current programme of molten fuel studies and recent progress are reviewed, and future plans, which are chiefly focussed on the study of thermal interactions between molten fuel and sodium coolant for the LMFBR are outlined. (author)

Sampling device for radioactive molten salt

International Nuclear Information System (INIS)

Shindo, Masato

1998-01-01

The present invention provides a device for accurately sampling molten salts to which various kinds of metals in a molten salt storage tank are mixed for analyzing them during a spent fuel dry type reprocessing. Namely, the device comprises a sampling tube having an opened lower end to be inserted into the radioactive molten salts stored in a tank and keeps reduced pressure from the upper end, and a pressure reducing pipeline having one end connected to the sampling tube and other end connected to an evacuating pump. In this device, the top end of the sampling tube is inserted to a position for sampling the radioactive molten salts (molten salts). The pressure inside the evacuating pipeline connected to the upper portion of the sampling tube is reduced for a while. In this case, the inside of the pressure reducing pipeline is previously evacuated by the evacuating pump so as to keep a predetermined pressure. Since the pressure in the sampling tube is lowered, molten salts are inserted into the sampling tube, the sampling tube is withdrawn, and the molten salts flown in the sampling tube are analyzed. (I.S.)

Dynamic Reference Electrode development for redox potential measurements in fluoride molten salt at high temperature

International Nuclear Information System (INIS)

Durán-Klie, Gabriela; Rodrigues, Davide; Delpech, Sylvie

2016-01-01

Measurement of redox potential in fluoride media is a major problem due to the difficulty to design a reference electrode with high stability, high mechanical resistance and high accuracy. In the frame of molten salt reactor studies, a dynamic reference electrode (DRE) is developed to measure redox potential in fluoride molten salt at high temperature. DRE is based on the in-situ generation of a transient redox system. The choice of the redox couple corresponds to the cathodic limit of the molten salt considered. As a preliminary step, the demonstration of feasibility of generating a DRE was done in LiF-NaF-KF (46.5–11.5–42 mol%) media at 500 °C. In this salt, the reference redox system generated by coulometry at applied current is KF/K, metallic potassium being electrodeposited on a tungsten wire electrode. The validation of the DRE response and the experimental optimization parameters for DRE generation were realized by following the NiF 2 /Ni redox potential evolution as a function of NiF 2 concentration in the fused salt. The current value applied for DRE generation was optimized. It depends on the amount of metallic cations contained in the fused salt and which can be electrochemically reduced simultaneously during the DRE generation. The current corresponding to the DRE generation has to be 4 times greater than the current corresponding to the reduction of the other elements.

Thermal performances of molten salt steam generator

International Nuclear Information System (INIS)

Yuan, Yibo; He, Canming; Lu, Jianfeng; Ding, Jing

2016-01-01

Highlights: • Thermal performances of molten salt steam generator were experimentally studied. • Overall heat transfer coefficient reached maximum with optimal molten salt flow rate. • Energy efficiency first rose and then decreased with salt flow rate and temperature. • Optimal molten salt flow rate and temperature existed for good thermal performance. • High inlet water temperature benefited steam generating rate and energy efficiency. - Abstract: Molten salt steam generator is the key technology for thermal energy conversion from high temperature molten salt to steam, and it is used in solar thermal power station and molten salt reactor. A shell and tube type molten salt steam generator was set up, and its thermal performance and heat transfer mechanism were studied. As a coupling heat transfer process, molten salt steam generation is mainly affected by molten salt convective heat transfer and boiling heat transfer, while its energy efficiency is also affected by the heat loss. As molten salt temperature increased, the energy efficiency first rose with the increase of heat flow absorbed by water/steam, and then slightly decreased for large heat loss as the absorbed heat flow still rising. At very high molten salt temperature, the absorbed heat flow decreased as boiling heat transfer coefficient dropping, and then the energy efficiency quickly dropped. As the inlet water temperature increased, the boiling region in the steam generator remarkably expanded, and then the steam generation rate and energy efficiency both rose with the overall heat transfer coefficient increasing. As the molten salt flow rate increased, the wall temperature rose and the boiling heat transfer coefficient first increased and then decreased according to the boiling curve, so the overall heat transfer coefficient first increased and then decreased, and then the steam generation rate and energy efficiency of steam generator both had maxima.

Selective extraction of palladium with caffeine from acidic chloride media; Sansei enkabutsu yoeki karano kafuein ni yoru parajiumu no sentakuteki chushutsu

Energy Technology Data Exchange (ETDEWEB)

Kaikake, K.; Baba, Y. [Miyazaki University, Miyazaki (Japan). Faculty of Engineering

1999-06-10

In order to examine the possibility of caffeine as an extractant, the extraction of metal ions from acidic chloride media was studied at 298 K using the mixture solvent of chloroform and 2-ethyl-1-hexanol. Caffeine has exhibited a high selectivity for palladium (2) over base metals such as copper (2), nickel (2), and iron (3), and over precious metal such as platinum (4). The stoichiometric relation in the extraction of palladium (2) with caffeine was elucidated by examining the effects of chloride ion, hydrogen ion, and caffeine concentrations on its extractability. In addition, palladium (2) was found to be extracted selectively with caffeine from the mixture containing a 25-fold amount of platinum (4) or copper (2). The stripping of palladium (2) was performed to an extent of 80% by a single batchwise treatment with an aqueous mixture solution of hydrochloric acid and thiourea. (author)

Stability constants of the Europium complexes with the chloride ions

International Nuclear Information System (INIS)

Jimenez R, M.; Solache R, M.; Rojas H, A.

2000-01-01

The stability constants of lanthanides complexes with chloride ions which were determined at the same ionic force but in different media, are significantly different. It does not exist a systematic study over these stability constants. The purpose of this work is to determine the stability constants of the europium complexes with chloride ions at 303 K, by the solvents extraction method. (Author)

The structure of molten CuCl: Reverse Monte Carlo modeling with high-energy X-ray diffraction data and molecular dynamics of a polarizable ion model

Energy Technology Data Exchange (ETDEWEB)

Alcaraz, Olga; Trullàs, Joaquim, E-mail: quim.trullas@upc.edu [Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya, Campus Nord UPC B4-B5, 08034 Barcelona (Spain); Tahara, Shuta [Department of Physics and Earth Sciences, Faculty of Science, University of the Ryukyus, Okinawa 903-0213 (Japan); Kawakita, Yukinobu [J-PARC Center, Japan Atomic Energy Agency (JAEA), Ibaraki 319-1195 (Japan); Takeda, Shin’ichi [Department of Physics, Faculty of Sciences, Kyushu University, Fukuoka 819-0395 (Japan)

2016-09-07

The results of the structural properties of molten copper chloride are reported from high-energy X-ray diffraction measurements, reverse Monte Carlo modeling method, and molecular dynamics simulations using a polarizable ion model. The simulated X-ray structure factor reproduces all trends observed experimentally, in particular the shoulder at around 1 Å{sup −1} related to intermediate range ordering, as well as the partial copper-copper correlations from the reverse Monte Carlo modeling, which cannot be reproduced by using a simple rigid ion model. It is shown that the shoulder comes from intermediate range copper-copper correlations caused by the polarized chlorides.

The structure of molten CuCl: Reverse Monte Carlo modeling with high-energy X-ray diffraction data and molecular dynamics of a polarizable ion model

International Nuclear Information System (INIS)

Alcaraz, Olga; Trullàs, Joaquim; Tahara, Shuta; Kawakita, Yukinobu; Takeda, Shin’ichi

2016-01-01

The results of the structural properties of molten copper chloride are reported from high-energy X-ray diffraction measurements, reverse Monte Carlo modeling method, and molecular dynamics simulations using a polarizable ion model. The simulated X-ray structure factor reproduces all trends observed experimentally, in particular the shoulder at around 1 Å −1 related to intermediate range ordering, as well as the partial copper-copper correlations from the reverse Monte Carlo modeling, which cannot be reproduced by using a simple rigid ion model. It is shown that the shoulder comes from intermediate range copper-copper correlations caused by the polarized chlorides.

Molten salt power towers operating at 600–650 °C: Salt selection and cost benefits

Energy Technology Data Exchange (ETDEWEB)

Turchi, Craig S. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Vidal, Judith [National Renewable Energy Lab. (NREL), Golden, CO (United States); Bauer, Matthew

2018-04-01

This analysis examines the potential benefit of adopting the supercritical carbon dioxide (sCO₂) Brayton cycle at 600-650 degrees C compared to the current state-of-the-art power tower operating a steam-Rankine cycle with solar salt at approximately 574 degrees C. The analysis compares a molten-salt power tower configuration using direct storage of solar salt (60:40 wt% sodium nitrate: potassium nitrate) or single-component nitrate salts at 600 degrees C or alternative carbonate- or chloride-based salts at 650 degrees C.

Antisense oligonucleotides suppress cell-volume-induced activation of chloride channels.

Science.gov (United States)

Gschwentner, M; Nagl, U O; Wöll, E; Schmarda, A; Ritter, M; Paulmichl, M

1995-08-01

Cell volume regulation is an essential feature of most cells. After swelling in hypotonic media, the simultaneous activation of potassium and chloride channels is believed to be the initial, time-determining step in cell volume regulation. The activation of both pathways is functionally linked and enables the cells to lose ions and water, subsequently leading to cell shrinkage and readjustment of the initial volume. NIH 3T3 fibroblasts efficiently regulate their volume after swelling and bear chloride channels that are activated by decreasing extracellular osmolarity. The chloride current elicited in these cells after swelling is reminiscent of the current found in oocytes expressing an outwardly rectifying chloride current termed ICln. Introduction of antisense oligodeoxynucleotides complementary to the first 30 nucleotides of the coding region of the ICln channel into NIH 3T3 fibroblasts suppresses the activation of the swelling-induced chloride current. The experiments directly demonstrate an unambiguous link between a volume-activated chloride current and a cloned protein involved in chloride transport.

Accelerator molten-salt breeding and thorium fuel cycle

International Nuclear Information System (INIS)

Furukawa, Kazuo; Nakahara, Yasuaki; Kato, Yoshio; Ohno, Hideo; Mitachi, Kohshi.

1990-01-01

The recent efforts at the development of fission energy utilization have not been successful in establishing fully rational technology. A new philosophy should be established on the basis of the following three principles: (1) thorium utilization, (2) molten-salt fuel concept, and (3) separation of fissile-breeding and power-generating functions. Such philosophy is called 'Thorium Molten-Salt Nuclear Energy Synergetics [THORIMS-NES]'. The present report first addresses the establishment of 233 U breeding fuel cycle, focusing on major features of the Breeding and Chemical Processing Centers and a small molten-salt power station (called FUJI-II). The development of fissile producing breeders is discussed in relation to accelerator molten-salt breeder (AMSB), impact fusion molten-salt breeder, and inertial-confined fusion hybrid molten-salt breeder. Features of the accelerator molten-salt breeder are described, focusing on technical problems with accelerator breeders (or spallators), design principle of the accelerator molten-salt breeder, selection of molten salt compositions, and nuclear- and reactor-chemical aspects of AMSB. Discussion is also made of further research and development efforts required in the future for AMSB. (N.K.)

Extraction of lanthanide elements and bismuth in molten lithium chloride-liquid bismuth-lithium alloy system

International Nuclear Information System (INIS)

Harada, Makoto; Adachi, Motonari; Kai, Yuichi; Koike, Kenichi

1987-01-01

The equilibrium distributions of neodymium and samarium between molten LiCl and liquid Bi-Li alloy were measured in a wide range of Li-mole fraction in the alloy phase, X Li . These lanthanide elements were extracted through redox reactions. In high X Li range, X Li > 0.03, the distributions of neodymium and bismuth in the salt phase increased markedly. The anomalous increase is attributed to the formation of the compound comprized of Nd, Li, Bi and oxygen in the salt phase. The reaction processes in samarium and neodymium were very fast and the extraction rates are controlled by the diffusion processes of the solutes and metallic lithium. (author)

Compatibility of molten salt and structural materials

International Nuclear Information System (INIS)

Kawakami, Masahiro

1994-01-01

As the important factors for considering the compatibility of fuel salt and coolant salt with structural materials in molten salt reactors, there are the moisture remaining in molten salt and the fluorine potential in molten salt. In this study, as for the metals which are the main components of corrosion resistant alloys, the corrosion by the moisture remaining in molten salt and the dependence of the corrosion on fluorine potential were examined. As the molten salts, an eutectic molten salt LiF-BeF 2 was mainly used, and LiF-KF was used in combination. As the metallic materials, Cr, Ni and Cu which are the main components of corrosion resistant and heat resistant alloys, Hastelloy and Monel, were used. In the experiment, the metal pieces were immersed in the molten salt, and by sampling the molten salt, the change with time lapse of the concentration of the dissolved metals was examined. Besides, the electrochemical measurement was carried out for Cr, of which the corrosion was remarkable, and the change with time lapse of the dissolved ions was examined. The experimental setup, the experimental method, and the results of the immersion test and the electrochemical test are reported. The experiment on the corrosion of metals depending on fluorine potential is also reported. (K.I.)

Study of chemical and electrochemical properties of some elements in molten NaAlCl

International Nuclear Information System (INIS)

Bermond, Alain

1976-01-01

We describe a study of the electrochemical and chemical properties in molten mixtures of Aluminium Chloride-Sodium chloride, at 210 deg. C and the concept of acidity, related to chloride activity, is previously summarized. In a first part, the study of Mercury and Cadmium by means of electro-analytical techniques, states the Hg 2+ 2 , Hg 2+ , Cd 2+ 2 and Cd 2+ ions and their acid properties. Some diagrams Equilibrium potential vs acidity are the synthesis of these results. In a second part, it is shown that a nickel electrode is an indicator of the presence of oxide ions; from interpretation of electrochemical results, O 2 appears to behave, in terms of the chloro-acido-basicity concept, as a strong di-base, giving the solvated form AlOCl - 2 , or a strong tri-base giving AlOCl. A saturation effect by Al 2 O 3 appears when the oxide concentration is increased; the solubility of Al 2 O 3 versus acidity is determined from the electrochemical results. In a third part, results for the Ni/Ni(II) or HCl/H 2 O systems are related to dissolved oxide ion presence in chloroaluminate melts; elimination of oxide ions, through H 2 O formation, by reaction with HCl is noteworthy. (author) [fr

Effect of the chloride ions on the hydrolysis of praseodymium in a 2M ion force media

International Nuclear Information System (INIS)

Lopez G, H.; Jimenez R, M.; Solache R, M.; Rojas H, A.

2004-01-01

The constants of the product of solubility and the first of hydrolysis were determined of the Praseodymium in media 2M of NaClO 4 and 2M of NaCl, to 303 K and under conditions free of CO 2 . The diagram of solubility was obtained (pPr (ac) - pC H ), by means of a radiochemical method and with it was established the pC H that limit the saturation and non saturation areas; that diagram allowed, also, to calculate the constant of the product of solubility. Also, it was adjusted with the polynomial of solubility equation, that it allowed to determine and to check the values of the constants of the product of solubility and the first of hydrolysis. Independently, it was determined the first constant of hydrolysis of the element, by means of potentiometric titrations whose data were treated with the computer program named SUPERQUAD and with the adjustment of the equation of the average number of bonds. It was also calculates the log constant β Pr,Cl of the specie PrCI 2+ starting from the hydrolysis constants obtained in the perchlorate and chloride media. (Author)

Conductometric study of lanthanum chloride interaction with potash soaps of higher fatty acids

International Nuclear Information System (INIS)

Skrylev, L.D.; Sazonova, V.F.; Kornelli, M.Eh.; Shumilina, N.A.

1978-01-01

Interaction of lanthanum chloride with potassium salts of higher aliphatic acids, containing from 10 to 16 carbon atoms, at room temperature in weakly acid media (pH=5.5) gives rise to neutral soaps of the La[CHsub(3)(CHsub(2))sub(n)COO]sub(3) composition, while in alkaline media (pH=8.0) base soaps of the LaOH[CHsub(3)(CHsub(2))sub(n)COO]sub(2) composition are formed. In acid solutions (pH=2.0) no interaction of lanthanum chloride with potassium soaps of the above carboxylic acids is observed

Modeling of the ionic transfers in saturated porous media: application to the penetration of chlorides through cementing materials

International Nuclear Information System (INIS)

Khitab, Anwar

2005-09-01

In this work, the problem of ionic species transport through concrete porous media has been documented. Chloride ions penetration in cementitious materials is one of the processes widely responsible for the degradation of concrete structures. Therefore there exists an immense need for its correct understanding and quantification. Different research groups worldwide have proposed different chloride ingress models. Here, a one-dimensional model based on a multi-species approach of the ionic transport is presented. It is the new version of a previous model MsDiff developed a few years ago in our group that describes the diffusion of ionic species with the Nernst-Planck equation instead of Fick's laws. This newer version is named, the package version of MsDiff after it requires a package of five input data at any given age of concrete. With a multi-species approach, it is possible to take into account the interactions, which exist among different ionic species in pore solution of concrete. The numerical scheme of the model is based on finite difference method with Crank-Nickolson and Law-Wendroff techniques. In order to run MsDiff, we do need an input data. Several experiments were performed accordingly to provide experimental feedback to MsDiff. Standard immersion tests were conducted to validate the outcomes of MsDiff. Special attention is given to the diffusion coefficients of the ions and the interactions between the ionic species and the solid phase. In addition to MsDiff, some other existing models were also tried for the sake of comparison with the experimental chloride profiles. Certain experimentation was conducted to watch the effect of exposure period, concrete age at exposure and concentration in the environmental solution. In the end, the simulations were performed with MsDiff in order to calculate the chloride-induced corrosion initiation time using the experimental data already achieved while making use of different criteria adopted by different research

Compatibility of molten salt and structural materials

Energy Technology Data Exchange (ETDEWEB)

Kawakami, Masahiro [Toyohashi Univ. of Technology, Aichi (Japan)

1994-12-01

As the important factors for considering the compatibility of fuel salt and coolant salt with structural materials in molten salt reactors, there are the moisture remaining in molten salt and the fluorine potential in molten salt. In this study, as for the metals which are the main components of corrosion resistant alloys, the corrosion by the moisture remaining in molten salt and the dependence of the corrosion on fluorine potential were examined. As the molten salts, an eutectic molten salt LiF-BeF{sub 2} was mainly used, and LiF-KF was used in combination. As the metallic materials, Cr, Ni and Cu which are the main components of corrosion resistant and heat resistant alloys, Hastelloy and Monel, were used. In the experiment, the metal pieces were immersed in the molten salt, and by sampling the molten salt, the change with time lapse of the concentration of the dissolved metals was examined. Besides, the electrochemical measurement was carried out for Cr, of which the corrosion was remarkable, and the change with time lapse of the dissolved ions was examined. The experimental setup, the experimental method, and the results of the immersion test and the electrochemical test are reported. The experiment on the corrosion of metals depending on fluorine potential is also reported. (K.I.).

Electrochemical reduction of actinides oxides in molten salts

International Nuclear Information System (INIS)

Claux, B.

2011-01-01

Reactive metals are currently produced from their oxide by multiple steps reduction techniques. A one step route from the oxide to the metal has been suggested for metallic titanium production by electrolysis in high temperature molten chloride salts. In the so-called FFC process, titanium oxide is electrochemically reduced at the cathode, generating O 2- ions, which are converted on a graphite anode into carbon oxide or dioxide. After this process, the spent salt can in principle be reused for several batches which is particularly attractive for a nuclear application in terms of waste minimization. In this work, the electrochemical reduction process of cerium oxide (IV) is studied in CaCl 2 and CaCl 2 -KCl melts to understand the oxide reduction mechanism. Cerium is used as a chemical analogue of actinides. Electrolysis on 10 grams of cerium oxide are made to find optimal conditions for the conversion of actinides oxides into metals. The scale-up to hundred grams of oxide is also discussed. (author) [fr

The molten salt reactor adventure

International Nuclear Information System (INIS)

MacPherson, H.G.

1985-01-01

A personal history of the development of molten salt reactors in the United States is presented. The initial goal was an aircraft propulsion reactor, and a molten fluoride-fueled Aircraft Reactor Experiment was operated at Oak Ridge National Laboratory in 1954. In 1956, the objective shifted to civilian nuclear power, and reactor concepts were developed using a circulating UF 4 -ThF 4 fuel, graphite moderator, and Hastelloy N pressure boundary. The program culminated in the successful operation of the Molten Salt Reactor Experiment in 1965 to 1969. By then the Atomic Energy Commission's goals had shifted to breeder development; the molten salt program supported on-site reprocessing development and study of various reactor arrangements that had potential to breed. Some commercial and foreign interest contributed to the program which, however, was terminated by the government in 1976. The current status of the technology and prospects for revived interest are summarized

Structure and thermodynamics of molten salts

International Nuclear Information System (INIS)

Papatheodorou, G.N.

1983-01-01

This chapter investigates single-component molten salts and multicomponent salt mixtures. Molten salts provide an important testing ground for theories of liquids, solutions, and plasmas. Topics considered include molten salts as liquids (the pair potential, the radial distribution function, methods of characterization), single salts (structure, thermodynamic correlations), and salt mixtures (the thermodynamics of mixing; spectroscopy and structure). Neutron and X-ray scattering techniques are used to determine the structure of molten metal halide salts. The corresponding-states theory is used to obtain thermodynamic correlations on single salts. Structural information on salt mixtures is obtained by using vibrational (Raman) and electronic absorption spectroscopy. Charge-symmetrical systems and charge-unsymmetrical systems are used to examine the thermodynamics of salt mixtures

Cytotoxic effects of nanosilver are highly dependent on the chloride concentration and the presence of organic compounds in the cell culture media.

Science.gov (United States)

Kaiser, Jean-Pierre; Roesslein, Matthias; Diener, Liliane; Wichser, Adrian; Nowack, Bernd; Wick, Peter

2017-01-06

Nanosilver shows great promise for use in industrial, consumer or medical products because of its antimicrobial properties. However, the underlying mechanisms of the effects of silver nanoparticles on human cells are still controversial. Therefore, in the present study the influence of the chloride concentration and different serum content of culture media on the cytotoxic effects of nanosilver was systematically evaluated. Our results show that nanosilver toxicity was strongly affected by the composition of the culture media. The chloride concentration, as well as the carbon content affected the silver agglomeration and the complex formation. But also the dissolution of nanosilver and the availability of free silver ions (Ag + ) were severely affected by the compositions of the culture media. Cells, only exposed to silver particles in suspension and dissolved silver complexes, did not show any effects under all conditions. Nanosilver agglomerates and silver complexes were not very soluble. Thus, cells growing on the bottom of the culture dishes were exposed to sedimented nanosilver agglomerates and precipitated silver complexes. Locally, the concentration of silver on the cell surface was very high, much higher compared the silver concentration in the bulk solution. The cytotoxic effects of nanosilver are therefore a combination of precipitated silver complexes and organic silver compounds rather than free silver ions. Silver coatings are used in health care products due to their bacteriostatic or antibacterial properties. The assessment of the toxicity of a certain compound is mostly done using in vitro assays. Therefore, cytotoxicity studies of nanosilver using human cell cultures have to be undertaken under well controlled and understood cultivations conditions in order to improve the compatibility of different studies. Especially when eukaryotic versus prokaryotic systems are compared for the evaluation of the use of nanosilver as antibacterial coatings for

Molten salt destruction process for mixed wastes

International Nuclear Information System (INIS)

Upadhye, R.S.; Wilder, J.G.; Karlsen, C.E.

1993-04-01

We are developing an advanced two-stage process for the treatment of mixed wastes, which contain both hazardous and radioactive components. The wastes, together with an oxidant gas, such as air, are injected into a bed of molten salt comprising a mixture of sodium-, potassium-, and lithium-carbonates, with a melting point of about 580 degree C. The organic constituents of the mixed waste are destroyed through the combined effect of pyrolysis and oxidation. Heteroatoms. such as chlorine, in the mixed waste form stable salts, such as sodium chloride, and are retained in the melt. The radioactive actinides in the mixed waste are also retained in the melt because of the combined action of wetting and partial dissolution. The original process, consists of a one-stage unit, operated at 900--1000 degree C. The advanced two-stage process has two stages, one for pyrolysis and one for oxidation. The pyrolysis stage is designed to operate at 700 degree C. The oxidation stage can be operated at a higher temperature, if necessary

Chemical Engineering Division fuel cycle programs. Quarterly progress report, April-June 1979. [Pyrochemical/dry processing; waste encapsulation in metal; transport in geologic media

Energy Technology Data Exchange (ETDEWEB)

Steindler, M.J.; Ader, M.; Barletta, R.E.

1980-09-01

For pyrochemical and dry processing materials development included exposure to molten metal and salt of Mo-0.5% Ti-0.07% Ti-0.01% C, Mo-30% W, SiC, Si/sub 2/ON/sub 2/, ZrB/sub 2/-SiC, MgAl/sub 2/O/sub 4/, Al/sub 2/O/sub 3/, AlN, HfB/sub 2/, Y/sub 2/O/sub 3/, BeO, Si/sub 3/N/sub 4/, nickel nitrate-infiltrated W, W-coated Mo, and W-metallized alumina-yttria. Work on Th-U salt transport processing included solubility of Th in liquid Cd, defining the Cd-Th and Cd-Mg-Th phase diagrams, ThO/sub 2/ reduction experiments, and electrolysis of CaO in molten salt. Work on pyrochemical processes and associated hardware for coprocessing U and Pu in spent FBR fuels included a second-generation computer model of the transport process, turntable transport process design, work on the U-Cu-Mg system, and U and Pu distribution coefficients between molten salt and metal. Refractory metal vessels are being service-life tested. The chloride volatility processing of Th-based fuel was evaluated for its proliferation resistance, and a preliminary ternary phase diagram for the Zn-U-Pu system was computed. Material characterization and process analysis were conducted on the Exportable Pyrochemical process (Pyro-Civex process). Literature data on oxidation of fissile metals to oxides were reviewed. Work was done on chemical bases for the reprocessing of actinide oxides in molten salts. Flowsheets are being developed for the processing of fuel in molten tin. Work on encapsulation of solidified radioactive waste in metal matrix included studies of leach rate of crystalline waste materials and of the impact resistance of metal-matrix waste forms. In work on the transport properties of nuclear waste in geologic media, adsorption of Sr on oolitic limestone was studied, as well as the migration of Cs in basalt. Fitting of data on the adsorption of iodate by hematite to a mathematical model was attempted.

Physical properties of molten carbonate electrolyte

Energy Technology Data Exchange (ETDEWEB)

Kojima, T.; Yanagida, M.; Tanimoto, K. [Osaka National Research Institute (Japan)] [and others

1996-12-31

Recently many kinds of compositions of molten carbonate electrolyte have been applied to molten carbonate fuel cell in order to avoid the several problems such as corrosion of separator plate and NiO cathode dissolution. Many researchers recognize that the addition of alkaline earth (Ca, Sr, and Ba) carbonate to Li{sub 2}CO{sub 3}-Na{sub 2}CO{sub 3} and Li{sub 2}CO{sub 3}-K{sub 2}CO{sub 3} eutectic electrolytes is effective to avoid these problems. On the other hand, one of the corrosion products, CrO{sub 4}{sup 2-} ion is found to dissolve into electrolyte and accumulated during the long-term MCFC operations. This would affect the performance of MCFC. There, however, are little known data of physical properties of molten carbonate containing alkaline earth carbonates and CrO{sub 4}{sup 2-}. We report the measured and accumulated data for these molten carbonate of electrical conductivity and surface tension to select favorable composition of molten carbonate electrolytes.

Aluminum titanate crucible for molten uranium

International Nuclear Information System (INIS)

Asbury, J.J.

1975-01-01

An improved crucible for molten uranium is described. The crucible or crucible liner is formed of aluminum titanate which essentially eliminates contamination of uranium and uranium alloys during molten states thereof. (U.S.)

Study of behaviour of lanthanum- and yttrium electrodes in chloride melts

International Nuclear Information System (INIS)

Shkol'nikov, S.I.; Tolypin, E.S.; Yur'ev, B.P.

1984-01-01

A study was made on the lanthanum- and yttrium behaviour in a mixture of molten potassium- and sodium chlorides at various temperatures. It is shown that the lanthanum- and yttrium behaviour in KCl-NaCl melt is similar to the behaviour of other metals. Their corrosion rate is much higher as compared to other metals and it grows rapidly with increasing melt temperature. The temperature growth by 200 deg C results in an increase in the corrosion rate almost by an order. The potentials of lanthanum- and yttrium electrodes at the instant they are immersed in the melt have more negative values than the potentials of alkali metals under similar conditions

Liquid-liquid extraction from molten alkaline nitrates by using nitrogenous and organophosphorus derivatives

International Nuclear Information System (INIS)

Vittori, Olivier

1971-01-01

This research thesis reports the use of a system made of the LiNO 3 -KNO 3 eutectic at 160 deg. C and poly-phenyls in order to study the behaviour of phosphine and arsine oxides as extracting agents in a liquid-liquid process. In a first part, the author presents the studied system, its physical characteristics and its preparation, and the various analytical methods which have used. He discusses existing computation methods adapted to the separation of molten salts and organic phase, and proposes a specific method. Then, he reports the study of the behaviour of a phosphine oxide with Cobalt II and Nickel II, and discusses its application to the separation of this pair, Co II and Ni II. He highlights the different possibilities of three agents which are derivatives of phosphine and arsine in their ability to extract rare earths. A study of separation of rare earths is then addressed. The author reports the application of extraction equilibriums to the study of equilibriums in environments of molten salts with the Co II - chloride ions system. The author finally addresses the synergic phenomenon that pairs of neutral complexing agents of neighbouring structure or different donor central atom may display in liquid-liquid extraction

Polyamorphism and the evolution of intermediate-range order in molten ZnCl{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Sharma, Bevan K [Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ (United Kingdom); Wilson, Mark [Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ (United Kingdom)

2008-06-18

The pressure- and temperature-dependent properties of molten zinc chloride are investigated by means of molecular dynamics computer simulation. The potential model used is based on a pair potential augmented with a description of the (many-body) anion polarization. The static experimental and simulated structural properties are briefly reviewed. The structural properties obtained from the simulation model are compared with those obtained from experimental investigations and trends with the change in system pressure and temperature are discussed. Preliminary studies of the pressure behaviour of the simulated glassy states show the existence of low-and high-density amorphous states (LDA and HDA). The LDA/HDA coexistence line is established and its relationship to the underlying phase diagram is discussed.

LIFE Materails: Molten-Salt Fuels Volume 8

Energy Technology Data Exchange (ETDEWEB)

Moir, R; Brown, N; Caro, A; Farmer, J; Halsey, W; Kaufman, L; Kramer, K; Latkowski, J; Powers, J; Shaw, H; Turchi, P

2008-12-11

The goals of the Laser Inertial Fusion Fission Energy (LIFE) is to use fusion neutrons to fission materials with no enrichment and minimum processing and have greatly reduced wastes that are not of interest to making weapons. Fusion yields expected to be achieved in NIF a few times per day are called for with a high reliable shot rate of about 15 per second. We have found that the version of LIFE using TRISO fuel discussed in other volumes of this series can be modified by replacing the molten-flibe-cooled TRISO fuel zone with a molten salt in which the same actinides present in the TRISO particles are dissolved in the molten salt. Molten salts have the advantage that they are not subject to radiation damage, and hence overcome the radiation damage effects that may limit the lifetime of solid fuels such as TRISO-containing pebbles. This molten salt is pumped through the LIFE blanket, out to a heat exchanger and back into the blanket. To mitigate corrosion, steel structures in contact with the molten salt would be plated with tungsten or nickel. The salt will be processed during operation to remove certain fission products (volatile and noble and semi-noble fission products), impurities and corrosion products. In this way neutron absorbers (fission products) are removed and neutronics performance of the molten salt is somewhat better than that of the TRISO fuel case owing to the reduced parasitic absorption. In addition, the production of Pu and rare-earth elements (REE) causes these elements to build up in the salt, and leads to a requirement for a process to remove the REE during operation to insure that the solubility of a mixed (Pu,REE)F3 solid solution is not exceeded anywhere in the molten salt system. Removal of the REE will further enhance the neutronics performance. With molten salt fuels, the plant would need to be safeguarded because materials of interest for weapons are produced and could potentially be removed.

LIFE Materails: Molten-Salt Fuels Volume 8

International Nuclear Information System (INIS)

Moir, R.; Brown, N.; Caro, A.; Farmer, J.; Halsey, W.; Kaufman, L.; Kramer, K.; Latkowski, J.; Powers, J.; Shaw, H.; Turchi, P.

2008-01-01

The goals of the Laser Inertial Fusion Fission Energy (LIFE) is to use fusion neutrons to fission materials with no enrichment and minimum processing and have greatly reduced wastes that are not of interest to making weapons. Fusion yields expected to be achieved in NIF a few times per day are called for with a high reliable shot rate of about 15 per second. We have found that the version of LIFE using TRISO fuel discussed in other volumes of this series can be modified by replacing the molten-flibe-cooled TRISO fuel zone with a molten salt in which the same actinides present in the TRISO particles are dissolved in the molten salt. Molten salts have the advantage that they are not subject to radiation damage, and hence overcome the radiation damage effects that may limit the lifetime of solid fuels such as TRISO-containing pebbles. This molten salt is pumped through the LIFE blanket, out to a heat exchanger and back into the blanket. To mitigate corrosion, steel structures in contact with the molten salt would be plated with tungsten or nickel. The salt will be processed during operation to remove certain fission products (volatile and noble and semi-noble fission products), impurities and corrosion products. In this way neutron absorbers (fission products) are removed and neutronics performance of the molten salt is somewhat better than that of the TRISO fuel case owing to the reduced parasitic absorption. In addition, the production of Pu and rare-earth elements (REE) causes these elements to build up in the salt, and leads to a requirement for a process to remove the REE during operation to insure that the solubility of a mixed (Pu,REE)F3 solid solution is not exceeded anywhere in the molten salt system. Removal of the REE will further enhance the neutronics performance. With molten salt fuels, the plant would need to be safeguarded because materials of interest for weapons are produced and could potentially be removed.

Molten-salt converter reactors

International Nuclear Information System (INIS)

Perry, A.M.

1975-01-01

Molten-salt reactors appear to have substantial promise as advanced converters. Conversion ratios of 0.85 to 0.9 should be attainable with favourable fuel cycle costs, with 235 U valued at $12/g. An increase in 235 U value by a factor of two or three ($10 to $30/lb. U 3 O 8 , $75/SWU) would be expected to increase the optimum conversion ratio, but this has not been analyzed in detail. The processing necessary to recover uranium from the fuel salt has been partially demonstrated in the MSRE. The equipment for doing this would be located at the reactor, and there would be no reliance on an established recycle industry. Processing costs are expected to be quite low, and fuel cycle optimization depends primarily on inventory and burnup or replacement costs for the fuel and for the carrier salt. Significant development problems remain to be resolved for molten-salt reactors, notably the control of tritium and the elimination of intergranular cracking of Hastelloy-N in contact with tellurium. However, these problems appear to be amenable to solution. It is appropriate to consider separating the development schedule for molten-salt reactors from that for the processing technology required for breeding. The Molten-Salt Converter Reactor should be a useful reactor in its own right and would be an advance towards the achievement of true breeding in thermal reactors. (author)

Contribution to the study of the vertical molten zone process (1963); Contribution a l'etude du procede de la zone fondue verticale (1963)

Energy Technology Data Exchange (ETDEWEB)

Lenzin, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1963-07-01

Construction and use of several molten zone apparatuses operating either vertically or horizontally. Efficient purification of uranyl nitrate hexahydrate but less successful in the case of other hydrated double salts and of zirconyl chloride in the hydrochloric gel form. Demonstration and study of the dissymmetry in the direction of the transport of the impurity during, the purification by a vertical molten zone process. (author) [French] Construction et utilisation de plusieurs appareils de zone fondue travaillant soit en vertical, soit en horizontal. Purification efficace du nitrate d'uranyle hexahydrate mais peu significative dans le cas des autres couples de sels hydrates et du chlorure de zirconyle a l'etat de gel chlorhydrique. Mise en evidence et etude de la dissymetrie sur le sens de transport de l'impurete au cours de la purification par zone fondue verticale. (auteur)

High-temperature corrosion of lanthanum in equimole mixture of sodium and potassium chlorides

International Nuclear Information System (INIS)

Kochergin, V.P.; Obozhina, R.N.; Dragoshanskaya, T.I.; Startsev, B.P.

1984-01-01

Results of investigation into the process of lanthanum corrosion in the molted equimole NaCl-KCl mixture after the change of test time, temperature and lanthanum trichloride were summarized. It was shown that polarization of lanthanum anode in equimole NaCl-KCl melt is controlled by La 3+ diffusion from near-electrode layer to electrolyte depth, which results in decrease of corrosion rate in time. The established electrochemical properties of metallic lanthanum in equimole NaCl-KCl mixture must be considered when improving the technology of electrochemical production of lanthanum or its alloys of molten chlorides of lanthanum and alkaline metals

A method of measuring a molten metal liquid pool volume

Science.gov (United States)

Garcia, G.V.; Carlson, N.M., Donaldson, A.D.

1990-12-12

A method of measuring a molten metal liquid pool volume and in particular molten titanium liquid pools, including the steps of (a) generating an ultrasonic wave at the surface of the molten metal liquid pool, (b) shining a light on the surface of a molten metal liquid pool, (c) detecting a change in the frequency of light, (d) detecting an ultrasonic wave echo at the surface of the molten metal liquid pool, and (e) computing the volume of the molten metal liquid. 3 figs.

Bibliographical study for the development of an electrochemical preparation of plutonium molten salts; Etude bibliographique en vue de la mise au point d'une preparation electrochimique en sels fondus du plutonium

Energy Technology Data Exchange (ETDEWEB)

Lefevre, J.

1957-01-15

Based on an analogy with methods of electrochemical preparation of uranium molten salts, this bibliographical study reports data of physical properties of plutonium (melting point, density, ranges of existence of the different plutonium phases, resistivity, resistivity variation coefficient), discusses the search for an electrolytic bath (properties of plutonium bromides, chlorides and fluorides), and the required apparatus (an electrolysis cell)

Chloride stress corrosion cracking of Alloy 600 in boric acid solutions

International Nuclear Information System (INIS)

Berge, Ph.; Noel, D.; Gras, J.M.; Prieux, B.

1997-10-01

The high nickel austenitic alloys are generally considered to have good resistance to chloride stress corrosion cracking. In the standard boiling magnesium chloride solution tests, alloys with more than 40% nickel are immune. Nevertheless, more recent data show that cracking can occur in both Alloys 600 and 690 if the solution is acidified. In other low pH media, such as boric acid solution at 100 deg C, transgranular and intergranular cracking are observed in Alloy 600 in the presence of minor concentrations of sodium chloride (2g/I). In concentrated boric acid at higher temperatures (250 and 290 deg C), intergranular cracking also occurs, either when the chloride concentration is high, or at low chloride contents and high oxygen levels. The role of pH and a possible specific action of boric acid are discussed, together with the influence of electrochemical potential. (author)

Studies on components for a molten salt reactor

International Nuclear Information System (INIS)

Nejedly, M.; Matal, O.

2003-01-01

The aim is contribute to a design of selected components of molten salt reactors with fuel in the molten fluoride salt matrix. Molten salt reactors (MSRs) permit the utilization of plutonium and minor actinides as new nuclear fuel from a traditional nuclear power station with production of electric energy. Results of preliminary feasibility studies of an intermediate heat exchanger, a small power molten salt pump and a modular conception of a steam generator for a demonstration unit of the MSR (30 MW) are summarized. (author)

Fast Thorium Molten Salt Reactors Started with Plutonium

International Nuclear Information System (INIS)

Merle-Lucotte, E.; Heuer, D.; Le Brun, C.; Brissot, R.; Liatard, E.; Meplan, O.; Nuttin, A.; Mathieu, L.

2006-01-01

One of the pending questions concerning Molten Salt Reactors based on the 232 Th/ 233 U fuel cycle is the supply of the fissile matter, and as a consequence the deployment possibilities of a fleet of Molten Salt Reactors, since 233 U does not exist on earth and is not yet produced in the current operating reactors. A solution may consist in producing 233 U in special devices containing Thorium, in Pressurized Water or Fast Neutrons Reactors. Two alternatives to produce 233 U are examined here: directly in standard Molten Salt Reactors started with Plutonium as fissile matter and then operated in the Th/ 233 U cycle; or in dedicated Molten Salt Reactors started and fed with Plutonium as fissile matter and Thorium as fertile matter. The idea is to design a critical reactor able to burn the Plutonium and the minor actinides presently produced in PWRs, and consequently to convert this Plutonium into 233 U. A particular reactor configuration is used, called 'unique channel' configuration in which there is no moderator in the core, leading to a quasi fast neutron spectrum, allowing Plutonium to be used as fissile matter. The conversion capacities of such Molten Salt Reactors are excellent. For Molten Salt Reactors only started with Plutonium, the assets of the Thorium fuel cycle turn out to be quickly recovered and the reactor's characteristics turn out to be equivalent to Molten Salt Reactors operated with 233 U only. Using a combination of Molten Salt Reactors started or operated with Plutonium and of Molten Salt Reactors started with 233 U, the deployment capabilities of these reactors fully satisfy the condition of sustainability. (authors)

Waste treatment using molten salt oxidation

International Nuclear Information System (INIS)

Navratil, J.D.; Stewart, A.E.

1996-01-01

MSO technology can be characterized as a submerged oxidation process; the basic concept is to introduce air and wastes into a bed of molten salt, oxidize the organic wastes in the molten salt, use the heat of oxidation to keep the salt molten and remove the salt for disposal or processing and recycling. The molten salt (usually sodium carbonate at 900-1000 C) provides four waste management functions: providing a heat transfer medium, catalyzing the oxidation reaction, preventing the formation of acid gases by forming stable salts, and efficiently capturing ash particles and radioactive materials by the combined effects of wetting, encapsulation and dissolution. The MSO process requires no wet scrubbing system for off-gas treatment. The process has been developed through bench-scale and pilot-scale testing, with successful destruction demonstration of a wide variety of hazardous and mixed (radioactive and hazardous wastes). (author). 24 refs, 2 tabs, 2 figs

Molten fuel-moderator interaction

International Nuclear Information System (INIS)

Lee, J.H.S.; Kynstautas, R.

1987-02-01

A critical review of the current understanding of vapor explosions was carried out. It was concluded that, on the basis of actual industrial accidents and large scale experiments, energetic high yield steam explosion cannot be regarded as an improbable event if large quantities of molten fuel and coolant are mixed together. This study also reviewed a hydrodynamic transient model proposed by Henry and Fauske Associates to assess a molten fuel-moderator interaction event. It was found that the proposed model negates a priori the possibility of a violent event, by introducing two assumptions: 1) fine fragmentation of the molten fuel, and ii) rapid heat transfer from the fine fragments to form steam. Using the Hicks and Menzies thermodynamic model, maximum work potential and pressure rise in the calandria were estimated. However, it is recommended that a more representative upper bound model based on an underwater explosion of a pressurized volume of steam be developed

Electrochemical oxidation of synthetic tannery wastewater in chloride-free aqueous media

International Nuclear Information System (INIS)

Costa, Carla Regina; Montilla, Francisco; Morallon, Emilia; Olivi, Paulo

2010-01-01

The electrochemical treatment of a synthetic tannery wastewater, prepared with several compounds used by finishing tanneries, was studied in chloride-free media. Boron-doped diamond (Si/BDD), antimony-doped tin dioxide (Ti/SnO 2 -Sb), and iridium-antimony-doped tin dioxide (Ti/SnO 2 -Sb-Ir) were evaluated as anode. The influence of pH and current density on the treatment was assessed by means of the parameters used to measure the level of organic contaminants in the wastewater; i.e., total phenols, chemical oxygen demand (COD), total organic carbon (TOC), and absorbance. Results showed that faster decrease in these parameters occurred when the Si/BDD anode was used. Good results were obtained with the Ti/SnO 2 -Sb anode, but its complete deactivation was reached after 4 h of electrolysis at 25 mA cm -2 , indicating that the service life of this electrode is short. The Ti/SnO 2 -Sb-Ir anode is chemically and electrochemically more stable than the Ti/SnO 2 -Sb anode, but it is not suitable for the electrochemical treatment under the studied conditions. No significant changes were observed for electrolyses performed at different pH conditions with Si/BDD, and this electrode led to almost complete mineralization after 4 h of electrolysis at 100 mA cm -2 . The increase in current density resulted in faster wastewater oxidation, with lower current efficiency and higher energy consumption. Si/BBD proved to be the best electrodic material for the direct electrooxidation of tannery wastewaters.

Plutonium recovery from spent reactor fuel by uranium displacement

Science.gov (United States)

Ackerman, J.P.

1992-03-17

A process is described for separating uranium values and transuranic values from fission products containing rare earth values when the values are contained together in a molten chloride salt electrolyte. A molten chloride salt electrolyte with a first ratio of plutonium chloride to uranium chloride is contacted with both a solid cathode and an anode having values of uranium and fission products including plutonium. A voltage is applied across the anode and cathode electrolytically to transfer uranium and plutonium from the anode to the electrolyte while uranium values in the electrolyte electrolytically deposit as uranium metal on the solid cathode in an amount equal to the uranium and plutonium transferred from the anode causing the electrolyte to have a second ratio of plutonium chloride to uranium chloride. Then the solid cathode with the uranium metal deposited thereon is removed and molten cadmium having uranium dissolved therein is brought into contact with the electrolyte resulting in chemical transfer of plutonium values from the electrolyte to the molten cadmium and transfer of uranium values from the molten cadmium to the electrolyte until the first ratio of plutonium chloride to uranium chloride is reestablished.

Plutonium recovery from spent reactor fuel by uranium displacement

International Nuclear Information System (INIS)

Ackerman, J.P.

1992-01-01

A process is described for separating uranium values and transuranic values from fission products containing rare earth values when the values are contained together in a molten chloride salt electrolyte. A molten chloride salt electrolyte with a first ratio of plutonium chloride to uranium chloride is contacted with both a solid cathode and an anode having values of uranium and fission products including plutonium. A voltage is applied across the anode and cathode electrolytically to transfer uranium and plutonium from the anode to the electrolyte while uranium values in the electrolyte electrolytically deposit as uranium metal on the solid cathode in an amount equal to the uranium and plutonium transferred from the anode causing the electrolyte to have a second ratio of plutonium chloride to uranium chloride. Then the solid cathode with the uranium metal deposited thereon is removed and molten cadmium having uranium dissolved therein is brought into contact with the electrolyte resulting in chemical transfer of plutonium values from the electrolyte to the molten cadmium and transfer of uranium values from the molten cadmium to the electrolyte until the first ratio of plutonium chloride to uranium chloride is reestablished

Metal Production by Molten Salt Electrolysis

DEFF Research Database (Denmark)

Grjotheim, K.; Kvande, H.; Qingfeng, Li

Chemistry and electrochemistry of molten salts are reviewed. Technological aspects of electrolytic production of aluminium, magnesium, and other metals are comprehensively surveyed.......Chemistry and electrochemistry of molten salts are reviewed. Technological aspects of electrolytic production of aluminium, magnesium, and other metals are comprehensively surveyed....

Thorium-based Molten Salt Reactor (TMSR) project in China

International Nuclear Information System (INIS)

Dai, Zhimin; Liu, Wei

2013-01-01

Making great efforts in development of nuclear energy is one of the long-term-plan in China's energy strategies. The advantages of Thorium-based nuclear energy are: rich resource in nature, less nuclear waste, low toxicity, nuclear non-proliferation and so on. Furthermore, China is a country with abundant thorium, thus it is necessary to develop the Thorium-based Molten Salt Reactor (TMSR) in China. Shanghai Institute of Applied Physics, Chinese Academy of Sciences (SINAP) had designed and constructed the first China's light-water reactor and developed a zero-power thorium-based molten salt reactor successfully in the early 1970s. The applied research project 'thorium molten salt reactor nuclear power system' by SINAP together with several other institutes had been accepted and granted by China government in 2011. The whole project has been divided into three stages: Firstly, built a 2 MW-zero-power high temperature solid molten salt reactor in 2015 and a 2 MW-zero-power high temperature liquid molten salt reactor in 2017. Secondly, in 2020 built a 10 MW high temperature liquid molten salt reactor. Thirdly, on the base of previous work, a 100 MW high temperature molten salt reactor should be achieving in 2030. After more than one years of efforts, a high quality scientific research team has been formed, which is able to design the molten salt reactor, the molten salt loop and related key equipment, the systems of molten salt preparation, purification and the radioactive gas removal. In the past one year, the initial physical design of high temperature molten salt reactor has been completed; the nuclear chemistry and radiation chemical laboratory has been built, a high temperature salt (HTS) loop and radioactive gas removal experiment device system have been successfully developed and constructed. Further, the preliminary study on reactor used carbon-carbon composite material has been investigated. (author)

Molten salt-mediated formation of g-C3N4-MoS2 for visible-light-driven photocatalytic hydrogen evolution

Science.gov (United States)

Li, Ni; Zhou, Jing; Sheng, Ziqiong; Xiao, Wei

2018-02-01

Construction of two-dimensional/two-dimensional (2D/2D) hybrid with well-defined composition and microstructure is a general protocol to achieve high-performance catalysts. We herein report preparation of g-C3N4-MoS2 hybrid by pyrolysis of affordable melamine and (NH4)2MoS4 in molten LiCl-NaCl-KCl at 550 °C. Molten salts are confirmed as ideal reaction media for formation of homogeneous hybrid. Characterizations suggest a strong interaction between g-C3N4 and MoS2 in the hybrid, which results in an enhanced visible-light-driven photocatalytic hydrogen generation of the hybrid with an optimal g-C3N4/MoS2 ratio. The present study highlights the merits of molten salt methods on preparation of 2D photocatalysts and provides a rational design of 2D/2D hybrid catalysts for advanced environmental and energy applications.

Molten salt extraction process for the recovery of valued transition metals from land-based and deep-sea minerals

Science.gov (United States)

Maroni, V.A.; von Winbush, S.

1987-05-01

A process for extracting transition metals and particularly cobalt and manganese together with iron, copper and nickel from low grade ores (including ocean-floor nodules) by converting the metal oxides or other compositions to chlorides in a molten salt, and subsequently using a combination of selective distillation at temperatures below about 500/degree/C, electrolysis at a voltage not more negative that about /minus/1.5 volt versus Ag/AgCl, and precipitation to separate the desired manganese and cobalt salts from other metals and provide cobalt and manganese in metallic forms or compositions from which these metals may be more easily recovered.

Inertia-confining thermonuclear molten salt reactors

International Nuclear Information System (INIS)

Furukawa, Kazuo; Yamanaka, Chiyoe; Nakai, Sadao; Imon, Shunji; Nakajima, Hidenori; Nakamura, Norio; Kato, Yoshio.

1984-01-01

Purpose: To increase the heat generating efficiency while improving the reactor safety and thereby maintaining the energy balance throughout the reactor. Constitution: In an inertia-confining type D-T thermonuclear reactor, the blanket is made of lithium-containing fluoride molten salts (LiF.BeF 2 , LiF.NaF.KF, LiF.KF, etc) which are cascaded downwardly in a large thickness (50 - 100 cm) along the inner wall of the thermonuclear reaction vessel, and neutrons generated by explosive compression are absorbed to lithium in the molten salts to produce tritium, Heat transportation is carried out by the molten salts. (Ikeda, J.)

Thorium Molten Salt Nuclear Energy Synergetic System (THORIMS-NES)

International Nuclear Information System (INIS)

Yoshioka, Ritsuo; Mitachi, Koshi

2013-01-01

The authors have been promoting nuclear energy technology based on thorium molten salt as Thorium Molten Salt Nuclear Energy Synergetic System (THORIMS-NES). This system is a combination of fission power reactor of Molten Salt Reactor (MSR), and Accelerator Molten Salt Breeder (AMSB) for production of fissile 233 U with connecting chemical processing facility. In this paper, concept of THORIMS-NES, advantages of thorium and molten salt recent MSR design results such as FUJI-U3 using 233 U fuel, FUJI-Pu, large sized super-FUJI, pilot plant miniFUJI, AMSB, and chemical processing facility are described. (author)

Molten salt: Corrosion problems and electrometallurgy in nuclear applications

International Nuclear Information System (INIS)

Santarini, G.

1981-01-01

A bibliographic survey is given of corrosion problems and electrometallurgical problems of molten salt in nuclear reactor applications. Due to the high potential to be achieved, their high ionic conductivity and the rapidity of reactions in a molten salt atmosphere, molten salts are interesting solvents for various electrometallurgical processes. Another important field of application is in the separation or electrolytical refining of various metals (Be, U, Pu, Th, Hf, Zr). However, these very characteristics of molten salts may also cause serious corrosion problems. Results obtained for the molten-salt reactor and the different causes of corrosion are reviewed an possible countermeasures analyzed. (orig.)

Performance of the mesh-type liquid cadmium cathode structure for the electrodeposition of uranium from the molten salt

International Nuclear Information System (INIS)

Paek, S.; Kim, S.H.; Lee, H.; Ahn, D.H.; Yoon, D.S.

2010-01-01

A mesh-type liquid cadmium cathode (LCC) structure has been devised to improve the performance of the electro-winning process for the recovery of actinides in a molten chloride system. For the verification of its performance, electrodeposition experiments of uranium from the molten LiCl-KCl-UCl 3 salt were conducted at 773 K for different current densities using the mesh-type LCC structure. Uranium was successfully collected over 5 wt. % in the LCC without growing uranium dendrites. The mesh-type LCC structure prevented the uncontrolled growth of uranium dendrites into the electrolyte phase above the cadmium surface and caused the LCC deposit to accumulate at the higher in the cadmium phase over uranium solubility in cadmium. After cooling the LCC crucible, its solid deposits were identified as an intermetallic compound UCd 11 by EPMA and XRD analysis. The cathode potential profiles from the electrochemical experiments and the chemical structure of the LCC deposits showed that it could be applied practically to recover the actinides above their solubility in cadmium. (orig.)

Separation and recovery of uranium ore by chlorinating, chelate resin and molten salt treatment

International Nuclear Information System (INIS)

Taki, Tomohiro

2000-12-01

Three fundamental researches of separation and recovery of uranium from uranium ore are reported in this paper. Three methods used the chloride pyrometallurgy, sodium containing molten salts and chelate resin. When uranium ore is mixed with activated carbon and reacted for one hour under the mixed gas of chlorine and oxygen at 950 C, more than 90% uranium volatilized and vaporization of aluminum, silicone and phosphorus were controlled. The best activated carbon was brown coal because it was able to control the large range of oxygen concentration. By blowing oxygen into the molten sodium hydroxide, the elution rate of uranium attained to about 95% and a few percent of uranium was remained in the residue. On the uranium ore of unconformity-related uranium deposits, a separation method of uranium, molybdenum, nickel and phosphorus from the sulfuric acid elusion solution with U, Ni, As, Mo, Fe and Al was developed. Methylene phosphonic acid type chelate resin (RCSP) adsorbed Mo and U, and then 100 % Mo was eluted by sodium acetate solution and about 100% U by sodium carbonate solution. Ni and As in the passing solution were recovered by imino-diacetic acid type chelate resin and iron hydroxide, respectively. (S.Y.)

Ceramics for Molten Materials Transfer

Science.gov (United States)

Standish, Evan; Stefanescu, Doru M.; Curreri, Peter A.

2009-01-01

The paper reviews the main issues associated with molten materials transfer and handling on the lunar surface during the operation of a hig h temperature electrowinning cell used to produce oxygen, with molten iron and silicon as byproducts. A combination of existing technolog ies and purposely designed technologies show promise for lunar exploi tation. An important limitation that requires extensive investigation is the performance of refractory currently used for the purpose of m olten metal containment and transfer in the lunar environment associa ted with electrolytic cells. The principles of a laboratory scale uni t at a scale equivalent to the production of 1 metric ton of oxygen p er year are introduced. This implies a mass of molten materials to be transferred consistent with the equivalent of 1kg regolithlhr proces sed.

Molten salt fueled reactors with a fast salt draining

International Nuclear Information System (INIS)

Ventre, Edmond; Blum, J.M.

1976-01-01

This invention relates to a molten salt nuclear reactor which comprises a new arrangement for shutting it down in complete safety. This nuclear reactor has a molten salt primary circuit comprising, in particular, the core of this reactor. It includes a leak tight vessel the capacity of which is appreciably greater than that of the molten salt volume of the circuit and placed so that the level of the molten salt, when all the molten salt of the circuit is contained in this vessel, is less than that of the base of the core. There are facilities for establishing and maintaining an inert gas pressure in the vessel above the molten salt, for releasing the compressed gas and for connecting the vessel to the primary circuit entering this vessel at a lower level than that of the molten salt and enabling molten salt to enter or leave the vessel according to the pressure of the inert gas. The particular advantage of this reactor is that it can be shut down safely since the draining of the primary circuit no longer results from a 'positive action' but from the suppression of an arrangement essential for the operation of the reactor consisting of the build-up of the said inert gas pressure in the said vessel [fr

The Experiences and Challenges in Drilling into Semi molten or Molten Intrusive in Menengai Geothermal Field

Science.gov (United States)

Mortensen, A. K.; Mibei, G. K.

2017-12-01

Drilling in Menengai has experienced various challenges related to drilling operations and the resource itself i.e. quality discharge fluids vis a vis gas content. The main reason for these challenges is related to the nature of rocks encountered at depths. Intrusives encountered within Menengai geothermal field have been group into three based on their geological characteristics i.e. S1, S2 and S3.Detailed geology and mineralogical characterization have not been done on these intrusive types. However, based on physical appearances, S1 is considered as a diorite dike, S2 is syenite while S3 is molten rock material. This paper summarizes the experiences in drilling into semi molten or molten intrusive (S3).

New rational nuclear energy system composed of accelerator molten-salt breeder (AMSB) and molten-salt power stations (MSCR)

International Nuclear Information System (INIS)

Furukawa, K.

1985-01-01

For the next century, it was predicted that some rational fission energy system breeding in significantly short doubling time less than 10 years should be developed replacing the fossil fuels. In practice, this rationality, that is, simplicity and high economy could be realized by the natural combination of: molten salt fuel concept; accelerator (spallation) breeding concept; and Thorium fuel cycle concept, in the symbiont system of Accelerator Molten-Salt breeders and Molten-Salt Power Stations. The economy of this system might significantly become better than the other breeder systems, although the prediction in Chapter 6 was too much conservative. Its more important aspect is the low cost of future R and D, which depend on the rational character of Molten-Fluoride Technology and really is verified by the basic R and D cost (only $0.13 B) in Oak Ridge N.L. It is interesting that molten-salt technology will be able to apply to chemical processing of U-Pu oxide fuels by the developing effort by USSR in near future. This fact and the demand of small power stations such as 150MWe MSCR presented here will be able to bridge between the present and the next century

Saturated vapor pressure over molten mixtures of GaCl3 and alkali metal chlorides

International Nuclear Information System (INIS)

Salyulev, A.B.; Smolenskij, V.V.; Moskalenko, N.I.

2004-01-01

Volatilities of GaCl 3 and alkali metal chlorides over diluted (up to 3 mol %) solutions of GaCl 3 in LiCl, NaCl, KCl, RbCl, and CsCl were measured at 1100 K by dynamic and indirect static methods. Chemical composition of saturated vapor over the mixed melts was determined. Partial pressures of the components were calculated. Their values depend essentially on specific alkali metal cation and on concentration of GaCl 3 ; their variation permits altering parameters of GaCl 3 distillation from the salt melt in a wide range [ru

Quantitative analysis of trivalent uranium and lanthanides in a molten chloride by absorption spectrophotometry

International Nuclear Information System (INIS)

Toshiyuki Fujii; Akihiro Uehara; Hajimu Yamana

2013-01-01

As an analytical application for pyrochemical reprocessing using molten salts, quantitative analysis of uranium and lanthanides by UV/Vis/NIR absorption spectrophotometry was performed. Electronic absorption spectra of LiCl-KCl eutectic at 773 K including trivalent uranium and eight rare earth elements (Y, La, Ce, Pr, Nd, Sm, Eu, and Gd as fission product elements) were measured in the wavenumber region of 4,500-33,000 cm -1 . The composition of the solutes was simulated for a reductive extraction condition in a pyroreprocessing process for spent nuclear fuels, that is, about 2 wt% U and 0.1-2 wt% rare earth elements. Since U(III) possesses strong absorption bands due to f-d transitions, an optical quartz cell with short light path length of 1 mm was adopted in the analysis. The quantitative analysis of trivalent U, Nd, Pr, and Sm was possible with their f-f transition intensities in the NIR region. The analytical results agree with the prepared concentrations within 2σ experimental uncertainties. (author)

Compatibility studies of potential molten-salt breeder reactor materials in molten fluoride salts

International Nuclear Information System (INIS)

Keiser, J.R.

1977-05-01

The molten fluoride salt compatibility studies carried out during the period 1974--76 in support of the Molten-Salt Reactor Program are summarized. Thermal-convection and forced-circulation loops were used to measure the corrosion rate of selected alloys. Results confirmed the relationship of time, initial chromium concentration, and mass loss developed by previous workers. The corrosion rates of Hastelloy N and Hastelloy N modified by the addition of 1--3 wt percent Nb were well within the acceptable range for use in an MSBR. 13 figures, 3 tables

Crust formation and its effect on the molten pool coolability

Energy Technology Data Exchange (ETDEWEB)

Park, R.J.; Lee, S.J.; Sim, S.K. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1995-09-01

Experimental and analytical studies of the crust formation and its effect on the molten pool coolability have been performed to examine the crust formation process as a function of boundary temperatures as well as to investigate heat transfer characteristics between molten pool and overlying water in order to evaluate coolability of the molten pool. The experimental test results have shown that the surface temperature of the bottom plate is a dominant parameter in the crust formation process of the molten pool. It is also found that the crust thickness of the case with direct coolant injection into the molten pool is greater than that of the case with a heat exchanger. Increasing mass flow rate of direct coolant injection to the molten pool does not affect the temperature of molten pool after the crust has been formed in the molten pool because the crust behaves as a thermal barrier. The Nusselt number between the molten pool and the coolant of the case with no crust formation is greater than that of the case with crust formation. The results of FLOW-3D analyses have shown that the temperature distribution contributes to the crust formation process due to Rayleigh-Benard natural convection flow.

Molten salt based nanofluids based on solar salt and alumina nanoparticles: An industrial approach

Science.gov (United States)

Muñoz-Sánchez, Belén; Nieto-Maestre, Javier; Guerreiro, Luis; Julia, José Enrique; Collares-Pereira, Manuel; García-Romero, Ana

2017-06-01

Thermal Energy Storage (TES) and its associated dispatchability is extremely important in Concentrated Solar Power (CSP) plants since it represents the main advantage of CSP technology in relation to other renewable energy sources like photovoltaic (PV). Molten salts are used in CSP plants as a TES material because of their high operational temperature and stability of up to 600°C. Their main problems are their relative poor thermal properties and energy storage density. A simple cost-effective way to improve the thermal properties of molten salts is to dope them with nanoparticles, thus obtaining the so-called salt-based nanofluids. Additionally, the use of molten salt based nanofluids as TES materials and Heat Transfer Fluid (HTF) has been attracting great interest in recent years. The addition of tiny amounts of nanoparticles to the base salt can improve its specific heat as shown by different authors1-3. The application of these nano-enhanced materials can lead to important savings on the investment costs in new TES systems for CSP plants. However, there is still a long way to go in order to achieve a commercial product. In this sense, the improvement of the stability of the nanofluids is a key factor. The stability of nanofluids will depend on the nature and size of the nanoparticles, the base salt and the interactions between them. In this work, Solar Salt (SS) commonly used in CSP plants (60% NaNO3 + 40% KNO3 wt.) was doped with alumina nanoparticles (ANPs) at a solid mass concentration of 1% wt. at laboratory scale. The tendency of nanoparticles to agglomeration and sedimentation is tested in the molten state by analyzing their size and concentration through the time. The specific heat of the nanofluid at 396 °C (molten state) is measured at different times (30 min, 1 h, 5 h). Further research is needed to understand the mechanisms of agglomeration. A good understanding of the interactions between the nanoparticle surface and the ionic media would provide

Molten salt engineering for thorium cycle. Electrochemical studies as examples

International Nuclear Information System (INIS)

Ito, Yasuhiko

1998-01-01

A Th-U nuclear energy system utilizing accelerator driven subcritical molten salt breeder reactor has several advantages compared to conventional U-Pu nuclear system. In order to obtain fundamental data on molten salt engineering of Th-U system, electrochemical study was conducted. As the most primitive simulated study of beam irradiation of molten salt, discharge electrolysis was investigated in molten LiCl-KCl-AgCl system. Stationary discharge was generated under atmospheric argon gas and fine Ag particles were obtained. Hydride ion (H - ) behavior in molten salts was also studied to predict the behavior of tritide ion (T - ) in molten salt fuel. Finally, hydrogen behavior in metals at high temperature was investigated by electrochemical method, which is considered to be important to confine and control tritium. (author)

Feet sunk in molten aluminium: The burn and its prevention.

Science.gov (United States)

Alonso-Peña, David; Arnáiz-García, María Elena; Valero-Gasalla, Javier Luis; Arnáiz-García, Ana María; Campillo-Campaña, Ramón; Alonso-Peña, Javier; González-Santos, Jose María; Fernández-Díaz, Alaska Leonor; Arnáiz, Javier

2015-08-01

Nowadays, despite improvements in safety rules and inspections in the metal industry, foundry workers are not free from burn accidents. Injuries caused by molten metals include burns secondary to molten iron, aluminium, zinc, copper, brass, bronze, manganese, lead and steel. Molten aluminium is one of the most common causative agents of burns (60%); however, only a few publications exist concerning injuries from molten aluminium. The main mechanisms of lesion from molten aluminium include direct contact of the molten metal with the skin or through safety apparel, or when the metal splash burns through the pants and rolls downward along the leg. Herein, we report three cases of deep dermal burns after 'soaking' the foot in liquid aluminium and its evolutive features. This paper aims to show our experience in the management of burns due to molten aluminium. We describe the current management principles and the key features of injury prevention. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.

Research on electrochemical methods for concentration measurement of dissolved ion in molten salt to apply to electrolytic process control. Innovative research adopted in 2002 fiscal year

International Nuclear Information System (INIS)

Nagai, Takayuki

2005-03-01

The purpose of this research is to establish the online (in-situ) technique for concentration measuring of dissolved ion in the molten salt, and this technique is due to the electrochemical method for the concentration measuring of dissolved ion in solutions like the polarization curve measurement. This research executed the following four items. 1) Examination of possibility for concentration measuring of dissolved ion in molten salt by cyclic voltammetry. 2) Examination of possibility for concentration measuring of dissolved ion in molten salt by various electrochemical methods. 3) Examination of suitable electrochemical method for concentration measuring of dissolved ion. 4) Confirmation of selected electrochemical method for concentration measuring of dissolved ion. It has been understood that the differential pulse voltammetry (DPV) is a promising electrochemical technique for the concentration measuring of dissolved ion in the molten salt as a result of this research. An appropriate measurement condition is as follows, the potential sweep rate is -0.1 V/s, the pulse cycle is 0.1 s, the pulse width is 10 ms, and the pulse voltage is 50 mV. As for the electrodes, the platinum working electrode, the glassy carbon counter electrode, and silver/silver chloride reference electrode are suitable. Moreover, the molar absorptivities of U 3+ , U 4+ , UO 2 + , UO 2 2+ , and the standard redox potentials of couples of U 4+ /U 3+ and UO 2 2+ /UO 2 + were acquired as a basic data of the uranium and the uranyl ion in molten NaCl-2CsCl. (author)

Pitting corrosion of Inconel 600 in chloride and sulfate solutions at low temperature

International Nuclear Information System (INIS)

Chang Mingyu; Yu Geping

1993-01-01

Pitting corrosion of Inconel 600 was examined in chloride and sulfate solutions through usage of potentiodynamic polarization techniques. The effects of chloride and sulfate concentration were investigated in the range of 0.0001 to 0.1 M. Increasing chloride concentrations resulted in active shifts of the pit nucleation potential. Immunity to pitting corrosion was evident at a chloride level below 0.005 M. Increasing sulfate concentrations resulted in improved pitting resistance of Inconel 600 in chloride solutions. Detrimental effects associated with pitting were evident with low-level sulfate being added to dilute chloride media. The density of pits increased with increasing chloride concentrations or temperature between room temperature and 70 C. Systematic trends for the depth of pits were not evident. The observations of pitting corrosion in open immersion were consistent with those in polarization methods. Corrosion products contained in the pits were enriched in nickel, chromium and iron with a small amount of titanium and silicon. The enrichment of chlorine or sulfur was still, however, not found. (orig.)

The dissolution of chalcopyrite in chloride media

International Nuclear Information System (INIS)

Ibanez, T.; Velasquez, L.

2013-01-01

The aim of this investigation is to determinate the effects of parameters and additives on the kinetics of dissolution of chalcopyrite on moderated conditions by means of dissolutions test with chalcopyrite concentrate and pure chalcopyrite in shake flasks and instrumented stirred reactors. A study of the dissolution of chalcopyrite in chloride solutions has demonstrated that the rate of dissolution of chalcopyrite is strongly dependent on the potential of the solution within a range of 540 to 630 mV (versus SHE). Leaching at pH around 2.5 results in increased rates of copper dissolution suggesting the possibility to keep the solution potential within the range. Both pyrite and silver ions enhance the dissolution of chalcopyrite and this effect increases when both species are present. The MnO 2 has a negative effect on the dissolution increasing the solution potential to values where the rate decreases considerably. (Author)

Experimental studies of oxidic molten corium-vessel steel interaction

International Nuclear Information System (INIS)

Bechta, S.V.; Khabensky, V.B.; Vitol, S.A.; Krushinov, E.V.; Lopukh, D.B.; Petrov, Yu.B.; Petchenkov, A.Yu.; Kulagin, I.V.; Granovsky, V.S.; Kovtunova, S.V.; Martinov, V.V.; Gusarov, V.V.

2001-01-01

The experimental results of molten corium-steel specimen interaction with molten corium on the 'Rasplav-2' test facility are presented. In the experiments, cooled vessel steel specimens positioned on the molten pool bottom and uncooled ones lowered into the molten pool were tested. Interaction processes were studied for different corium compositions, melt superheating and in alternative (inert and air) overlying atmosphere. Hypotheses were put forward explaining the observed phenomena and interaction mechanisms. The studies presented in the paper were aimed at the detection of different corium-steel interaction mechanisms. Therefore certain identified phenomena are more typical of the ex-vessel localization conditions than of the in-vessel corium retention. Primarily, this can be referred to the phenomena of low-temperature molten corium-vessel steel interaction in oxidizing atmosphere

Experimental studies of oxidic molten corium-vessel steel interaction

Energy Technology Data Exchange (ETDEWEB)

Bechta, S.V. E-mail: niti-npc@sbor.net; Khabensky, V.B.; Vitol, S.A.; Krushinov, E.V.; Lopukh, D.B.; Petrov, Yu.B.; Petchenkov, A.Yu.; Kulagin, I.V.; Granovsky, V.S.; Kovtunova, S.V.; Martinov, V.V.; Gusarov, V.V

2001-12-01

The experimental results of molten corium-steel specimen interaction with molten corium on the 'Rasplav-2' test facility are presented. In the experiments, cooled vessel steel specimens positioned on the molten pool bottom and uncooled ones lowered into the molten pool were tested. Interaction processes were studied for different corium compositions, melt superheating and in alternative (inert and air) overlying atmosphere. Hypotheses were put forward explaining the observed phenomena and interaction mechanisms. The studies presented in the paper were aimed at the detection of different corium-steel interaction mechanisms. Therefore certain identified phenomena are more typical of the ex-vessel localization conditions than of the in-vessel corium retention. Primarily, this can be referred to the phenomena of low-temperature molten corium-vessel steel interaction in oxidizing atmosphere.

Modification Of Carry-Blair Transport Media For Storage Salmonella typhi

Directory of Open Access Journals (Sweden)

Yati Supriatin

2016-09-01

Full Text Available The aim of this study was to determine transport media modification as alternative media to replace Carry Blair. One type of transport media that often use to carry faeces specimens suspected to contain Salmonella typhi is Carry-Blair media. Studies have been conducted experimentally by storing Salmonella typhi on alternative transport media with Peptone composition, disodium Phosphate, Sodium chloride, Calcium chloride, which is made using a semi-solid and Carry-Blair as a control. Three variety of storage was done (0 hour,6 hours,9 hours at a temperature 4⁰-8⁰C and then Salmonella typhi was inoculated in Salmonella Shigella Agar using spread plate technique incubated during 24 hours at 37⁰C, counted the number of colonies by the plate count method using the colony counter. The results of ANOVA could be concluded that modification media could be use as alternative media replace Carry-Blair at 6 hours. Based on regression correlation test was assumed that the Salmonella typhi bacteria still life at less than 11 hours 54 minutes.

Modelling of molten fuel/concrete interactions

International Nuclear Information System (INIS)

Muir, J.F.; Benjamin, A.S.

1980-01-01

A computer program modelling the interaction between molten core materials and structural concrete (CORCON) is being developed to provide quantitative estimates of fuel-melt accident consequences suitable for risk assessment of light water reactors. The principal features of CORCON are reviewed. Models developed for the principal interaction phenomena, inter-component heat transfer, concrete erosion, and melt/gas chemical reactions, are described. Alternative models for the controlling phenomenon, heat transfer from the molten pool to the surrounding concrete, are presented. These models, formulated in conjunction with the development of CORCON, are characterized by the presence or absence of either a gas film or viscous layer of molten concrete at the melt/concrete interface. Predictions of heat transfer based on these models compare favorably with available experimental data

Molten salt oxidation of organic hazardous waste with high salt content.

Science.gov (United States)

Lin, Chengqian; Chi, Yong; Jin, Yuqi; Jiang, Xuguang; Buekens, Alfons; Zhang, Qi; Chen, Jian

2018-02-01

Organic hazardous waste often contains some salt, owing to the widespread use of alkali salts during industrial manufacturing processes. These salts cause complications during the treatment of this type of waste. Molten salt oxidation is a flameless, robust thermal process, with inherent capability of destroying the organic constituents of wastes, while retaining the inorganic ingredients in the molten salt. In the present study, molten salt oxidation is employed for treating a typical organic hazardous waste with a high content of alkali salts. The hazardous waste derives from the production of thiotriazinone. Molten salt oxidation experiments have been conducted using a lab-scale molten salt oxidation reactor, and the emissions of CO, NO, SO 2 , HCl and dioxins are studied. Impacts are investigated from the composition of the molten salts, the types of feeding tube, the temperature of molten carbonates and the air factor. Results show that the waste can be oxidised effectively in a molten salt bath. Temperature of molten carbonates plays the most important role. With the temperature rising from 600 °C to 750 °C, the oxidation efficiency increases from 91.1% to 98.3%. Compared with the temperature, air factor has but a minor effect, as well as the composition of the molten salts and the type of feeding tube. The molten carbonates retain chlorine with an efficiency higher than 99.9% and the emissions of dioxins are below 8 pg TEQ g -1 sample. The present study shows that molten salt oxidation is a promising alternative for the disposal of organic hazardous wastes containing a high salt content.

Dynamics of the Molten Contact Line

Science.gov (United States)

Sonin, Ain A.; Duthaler, Gregg; Liu, Michael; Torresola, Javier; Qiu, Taiqing

1999-01-01

The purpose of this program is to develop a basic understanding of how a molten material front spreads over a solid that is below its melting point, arrests, and freezes. Our hope is that the work will contribute toward a scientific knowledge base for certain new applications involving molten droplet deposition, including the "printing" of arbitrary three-dimensional objects by precise deposition of individual molten microdrops that solidify after impact. Little information is available at this time on the capillarity-driven motion and arrest of molten contact line regions. Schiaffino and Sonin investigated the arrest of the contact line of a molten microcrystalline wax spreading over a subcooled solid "target" of the same material. They found that contact line arrest takes place at an apparent liquid contact angle that depends primarily on the Stefan number S=c(T(sub f) -T(sub t)/L based on the temperature difference between the fusion point and the target temperature, and proposed that contact line arrest occurs when the liquid's dynamic contact angle approaches the angle of attack of the solidification front just behind the contact line. They also showed, however, that the conventional continuum equations and boundary conditions have no meaningful solution for this angle. The solidification front angle is determined by the heat flux just behind the contact line, and the heat flux is singular at that point. By comparing experiments with numerical computations, Schiaffino and Sonin estimated that the conventional solidification model must break down within a distance of order 0.1 - 1 microns of the contact line. The physical mechanism for this breakdown is as yet undetermined, and no first-principles theory exists for the contact angle at arrest. Schiaffino and Sonin also presented a framework for understanding how to moderate Weber number molten droplet deposition in terms of similarity laws and experimentation. The study is based on experiments with three molten

Core-concrete molten pool dynamics and interfacial heat transfer

International Nuclear Information System (INIS)

Benjamin, A.S.

1980-01-01

Theoretical models are derived for the heat transfer from molten oxide pools to an underlying concrete surface and from molten steel pools to a general concrete containment. To accomplish this, two separate effects models are first developed, one emphasizing the vigorous agitation of the molten pool by gases evolving from the concrete and the other considering the insulating effect of a slag layer produced by concrete melting. The resulting algebraic expressions, combined into a general core-concrete heat transfer representation, are shown to provide very good agreement with experiments involving molten steel pours into concrete crucibles

Extraction and separation of zinc and cadmium chlorides by TOPO from mixed media

International Nuclear Information System (INIS)

Ben Mousa, S.; Altakrory, A.; Abdel Raouf, M.W.; Alian, A.

1997-01-01

The effect of water-miscible alcohols and acetone on the extraction and separation of Cd and Zn chlorides by TOPO was systematically investigated. The maximum extraction of Zn chloride with 0.1 M TOPO decreases in the order: acetone> methanol> ethanol> 2-propanol> 2-butanol. For alcohols, the sequence of decreasing extractability is thus parallel to the order of their dielectric constants. This can be explained by the increase of HCl extraction by TOPO in the same direction. The presence of additives in the polar phase prevents the formation of a bulky white precipitate encountered during extraction of Zn Cl 2 from pure aqueous solutions. A decrease of Cd chloride extraction was generally noticed in presence of additives; this is more noticeable for the longer chain alcohols. The highest separation factor (E) for Zn Cl 2 and Cd Cl 2 in 0.4 M HCl is obtained from 30% methanol (13.8 compared to about 3.8 in absence of methanol) and from 10-20% acetone where it reaches 30

Electrochemical ion separation in molten salts

Science.gov (United States)

Spoerke, Erik David; Ihlefeld, Jon; Waldrip, Karen; Wheeler, Jill S.; Brown-Shaklee, Harlan James; Small, Leo J.; Wheeler, David R.

2017-12-19

A purification method that uses ion-selective ceramics to electrochemically filter waste products from a molten salt. The electrochemical method uses ion-conducting ceramics that are selective for the molten salt cations desired in the final purified melt, and selective against any contaminant ions. The method can be integrated into a slightly modified version of the electrochemical framework currently used in pyroprocessing of nuclear wastes.

An experimental test plan for the characterization of molten salt thermochemical properties in heat transport systems

International Nuclear Information System (INIS)

Calderoni, Pattrick

2010-01-01

Molten salts are considered within the Very High Temperature Reactor program as heat transfer media because of their intrinsically favorable thermo-physical properties at temperatures starting from 300 C and extending up to 1200 C. In this context two main applications of molten salt are considered, both involving fluoride-based materials: as primary coolants for a heterogeneous fuel reactor core and as secondary heat transport medium to a helium power cycle for electricity generation or other processing plants, such as hydrogen production. The reference design concept here considered is the Advanced High Temperature Reactor (AHTR), which is a large passively safe reactor that uses solid graphite-matrix coated-particle fuel (similar to that used in gas-cooled reactors) and a molten salt primary and secondary coolant with peak temperatures between 700 and 1000 C, depending upon the application. However, the considerations included in this report apply to any high temperature system employing fluoride salts as heat transfer fluid, including intermediate heat exchangers for gas-cooled reactor concepts and homogeneous molten salt concepts, and extending also to fast reactors, accelerator-driven systems and fusion energy systems. The purpose of this report is to identify the technical issues related to the thermo-physical and thermo-chemical properties of the molten salts that would require experimental characterization in order to proceed with a credible design of heat transfer systems and their subsequent safety evaluation and licensing. In particular, the report outlines an experimental R and D test plan that would have to be incorporated as part of the design and operation of an engineering scaled facility aimed at validating molten salt heat transfer components, such as Intermediate Heat Exchangers. This report builds on a previous review of thermo-physical properties and thermo-chemical characteristics of candidate molten salt coolants that was generated as part

An experimental test plan for the characterization of molten salt thermochemical properties in heat transport systems

Energy Technology Data Exchange (ETDEWEB)

Pattrick Calderoni

2010-09-01

Molten salts are considered within the Very High Temperature Reactor program as heat transfer media because of their intrinsically favorable thermo-physical properties at temperatures starting from 300 C and extending up to 1200 C. In this context two main applications of molten salt are considered, both involving fluoride-based materials: as primary coolants for a heterogeneous fuel reactor core and as secondary heat transport medium to a helium power cycle for electricity generation or other processing plants, such as hydrogen production. The reference design concept here considered is the Advanced High Temperature Reactor (AHTR), which is a large passively safe reactor that uses solid graphite-matrix coated-particle fuel (similar to that used in gas-cooled reactors) and a molten salt primary and secondary coolant with peak temperatures between 700 and 1000 C, depending upon the application. However, the considerations included in this report apply to any high temperature system employing fluoride salts as heat transfer fluid, including intermediate heat exchangers for gas-cooled reactor concepts and homogenous molten salt concepts, and extending also to fast reactors, accelerator-driven systems and fusion energy systems. The purpose of this report is to identify the technical issues related to the thermo-physical and thermo-chemical properties of the molten salts that would require experimental characterization in order to proceed with a credible design of heat transfer systems and their subsequent safety evaluation and licensing. In particular, the report outlines an experimental R&D test plan that would have to be incorporated as part of the design and operation of an engineering scaled facility aimed at validating molten salt heat transfer components, such as Intermediate Heat Exchangers. This report builds on a previous review of thermo-physical properties and thermo-chemical characteristics of candidate molten salt coolants that was generated as part of the

Thorium Molten-Salt Nuclear Energy Synergetics

International Nuclear Information System (INIS)

Furukawa, Kazuo; Lecocq, A.; Kato, Yoshio; Mitachi, Kohshi.

1990-01-01

In the next century, the 'fission breeder' concept will not be practical to solve the global energy problems, including environmental and North-South problems. As a new measure, a simple rational Th molten salt breeding fuel cycle system, named 'Thorium Molten-Salt Nuclear Energy Synergetics (THORIMS-NES)', which composed of simple power stations and fissile producers, is proposed. This is effective to establish the essential improvement in issues of resources, safety, power-size flexibility, anti-nuclear proliferation and terrorism, radiowaste, economy, etc. securing the simple operation, maintenance, chemical processing, and rational breeding fuel cycle. As examples, 155 MWe fuel self-sustaining power station 'FUJI-II', 7 MWe pilot-plant 'miniFUJI-II', 1 GeV-300 mA proton Accelerator Molten-Salt Breeder 'AMSB', and their combined fuel cycle system are explained. (author)

Design study of advanced nuclear fuel recycle system. Conceptual study of recycle system using molten salt

International Nuclear Information System (INIS)

Kakehi, I.; Shirai, N.; Hatano, M.; Kajitani, M.; Yonezawa, S.; Kawai, T.; Kawamura, F.; Tobe, K.; Takahashi, K.

1996-12-01

For the purpose of developing the future nuclear fuel recycle system, the design study of the advanced nuclear fuel recycle system is being conducted. This report describes intermediate accomplishments in the conceptual system study of the advanced nuclear fuel recycle system. Fundamental concepts of this system is the recycle system using molten salt which intend to break through the conventional concepts of purex and pellet fuel system. Contents of studies in this period are as follows, 1)feasibility study of the process by Cd-cathode for nitride fuel, 2)application study for the molten salt of low melting point (AlCl3+organic salt), 3)research for decladding (advantage of decladding by heat treatment), 4)behavior of FPs in electrorefining (behavior of iodine and volatile FP chlorides, FPs behavior in chlorination), 5)criticality analysis in electrorefiner, 6)drawing of off-gas flow diagram, 7)drawing of process machinery concept (cathode processor, vibration packing), 8)evaluation for the amounts of the high level radioactive wastes, 9)quality of the recycle fuels (FPs contamination of recycle fuel), 10)conceptual study of in-cell handling system, 11)meaning of the advanced nuclear fuel recycle system. The conceptual system study will be completed in describing concepts of the system and discussing issues for the developments. (author)

Conceptual design of Indian molten salt breeder reactor

International Nuclear Information System (INIS)

Vijayan, P.K.; Basak, A.; Dulera, I.V.; Vaze, K.K.; Basu, S.; Sinha, R.K.

2014-01-01

The fuel in a molten salt breeder reactor is in the form of a continuously circulating molten salt. Fluoride based salts have been almost universally proposed. A crucial part for achieving reasonable breeding in such reactors is the need to reprocess the salt continuously, either online or in batch mode. This constitutes a major technological challenge for this type of reactors. India has recently started carrying out fundamental studies so as to arrive at a conceptual design of Indian Molten Salt Breeder Reactor (IMSBR). Presently various design options and possibilities are being studied from the point of view of reactor physics and thermal hydraulic design. In parallel fundamental studies as regards various molten salts have also been initiated. This paper would discuss conceptual design of these reactors, as well as associated issues and technologies

Measurement and analyses of molten Ni-Co alloy density

Institute of Scientific and Technical Information of China (English)

XIAO Feng; K. MUKAI; FANG Liang; FU Ya; YANG Ren-hui

2006-01-01

With the advent of powerful mathematical modeling techniques for material phenomena, there is renewed interest in reliable data for the density of the Ni-based superalloys. Up to now, there has been few report on the density of molten Ni-Co alloy.In order to obtain more accurate density data for molten Ni-Co alloy, the density of molten Ni-Co alloy was measured with a modified sessile drop method, and the accommodation of different atoms in molten Ni-Co alloy was analyzed. The density of alloy is found to decrease with increasing temperature and Co concentration in the alloy. The molar volume of molten Ni-Co alloy increases with increasing Co concentration. The molar volume of Ni-Co alloy determined shows a positive deviation from the linear molar volume, and the deviation of molar volume from ideal mixing increases with increasing Co concentration over the experimental concentration range.

Molten core material holding device in a nuclear reactor

International Nuclear Information System (INIS)

Nakamura, Hisashi; Tanaka, Nobuo; Takahashi, Katsuro.

1985-01-01

Purpose: To improve the function of cooling to hold molten core materials in a molten core material holding device. Constitution: Plenum structures are formed into a pan-like configuration, in which liners made of metal having high melting point and relatively high heat conductivity such as tantalum, tungsten, rhenium or alloys thereof are integrally appended to hold and directly cool the molten reactor core materials. Further, a plurality of heat pipes, passing through the plenum structures, facing the cooling portion thereof to the coolants at the outer side and immersing the heating portion into the molten core materials fallen to deposit in the inner liners are disposed radially. Furthermore, heat pipes embodded in the plenum structure are disposed in the same manner below the liners. Thus, the plenum structures and the molten reactor core materials can be cooled at a high efficiency. (Seki, T.)

Chloride Ingress in Chemically Activated Calcined Clay-Based Cement

Directory of Open Access Journals (Sweden)

Joseph Mwiti Marangu

2018-01-01

Full Text Available Chloride-laden environments pose serious durability concerns in cement based materials. This paper presents the findings of chloride ingress in chemically activated calcined Clay-Ordinary Portland Cement blended mortars. Results are also presented for compressive strength development and porosity tests. Sampled clays were incinerated at a temperature of 800°C for 4 hours. The resultant calcined clay was blended with Ordinary Portland Cement (OPC at replacement level of 35% by mass of OPC to make test cement labeled PCC35. Mortar prisms measuring 40 mm × 40 mm × 160 mm were cast using PCC35 with 0.5 M Na2SO4 solution as a chemical activator instead of water. Compressive strength was determined at 28th day of curing. As a control, OPC, Portland Pozzolana Cement (PPC, and PCC35 were similarly investigated without use of activator. After the 28th day of curing, mortar specimens were subjected to accelerated chloride ingress, porosity, compressive strength tests, and chloride profiling. Subsequently, apparent diffusion coefficients (Dapp were estimated from solutions to Fick’s second law of diffusion. Compressive strength increased after exposure to the chloride rich media in all cement categories. Chemically activated PCC35 exhibited higher compressive strength compared to nonactivated PCC35. However, chemically activated PCC35 had the least gain in compressive strength, lower porosity, and lower chloride ingress in terms of Dapp, compared to OPC, PPC, and nonactivated PCC35.

Plutonium scrap waste processing based on aqueous nitrate and chloride media

International Nuclear Information System (INIS)

Navratil, J.D.

1985-01-01

A brief review of plutonium scrap aqueous waste processing technology at Rocky Flats is given. Nitric acid unit operations include dissolution and leaching, anion exchange purification and precipitation. Chloride waste processing consists of cation exchange and carbonate precipitation. Ferrite and carrier precipitation waste treatment processes are also described. 3 figs

Effect of milling on morphology of molten salt synthesized Sr3Ti2O7 crystals

Directory of Open Access Journals (Sweden)

Kijamnajsuk, S.

2007-07-01

Full Text Available Effect of milling liquid (acetone and ethanol, and milling times on morphology of Sr3Ti2O7 (ST7 crystals grow in molten potassium chloride salt at 1250oC for 4 h was investigated. Two kinds of crystals with different morphologies were found: ST7 crystals having a tabular shape of less than 20 μm diameter and small secondary-phase crystals having high symmetry. Milling starting materials in ethanol yielded ST7 crystals that were up to 3 times thinner than those milled with acetone, increasing the (00l Lotgering factor almost twice that when prepared with acetone. Large crystals become a bit smaller and the number of small crystals increased when the milling time increased.

An experimental study on Sodalite and SAP matrices for immobilization of spent chloride salt waste

Science.gov (United States)

Giacobbo, Francesca; Da Ros, Mirko; Macerata, Elena; Mariani, Mario; Giola, Marco; De Angelis, Giorgio; Capone, Mauro; Fedeli, Carlo

2018-02-01

In the frame of Generation IV reactors a renewed interest in pyro-processing of spent nuclear fuel is underway. Molten chloride salt waste arising from the recovering of uranium and plutonium through pyro-processing is one of the problematic wastes for direct application of vitrification or ceramization. In this work, Sodalite and SAP have been evaluated and compared as potential matrices for confinement of spent chloride salt waste coming from pyro-processing. To this aim Sodalite and SAP were synthesized both in pure form and mixed with different glass matrices, i.e. commercially available glass frit and borosilicate glass. The confining matrices were loaded with mixed chloride salts to study their retention capacities with respect to the elements of interest. The matrices were characterized and leached for contact times up to 150 days at room temperature and at 90 °C. SEM analyses were also performed in order to compare the matrix surface before and after leaching. Leaching results are discussed and compared in terms of normalized releases with similar results reported in literature. According to this comparative study the SAP matrix with glass frit binder resulted in the best matrix among the ones studied, with respect to retention capacities for both matrix and spent fuel elements.

Fundamental experiment on simulated molten core/concrete interaction

International Nuclear Information System (INIS)

Toda, S.; Katsumura, Y.

1994-01-01

If a complete and prolonged failure of coolant flow were to occur in a LWR or FBR, fission product decay heat would cause the fuel to overheat. If no available action to cool the fuel were taken, it would eventually melt. Ibis could lead to slumping of the molten core material and to the failure of the reactor pressure vessel and deposition of these materials into the concrete reactor cavity. Consequently, the molten core could melt and decompose the concrete. Vigorous agitation of the molten core pool by concrete decomposition gases is expected to enhance the convective heat transfer process. Besides the decomposition gases, melting concrete (slag) generated under the molten core pool will be buoyed up, and will also affect the downward heat transfer. Though, in this way, the heat transfer process across the interface is complicated by the slag and the gases evolved from the decomposed concrete, it is very important to make its process clear for the safety evaluation of nuclear reactors. Therefore, in this study, fundamental experiments were performed using simulated materials to observe the behaviors of the hot pool, slag and gases at the interface. Moreover, from the experimental observation, a correlation without empirical constants was proposed to calculate the interface heat transfer. The heat transfer across the interface would depend on thermo-physical interactions between the pool, slag and concrete which are changed by their thermal properties and interface temperature and so on. For example, the molten concrete is miscible in molten oxidic core debris, but is immiscible in metallic core debris. If a contact temperature between the molten core pool and the concrete falls below the solidus of the pool, solidification of the pool will occur. In this study, the case of immiscible slag in the pool is treated and solidification of the pool does not occur. Thus, water, paraffin and air were selected as the simulated molten core pool, concrete, and decomposition

Application of lithium in molten-salt reduction processes

International Nuclear Information System (INIS)

Gourishankar, K. V.

1998-01-01

Metallothermic reductions have been extensively studied in the field of extractive metallurgy. At Argonne National Laboratory (ANL), we have developed a molten-salt based reduction process using lithium. This process was originally developed to reduce actinide oxides present in spent nuclear fuel. Preliminary thermodynamic considerations indicate that this process has the potential to be adapted for the extraction of other metals. The reduction is carried out at 650 C in a molten-salt (LiCl) medium. Lithium oxide (Li 2 O), produced during the reduction of the actinide oxides, dissolves in the molten salt. At the end of the reduction step, the lithium is regenerated from the salt by an electrowinning process. The lithium and the salt from the electrowinning are then reused for reduction of the next batch of oxide fuel. The process cycle has been successfully demonstrated on an engineering scale in a specially designed pyroprocessing facility. This paper discusses the applicability of lithium in molten-salt reduction processes with specific reference to our process. Results are presented from our work on actinide oxides to highlight the role of lithium and its effect on process variables in these molten-salt based reduction processes

Structure of molten Bi-Sb-alloys by means of neutron diffraction

International Nuclear Information System (INIS)

Lamparter, P.; Knoll, W.; Steeb, S.

1976-01-01

The structural investigations with melts can be subdivided into two groups: The first group contains molten metals and molten alloys, and one can state that the structure of molten metals and of molten alloys nowadays is rather well understood. Interference functions of molten metals may be described by a hard sphere model. This is valid also for molten alloys with statistical distribution. For the second group, namely molten non-metals and molecular melts, the interference functions as well as the pair correlation functions are very offen rather complicated and not well understood. The present study is concerned with the transition region between these two groups. It is shown that the melts of the Bi-Sb system exhibit a change from metallic to non-metallic structure. Regarding the experimental details: the experiments were done with the two-axes spectrometer D 4 at the high-flux reactor at Grenoble. The containers consisted of cylindrical quartz tubes with a wall thickness of 0.1 cm. The furnace consisted of a direct-heated vanadium tube. The wavelength of the neutrons was 0.695 A. The final result is that the structure in molten Bi-Sb-alloys consists of primitive tetrahedra with coordination number 3. There are less tetrahedra in molten Bi than in molten Sb. Also with rising temperature the number of tetrahedra decreases. It is shown how to compose the coordination numbers of two structures to get the observed coordination number. The observed values are always the mean values of the two structures. (orig./HK) [de

Advances in molten salt electrochemistry towards future energy systems

International Nuclear Information System (INIS)

Ito, Yasuhiko

2005-01-01

This review article describes some selected novel molten salt electrochemical processes which have been created/developed by the author and his coworkers, with emphasis on the applications towards future energy systems. After showing a perspective of the applications of molten salt electrochemistry from the viewpoints of energy and environment, several selected topics are described in detail, which include nitride fuel cycle in a nuclear field, hydrogen energy system coupled with ammonia economy, thermally regenerative fuel cell systems, novel Si production process for solar cell and novel molten salt electrochemical processes for various energy and environment related functional materials including nitrides, rare earth-transition metal alloys, fine particles obtained by plasma-induced electrolysis, and carbon film. And finally, the author stresses again, the importance and potential of molten salt electrochemistry, and encourages young students, scientists and researchers to march in a procession hand in hand towards a bright future of molten salts. (author)

Partially molten magma ocean model

International Nuclear Information System (INIS)

Shirley, D.N.

1983-01-01

The properties of the lunar crust and upper mantle can be explained if the outer 300-400 km of the moon was initially only partially molten rather than fully molten. The top of the partially molten region contained about 20% melt and decreased to 0% at 300-400 km depth. Nuclei of anorthositic crust formed over localized bodies of magma segregated from the partial melt, then grew peripherally until they coverd the moon. Throughout most of its growth period the anorthosite crust floated on a layer of magma a few km thick. The thickness of this layer is regulated by the opposing forces of loss of material by fractional crystallization and addition of magma from the partial melt below. Concentrations of Sr, Eu, and Sm in pristine ferroan anorthosites are found to be consistent with this model, as are trends for the ferroan anorthosites and Mg-rich suites on a diagram of An in plagioclase vs. mg in mafics. Clustering of Eu, Sr, and mg values found among pristine ferroan anorthosites are predicted by this model

Molten salts processes and generic simulation

International Nuclear Information System (INIS)

Ogawa, Toru; Minato, Kazuo

2001-01-01

Development of dry separation process (pyrochemical process) using molten salts for the application of spent-nuclear fuel reprocessing requires a rather complete fundamental database as well as process simulation technique with wide applicability. The present report concerns recent progress and problems in this field taking behaviors of co-electrodeposition of UO 2 and PuO 2 in molten salts as an example, and using analytical simulation of local equilibrium combined with generic diffusion. (S. Ohno)

The evaluation of organic inhibitors for the protection of grade 5 titanium in chloride media

International Nuclear Information System (INIS)

Popa, L.; Tunaru, M.; Velciu, L.

2013-01-01

The corrosion failures of titanium and titanium alloys are inevitably associated with the non-observance of environmental limits prescribed in corrosion handbooks, such as its use in solutions chloride. Titanium alloys are often used in the thermal transfer technology especially in the heat exchangers cooled with sea cooled water. However, it is not indicated its use in strong oxidant and any concentrated chloride environments. For the evaluation of grade 5 titanium alloy samples behaviour in solutions containing chloride ions in presence, respectively, absence of some organic inhibitors were performed by potentiodynamic polarization method. On the basis of our experimental results we consider that the most adequate inhibitor for the system Ti- 5 alloys/0 .083 M NaCl solution is the resorcinol. (authors)

Refractory thermowell for continuous high temperature measurement of molten metal

International Nuclear Information System (INIS)

Thiesen, T.J.

1992-01-01

This patent describes a vessel for handling molten metal having an interior refractory lining, apparatus for continuous high temperature measurement of the molten metal. It comprises a thermowell; the thermowell containing a multiplicity of thermocouples; leads being coupled to a means for continuously indicating the temperature of the molten metal in the vessel

Parametric study of natural circulation flow in molten salt fuel in molten salt reactor

Energy Technology Data Exchange (ETDEWEB)

Pauzi, Anas Muhamad, E-mail: Anas@uniten.edu.my [Centre of Nuclear Energy, Universiti Tenaga Nasional (UNITEN), Jalan IKRAM-UNITEN, 43000 Kajang, Selangor (Malaysia); Cioncolini, Andrea; Iacovides, Hector [School of Mechanical, Aerospace, and Civil Engineering (MACE), University of Manchester, Oxford Road, M13 9PL Manchester (United Kingdom)

2015-04-29

The Molten Salt Reactor (MSR) is one of the most promising system proposed by Generation IV Forum (GIF) for future nuclear reactor systems. Advantages of the MSR are significantly larger compared to other reactor system, and is mainly achieved from its liquid nature of fuel and coolant. Further improvement to this system, which is a natural circulating molten fuel salt inside its tube in the reactor core is proposed, to achieve advantages of reducing and simplifying the MSR design proposed by GIF. Thermal hydraulic analysis on the proposed system was completed using a commercial computation fluid dynamics (CFD) software called FLUENT by ANSYS Inc. An understanding on theory behind this unique natural circulation flow inside the tube caused by fission heat generated in molten fuel salt and tube cooling was briefly introduced. Currently, no commercial CFD software could perfectly simulate natural circulation flow, hence, modeling this flow problem in FLUENT is introduced and analyzed to obtain best simulation results. Results obtained demonstrate the existence of periodical transient nature of flow problem, hence improvements in tube design is proposed based on the analysis on temperature and velocity profile. Results show that the proposed system could operate at up to 750MW core power, given that turbulence are enhanced throughout flow region, and precise molten fuel salt physical properties could be defined. At the request of the authors and the Proceedings Editor the name of the co-author Andrea Cioncolini was corrected from Andrea Coincolini. The same name correction was made in the Acknowledgement section on page 030004-10 and in reference number 4. The updated article was published on 11 May 2015.

Study on mechanical interaction between molten alloy and water

International Nuclear Information System (INIS)

Nishimura, Satoshi; Ueda, Nobuyuki; Nishi, Yoshihisa; Furuya, Masahiro; Kinoshita, Izumi

1999-01-01

Simulant experiments using low melting point molten alloy and water have been conducted to observe both fragmentation behavior of molten jet and boiling phenomena of water, and to measure both particle size and shape of fragmented solidified jet, focusing on post-pin-failure molten fuel-coolant interaction (FCl) which was important to evaluate the sequence of the initiating phase for metallic fueled FBR. In addition, characteristics of coolant boiling phenomena on FCIs have been investigated, focusing on the boiling heat transfer in the direct contact heat transfer mode. As a results, it is concluded that the fragmentation of poured molten alloy jet is affected by a degree of boiling of water and is classified into three modes by thermal conditions of both the instantaneous contact interface temperature of two liquids and subcooling of water. In the case of forced convection boiling in direct contact mode, it is found that the heat transfer performance is enhanced by increase of the heat transfer area, due to oscillation of the surface and fragmentation of molten alloy. As a results of preliminary investigation of FCI behavior for metallic fuel core based on these results, it is expected that the ejected molten fuel is fragmented into almost spherical particles due to the developed boiling of sodium. (author)

A basic study on fluoride-based molten salt electrolysis technology

Energy Technology Data Exchange (ETDEWEB)

Hwang, Il Soon [Seoul National University, Seoul (Korea); Kim, Kwang Bum [Yonsei University, Seoul (Korea); Park, Byung Gi [Seoul National University, Seoul (Korea)

2001-04-01

The objective of this project is to study on the physicochemical properties of fluoride molten salt, to develop numerical model for simulation of molten salt electrolysis, and to establish experimental technique of fluoride molten salt. Physicochemical data of fluoride molten salt are investigated and summarized. The numerical model, designated as REFIN is developed with diffusion-layer theory and electrochemical reaction kinetics. REFIN is benchmarked with published experimental data. REFIN has a capability to simulate multicomponent electrochemical system at transient conditions. Experimental device is developed to measure electrochemical properties of structural material for fluoride molten salt. Ni electrode is measured with cyclic voltammogram in the conditions of 600 .deg. C LiF-BeF{sub 2} and 700 .deg. C LiF-BeF{sub 2}. 74 refs., 23 figs., 57 tabs. (Author)

Stability of oxaliplatin in chloride-containing carrier solutions used in hyperthermic intraperitoneal chemotherapy

NARCIS (Netherlands)

Mehta, A M; Van den Hoven, J M; Rosing, H; Hillebrand, M J X; Nuijen, B; Huitema, A D R; Beijnen, J H; Verwaal, V J

2015-01-01

PURPOSE: Oxaliplatin is increasingly becoming the chemotherapeutic drug of choice for the treatment of peritoneal malignancies using cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC). Oxaliplatin is unstable in chloride-containing media, resulting in the use of 5%

UV-VIS absorption spectra of molten AgCl and AgBr and of their mixtures with group I and II halide salts

Energy Technology Data Exchange (ETDEWEB)

Greening, Giorgio G.W. [Technische Universitaet Darmstadt (Germany). Eduard-Zintl-Institut fuer Anorganische und Physikalische Chemie

2015-07-01

The UV-VIS absorption spectra of (Ag{sub 1-X}[Li-Cs, Ba]{sub X})Cl and of (Ag{sub 1-X}[Na, K, Cs]{sub X})Br at 823 K at the concentrations X=0.0, 0.1, 0.2 have been measured. The findings show that on adding the respective halides to molten silver chloride and silver bromide, shifts of the fundamental absorption edge to shorter wavelengths result. A correlation between the observed shifts and the expansion of the silver sub-lattice is found, which is valid for both silver halide systems studied in this work.

Rheological behavior and constitutive equations of heterogeneous titanium-bearing molten slag

Science.gov (United States)

Jiang, Tao; Liao, De-ming; Zhou, Mi; Zhang, Qiao-yi; Yue, Hong-rui; Yang, Song-tao; Duan, Pei-ning; Xue, Xiang-xin

2015-08-01

Experimental studies on the rheological properties of a CaO-SiO2-Al2O3-MgO-TiO2-(TiC) blast furnace (BF) slag system were conducted using a high-temperature rheometer to reveal the non-Newtonian behavior of heterogeneous titanium-bearing molten slag. By measuring the relationships among the viscosity, the shear stress and the shear rate of molten slags with different TiC contents at different temperatures, the rheological constitutive equations were established along with the rheological parameters; in addition, the non-Newtonian fluid types of the molten slags were determined. The results indicated that, with increasing TiC content, the viscosity of the molten slag tended to increase. If the TiC content was less than 2wt%, the molten slag exhibited the Newtonian fluid behavior when the temperature was higher than the critical viscosity temperature of the molten slag. In contrast, the molten slag exhibited the non-Newtonian pseudoplastic fluid characteristic and the shear thinning behavior when the temperature was less than the critical viscosity temperature. However, if the TiC content exceeded 4wt%, the molten slag produced the yield stress and exhibited the Bingham and plastic pseudoplastic fluid behaviors when the temperature was higher and lower than the critical viscosity temperature, respectively. When the TiC content increased further, the yield stress of the molten slag increased and the shear thinning phenomenon became more obvious.

Molten core retention assembly

International Nuclear Information System (INIS)

Lampe, R.F.

1976-01-01

Molten fuel produced in a core overheating accident is caught by a molten core retention assembly consisting of a horizontal baffle plate having a plurality of openings therein, heat exchange tubes having flow holes near the top thereof mounted in the openings, and a cylindrical imperforate baffle attached to the plate and surrounding the tubes. The baffle assembly is supported from the core support plate of the reactor by a plurality of hanger rods which are welded to radial beams passing under the baffle plate and intermittently welded thereto. Preferably the upper end of the cylindrical baffle terminates in an outwardly facing lip to which are welded a plurality of bearings having slots therein adapted to accept the hanger rods

Comparison of corrosion performance of grade 316 and grade 347H stainless steels in molten nitrate salt

Science.gov (United States)

Trent, M. C.; Goods, S. H.; Bradshaw, R. W.

2016-05-01

Stainless steel samples machined from SA-312 TP316 and SA-213 TP347H pipe were exposed to a molten nitrate salt environment at 600°C (1112°F) for up to 3000 hours in order to generate corrosion rates for use in concentrated solar power (CSP) facilities. Descaled weight loss measurements were made at 1000, 2000, and 3000 hours, with optical and scanning electron microscopy being performed on samples at the longest exposure time. The 316 and 347H alloys exhibited metal losses of 4.4 and 4.8 um respectively at 3000 hours. A linear fit to the data sets yielded annualized metal loss rates of 8.4 and 8.8 um/yr. The oxides were relatively uniform in thickness and multilayered. The inner layer consisted of a (Fe, Cr)-spinel with appreciable amounts of Mn while the outer layer was an oxide composed of only Fe. No pitting, intergranular attack, or other localized attack was found, despite the presence of a sensitized microstructure in both alloys and chloride impurity in the salt mixture. The observations presented here indicate that the two alloys perform quite comparably with respect to molten salt-induced corrosion and in that regard; either would be expected to perform satisfactorily in the intended application.

Dynamics and control of molten-salt breeder reactor

Energy Technology Data Exchange (ETDEWEB)

Sing, Vikram; Lish, Matthew R.; Chvala, Ondrej; Upadhyaya, Belle R. [Dept. of Nuclear Engineering, University of Tennessee, Knoxville (United States)

2017-08-15

Preliminary results of the dynamic analysis of a two-fluid molten-salt breeder reactor (MSBR) system are presented. Based on an earlier work on the preliminary dynamic model of the concept, the model presented here is nonlinear and has been revised to accurately reflect the design exemplified in ORNL-4528. A brief overview of the model followed by results from simulations performed to validate the model is presented. Simulations illustrate stable behavior of the reactor dynamics and temperature feedback effects to reactivity excursions. Stable and smooth changes at various nodal temperatures are also observed. Control strategies for molten-salt reactor operation are discussed, followed by an illustration of the open-loop load-following capability of the molten-salt breeder reactor system. It is observed that the molten-salt breeder reactor system exhibits “self-regulating” behavior, minimizing the need for external controller action for load-following maneuvers.

Dynamics and control of molten-salt breeder reactor

Directory of Open Access Journals (Sweden)

Vikram Singh

2017-08-01

Full Text Available Preliminary results of the dynamic analysis of a two-fluid molten-salt breeder reactor (MSBR system are presented. Based on an earlier work on the preliminary dynamic model of the concept, the model presented here is nonlinear and has been revised to accurately reflect the design exemplified in ORNL-4528. A brief overview of the model followed by results from simulations performed to validate the model is presented. Simulations illustrate stable behavior of the reactor dynamics and temperature feedback effects to reactivity excursions. Stable and smooth changes at various nodal temperatures are also observed. Control strategies for molten-salt reactor operation are discussed, followed by an illustration of the open-loop load-following capability of the molten-salt breeder reactor system. It is observed that the molten-salt breeder reactor system exhibits “self-regulating” behavior, minimizing the need for external controller action for load-following maneuvers.

Chloride metallurgy for uranium recovery: concept and costs

International Nuclear Information System (INIS)

Campbell, M.C.; Ritcey, G.M.; Joe, E.G.

1982-01-01

Uranium, thorium and radium are all effectively solubilized in chloride media. This provides a means to separate and isolate these species for ultimate sale or disposal. The laboratory work on the applications of hydrochloric acid leaching, chlorine assisted leaching and high temperature chlorination is reviewed. An indication of costs and benefits is provided to enable the evaluation of this technology as an option for reducing the environmental impact of tailings

Molten salts processes and generic simulation

Energy Technology Data Exchange (ETDEWEB)

Ogawa, Toru; Minato, Kazuo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

2001-12-01

Development of dry separation process (pyrochemical process) using molten salts for the application of spent-nuclear fuel reprocessing requires a rather complete fundamental database as well as process simulation technique with wide applicability. The present report concerns recent progress and problems in this field taking behaviors of co-electrodeposition of UO{sub 2} and PuO{sub 2} in molten salts as an example, and using analytical simulation of local equilibrium combined with generic diffusion. (S. Ohno)

Development of viscometers for molten salts

International Nuclear Information System (INIS)

Hayashi, Hirokazu; Kato, Yoshio; Ogawa, Toru; Sato, Yuzuru.

1997-06-01

Viscometers specially designed for molten salts were made. One is a oscillating cup type and the other is a capillary type. In the case of the oscillating cup viscometer, the viscosity is determined absolutely through the period and the logarithmic decrement of oscillation with other physical parameters. The period and the logarithmic decrement are calculated from the time intervals between two photo-detectors' intercepts of the reflected laser beam. The capillary viscometer used is made of quartz and the sample is sealed under vacuum, which is placed in a transparent furnace. Efflux time is measured by direct visual observation. Cell constants are determined with distilled water as a calibrating liquid. Viscosities of molten KCl are measured with each viscometer. The differences between measured and standard values of molten KCl at several temperatures are within 5% for the oscillating cup viscometer and within 3% for the capillary viscometer. (author)

Computer simulation on molten ionic salts

International Nuclear Information System (INIS)

Kawamura, K.; Okada, I.

1978-01-01

The extensive advances in computer technology have since made it possible to apply computer simulation to the evaluation of the macroscopic and microscopic properties of molten salts. The evaluation of the potential energy in molten salts systems is complicated by the presence of long-range energy, i.e. Coulomb energy, in contrast to simple liquids where the potential energy is easily evaluated. It has been shown, however, that no difficulties are encountered when the Ewald method is applied to the evaluation of Coulomb energy. After a number of attempts had been made to approximate the pair potential, the Huggins-Mayer potential based on ionic crystals became the most often employed. Since it is thought that the only appreciable contribution to many-body potential, not included in Huggins-Mayer potential, arises from the internal electrostatic polarization of ions in molten ionic salts, computer simulation with a provision for ion polarization has been tried recently. The computations, which are employed mainly for molten alkali halides, can provide: (1) thermodynamic data such as internal energy, internal pressure and isothermal compressibility; (2) microscopic configurational data such as radial distribution functions; (3) transport data such as the diffusion coefficient and electrical conductivity; and (4) spectroscopic data such as the intensity of inelastic scattering and the stretching frequency of simple molecules. The computed results seem to agree well with the measured results. Computer simulation can also be used to test the effectiveness of a proposed pair potential and the adequacy of postulated models of molten salts, and to obtain experimentally inaccessible data. A further application of MD computation employing the pair potential based on an ionic model to BeF 2 , ZnCl 2 and SiO 2 shows the possibility of quantitative interpretation of structures and glass transformation phenomena

Diffusion, electrical mobility and ionic interactions in molten Salts

International Nuclear Information System (INIS)

Lantelme, F.

1965-05-01

The diffusion and the electrical migration of ions in the molten alkali nitrates LiNO 3 , NaNO 3 and KNO 3 and in their mixtures have been examined using stable or radio-active isotope indicators. This experimental works shows that there are large differences in the diffusion coefficients and the electric mobilities when they are compared using the Nernst-Einstein formula. An interpretive model has been put forward which shows the role played by poly-ionic displacements: in a salt AC the particles moving are not only the free ions A - and C + but also the groups [A n C m ] (m-n)+ ... These results confirm the importance of electrostatic attraction and of the polarizability of the ions. This mechanisms, furthermore, explains the inversions of electrical mobilities often observed in liquid ionic media. (author) [fr

Effects of ethylene inhibitors, silver nitrate (AgNO3), cobalt chloride ...

African Journals Online (AJOL)

Significant increase in shoot regeneration, leaf chlorophyll content and rooting occurred when silver nitrate (AgNO3), cobalt chloride (CoCl2) or aminooxyacetic acid (AOA) were added to banana culture medium. The highest numbers of shoots per explants shoot length and leaf surface area was obtained when media were ...

Development of High Temperature Transport System for Molten Salt

International Nuclear Information System (INIS)

Lee, S. H.; Lee, H. S.; Kim, J. G.

2011-01-01

Pyroprocessing technology is one of the the most promising technologies for the advanced fuel cycle with favorable economic potential and intrinsic proliferation-resistance. The electrorefining process, one of main processes which is composed of pyroprocess to recover the useful elements from spent fuel, is under development at the Korea Atomic Energy Research Institute as a sub process of the pyrochemical treatment of spent PWR fuel. High-temperature molten salt transport technologies are required because a molten salt should be transported from the electrorefiner to electrowiner after the electrorefining process. Therefore, in pyrometallurgical processing, the development of high-temperature molten salt transport technologies is a crucial prerequisite. However, there have been a few transport studies on high-temperature molten salt. In this study, an apparatus for suction transport experiments was designed and constructed for the development of high temperature transport technology for molten salt, and the performance test of the apparatus was performed. And also, predissolution test of the salt was carried out using the reactor with furnace in experimental apparatus

Eclogite-associated potassic silicate melts and chloride-rich fluids in the mantle: a possible connection

Science.gov (United States)

Safonov, O.; Butvina, V.

2009-04-01

Relics of potassium-rich (4-14 wt. % of K2O and K2O/Na2O > 1.0) melts are a specific features of some partially molten diamondiferous eclogite xenoliths in kimberlites worldwide [1, 2]. In addition, potassic silicic melt inclusions with up to 16 wt. % of K2O are associated with eclogite phases in kimberlitic diamonds (O. Navon, pers. comm.). According to available experimental data, no such potassium contents can be reached by "dry" and hydrous melting of eclogite. These data point to close connection between infiltration of essentially potassic fluids, partial melting and diamond formation in mantle eclogites [2]. Among specific components of these fluids, alkali chlorides, apparently, play an important role. This conclusion follows from assemblages of the melt relics with chlorine-bearing phases in eclogite xenoliths [1], findings of KCl-rich inclusions in diamonds from the xenoliths [3], and concentration of Cl up to 0.5-1.5 wt. % in the melt inclusions in diamonds. In this presentation, we review our experimental data on reactions of KCl melts and KCl-bearing fluids with model and natural eclogite-related minerals and assemblages. Experiments in the model system jadeite(±diopside)-KCl(±H2O) at 4-7 GPa showed that, being immiscible, chloride liquids provoke a strong K-Na exchange with silicates (jadeite). As a result, low-temperature ultrapotassic chlorine-bearing (up to 3 wt. % of Cl) aluminosilicate melts form. These melts is able to produce sanidine, which is characteristic phase in some partially molten eclogites. In addition, in presence of water Si-rich Cl-bearing mica (Al-celadonite-phlogopite) crystallizes in equilibrium with sanidine and/or potassic melt and immiscible chloride liquid. This mica is similar to that observed in some eclogitic diamonds bearing chloride-rich fluid inclusions [4], as well as in diamonds in partially molten eclogites [2]. Interaction of KCl melt with pyrope garnet also produce potassic aluminosilicate melt because of high

46 CFR 151.50-34 - Vinyl chloride (vinyl chloride monomer).

Science.gov (United States)

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Vinyl chloride (vinyl chloride monomer). 151.50-34... chloride (vinyl chloride monomer). (a) Copper, aluminum, magnesium, mercury, silver, and their alloys shall... equipment that may come in contact with vinyl chloride liquid or vapor. (b) Valves, flanges, and pipe...

Polyvinyl chloride resin

International Nuclear Information System (INIS)

Kim, Hong Jae

1976-06-01

This book contains polyvinyl chloride resin industry with present condition such as plastic industry and polyvinyl chloride in the world and Japan, manufacture of polyvinyl chloride resin ; suspension polymerization and solution polymerization, extruding, injection process, hollow molding vinyl record, vacuum forming, polymer powders process, vinyl chloride varnish, vinyl chloride latex, safety and construction on vinyl chloride. Each chapter has descriptions on of process and kinds of polyvinyl chloride resin.

Controlling the discharge of molten material

International Nuclear Information System (INIS)

Geel, J. van; Dobbels, F.; Theunissen, W.

1980-01-01

A method and device are described for controlling the discharge of molten material from a melter or an intermediate vessel, in which a primary outflow is fed to an overflow system, the working level of which is regulated by means of pneumatic pressure on a communicating chamber pertaining to the overflow system. Molten material may be led into a primary overflow by means of a pneumatic lift. The material melted may be a glass used for disposing of radioactive liquid wastes. (author)

Broadband phase difference method for ultrasonic velocimetry in molten glass

International Nuclear Information System (INIS)

Kikura, Hiroshige; Ihara, Tomonori

2016-01-01

This study aims to develop ultrasonic Doppler velocimetry in molten glass. Realization of such a technique has two difficulties: ultrasonic transmission into molten salt and Doppler signal processing. Buffer rod technique was developed in our research to transmit ultrasound into high temperature molten glass. This article discusses newly developed signal processing technique named broadband phase difference method. (J.P.N.)

Thermohydraulic behaviour and heat transfer in the molten core

International Nuclear Information System (INIS)

Reineke, H.H.

1977-01-01

Increasing the application of nuclear reactors to produce electrical power extremely unprobable accidents should be investigated too. In the Federal Republic of Germany, a research program is performed for some years engaged in accidents at light water reactors in which the melting of the reactor core is presumed. A part of this program is to investigate the thermohydraulic and the heat transfer behavior in an accumulation of molten core material. The knowledge of these events is necessary to analyse the accident exactly. Further on the results of this work are of great importance to build a catcher for the molten core material. As a result of the decay heat the molten material is heated up and the density differences induce a free convection motion. In this work the thermohydraulic behavior and the distribution of the escaping heat fluxes for several accumulations of molten core material were determined. The numerical methods for solving the system of partial differential equation were used to develop computer codes, able to compute the average and local heat fluxes at the walls enclosing the molten core material and the inside increase of the temperature. The numerical computations were confirmed and verified by experimental investigations. In these investigations the molten core material was always assumed as a homogeneous fluid. In this case, the results could be reproduced by simple power laws

Heat transfer on liquid-liquid interface of molten-metal and water

International Nuclear Information System (INIS)

Tanaka, T.; Saito, Yasushi; Mishima, Kaichiro

2001-01-01

Molten-core pool had been formed in the lower-head of TMI-2 pressure vessel at the severe accident. The lower head, however, didn't receive any damage by reactor core cooling. Heat transfer at outside of the lower head and boiling heat transfer at liquid-liquid interface of molten-metal and water, however, are important for initial cooling process of the molten-core pool. The heat transfer experiments for the liquid-liquid interface of molten-metal and water are carried out over the range of natural convection to film boiling region. Phenomenon on the heat transfer experiments are visualized by using of high speed video camera. Wood's metal and U-alloy 78 are used as molten-metal. The test section of the experiments consists of a copper block with heater, wood's metal, and water. Three thermocouple probes are used for temperature measurement of water side and the molten-metal side. Stability of the liquid-liquid interface is depended on the wetness of container wall for molten metal and the temperature distribution of the interface. Entrainment phenomena of molten-metal occurs by a fluctuation of the interface after boiling on the container wall surface. The boiling curves obtained from the liquid-liquid interface experiments are agree with the nucleate boiling and the film boiling correlations of solid-liquid system. (Suetake, M.)

Experimental studies on natural circulation in molten salt loops

International Nuclear Information System (INIS)

Srivastava, A.K.; Borgohain, A.; Maheshwari, N.K.; Vijayan, P.K.

2015-01-01

Molten salts are increasingly getting attention as a coolant and storage medium in solar thermal power plants and as a liquid fuel, blanket and coolant in Molten Salt Reactors (MSR’s). Two different test facilities named Molten Salt Natural Circulation Loop (MSNCL) and Molten Active Fluoride salt Loop (MAFL) have been setup for thermal hydraulics, instrument development and material related studies relevant to MSR and solar power plants. The working medium for MSNCL is a molten nitrate salt which is a mixture of NaNO 3 and KNO 3 in 60:40 ratio and proposed as one of the coolant option for molten salt based reactor and coolant as well as storage medium for solar thermal power application. On the other hand, the working medium for MAFL is a eutectic mixture of LiF and ThF 4 and proposed as a blanket salt for Indian Molten Salt Breeder Reactor (MSBR). Steady state natural circulation experiments at different power level have been performed in the MSNCL. Transient studies for startup of natural circulation, loss of heat sink, heater trip and step change in heater power have also been carried out in the same. A 1D code LeBENC, developed in-house to simulate the natural circulation characteristics in closed loops, has been validated with the experimental data obtained from MSNCL. Further, LeBENC has been used for Pretest analysis of MAFL. This paper deals with the description of both the loops and experimental studies carried out in MSNCL. Validation of LeBENC along with the pretest analysis of MAFL using the same are also reported in this paper. (author)

Compatibility tests between molten salts and metal materials (2)

International Nuclear Information System (INIS)

Shiina, Yasuaki

2003-08-01

Latent heat storage technology using molten salts can reduce temperature fluctuations of heat transfer fluid by latent heat for middle and high temperature regions. This enables us to operate several heat utilization systems in cascade connected to High Temperature Gas Cooled Reactors (HTGRs) from high to low temperature range by setting the latent heat storage system after a heat utilization system to reduce thermal load after the heat utilization systems. This latent heat technology is expected to be used for effective use of heat such as equalization of electric load between night and daytime. In the application of the latent heat technology, compatibility between molten salts and metal materials is very important because molten salts are corrosive, and heat transfer pipes and vessels will contact with the molten salts. It will be necessary to prevail the latent heat storage technique that normal metal materials can be used for the pipes and vessels. However, a few studies have been reported of compatibility between molten salts and metals in middle and high temperature ranges. In this study, four molten salts, range of the melting temperature from 490degC to 800degC, are selected and five metals, high temperature and corrosion resistance steels of Alloy600, HastelloyB2, HastelloyC276, SUS310S and pure Nickel are selected for the test with the consideration of metal composition. Test was performed in an electric furnace by setting the molten salts and the metals in melting pots in an atmosphere of nitrogen. Results revealed excellent corrosion resistance of pure Nickel and comparatively low corrosion resistance of nickel base alloys such as Alloy600 and Hastelloys against Li 2 CO 3 . Corrosion resistance of SUS310S was about same as nickel based alloys. Therefore, if some amount of corrosion is permitted, SUS310S would be one of the candidate alloys for structure materials. These results will be used as reference data to select metals in latent heat technology

Break-up and quench behavior of molten material in coolant

International Nuclear Information System (INIS)

Abe, Y.; Kizu, T.; Arai, T.; Nariai, H.; Chitose, K.; Koyama, K.

2003-01-01

In a Core Disruptive Accident (CDA) of a Fast Breeder Reactor, the Post Accident Heat Removal(PAHR) is crucial for the accident mitigation. The molten core material should be solidified in the sodium coolant in the reactor vessel. The material, being fragmented while solidification and forming debris bed, will be cooled in the coolant. In the experiment, molten material jet is injected into water to experimentally obtain fragments and the visualized information of the fragmentation and boiling phenomena during PAHR in CDA. The distributed particle behavior of the molten material jet is observed with high-speed video camera. The experimental results are compared with the existing theories. Consequently, the marginal wavelength on the surface of a water jet is close to the value estimated based on the Rayleigh-Taylor instability. Moreover, the fragmented droplet diameter obtained from the interaction of molten material and water is close to the value estimated based on the Kelvin-Helmholtz instability. Once the particle diameter of the fragmented molten material could be known from a hydrodynamic model, it becomes possible to estimate the mass of the molten particle with some appropriate heat transfer model

Thermal behavior of molten corium during TMI-2 core relocation event

International Nuclear Information System (INIS)

Anderson, J.L.; Sienicki, J.J.

1988-01-01

During the TMI-2 accident, a pool of molten corium formed in the central region of the core and was contained by solidified crusts. Failure of the crust surrounding the molten material, at approximately 224 min, resulted in a relocation of an estimated 20-25 tons of molten corium through peripheral fuel assemblies in the east side of the vessel, as well as through the core barrel assembly (CBA) at the periphery of the core. This paper presents the results of an analyses carried out to investigate the thermal interactions of molten corium with the CBA structures during the relocation event. The principal objectives of the analyses are: (a) to assess the potential for relocation to take place through the CBA versus the flow of molten core material directly downward through the core via the fuel assemblies; and (b) to understand the distribution of prior molten corium observed during vessel defueling examinations. 5 refs., 1 fig

Experimental study on forced convection boiling heat transfer on molten alloy

International Nuclear Information System (INIS)

Nishimura, Satoshi; Ueda, Nobuyuki; Nishi, Yoshihisa; Furuya, Masahiro; Kinoshita, Izumi

1999-01-01

In order to clarify the characteristics of forced convection boiling heat transfer on molten metal, basic experiments have been carried out with subcooled water flowing on molten Wood's alloy pool surface. In these experiments, water flows horizontally in a rectangular duct. A cavity filled with Wood's alloy is present in a portion of the bottom of the duct. Wood's alloy is heated by a copper conductor at the bottom of the cavity. The experiments have been carried out with various velocities and subcoolings of water, and temperature of Wood's alloy. Boiling curves on the molten alloy surface were obtained and compared with that on a solid heat transfer surface. It is observed that the boiling curve on molten alloy is in a lower superheat region than the boiling curve on a solid surface. This indicates that the heat transfer performance of forced convection boiling on molten alloy is enhanced by increase of the heat transfer area, due to oscillation of the surface and fragmentation of molten alloy

Compatibility of AlN ceramics with molten lithium

Energy Technology Data Exchange (ETDEWEB)

Yoneoka, Toshiaki; Sakurai, Toshiharu; Sato, Toshihiko; Tanaka, Satoru [Tokyo Univ., Department of Quantum Engineering and Systems Science, Tokyo (Japan)

2002-04-01

AlN ceramics were a candidate for electrically insulating materials and facing materials against molten breeder in a nuclear fusion reactor. In the nuclear fusion reactor, interactions of various structural materials with solid and liquid breeder materials as well as coolant materials are important. Therefore, corrosion tests of AlN ceramics with molten lithium were performed. AlN specimens of six kinds, different in sintering additives and manufacturing method, were used. AlN specimens were immersed into molten lithium at 823 K. Duration for the compatibility tests was about 2.8 Ms (32 days). Specimens with sintering additive of Y{sub 2}O{sub 3} by about 5 mass% formed the network structure of oxide in the crystals of AlN. It was considered that the corrosion proceeded by reduction of the oxide network and the penetration of molten lithium through the reduced pass of this network. For specimens without sintering additive, Al{sub 2}O{sub 3} containing by about 1.3% in raw material was converted to fine oxynitride particles on grain boundary or dissolved in AlN crystals. After immersion into lithium, these specimens were found to be sound in shape but reduced in electrical resistivity. These degradation of the two types specimens were considered to be caused by the reduction of oxygen components. On the other hand, a specimen sintered using CaO as sintering additive was finally became appreciably high purity. This specimen showed good compatibility for molten lithium at least up to 823 K. It was concluded that the reduction of oxygen concentration in AlN materials was essential in order to improve the compatibility for molten lithium. (author)

Stress corrosion cracking of austenitic stainless steels in NaCl-AlCl/sub 3/ at 175C

International Nuclear Information System (INIS)

Smyrl, W.H.

1987-01-01

Austenitic stainless steels are susceptible to stress corrosion cracking in chloride media. A test that is often used to determine the susceptibility of a new alloy involves boiling aqueous MgCl/sub 2/ solutions. The compositions of the solution is not controlled in the tests, and changes as water is evaporated. The pH may change as well. Such poorly defined conditions make any mechanistic interpretation very tenuous, and the results may be tabulated as purely empirical data. the choice of the molten salt in the present investigation was made for two reasons. First, the studies could be carried in the molten salt media with the exclusion of H/sub 2/O. Second, the crack propagation could be investigated under well controlled electrochemical conditions. Therefore, the results may help to identify the controlling processes that occur during stress corrosion cracking, and the comparison to results in boiling MgCl/sub 2/ may help to reveal the controlling processes in that medium as well. Crack propagation has been studied for several nitronic stainless steels in the molten salt medium under controlled electrochemical potential conditions. The alloys were studied under fully austenitic conditions. The material was studied in the annealed and work hardened condition, and both were susceptible to cracking in the molten salt. The velocity of cracking was studied as a function of applied stress at several electrochemical potentials

Modelization of the SECM in molten salts environment

International Nuclear Information System (INIS)

Lucas, M.; Slim, C.; Di Caprio, D.; Delpech, S.; Stafiej, J.

2013-01-01

We develop a cellular automata simulation of SECM (Scanning Electrochemical Microscopy)experiments to study corrosion in molten salt media for generation IV nuclear reactors. The electrodes used in these experiments are cylindrical glass tips with a coaxial metal wire inside. As the result of simulations we obtain the current approach curves of the electrodes with geometries characterized by several values of the ratios of glass to metal area at the tip. We compare these results with predictions of the known analytic expressions, solutions of partial differential equations for flat uniform geometry of the substrate. We present also the results for other, more complicated substrate surface geometries e. g. regular saw modulated surface, or surface obtained by an Eden model process. We show that with a simple cellular automata model we can reasonably well simulate the results of SECM setup. The stochastic resolution of the diffusion equations is made possible by the parallel code implemented on GPU

Behavior of molybdenum in pyrochemical reprocessing: A spectroscopic study of the chlorination of molybdenum and its oxides in chloride melts

International Nuclear Information System (INIS)

Volkovicha, Vladimir A.; Griffiths, Trevor R.; Thied, Robert C.; Lewin, Bob

2003-01-01

The high temperature reactions of molybdenum and its oxides with chlorine and hydrogen chloride in molten alkali metal chlorides were investigated between 400 and 700 deg. C. The melts studied were LiCl-KCl, NaCl-CsCl and NaCl-KCl and the reactions were followed by in situ electronic absorption spectroscopy measurements. In these melts Mo reacts with Cl 2 and initially produces MoCl 6 2- and then a mixture of Mo(III) and Mo(V) chlorocomplexes, the final proportion depending on the reaction conditions. The Mo(V) content can be removed as MoCl 5 from the melt under vacuum or be reduced to Mo(III) by Mo metal. The reaction of Mo when HCl gas is bubbled into alkali chloride melts yields only MoCl 6 3- . MoO 2 reacts in these melts with chlorine to form soluble MoOCl 5 2- and volatile MoO 2 Cl 2 . MoO 3 is soluble in chloride melts and then decomposes into the oxychloride MoO 2 Cl 2 , which sublimes or can be sparged from the melt, and molybdate. Pyrochemical reprocessing can thus be employed for molybdenum since, after various intermediates, the end-products are chloride melts containing chloro and oxychloro anions of molybdenum plus molybdate, and volatile chlorides and oxychlorides that can be readily separated off. The reactions were fastest in the NaCl-KCl melt. The X-ray diffraction pattern of MoO 2 Cl 2 is reported for the first time

Indian programme on molten salt cooled nuclear reactors

International Nuclear Information System (INIS)

DuIera, I.V.; Vijayan, P.K.; Sinha, R.K.

2013-01-01

Bhabha Atomic Research Centre (BARC) is developing a 600 MWth pebble bed high temperature reactor, cooled by natural circulation of molten fluoride salts and is capable of supplying process heat at 1000 ℃ to facilitate hydrogen production by splitting water. BARC has also initiated studies for a reactor concept in which salts of molten fluoride fuel and coolant in fluid form, flows through the reactor core of graphite moderator, resulting in nuclear fission within the molten salt. For thorium fuel cycle, this concept is very attractive, since the fuel can be re-processed on-line, enabling it to be an efficient neutron breeder. (author)

Effect of the graphite electrode material on the characteristics of molten salt electrolytically produced carbon nanomaterials

International Nuclear Information System (INIS)

Kamali, Ali Reza; Schwandt, Carsten; Fray, Derek J.

2011-01-01

The electrochemical erosion of a graphite cathode during the electrolysis of molten lithium chloride salt may be used for the preparation of nano-structured carbon materials. It has been found that the structures and morphologies of these carbon nanomaterials are dependent on those of the graphite cathodes employed. A combination of tubular and spherical carbon nanostructures has been produced from a graphite with a microstructure of predominantly planar micro-sized grains and a minor fraction of more irregular nano-sized grains, whilst only spherical carbon nanostructures have been produced from a graphite with a microstructure of primarily nano-sized grains. Based on the experimental results, a best-fit regression equation is proposed that relates the crystalline domain size of the graphite reactants and the carbon products. The carbon nanomaterials prepared possess a fairly uniform mesoporosity with a sharp peak in pore size distribution at around 4 nm. The results are of crucial importance to the production of carbon nanomaterials by way of the molten salt electrolytic method. - Highlights: → Carbon nanomaterials are synthesised by LiCl electrolysis with graphite electrodes. → The degree of crystallinity of graphite reactant and carbon product are related. → A graphite reactant is identified that enables the preparation of carbon nanotubes. → The carbon products possess uniform mesoporosity with narrow pore size distribution.

State-of-the-Art Report on Molten Corium Concrete Interaction and Ex-Vessel Molten Core Coolability

International Nuclear Information System (INIS)

Bonnet, Jean-Michel; Cranga, Michel; Vola, Didier; Marchetto, Cathy; Kissane, Martin; ); Robledo, Fernando; Farmer, Mitchel T.; Spengler, Claus; Basu, Sudhamay; Atkhen, Kresna; Fargette, Andre; Fisher, Manfred; Foit, Jerzi; Hotta, Akitoshi; Morita, Akinobu; Journeau, Christophe; Moiseenko, Evgeny; Polidoro, Franco; Zhou, Quan

2017-01-01

Activities carried out over the last three decades in relation to core-concrete interactions and melt coolability, as well as related containment failure modes, have significantly increased the level of understanding in this area. In a severe accident with little or no cooling of the reactor core, the residual decay heat in the fuel can cause the core materials to melt. One of the challenges in such cases is to determine the consequences of molten core materials causing a failure of the reactor pressure vessel. Molten corium will interact, for example, with structural concrete below the vessel. The reaction between corium and concrete, commonly referred to as MCCI (molten core concrete interaction), can be extensive and can release combustible gases. The cooling behaviour of ex-vessel melts through sprays or flooding is also complex. This report summarises the current state of the art on MCCI and melt coolability, and thus should be useful to specialists seeking to predict the consequences of severe accidents, to model developers for severe-accident computer codes and to designers of mitigation measures

Feasibility study of LiF-BeF2 and chloride salts as blanket coolants for fusion power reactors

International Nuclear Information System (INIS)

Imamura, Y.

1977-09-01

The feasibility of using molten salts, in particular, nonberyllium-bearing chloride salts, as blanket coolants for Tokamak fusion reactors has been examined for the nucleonic and thermal/hydraulic aspects. It is concluded that the chloride salts, i.e., LiCl--KCl, LiCl--PbCl 2 and LiCl--SnCl 2 , can be used as the blanket coolant for a static lithium metal blanket provided that large blanket thickness can be tolerated, along with the use of U-238 for neutron multiplication in the cases of LiCl--KCl or LiCl--SnCl 2 cooled blankets. However, to make the appraisal complete, the tritium recovery and corrosion problems must be examined extensively, based on data not yet at hand. As for LiF--BeF 2 , it is observed that although the salt mixture can be used for a single fluid blanket with satisfactory nuclear performance, careful attention should be paid to the cooling capability

The preparation and certification of zirconyl chloride CRM-inhouse from process result of zircon mineral

International Nuclear Information System (INIS)

Samin; Sajimo; Supriyanto; Isman Mulyadi T

2015-01-01

The preparation and certification of the zirconyl chloride certified reference material (CRM) has been carried out from the row material of the zircon mineral. The zircon mineral was processing in the Feeder with the velocity of 17 kg/hour and produced the zircon concentrate. The zircon concentrate was mixed with NaOH, NaF, Na 2 CO 3 and H 2 O. The mixture was melted in the Furnace at 750°C for 2 hours. The results of molten was pressed with aquadest and then was participated for 24 hours. The solid was separated from the filtrate, and then it was dried in the Oven at 105°C for 3 hours, those result was called sodium zirconate. Sodium zirconate was leaching with HCl, it was found the zirconyl chloride solution and then was evaporated it was found the zirconyl chloride concentrated solution. This solution was crystallized, then obtained the zirconyl chloride crystal. It was washed with ethanol, so retrieved the crystal white zirconyl chloride. The crystal white zirconyl chloride was dried in the Oven at 90°C, it was crushed with stainless steel powder and sieved to 200 mesh of the particle size. The crystal white zirconyl chloride was stirred up to homogenous in the Homogenizer. Next was treated the homogenization and the stabilisation testing with statistically method. Zirconyl chloride crystals was standardized by using standard ZrOCl 2 8 H 2 O made in E. Merck, were include the chemical compounds test with XRD Spectrometry, the composition the content of crystals and the specific gravity. From the evaluation of the homogenization and stabilisation testing, the crystal zirconyl chloride was homogeneous, stable and it was fulfil to physically behavior as CRM. Compared with the standard zirconyl chloride, ZrOCl 2 8 H 2 O, the XRD spectra and chemical composition (96,263%), the content of crystals (98,625%). and specific gravity (97,190%) of the zirconyl chloride crystal were nearly same respectively. Certificate of the parameters testing results in the CRM the

Degradation of organochloride pesticides by molten salt oxidation at IPEN: spin-off nuclear activities

International Nuclear Information System (INIS)

Lainetti, Paulo E.O.

2013-01-01

Nuclear spin-off has at least two dimensions. It may provide benefits to the society such as enlarge knowledge base, strengthen infrastructure and benefit technology development. Besides this, to emphasize that some useful technologies elapsed from nuclear activities can affect favorably the public opinion about nuclear energy. In this paper is described a technology developed initially by the Rockwell Int. company in the USA more than thirty years ago to solve some problems of nuclear fuel cycle wastes. For different reasons the technology was not employed. In the last years the interest in the technology was renewed and IPEN has developed his version of the method applicable mainly to the safe degradation of hazardous wastes. This study was motivated by the world interest in the development of advanced processes of waste decomposition, due to the need of safer decomposition processes, particularly for the POPs - persistent organic pollutants and particularly for the organ chlorides. A tendency observed at several countries is the adoption of progressively more demanding legislation for the atmospheric emissions, resultants of the waste decomposition processes. The suitable final disposal of hazardous organic wastes such as PCBs (polychlorinated biphenyls), pesticides, herbicides and hospital residues constitutes a serious problem. In some point of their life cycles, these wastes should be destroyed, in reason of the risk that they represent for the human being, animals and plants. The process involves using a chemical reactor containing molten salts, sodium carbonate or some alkaline carbonates mixtures to decompose the organic waste. The decomposition is performed by submerged oxidation and the residue is injected below the surface of a turbulent salt bath along with the oxidizing agent. Decomposition of halogenated compounds, among which some pesticides, is particularly effective in molten salts. The process presents properties such as intrinsically safe

Metalcasting: Filtering Molten Metal

International Nuclear Information System (INIS)

Lauren Poole; Lee Recca

1999-01-01

A more efficient method has been created to filter cast molten metal for impurities. Read about the resulting energy and money savings that can accrue to many different industries from the use of this exciting new technology

Molten metal feed system controlled with a traveling magnetic field

International Nuclear Information System (INIS)

Praeg, W.F.

1991-01-01

This patent describes a continuous metal casting system in which the feed of molten metal controlled by means of a linear induction motor capable of producing a magnetic traveling wave in a duct that connects a reservoir of molten metal to a caster. The linear induction motor produces a traveling magnetic wave in the duct in opposition to the pressure exerted by the head of molten metal in the reservoir

Liquid Salts as Media for Process Heat Transfer from VHTR's: Forced Convective Channel Flow Thermal Hydraulics, Materials, and Coating

Energy Technology Data Exchange (ETDEWEB)

Sridharan, Kumar; Anderson, Mark; Allen, Todd; Corradini, Michael

2012-01-30

The goal of this NERI project was to perform research on high temperature fluoride and chloride molten salts towards the long-term goal of using these salts for transferring process heat from high temperature nuclear reactor to operation of hydrogen production and chemical plants. Specifically, the research focuses on corrosion of materials in molten salts, which continues to be one of the most significant challenges in molten salts systems. Based on the earlier work performed at ORNL on salt properties for heat transfer applications, a eutectic fluoride salt FLiNaK (46.5% LiF-11.5%NaF-42.0%KF, mol.%) and a eutectic chloride salt (32%MgCl2-68%KCl, mole %) were selected for this study. Several high temperature candidate Fe-Ni-Cr and Ni-Cr alloys: Hastelloy-N, Hastelloy-X, Haynes-230, Inconel-617, and Incoloy-800H, were exposed to molten FLiNaK with the goal of understanding corrosion mechanisms and ranking these alloys for their suitability for molten fluoride salt heat exchanger and thermal storage applications. The tests were performed at 850C for 500 h in sealed graphite crucibles under an argon cover gas. Corrosion was noted to occur predominantly from dealloying of Cr from the alloys, an effect that was particularly pronounced at the grain boundaries Alloy weight-loss due to molten fluoride salt exposure correlated with the initial Cr-content of the alloys, and was consistent with the Cr-content measured in the salts after corrosion tests. The alloys weight-loss was also found to correlate to the concentration of carbon present for the nominally 20% Cr containing alloys, due to the formation of chromium carbide phases at the grain boundaries. Experiments involving molten salt exposures of Incoloy-800H in Incoloy-800H crucibles under an argon cover gas showed a significantly lower corrosion for this alloy than when tested in a graphite crucible. Graphite significantly accelerated alloy corrosion due to the reduction of Cr from solution by graphite and formation

Visualization study of molten metal-water interaction by using neutron radiography

International Nuclear Information System (INIS)

Mishima, K.; Hibiki, T.; Saito, Y.

1999-01-01

The purpose of this study is to visualize the behavior of molten metal dropped into water during the premixing process by means of neutron radiography which makes use of the difference in the attenuation characteristics of materials. For this purpose, a high-sensitive, high-frame-rate imaging system using neutron radiography was constructed and was applied to visualization of the behavior of molten metal dropped into water. The test rig consisted of a furnace and a test section. The furnace could heat the molten metal up to 650 C. The test section was a rectangular tank made of aluminum alloy. The tank was filled with heavy water and molten Wood's metal was dropped into heavy water. Visualization study was carried out with use of the high-frame-rate neutron radiography to see the breakup of molten metal jet or lump dropped into heavy water pool. In the images obtained, water, steam or air bubbles, molten metal jets or droplets, cloud of small particles of molten metal after atomization could be distinguished. The debris of Wood's metal was collected after the experiment, and the relation between the break-up behavior and the size and the shape of the debris particles was investigated. (orig.)

Molten salt reactors and possible scenarios for future nuclear power deployment

International Nuclear Information System (INIS)

Merle-Lucotte, E.; Mathieu, L.; Heuer, D.; Loiseaux, J. M.; Billebaud, A.; Brissot, R.; David, S.; Garzenne, C.; Laulan, O.; Le Brun, C.; Lecarpentier, D.; Liatard, E.; Meplan, O.; Michel-Sendis, F.; Nuttin, A.; Perdu, F.

2004-01-01

An important fraction of the nature energy demand may be satisfied by nuclear power. In this context, the possibilities of worldwide nuclear deployment are studied. We are convinced that the Molten Salt Reactors may play a central role in this deployment. The Molten Salt Reactor needs to be coupled to a reprocessing unit in order to extract the Fission Products which poison the core. The efficiency of this reprocessing has a crucial influence on reactor behavior especially for the breeding ratio. The Molten Salt Breeder Reactor project was based on an intensive reprocessing for high breeding purposes. A new concept of Thorium Molten Salt Reactor is presented here. Including this new concept in the worldwide nuclear deployment, to satisfy these power needs, we consider three typical scenarios, based on three reactor types: Pressurized Water Reactor, Fast Neutron Reactor and Thorium Molten Salt Reactor. The aim of this paper is to demonstrate, in a first hand that a Thorium Molten Salt Reactor can be realistic, with correct temperature coefficients and at least iso-breeder with slow reprocessing and new geometry; on the other hand that such Molten Salt Reactors enable a successful nuclear deployment, while minimizing fuel and waste management problems. (authors)

Galvanic reduction of uranium(III) chloride from LiCl-KCl eutectic salt using gadolinium metal

Science.gov (United States)

Bagri, Prashant; Zhang, Chao; Simpson, Michael F.

2017-09-01

The drawdown of actinides is an important unit operation to enable the recycling of electrorefiner salt and minimization of waste. A new method for the drawdown of actinide chlorides from LiCl-KCl molten salt has been demonstrated here. Using the galvanic interaction between the Gd/Gd(III) and U/U(III) redox reactions, it is shown that UCl3 concentration in eutectic LiCl-KCl can be reduced from 8.06 wt.% (1.39 mol %) to 0.72 wt.% (0.12 mol %) in about an hour via plating U metal onto a steel basket. This is a simple process for returning actinides to the electrorefiner and minimizing their loss to the salt waste stream.

Tritium loss in molten flibe systems

Energy Technology Data Exchange (ETDEWEB)

Longhurst, G.R.; Anderl, R.A. [Idaho National Eng. and Environ. Lab., Idaho Falls, ID (United States); Scott Willms, R. [Los Alamos National Lab., NM (United States)

2000-04-01

An emerging issue relative to beryllium technology in fusion involves tritium interactions with molten beryllium-bearing salts. Innovative designs for fusion reactors, both magnetic and inertially confined, feature the molten salt mixture 2LiF.BeF{sub 2}, commonly called Flibe, as a tritium breeder and coolant. Tritium is bred in the Flibe as neutrons from the plasma are absorbed by Li atoms, which then transmute to tritium and helium. Transmutation of tritium from Be also occurs. Among the issues to be resolved for such coolant systems is the potential loss of tritium from the Flibe coolant to the walls of the system, particularly through heat exchanger tubes, and from there into secondary coolants or working fluids and the environment. Effectively removing tritium from Flibe in clean-up units is also important. In quiescent or low Reynolds number flow, tritium movement through Flibe is governed by diffusion. For Flibe in turbulent flow, as in heat exchanger tubes, transport is by turbulent mixing, and the same flow conditions and structural design features that maximize heat transfer to the heat exchanger walls will enhance the transport of tritium to those same surfaces. Analyses have been performed to estimate the fractional loss of tritium through heat exchanger tubes and release rates from Flibe droplets in vacuum disengagers in molten Flibe systems. The calculations suggest unacceptably large losses of tritium through heat exchanger tubes. The gravity of the implications of these estimates calls for experimental verification to determine if tritium losses through molten Flibe heat exchangers or other Flibe systems can really be so high and whether vacuum disengagers will really work. There is also a need for better information on evolution of tritium from Flibe droplets in a vacuum. Several experiments are presently being planned to address these issues and are discussed. These include experiments to induce tritium in Flibe using spontaneous fission neutrons

Tritium loss in molten flibe systems

International Nuclear Information System (INIS)

Longhurst, G.R.; Anderl, R.A.; Scott Willms, R.

2000-01-01

An emerging issue relative to beryllium technology in fusion involves tritium interactions with molten beryllium-bearing salts. Innovative designs for fusion reactors, both magnetic and inertially confined, feature the molten salt mixture 2LiF.BeF 2 , commonly called Flibe, as a tritium breeder and coolant. Tritium is bred in the Flibe as neutrons from the plasma are absorbed by Li atoms, which then transmute to tritium and helium. Transmutation of tritium from Be also occurs. Among the issues to be resolved for such coolant systems is the potential loss of tritium from the Flibe coolant to the walls of the system, particularly through heat exchanger tubes, and from there into secondary coolants or working fluids and the environment. Effectively removing tritium from Flibe in clean-up units is also important. In quiescent or low Reynolds number flow, tritium movement through Flibe is governed by diffusion. For Flibe in turbulent flow, as in heat exchanger tubes, transport is by turbulent mixing, and the same flow conditions and structural design features that maximize heat transfer to the heat exchanger walls will enhance the transport of tritium to those same surfaces. Analyses have been performed to estimate the fractional loss of tritium through heat exchanger tubes and release rates from Flibe droplets in vacuum disengagers in molten Flibe systems. The calculations suggest unacceptably large losses of tritium through heat exchanger tubes. The gravity of the implications of these estimates calls for experimental verification to determine if tritium losses through molten Flibe heat exchangers or other Flibe systems can really be so high and whether vacuum disengagers will really work. There is also a need for better information on evolution of tritium from Flibe droplets in a vacuum. Several experiments are presently being planned to address these issues and are discussed. These include experiments to induce tritium in Flibe using spontaneous fission neutrons

Molar Volume Analysis of Molten Ni-Al-Co Alloy by Measuring the Density

Institute of Scientific and Technical Information of China (English)

XIAO Feng; FANG Liang; FU Yuechao; YANG Lingchuan

2004-01-01

The density of molten Ni-Al-Co alloys was measured in the temperature range of 1714～1873K using a modified pycnometric method, and the molar volume of molten alloys was analyzed. The density of molten Ni-Al-Co alloys was found to decrease with increasing temperature and Co concentration in alloys. The molar volume of molten Ni-Al-Co alloys increases with increasing Co concentration in alloys. The molar volume of molten Ni-Al-Co alloys shows a negative deviation from the linear molar volume.

Optimization of staged bioleaching of low-grade chalcopyrite ore in the presence and absence of chloride in the irrigating lixiviant: ANFIS simulation.

Science.gov (United States)

Vakylabad, Ali Behrad; Schaffie, Mahin; Naseri, Ali; Ranjbar, Mohammad; Manafi, Zahra

2016-07-01

In this investigation, copper was bioleached from a low-grade chalcopyrite ore using a chloride-containing lixiviant. In this regard, firstly, the composition of the bacterial culture media was designed to control the cost in commercial application. The bacterial culture used in this process was acclimated to the presence of chloride in the lixiviant. Practically speaking, the modified culture helped the bio-heap-leaching system operate in the chloridic media. Compared to the copper recovery from the low-grade chalcopyrite by bioleaching in the absence of chloride, bioleaching in the presence of chloride resulted in improved copper recovery. The composition of the lixiviant used in this study was a modification with respect to the basal salts in 9 K medium to optimize the leaching process. When leaching the ore in columns, 76.81 % Cu (based on solid residues of bioleaching operation) was recovered by staged leaching with lixiviant containing 34.22 mM NaCl. The quantitative findings were supported by SEM/EDS observations, X-ray elemental mapping, and mineralogical analysis of the ore before and after leaching. Finally, Adaptive neuro-fuzzy inference system (ANFIS) was used to simulate the operational parameters affecting the bioleaching operation in chloride-sulfate system.

Facile preparation of highly pure KF-ZrF4 molten salt

Science.gov (United States)

Zong, Guoqiang; Cui, Zhen-Hua; Zhang, Zhi-Bing; Zhang, Long; Xiao, Ji-Chang

2018-03-01

The preparation of highly pure KF-ZrF4 (FKZr) molten salt, a potential secondary coolant in molten salt reactors, was realized simply by heating a mixture of (NH4)2ZrF6 and KF. X-ray diffraction analysis indicated that the FKZr molten salt was mainly composed of KZrF5 and K2ZrF6. The melting point of the prepared FKZr molten salt was 420-422 °C under these conditions. The contents of all metal impurities were lower than 20 ppm, and the content of oxygen was lower than 400 ppm. This one-step protocol avoids the need for a tedious procedure to prepare ZrF4 and for an additional purification process to remove oxide impurities, and is therefore a convenient, efficient and economic preparation method for high-purity FKZr molten salt.

Molten Salts for High Temperature Reactors: University of Wisconsin Molten Salt Corrosion and Flow Loop Experiments -- Issues Identified and Path Forward

Energy Technology Data Exchange (ETDEWEB)

Piyush Sabharwall; Matt Ebner; Manohar Sohal; Phil Sharpe; Thermal Hydraulics Group

2010-03-01

Considerable amount of work is going on regarding the development of high temperature liquid salts technology to meet future process needs of Next Generation Nuclear Plant. This report identifies the important characteristics and concerns of high temperature molten salts (with lesson learned at University of Wisconsin-Madison, Molten Salt Program) and provides some possible recommendation for future work

Effect of media composition on bioavailability and toxicity of silver and silver nanoparticles in fish intestinal cells (RTgutGC).

Science.gov (United States)

Minghetti, Matteo; Schirmer, Kristin

2016-12-01

To understand conditions affecting bioavailability and toxicity of citrate-coated silver nanoparticles (cit-AgNP) and dissolved silver at the luminal enterocyte interface, we exposed rainbow trout (Oncorhynchus mykiss) gut cells (RTgutGC) in media of contrasting composition: two amino acid-containing media, one of which was supplemented with proteins, as can be expected during digestion; and two protein and amino acid-free media contrasting low and high chloride content, as can be expected in the lumen of fish adapting to freshwater or seawater, respectively. Dose-response curves were generated measuring cell metabolic activity, membrane and lysosome integrity over a period of 72 hours. Then, nontoxic doses were applied and total silver accumulation, metallothionein and glutathione reductase mRNA levels were determined. The presence of proteins stabilized cit-AgNP keeping them in suspension. Conversely, in protein-free media, cit-AgNP agglomerated and settled, resulting in higher cellular accumulation of silver and toxicity. Chloride concentrations in exposure media modulated the toxicity of AgNO 3 but not of cit-AgNP. Moreover, while amino acid-containing media are protective against AgNO 3 , likely due to the formation of thiolate complexes, they are only partially protective against cit-AgNP. Viability assays indicated that lysosomes are targets of cit-AgNP, supporting the hypothesis that cit-AgNP exert toxicity intracellularly. Metallothionein, a sensor of metal bioavailability, was induced by cit-AgNP in high chloride medium but not in low chloride medium, indicating that chloride might have a role in mobilizing silver from intercellular vesicles. Overall, this study shows that AgNP bioavailability and toxicity in the intestine is linked to its luminal content.

Synthesis and characterization of zinc chloride containing poly(acrylic acid) hydrogel by gamma irradiation

International Nuclear Information System (INIS)

Park, Jong-Seok; Kuang, Jia; Gwon, Hui-Jeong; Lim, Youn-Mook; Jeong, Sung-In; Shin, Young-Min; Seob Khil, Myung; Nho, Young-Chang

2013-01-01

In this study, the characterization of zinc chloride incorporated into a poly(acrylic acid) (PAAc) hydrogel prepared by gamma-ray irradiation was investigated. Zinc chloride powder with different concentrations was dissolved in the PAAc solution, and it was crosslinked with gamma-ray irradiation. The effects of various parameters such as zinc ion concentration and irradiation doses on characteristics of the hydrogel formed were investigated in detail for obtaining an antibacterial wound dressing. In addition, the gel content, pH-sensitive (pH 4 or 7) swelling ratio, and UV–vis absorption spectra of the zinc particles in the hydrogels were characterized. Moreover, antibacterial properties of these new materials against Staphylococcus aureus and Escherichia coli strains were observed on solid growth media. The antibacterial tests indicated that the zinc chloride containing PAAc hydrogels have good antibacterial activity. - Highlights: • The characterization of zinc chloride containing PAA hydrogel was investigated. • The gel content increased with an increase in absorbed dose up to 75 kGy. • Finally, the zinc chloride based hydrogels have an antibacterial activity

Impact on breeding rate of different Molten Salt reactor core structures

International Nuclear Information System (INIS)

Wang Haiwei; Mei Longwei; Cai Xiangzhou; Chen Jingen; Guo Wei; Jiang Dazhen

2013-01-01

Background: Molten Salt Reactor (MSR) has several advantages over the other Generation IV reactor. Referred to the French CNRS research and compared to the fast reactor, super epithermal neutron spectrum reactor type is slightly lower and beading rate reaches 1.002. Purpose: The aim is to explore the best conversion zone layout scheme in the super epithermal neutron spectrum reactor. This study can make nuclear fuel as one way to solve the energy problems of mankind in future. Methods: Firstly, SCALE program is used for molten salt reactor graphite channel, molten salt core structure, control rods, graphite reflector and layer cladding structure. And the SMART modules are used to record the important actinides isotopes and their related reaction values of each reaction channel. Secondly, the thorium-uranium conversion rate is calculated. Finally, the better molten salt reactor core optimum layout scheme is studied comparing with various beading rates. Results: Breading zone layout scheme has an important influence on the breading rate of MSR. Central graphite channels in the core can get higher neutron flux irradiation. And more 233 Th can convert to 233 Pa, which then undergoes beta decay to become 233 U. The graphite in the breading zone gets much lower neutron flux irradiation, so the life span of this graphite can be much longer than that of others. Because neutron flux irradiation in the uranium molten salt graphite has nearly 10 times higher than the graphite in the breading zone, it has great impact on the thorium-uranium conversion rates. For the super epithermal neutron spectrum molten salt reactors, double salt design cannot get higher thorium-uranium conversion rates. The single molten salt can get the same thorium-uranium conversion rate, meanwhile it can greatly extend the life of graphite in the core. Conclusions: From the analysis of calculation results, Blanket breeding area in different locations in the core can change the breeding rates of thorium

Natural convection heat transfer in the molten metal pool

International Nuclear Information System (INIS)

Park, R.J.; Kim, S.B.; Kim, H.D.; Choi, S.M.

1997-01-01

Analytical studies using the FLOW-3D computer program have been performed on natural convection heat transfer of a high density molten metal pool, in order to evaluate the coolability of the corium pool. The FLOW-3D results on the temperature distribution and the heat transfer rate in the molten metal pool region have been compared and evaluated with the experimental data. The FLOW-3D results have shown that the developed natural convection flow contributes to the solidified crust formation of the high density molten metal pool. The present FLOW-3D results, on the relationship between the Nusselt number and the Rayleigh number in the molten metal pool region, are more similar to the calculated results of Globe and Dropkin's correlation than any others. The natural convection heat transfer in the low aspect ratio case is more substantial than that in the high aspect ratio case. The FLOW-3D results, on the temperature profile and on the heat transfer rate in the molten metal pool region, are very similar to the experimental data. The heat transfer rate of the internal heat generation case is higher than that of the bottom heating case at the same heat supply condition. (author)

Postaccident heat removal: large-scale molten-fuel-sodium interaction experiments

International Nuclear Information System (INIS)

Johnson, T.R.; Pavlik, J.R.; Baker, L. Jr.

1975-02-01

Kilogram-scale interactions between molten UO 2 and sodium were performed in an unrestrained geometry to study the resulting energetics and fragmentation. The molten UO 2 was producted by the exothrmic reaction between uranium and MoO 3 powders. Under the conditions of the experiments completed to date, the short-rise-time pressure pulses created in the liquid phase had negligible work potential, and their magnitude did not increase with the amount of molten fuel. No significant gas-phase shock pressures were generated. The largest potential for mechanical work was the sodium vapor generated over a period of roughly 1 sec. About 20 percent of the heat was effective in generating vapor. The ex- perimental results show a marked tendency of molten UO 2 to form particulate after passage through only a few inches of sodium. Particle size distributions obtained under the conditions of the experiments were not significantly different from those obtained in prior small-scale tests and in TREAT tests. Also, the results indicate that the metallic component of the molten mixture formed larger particles than the oxide component. (U.S.)

Molten salt breeder reactor

International Nuclear Information System (INIS)

Furukawa, Kazuo; Tsukada, Kineo; Nakahara, Yasuaki; Oomichi, Toshihiko; Oono, Hideo.

1982-01-01

Purpose: To simplify the structure, as well as improve the technical reliability and safety by the elimination of a proton beam entering window. Constitution: The nuclear reactor container main body is made of Hastelloy N and provided at the inner surface with two layers of graphite shields except for openings. An aperture was formed in the upper surface of the container, through which protons accelerated by a linear accelerator are directly entered to the liquid surface of molten salts such as 7LiF-BeF 2 -ThF 4 , 7LiF-NaF-ThF 4 , 7LiF-Rb-UF 4 , NaF-KF-UF 4 and the like. The heated molten salts are introduced by way of a pipeway into a heat exchanger where the heat is transferred to coolant salts and electric generation is conducted by way of heated steams. (Furukawa, Y.)

Novel waste printed circuit board recycling process with molten salt.

Science.gov (United States)

Riedewald, Frank; Sousa-Gallagher, Maria

2015-01-01

The objective of the method was to prove the concept of a novel waste PCBs recycling process which uses inert, stable molten salts as the direct heat transfer fluid and, simultaneously, uses this molten salt to separate the metal products in either liquid (solder, zinc, tin, lead, etc.) or solid (copper, gold, steel, palladium, etc.) form at the operating temperatures of 450-470 °C. The PCB recovery reactor is essentially a U-shaped reactor with the molten salt providing a continuous fluid, allowing molten salt access from different depths for metal recovery. A laboratory scale batch reactor was constructed using 316L as suitable construction material. For safety reasons, the inert, stable LiCl-KCl molten salts were used as direct heat transfer fluid. Recovered materials were washed with hot water to remove residual salt before metal recovery assessment. The impact of this work was to show metal separation using molten salts in one single unit, by using this novel reactor methodology. •The reactor is a U-shaped reactor filled with a continuous liquid with a sloped bottom representing a novel reactor concept.•This method uses large PCB pieces instead of shredded PCBs as the reactor volume is 2.2 L.•The treated PCBs can be removed via leg B while the process is on-going.

Hydrogen permeation through Flinabe fluoride molten salts for blanket candidates

Energy Technology Data Exchange (ETDEWEB)

Nishiumi, Ryosuke, E-mail: r.nishiumi@aees.kyushu-u.ac.jp; Fukada, Satoshi; Nakamura, Akira; Katayama, Kazunari

2016-11-01

Highlights: • H{sub 2} diffusivity, solubility and permeability in Flinabe as T breeder are determined. • Effects in composition differences among Flibe, Fnabe and Flinabe are compared. • Changes of pressure dependence of Flinabe permeation rate are clarified. - Abstract: Fluoride molten salt Flibe (2LiF + BeF{sub 2}) is a promising candidate for the liquid blanket of a nuclear fusion reactor, because of its large advantages of tritium breeding ratio and heat-transfer fluid. Since its melting point is higher than other liquid candidates, another new fluoride molten salt Flinabe (LiF + NaF + BeF{sub 2}) is recently focused on because of its lower melting point while holding proper breeding properties. In this experiment, hydrogen permeation behavior through the three molten salts of Flibe (2LiF + BeF{sub 2}), Fnabe (NaF + BeF{sub 2}) and Flinabe are investigated in order to clarify the effects of their compositions on hydrogen transfer properties. After making up any of the three molten salts and purifying it using HF, hydrogen permeability, diffusivity and solubility of the molten salts are determined experimentally by using a system composed of tertiary cylindrical tubes. Close agreement is obtained between experimental data and analytical solutions. H{sub 2} permeability, diffusivity and solubility are correlated as a function of temperature and are compared among the three molten salts.

Novel waste printed circuit board recycling process with molten salt

Science.gov (United States)

Riedewald, Frank; Sousa-Gallagher, Maria

2015-01-01

The objective of the method was to prove the concept of a novel waste PCBs recycling process which uses inert, stable molten salts as the direct heat transfer fluid and, simultaneously, uses this molten salt to separate the metal products in either liquid (solder, zinc, tin, lead, etc.) or solid (copper, gold, steel, palladium, etc.) form at the operating temperatures of 450–470 °C. The PCB recovery reactor is essentially a U-shaped reactor with the molten salt providing a continuous fluid, allowing molten salt access from different depths for metal recovery. A laboratory scale batch reactor was constructed using 316L as suitable construction material. For safety reasons, the inert, stable LiCl–KCl molten salts were used as direct heat transfer fluid. Recovered materials were washed with hot water to remove residual salt before metal recovery assessment. The impact of this work was to show metal separation using molten salts in one single unit, by using this novel reactor methodology. • The reactor is a U-shaped reactor filled with a continuous liquid with a sloped bottom representing a novel reactor concept. • This method uses large PCB pieces instead of shredded PCBs as the reactor volume is 2.2 L. • The treated PCBs can be removed via leg B while the process is on-going. PMID:26150977

Advancing Molten Salts and Fuels at Sandia National Laboratories

Energy Technology Data Exchange (ETDEWEB)

Rodriguez, Salvador B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-09-26

SNL has a combination of experimental facilities, nuclear engineering, nuclear security, severe nuclear accidents, and nuclear safeguards expertise that can enable significant progress towards molten salts and fuels for Molten Salt Reactors (MSRs). The following areas and opportunities are discussed in more detail in this white paper.

Experimental investigation of a molten salt thermocline storage tank

Science.gov (United States)

Yang, Xiaoping; Yang, Xiaoxi; Qin, Frank G. F.; Jiang, Runhua

2016-07-01

Thermal energy storage is considered as an important subsystem for solar thermal power stations. Investigations into thermocline storage tanks have mainly focused on numerical simulations because conducting high-temperature experiments is difficult. In this paper, an experimental study of the heat transfer characteristics of a molten salt thermocline storage tank was conducted by using high-temperature molten salt as the heat transfer fluid and ceramic particle as the filler material. This experimental study can verify the effectiveness of numerical simulation results and provide reference for engineering design. Temperature distribution and thermal storage capacity during the charging process were obtained. A temperature gradient was observed during the charging process. The temperature change tendency showed that thermocline thickness increased continuously with charging time. The slope of the thermal storage capacity decreased gradually with the increase in time. The low-cost filler material can replace the expensive molten salt to achieve thermal storage purposes and help to maintain the ideal gravity flow or piston flow of molten salt fluid.

Novel waste printed circuit board recycling process with molten salt

OpenAIRE

Riedewald, Frank; Sousa-Gallagher, Maria

2015-01-01

The objective of the method was to prove the concept of a novel waste PCBs recycling process which uses inert, stable molten salts as the direct heat transfer fluid and, simultaneously, uses this molten salt to separate the metal products in either liquid (solder, zinc, tin, lead, etc.) or solid (copper, gold, steel, palladium, etc.) form at the operating temperatures of 450?470??C. The PCB recovery reactor is essentially a U-shaped reactor with the molten salt providing a continuous fluid, a...

Time-of-flight pulsed neutron diffraction of molten salts

Energy Technology Data Exchange (ETDEWEB)

Fukushima, Y; Misawa, M; Suzuki, K [Tohoku Univ., Sendai (Japan). Research Inst. for Iron, Steel and Other Metals

1975-06-01

In this work, the pulsed neutron diffraction of molten alkali metal nitrate and bismuth trihalide was measured by the time-of-flight method. An electron linear accelerator was used as the pulsed neutron source. All the measurements were carried out with the T-O-F neutron diffractometer installed on the 300 MeV electron lineac. Molten NaNO/sub 3/ and RbNO/sub 3/ were adopted as the samples for alkali metal nitrate. The measurement is in progress for KNO/sub 3/ and LiNO/sub 3/. As the first step of the study on bismuth-bismuth trihalide system, the temperature dependence of structure factors was observed for BiCl/sub 3/, BiBr/sub 3/ and BiI/sub 3/ in the liquid state. The structure factors Sm(Q) for molten NaNO/sub 3/ at 340/sup 0/C and RbNO/sub 3/ at 350/sup 0/C were obtained, and the form factor F/sub 1/(Q) for single NO/sub 3//sup -/ radical with equilateral triangle structure was calculated. In case of molten NaNO/sub 3/, the first peak of Sm(Q) is simply smooth and a small hump can be observed in the neighbourhood of the first minimum Q position. The first peak of Sm(Q) for molten RbNO/sub 3/ is divided into two peaks, whereas a hump at the first minimum becomes big, and shifts to the low Q side of the second peak. The size of the NO/sub 3//sup -/ radical in molten NaNO/sub 3/ is a little smaller than that in molten RbNO/sub 3/. The values of the bond length in the NO/sub 3//sup -/ radical are summarized for crystal state and liquid state. The temperature dependence of the structure factor S(Q) was observed for BiCl/sub 3/, BiBr/sub 3/ and BiI/sub 3/, and shown in a figure.

Nuclear energy synergetics and molten-salt technology

International Nuclear Information System (INIS)

Furukawa, Kazuo

1988-01-01

There are various problems with nuclear energy techniques in terms of resources, safety, environmental effects, nuclear proliferation, reactor size reduction and overall economics. To overcome these problems, future studies should be focused on utilization of thorium resources, separation of multiplication process and power generation process, and application of liquid nuclear fuel. These studies will lead to the development of molten thorium salt nuclear synergetics. The most likely candidate for working medium is Lif-BeF 2 material (flibe). 233 U production facilities are required for the completion of the Th cycle. For this, three ideas have been proposed: accelerator M.S. breeder, impact fusion MSB and inertial conf. fusion hybrid MSB. The first step toward the development of molten Th salt nuclear energy synergetics will be the construction of a pilot plant of an extreme small size. As candidate reactor, the author has selected mini FUJI-II (7.0 MWe), an extremely small molten salt power reactor. Mini FUJI-II facilities are expected to be developed in 7 - 8 years. For the next step (demonstration step), the designing of a small power reactor (FUJI 160 MWe) has already been carried out. A small molten salt reactor will have good safety characteristics in terms of chemistry, material, structure, nuclear safety and design basis accidents. Such reactors will also have favorable economic aspects. (Nogami, K.)

Molten salt thermal energy storage systems: salt selection

Energy Technology Data Exchange (ETDEWEB)

Maru, H.C.; Dullea, J.F.; Huang, V.S.

1976-08-01

A research program aimed at the development of a molten salt thermal energy storage system commenced in June 1976. This topical report describes Work performed under Task I: Salt Selection is described. A total of 31 inorganic salts and salt mixtures, including 9 alkali and alkaline earth carbonate mixtures, were evaluated for their suitability as heat-of-fusion thermal energy storage materials at temperatures of 850 to 1000/sup 0/F. Thermophysical properties, safety hazards, corrosion, and cost of these salts were compared on a common basis. We concluded that because alkali carbonate mixtures show high thermal conductivity, low volumetric expansion on melting, low corrosivity and good stability, they are attractive as heat-of-fusion storage materials in this temperature range. A 35 wt percent Li/sub 2/CO/sub 3/-65 wt percent K/sub 2/CO/sub 3/ (50 mole percent Li/sub 2/CO/sub 3/-50 mole percent K/sub 2/CO/sub 3/) mixture was selected as a model system for further experimental work. This is a eutectoid mixture having a heat of fusion of 148 Btu/lb (82 cal/g) that forms an equimolar compound, LiKCO/sub 3/. The Li/sub 2/CO/sub 3/-K/sub 2/CO/sub 3/ mixture is intended to serve as a model system to define heat transfer characteristics, potential problems, and to provide ''first-cut'' engineering data required for the prototype system. The cost of a thermal energy storage system containing this mixture cannot be predicted until system characteristics are better defined. However, our comparison of different salts indicated that alkali and alkaline earth chlorides may be more attractive from a salt cost point of view. The long-term corrosion characteristics and the effects of volume change on melting for the chlorides should be investigated to determine their overall suitability as a heat-of-fusion storage medium.

Online monitoring of corrosion behavior in molten metal using laser-induced breakdown spectroscopy

Science.gov (United States)

Zeng, Qiang; Pan, Congyuan; Li, Chaoyang; Fei, Teng; Ding, Xiaokang; Du, Xuewei; Wang, Qiuping

2018-04-01

The corrosion behavior of structure materials in direct contact with molten metals is widespread in metallurgical industry. The corrosion of casting equipment by molten metals is detrimental to the production process, and the corroded materials can also contaminate the metals being produced. Conventional methods for studying the corrosion behavior by molten metal are offline. This work explored the application of laser-induced breakdown spectroscopy (LIBS) for online monitoring of the corrosion behavior of molten metal. The compositional changes of molten aluminum in crucibles made of 304 stainless steel were obtained online at 1000 °C. Several offline techniques were combined to determine the corrosion mechanism, which was highly consistent with previous studies. Results proved that LIBS was an efficient method to study the corrosion mechanism of solid materials in molten metal.

Mechanical structure and problem of thorium molten salt reactor

International Nuclear Information System (INIS)

Kamei, Takashi

2011-01-01

After Fukushima Daiichi accident, there became great interest in Thorium Molten Salt Reactor (MSR) for the safety as station blackout leading to auto drainage of molten salts with freeze valve. This article described mechanical structure of MSR and problems of materials and pipes. Material corrosion problem by molten salts would be solved using modified Hastelloy N with Ti and Nb added, which should be confirmed by operation of an experimental reactor. Trends in international activities of MSR were also referred including China declaring MSR development in January 2011 to solve thorium contamination issues at rare earth production and India rich in thorium resources. (T. Tanaka)

Molten salt burner fuel behaviour and treatment

International Nuclear Information System (INIS)

Ignatiev, V.V.; Zakirov, R.Y.; Grebenkine, K.F.

2001-01-01

The objective of this paper is to discuss the feasibility of molten salt reactor technology for treatment of Pu, minor actinides and fission products, when the reactor and fission product clean-up unit are planned as an integral system. This contribution summarises the available R and D which led to selection of the fuel compositions for the molten salt reactor of the TRU burner type (MSB). Special characteristics of behaviour of TRUs and fission products during power operation of MSB concepts are presented. The present paper briefly reviews the processing developments underlying the prior molten salt reactor programmes and relates them to the separation requirements of the MSB concept, including the permissible range of processing cycle times and removal times. Status and development needs in the thermodynamic properties of fluorides, fission product clean-up methods and container materials compatibility with the working fluids for the fission product clean-up unit are discussed. (authors)

Thermal interaction of molten copper with water

International Nuclear Information System (INIS)

Zyszkowski, W.

1975-01-01

Experimental work was performed to study the thermal interaction between molten copper particles (in the range of temperature from the copper melting point to about 1800 0 C) and water from about 15-80 0 C. The transient temperatures of the copper particles and water before and during their thermal interaction were measured. The history of the phenomena was filmed by means of a high speed FASTAX camera (to 8000 f/s). Classification of the observed phenomena and description of the heat-transfer modes were derived. One among the phenomena was the thermal explosion. The necessary conditions for the thermal explosion are discussed and their physical interpretation is given. According to the hypothesis proposed, the thermal explosion occurs when the molten metal has the temperature of its solidification and the heat transfer on its surface is sufficiently intensive. The 'sharp-change' of the crystalline structure during the solidification of the molten metal is the cause of the explosion fragmentation. (author)

Cold crucible technique for interaction test of molten corium with structure

International Nuclear Information System (INIS)

Ha, Kwang Soon; An, Sang Mo; Min, Beong Tae; Kim, Hwan Yeol

2012-01-01

During a severe accident, the molten corium might interact with several structures in a nuclear power plant such as core peripheral structures, lower plenum, lower head vessel, and external structures of a reactor vessel. The interaction of the molten corium with the structure depends on the molten corium composition, temperature, structural materials, and environmental conditions such as pressure and humidity. For example, the interaction of a metallic molten corium containing metal uranium (U) and zirconium (Zr) with the oxidized steel structure (Fe 2O3 ) is affected by not only thermal ablation but oxidation reduction reaction because the oxidation quotients of the U and Zr are higher than that of Fe. KAERI set up an experimental facility and technique using a cold crucible melting method to verify the interaction mechanism between the metallic molten corium and structural materials. This technique includes the generation of the metallic melt, melt delivery, measurement of the interaction process, and post analyses after the test

Preliminary Study on the High Temperature Transport System for Molten Salt

International Nuclear Information System (INIS)

Lee, S. H.; Lee, H. S.; Kim, J. G.

2012-01-01

Pyroprocessing technology is one of the the most promising technologies for the advanced fuel cycle with favorable economic potential and intrinsic proliferation-resistance. The electrorefining process, one of main processes is compos- ed of pyroprocess to recover the useful elements from spent fuel, is under development at the Korea Atomic Energy Research Institute as a sub process of the pyrochemical treatment of spent PWR fuel. High-temperature molten salt transport technologies are required because a molten salt should be transported from the electrorefiner to electrowiner after the electrorefining process. Therefore, in pyroprocessing technology, the development of high-temperature transport technologies for molten salt is a crucial prerequisite. However, there have been a few transport studies on high-temperature molten salt. In this study, an apparatus for suction transport experiments was designed and constructed for the development of high temperature molten salt transport technology. Suction transport experiments were performed using LiC-KCl eutectic salt

Protection of nuclear graphite toward fluoride molten salt by glassy carbon deposit

International Nuclear Information System (INIS)

Bernardet, V.; Gomes, S.; Delpeux, S.; Dubois, M.; Guerin, K.; Avignant, D.; Renaudin, G.; Duclaux, L.

2009-01-01

Molten salt reactor represents one of the promising future Generation IV nuclear reactors families where the fuel, a liquid molten fluoride salt, is circulating through the graphite reactor core. The interactions between nuclear graphite and fluoride molten salt and also the graphite surface protection were investigated in this paper by powder X-ray diffraction, micro-Raman spectroscopy and scanning electron microscopy coupled with X-ray microanalysis. Nuclear graphite discs were covered by two kinds of protection deposit: a glassy carbon coating and a double coating of pyrolitic carbon/glassy carbon. Different behaviours have been highlighted according to the presence and the nature of the coated protection film. Intercalation of molten salt between the graphite layers did not occur. Nevertheless the molten salt adhered more or less to the surface of the graphite disc, filled more or less the graphite surface porosity and perturbed more or less the graphite stacking order at the disc surface. The behaviour of unprotected graphite was far to be satisfactory after two days of immersion of graphite in molten salt at 500 deg. C. The best protection of the graphite disc surface, with the maximum of inertness towards molten salt, has been obtained with the double coating of pyrolitic carbon/glassy carbon

Heat transfer investigation of molten salts under laminar and turbulent flow regimes

International Nuclear Information System (INIS)

Srivastava, A.K.; Vaidya, A.M.; Maheshwari, N.K.; Vijayan, P.K.

2014-01-01

High temperature reactor and solar thermal power plants use Molten Salt as a coolant, as it has low melting point and high boiling point, enabling us to operate the system at low pressure. Molten fluoride salt (eutectic mixture of LiF-NaF-KF) and molten nitrate salt (mixture of NaNO 3 and KNO 3 in 60:40 ratios by weight) are proposed as a candidate coolant for High Temperature Reactors (HTR) and solar power plant respectively. BARC is developing a 600 MWth pebble bed high temperature reactor, cooled by natural circulation of fluoride salt and capable of supplying process heat at 1000℃ to facilitate hydrogen production by splitting water. Beside this, BARC is also developing a 2MWe solar power tower system using molten nitrate salt as a primary coolant and storage medium. In order to design this, it is necessary to study the heat transfer characteristics of various molten salts. Most of the previous studies related to molten salts are based on the experimental works. These experiments essentially measured the physical properties of molten salts and their heat transfer characteristics. Ferri et al. introduced the property definitions for molten salts in the RELAP5 code to perform transient simulations at the ProvaCollettoriSolari (PCS) test facility. In this paper, a CFD analysis has been performed to study the heat transfer characteristics of molten fluoride salt and molten nitrate salt flowing in a circular pipe for various regimes of flow. Simulation is performed with the help of in-house developed CFD code, NAFA, acronym for Numerical Analysis of Flows in Axi-symmetric geometries. Uniform velocity and temperature distribution are set as the inlet boundary condition and pressure is employed at the outlet boundary condition. The inlet temperature for all simulation is set as 300℃ for nitrate salt and 500℃ for fluoride salt and the operating pressure is 1 atm in both the cases

Development of High-Temperature Transport System for Molten Salt in Pyroprocessing

International Nuclear Information System (INIS)

Lee, Sung Ho; Kim, In Tae; Park, Sung Bin

2014-01-01

The electrorefining process, which is a key process in pyroprocessing, is composed of two parts, electrorefining to deposit a uranium with a solid cathode and electrowinning to co-deposit TRU and RE with a liquid cadmium cathode (LCC). As the electrorefining operation proceedes, TRU and RE are accumulated in electrolyte LiCl-KCl salt, and after the electrorefining process, the molten salt used in an electrorefining reactor should by transported to the next process, the electrowinning process, to recover U/TRU/RE; Thus, a molten salt transfer system by suction is now being developed. An apparatus for suction transport experiments was designed and constructed for the development of high- temperature molten salt transport technology. Suction transport experiments were performed using LiC-KCl eutectic salt. The feasibility of pyro-reprocessing has been demonstrated through many laboratory-scale experiments. In pyroprocessing, a eutectic LiCl-KCl salt was used as a liquid elextrolyte for a recovery of actinides. However, reliable transport technologies for these high temperature liquids have not yet been developed. A preliminary study on high-temperature transport technology for molten salt by suction is now being carried out. In this study, three different salt transport technologies (gravity, suction pump, and centrifugal pump) were investigated to select the most suitable method for molten salt transport. An apparatus for suction transport experiments was designed and installed for the development of high-temperature molten salt transport technology. Basic preliminary suction transport experiments were carried out using the prepared LiC-KCl eutectic salt at 500 .deg. C to observe the transport behavior of LiCl-KCl molten salt. In addition, a PRIDE salt transport system was designed and installed for an engineering-scale salt transport demonstration. Several types of suction transport experiments using molten salt (LiCl-KCl eutectics) for the development of a high

Development of High-Temperature Transport System for Molten Salt in Pyroprocessing

Energy Technology Data Exchange (ETDEWEB)

Lee, Sung Ho; Kim, In Tae; Park, Sung Bin [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-05-15

The electrorefining process, which is a key process in pyroprocessing, is composed of two parts, electrorefining to deposit a uranium with a solid cathode and electrowinning to co-deposit TRU and RE with a liquid cadmium cathode (LCC). As the electrorefining operation proceedes, TRU and RE are accumulated in electrolyte LiCl-KCl salt, and after the electrorefining process, the molten salt used in an electrorefining reactor should by transported to the next process, the electrowinning process, to recover U/TRU/RE; Thus, a molten salt transfer system by suction is now being developed. An apparatus for suction transport experiments was designed and constructed for the development of high- temperature molten salt transport technology. Suction transport experiments were performed using LiC-KCl eutectic salt. The feasibility of pyro-reprocessing has been demonstrated through many laboratory-scale experiments. In pyroprocessing, a eutectic LiCl-KCl salt was used as a liquid elextrolyte for a recovery of actinides. However, reliable transport technologies for these high temperature liquids have not yet been developed. A preliminary study on high-temperature transport technology for molten salt by suction is now being carried out. In this study, three different salt transport technologies (gravity, suction pump, and centrifugal pump) were investigated to select the most suitable method for molten salt transport. An apparatus for suction transport experiments was designed and installed for the development of high-temperature molten salt transport technology. Basic preliminary suction transport experiments were carried out using the prepared LiC-KCl eutectic salt at 500 .deg. C to observe the transport behavior of LiCl-KCl molten salt. In addition, a PRIDE salt transport system was designed and installed for an engineering-scale salt transport demonstration. Several types of suction transport experiments using molten salt (LiCl-KCl eutectics) for the development of a high

Propagating particle density fluctuations in molten NaCl

International Nuclear Information System (INIS)

Demmel, F.; Hosokawa, S.; Pilgrim, W.-C.; Lorenzen, M.

2004-01-01

In this paper we present the observation of acoustic modes in the spectra of molten NaCl measured over a large momentum transfer range using synchrotron radiation. A surprisingly large positive dispersion was deduced with a mode velocity exceeding the adiabatic value by nearly 70%. The large effect seems to be describable as a viscoelastic reaction of the liquid. Additionally, the derived dispersion resembles the Q-ω relation of the acoustic modes in liquid sodium. As an explanation for the large positive dispersion we propose that the density fluctuations in molten NaCl can be interpreted as a decoupled motion of the lighter and smaller cations on a nearly resting anionic background. These molten alkali halide measurements are the first experimental evidences for the so-called fast sound in a binary ionic liquid

Steam gasification of plant biomass using molten carbonate salts

International Nuclear Information System (INIS)

Hathaway, Brandon J.; Honda, Masanori; Kittelson, David B.; Davidson, Jane H.

2013-01-01

This paper explores the use of molten alkali-carbonate salts as a reaction and heat transfer medium for steam gasification of plant biomass with the objectives of enhanced heat transfer, faster kinetics, and increased thermal capacitance compared to gasification in an inert gas. The intended application is a solar process in which concentrated solar radiation is the sole source of heat to drive the endothermic production of synthesis gas. The benefits of gasification in a molten ternary blend of lithium, potassium, and sodium carbonate salts is demonstrated for cellulose, switchgrass, a blend of perennial plants, and corn stover through measurements of reaction rate and product composition in an electrically heated reactor. The feedstocks are gasified with steam at 1200 K in argon and in the molten salt. The use of molten salt increases the total useful syngas production by up to 25%, and increases the reactivity index by as much as 490%. Secondary products, in the form of condensable tar, are reduced by 77%. -- Highlights: ► The presence of molten salt increases the rate of gasification by up to 600%. ► Reaction rates across various feedstocks are more uniform with salt present. ► Useful syngas yield is increased by up to 30% when salt is present. ► Secondary production of liquid tars are reduced by 77% when salt is present.

New primary energy source by thorium molten-salt reactor technology

International Nuclear Information System (INIS)

Furukawa, Kazuo; Kato, Yoshio; Furuhashi, Akira; Numata, Hiroo; Mitachi, Koushi; Yoshioka, Ritsuo; Sato, Yuzuru; Arakawa, Kazuto

2005-01-01

Among the next 30 years, we have to implement a practical measure in the global energy/environmental problems, solving the followings: (1) replacing the fossil fuels without CO 2 emission, (2) no severe accidents, (3) no concern on military, (4) minimizing wastes, (5) economical, (6) few R and D investment and (7) rapid/huge global application supplying about half of the total primary energy till 50 years later. For this purpose the following system was proposed: THORIMS-NES [Thorium Molten-Salt Nuclear Energy Synergetic System], which is composed of (A) simple fission Molten-Salt power stations (FUJI), and (B) fissile-producing Accelerator Molten-Salt Breeder (AMSB). It has been internationally prepared a practical Developmental Program for its huge-size industrialization of Th breeding fuel cycle to produce a new rational primary energy. Here it is explained the social meaning, the conceptual system design and technological bases, especially, including the molten fluoride salt technology, which was developed as the triple-functional medium for nuclear-engineering, heat-transfer and chemical engineering. The complex function of this system is fully achieved by the simplified facility using a single phase molten-salt only. (author)

Overview on CO{sub 2} Valorization: Challenge of Molten Carbonates

Energy Technology Data Exchange (ETDEWEB)

Chery, Déborah; Lair, Virginie; Cassir, Michel, E-mail: michel.cassir@chimie-paristech.fr [Chimie ParisTech, CNRS, Institut de Recherche de Chimie Paris, PSL Research University, Paris (France)

2015-10-02

The capture and utilization of CO{sub 2} is becoming progressively one of the significant challenges in the field of energetic resources. Whatever the energetic device, it is impossible to avoid completely the production of greenhouse gas, even parting from renewable energies. Transforming CO{sub 2} into a valuable fuel, such as alcohols, CO, or even C, could constitute a conceptual revolution in the energetic bouquet offering a huge application domain. Although several routes have been tested for this purpose, on which a general panorama will be given here, molten carbonates are attracting a renewed interest aiming at dissolving and reducing carbon dioxide in such melts. Because of their unique properties, molten carbonates are already used as electrolytes in molten carbonate fuel cells; they can also provoke a breakthrough in a new economy considering CO{sub 2} as an energetic source rather than a waste. Molten carbonates’ science and technology is becoming a strategic field of research for energy and environmental issues. Our aim in this review is to put in evidence the benefits of molten carbonates to valorize CO{sub 2} and to show that it is one of the most interesting routes for such application.

Thorium molten-salt nuclear energy synergetics

International Nuclear Information System (INIS)

Furukawa, Kazuo

1989-01-01

One of the most practical and rational approaches for establishing the idealistic Thorium resource utilization program has been presented, which might be effective to solve the principal energy problems, concerning safety, proliferation and terrorism, resource, power size and fuel cycle economy, for the next century. The first step will be the development of Small Molten-Salt Reactors as a flexible power station, which is suitable for early commercialization of Th reactors not necessarily competing with proven Large Solid-Fuel Reactors. Therefore, the more detailed design works and practical R and D planning should be performed under the international cooperations soon, soundly depending on the basic technology established by ORNL already. R and D cost would be surprisingly low. This reactor(MSR) seems to be idealistic not only in power-size, siting, safety, safeguard and economy, but also as an effective partner of Molten-Salt Fissile Breeders(MSB) in order to establish the simplest and economical Thorium molten-salt breeding fuel cycle named THORIMS-NES in all over the world including the developing countries and isolated areas. This would be one of the most practical replies to the Lilienthal's appeal of 'A NEW START' in Nuclear Energy. (author)

Performance Testing of Molten Regolith Electrolysis with Transfer of Molten Material for the Production of Oxygen and Metals on the Moon

Science.gov (United States)

Sibille, Laurent; Sadoway, Donald; Tripathy, Prabhat; Standish, Evan; Sirk, Aislinn; Melendez, Orlando; Stefanescu, Doru

2010-01-01

Previously, we have demonstrated the production of oxygen by electrolysis of molten regolith simulants at temperatures near 1600 C. Using an inert anode and suitable cathode, direct electrolysis (no supporting electrolyte) of the molten silicate is carried out, resulting in the production of molten metallic products at the cathode and oxygen gas at the anode. Initial direct measurements of current efficiency have confirmed that the process offer potential advantages of high oxygen production rates in a smaller footprint facility landed on the moon, with a minimum of consumables brought from Earth. We now report the results of a scale-up effort toward the goal of achieving production rates equivalent to 1 metric ton O2/year, a benchmark established for the support of a lunar base. We previously reported on the electrochemical behavior of the molten electrolyte as dependent on anode material, sweep rate and electrolyte composition in batches of 20-200g and at currents of less than 0.5 A. In this paper, we present the results of experiments performed at currents up to 10 Amperes) and in larger volumes of regolith simulant (500 g - 1 kg) for longer durations of electrolysis. The technical development of critical design components is described, including: inert anodes capable of passing continuous currents of several Amperes, container materials selection, direct gas analysis capability to determine the gas components co-evolving with oxygen. To allow a continuous process, a system has been designed and tested to enable the withdrawal of cathodically-reduced molten metals and spent molten oxide electrolyte. The performance of the withdrawal system is presented and critiqued. The design of the electrolytic cell and the configuration of the furnace were supported by modeling the thermal environment of the system in an effort to realize a balance between external heating and internal joule heating. We will discuss the impact these simulations and experimental findings have

Measurement and Analysis of Density of Molten Ni-W Alloys

Institute of Scientific and Technical Information of China (English)

FANG Liang; XIAO Feng; TAO Zainan; MuKai Kusuhiro

2005-01-01

The density of molten Ni-W alloys was measured with a modified pycnometric method. It is found that the density of the molten Ni- W alloys decreases with temperature rising, but increases with the increase of tungsten concentration in the alloys. The molar volume of molten Ni- W binary alloys increases with the increase of temperature and tungsten concentration. The partial molar volume of tungsten in liquid Ni- W binary alloy has been calculated approximately as ( - 1.59+ 5.64 × 10-3 T) × 10-6m3 ·mol-1.

Cerium(terbium, erbium)chloride-choline chloride aqueous systems

International Nuclear Information System (INIS)

Gajfutdinova, R.K.; Zhuravlev, E.F.; Bikbaeva, G.G.; Domrachev, V.N.; Vanskova, G.I.

1985-01-01

To clarify the effect of rare earth nature on mutual solubility of rare earth salts and amines the solubility of solid phases in the systems, consisting of choline chloride, water and cerium, terbium, erbium chlorides, has been studied. It is established, that solubility isotherms of all the systems, testify to the formation of new solid phases of the composition: Ce(Tb, Er)xCl 3 x2C 5 H 14 ONClx3H 2 O. Individuality of new solid phases is proved by DTA method, the composition is confirmed by chemical analysis and data of PMR spectra, for choline chloride and its complexes with rare earth chlorides of the given composition PMR and IR spectra are studied

Flue Gas Cleaning With Alternative Processes and Reaction Media

DEFF Research Database (Denmark)

Rasmussen, Søren Birk; Huang, Jun; Riisager, Anders

2007-01-01

Alternative methods to the traditional industrial NOX and SOXflue gas cleaning processes working at lower temperatures and/orleading to useful products are desired. In this work we presentour latest results regarding the use of molten ionic media inelectrocatalytic membrane separation, ionic liquid...... reversibleabsorption and supported ionic liquid deNOX catalysis. Furtherdevelopment of the methods will hopefully make them suitable forinstallation in different positions in the flue gas duct ascompared to the industrial methods available today....

Rare earths and rare earth alloys electrolytic preparation process and device for this process

International Nuclear Information System (INIS)

Seon, F.; Barthole, G.

1986-01-01

Electrolysis of a molten salt of rare earth or rare earth alloy for preparation of the metal or alloy is described. The molten salt bath comprises at least a rare earth chloride, at least an alkaline or alkaline earth chloride and at least an alkaline or alkaline earth fluoride [fr

Molten-salt reactor information system

International Nuclear Information System (INIS)

Haubenreich, P.N.; Cardwell, D.W.; Engel, J.R.

1975-06-01

The Molten-Salt Reactor Information System (MSRIS) is a computer-based file of abstracts of documents dealing with the technology of molten-salt reactors. The file is stored in the IBM-360 system at ORNL, and may be searched through the use of established interactive computer programs from remote terminals connected to the computer via telephone lines. The system currently contains 373 entries and is subject to updating and expansion as additional information is developed. The nature and general content of the data file, a general approach for obtaining information from it, and the manner in which material is added to the file are described. Appendixes provide the list of keywords currently in use, the subject categories under which information is filed, and simplified procedures for searching the file from remote terminals. (U.S.)

Study on the quench behavior of molten fuel material jet into coolant

International Nuclear Information System (INIS)

Abe, Yutaka; Kizu, Tetsuya; Arai, Takahiro; Nariai, Hideki; Chitose, Keiko; Koyama, Kazuya

2004-01-01

In a core disruptive accident (CDA) of a Fast Breeder Reactor, the post accident heat removal (PAHR) is crucial for the accident mitigation. The molten core material should be solidified in the sodium coolant in the reactor vessel. In the present experiment, molten material jet is injected into water to experimentally obtain fragments and the visualized information of the fragmentation. The distributed particle behavior of the molten material jet is observed with high-speed video camera. The distributions of the fragmented droplet diameter from the molten material jet are evaluated by correcting the solidified particles. The experimental results of the mean fragmented droplet diameter are compared with the existing theories. Consequently, the fragmented droplet diameter is close to the value estimated based on the Kelvin-Helmholtz instability. Once the particle diameter of the fragmented molten material could be known from a hydrodynamic model, it becomes possible to estimate the mass ratio of the molten particle to the total injected mass by combining an appropriate heat transfer model. The heat transfer model used in the present study is composed of the fragmentation model based on the Kelvin-Helmholtz instability. The mass ratio of the molten fragment to total mass of the melted mixed oxide fuel in sodium coolant estimated in the present study is very small. The result means that most of the molten mixed oxide fuel material injected into the sodium coolant can be cooled down under the solidified temperature, that is so called quenched, if the amount of the coolant is sufficient. (author)

Mechanistic understanding and kinetic studies of highly selective oxidative dehydrogenation of ethane over novel supported molten chloride catalysts

Energy Technology Data Exchange (ETDEWEB)

Gaertner, C.; Veen, A.C. van; Lercher, J.A. [Technische Univ. Muenchen, Garching (Germany). Dept. of Chemistry

2012-07-01

Ethene is one of the most important feedstocks for chemical industry, nowadays mainly produced via steam cracking. However, oxidative dehydrogenation becomes a more important process route, allowing to produce ethene selectively and at lower temperatures. Supported alkali chloride catalysts are promising materials. However, the ODH mechanism of this class of catalysts is not well investigated so far. The investigation of the reaction mechanism is thus the aim of this contribution. (orig.)

Treatment of plutonium process residues by molten salt oxidation

Energy Technology Data Exchange (ETDEWEB)

Stimmel, J.; Wishau, R.; Ramsey, K.B.; Montoya, A.; Brock, J. [Los Alamos National Lab., NM (United States); Heslop, M. [Naval Surface Warfare Center (United States). Indian Head Div.; Wernly, K. [Molten Salt Oxidation Corp. (United States)

1999-04-01

Molten Salt Oxidation (MSO) is a thermal process that can remove more than 99.999% of the organic matrix from combustible {sup 238}Pu material. Plutonium processing residues are injected into a molten salt bed with an excess of air. The salt (sodium carbonate) functions as a catalyst for the conversion of the organic material to carbon dioxide and water. Reactive species such as fluorine, chlorine, bromine, iodine, sulfur, phosphorous and arsenic in the organic waste react with the molten salt to form the corresponding neutralized salts, NaF, NaCl, NaBr, NaI, Na{sub 2}SO{sub 4}, Na{sub 3}PO{sub 4} and NaAsO{sub 2} or Na{sub 3}AsO4. Plutonium and other metals react with the molten salt and air to form metal salts or oxides. Saturated salt will be recycled and aqueous chemical separation will be used to recover the {sup 238}Pu. The Los Alamos National Laboratory system, which is currently in the conceptual design stage, will be scaled down from current systems for use inside a glovebox.

Treatment of plutonium process residues by molten salt oxidation

International Nuclear Information System (INIS)

Stimmel, J.; Wishau, R.; Ramsey, K.B.; Montoya, A.; Brock, J.; Heslop, M.

1999-01-01

Molten Salt Oxidation (MSO) is a thermal process that can remove more than 99.999% of the organic matrix from combustible 238 Pu material. Plutonium processing residues are injected into a molten salt bed with an excess of air. The salt (sodium carbonate) functions as a catalyst for the conversion of the organic material to carbon dioxide and water. Reactive species such as fluorine, chlorine, bromine, iodine, sulfur, phosphorous and arsenic in the organic waste react with the molten salt to form the corresponding neutralized salts, NaF, NaCl, NaBr, NaI, Na 2 SO 4 , Na 3 PO 4 and NaAsO 2 or Na 3 AsO4. Plutonium and other metals react with the molten salt and air to form metal salts or oxides. Saturated salt will be recycled and aqueous chemical separation will be used to recover the 238 Pu. The Los Alamos National Laboratory system, which is currently in the conceptual design stage, will be scaled down from current systems for use inside a glovebox

Development of the scientific concept of the phosphate methods for actinide-containing waste handling (pyrochemical fuel reprocessing)

International Nuclear Information System (INIS)

Orlova, A.I.; Orlova, V.A.; Skiba, O.V.; Bychkov, A.V.; Volkov, Yu.F.; Lukinykh, A.N.; Tomilin, S.V.; Lizin, A.A.

2008-01-01

Full text of publication follows: The crystallochemical phosphate concept in question is developed successfully in the new pyro-electrochemical reprocessing technology of irradiated fuel in molten chlorides of alkaline elements at one of the leading scientific nuclear centers - Research Institute of Atomic Reactors. Irradiated fuel is dissolved in molten chlorides of alkaline elements by mean of treating by chlorine. Then uranium and plutonium dioxides are removed electrochemically. The melt, when used many times, is contaminated by the residual actinide and contains fission products and the so called 'process' elements. This melt is unacceptable for future use. Phosphate methods can be applied for the solution of the following tasks: a) reprocessing (purification) of molten chloride salt solvents; b) conversion of the spent chloride melts to the insoluble stable crystalline product for safe storage and disposal. Within the framework of task 'a' phosphate methods may be realized by the several ways: 1) phosphate concentrating of impurities and their extraction from molten chlorides into solid phase by mean of chemical precipitation, co-precipitation, ion exchange and other chemical interactions, 2) conversion of precipitated waste phosphates to stable crystalline phosphate powders or ceramics for safe storage and disposal. (authors)

Study for electrochemical behavior of uranium oxide in a molten LiCl-Li2O system

International Nuclear Information System (INIS)

Park, Sung Bin; Park, Byung Heung; Seo, Chung Seok; Jung, Ki Jung; Park, Seong Won

2005-01-01

Interest in the electrolytic reduction of uranium oxide is increasing in the treatment of spent fuel oxides. With complicated and expensive procedures many reactive metals can be prepared in a pure metal form, the electrochemical reduction of a metal oxide has been recently proposed in metallurgy. The electrochemical reduction process is simple and rapid when compared to the conventional processes. The process can reduce the production costs and be applicable to a wide range of metal oxides. Chen et al. proposed the direct electrochemical reduction of titanium dioxide to titanium in a molten calcium chloride. Argonne National Laboratory (ANL) has reported the experimental results of an electrochemical reduction of the uranium oxide fuel in a bench-scale apparatus with a cyclic voltammetry, and has designed high-capacity reduction (HCR) cells and conducted three kg-scale UO 2 reduction runs. Gourishankar et al. classified the mechanisms of the electrolytic reduction of the metal oxides in a LiCl-Li 2 O molten salt system into two types; the simultaneous reduction and the direct electrochemical reduction. The uranium oxide in LiCl-Li 2 O molten salt was converted to uranium metal according to two mechanisms. Korea Atomic Energy Research Institute (KAERI) has developed the Advanced Spent Fuel Conditioning Process (ACP) to be an innovative technology in handling the PWR spent fuel. As part of ACP, the electrolytic reduction process (ER process) is the electrochemical reduction process of uranium oxide to uranium metal in molten salt. The ER process has advantages in a technical stability, an economic potential and a good proliferation resistance. KAERI has reported on the good experimental results of an electrochemical reduction of the uranium oxide in a 20 kg HM/batch lab-scale. In this work, cyclic voltammograms for a LiCl-3 wt% Li 2 O system and an U 3 O 8 -LiCl-3 wt% Li 2 O system with the integrated cathode assembly have been obtained. From the cyclic

Experimental studies of actinides in molten salts

Energy Technology Data Exchange (ETDEWEB)

Reavis, J.G.

1985-06-01

This review stresses techniques used in studies of molten salts containing multigram amounts of actinides exhibiting intense alpha activity but little or no penetrating gamma radiation. The preponderance of studies have used halides because oxygen-containing actinide compounds (other than oxides) are generally unstable at high temperatures. Topics discussed here include special enclosures, materials problems, preparation and purification of actinide elements and compounds, and measurements of various properties of the molten volts. Property measurements discussed are phase relationships, vapor pressure, density, viscosity, absorption spectra, electromotive force, and conductance. 188 refs., 17 figs., 6 tabs.

Experimental studies of actinides in molten salts

International Nuclear Information System (INIS)

Reavis, J.G.

1985-06-01

This review stresses techniques used in studies of molten salts containing multigram amounts of actinides exhibiting intense alpha activity but little or no penetrating gamma radiation. The preponderance of studies have used halides because oxygen-containing actinide compounds (other than oxides) are generally unstable at high temperatures. Topics discussed here include special enclosures, materials problems, preparation and purification of actinide elements and compounds, and measurements of various properties of the molten volts. Property measurements discussed are phase relationships, vapor pressure, density, viscosity, absorption spectra, electromotive force, and conductance. 188 refs., 17 figs., 6 tabs

Deuterium retention in molten salt electrodeposition tungsten coatings

International Nuclear Information System (INIS)

Zhou, Hai-Shan; Xu, Yu-Ping; Sun, Ning-Bo; Zhang, Ying-Chun; Oya, Yasuhisa; Zhao, Ming-Zhong; Mao, Hong-Min; Ding, Fang; Liu, Feng; Luo, Guang-Nan

2016-01-01

Highlights: • We investigate D retention in electrodeposition W coatings. • W coatings are exposed to D plasmas in the EAST tokamak. • A cathodic current density dependence on D retention is found. • Electrodeposition W exhibits lower D retention than VPS-W. - Abstract: Molten salt electrodeposition is a promising technology to manufacture the first wall of a fusion reactor. Deuterium (D) retention behavior in molten salt electrodeposition tungsten (W) coatings has been investigated by D-plasma exposure in the EAST tokamak and D-ion implantation in an ion beam facility. Tokamak exposure experiments demonstrate that coatings prepared with lower current density exhibit less D retention and milder surface damage. Deuterium-ion implantation experiments indicate the D retention in the molten salt electrodeposition W is less than that in vacuum plasma spraying W and polycrystalline W.

Deuterium retention in molten salt electrodeposition tungsten coatings

Energy Technology Data Exchange (ETDEWEB)

Zhou, Hai-Shan [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China); Xu, Yu-Ping [Science Island Branch of Graduate School, University of Science and Technology of China, Hefei (China); Sun, Ning-Bo; Zhang, Ying-Chun [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing (China); Oya, Yasuhisa [Radioscience Research Laboratory, Faculty of Science, Shizuoka University, Shizuoka (Japan); Zhao, Ming-Zhong [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China); Mao, Hong-Min [Science Island Branch of Graduate School, University of Science and Technology of China, Hefei (China); Ding, Fang; Liu, Feng [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China); Luo, Guang-Nan, E-mail: gnluo@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China); Science Island Branch of Graduate School, University of Science and Technology of China, Hefei (China); Hefei Center for Physical Science and Technology, Hefei (China); Hefei Science Center of Chinese Academy of Science, Hefei (China)

2016-12-15

Highlights: • We investigate D retention in electrodeposition W coatings. • W coatings are exposed to D plasmas in the EAST tokamak. • A cathodic current density dependence on D retention is found. • Electrodeposition W exhibits lower D retention than VPS-W. - Abstract: Molten salt electrodeposition is a promising technology to manufacture the first wall of a fusion reactor. Deuterium (D) retention behavior in molten salt electrodeposition tungsten (W) coatings has been investigated by D-plasma exposure in the EAST tokamak and D-ion implantation in an ion beam facility. Tokamak exposure experiments demonstrate that coatings prepared with lower current density exhibit less D retention and milder surface damage. Deuterium-ion implantation experiments indicate the D retention in the molten salt electrodeposition W is less than that in vacuum plasma spraying W and polycrystalline W.

Evaluation of a molten salt electrolyte for direct reduction of actinides

International Nuclear Information System (INIS)

Alangi, Nagaraj; Anupama, P.; Mukherjee, Jaya; Gantayet, L.M.

2011-01-01

Use of molten fluoride salt towards direct reduction of actinides and lanthanides by molten salt electrolysis is of interest for problems related to metallic nuclear fuels. The performance of the molten salt bath is dependent on the pre-conditioning of the molten salt. A procedure for conditioning of LiF-BaF 2 salt mixtures has been developed based on systematic electrochemical experimental investigations using voltammetry with graphite and platinum as electrode materials. We utilize the linear sweep voltammetry (LSV) as a diagnostic tool for assessment of the electrolyte condition. This technique is fast and offers the advantage of in-situ/online measurement eliminating the need for sampling. The conditioning procedure that was developed was tried on LiF-CaF 2

Proceedings of the workshop on molten salts technology and computer simulation

Energy Technology Data Exchange (ETDEWEB)

Hayashi, Hirokazu; Minato, Kazuo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

2001-12-01

Applications of molten salts technology to separation and synthesis of materials have been studied eagerly, which would develop new fields of materials science. Research Group for Actinides Science, Department of Materials Science, Japan Atomic Energy Research Institute (JAERI), together with Reprocessing and Recycle Technology Division, Atomic Energy Society of Japan, organized the Workshop on Molten Salts Technology and Computer Simulation at Tokai Research Establishment, JAERI on July 18, 2001. In the workshop eleven lectures were made and lively discussions were there on the fundamentals and applications of the molten salts technology that covered the structure and basic properties of molten salts, the pyrochemical reprocessing technology and the relevant computer simulation. The 10 of the presented papers are indexed individually. (J.P.N.)

Equilibrium electrode U(4)-U and redox U(4)-U(3) potentials in molten alkali metal chlorides medium

Energy Technology Data Exchange (ETDEWEB)

Smirnov, M V; Kudyakov, V Ya; Komarov, V E; Salyulev, A B [AN SSSR, Sverdlovsk. Inst. Ehlektrokhimii

1979-02-01

Conditional standard electrode potentials of uranium are determined for diluted solutions of its tetrachloride in alkali metal chloride melts (LiCl, NaCl, NaCl-KCl, KCl, RbCl and CsCl) when using U(4) ion activity coefficient values experimentally found by the tensimetric method. These potentials shift to the electronegative side at the temperature decrease and alkali cation radius increase rsub(Msup(+)) according to the empiric ratio E*U(4)-U= -3.06+6.87x10/sup -4/ T-(1.67-10/sup -4/T-0.44) 1/rsub(Msup(+)) +-0.01. The temperature dependences of formal conditional redox potentials of the U(4)-U(3) system for above melted chlorides are estimated. The E*U(4)-U(3) value also becomes more electronegative in the series LiCl, NaCl, NaCl-KCl, KCl, RbCl and CsCl. This alternation is satisfactorily described by the empiric expression E*U(4)-U(3)= -1.74+1.74x10/sup -4/T-(0.71x10/sup -4/T-0.20) 1rsub(Msup(+)) +-0.05. The calculated values Eu*(4)-U(3) are compared with those directly measured for the NaCl-KCl equimolar mixture and 3LiCl-2KCl eutectic mixture. A satisfactory confirmity has been observed.

Equilibrium electrode U(4)-U and redox U(4)-U(3) potentials in molten alkali metal chlorides medium

International Nuclear Information System (INIS)

Smirnov, M.V.; Kudyakov, V.Ya.; Komarov, V.E.; Salyulev, A.B.

1979-01-01

Conditional standard electrode potentials of uranium are determined for diluted solutions of its tetrachloride in alkali metal chloride melts (LiCl, NaCl, NaCl-KCl, KCl, RbCl and CsCl) when using U(4) ion activity coefficient values experimentally found by the tensimetric method. These potentials shift to the electronegative side at the temperature decrease and alkali cation radius increase rsub(Msup(+)) according to the empiric ratio E*U(4)-U= -3.06+6.87x10 -4 T-(1.67-10 -4 T-0.44) 1/rsub(Msup(+)) +-0.01. The temperature dependences of formal conditional redox potentials of the U(4)-U(3) system for above melted chlorides are estimated. The E*U(4)-U(3) value also becomes more electronegative in the series LiCl, NaCl, NaCl-KCl, KCl, RbCl and CsCl. This alternation is satisfactorily described by the empiric expression E*U(4)-U(3)= -1.74+1.74x10 -4 T-(0.71x10 -4 T-0.20) 1rsub(Msup(+)) +-0.05. The calculated values Eu*(4)-U(3) are compared with those directly measured for the NaCl-KCl equimolar mixture and 3LiCl-2KCl eutectic mixture. A satisfactory confirmity has been observed

Propagation mechanisms of molten fuel/moderator interactions

International Nuclear Information System (INIS)

Frost, D.L.; Ciccarelli, G.

1991-06-01

It is well known that a vapor explosion can result when molten is suddenly brought into contact with a cold volatile liquid such as water. However, the rapid melt fragmentation and heat transfer processes that occur during a propagating melt-water interaction are poorly understood. Experiments were carried out in the present work to investigate the fragmentation processes for single molten metal drops in water. To determine the time scale for the fragmentation of a drop, liquid metal drops (in thermal equilibrium with the water) as well as hot molten drops surrounded by a vapor film were subjected to underwater shocks with overpressures of up to about 20 MPa. In the hot molten drop tests, the induction time for the initiation of the explosion is typically less than 100 μs; at a corresponding time in the cold drop tests, very little or no direct hydrodynamic fragmentation of the drop has occurred. Therefore, in the hot drop case the fragmentation of the drop is dominated by thermal effects; i.e., the heat transfer from the melt to the water leads to violent boiling, pressurization, and drop fragmentation. The melt-water interaction consists of several cycles involving bubble growth and collapse. The strength of the interaction was not found to be a strong function of initial shock pressure (for molten tin drops with trigger pressures of up to 20 MPa), but depends on the thermal energy in the melt: high-temperature thermite drops generated a larger first bubble than lower temperature melt drops. A model for the fine fragmentation process for a hot drop is proposed that is based on thermal effects. The fragmentation processes governed by thermal effects observed in the present experiments are expected to play an important role in the escalation of a local interaction to a large-scale coherent vapor explosion, and are not accounted for in current transient models for propagating vapor explosions

Molten fluoride mixtures as possible fission reactor fuels

International Nuclear Information System (INIS)

Grimes, W.R.

1978-01-01

Molten mixtures of fluorides with UF 4 as a component have been used as combined fuel and primary heat transfer agent in experimental high-temperature reactors and have been proposed for use in breeders or converters of 233 U from thorium. Such use places stringent and diverse demands upon the fluid fuel. A brief review of chemical behavior of molten fluorides is given to show some of their strengths and weaknesses for such service

The study of interaction of lanthanum-, cerium- and neodymium chlorides with sodium borohydride in pyridine- and tetrahydrofuran medium

International Nuclear Information System (INIS)

Mirsaidov, U.; Rotenberg, T.G.; Dymova, T.N.

1976-01-01

Bis-tetrahydrofurans of lanthanum and neodymium borohydrides and bis-pyridinates of lanthanum, cerium and neodymium borohydrides were obtained by interacting sodium borohydride with lanthanum-, cerium and neodymium chlorides in pyridine and tetrahydrofuran media. All operations involving reagent combination, sampling and phase separation are performed in inert atmosphere using argonvacuum equipment. The reaction in pyridine was virtually instantaneous and accompanied by flocculanet precipitation. The interaction of lanthanum chloride and neodymium chloride with sodium borohydride in tetrahydrofuran (THF) was a slow (23-30 hr) heterophase process. The interaction rate was affected by size reduction of the intial substances, temperature, reagent proportion and mixing rate. The reaction time was twice reduced with boiling tetrahydrofuran

Electrochemical noise measurements of steel corrosion in the molten NaCl-K2SO4 system

DEFF Research Database (Denmark)

Cappeln, Frederik Vilhelm; Bjerrum, Niels; Petrushina, Irina

2005-01-01

-called active corrosion (i.e., the corrosion proceeds with no passivation due to the influence of chlorine), characterized by the formation of volatile metal chlorides as a primary corrosion product. It was found possible to obtain an empirical separation of general and intergranular corrosion using kurtosis (a......Electrochemical noise measurements have been carried out on AISI347, 10CrMo910, 15Mo3, and X20CrMoV121 steels in molten NaCl-K2SO4 at 630 degrees C. Different types of current noise have been identified for pitting, intergranular and peeling corrosion. The corrosion mechanism was the so...... statistical parameter calculated from the electrochemical noise data). It was found that average kurtosis values above 6 indicated intergranular corrosion and average values below 6 indicated general corrosion. The response time for localized corrosion detection in in-plant monitoring was approximately 90 min...

Experimental study on thermal interaction between a high-temperature molten jet and plates

International Nuclear Information System (INIS)

Sato, K.; Saito, M.; Furutani, A.; Isozaki, M.; Imahori, S.; Konishi, K.

1994-01-01

This paper summarizes the recent simulant experiments to study molten corium-structure interactions under postulated core disruptive accident (CDA) conditions in liquid-metal fast breeder reactors (LMFMRs). These experiments were conducted in the MELT-II facility generating high-temperature molten simulants by an induction heating technique. From a series of molten jet-structure interaction experiments, the effects of the solidified crust layer and molten layer on the erosion behavior were identified, and analytical models were developed to assess the structure erosion rate with and without crust formation. Especially, we revealed the inherent mitigation mechanism that when the molten oxide jet with high melting point falls down onto the structure plate, solidified crust of the oxide can significantly reduce the erosion rate. (author)

Molten salt reactors. The AMSTER concept

International Nuclear Information System (INIS)

Vergnes, J.; Garzenne, C.; Lecarpentier, D.; Mouney, H.

2001-01-01

This article presents the concept of actinide molten salt transmuter (AMSTER). This reactor is graphite-moderated and is dedicated to the burning of actinides. The main difference with a molten salt reactor is that its liquid fuel undergoes an on-line partial reprocessing in which fission products are extracted and heavy nuclei are reintroduced into the fuel. In order to maintain the reactivity regular injections of 235 U-salt are made. In classical reactors, fuel burn-up is limited by the swelling of the cladding and the radiation fuel pellets resistance, in AMSTER there is no limitation to the irradiation time of the fuel, so all the actinides can be burnt or transmuted. (A.C.)

Development of semiindustrial technology for electrolytic powder production

International Nuclear Information System (INIS)

Suchkov, A.B.; Kovalev, B.F.; Zhbanov, A.M.; Rabinovich, E.M.; Sozina, A.L.

1978-01-01

The technology of the production of Fe, Mn, Cr, W pure metal powders by electrolysis of industrial waste in molten chloride-fluoride media with the addition of lower chlorides of refining metal was tested in laboratory and then in industrial electrolysers (2kA). The cathode deposit was subjected to hydrometallurgical treatment. Approximate technological parameters of electrorefining are presented. A high-temperature (700-1000 deg C) hydrogen annealing was applied to increase the quality and to change physicochemical and technological characteristics of electrolytic powders. The data on the chemical composition of Mowders are presented, testifying to their high purity. It is shown that electrolytic powders are not uniform in granulometric composition (from 1 to 100 μm), their particles being characterized mainly by the dendrite structure

On the ionic equilibrium between complexes in molten fluoroaluminates

International Nuclear Information System (INIS)

Akdeniz, Z.; Tankeshwar, K.; Tosi, M.P.

1991-02-01

We discuss theoretically (i) the effect of the alkali cation species on the ionic equilibrium between (AlF 6 ) 3- and (AlF 4 ) - complexes in molten alkali fluoroaluminates, and (ii) the possible presence of (AlF 5 ) 2 - complexes in molten cryolite, in relation to very recent Raman scattering experiments by Gilbert and Materne. (author). 7 refs, 2 tabs

Molten metal feed system controlled with a traveling magnetic field

Science.gov (United States)

Praeg, Walter F.

1991-01-01

A continuous metal casting system in which the feed of molten metal is controlled by means of a linear induction motor capable of producing a magnetic traveling wave in a duct that connects a reservoir of molten metal to a caster. The linear induction motor produces a traveling magnetic wave in the duct in opposition to the pressure exerted by the head of molten metal in the reservoir so that p.sub.c =p.sub.g -p.sub.m where p.sub.c is the desired pressure in the caster, p.sub.g is the gravitational pressure in the duct exerted by the force of the head of molten metal in the reservoir, and p.sub.m is the electromagnetic pressure exerted by the force of the magnetic field traveling wave produced by the linear induction motor. The invention also includes feedback loops to the linear induction motor to control the casting pressure in response to measured characteristics of the metal being cast.

Molten-salt reactor strategies viewed from fuel conservation effect, (1)

International Nuclear Information System (INIS)

Furuhashi, Akira

1976-01-01

Saving of material requirements in the long-term fuel cycle is studied by introducing molten-salt reactors with good neutron economy into a projection of nuclear generating capacity in Japan. In this first report an examination is made on the effects brought by the introduction of molten-salt converter reactors starting with Pu which are followed by 233 U breeders of the same type. It is shown that the sharing of some Pu in the light water- and fast breeder-reactor system with molten-salt reactors provides a more rapid transition to the self-supporting, breeding cycle than the simple fast breeding system, thus leading to an appreciable fuel conservation. Considerations are presented on the strategic repartition of generating capacity among reactor types and it is shown that all of the converted 233 U should be promptly invested to molten-salt breeders to quickly establish the dual breeding system, instead of recycling to converters themselves. (auth.)

Internal cation mobilities in molten lithium. Potassium fluoride

International Nuclear Information System (INIS)

Matsuura, Haruaki; Ohashi, Ryo; Chou, Pao-Hwa; Takagi, Ryuzo

2006-01-01

Relative differences between internal cation mobilities in molten (Li, K) F have been measured by countercurrent electromigration (Klemm method) at 1023 K. Internal mobilities of K + are larger than those of Li + in all composition on which we have measured so far. More striking feature is that the isotherms have minimum of mobilities at ca. x K =0.5. The local structural parameters would be highly related to the ionic conduction behavior in molten fluorides. (author)

Behaviour of molten reactor fuels under accident conditions

International Nuclear Information System (INIS)

Xavier Swamikannu, A.; Mathews, C.K.

1980-01-01

The behaviour of molten reactor fuels under accident conditions has received considerable importance in recent times. The chemical processes that occur in the molten state among the fuel, the clad components and the concrete of the containment building under the conditions of a core melt down accident in oxide fuelled reactors have been reviewed with the purpose of identifying areas of developmental work required to be performed to assess and minimize the consequences of such an accident. This includes the computation and estimation of vapour pressure of various gaseous species over the fuel, the clad and the coolant, providing of sacrificial materials in the concrete in order to protect the containment building in order to prevent release of radioactive gases into the atmosphere and understanding the distribution and chemical state of fission products in the molten fuel in order to provide for the effective removal of their decay heats. (auth.)

Molten salt oxidation as an alternative to incineration

International Nuclear Information System (INIS)

Gray, L.W.; Adamson, M.G.; Cooper, J.F.; Farmer, J.C.; Upadhye, R.S.

1992-03-01

Molten Salt Oxidation was originally developed by Rockwell International as part of their coal gasification, and nuclear-and hazardous-waste treatment programs. Single-stage oxidation units employing molten carbonate salt mixtures were found to process up to one ton/day of common solid and liquid wastes (such as paper, rags, plastics, and solvents), and (in larger units) up to one ton/hour of coal. After the oxidation of coal with excess oxygen, coal ash residuals (alumina-silicates) were found adhering to the vessel walls above the liquid level. The phenomenon was not observed with coal gasification-i.e., under oxygen-deficient conditions. Lawrence Livermore National Laboratory (LLNL) is developing a two-stage/two-vessel approach as a possible means of extending the utility of the process to wastes which contain high concentrations of alumina-silicates in the form of soils or clays, or high concentrations of nitrates including low-level and transuranic wastes. The first stage operates under oxygen-deficient (''pyrolysis'') conditions; the second stage completes oxidation of the evolved gases. The process allows complete oxidation of the organic materials without an open flame. In addition, all acidic gases that would be generated in incinerators are directly metathesized via the molten Na 2 CO 3 to form stable salts (NaCl, Na 2 SO 4 etc.). Molten salt oxidation therefore avoids the corrosion problems associated with free HCl in incineration. The process is being developed to use pure O 2 feeds in lieu of air, in order to reduce offgas volume and retain the option of closed system operation. In addition, ash is wetted and retained in the melt of the first vessel which must be replaced (continuously or batch-wise). The LLNL Molten Salt unit is described together with the initial operating data

Electrolytic recovery of calcium from molten CaO-CaCl2 salt-mix

International Nuclear Information System (INIS)

Mishra, B.; Olson, D.L.

1993-01-01

Calciothermic reduction of plutonium oxide is an industrial process for producing plutonium metal. The process is carried out in a molten calcium chloride medium which has a significantly high solubility for calcium oxide. However, the CaO-CaCl 2 salt-mix is radioactively contaminated and can not be discarded as such. Fused salt electrolysis of a simulated mix has been carried out using graphite anode and steel cathode to produce calcium. The dissolved calcium in CaCl 2 salt can be used insitu to reduce plutonium oxide. The primary difficulty in obtaining a cathodic calcium deposit was the use of graphite anose which indirectly controls all the back-reactions in the cell through which the deposited calcium is lost. A porous ceramic sheath has been used to essentially keep the anodic and cathodic products separate. The porosity of the sheath has been optimized by measuring its diffusion coefficient as a function of temperature. The influence of a porous sheath on the cell potential has been also analyzed

A study on the corrosion test of equipment material handling hot molten salt

International Nuclear Information System (INIS)

Ro, Seung Gy; Jeong, M.S.; Hong, S.S.; Cho, S.H.; Shin, Y.J.; Park, H.S.; Zhang, J.S.

1999-02-01

On this technical report, corrosion behavior of austenitic stainless steels of SUS 316L and SUS 304L in molten salt of LiCl-Li 2 O has been investigated in the temperature range of 650 - 850 dg C. Corrosion products of SUS 316L in molten salt consisted of two layers, an outer layer of LiCrO 2 and inner layer of Cr 2 O 3 .The corrosion layer was uniform in molten salt of LiCl, but the intergranular corrosion occurred in addition to the uniform corrosion in mixed molten salt of LiCl-Li 2 O. The corrosion rate increased slowly with the increase of temperature up to 750 dg C, but above 750 dg C rapid increase in corrosion rate observed. SUS 316L stainless steel showed slower corrosion rate and higher activation energy for corrosion than SUS 304L, exhibiting higher corrosion resistance in the molten salt. In heat-resistant alloy, dense protective oxide scale of LiCrO 2 was formed in molten salt of LiCl. Whereas in mixed molten salt of LiCl-Li 2 O, porous non-protective scale of Li(Cr, Ni, Fe)O 2 was formed. (Author). 44 refs., 4 tabs., 16 figs

Thorium cycle and molten salt reactors: field parameters and field constraints investigations toward 'thorium molten salt reactor' definition

International Nuclear Information System (INIS)

Mathieu, L.

2005-09-01

Producing nuclear energy in order to reduce the anthropic CO 2 emission requires major technological advances. Nuclear plants of 4. generation have to respond to several constraints, as safety improvements, fuel breeding and radioactive waste minimization. For this purpose, it seems promising to use Thorium Cycle in Molten Salt Reactors. Studies on this domain have already been carried out. However, the final concept suffered from serious issues and was discontinued. A new reflection on this topic is being led in order to find acceptable solutions, and to design the Thorium Molten Salt Reactor concept. A nuclear reactor is simulated by the coupling of a neutron transport code with a materials evolution code. This allows us to reproduce the reactor behavior and its evolution all along its operation. Thanks to this method, we have studied a large number of reactor configurations. We have evaluated their efficiency through a group of constraints they have to satisfy. This work leads us to a better understanding of many physical phenomena controlling the reactor behavior. As a consequence, several efficient configurations have been discovered, allowing the emergence of new points of view in the research of Molten Salt Reactors. (author)

Stability constants of the Europium complexes with the chloride ions; Constantes de estabilidad de los complejos del europio con los iones cloruro

Energy Technology Data Exchange (ETDEWEB)

Jimenez R, M.; Solache R, M.; Rojas H, A. [Instituto Nacional de Investigaciones Nucleares, Departamento de Quimica, A.P. 18-1027, C.P. 11801 Mexico D.F. (Mexico)

2000-07-01

The stability constants of lanthanides complexes with chloride ions which were determined at the same ionic force but in different media, are significantly different. It does not exist a systematic study over these stability constants. The purpose of this work is to determine the stability constants of the europium complexes with chloride ions at 303 K, by the solvents extraction method. (Author)

Effects of melt-temperature on limiting current density in Al electrodeposition and morphology of Al electrodeposits obtained from ambient temperature type molten salt; Joongata yoyuen kara no denki aluminium mekki no genkai denryu mitsudo oyobi denseki keitai ni oyobosu mekki ekion no eikyo

Energy Technology Data Exchange (ETDEWEB)

Shimizu, T.; Tatano, M.; Uchida, Y. [Nisshin Steel Co. Ltd., Tokyo (Japan)

1996-03-31

Some of more important electrolytic solutions for Al electrodeposition are organic solvents, high-temperature type molten salts and low-temperature type molten salts having a melting point of 30{degree}C or lower, such as ethylmethylimidazolium chloride (EMIC). This study uses a molten salt of AlCl3-EMIC as the low-temperature type solution for high-speed electrodeposition. Discussed herein are the effects of melt temperature on limiting current density in Al electrodeposition and Al electrodeposit morphology. Limiting current density increases as melt temperature increases at any AlCl3 concentration used in this study. The AlCl3 concentration that gives the maximum limiting current density shifts from 64 to 67mol% at a melt temperature of 120{degree}C. A dense, smooth Al electrodeposited film results at a melt temperature of 100{degree}C or lower, but the electrodeposited grains become coarser as melt temperature increases. Melt temperature can be increased to 140{degree}C to secure a smooth electrodeposited film, showing possibility of 2 times faster electrodeposition than the conventional one. 21 refs., 12 figs., 1 tab.

Measurement of emittance of metal interface in molten salt

International Nuclear Information System (INIS)

Araki, N.; Makino, A.; Nakamura, Y.

1995-01-01

A new technique for measuring the total normal emittance of a metal in a semi-transparent liquid has been proposed and this technique has been applied to measure the emittance of stainless steel (SUS304), nickel, and gold in molten potassium nitrate KNO 3 . These emittance data are indispensable to analyzing the radiative heat transfer between a metal and a semitransparent liquid, such as a molten salt

Molten salt reactors: chemistry

International Nuclear Information System (INIS)

1983-01-01

This work is a critical analysis of the 1000 MW MSBR project. Behavior of rare gases in the primary coolant circuit, their extraction from helium. Coating of graphite by molybdenum, chemistry of protactinium and niobium produced in the molten salt, continuous reprocessing of the fuel salt and use of stainless steel instead of hastelloy are reviewed [fr

Hot filament technique for measuring the thermal conductivity of molten lithium fluoride

Science.gov (United States)

Jaworske, Donald A.; Perry, William D.

1990-01-01

Molten salts, such as lithium fluoride, are attractive candidates for thermal energy storage in solar dynamic space power systems because of their high latent heat of fusion. However, these same salts have poor thermal conductivities which inhibit the transfer of heat into the solid phase and out of the liquid phase. One concept for improving the thermal conductivity of the thermal energy storage system is to add a conductive filler material to the molten salt. High thermal conductivity pitch-based graphite fibers are being considered for this application. Although there is some information available on the thermal conductivity of lithium fluoride solid, there is very little information on lithium fluoride liquid, and no information on molten salt graphite fiber composites. This paper describes a hot filament technique for determining the thermal conductivity of molten salts. The hot filament technique was used to find the thermal conductivity of molten lithium fluoride at 930 C, and the thermal conductivity values ranged from 1.2 to 1.6 W/mK. These values are comparable to the slightly larger value of 5.0 W/mK for lithium fluoride solid. In addition, two molten salt graphite fiber composites were characterized with the hot filament technique and these results are also presented.

Investigation of Inner Vacuum Sucking method for degassing of molten aluminum

International Nuclear Information System (INIS)

Zeng, Jianmin; Gu, Ping; Wang, Youbing

2012-01-01

Hydrogen is a harmful gas element that is appreciably soluble in aluminum and its alloys. Removal of hydrogen from molten aluminum has been one of the most important tasks in aluminum melt processing. In this paper, a patented degassing process, which is based on principle of vacuum metallurgy, is proposed. A porous head that connects a vacuum system is immersed in the molten aluminum. The vacuum is created within the porous head and the dissolved hydrogen will diffuse unidirectionally towards the porous head according to Sievert's law. In this way, the hydrogen in the molten aluminum can be removed. The Fick's diffusion equation is used to explain hydrogen transfer in the molten aluminum. RPT experiments are carried out to evaluate the effectiveness of the new degassing process. The experiments indicate that the hydrogen content can be dramatically reduced by use of this process.

Numerical study on heat transfer characteristics of liquid-fueled molten salt using OpenFOAM

International Nuclear Information System (INIS)

Jeong, Yeong Shin; Bang, In Cheol

2017-01-01

To pursue sustainability and safety enhancement of nuclear energy, molten salt reactor is regarded as a promising candidate among various types of gen-IV reactors. Besides, pyroprocessing, which treats molten salt containing fission products, should consider safety related to decay heat from fuel material. For design of molten salt-related nuclear system, it is required to consider both thermal-hydraulic characteristics and neutronic behaviors for demonstration. However, fundamental heat transfer study of molten salt in operation condition is not easy to be experimentally studied due to its large scale, high temperature condition as well as difficulties of treating fuel material. >From that reason, numerical study can have benefit to investigate behaviors of liquid-fueled molten salt in real condition. In this study, open source CFD package OpenFOAM was used to analyze liquid-fueled molten salt loop having internal heat source as a first step of research. Among various molten salts considered as a candidate of liquid fueled molten salt reactors, in this study, FLiBe was chosen as liquid salt. For simulating heat generation from fuel material within fluid flow, volumetric heat source was set for fluid domain and OpenFOAM solver was modified as fvOptions as customized. To investigate thermal-hydraulic behavior of molten salt, CFD model was developed and validated by comparing experimental results in terms of heat transfer and pressure drop. As preliminary stage, 2D cavity simulations were performed to validate the modeling capacity of modified solver of OpenFOAM by comparison with those of ANSYS-CFX. In addition, cases of external heat flux and internal heat source were compared to configure the effect of heat source setting in various operation condition. As a result, modified solver of OpenFOAM considering internal heat source have sufficient modeling capacity to simulate liquid-fueled molten salt systems including heat generation cases. (author)

Chrono-potentiometry in molten chlorides. Application to the study of the electrochemical properties of uranium and plutonium in the LiCl-KCl eutectic; Chronopotentiometrie dans les chlorures fondus. Application a l'etude des proprietes electrochimiques de l'uranium et du plutonium dans l'eutectique LiCl-KCl

Energy Technology Data Exchange (ETDEWEB)

Leseur, A. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1969-05-01

Using solutions of cadmium chloride in the eutectic LiCl-KCl, a chrono-potentiometric method has been developed with a view to its application to the study of molten solutions. Particular attention has been paid to the choice of the indicator electrodes. The method makes it possible to analyze molten solutions quantitatively and to determine diffusion coefficients and their activation energies; it yields furthermore information about the nature and the behaviour of ionic species in solution. The method has been applied to the study of solutions of uranium and plutonium chloride in the eutectic LiCl-KCl. Linear chrono-amperometry has been used for studying these solutions quantitatively, but chrono-potentiometry, of which the theory is better developed, is better suited to a quantitative study. The results obtained have made it possible to determine the diffusion coefficients of the ions Cd{sup 2+}, U{sup 3+}, U{sup 4+} and U(IV) in the presence of F{sup -} and Pu{sup 3+} ions, as well as the activation energy of the diffusion coefficients. (author) [French] La mise au point de la chronopotentiometrie comme moyen d'etude des solutions fondues a ete effectuee avec des solutions de chlorure de cadmium dans l'eutectique LiCl-KCl. Le probleme du choix des electrodes indicatrices a ete particulierement etudie. La methode permet l'analyse quantitative des solutions fondues ainsi que la determination des coefficients de diffusion et de leurs energies d'activation: elle donne en outre des renseignements sur la nature et le comportement des especes ioniques en solution. Elle a ete appliquee a l'etude des solutions des chlorures d'uranium et de plutonium dans l'eutectique LiCl-KCl. La chronoamperometrie lineaire a ete utilisee pour l'etude qualitative de ces solutions, mais la chronopotentiometrie, dont la theorie est plus complete, convient mieux pour l'etude quantitative. Les resultats obtenus ont permis de determiner les

Chloride ingress prediction

DEFF Research Database (Denmark)

Frederiksen, Jens Mejer; Geiker, Mette Rica

2008-01-01

Prediction of chloride ingress into concrete is an important part of durability design of reinforced concrete structures exposed to chloride containing environment. This paper presents experimentally based design parameters for Portland cement concretes with and without silica fume and fly ash...... in marine atmospheric and submersed South Scandinavian environment. The design parameters are based on sequential measurements of 86 chloride profiles taken over ten years from 13 different types of concrete. The design parameters provide the input for an analytical model for chloride profiles as function...... of depth and time, when both the surface chloride concentration and the diffusion coefficient are allowed to vary in time. The model is presented in a companion paper....

Basic studies for molten-salt reactor engineering in Japan

International Nuclear Information System (INIS)

Ishiguro, R.; Sugiyama, K.; Sakashita, H.

1985-01-01

A research project of nuclear engineering for the molten-salt reactor is underway which is supported by the Grant-in-Aid for Scientific Research of the Ministry of Education of Japan. At present, the major effort is devoted only to basic engineering problems because of the limited amount of the grant. The reporters introduce these and related studies that have been carrying out in Japanese universities. Discussions on the following four subjects are summerized in this report: a) Vapour explosion when hight temperature molten-salts are brought into direct contact with water. b) Measurements of exact thermophysical properties of molten-salt. c) Free convection heat transfer with uniform internal heat generation and a constant heating rate from the bottem. d) Stability of frozen salt film on the container surface. (author)

The molten salt reactor: R and D status and perspectives in Europe

International Nuclear Information System (INIS)

Renault, Claude; Delpech, Sylvie; Merle-Lucotte, Elsa; Konings, Rudy; Hron, Miloslav; Ignatiev, Victor

2010-01-01

The paper concentrates on molten salt fast reactor (MSFR) concepts which are receiving most attention in the EU context. It shows the main R and D achievements and some remaining issues to be addressed in such essential areas as (a) reactor conceptual design, (b) molten salt properties, (c) fuel salt clean-up scheme and (d) high temperature materials. The status and perspectives of molten salt reactor R and D efforts in Europe are then discussed

Densities of molten Ni-(Cr, Co, W) superalloys

Institute of Scientific and Technical Information of China (English)

XIAO Feng; YANG Ren-hui; FANG Liang; LIU Lan-xiao; ZHAO Hong-kai

2008-01-01

In order to obtain more accurate density for molten Ni-(Cr, Co, W) binary alloy, the densities of molten pure Ni and Ni-Cr, Ni-Co, Ni-W alloys were measured with a sessile drop method. It is found that the measured densities of molten pure Ni and Ni-Cr, Ni-Co, Ni-W alloys decrease with increasing temperature in the experimental temperature range. The density of alloys increases with increasing W and Co concentrations while it decreases with increasing Cr concentration in the alloy at 1 773-1 873 K. The molar volume of Ni-based alloys increases with increasing W concentration while it decreases with increasing Co concentration. The effect of Cr concentration on the molar volume of the alloy is little in the studied concentration range. The accommodation among atomic species was analyzed. The deviation of molar volume from ideal mixing shows an ideal mixing of Ni-(Cr, Co, W) binary alloys.

Application of molten salt oxidation for the minimization and recovery of plutonium-238 contaminated wastes

International Nuclear Information System (INIS)

Wishau, R.

1998-05-01

Molten salt oxidation (MSO) is proposed as a 238 Pu waste treatment technology that should be developed for volume reduction and recovery of 238 Pu and as an alternative to the transport and permanent disposal of 238 Pu waste to the WIPP repository. In MSO technology, molten sodium carbonate salt at 800--900 C in a reaction vessel acts as a reaction media for wastes. The waste material is destroyed when injected into the molten salt, creating harmless carbon dioxide and steam and a small amount of ash in the spent salt. The spent salt can be treated using aqueous separation methods to reuse the salt and to recover 99.9% of the precious 238 Pu that was in the waste. Tests of MSO technology have shown that the volume of combustible TRU waste can be reduced by a factor of at least twenty. Using this factor the present inventory of 574 TRU drums of 238 Pu contaminated wastes is reduced to 30 drums. Further 238 Pu waste costs of $22 million are avoided from not having to repackage 312 of the 574 drums to a drum total of more than 4,600 drums. MSO combined with aqueous processing of salts will recover approximately 1.7 kilograms of precious 238 Pu valued at 4 million dollars (at $2,500/gram). Thus, installation and use of MSO technology at LANL will result in significant cost savings compared to present plans to transport and dispose 238 Pu TRU waste to the WIPP site. Using a total net present value cost for the MSO project as $4.09 million over a five-year lifetime, the project can pay for itself after either recovery of 1.6 kg of Pu or through volume reduction of 818 drums or a combination of the two. These savings show a positive return on investment

Analysis of molten salt thermal-hydraulics using computational fluid dynamics

International Nuclear Information System (INIS)

Yamaji, B.; Csom, G.; Aszodi, A.

2003-01-01

To give a good solution for the problem of high level radioactive waste partitioning and transmutation is expected to be a pro missing option. Application of this technology also could extend the possibilities of nuclear energy. Large number of liquid-fuelled reactor concepts or accelerator driven subcritical systems was proposed as transmutors. Several of these consider fluoride based molten salts as the liquid fuel and coolant medium. The thermal-hydraulic behaviour of these systems is expected to be fundamentally different than the behaviour of widely used water-cooled reactors with solid fuel. Considering large flow domains three-dimensional thermal-hydraulic analysis is the method seeming to be applicable. Since the fuel is the coolant medium as well, one can expect a strong coupling between neutronics and thermal-hydraulics too. In the present paper the application of Computational Fluid Dynamics for three-dimensional thermal-hydraulics simulations of molten salt reactor concepts is introduced. In our past and recent works several calculations were carried out to investigate the capabilities of Computational Fluid Dynamics through the analysis of different molten salt reactor concepts. Homogenous single region molten salt reactor concept is studied and optimised. Another single region reactor concept is introduced also. This concept has internal heat exchanges in the flow domain and the molten salt is circulated by natural convection. The analysis of the MSRE experiment is also a part of our work since it may form a good background from the validation point of view. In the paper the results of the Computational Fluid Dynamics calculations with these concepts are presented. In the further work our objective is to investigate the thermal-hydraulics of the multi-region molten salt reactor (Authors)

Density and Structure Analysis of Molten Ni-W Alloys

Institute of Scientific and Technical Information of China (English)

Feng XIAO; Liang FANG

2004-01-01

Density of molten Ni and Ni-W alloys was measured in the temperature range of 1773～1873 K with a sessile drop method.The density of molten Ni and Ni-W alloys trends to decrease with increasing temperature. The density and molar volume of the alloys trend to increase with increasing W concentration in the alloys. The calculation result shows an ideal mixing of Ni-W alloys.

Molten salt reactors. Synthesis of studies realized between 1973 and 1983. General synthesis

International Nuclear Information System (INIS)

Hery, M.; Lecocq, A.

1983-03-01

After a brief recall of the MSBR project, French studies on molten salt reactors are summed up. Theoretical and experimental studies for a graphite moderated 1000 MWe reactor using molten Li, Be, Th and U fluorides cooled by salt-lead direct contact are given. These studies concern the core, molten salt chemistry, graphite, metals (molybdenum, alloy TZM), corrosion, reactor components [fr

A radioactive tracer dilution method to determine the mass of molten salt

International Nuclear Information System (INIS)

Lei Cao; Jarrell, Josh; Hardtmayer, D.E.; White, Susan; Herminghuysen, Kevin; Kauffman, Andrew; Sanders, Jeff; Li, Shelly

2017-01-01

A new technique for molten salt mass determination, termed radioactive tracer dilution, that uses 22 Na as a tracer was validated at bench scale. It has been a challenging problem to determine the mass of molten salt in irregularly shaped containers, where a highly radioactive, high-temperature molten salt was used to process nuclear spent/used fuel during electrochemical recycling (pyro-processing) or for coolant/fuel salt from molten salt reactors. A radioactive source with known activity is dissolved into the salt. After a complete mixture, a small amount of the salt is sampled and measured in terms of its mass and radioactivity. By finding the ratio of the mass to radioactivity, the unknown salt mass in the original container can be precisely determined. (author)

Conduit for high temperature transfer of molten semiconductor crystalline material

Science.gov (United States)

Fiegl, George (Inventor); Torbet, Walter (Inventor)

1983-01-01

A conduit for high temperature transfer of molten semiconductor crystalline material consists of a composite structure incorporating a quartz transfer tube as the innermost member, with an outer thermally insulating layer designed to serve the dual purposes of minimizing heat losses from the quartz tube and maintaining mechanical strength and rigidity of the conduit at the elevated temperatures encountered. The composite structure ensures that the molten semiconductor material only comes in contact with a material (quartz) with which it is compatible, while the outer layer structure reinforces the quartz tube, which becomes somewhat soft at molten semiconductor temperatures. To further aid in preventing cooling of the molten semiconductor, a distributed, electric resistance heater is in contact with the surface of the quartz tube over most of its length. The quartz tube has short end portions which extend through the surface of the semiconductor melt and which are lef bare of the thermal insulation. The heater is designed to provide an increased heat input per unit area in the region adjacent these end portions.

Workshop on large molten pool heat transfer summary and conclusions

International Nuclear Information System (INIS)

1994-01-01

The CSNI Workshop on Large Molten Heat Transfer held at Grenoble (France) in March 1994 was organised by CSNI's Principal Working Group on the Confinement of Accidental Radioactive Releases (PWG4) with the cooperation of the Principal Working Group on Coolant System Behaviour (FWG2) and in collaboration with the Grenoble Nuclear Research Centre of the French Commissariat a l'Energie Atomique (CEA). Conclusions and recommendations are given for each of the five sessions of the workshops: Feasibility of in-vessel core debris cooling through external cooling of the vessel; Experiments on molten pool heat transfer; Calculational efforts on molten pool convection; Heat transfer to the surrounding water - experimental techniques; Future experiments and ex-vessel studies (open forum discussion)

Mechanism study of freeze-valve for molten salt reactor (MSR)

International Nuclear Information System (INIS)

Qinhua, Zhang

2014-01-01

Molten salt reactor (MSR) is one of the fourth generation nuclear reactor, ordinary nuclear grade valve is unsuitable for MSR due to its special coolant and extraordinary working temperature. Freeze-valve is proposed as the most appropriate valve for MSR, but the technology issue about freeze-valve has not been report in recent decades. Its significance to test the comprehensive property of freeze-valve for the application in MSR. A high temperature molten salt test loop was built which the physics property of salt is similar to the coolant of MSR. The results indicate that freeze-valve has a good performance use in the molten salt circumstances of high temperature (max 700 deg. C) and strong corrosion (authors)

Media for the isolation and enumeration of bifidobacteria in dairy products.

Science.gov (United States)

Roy, D

2001-09-28

Bifidobacteria are commonly used for the production of fermented milks, alone or in combination with other lactic acid bacteria. Bifidobacteria populations in fermented milks should be over 10(6) bifidobacteria/g at the time of consumption of strain added to the product. Hence, rapid and reliable methods are needed to routinely determine the initial inoculum and to estimate the storage time period bifidobacteria remain viable. Plate count methods are still preferable for quality control measurements in dairy products. It is, therefore, necessary to have a medium that selectively promotes the growth of bifidobacteria, whereas other bacteria are suppressed. The present paper is an overview of media and methods including summaries of published comparisons between different selective media. Culture media for bifidobacteria may be divided into basal, elective, differential and selective culture medium. Non-selective media are useful for routine enumeration of bifidobacteria when present in non-fermented milks. Reinforced Clostridial Agar and De Man Rogosa Sharpe (MRS) supplemented with cysteine and agar available commercially are the media of choice for industrial quality control laboratories. Several media for selective or differential isolation have been described for enumeration of bifidobacteria from other lactic acid bacteria. From the large number of selective media available, it can be concluded that there is no standard medium for the detection of bifidobacteria. However, Columbia agar base media supplemented with lithium chloride and sodium propionate and MRS medium supplemented with neomycin, paromomycin, nalidixic acid and lithium chloride can be recommended for selective enumeration of bifidobacteria in dairy products.

Subcritical enhanced safety molten-salt reactor concept

International Nuclear Information System (INIS)

Alekseev, P.N.; Ignatiev, V.V.; Men'shikov, L.I.; Prusakov, V.N.; Ponomarev-Stepnoy, N.N.; Subbotin, S.A.; Krasnykh, A.K.; Rudenko, V.T.; Somov, L.N.

1995-01-01

The nuclear power and its fuel cycle safety requirements can be met in the main by providing nuclear power with subcritical molten salt reactors (SMSR) - 'burner' with an external neutron source. The utilized molten salt fuel is the decisive advantage of the SMSR over other burners. Fissile and fertile nuclides in the burner are solved in a liquid salt in the form of fluorides. This composition acts simultaneously as: a) fuel, b) coolant, c) medium for chemical partitioning and reprocessing. The effective way of reducing the external source power consists in the cascade neutron multiplication in the system of coupled reactors with suppressed feedback between them. (author)

Prospects of subcritical molten salt reactor for minor actinides incineration in closed fuel cycle

Energy Technology Data Exchange (ETDEWEB)

Alekseev, Pavel N.; Balanin, Andrey L.; Dudnikov, Anatoly A.; Fomichenko, Petr A.; Nevinitsa, Vladimir A.; Frolov, Aleksey A.; Lubina, Anna S.; Sedov, Aleksey A.; Subbotin, Aleksey S.; Blandinsky, Viktor Yu. [Nuclear Research Centre ' ' Kurchatov Institute' ' , Moscow (Russian Federation)

2015-09-15

A subcritical molten salt reactor is proposed for minor actinides (separated from spent fuel VVER-1000 light water reactor) incineration and for {sup 233}U conversion from {sup 232}Th. Here the subcritical molten salt reactor with fuel composition of heavy nuclide fluorides in molten LiF - NaF - KF salt and with external neutron source, based on 1 GeV proton accelerator and molten salt cooled tungsten target is considered. The paper presents the results of parametrical analysis of equilibrium nuclide composition of molten salt reactor with minor actinides feed in dependence of core dimensions, average neutron flux and external neutron source intensity. Reactor design is defined; requirements to external neutron source are posed; heavy nuclides equilibrium and fuel cycle main parameters are calculated.

Experimental and theoretical studies in Molten Salt Natural Circulation Loop (MSNCL)

International Nuclear Information System (INIS)

Srivastava, A.K.; Borgohain, A.; Jana, S.S.; Bagul, R.K.; Singh, R.R.; Maheshwari, N.K.; Belokar, D.G.; Vijayan, P.K.

2014-12-01

High Temperature Reactors (HTR) and solar thermal power plants use molten salt as a coolant, as it has low melting point and high boiling point, enabling us to operate the system at low pressure. Molten fluoride salt and molten nitrate salt are proposed as a candidate coolant for High Temperature Reactors (HTR) and solar power plant respectively. BARC is developing a 600 MWth pebble bed high temperature reactor, cooled by natural circulation of fluoride salt and capable of supplying process heat at 1000°C to facilitate hydrogen production by splitting water. Beside this, BARC is also developing a 2MWe solar power tower system using molten nitrate salt. With these requirements, a Molten Salt Natural Circulation Loop (MSNCL) has been designed, fabricated, installed and commissioned in Hall-7, BARC for thermal hydraulic, instrumentation development and material compatibility related studies. Steady state natural circulation experiments with molten nitrate salt (mixture of NaNO 3 and KNO 3 in 60:40 ratio) have been carried out in the loop at different power level. Various transients viz. startup of natural circulation, step power change, loss of heat sink and heater trip has also been studied in the loop. A well known steady state correlation given by Vijayan et. al. has been compared with experimental data. In-house developed code LeBENC has also been validated against all steady state and transient experimental results. The detailed description of MSNCL, steady state and transient experimental results and validation of in-house developed code LeBENC have been described in this report. (author)

Experiment on heat transfer in simulated molten core/concrete interaction

International Nuclear Information System (INIS)

Katsumura, Yukihiro; Hashizume, Hidetoshi; Toda, Saburo; Kawaguchi, Takahiro.

1993-01-01

In order to investigate heat transfer between molten core and concrete in LWR severe accidents, experiments were performed using water as the molten core, paraffin as the concrete, and air as gases from the decomposition of concrete. It was found that the heat transfer on the interface between paraffin and water were promoted strongly by the air gas. (author)

Visualization of steam bubbles with evaporation in molten alloy

International Nuclear Information System (INIS)

Nishi, Yoshihisa; Furuya, Masahiro; Kinoshita, Izumi; Takenaka, Nobuyuki; Matsubayashi, Masahito

1997-01-01

An innovative Steam Generator concept of Fast Breeder Reactors by using liquid-liquid direct contact heat transfer has been developed. In this concept, the SG shell is filled with a molten alloy heated by primary sodium. Water is fed into the high temperature molten alloy, and evaporates by direct contact heating. In order to obtain the fundamental information to discuss the heat transfer mechanisms of the direct contact between the water and the molten alloy, this phenomenon was visualized by neutron radiography. JRR-3M radiography in Japan Atomic Energy Research Institute was used. Followings are main results. (1) The bubbles with evaporation are risen with vigorous form changing, coalescence and break-up. Because of these vigorous evaporation, this system have the high heat transfer performance. (2) The rising velocities and volumes of bubbles are calculated from pixcel values of images. The velocities of the bubbles with evaporation are about 60 cm/s, which is larger than that of inert gas bubbles in molten alloy (20-40 cm/s). (3) The required heat transfer length of evaporation is calculated from pixcel values of images. The relation between heat transfer length and superheat temperature, obtained through the heat transfer test, is conformed by this calculation. (author)

Chloride Test

Science.gov (United States)

... metabolic acidosis ) or when a person hyperventilates (causing respiratory alkalosis ). A decreased level of blood chloride (called hypochloremia) ... disease , emphysema or other chronic lung diseases (causing respiratory ... metabolic alkalosis). An increased level of urine chloride can indicate ...

Structural Analysis of Molten NaNO3 by Molecular Dynamics Simulation

Science.gov (United States)

Tahara, Shuta; Toyama, Hiroshi; Shimakura, Hironori; Fukami, Takanori

2017-08-01

MD simulation for molten NaNO3 has been performed by using the Born-Mayer-Huggins-type potentials. The new structural features of molten NaNO3 are investigated by several analytical methods. The coordination-number and bond-angle distributions are similar to those of simple molten salts such as NaCl except for the variation caused by the different size of the anion and cation. Na+ ions are attracted toward O- ions, and get separated from N+ ions by Coulomb interactions. The distribution of the dihedral angle between NO3 - plannar ionic molecules has also been investigated.

Development of high temperature molten salt transport technology for pyrometallurgical reprocessing

International Nuclear Information System (INIS)

Hijikata, Takatoshi; Koyama, Tadafumi

2009-01-01

Pyrometallurgical reprocessing technology is currently being focused in many countries for closing actinide fuel cycle because of its favorable economic potential and an intrinsic proliferation-resistant feature due to the inherent difficulty of extracting weapons-usable plutonium. The feasibility of pyrometallurgical reprocessing has been demonstrated through many laboratory scale experiments. Hence the development of the engineering technology necessary for pyrometallurgical reprocessing is a key issue for industrial realization. The development of high-temperature transport technologies for molten salt and liquid cadmium is crucial for pyrometallurgical processing; however, there have been very few transport studies on high-temperature fluids. In this study, a salt transport test rig was installed in an argon glove box with the aim of developing technologies for transporting molten salt at approximately 773 K. The gravitation transport of the molten salt at approximately 773 K could be well controlled at a velocity from 0.1 to 1.2 m/s by adjusting the valve. Consequently, the flow in the molten salt can be controlled from laminar flow to turbulent flow. It was demonstrated that; using a centrifugal pump, molten salt at approximately 773 K could be transported at a controlled rate from 2.5 to 8 dm 3 /min against a 1 m head. (author)

Treatment of waste salt from the advanced spent fuel conditioning process (I): characterization of Zeolite A in Molten LiCl Salt

International Nuclear Information System (INIS)

Kim, Jeong Guk; Lee, Jae Hee; Yoo, Jae Hyung; Kim, Joon Hyung

2004-01-01

The oxide fuel reduction process based on the electrochemical method (Advanced spent fuel Conditioning Process; ACP) and the long-lived radioactive nuclides partitioning process based on electro-refining process, which are being developed ay the Korea Atomic Energy Research Institute (KAERI), are to generate two types of molten salt wastes such as LiCl salt and LiCl-KCl eutectic salt, respectively. These waste salts must meet some criteria for disposal. A conditioning process for LiCl salt waste from ACP has been developed using zeolite A. This treatment process of waste salt using zeolite A was first developed by US ANL (Argonne National Laboratory) for LiCl-KCl eutectic salt waste from an electro-refining process of EBR (Experimental Breeder Reactor)-II spent fuel. This process has been developed recently, and a ceramic waste form (CWF) is produced in demonstration-scale V-mixer (50 kg/batch). However, ANL process is different from KAERI treatment process in waste salt, the former is LiCl-KCl eutectic salt and the latter is LiCl salt. Because of melting point, the immobilization of eutectic salt is carried out at about 770 K, whereas LiCl salt at around 920 K. Such difference has an effect on properties of immobilization media, zeolite A. Here, zeolite A in high-temperature (923 K) molten LiCl salt was characterized by XRD, Ion-exchange, etc., and evaluated if a promising media or not

The reduction of pertechnetate-99 by stannous chloride

International Nuclear Information System (INIS)

Steigman, J.; Meinken, G.; Richards, P.

1975-01-01

The reduction of pertechnetate-99 by excess stannous chloride in several media was investigated as a possible model for radiopharmaceutical preparations which are based on the reduction of pertechnetate-99m by the same reagent. Polarographic and iodimetric techniques were used to analyze for unreacted stannous ion. It was found that pertechnetate is reduced to the +4 state in a citrate buffer at pH7, to the +3 state in a DTPA buffer at pH4, and possibly to the +4 state in HCl. The reaction in DTPA solution was found to be complete within several minutes. The reduction in the citrate buffer proceeded rapidly to the +5 state, and much more slowly to the +4 state. The implications of these rate studies for the radiopharmaceutical preparations were discussed. Direct potentiometric titrations of pertechnetate-99 with stannous chloride showed that the technetium was in the +4 state in HCl, in the +5 state in citrate solution, and in both the +3 and +4 states in DTPA. (author)

Plutonium and americium recovery from spent molten-salt-extraction salts with aluminum-magnesium alloys

International Nuclear Information System (INIS)

Cusick, M.J.; Sherwood, W.G.; Fitzpatrick, R.F.

1984-01-01

Development work was performed to determine the feasibility of removing plutonium and americium from spent molten-salt-extraction (MSE) salts using Al-Mg alloys. If the product buttons from this process are compatible with subsequent aqueous processing, the complex chloride-to-nitrate aqueous conversion step which is presently required for these salts may be eliminated. The optimum alloy composition used to treat spent 8 wt % MSE salts in the past yielded poor phase-disengagement characteristics when applied to 30 mol % salts. After a limited investigation of other alloy compositions in the Al-Mg-Pu-Am system, it was determined that the Al-Pu-Am system could yield a compatible alloy. In this system, experiments were performed to investigate the effects of plutonium loading in the alloy, excess magnesium, age of the spent salt on actinide recovery, phase disengagement, and button homogeneity. Experimental results indicate that 95 percent plutonium recoveries can be attained for fresh salts. Further development is required for backlog salts generated prior to 1981. A homogeneous product alloy, as required for aqueous processing, could not be produced

Molten salt reactor concept

International Nuclear Information System (INIS)

Sood, D.D.

1980-01-01

Molten salt reactor is an advanced breeder concept which is suited for the utilization of thorium for nuclear power production. This reactor is based on the use of solutions of uranium or plutonium fluorides in LiF-BeF 2 -ThF 4 as fuel. Unlike the conventional reactors, no external coolant is used in the reactor core and the fuel salt itself is circulated through heat exchangers to transfer the fission produced heat to a secondary salt (NaF-NaBF 4 ) for steam generation. A part of the fuel stream is continuously processed to isolate 233 Pa, so that it can decay to fissile 233 U without getting converted to 234 Pa, and for the removal of neutron absorbing fission products. This on-line processing scheme makes this reactor concept to achieve a breeding ratio of 1.07 which is the highest for any thermal breeder reactor. Experimental studies at the Bhabha Atomic Research Centre, Bombay, have established the use of plutonium as fuel for this reactor. This molten salt reactor concept is described and the work conducted at the Bhabha Atomic Research Centre is summarised. (auth.)

Thermochemical investigation of molten fluoride salts for Generation IV nuclear applications - an equilibrium exercise

NARCIS (Netherlands)

van der Meer, J.P.M.

2006-01-01

The concept of the Molten Salt Reactor, one of the so-called Generation IV future reactors, is that the fuel, a fissile material, which is dissolved in a molten fluoride salt, circulates through a closed circuit. The heat of fission is transferred to a second molten salt coolant loop, the heat of

Reduction reaction of chlorine gas in an Al-Cl2 chemical cell composed of molten chloride salts; Enkabutsu yoyuenkei Al-Cl2 kagaku denchi ni okeru enso gas no kangen hanno kyodo

Energy Technology Data Exchange (ETDEWEB)

Konda, S.; Sasaki, T.; Ishikawa, T. [Hokkaido University, Sapporo (Japan)

1996-10-05

The molten salt system electrochemical cycle was proposed to reproduce pure Al from scrap Al. The cycle is composed of production of rough AlCl3 by chlorination of scrap Al, refining of rough AlCl3 mainly by sublimation, and electrolytic reproduction of pure Al from refined AlCl3. In production of AlCl3, the Al-Cl2 molten salt system cell composed of anode dissolution reaction of Al and cathode reduction reaction of chlorine gas can generate electric power for the electrolytic reproduction. Chlorine gas can be recycled as anode product. Various experiments were carried out to improve molten salt system cells. In analysis of cell output, voltage drop from open circuit voltage was divided into that due to electrolytic bath resistance, and that due to reaction resistance. The electrolytic bath resistance could be determined from transient characteristics of voltage change just after cutoff of output current. The product of the obtained reaction resistance and a meniscus length was constant regardless of a meniscus length, and useful to predict scale-up cell performance. Output characteristics dependent on meniscus position were also obtained. 16 refs., 11 figs.

Molten salt hazardous waste disposal process utilizing gas/liquid contact for salt recovery

International Nuclear Information System (INIS)

Grantham, L.F.; McKenzie, D.E.

1984-01-01

The products of a molten salt combustion of hazardous wastes are converted into a cooled gas, which can be filtered to remove hazardous particulate material, and a dry flowable mixture of salts, which can be recycled for use in the molten salt combustion, by means of gas/liquid contact between the gaseous products of combustion of the hazardous waste and a solution produced by quenching the spent melt from such molten salt combustion. The process results in maximizing the proportion of useful materials recovered from the molten salt combustion and minimizing the volume of material which must be discarded. In a preferred embodiment a spray dryer treatment is used to achieve the desired gas/liquid contact

40 CFR 61.65 - Emission standard for ethylene dichloride, vinyl chloride and polyvinyl chloride plants.

Science.gov (United States)

2010-07-01

... dichloride, vinyl chloride and polyvinyl chloride plants. 61.65 Section 61.65 Protection of Environment... AIR POLLUTANTS National Emission Standard for Vinyl Chloride § 61.65 Emission standard for ethylene dichloride, vinyl chloride and polyvinyl chloride plants. An owner or operator of an ethylene dichloride...

thermic oil and molten salt

African Journals Online (AJOL)

Boukelia T.E, Mecibah M.S and Laouafi A

1 mai 2016 ... [27] Zavoico, AB. Solar Power Tower Design Basis Document. Tech. rep, Sandia National. Laboratories, SAND2001-2100, 2001. How to cite this article: Boukelia T.E, Mecibah M.S and Laouafi A. Performance simulation of parabolic trough solar collector using two fluids (thermic oil and molten salt).

Establishment of cooperation basis of joint research on the mixed waste molten salt oxidation technology

International Nuclear Information System (INIS)

Yang, Hee Chul; Cho, Y. J.; Kim, J. H.; Yoo, J. H.; Yun, H. C.; Lee, D. G.

2005-08-01

Molten salt oxidation, MSO for short, is a robust technology that can effectively treat mixed waste (radioactive waste including hazardous metals or organics). It can safely and economically treat the difficult wastes such as not-easily destroyable toxic organic waste, medical waste, chemical warfare and energetic materials such as propellant and explosives, all of which are not easily treated by an incinerator or other currently existing thermal treatment system. Therefore, molten salt oxidation technology should be developed and utilized to treat a lot of niche waste stored in the nuclear and environmental industries. So, if we put the MSO technology to practical use by Korea-Vietnam joint research, we can reduce R and D fund for MSO technology by ourselves and we can expect an export of the outcome of nuclear R and D in Korea. For Establishment of cooperation basis of joint research concerning molten salt oxidation technology between KOREA and VIETNAM, in this research, We invited two Vietnamese researchers and we introduced our experimental scale molten salt oxidation system in order to let them understand molten salt oxidation technology. We also visited Viet man and we consulted about molten salt oxidation process. We held seminar on the mixed waste molten salt oxidation technology, discussed on the joint research on the mixed waste molten salt oxidation technology and finally we wrote MOU for joint research

Establishment of cooperation basis of joint research on the mixed waste molten salt oxidation technology

Energy Technology Data Exchange (ETDEWEB)

Yang, Hee Chul; Cho, Y. J.; Kim, J. H.; Yoo, J. H.; Yun, H. C.; Lee, D. G

2005-08-01

Molten salt oxidation, MSO for short, is a robust technology that can effectively treat mixed waste (radioactive waste including hazardous metals or organics). It can safely and economically treat the difficult wastes such as not-easily destroyable toxic organic waste, medical waste, chemical warfare and energetic materials such as propellant and explosives, all of which are not easily treated by an incinerator or other currently existing thermal treatment system. Therefore, molten salt oxidation technology should be developed and utilized to treat a lot of niche waste stored in the nuclear and environmental industries. So, if we put the MSO technology to practical use by Korea-Vietnam joint research, we can reduce R and D fund for MSO technology by ourselves and we can expect an export of the outcome of nuclear R and D in Korea. For Establishment of cooperation basis of joint research concerning molten salt oxidation technology between KOREA and VIETNAM, in this research, We invited two Vietnamese researchers and we introduced our experimental scale molten salt oxidation system in order to let them understand molten salt oxidation technology. We also visited Viet man and we consulted about molten salt oxidation process. We held seminar on the mixed waste molten salt oxidation technology, discussed on the joint research on the mixed waste molten salt oxidation technology and finally we wrote MOU for joint research.

Actinide removal from molten salts by chemical oxidation and salt distillation

Energy Technology Data Exchange (ETDEWEB)

McNeese, J.A.; Garcia, E.; Dole, V.R. [Los Alamos National Laboratory, NM (United States)] [and others

1995-10-01

Actinide removal from molten salts can be accomplished by a two step process where the actinide is first oxidized to the oxide using a chemical oxidant such as calcium carbonate or sodium carbonate. After the actinide is precipitated as an oxide the molten salt is distilled away from the actinide oxides leaving a oxide powder heel and an actinide free distilled salt that can be recycled back into the processing stream. This paper discusses the chemistry of the oxidation process and the physical conditions required to accomplish a salt distillation. Possible application of an analogous process sequence for a proposed accelerator driven transmutation molten salt process is also discussed.

Actinide removal from molten salts by chemical oxidation and salt distillation

International Nuclear Information System (INIS)

McNeese, James A.; Garcia, Eduardo; Dole, Vonda R.; Griego, Walter J.

1995-01-01

Actinide removal from molten salts can be accomplished by a two step process where the actinide is first oxidized to the oxide using a chemical oxidant such as calcium carbonate or sodium carbonate. After the actinide is precipitated as an oxide the molten salt is distilled away from the actinide oxides leaving a oxide powder heel and an actinide free distilled salt that can be recycled back into the processing stream. This paper discusses the chemistry of the oxidation process and the physical conditions required to accomplish a salt distillation. Possible application of an analogous process sequence for a proposed accelerator driven transmutation molten salt process is also discussed

The effect of conditioning agents on the corrosive properties of molten urea

Energy Technology Data Exchange (ETDEWEB)

Nichols, D E; Nguyen, D T; Norton, M M; Parker, B R; Daniels, L E

1991-01-01

From the process case histories of the failure of several heat exchanger tube bundles, it was revealed that molten urea containing lignosulfonate as a granulation conditioning-hardening agent (Urea LS[trademark]) is corrosive to Types 304 and 316 stainless steel. The results of field and laboratory immersion corrosion tests indicated that the corrosivity of molten urea is strongly dependent on the process temperature rather than the conditioner composition. At temperatures below 295F, molten Urea LS[trademark] is not aggressive to these stainless steels. However, at temperatures above 300F, the corrosion of these stainless steels is extremely severe. The corrosion rate of Types 304, 304L, 316, and 316L is as high as hundreds of mils per year. The corrosion mechanism tends to be more general than localized. The results of the laboratory corrosion test also revealed that among alloying elements, copper is detrimental to corrosion resistance of stainless steel exposed to molten Urea LS[trademark], chromium is the most beneficial, and nickel has only a minor effect. Thus, copper-free and chromium stainless steels have superior corrosion resistance to the molten Urea LS[trademark] at a wide range of temperatures up to 345F.

A study on the initiation of pitting corrosion in carbon steel in chloride-containing media using scanning electrochemical probes

International Nuclear Information System (INIS)

Lin Bin; Hu Ronggang; Ye Chenqing; Li Yan; Lin Changjian

2010-01-01

Scanning electrochemical probes of corrosion potential and chloride ions were developed for the in situ monitoring of localized corrosion processes of reinforcing steel in NaCl-containing solution. The results indicated that the chloride ions (Cl - ) preferentially adsorbed and accumulated at the imperfect/defective sites, resulting in initiation and propagation of pitting corrosion on the reinforcing steel surface. An electron microprobe analyzer (EMPA) was used to examine the corrosion morphology and elemental distribution at the corroded location to investigate the origins of the preferential Cl - adsorption and pitting corrosion. By combining the in situ and ex situ images, we concluded that manganese sulfide inclusions in reinforcing steel are the most susceptible defects to pitting corrosion in chloride-containing solution.

Study of the pyrochemical treatment-recycling process of the Molten Salt Reactor fuel

International Nuclear Information System (INIS)

Boussier, H.; Heuer, D.

2010-01-01

The Separation Processes Studies Laboratory (Commissariat a l'energie Atomique) has made a preliminary assessment of the reprocessing system associated with Molten Salt Fast Reactor (MSFR). The scheme studied in this paper is based on the principle of reductive extraction and metal transfer that constituted the core process designed for the Molten Salt Breeder Reactor (MSBR), although the flow diagram has been adapted to the current needs of the Molten Salt Reactor Fast (MSFR).

Concept of the demonstration molten salt unit for the transuranium elements transmutations

International Nuclear Information System (INIS)

Alekseev, P.; Dudnikov, A.; Prusakov, V.; Subbotin, S.; Zakirov, R.; Lelek, V.; Peka, I.

1999-01-01

Fluorine reprocessing is discussed of spent fuel and of fluoride molten salt reactor in critical and subcritical modes for plutonium and minor actinides burning. International collaboration for creation of such system is proposed. Additional neutron source in the core will have positive influence on the transmutation processes in the reactor. Demonstration critical molten salt reactor of small power capacity will permit to decide the most part of problems inherent to large critical reactors and subcritical drivers. It could be expected that fluoride molten salt transmuter can work without accelerator as a critical reactor. (author)

Corrosion Behavior of Superalloys in Hot Lithium Molten Salt

International Nuclear Information System (INIS)

Cho, Soo-Haeng; Hur, Jin-Mok; Seo, Chung-Seok; Park, Seoung-Won

2006-01-01

The Li-reduction process involves the chemical reduction of spent fuel oxides by liquid lithium metal in a molten LiCl salt bath at 650 .deg. C followed by a separate electrochemical reduction of lithium oxide (Li 2 O), which builds up in the salt bath. This process requires a high purity inert gas atmosphere inside remote hot cell nuclear facility to prevent unwanted Li oxidation and fires during the handling of chemically active Li metal. In light of the limitations of the Li-reduction process, a direct electrolytic reduction technology is being developed by KAERI to enhance process safety and economic viability. The electrolytic reduction of spent oxide fuel involves the liberation of oxygen in a molten LiCl electrolyte, which results in a chemically aggressive environment that is too corrosive for typical structural materials. Even so, the electrochemical process vessel must be resilient at ∼ 650 .deg. C in the presence of oxygen to enable high processing rates and an extended service life. But, the mechanism and the rate of the corrosion of metals in LiCl-Li 2 O molten salt under oxidation condition are not clear. In the present work, the corrosion behavior and corrosion mechanism of superalloys have been studied in the molten salt of LiCl-Li 2 O under oxidation condition

Effect of crust increase on natural convection heat transfer in the molten metal pool

International Nuclear Information System (INIS)

Park, Rae Joon; Kim, Sang Baik; Kim, Hee Dong; Choi, Sang Min

1999-01-01

An experimental study has been performed on natural convection heat transfer with a rapid crust formation in the molten metal pool of a low Prandtl number fluid. Two types of steady state tests, a low and high geometric aspect ratio cases in the molten metal pool, were performed. The crust thickness by solidification was measured as a function of boundary surface temperatures. The experimental results on the relationship between the Nusselt number and Rayleigh number in the molten metal pool with a crust formation were compared with existing correlations. The experimental study has shown that the bottom surface temperature of the molten metal layer, in all experiments, is the major influential parameter in the crust formation, due to the natural convection flow. The Nusselt number of the case without a crust formation in the molten metal pool is greater than that of the case with the crust formation at the same Rayleigh number. The present experimental results on the relationship between the Nusselt number and Rayleigh number in the molten metal pool match well with Globe and Dropkin's correlation. From the experimental results, a new correlation between the Nusselt number and Rayleigh number in the molten metal pool with the crust formation was developed as Nu=0.0923 (Ra) 0.0923 (2 X 10 4 7 ). (author)

Convective heat transfer the molten metal pool heated from below and cooled by two-phase flow

International Nuclear Information System (INIS)

Cho, J. S.; Suh, K. Y.; Chung, C. H.; Park, R. J.; Kim, S. B.

1998-01-01

During a hypothetical servere accident in the nuclear power plant, a molten core material may form stratified fluid layers. These layers may be composed of high temperature molten debris pool and water coolant in the lower plenum of the reactor vessel or in the reactor cavity. This study is concerned with the experimental test and numerical analysis on the heat transfer and solidification of the molten metal pool with overlying coolant with boiling. This work examines the crust formation and the heat transfer characteristics of the molten metal pool immersed in the boiling coolant. The metal pool is heated from the bottom surface and coolant is injected onto the molten metal pool. The simulant molten pool material is tin (Sn) with the melting temperature of 232 .deg. C. Demineralized water is used as the working coolant. Tests were performed under the condition of the bottom surface heating in the test section and the forced convection of the coolant being injected onto the molten metal pool. The constant temperature and constant heat flux conditions are adopted for the bottom heating. The test parameters included the heated bottom surface temperature of the molten metal pool, the input power to the heated bottom surface of the test section, and the coolant injection rate. Numerical analyses were simultaneously performed in a two-dimensional rectangular domain of the molten metal pool to check on the measured data. The numerical program has been developed using the enthalpy method, the finite volume method and the SIMPLER algorithm. The experimental results of the heat transfer show general agreement with the calculated values. In this study, the relationship between the Nusselt number and Rayleigh number in the molten metal pool region was estimated and compared with the dry experiment without coolant nor solidification of the molten metal pool, and with the crust formation experiment with subcooled coolant, and against other correlations. In the experiments, the

Lithium chloride protects retinal neurocytes from nutrient deprivation by promoting DNA non-homologous end-joining

International Nuclear Information System (INIS)

Zhuang Jing; Li Fan; Liu Xuan; Liu Zhiping; Lin Jianxian; Ge Yihong; Kaminski, Joseph M.; Summers, James Bradley; Wang Zhichong; Ge Jian; Yu Keming

2009-01-01

Lithium chloride is a therapeutic agent for treatment of bipolar affective disorders. Increasing numbers of studies have indicated that lithium has neuroprotective effects. However, the molecular mechanisms underlying the actions of lithium have not been fully elucidated. This study aimed to investigate whether lithium chloride produces neuroprotective function by improving DNA repair pathway in retinal neurocyte. In vitro, the primary cultured retinal neurocytes (85.7% are MAP-2 positive cells) were treated with lithium chloride, then cultured with serum-free media to simulate the nutrient deprived state resulting from ischemic insult. The neurite outgrowth of the cultured cells increased significantly in a dose-dependent manner when exposed to different levels of lithium chloride. Genomic DNA electrophoresis demonstrated greater DNA integrity of retinal neurocytes when treated with lithium chloride as compared to the control. Moreover, mRNA and protein levels of Ligase IV (involved in DNA non-homologous end-joining (NHEJ) pathway) in retinal neurocytes increased with lithium chloride. The end joining activity assay was performed to determine the role of lithium on NHEJ in the presence of extract from retinal neurocytes. The rejoining levels in retinal neurocytes treated with lithium were significantly increased as compared to the control. Furthermore, XRCC4, the Ligase IV partner, and the transcriptional factor, CREB and CTCF, were up-regulated in retinal cells after treating with 1.0 mM lithium chloride. Therefore, our data suggest that lithium chloride protects the retinal neural cells from nutrient deprivation in vitro, which may be similar to the mechanism of cell death in glaucoma. The improvement in DNA repair pathway involving in Ligase IV might have an important role in lithium neuroprotection. This study provides new insights into the neural protective mechanisms of lithium chloride.

Study of an F center in molten KCl

Energy Technology Data Exchange (ETDEWEB)

Parrinello, M.; Rahman, A.

1984-01-15

It is shown that a discretized version of Feynman's path integral provides a convenient tool for the numerical investigation of the properties of an electron solvated in molten KCl. The binding energy, the magnetic susceptibility, and the pair correlation functions are calculated. The local structure around the solute electron appears to be different from that of an F center in the solid. The Feynman path of the electron dissolved in molten KCl is highly localized thus justifying the F center model. The effect of varying the e/sup -/-K/sup +/ pseudopotential is also reported.

Molten core debris-sodium interactions: M-Series experiments

International Nuclear Information System (INIS)

Sowa, E.S.; Gabor, J.D.; Pavlik, J.R.; Cassulo, J.C.; Cook, C.J.; Baker, L. Jr.

1979-01-01

Five new kilogram-scale experiments have been carried out. Four of the experiments simulated the situation where molten core debris flows from a breached reactor vessel into a dry reactor cavity and is followed by a flow of sodium (Ex-vessel case) and one experiment simulated the flow of core debris into an existing pool of sodium (In-vessel case). The core debris was closely simulated by a thermite reaction which produced a molten mixture of UO 2 , ZrO 2 , and stainless steel. There was efficient fragmentation of the debris in all experiments with no explosive interactions observed

Metallic materials corrosion problems in molten salt reactors

International Nuclear Information System (INIS)

Chauvin, G.; Dixmier, J.; Jarny, P.

1977-01-01

The USA forecastings concerning the molten salt reactors are reviewed (mixtures of fluorides containing the fuel, operating between 560 and 700 0 C). Corrosion problems are important in these reactors. The effects of certain characteristic factors on corrosion are analyzed: humidity and metallic impurities in the salts, temperature gradients, speed of circulation of salts, tellurium from fission products, coupling. In the molten fluorides and experimental conditions, the materials with high Ni content are particularly corrosion resistant alloys (hastelloy N). The corrosion of this material is about 2.6 mg.cm -2 at 700 0 C [fr

Measurement of europium (III)/europium (II) couple in fluoride molten salt for redox control in a molten salt reactor concept

Science.gov (United States)

Guo, Shaoqiang; Shay, Nikolas; Wang, Yafei; Zhou, Wentao; Zhang, Jinsuo

2017-12-01

The fluoride molten salt such as FLiNaK and FLiBe is one of the coolant candidates for the next generation nuclear reactor concepts, for example, the fluoride salt cooled high temperature reactor (FHR). For mitigating corrosion of structural materials in molten fluoride salt, the redox condition of the salts needs to be monitored and controlled. This study investigates the feasibility of applying the Eu3+/Eu2+ couple for redox control. Cyclic voltammetry measurements of the Eu3+/Eu2+ couple were able to obtain the concentrations ratio of Eu3+/Eu2+ in the melt. Additionally, the formal standard potential of Eu3+/Eu2+ was characterized over the FHR's operating temperatures allowing for the application of the Nernst equation to establish a Eu3+/Eu2+ concentration ratio below 0.05 to prevent corrosion of candidate structural materials. A platinum quasi-reference electrode with potential calibrated by potassium reduction potential is shown as reliable for the redox potential measurement. These results show that the Eu3+/Eu2+ couple is a feasible redox buffering agent to control the redox condition in molten fluoride salts.

Solar gasification of biomass: design and characterization of a molten salt gasification reactor

Science.gov (United States)

Hathaway, Brandon Jay

The design and implementation of a prototype molten salt solar reactor for gasification of biomass is a significant milestone in the development of a solar gasification process. The reactor developed in this work allows for 3 kWth operation with an average aperture flux of 1530 suns at salt temperatures of 1200 K with pneumatic injection of ground or powdered dry biomass feedstocks directly into the salt melt. Laboratory scale experiments in an electrically heated reactor demonstrate the benefits of molten salt and the data was evaluated to determine the kinetics of pyrolysis and gasification of biomass or carbon in molten salt. In the presence of molten salt overall gas yields are increased by up to 22%; pyrolysis rates double due to improved heat transfer, while carbon gasification rates increase by an order of magnitude. Existing kinetic models for cellulose pyrolysis fit the data well, while carbon gasification in molten salt follows kinetics modeled with a 2/3 order shrinking-grain model with a pre-exponential factor of 1.5*106 min-1 and activation energy of 158 kJ/mol. A reactor concept is developed based around a concentric cylinder geometry with a cavity-style solar receiver immersed within a volume of molten carbonate salt. Concentrated radiation delivered to the cavity is absorbed in the cavity walls and transferred via convection to the salt volume. Feedstock is delivered into the molten salt volume where biomass gasification reactions will be carried out producing the desired product gas. The features of the cavity receiver/reactor concept are optimized based on modeling of the key physical processes. The cavity absorber geometry is optimized according to a parametric survey of radiative exchange using a Monte Carlo ray tracing model, resulting in a cavity design that achieves absorption efficiencies of 80%-90%. A parametric survey coupling the radiative exchange simulations to a CFD model of molten salt natural convection is used to size the annulus

Molten pool-lower head integrity. Heat transfer models including advanced numerical simulations (DNS)

Energy Technology Data Exchange (ETDEWEB)

Seiler, J.M.; Bonnet, J.M.; Bernaz, L. [CEA Grenoble (France)

2001-07-01

Extensive studies have been performed to investigate the heat transfer within a molten corium pool (homogeneous, stratified and with miscibility gap): Synthesis of heat transfer correlations in molten pool (homogeneous and stratified), Focusing effect in stratified metal layer, DNS analysis of Rayleigh Benard instabilities at the top boundary; interpretation of the different convection regimes and exponents affecting the Rayleigh number in the heat transfer correlations, Molten pool model for corium presenting a miscibility gap. Condition for de-stratification. (authors)

Molten pool-lower head integrity. Heat transfer models including advanced numerical simulations (DNS)

International Nuclear Information System (INIS)

Seiler, J.M.; Bonnet, J.M.; Bernaz, L.

2001-01-01

Extensive studies have been performed to investigate the heat transfer within a molten corium pool (homogeneous, stratified and with miscibility gap): Synthesis of heat transfer correlations in molten pool (homogeneous and stratified), Focusing effect in stratified metal layer, DNS analysis of Rayleigh Benard instabilities at the top boundary; interpretation of the different convection regimes and exponents affecting the Rayleigh number in the heat transfer correlations, Molten pool model for corium presenting a miscibility gap. Condition for de-stratification. (authors)