Cesium diffusion in Bure mud-rock: effect of cesium sorption and of the surface structure of the clay

International Nuclear Information System (INIS)

Melkior, T.; Motellier, S.; Yahiaoui, S.

2005-01-01

Full text of publication follows: This work is devoted to cesium diffusion through mud-rock samples from Bure (Meuse/Haute- Marne, France). This rock is mainly composed of interstratified illite/smectite, quartz and calcite. According to published data, positively charged solutes exhibit high diffusion coefficients in argillaceous media compared to neutral species. This effect was actually observed for cesium in Bure mud-rock samples: the effective diffusion coefficients (De) of tritiated water and cesium were found to be ca. 2 x 10 -11 m 2 s -1 and 2.5 x 10 -10 m 2 s -1 , respectively. Some authors assign this 'enhanced diffusion' of cations to the particular migration of ions within the electrical double layer, next to mineral surfaces (surface diffusion mechanism). To assess the role of sorbed ions in the diffusive transfer, cesium diffusion coefficients in Bure mud-rock were measured at different cesium concentrations. The distribution coefficient of cesium onto Bure mud-rock was measured in batch: it significantly varies over the concentration range investigated in the diffusion tests (between 2 x 10 -6 M and 2 x 10 -2 M). If sorbed ions contribute to the transfer, the effective diffusion coefficients deduced from these different tests should depend on cesium concentration. Nevertheless, the measured effective diffusion coefficients are found to be relatively unaffected by cesium concentration. It is thus concluded that ions at the sorbed state play a minor role in the diffusion. Following the assumption of an 'accelerated' transfer due to ions located in the diffuse double layer, the charge of the clay particles should affect the 'enhanced diffusion' of cesium. Therefore, a mud-rock sample was first crushed and contacted with a cationic surfactant at different solid/liquid ratios. The conditions were adjusted to obtain suspensions having positive, neutral and negative zeta potentials respectively. Three compact samples were then made with these different

Effect of electrolytes concentration on recovery of cesium from AMP-PAN by Electrodialysis-Ion Exchange (EDIX)

International Nuclear Information System (INIS)

Mahendra, Ch.; Rajan, K.K.; SatyaSai, P.M.; Anand Babu, C.

2014-01-01

Cesium from the simulated acidic waste solution was separated using Ammonium Molybdophosphate (AMP) - Polyacrylonitrile (PAN) ion exchange resin in column operations. Electrodialysis - Ion exchange (EDIX) has been tried for the recovery of cesium from the AMP-PAN which was saturated with cesium. The electrodialysis setup consists of three compartments; cesium loaded AMP-PAN is placed in the middle compartment and is separated from the anode and cathode compartments by cation exchange membranes. Ammonium sulphate was used as anolyte and HNO 3 as catholyte. 0.1N HNO 3 was circulated in the middle compartment containing AMP-PAN to keep the resin in acidic form. On application of potential, the ammonium ions from the anode compartment migrate towards cathode through the middle compartment where they exchange with cesium ions on the resin and the exchanged cesium ions migrate towards cathode to get concentrated. Some part of cesium is recovered in the middle compartment due to convection. Cesium recovery from the AMP-PAN in the electrodialysis setup was studied at different anolyte and catholyte concentrations. All the experiments were carried out at constant current density of 40 mA/cm 2 for 15h. It was found that more than 50% of cesium recovery was observed for all the experiments studied and recovery percentage increased with increasing the anolyte concentration. It was observed that the electrolytes concentration affects the voltage drop across the cell

Performance evaluation of 24 ion exchange materials for removing cesium and strontium from actual and simulated N-Reactor storage basin water

Energy Technology Data Exchange (ETDEWEB)

Brown, G.N.; Carson, K.J.; DesChane, J.R.; Elovich, R.J.

1997-09-01

This report describes the evaluation of 24 organic and inorganic ion exchange materials for removing cesium and strontium from actual and simulated waters from the 100 Area 105 N-Reactor fuel storage basin. The data described in this report can be applied for developing and evaluating ion exchange pre-treatment process flowsheets. Cesium and strontium batch distribution ratios (K{sub d}`s), decontamination factors (DF), and material loadings (mmol g{sup -1}) are compared as a function of ion exchange material and initial cesium concentration. The actual and simulated N-Basin waters contain relatively low levels of aluminum, barium, calcium, potassium, and magnesium (ranging from 8.33E-04 to 6.40E-05 M), with slightly higher levels of boron (6.63E-03 M) and sodium (1.62E-03 M). The {sup 137}Cs level is 1.74E-06 Ci L-{sup 1} which corresponds to approximately 4.87E-10 M Cs. The initial Na/Cs ratio was 3.33E+06. The concentration of total strontium is 4.45E-06 M, while the {sup 90}Sr radioactive component was measured to be 6.13E-06 Ci L{sup -1}. Simulant tests were conducted by contacting 0.067 g or each ion exchange material with approximately 100 mL of either the actual or simulated N-Basin water. The simulants contained variable initial cesium concentrations ranging from 1.00E-04 to 2.57E- 10 M Cs while all other components were held constant. For all materials, the average cesium K{sub d} was independent of cesium concentration below approximately 1.0E-06 M. Above this level, the average cesium K{sub d} values decreased significantly. Cesium K{sub d} values exceeding 1.0E+07 mL g{sup -1} were measured in the simulated N-Basin water. However, when measured in the actual N-Basin water the values were several orders of magnitude lower, with a maximum of 1.24E+05 mL g{sup -1} observed.

Sugar-metal ion interactions: The coordination behavior of cesium ion with lactose, D-arabinose and L-arabinose

Science.gov (United States)

Jiang, Ye; Xue, Junhui; Wen, Xiaodong; Zhai, Yanjun; Yang, Limin; Xu, Yizhuang; Zhao, Guozhong; Kou, Kuan; Liu, Kexin; Chen, Jia'er; Wu, Jinguang

2016-04-01

The novel cesium chloride-lactose complex (CsCl·C12H22O10 (Cs-Lac), cesium chloride-D-arabinose and L-arabinose complexes (CsCl·C5H10O5, Cs-D-Ara and Cs-L-Ara) have been synthesized and characterized using X-ray diffraction, FTIR, FIR, THz and Raman spectroscopies. Cs+ is 9-coordinated to two chloride ions and seven hydroxyl groups from five lactose molecules in Cs-Lac. In the structures of CsCl-D-arabinose and CsCl-L-arabinose complexes, two kinds of Cs+ ions coexist in the structures. Cs1 is 10-coordinated with two chloride ions and eight hydroxyl groups from five arabinose molecule; Cs2 is 9-coordinated to three chloride ions and six hydroxyl groups from five arabinose molecules. Two coordination modes of arabinose coexist in the structures. α-D-arabinopyranose and α-L-arabinopyranose appear in the structures of Cs-D-Ara and Cs-L-Ara complexes. FTIR and Raman results indicate variations of hydrogen bonds and the conformation of the ligands after complexation. FIR and THz spectra also confirm the formation of Cs-complexes. Crystal structure, FTIR, FIR, THz and Raman spectra provide detailed information on the structure and coordination of hydroxyl groups to metal ions in the cesium chloride-lactose, cesium chloride-D- and L-arabinose complexes.

Advance in the study of removal of cesium from radioactive wastewater by inorganic ion exchangers

International Nuclear Information System (INIS)

Wang Songping; Wang Xiaowei; Du Zhihui

2014-01-01

The excellent performance in the removal of cesium from radioactive wastewater by inorganic ion exchangers has received extensive attention due to their characteristic physico-chemical features. The paper summarized research progress of removal of cesium by different inorganic ion exchangers such as silicoaluminate, salts of hetero polyacid, hexacyanoferrate, insoluble salts of acid with multivalent metals, insoluble hydrous oxides of multivalent metals and silicotitanate and reviewed several removal systems of cesium by inorganic ion exchangers which might offer China some reference in treatment and disposal of radioactive wastewater. (authors)

Cesium Ion Exchange Program at the Hanford River Protection Project Waste Treatment Plant

International Nuclear Information System (INIS)

CHARLES, NASH

2004-01-01

The River Protection Project - Hanford Tank Waste Treatment and Immobilization Plant will use cesium ion exchange to remove 137Cs from Low Activity Waste down to 0.3 Ci/m3 in the Immobilized LAW, ILAW product. The project baseline for cesium ion exchange is the elutable SuperLig, R, 644, SL-644, resin registered trademark of IBC Advanced Technologies, Inc., American Fork, UT or the Department of Energy approved equivalent. SL-644 is solely available through IBC Advanced Technologies. To provide an alternative to this sole-source resin supply, the RPP--WTP initiated a three-stage process for selection and qualification of an alternative ion exchange resin for cesium removal in the RPPWTP. It was recommended that resorcinol formaldehyde RF be pursued as a potential alternative to SL-644

Formation, decomposition and cesium adsorption mechanisms of highly alkali-tolerant nickel ferrocyanide prepared by interfacial synthesis

International Nuclear Information System (INIS)

Ichikawa, Tsuneki; Yamada, Kazuo; Osako, Masahiro; Haga, Kazuko

2017-01-01

Highly alkali-tolerant nickel ferrocyanide was prepared as an adsorbent for preventing the leaching of radioactive cesium from municipal solid waste incinerator fly ash containing large amounts of calcium hydroxide and potassium chloride, which act as an alkaline source and the suppressor for cesium adsorption, respectively. Nickel ferrocyanide prepared by contacting concentrated nickel and ferrocyanide solutions without mixing adsorbed cesium ions in alkaline conditions even the concentration of coexisting potassium ions was more than ten thousand times higher than that of the cesium ions. Large particles of nickel ferrocyanide slowly grew at the interface between the two solutions, which reduced the surface energy of the particles and therefore increased the alkali tolerance. The interfacially-synthesized nickel ferrocyanide was possible to prevent the leaching of radioactive cesium from cement-solidified fly ash for a long period. The mechanisms of the formation, selective cesium adsorption, and alkali-induced decomposition of the nickel ferrocyanide were elucidated. Comparison of the cesium adsorption mechanism with that of the other adsorbents revealed that an adsorbent can selectively adsorb cesium ions without much interference from potassium ions, if the following conditions are fulfilled. 1) The adsorption site is small enough for supplying sufficient electrostatic energy for the dehydration of ions adsorbed. 2) Both the cesium and potassium ions are adsorbed as dehydrated ions. 3) The adsorption site is flexible enough for permitting the penetration of dehydrated ions with the size comparable to that of the site. (author)

Enhanced capacity and stability for the separation of cesium in electrically switched ion exchange

International Nuclear Information System (INIS)

Tawfic, A.F.; Dickson, S.E.; Kim, Y.; Mekky, W.

2015-01-01

Electrically switched ion exchange (ESIX) can be used to separate ionic contaminants from industrial wastewater, including that generated by the nuclear industry. The ESIX method involves sequential application of reduction and oxidation potentials to an ion exchange film to induce the respective loading and unloading of cesium. This technology is superior to conventional methods (e.g electrodialysis reversal or reverse osmosis) as it requires very little energy for ionic separation. In previous studies, ESIX films have demonstrated relatively low ion exchange capacities and limited film stabilities over repeated potential applications. In this study, the methodology for the deposition of electro-active films (nickel hexacyanoferrate) on nickel electrodes was modified to improve the ion exchange capacity for cesium removal using ESIX. Cyclic voltammetry was used to investigate the ion exchange capacity and stability. Scanning electron microscopy (SEM) was used to characterize the modified film surfaces. Additionally, the films were examined for the separation of cesium ions. This modified film preparation technique enhanced the ion exchange capacity and improves the film stability compared to previous methods for the deposition of ESIX films. (authors)

Enhanced capacity and stability for the separation of cesium in electrically switched ion exchange

Energy Technology Data Exchange (ETDEWEB)

Tawfic, A.F.; Dickson, S.E.; Kim, Y. [McMaster University, Hamilton, ON (Canada); Mekky, W. [AMEC NSS, Power and Process America, Toronto (Canada)

2015-03-15

Electrically switched ion exchange (ESIX) can be used to separate ionic contaminants from industrial wastewater, including that generated by the nuclear industry. The ESIX method involves sequential application of reduction and oxidation potentials to an ion exchange film to induce the respective loading and unloading of cesium. This technology is superior to conventional methods (e.g electrodialysis reversal or reverse osmosis) as it requires very little energy for ionic separation. In previous studies, ESIX films have demonstrated relatively low ion exchange capacities and limited film stabilities over repeated potential applications. In this study, the methodology for the deposition of electro-active films (nickel hexacyanoferrate) on nickel electrodes was modified to improve the ion exchange capacity for cesium removal using ESIX. Cyclic voltammetry was used to investigate the ion exchange capacity and stability. Scanning electron microscopy (SEM) was used to characterize the modified film surfaces. Additionally, the films were examined for the separation of cesium ions. This modified film preparation technique enhanced the ion exchange capacity and improves the film stability compared to previous methods for the deposition of ESIX films. (authors)

Measurements of the cesium flow from a surface-plasma H- ion source

International Nuclear Information System (INIS)

Smith, H.V.; Allison, P.W.

1979-01-01

A surface ionization gauge (SIG) was constructed and used to measure the Cs 0 flow rate through the emission slit of a surface-plasma source (SPS) of H - ions with Penning geometry. The equivalent cesium density in the SPS discharge is deduced from these flow measurements. For dc operation the optimum H - current occurs at an equivalent cesium density of approx. 7 x 10 12 cm -3 (corresponding to an average cesium consumption rate of 0.5 mg/h). For pulsed operation the optimum H - current occurs at an equivalent cesium density of approx. 2 x 10 13 cm -3 (1-mg/h average cesium consumption rate). Cesium trapping by the SPS discharge was observed for both dc and pulsed operation. A cesium energy of approx. 0.1 eV is deduced from the observed time of flight to the SIG. In addition to providing information on the physics of the source, the SIG is a useful diagnostic tool for source startup and operation

Development of an ion-exchange process for removing cesium from high-level radioactive liquid wastes

International Nuclear Information System (INIS)

Baumgarten, P.K.; Wallace, R.M.; Whitehurst, D.A.; Steed, J.M.

1979-11-01

Methods to determine resin characteristics, i.e., cesium equilibria and diffusion rates, were developed. These parameters can now guide resin selection and aid in interpreting column performance. The K/sub D/ cesium ion concentration relation gives evidence of three different types of ion exchange sites. The countercurrent load/elution/regeneration cycle for the removal of cesium by ion exchange repeatedly reached the goal decontamination factor (DF) of 10,000 at throughputs up to 60 column volumes. Resin backwashing appears feasible, but further development of column geometry will be required. The proposed ammonium elutriant is satisfactory. Regeneration end-point can be controlled by electrical conductivity monitoring

Experiments and simulations for the dynamics of cesium in negative hydrogen ion sources for ITER N-NBI

Energy Technology Data Exchange (ETDEWEB)

Gutser, Raphael

2010-07-21

The injection of fast neutral particles (NBI) into a fusion plasma is an important method for plasma heating and current drive. A source for negative deuterium ions delivering an 1 MeV beam that is accelerated to a specific energy and neutralized by a gas target is required for the ITER-NBI. Cesium seeding is required to extract high negative ion current densities from these sources. The optimization of the cesium homogeneity and control are major objectives to achieve the source requirements imposed by ITER. Within the scope of this thesis, the Monte Carlo based numerical transport simulation CsFlow3D was developed, which is the first computer model that is capable of simulating the flux and the accumulation of cesium on the surfaces of negative-ion sources. Basic studies that support the code development were performed at a dedicated experiment at the University of Augsburg. Input parameters of the ad- and desorption of cesium at ion source relevant conditions were taken from systematic measurements with a quartz micro balance, while the injection rate of the cesium oven at the ion source was determined by surface ionization detection. This experimental setup was used for further investigations of the work function of cesium-coated samples during plasma exposure. (orig.)

Experiments and simulations for the dynamics of cesium in negative hydrogen ion sources for ITER N-NBI

International Nuclear Information System (INIS)

Gutser, Raphael

2010-01-01

The injection of fast neutral particles (NBI) into a fusion plasma is an important method for plasma heating and current drive. A source for negative deuterium ions delivering an 1 MeV beam that is accelerated to a specific energy and neutralized by a gas target is required for the ITER-NBI. Cesium seeding is required to extract high negative ion current densities from these sources. The optimization of the cesium homogeneity and control are major objectives to achieve the source requirements imposed by ITER. Within the scope of this thesis, the Monte Carlo based numerical transport simulation CsFlow3D was developed, which is the first computer model that is capable of simulating the flux and the accumulation of cesium on the surfaces of negative-ion sources. Basic studies that support the code development were performed at a dedicated experiment at the University of Augsburg. Input parameters of the ad- and desorption of cesium at ion source relevant conditions were taken from systematic measurements with a quartz micro balance, while the injection rate of the cesium oven at the ion source was determined by surface ionization detection. This experimental setup was used for further investigations of the work function of cesium-coated samples during plasma exposure. (orig.)

Thermal Performance Analysis For Small Ion-Exchange Cesium Removal Process

International Nuclear Information System (INIS)

Lee, S.; King, W.

2009-01-01

The In-Riser Ion Exchange program focuses on the development of in-tank systems to decontaminate high level waste (HLW) salt solutions at the Savannah River Site (SRS) and the Hanford Site. Small Column Ion Exchange (SCIX) treatment for cesium removal is a primary in-riser technology for decontamination prior to final waste immobilization in Saltstone. Through this process, radioactive cesium from the salt solution is adsorbed onto the ion exchange media which is packed within a flow-through column. Spherical Resorcinol-Formaldehyde (RF) is being considered as the ion exchange media for the application of this technology at both sites. A packed column loaded with media containing radioactive cesium generates significant heat from radiolytic decay. Under normal operating conditions, process fluid flow through the column can provide adequate heat removal from the columns. However, in the unexpected event of loss of fluid flow or fluid drainage from the column, the design must be adequate to handle the thermal load to avoid unacceptable temperature excursions. Otherwise, hot spots may develop locally which could degrade the performance of the ion-exchange media or the temperature could rise above column safety limits. Data exists which indicates that performance degradation with regard to cesium removal occurs with RF at 65C. In addition, the waste supernate solution will boil around 130C. As a result, two temperature limits have been assumed for this analysis. An additional upset scenario was considered involving the loss of the supernate solution due to inadvertent fluid drainage through the column boundary. In this case, the column containing the loaded media could be completely dry. This event is expected to result in high temperatures that could damage the column or cause the RF sorbent material to undergo undesired physical changes. One objective of these calculations is to determine the range of temperatures that should be evaluated during testing with the RF

Study of the removal of cesium from aqueous solutions by graphene oxide

International Nuclear Information System (INIS)

Bueno, Vanessa N.; Rodrigues, Debora F.; Vitta, Patricia B. Di

2013-01-01

Graphene oxide, used in this work, was synthesized from the oxidation of graphite by Hummer method. The experiments were performed in batch and analyzed for the following parameters: contact time, pH, cesium ion concentration in aqueous solution and removing capacity of the graphene oxide. After the experiments the samples were vacuum filtered and the remaining cesium in solution was quantified by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). The equilibrium was reached after 60 minutes of contact in neutral solution. The percentage of removal was around 80%

Assessment of commercially available ion exchange materials for cesium removal from highly alkaline wastes

International Nuclear Information System (INIS)

Brooks, K.P.; Kim, A.Y.; Kurath, D.E.

1996-04-01

Approximately 61 million gallons of nuclear waste generated in plutonium production, radionuclide removal campaigns, and research and development activities is stored on the Department of Energy's Hanford Site, near Richland, Washington. Although the pretreatment process and disposal requirements are still being defined, most pretreatment scenarios include removal of cesium from the aqueous streams. In many cases, after cesium is removed, the dissolved salt cakes and supernates can be disposed of as LLW. Ion exchange has been a leading candidate for this separation. Ion exchange systems have the advantage of simplicity of equipment and operation and provide many theoretical stages in a small space. The organic ion exchange material Duolite trademark CS-100 has been selected as the baseline exchanger for conceptual design of the Initial Pretreatment Module (IPM). Use of CS-100 was chosen because it is considered a conservative, technologically feasible approach. During FY 96, final resin down-selection will occur for IPM Title 1 design. Alternate ion exchange materials for cesium exchange will be considered at that time. The purpose of this report is to conduct a search for commercially available ion exchange materials which could potentially replace CS-100. This report will provide where possible a comparison of these resin in their ability to remove low concentrations of cesium from highly alkaline solutions. Materials which show promise can be studied further, while less encouraging resins can be eliminated from consideration

Assessment of commercially available ion exchange materials for cesium removal from highly alkaline wastes

Energy Technology Data Exchange (ETDEWEB)

Brooks, K.P.; Kim, A.Y.; Kurath, D.E.

1996-04-01

Approximately 61 million gallons of nuclear waste generated in plutonium production, radionuclide removal campaigns, and research and development activities is stored on the Department of Energy`s Hanford Site, near Richland, Washington. Although the pretreatment process and disposal requirements are still being defined, most pretreatment scenarios include removal of cesium from the aqueous streams. In many cases, after cesium is removed, the dissolved salt cakes and supernates can be disposed of as LLW. Ion exchange has been a leading candidate for this separation. Ion exchange systems have the advantage of simplicity of equipment and operation and provide many theoretical stages in a small space. The organic ion exchange material Duolite{trademark} CS-100 has been selected as the baseline exchanger for conceptual design of the Initial Pretreatment Module (IPM). Use of CS-100 was chosen because it is considered a conservative, technologically feasible approach. During FY 96, final resin down-selection will occur for IPM Title 1 design. Alternate ion exchange materials for cesium exchange will be considered at that time. The purpose of this report is to conduct a search for commercially available ion exchange materials which could potentially replace CS-100. This report will provide where possible a comparison of these resin in their ability to remove low concentrations of cesium from highly alkaline solutions. Materials which show promise can be studied further, while less encouraging resins can be eliminated from consideration.

Cesium ion exchange using actual waste: Column size considerations

International Nuclear Information System (INIS)

Brooks, K.P.

1996-04-01

It is presently planned to remove cesium from Hanford tank waste supernates and sludge wash solutions using ion exchange. To support the development of a cesium ion exchange process, laboratory experiments produced column breakthrough curves using wastes simulants in 200 mL columns. To verify the validity of the simulant tests, column runs with actual supernatants are being planned. The purpose of these actual waste tests is two-fold. First, the tests will verify that use of the simulant accurately reflects the equilibrium and rate behavior of the resin compared to actual wastes. Batch tests and column tests will be used to compare equilibrium behaviors and rate behaviors, respectively. Second, the tests will assist in clarifying the negative interactions between the actual waste and the ion exchange resin, which cannot be effectively tested with simulant. Such interactions include organic fouling of the resin and salt precipitation in the column. These effects may affect the shape of the column breakthrough curve. The reduction in column size also may change the shape of the curve, making the individual effects even more difficult to sort out. To simplify the evaluation, the changes due to column size must be either understood or eliminated. This report describes the determination of the column size for actual waste testing that best minimizes the effect of scale-down. This evaluation will provide a theoretical basis for the dimensions of the column. Experimental testing is still required before the final decision can be made. This evaluation will be confined to the study of CS-100 and R-F resins with NCAW simulant and to a limited extent DSSF waste simulant. Only the cesium loading phase has been considered

Decontamination of spent ion-exchangers contaminated with cesium radionuclides using resorcinol-formaldehyde resins.

Science.gov (United States)

Palamarchuk, Marina; Egorin, Andrey; Tokar, Eduard; Tutov, Mikhail; Marinin, Dmitry; Avramenko, Valentin

2017-01-05

The origin of the emergence of radioactive contamination not removable in the process of acid-base regeneration of ion-exchange resins used in treatment of technological media and liquid radioactive waste streams has been determined. It has been shown that a majority of cesium radionuclides not removable by regeneration are bound to inorganic deposits on the surface and inside the ion-exchange resin beads. The nature of the above inorganic inclusions has been investigated by means of the methods of electron microscopy, IR spectrometry and X-ray diffraction. The method of decontamination of spent ion-exchange resins and zeolites contaminated with cesium radionuclides employing selective resorcinol-formaldehyde resins has been suggested. Good prospects of such an approach in deep decontamination of spent ion exchangers have been demonstrated. Copyright © 2016 Elsevier B.V. All rights reserved.

Effect of electrode materials on a negative ion production in a cesium seeded negative ion source

Energy Technology Data Exchange (ETDEWEB)

Shimizu, Takashi; Morishita, Takutoshi; Kashiwagi, Mieko; Hanada, Masaya; Iga, Takashi; Inoue, Takashi; Watanabe, Kazuhiro; Imai, Tsuyoshi [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment; Wada, Motoi [Doshisha Univ., Kyoto (Japan)

2003-03-01

Effects of plasma grid materials on the negative ion production efficiency in a cesium seeded ion source have been experimentally studied. Grid materials of Au, Ag, Cu, Ni, and Mo were examined. A 2.45 GHz microwave ion source was utilized in the experiment to avoid contamination of tungsten from filament cathode. Relations between the negative ion currents and work functions of the grid were measured for these materials. Influence of the contamination by tungsten on the grid was also investigated. If was clarified that the negative ion production efficiency was determined only by the work function of the grid. The efficiency did not depend on the material itself. The lowest work function of 1.42 eV was obtained for Au grid with Cs, and a high H{sup -} production efficiency of 20.7 mA/kW was measured. This efficiency is about 1.3 times larger than that of Cs/Mo and Cs/Cu. Further improvement of the production efficiency was observed by covering the plasma grid with tungsten and cesium simultaneously. Such co-deposition of W and Cs on the plasma grid produced the negative ion production efficiency of 1.7 times higher than that from the tungsten grid simply covered with Cs. (author)

Adsorption of cesium on cement mortar from aqueous solutions

Energy Technology Data Exchange (ETDEWEB)

Volchek, Konstantin, E-mail: konstantin.volchek@ec.gc.ca [Emergencies Science and Technology Section, Environment Canada, 335 River Road, Ottawa, Ontario, Canada K1A 0H3 (Canada); Miah, Muhammed Yusuf [Emergencies Science and Technology Section, Environment Canada, 335 River Road, Ottawa, Ontario, Canada K1A 0H3 (Canada); Department of Applied Chemistry and Chemical Technology, Noakhali Science and Technology University (Bangladesh); Kuang, Wenxing; DeMaleki, Zack [Emergencies Science and Technology Section, Environment Canada, 335 River Road, Ottawa, Ontario, Canada K1A 0H3 (Canada); Tezel, F. Handan [Department of Chemical and Biological Engineering, University of Ottawa, 161 Louis-Pasteur, Ottawa, Ontario, Canada K1N 6N5 (Canada)

2011-10-30

Highlights: {yields} The adsorption of cesium on cement mortar was investigated in a range of temperatures and cesium concentrations. {yields} The pseudo-second order kinetic model produced a good fit with the experimental kinetic data. {yields} Equilibrium test results correlated well with the Freundlich isotherm adsorption model. {yields} The interaction between cesium ions and cement mortar was dominated by chemical adsorption. - Abstract: The adsorption of cesium on cement mortar from aqueous solutions was studied in series of bench-scale tests. The effects of cesium concentration, temperature and contact time on process kinetics and equilibrium were evaluated. Experiments were carried out in a range of initial cesium concentrations from 0.0103 to 10.88 mg L{sup -1} and temperatures from 278 to 313 K using coupons of cement mortar immersed in the solutions. Non-radioactive cesium chloride was used as a surrogate of the radioactive {sup 137}Cs. Solution samples were taken after set periods of time and analyzed by inductively coupled plasma mass spectroscopy. Depending on the initial cesium concentration, its equilibrium concentration in solution ranged from 0.0069 to 8.837 mg L{sup -1} while the respective surface concentration on coupons varied from 0.0395 to 22.34 {mu}g cm{sup -2}. Equilibrium test results correlated well with the Freundlich isotherm model for the entire test duration. Test results revealed that an increase in temperature resulted in an increase in adsorption rate and a decrease in equilibrium cesium surface concentration. Among several kinetic models considered, the pseudo-second order reaction model was found to be the best to describe the kinetic test results in the studied range of concentrations. The adsorption activation energy determined from Arrhenius equation was found to be approximately 55.9 kJ mol{sup -1} suggesting that chemisorption was the prevalent mechanism of interaction between cesium ions and cement mortar.

Preparation and use of polymeric materials containing hydrophobic anions and plasticizers for separation of cesium and strontium

International Nuclear Information System (INIS)

Abney, K.D.; Kinkead, S.A.; Mason, C.F.V.; Rais, J.

1997-01-01

Preparation and use is described for polymeric materials containing hydrophobic anions and plasticizers for extraction of cesium and strontium. The use of polymeric materials containing plasticizers which are solvents for hydrophobic anions such as derivatives of cobalt dicarbollide or tetraphenylborate which are capable of extracting cesium and strontium ions from aqueous solutions in contact with the polymeric materials, is described. The polymeric material may also include a synergistic agent for a given ion like polyethylene glycol or a crown ether, for removal of radioactive isotopes of cesium and strontium from solutions of diverse composition and, in particular, for solutions containing large excess of sodium nitrate

Innovative Highly Selective Removal of Cesium and Strontium Utilizing a Newly Developed Class of Inorganic Ion Specific Media - 16221

International Nuclear Information System (INIS)

Denton, Mark S.; Kanatzidis, Mercouri G.

2009-01-01

Highly selective removal of Cesium and Strontium is critical for waste treatment and environmental remediation. Cesium-137 is a beta-gamma emitter and Strontium-90 is a beta emitter with respective half-lives of 30 and 29 years. Both elements are present at many nuclear sites. Cesium and Strontium can be found in wastewaters at Washington State's Hanford Site, as well as in waste streams of many Magnox reactor sites. Cesium and Strontium are found in the Reactor Coolant System of light water reactors at nuclear power plants. Both elements are also found in spent nuclear fuel and in high-level waste (HLW) at DOE sites. Cesium and Strontium are further major contributors to the activity and the heat load. Therefore, technologies to extract Cesium and Strontium are critical for environmental remediation waste treatment and dose minimization. Radionuclides such as Cesium-137 and Strontium-90 are key drivers of liquid waste classification at light water reactors and within the DOE tank farm complexes. The treatment, storage, and disposal of these wastes represents a major cost for nuclear power plant operators, and comprises one of the most challenging technology-driven projects for the DOE Environmental Management (EM) program. Extraction technologies to remove Cesium and Strontium have been an active field of research. Four notable extraction technologies have been developed so far for HLW: solvent extraction, prussian blue, crystalline silico-titanate (CST) and organic ion-exchangers (e.g., resorcinol formaldehyde and SuperLig). The use of one technology over another depends on the specific application. For example, the waste treatment plant (WTP) at Hanford is planning on using a highly-selective organic ion-exchange resin to remove Cesium and Strontium. Such organic ion-exchangers use molecular recognition to selectively bind to Cesium and Strontium. However, these organic ion-exchangers are synthesized using multi-step organic synthesis. The associated cost to

Radioactive cesium removal from seawater using adsorptive fibers prepared by radiation-induced graft polymerization

International Nuclear Information System (INIS)

Goto, Shota; Kawai-Noma, Shigeko; Umeno, Daisuke; Saito, Kyoichi; Fujiwara, Kunio; Sugo, Takanobu; Kikuchi, Takahiro; Morimoto, Yasutomi

2015-01-01

The meltdown of three reactors of the TEPCO Fukushima Daiichi nuclear power station (NPS) caused by the Great East Japan Earthquake on March 11th 2011 resulted in the emission of radionuclides such as cesium-137 and strontium-90 to the environment. For example, radioactive cesium exceeding the legal discharge limit (90 Bq/L, 2×10 -13 M) was detected in the seawater of the seawater-intake area of the NPS at the end of September 2014. Adsorbents with a high selectivity for cesium ions over other alkali metal ions such as sodium and potassium ions are required for cesium removal from seawater because sodium and potassium ions dissolve respectively at much higher concentrations of 5×10 -1 and 1×10 -2 M than cesium ions (2×10 -9 M). In addition, the simple operations of the immersion in seawater and the recovery of the adsorbents from seawater are desirable at decontamination sites. We prepared a cobalt-ferrocyanide-impregnated fiber capable of specifically capturing cesium ions in seawater by radiation-induced graft polymerization and chemical modifications. First, a commercially available 6-nylon fiber was irradiated with γ-rays. Second, an epoxy-group-containing vinyl monomer, glycidyl methacrylate, was graft-polymerized onto the γ-ray-irradiated nylon fiber. Third, the epoxy ring of the grafted polymer chain was reacted with triethylenediamine to obtain an anion-exchange fiber. Fourth, ferrocyanide ions, [Fe(CN) 6 ] 4 - , were bound to the anion-exchange group of the polymer chains. Finally, the ferrocyanide-ion-bound-fiber was placed in contact with cobalt chloride to precipitate insoluble cobalt ferrocyanide onto the polymer chains. Insoluble cobalt ferrocyanide was immobilized at the periphery of the fiber. However, the impregnation structure remains unclear. Here, we clarified the structure of insoluble cobalt ferrocyanide impregnated onto the polymer chain grafted onto the fiber to ensure the chemical and physical stability of the adsorptive fiber in

Formation of negative ions on a metal surface

International Nuclear Information System (INIS)

Amersfoort, P.W. van.

1987-01-01

In this thesis a fundamental study of the charge exchange process of positive ions on the converter surface is presented. Beams of hydrogen ad cesium ions are scattered from a thoroughly cleaned W(110) surface, under ultra-high vacuum conditions. The cesium coverage of the surface is a controlled parameter. Ch. 2 deals with the negative-ion formation probability for hydrogen atoms. The influence of coabsorption of hydrogen is studied in Ch. 3. These measurements are important for understanding the formation process in plasma sources, because the converter surface is expected to be strongly contaminated with hydrogen. The charge state of scattered cesium particles is investigated in Ch. 4. Knowledge of this parameter is essential for Ch. 5, in which a model study of adsorption of cesium on a metal surface in contact with a plasma is presented. Finally, the negative-ion formation process in a plasma environment is studied in Ch. 6. Measurements done on a hollow-cathode discharge equipped with a novel type of converter, a porous tungsten button, are discussed. Liquid cesium diffuses through this button towards the side in contact with the plasma. (Auth.)

Small Column Ion Exchange Analysis for Removal of Cesium from SRS Low Curie Salt Solutions Using Crystalline Silicotitanate (CST) Resin

International Nuclear Information System (INIS)

ALEMAN, SEBASTIAN

2004-01-01

Savannah River Technology Center (SRTC) researchers modeled ion exchange removal of cesium from dissolved salt waste solutions. The results assist in evaluating proposed configurations for an ion exchange process to remove residual cesium from low curie waste streams. A process for polishing (i.e., removing small amounts) of cesium may prove useful should supernate draining fail to meet the Low Curie Salt (LCS) target limit of 0.1 Ci of Cs-137 per gallon of salt solution. Cesium loading isotherms and column breakthrough curves for Low Curie dissolved salt solutions were computed to provide performance predictions for various column designs

Ion-exchange properties of cesium and strontium into zeolites from sodium salt solutions

International Nuclear Information System (INIS)

Kanno, Takuji; Hashimoto, Hiroyuki; Ohtani, Tozo.

1978-01-01

The ion-exchange properties of cesium and strontium into zeolite from sodium salt solution has been studied in zeolite A, zeolite X, zeolite Y, mordenite and clinoptilolite. The distribution of cesium into mordenite from about 1 -- 2 M sodium chloride and sodium hydroxide solutions is considerably larger than that into zeolite A. The distribution coefficient for 2 M solution of sodium salts was about 300. Therefore, the separation of cesium from sodium salt solution is possible by using mordenite. The distribution of strontium into zeolites form 1 -- 2 M solutions of sodium chloride and sodium nitrate were in the order of zeolite A>zeolite X>zeolite Y asymptoticaly equals mordenite. The distribution coefficient of 230 was obtained for 1 M solutions of sodium salts. The anion in solutions had no effect on the distribution of cesium and strontium into zeolite from sodium salt solution. (author)

Surface negative ion production in ion sources

International Nuclear Information System (INIS)

Belchenko, Y.

1993-01-01

Negative ion sources and the mechanisms for negative ion production are reviewed. Several classes of sources with surface origin of negative ions are examined in detail: surface-plasma sources where ion production occurs on the electrode in contact with the plasma, and ''pure surface'' sources where ion production occurs due to conversion or desorption processes. Negative ion production by backscattering, impact desorption, and electron- and photo-stimulated desorption are discussed. The experimental efficiencies of intense surface negative ion production realized on electrodes contacted with hydrogen-cesium or pure hydrogen gas-discharge plasma are compared. Recent modifications of surface-plasma sources developed for accelerator and fusion applications are reviewed in detail

Cesium removal from liquid acidic wastes with the primary focus on ammonium molybdophosphate as an ion exchanger: A literature review

International Nuclear Information System (INIS)

Miller, C.J.

1995-03-01

Many articles have been written concerning the selective removal of cesium from both acidic and alkaline defense wastes. The majority of the work performed for cesium removal from defense wastes involves alkaline feed solutions. Several different techniques for cesium removal from acidic solutions have been evaluated such as precipitation, solvent extraction, and ion exchange. The purpose of this paper is to briefly review various techniques for cesium removal from acidic solutions. The main focus of the review will be on ion exchange techniques, particularly those involving ammonium molybdophosphate as the exchanger. The pertinent literature sources are condensed into a single document for quick reference. The information contained in this document was used as an aid in determining techniques to evaluate cesium removal from the acidic Idaho Chemical Processing Plant waste matrices. 47 refs., 2 tabs

Small-Scale Ion Exchange Removal of Cesium and Technetium from Hanford Tank 241-AN-102

International Nuclear Information System (INIS)

Hassan, N.M.

2000-01-01

The pretreatment process for BNFL, Inc.'s Hanford River Protection Project is to provide decontaminated low activity waste and concentrated eluate streams for vitrification into low and high activity waste glass, respectively. The pretreatment includes sludge washing, filtration, precipitation, and ion exchange processes to remove entrained solids, cesium, transuranics, technetium, and strontium. The cesium (Cs-137) and technetium (Tc-99) ion exchange removal is accomplished by using SuperLig 644, and 639 resins from IBC Advanced Technologies, American Fork, Utah. The resins were shown to selectively remove cesium and technetium (as anionic pertechnetate ) from alkaline salt solutions. The efficiency of ion exchange column loading and elution is a complex function involving feed compositions, equilibrium and kinetic behavior of ion exchange resins, diffusion, and the ionic strength and pH of the aqueous solution. A previous experimental program completed at the Savannah River Tech nology Center2 demonstrated the conceptualized flow sheet parameters with an Envelope C sample from Hanford Tank 241-AN-107. Those experiments also included determination of Cs and Tc batch distribution coefficients by SuperLig 644 and 639 resins and demonstration of small-scale column breakthrough and elution. The experimental findings were used in support of preliminary design bases and pretreatment flow sheet development by BNFL, Inc

Evaluation of selected ion exchangers for the removal of cesium from MVST W-25 supernate

International Nuclear Information System (INIS)

Collins, J.L.; Egan, B.Z.; Anderson, K.K.; Chase, C.W.; Mrochek, J.E.; Bell, J.T.; Jernigan, G.E.

1995-04-01

The goal of this batch-test equilibration study was to evaluate the effectiveness of certain ion exchangers for removing cesium from supernate taken from tank W-25 of the Melton Valley Storage Tank (MVST) Facility located at the Oak Ridge National Laboratory (ORNL). These exchangers were selective for removing cesium from alkaline supernatant solutions with high salt concentrations. Since the supernates of evaporator concentrates stored in tanks at the MVST facility have compositions similar to some of those stored in tanks at Hanford, the data generated in this study should prove useful in the overall evaluation of the ion exchangers for applications to Hanford and other US Department of Energy (USDOE) sites. A goal of the waste processing effort at Hanford is to remove enough cesium to ensure that the resulting LLW will meet the Nuclear Regulatory Commission (NRC) 10 CFR 61 class A limit for 137 Cs (1 Ci/m 3 or 1 μCi/mL). The separated cesium may be concentrated and vitrified for disposal in the high-level waste repository. The decontaminated effluent would be solidified for near-surface disposal

Crystalline silicotitanates -- novel commercial cesium ion exchangers

International Nuclear Information System (INIS)

Braun, R.; Dangieri, T.J.; Fennelly, D.J.

1996-01-01

A new class of inorganic ion exchangers called crystalline silicotitanates (CST), invented by researchers at Sandia National Laboratories and Texas A ampersand M University, has been commercialized in a joint Sandia-UOP effort. The original developmental materials exhibited high selectivity for the ion exchange of cesium, strontium, and several other radionuclides from highly alkaline solutions containing molar concentrations of Na + . The materials also showed excellent chemical and radiation stability. These CST properties made them excellent candidates for treatment of solutions such as the Hanford tank supernates and other DOE radwastes. Sandia and UOP, under a Cooperative Research and Development Agreement (CRADA), developed CSTs in the powdered form and in an engineered form suitable for column ion exchange use. A continuous-flow, column ion exchange process is expected to be used to remove Cs and other radionuclides from the Hanford supernatant. The powder material invented by Sandia and Texas A ampersand M consists of submicron-size particles. It is not designed for column ion exchange but may be used in other applications such as batch waste processing. Data are also presented confirming the excellent stability of the commercial CSTs over a broad pH range and the high radiation stability of the exchangers. In addition, data are provided that demonstrate the high physical strength and attrition resistance of IONSIV reg-sign IE-911, critical properties for column ion exchange applications

Efficiency of Dry (Psidium guava) Leaves for The Removal of Cesium-137 from Aqueous Solutions

International Nuclear Information System (INIS)

Omar, H.A.; Abu-Kharda, S.A.; Abd El -Baset, L.A.; Abu-Shohba, R.M.

2012-01-01

Batch experiments for the removal of cesium-137 from aqueous solution onto guava leaves (psidium guava) and carbonized guava leaves were studied as a function of contact time, dosage, ph value and initial concentration ion. The sorption process was described by pseudo first-order, pseudo second-order, Morris and Elovich kinetic models. Cesium concentrations were ranged between 2x10 -5 - 1x10 -3 M. Sorption data have been interpreted in terms of Langmuir, Freundlich and Dubinin-Radushkevich isotherms. The maximum sorption capacity of carbonized guava leaves adsorbent for cesium removal was 8.02 mgg -1 . The results of the present study suggest that carbonized guava leaves can be used beneficially for cesium removal from aqueous solution.

Production of rare-earth atomic negative ion beams in a cesium-sputter-type negative ion source

International Nuclear Information System (INIS)

Davis, V.T.; Covington, A.M.; Duvvuri, S.S.; Kraus, R.G.; Emmons, E.D.; Kvale, T.J.; Thompson, J.S.

2007-01-01

The desire to study negative ion structure and negative ion-photon interactions has spurred the development of ion sources for use in research and industry. The many different types of negative ion sources available today differ in their characteristics and abilities to produce anions of various species. Thus the importance of choosing the correct type of negative ion source for a particular research or industrial application is clear. In this study, the results of an investigation on the production of beams composed of negatively-charged rare-earth ions from a cylindrical-cathode-geometry, cesium-sputter-type negative ion source are presented. Beams of atomic anions have been observed for most of the first-row rare-earth elements, with typical currents ranging from hundreds of picoamps to several nanoamps

Vitrification of cesium-contaminated organic ion exchange resin

International Nuclear Information System (INIS)

Sargent, T.N. Jr.

1994-08-01

Vitrification has been declared by the Environmental Protection Agency (USEPA) as the Best Demonstrated Available Technology (BDAT) for the permanent disposal of high-level radioactive waste. Savannah River Site currently uses a sodium tetraphenylborate (NaTPB) precipitation process to remove Cs-137 from a wastewater solution created from the processing of nuclear fuel. This process has several disadvantages such as the formation of a benzene waste stream. It has been proposed to replace the precipitation process with an ion exchange process using a new resorcinol-formaldehyde resin developed by Savannah River Technical Center (SRTC). Preliminary tests, however, showed that problems such as crust formation and a reduced final glass wasteform exist when the resin is placed in the melter environment. The newly developed stirred melter could be capable of overcoming these problems. This research explored the operational feasibility of using the stirred tank melter to vitrify an organic ion exchange resin. Preliminary tests included crucible studies to determine the reducing potential of the resin and the extent of oxygen consuming reactions and oxygen transfer tests to approximate the extent of oxygen transfer into the molten glass using an impeller and a combination of the impeller and an external oxygen transfer system. These preliminary studies were used as a basis for the final test which was using the stirred tank melter to vitrify nonradioactive cesium loaded organic ion exchange resin. Results from this test included a cesium mass balance, a characterization of the semi-volatile organic compounds present in the off gas as products of incomplete combustion (PIC), a qualitative analysis of other volatile metals, and observations relating to the effect the resin had on the final redox state of the glass

Development of electrochemical ion exchange electrodes for the treatment of wastes containing chromium or cesium ions

International Nuclear Information System (INIS)

Manosso, Helena Cristina

2006-01-01

Nowadays, environmental preservation using technologies that do not attack it, generating non-toxic residues and reduced volumes, has been discussed. Hazardous effluents, containing metals, as chromium, have been poured in the soils and rivers, degrading the water. Not different are the problems originated from some nuclear activities that generate wastes, as in chemical research laboratories. Although those wastes are not poured in the environment, sometimes they are inadequately stored, what can cause serious accidents. With the purpose of solving this problem, there are some techniques to waste treatment, between them there is the electrochemical ion exchange (EIX). EIX is an advanced process that has advantages over traditional ion exchange and the fact of using the electron as the only reagent, reduces the volume of the solution to be treated. This technique consists of development of an electrode, where an ion exchanger is physically incorporated in an electrode structure with a binder. In this study, cationic resin Amberlite CG-50 and zirconium phosphate have been chosen for the separation of chromium and cesium from waste, respectively. They were chosen because they present high chemical stability in oxidizing media and at ionizing radiation. The quantity of charcoal, graphite and binder used in formulation of electrode have been studied either. Before choosing the best electrode, it was verified sorption percentage of 99,3% for chromium and 99,8% for cesium. The greater advantage of this process is the total elution of chromium as much as cesium, without reagents addition, being possible to reuse the electrode without losing its capacity. Beside on the results, a continuous process for the wastes containing Cr and Cs, using a flux electrolytic cell (CELFLUX) of high retention capacity, was presented. The high efficiency of this cell for both retention and elution, leading to an important reduction of waste volume, and, every more, making possible the

Contact isotopic- and contact ion-exchange between two adsorbents

International Nuclear Information System (INIS)

Bunzl, K.; Mohan, R.; Haimerl, M.

1975-01-01

The kinetics of contact ion exchange processes between an ion exchange membrane and resin ion exchange beads, stirred in pure water, was investigated. A general criterion was derived, which indicates whether diffusion of the ions between the intermingling electric double layers or the collision frequency between the two adsorbents is the rate dermining step. Since the latter process proved to be rate controlling under our experimental conditions, the corresponding rate equations were derived under various initial and boundary conditions. Experimentally, the kinetics of contact isotopic exchange of Cs + - and Na + -ions as well as of the reverse contact ion exchange process of Cs + -versus Na + -ions were investigated by using Na 22 and Cs 137 radioisotopes. The experiments reveal in quantitative accord with the theory that the rate of collision controlled contact ion exchange processes depends mainly on the 'exchange coefficient', the separation factor and the collision frequency. While the latter two quantities were determined independently by separate experiments, the 'exchange coefficient' was evaluated from a contact isotopic exchange experiment. (orig.) [de

3-(Dicyanomethylidene)indan-1-one-Functionalized Calix[4]arene-Calix[4]pyrrole Hybrid: An Ion-Pair Sensor for Cesium Salts.

Science.gov (United States)

Yeon, Yerim; Leem, Soojung; Wagen, Corin; Lynch, Vincent M; Kim, Sung Kuk; Sessler, Jonathan L

2016-09-02

A chromogenic calix[4]arene-calix[4]pyrrole hybrid ion pair receptor bearing an indane substituent at a β-pyrrolic position has been prepared. On the basis of solution-phase UV-vis spectroscopic analysis and (1)H NMR spectroscopic studies carried out in 10% methanol in chloroform, receptor 1 is able to bind only cesium ion pairs (e.g., CsF, CsCl, and CsNO3) but not the constituent cesium cation (as its perchlorate salt) or the F(-), Cl(-), or NO3(-) anions (as the tetrabutylammonium salts). It thus displays rudimentary AND logic gate behavior. Receptor 1 shows a colorimetric response to cesium ion pairs under conditions of solid-liquid (nitrobenzene) and liquid-liquid (D2O-nitrobenzene-d5) extraction.

Using copper hexacyanoferrate (II) impregnated zeolite for cesium removal from radioactive liquid waste

International Nuclear Information System (INIS)

Fumio, K.; Kenji, M.

1982-01-01

Experiments were performed to obtain fundamental data on cesium ion removal characteristics of metal hexacyanoferrate (II) impregnated zeolite in radioactive liquid waste containing a large amount of sodium sulfate. Copper hexacyanoferrate (II) impregnated zeolite (CuFZ) was prepared and showed a high selectivity for cesium ion. The material was suitable for use in an ion exchange column. This exchanger could selectively and efficiently remove the cesium even if there is 15 wt% Na 2 SO 4 in the solution. Cesium removal ability and stability of CuFZ were excellent over a wide pH range between 1.5 and 10. The cesium ion exchange ability was not influenced by the presence of the alkali metal ions, calcium and magnesium, and carbonate ions even at concentrations 25 times greater than the cesium ion. However, since ammonium ion behaves similarly to cesium ion and interrupts latter ion adsorption, the presence of ammonium ion is not desirable. The CuFZ offers the possibility of separating and removing cesium from liquid wastes produced in facilities handling radioactive materials

Removal of cesium radioisotopes from solutions using granulated zeolites

International Nuclear Information System (INIS)

Bronic, J.; Subotic, B.

1991-01-01

The influence of type of zeolite and the flow rate of solution through the column on the removal efficiency of radioactive cesium ions from solution has been investigated. The analysis of the change in the concentration of cesium ions in the solutions and distribution of cesium ions in the column fillings (granulated zeolites), after passing the solutions through the columns filled with various granulated zeolites (zeolite 4A, zeolite 13X, synthetic mordenite) was performed. On the basis of the results of this study, the conditions for the most efficient removal of cesium ions from solutions have been discussed. (author) 35 refs.; 9 figs.; 1 tab

ION EXCHANGE MODELING FOR REMOVAL OF CESIUM FROM HANFORD WASTE USING SUPERLIG 644 RESIN

International Nuclear Information System (INIS)

Hamm, L

2004-01-01

The expected performance of a proposed ion exchange column using SuperLig(reg s ign) 644 resin for the removal of cesium from Hanford high level radioactive alkaline waste is discussed. This report represents a final report on the ability and knowledge with regard to modeling the Cesium-SuperLig(reg s ign) 644 resin ion exchange system. Only the loading phase of the cycle process is addressed within this report. Pertinent bench-scale column tests and batch equilibrium experiments are addressed. The methodology employed and sensitivity analyses are also included (i.e., existing methodology employed is referenced to prior developmental efforts while updated methodology is discussed). Pilot-scale testing is not assessed since no pilot-scale testing was available at the time of this report. Column performance predictions are made considering three selected feed compositions under nominal operating conditions. The sensitivity analyses provided help to identify key parameters that aid in resin procurement acceptance criteria. The methodology and application presented within this report reflect the expected behavior of SuperLig(reg s ign) 644 resin manufactured at the production-scale (i.e, 250 gallon batch size level). The primary objective of this work was, through modeling and verification based on experimental assessments, to predict the cesium removal performance of SuperLig(reg s ign) 644 resin for application in the RPP pretreatment facility

Study of the removal of cesium from aqueous solutions by graphene oxide; Estudo da remocao de cesio em solucoes aquosas por oxido de grafeno

Energy Technology Data Exchange (ETDEWEB)

Bueno, Vanessa N.; Rodrigues, Debora F. [University of Houston (UH), Houston, TX (United States); Vitta, Patricia B. Di [Universidade de Sao Paulo (STRES/USP), Sao Paulo, SP (Brazil). Inst. de Quimica. Setor Tecnico de Residuos Quimicos e Solventes; Oshiro, Mauricio T.; Vicente, Roberto; Hiromoto, Goro; Potiens Junior, Ademar; Sakata, Solange K., E-mail: sksakata@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2013-07-01

Graphene oxide, used in this work, was synthesized from the oxidation of graphite by Hummer method. The experiments were performed in batch and analyzed for the following parameters: contact time, pH, cesium ion concentration in aqueous solution and removing capacity of the graphene oxide. After the experiments the samples were vacuum filtered and the remaining cesium in solution was quantified by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). The equilibrium was reached after 60 minutes of contact in neutral solution. The percentage of removal was around 80%.

Ion exchange removal of cesium from simulated and actual supernate from Hanford tanks 241-SY-101 and 241-SY-103

International Nuclear Information System (INIS)

Brown, G.N.; Bontha, J.R.; Carlson, C.D.

1995-09-01

Pacific Northwest Laboratory (PNL), in conjunction with the Process Chemistry and Statistics Section of Westinghouse Hanford Company (WHC), conducted this study as part of the Supernatant Treatment Development Task for the Initial Pretreatment Module (IPM) Applied Engineering Project. The study assesses the performance of the CS-100 ion exchange material for removing cesium from simulated and actual alkaline supernate from Hanford tanks 241-SY-101 and 241-SY-103. The objective of these experiments is to compare the cesium ion exchange loading and elution profiles of actual and simulated wastes. Specific experimental objectives include (1) demonstration of decontamination factors (DF) for cesium removal, 92) verification of simulant performance, (3) investigation of waste/exchanger chemistry, and (4) determination of the radionuclide content of the regenerated CS-100 resin prior to disposal

Cesium absorption from acidic solutions using ammonium molybdophosphate on a polyacrylonitrile support (AMP-PAN)

International Nuclear Information System (INIS)

Miller, C.J.; Olson, A.L.; Johnson, C.K.

1995-01-01

Recent efforts at the Idaho Chemical Processing Plant (ICPP) have included evaluation of cesium removal technologies as applied to ICPP acidic radioactive waste streams. Ammonium molybdophosphate (AMP) immobilized on a polyacrylonitrile support (AMP-PAN) has been studied as an ion exchange agent for cesium removal from acidic waste solutions. Capacities, distribution coefficients, elutability, and kinetics of cesium-extraction have been evaluated. Exchange breakthrough curves using small columns have been determined from 1M HNO 3 and simulated waste solutions. The theoretical capacity of AMP is 213 g Cs/kg AMP. The average experimental capacity in batch contacts with various acidic solutions was 150 g Cs/kg AMP. The measured cesium distribution coefficients from actual waste solutions were 3287 mL/g for dissolved zirconia calcines, and 2679 mL/g for sodium-bearing waste. The cesium in the dissolved alumina calcines was analyzed for; however, the concentration was below analytical detectable limits resulting in inconclusive results. The reaction kinetics are very rapid (2-10 minutes). Cesium absorption appears to be independent of acid concentration over the range tested (0.1 M to 5 M HNO 3 )

DEVELOPMENT OF PROTOTYPE TITANATE ION EXCHANGE LOADED MEMBRANES FOR STRONTIUM, CESIUM AND ACTINIDE DECONTAMINATION FROM AQUEOUS MEDIA

Energy Technology Data Exchange (ETDEWEB)

Oji, L; Keisha Martin, K; David Hobbs, D

2008-05-30

We have successfully incorporated high surface area particles of titanate ion exchange materials (monosodium titanate and crystalline silicotitanate) with acceptable particle size distribution into porous and inert support membrane fibrils consisting of polytetrafluoroethylene (Teflon{reg_sign}), polyethylene and cellulose materials. The resulting membrane sheets, under laboratory conditions, were used to evaluate the removal of surrogate radioactive materials for cesium-137 and strontium-90 from high caustic nuclear waste simulants. These membrane supports met the nominal requirement for nonchemical interaction with the embedded ion exchange materials and were porous enough to allow sufficient liquid flow. Some of this 47-mm size stamped out prototype titanium impregnated ion exchange membrane discs was found to remove more than 96% of dissolved cesium-133 and strontium-88 from a caustic nuclear waste salt simulants. Since in traditional ion exchange based column technology monosodium titanate (MST) is known to have great affinity for the sorbing of other actinides like plutonium, neptunium and even uranium, we expect that the MST-based membranes developed here, although not directly evaluated for uptake of these three actinides because of costs associated with working with actinides which do not have 'true' experimental surrogates, would also show significant affinity for these actinides in aqueous media. It was also observed that crystalline silicotitanate impregnated polytetrafluoroethylene or polyethylene membranes became less selective and sorbed both cesium and strontium from the caustic aqueous salt simulants.

Steady State Sputtering Yields and Surface Compositions of Depleted Uranium and Uranium Carbide bombarded by 30 keV Gallium or 16 keV Cesium Ions.

Energy Technology Data Exchange (ETDEWEB)

Siekhaus, W. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Teslich, N. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Weber, P. K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2014-10-23

Depleted uranium that included carbide inclusions was sputtered with 30-keV gallium ions or 16-kev cesium ions to depths much greater than the ions’ range, i.e. using steady-state sputtering. The recession of both the uranium’s and uranium carbide’s surfaces and the ion corresponding fluences were used to determine the steady-state target sputtering yields of both uranium and uranium carbide, i.e. 6.3 atoms of uranium and 2.4 units of uranium carbide eroded per gallium ion, and 9.9 uranium atoms and 3.65 units of uranium carbide eroded by cesium ions. The steady state surface composition resulting from the simultaneous gallium or cesium implantation and sputter-erosion of uranium and uranium carbide were calculated to be U₈₆Ga₁₄, (UC)₇₀Ga₃₀ and U₈₁Cs₉, (UC)₇₉Cs₂₁, respectively.

Preliminary Ion Exchange Modeling for Removal of Cesium from Hanford Waste Using SuperLig 644 Resin

International Nuclear Information System (INIS)

Hamm, L.L.

2000-01-01

A proposed facility is being designed for the immobilization of Hanford high-level radioactive waste. One unit process in the facility is designed to remove radioactive cesium by ion-exchange from the strongly alkaline aqueous phase. A resin specifically designed with high selectivity of cesium under alkaline conditions is being investigated. The resin also is elutable under more acidic conditions. The proposed design of the facility consists of two sets of two packed columns placed in series (i.e., a lead column followed by a lag (guard) column configuration). During operation, upon reaching a specified cesium concentration criterion at the exit of the lag column, operation is switched to the second set of lead and lag columns. The cesium-loaded lead column is processed (i.e., washed and eluted) and switched to the lag position. the previous lag column is then placed in the lead position (without eluting) and the system is ready for use in the next cycle. For a well designed process, the loading and elution processes result in significant volume reductions in aqueous high-level waste

Effect of Temperature on the Removal of Cesium and Strontium Ions from Aqueous Solutions Using Zeolite A

International Nuclear Information System (INIS)

El-Kamash, A.M.; El-Naggar, M.R.; El-Dessouky, M.I.

2008-01-01

Ion exchange experiments between synthetic zeolite A and aqueous solutions of cesium and strontium ions were conducted at constant total ion concentrations of 0.1 N and at different temperatures in the range from 25 to 60 degree C. Thermodynamic equilibrium constants, calculated from the corresponding Kielland's plots, were used for the calculation of . δG degree δH degree and δS degree. The obtained data indicated that zeolite A exhibits higher affinity for Cs + and Sr +2 ions from solution than host Na + ions

Research advances in adsorption treatment of cesium and cobalt in waste liquid of nuclear power plants by ion exchange resin

International Nuclear Information System (INIS)

Liu Dan; Wang Xin; Liu Jiean; Zhu Laiye; Chen Bin; Weng Minghui

2014-01-01

Liquid radwaste is unavoidably produced during the operation of nuclear power plants (NPP). With the development of China's nuclear power, much more attention will be paid to the impact of NPP construction on water environment. Radionuclides are the main targets for adsorption treatment of NPP liquid radwaste. Thereinto, cesium and cobalt are typical cationic ones. Currently, ion exchange process is widely used in liquid radwaste treatment system (WLS) of NPP, wherein resin plays a key role. The paper reviewed the research progress on adsorption of cesium and cobalt existed in NPP liquid radwaste using ion exchange resin. (authors)

Sorptive Removal of Cesium and Cobalt Ions in a Fixed bed Column Using Lewatit S100 Cation Exchange Resin

International Nuclear Information System (INIS)

El-Naggar, M.R.; Ibrahim, H.A.; El-Kamash, A.M.

2014-01-01

The sorptive removal of cesium and cobalt ions from aqueous solutions in a fixed bed column packed with Lewatit S100® cation exchange resin has been investigated. A preliminary batch studies were performed to estimate the effect of pH and contact time on the sorption process. Results indicated that Cs + and Co 2+ could be efficiently removed using Lewatit S100® at a ph range of 4-7 with more affinity towards Cs than Co 2+ . Kinetic models have been applied to the sorption rate data and the relevant parameters were determined. The obtained results indicated that the sorption of both Cs + and Co 2+ on Lewatit S100 followed pseudo second-order rather than pseudo first-order or Morris-Webber model. Fixed bed experiments were conducted at a constant initial concentration of 100 mg/l whereas the effect of bed depth (3, 4.5 and 6 cm) and volumetric flow rate (3 and 5 ml/min.) on the breakthrough characteristics of the fixed bed sorption systems were determined. The experimental sorption data were fitted to the well-established column models namely; Thomas and BDST models to compute the different model parameters. The higher column sorption capacities were obtained at bed depth of 3 cm with a flow rate of 3 ml/min., for both Cs + and Co 2+ . The BDST model appeared to describe experimental results better than Thomas model. Results indicate that Lewatit S100® is an efficient material for the removal of cesium and cobalt ions from aqueous solutions.

Removal of cesium using coconut fiber in raw and modified forms for the treatment of radioactive liquid wastes

International Nuclear Information System (INIS)

Jesus, Nella N.M. de; Nobre, Vanessa B.; Potiens Junior, Ademar J.; Sakata, Solange K.; Di Vitta, Patricia B.

2013-01-01

Sorption is one of the most studied methods to reduce the volume of radioactive waste streams. Cesium-137 is a radioisotope formed by the fission of uranium and it can cause health problems due to its easy assimilation by cells. The aim of this study is to evaluate the potential of coconut fiber in removing cesium from radioactive liquid wastes; this process can help in disposing radioactive waste. The experiments were performed in batch and the particle size of the fiber ranged between 0.30 mm and 0.50 mm. The fiber was treated with hydrogen peroxide in alkaline medium. The following parameters were analyzed: contact time, pH and concentration of cesium ions in aqueous solution. After the experiments the samples were filtered and cesium remaining in solution was quantified by inductively coupled plasma optical emission spectrometry. (author)

Removal of cesium using coconut fiber in raw and modified forms for the treatment of radioactive liquid wastes

Energy Technology Data Exchange (ETDEWEB)

Jesus, Nella N.M. de; Nobre, Vanessa B.; Potiens Junior, Ademar J.; Sakata, Solange K., E-mail: sksakata@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Di Vitta, Patricia B. [Universidade de Sao Paulo (USP), SP (Brazil). Instituto de Quimica

2013-07-01

Sorption is one of the most studied methods to reduce the volume of radioactive waste streams. Cesium-137 is a radioisotope formed by the fission of uranium and it can cause health problems due to its easy assimilation by cells. The aim of this study is to evaluate the potential of coconut fiber in removing cesium from radioactive liquid wastes; this process can help in disposing radioactive waste. The experiments were performed in batch and the particle size of the fiber ranged between 0.30 mm and 0.50 mm. The fiber was treated with hydrogen peroxide in alkaline medium. The following parameters were analyzed: contact time, pH and concentration of cesium ions in aqueous solution. After the experiments the samples were filtered and cesium remaining in solution was quantified by inductively coupled plasma optical emission spectrometry. (author)

Development of a new all solid contact Cs"+ ion selective electrode

International Nuclear Information System (INIS)

Ramanjaneyulu, P.S.; Abha Naveen Kumar; Sharma, M.K.

2017-01-01

Studies were carried out to develop all solid contact cesium ion selective electrode with 25,27-bis(1-octyloxy)calix[4]arene-crown-6 as an ionophore. Polyaniline (PANI), deposited on Pt electrode by electrochemical method, was used as a transducer. Three different types of electrodes were made with variation in thickness of PANI film and gold nanoparticles doped PANI as transducers. The best response was observed with ISE having Au nanoparticles doped PANI as a transducer. The optimised ISE gave Nernstian response in the range 10"-"7 to 10"-"2 M with the slope of 55.0 ± 0.6 mV/decade of Cs"+. The response of ISE for Cs"+ is fairly constant above the pH 4. The developed ISE was successfully employed to determine Cs"+ in simulated high level nuclear waste solutions and CsCl spiked tap water samples. (author)

Lithium, rubidium and cesium ion removal using potassium iron(III) hexacyanoferrate(II) supported on polymethylmethacrylate

International Nuclear Information System (INIS)

Shabana Taj; Din Muhammad; Ashraf Chaudhry, M.; Muhammad Mazhar

2011-01-01

Potassium iron(III) hexacyanoferrate(II) supported on poly methyl methacrylate, has been developed and investigated for the removal of lithium, rubidium and cesium ions. The material is capable of sorbing maximum quantities of these ions from 5.0, 2.5 and 4.5 M HNO 3 solutions respectively. Sorption studies, conducted individually for each metal ion, under optimized conditions, demonstrated that it was predominantly physisorption in the case of lithium ion while shifting to chemisorption with increasing ionic size. Distribution coefficient (K d ) values followed the order Cs + > Rb + > Li + at low concentrations of metal ions. Following these findings Cs + can preferably be removed from 1.5 to 5 M HNO 3 nuclear waste solutions. (author)

Cesium removal flow studies using ion exchange

International Nuclear Information System (INIS)

Lee, D.D.; Walker, J.F. Jr.; Taylor, P.A.

1997-01-01

Cesium and strontium radionuclides are a small fraction of the mainly sodium and potassium salts in underground storage tank supernatant at US Department of Energy (DOE) sites at Hanford, Oak Ridge, Savannah River, and Idaho that DOE must remediate. Cesium-137 ( 137 Cs) is the primary gamma radiation source in the dissolved tank waste at these sites, and its removal from the supernatant can reduce the hazard and waste classification of the treated waste reducing the further treatment and disposal costs. Several cesium removal sorbents have been developed by private industry and the US DOE's Office of Science and Technology. Several of these removal technologies have been previously tested in small batch and column tests using simulated and a few actual supernatant under DOE's Environmental Management (EM) programs including the Tanks Focus Area (TFA) and the Efficient Separations and Processing (ESP) Cross-Cutting Program

A new ion selective electrode for cesium (I) based on calix[4]arene-crown-6 compounds.

Science.gov (United States)

Ramanjaneyulu, P S; Kumar, Abha Naveen; Sayi, Y S; Ramakumar, K L; Nayak, S K; Chattopadhyay, S

2012-02-29

A polyvinylchloride (PVC) based liquid membrane ion selective electrode (ISE) for cesium has been developed. 25,27-Dihydroxycalix[4]arene-crown-6 (L1), 5,11,17,23-tetra-tert-butyl-25,27-dimethoxycalix[4]arene-crown-6 (L2) and 25,27-bis(1-octyloxy)calix[4]arene-crown-6 (L3) were investigated for their use as ionophores. The cation exchange resin DOWEX-50W was used to maintain low activity Cs+ in inner filling solution to improve the performance. The best response for cesium was observed with L3 along with optimized membrane constituents and composition. Excellent Nernstian response (56.6 mV/decade of Cs(I)) over the concentration range 10(-7) to 10(-2)M of Cs(I) was obtained with a fast response time of less than 10s. Detection limit for Cs(I) using the present ISE is 8.48×10(-8) M Cs(I). Separate solution method (SSM) was applied to ascertain the selectivity for Cs(I) over alkali, alkaline earth and transition metal ions. The response of ISE for Cs(I) was fairly constant over the pH range of 4-11. The lifetime of the electrode is 10 months which is the highest life for any membrane based Cs-ISE so far developed. The concentration of cesium ion in two simulated high level active waste streams was determined and results agreed well with those obtained independently employing AAS. Copyright © 2011 Elsevier B.V. All rights reserved.

Recognition and extraction of cesium hydroxide and carbonate by using a neutral multitopic ion-pair receptor

Energy Technology Data Exchange (ETDEWEB)

He, Qing; Peters, Gretchen Marie; Lynch, Vincent M.; Sessler, Jonathan L. [Department of Chemistry, University of Texas, Austin, TX (United States)

2017-10-16

Current approaches to lowering the pH of basic media rely on the addition of a proton source. An alternative approach is described herein that involves the liquid-liquid extraction-based removal of cesium salts, specifically CsOH and Cs{sub 2}CO{sub 3}, from highly basic media. A multitopic ion-pair receptor (2) is used that can recognize and extract the hydroxide and carbonate anions as their cesium salts, as confirmed by {sup 1}H NMR spectroscopic titrations, ICP-MS, single-crystal structural analyses, and theoretical calculations. A sharp increase in the pH and cesium concentrations in the receiving phase is observed when receptor 2 is employed as a carrier in U-tube experiments involving the transport of CsOH through an intervening chloroform layer. The pH of the source phase likewise decreases. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

Secondary emission of negative ions and electrons resulting from electronic sputtering of cesium salts

International Nuclear Information System (INIS)

Allali, H.; Nsouli, B.; Thomas, J.P.

1993-04-01

Secondary ion emission of negative ions and electrons from alkali salts bombarded with high energy (9 MeV) Ar +++ is discussed. Quite different features are observed according to the nature of the salt investigated (halide or oxygenated). In the case of cesium, the electron emission from halides is characterized by intense electron showers (several hundred electrons) with narrow distributions in intensity and orientation. Conversely, for oxygenated salts, these distributions are broader, much less intense (one order of magnitude), and the ion emission exhibits an dissymmetry, which has never been observed for inorganics. This last result is interpreted in terms of radiolysis of the oxygenated salt, a process well documented for gamma-ray irradiation, but not yet reported in secondary ion emission. (author) 17 refs.; 10 figs

Numerical study of cesium effects on negative ion production in volume H-and D- ion sources

International Nuclear Information System (INIS)

Fukumasa, Osamu; Niitani, Eiji; Yoshino, Kyougo

1997-01-01

We present the results of model calculation on H - /D - isotope effects in the tandem volume source. The model includes the surface production due to cesium injection. On the electron density n e dependence of H - /D - production, we have observed an interesting phenomena. Namely D - production, i.e D - density, is higher than H - production in low n e , but in high n e H - production is higher than D - production. The atomic density plays an important role in the density inversion between H - and D - ions. (author)

Chemical and radiation stability of SuperLig reg-sign 644, resorcinol-formaldehyde, and CS-100 cesium ion exchange materials

International Nuclear Information System (INIS)

Brown, G.N.; Adami, S.R.; Bray, L.A.

1995-09-01

At the request of the Initial Pretreatment Module Project within Westinghouse Hanford Company, Pacific Northwest Laboratory (PNL) conducted this study for the Efficient Separations and Processing Crosscutting Program (ESP) under the task ''Develop and Test Sorbents.'' The purpose of the study was to assess and compare the chemical and radiolytic stability of several cesium-selective ion exchange materials in simulated alkaline Hanford tank waste matrices. Pretreatment of nuclear process wastes to remove of cesium and other radionuclides by ion exchange was proposed previously as one method of minimizing the amount of high-level radioactive waste at Hanford. In this study, PNL evaluated three cesium-selective materials SuperLig reg-sign 644, resorcinol-formaldehyde (R-F), and CS-100 for chemical and radiation stability in 1 M NaOH and a simulated neutralized current acid waste (NCAW). The objective of the study is to investigate the stability of the newly produced SuperLig reg-sign 644 under a variety of conditions in an attempt to simulate and predict the degradation process. The following specific conclusions and recommendations resulted from the study

Chemical and radiation stability of SuperLig{reg_sign}644, resorcinol-formaldehyde, and CS-100 cesium ion exchange materials

Energy Technology Data Exchange (ETDEWEB)

Brown, G.N.; Adami, S.R.; Bray, L.A. [and others

1995-09-01

At the request of the Initial Pretreatment Module Project within Westinghouse Hanford Company, Pacific Northwest Laboratory (PNL) conducted this study for the Efficient Separations and Processing Crosscutting Program (ESP) under the task ``Develop and Test Sorbents.`` The purpose of the study was to assess and compare the chemical and radiolytic stability of several cesium-selective ion exchange materials in simulated alkaline Hanford tank waste matrices. Pretreatment of nuclear process wastes to remove of cesium and other radionuclides by ion exchange was proposed previously as one method of minimizing the amount of high-level radioactive waste at Hanford. In this study, PNL evaluated three cesium-selective materials SuperLig{reg_sign}644, resorcinol-formaldehyde (R-F), and CS-100 for chemical and radiation stability in 1 M NaOH and a simulated neutralized current acid waste (NCAW). The objective of the study is to investigate the stability of the newly produced SuperLig{reg_sign}644 under a variety of conditions in an attempt to simulate and predict the degradation process. The following specific conclusions and recommendations resulted from the study.

Sorption kinetics of cesium on hydrous titanium dioxide

International Nuclear Information System (INIS)

Altas, Y.; Tel, H.; Yaprak, G.

2003-01-01

Two types of hydrous titanium dioxide possessing different surface properties were prepared and characterized to study the sorption kinetics of cesium. The effect of pH on the adsorption capacity were determined in both type sorbents and the maximum adsorption percentage of cesium were observed at pH 12. To elucidate the kinetics of ion-exchange reaction on hydrous titanium dioxide, the isotopic exchange rates of cesium ions between hydrous titanium dioxides and aqueous solutions were measured radiochemically and compared with each other. The diffusion coefficients of Cs + ion for Type1 and Type2 titanium dioxides at pH 12 were calculated as 2.79 x 10 -11 m 2 s -1 and 1.52 x 10 -11 m 2 s -1 , respectively, under particle diffusion controlled conditions. (orig.)

Ion exchange removal of cesium from Hanford tank waste supernates with SuperLigR 644 resin

International Nuclear Information System (INIS)

Hassan, N.M.; McCabe, D.J.; King, W.D.; Hamm, L.L.

2002-01-01

SuperLig R 644 ion exchange resin is currently being evaluated for cesium ( 137 Cs) removal from radioactive Hanford tank waste supernates as part of the River Protection Project. Testing was performed with actual Hanford tank wastes of widely different compositions using two identical ion exchange columns connected in series each containing approximately 5.5-6.5 ml of SuperLig R 644 resin. The ion exchange columns utilized the same resin material that was eluted between the column tests. This was done to demonstrate the performance of the SuperLig R 644 resin for cesium removal from waste samples of different compositions, determine the loading and elution profiles, and to validate design assumptions for full-scale column performances. Decontaminated product solutions generated at the same operating temperature and constant residence times (bed volumes per hour) exhibited the same chemical compositions as their feed samples. The compositions of eluate solutions were generally as expected with the exception of uranium and total organic carbon, which where concentrated by the resin. Development of a pretreatment method for the SuperLig R 644 resin has been critical to successful column operation with different waste solutions. (author)

Conceptual design of cesium removal device for ITER NBI maintenance

Energy Technology Data Exchange (ETDEWEB)

Oka, Kiyoshi; Shibanuma, Kiyoshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

2003-03-01

Cesium is required in order to generate a stable negative ion of hydrogen in an ion source of the neutral beam injector (NBI), which is one of the plasma-heating devices for International Thermonuclear Experimental Reactor (ITER). After long time operation of the NBI, the cesium deposits to the insulators supporting the electrode. Due to the deterioration of the insulation resistance, the continuous operation of the NBI will be difficult. In addition, the NBI device is activated by neutrons from D-T plasma, so that periodic removal and cleaning of the cesium on the insulators by remove handling is required. A study of the cesium removal scenario and the device is therefore required considering remote handling. In this report, a cesium removal procedure and conceptual design of the cesium removal device using laser ablation technique are studied, and the feasibility of the laser ablation method is shown. (author)

Evaluating Effects from Contacting Superlig(R) 644 Resin with Sodium Permanganate

International Nuclear Information System (INIS)

Crooks, W.J. III

2002-01-01

This work simulates the inadvertent transfer of 1M sodium permanganate solution into the lead cesium ion exchange column containing SuperLig(R) 644 resin. The effects of contacting 1 molar sodium permanganate with SuperLig(R) 644 are characterized using the Advanced Reactive System Screening Tool

Numerical study of cesium effects on negative ion production in volume sources

Energy Technology Data Exchange (ETDEWEB)

Fukumasa, Osamu; Niitani, Eiji [Yamaguchi Univ., Ube (Japan). Faculty of Engineering

1997-02-01

Effects of cesium vapor injection of H{sup -} production in a tandem negative ion source are studied numerically as a function of plasma parameters. Model calculation is done by solving a set of particle balance equations in a steady-state hydrogen discharge plasmas. Here, the results which focus on gas pressure and electron temperature dependences of H{sup -} volume production are presented and discussed. With including H{sup -} surface production processes caused by both H atoms and positive hydrogen ions, enhancement of H{sup -} production and pressure dependence of H{sup -} production observed experimentally are well reproduced in the model. To enhance H{sup -} production, however, so-called electron cooling is not so effective if plasma parameters are initially optimized with the use of magnetic filter. (author)

Cesium removal using crystalline silicotitanate. Innovative technology summary report

International Nuclear Information System (INIS)

1999-05-01

Approximately 100 million gallons of radioactive waste is stored in underground storage tanks at the Hanford Site, Idaho National Engineering and Environmental Laboratory (INEEL), Oak Ridge Reservation, and Savannah River Site (SRS). Most of the radioactivity comes from 137 Cs, which emits high-activity gamma radiation. The Cesium Removal System is a modular, transportable, ion-exchange system configured as a compact processing unit. Liquid tank waste flows through columns packed with solid material, called a sorbent, that selectively adsorbs cesium and allows the other materials to pass through. The sorbent is crystalline silicotitanate (CST), an engineered material with a high capacity for sorbing cesium from alkaline wastes. The Cesium Removal System was demonstrated at Oak Ridge using Melton Valley Storage Tank (MVST) waste for feed. Demonstration operations began in September 1996 and were completed during June 1997. Prior to the demonstration, a number of ion-exchange materials were evaluated at Oak Ridge with MVST waste. Also, three ion-exchange materials and three waste types were tested at Hanford. These bench-scale tests were conducted in a hot cell. Hanford's results showed that 300 times less sorbent was used by selecting Ionsiv IE-911 over organic ion-exchange resins for cesium removal. This paper gives a description of the technology and discusses its performance, applications, cost, regulatory and policy issues and lessons learned

Studies of equilibrium and kinetics of adsorption of cesium ions by graphene oxide

International Nuclear Information System (INIS)

Oliveira, Fernando M.; Bueno, Vanessa N.; Oshiro, Maurício T.; Potiens Junior, Ademar J.; Hiromoto, Goro; Sakata, Solange K.; Rodrigues, Debora F.

2017-01-01

Cesium is one of the fission products of major radiological concern, it is often found in nuclear radioactive waste generated at nuclear power plants. Graphene Oxide (GO) has attracted great attention due to its functionalized surface, which includes hydroxyl, epoxy, carbonyl and carboxyl groups, with great capacity of complexation with metal ions and can be used as adsorbent to remove cations from aqueous solutions. In this work, a treatment of radioactive waste containing 137 Cs was studied. For the batch experiments of Cs + removal, 133 Cs concentrations remained after the adsorption were determined by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) and the results obtained were analyzed according to the Langmuir and Freundlich isotherms models. The kinetics of adsorption and Gibbs free energy were also determined. The Langmuir model was the best fit and defined a favorable adsorption. The cesium adsorption process is the pseudo-second model and the Gibbs free energy calculation indicated that the adsorption process is spontaneous. (author)

Studies of equilibrium and kinetics of adsorption of cesium ions by graphene oxide

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Fernando M.; Bueno, Vanessa N.; Oshiro, Maurício T.; Potiens Junior, Ademar J.; Hiromoto, Goro; Sakata, Solange K., E-mail: fmoliveira@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil); Rodrigues, Debora F., E-mail: dfrigiro@central.uh.edu [Department of Civil and Environmental Engineering, University of Houston, TX (United States)

2017-07-01

Cesium is one of the fission products of major radiological concern, it is often found in nuclear radioactive waste generated at nuclear power plants. Graphene Oxide (GO) has attracted great attention due to its functionalized surface, which includes hydroxyl, epoxy, carbonyl and carboxyl groups, with great capacity of complexation with metal ions and can be used as adsorbent to remove cations from aqueous solutions. In this work, a treatment of radioactive waste containing {sup 137}Cs was studied. For the batch experiments of Cs{sup +} removal, {sup 133}Cs concentrations remained after the adsorption were determined by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) and the results obtained were analyzed according to the Langmuir and Freundlich isotherms models. The kinetics of adsorption and Gibbs free energy were also determined. The Langmuir model was the best fit and defined a favorable adsorption. The cesium adsorption process is the pseudo-second model and the Gibbs free energy calculation indicated that the adsorption process is spontaneous. (author)

Hot tungsten plate based ionizer for cesium plasma in a multi-cusp field experiment

International Nuclear Information System (INIS)

Patel, Amitkumar D.; Sharma, Meenakshee; Ramasubramanian, Narayanan; Chattopadhyay, Prabal K.

2015-01-01

In a newly proposed basic experiment, contact-ionized cesium ions will be confined by a multi cups magnetic field configuration. The cesium ion will be produced by impinging collimated neutral atoms on an ionizer consisting of the hot tungsten plate. The temperature of the tungsten plate will also be made high enough (∼2700 K) such that it will contribute electrons also to the plasma. It is expected that at this configuration the cesium plasma would be really quiescent and would be free from even the normal drift waves observed in the classical Q-machines. For the ionizer a design based on F. F. Chen's design was made. This ionizer is very fine machining and exotic material like Tungsten plate, Molybdenum screws, rings, and Boron Nitride ceramics etc. The fine and careful machining of these materials was very hard. In this paper, the experience about to join the tungsten wire to molybdenum plate and alloy of tantalum and molybdenum ring is described. In addition experimental investigations have been made to measure 2D temperature distribution profile of the Tungsten hot plate using infrared camera and the uniformity of temperature distribution over the hot plate surface is discussed. (author)

Desorption of cesium ions from vermiculite with sea water by hydrothermal process

International Nuclear Information System (INIS)

Yin, Xiangbiao; Takahashi, Hideharu; Inaba, Yusuke; Takeshita, Kenji

2016-01-01

Cesium ions (Cs + ) strongly intercalated in vermiculite clay (Verm) had been effectively removed using sea water for its free utility, totally environmental friendly feature, and within containing numerous salt by the hydrothermal treatment process (HTT), which can help significantly promote desorption by the cation-exchange mechanism in subcritical condition. >74-100% removal was achieved to the interacted Cs + for a loading capacity of 4.8-50 mg g −1 . XRD results indicated that cation exchange proceeded between the intercalated Cs + and various cations in sea water during HTT. (author)

Cesium separation using integrated electro-membrane technique

International Nuclear Information System (INIS)

Fors, Patrik; Lillfors-Pintér, Christina; Widestrand, Henrik; Velin, Anna; Bengtsson, Bernt

2014-01-01

Conventional separation technologies such as ion exchange, electro-deionisation and cross flow filtration are not always effective to eliminate nuclides, which are weekly ionised, complexed or hydrated in effluents. Specific nuclide selective absorbers perform well for the treatment of active and contaminated wastewaters but most absorbers generate additional waste while treating high volumes of contaminated water and often show limitations in operating at high flow rates. Electrochemical Ion Exchange (EIX) and EIX in combination with absorbers may offer an alternative solution that overcomes those limitations. This paper reports on the optimization and performance of the integrated technique EIX, for the treatment of low activity effluents that contain cesium and other nuclides. The three-compartment EIX system, which operates with authentic reactor coolant with enhanced nuclide content, indicates high, over 90%, elimination of cesium in a single pass operation mode. With the in-situ and instant ion exchange regeneration, the system successfully reduces the activity from an initial range of 400-2600 Bq/kg to close to detection limit at a velocity of 10-15 cm/min. The applied current density varies between 50-200 mA/cm 2 and the mass balance is close to 100%. During the process, the eliminated cesium and other nuclides are concentrated up to the limits where reverse migration from the concentrated chamber occurs. The concentrate could then be treated with specific absorbents at low flow rates. EIX in combination with cesium-selective ion exchanger CsTreat ® separates the cesium-137 efficiently, but up to now the process does not perform according to EIX principles for the treatment of low grade radioactive wastewaters it rather performs as an irreversible adsorber. The aim with the outcome of the presently ongoing long-term tests is to further support the Best Available Technique Minimizing All Nuclide (BATMAN) projects of Vattenfall NPPs. (author)

Experimental and numerical investigation of ion signals in boosted HCCI combustion using cesium and potassium acetate additives

International Nuclear Information System (INIS)

Mack, J. Hunter; Butt, Ryan H.; Chen, Yulin; Chen, Jyh-Yuan; Dibble, Robert W.

2016-01-01

Highlights: • HCCI engine experiments show that CsOAc and KOAc additives increased the ion SNR. • The ion signal is more apparent at higher equivalence ratios. • An increase in intake pressure produces a decrease in the ion signal. • Use of metal acetates as additives yielded reductions in IMEP g and maximum ROHR. • A numerical model predicted peak ion signal, CA50, and p intake dependence. - Abstract: A sparkplug ion sensor can be used to measure the ion current in a homogeneous charge compression ignition (HCCI) engine, providing insight into the ion chemistry inside the cylinders during combustion. HCCI engines typically operate at lean equivalence ratios (ϕ) at which the ion current becomes increasingly indistinguishable from background noise. This paper investigates the effect of fuel additives on the ion signal at low equivalence ratios, determines side effects of metal acetate addition, and validates numerical model for ionization chemistry. Cesium acetate (CsOAc) and potassium acetate (KOAc) were used as additives to ethanol as the primary fuel. Concentration levels of 100, 200, and 400 mg/L of metal acetate-in-ethanol are investigated at equivalence ratios of 0.08, 0.20, and 0.30. The engine experiments were conducted at a boosted intake pressure of 1.8 bar absolute and compared to naturally aspirated results. Combustion timing was maintained at 2.5° after top-dead-center (ATDC), as defined by the crank angle degree (CAD) where 50% of the cumulative heat release occurs (CA50). CsOAc consistently produced the strongest ion signals at all conditions when compared to KOAc. The ion signal was found to decrease with increased intake pressure; an increase in the additive concentration increased the ion signal for all cases. However, the addition of the metal acetates decreased the gross indicated mean effective pressure (IMEP g ), maximum rate of heat release (ROHR), and peak cylinder pressure. Experimental results were used to validate ion chemistry

Copper ferrocyanide - polyurethane foam as a composite ion exchanger for removal of radioactive cesium

International Nuclear Information System (INIS)

Rao, S.V.S.; Lal, K.B.; Ahmed, J.; Narasimhan, S.V.

1999-01-01

A method has been developed for the removal of cesium from the aqueous radioactive waste using a composite ion-exchanger consisting of Copper-Ferrocyanide Powder (CFC) and Polyurethane (PU) Foam. Polyvinyl acetate has been used as a binder in the preparation of CFC-PU foam. The physical properties of CFC such as density, surface area, IR stretching frequency and lattice parameters have been evaluated and also its potassium and copper(II) content have been estimated. Optimization of loading of CFC on PU foam has been studied. The CFC-PU was viewed under microscope to find out the homogeneity of distribution. Exchange capacities of the CFC-PU foam in different media have been determined and column studies have been carried out. Studies have been undertaken on extraction of cesium from CFC foam and also on digestion of spent CFC-PU foam and immobilization of digested solution in cement matrix. The cement matrices have been characterized with respect to density, bio-resistance and leaching resistance. (author)

Cesium-137 uptake studies on ammonium phospho molybdate irradiated with electrons

International Nuclear Information System (INIS)

Rao, K.L.N.; Balasubramanian, K.R.; Shukla, J.P.

1992-01-01

Ammonium phospho molybdate is an important inorganic ion exchanger having high selectivity for cesium. This paper discusses the effects of electron irradiation to a dose of 1 mGy on this exchanger with special reference to its ion exchange performance using cesium-137 as a tracer. An explanation is attempted for the slight increase in the distribution coefficients. (author). 5 refs., 1 tab

THERMIONIC EMISSION ENHANCEMENT FROM CESIUM COATED RHENIUM IN ELECTRIC FIELDS

Energy Technology Data Exchange (ETDEWEB)

de Steese, J. G.; Zollweg, R. J.

1963-04-15

The plasma-anode technique was used to observe anomalously high thermionic emission from a rhenium surface with small cesium coverage, where the work function of the composite surface is greater than the ionization potential of cesium. Data suggest that emission enhancement is caused by increased cesium coverage because of cesiumion trapping near the emitter surface under the influence of an ion-rich sheath. (auth)

Room temperature deposition of crystalline indium tin oxide films by cesium-assisted magnetron sputtering

International Nuclear Information System (INIS)

Lee, Deuk Yeon; Baik, Hong-Koo

2008-01-01

Indium tin oxide (ITO) films were deposited on a Si (1 0 0) substrate at room temperature by cesium-assisted magnetron sputtering. Including plasma characteristics, the structural, electrical, and optical properties of deposited films were investigated as a function of cesium partial vapor pressure controlled by cesium reservoir temperature. We calculated the cesium coverage on the target surface showing maximum formation efficiency of negative ions by means of the theoretical model. Cesium addition promotes the formation efficiency of negative ions, which plays important role in enhancing the crystallinity of ITO films. In particular, the plasma density was linearly increased with cesium concentrations. The resultant decrease in specific resistivity and increase in transmittance (82% in the visible region) at optimum cesium concentration (4.24 x 10 -4 Ω cm at 80 deg. C of reservoir temperature) may be due to enhanced crystallinity of ITO films. Excess cesium incorporation into ITO films resulted in amorphization of its microstructure leading to degradation of ITO crystallinity. We discuss the cesium effects based on the growth mechanism of ITO films and the plasma density

Uptake behavior of titanium molybdophosphate for cesium and strontium

International Nuclear Information System (INIS)

Yavari, R.; Ahmadi, S.J.; Huang, Y.D.

2010-01-01

This study investigates uptake of cesium and strontium from aqueous solution similar to nuclear waste on three samples of titanium molybdophosphate (TMP) synthesized under various conditions. Effects of concentration of sodium nitrate, pH and contact time on the uptake of cesium and strontium have been studied by bath method. The results showed that TMP has high affinity toward cesium and strontium at pH > 2 and relatively low concentration of sodium nitrate. Kinetic data indicated that cesium uptake process to achieve equilibrium was faster than strontium. Cesium and strontium breakthrough curves were examined at 25 deg C using column packed with H 3 O + form of TMP and breakthrough curves showed symmetrical S-shaped profiles. At the same time, the calculated breakthrough capacity for cesium was higher than strontium. The results of desorption studies showed that over 99% of cesium and strontium was washed out of column by using 4 M NH 4 Cl solution. This study suggests that TMP can have great potential applications for the removal of strontium and specially cesium from nuclear waste solution. (author)

Cesium heat-pipe thermostat

Energy Technology Data Exchange (ETDEWEB)

Wu, F.; Song, D.; Sheng, K.; Wu, J. [Changcheng Institute of Metrology and Measurement, 100095, Beijing (China); Yi, X. [China National South Aviation industry CO., LTD., 412002, Hunan (China); Yu, Z. [Dalian Jinzhou Institute of Measurement and Testing, 116100, Liaoning (China)

2013-09-11

In this paper the authors report a newly developed Cesium Heat-Pipe Thermostat (Cs HPT) with the operation range of 400 °C to 800 °C. The working medium is cesium (Cs) of 99.98% purity and contains no radioisotope. A Cs filing device is developed which can prevent Cs being in contact with air. The structural material is stainless steel. A 5000 h test has been made to confirm the compatibility between cesium and stainless steel. The Cs HPT has several thermometer wells of 220mm depth with different diameters for different sizes of thermometers. The temperature uniformity of the Cs HPT is 0.06 °C to 0.20 °C. A precise temperature controller is used to ensure the temperature fluctuation within ±0.03 °C. The size of Cs HPT is 380mm×320mm×280mm with foot wheels for easy moving. The thermostat has been successfully used for the calibration of industrial platinum resistance thermometers and thermocouples.

Desorption of radioactive cesium by seawater from the suspended particles in river water.

Science.gov (United States)

Onodera, Masaki; Kirishima, Akira; Nagao, Seiya; Takamiya, Kouichi; Ohtsuki, Tsutomu; Akiyama, Daisuke; Sato, Nobuaki

2017-10-01

In 2011, the accident at the Fukushima-Daiichi nuclear power plant dispersed radioactive cesium throughout the environment, contaminating the land, rivers, and sea. Suspended particles containing clay minerals are the transportation medium for radioactive cesium from rivers to the ocean because cesium is strongly adsorbed between the layers of clay minerals, forming inner sphere complexes. In this study, the adsorption and desorption behaviors of radioactive cesium from suspended clay particles in river water have been investigated. The radioactive cesium adsorption and desorption experiments were performed with two kinds of suspended particulate using a batch method with 137 Cs tracers. In the cesium adsorption treatment performed before the desorption experiments, simulated river water having a total cesium concentration ([ 133+137 Cs + ] total ) of 1.3 nM (10 -9  mol/L) was used. The desorption experiments were mainly conducted at a solid-to-liquid ratio of 0.17 g/L. The desorption agents were natural seawater collected at 10 km north of the Fukushima-Daiichi nuclear power plant, artificial seawater, solutions of NaCl, KCl, NH 4 Cl, and 133 CsCl, and ultrapure water. The desorption behavior, which depends on the preloaded cesium concentration in the suspended particles, was also investigated. Based on the cesium desorption experiments using suspended particles, which contained about 1000 ng/g loaded cesium, the order of cesium desorption ratios for each desorption agent was determined as 1 M NaCl (80%) > 470 mM NaCl (65%) > 1 M KCl (30%) ≈ seawater (natural seawater and Daigo artificial seawater) > 1 M NH 4 Cl (20%) > 1 M 133 CsCl (15%) ≫ ultrapure water (2%). Moreover, an interesting result was obtained: The desorption ratio in the 470 mM NaCl solution was much higher than that in seawater, even though the Na + concentrations were identical. These results indicate that the cesium desorption mechanism is not a simple ion exchange reaction

Phase separation of cesium from lead borosilicate glass by heat treatment under a reducing atmosphere

Energy Technology Data Exchange (ETDEWEB)

Xu, Zhanglian; Okada, Takashi, E-mail: t-okada@u-fukui.ac.jp; Nishimura, Fumihiro; Yonezawa, Susumu

2016-11-05

Highlights: • Cesium was phase separated from lead borosilicate glass under a reductive atmosphere. • The phase separation occurred on the glass surface that was in contact with the gas. • The leachability of cesium was enhanced by the phase separation. • The degree of such enhancement varied depending on the heat treatment conditions. - Abstract: A phase-separation technique for removing sodium from glass using a heat-treatment method under a reducing atmosphere was previously developed for sodium recovery from waste glass. In this study, this technique was applied to cesium-containing lead borosilicate glass to concentrate the cesium in phase-separated sodium-rich materials for efficient cesium extraction. The theoretical phase-separation temperature of the sodium-rich phase was simulated by thermodynamic equilibrium calculations and was predicted to occur below 700 °C for lead borosilicate glass. Experimentally, a simulated lead borosilicate glass was melted at 1000 °C and subsequently annealed below 700 °C under a CO-containing reducing atmosphere. The phase separation of cesium was found to occur with sodium enrichment on the glass surface that was in contact with the gas phase, promoting cesium extraction from the treated glass using water. The cesium extraction efficiency was affected by the surface area of the treated glass that was in contact with water, and under the examined conditions, the cesium extraction efficiency was up to 66%. Phase separation using reductive heat treatment, combined with a water leaching technique, is suggested to be effective for extracting cesium incorporated in borosilicate glass waste.

New Calix[4]arene dibenzocrown ethers for selective sensing of cesium ion in aqueous environment

International Nuclear Information System (INIS)

Kim, Jong Seung; Kim, Jong Kuk; Choi, Wang Kyu; Lee, Kune Woo; Oh, Won Jin

1997-01-01

1,3-dialkoxycalix[4]arene dibenzocrown ethers (6-9) were successfully synthesized in the fixed 1,3-alternate conformation with over 90% yields by the reaction of corresponding 1,3dialkoxycalix[4]arenes 2-5 with dibenzodimesylate 13 in acetonitrile as a solvent in the presence of cesium carbonate as a base. In view of cyclization yield, the use of dimesylate is found to be better than that of dibenzoditosylate. With an unusual AB pattern in 1 H NMR spectrum for compound 9, it is suggested that conformational structure of 1,3-diallyloxycalix[4]arene dibenzocrown ether be less flexible than that of usual 1,3-alternate calixcrown ether, probably due to steric effects of two ally1 group. Complexation of the corresponding calix[4]arene 6-9 toward alkali metal ions using single flux method through bulk liquid membrane system was found to give a high cesium selectivity. 28 refs., 1 tab., 1 fig

New Calix[4]arene dibenzocrown ethers for selective sensing of cesium ion in aqueous environment

Energy Technology Data Exchange (ETDEWEB)

Kim, Jong Seung; Kim, Jong Kuk [Konyang University, Nonsan (Korea, Republic of); Choi, Wang Kyu; Lee, Kune Woo; Oh, Won Jin [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1997-12-31

1,3-dialkoxycalix[4]arene dibenzocrown ethers (6-9) were successfully synthesized in the fixed 1,3-alternate conformation with over 90% yields by the reaction of corresponding 1,3dialkoxycalix[4]arenes 2-5 with dibenzodimesylate 13 in acetonitrile as a solvent in the presence of cesium carbonate as a base. In view of cyclization yield, the use of dimesylate is found to be better than that of dibenzoditosylate. With an unusual AB pattern in {sup 1}H NMR spectrum for compound 9, it is suggested that conformational structure of 1,3-diallyloxycalix[4]arene dibenzocrown ether be less flexible than that of usual 1,3-alternate calixcrown ether, probably due to steric effects of two ally1 group. Complexation of the corresponding calix[4]arene 6-9 toward alkali metal ions using single flux method through bulk liquid membrane system was found to give a high cesium selectivity. 28 refs., 1 tab., 1 fig.

Comparison of inorganic ion exchange materials for removing cesium, strontium, and transuranic elements from K-basin water

International Nuclear Information System (INIS)

Brown, G.N.; Bontha, J.R.; Carson, K.J.; Elovich, R.J.; DesChane, J.R.

1997-10-01

The work presented in this report was conducted by the Pacific Northwest National Laboratory (PNNL) under the Efficient Separations and Crosscutting Program (ESP), Office of Science and Technology, U.S. Department of Energy (DOE). The objective of this work was to investigate radionuclide uptake by several newly produced ion exchange materials under actual waste conditions, and to compare the performance of those materials with that of commercially available ion exchangers. The equilibrium uptake data presented in this report are useful for identifying potential materials that are capable of removing cesium and strontium from 105-KE Basin water. The data show the relative selectivities of the ion exchange materials under similar operating conditions. Additional flow studies are needed to predict material capacities and to develop complete ion exchange process flow sheets. The materials investigated in this study include commercially available ion exchangers such as IONSIV reg-sign IE-911 (manufactured by UOP), clinoptilolite (a naturally occurring zeolite), and materials produced on an experimental basis by AlliedSignal (biotites and nonatitanates), 3M (hexacyanoferrates), Selion Technologies, Inc. (hexacyanoferrates and titanates), and Texas A ampersand M University (pharmacosiderites, biotites, and nonatitanates). In all, the performance of 14 ion exchange materials was evaluated at two solution-to-exchanger mass ratios (i.e., 10 4 and 10 5 ) using actual 105-KE Basin water. Evaluation consisted of determining cesium and strontium batch distribution coefficients, loading, and decontamination factors. Actual 105-KE Basin water was obtained from a sample collected during the sludge dissolution work conducted by PNNL in FY 1996. This sample was taken from the bottom of the basin and contained significantly higher concentrations of the radioactive constituents than do samples taken from the top of the basin

Comparison of inorganic ion exchange materials for removing cesium, strontium, and transuranic elements from K-basin water

Energy Technology Data Exchange (ETDEWEB)

Brown, G.N.; Bontha, J.R.; Carson, K.J.; Elovich, R.J.; DesChane, J.R.

1997-10-01

The work presented in this report was conducted by the Pacific Northwest National Laboratory (PNNL) under the Efficient Separations and Crosscutting Program (ESP), Office of Science and Technology, U.S. Department of Energy (DOE). The objective of this work was to investigate radionuclide uptake by several newly produced ion exchange materials under actual waste conditions, and to compare the performance of those materials with that of commercially available ion exchangers. The equilibrium uptake data presented in this report are useful for identifying potential materials that are capable of removing cesium and strontium from 105-KE Basin water. The data show the relative selectivities of the ion exchange materials under similar operating conditions. Additional flow studies are needed to predict material capacities and to develop complete ion exchange process flow sheets. The materials investigated in this study include commercially available ion exchangers such as IONSIV{reg_sign} IE-911 (manufactured by UOP), clinoptilolite (a naturally occurring zeolite), and materials produced on an experimental basis by AlliedSignal (biotites and nonatitanates), 3M (hexacyanoferrates), Selion Technologies, Inc. (hexacyanoferrates and titanates), and Texas A&M University (pharmacosiderites, biotites, and nonatitanates). In all, the performance of 14 ion exchange materials was evaluated at two solution-to-exchanger mass ratios (i.e., 10{sup 4} and 10{sup 5}) using actual 105-KE Basin water. Evaluation consisted of determining cesium and strontium batch distribution coefficients, loading, and decontamination factors. Actual 105-KE Basin water was obtained from a sample collected during the sludge dissolution work conducted by PNNL in FY 1996. This sample was taken from the bottom of the basin and contained significantly higher concentrations of the radioactive constituents than do samples taken from the top of the basin.

Preparation and characterization of cesium-137 aluminosilicate pellets for radioactive source applications

International Nuclear Information System (INIS)

Schultz, F.J.; Tompkins, J.A.; Haff, K.W.; Case, F.N.

1981-07-01

Twenty-seven fully loaded 137 Cs aluminosilicate pellets were fabricated in a hot cell by the vacuum hot pressing of a cesium carbonate/montmorillonite clay mixture at 1500 0 C and 570 psig. Four pellets were selected for characterization studies which included calorimetric measurements, metallography, scanning electron microscope and electron backscattering (SEM-BSE), electron microprobe, x-ray diffraction, and cesium ion leachability measurements. Each test pellet contained 437 to 450 curies of 137 Cs as determined by calorimetric measurements. Metallographic examinations revealed a two-phase system: a primary, granular, gray matrix phase containing large and small pores and small pore agglomerations, and a secondary fused phase interspersed throughout the gray matrix. SEM-BSE analyses showed that cesium and silicon were uniformly distributed throughout both phases of the pellet. This indicated that the cesium-silicon-clay reaction went to completion. Aluminum homogeneity was unconfirmed due to the high background noise associated with the inherent radioactivity of the test specimens. X-ray diffraction analyses of both radioactive and non-radioactive aluminosilicate pellets confirmed the crystal lattice structure to be pollucite. Cesium ion quasistatic leachability measurements determined the leach rates of fully loaded 137 Cs sectioned pollucite pellets to date to be 4.61 to 34.4 x 10 -10 kg m -2 s -1 , while static leach tests performed on unsectioned fully loaded pellets showed the leach rates of the cesium ion to date to be 2.25 to 3.41 x 10 -12 kg m -2 s -1 . The cesium ion diffusion coefficients through the pollucite pellet were calculated using Fick's first and second laws of diffusion. The diffusion coefficients calculated for three tracer level 137 Cs aluminosilicate pellets were 1.29 x 10 -16 m 2 s -1 , 6.88 x 10 -17 m 2 s -1 , and 1.35 x 10 -17 m 2 s -1 , respectively

New separation techniques of cesium by redox type ion exchange materials

International Nuclear Information System (INIS)

Tanihara, Koichi

1998-01-01

RIECS method, new cesium separation method, was developed in which a porous strong base anionic exchanger with copper ferrocyanide (CuFC) and inhibitor were used. Cesium could be separated from the high concentration nitric solution. By developing new impregnation method, large amount of CuFC was impregnated into the micropolar porous resin and silica gel pores. KFC adhered to outside of pores was recovered. Good complex with CuFC was prepared by use of copper chloride in ethyl alcohol solution. The adsorption ratio of cesium increased radically to 80% level in the very small range of hydrazine concentration 1.7 to 2.4x10 -4 M. The adsorption-desorption ratio of cesium did not decrease by repeating it seven times. The glassificated materials decreased large amount of γ-ray unless increase of volume could be produced by built RIECS method in the high level waste processing system. (S.Y.)

Preliminary flowsheet: Ion exchange for separation of cesium from Hanford tank waste using resorcinol-formaldehyde resin

International Nuclear Information System (INIS)

Penwell, D.L.

1994-01-01

This preliminary flowsheet document describes an ion exchange process which uses resorcinol-formaldehyde (R-F) resin to remove cesium from Hanford tank waste. The flowsheet describes one possible equipment configuration, and contains mass balances based on that configuration with feeds of Neutralized Current Acid Waste, and Double Shell Slurry Feed. The flowsheet also discusses process alternatives, unresolved issues, and development needs associated with the ion exchange process. It is expected that this flowsheet will evolve as open issues are resolved and progress is made on development needs. This is part of the Tank Waste Remediation Program at Hanford. 26 refs, 6 figs, 25 tabs

Process for recovering cesium from cesium alum

International Nuclear Information System (INIS)

Mein, P.G.

1984-01-01

Cesium is recovered from cesium alum, CsAl(SO 4 ) 2 , by a two-reaction sequence in which the cesium alum is first dissolved in an aqueous hydroxide solution to form cesium alum hydroxide, CsAl(OH) 3 , and potassium sulfate, K 2 SO 4 . Part of the K 2 SO 4 precipitates and is separated from the supernatant solution. In the second reaction, a water-soluble permanganate, such as potassium permanganate, KMnO 4 , is added to the supernatant. This reaction forms a precipitate of cesium permanganate, CsMnO 4 . This precipitate may be separated from the residual solution to obtain cesium permanganate of high purity, which can be sold as a product or converted into other cesium compounds

METHOD FOR THE RECOVERY OF CESIUM VALUES

Science.gov (United States)

Rimshaw, S.J.

1960-02-16

A method is given for recovering Cs/sup 137/ from radioactive waste solutions together with extraneous impurities. Ammonium alum is precipitated in the waste solution. The alum, which carries the cesium, is separated from the supernatant liquid and then dissolved in water. The resulting aqueous solution is then provided with a source of hydroxyl ions, which precipitates aluminum as the hydroxide, and the aluminum hydroxide is separated from the resulting liquid. This liquid, which contains anionic impurities together with ammonium and cesium, is passed through an anion exchange resin bed which removes the anionic impurities. The ammonium in the effluent is removed by destructive distiilation, leaving a substantiaily pure cesium salt in the effluent.

Cesium immobilization into potassium magnesium phosphate matrix

International Nuclear Information System (INIS)

Sayenko, S.Y.; Shkuropatenko, V.A.; Bereznyak, O.P.; Hodyreva, Y.S.; Tarasov, R.V.; Virych, V.D.; Ulybkina, E.A.; Pylypenko, O.V.; Kholomeev, G.O.; Zykova, A.V.; Wagh, Arun S.

2017-01-01

The possibility of isomorphous substitution of potassium ions by cesium ions in the structure of potassium magnesium phosphate KMgPO 4 centred dot 6H 2 O (PMP) was shown. It was established, that the Cs included into the PMP matrix does not transfer to the environment during high temperatures heating process (1176 deg C, 3 hours). Analysis of the IR absorption spectrum of the PMP sample has demonstrated that an increase in the amount of additive of the cesium chloride resulted in the shift of the main bands in the spectrum to the low-frequency region with average shift value 10 cm -1 , which indicates the strengthening of bonds in the crystal lattice of matter. The calculated degree of substitution of potassium by cesium during energy release process in the PMP matrix at the level of vitrified high level wastes is about 4%, i. e. the PMP matrix should correspond to the formula K 0.96 Cs 0.04 MgPO 4 centred dot 6H 2 O.

Two-Step Method for Preparation of NaA-X Zeolite Blend from Fly Ash for Removal of Cesium ions

International Nuclear Information System (INIS)

El-Naggar, M.R.; El-Kamash, A.M.; El-Dessouky, M.I.; Ghonaim, A.K.

2008-01-01

Pure zeolites can be synthesized from silica extracts obtained from fly ash by alkaline leaching. The extraction potential of industrial by-product fly ash was investigated under repeated fusion process conditions. The amount of extracted silica was 131.43 g/kg ash while the amount extracted alumina was limited to 41.72 g/kg ash. The results of zeolite synthesis from the Si-bearing extracts demonstrated that pure zeolites with high cation exchange capacity (4.624 m eq/g) can be produced. The sorption potential of synthesized A-X zeolite blend for the removal of cesium ions has been investigated. The influences of ph, contact time and temperature have been reported. Thermodynamic parameters such as changes in Gibbs free energy (δG degree), enthalpy (δH degree) and entropy (δS degree) were calculated. A comparison of kinetic models applied to the sorption data was evaluated for pseudo-first order, pseudo-second order and homogeneous particle diffusion models. The results showed that both the pseudo-second order and the homogeneous particle diffusion models were found to best correlate the experimental rate data

Generation of H-, D- ions on composite surfaces with application to surface/plasma ion source systems

International Nuclear Information System (INIS)

Hiskes, J.R.; Karo, A.M.; Wimmer, E.; Freeman, A.J.; Chubb, S.R.

1983-01-01

We review some salient features of the experimental and theoretical data pertaining to hydrogen negative ion generation on minimum-work-function composite surfaces consisting of Cs/transition metal substrates. Cesium or hydrogen ion bombardment of a cesium-activated negatively-biased electrode exposed to a cesium-hydrogen discharge results in the release of hydrogen negative ions. These ions originate through desorbtion of hydrogen particles by incident cesium ions, desorbtion by incident hydrogen ions, and by backscattering of incident hydrogen. Each process is characterized by a specific energy and angular distribution. The calculation of ion formation in the crystal selvage region is discussed for different approximations to the surface potential. An ab initio, all-electron, local density functional model for the composite surface electronics is discussed

Protection of cesium-antimony photocathodes

International Nuclear Information System (INIS)

Buzulutskov, A.; Breskin, A.; Chechik, R.; Prager, M.; Shefer, E.

1996-06-01

In order to operate gaseous photomultipliers in the visible range it was suggested to protect sensitive photocathodes against contact to air and counting gases by their coating with a thin solid dielectric film. We present data on coating of cesium- antimony photocathodes with alkali-halide (NaI, CsI, CsF, NaF), oxide (SiO) and organic (hexatriacontane, calcium stearate) films. The photoelectron transmission through these films and their protection capability have been studied in detail. Cesium-antimony photocathodes are shown to withstand exposure to considerable doses of oxygen and dry air when coated with Nal films. This opens ways to their operation in gas media. (authors), 11 refs., 6 figs

Efficient removal of cesium from low-level radioactive liquid waste using natural and impregnated zeolite minerals.

Science.gov (United States)

Borai, E H; Harjula, R; Malinen, Leena; Paajanen, Airi

2009-12-15

The objective of the proposed work was focused to provide promising solid-phase materials that combine relatively inexpensive and high removal capacity of some radionuclides from low-level radioactive liquid waste (LLRLW). Four various zeolite minerals including natural clinoptilolite (NaNCl), natural chabazite (NaNCh), natural mordenite (NaNM) and synthetic mordenite (NaSM) were investigated. The effective key parameters on the sorption behavior of cesium (Cs-134) were investigated using batch equilibrium technique with respect to the waste solution pH, contacting time, potassium ion concentration, waste solution volume/sorbent weight ratio and Cs ion concentration. The obtained results revealed that natural chabazite (NaNCh) has the higher distribution coefficients and capacity towards Cs ion rather than the other investigated zeolite materials. Furthermore, novel impregnated zeolite material (ISM) was prepared by loading Calix [4] arene bis(-2,3 naphtho-crown-6) onto synthetic mordenite to combine the high removal uptake of the mordenite with the high selectivity of Calix [4] arene towards Cs radionuclide. Comparing the obtained results for both NaSM and the impregnated synthetic mordenite (ISM-25), it could be observed that the impregnation process leads to high improvement in the distribution coefficients of Cs+ ion (from 0.52 to 27.63 L/g). The final objective in all cases was aimed at determining feasible and economically reliable solution to the management of LLRLW specifically for the problems related to the low decontamination factor and the effective recovery of monovalent cesium ion.

Efficient removal of cesium from low-level radioactive liquid waste using natural and impregnated zeolite minerals

International Nuclear Information System (INIS)

Borai, E.H.; Harjula, R.; Malinen, Leena; Paajanen, Airi

2009-01-01

The objective of the proposed work was focused to provide promising solid-phase materials that combine relatively inexpensive and high removal capacity of some radionuclides from low-level radioactive liquid waste (LLRLW). Four various zeolite minerals including natural clinoptilolite (NaNCl), natural chabazite (NaNCh), natural mordenite (NaNM) and synthetic mordenite (NaSM) were investigated. The effective key parameters on the sorption behavior of cesium (Cs-134) were investigated using batch equilibrium technique with respect to the waste solution pH, contacting time, potassium ion concentration, waste solution volume/sorbent weight ratio and Cs ion concentration. The obtained results revealed that natural chabazite (NaNCh) has the higher distribution coefficients and capacity towards Cs ion rather than the other investigated zeolite materials. Furthermore, novel impregnated zeolite material (ISM) was prepared by loading Calix [4] arene bis(-2,3 naphtho-crown-6) onto synthetic mordenite to combine the high removal uptake of the mordenite with the high selectivity of Calix [4] arene towards Cs radionuclide. Comparing the obtained results for both NaSM and the impregnated synthetic mordenite (ISM-25), it could be observed that the impregnation process leads to high improvement in the distribution coefficients of Cs + ion (from 0.52 to 27.63 L/g). The final objective in all cases was aimed at determining feasible and economically reliable solution to the management of LLRLW specifically for the problems related to the low decontamination factor and the effective recovery of monovalent cesium ion.

Selective removal of cesium and strontium using porous frameworks from high level nuclear waste.

Science.gov (United States)

Aguila, Briana; Banerjee, Debasis; Nie, Zimin; Shin, Yongsoon; Ma, Shengqian; Thallapally, Praveen K

2016-05-01

Efficient and cost-effective removal of radioactive (137)Cs and (90)Sr found in spent fuel is an important step for safe, long-term storage of nuclear waste. Solid-state materials such as resins and titanosilicate zeolites have been assessed for the removal of Cs and Sr from aqueous solutions, but there is room for improvement in terms of capacity and selectivity. Herein, we report the Cs(+) and Sr(2+) exchange potential of an ultra stable MOF, namely, MIL-101-SO3H, as a function of different contact times, concentrations, pH levels, and in the presence of competing ions. Our preliminary results suggest that MOFs with suitable ion exchange groups can be promising alternate materials for cesium and strontium removal.

Contributions to the study of positive ion kinetics in gases

International Nuclear Information System (INIS)

Popescu, A.

1978-01-01

Extensive studies on cesium ion kinetics in cesium and cesium-noble gas mixtures were performed. The obtained data are correlated with the measured parameters of the thermionic diodes. The mobility of atomic and molecular cesium ions at low electric fields, including zero electric field, in cesium and cesium krypton mixtures were measured using the time of flight method and a special thermionic ion detector. The atomic ion conversion into molecular ions is theoretically considered in the diffusion equation of the charged particles and the obtained analytical relation is in good agreement with the experimental cesium measured data. The reaction rate of the ion conversion in cesium is considered from these measurements. Measurements on the diffused plasma through the anode (provided with holes) of the cesium thermionic diode supply data on the anode sheath, the ratio of electronic and ionic current, electron temperature and the nature of the cesium ions (atomic or molecular) for various modes of the low voltage arc discharge. The obtained data have been used for the optimization of the thermionic diode parameters, as well as for the development of a new type of device for the detection of impurities in the air. (author)

Studies on synthesis of some composites and their uses for cesium separation

International Nuclear Information System (INIS)

Someda, H.H.; El-Zahhar, A.A.; Shehata, M.K.K.; El-Naggar, H.A.

2002-01-01

In this study some composite sorbents were prepared by supporting hexacyanoferrate complexes of some transition metals like Co, Ni, Fe and Zn on some different solid supports e.g. cellulose and other natural materials as wood powder. These composites were used for cesium sorption and showed that the highest sorption capacity is for zinc composite and the lowest is for cobalt composite. Also the factors affecting the sorption capacity like acid concentration, competing ions and cesium ion concentration were studied. The release of the sorbed cesium from the composite materials was also studied under different concentrations of different solutions like sodium nitrate, silver nitrate, ammonium nitrate and a mixture of ammonium nitrate and silver nitrate solutions

Effect of implanted doses of N+-ions on the contact resistance of copper contacts

International Nuclear Information System (INIS)

Dubravec, B.; Kovac, P.; Lipka, F.; Padysak, M.

1997-01-01

The paper deals with the effect of implanted doses of N + ions on the contact resistance. Dependencies of the contact resistance versus contact force R c =f(F c ) and microhardness of implanted surfaces were measured for three implanted profiles. The influence of the aggressive environs on the contact resistance of implanted contact is given too

Leachability of cesium from cemented evaporator concentrates and ion-exchange resins

International Nuclear Information System (INIS)

Muurinen, A.

1985-03-01

Leachabilities of cesium from cemented evaporator concentrates and ion-exchange resins were measured. The standard draft of the International Organization for Standardization (ISO, 1979) for long-term leach testing was followed in the research. Three resin concretes and three concentrate concretes were tested. Deionized water and groundwater were used as leachants. The leaching temperature was 20-23 deg C. The incremental leach rate at the end of the three and a half year test varied between 5x10 -12 - 15x10 -12 m/s and the cumulative activity fraction leached between 1.5x10 -3 - 6x10 -3 m. The apparent diffusion coefficients in groundwater varied between 10 -9 - 10 -8 m/day. Because of the cracking the specimens cannot, however, be regarded as whole blocks, but the effects of cracking should be taken into account. (author)

Biosorption of cesium by native and chemically modified biomass of marine algae: introduce the new biosorbents for biotechnology applications

International Nuclear Information System (INIS)

Jalali-Rad, R.; Ghafourian, H.; Asef, Y.; Dalir, S.T.; Sahafipour, M.H.; Gharanjik, B.M.

2004-01-01

Biosorption batch experiments were conducted to determine the cesium binding ability of native biomass and chemically modified biosorbents derived from marine algae, namely ferrocyanide algal sorbents type 1 and type 2 (FASs1 and FASs2). The applicability of the Langmuir and Freundlich isotherms for representation of the experimental data was investigated. The cesium sorption performances of the various types of sorbents were compared using the maximum capacities (q max values) obtained from fitting the Langmuir isotherm to the values calculated from the sorption experiments, which FASs type 1 and type 2 showed better sorption performances for cesium. FASs1 and FASs2 derived from formaldehyde and glutaraldehyde crosslinked Padina australis exhibited lower sorption capacities than those prepared from the non-crosslinked one. Most of the cesium ions were bound to FASs1, derived from Sargassum glaucescens and P. australis, in <2 min and equilibrium reached within the first 30 min of contact. Biosorption of cesium by FASs1 derived from P. australis and Cystoseria indica was constantly occurred at a wide range of pH, between 1 and 10, and the highest removal took place at pH 4. The presence of sodium and potassium at 0.5 and 1 mM did not inhibit cesium biosorption by algae biomass. The maximum cesium uptake was acquired using the large particles of FAS2 originated from S. glaucescens (2-4 mm). Desorption of cesium from the metal-laden FASs1 (from P. australis, S. glaucescens and Dictyota indica) was completely achieved applying 0.5 and 1 M NaOH and KOH, although the cesium sorption capacity of the biosorbents (from C. indica and S. glaucescens) decreased by 46-51% after 9 sorption-desorption cycles

Biosorption of cesium by native and chemically modified biomass of marine algae: introduce the new biosorbents for biotechnology applications

Energy Technology Data Exchange (ETDEWEB)

Jalali-Rad, R. [Department of Biotechnology, Nuclear Research Center, Atomic Energy Organization of Iran, Tehran (Iran, Islamic Republic of)]. E-mail: rjalali@aeoi.org.ir; Ghafourian, H. [Department of Biotechnology, Nuclear Research Center, Atomic Energy Organization of Iran, Tehran (Iran, Islamic Republic of); Asef, Y. [Department of Biotechnology, Nuclear Research Center, Atomic Energy Organization of Iran, Tehran (Iran, Islamic Republic of); Dalir, S.T. [Department of Biotechnology, Nuclear Research Center, Atomic Energy Organization of Iran, Tehran (Iran, Islamic Republic of); Sahafipour, M.H. [Department of Biotechnology, Nuclear Research Center, Atomic Energy Organization of Iran, Tehran (Iran, Islamic Republic of); Gharanjik, B.M. [Offshore Fisheries Research Center, Chabahar (Iran, Islamic Republic of)

2004-12-10

Biosorption batch experiments were conducted to determine the cesium binding ability of native biomass and chemically modified biosorbents derived from marine algae, namely ferrocyanide algal sorbents type 1 and type 2 (FASs1 and FASs2). The applicability of the Langmuir and Freundlich isotherms for representation of the experimental data was investigated. The cesium sorption performances of the various types of sorbents were compared using the maximum capacities (q{sub max} values) obtained from fitting the Langmuir isotherm to the values calculated from the sorption experiments, which FASs type 1 and type 2 showed better sorption performances for cesium. FASs1 and FASs2 derived from formaldehyde and glutaraldehyde crosslinked Padina australis exhibited lower sorption capacities than those prepared from the non-crosslinked one. Most of the cesium ions were bound to FASs1, derived from Sargassum glaucescens and P. australis, in <2 min and equilibrium reached within the first 30 min of contact. Biosorption of cesium by FASs1 derived from P. australis and Cystoseria indica was constantly occurred at a wide range of pH, between 1 and 10, and the highest removal took place at pH 4. The presence of sodium and potassium at 0.5 and 1 mM did not inhibit cesium biosorption by algae biomass. The maximum cesium uptake was acquired using the large particles of FAS2 originated from S. glaucescens (2-4 mm). Desorption of cesium from the metal-laden FASs1 (from P. australis, S. glaucescens and Dictyota indica) was completely achieved applying 0.5 and 1 M NaOH and KOH, although the cesium sorption capacity of the biosorbents (from C. indica and S. glaucescens) decreased by 46-51% after 9 sorption-desorption cycles.

Co-precipitation and solubility studies of cesium, potassium and sodium tetraphenylborate

International Nuclear Information System (INIS)

Peterson, R.A.

2000-01-01

This report contains the results from a study requested by High Level Waste on the co-precipitation and solubility of cesium, potassium, and sodium tetraphenylborate. Co-precipitation of cesium (Cs), potassium (K), and sodium (Na) tetraphenylborate (TPB) helps determine the efficiency of reagent usage in the Small Tank Precipitation Process. This process uses NaTPB to remove cesium from waste by means of precipitation. Previous studies by McCabe suggested that if the sodium ion concentration [Na + ] increased the rate at which cesium tetraphenylborate (CsTPB) precipitates also increases. Serkiz also demonstrated that the precipitation of potassium tetraphenylborate (KTPB) in the presence of high [Na + ] (∼5M) appears to produce a mixed solid phase composed of NaTPB and KTPB together in the crystal lattice. In the crystallographic structure of these three tetraphenylborate salts (Cs,K,NaTPB), the tetraphenylborate ion dominates the size of the crystals. Also, note that the three crystals have nearly identical structures with the exception of two additional peaks in the cesium pattern. Given these similarities, TPB precipitation in the presence of Na + , Cs + and K + likely produces an impure isomorphic crystalline mixture of CsTPB, KTPB and NaTPB. The authors speculate that the primary crystalline structure resembles that of KTPB with NaTPB and CsTPB mixed throughout the crystal structure. The precipitation of NaTPB makes some of the anticipated excess tetraphenylborate relatively unavailable for precipitation of cesium. Thus, the amount of excess tetraphenylborate required to completely precipitate all of the potassium and cesium may increase significantly

Comparison of organic and inorganic ion exchangers for removal of cesium and strontium from simulated and actual Hanford 241-AW-101 DSSF tank waste

International Nuclear Information System (INIS)

Brown, G.N.; Bray, L.A.; Carlson, C.D.

1996-04-01

A number of organic and inorganic exchangers are being developed and evaluated for cesium removal from Hanford tank wastes. The exchangers of interest that are investigated in this work include powdered (IONSIV reg-sign IE-910; referred to as IE-910) and engineered (IONSIV reg-sign IE-911; referred to as IE-911) forms of the crystalline silico-titanate (CST) inorganic sorbent developed by Sandia National Laboratories (SNL)/Texas A and M and prepared by UOP; a phenol-formaldehyde (CS-100) resin developed by Rohm and Haas; a resorcinol-formaldehyde (R-F) polymer developed at the Westinghouse Savannah River Company (WSRC) and produced by Boulder Scientific; an inorganic zeolite exchanger produced by UOP (IONSIV reg-sign TIE-96; referred to as TIE-96); an inorganic sodium titanate produced by Allied Signal/Texas A and M (NaTi); and a macrocyclic organic resin developed and produced by IBC Advanced Technologies (SuperLig reg-sign 644; referred to as SL-644). Several of these materials are still under development and may not be in the optimal form. The work described in this report involves the direct comparison of the ion exchange materials for the pretreatment of actual and simulated Hanford tank waste. Data on the performance of all of the exchangers with simulated and actual double shell slurry feed (DSSF) is included. The DSSF waste is a mixture of the supernate from tanks 101-AW (70%), 106-AP (20%) and 102-AP (10%). The comparative parameters include radionuclide removal efficiency under a variety of conditions and material properties (e.g., bed density and percent removable water). Cesium and strontium distribution (K d ), lambda (λ = K d x ρ b ), and decontamination factors (DF) are compared as a function of exchanger contact duration, solution composition (Na and Cs concentration), exchanger/waste phase ratio, and multiple sequential contacts

Sympathetic cooling in a rubidium cesium mixture: Production of ultracold cesium atoms

International Nuclear Information System (INIS)

Haas, M.

2007-01-01

This thesis presents experiments for the production of ultracold rubidium cesium mixture in a magnetic trap. The long-termed aim of the experiment is the study of the interaction of few cesium atoms with a Bose-Einstein condensate of rubidium atoms. Especially by controlled variation of the cesium atom number the transition in the description of the interaction by concepts of the one-particle physics to the description by concepts of the many-particle physics shall be studied. The rubidium atoms are trapped in a magneto-optical trap (MOT) and from there reloaded into a magnetic trap. In this the rubidium atoms are stored in the state vertical stroke f=2,m f =2 right angle of the electronic ground state and evaporatively cooled by means of microwave-induced transitions into the state vertical stroke f=1,m f =1] (microwave cooling). The cesium atoms are also trppaed in a MOT and into the same magnetic trap reloaded, in which they are stored in the state vertical stroke f=4,m f =4 right angle of the electronic ground state together with rubidium. Because of the different hyperfine splitting only rubidium is evaporatively cooled, while cesium is cooled jointly sympathetically - i.e. by theramal contact via elastic collisions with rubidium atoms. The first two chapters contain a description of interatomic interactions in ultracold gases as well as a short summary of theoretical concepts in the description of Bose-Einstein condensates. The chapters 3 and 4 contain a short presentation of the methods applied in the experiment for the production of ultracold gases as well as the experimental arrangement; especially in the framework of this thesis a new coil system has been designed, which offers in view of future experiments additionally optical access for an optical trap. Additionally the fourth chapter contains an extensive description of the experimental cycle, which is applied in order to store rubidium and cesium atoms together into the magnetic trap. The last chapter

Process for recovering cesium from cesium alum

International Nuclear Information System (INIS)

Mein, P.G.

1984-01-01

Cesium is recovered from cesium alum, CsAl(SO 4 ) 2 , by an aqueous conversion and precipitation reaction using a critical stoichiometric excess of a water-soluble permanganate to form solid cesium permanganate (CsMnO 4 ) free from cesium alum. The other metal salts remain in solution, providing the final pH does not cause hydroxides of aluminium or iron to form. The precipitate is separated from the residual solution to obtain CsMnO 4 of high purity

Ion selective electrode for cesium based on 5-(4'-nitrophenylazo)25,27-bis(2-propyloxy)26,28-dihydroxycalix[4]arene.

Science.gov (United States)

Ramanjaneyulu, P S; Singh, Parminder; Sayi, Y S; Chawla, H M; Ramakumar, K L

2010-03-15

A polyvinylchloride (PVC) based liquid membrane ion selective electrode (ISE) for cesium was fabricated with 5-(4'-nitrophenylazo)25,27-bis(2-propyloxy)26,28-dihydroxycalix[4]arene as ionophore. Different membrane constituents were investigated to realise optimum performance of the ISE developed. Of the four plasticizers and two ion additives studied, the best response was observed with membrane having 2-nitro phenyl octyl ether (oNPOE) as plasticizer and potassium tetrakis (perchloro phenyl) borate (KTpClPB) as ion additive. Linear response over concentration range of 10(-5)-10(-1)M CsCl was obtained. The Nernstian slope of the response was 56 mV per decade for Cs with a response time less than 20s. Matched potential method has been applied to find out the selectivity for Cs over several ions like Rb(+), K(+), Na(+), NH(4)(+), Sr(2+), Ba(2+), Ca(2+), Mg(2+), Cu(2+), Pb(2+), Zn(2+), Ni(2+) and Ce(3+). The response of ISE for Cs(+) was fairly constant over the pH range of 3-11. The lifetime of the electrode is 9 months which is the longest life for any membrane-based Cs-ISE so far developed. The concentration of cesium in two simulated high level active waste streams was determined and results agreed well with those obtained independently employing atomic absorption spectrometry. (c) 2009 Elsevier B.V. All rights reserved.

Co-precipitation and solubility studies of cesium, potassium and sodium tetraphenylborate

International Nuclear Information System (INIS)

Peterson, R.A.

1999-01-01

This report contains the results from a study requested by High Level Waste Division on the co-precipitation and solubility of cesium, potassium, and sodium tetraphenylborate. Co-precipitation of cesium (Cs), potassium (K), and sodium (Na) tetraphenylborate (TPB) helps determine the efficiency of reagent usage in the Small Tank Precipitation Process. This process uses NaTPB to remove cesium from waste by means of precipitation. Previous studies by McCabe suggested that if the sodium ion concentration [Na+] increased the rate at which cesium tetraphenylborate (KTPB) in the presence of high [Na+] (∼5M) appears to produce a mixed solid phase composed of NaTPB and KTPB together in the crystal lattice

Crown bridged thiacalix[4]arenes as cesium-selective ionophores in solvent polymeric membrane electrodes

International Nuclear Information System (INIS)

Bereczki, Robert; Csokai, Viktor; Gruen, Alajos; Bitter, Istvan; Toth, Klara

2006-01-01

Novel 1,3-alternate thiacalix[4]mono- and biscrown-6 ethers were studied as ionophores in poly(vinyl chloride) membrane electrodes. Their selectivity behavior was characterized with respect to large number of cations, including potential interferents in environmental samples, and the membrane composition was optimized for cesium ion response. Among the ionophores, 1,3-alternate thiacalix[4]mono(crown-6) ether showed, especially high selectivity for cesium over other alkali-metal ions. Transition and heavy metal ions did not interfere seriously with the electrode response, which indicates that the bridging sulfur atoms do not take part in the ion recognition process. The potentiometric cesium responses of all electrodes involved in this study were found close to Nernstian and the detection limits were lower than 10 -7 M. The Cs + /Na + selectivity of the different ionophore-based sensors and the solvent extraction ability of the ligands were interpreted based on the respective constants of complex formation

New Signal Readout Principle for Solid-Contact Ion-Selective Electrodes.

Science.gov (United States)

Vanamo, Ulriika; Hupa, Elisa; Yrjänä, Ville; Bobacka, Johan

2016-04-19

A novel approach to signal transduction concerning solid-contact ion-selective electrodes (SC-ISE) with a conducting polymer (CP) as the solid contact is investigated. The method presented here is based on constant potential coulometry, where the potential of the SC-ISE vs the reference electrode is kept constant using a potentiostat. The change in the potential at the interface between the ion-selective membrane (ISM) and the sample solution, due to the change in the activity of the primary ion, is compensated with a corresponding but opposite change in the potential of the CP solid contact. This enforced change in the potential of the solid contact results in a transient reducing/oxidizing current flow through the SC-ISE. By measuring and integrating the current needed to transfer the CP to a new state of equilibrium, the total cumulated charge that is linearly proportional to the change of the logarithm of the primary ion activity is obtained. In this work, different thicknesses of poly(3,4-ethylenedioxythiophene) (PEDOT) doped with poly(styrenesulfonate) (PSS) were used as solid contact. Also, coated wire electrodes (CWEs) were included in the study to show the general validity of the new approach. The ISM employed was selective for K(+) ions, and the selectivity of the membrane under implementation of the presented transduction mechanism was confirmed by measurements performed with a constant background concentration of Na(+) ions. A unique feature of this signal readout principle is that it allows amplification of the analytical signal by increasing the capacitance (film thickness) of the solid contact of the SC-ISE.

Extraction of cesium and strontium from nuclear waste

Science.gov (United States)

Davis, Jr., Milton W.; Bowers, Jr., Charles B.

1988-01-01

Cesium is extracted from acidified nuclear waste by contacting the waste with a bis 4,4'(5) [1-hydroxy-2-ethylhexyl]benzo 18-crown-6 compound and a cation exchanger in a matrix solution. Strontium is extracted from acidified nuclear waste by contacting the waste with a bis 4,4'(5') [1-hydroxyheptyl]cyclohexo 18-crown-6 compound, and a cation exchanger in a matrix solution.

Measurement of low levels of cesium-137 in water

International Nuclear Information System (INIS)

Milham, R.C.; Kantelo, M.V.

1984-10-01

Large volume water sampling systems were developed to measure very low levels of cesium-137 in river water and in finished water from water treatment plants. Three hundred to six hundred liters of filtered water are passed through the inorganic ion exchanger potassium cobalti-ferrocyanide to remove greater than 90% of the cesium. Measurement of cesium-137 by gamma ray spectrometry results in a sensitivity of 0.001 pCi/L. Portable as well as stationary samplers were developed to encompass a variety of applications. Results of a one year study of water from the Savannah River and from water treatment plants processing Savannah River water are presented. 3 references, 7 figures

Review and assessment of technologies for the separation of cesium from acidic media

Energy Technology Data Exchange (ETDEWEB)

Orth, R.J.; Brooks, K.P.; Kurath, D.E.

1994-09-01

A preliminary literature survey has been conducted to identify and evaluate methods for the separation of cesium from acidic waste. The most promising solvent extraction, precipitation, and ion exchange methods, along with some of the attributes for each method, are listed. The main criteria used in evaluating the separation methods were as follows: (1) good potential for cesium separation must be demonstrated (i.e., cesium decontamination factors on the order of 50 to 100). (2) Good selectivity for cesium over bulk components must be demonstrated. (3) The method must show promise for evolving into a practical and fairly simple process. (4) The process should be safe to operate. (5) The method must be robust (i.e., capable of separating cesium from various acidic waste types). (6) Secondary waste generation must be minimized. (7) The method must show resistance to radiation damage. The most promising separation methods did not necessarily satisfy all of the above criteria, thus key areas requiring further development are suggested for each method. The report discusses in detail these and other areas requiring further development, as well as alternative solvent extraction, precipitation, ion exchange, and {open_quote}other{close_quote} technologies that, based on current information, show less promise for the separation of cesium from acidic wastes because of significant process limitations. When appropriate, the report recommends areas of future development.

Selective cesium and strontium removal for TRU-liquid waste including fission products and concentrated nitric acids

International Nuclear Information System (INIS)

Mimori, T.; Miyajima, K.; Kozeki, M.; Kubota, T.; Tusa, E.; Keskinen, A.

1996-01-01

A nuclide removal system was designed for treatment of liquid radioactive waste at the Japan Atomic Energy Research Institute (JAERI) Tokai site. Total system will include removal of plutonium, cesium and strontium. Removal of plutonium will be carried out by a method developed by JAERI. Removal of cesium and strontium will be carried out by the methods developed in Finland. The whole project will be implemented for JAERI in cooperation between Mitsui Engineering and Shipbuilding and IVO International. This project has been carried out under the Science and Technology Agency (STA) of Japan. The liquid to be treated includes 7.4x10 9 Bq/L of cesium and 7.4x10 9 Bq/L of strontium. The amount of alpha nuclides is 3.7x10 6 Bq/L. Nitric acid concentration is 1.74 mol/L. The volume of 11,000 liters had to be treated in 200 batches of operation. Removal of cesium and strontium is based on the use of new ion exchange materials developed in Finland. These inorganic ion exchange materials have extremely good properties to separate cesium and strontium from even very difficult liquids. Ion exchange material will be used in columns, where there are materials both for cesium and strontium. According to column tests with simulated waste, one 2 liter column will effectively reach the required DF during 10 batches of operation. Purified liquid can be led to further liquid treatment at the site. After treatment of liquids, both used particle filters and used ion exchange columns will be drained and stored to wait for final treatment and disposal. The designed treatment system has a special beneficial feature as it does not produce secondary waste. Final waste is in the form of particle filters or ion exchange columns with material. Used ion exchange columns and filters will be replaced with new ones by means of remote handling. Construction of the treatment system will be scheduled to commence in FY1995 and assemblying at the site in FY1996. (J.P.N.)

Removal of cesium and strontium from low active waste solutions by zeolites

International Nuclear Information System (INIS)

Jain, Savita; Ramaswamy, M.; Theyyunni, T.K.

1994-01-01

Ion exchange, crystallographic and thermal characteristics of sodium, cesium and strontium forms of locally available synthetic zeolites have been investigated. X-ray and differential thermal analyses have confirmed that the synthetic materials AR1 and 4A belonged to the mordenite and A type families of zeolites respectively. Equilibrium uptake of cesium and strontium ions by sodium forms of zeolite was studied as a function of time, pH and sodium concentration. It was found that the rate of sorption by AR1 was higher than that by 4A. In regard to pH, distribution of nuclides on zeolites was found to pass through maxima at a pH value of around 9. Sodium ion interfered with the sorption of cesium and strontium by zeolites. However, at sodium concentration ≤ 0.01 M, distribution coefficient values for these nuclides were sufficiently high to merit consideration of these zeolites for low level waste treatment. Lab-scale column runs using 5 ml beds of materials showed that the zeolites AR1 and 4A were very effective in removing cesium and strontium nuclides respectively from large volumes (a decontamination factor of 50 for a throughput of 6000 bed volumes) of actual low level waste solutions. Thus, the zeolite system has a potential future for large scale application in the treatment of low level wastes. (author). 6 refs., 5 figs., 6 tabs

Theoretical study of the chemical properties of cesium hydride; Teoreticke studium chemickych vlastnosti hydridu cezia

Energy Technology Data Exchange (ETDEWEB)

Skoviera, J [Univerzita Komenskeho v Bratislave, Prirodovedecka fakulta, Katedra fyzikalnej a teoretickej chemie, 84215 Bratislava (Slovakia)

2012-04-25

A theoretical study of radiofrequency source of hydrogen ions in the International Thermonuclear Experimental Reactor (ITER) used a cesium grid as a source of electrons for ionization of hydrogen. In the process of ionization of hydrogen, however, there is a weathering of cesium grid, resulting into a group of undesired products - cesium hydrides and materials derived from cesium hydride. We calculated the potential curves of cesium hydride and of its anion and cation, their spectroscopic properties and partly their electrical properties. To make electrical properties comparable with the experiment, we calculated for all also the vibration corrections. Lack of convergence in RASSCF step caused, that the electrical properties of excited states are still an open question of chemical properties of cesium hydride. (authors)

Recent negative ion source developments

International Nuclear Information System (INIS)

Alton, G.D.

1978-01-01

This report describes recent results obtained from studies associated with the development of negative ion sources which utilize sputtering in a diffuse cesium plasma as a means of ion beam generation. Data are presented which relate negative ion yield and important operational parameters such as cesium oven temperature and sputter probe voltage from each of the following sources: (1) A source based in principle according to the University of Aarhus design and (2) an axial geometry source. The important design aspects of the sources are given--along with a list of the negative ion intensities observed to date. Also a qualitative description and interpretation of the negative ion generation mechanism in sources which utilize sputtering in the presence of cesium is given

Ion Exchange Modeling Of Cesium Removal From Hanford Waste Using Spherical Resorcinol-Formaldehyde Resin

Energy Technology Data Exchange (ETDEWEB)

Aleman, S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hamm, L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Smith, F. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2007-06-27

This report discusses the expected performance of spherical Resorcinol-Formaldehyde (RF) ion exchange resin for the removal of cesium from alkaline Hanford radioactive waste. Predictions of full scale column performance in a carousel mode are made for the Hot Commissioning, Envelope B, and Subsequent Operations waste compositions under nominal operating conditions and for perturbations from the nominal. Only the loading phase of the process cycle is addressed in this report. Pertinent bench-scale column tests, kinetic experiments, and batch equilibrium experiments are used to estimate model parameters and to benchmark the ion-exchange model. The methodology and application presented in this report reflect the expected behavior of spherical RF resin manufactured at the intermediate-scale (i.e., approximately 100 gallon batch size; batch 5E-370/641). It is generally believed that scale-up to production-scale in resin manufacturing will result in similarly behaving resin batches whose chemical selectivity is unaffected while total capacity per gram of resin may vary some. As such, the full-scale facility predictions provided within this report should provide reasonable estimates of production-scale column performance.

Validation and Application of Concentrated Cesium Eluate Physical Property Models

International Nuclear Information System (INIS)

Choi, A.S.

2004-01-01

This work contained two objectives. To verify the mathematical equations developed for the physical properties of concentrated cesium eluate solutions against experimental test results obtained with simulated feeds. To estimate the physical properties of the radioactive AW-101 cesium eluate at saturation using the validated models. The Hanford River Protection Project (RPP) Hanford Waste Treatment and Immobilization Plant (WTP) is currently being built to extract radioisotopes from the vast inventory of Hanford tank wastes and immobilize them in a silicate glass matrix for eventual disposal at a geological repository. The baseline flowsheet for the pretreatment of supernatant liquid wastes includes removal of cesium using regenerative ion-exchange resins. The loaded cesium ion-exchange columns will be eluted with nitric acid nominally at 0.5 molar, and the resulting eluate solution will be concentrated in a forced-convection evaporator to reduce the storage volume and to recover the acid for reuse. The reboiler pot is initially charged with a concentrated nitric acid solution and kept under a controlled vacuum during feeding so the pot contents would boil at 50 degrees Celsius. The liquid level in the pot is maintained constant by controlling both the feed and boilup rates. The feeding will continue with no bottom removal until the solution in the pot reaches the target endpoint of 80 per cent saturation with respect to any one of the major salt species present

Laboratory plant for the separation of cesium from waste solutions of the PUREX process

International Nuclear Information System (INIS)

Richter, M.; Eckert, B.; Riemenschneider, J.; Mallon, C.; Mann, D.

1983-01-01

A laboratory plant for the separation of cesium from a fission product waste solution of the fuel reprocessing is described. The plant consists of two stages. In the first stage cesium is adsorbed on ammonium molybdatophosphate (AMP). Then the adsorbent is dissolved. From the solution cesium is adsorbed on a cationic ion exchanger in the second stage. Then AMP can be reproduced from this solution. For the elution of cesium in the second stage a NH 4 NO 3 solution (3 m) is used. Flow sheet, construction and the control device of the plant are described and the results of tests with a model solution are given. (author)

Concentrating cesium-137 from seawater using resorcinol-formaldehyde resin for radioecological monitoring

Energy Technology Data Exchange (ETDEWEB)

Egorin, Andrei; Tokar, Eduard; Tutov, Mikhail; Avramenko, Valentin [Institute of Chemistry FEBRAS, Vladivostok (Russian Federation); Far Eastern Federal Univ., Vladivostok (Russian Federation); Palamarchuk, Marina; Marinin, Dmitry [Institute of Chemistry FEBRAS, Vladivostok (Russian Federation)

2017-04-01

A method of preconcentrating cesium-137 from seawater using a resorcinol-formaldehyde resin, which enables one to optimize the ecological monitoring procedure, has been suggested. Studies of sorption of cesium-137 from seawater by resorcinol-formaldehyde resin have been performed, and it has been demonstrated that the cation exchanger is characterized by high selectivity with respect to cesium-137. It was found that the selectivity depended on the temperature of resin solidification and the seawater pH value. The maximal value of the cesium-137 distribution coefficient is equal to 4.1-4.5 x 10{sup 3} cm{sup 3} g{sup -1}. Under dynamic conditions, the ion-exchange resin capacity is 310-910 bed volumes depending on the seawater pH, whereas the efficiency of cesium removal exceeds 95%. The removal of more than 95% of cesium-137 has been attained using 1-3 M solutions of nitric acid: here, the eluate volume was 8-8.4 bed volumes. Application of 3 M solution of nitric acid results in resin degradation with the release of gaseous products.

Ion-recognizable hydrogels for efficient removal of cesium ions from aqueous environment

Energy Technology Data Exchange (ETDEWEB)

Yu, Hai-Rong [School of Chemical Engineering, Sichuan University, No. 24, Southern 1 Section, Yihuan Road, Chengdu, Sichuan, 610065 (China); College of Chemistry and Environment Protection Engineering, Southwest University for Nationalities, No. 16, Southern 4 Section, Yihuan Road, Chengdu, Sichuan, 610041 (China); Hu, Jia-Qi [School of Chemical Engineering, Sichuan University, No. 24, Southern 1 Section, Yihuan Road, Chengdu, Sichuan, 610065 (China); Liu, Zhuang, E-mail: liuz@scu.edu.cn [School of Chemical Engineering, Sichuan University, No. 24, Southern 1 Section, Yihuan Road, Chengdu, Sichuan, 610065 (China); Ju, Xiao-Jie; Xie, Rui; Wang, Wei [School of Chemical Engineering, Sichuan University, No. 24, Southern 1 Section, Yihuan Road, Chengdu, Sichuan, 610065 (China); State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, Sichuan 610065 (China); Chu, Liang-Yin, E-mail: chuly@scu.edu.cn [School of Chemical Engineering, Sichuan University, No. 24, Southern 1 Section, Yihuan Road, Chengdu, Sichuan, 610065 (China); State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, Sichuan 610065 (China); Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing, Jiangsu 211816 (China)

2017-02-05

Highlights: • An easy-to-get and low-cost Cs{sup +}-recognizable polymeric hydrogel has been developed. • The hydrogel displays rapid and selective adsorption towards Cs{sup +}. • Synergistic effect of AAc units and Cs{sup +}(B18C6){sub 2} host-guest complexes is good for adsorption. • The hydrogel shows great potential for decontamination of Cs{sup +} from radioactive contaminants. - Abstract: At present, selective and efficient removal of cesium ions (Cs{sup +}) from nuclear waste is of significant importance but still challenging. In this study, an easy-to-get and low-cost hydrogel adsorbent has been developed for effective adsorption and removal of Cs{sup +} from aqueous environment. The novel Cs{sup +}-recognizable poly(acrylic acid-co-benzo-18-crown-6-acrylamide) (poly(AAc-co-B18C6Am)) hydrogel is specifically designed with a synergistic effect, in which the AAc units are designed to attract Cs{sup +} via electrostatic attraction and the B18C6Am units are designed to capture the attracted Cs{sup +} by forming stable 2:1 “sandwich” complexes. The poly(AAc-co-B18C6Am) hydrogels are simply synthesized by thermally initiated free-radical copolymerization and display excellent Cs{sup +} adsorption from commonly coexisting metal ions. Important parameters affecting the adsorption are investigated comprehensively, and the adsorption kinetics and adsorption isotherms are also discussed systematically. The poly(AAc-co-B18C6Am) hydrogels exhibit rapid Cs{sup +} adsorption within 30 min and the adsorption process is governed by the pseudo-second order model. Adsorption isotherm results demonstrate that the equilibrium data are well fitted by the Langmuir isotherm model, indicating that the Cs{sup +} adsorption is probably a monolayer adsorption process. Such Cs{sup +}-recognizable hydrogel materials based on the host-guest complexation are promising as efficient and feasible candidates for adsorption and removal of radioactive Cs{sup +} from nuclear

Hot demonstration of proposed commercial cesium removal technology

International Nuclear Information System (INIS)

Lee, D.D.; Travis, J.R.; Gibson, M.R.

1997-12-01

This report describes the work done in support of the development of technology for the continuous removal and concentration of radioactive cesium in supernatant from Melton Valley Storage Tanks (MVSTs) at the ORNL site. The primary objective was to test candidate absorbers and ion exchangers under continuous-flow conditions using actual supernatant from the MVSTs. An experimental system contained in a hot-cell facility was constructed to test the materials in columns or modules using the same batch of supernatant to allow comparison on an equal basis. Resorcinol/formaldehyde (RF) resin was evaluated at three flow rates with 50% breakthrough ranges of 35 to 50 column volumes (CV) and also through a series of five loading/elution/regeneration cycles. The results reported here include the cesium loading breakthrough curves, elution curves (when applicable), and operational problems and observations for each material. The comparative evaluations should provide critical data for the selection of the sorbent for the ORNL Cesium Removal Demonstration project. These results will be used to help determine the design parameters for demonstration-scale systems. Such parameters include rates of cesium removal, quantity of resin or sorbent to be used, and elution and regeneration requirements, if applicable

Efficient cesiation in RF driven surface plasma negative ion source

Energy Technology Data Exchange (ETDEWEB)

Belchenko, Yu.; Ivanov, A.; Konstantinov, S.; Sanin, A., E-mail: sanin@inp.nsk.su; Sotnikov, O. [Budker Institute of Nuclear Physics, Siberian Branch of Russian Academy of Sciences, Novosibirsk (Russian Federation)

2016-02-15

Experiments on hydrogen negative ions production in the large radio-frequency negative ion source with cesium seed are described. The system of directed cesium deposition to the plasma grid periphery was used. The small cesium seed (∼0.5 G) provides an enhanced H{sup −} production during a 2 month long experimental cycle. The gradual increase of negative ion yield during the long-term source runs was observed after cesium addition to the source. The degraded H{sup −} production was recorded after air filling to the source or after the cesium washing away from the driver and plasma chamber walls. The following source conditioning by beam shots produces the gradual recovery of H{sup −} yield to the high value. The effect of H{sup −} yield recovery after cesium coverage passivation by air fill was studied. The concept of cesium coverage replenishment and of H{sup −} yield recovery due to sputtering of cesium from the deteriorated layers is discussed.

Photon interactions in a cesium beam

International Nuclear Information System (INIS)

Nygaard, K.J.; Jones, J.D.; Hebner, R.E. Jr

1974-01-01

Photoionization of excited cesium atoms in the 6 2 P3/2 - state has been studied in a triple crossed-beam experiment. A thermal beam of cesium atoms was intersected by one photon beam of wavelength 8521A that served to excite the atoms and another photon beam with wavelengths below 5060A that served to ionize the excited atoms. The resulting ions were detected with a channel electron multiplier. All background effects were discriminated against by chopping the beam of exciting radiation and by analyzing the net count rate with digital synchronous techniques. The relative cross section for photoionization fo Cs(6 2 P3/2) has been measured from threshold (5060A) to 2500A. The results fall off faster than the theoretical calculations of Weisheit and Norcross

Effects of cesium ion-implantation on mechanical and electrical properties of organosilicate low-k films

Energy Technology Data Exchange (ETDEWEB)

Li, W.; Pei, D.; Guo, X.; Cheng, M. K.; Lee, S.; Shohet, J. L. [Plasma Processing and Technology Laboratory, Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Lin, Q. [IBM T.J. Watson Research Center, Yorktown Heights, New York 10598 (United States); King, S. W. [Intel Corporation, Hillsboro, Oregon 97124 (United States)

2016-05-16

The effects of cesium (Cs) ion-implantation on uncured plasma-enhanced chemical-vapor-deposited organosilicate low dielectric constant (low-k) (SiCOH) films have been investigated and compared with an ultraviolet (UV) cured film. The mechanical properties, including the elastic modulus and hardness, of the SiCOH low-k films are improved by up to 30% with Cs implantation, and further up to 52% after annealing at 400 °C in a N{sub 2} ambient for 1 h. These improvements are either comparable to or better than the effects of UV-curing. They are attributed to an enhancement of the Si-O-Si network structure. The k-value of the SiCOH films increased slightly after Cs implantation, and increased further after annealing. These increases are attributed to two carbon-loss mechanisms, i.e., the carbon loss due to Si-CH{sub 3} bond breakage from implanted Cs ions, and the carbon loss due to oxidation during the annealing. The time-zero dielectric breakdown strength was improved after the Cs implantation and the annealing, and was better than the UV-cured sample. These results indicate that Cs ion implantation could be a supplement to or a substitution for the currently used UV curing method for processing SiCOH low-k films.

Recent development on the synthesis of calixcrowns and their application for cesium removal from high-level liquid waste

International Nuclear Information System (INIS)

Zhu Xiaowen; Gao Jianxun; Wang Jianchen; Yu Bo; Song Chongli

2002-01-01

The synthesis, extraction properties and molecular modeling of calixcrowns in concern of cesium removal is reviewed briefly. In particular, calix [4] crown-6 and some of its derivatives have been shown to be highly selective extractants for cesium ions

Contact ionization ion source

International Nuclear Information System (INIS)

Hashmi, N.; Van Der Houven Van Oordt, A.J.

1975-01-01

An ion source in which an apertured or foraminous electrode having a multiplicity of openings is spaced from one or more active surfaces of an ionisation electrode, the active surfaces comprising a material capable of ionising by contact ionization a substance to be ionized supplied during operation to the active surface or surfaces comprises means for producing during operation a magnetic field which enables a stable plasma to be formed in the space between the active surface or surfaces and the apertured electrode, the field strength of the magnetic field being preferably in the range between 2 and 8 kilogauss. (U.S.)

MODELING CST ION EXCHANGE FOR CESIUM REMOVAL FROM SCIX BATCHES 1 - 4

Energy Technology Data Exchange (ETDEWEB)

Smith, F.

2011-04-25

The objective of this work is, through modeling, to predict the performance of Crystalline Silicotitinate (CST) for the removal of cesium from Small Column Ion Exchange (SCIX) Batches 1-4 (as proposed in Revision 16 of the Liquid Waste System Plan). The scope of this task is specified in Technical Task Request (TTR) 'SCIX Feed Modeling', HLE-TTR-2011-003, which specified using the Zheng, Anthony, Miller (ZAM) code to predict CST isotherms for six given SCIX feed compositions and the VErsatile Reaction and SEparation simulator for Liquid Chromatography (VERSE-LC) code to predict ion-exchange column behavior. The six SCIX feed compositions provided in the TTR represent SCIX Batches 1-4 and Batches 1 and 2 without caustic addition. The study also investigated the sensitivity in column performance to: (1) Flow rates of 5, 10, and 20 gpm with 10 gpm as the nominal flow; and (2) Temperatures of 25, 35, and 45 C with 35 C as the nominal temperature. The isotherms and column predictions presented in this report reflect the expected performance of engineered CST IE-911. This form of CST was used in experiments conducted at the Savannah River National Laboratory (SRNL) that formed the basis for estimating model parameters (Hamm et al., 2002). As has been done previously, the engineered resin capacity is estimated to be 68% of the capacity of particulate CST without binder.

Studies on the feasibility of using crystalline silicotitanates for the separation of cesium-137 from fast reactor high-level liquid waste

International Nuclear Information System (INIS)

Venkatesan, K.A.; Sukumaran, V.; Antony, M.P.; Srinivasan, T.G.

2009-01-01

The commercially available crystalline silicotitanate inorganic ion xchanger, IONSIV IE-911, and its parent precursor, TAM-5, have been valuated for the removal of 137 Cs from nitric acid medium and simulated high-level liquid waste. The distribution coefficient (K d ) of cesium ecreased with increasing nitric acid concentration and at 3.0 M nitric acid, distribution coefficient of 1150 mL/g and 2600 mL/g were obtained for ONSIV IE-911 and TAM-5, respectively. Rapid uptake of cesium followed by the establishment of equilibrium occurring within three hours. Loading of cesium n ion exchangers increased with the increase in the concentration of cesium n aqueous phase and from Langmuir adsorption model the apparent capacity of cesium was 69 mg/g and 82 mg/g for IONSIV IE-911 and TAM-5, respectively. The performance of the sorbent under dynamic conditions was assessed by following breakthrough (BT) curve up to C/C o = 1, where C and C o are the concentrations of cesium in the effluent and feed, respectively. (author)

Cesium sorption from concentrated acidic tank wastes using ammonium molybdophosphate-polyacrylonitrile composite sorbents

International Nuclear Information System (INIS)

Todd, T.A.; Mann, N.R.; Tranter, T.J.; Sebesta, F.; John, J.; Motl, A.

2002-01-01

Ammonium molybdophosphate-polyacrylonitrile (AMP-PAN) composite sorbents have been evaluated for the removal of cesium from Idaho National Engineering and Environmental Laboratory (INEEL) concentrated acidic tank waste. Batch contacts were performed to qualitatively evaluate the effects of increased nitric acid, sodium and potassium. An equilibrium isotherm was generated with simulated concentrated tank waste solutions and fit to the Langmuir equation. Additional batch contact experiments were performed to determine if mercury, plutonium and americium would sorb onto AMP-PAN. Dynamic sorption was evaluated in column tests employing 1.5 cm 3 columns operating at 5, 10 and 20 bed volumes of flow per hour. Results indicate, as expected, that dynamic cesium sorption capacity is reduced as the flowrate is increased. Calculated dynamic capacities for cesium were 22.5, 19.8 and 19.6 mg Cs/g sorbent, for 5, 10 and 20 bed volume per hour flows, respectively. The thermal stability of loaded AMP-PAN was evaluated by performing thermogravimetric analysis (TGA) on samples of AMP, PAN (polymer), and AMP-PAN. Results indicate that AMP-PAN is stable to 400 deg C, with less than a 10% loss of weight, which is at least partially due to loss of water of hydration. The evaluation of AMP-PAN indicates that it will effectively remove cesium from concentrated acidic tank waste solutions. (author)

Ion-Induced Surface Modification of Magnetically Operated Contacts

Directory of Open Access Journals (Sweden)

Karen Arushanov

2012-02-01

Full Text Available A study has been made of permalloy (iron-nickel contacts of reed switches before and after ion-induced surface modification using atomic force and optical microscopy, Auger electron and X-ray photoelectron spectroscopy. It has been found that the formation of surface nitride layers enhances corrosion and erosion resistance of contacts. We proposed to produce such layers directly into sealed reed switches by means of pulsing glow-discharge nitrogen plasma.

Myocardial imaging with cesium-130

International Nuclear Information System (INIS)

Harper, P.V.; Resnekov, L.; Stark, V.; Odeh, N.

1984-01-01

Recently comparative studies using nitrogen-13 ammonia and cesium-130 have shown strikingly different myocardial localization patterns in the same subjects with ischemic heart disease. Initial localization of ammonia, an avidly extracted agent, reflects the perfusion pattern in viable myocardial tissue. The myocardial localization of cesium ion, taking place more slowly over 15 to 20 minutes, is apparently much less flow dependent, causing uptake defects shown with ammonia to be largely filled in. Cesium thus appears to provide information on the extent of the viable myocardial mass, apart from perfusion. Cesium-130 (t1/2 30 m) decays by positron emission and electron capture. The whole body radiation absorbed dose, assuming uniform distribution, is 24 mrad/mCi. While abundant production of Cs-130 results from proton bombardment of natural xenon [Xe-130(rho,n)Cs-130] at 15 MeV, small amounts of Cs-129, -131, and -132 are also produced, and enriched Xe-130 is not available. Alternatively almost completely uncontaminated Cs-130 is available by alpha bombardment of natural I-127. Anhydrous sodium iodide is dissolved in acetone and a thin layer (≅20 mg per centimeter squared) is evaporated onto the gold plated tip of the internal target backing which is oscillated vertically to spread out the area upon which the beam is incident. The target surface is inclined 2.5 degrees to the beam giving a power density of about 400 watts per centimeter squared at 100μA which is adequately handled by water cooling. A 30-minute bombardment yields 4 to 5 mCi of Cs-130 which is dissolved directly from the target. This approach appears to offer a new and helpful method for evaluating ischemic heart disease by permitting evaluation of viable myocardial mass

Recovery of cesium from nuclear waste using hollow fibre supported liquid membrane containing calix[4]arene-bis-(2,3-naphtho)-crown-6

International Nuclear Information System (INIS)

Kandwal, P.; Mohapatra, P.K.; Ansari, S.A.; Manchanda, Vijay K.

2011-01-01

Transport behaviour of cesium through hollow fibre supported liquid membrane (HFSLM) containing calix[4]arenebis-(2,3-naphtho)-crown-6 (CNC) as carrier extractant, has been investigated under various experimental conditions. At tracer concentration of cesium, > 99% recovery of cesium was achieved from 3M HNO 3 solution to distilled water with 1 mM of CNC in 80% NPOE + 20 % n-dodecane mixture. Effect of feed phase acidity, ligand concentration, metal ion concentration etc. has been investigated. Recovery of cesium from Pressurized Heavy Water Reactor Simulated High Level Waste (PHWR-SHLW) using 1 mM CNC dissolved proposed diluent as the extractant, was carried out and it was found that it takes 12 hours of continuous operation for 88% recovery of metal ion. Nevertheless, the complete recovery of cesium from SHLW was possible after neutralization of strip phase acidity with NaOH. (author)

Preliminary results from uranium/americium affinity studies under experimental conditions for cesium removal from NPP ''Kozloduy'' simulated wastes solutions

International Nuclear Information System (INIS)

Nikiforova, A.; Kinova, L.; Peneva, C.; Taskaeva, I.; Petrova, P.

2005-01-01

We use the approach described by Westinghouse Savannah River Company using ammonium molybdophosphate (AMP) to remove elevated concentrations of radioactive cesium to facilitate handling waste samples from NPP K ozloduy . Preliminary series of tests were carried out to determine the exact conditions for sufficient cesium removal from five simulated waste solutions with concentrations of compounds, whose complexing power complicates any subsequent processing. Simulated wastes solutions contain high concentrations of nitrates, borates, H 2 C 2 O 4 , ethylenediaminetetraacetate (EDTA) and Citric acid, according to the composition of the real waste from the NPP. On this basis a laboratory treatment protocol was created. This experiment is a preparation for the analysis of real waste samples. In this sense the results are preliminary. Unwanted removal of non-cesium radioactive species from simulated waste solutions was studied with gamma spectrometry with the aim to find a compromise between on the one hand the AMP effectiveness and on the other hand unwanted affinity to AMP of Uranium and Americium. Success for the treatment protocol is defined by proving minimal uptake of U and Am, while at the same time demonstrating good removal effectiveness through the use of AMP. Uptake of U and Am were determined as influenced by oxidizing agents at nitric acid concentrations, proposed by Savannah River National laboratory. It was found that AMP does not significantly remove U and Am when concentration of oxidizing agents is more than 0.1M for simulated waste solutions and for contact times inherent in laboratory treatment protocol. Uranium and Americium affinity under experimental conditions for cesium removal were evaluated from gamma spectrometric data. Results are given for the model experiment and an approach for the real waste analysis is chosen. Under our experimental conditions simulated wastes solutions showed minimal affinity to AMP when U and Am are most probably in

Treatment of Soil Decontamination Solution by the Cs{sup +} Ion Selective Ion Exchange Resin

Energy Technology Data Exchange (ETDEWEB)

Won, Hui Jun; Kim, Gye Nam; Jung, Chung Hun; Oh, Won Zin [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

2005-07-01

Occasionally, radioactively contaminated soils have been excavated and stored at the temporary storage facility. Cesium as a radionuclide is one of the most toxic elements and it has a long half decay life. During the operation of nuclear facility, soils near the facility would be contaminated with radioactive cesium and it will cause the deleterious effect to human body and environment. In this study, Cs{sup +} ion selective ion exchange resin was prepared by changing the functional group of commercial anion exchange resin for a ferrocyanide ion. Ion exchange capability of using the soil decontamination solution was investigated. We also performed the feasibility test of recycling the spent Cs ion selective ion exchange resin.

Studies on the synthesis and characterization of cesium-containing iron phosphate glasses

Science.gov (United States)

Joseph, Kitheri; Govindan Kutty, K. V.; Chandramohan, P.; Vasudeva Rao, P. R.

2009-02-01

Isotopes of cesium and strontium can be utilized as radiation source for various industrial and medical applications after their separation from high level nuclear waste. However, these elements need to be immobilized in a suitable matrix. In the present work, a systematic approach has been made to immobilize inactive cesium into iron phosphate glass. Up to 36 mol% of Cs 2O has been loaded successfully without crystallization. The glass transition temperature of the cesium loaded glass was found to increase initially and then decrease as a function of Cs 2O content. Mössbauer studies show that the concentration of Fe 3+ ions in the cesium loaded glasses is >95%. Volatilization experiments at 1263 K show that the weight loss is >0.5% for a period of 4 h. The 36 mol% of Cs 2O loaded iron phosphate glass with high Fe 3+ content described in this paper is reported for the first time.

Process for recovering cesium from pollucite

International Nuclear Information System (INIS)

Mein, P.G.

1985-01-01

Cesium is recovered from a cesium-bearing mineral such as pollucite by extraction with hydrochloric acid to obtain an extract of cesium chloride and other alkali metal and polyvalent metal chlorides. The iron and aluminum chlorides can be precipitated as the hydroxides and separated from the solution of the alkali metal chlorides to which is added potassium permanganate or other water-soluble permanganate to selectively precipitate cesium permanganate. The cesium precipitate is then separated from the residual solution containing the metal chlorides. The cesium permanganate, which is in a very pure form, can be converted to other cesium compounds by reaction with a reducing agent to obtain cesium carbonate and cesium delta manganese dioxide

Low-temperature phase transformation in rubidium and cesium superoxides

International Nuclear Information System (INIS)

Alikhanov, R.A.; Toshich, B.S.; Smirnov, L.S.

1980-01-01

Crystal structures of rubidium and cesium superoxides which are two interpenetrating lattices of metal ions and oxygen molecule ions reveal a number of phase transformations with temperature decrease. Crystal-phase transformations in CsO 2 are 1-2, 2-3 and low temperature one 3-4 at 378, 190 and 10 K. Low temperature transition is considered as the instability of lattice quadrupoles of oxygen molecule ions to phase transformation of the order-disorder type. Calculated temperatures of low temperature phase transformations in PbO 2 and CsO 2 agree with experimental calculations satisfactory [ru

Sorption of cesium on montmorillonite and effect of salt concentration

International Nuclear Information System (INIS)

Atun, G.; Bilgin, B.; Mardinli, A.

1996-01-01

The sorption behavior of cesium on montmorillonite type[e clay was studied by using radioactivity measurements. Concentrations of Cs + ions ranged from 10 -6 to 10 -2 M. Cesium retention reduced with increasing salt concentration which was varied between 10 -4 and 10 -1 M. Selectivity coefficients K CsNa for the exchange between Cs and Na were calculated for different equivalent fractions of Cs on the solid phase. Using the K CsNa values, free energy change was found to be 7.8 kJ/mol. The data could be fitted to a Freundlich isotherm, and empirical Freundlich parameters enabled the generation of a site distribution function. By fitting the data to the Dubinin-Radushkevich (D-R) isotherm, a mean energy of sorption of 8.6kJ/mole was calculated which corresponds to the energy of ion exchange reactions. The values of energy changes calculated by using two different methods were in good agreement. (author)

Crystalline silicotitanates--new ion exchanger for selective removal of cesium and strontium from radwastes

International Nuclear Information System (INIS)

Dosch, R.G.; Klavetter, E.A.; Stephens, H.P.; Brown, N.E.; Anthony, R.G.

1996-08-01

A new class of inorganic ion exchange material called crystalline silicotitanates (CST) has been developed for radioactive waste treatment in a collaborative effort between Sandia National Laboratories and Texas A ampersand M University. The Sandia National Laboratories Laboratory Directed Research and Development program provided the initial funding for this effort and this report summarizes the rapid progress that was achieved. A wide range of compositions were synthesized, evaluated for cesium (Cs) removal efficiency, and a composition called TAM-5 was developed that exhibits high selectivity and affinity for Cs and strontium (Sr). Tests show it can remove parts per million concentrations of Cs + from highly alkaline, high-sodium, simulated radioactive waste solutions modeled after those at Hanford, Oak Ridge, and Savannah River. In experiments with solutions that simulate highly alkaline Hanford defense wastes, the crystalline silicotitanates exhibit distribution coefficients for Cs + of greater than 2,000 ml/g, and distribution coefficients greater than 10,000 ml/g for solutions adjusted to a pH between 1 and 10. In addition, the CSTs were found to exhibit distribution coefficients for Sr + greater than 100,000 ml/g and for plutonium of 2,000 ml/g from simulated Hanford waste. The CST crystal structure was determined and positions of individual atoms identified using x-ray and neutron diffraction. The structural information has permitted identification of the ion exchange sites and provided insights into the strong effect of pH on Cs ion exchange. Information on the synthesis, composition, and structure of CST is considered proprietary and is not discussed in this report

Design and application of ion-implanted polySi passivating contacts for interdigitated back contact c-Si solar cells

International Nuclear Information System (INIS)

Yang, Guangtao; Ingenito, Andrea; Hameren, Nienke van; Isabella, Olindo; Zeman, Miro

2016-01-01

Ion-implanted passivating contacts based on poly-crystalline silicon (polySi) are enabled by tunneling oxide, optimized, and used to fabricate interdigitated back contact (IBC) solar cells. Both n-type (phosphorous doped) and p-type (boron doped) passivating contacts are fabricated by ion-implantation of intrinsic polySi layers deposited via low-pressure chemical vapor deposition and subsequently annealed. The impact of doping profile on the passivation quality of the polySi doped contacts is studied for both polarities. It was found that an excellent surface passivation could be obtained by confining as much as possible the implanted-and-activated dopants within the polySi layers. The doping profile in the polySi was controlled by modifying the polySi thickness, the energy and dose of ion-implantation, and the temperature and time of annealing. An implied open-circuit voltage of 721 mV for n-type and 692 mV for p-type passivating contacts was achieved. Besides the high passivating quality, the developed passivating contacts exhibit reasonable high conductivity (R sh n-type  = 95 Ω/□ and R sh p-type  = 120 Ω/□). An efficiency of 19.2% (V oc  = 673 mV, J sc  = 38.0 mA/cm 2 , FF = 75.2%, and pseudo-FF = 83.2%) was achieved on a front-textured IBC solar cell with polySi passivating contacts as both back surface field and emitter. By improving the front-side passivation, a V OC of 696 mV was also measured

Tunnel oxide passivated contacts formed by ion implantation for applications in silicon solar cells

International Nuclear Information System (INIS)

Reichel, Christian; Feldmann, Frank; Müller, Ralph; Hermle, Martin; Glunz, Stefan W.; Reedy, Robert C.; Lee, Benjamin G.; Young, David L.; Stradins, Paul

2015-01-01

Passivated contacts (poly-Si/SiO x /c-Si) doped by shallow ion implantation are an appealing technology for high efficiency silicon solar cells, especially for interdigitated back contact (IBC) solar cells where a masked ion implantation facilitates their fabrication. This paper presents a study on tunnel oxide passivated contacts formed by low-energy ion implantation into amorphous silicon (a-Si) layers and examines the influence of the ion species (P, B, or BF 2 ), the ion implantation dose (5 × 10 14  cm −2 to 1 × 10 16  cm −2 ), and the subsequent high-temperature anneal (800 °C or 900 °C) on the passivation quality and junction characteristics using double-sided contacted silicon solar cells. Excellent passivation quality is achieved for n-type passivated contacts by P implantations into either intrinsic (undoped) or in-situ B-doped a-Si layers with implied open-circuit voltages (iV oc ) of 725 and 720 mV, respectively. For p-type passivated contacts, BF 2 implantations into intrinsic a-Si yield well passivated contacts and allow for iV oc of 690 mV, whereas implanted B gives poor passivation with iV oc of only 640 mV. While solar cells featuring in-situ B-doped selective hole contacts and selective electron contacts with P implanted into intrinsic a-Si layers achieved V oc of 690 mV and fill factor (FF) of 79.1%, selective hole contacts realized by BF 2 implantation into intrinsic a-Si suffer from drastically reduced FF which is caused by a non-Ohmic Schottky contact. Finally, implanting P into in-situ B-doped a-Si layers for the purpose of overcompensation (counterdoping) allowed for solar cells with V oc of 680 mV and FF of 80.4%, providing a simplified and promising fabrication process for IBC solar cells featuring passivated contacts

Thermal change and ion exchange properties of zeolite L with cesium and strontium

International Nuclear Information System (INIS)

Mimura, Hitoshi; Akiba, Kenichi

1986-01-01

Thermal change and ion exchange properties of Cs and Sr have been studied for zeolite L. The zeolite structure is stable below 900 deg C and converts to the amorphous phase above 1000 deg C. The cesium form of zeolite L recrystallized to pollucite (CsAlSi 2 O 6 ) by calcination at 1400 deg C for 1 h or under hydrothermal condition (300 deg C, 290 atm, 24 h). Hydrogen-form zeolites were prepared by the acid treatment in 10 -2 ∼ 10 -1 M HNO 3 solutions or thermal decomposition of NH 4 form zeolites at 460 ∼ 500 deg C. The distribution of Cs and Sr was dependent on equilibrium pH and the distribution coefficient (K d ) was about 10 4 (ml/g) at pH 5 ∼ 7. The exchange capacity of Cs and Sr was 0.89 (meq./g zeolite) and exchanging ratio was 68 % at D sites in main channel. These cations in zeolite were completely eluted with 10 -1 M HNO 3 solution. (author)

Cs+ ion source for secondary ion mass spectrometry

International Nuclear Information System (INIS)

Bentz, B.L.; Weiss, H.; Liebl, H.

1981-12-01

Various types of cesium ionization sources currently used in secondary ion mass spectrometry are briefly reviewed, followed by a description of the design and performance of a novel, thermal surface ionization Cs + source developed in this laboratory. The source was evaluated for secondary ion mass spectrometry applications using the COALA ion microprobe mass analyzer. (orig.)

Copper hexacyanoferrate functionalized single-walled carbon nano-tubes for selective cesium extraction

International Nuclear Information System (INIS)

Draouil, H.; Alvarez, L.; Bantignies, J.L.; Causse, J.; Cambedouzou, J.; Flaud, V.; Zaibi, M.A.; Oueslati, M.

2017-01-01

Single-walled carbon nano-tubes (SWCNTs) are functionalized with copper hexacyanoferrate (CuHCF) nanoparticles to prepare solid substrates for sorption of cesium ions (Cs + ) from liquid outflows. The high mechanical resistance and large electrical conductivity of SWCNTs are associated with the ability of CuHCF nanoparticles to selectively complex Cs + ions in order to achieve membrane-like buckypapers presenting high loading capacity of cesium. The materials are thoroughly characterized using electron microscopy, Raman scattering, X-ray photoelectron spectroscopy and thermogravimetric analyses. Cs sorption isotherms are plotted after having measured the Cs + concentration by liquid phase ionic chromatography in the solution before and after exposure to the materials. It is found that the total sorption capacity of the material reaches 230 mg.g -1 , and that about one third of the sorbed Cs (80 mg.g -1 ) is selectively complexed in the CuHCF nanoparticles grafted on SWCNTs. The quantification of Cs + ions on different sorption sites is made for the first time, and the high sorption rates open interesting outlooks in the integration of such materials in devices for the controlled sorption and desorption of these ions. (authors)

Methods of producing cesium-131

Science.gov (United States)

Meikrantz, David H; Snyder, John R

2012-09-18

Methods of producing cesium-131. The method comprises dissolving at least one non-irradiated barium source in water or a nitric acid solution to produce a barium target solution. The barium target solution is irradiated with neutron radiation to produce cesium-131, which is removed from the barium target solution. The cesium-131 is complexed with a calixarene compound to separate the cesium-131 from the barium target solution. A liquid:liquid extraction device or extraction column is used to separate the cesium-131 from the barium target solution.

Uptake of vaporized molybdenum and cesium tracers by molten oxide mixtures as function of free oxygen ion activity

International Nuclear Information System (INIS)

Carmon, B.

1975-11-01

Molten mixtures of oxides containing Ca, Fe, Al, Na and Si were exposed to vaporized Mo-99 and Cs-137 tracers at 1100 and 1300 deg C. Uptake values at 1300 deg C were extrapolated to short heating times. The obtained ''attachment coefficients'' for that temperature are shown to have the relationship (Mo) approximately equal to (Cs)sup(-1/2). The chemical composition of the melts and their oxygen to metal ratio found to affect the uptake of both tracers. This is associated with the cationic field strengths and the free oxygen ion activities in the mixtures. Molybdenum and cesium apparently behave like glass-network forming and glass-network modifying species, respectively. (author)

Cobalt and nickel ferrocyanide-functionalized magnetic adsorbent for the removal of radioactive cesium

Energy Technology Data Exchange (ETDEWEB)

Hwang, Kyu Sun; Park, Chan Woo; Lee, Kune Woo; Yang, Hee Man [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Park, So Jin [Chungnam National University, Daejeon (Korea, Republic of)

2017-03-15

Cobalt ferrocyanide (CoFC) or nickel ferrocyanide (NiFC) magnetic nanoparticles (MNPs) were fabricated for efficient removal of radioactive cesium, followed by rapid magnetic separation of the absorbent from contaminated water. The Fe{sub 3}O{sub 4} nanoparticles, synthesized using a co-precipitation method, were coated with succinic acid (SA) to immobilize the Co or Ni ions through metal coordination to carboxyl groups in the SA. CoFC or NiFC was subsequently formed on the surfaces of the MNPs as Co or Ni ions coordinated with the hexacyanoferrate ions. The CoFC-MNPs and NiFC-MNPs possess good saturation magnetization values (43.2 emu∙g{sup -1} for the CoFC-MNPs, and 47.7 emu∙g{sup -1} for the NiFC-MNPs). The fabricated CoFC-MNPs and NiFC-MNPs were characterized by XRD, FT-IR, TEM, and DLS. The adsorption capability of the CoFC-MNPs and NiFC-MNPs in removing cesium ions from water was also investigated. Batch experiments revealed that the maximum adsorption capacity values were 15.63 mg∙g{sup -1} (CoFC-MNPs) and 12.11 mg∙g{sup -1} (NiFC-MNPs). Langmuir/ Freundlich adsorption isotherm equations were used to fit the experimental data and evaluate the adsorption process. The CoFC-MNPs and NiFC-MNPs exhibited a removal efficiency exceeding 99.09% for radioactive cesium from {sup 137}Cs solution (18-21 Bq∙g{sup -1}). The adsorbent selectively adsorbed {sup 137}Cs, even in the presence of competing cations.

1/f Fluctuations in ion implanted metal semiconductor contacts

International Nuclear Information System (INIS)

Stojanovic, M.; Marjanovic, N.; Radojevic, B.

1998-01-01

Ion implanted Metal-Semiconductor contacts is the most widely used structures in electrical devices. Weather complete devices or some parts are of interest, properties of metal-semiconductor junction strongly influence the quality and external characteristic of electronic devices. That is the reason why special attention is paid to the investigation of factor (noise for example) that could influence given junction. Low frequency 1/f fluctuations (noise) are constantly present in metal-semiconductor junction, so measurement of their level as well as the dependence on factors such as temperature must be taken into account in detailed analysis of electrical characteristics of devices such as contact, nuclear detector with surface barrier etc. In this paper we present the results of low frequency noise level measurements on TiN-Ti-Si structures produced by As + ion implantation. (author)

Prussian blue caged in spongiform adsorbents using diatomite and carbon nanotubes for elimination of cesium.

Science.gov (United States)

Hu, Baiyang; Fugetsu, Bunshi; Yu, Hongwen; Abe, Yoshiteru

2012-05-30

We developed a spongiform adsorbent that contains Prussian blue, which showed a high capacity for eliminating cesium. An in situ synthesizing approach was used to synthesize Prussian blue inside diatomite cavities. Highly dispersed carbon nanotubes (CNTs) were used to form CNT networks that coated the diatomite to seal in the Prussian blue particles. These ternary (CNT/diatomite/Prussian-blue) composites were mixed with polyurethane (PU) prepolymers to produce a quaternary (PU/CNT/diatomite/Prussian-blue), spongiform adsorbent with an in situ foaming procedure. Prussian blue was permanently immobilized in the cell walls of the spongiform matrix and preferentially adsorbed cesium with a theoretical capacity of 167 mg/g cesium. Cesium was absorbed primarily by an ion-exchange mechanism, and the absorption was accomplished by self-uptake of radioactive water by the quaternary spongiform adsorbent. Copyright © 2012 Elsevier B.V. All rights reserved.

Prussian blue caged in spongiform adsorbents using diatomite and carbon nanotubes for elimination of cesium

Energy Technology Data Exchange (ETDEWEB)

Hu, Baiyang [Graduate School of Environmental Science, Hokkaido University, Sapporo 060-0810 (Japan); Fugetsu, Bunshi, E-mail: hu@ees.hokudai.ac.jp [Graduate School of Environmental Science, Hokkaido University, Sapporo 060-0810 (Japan); Yu, Hongwen [Graduate School of Environmental Science, Hokkaido University, Sapporo 060-0810 (Japan); Abe, Yoshiteru [Kyoei Engineering Corporation, Niigata 959-1961 (Japan)

2012-05-30

Highlights: Black-Right-Pointing-Pointer Prussian blue was sealed in cavities of diatomite using carbon nanotubes. Black-Right-Pointing-Pointer The caged Prussian blue after being permanently immobilized in polyurethane spongy showed a 167 mg/g capability for absorbing cesium. Black-Right-Pointing-Pointer Cesium elimination was accomplished by simply adding the Prussian-blue based spongiform adsorbent to radioactive water. - Abstract: We developed a spongiform adsorbent that contains Prussian blue, which showed a high capacity for eliminating cesium. An in situ synthesizing approach was used to synthesize Prussian blue inside diatomite cavities. Highly dispersed carbon nanotubes (CNTs) were used to form CNT networks that coated the diatomite to seal in the Prussian blue particles. These ternary (CNT/diatomite/Prussian-blue) composites were mixed with polyurethane (PU) prepolymers to produce a quaternary (PU/CNT/diatomite/Prussian-blue), spongiform adsorbent with an in situ foaming procedure. Prussian blue was permanently immobilized in the cell walls of the spongiform matrix and preferentially adsorbed cesium with a theoretical capacity of 167 mg/g cesium. Cesium was absorbed primarily by an ion-exchange mechanism, and the absorption was accomplished by self-uptake of radioactive water by the quaternary spongiform adsorbent.

Phase transition in lithium ammonium sulphate doped with cesium metal ions

Science.gov (United States)

Gaafar, M.; Kassem, M. E.; Kandil, S. H.

2000-07-01

Effects of doped cesium (C s+) metal ions (with different molar ratios n) on the phase transition of lithium ammonium sulphate LiNH 4SO 4 system have been studied by measuring the specific heat Cp( T) of the doped systems in the temperature range from 400 to 480 K. The study shows a peculiar phase transition of the pure system ( n=0) characterized by double distinct peaks, changed to a single sharp and narrow one as a result of the doping process. The measurements exhibit different effects of enhanced molar ratios of dopants on the phase transition behaviour of this system. At low dopant content ( n≤3%), the excess specific heat (Δ Cp) max at the transition temperature T1 decreases till a minimum value at n=0.8%, then it increases gradually. In this case, Δ Cp( T) behaviour is varied quantitatively and not modified. Enhanced dopant content ( n>3%) has a pronounced effect on the critical behaviour, which is significantly changed and considerably modified relative to the pure system. In addition, broadening of the critical temperature region, and decrease of (Δ Cp) max associated with changes of the Landau expansion coefficients are obtained and discussed. The study deals with the contribution of the thermally excited dipoles to the specific heat in the ferroelectric region and shows that their energy depends on doping.

Ion implantation into amorphous Si layers to form carrier-selective contacts for Si solar cells

International Nuclear Information System (INIS)

Feldmann, Frank; Mueller, Ralph; Reichel, Christian; Hermle, Martin

2014-01-01

This paper reports our findings on the boron and phosphorus doping of very thin amorphous silicon layers by low energy ion implantation. These doped layers are implemented into a so-called tunnel oxide passivated contact structure for Si solar cells. They act as carrier-selective contacts and, thereby, lead to a significant reduction of the cell's recombination current. In this paper we address the influence of ion energy and ion dose in conjunction with the obligatory high-temperature anneal needed for the realization of the passivation quality of the carrier-selective contacts. The good results on the phosphorus-doped (implied V oc = 725 mV) and boron-doped passivated contacts (iV oc = 694 mV) open a promising route to a simplified interdigitated back contact (IBC) solar cell featuring passivated contacts. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Analysis of cesium extracting solvent using GCMS and HPLC

International Nuclear Information System (INIS)

White, T.L.; Herman, C.C.; Crump, S.L.; Marinik, A.R.; Lambert, D.P.; Eibling, R.E.

2007-01-01

A high-level waste (HLW) remediation process scheduled to begin in 2007 at the Savannah River Site is the Modular Caustic Side Solvent Extraction (CSSX) Unit (MCU). The MCU will use a hydrocarbon solvent (diluent) containing a cesium extractant, a calix[4]arene compound, to extract radioactive cesium from caustic HLW. The resulting decontaminated HLW waste or raffinate will be processed into grout at the Saltstone Production Facility (SPF). The cesium containing CSSX stream will undergo washing with dilute nitric acid followed by stripping of the cesium nitrate into a very dilute nitric acid or the strip effluent stream and the CSSX solvent will be recycled. The Defense Waste Processing Facility (DWPF) will receive the strip effluent stream and immobilize the cesium into borosilicate glass. Excess CSSX solvent carryover from the MCU creates a potential flammability problem during DWPF processing. Bench-scale DWPF process testing was performed with simulated waste to determine the fate of the CSSX solvent components. A simple high performance liquid chromatography (HPLC) method was developed to identify the modifier (which is used to increase Cs extraction and extractant solubility) and extractant within the DWPF process. The diluent and trioctylamine (which is used to suppress impurity effect and ion-pair disassociation) were determined using gas chromatography mass spectroscopy (GCMS). To close the organic balance, two types of sample preparation methods were needed. One involved extracting aqueous samples with methylene chloride or hexane, and the second was capturing the off gas of the DWPF process using carbon tubes and rinsing the tubes with carbon disulfide for analysis. This paper addresses the development of the analytical methods and the bench-scale simulated waste study results. (author)

Sorption of cesium in intact rock

International Nuclear Information System (INIS)

Puukko, E.

2014-04-01

The mass distribution coefficient K d is used in performance assessment (PA) to describe sorption of a radionuclide on rock. The R d is determined using crushed rock which causes uncertainty in converting the R d values to K d values for intact rock. This work describes a method to determine the equilibrium of sorption on intact rock. The rock types of the planned Olkiluoto waste disposal site were T-series mica gneiss (T-MGN), T-series tonalite granodiorite granite gneiss (T-TGG), P-series tonalite granodiorite granite gneiss (P-TGG) and pegmatitic granite (PGR). These rocks contain different amount of biotite which is the main sorbing mineral. The sorption of cesium on intact rock slices was studied by applying an electrical field to speed up migration of cesium into the rock. Cesium is in the solution as a noncomplex cation Cs + and it is sorbed by ion exchange. The tracer used in the experiments was 134 Cs. The experimental sorption on the intact rock is compared with values calculated using the in house cation exchange sorption model (HYRL model) in PHREEQC program. The observed sorption on T-MGN and T-TGG rocks was close to the calculated values. Two PGR samples were from a depth of 70 m and three samples were from a depth of 150 m. Cesium sorbed more than predicted on the two 70 m PGR samples. The sorption of Cs on the three 150 m PGR samples was small which was consistent with the calculations. The pegmatitic granite PGR has the smallest content of biotite of the four rock types. In the case of P-TGG rock the observed values of sorption were only half of the calculated values. Two kind of slices were cut from P-TGG drill core. The slices were against and to the direction of the foliation of the biotite rims. The sorption of cesium on P-TGG rock was same in both cases. The results indicated that there was no effect of the directions of the electric field and the foliation of biotite in the P-TGG rock. (orig.)

Pre-design safety analyses of cesium ion-exchange compact processing unit

International Nuclear Information System (INIS)

Richmond, W.G.; Ballinger, M.Y.

1993-11-01

This report describes an innovative radioactive waste pretreatment concept. This cost-effective, highly flexible processing approach is based on the use of Compact Processing Units (CPUs) to treat highly radioactive tank wastes in proximity to the tanks themselves. The units will be designed to treat tank wastes at rates from 8 to 20 liters per minute and have the capacity to remove cesium, and ultimately other radionuclides, from 4,000 cubic meters of waste per year. This new concept is being integrated into waste per year. This new concept is being integrated into Hanford's tank farm management plans by a team of PNL and Westinghouse Hanford Company scientists and engineers. The first CPU to be designed and deployed will be used to remove cesium from Hanford double-shell tank (DST) supernatant waste. Separating Cs from the waste would be a major step toward lowering the radioactivity in the bulk of the waste, allowing it to be disposed of as a low-level solid waste form (e.g.,grout), while concentrating the more highly radioactive material for processing as high-level solid waste

Cesium reservoir and interconnective components

International Nuclear Information System (INIS)

1994-03-01

The program objective is to demonstrate the technology readiness of a TFE (thermionic fuel element) suitable for use as the basic element in a thermionic reactor with electric power output in the 0.5 to 5.0 MW range. A thermionic converter must be supplied with cesium vapor for two reasons. Cesium atoms adsorbed on the surface of the emitter cause a reduction of the emitter work function to permit high current densities without excessive heating of the emitter. The second purpose of the cesium vapor is to provide space-charge neutralization in the emitter-collector gap so that the high current densities may flow across the gap unattenuated. The function of the cesium reservoir is to provide a source of cesium atoms, and to provide a reserve in the event that cesium is lost from the plasma by any mechanism. This can be done with a liquid cesium metal reservoir in which case it is heated to the desired temperature with auxiliary heaters. In a TFE, however, it is desirable to have the reservoir passively heated by the nuclear fuel. In this case, the reservoir must operate at a temperature intermediate between the emitter and the collector, ruling out the use of liquid reservoirs. Integral reservoirs contained within the TFE will produce cesium vapor pressures in the desired range at typical electrode temperatures. The reservoir material that appears to be the best able to meet requirements is graphite. Cesium intercalates easily into graphite, and the cesium pressure is insensitive to loading for a given intercalation stage. The goals of the cesium reservoir test program were to verify the performance of Cs-graphite reservoirs in the temperature-pressure range of interest to TFE operation, and to test the operation of these reservoirs after exposure to a fast neutron fluence corresponding to seven year mission lifetime. In addition, other materials were evaluated for possible use in the integral reservoir

Impedance study of the ion-to-electron transduction process for carbon cloth as solid-contact material in potentiometric ion sensors

International Nuclear Information System (INIS)

Mattinen, Ulriika; Rabiej, Sylwia; Lewenstam, Andrzej; Bobacka, Johan

2011-01-01

Carbon cloth was studied as solid-contact material in potentiometric ion sensors by using electrochemical impedance spectroscopy and potentiometry. The ion-to-electron transduction process was studied by electrochemical impedance spectroscopy by using a two-electrode symmetrical cell where a liquid electrolyte was sandwiched between two solid electrodes, including bare glassy carbon (GC), GC/carbon cloth and GC/poly(3,4-ethylenedioxythiophene). Impedance data for different electrode/electrolyte combinations were evaluated and compared. Solid-contact K + -selective electrodes were fabricated by coating the carbon cloth with a conventional plasticized PVC-based K + -selective membrane via drop casting. These K + -sensors showed proper analytical performance and acceptable long-term potential stability (potential drift ≈ 1 mV/day). Solid contact reference electrodes were fabricated in an analogous manner by coating the carbon cloth with a plasticized PVC membrane containing a moderately lipophilic salt. The results indicate that carbon cloth can be used as a solid-contact material in potentiometric ion sensors and pseudo-reference electrodes.

Plasma diagnostic tools for optimizing negative hydrogen ion sources

International Nuclear Information System (INIS)

Fantz, U.; Falter, H.D.; Franzen, P.; Speth, E.; Hemsworth, R.; Boilson, D.; Krylov, A.

2006-01-01

The powerful diagnostic tool of optical emission spectroscopy is used to measure the plasma parameters in negative hydrogen ion sources based on the surface mechanism. Results for electron temperature, electron density, atomic-to-molecular hydrogen density ratio, and gas temperature are presented for two types of sources, a rf source and an arc source, which are currently under development for a neutral beam heating system of ITER. The amount of cesium in the plasma volume is obtained from cesium radiation: the Cs neutral density is five to ten orders of magnitude lower than the hydrogen density and the Cs ion density is two to three orders of magnitude lower than the electron density in front of the grid. It is shown that monitoring of cesium lines is very useful for monitoring the cesium balance in the source. From a line-ratio method negative ion densities are determined. In a well-conditioned source the negative ion density is of the same order of magnitude as the electron density and correlates with extracted current densities

Simple fabrication of back contact heterojunction solar cells by plasma ion implantation

Science.gov (United States)

Koyama, Koichi; Yamaguchi, Noboru; Hironiwa, Daisuke; Suzuki, Hideo; Ohdaira, Keisuke; Matsumura, Hideki

2017-08-01

A back-contact amorphous-silicon (a-Si)/crystalline silicon (c-Si) heterojunction is one of the most promising structures for high-efficiency solar cells. However, the patterning of back-contact electrodes causes the increase in fabrication cost. Thus, to simplify the fabrication of back-contact cells, we attempted to form p-a-Si/i-a-Si/c-Si and n-a-Si/i-a-Si/c-Si regions by the conversion of a patterned area of p-a-Si/i-a-Si/c-Si to n-a-Si/i-a-Si/c-Si by plasma ion implantation. It is revealed that the conversion of the conduction type can be realized by the plasma ion implantation of phosphorus (P) atoms into p-a-Si/i-a-Si/c-Si regions, and also that the quality of passivation can be kept sufficiently high, the same as that before ion implantation, when the samples are annealed at around 250 °C and also when the energy and dose of ion implantation are appropriately chosen for fitting to a-Si layer thickness and bulk c-Si carrier density.

IBC c-Si solar cells based on ion-implanted poly-silicon passivating contacts

NARCIS (Netherlands)

Yang, G.; Ingenito, A.; Isabella, O.; Zeman, M.

2016-01-01

Ion-implanted poly-crystalline silicon (poly-Si), in combination with a tunnel oxide layer, is investigated as a carrier-selective passivating contact in c-Si solar cells based on an interdigitated back contact (IBC) architecture. The optimized poly-Si passivating contacts enable low interface

Mineral resource of the month: cesium

Science.gov (United States)

Angulo, Marc A.

2010-01-01

The article offers information on cesium, a golden alkali metal derived from the Latin word caesium which means bluish gray. It mentions that cesium is the first element discovered with the use of spectroscopy. It adds that the leading producer and supplier of cesium is Canada and there are 50,000 kilograms of cesium consumed of the world in a year. Moreover, it states that only 85% of the cesium formate can be retrieved and recycled.

Physical barrier effect of geopolymeric waste form on diffusivity of cesium and strontium.

Science.gov (United States)

Jang, J G; Park, S M; Lee, H K

2016-11-15

The present study investigates the physical barrier effect of geopolymeric waste form on leaching behavior of cesium and strontium. Fly ash-based geopolymers and slag-blended geopolymers were used as solidification agents. The leaching behavior of cesium and strontium from geopolymers was evaluated in accordance with ANSI/ANS-16.1. The diffusivity of cesium and strontium in a fly ash-based geopolymer was lower than that in Portland cement by a factor of 10(3) and 10(4), respectively, showing significantly improved immobilization performance. The leaching resistance of fly ash-based geopolymer was relatively constant regardless of the type of fly ash. The diffusivity of water-soluble cesium and strontium ions were highly correlated with the critical pore diameter of the binder. The critical pore diameter of the fly ash-based geopolymer was remarkably smaller than those of Portland cement and slag-blended geopolymer; consequently, its ability physically to retard the diffusion of nuclides (physical barrier effect) was superior. Copyright © 2016 Elsevier B.V. All rights reserved.

Fabrication of stimuli-sensitive hydrogel for the removal of cesium

Energy Technology Data Exchange (ETDEWEB)

Yang, Hee-Man; Bong, Sang Bum; Park, Chan Woo; Lee, Kune Woo; Seo, Bum-Kyoung; Moon, Jei Kwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-05-15

The nuclear accident at the Fukushima Daiichi nuclear power station in 2011 released a huge quantity of radioactive contaminants into the environment.1 Among these, cesium Cs-137 is the most problematic contaminant due to its long half-life (30.2 years), and high-energy gamma ray (γ-ray) emissions. 2 Various surface including road, roof, house, building were contaminated with Cs-137. These coating materials have some problems and limitation such as toxic component, and lack of reusability of materials related to the cost. Thus, a more cost-effective and environmental friendly coating materials is still desired. 3 In the present study, the stimuli-sensitive hydrogel were fabricated for the removal of radioactive Cs from solid surface. We describe the morphology, structure, and physical property of these stimuli sensitive hydrogel. In addition, their ability to eliminate cesium was also evaluated. The smart hydrogel coating materials showed an excellent morphology change from the liquid to film by addition of Ca ion. Therefore, the stimuli-sensitive hydrogel demonstrated good potential for the treatment of contaminated surface for the removal of radioactive cesium.

Fabrication of stimuli-sensitive hydrogel for the removal of cesium

International Nuclear Information System (INIS)

Yang, Hee-Man; Bong, Sang Bum; Park, Chan Woo; Lee, Kune Woo; Seo, Bum-Kyoung; Moon, Jei Kwon

2015-01-01

The nuclear accident at the Fukushima Daiichi nuclear power station in 2011 released a huge quantity of radioactive contaminants into the environment.1 Among these, cesium Cs-137 is the most problematic contaminant due to its long half-life (30.2 years), and high-energy gamma ray (γ-ray) emissions. 2 Various surface including road, roof, house, building were contaminated with Cs-137. These coating materials have some problems and limitation such as toxic component, and lack of reusability of materials related to the cost. Thus, a more cost-effective and environmental friendly coating materials is still desired. 3 In the present study, the stimuli-sensitive hydrogel were fabricated for the removal of radioactive Cs from solid surface. We describe the morphology, structure, and physical property of these stimuli sensitive hydrogel. In addition, their ability to eliminate cesium was also evaluated. The smart hydrogel coating materials showed an excellent morphology change from the liquid to film by addition of Ca ion. Therefore, the stimuli-sensitive hydrogel demonstrated good potential for the treatment of contaminated surface for the removal of radioactive cesium

Cesium-137 inventory of the undisturbed soil areas in the Londrina Region, Parana, Brazil

International Nuclear Information System (INIS)

Andrello, Avacir C.; Appoloni, Carlos Roberto

2005-01-01

Cesium-137 is an artificial radionuclide introduced in the environment through the radioactive fallout of the superficial tests of nuclear weapons. The cesium-137 deposition occurred to middles of the 1980-decade and, due to the Chernobyl accident, great part of Europe had a additional fallout of cesium-137. The contaminations of this accident do not have reached Southern Hemisphere. Cesium-137 is an alkaline metal, high electropositive, that in contact with the soil is strongly adsorbed to the clay in the FES (Frayed Edge Sites) and RES (Regular Edge Sites) positions, and it movement by chemical processes in the soil is insignificant. Because of this, cesium-137 became a good soil marker, and its movement is related to the soil movement particles, so that the cesium-137 have been used in the study of the soil redistribution processes, as a tool of quantifying the rates of soil losses and gain. To use this methodology, it is necessary the knowledge of the reference inventory of cesium-137, that is given as function of the total concentration of cesium-137 deposited in an area by the radioactive fallout. If a sampling point presents less cesium-137 than the reference inventory, this point is considered a point with soil loss; otherwise, the point is considered a point with soil deposition. To evaluate the cesium-137 inventory in the Londrina region, four areas of the undisturbed soil were sampling in grid of 3x3, with a distance of 9 meters among the points. Of these four sampling areas, three areas were of native forest (labeled Mata1, Mata2 and Mata UEL), and one was a pasture area. Cesium-137 inventory was 223 ± 41 Bq m -2 , 240 ± 65 Bq m -2 and 305 ± 36 Bq m -2 for Mata UEL, Mata1 and Mata2, respectively, and of 211 ± 28 Bq m -2 for the native pasture. Considering the deviation in each value, it is not possible to conclude that there are differences among the values of cesium-137 inventory, so that the average reference inventory of cesium-137 for the

Preparation of Modified Kaolin Filler with Cesium and Its Application in Security Paper

Directory of Open Access Journals (Sweden)

Houssni El-Saied

2013-01-01

Full Text Available In this study, cesium was added intentionally during paper manufacture for protecting the papers against forgery and counterfeiting by sorbing cesium ions (Cs+ on kaolin, used as special filler in papermaking. The sorption of cesium from aqueous solution by kaolin was studied as a function of pH, shaking time, cesium initial concentration, and mass of kaolin using batch technique. The results showed that a solution containing 10 mg/L Cs+ and 250 mg of kaolin at pH 6 can be used to modify the kaolin. Paper handsheets were prepared containing various percentages of the modified kaolin. The mechanical and optical properties of paper handsheets were studied. The prepared paper handsheets were irradiated by gamma irradiation using different doses. Fourier transform infrared (FTIR spectroscopy was used to study the effect of kaolin modification by cesium and gamma irradiation on paper handsheets properties. The results indicated that modified kaolin enhanced the mechanical and optical properties of paper handsheets. Electron spin resonance (ESR spectroscopy and laser-induced breakdown spectroscopy (LIBS were also used. They provided rapid, sensitive and nondestructive techniques in differentiating between different questioned documents. This study presents a new concept in manufacturing security papers and anticounterfeiting applications.

Development program for magnetically assisted chemical separation: Evaluation of cesium removal from Hanford tank supernatant

International Nuclear Information System (INIS)

Nunez, L.; Buchholz, B.A.; Ziemer, M.; Dyrkacz, G.; Kaminski, M.; Vandegrift, G.F.; Atkins, K.J.; Bos, F.M.; Elder, G.R.; Swift, C.A.

1994-12-01

Magnetic particles (MAG*SEP SM ) coated with various absorbents were evaluated for the separation and recovery of low concentrations of cesium from nuclear waste solutions. The MAG*SEP SM particles were coated with (1) clinoptilolite, (2) transylvanian volcanic tuff, (3) resorcinol formaldehyde, and (4) crystalline silico-titanate, and then were contacted with a Hanford supernatant simulant. Particles coated with the crystalline silico-titanate were identified by Bradtec as having the highest capacity for cesium removal under the conditions tested (variation of pH, ionic strength, cesium concentration, and absorbent/solution ratio). The MAG*SEP SM particles coated with resorcinol formaldehyde had high distribution ratios values and could also be used to remove cesium from Hanford supernant simulant. Gamma irradiation studies were performed on the MAG*SEP SM particles with a gamma dose equivalent to 100 cycles of use. This irradiation decreased the loading capacity and distribution ratios for the particles by greater than 75%. The particles demonstrated high sensitivity to radiolytic damage due to the degradation of the polymeric regions. These results were supported by optical microscopy measurements. Overall, use of magnetic particles for cesium separation under nuclear waste conditions was found to be marginally effective

Immobilization of inorganic ion-exchanger into bio-polymer foams - Application to cesium sorption

International Nuclear Information System (INIS)

Vincent, Chloe; Hertz, Audrey; Barre, Yves; Vincent, Thierry; Guibal, Eric

2014-01-01

Nickel-potassium ferrocyanide (along with other ferrocyanide sub-products, as shown by mineralization, SEM-EDX and XRD analyses) has been immobilized in highly porous discs of chitin for the sorption of Cs(I) from near neutral solutions. The immobilization process allows synthesizing stable materials that can bind up to 80 mg Cs g -1 (i.e., 240 mg Cs g -1 ion-exchanger). Cesium sorption is hardly affected by the pH between pH 2 and 8. The sorbent is selective to Cs(I) even in the presence of high concentrations of Na(I), K(I), Rb(I) or NH 4+ . The pseudo-second order rate equation fits well kinetic profiles: the rate coefficient increases with the flow rate of recirculation (to force the access to potentially non-interconnected pores), as an evidence of the control of uptake kinetics by diffusion properties. In fixed-bed columns, the breakthrough curve is accurately described by the Clark model and the sorption capacity (at sorbent saturation) is consistent with the values obtained in sorption isotherms. Preliminary tests performed on 137 Cs spiked solutions confirm the efficiency of the material for the treatment of effluents bearing radionuclides. (authors)

Pulsed vapor source for use in ion sources for heavy-ion accelerators

International Nuclear Information System (INIS)

Shiloh, J.; Chupp, W.; Faltens, A.; Keefe, D.; Kim, C.; Rosenblum, S.; Tiefenback, M.

1980-01-01

A pulsed cesium vapor source for use in ion sources for high-current heavy-ion accelerators is described. The source employs a vacuum spark in Cs and its properties are measured with a hot-filament Cs detector

H- ion production from different converter materials

International Nuclear Information System (INIS)

Leung, K.N.; Ehlers, K.W.

1984-10-01

For heating plasmas and for current drive in some fusion reactors, high energy neutral beams may be required. The high neutralization efficiency of H - or D - ions makes them favorable to form neutral atoms with energies in excess of 160 keV. It has been shown that a steady-state H - ion beam with current greater than 1 A can be generated by a surface conversion type source with Mo being used as the converter material. In order to achieve the proper cesium coverage and thereby increasing the H - ion yield, the application of porous cesium-dispensing converters is being investigated. It is also possible to optimize the H - production by choosing the proper converter material. In this paper, we compare the negative ion yield generated by different materials (such as Mo, Ti, V, Nb, Pt, Pd, Rh, Cu, Ta, Al, Au, LaB 6 and stainless-steel) in the pure hydrogen and cesium-hydrogen modes of operation

The emittance and brightness characteristics of negative ion sources suitable for MeV ion implantation

International Nuclear Information System (INIS)

Alton, G.D.

1987-01-01

This paper provides the description and beam properties of ion sources suitable for use with ion implantation devices. Particular emphasis is placed on the emittance and brightness properties of state-of-the-art, high intensity, negative ion sources based on the cesium ion sputter principle

Cesium in the nutrient cycle. Cesium metsaen ravinnekierrossa marjojen ja sienten cesium ei vaehene

Energy Technology Data Exchange (ETDEWEB)

Rantavaara, A

1992-01-01

Most radioactive cesium in forests is deposited in soil, from which it passes into berries and mushrooms, and further to game. The cesium contents of Finnish berries and mushrooms vary depending on the intensity of Chernobyl fallout. Northern Haeme, Pirkanmaa and parts of central Finland received the most fallout. Weather conditions and the environmental factors, and other circumstances during the growth period, also affect the contents. However, consumption of wild berries, mushrooms and game need not be restricted because of radioactivity anywhere in Finland.

Hyperfine structure, nuclear spins and magnetic moments of some cesium isotopes

International Nuclear Information System (INIS)

Ekstroem, C.; Ingelman, S.; Wannberg, G.

1977-03-01

Using an atomic-beam magnetic resonance apparatus connected on-line with the ISOLDE isotope separator, CERN, hyperfine structure measurements have been performed in the 2 Ssub(1/2) electronic ground state of some cesium isotopes. An on-line oven system which efficiently converts a mass separated ion-beam of alkali isotopes to an atomic beam is described in some detail. Experimentally determined nuclear spins of sup(120, 121, 121m, 122, 122m, 123, 124, 126, 128, 130m, 135m)Cs and magnetic moments of sup(122, 123, 124, 126, 128, 130)Cs are reported and discussed in terms of different nuclear models. The experimental data indicate deformed nuclear shapes of the lightest cesium isotopes. (Auth.)

Recent advances of numerical simulation studies for radioactive cesium adsorption on soil materials

International Nuclear Information System (INIS)

Okumura, Masahiko; Nakamura, Hiroki; Machida, Masahiko

2013-01-01

Radiocesium (Cesium 134 and 137) emitted from destroyed Fukushima Daiichi Nuclear Power Production Station is known mostly to remain for a long time on earth's surfaces and to become sources of radiation exposure to habitants. Large scale decontamination work carried out by national and local governments inevitably produces tremendous amount of radioactive wastes of soils whose volume must be effectively and economically reduced based on a scientifically reliable technique. This paper employs the atomic and molecular simulation method applied to adsorption mechanism of soils and cesium ions and presents the examples of proposals with the results of this field. (S. Ohno)

Comparison or organic and inorganic ion exchange materials for removal of cesium and strontium from Hanford waste

Energy Technology Data Exchange (ETDEWEB)

Brown, G.N.; Carson, K.J.; DesChane, J.R.; Elovich, R.J. [Pacific Northwest National Lab., Richland, WA (United States)

1997-10-01

This work is part of an ESP-CP task to develop and evaluate high-capacity, selective, solid extractants for the uptake of cesium, strontium, and technetium (Cs, Sr, and Tc) from nuclear wastes. Pacific Northwest National Laboratory (PNNL) staff, in collaboration with researchers from industry, academia, and national laboratories are investigating these and other novel and commercial ion exchangers for use in nuclear waste remediation of groundwater, HLW, and LLW. Since FY 1995, experimental work at PNNL has focused on small-scale batch distribution (K{sub d}) testing of numerous solid sorbents with actual and simulated Hanford wastes, chemical and radiolytic stability of various organic ion exchanger resins, bench-scale column ion exchange testing in actual and simulated Complexant Concentrate (CC) and Neutralized Current Acid Waste (NCAW), and Tc and Sr removal from groundwater and LLW. In addition, PNNL has continued to support various site demonstrations at the Idaho National Engineering Laboratory, Savannah River Site, West Valley Nuclear Services, Hanford N-Springs, and Hanford N-Basin using technologies developed by their industrial partners. This summary will focus on batch distribution results from the actual waste tests. The data collected in these development and testing tasks provide a rational basis for the selection and direct comparison of various ion exchange materials in simulated and actual HLW, LLW, and groundwater. In addition, prediction of large-scale column loading performance for the materials tested is possible using smaller volumes of actual waste solution. The method maximizes information while minimizing experimental expense, time, and laboratory and process wastes.

Fundamental properties of secondary negative ion emission by sputtering

International Nuclear Information System (INIS)

Shimizu, Toshiki; Tsuji, Hiroshi; Ishikawa, Junzo

1989-01-01

The report describes some results obtained from preliminary experiments on secondary negative ion emission from a cesiated surface by Xe-ion beam sputtering, which give the production probability. A measuring system is constructed for secondary negative ion emission. The system consists of a microwave ion source with a lens, a sputtering target holder with a heater, a cesium oven, a limiting aperture with a substrate for deposition, a negative-ion extractor and lens, and a ExB type mass separator. Observations are made on the dependence of negative ion current on cesium supply, dependence of negative ion current on target temperature, and negative ion production probability. The cesium supply and the target temperature are found to strongly influence the negative ion emission. By controlling these factors, the optimum condition for secondary negative ion emission is achieved with a minimum surface work function. The production probability of the negative ion is found to be very high, about 20% for carbon. Therefore, the secondary negative ion emission is considered a useful and highly efficient method to obtain high current ion beams. The constant in the Rasser's theoretical equation is experimentally determined to be 4.1 x 10 -4 eV sec/m. (N.K.)

Strontium-90 and cesium-137 in sea sediments (from May 1984 to Sep 1984)

International Nuclear Information System (INIS)

1984-01-01

Strontium-90 and cesium-137 monitoring results are presented for sea sediment samples of 12 sampling points located all over Japan from Tomari, Hokkaido to Kinnakagusuku Bay, Okinawa. The samples were collected by considering of enough sea water depth, no significant sedimental movement and sediment characteristics, and by employing a conventional sampling device. Approximately 4 kg-wet sample was dried and was passed through a 20 cm mesh sieve. After adding of strontium and cesium carriers, strontium-90 and cesium-137 were leached with a hot hydrochloric acid solution. The leachate was treated by ion exchange and coprecipitation to concentrate and isolate strontium-90 or cesium-137. Radiation counting was carried out by employing a low background beta counter usually for 60 minutes for the samples of strontium carbonate or cesium chloroplatinate. Determined strontium-90 contents in sea sediment were distributed from 0 +- 2.7 pCi/kg-dry (Mutsu Bay, Aomori, Yamaguchi Bay, Yamaguchi) to 14 +- 3.2 pCi/kg-dry (Mutsu Bay), and those of cesium-137 were from 9 +- 3.5 pCi/kg-dry (Mutsu Bay) to 250 +- 9 pCi/kg-dry (Off-Niigata Port, Niigata). Local variation of the contents of these radionuclides was very large, and for seasonal variation, it was also found large for the both nuclides content in the Mutsu Bay samples of May, 1984 and August 1984, as for strontium-90, 0 +- 2.7 pCi/kg and 14 +- 3.2 pCi/kg, for cesium-137, 9 +- 3.5 pCi/kg and 200 +- 8 pCi/kg, respectively. (Takagi, S.)

Electrically switched ion exchange

Energy Technology Data Exchange (ETDEWEB)

Lilga, M.A. [Pacific Northwest National Lab., Richland, WA (United States); Schwartz, D.T.; Genders, D.

1997-10-01

A variety of waste types containing radioactive {sup 137}Cs are found throughout the DOE complex. These waste types include water in reactor cooling basins, radioactive high-level waste (HLW) in underground storage tanks, and groundwater. Safety and regulatory requirements and economics require the removal of radiocesium before these wastes can be permanently disposed of. Electrically Switched Ion Exchange (ESIX) is an approach for radioactive cesium separation that combines IX and electrochemistry to provide a selective, reversible, and economic separation method that also produces little or no secondary waste. In the ESIX process, an electroactive IX film is deposited electrochemically onto a high-surface area electrode, and ion uptake and elution are controlled directly by modulating the potential of the film. For cesium, the electroactive films under investigation are ferrocyanides, which are well known to have high selectivities for cesium in concentrated sodium solutions. When a cathode potential is applied to the film, Fe{sup +3} is reduced to the Fe{sup +2} state, and a cation must be intercalated into the film to maintain charge neutrality (i.e., Cs{sup +} is loaded). Conversely, if an anodic potential is applied, a cation must be released from the film (i.e., Cs{sup +} is unloaded). Therefore, to load the film with cesium, the film is simply reduced; to unload cesium, the film is oxidized.

Physical Property Modeling of Concentrated Cesium Eluate Solutions, Part I - Derivation of Models

Energy Technology Data Exchange (ETDEWEB)

Choi, A.S.; Pierce, R. A.; Edwards, T. B.; Calloway, T. B.

2005-09-15

Major analytes projected to be present in the Hanford Waste Treatment Plant cesium ion-exchange eluate solutions were identified from the available analytical data collected during radioactive bench-scale runs, and a test matrix of cesium eluate solutions was designed within the bounding concentrations of those analytes. A computer model simulating the semi-batch evaporation of cesium eluate solutions was run in conjunction with a multi-electrolyte aqueous system database to calculate the physical properties of each test matrix solution concentrated to the target endpoints of 80% and 100% saturation. The calculated physical properties were analyzed statistically and fitted into mathematical expressions for the bulk solubility, density, viscosity, heat capacity and volume reduction factor as a function of temperature and concentration of each major analyte in the eluate feed. The R{sup 2} of the resulting physical property models ranged from 0.89 to 0.99.

Sympathetic cooling in a rubidium cesium mixture: Production of ultracold cesium atoms; Sympathetisches Kuehlen in einer Rubidium-Caesium-Mischung: Erzeugung ultrakalter Caesiumatome

Energy Technology Data Exchange (ETDEWEB)

Haas, M.

2007-07-01

This thesis presents experiments for the production of ultracold rubidium cesium mixture in a magnetic trap. The long-termed aim of the experiment is the study of the interaction of few cesium atoms with a Bose-Einstein condensate of rubidium atoms. Especially by controlled variation of the cesium atom number the transition in the description of the interaction by concepts of the one-particle physics to the description by concepts of the many-particle physics shall be studied. The rubidium atoms are trapped in a magneto-optical trap (MOT) and from there reloaded into a magnetic trap. In this the rubidium atoms are stored in the state vertical stroke f=2,m{sub f}=2 right angle of the electronic ground state and evaporatively cooled by means of microwave-induced transitions into the state vertical stroke f=1,m{sub f}=1] (microwave cooling). The cesium atoms are also trppaed in a MOT and into the same magnetic trap reloaded, in which they are stored in the state vertical stroke f=4,m{sub f}=4 right angle of the electronic ground state together with rubidium. Because of the different hyperfine splitting only rubidium is evaporatively cooled, while cesium is cooled jointly sympathetically - i.e. by theramal contact via elastic collisions with rubidium atoms. The first two chapters contain a description of interatomic interactions in ultracold gases as well as a short summary of theoretical concepts in the description of Bose-Einstein condensates. The chapters 3 and 4 contain a short presentation of the methods applied in the experiment for the production of ultracold gases as well as the experimental arrangement; especially in the framework of this thesis a new coil system has been designed, which offers in view of future experiments additionally optical access for an optical trap. Additionally the fourth chapter contains an extensive description of the experimental cycle, which is applied in order to store rubidium and cesium atoms together into the magnetic trap. The

Physical barrier effect of geopolymeric waste form on diffusivity of cesium and strontium

Energy Technology Data Exchange (ETDEWEB)

Jang, J.G.; Park, S.M.; Lee, H.K., E-mail: haengki@kaist.ac.kr

2016-11-15

Highlights: • Physical immobilization of radionuclides in geopolymer was quantitatively assessed. • Fly ash-based geopolymer showed excellent immobilization performance. • Diffusivity of soluble Cs and Sr was highly correlated with critical pore diameter. - Abstract: The present study investigates the physical barrier effect of geopolymeric waste form on leaching behavior of cesium and strontium. Fly ash-based geopolymers and slag-blended geopolymers were used as solidification agents. The leaching behavior of cesium and strontium from geopolymers was evaluated in accordance with ANSI/ANS-16.1. The diffusivity of cesium and strontium in a fly ash-based geopolymer was lower than that in Portland cement by a factor of 10{sup 3} and 10{sup 4}, respectively, showing significantly improved immobilization performance. The leaching resistance of fly ash-based geopolymer was relatively constant regardless of the type of fly ash. The diffusivity of water-soluble cesium and strontium ions were highly correlated with the critical pore diameter of the binder. The critical pore diameter of the fly ash-based geopolymer was remarkably smaller than those of Portland cement and slag-blended geopolymer; consequently, its ability physically to retard the diffusion of nuclides (physical barrier effect) was superior.

Cesium transport data for HTGR systems

International Nuclear Information System (INIS)

Myers, B.F.; Bell, W.E.

1979-09-01

Cesium transport data on the release of cesium from HTGR fuel elements are reviewed and discussed. The data available through 1976 are treated. Equations, parameters, and associated variances describing the data are presented. The equations and parameters are in forms suitable for use in computer codes used to calculate the release of metallic fission products from HTGR fuel elements into the primary circuit. The data cover the following processes: (1) diffusion of cesium in fuel kernels and pyrocarbon, (2) sorption of cesium on fuel rod matrix material and on graphite, and (3) migration of cesium in graphite. The data are being confirmed and extended through work in progress

Large aperture contact ionized Cs+1 ion source for an induction linac

International Nuclear Information System (INIS)

Abbott, S.; Chupp, W.; Faltens, A.; Herrmannsfeldt, W.; Hoyer, E.; Keefe, D.; Kim, C.H.; Rosenblum, S.; Shiloh, J.

1979-03-01

A 500 KeV one-ampere Cs +1 ion beam has been generated by contact ionization with a 30 cm dia. iridium hot plate. Reproducibility of space charge limited ion current wave forms at repetition rates up to 1 Hz has been verified. The beam is characterized to be very bright and suitable as an ion source for the induction linac based heavy ion fusion scheme. The hot anode plate was found to be reliable and self-cleaning during the operation

Colloid stable sorbents for cesium removal: Preparation and application of latex particles functionalized with transition metals ferrocyanides

Energy Technology Data Exchange (ETDEWEB)

Avramenko, Valentin [Institute of Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159 ave 100-letiya Vladivostoka, Vladivostok 690022 (Russian Federation); Bratskaya, Svetlana, E-mail: sbratska@ich.dvo.ru [Institute of Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159 ave 100-letiya Vladivostoka, Vladivostok 690022 (Russian Federation); Zheleznov, Veniamin; Sheveleva, Irina [Institute of Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159 ave 100-letiya Vladivostoka, Vladivostok 690022 (Russian Federation); Voitenko, Oleg [Far Eastern Federal University, Laboratory of Electron Microscopy and Image Processing, 27, Oktyabr' skaya Street, Vladivostok 690950 (Russian Federation); Sergienko, Valentin [Institute of Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159 ave 100-letiya Vladivostoka, Vladivostok 690022 (Russian Federation)

2011-02-28

In this paper we suggest a principally new approach to preparation of colloid stable selective sorbents for cesium uptake using immobilization of transition metals (cobalt, nickel, and copper) ferrocyanides in nanosized carboxylic latex emulsions. The effects of ferrocyanide composition, pH, and media salinity on the sorption properties of the colloid stable sorbents toward cesium ions were studied in solutions containing up to 200 g/L of sodium nitrate or potassium chloride. The sorption capacities of the colloid sorbents based on mixed potassium/transition metals ferrocyanides were in the range 1.3-1.5 mol Cs/mol ferrocyanide with the highest value found for the copper ferrocyanide. It was shown that the obtained colloid-stable sorbents were capable to penetrate through bulk materials without filtration that made them applicable for decontamination of solids, e.g. soils, zeolites, spent ion-exchange resins contaminated with cesium radionuclides. After decontamination of liquid or solid radioactive wastes the colloid-stable sorbents can be easily separated from solutions by precipitation with cationic flocculants providing localization of radionuclides in a small volume of the precipitates formed.

Extraction of radioactive cesium from tea leaves

International Nuclear Information System (INIS)

Yano, Yukiko; Kubo, M. Kenya; Higaki, Shogo; Hirota, Masahiro; Nomura, Kiyoshi

2011-01-01

Radioactive contamination of foodstuffs attributed to the Fukushima Daiichi nuclear disaster has become a social problem. This study investigated the extraction of radioactive cesium from the contaminated leaves to the tea. The green tea was brewed twice reusing the same leaves to study the difference in extraction of cesium between the first and second brew. Moreover, the extraction of cesium was studied in correlation to brewing time. The concentration of radioactive cesium was determined with gamma spectrometry, and the concentration of caffeine was determined with absorption spectrometry. About 40% of cesium was extracted from leaves in the first brew, and about 80% was extracted in the second brew. The extraction of cesium increased over time, and it reached about 80% after 10 minutes brew. The ratio of radioactive cesium to caffeine decreased linearly over time. This study revealed that the extraction of cesium was higher for the second brew, and a rapid increase in extraction was seen as the tea was brewed for 6 minutes and more. Therefore, the first brew of green tea, which was brewed within 5 minutes, contained the least extraction of radioactive cesium from the contaminated leaves. (author)

Observations of Two-Stream Ion Wave Instability

DEFF Research Database (Denmark)

Christoffersen, G.B.; Prahm, L.P.

1973-01-01

A double‐humped ion velocity distribution function is produced in a Q‐machine cesium plasma. When the plasma becomes unstable, a growing wave amplitude and a characteristic change in the phase velocity of a grid‐excited ion‐acoustic wave are observed.......A double‐humped ion velocity distribution function is produced in a Q‐machine cesium plasma. When the plasma becomes unstable, a growing wave amplitude and a characteristic change in the phase velocity of a grid‐excited ion‐acoustic wave are observed....

Characterization of cesium uptake mediated by a potassium transport system of bacteria in a soil conditioner

International Nuclear Information System (INIS)

Zhang, Pengyao; Idota, Yoko; Yano, Kentaro; Negishi, Masayuki; Kawabata, Hideaki; Arakawa, Hiroshi; Ogihara, Takuo; Morimoto, Kaori; Tsuji, Akira

2014-01-01

We found that bacteria in a commercial soil conditioner sold in Ishinomaki, Miyagi, exhibited concentrative and saturable cesium ion (Cs + ) uptake in the natural range of pH and temperature. The concentration of intracellular Cs + could be condensed at least a few times higher compared with the outside medium of the cells. This uptake appeared to be mediated by a K + transport system, since Cs + uptake was dose-dependently inhibited by potassium ion (K + ). Eadie-Hofstee plot analysis indicated that the Cs + uptake involved a single saturable process. The maximum uptake amount (J max ) was the same in the presence and absence of K + , suggesting that Cs + and K + uptakes were competitive with respect to each other. These bacteria might be useful for bioremediation of cesium-contaminated soil. (author)

Ion vs. ion pair receptor: NMR and DFT study of the interaction of Thallium and Cesium ions and ion pairs with meso-octamethylcalix[4]pyrrole

Czech Academy of Sciences Publication Activity Database

Kříž, Jaroslav; Dybal, Jiří; Makrlík, E.; Sedláková, Zdeňka

2012-01-01

Roč. 400, 25 May (2012), s. 19-28 ISSN 0301-0104 R&D Projects: GA ČR GA203/09/1478 Institutional research plan: CEZ:AV0Z40500505 Keywords : calix[4]pyrrole * cesium receptor * fluoride receptor Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.957, year: 2012

Metabolism of {sup 137}cesium, {sup 137}barium in the rat. Therapeutics of the contamination; Metabolisme du {sup 137}cesium, {sup 137}baryum chez le rat. Therapeutique de la contamination

Energy Technology Data Exchange (ETDEWEB)

Remy, J; Philippon, A; Lafuma, J; Walter, C [Commissariat a l' Energie Atomique, 92 - Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires. Departement de la Protection Sanitaire, Laboratoire de Radiopathologie

1967-07-01

The authors carry out research into the distribution kinetics, the metabolism and the excretion of {sup 137}Cs - {sup 137}Ba in the rat. They show that these phenomena are independent of the method of applying a single dose. The distribution tends to adopt in all cases a typical shape which remains the same depending on the body burden. Biological analysis of the state of the cesium in the biological media shows that it is transported in the free and ionised form. Considering the problem of the method of penetration of the cesium ion in the intracellular medium, and in particular by the in vivo and in vitro kinetic study of the plasma - red cell system, the authors make the assumption that an active transport of cesium occurs by the cell membrane. They thus arrive at an overall picture of the cesium distribution in the organism which is essentially characterized by a dynamic distribution equilibrium between two compartments: 99 per cent of the cesium accumulates in the intracellular pool, 1 per cent in the extracellular liquids. This latter compartment is open to the emunctories. Because, of the active transport by the cell membranes, the intracellular pool is filled rapidly but discharge is slow. This phenomenon is the limiting factor in the decrease of the body burden. From this representation, the authors deduce the reasons for the relative failure of the various therapeutic methods examined up till now by themselves or by other authors. The stimulation of the natural emunctories in the case of diuretics for example, can only improve the purification of the extracellular compartment. Now this latter contains only 1 per cent of the body burden and recharging is slow. Furthermore the methods designed to counteract or inhibit the active transport of cesium by the cell membrane are still at the present time incompatible with the survival of the cell. (authors) [French] Les auteurs etudient experimentalement la cinetique de distribution, le metabolisme et l

Metabolism of {sup 137}cesium, {sup 137}barium in the rat. Therapeutics of the contamination; Metabolisme du {sup 137}cesium, {sup 137}baryum chez le rat. Therapeutique de la contamination

Energy Technology Data Exchange (ETDEWEB)

Remy, J.; Philippon, A.; Lafuma, J.; Walter, C. [Commissariat a l' Energie Atomique, 92 - Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires. Departement de la Protection Sanitaire, Laboratoire de Radiopathologie

1967-07-01

The authors carry out research into the distribution kinetics, the metabolism and the excretion of {sup 137}Cs - {sup 137}Ba in the rat. They show that these phenomena are independent of the method of applying a single dose. The distribution tends to adopt in all cases a typical shape which remains the same depending on the body burden. Biological analysis of the state of the cesium in the biological media shows that it is transported in the free and ionised form. Considering the problem of the method of penetration of the cesium ion in the intracellular medium, and in particular by the in vivo and in vitro kinetic study of the plasma - red cell system, the authors make the assumption that an active transport of cesium occurs by the cell membrane. They thus arrive at an overall picture of the cesium distribution in the organism which is essentially characterized by a dynamic distribution equilibrium between two compartments: 99 per cent of the cesium accumulates in the intracellular pool, 1 per cent in the extracellular liquids. This latter compartment is open to the emunctories. Because, of the active transport by the cell membranes, the intracellular pool is filled rapidly but discharge is slow. This phenomenon is the limiting factor in the decrease of the body burden. From this representation, the authors deduce the reasons for the relative failure of the various therapeutic methods examined up till now by themselves or by other authors. The stimulation of the natural emunctories in the case of diuretics for example, can only improve the purification of the extracellular compartment. Now this latter contains only 1 per cent of the body burden and recharging is slow. Furthermore the methods designed to counteract or inhibit the active transport of cesium by the cell membrane are still at the present time incompatible with the survival of the cell. (authors) [French] Les auteurs etudient experimentalement la cinetique de distribution, le metabolisme et l

Decorporation of cesium-137; Decorporation du cesium-137

Energy Technology Data Exchange (ETDEWEB)

Le Fleche, Ph; Destombe, C; Grasseau, A; Mathieu, J; Chancerelle, Y; Mestries, J C [GMR, Direction des Recherches, Etudes et Techniques, 94 - Arcueil (France)

1998-12-31

Cesium radio-isotopes, especially cesium-137 ({sup 137}Cs) are among the radionuclides of main importance produced by a fission reaction in reactor or a nuclear weapon explosion. In the environment, {sup 137}Cs is a major contaminant which can cause severe {beta}, {gamma}irradiations and contaminations. {sup 137}Cs is distributed widely and relatively uniformly throughout the body with the highest concentration in skeletal muscles. A treatment becomes difficult afterwards. The purposes of this report are Firstly to compare the Prussian blue verses cobalt and potassium ferrocyanide (D.I. blue) efficiency for the {sup 137}Cs decorporation and secondly to assess a chronological treatment with D.I. blue. (author)

Decorporation of cesium-137; Decorporation du cesium-137

Energy Technology Data Exchange (ETDEWEB)

Le Fleche, Ph.; Destombe, C.; Grasseau, A.; Mathieu, J.; Chancerelle, Y.; Mestries, J.C. [GMR, Direction des Recherches, Etudes et Techniques, 94 - Arcueil (France)

1997-12-31

Cesium radio-isotopes, especially cesium-137 ({sup 137}Cs) are among the radionuclides of main importance produced by a fission reaction in reactor or a nuclear weapon explosion. In the environment, {sup 137}Cs is a major contaminant which can cause severe {beta}, {gamma}irradiations and contaminations. {sup 137}Cs is distributed widely and relatively uniformly throughout the body with the highest concentration in skeletal muscles. A treatment becomes difficult afterwards. The purposes of this report are Firstly to compare the Prussian blue verses cobalt and potassium ferrocyanide (D.I. blue) efficiency for the {sup 137}Cs decorporation and secondly to assess a chronological treatment with D.I. blue. (author)

Negative ion source improvement by introduction of a shutter mask

International Nuclear Information System (INIS)

Belchenko, Yu.I.; Oka, Y.; Kaneko, O.; Takeiri, Y.; Tsumori, K.; Osakabe, M.; Ikeda, K.; Asano, E.; Kawamoto, T.

2004-01-01

Studies of a multicusp source were recently done at the National Institute for Fusion Science by plasma grid masking. The maximal H - ion yield is ∼1.4 times greater for the shutter mask case than that for the standard source. Negative ion current evolution during the cesium feed to the masked plasma grid evidenced that about 60% of negative ions are produced on the shutter mask surface, while about 30% are formed on the plasma grid emission hole edges, exposed by cesium with the mask open

Method for primary containment of cesium wastes

International Nuclear Information System (INIS)

Angelini, P.; Arnold, W.D.; Blanco, R.E.; Bond, W.D.; Lackey, W.J.; Stinton, D.P.

1983-01-01

A method for producing a cesium-retentive waste form, characterized by a high degree of compositional stability and mechanical integrity, is provided by subjecting a cesium-loaded zeolite to heat under conditions suitable for stabilizing the zeolite and immobilizing the cesium, and coating said zeolite for sufficient duration within a suitable environment with at least one dense layer of pyrolytic carbon to seal therein said cesium to produce a final, cesium-bearing waste form. Typically, the zeolite is stabilized and the cesium immobilized in less than four hours by confinement within an air environment maintained at about 600 0 C. Coatings are thereafter applied by confining the calcined zeolite within a coating environment comprising inert fluidizing and carbon donor gases maintained at 1,000* C. For a suitable duration

Contact ion pair formation between hard acids and soft bases in aqueous solutions observed with 2DIR spectroscopy.

Science.gov (United States)

Sun, Zheng; Zhang, Wenkai; Ji, Minbiao; Hartsock, Robert; Gaffney, Kelly J

2013-12-12

The interaction of charged species in aqueous solution has important implications for chemical, biological, and environmental processes. We have used 2DIR spectroscopy to study the equilibrium dynamics of thiocyanate chemical exchange between free ion (NCS(-)) and contact ion pair configurations (MNCS(+)), where M(2+) = Mg(2+) or Ca(2+). Detailed studies of the influence of anion concentration and anion speciation show that the chemical exchange observed with the 2DIR measurements results from NCS(-) exchanging with other anion species in the first solvation shell surrounding Mg(2+) or Ca(2+). The presence of chemical exchange in the 2DIR spectra provides an indirect, but robust, determinant of contact ion pair formation. We observe preferential contact ion pair formation between soft Lewis base anions and hard Lewis acid cations. This observation cannot be easily reconciled with Pearson's acid-base concept or Collins' Law of Matching Water Affinities. The anions that form contact ion pairs also correspond to the ions with an affinity for water and protein surfaces, so similar physical and chemical properties may control these distinct phenomena.

Effect of Suez Canal Marine Sediment on Sorption of Cesium

International Nuclear Information System (INIS)

Hassan, H.B.

2016-01-01

Suez Canal is surrounded by navigation, industrial, agricultural activities and suffers from high rate of population growth that discharging waste into Suez Canal. The Suez Canal coastal waters are influenced by a complex variety of physical, geochemical and biological processes, which influence the behavior, transport and fate of containments released into the marine environment. Sorption of releasing containment such as cesium in Suez Canal water is investigated because of its toxic effect on the marine environment. The object of present study is to determine the effects some of physical and chemical characteristics of collected sediment samples from the three important locations on Suez Canal (Suez Bay, Bitter Lakes and El- Temsah Lake beaches) on sorption behavior of cesium by using batch experiment. Batch experiment was used to study the sorption of the cesium ion. The sorption process is dependent on mineral constituents of Suez Canal sediment and their characteristics. Analytical methods which included particle size and X-ray diffraction (XRD) analyses found that particle size of Suez Canal sediment samples is characterized by sand to fine sand and quartz is the main mineralogical species. Distribution coefficient (K d ) which represent geochemical processes and particle size of these sediment samples effect on the degree of cesium sorption to the sediment. Also (K d ) increase with increase cation exchangeable capacity (CEC). The Suez Canal sediment samples have low (K d ) values which effected by their physical and chemical properties. Sample (2) has highest distribution coefficient (K d ) between measured samples due to containing ratio 30% of fine sand and high ratio of organic matter.

Zirconium phosphate waste forms for low-temperature stabilization of cesium-137-containing waste streams

International Nuclear Information System (INIS)

Singh, D.; Wagh, A.S.; Tlustochowicz.

1996-04-01

Novel chemically bonded phosphate ceramics are being developed and fabricated for low-temperature stabilization and solidification of waste streams that are not amenable to conventional high-temperature stabilization processes because volatiles are present in the wastes. A composite of zirconium-magnesium phosphate has been developed and shown to stabilize ash waste contaminated with a radioactive surrogate of 137 Cs. Excellent retainment of cesium in the phosphate matrix system was observed in Toxicity Characteristic Leaching Procedure tests. This was attributed to the capture of cesium in the layered zirconium phosphate structure by intercalation ion-exchange reaction. But because zirconium phosphate has low strength, a novel zirconium/magnesium phosphate composite waste form system was developed. The performance of these final waste forms, as indicated by compression strength and durability in aqueous environments, satisfy the regulatory criteria. Test results indicate that zirconium-magnesium-phosphate-based final waste forms present a viable technology for treatment and solidification of cesium-contaminated wastes

Laboratory-Scale Column Testing Using IONSIV IE-911 for Removing Cesium from Acidic Tank Waste Simulant. 1: Cesium Exchange Capacity of a 15-cm3 Column and Dynamic Stability of the Exchange Media

International Nuclear Information System (INIS)

T.J. Tranter; R.D. Tillotson; T.A. Todd

2005-01-01

Bench-scale column tests were performed using a commercial form of crystalline silicotitanate (CST) for removing radio-cesium from a surrogate acidic tank solution representative of liquid waste stored at the Idaho National Engineering and Environmental Laboratory (INEEL). An engineered form of CST ion exchanger, known as IONSIVtm IE-911 (UOP, Mt Laurel, NJ, USA), was tested in 15 cm3 columns at a flow rate of 5 bed volumes per hour. These experiments showed the ion exchange material to have reasonable selectivity and capacity for removing cesium from the complex chemical matrix of the solution. However, previous testing indicated that partial neutralization of the feed stream was necessary to increase the stability of the ion exchange media. Thus, in these studies, CST degradation was determined as a function of throughput in order to better assess the stability characteristics of the exchanger for potential future waste treatment applications. Results of these tests indicate that the degradation of the CST reaches a maximum very soon after the acidic feed is introduced to the column and then rapidly declines. Total dissolution of bed material did not exceed 3% under the experimental regime used

GANIL Workshop on Ion Sources; Journees Sources d'Ions

Energy Technology Data Exchange (ETDEWEB)

Leroy, Renan [Grand Accelerateur National d' Ions Lourds (GANIL), 14 - Caen (France)

1999-07-01

The proceedings of the GANIL Workshop on Ion Sources held at GANIL - Caen on 18-19 March 1999 contains 13 papers aiming at improving the old source operation and developing new types of sources for nuclear research and studies of ion physics. A number of reports are devoted to applications like surface treatment, ion implantation or fusion injection. The 1+{yields}n+ transformation, charged particle transport in ECR sources, addition of cesium and xenon in negative ion sources and other basic issues in ion sources are also addressed.

Management of cesium loaded AMP- Part I preparation of 137Cesium concentrate and cementation of secondary wastes

International Nuclear Information System (INIS)

Singh, I.J.; Sathi Sasidharan, N.; Yalmali, Vrunda S.; Deshingkar, D.S.; Wattal, P.K.

2005-11-01

Separation of 137 cesium from High Level Waste can be achieved by use of composite-AMP, an engineered form of Ammonium Molybdo-Phosphate(AMP). Direct vitrification of cesium loaded composite AMP in borosilicate glass matrix leads to separation of water soluble molybdate phase. A proposed process describes two different routes of selective separation of molybdates and phosphate to obtain solutions of cesium concentrates. Elution of 137 Cesium from composite-AMP by decomposing it under flow conditions using saturated barium hydroxide was investigated. This method leaves molybdate and phosphate embedded in the column but only 70% of total cesium loaded on column could be eluted. Alternatively composite-AMP was dissolved in sodium hydroxide and precipitation of barium molybdate-phosphate from the resultant solution, using barium nitrate was investigated by batch methods. The precipitation technique gave over 99.9% of 137 Cesium activity in solutions, free of molybdates and phosphates, which is ideally suited for immobilization in borosilicate glass matrix. Detailed studies were carried out to immobilize secondary waste of 137 Cesium contaminated barium molybdate-phosphate precipitates in the slag cement matrix using vermiculite and bentonite as admixtures. The cumulative fraction of 137 Cs leached from the cement matrix blocks was 0.05 in 140 days while the 137 Cs leach rate was 0.001 gm/cm 2 /d. (author)

Cesium Concentration in MCU Solvent

International Nuclear Information System (INIS)

Walker, D

2006-01-01

During Modular Caustic-Side Solvent Extraction (CSSX) Unit (MCU) operations, Cs-137 concentrations in product streams will vary depending on the location in the process and on the recent process conditions. Calculations of cesium concentrations under a variety of operating conditions reveal the following: (1) Under nominal operations with salt solution feed containing 1.1 Ci Cs-137 per gallon, the maximum Cs-137 concentration in the process will occur in the strip effluent (SE) and equal 15-16.5 Ci/gal. (2) Under these conditions, the majority of the solvent will contain 0.005 to 0.01 Ci/gal, with a limited portion of the solvent in the contactor stages containing ∼4 Ci/gal. (3) When operating conditions yield product near 0.1 Ci Cs-137/gal in the decontaminated salt solution (DSS), the SE cesium concentration will be the same or lower than in nominal operations, but majority of the stripped solvent will increase to ∼2-3 Ci/gal. (4) Deviations in strip and waste stream flow rates cause the largest variations in cesium content: (a) If strip flow rates deviate by -30% of nominal, the SE will contain ∼23 Ci/gal, although the cesium content of the solvent will increase to only 0.03 Ci/gal; (b) If strip flow rate deviates by -77% (i.e., 23% of nominal), the SE will contain 54 Ci/gal and solvent will contain 1.65 Ci/gal. At this point, the product DSS will just reach the limit of 0.1 Ci/gal, causing the DSS gamma monitors to alarm; and (c) Moderate (+10 to +30%) deviations in waste flow rate cause approximately proportional increases in the SE and solvent cesium concentrations. Recovery from a process failure due to poor cesium stripping can achieve any low cesium concentration required. Passing the solvent back through the contactors while recycling DSS product will produce a ∼70% reduction during one pass through the contactors (assuming the stripping D value is no worse than 0.36). If the solvent is returned to the solvent hold tank (containing additional

Highways for ions in polymers - 3D–imaging of electrochemical interphase formation

International Nuclear Information System (INIS)

Wesp, Veronika; Zakel, Julia; Schäfer, Martin; Paulus, Ilka; Greiner, Andreas; Weitzel, Karl-Michael

2015-01-01

Graphical abstract: Display Omitted -- Abstract: The formation of a cesium interphase in-between a polymer film and a platinum electrode has been initiated by low energy bombardment induced ion transport. To this end two different samples of a poly(p-xylylene)(PPX) film, deposited on a platinum electrode have been bombarded by a low energy cesium ion beam. Ions are transported through the film according to the laws of electro-diffusion. They are neutralized at the interface between the PPX film and the metal electrode. Consequently, a cesium interphase is formed. 3D imaging of the interphase by means of time-of-flight secondary ion mass spectrometry (ToF-SIMS) reveals a correlation between structural characteristics of the interphase and conduction properties of the PPX film. The bombardment of PPX films consisting of a homogenous network leads to the formation of a uniform interphase. The bombardment of PPX films with non-intermittent pathways (NIPs) for the transport of ions leads to the formation of cesium islands which ultimately spread out laterally leading to a non-uniform interphase behind the PPX film. This picture is supported by measurements of the ionic conductivity which differs characteristically for the two kinds of PPX films

Initial evaluation of Sandia National Laboratory-prepared crystalline silico-titanates for cesium recovery

International Nuclear Information System (INIS)

Bray, L.A.; Carson, K.J.; Elovich, R.J.

1993-10-01

Pacific Northwest Laboratory initiated a study of a new class of inorganic ion exchange materials that selectively extracts cesium (Cs), strontium (Sr), and plutonium (Pu) from alkaline radioactive waste solutions. These materials, identified as crystalline silico-titanates (CST), were developed by scientists at the Sandia National Laboratory (SNL) and Texas A ampersand M. This report summarizes preliminary results for the measurement of batch distribution coefficient (K d ) values for the powdered CST materials compared to previously tested ion exchange materials: IONSIV IE-96 (a zeolite produced by UOP), CS-100 (an organic resin produced by Rohm and Haas), and BIB-DJ (a new resorcinol-formaldehyde organic resin produced by Boulder Scientific). Excellent results were obtained for CST inorganic exchangers that could be significant in the development of processes for the near-term pretreatment of Hanford alkaline wastes. The following observations and conclusions resulted from this study: (1) Several CST samples prepared at SNL had a higher capacity to remove Cs from solution as compared to BIB-DJ, IE-96, and CS-100. (2) Cesium distribution results showed that CST samples TAM-40, -42, -43, -70, and -74 had λ values of ∼2,200 (λ = Cs K d x ρ b ; where λ represents the number of exchanger bed volumes of feed that can be loaded on an ion exchange column) at a pH value >14. (3) Cesium distribution values for CST exchangers doubled as the aqueous temperature decreased from 40 degrees to 10 degrees C. (4) Crystalline silico-titanates have the capacity to remove Cs as well as Sr and Pu from alkaline wastes unless organic complexants are present. Experimental results indicated that complexed Sr was not removed, and Pu is not expected to be removed

Cesium removal and kinetics equilibrium: Precipitation kinetics

International Nuclear Information System (INIS)

Barnes, M.J.

1999-01-01

This task consisted of both non-radioactive and radioactive (tracer) tests examining the influence of potentially significant variables on cesium tetraphenylborate precipitation kinetics. The work investigated the time required to reach cesium decontamination and the conditions that affect the cesium precipitation kinetics

Metabolism of 137cesium, 137barium in the rat. Therapeutics of the contamination

International Nuclear Information System (INIS)

Remy, J.; Philippon, A.; Lafuma, J.; Walter, C.

1967-01-01

The authors carry out research into the distribution kinetics, the metabolism and the excretion of 137 Cs - 137 Ba in the rat. They show that these phenomena are independent of the method of applying a single dose. The distribution tends to adopt in all cases a typical shape which remains the same depending on the body burden. Biological analysis of the state of the cesium in the biological media shows that it is transported in the free and ionised form. Considering the problem of the method of penetration of the cesium ion in the intracellular medium, and in particular by the in vivo and in vitro kinetic study of the plasma - red cell system, the authors make the assumption that an active transport of cesium occurs by the cell membrane. They thus arrive at an overall picture of the cesium distribution in the organism which is essentially characterized by a dynamic distribution equilibrium between two compartments: 99 per cent of the cesium accumulates in the intracellular pool, 1 per cent in the extracellular liquids. This latter compartment is open to the emunctories. Because, of the active transport by the cell membranes, the intracellular pool is filled rapidly but discharge is slow. This phenomenon is the limiting factor in the decrease of the body burden. From this representation, the authors deduce the reasons for the relative failure of the various therapeutic methods examined up till now by themselves or by other authors. The stimulation of the natural emunctories in the case of diuretics for example, can only improve the purification of the extracellular compartment. Now this latter contains only 1 per cent of the body burden and recharging is slow. Furthermore the methods designed to counteract or inhibit the active transport of cesium by the cell membrane are still at the present time incompatible with the survival of the cell. (authors) [fr

Development of composite ion exchanger for separation of cesium from high level liquid waste

International Nuclear Information System (INIS)

Kumar, A.; Varshney, L.

2010-01-01

137 Cs (t 1/2 = 30 years) is one of the major radioisotope present in high level liquid waste (HLLW) generated during the reprocessing of nuclear fuel. Separation of 137 Cs from HLLW results in reduction of personal radiation exposure during the conditioning, transportation, storage and disposal. In addition, 137 Cs has enormous application as a radiation source in food preservation, sterilization of medical products, brachytherapy, blood irradiation, hygienization of sewage sludge etc. Ammonium molybdophosphate (AMP), an inorganic ion exchanger, has high selectivity and high exchange capacity for Cs. It exits as microcrystalline powder which is not amenable for column operation. ALIX is a composite material in which AMP is physically blended with inert polymeric substrate to improve its column property, exchange kinetics and increase its mechanical strength. The observed excellent properties of the composite are attributed to its engineered structure which is formed during its production. SEM analysis of ALIX shows that AMP crystals embedded in the cavities are not covered by the polymer which greatly enhances its availability for cesium exchange. The highly porous structure of the composite having 49% void volume facilitates faster kinetics of exchange of Cs from the aqueous phase and increased rate of reaction with alkali required during its dissolution

Radiochemical determination of cesium-137 in seawater

International Nuclear Information System (INIS)

Cunha, I.I.L.; Munita, C.S.; Paiva, R.P.

1990-01-01

Seawater samples were collected from the Atlantic Ocean, in the vicinity of Ubatuba (Sao Paulo State - Brazil), acidified to pH 1 and stored in polyethylene containers. Cesium was precipitated with ammonium phospho molybdate (AMP), synthesized in our laboratory. The elements potassium and rubidium present in the seawater are also coprecipitated by AMP and adequate decontamination of the cesium is made by preparing a column by mixing Cs-137 AMP precipitate and asbestos. The interfering elements were eluted with 1.0 M ammonium nitrate solution whereas cesium was eluted with 1.0 M sodium hydroxide solution. Cesium was reprecipitated by acidifying the solution with concentrated hydrochloric acid. The overall chemical yield of cesium was of 75%. (author)

Negative-ion-beam generation with the ORNL SITEX source

International Nuclear Information System (INIS)

Dagenhart, W.K.; Stirling, W.L.; Kim, J.

1982-05-01

Parametric studies were made on a hot cathode reflex discharge H - Surface Ionization source with Transverse Extraction (SITEX) in both the pure hydrogen and the mixed hydrogen-cesium mode. Extraction current density, beam current, gas efficiency, extracted electron-to-H - current ratio, heavy negative ion impurities, optics, and long pulse operation were investigated as a function of time, arc voltage, arc current, converter voltage, H 2 gas flow, cesium feed rate, and plasma generator geometries. Initial results of the research were an extracted H - beam current density of 56 mA/cm 2 at 23 mA for 5 s pulses and, gas efficiency of 3%, theta/sub perpendicular/ (1/e) approx. 2 +- 1 0 , theta/sub parallel/ (1/e) approx. 1 +- 1 0 , at a beam energy of 25 keV. Negative heavy ion beam impurities were reduced to - ions are produced prinicpally by positive ion surface conversion using elemental cesium fractional monolayer coverage on a molybdenum converter substrate, which is biased negatively with respect to the anode

Synthesis, structural characterization, and performance evaluation of resorcinol-formaldehyde (R-F) ion-exchange resin

International Nuclear Information System (INIS)

Hubler, T.L.; Franz, J.A.; Shaw, W.J.; Bryan, S.A.; Hallen, R.T.; Brown, G.N.; Bray, L.A.; Linehan, J.C.

1995-08-01

The 177 underground storage tanks at the DOE's Hanford Site contain an estimated 180 million tons of high-level radioactive wastes. It is desirable to remove and concentrate the highly radioactive fraction of the tank wastes for vitrification. Resorcinol-formaldehyde (R-F) resin, an organic ion-exchange resin with high selectivity and capacity for the cesium ion, which is a candidate ion-exchange material for use in remediation of tank wastes. The report includes information on the structure/function analysis of R-F resin and the synthetic factors that affect performance of the resin. CS-100, a commercially available phenol-formaldehyde (P-F) resin, and currently the baseline ion-exchanger for removal of cesium ion at Hanford, is compared with the R-F resin. The primary structural unit of the R-F resin was determined to consist of a 1,2,3,4-tetrasubstituted resorcinol ring unit while CS-100, was composed mainly of a 1,2,4-trisubstituted ring. CS-100 shows the presence of phenoxy-ether groups, and this may account for the much lower decontamination factor of CS-100 for cesium ion. Curing temperatures for the R-F resin were found to be optimal at 105--130C. At lower temperatures, insufficient curing, hence crosslinking, of the polymer resin occurs and selectivity for cesium drops. Curing at elevated temperatures leads to chemical degradation. Optimal particle size for R-F resin is in the range of 20--50 mesh-sized particles. R-F resin undergoes chemical degradation or oxidation which destroys ion-exchange sites. The ion-exchange sites (hydroxyl groups) are converted to quinones and ketones. CS-100, though it has much lower performance for cesium ion-exchange, is significantly more chemically stable than R-F resin. To gamma radiation, CS-100 is more radiolytically stable than R-F resin

Synthesis, structural characterization, and performance evaluation of resorcinol-formaldehyde (R-F) ion-exchange resin

Energy Technology Data Exchange (ETDEWEB)

Hubler, T.L.; Franz, J.A.; Shaw, W.J.; Bryan, S.A.; Hallen, R.T.; Brown, G.N.; Bray, L.A.; Linehan, J.C.

1995-08-01

The 177 underground storage tanks at the DOE`s Hanford Site contain an estimated 180 million tons of high-level radioactive wastes. It is desirable to remove and concentrate the highly radioactive fraction of the tank wastes for vitrification. Resorcinol-formaldehyde (R-F) resin, an organic ion-exchange resin with high selectivity and capacity for the cesium ion, which is a candidate ion-exchange material for use in remediation of tank wastes. The report includes information on the structure/function analysis of R-F resin and the synthetic factors that affect performance of the resin. CS-100, a commercially available phenol-formaldehyde (P-F) resin, and currently the baseline ion-exchanger for removal of cesium ion at Hanford, is compared with the R-F resin. The primary structural unit of the R-F resin was determined to consist of a 1,2,3,4-tetrasubstituted resorcinol ring unit while CS-100, was composed mainly of a 1,2,4-trisubstituted ring. CS-100 shows the presence of phenoxy-ether groups, and this may account for the much lower decontamination factor of CS-100 for cesium ion. Curing temperatures for the R-F resin were found to be optimal at 105--130C. At lower temperatures, insufficient curing, hence crosslinking, of the polymer resin occurs and selectivity for cesium drops. Curing at elevated temperatures leads to chemical degradation. Optimal particle size for R-F resin is in the range of 20--50 mesh-sized particles. R-F resin undergoes chemical degradation or oxidation which destroys ion-exchange sites. The ion-exchange sites (hydroxyl groups) are converted to quinones and ketones. CS-100, though it has much lower performance for cesium ion-exchange, is significantly more chemically stable than R-F resin. To gamma radiation, CS-100 is more radiolytically stable than R-F resin.

Determination and preconcentration of natural and radio-cesium from aqueous solution

International Nuclear Information System (INIS)

Gueclue, K.; Apak, R.; Tuetem, E.; Atun, G.

2004-01-01

A modified atomic emission spectrometric (AES) method to determine cesium(I), based on the measurement of emission intensity at 455.5 nm with a limit of quantitation (LOQ) of 5.5 mg/l and a linear range up to 100 mg/l is reported. In order to increase the sensitivity and lower the detection limits, potential sorbents were investigated for preconcentrating Cs from natural waters. Among the various ion-exchange materials synthesized, potassium hexanitrocobaltate (PHNCo) yielded the highest capacity for 137 Cs tagged Cs + solutions as measured by gamma-spectrometry with a HPGe detector, showing the potential of a cesium preconcentration sorbent. As an alternative to AES determination, the PHNCo sorbent may be used for Cs + collection from radiocesium tagged solutions and the retained activity in the dry solid exchanger be determined by gamma-spectrometry. (author)

Cesium removal from the fuel storage water at the Savannah River Site R-Building Disassembly Basin using 3M Empore reg-sign-membrane filter technology

International Nuclear Information System (INIS)

Oji, L.N.; Thompson, M.C.; Peterson, K.; May, C.; Kafka, T.M.

1998-01-01

This report describes results from a seven-day demonstration of the use of 3M Empore membrane filter loaded with ion exchange material (potassium cobalt hexacynoferrate (CoHex)) for cesium uptake from the R-Disassembly Basin at the Savannah River Site. The goal of the demonstration was to evaluate the ability of the Process Absorber Development unit (PADU), a water pre-filtration /CoHex configuration on a skid, to remove cesium from R-Disassembly Basin at a linear processing flow rate of 22.7 liters per minute (1,195.8 liters/minute/m 2 or 29.35 gallons/minute/ft 2 ). Over 210,000 liters (> 55,500 gallons) of R-Disassembly Basin water was processed through the PADU without a cesium breakthrough, that is, the effluent after treatment with CoHex, contained less than detectable amounts of radioactive cesium. Some of the observed advantages of the Empore membrane filter technology over conventional packed column ion exchange systems includes rapid flow rates without channeling effects, low volume secondary waste and fast extraction or rapid kinetics per unit of flow

An experimental study of charge exchange process in the energy range 1-30 keV during the passage of alkali metal ions and atoms through cesium and potassium vapour

International Nuclear Information System (INIS)

Wittchow, F.

1979-01-01

An experimental study is presented of the charge exchange processes in the energy range of about 1-30 keV during the passage of positive alkali ions and alkali atoms through potassium and cesium vapour. The experimental set-up designed for this experiment includes a thermionic source for positive alkali ions with an acceleration stage, a first charge exchange cell to produce fast alkali atoms, a second charge exchange cell with a surface ionisation detector to determine the alkali metal vapor target thickness and a detection system with electrostatic bending of the charged secondary species. The maximum negative ion yield has been determined for the collision systems Li + + K, Na + + K, K + + K, and Rb + + K, and for another eleven systems the charge transfer cross-sections have been measured too. (orig./GG) [de

Cesium migration in LMFBR fuel pins

International Nuclear Information System (INIS)

Karnesky, R.A.; Jost, J.W.; Stone, I.Z.

1978-10-01

The factors affecting the axial migration of cesium in mixed oxide fuel pins and the effects of cesium migration on fuel pin performance are examined. The development and application of a correlated model which will predict the occurrence of cesium migration in a mixed oxide (75 w/o UO 2 + 25 w/o PuO 2 ) fuel pins over a wide range of fabrication and irradiation conditions are described

Cesium levels in foodstuffs fall slowly

International Nuclear Information System (INIS)

Rantavaara, A.

1994-01-01

Since spring 1986, radioactive decay has reduced the total amount of radioactive cesium 137 in the Finnish environment, originating in Chernobyl, by 17 per cent. The cesium content in fish keeps falling at a diminishing rate, depending on the species of fish and environmental factors. The use of fish from lakes need not be restricted anymore. The cesium contents of game, mushrooms and wild berries have remained steady for some years now. The same is true for agricultural produce. The contents in milk and meat still keep falling slowly. Most of the cesium ingested by finns comes from fish, then from game, reindeer and gathered foods; the lowest amounts are received from agricultural products. (orig.)

Microbial uptake of uranium, cesium, and radium

Energy Technology Data Exchange (ETDEWEB)

Strandberg, G.W.; Shumate, S.E. II; Parrott, J.R. Jr.; McWhirter, D.A.

1980-01-01

The ability of diverse microbial species to concentrate uranium, cesium, and radium was examined. Saccharomyces cerevisiae, Pseudomonas aeruginosa, and a mixed culture of denitrifying bacteria accumulated uranium to 10 to 15% of the dry cell weight. Only a fraction of the cells in a given population had visible uranium deposits in electron micrographs. While metabolism was not required for uranium uptake, mechanistic differences in the metal uptake process were indicated. Uranium accumulated slowly (hours) on the surface of S. cerevisiae and was subject to environmental factors (i.e., temperature, pH, interfering cations and anions). In contrast, P. aeruginosa and the mixed culture of denitrifying bacteria accumulated uranium rapidly (minutes) as dense, apparently random, intracellular deposits. This very rapid accumulation has prevented us from determining whether the uptake rate during the transient between the initial and equilibrium distribution of uranium is affected by environmental conditions. However, the final equilibrium distributions are not affected by those conditions which affect uptake by S. cerevisiae. Cesium and radium were concentrated to a considerably lesser extent than uranium by the several microbial species tested. The potential utility of microorganisms for the removal and concentration of these metals from nuclear processing wastes and several bioreactor designs for contacting microorganisms with contaminated waste streams will be discussed.

Studies on release and deposition behaviour of cesium from contaminated sodium pools and cesium trap development for FBTR

International Nuclear Information System (INIS)

Sahoo, P.; Kannan, S.E.; Muralidharan, P.; Chandran, K.

1996-01-01

Investigations were carried out on the release and deposition behaviour of cesium from sodium pools in air-filled chamber in the temperature range of 673 to 873 K, using Cs-134 to simulate Cs-137. About 0.12 kg of sodium was loaded in a burn-pot together with 92.5 kBq of cesium. Experiments were carried out with 21% oxygen. Natural burning period of sodium and specific activity ratio between cesium and sodium showed a tendency to decrease and release fractions of both the species tended to increase with temperature. From the surface deposited aerosols it was observed that cesium has propensity to settle down closer to the point of release. A cesium trap has been developed for FBTR with RVC as getter material. Absorption kinetics and particle release behaviour studies pointed to its intended satisfactory performance in the plant. (author)

Cesium-137 in ash from combustion of biofuels. Application of regulations from the Swedish Radiation Safety Authority; Cesium-137 i aska fraan foerbraenning av biobraenslen. Tillaempning av Straalsaekerhetsmyndighetens regler

Energy Technology Data Exchange (ETDEWEB)

Sjoeblom, Rolf (Tekedo AB, Nykoeping (SE))

2009-03-19

. The differences are large. The transitions between Cesium/Potassium in the pore water and in the exchangeable positions are rapid. Other transitions are slow. Over the course of a few years, Cesium becomes bonded as non-exchangeable and after a few decades, the content of non-exchangeable and mineral Cesium may be comparable in magnitude. The migration rate depends on the availability. Before Cesium-137 in fallout becomes absorbed, it is transported with the water, and this is the reason for the initial rapid penetration into soil on the order of a decimeter. When most of the Cesium-137 has become non-exchangeable and mineral, the migration rate may be as low as on the order of a millimetre per year. There is an interesting finding to report about clay. For short term migration, i e shortly after a fallout, clay provides a retention that is far superior to that of sand. This is probably related to the fact that clay contains many more positions for ion exchange as compared to sand. After some time when most of the Cesium appears in non-exchangeable and mineral positions, clay and sand are comparable. It might be tempting to assume that organic soils would provide a good retention since they can absorb nutrients from artificial fertilizers and keep them available to plants. Measurements have shown, however, that Cesium-137 may migrate rapidly in soils that lack a mineral component, e g soils consisting of peat. This can be assumed to relate to the fact that the bonding to the many exchangeable positions is much weaker as compared to those in non-exchangeable and in mineral positions. The data on ash are scarce. The data found indicate that the availability of Cesium-137 is high in fresh ash, but that the bonding is remarkably strong already after a few years. It cannot be taken for granted without further information that fresh water conditions apply also when the salt content in the pore water is high. Investigations have shown, however, that the solid mineral phase

A procedure for preferential trapping of cesium cations from aqueous solutions and their separation from other inorganic cations

International Nuclear Information System (INIS)

Plesek, J.; Hermanek, S.; Selucky, P.; Williams, R.E.

1995-01-01

The title procedure is as follows. Deltahedral heteroborane anions are added to the aqueous solution containing cesium ions, precipitate (if any) is separated off, and the cesium salts involving the deltahedral heteroborane anions are trapped on activated carbon. The cobaltocarborane anion [3-Co-(1,2-C 2 B 9 H 11 ) 2 ] and/or its substitution derivatives are particularly well suited to this purpose. The process can find use in the separation of radionuclides present in waste solutions arising from spent nuclear fuel treatment. (P.A.). 1 fig

Bentonite-Clay Waste Form for the Immobilization of Cesium and Strontium from Fuel Processing Waste Streams

Energy Technology Data Exchange (ETDEWEB)

Kaminski, Michael D. [Argonne National Lab. (ANL), Argonne, IL (United States); Mertz, Carol J. [Argonne National Lab. (ANL), Argonne, IL (United States)

2016-01-01

The physical properties of a surrogate waste form containing cesium, strontium, rubidium, and barium sintered into bentonite clay were evaluated for several simulant feed streams: chlorinated cobalt dicarbollide/polyethylene glycol (CCD-PEG) strip solution, nitrate salt, and chloride salt feeds. We sintered bentonite clay samples with a loading of 30 mass% of cesium, strontium, rubidium, and barium to a density of approximately 3 g/cm³. Sintering temperatures of up to 1000°C did not result in volatility of cesium. Instead, there was an increase in crystallinity of the waste form upon sintering to 1000ºC for chloride- and nitrate-salt loaded clays. The nitrate salt feed produced various cesium pollucite phases, while the chloride salt feed did not produce these familiar phases. In fact, many of the x-ray diffraction peaks could not be matched to known phases. Assemblages of silicates were formed that incorporated the Sr, Rb, and Ba ions. Gas evolution during sintering to 1000°C was significant (35% weight loss for the CCD-PEG waste-loaded clay), with significant water being evolved at approximately 600°C.

Laboratory-Scale Column Testing Using IONSIV IE-911 for Removing Cesium from Acidic Tank Waste Simulant. 2: Determination of Cesium Exchange Capacity and Effective Mass Transfer Coefficient from a 500-cm3 Column Experiment

International Nuclear Information System (INIS)

T.J. Tranter; R.D. Tillotson; T.A. Todd

2005-01-01

A semi-scale column test was performed using a commercial form of crystalline silicotitanate (CST) for removing radio-cesium from a surrogate acidic tank solution, which represents liquid waste stored at the Idaho National Engineering and Environmental Laboratory (INEEL). The engineered form of CST ion exchanger, known as IONSIVtmIE-911 (UOP, Mt. Laurel, NJ, USA), was tested in a 500-cm3 column to obtain a cesium breakthrough curve. The cesium exchange capacity of this column matched that obtained from previous testing with a 15-mc3 column. A numerical algorithm using implicit finite difference approximations was developed to solve the governing mass transport equations for the CST columns. An effective mass transfer coefficient was derived from solving these equations for previously reported 15 cm3 tests. The effective mass transfer coefficient was then used to predict the cesium breakthrough curve for the 500-cm3 column and compared to the experimental data reported in this paper. The calculated breakthrough curve showed excellent agreement with the data from the 500-cm3 column even though the interstitial velocity was a factor of two greater. Thus, this approach should provide a reasonable method for scale up to larger columns for treating actual tank waste

Estimation of Sputtering Damages on a Magnetron H- Ion Source Induced by Cs+ and H+ Ions

CERN Document Server

Pereira, H; Alessi, J; Kalvas, t

2013-01-01

An H− ion source is being developed for CERN’s Linac4 accelerator. A beam current requirement of 80 mA and a reliability above 99% during 1 year with 3 month uninterrupted operation periods are mandatory. To design a low-maintenance long life-time source, it is important to investigate and understand the wear mechanisms. A cesiated plasma discharge ion source, such as the BNL magnetron source, is a good candidate for the Linac4 ion source. However, in the magnetron source operated at BNL, the removal of material from the molybdenum cathode and the stainless steel anode cover plate surfaces is visible after extended operation periods. The observed sputtering traces are shown to result from cesium vapors and hydrogen gas ionized in the extraction region and subsequently accelerated by the extraction field. This paper presents a quantitative estimate of the ionization of cesium and hydrogen by the electron and H− beams in the extraction region of BNL’s magnetron ion source. The respective contributions o...

''Crown molecules'' for separating cesium

International Nuclear Information System (INIS)

Dozol, J.F.; Lamare, V.

2002-01-01

After the minor actinides, the second category of radionuclides that must be isolated to optimize nuclear waste management concerns fission products, especially two cesium isotopes. If the cesium-135 isotope could be extracted, it could subsequently be transmuted or conditioned using a tailor-made process. Eliminating the 137 isotope from reprocessing and nuclear facility-dismantling waste would allow to dispose of most of this waste in near-surface facilities, and simply process the small remaining quantity containing long-lived elements. CEA research teams and their international partners have thought up crown molecules that could be used to pick out the cesium and meet these objectives. (authors)

A combined cesium-strontium extraction/recovery process

International Nuclear Information System (INIS)

Horwitz, E.P.; Dietz, M.L.; Jensen, M.P.

1996-01-01

A new solvent extraction process for the simultaneous extraction of cesium and strontium from acidic nitrate media is described. This process uses a solvent formulation comprised of 0.05 M di-t-butylcyclohexano-18-crown-6 (DtBuCH18C6), 0.1 M Crown 100' (a proprietary, cesium-selective derivative of dibenzo-18-crown-6), 1.2 M tributyl phosphate (TBP), and 5% (v/v) lauryl nitrile in an isoparaffinic hydrocarbon diluent. Distribution ratios for cesium and strontium from 4 M nitric acid are 4.13 and 3.46, respectively. A benchtop batch countercurrent extraction experiment indicates that >98% of the cesium and strontium initially present in the feed solution can be removed in only four extraction stages. Through proper choice of extraction and strip conditions, extracted cesium and strontium can be recovered either together or individually

Removal of cesium and separation of strontium the analysis of the leachate of spent fuel

International Nuclear Information System (INIS)

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

2002-01-01

The selective removal of cesium by ammonium molybdophosphate (AMP) was studied in order to reduce an interference by high radioactivity of cesium on the determination of low radioactive elements in leachate of spent fuel. The removal of Cs, U, Ce, La, Co, Na Sr and K was investigated for the leachate and the bentonite in contact with a spent fuel. More than 90% of cesium was removed by AMP and Ca, Na, Co and Sr was remained in 0.1M HNO 3 . However, three valence elements such as La and Ce were also removed by AMP. Though a little of potassium of the bentonite components was adsorbed on AMP, the potassium in the bentonite solution diluted to its concentration in a real sample would not affect the capacity of AMP greatly. From another experiment for the separation of strontium as a leaching indicator of spent fuel, the recovery of strontium in 8.0 M HNO 3 solution by using Sr-resin (Eichrom, P/N SR-B50-A) was more than 95% by eluting with 0.05 M HNO 3

Properties of calcium depleted hydrated cement paste: mineralogical characterization and cesium adsorption

International Nuclear Information System (INIS)

Babaahmadi, A.; Tang, L.; Zareen, A.

2015-01-01

Understanding the changes in adsorption properties of cementitious barriers and the effect on the release of radio-nuclides to the environment during the service life of the repository is of high importance. A major degradation scenario within safety assessment analysis of nuclear waste repositories is decalcification of cementitious materials due to long-term contact with groundwater. In order to decrease the uncertainty in the simulation of this process due to extrapolating short term data sets based on short term experimental analysis, acceleration methods enhancing the decalcification process can be used. However it is not yet completely proved that how different the properties of the aged samples through accelerated leaching is compared to the samples aged in natural ageing process. In this study the changes in cesium adsorption of the hydrated cement paste due to calcium depletion is taken in to consideration. The aged samples are prepared with application of an accelerating electro-chemical migration method. The mineralogical properties of decalcified specimens are characterized to demonstrate their comparability with naturally leached samples. The gradual effect of migration function on cementitious materials indicates a relatively homogenous leaching in cementitious specimens and a considerable increase in specific surface area due to the leaching of calcium. It is concluded that the aged samples having a larger surface area and less calcium and alkalis ions compared to pristine materials, exhibit a higher binding potential for Cs ions

Selective chemical binding enhances cesium tolerance in plants through inhibition of cesium uptake.

Science.gov (United States)

Adams, Eri; Chaban, Vitaly; Khandelia, Himanshu; Shin, Ryoung

2015-03-05

High concentrations of cesium (Cs(+)) inhibit plant growth but the detailed mechanisms of Cs(+) uptake, transport and response in plants are not well known. In order to identify small molecules with a capacity to enhance plant tolerance to Cs(+), chemical library screening was performed using Arabidopsis. Of 10,000 chemicals tested, five compounds were confirmed as Cs(+) tolerance enhancers. Further investigation and quantum mechanical modelling revealed that one of these compounds reduced Cs(+) concentrations in plants and that the imidazole moiety of this compound bound specifically to Cs(+). Analysis of the analogous compounds indicated that the structure of the identified compound is important for the effect to be conferred. Taken together, Cs(+) tolerance enhancer isolated here renders plants tolerant to Cs(+) by inhibiting Cs(+) entry into roots via specific binding to the ion thus, for instance, providing a basis for phytostabilisation of radiocesium-contaminated farmland.

Simultaneous solid phase extraction of cobalt, strontium and cesium from liquid radioactive waste using microcrystalline naphthalene

International Nuclear Information System (INIS)

Hamed, Mostafa Mohamed; Attallah, Mohamed Fathy; Metwally, Sayed Sayed

2014-01-01

Most of the procedures developed for the extraction of cobalt, strontium and cesium by solid phase extraction do not employ simultaneous extraction of them. In this study, rapid simultaneous removal of Co 2+ , Sr 2+ and Cs + on microcrystalline naphthalene as solid-phase extractant was investigated. These ions were allowed to form chelates with oxine and then adsorbed on freshly microcrystalline naphthalene from aqueous solutions. The solid phase extraction procedure (SPE) was optimized by using model solution containing Co 2+ , Sr 2+ and Cs + in batch system. The effects of different parameters such as variation in pH, reagent concentration, standing time, naphthalene solution concentration and contact time on the simultaneous removal of these ions was studied. The obtained results indicated that, sorption was found to be rapid, and the percentage removal of Co 2+ , Sr 2+ and Cs + was found to be 98, 79 and 68% within 10 min, respectively. The kinetics of the sorption process was investigated to understand the kinetic characteristics of sorption of metal chelates onto microcrystalline naphthalene. The developed procedure has been successfully applied to the removal and recovery of 60 Co and 134 Cs from liquid radioactive waste. The parameters can be used for designing a plant for treatment of wastewater economically.

Thermodynamics of soluble fission products cesium and iodine in the Molten Salt Reactor

Science.gov (United States)

Capelli, E.; Beneš, O.; Konings, R. J. M.

2018-04-01

The present study describes the full thermodynamic assessment of the Li,Cs,Th//F,I system. The existing database for the relevant fluoride salts considered as fuel for the Molten Salt Reactor (MSR) has been extended with two key fission products, cesium and iodine. A complete evaluation of all the common-ion binary and ternary sub-systems of the LiF-ThF4-CsF-LiI-ThI4-CsI system has been performed and the optimized parameters are presented in this work. New equilibrium data have been measured using Differential Scanning Calorimetry and were used to assess the reciprocal ternary systems and confirm the extrapolated phase diagrams. The developed database significantly contributes to the understanding of the behaviour of cesium and iodine in the MSR, which strongly depends on their concentration and chemical form. Cesium bonded with fluorine is well retained in the fuel mixture while in the form of CsI the solubility of these elements is very limited. Finally, the influence of CsI and CsF on the physico-chemical properties of the fuel mixture was calculated as function of composition.

On mobility of cesium-137, sodium, potassium in various types of soils and prediction of cesium-137 cumulation in agricultural plants

International Nuclear Information System (INIS)

Ashkinazi, Eh.I.

1990-01-01

Mobility of cesium-137, sodium and potassium in the natural environment in podzolic gray and chernozem medium-loamy, sward podzolic sandy soils and chernozem has been studied. Durability of fixation of cesium-137 increases in a number of soils and increase of the level of metabolic potassium. Coefficient of transition of level of metabolic cesium-137 by potassium and sodium, and of sodium by potassium. The mentioned above coefficients can be used for the prediction of cesium-137 cumulation in plants

Separation of cesium and strontium with zeolites

Energy Technology Data Exchange (ETDEWEB)

Kanno, T; Hashimoto, H [Tohoku Univ., Sendai (Japan). Research Inst. of Mineral Dressing and Metallurgy

1976-06-01

The basic studies of separation of cesium and strontium were made with specimens of zeolite, which are synthetic zeolites A, X and Y; synthetic mordenite; natural mordenite; and clinoptilolite. Ammonium chloride was used as eluent, because it was considered to be a most appropriate eluent in alkaline chlorides. Cesium was easily eluted from the zeolites A and X by ammonium chloride solution, but it was difficult to elute from the synthetic mordenite, natural mordenite and clinoptilolite by ammonium chloride solution, but it was difficult to elute from the zeolites A and X. The zeolite Y is the only one zeolite among these zeolites from which both of cesium and strontium were easily eluted by ammonium chloride solution. Strontium could be separated from cesium with zeolites by formation of Sr-EDTA chelate at pH above 11. In this process, cesium was only exchanged in zeolite column, but strontium flow out from it.

Separation of cesium and strontium with zeolites

International Nuclear Information System (INIS)

Kanno, Takuji; Hashimoto, Hiroyuki

1976-01-01

The basic studies of separation of cesium and strontium were made with specimens of zeolite, which are synthetic zeolites A, X and Y; synthetic mordenite; natural mordenite; and clinoptilolite. Ammonium chloride was used as eluent, because it was considered to be a most appropriate eluent in alkaline chlorides. Cesium was easily eluted from the zeolites A and X by ammonium chloride solution, but it was difficult to elute from the synthetic mordenite, natural mordenite and clinoptilolite by ammonium chloride solution, but it was difficult to elute from the zeolites A and X. The zeolite Y is the only one zeolite among these zeolites from which both of cesium and strontium were easily eluted by ammonium chloride solution. Strontium could be separated from cesium with zeolites by formation of Sr-EDTA chelate at pH above 11. In this process, cesium was only exchanged in zeolite column, but strontium flow out from it. (auth.)

On the mechanism of ion exchange in zirconium phosphates

International Nuclear Information System (INIS)

Kullberg, L.; Clearfield, A.

1981-01-01

An equilibrium study of the Na + -Cs + -H + exchange on crystalline α-zirconium phosphate has been carried out. Isotherms for the ion exchange have been determined and phases formed during the exchange have been identified. The surface groups of the exchanger were found to greatly prefer cesium to sodium. For exchange in the interior, cesium was found to be preferred to sodium for 0 to 50% of exchange, while sodium is slightly preferred to cesium for the second half of exchange. The influence of surface equilibria on the total exchange mechanism is discussed. (author)

Magnetic circular Dichroism and Faraday rotation of cesium-argon excimers and cesium dimers

International Nuclear Information System (INIS)

Islam, M.A.

1981-01-01

Magnetic Circular Dichroism (MCD) and Faraday Rotation (FR) of excimer absorption bands in gases are measured to obtain the first direct information about the angular momentum quantum numbers and the angular momentum coupling schemes of excimer molecules. So far, there has been no experimental method to obtain information about the axial angular momentum and the angular momentum coupling schemes of excimer molecules. In this experiment, the MCD and the FR of cesium-argon excimer and cesium dimer absorption bands between 5000 A and 10,000 A are measured for the range of temperature from 116 0 to 355 0 C. Of particular interest is the blue wing of D 2 line in cesium which has been the subject of vigorous investigation. The measured MCD data at the blue wing of D 2 line clearly shows that the assignment of 2 μ/sub 1/2/ to this excited state assuming Hund's case (b) is a poor approximation. By a simple inspection of the MCD data, it is found that the coupling scheme is more nearly Hund's case (c) than Hynd's case (b). Several other new and interesting results are obtained. The blue wing associated with 5D transition in atomic cesium is devoid of MCD and exhibits strong MCD in the red wings. Thus, the assignment of 2 μ/sub 1/2/ and 2 π to the blue and red wings, respectively, assuming Hund's case (a) and (b), is a very good approximation. Again the yellow-green band associated with 7s-6s transition in atomic cesium shows no MCD. It is therefore also a good approximation to assign 2 μ/sub 1/2/ to the upper state assuming Hund's case (b). Much more information can be obtained by a detailed analysis of the MCD data

Cesium Eluate Analytical Data Evaluation

International Nuclear Information System (INIS)

Pierce, R.A.

2003-01-01

Bechtel National Inc. (BNI) is using IBC Company's SuperLigand ion exchange resins to separate Cs and Tc from low-activity waste (LAW) solutions (IBC-1996). Cesium is removed using the SuperLig(R) 644 resin. The resin is then eluted after each use cycle with 0.5M nitric acid solution. BNI is planning to evaporate the Cs eluate solution to reduce the storage volume and recover eluate for re-use. The primary issue associated with evaporation is end point, or salt matrix solubility. To preclude formation of solids during the storage of evaporator products, an additional criteria has been set that limits the concentration of the evaporator bottoms to 80 percent of saturation at 25 degrees C. As a result, an understanding of the effects of constituent species on the bulk solubility must be developed prior to effective evaporator operations

Cesium Salts of Phosphotungstic Acid: Comparison of Surface ...

African Journals Online (AJOL)

NICO

acidity and lowest solubility in reaction media in comparison with the other cesium content salts. KEYWORDS. Polyoxometalates, cesium ... insoluble salt of HPA is cesium salt of tungstophosphoric acid,. CsxH3-xPW12O40 (CsxPW), a ... of Cs2CO3, very fine particles (precipitates) were formed to make the solution milky.

Method of processing radioactive cesium liquid wastes

International Nuclear Information System (INIS)

Nishijima, Hiroaki; Asaoka, Sachio; Kondo, Tadami; Suzuki, Isao.

1985-01-01

Purpose: To convert and settle cesium, mainly, Cs-137 in liquid wastes in the form of pollucites, that is, cesium-containing ores. Constitution: Water, silica, alumina and alkali metal source are mixed with radioactive liquid wastes containing cesium as the main metal element ingredient, to which an onium compound is further added and they are brought into reaction till pollucite ores (Cs 16 (Al 16 Si 32 O 96 )) are formed. Since most portion of cesium is thus settled in the form of pollucites, storage safety can be attained. Further, the addition of the onium compound can moderate the condition and shorten the time till the pollucite ores are formed. The onium compound usable herein includes tetramethyl ammonium. (Kamimura, M.)

Recent negative ion source developments at ORNL

International Nuclear Information System (INIS)

Alton, G.D.

1979-01-01

According to specifications written for the 25 MV ORNL tandem accelerator, the ion source used during acceptance testing must be capable of producing a negative ion beam of intensity greater than or equal to 7.5 μA within a phase space of less than or equal to 1 π cm-mrad (MeV)/sup 1/2/. The specifications were written prior to the development of an ion source with such capabilities but fortunately Andersen and Tykesson introduced a source in 1975 which could easily meet the specified requirements. The remarkable beam intensity and quality properties of this source has motivated the development of other sources which utilize sputtering in the presence of a diffuse cesium plasma - some of which will be described in these proceedings. This report describes results of studies associated with the development of a modified Aarhus geometry and an axial geometry source which utilize sputtering in the presence of a diffuse cesium plasma for the production of negative ion beams

Selective cesium removal from radioactive liquid waste by crown ether immobilized new class conjugate adsorbent.

Science.gov (United States)

Awual, Md Rabiul; Yaita, Tsuyoshi; Taguchi, Tomitsugu; Shiwaku, Hideaki; Suzuki, Shinichi; Okamoto, Yoshihiro

2014-08-15

Conjugate materials can provide chemical functionality, enabling an assembly of the ligand complexation ability to metal ions that are important for applications, such as separation and removal devices. In this study, we developed ligand immobilized conjugate adsorbent for selective cesium (Cs) removal from wastewater. The adsorbent was synthesized by direct immobilization of dibenzo-24-crown-8 ether onto inorganic mesoporous silica. The effective parameters such as solution pH, contact time, initial Cs concentration and ionic strength of Na and K ion concentrations were evaluated and optimized systematically. This adsorbent was exhibited the high surface area-to-volume ratios and uniformly shaped pores in case cavities, and its active sites kept open functionality to taking up Cs. The obtained results revealed that adsorbent had higher selectivity toward Cs even in the presence of a high concentration of Na and K and this is probably due to the Cs-π interaction of the benzene ring. The proposed adsorbent was successfully applied for radioactive Cs removal to be used as the potential candidate in Fukushima nuclear wastewater treatment. The adsorbed Cs was eluted with suitable eluent and simultaneously regenerated into the initial form for the next removal operation after rinsing with water. The adsorbent retained functionality despite several cycles during sorption-elution-regeneration operations. Copyright © 2014 Elsevier B.V. All rights reserved.

Cesium Isotherm Testing with Spherical Resorcinol-Formaldehyde Resin at High Sodium Concentrations

Energy Technology Data Exchange (ETDEWEB)

Russell, Renee L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fiskum, Sandra K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Smoot, Margaret R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Rinehart, Donald E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2016-04-01

Washington River Protection Solutions (WRPS) is developing a Low-Activity Waste Pretreatment System (LAWPS) to provide low-activity waste (LAW) directly to the Hanford Tank Waste Treatment and Immobilization Plant (WTP) Low-Activity Waste Facility for immobilization. The pretreatment that will be conducted on tank waste supernate at the LAWPS facility entails filtration to remove entrained solids and cesium (Cs) ion exchange to remove Cs from the product sent to the WTP. Currently, spherical resorcinol-formaldehyde (sRF) resin (Microbeads AS, Skedsmokorset, Norway) is the Cs ion exchange resin of choice. Most work on Cs ion exchange efficacy in Hanford tank waste has been conducted at nominally 5 M sodium (Na). WRPS is examining the possibility of processing supernatant at high Na concentrations—up to 8 M Na—to maximize processing efficiency through the LAWPS. Minimal Cs ion exchange work has been conducted at 6 M and 8 M Na concentrations..

GANIL Workshop on Ion Sources

International Nuclear Information System (INIS)

Leroy, Renan

1999-01-01

The proceedings of the GANIL Workshop on Ion Sources held at GANIL - Caen on 18-19 March 1999 contains 13 papers aiming at improving the old source operation and developing new types of sources for nuclear research and studies of ion physics. A number of reports are devoted to applications like surface treatment, ion implantation or fusion injection. The 1+→n+ transformation, charged particle transport in ECR sources, addition of cesium and xenon in negative ion sources and other basic issues in ion sources are also addressed

Seasonal variation of cesium 134 and cesium 137 in semidomestic reindeer in Norway after the Chernobyl accident

International Nuclear Information System (INIS)

Eikelmann, I.M.H.; Bye, K.; Sletten, H.D.

1990-01-01

The Chernobyl accident had a great impact on the semidomestic reindeer husbandry in central Norway. Seasonal differences in habitat and diet resulted in large variations in observed radiocesium concentrations in reindeer after the Chernobyl accident. In three areas with high values of cesium-134 and cesium-137 in lichens, the main feed for reindeer in winter, reindeer were sampled every second month to monitor the seasonal variation and the decrease rate of the radioactivity. The results are based on measurements of cesium-134 and cesium-137 content in meat and blood and by whole-body monitoring of live animals. In 1987 the increase of radiocesium content in reindeer in Vågå were 4x from August to January. The mean reductions in radiocesium content from the winter 1986/87 to the winter 1987/88 were 32%, 50% and 43% in the areas of Vågå, Østre-Namdal and Lom respectively

Sintered bentonite ceramics for the immobilization of cesium- and strontium-bearing radioactive waste

Science.gov (United States)

Ortega, Luis Humberto

The Advanced Fuel Cycle Initiative (AFCI) is a Department of Energy (DOE) program, that has been investigating technologies to improve fuel cycle sustainability and proliferation resistance. One of the program's goals is to reduce the amount of radioactive waste requiring repository disposal. Cesium and strontium are two primary heat sources during the first 300 years of spent nuclear fuel's decay, specifically isotopes Cs-137 and Sr-90. Removal of these isotopes from spent nuclear fuel will reduce the activity of the bulk spent fuel, reducing the heat given off by the waste. Once the cesium and strontium are separated from the bulk of the spent nuclear fuel, the isotopes must be immobilized. This study is focused on a method to immobilize a cesium- and strontium-bearing radioactive liquid waste stream. While there are various schemes to remove these isotopes from spent fuel, this study has focused on a nitric acid based liquid waste. The waste liquid was mixed with the bentonite, dried then sintered. To be effective sintering temperatures from 1100 to 1200°C were required, and waste concentrations must be at least 25 wt%. The product is a leach resistant ceramic solid with the waste elements embedded within alumino-silicates and a silicon rich phase. The cesium is primarily incorporated into pollucite and the strontium into a monoclinic feldspar. The simulated waste was prepared from nitrate salts of stable ions. These ions were limited to cesium, strontium, barium and rubidium. Barium and rubidium will be co-extracted during separation due to similar chemical properties to cesium and strontium. The waste liquid was added to the bentonite clay incrementally with drying steps between each addition. The dry powder was pressed and then sintered at various temperatures. The maximum loading tested is 32 wt. percent waste, which refers to 13.9 wt. percent cesium, 12.2 wt. percent barium, 4.1 wt. percent strontium, and 2.0 wt. percent rubidium. Lower loadings of waste

Application of Cesium isotopes in daily life

International Nuclear Information System (INIS)

Jordao, B.O.; Quaresma, D.S.; Carvalho, R.J.; Peixoto, J.G.P.

2014-01-01

In the world of science, the desire of the scientific community to discover new chemical elements is crucial for the development of new technologies in various fields of knowledge. And the main chemical element addressed by this article is Cesium, but specifically 133 Cesium isotope and radioisotope 137 Cesium, exemplifying their physical and chemical characteristics, and their applications. This article will also show how these isotopes have provided researchers a breakthrough in the field of radiological medicine and in time and frequency metrology. (author)

An argon ion beam milling process for native AlOx layers enabling coherent superconducting contacts

Science.gov (United States)

Grünhaupt, Lukas; von Lüpke, Uwe; Gusenkova, Daria; Skacel, Sebastian T.; Maleeva, Nataliya; Schlör, Steffen; Bilmes, Alexander; Rotzinger, Hannes; Ustinov, Alexey V.; Weides, Martin; Pop, Ioan M.

2017-08-01

We present an argon ion beam milling process to remove the native oxide layer forming on aluminum thin films due to their exposure to atmosphere in between lithographic steps. Our cleaning process is readily integrable with conventional fabrication of Josephson junction quantum circuits. From measurements of the internal quality factors of superconducting microwave resonators with and without contacts, we place an upper bound on the residual resistance of an ion beam milled contact of 50 mΩ μm2 at a frequency of 4.5 GHz. Resonators for which only 6% of the total foot-print was exposed to the ion beam milling, in areas of low electric and high magnetic fields, showed quality factors above 106 in the single photon regime, and no degradation compared to single layer samples. We believe these results will enable the development of increasingly complex superconducting circuits for quantum information processing.

Method for removing cesium from aqueous liquid, method for purifying the reactor coolant in boiling water and pressurized water reactors and a mixed ion exchanged resin bed, useful in said purification

International Nuclear Information System (INIS)

Otte, J.N.A.; Liebmann, D.

1989-01-01

The invention relates to a method for removing cesium from an aqueous liquid, and to a resin bed containing a mixture of an anion exchange resin and cation exchange resin useful in said purification. In a preferred embodiment, the present invention is a method for purifying the reactor coolant of a presurized water or boiling water reactor. Said method, which is particularly advantageously employed in purifying the reactor coolant in the primary circuit of a pressurized reactor, comprises contacting at least a portion of the reactor coolant with a strong base anion exchange resin and the strong acid cation exchange resin derived from a highly cross-linked, macroporous copolymer of a monovinylidene aromatic and a cross-linking monomer copolymerizable therewith. Although the reactor coolant can sequentially be contacted with one resin type and thereafter with the second resin type, the contact is preferably conducted using a resin bed comprising a mixture of the cation and anion exchange resins. 1 fig., refs

The burden of cesium 137 in forest clerks

International Nuclear Information System (INIS)

Piechotowski, I.; Jaroni, J.; Link, B.; Groezinger, O.

2000-01-01

In 47 forest clerks from the regions Ortenau and Oberschwaben in south-west Germany the incorporation of cesium 137 and potassium 40 was measured in autumn 1994. Soil burden as well as burden of nutrition with cesium 137 are different in these regions for geological reasons and as a result of the nuclear accident of Chernobyl. Caused by low content of clay in Oberschwaben, the transfer of cesium to plants is assisted. Heavy rainfall after the nuclear accident led to an additional increase of burden. The median of the concentration of cesium 137 was 1.4 Bq/kg body weight. The median for potassium 40 was 58 Bq/kg body weight. For cesium 137 regional differences were observed. For persons from Oberschwaben the median for cesium 137 was with 2.8 Bq/kg body weight clearly higher than for persons from Ortenau with 0,6 Bq/kg body weight. Concerning nutrition habits, the clearest difference was found comparing persons who had ate a minimum of four portions of deer from the surroundings within the last four weeks with persons who had ate less than four portions of deer from the surroundings within the last four weeks. The difference was greater in Oberschwaben than in Ortenau. The effective dose of cesium 137 calculated on the basis of the incorporation is very low compared to natural radiation. This is also valid for persons from Oberschwaben. (orig.) [de

Thermal Analysis for Ion-Exchange Column System

Energy Technology Data Exchange (ETDEWEB)

Lee, Si Y.; King, William D.

2012-12-20

Models have been developed to simulate the thermal characteristics of crystalline silicotitanate ion exchange media fully loaded with radioactive cesium either in a column configuration or distributed within a waste storage tank. This work was conducted to support the design and operation of a waste treatment process focused on treating dissolved, high-sodium salt waste solutions for the removal of specific radionuclides. The ion exchange column will be installed inside a high level waste storage tank at the Savannah River Site. After cesium loading, the ion exchange media may be transferred to the waste tank floor for interim storage. Models were used to predict temperature profiles in these areas of the system where the cesium-loaded media is expected to lead to localized regions of elevated temperature due to radiolytic decay. Normal operating conditions and accident scenarios (including loss of solution flow, inadvertent drainage, and loss of active cooling) were evaluated for the ion exchange column using bounding conditions to establish the design safety basis. The modeling results demonstrate that the baseline design using one central and four outer cooling tubes provides a highly efficient cooling mechanism for reducing the maximum column temperature. In-tank modeling results revealed that an idealized hemispherical mound shape leads to the highest tank floor temperatures. In contrast, even large volumes of CST distributed in a flat layer with a cylindrical shape do not result in significant floor heating.

Micro-PIXE evaluation of radioactive cesium transfer in contaminated soil samples

International Nuclear Information System (INIS)

Fujishiro, F.; Ishii, K.; Matsuyama, S.; Arai, H.; Ishizaki, A.; Osada, N.; Sugai, H.; Kusano, K.; Nozawa, Y.; Yamauchi, S.; Karahashi, M.; Oshikawa, S.; Kikuchi, K.; Koshio, S.; Watanabe, K.; Suzuki, Y.

2014-01-01

Highlights: • There are radioactively contaminated soils having a radioactive cesium transfer of 0.01. • Micro-PIXE analysis has revealed an existence of phosphorus in a contaminated soil. • Radioactive cesium captured by phosphorus compound would be due to radioactive transfer. -- Abstract: Micro-PIXE analysis has been performed on two soil samples with high cesium activity concentrations. These soil samples were contaminated by fallout from the accident at Fukushima Daiichi Nuclear Power Plant. One exhibits a radioactive cesium transfer of ∼0.01, and the other shows a radioactive cesium transfer of less than 0.001, even though both samples have high cesium activity concentrations exceeding 10,000 Bq/kg. X-ray spectra and elemental images of the soil samples revealed the presence of chlorine, which can react with cesium to produce an inorganic soluble compound, and phosphorus-containing cesium-capturable organic compounds

Method for synthesizing pollucite from chabazite and cesium chloride

International Nuclear Information System (INIS)

Pereira, C.

1999-01-01

A method is described for immobilizing waste chlorides salts containing radionuclides and hazardous nuclear material for permanent disposal, and in particular, a method is described for immobilizing waste chloride salts containing cesium, in a synthetic form of pollucite. The method for synthesizing pollucite from chabazite and cesium chloride includes mixing dry, non-aqueous cesium chloride with chabazite and heating the mixture to a temperature greater than the melting temperature of the cesium chloride, or above about 700 C. The method further comprises significantly improving the rate of retention of cesium in ceramic products comprised of a salt-loaded zeolite by adding about 10% chabazite by weight to the salt-loaded zeolite prior to conversion at elevated temperatures and pressures to the ceramic composite. 3 figs

LITERATURE REVIEWS TO SUPPORT ION EXCHANGE TECHNOLOGY SELECTION FOR MODULAR SALT PROCESSING

Energy Technology Data Exchange (ETDEWEB)

King, W

2007-11-30

This report summarizes the results of literature reviews conducted to support the selection of a cesium removal technology for application in a small column ion exchange (SCIX) unit supported within a high level waste tank. SCIX is being considered as a technology for the treatment of radioactive salt solutions in order to accelerate closure of waste tanks at the Savannah River Site (SRS) as part of the Modular Salt Processing (MSP) technology development program. Two ion exchange materials, spherical Resorcinol-Formaldehyde (RF) and engineered Crystalline Silicotitanate (CST), are being considered for use within the SCIX unit. Both ion exchange materials have been studied extensively and are known to have high affinities for cesium ions in caustic tank waste supernates. RF is an elutable organic resin and CST is a non-elutable inorganic material. Waste treatment processes developed for the two technologies will differ with regard to solutions processed, secondary waste streams generated, optimum column size, and waste throughput. Pertinent references, anticipated processing sequences for utilization in waste treatment, gaps in the available data, and technical comparisons will be provided for the two ion exchange materials to assist in technology selection for SCIX. The engineered, granular form of CST (UOP IE-911) was the baseline ion exchange material used for the initial development and design of the SRS SCIX process (McCabe, 2005). To date, in-tank SCIX has not been implemented for treatment of radioactive waste solutions at SRS. Since initial development and consideration of SCIX for SRS waste treatment an alternative technology has been developed as part of the River Protection Project Waste Treatment Plant (RPP-WTP) Research and Technology program (Thorson, 2006). Spherical RF resin is the baseline media for cesium removal in the RPP-WTP, which was designed for the treatment of radioactive waste supernates and is currently under construction in Hanford, WA

LITERATURE REVIEWS TO SUPPORT ION EXCHANGE TECHNOLOGY SELECTION FOR MODULAR SALT PROCESSING

International Nuclear Information System (INIS)

King, W.

2007-01-01

This report summarizes the results of literature reviews conducted to support the selection of a cesium removal technology for application in a small column ion exchange (SCIX) unit supported within a high level waste tank. SCIX is being considered as a technology for the treatment of radioactive salt solutions in order to accelerate closure of waste tanks at the Savannah River Site (SRS) as part of the Modular Salt Processing (MSP) technology development program. Two ion exchange materials, spherical Resorcinol-Formaldehyde (RF) and engineered Crystalline Silicotitanate (CST), are being considered for use within the SCIX unit. Both ion exchange materials have been studied extensively and are known to have high affinities for cesium ions in caustic tank waste supernates. RF is an elutable organic resin and CST is a non-elutable inorganic material. Waste treatment processes developed for the two technologies will differ with regard to solutions processed, secondary waste streams generated, optimum column size, and waste throughput. Pertinent references, anticipated processing sequences for utilization in waste treatment, gaps in the available data, and technical comparisons will be provided for the two ion exchange materials to assist in technology selection for SCIX. The engineered, granular form of CST (UOP IE-911) was the baseline ion exchange material used for the initial development and design of the SRS SCIX process (McCabe, 2005). To date, in-tank SCIX has not been implemented for treatment of radioactive waste solutions at SRS. Since initial development and consideration of SCIX for SRS waste treatment an alternative technology has been developed as part of the River Protection Project Waste Treatment Plant (RPP-WTP) Research and Technology program (Thorson, 2006). Spherical RF resin is the baseline media for cesium removal in the RPP-WTP, which was designed for the treatment of radioactive waste supernates and is currently under construction in Hanford, WA

Micro-PIXE evaluation of radioactive cesium transfer in contaminated soil samples

Science.gov (United States)

Fujishiro, F.; Ishii, K.; Matsuyama, S.; Arai, H.; Ishizaki, A.; Osada, N.; Sugai, H.; Kusano, K.; Nozawa, Y.; Yamauchi, S.; Karahashi, M.; Oshikawa, S.; Kikuchi, K.; Koshio, S.; Watanabe, K.; Suzuki, Y.

2014-01-01

Micro-PIXE analysis has been performed on two soil samples with high cesium activity concentrations. These soil samples were contaminated by fallout from the accident at Fukushima Daiichi Nuclear Power Plant. One exhibits a radioactive cesium transfer of ˜0.01, and the other shows a radioactive cesium transfer of less than 0.001, even though both samples have high cesium activity concentrations exceeding 10,000 Bq/kg. X-ray spectra and elemental images of the soil samples revealed the presence of chlorine, which can react with cesium to produce an inorganic soluble compound, and phosphorus-containing cesium-capturable organic compounds.

Sorption of cesium on titanium and zirconium phosphates

International Nuclear Information System (INIS)

Lebedev, V.N.; Mel'nik, N.A.; Rudenko, A.V.

2003-01-01

Titanium and zirconium phosphates were prepared from mineral raw materials of the Kola Peninsula. Their capability to recover cesium cations from the model solutions and liquid radioactive waste (LRW) was studied. Titanium phosphate prepared from solutions formed by titanite breakdown demonstrates greater distribution coefficients of cesium as compared to zirconium phosphate. Titanium phosphate as a cheaper agent featuring greater sorption capacity was recommended for treatment of LRW to remove cesium [ru

Non-Contact Measurement of Thermal Diffusivity in Ion-Implanted Nuclear Materials

Science.gov (United States)

Hofmann, F.; Mason, D. R.; Eliason, J. K.; Maznev, A. A.; Nelson, K. A.; Dudarev, S. L.

2015-11-01

Knowledge of mechanical and physical property evolution due to irradiation damage is essential for the development of future fission and fusion reactors. Ion-irradiation provides an excellent proxy for studying irradiation damage, allowing high damage doses without sample activation. Limited ion-penetration-depth means that only few-micron-thick damaged layers are produced. Substantial effort has been devoted to probing the mechanical properties of these thin implanted layers. Yet, whilst key to reactor design, their thermal transport properties remain largely unexplored due to a lack of suitable measurement techniques. Here we demonstrate non-contact thermal diffusivity measurements in ion-implanted tungsten for nuclear fusion armour. Alloying with transmutation elements and the interaction of retained gas with implantation-induced defects both lead to dramatic reductions in thermal diffusivity. These changes are well captured by our modelling approaches. Our observations have important implications for the design of future fusion power plants.

Non-Contact Measurement of Thermal Diffusivity in Ion-Implanted Nuclear Materials

International Nuclear Information System (INIS)

Hofmann, F.; Mason, D. R.; Eliason, J. K.; Maznev, A. A.; Nelson, K. A.; Dudarev, S. L.

2015-01-01

Knowledge of mechanical and physical property evolution due to irradiation damage is essential for the development of future fission and fusion reactors. Ion-irradiation provides an excellent proxy for studying irradiation damage, allowing high damage doses without sample activation. Limited ion-penetration-depth means that only few-micron-thick damaged layers are produced. Substantial effort has been devoted to probing the mechanical properties of these thin implanted layers. Yet, whilst key to reactor design, their thermal transport properties remain largely unexplored due to a lack of suitable measurement techniques. Here we demonstrate non-contact thermal diffusivity measurements in ion-implanted tungsten for nuclear fusion armour. Alloying with transmutation elements and the interaction of retained gas with implantation-induced defects both lead to dramatic reductions in thermal diffusivity. These changes are well captured by our modelling approaches. Our observations have important implications for the design of future fusion power plants

New technique for synthesizing AMP : precipitation inside an ion-exchange resin and its application to separation of cesium from fission-products and to A137sub(m) Ba generator

International Nuclear Information System (INIS)

Matsuda, H.T.; Abrao, A.

1980-06-01

A new technique for synthesizing ammonium molybdophosphate, an inorganic ion exchanger which retains selectively cesium-137 from a mixture of fission products, is dealt with. Normally the use of this exchanger in column operation requires the use of asbestos, silica-gel or organic polymers as binder, due to its microcrystalline form. The new process employs a strong anionic resin, saturated with molybdate anions. This method enables the precipitation of ammonium molybdophosphate directly into the resinous structure by adding dihydrogen ammonium phosphate in 7,5M HNO 3 . The reactants maintened at 60 0 C for a period of four hours has been found to be the optimum condition for a maximum yield of this compound (anionic resin-ammonium molybdophosphate=R-AMP). The tests performed for characterizing this compound are: molybdenum-phosphorus ratio determination, electronic absorption spectra, infra-red absorption spectra, reflection microscopy observations, electron probe micro-analysis and X-ray powder patterns. The mentioned analysis confirmed the presence of the ammonium molybdophosphate in the resinous structure, permitting, thereby, its use as a cation exchanger. R-AMP showed a capacity of 0,48mE/g of dry material. The cesium retention studies were made using columns charged with R-AMP compound. The behavior of some polivalent fission products was also studied. The R-AMP columns was finally applied to separate cesium from irradiated uranium solutions. A method for the isolation of sup(137m)Ba by successive elutions from R-AMP ( 137 Cs) exchanger (generator) is described. (Author) [pt

Cesium-137 inventories in undisturbed areas in different regions of Brazil

Energy Technology Data Exchange (ETDEWEB)

Andrello, Avacir C.; Appoloni, Carlos R., E-mail: acandrello@uel.b [Universidade Estadual de Londrina, PR (Brazil). Dept. de Fisica; Araujo, Ednaldo S. [EMBRAPA Agrobiologia, Seropedica, RJ (Brazil); Thomaz, Edivaldo L. [Universidade Estadual do Centro-Oeste - UNICENTRO, Guarapuava, PR (Brazil). Dept. de Geografia; Medeiros, Pedro Henrique Augusto [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Dept. de Engenharia Agricola; Macedo, Iris L. [Universidade de Brasilia (UnB), DF (Brazil). Faculdade de Tecnologia. Dept. de Engenharia Civil e Ambiental

2009-07-01

Cesium-137 is an anthropogenic radionuclide introduced in the environment in the early of 1960s to the end of 1970s. The Cesium-137 has very used to assess soil redistribution in the landscape because this is very tight in the fine soil particles and its movement in the landscape is due to soil redistribution. To use Cesium-137 to assess soil redistribution is need to known the Cesium-137 inventory in an area that not has experimented soil erosion neither soil deposition. So, this work present Cesium-137 inventories in undisturbed areas in different regions of Brazil, from South to Northeast of Brazil. The inventories in these areas represent the variational deposition of Cesium-137 in the whole national territory of Brazil. The inventories of Cesium-137 varied from 200 +- 15 Bq.m{sup -2} for South region to 15 +- 2 Bq.m{sup -2} for Northeast region. Moreover, was verified that the Cesium- 137 inventories depend on latitude and altitude of the area. (author)

Cesium-137 inventories in undisturbed areas in different regions of Brazil

International Nuclear Information System (INIS)

Andrello, Avacir C.; Appoloni, Carlos R.; Thomaz, Edivaldo L.; Medeiros, Pedro Henrique Augusto; Macedo, Iris L.

2009-01-01

Cesium-137 is an anthropogenic radionuclide introduced in the environment in the early of 1960s to the end of 1970s. The Cesium-137 has very used to assess soil redistribution in the landscape because this is very tight in the fine soil particles and its movement in the landscape is due to soil redistribution. To use Cesium-137 to assess soil redistribution is need to known the Cesium-137 inventory in an area that not has experimented soil erosion neither soil deposition. So, this work present Cesium-137 inventories in undisturbed areas in different regions of Brazil, from South to Northeast of Brazil. The inventories in these areas represent the variational deposition of Cesium-137 in the whole national territory of Brazil. The inventories of Cesium-137 varied from 200 ± 15 Bq.m -2 for South region to 15 ± 2 Bq.m -2 for Northeast region. Moreover, was verified that the Cesium- 137 inventories depend on latitude and altitude of the area. (author)

Method for aqueous radioactive waste treatment

Science.gov (United States)

Bray, L.A.; Burger, L.L.

1994-03-29

Plutonium, strontium, and cesium found in aqueous waste solutions resulting from nuclear fuel processing are removed by contacting the waste solutions with synthetic zeolite incorporating up to about 5 wt % titanium as sodium titanate in an ion exchange system. More than 99.9% of the plutonium, strontium, and cesium are removed from the waste solutions. 3 figures.

H- formation process in a multicusp ion source

International Nuclear Information System (INIS)

Leung, K.N.; Kunkel, W.B.

1987-07-01

In recent years, H - ions have been found important applications in high energy accelerators and in neutral beam heating of fusion plasmas. There are different techniques for producing the H - or D - ions. The most attractive scheme is the direct extraction of H - ions from a hydrogen discharge. This technique requires no cesium and it utilizes the existing large area positive ion source technology. This paper investigates this techniques. 14 refs

Adsorption of Cesium, Strontium, and Rubidium radionuclides in the Mag-molecular process: The influence of important factors

Directory of Open Access Journals (Sweden)

Fatemeh Tangestani

2017-09-01

Full Text Available In this study, the adsorption of cesium, strontium, and rubidium radionuclides by ferritin magmolecules in a batch system was investigated under different experimental conditions. The experiments were conducted in a pilot plant that involved the contactor unit and the magnetic separator unit. The impact of the pollutant concentrations, adsorbent concentration, and pH on the efficiency of the process were investigated thoroughly. The maximum recovery of radionuclides in the studied domain were 57.05%, 85.42% and 71.82% for Cs+, Sr2+ and Rb+ ,respectively, in which the pollutant concentration was 363.63 mg/l, the adsorbent concentration was 0.011 g/l, and the pH was 7.5. The results showed that the ferritin adsorbent in the magmolecular process manifested a higher efficiency in adsorbing the bivalent ions of strontium compared to the univalent ions of cesium and rubidium. Furthermore, the results were statistically analyzed and the model and residual plots of each radionuclide were presented. The results also signified  relationships between the independent variables and recovery.

Observation of water separated ion-pairs between cations and phospholipid headgroups.

Science.gov (United States)

van der Post, Sietse T; Hunger, Johannes; Bonn, Mischa; Bakker, Huib J

2014-04-24

In this work, we present evidence for ion pair formation of cations with a high surface charge density (Na(+) and Ca(2+)) and phosphate groups of phospholipids. We used femto-second infrared pump-probe and dielectric spectroscopy to probe the dynamics of water molecules in solutions of phosphorylethanolamine and different types of cations. We find that sodium and calcium cooperatively retard the dynamics of water in solutions of phosphorylethanolamine, implying the formation of solvent separated ion pairs. This ion-specific interaction is absent for potassium, cesium and ammonium. We compare our results to dielectric spectroscopy experiments, which probes the rotation of all dipolar molecules and ions in solution. The rotation of the dipolar phosphorylethanolamine ion shows that long-lived ion-pairs are only formed with calcium and not with ammonium, cesium, potassium, and sodium. This finding implies that the association between calcium and the phosphate is strong with lifetimes exceeding 200 ps, while the interaction with sodium is relatively short-lived (∼20-100 ps).

Surface interactions of cesium and boric acid with stainless steel

International Nuclear Information System (INIS)

Grossman-Canfield, N.

1995-08-01

In this report, the effects of cesium hydroxide and boric acid on oxidized stainless steel surfaces at high temperatures and near one atmosphere of pressure are investigated. This is the first experimental investigation of this chemical system. The experimental investigations were performed using a mass spectrometer and a mass electrobalance. Surfaces from the different experiments were examined using a scanning electron microscope to identify the presence of deposited species, and electron spectroscopy for chemical analysis to identify the species deposited on the surface. A better understanding of the equilibrium thermodynamics, the kinetics of the steam-accelerated volatilizations, and the release kinetics are gained by these experiments. The release rate is characterized by bulk vaporization/gas-phase mass transfer data. The analysis couples vaporization, deposition, and desorption of the compounds formed by cesium hydroxide and boric acid under conditions similar to what is expected during certain nuclear reactor accidents. This study shows that cesium deposits on an oxidized stainless steel surface at temperatures between 1000 and 1200 Kelvin. Cesium also deposits on stainless steel surfaces coated with boric oxide in the same temperature ranges. The mechanism for cesium deposition onto the oxide layer was found to involve the chemical reaction between cesium and chromate. Some revaporization in the cesium hydroxide-boric acid system was observed. It has been found that under the conditions given, boric acid will react with cesium hydroxide to form cesium metaborate. A model is proposed for this chemical reaction

Micropatterning of poly(4-hydroxystyrene) by ion beam contact lithography for the control of cell adhesion

International Nuclear Information System (INIS)

Hwang, In Tae; Jung, Chan Hee; Choi, Jae Hak; Nho, Young Chang; Lee, Byoung Min; Hong, Sung Kwon

2009-01-01

In this study, we report on a simple method of micropatterning of cells by using ion beam contact lithography. Thin poly(4-hydroxystyrene) (Phds) films spin-coated on a silicon wafer were irradiated through a pattern mask in a contact mode with proton ions and then developed to generate the patterns of the Phds. Well-defined 50 μm line (pitch 150 μm) patterns were obtained without using any additives. The remaining thickness after development was increased with an increasing fluence up to 3 x 10 14 ions cm -2 after which it leveled off. The in-vitro cell culture test revealed that the cells were preferentially adhered to and proliferated only on the space regions between the Phds line patterns. Inhibition of cell adhesion on the Phds patterns could be due to antifouling property of the irradiated PHS

Hanford waste encapsulation: strontium and cesium

International Nuclear Information System (INIS)

Jackson, R.R.

1976-06-01

The strontium and cesium fractions separated from high radiation level wastes at Hanford are converted to the solid strontium fluoride and cesium chloride salts, doubly encapsulated, and stored underwater in the Waste Encapsulation and Storage Facility (WESF). A capsule contains approximately 70,000 Ci of 137 Cs or 70,000 to 140,000 Ci of 90 Sr. Materials for fabrication of process equipment and capsules must withstand a combination of corrosive chemicals, high radiation dosages and frequently, elevated temperatures. The two metals selected for capsules, Hastelloy C-276 for strontium fluoride and 316-L stainless steel for cesium chloride, are adequate for prolonged containment. Additional materials studies are being done both for licensing strontium fluoride as source material and for second generation process equipment

Axial migratin of cesium in LMFBR fuel pins

International Nuclear Information System (INIS)

Karnesky, R.A.; Bridges, A.E.; Jost, J.W.

1981-11-01

A correlated model for quantitatively predicting the behavior of cesium in LMFBR fuel pins has been developed. This correlation was shown to be in good agreement with experimental data. It has been used to predict the behavior of cesium in the FFTF driver fuel and as the result of this analysis it has been shown that the accumulation of cesium in the insulator pellets at the ends of the fuel column will not be life limiting

Effects of C+ ion implantation on electrical properties of NiSiGe/SiGe contacts

International Nuclear Information System (INIS)

Zhang, B.; Yu, W.; Zhao, Q.T.; Buca, D.; Breuer, U.; Hartmann, J.-M.; Holländer, B.; Mantl, S.; Zhang, M.; Wang, X.

2013-01-01

We have investigated the morphology and electrical properties of NiSiGe/SiGe contact by C + ions pre-implanted into relaxed Si 0.8 Ge 0.2 layers. Cross-section transmission electron microscopy revealed that both the surface and interface of NiSiGe were improved by C + ions implantation. In addition, the effective hole Schottky barrier heights (Φ Bp ) of NiSiGe/SiGe were extracted. Φ Bp was observed to decrease substantially with an increase in C + ion implantation dose

Quantum mechanical theory of positron production in heavy ion collisions with nuclear contact

International Nuclear Information System (INIS)

Heinz, U.

1986-01-01

The interplay between atomic and nuclear interactions in heavy ion collisions with nuclear contact is studied. The general theoretical description is outlined and analyzed in a number of different limits (semiclassical approximation, DWBA, fully quantal description). The two most important physical mechanisms for generating atomic-nuclear interference, i.e., energy conservation and the introduction of additional phase shifts by nuclear reactions, are extracted. The resulting typical coupling matrix elements are analyzed for their relative importance in atomic and nuclear excitations. The description of nuclear influence on atomic excitations in terms of a classical time delay caused by nuclear reactions is reviewed, and its relationship to the underlying quantal character of the nuclear reaction is discussed. The theory is applied to spontaneous positron emission in supercritical heavy-ion collisions (Z/sub tot/ ≥ 173). It is shown that nuclear contact can lead to line structures in the positron energy spectra if the probability distribution for nuclear delay times caused by the contact has contributions for T ≥ 10 -19 sec. We explicitly evaluate a model where a pocket in the internuclear potential near the touching configuration leads to formation of nuclear molecules, and predict a resonance-like excitation function for the positron peak. 25 refs., 7 figs

Cesium glass irradiation sources

International Nuclear Information System (INIS)

Plodinec, M.J.

1982-01-01

The precipitation process for the decontamination of soluble SRP wastes produces a material whose radioactivity is dominated by 137 Cs. Potentially, this material could be vitrified to produce irradiation sources similar to the Hanford CsCl sources. In this report, process steps necessary for the production of cesium glass irradiation sources (CGS), and the nature of the sources produced, are examined. Three options are considered in detail: direct vitrification of precipitation process waste; direct vitrification of this waste after organic destruction; and vitrification of cesium separated from the precipitation process waste. Direct vitrification is compatible with DWPF equipment, but process rates may be limited by high levels of combustible materials in the off-gas. Organic destruction would allow more rapid processing. In both cases, the source produced has a dose rate of 2 x 10 4 rads/hr at the surface. Cesium separation produces a source with a dose rate of 4 x 10 5 at the surface, which is nearer that of the Hanford sources (2 x 10 6 rads/hr). Additional processing steps would be required, as well as R and D to demonstrate that DWPF equipment is compatible with this intensely radioactive material

Spatial variability and Cesium-137 inventories in native forest

International Nuclear Information System (INIS)

Andrello, A.C.; Appoloni, C.R.

2004-01-01

With the nuclear fission discovery and development of nuclear weapons in 1940s, artificial radioisotopes were introduced in the environment. This contamination is due to worldwide fallout by superficial nuclear tests realized from early 1950s to late 1970s by USA, former URSS, UK, France and China. One of theses radioisotopes that have been very studied is cesium-137. Cesium-137 has a half-life of 30.2 years and its biological behavior is similar to the potassium. The behavior in soil matrix, depth distribution, spatial variability and inventories values of cesium-137 has been determinate for several regions of the world. In Brazil, some research groups have worked on this subject, but there are few works published about theses properties of cesium-137. The aim of this paper was study the depth distribution, spatial variability, and inventory of cesium-137 in native forest. Two native forests (Mata 1 and Mata UEL) were sampling in region of Londrina, PR. The results shows that there is a spatial variability of 40% for Mata 1 and 42% for Mata UEL. The depth distribution of cesium-137 for two forests presented a exponential form, characteristic to undisturbed soil. Cesium-137 inventory determinate for Mata 1 was 358 Bq m -2 and for Mata UEL was 320 Bq m -2 . (author)

Decorporation of cesium-137

International Nuclear Information System (INIS)

Le Fleche, Ph.; Destombe, C.; Grasseau, A.; Mathieu, J.; Chancerelle, Y.; Mestries, J.C.

1997-01-01

Cesium radio-isotopes, especially cesium-137 ( 137 Cs) are among the radionuclides of main importance produced by a fission reaction in reactor or a nuclear weapon explosion. In the environment, 137 Cs is a major contaminant which can cause severe β, γirradiations and contaminations. 137 Cs is distributed widely and relatively uniformly throughout the body with the highest concentration in skeletal muscles. A treatment becomes difficult afterwards. The purposes of this report are Firstly to compare the Prussian blue verses cobalt and potassium ferrocyanide (D.I. blue) efficiency for the 137 Cs decorporation and secondly to assess a chronological treatment with D.I. blue. (author)

Ionization mechanism of cesium plasma produced by irradiation of dye laser

International Nuclear Information System (INIS)

Yamada, Jun; Shibata, Kohji; Uchida, Yoshiyuki; Hioki, Yoshiaki; Sahashi, Toshio.

1992-01-01

When a cesium vapor was irradiated by a dye laser which was tuned to the cesium atomic transition line, the number of charged particles produced by the laser radiation was observed. Several sharp peaks in the number of charged particles were observed, which corresponded to the atomic transition where the lower level was the 6P excited atom. The ionization mechanism of the laser-produced cesium plasma has been discussed. An initial electron is produced by laser absorptions of the cesium dimer. When the cesium density is high, many 6P excited atoms are excited by electron collisions. The 6P excited atom further absorbs the laser photon and is ionized through the higher-energy state. As the cesium vapor pressure increases, the resonance effect becomes observable. The 6P excited atom plays dominant role in the ionization mechanism of the laser-produced cesium plasma. (author)

modern techniques and new sensors for determination of some metal ions

International Nuclear Information System (INIS)

Aglan, R.F.E.S.

2004-01-01

this work has been carried out to prepare some new sensors that can be used i the radioactive media. A novel homogenous solid state sensor responding to potassium ion was developed. i revealed good linear response with slope 44 ± 0.5 mV/decade over he concentration range 10 -4 -1.0 mol 1 -1 potassium ion with long life, high thermal and radiation stability. the influence of plasticizer, ionophore and conducting substrate on the analytical characterization of uranyl ion selective electrode was investigated. A new cesium sensor incorporating Cs-12- molybdophosphate as a sensing materials and DOP as solvent mediator in PVC matrix was constructed and used in the determination of cesium ion in the rage of 10 -5 10 -1 mol 1 -1 with a stop of 46±1.0 mV/decade in Ph range of 4-6

Extraction of cesium from acid solutions

International Nuclear Information System (INIS)

Katykhin, G.S.; Simonov, A.S.

1983-01-01

The extraction of cesium from acidic solutions is studied. Halogen-substituted carboxylic acids were chosen for the aqueous phase and nitrobenzene the diluent. The distribution coefficients are determined by the use of radioactive tracers 134 Cs and 137 Cs. It is believed that large singly charged anions of strong acids are necessary for the extraction of cesium. Metal halide acids are selected for supplying the anions

Development and properties of crystalline silicotitanate (CST) ion exchangers for radioactive waste applications

Energy Technology Data Exchange (ETDEWEB)

Miller, J.E.; Brown, N.E.

1997-04-01

Crystalline silicotitanates (CSTs) are a new class of ion exchangers that were jointly invented by researchers at Sandia National Laboratories and Texas A&M University. One particular CST, known as TAM-5, is remarkable for its ability to separate parts-per-million concentrations of cesium from highly alkaline solutions (pH> 14) containing high sodium concentrations (>5M). It is also highly effective for removing cesium from neutral and acidic solutions, and for removing strontium from basic and neutral solutions. Cesium isotopes are fission products that account for a large portion of the radioactivity in waste streams generated during weapons material production. Tests performed at numerous locations with early lab-scale TAM-5 samples established the material as a leading candidate for treating radioactive waste volumes such as those found at the Hanford site in Washington. Thus Sandia developed a Cooperative Research and Development Agreement (CRADA) partnership with UOP, a world leader in developing, commercializing, and supplying adsorbents and associated process technology to commercialize and further develop the material. CSTs are now commercially available from UOP in a powder (UOP IONSIV{reg_sign} IE-910 ion exchanger) and granular form suitable for column ion exchange operations (UOP IONSIV{reg_sign} IE-911 ion exchanger). These materials exhibit a high capacity for cesium in a wide variety of solutions of interest to the Department of Energy, and they are chemically, thermally, and radiation stable. They have performed well in tests at numerous sites with actual radioactive waste solutions, and are being demonstrated in the 100,000 liter Cesium Removal Demonstration taking place at Oak Ridge National Laboratory with Melton Valley Storage Tank waste. It has been estimated that applying CSTs to the Hanford cleanup alone will result in a savings of more than $300 million over baseline technologies.

Development and properties of crystalline silicotitanate (CST) ion exchangers for radioactive waste applications

International Nuclear Information System (INIS)

Miller, J.E.; Brown, N.E.

1997-04-01

Crystalline silicotitanates (CSTs) are a new class of ion exchangers that were jointly invented by researchers at Sandia National Laboratories and Texas A ampersand M University. One particular CST, known as TAM-5, is remarkable for its ability to separate parts-per-million concentrations of cesium from highly alkaline solutions (pH> 14) containing high sodium concentrations (>5M). It is also highly effective for removing cesium from neutral and acidic solutions, and for removing strontium from basic and neutral solutions. Cesium isotopes are fission products that account for a large portion of the radioactivity in waste streams generated during weapons material production. Tests performed at numerous locations with early lab-scale TAM-5 samples established the material as a leading candidate for treating radioactive waste volumes such as those found at the Hanford site in Washington. Thus Sandia developed a Cooperative Research and Development Agreement (CRADA) partnership with UOP, a world leader in developing, commercializing, and supplying adsorbents and associated process technology to commercialize and further develop the material. CSTs are now commercially available from UOP in a powder (UOP IONSIV reg-sign IE-910 ion exchanger) and granular form suitable for column ion exchange operations (UOP IONSIV reg-sign IE-911 ion exchanger). These materials exhibit a high capacity for cesium in a wide variety of solutions of interest to the Department of Energy, and they are chemically, thermally, and radiation stable. They have performed well in tests at numerous sites with actual radioactive waste solutions, and are being demonstrated in the 100,000 liter Cesium Removal Demonstration taking place at Oak Ridge National Laboratory with Melton Valley Storage Tank waste. It has been estimated that applying CSTs to the Hanford cleanup alone will result in a savings of more than $300 million over baseline technologies

Determination of microquantities of cesium in leaching tests by atomic absorption spectrometry with electrothermal atomization

International Nuclear Information System (INIS)

Crubellati, R.O.; Di Santo, N.R.

1988-01-01

An original method for cesium determinations by atomic absorption spectrometry with electrothermal atomization is described. The effect of foreign ions (alkali and earth alkaline metals) present in leaching test of glasses with incorporated radioactive wastes was studied. The effect of different mineral acids was also investigated. A comparison between the flame excitation method and the electrothermal atomization one was made. Under optimum conditions, cesium in quantities down to 700 ng in 1000 ml of sample could be determined. The calibration curve was linear in the range of 0.7 - 15 ng/mL. The fact that the proposed determinations can be performed in a short time and that a small sample volume is required are fundamental advantages of this method, compared with the flame excitation procedure. Besides, it is adaptable to be applied in hot cells and glove boxes. (Author) [es

Process for producing zeolite adsorbent and process for treating radioactive liquid waste with the zeolite adsorbent

International Nuclear Information System (INIS)

Motojima, K.; Kawamura, F.

1984-01-01

Zeolite is contacted with an aqueous solution containing at least one of copper, nickel, cobalt, manganese and zinc salts, preferably copper and nickel salts, particularly preferably copper salt, in such a form as sulfate, nitrate, or chloride, thereby adsorbing the metal on the zeolite in its pores by ion exchange, then the zeolite is treated with a water-soluble ferrocyanide compound, for example, potassium ferrocyanide, thereby forming metal ferrocyanide on the zeolite in its pores. Then, the zeolite is subjected to ageing treatment, thereby producing a zeolite adsorbent impregnated with metal ferrocyanide in the pores of zeolite. The adsorbent can selectively recover cesium with a high percent cesium removal from a radioactive liquid waste containing at least radioactive cesium, for example, a radioactive liquid waste containing cesium and such coexisting ions as sodium, magnesium, calcium and carbonate ions at the same time at a high concentration. The zeolite adsorbent has a stable adsorbability for a prolonged time

Cesium in the nutrient cycle

International Nuclear Information System (INIS)

Rantavaara, A.

1992-01-01

Most radioactive cesium in forests is deposited in soil, from which it passes into berries and mushrooms, and further to game. The cesium contents of Finnish berries and mushrooms vary depending on the intensity of Chernobyl fallout. Northern Haeme, Pirkanmaa and parts of central Finland received the most fallout. Weather conditions and the environmental factors, and other circumstances during the growth period, also affect the contents. However, consumption of wild berries, mushrooms and game need not be restricted because of radioactivity anywhere in Finland

Study of strontium and cesium migration in fractured crystalline rock

International Nuclear Information System (INIS)

Gustafsson, E.; Klockars, C.E.

1984-01-01

The purpose of this investigation has been to study the retardation and dilution of non-active strontium and cesium relative to a non-absorbing substance (iodide) in a well-defined fracture zone in the Finnsjoen field research area. The investigation was carried out in a previously tracer-tested fracture zone. The study has encompassed two separate test runs with prolonged injection of strontium and iodide and of cesium and iodide. The test have shown that: - Strontium is not retarded, but rather absorbed to about 40% at equilibrium. - At injection stop, 36.3% of the injected mass of strontium has been absorbed and there is no deabsorption. -Cesium is retarded a factor of 2-3 and absorbed to about 30% at equilibrium. - At injection stop, 39.4% of the injected mass of cesium has been absorbed. Cesium is deabsorbed after injection stop (400h) and after 1300 hours, only 22% of the injected mass of cesium is absorbed. (author)

Effect of thermal contact resistances on fast charging of large format lithium ion batteries

International Nuclear Information System (INIS)

Ye, Yonghuang; Saw, Lip Huat; Shi, Yixiang; Somasundaram, Karthik; Tay, Andrew A.O.

2014-01-01

Highlights: • The effect of thermal contact resistance on thermal performance of large format lithium ion batteries. • The effect of temperature gradient on electrochemical performance of large format batteries during fast charging. • The thermal performance of lithium ion battery utilizing pulse charging protocol. • Suggestions on battery geometry design optimization to improve thermal performance. - Abstract: A two dimensional electrochemical thermal model is developed on the cross-plane of a laminate stack plate pouch lithium ion battery to study the thermal performance of large format batteries. The effect of thermal contact resistance is taken into consideration, and is found to greatly increase the maximum temperature and temperature gradient of the battery. The resulting large temperature gradient would induce in-cell non-uniformity of charging-discharging current and state of health. Simply increasing the cooling intensity is inadequate to reduce the maximum temperature and narrow down the temperature difference due to the poor cross-plane thermal conductivity. Pulse charging protocol does not help to mitigate the temperature difference on the bias of same total charging time, because of larger time-averaged heat generation rate than constant current charging. Suggestions on battery geometry optimizations for both prismatic/pouch battery and cylindrical battery are proposed to reduce the maximum temperature and mitigate the temperature gradient within the lithium ion battery

Cesium vapor cycle for an advanced LMFBR

International Nuclear Information System (INIS)

Fraas, A.P.

1975-01-01

A review indicates that a cesium vapor topping cycle appears attractive for use in the intermediate fluid circuit of an advanced LMFBR designed for a reactor outlet temperature of 1250 0 F or more and would have the following advantages: (1) it would increase the thermal efficiency by about 5 to 10 points (from approximately 40 percent to approximately 45 to 50 percent) thus reducing the amount of waste heat rejected to the environment by 15 to 30 percent. (2) the higher thermal efficiency should reduce the overall capital cost of the reactor plant in dollars per kilowatt. (3) the cesium can be distilled out of the intermediate fluid circuit to leave it bone-dry, thus greatly reducing the time and cost of maintenance work (particularly for the steam generator). (4) the large volume and low pressure of the cesium vapor region in the cesium condenser-steam generator greatly reduces the magnitude of pressure fluctuations that might occur in the event of a leak in a steam generator tube, and the characteristics inherent in a condenser make it easy to design for rapid concentration of any noncondensibles that may form as a consequence of a steam leak into the cesium region so that a steam leak can be detected easily in the very early stages of its development

Selective cesium removal from radioactive liquid waste by crown ether immobilized new class conjugate adsorbent

OpenAIRE

Awual, M. R.; 矢板 毅; 田口 富嗣; 塩飽 秀啓; 鈴木 伸一; 岡本 芳浩

2014-01-01

Conjugate materials can provide chemical functionality, enabling an assembly of the ligand complexation ability to metal ions that are important for applications, such as separation and removal devices. In this study, we developed ligand immobilized conjugate adsorbent for selective cesium (Cs) removal from wastewater. The adsorbent was synthesized by direct immobilization of DB24C8 onto inorganic mesoporous silica. The obtained results revealed that adsorbent had higher selectivity towards C...

Modeling of the sorptive behavior of a clay material used as reactive barrier for cesium migration in Huelva (Spain)

International Nuclear Information System (INIS)

Missana, Tiziana; Garcia-Gutierrez, Miguel

2012-01-01

Document available in extended abstract form only. On 1998 a 137 Cs source was accidentally molten in the installations of a Spanish company of stainless steel production. Not being aware of the contamination with Cs, the produced powder was treated in an inert plant and these inert materials were normally used as filling material to restore phosphogypsum piles. The contaminated material ended up in the phosphogypsum piles at the Center of Inert Recuperation (CRI), located at the salt marshes of Huelva (Spain). This is a large extension oriented towards the sea with marsh vegetation subject to the tide. Since the cesium contamination was discovered, this zone has been thoroughly analyzed in order to evaluate the radiological impact of the presence of cesium and the possible contamination of soils and water in the surrounding. Recently, in two different locations at CRI, permeable reactive barriers were constructed to retard cesium migration. The main component of these barriers is a clay material called Rojo Carbonero (RC), whose properties as cesium sorbent have to be analyzed in depth. This material is mainly formed by: quartz (27%), phyllosilicates (58%), dolomite (8%), feldspar (2%), hematite (5%). The clayey fraction (<2 μm) is composed by a 98% of illite and the rest is chlorite/kaolinite. Different studies were carried out to quantify the sorption of cesium in this material previous to the construction of the reactive barriers. Due to the large variability of the chemical composition of the waters at the site a significant variability of sorption values, in terms of distribution coefficients (Kd) was also observed. In order to predict the migration of cesium in these barriers, taking into account this variability and the presence of competing ions, a detailed experimental study was carried out with the aim of determining the selectivity coefficients of cesium with respect to the main ions present in the water. Basically, the material was converted in

Selective removal of cesium from aqueous solutions with nickel (II) hexacyanoferrate (III) functionalized agricultural residue–walnut shell

International Nuclear Information System (INIS)

Ding, Dahu; Lei, Zhongfang; Yang, Yingnan; Feng, Chuanping; Zhang, Zhenya

2014-01-01

Highlights: • Novel biosorbent for cesium removal was derived from agricultural residue. • It could remove cesium effectively from aqueous solution. • Large size of granules makes it easy to be separated from solutions. • The volume of used biosorbent could be significantly reduced after incineration. • Incinerated biosorbent has a low volume and a low cost final disposal. - Abstract: A novel nickel (II) hexacyanoferrate (III) functionalized agricultural residue-walnut shell (Ni II HCF III -WS) was developed to selectively remove cesium ion (Cs + ) from aqueous solutions. This paper showed the first integral study on Cs + removal behavior and waste reduction analysis by using biomass adsorption material. The results indicated that the removal process was rapid and reached saturation within 2 h. As a special characteristic of Ni II HCF III -WS, acidic condition was preferred for Cs + removal, which was useful for extending the application scope of the prepared biomass material in treating acidic radioactive liquid waste. The newly developed Ni II HCF III -WS could selectively remove Cs + though the coexisting ions (Na + and K + in this study) exhibited negative effects. In addition, approximately 99.8% (in volume) of the liquid waste was reduced by using Ni II HCF III -WS and furthermore 91.9% (in volume) of the spent biomass material (Cs-Ni II HCF III -WS) was reduced after incineration (at 500 °C for 2 h). Due to its relatively high distribution coefficient and significant volume reduction, Ni II HCF III -WS is expected to be a promising material for Cs + removal in practice

Cesium and Strontium Separation Technologies Literature Review

Energy Technology Data Exchange (ETDEWEB)

T. A. Todd; T. A. Todd; J. D. Law; R. S. Herbst

2004-03-01

Integral to the Advanced Fuel Cycle Initiative (AFCI) Program’s proposed closed nuclear fuel cycle, the fission products cesium and strontium in the dissolved spent nuclear fuel stream are to be separated and managed separately. A comprehensive literature survey is presented to identify cesium and strontium separation technologies that have the highest potential and to focus research and development efforts on these technologies. Removal of these high-heat-emitting fission products reduces the radiation fields in subsequent fuel cycle reprocessing streams and provides a significant short-term (100 yr) heat source reduction in the repository. This, along with separation of actinides, may provide a substantial future improvement in the amount of fuel that could be stored in a geologic repository. The survey and review of the candidate cesium and strontium separation technologies are presented herein. Because the AFCI program intends to manage cesium and strontium together, technologies that simultaneously separate both elements are of the greatest interest, relative to technologies that separate only one of the two elements.

Biochemical changes in rats under the influence of cesium chloride

Directory of Open Access Journals (Sweden)

N. M. Melnikova

2013-04-01

Full Text Available Cesium is lately accumulated actively in the environment, but its influence on human and ani­mal organism is the least studied among heavy metals. It is shown that the action of cesium chloride in rats caused significant changes in blood chemistry, which are characterized by a decrease of total protein content, pH, an increase in the level of urea, creatinine, glucose and total hemoglobin. The results showed that potassium content in all the studied organs and tissues of poisoned rats decreases under the action of cesium chloride. Histological examination of the heart tissue in rats poisoned with cesium chloride indicates the onset of pathology of cardiovascular system. It was found out that use of the drug “Asparkam” reduces the negative effect of cesium chloride on the body of rats.

Rapid determination of trace level copper in tea infusion samples by solid contact ion selective electrode

Directory of Open Access Journals (Sweden)

Aysenur Birinci

2016-07-01

Full Text Available A new solid contact copper selective electrode with a poly (vinyl chloride (PVC membrane consisting of o-xylylenebis(N,N-diisobutyldithiocarbamate as ionophore has been prepared. The main novelties of constructed ion selective electrode concept are the enhanced robustness, cheapness, and fastness due to the use of solid contacts. The electrode exhibits a rapid (< 10 seconds and near-Nernstian response to Cu2+ activity from 10−1 to 10−6 mol/L at the pH range of 4.0–6.0. No serious interference from common ions was found. The electrode characterizes by high potential stability, reproducibility, and full repeatability. The electrode was used as an indicator electrode in potentiometric titration of Cu(II ions with EDTA and for the direct assay of tea infusion samples by means of the calibration graph technique. The results compared favorably with those obtained by the atomic absorption spectroscopy (AAS.

Langmuir probes for SPIDER (source for the production of ions of deuterium extracted from radio frequency plasma) experiment: Tests in BATMAN (Bavarian test machine for negative ions)

Science.gov (United States)

Brombin, M.; Spolaore, M.; Serianni, G.; Pomaro, N.; Taliercio, C.; Palma, M. Dalla; Pasqualotto, R.; Schiesko, L.

2014-11-01

A prototype system of the Langmuir probes for SPIDER (Source for the production of Ions of Deuterium Extracted from RF plasma) was manufactured and experimentally qualified. The diagnostic was operated in RF (Radio Frequency) plasmas with cesium evaporation on the BATMAN (BAvarian Test MAchine for Negative ions) test facility, which can provide plasma conditions as expected in the SPIDER source. A RF passive compensation circuit was realised to operate the Langmuir probes in RF plasmas. The sensors' holder, designed to better simulate the bias plate conditions in SPIDER, was exposed to a severe experimental campaign in BATMAN with cesium evaporation. No detrimental effect on the diagnostic due to cesium evaporation was found during the exposure to the BATMAN plasma and in particular the insulation of the electrodes was preserved. The paper presents the system prototype, the RF compensation circuit, the acquisition system (as foreseen in SPIDER), and the results obtained during the experimental campaigns.

Langmuir probes for SPIDER (source for the production of ions of deuterium extracted from radio frequency plasma) experiment: Tests in BATMAN (Bavarian test machine for negative ions)

International Nuclear Information System (INIS)

Brombin, M.; Spolaore, M.; Serianni, G.; Pomaro, N.; Taliercio, C.; Palma, M. Dalla; Pasqualotto, R.; Schiesko, L.

2014-01-01

A prototype system of the Langmuir probes for SPIDER (Source for the production of Ions of Deuterium Extracted from RF plasma) was manufactured and experimentally qualified. The diagnostic was operated in RF (Radio Frequency) plasmas with cesium evaporation on the BATMAN (BAvarian Test MAchine for Negative ions) test facility, which can provide plasma conditions as expected in the SPIDER source. A RF passive compensation circuit was realised to operate the Langmuir probes in RF plasmas. The sensors’ holder, designed to better simulate the bias plate conditions in SPIDER, was exposed to a severe experimental campaign in BATMAN with cesium evaporation. No detrimental effect on the diagnostic due to cesium evaporation was found during the exposure to the BATMAN plasma and in particular the insulation of the electrodes was preserved. The paper presents the system prototype, the RF compensation circuit, the acquisition system (as foreseen in SPIDER), and the results obtained during the experimental campaigns

Cesium-134 and cesium-137 in honey bees and cheese samples collected in the U. S. after the Chernobyl accident

Energy Technology Data Exchange (ETDEWEB)

Ford, B C; Jester, W A; Griffith, S M; Morse, R A; Zall, R R; Lisk, D J; Burgett, D M; Bodyfelt, F W

1988-01-01

As a result of the Chernobyl accident on April 25, 1986, possible radioactive contamination of honey bees and cheese sampled in several areas of the United States were measured. Of bees collected in May and June of 1986 in both Oregon and New York, only those from Oregon showed detectable levels of cesium-134 (T1/2 = 2.05 years), a radionuclide which would have originated from the Chernobyl incident. Cheese produced in Oregon and New York before the accident showed only cesium-137 (T1/2 = 30.23 years) but cheese produced afterwards (May and September, 1986) in Oregon contained cesium-134. Cheese produced in Ohio and California at the time of the accident and thereafter contained only cesium-137. In general, the levels of radioactivity were higher in the West coast samples as compared to those taken in the East. The levels of radioactivity detected were considered to be toxicologically of no consequence.

Electrochemical assessment of water|ionic liquid biphasic systems towards cesium extraction from nuclear waste

OpenAIRE

Stockmann, T. Jane; Zhang, Jing; Montgomery, Anne-Marie; Ding, Zhifeng

2014-01-01

A room temperature ionic liquid (IL) composed of a quaternary alkylphosphonium (trihexyltetradecylphosphonium, P66614(+)) and tetrakis(pentafluorophenyl) borate anion (TB) was employed within a water| P66614TB (w|P66614TB or w|IL) biphasic system to evaluate cesium ion extraction in comparison to that with a traditional water|organic solvent (w|o) combination. Cs-137 is a major contributor to the radioactivity of spent nuclear fuel as it leaves the reactor, and its extraction efficiency is th...

Sorption of cesium and strontium from concentrated brines by backfill barrier materials

International Nuclear Information System (INIS)

Winslow, C.D.

1981-03-01

The sorption of radionuclides from potentially intruding groundwater at a nuclear waste repository is a major chemical function of backfill barriers. In this study, various materials (including clays, zeolites and an inorganic ion exchanger) were screened for the sorption of the fission products cesium and strontium in concentrated brines. Representative brines A and B for the Waste Isolation Pilot Plant (WIPP), a proposed radioactive waste repository and test facility in bedded salt were used. Sorption properties were quantified using empirical distribution coefficients, k/sub d/. Of the materials examined, sodium titanate had the highest k/sub d/ for the sorption of Sr(II) in both brine A (k/sub d/ = 125 ml/g) and brine B(k/sub d/ = 500 to 600 ml/g). A mordenite-type zeolite was the most effective getter for Cs(I) in brine A (k/sub d = 27 ml/g), while illite yielded the highest k/sub d/ for Cs(I) in brine B (k/sub d/ = 115 ml/g). The relative merit of these k/sub d/ values is evaluated in terms of calculated estimates of breakthrough times for a backfill barrier containing the getter. Results show that a backfill mixture containing these getters is potentially an effective barrier to the migration of Sr(II) and Cs(I), although further study (especially for the sorption of cesium from brine A) is recommended. Initial mechanistic studies revealed competing ion effects which would support an ion exchange mechanism. K/sub d/'s were constant over a Sr(II) concentration range of 10 -11 to 10 -5 M and a Cs(I) concentration range of 10 -8 to 10 -5 M, supporting the choice of a linear sorption isotherm as a model for the results. Constant batch composition was shown to be attained within one week

Electron-stimulated desorption of cesium atoms from cesium layers adsorbed on gold-covered tungsten

Energy Technology Data Exchange (ETDEWEB)

Ageev, V N; Kuznetsov, Yu A; Potekhina, N D, E-mail: kuznets@ms.ioffe.r [A F Ioffe Physico-Technical Institute, Russian Academy of Sciences, 194021, St Petersburg (Russian Federation)

2010-03-03

The electron-stimulated desorption (ESD) yields and energy distributions (ED) for neutral cesium atoms have been measured from cesium layers adsorbed on a gold-covered tungsten surface as a function of electron energy, gold film thickness, cesium coverage and substrate temperature. The measurements have been carried out using a time-of-flight method and surface ionization detector in the temperature range 160-300 K. A measurable ESD yield for Cs atoms is observed only after deposition of more than one monolayer of gold and cesium on a tungsten surface at a temperature T = 300 K, which is accompanied by the formation of a CsAu semiconductor film covered with a cesium atom monolayer. The Cs atom ESD yield as a function of incident electron energy has a resonant character and consists of two peaks, the appearance of which depends on both electron energy and substrate temperature. The first peak has an appearance threshold at an electron energy of 57 eV and a substrate temperature of 300 K that is due to Au 5p{sub 3/2} core level excitation in the substrate. The second peak appears at an electron energy of 24 eV and a substrate temperature of 160 K. It is associated with a Cs 5s core level excitation in the Cs adsorbed layer. The Au 5p{sub 3/2} level excitation corresponds to a single broad peak in the ED with a maximum at a kinetic energy of 0.45 eV at a substrate temperature T = 300 K, which is split into two peaks with maxima at kinetic energies of 0.36 and 0.45 eV at a substrate temperature of 160 K, associated with different Cs atom ESD channels. The Cs 5s level excitation leads to an ED for Cs atoms with a maximum at a kinetic energy of approx 0.57 eV which exists only at T < 240 K and low Cs concentrations. The mechanisms for all the Cs atom ESD channels are proposed and compared with the Na atom ESD channels in the Na-Au-W system.

Nanomaterials-Enhanced Electrically Switched Ion Exchange Process for Water Treatment

International Nuclear Information System (INIS)

Lin, Yuehe; Choi, Daiwon; Wang, Jun; Bontha, Jagannadha R.

2009-01-01

The objective of our work is to develop an electrically switched ion exchange (ESIX) system based on conducting polymer/carbon nanotube (CNT) nanocomposites as a new and cost-effective approach for removal of radioactive cesium, chromate, and perchlorate from contaminated groundwater. The ESIX technology combines ion exchange and electrochemistry to provide a selective, reversible method for the removal of target species from wastewater. In this technique, an electroactive ion exchange layer is deposited on a conducting substrate, and ion uptake and elution are controlled directly by modulation of the potential of the layer. ESIX offers the advantages of highly-efficient use of electrical energy combined with no secondary waste generation. Recently, we have improved upon the ESIX process by modifying the conducting substrate with carbon nanotubes prior to the deposition of the electroactive ion exchanger. The nanomaterial-based electroactive ion exchange technology will remove cesium-137, chromate, and perchlorate rapidly from wastewater. The high porosity and high surface area of the electroactive ion exchange nanocomposites results in high loading capacity and minimize interferences for non-target species. Since the ion adsorption/desorption is controlled electrically without generating a secondary waste, this electrically active ion exchange process is a green process technology that will greatly reduce operating costs

Cesium-137 retention in irops obtained from various soils

International Nuclear Information System (INIS)

Gulyakin, I.V.; Yudintseva, E.V.; Gorina, L.I.

1974-01-01

A non-station experiment has shown that the accumulation of cesium-137 in a plant yield depends on the type of soil. The highest contents of cesium-137 were found in the yield of plants from soddy-podzolic sandy loam soils, and the lowest- in those from leached chernozem. The accumulation of radiocesium in the yield of the basic produce strongly depended on the plant species. The amount of cesium-137 differed 5- to 7-fold in different crops

Hypothesis for the mechanism of negative ion production in the surface-plasma negative hydrogen ion source

International Nuclear Information System (INIS)

Hiskes, J.R.

1975-01-01

An analysis of the surface-plasma negative hydrogen ion source has shown that the tungsten cathode supports approximately a monolayer of cesium. The backscattering of protons from the cathode as energetic neutrals and the subsequent backscattering of these neutrals from the anode provides for a flux of energetic atoms incident upon the cathode which is comparable to the ion flux. A hypothesis is proposed for the generation of negative ions during the collision of these energetic atoms with the cathode. Several mechanisms for negative ion production by proton collision with the surface are discussed. (U.S.)

Restoring the consistency with the contact density theorem of a classical density functional theory of ions at a planar electrical double layer.

Science.gov (United States)

Gillespie, Dirk

2014-11-01

Classical density functional theory (DFT) of fluids is a fast and efficient theory to compute the structure of the electrical double layer in the primitive model of ions where ions are modeled as charged, hard spheres in a background dielectric. While the hard-core repulsive component of this ion-ion interaction can be accurately computed using well-established DFTs, the electrostatic component is less accurate. Moreover, many electrostatic functionals fail to satisfy a basic theorem, the contact density theorem, that relates the bulk pressure, surface charge, and ion densities at their distances of closest approach for ions in equilibrium at a smooth, hard, planar wall. One popular electrostatic functional that fails to satisfy the contact density theorem is a perturbation approach developed by Kierlik and Rosinberg [Phys. Rev. A 44, 5025 (1991)PLRAAN1050-294710.1103/PhysRevA.44.5025] and Rosenfeld [J. Chem. Phys. 98, 8126 (1993)JCPSA60021-960610.1063/1.464569], where the full free-energy functional is Taylor-expanded around a bulk (homogeneous) reference fluid. Here, it is shown that this functional fails to satisfy the contact density theorem because it also fails to satisfy the known low-density limit. When the functional is corrected to satisfy this limit, a corrected bulk pressure is derived and it is shown that with this pressure both the contact density theorem and the Gibbs adsorption theorem are satisfied.

Molecular and negative ion production by a standard electron cyclotron resonance ion source

Energy Technology Data Exchange (ETDEWEB)

Racz, R. [Institute of Nuclear Research (ATOMKI), Bem ter 18/c, H-4026 Debrecen (Hungary); University of Debrecen, Egyetem ter 1, H-4010 Debrecen (Hungary); Biri, S.; Juhasz, Z.; Sulik, B. [Institute of Nuclear Research (ATOMKI), Bem ter 18/c, H-4026 Debrecen (Hungary); Palinkas, J. [University of Debrecen, Egyetem ter 1, H-4010 Debrecen (Hungary)

2012-02-15

Molecular and negative ion beams, usually produced in special ion sources, play an increasingly important role in fundamental and applied atomic physics. The ATOMKI-ECRIS is a standard ECR ion source, designed to provide highly charged ion (HCI) plasmas and beams. In the present work, H{sup -}, O{sup -}, OH{sup -}, O{sub 2}{sup -}, C{sup -}, C{sub 60}{sup -} negative ions and H{sub 2}{sup +}, H{sub 3}{sup +}, OH{sup +}, H{sub 2}O{sup +}, H{sub 3}O{sup +}, O{sub 2}{sup +} positive molecular ions were generated in this HCI-ECRIS. Without any major modification in the source and without any commonly applied tricks (such as usage of cesium or magnetic filter), negative ion beams of several {mu}A and positive molecular ion beams in the mA range were successfully obtained.

Selective extraction of cesium: from compound to process

International Nuclear Information System (INIS)

Simon, N.; Eymard, S.; Tournois, B.; Dozol, J.F.

2000-01-01

Under the French law of 30 December 1991 on nuclear waste management, research is conducted to recover long-lived fission products from high-level radioactive effluents generated by spent fuel reprocessing, in order to destroy them by transmutation or encapsulate them in specific matrices. Cesium extraction with mono and bis-crown calix(4)arenes (Frame 1) is a candidate for process development. These extractants remove cesium from highly acidic or basic pH media even with high salinity. A real raffinate was treated in 1994 in a hot cell to extract cesium with a calix-crown extractant. The success of this one batch experiment confirmed the feasibility of cesium decontamination from high-level liquid waste. It was then decided to develop a process flowchart to extract cesium selectively from high-level raffinate, to be included in the general scheme of long-lived radionuclide partitioning. It was accordingly decided to develop a process based on liquid-liquid extraction and hence optimize a calixarene/diluent solvent according to: - hydraulic properties: density, viscosity, interfacial tension, - chemical criteria: sufficient cesium extraction (depending on the diluent), kinetics, third phase elimination... New mono-crown-calixarenes branched with long aliphatic groups (Frame 2) were designed to be soluble in aliphatic diluents. To prevent third phase formation associated with nitric acid extraction, the addition of modifiers (alcohol, phosphate and amide) in the organic phase was tested (Frame 3). Table 1 shows examples of calixarene/diluent systems suitable for a process flowchart, and Figure 2 provides data on cesium extraction with these new systems. Alongside these improvements, a system based on a modified 1,3-di(n-octyl-oxy)2,4-calix[4]arene crown and a modified diluent was also developed, considering a mixed TPH/NPHE system as the diluent, where TPH (hydrogenated tetra propylene) is a common aliphatic industrial solvent and NPHE is nitrophenyl

Structural changes of electron and ion beam-deposited contacts in annealed carbon-based electrical devices.

Science.gov (United States)

Batra, Nitin M; Patole, Shashikant P; Abdelkader, Ahmed; Anjum, Dalaver H; Deepak, Francis L; Costa, Pedro M F J

2015-11-06

The use of electron and ion beam deposition to make devices containing discrete nanostructures as interconnectors is a well-known nanofabrication process. Classically, one-dimensional materials such as carbon nanotubes (CNTs) have been electrically characterized by resorting to these beam deposition methods. While much attention has been given to the interconnectors, less is known about the contacting electrodes (or leads). In particular, the structure and chemistry of the electrode-interconnector interface is a topic that deserves more attention, as it is critical to understand the device behavior. Here, the structure and chemistry of Pt electrodes, deposited either with electron or ion beams and contacted to a CNT, are analyzed before and after thermally annealing the device in a vacuum. Free-standing Pt nanorods, acting as beam-deposited electrode models, are also characterized pre- and post-annealing. Overall, the as-deposited leads contain a non-negligible amount of amorphous carbon that is consolidated, upon heating, as a partially graphitized outer shell enveloping a Pt core. This observation raises pertinent questions regarding the definition of electrode-nanostructure interfaces in electrical devices, in particular long-standing assumptions of metal-CNT contacts fabricated by direct beam deposition methods.

Structural changes of electron and ion beam-deposited contacts in annealed carbon-based electrical devices

KAUST Repository

Batra, Nitin M; Patole, Shashikant P.; Abdelkader, Ahmed; Anjum, Dalaver H.; Deepak, Francis L; Da Costa, Pedro M. F. J.

2015-01-01

The use of electron and ion beam deposition to make devices containing discrete nanostructures as interconnectors is a well-known nanofabrication process. Classically, one-dimensional materials such as carbon nanotubes (CNTs) have been electrically characterized by resorting to these beam deposition methods. While much attention has been given to the interconnectors, less is known about the contacting electrodes (or leads). In particular, the structure and chemistry of the electrode–interconnector interface is a topic that deserves more attention, as it is critical to understand the device behavior. Here, the structure and chemistry of Pt electrodes, deposited either with electron or ion beams and contacted to a CNT, are analyzed before and after thermally annealing the device in a vacuum. Free-standing Pt nanorods, acting as beam-deposited electrode models, are also characterized pre- and post-annealing. Overall, the as-deposited leads contain a non-negligible amount of amorphous carbon that is consolidated, upon heating, as a partially graphitized outer shell enveloping a Pt core. This observation raises pertinent questions regarding the definition of electrode–nanostructure interfaces in electrical devices, in particular long-standing assumptions of metal-CNT contacts fabricated by direct beam deposition methods.

Structural changes of electron and ion beam-deposited contacts in annealed carbon-based electrical devices

KAUST Repository

Batra, Nitin M

2015-10-09

The use of electron and ion beam deposition to make devices containing discrete nanostructures as interconnectors is a well-known nanofabrication process. Classically, one-dimensional materials such as carbon nanotubes (CNTs) have been electrically characterized by resorting to these beam deposition methods. While much attention has been given to the interconnectors, less is known about the contacting electrodes (or leads). In particular, the structure and chemistry of the electrode–interconnector interface is a topic that deserves more attention, as it is critical to understand the device behavior. Here, the structure and chemistry of Pt electrodes, deposited either with electron or ion beams and contacted to a CNT, are analyzed before and after thermally annealing the device in a vacuum. Free-standing Pt nanorods, acting as beam-deposited electrode models, are also characterized pre- and post-annealing. Overall, the as-deposited leads contain a non-negligible amount of amorphous carbon that is consolidated, upon heating, as a partially graphitized outer shell enveloping a Pt core. This observation raises pertinent questions regarding the definition of electrode–nanostructure interfaces in electrical devices, in particular long-standing assumptions of metal-CNT contacts fabricated by direct beam deposition methods.

Selective removal of cesium from aqueous solutions with nickel (II) hexacyanoferrate (III) functionalized agricultural residue–walnut shell

Energy Technology Data Exchange (ETDEWEB)

Ding, Dahu, E-mail: dingdahu@gmail.com [Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572 (Japan); Lei, Zhongfang; Yang, Yingnan [Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572 (Japan); Feng, Chuanping [School of Water Resources and Environment, China University of Geosciences (Beijing), Key Laboratory of Groundwater Circulation and Evolution, Ministry of Education, Beijing 100083 (China); Zhang, Zhenya, E-mail: zhang.zhenya.fu@u.tsukuba.ac.jp [Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572 (Japan)

2014-04-01

Highlights: • Novel biosorbent for cesium removal was derived from agricultural residue. • It could remove cesium effectively from aqueous solution. • Large size of granules makes it easy to be separated from solutions. • The volume of used biosorbent could be significantly reduced after incineration. • Incinerated biosorbent has a low volume and a low cost final disposal. - Abstract: A novel nickel (II) hexacyanoferrate (III) functionalized agricultural residue-walnut shell (Ni{sup II}HCF{sup III}-WS) was developed to selectively remove cesium ion (Cs{sup +}) from aqueous solutions. This paper showed the first integral study on Cs{sup +} removal behavior and waste reduction analysis by using biomass adsorption material. The results indicated that the removal process was rapid and reached saturation within 2 h. As a special characteristic of Ni{sup II}HCF{sup III}-WS, acidic condition was preferred for Cs{sup +} removal, which was useful for extending the application scope of the prepared biomass material in treating acidic radioactive liquid waste. The newly developed Ni{sup II}HCF{sup III}-WS could selectively remove Cs{sup +} though the coexisting ions (Na{sup +} and K{sup +} in this study) exhibited negative effects. In addition, approximately 99.8% (in volume) of the liquid waste was reduced by using Ni{sup II}HCF{sup III}-WS and furthermore 91.9% (in volume) of the spent biomass material (Cs-Ni{sup II}HCF{sup III}-WS) was reduced after incineration (at 500 °C for 2 h). Due to its relatively high distribution coefficient and significant volume reduction, Ni{sup II}HCF{sup III}-WS is expected to be a promising material for Cs{sup +} removal in practice.

Method and article for primary containment of cesium wastes. [DOE patent application

Science.gov (United States)

Angelini, P.; Lackey, W.J.; Stinton, D.P.; Blanco, R.E.; Bond, W.D.; Arnold, W.D. Jr.

1981-09-03

A method for producing a cesium-retentive waste form, characterized by a high degree of compositional stability and mechanical integrity, is provided by subjecting a cesium-loaded zeolite to heat under conditions suitable for stabilizing the zeolite and immobilizing the cesium, and coating said zeolite for sufficient duration within a suitable environment with at least one dense layer of pyrolytic carbon to seal therein said cesium to produce a final, cesium-bearing waste form. Typically, the zolite is stabilized and the cesium immobilized in less than four hours by confinement within an air environment maintained at about 600/sup 0/C. Coatings are thereafter applied by confining the calcined zeolite within a coating environment comprising inert fluidizing and carbon donor gases maintained at 1000/sup 0/C for a suitable duration.

Cesium Toxicity Alters MicroRNA Processing and AGO1 Expressions in Arabidopsis thaliana.

Directory of Open Access Journals (Sweden)

Il Lae Jung

Full Text Available MicroRNAs (miRNAs are short RNA fragments that play important roles in controlled gene silencing, thus regulating many biological processes in plants. Recent studies have indicated that plants modulate miRNAs to sustain their survival in response to a variety of environmental stimuli, such as biotic stresses, cold, drought, nutritional starvation, and toxic heavy metals. Cesium and radio-cesium contaminations have arisen as serious problems that both impede plant growth and enter the food chain through contaminated plants. Many studies have been performed to define plant responses against cesium intoxication. However, the complete profile of miRNAs in plants during cesium intoxication has not been established. Here we show the differential expression of the miRNAs that are mostly down-regulated during cesium intoxication. Furthermore, we found that cesium toxicity disrupts both the processing of pri-miRNAs and AGONOUTE 1 (AGO1-mediated gene silencing. AGO 1 seems to be especially destabilized by cesium toxicity, possibly through a proteolytic regulatory pathway. Our study presents a comprehensive profile of cesium-responsive miRNAs, which is distinct from that of potassium, and suggests two possible mechanisms underlying the cesium toxicity on miRNA metabolism.

Redistribution of strontium and cesium during alteration of smectite to illite

International Nuclear Information System (INIS)

Ohnuki, Toshihiko; Murakami, Takashi; Sato, Tsutomu; Isobe, Hiroshi

1994-01-01

The redistribution of strontium and cesium during the alteration of smectite to illite has been studied under hydrothermal conditions at 200 C using solutions of 1x10 -4 M Sr and Cs. Two different sorption conditions were applied for the hydrothermal experiments. One was the condition in which strontium and cesium were sorbed by smectite before the hydrothermal experiments (dynamic condition). The other was the condition in which strontium and cesium were sorbed by the alteration products, illite/smectite (I/S) interstratified minerals after the hydrothermal experiments (static condition). The sorption characteristics of strontium and cesium by smectite, I/S interstratified minerals were examined by a sequential extraction method. Most of the strontium was desorbed from smectite and the I/S interstratified minerals with a 1 M KCl solution under both the dynamic and static conditions. Less than 1% of cesium was desorbed from the I/S interstratified minerals with any solution of a 1 M KCl, a 1 M HCl and a 6 M HCl under the dynamic condition, while most of cesium was desorbed with either solution of a 1 M KCl and 1 M HCl from smectite and from the I/S interstratified minerals under the static condition. These suggest that cesium sorbed by smectite changes its sorption characteristic during the alteration process, but strontium does not. Possible sites for more strongly bounded cesium to the I/S interstratified minerals may be at the 'ditrigonal cavity' of adjacent tetrahedral layers. (orig.)

Chemistry of radioactive cesium in the hydrosphere and in the geosphere

International Nuclear Information System (INIS)

Lieser, K.H.; Steinkopff, T.

1989-01-01

Cesium is sorbed with relatively high selectivity by clay minerals. Accordingly, in groundwaters Cs is found in high amounts in suspended matter or in colloids, if these consist of or contain clay minerals. The sorption of Cs in sediments is also mainly determined by the presence of clay minerals and the sorption ratio at low salinity is found to be roughly proportional to the clay content in the sediments. Furthermore, with the same sediment the sorption ratio is inversily proportional to the concentration of NaCl which proves that ion exchange on the clay minerals is the prevailing sorption mechanism for Cs. It shown that the sediments contain small amounts of sorption sites of high selectivity for Cs + which govern the sorptions behaviour at very small concentrations of Cs + ions. These sorption sites are also responsible for Cs + sorption on suspended particulates of clay in the groundwaters. (orig.)

Selective cation-exchange separation of cesium(I) on chromium ferricyanide gel

International Nuclear Information System (INIS)

Jain, A.K.; Agrawal, S.; Singh, R.P.

1980-01-01

The removal of 137 Cs from liquid streams of nuclear power plants and from processed radioactive waste of nuclear fission has received increasing attention from ion-exchange chemists. A desirable exchanger (adsorbent) for 137 Cs removal is one which can adsorb it significantly and selectively in the presence of appreciable amounts (approx. 2molL -1 ) of Na + , NH 4 + , and H + . This paper deals with the exchange properties of the inorganic exchanger, chromium ferricyanide gel (CFiC). The stability of the gel in both acid and salt solutions and its high specificity for cesium are responsible for its good scavanger properties in removing long lived 137 Cs from radioactive waste. The chromium ferricyanide exchanger is highly selective for monovalent cations, the order being Ag + >Tl + >Cs + >Rb + >K + >Na + . It does not adsorb any bivalent, trivalent, and tetravalent ions even when present in trace amounts. (2 figures, 3 tables)

Radiation safety for incineration of radioactive waste contaminated by cesium

International Nuclear Information System (INIS)

Veryuzhs'kij, Yu.V.; Gryin'ko, O.M.; Tokarevs'kij, V.V.

2016-01-01

Problems in the treatment of radioactive waste contaminated by cesium nuclides are considered in the paper. Chornobyl experience in the management of contaminated soil and contaminated forests is analyzed in relation to the accident at Fukushima-1. The minimization of release of cesium aerosols into atmosphere is very important. Radiation influence of inhaling atmosphere aerosols polluted by cesium has damage effect for humans. The research focuses on the treatment of forests contaminated by big volumes of cesium. One of the most important technologies is a pyro-gasification incineration with chemical reactions of cesium paying attention to gas purification problems. Requirements for process, physical and chemical properties of treatment of radioactive waste based on the dry pyro-gasification incineration facilities are considered in the paper together with the discussion of details related to incineration facilities. General similarities and discrepancies in the environmental pollution caused by the accidents at Chornobyl NPP and Fukushima-1 NPP in Japan are analyzed

Recent operating experience with the H- ion injector at LAMPF/LANSCE

International Nuclear Information System (INIS)

Ingalls, W.B.; Stelzer, J.E.; Williams, H.E. III.

1996-01-01

A cusp-field cesium conversion ion source has provided H - beams at LAMPF/LANSCE since 1984. three interchangeable sources are now used during beam production cycles to minimize down time during scheduled source change-outs. Ion source change-outs are scheduled to prevent unscheduled loss of beam time due to finite filament lifetime. Ion source operating parameters and filament lifetime data are presented

SiO2, TiO2 and Al2O3 colloid characterization and their cesium and iodine sorption part

International Nuclear Information System (INIS)

Hakem, N.

1995-03-01

Recent studies have shown the important role played by colloids in the transport behaviour of radionuclides. In the present study, we have investigated the sorption, at tracer level, to two radionuclides 131 I and 137 Cs on some mineral oxide colloids (100 to 500 nm in size) chosen as ''models'' owing to their very distinct isoelectric points; SiO 2 , TiO 2 and A1 2 O 3 (i.e.p. = 2, 6,25, 9,5 respectively). These colloids have first been characterized, under various pH and ionic strength conditions, by potentiometric and electro kinetic measurements. We have then measured the sorption ratios R, resulting from the partition, at equilibrium, of each radionuclide between the colloidal and aqueous phases in the contact. In a second step, we have attempted to describe the sorption mechanisms of iodine and cesium on the three oxide colloids under investigation, using following models: ion-exchange reaction, physical adsorption, Langmuir and Freundlich isotherms and surface complexation theories. (author). 53 refs., 13 tabs., 43 figs., 4 appendixes

Strontium-90 and cesium-137 in powdered milk

International Nuclear Information System (INIS)

1977-01-01

Japan Chemical Analysis Center has analysed the strontium-90 and cesium-137 content in powdered milk. The samples were purchased on the open market in Tokyo from the powdered milk producers. The analysis of Strontium-90 and Cesium-137 content was carried out using the method recommended by Science and Technology Agency. (author)

Sericitization of illite decreases sorption capabilities for cesium

Science.gov (United States)

Choung, S.; Hwang, J.; Han, W.; Shin, W.

2017-12-01

Release of radioactive cesium (137Cs) to environment occurs through nuclear accidents such as Chernobyl and Fukushima. The concern is that 137Cs has long half-life (t1/2 = 30.2 years) with chemical toxicity and γ-radiation. Sorption techniques are mainly applied to remove 137Cs from aquatic environment. In particular, it has been known well that clay minerals (e.g, illite) are effective and economical sorbents for 137Cs. Illite that was formed by hydrothermal alteration exist with sericite through "sericitization" processes. Although sericite has analogous composition and lattice structure with illite, the sorptive characteristics of illite and sericite for radiocesium could be different. This study evaluated the effects of hydrothermal alteration and weathering process on illite cesium sorption properties. Natural illite samples were collected at Yeongdong area in Korea as the world-largest hydrothermal deposits for illite. The samples were analyzed by XRF, XRD and SEM-EDX to determine mineralogy, chemical compositions and morphological characteristics, and used for batch sorption experiments. The Yeongdong illites predominantly consist of illite, sericite, quartz, and albite. The measured cesium sorption distribution coefficients (Kd,Cs) of reference illite and sericite were approximately 6000 and 400 L kg-1 at low aqueous concentration (Cw 10-7 M), respectively. In contrast, Kd,Cs values for the Yeongdong illite samples ranged from 500 to 4000 L kg-1 at identical concentration. The observed narrow and sharp XRD peak of sericite indicated that the sericite has better crystallinity compared to illite. These experimental results suggested that sericitization processes of illite can decline the sorption capabilities of illite for cesium under various hydrothermal conditions. In particular, weathering experiments raised the cesium sorption to illite, which seems to be related to the increase of preferential sorption sites for cesium through crystallinity destruction

Separation of cesium by ion exchange columns

International Nuclear Information System (INIS)

Bonini, Alberto; Falcon, Marcelo F.; Devida, Claudio A.; Tadey, D.; Vaccaro, Jorge O.; Maset, Elvira

2003-01-01

Crystalline silico titanate (CST) has been tested as a selective inorganic ion exchanger to separate Cs 137 from the residual fission product s solution of the Mo 99 plant. The tests are described in detail and show decontamination factors higher than 6000 and a good elution yield

Cesium removal demonstration utilizing crystalline silicotitanate sorbent for processing Melton Valley Storage Tank supernate: Final report

Energy Technology Data Exchange (ETDEWEB)

Walker, J.F. Jr.; Taylor, P.A.; Cummins, R.L. [and others

1998-03-01

This report provides details of the Cesium Removal Demonstration (CsRD), which was conducted at Oak Ridge National Laboratory (ORNL) on radioactive waste from the Melton Valley Storage Tanks. The CsRD was the first large-scale use of state-of-the-art sorbents being developed by private industry for the selective removal of cesium and other radionuclides from liquid wastes stored across the DOE complex. The crystalline silicotitanate sorbent used in the demonstration was chosen because of its effectiveness in laboratory tests using bench-scale columns. The demonstration showed that the cesium could be removed from the supernate and concentrated on a small-volume, solid waste form that would meet the waste acceptance criteria for the Nevada Test Site. During this project, the CsRD system processed > 115,000 L (30,000 gal) of radioactive supernate with minimal operational problems. Sluicing, drying, and remote transportation of the sorbent, which could not be done on a bench scale, were successfully demonstrated. The system was then decontaminated to the extent that it could be contact maintained with the use of localized shielding only. By utilizing a modular, transportable design and placement within existing facilities, the system can be transferred to different sites for reuse. The initial unit has now been removed from the process building and is presently being reinstalled for use in baseline operations at ORNL.

Cesium removal demonstration utilizing crystalline silicotitanate sorbent for processing Melton Valley Storage Tank supernate: Final report

International Nuclear Information System (INIS)

Walker, J.F. Jr.; Taylor, P.A.; Cummins, R.L.

1998-03-01

This report provides details of the Cesium Removal Demonstration (CsRD), which was conducted at Oak Ridge National Laboratory (ORNL) on radioactive waste from the Melton Valley Storage Tanks. The CsRD was the first large-scale use of state-of-the-art sorbents being developed by private industry for the selective removal of cesium and other radionuclides from liquid wastes stored across the DOE complex. The crystalline silicotitanate sorbent used in the demonstration was chosen because of its effectiveness in laboratory tests using bench-scale columns. The demonstration showed that the cesium could be removed from the supernate and concentrated on a small-volume, solid waste form that would meet the waste acceptance criteria for the Nevada Test Site. During this project, the CsRD system processed > 115,000 L (30,000 gal) of radioactive supernate with minimal operational problems. Sluicing, drying, and remote transportation of the sorbent, which could not be done on a bench scale, were successfully demonstrated. The system was then decontaminated to the extent that it could be contact maintained with the use of localized shielding only. By utilizing a modular, transportable design and placement within existing facilities, the system can be transferred to different sites for reuse. The initial unit has now been removed from the process building and is presently being reinstalled for use in baseline operations at ORNL

Cesium transport in Four Mile Creek of the Savannah River Plant

International Nuclear Information System (INIS)

Kiser, D.L.

1979-04-01

The behavior of a large radioactive cesium release to a Savannah River Plant (SRP) stream was examined using a stable cesium release to Four Mile Creek. Measurements following the release show that most of the cesium released was transported downstream; however, sorption and desorption decreased the maximum concentration and increased the travel time and duration, relative to a dye tracer, at sampling stations downstream. The study was made possible by the development of an analytical technique using ammonium molybdophosphate and neutron activation that permitted the measurement of stable cesium concentrations as low as 0.2 μg/L

Hydrological Methods can Separate Cesium from Nuclear Waste Saltcake

International Nuclear Information System (INIS)

Brooke, J.N.; Peters, J.F.; Staheli, K.

1999-01-01

Interstitial Fluid Displacement (IFD) is a new and novel method for separating cesium from saltcake waste. Hydrologic modeling of liquid flow through porous saltcake suggests that the cesium, potassium and sodium hydroxide can be separated at high recovery and low volume using IFD.'

Inorganic ion exchangers. Application to liquid effluent processing

International Nuclear Information System (INIS)

Dozol, M.

1983-10-01

Main inorganic ion exchangers used for radioactive liquid effluents presented in this report are: synthetic and natural zeolites, in titanium oxides, titanates, niobates, tantalates, zirconates, some insoluble salts of zirconium, molybdenum and tin, heteropolyacids and polyantimonic acid. Properties of these ion exchangers are described: structure, adsoption, radiation effects and thermal stability, application to waste processing, radioactive waste storage uranium and cesium 137 recovery are evoked [fr

A model for radial cesium transport in a fuel pellet

International Nuclear Information System (INIS)

Imoto, Shosuke

1989-01-01

In order to explain the radial redistribution of cesium in an irradiated pellet, a two-step release model is proposed. The first step involves the migration of cesium by atomic diffusion to some channels, such as grain boundaries and cracks, and the second step assumes a thermomigration down along the temperature gradient. Distribution profiles of cesium are obtained by numerical calculation with the present model assuming a constant and spatially uniform birth rate of cesium in the pellet. The result agrees well with the profile observed by micro-gamma scanning for the LWR fuel in the outer region of the pellet but diverges from it at the inner region. Discussion is made on the steady-state model hitherto generally utilized. (orig.)

Accumulation and mobility of cesium in roots of tulip popular seedlings

International Nuclear Information System (INIS)

Cox, T.L.

1975-01-01

Tulip poplar, Liriodendron tulipifera L., seedlings were stem-well tagged with cesium, periodically harvested, and separated into root and shoot compartments to determine seasonal cesium distributions in different root-diameter classes and to delineate element pathways to forest soils. The cesium concentration (μCi/g) in roots less than 0.1 cm in diameter averaged 1.5 and 3.0 times greater than in roots in the 0.5- to 0.1-cm- and 1.0- to 0.5-cm-diameter classes, respectively. Roots contained 24 percent of the seedling pool of cesium in 1 week and about 40 percent in 7 weeks after inoculation. Sixty-five percent of the seedling content was in the root system 8 months after tagging. On an annual basis, roots of the less than 0.5-cm-diameter classes contained an average of 36 percent of the seedling pool (root and shoot) and 72 percent of the root pool of cesium. This is important because small roots constituted a considerable portion of the annual turnover in these root systems. Soil content of cesium (3.37 μCi) at the termination of the study and analysis of treatment effects (aboveground inputs to soil allowed or not allowed) indicated that root processes contributed twice as much cesium to the soil during the study period as the combined aboveground processes contributed

Ion exchange media testing for processing recyclable and nonrecyclable liquids at Diablo Canyon Power Plant

International Nuclear Information System (INIS)

James, K.L.; Miller, C.C.

1989-01-01

This paper reports on several ion exchange materials tested for processing nonrecyclable and recyclable liquid wastes at Diablo Canyon Power Plant. These ion exchange materials include inorganic Durasil media, natural and synthetic zeolites, and various organic resins. Additional tests were performed using a polyelectrolyte pretreatment technique to enhance processing of liquid wastes by ion exchange. A 9:1 ratio of cation to anion resin, consisting of IRN-77 and Sybron A-642 was effective in decontaminating cesium and cobalt radionuclides for low conductivity nonrecyclable liquids. A mixture of zeolite and Durasil media was most effective in removing cesium and cobalt from nonrecyclable high conductivity liquids. The experimental Dow resins achieved the best results in decontaminating recyclable liquids and minimized the effluent levels of chlorides, sulfates, and silica

Cesium-137 as a radiation source

International Nuclear Information System (INIS)

McMullen, W.H.; Sloan, D.P.

1985-01-01

The U.S. Department of Energy (DOE) Byproducts Utilization Program (BUP) seeks to develop and encourage widespread commercial use of defense byproducts that are produced by DOE. Cesium-l37 is one such byproduct that is radioactive and decays with emission of gamma rays. The beneficial use of this radiation to disinfect sewage sludge or disinfest food commodities is actively being pursued by the program. The radiation produced by cesium-l37(Cs-l37) is identical in form to that produced by cobalt-60(Co-60), an isotope that is widely used in commercial applications such as medical product sterilization. The choice of isotope to use depends on several factors ranging from inherent properties of the isotopes to availability and cost. The BUP, although centrally concerned with the beneficial use of Cs-l37, by investigating and assessing the feasibility of various uses hopes to define appropriate circumstances where cesium or cobalt might best be used to accomplish specific objectives. This paper discusses some of the factors that should be considered when evaluating potential uses for isotopic sources

Selective separation of cesium from simulated high level liquid waste solution using 1,3-dioctyloxy calix[4]arene-benzo-crown-6

International Nuclear Information System (INIS)

Vikas Kumar; Sharma, J.N.; Hubli, R.C.

2014-01-01

The 25,27-di(octyloxy)calix[4]arenebenzocrown-6 (CBC) in 1,3-alternate conformation was synthesized indigenously starting from its intermediates in good yield and purity. The extraction studies of CBC were carried out by using two different phase modifiers namely isodecyl alcohol and ortho-nitrophenyl hexyl ether. Detailed investigations on the effect of various parameters like, concentration of phase modifiers, aqueous phase acidity, ligand concentration, nitrate ion concentration and effect of temperature on extraction of cesium have been carried out. The concentration of phase modifiers was optimized to be 30 % in n-dodecane to ensure optimum extraction of cesium. Stoichiometry of the extracted complex determined by slope analysis method reveals 1:1:1 molar ratio for CsNO 3 :CBC:HNO 3 . The extraction process was found to be exothermic as determined from the plot of log K ex versus 1/T. The solvent system with a composition 0.01 M CBC/30 % phase modifier/n-dodecane was found to be effective for selective separation of cesium from simulated high level liquid waste solution. (author)

Development of Effective Solvent Modifiers for the Solvent Extraction of Cesium from Alkaline High-Level Tank Waste

International Nuclear Information System (INIS)

Bonnesen, Peter V.; Delmau, Laetitia H.; Moyer, Bruce A.; Lumetta, Gregg J.

2003-01-01

A series of novel alkylphenoxy fluorinated alcohols were prepared and investigated for their effectiveness as modifiers in solvents containing calix(4)arene-bis-(tert-octylbenzo)-crown-6 for extracting cesium from alkaline nitrate media. A modifier that contained a terminal 1,1,2,2-tetrafluoroethoxy group was found to decompose following long-term exposure to warm alkaline solutions. However, replacement of the tetrafluoroethoxy group with a 2,2,3,3-tetrafluoropropoxy group led to a series of modifiers that possessed the alkaline stability required for a solvent extraction process. Within this series of modifiers, the structure of the alkyl substituent (tert-octyl, tert-butyl, tert-amyl, and sec-butyl) of the alkylphenoxy moiety was found to have a profound impact on the phase behavior of the solvent in liquid-liquid contacting experiments, and hence on the overall suitability of the modifier for a solvent extraction process. The sec-butyl derivative(1-(2,2,3,3-tetrafluoropropoxy)-3- (4-sec-butylphenoxy)-2-propanol) (Cs-7SB) was found to possess the best overall balance of properties with respect to third phase and coalescence behavior, cleanup following degradation, resistance to solids formation, and cesium distribution behavior. Accordingly, this modifier was selected for use as a component of the solvent employed in the Caustic-Side Solvent Extraction (CSSX) process for removing cesium from high level nuclear waste (HLW) at the U.S. Department of Energy's (DOE) Savannah River Site. In batch equilibrium experiments, this solvent has also been successfully shown to extract cesium from both simulated and actual solutions generated from caustic leaching of HLW tank sludge stored in tank B-110 at the DOE's Hanford Site.

Development of a multi-ampere H- ion source at JAERI

International Nuclear Information System (INIS)

Inoue, T.; Hanada, M.; Mizuno, M.; Ohara, Y.; Okumura, Y.; Suzuki, Y.; Tanaka, M.; Watanabe, K.

1992-01-01

Recent results of R ampersand D on high current negative ion source at JAERI are presented. After succeeding in ten ampere H - ion beam production, the R ampersand D work has been progressed toward longer pulse beam production and the beam optics. A long pulse operation for 24 hours was demonstrated stably with a small cesiated volume source. It was confirmed that the heat load in the source is a modest level allowable for the long pulse operation. The cesium effect lasted for 24 hours, once the cesium was seeded before operation. In beam optics study, we have produced a beam with very small divergent angle of 1.5 mrad. To take this advantage for a design of compact neutral beam system, beamlet focusing technique by aperture displacement was applied in the H - beam extractor

Cesium-137 in ash from combustion of biofuels. Application of regulations from the Swedish Radiation Safety Authority

International Nuclear Information System (INIS)

Sjoeblom, Rolf

2009-01-01

. The differences are large. The transitions between Cesium/Potassium in the pore water and in the exchangeable positions are rapid. Other transitions are slow. Over the course of a few years, Cesium becomes bonded as non-exchangeable and after a few decades, the content of non-exchangeable and mineral Cesium may be comparable in magnitude. The migration rate depends on the availability. Before Cesium-137 in fallout becomes absorbed, it is transported with the water, and this is the reason for the initial rapid penetration into soil on the order of a decimeter. When most of the Cesium-137 has become non-exchangeable and mineral, the migration rate may be as low as on the order of a millimetre per year. There is an interesting finding to report about clay. For short term migration, i e shortly after a fallout, clay provides a retention that is far superior to that of sand. This is probably related to the fact that clay contains many more positions for ion exchange as compared to sand. After some time when most of the Cesium appears in non-exchangeable and mineral positions, clay and sand are comparable. It might be tempting to assume that organic soils would provide a good retention since they can absorb nutrients from artificial fertilizers and keep them available to plants. Measurements have shown, however, that Cesium-137 may migrate rapidly in soils that lack a mineral component, e g soils consisting of peat. This can be assumed to relate to the fact that the bonding to the many exchangeable positions is much weaker as compared to those in non-exchangeable and in mineral positions. The data on ash are scarce. The data found indicate that the availability of Cesium-137 is high in fresh ash, but that the bonding is remarkably strong already after a few years. It cannot be taken for granted without further information that fresh water conditions apply also when the salt content in the pore water is high. Investigations have shown, however, that the solid mineral phase

Fast concentration of dissolved forms of cesium radioisotopes from large seawater samples

International Nuclear Information System (INIS)

Jan Kamenik; Henrieta Dulaiova; Ferdinand Sebesta; Kamila St'astna; Czech Technical University, Prague

2013-01-01

The method developed for cesium concentration from large freshwater samples was tested and adapted for analysis of cesium radionuclides in seawater. Concentration of dissolved forms of cesium in large seawater samples (about 100 L) was performed using composite absorbers AMP-PAN and KNiFC-PAN with ammonium molybdophosphate and potassium–nickel hexacyanoferrate(II) as active components, respectively, and polyacrylonitrile as a binding polymer. A specially designed chromatography column with bed volume (BV) 25 mL allowed fast flow rates of seawater (up to 1,200 BV h -1 ). The recovery yields were determined by ICP-MS analysis of stable cesium added to seawater sample. Both absorbers proved usability for cesium concentration from large seawater samples. KNiFC-PAN material was slightly more effective in cesium concentration from acidified seawater (recovery yield around 93 % for 700 BV h -1 ). This material showed similar efficiency in cesium concentration also from natural seawater. The activity concentrations of 137 Cs determined in seawater from the central Pacific Ocean were 1.5 ± 0.1 and 1.4 ± 0.1 Bq m -3 for an offshore (January 2012) and a coastal (February 2012) locality, respectively, 134 Cs activities were below detection limit ( -3 ). (author)

Cesium-137, a drama recounted

International Nuclear Information System (INIS)

Vieira, Suzane de Alencar

2013-01-01

The radiological accident with Cesium-137, which started on Goiania in 1987, did not stop with the end of radiological contamination and continues in a judicial, scientific and narrative process of identification and recognition of new victims. The drama occupies a central place on the dynamics of radiological event, as it extends its limits, inflects its intensity and updates the event. As a narrative of the event, the ethnography incorporates and brings up to date the drama as an analysis landmark and the description of the theme as it is absorbed by a dramatic process. Cesium-137, a drama recounted is a textual experimentation based on real events and characters picked out from statements reported in various narratives about the radiological accident. (author)

Separation of cesium from aqueous solutions using alkylated tetraaryl borates

International Nuclear Information System (INIS)

Feldmaier, F.

1991-01-01

The water solubility of cesium tetraaryl borates was lowered by introducing hydrophobic aliphatic side chains into corresponding acid-resistant fluorosubstituted tetraaryl borates. This improved cesium spearability both in precipitation and in extraction from aqueous solutions. (orig.) [de

Improvement of cesium retention in uranium dioxide by additional phases

International Nuclear Information System (INIS)

Gamaury Dubois, S.

1995-01-01

The objective of this study is to improve the cesium retention in nuclear fuel. A bibliographic survey indicates that cesium is rapidly released from uranium dioxide in an accident condition. At temperatures higher than 1500 deg C or in oxidising conditions, our experiments show the difficulty of maintaining cesium inside simulated fuel. Two ternary systems are potentially interesting for the retention of cesium and to reduce the kinetics of release from the fuel: Cs 2 O-Al 2 O 3 -SiO 2 et Cs 2 O-ZrO 2 -SO 2 . The compounds CsAISi 2 O 6 and Cs 2 ZrSi 6 O 15 were studied from 1200 deg C to 2000 deg C by thermogravimetric analysis. The volumetric diffusion coefficients of cesium in these structures, in solid state as well as in liquid one, were measured. A fuel was sintered with (Al 2 O 3 + SiO 2 ) or (ZrO 2 + SiO 2 ) and the intergranular phase was characterized. In the presence of (Al 2 O 3 + SiO 2 ), the sintering is realized at 1610 deg C in H 2 . It is a liquid phase sintering. On the other end, with (ZrO 2 + SiO 2 ), the sintering is a low temperature one in oxidising atmosphere. Finally, cesium containing simulated fuels were produced with these additives. According to the effective diffusion coefficients that were measured, the additives improved the retention of cesium. We have predicted the improvement that could be hoped for in a nuclear reactor, depending on the dispersion of the intergranular additives, the temperature and the degree of oxidation of the UO 2+x . We wait for a factor of 2 for x=0 and more than 8 for x=0.05, up to 2000 deg C. (author). 148 refs., 122 figs., 34 tabs

Measurements of cesium and strontium diffusion in biotite gneiss

International Nuclear Information System (INIS)

Skagius, K.; Neretnieks, I.

1988-01-01

A significant retardation of radionuclides transported by flowing water from an underground repository can be expected if the nuclides are able to diffuse into the water filled micropores in the rock. This diffusion into the pores will also increase the surface available to interactions between the nuclides in the ground water and the rock material, such as sorption. To calculate the retardation, it is necessary to know the sorption properties and the diffusivities in the rock matrix for the radionuclides. Diffusion experiments with cesium and strontium in biotite gneiss samples have been performed. Both the transport of strontium and cesium through rock samples and the concentration profiles of cesium and strontium inside rock samples have been determined. The result shows that diffusion of cesium and strontium occurs in the rock material. A diffusion model has been used to evaluate the diffusivity. Both pore diffusion and surface diffusion had to be included in the model to give good agreement with the experimental data. If surface diffusion is not included in the model, the effective pore diffusivity that gives the best fit to the experimental data is found to be higher than expected from earlier measurement of iodide diffusion in the same type of rock material. This indicates that the diffusion of cesium and strontium (sorbing components) in rock material is caused by both pore diffusion and surface diffusion acting in parallel

Diffusion measurements of cesium and strontium in biotite gneiss

International Nuclear Information System (INIS)

Skagius, K.; Neretnieks, I.

1985-01-01

A significant retardation of radionuclides transported by flowing water from an underground repository can be expected if the nuclides are able to diffuse into the water filled micropores in the rock. This diffusion into the pores will also increase the surface available to interaction between the nuclides in the groundwater and the rock material, such as sorption. To calculate the retardation it is necessary to know the sorption properties and the diffusivities in the rock matrix for the radionuclides. Diffusion experiments with cesium and strontium in biotite gneiss samples have been performed. Both the transport of strontium and cesium through rock samples and the concentration profiles of cesium and strontium inside rock samples have been determined. The result show that diffusion of cesium and strontium occurs in the rock material. A diffusion model has been used to evaluate the diffusivity. Both pore diffusion and surface diffusion had to be included in the model to give good agreement with the experimental data. If surface diffusion is not included in the model, the effective pore diffusivity that gives the best fit to the experimental data is found to be higher than expected from earlier measurements of iodide diffusion in the same type of rock material. This indicates that the diffusion of cesium and strontium (sorbing components) in rock material is caused by both pore diffusion and surface diffusion acting in parallel. (author)

The novel composite mechanism of ammonium molybdophosphate loaded on silica matrix and its ion exchange breakthrough curves for cesium

Energy Technology Data Exchange (ETDEWEB)

Deng, Hao [State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Mianyang 621010 (China); Li, Yuxiang, E-mail: superfigure@163.com [State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Mianyang 621010 (China); School of Materials Science and Engineering, Southwest University of Science and Technology, Mianyang 621010 (China); National Defense Key Discipline Laboratory for Nuclear Wastes and Environmental Safety, Southwest University of Science and Technology, Mianyang 621010 (China); Wu, Lang [State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Mianyang 621010 (China); Ma, Xue [School of Materials Science and Engineering, Southwest University of Science and Technology, Mianyang 621010 (China)

2017-02-15

Highlights: • The granular composites were fabricated by the sequential annealing mechanism. • The method controls the porous characteristics and stable structure of materials. • The breakthrough curve of Cs{sup +} follows the Thomas model with a high removal rate. • It is a probable for SM-AMP20 to recycle Cs{sup +} using an eluent of 2–3 mol/L NH{sub 4}NO{sub 3}. - Abstract: Long-lived {sup 137}Cs (over 30 years), a byproduct of the spent fuel fission processes, comprises the majority of high-level and prolific heat-generating waste in downstream processing. This study reports a novel sequential annealing mechanism with cross-linked network of polyvinyl alcohol, fabricating the composite of ammonium molybdophosphate loaded on silica matrix (SM-AMP20, 20 wt% AMP) as an excellent granular ion exchanger for removal Cs{sup +}. When the matrix is remarkably sequential annealed, well-dispersed SM-AMP20 particles are formed by firmly anchoring themselves on controlling the porous characteristics and stable structure. The material crystallizes in the complex cubic space group Pn-3m with cell parameters of crystalline AMP formation. The breakthrough curve of Cs{sup +} by SM-AMP20 follows the Thomas model with a high removal rate of 88.23% (∼10 mg/L of Cs{sup +}) and breakthrough time as high as 26 h (flow rate Q ≈ 2.5 mL/min and bed height Z ≈ 11 cm) at neutral pH. We also report on sorbents that could efficiently remove Cs{sup +} ions from complex solutions containing different competitive cations (Na{sup +}, Al{sup 3+}, Fe{sup 3+}, and Ni{sup 2+}, respectively) in large excess. Furthermore, this study shows that there is a probability for SM-AMP20 to recycle cesium using an eluent of 2–3 mol/L NH{sub 4}NO{sub 3} solution.

Design of laser-aided diagnostics for the negative hydrogen ion source SPIDER

International Nuclear Information System (INIS)

Pasqualotto, R

2012-01-01

ITER nuclear fusion experiment requires additional heating via neutral beams by means of two injectors, delivering 16.5 MW each, up to one hour. This power level results from the neutralization of negative deuterium ions generated by an RF source and accelerated to 1 MeV. Such specifications have never been simultaneously achieved so far and therefore a test facility is being constructed at Consorzio RFX, to demonstrate the feasibility of a prototype neutral beam injector. The facility will host two experimental devices: SPIDER, a 100 kV negative hydrogen/deuterium RF source, full size prototype of the ITER source, and MITICA, a prototype of the full ITER injector. SPIDER will be devoted to optimize the extracted negative ion current density and its spatial uniformity and to minimize the co-extracted electron current. Negative hydrogen is mainly produced by conversion of hydrogen particles at the cesium coated surface of the plasma grid. The interplay of these two species is fundamental to understand and optimize the source performance. Two laser-aided diagnostics play an important role in measuring the negative hydrogen and cesium density: cavity ring down spectroscopy and laser absorption spectroscopy. Cavity ring down spectroscopy will use the photo-detachment process to measure the absolute line-of-sight integrated negative ion density in the extraction region of the source. Laser absorption spectroscopy will be employed to measure the line integrated neutral cesium density, allowing to study the cesium distribution in the source volume, during both the plasma and the vacuum phases. In this paper, the design of the laser-aided diagnostic systems on SPIDER is presented, supported by a review of results obtained in other operating experiments.

High-energy particle emission from galena and pyrite bombarded with Cs and O ions

International Nuclear Information System (INIS)

Karpuzov, D.S.; McIntyre, N.S.

2002-01-01

The ejection of energetic particles during steady-state ion surface bombardment has been investigated by means of a dynamic computer simulation as well as in a secondary ion mass spectrometry (SIMS)/low-energy ion scattering from surfaces (LEIS) experiment. The emphasis of this comparative study is on the mass dependence of high-energy tails in sputtering and backscattering for the bombardment of galena (PbS) and pyrite (FeS 2 ) with keV energy ion beam of cesium and oxygen. In the experiment, kinetic energy distributions of sputtered secondary ions (S + , Fe + , Pb + , S - ), as well as backscattered or re-sputtered primary ions (Cs + , O + , O - ), have been measured on a modified Cameca IMS-3f magnetic sector mass spectrometer for keV cesium (Cs + ) and oxygen (O 2 + , O - ) bombardment of galena and pyrite. Ejection of high-energy particles, with emission energies of up to ∼40% or up to ∼60% of the bombarding energy for sputtering of the lighter component (S ± ) with cesium or oxygen, respectively, and of up to ∼40% (Cs + ) and ∼80% (O ± ) for backscattering, has been observed for PbS. The computer simulations were based on the well-known MARLOWE code. In order to model the change of the stoichiometry of the binary compounds, dynamic modification of the target composition in the near-surface region was introduced. Cs incorporation was included, and a relative enrichment of the metallic component (Pb, Fe) in the top few layers due to preferential sputtering of sulfur was allowed. The computer simulations provide information on the formation of altered layer under sputter equilibrium as well as on the energy and angular emission distributions of sputtered and backscattered particles in steady-state conditions. Multiple scattering of Cs projectiles and dynamic re-sputtering of cesium that was previously incorporated in the altered near-surface region can be distinguished in the simulation, and matched with the experimental observations. In addition

Test procedures and instructions for Hanford tank waste supernatant cesium removal

Energy Technology Data Exchange (ETDEWEB)

Hendrickson, D.W., Westinghouse Hanford

1996-05-31

This document provides specific test procedures and instructions to implement the test plan for the preparation and conduct of a cesium removal test using Hanford Double-Shell Slurry Feed supernatant liquor from tank 251-AW-101 in a bench-scale column.Cesium sorbents to be tested include resorcinol-formaldehyde resin and crystalline silicotitanate. The test plan for which this provides instructions is WHC-SD-RE-TP-022, Hanford Tank Waste Supernatant Cesium Removal Test Plan.

Potassium effect on cesium 137 behaviour in natural waters of contaminated regions (Belarus)

International Nuclear Information System (INIS)

Kudel'skij, A.V.; Pashkevich, V.I.; Ovsyannikova, S.V.; Petrovich, A.A.; Smit, D.T.

1998-01-01

Very close relationships between cesium 137 activity of water objects (soil solutions, bog and lake water) and their stable potassium contents have been revealed in the contaminated area in south-eastern Belarus. It was revealed the increase of cesium 137 activity in soil solutions and bog ecosystems proportionally with the increase of potassium content. The exponential dependence of cesium 137 activity of fish production was similar to reverse. The coefficient of cesium 137 accumulation in plants was estimated to be reverse connected with the potassium content in soils. So an universal character of these relations and their specificity are of interest when elaborating countermeasures for reducing population dose loads due to cesium 137 water migration

Decontamination of cesium, strontium, and cobalt from aqueous solutions by bentonite

Energy Technology Data Exchange (ETDEWEB)

Khan, M.A. [Univ. of the Punjab, Lahore (Pakistan); Khan, S.A. [Government F.C. College, Lahore (Pakistan)

1996-12-31

Sorption studies of cesium, strontium, and cobalt (Cs, Sr, and Co) on bentonite under various experimental conditions, such as contact time, pH, sorbent and sorbate concentration, and temperature, have been performed. The sorption data for all these metals have been interpreted in terms of Freundlich, Langmuir, and Dubinin-Radushkevich equations. Thermodynamics parameters, such as heat of sorption {Delta}H{degrees}, free energy change {Delta}G{degrees}, and entropy change {Delta}S{degrees}, for the sorption of these metals on bentonite have been calculated. The value of {Delta}H{degrees} shows that the sorption of Cs was exothermic, while the sorption of Sr and Co on bentonite were endothermic in nature. The value of {Delta}G{degrees} for their sorption was negative, showing the spontaneity of the process. The maximum loading capacity of Cs, Sr, and Co were 75.5, 22, and 27.5 meq, respectively, for 100 g of bentonite. The mean free energy E of Cs, Sr, and Co sorption on bentonite was 14.5, 9, and 7.7 kJ/mol, respectively. The value of E indicates that ion exchange may be the predominant mode of sorption for these radionuclides. The desorption studies with 0.01 M CaCl{sub 2} and groundwater at low-metal loading on bentonite showed that about 95% of Cs, 85-90% of Sr, and 97% of Co were irreversibly sorbed. Bentonite could be effectively used for the decontamination of wastewater effluent containing low concentrations of radioactive nuclides of Cs, Sr, and Co. 16 refs., 7 figs., 3 tabs.

Cesium immobilization in (Ba,Cr)-hollandites: Effects on structure

Science.gov (United States)

Tumurugoti, Priyatham; Sundaram, S. K.; Misture, Scott T.

2018-02-01

Hollandites with compositions Ba1.15-xCs2xCr2.3Ti5.7O16 (0 ≤ x ≤ 1.15) intended for the immobilization of cesium (Cs) from nuclear waste have been prepared, characterized, and analyzed for Cs retention properties. Sol-gel synthesized powders were used for structural characterization using a combination of X-ray, neutron, and electron diffraction techniques. Phase-pure hollandites adopting tetragonal (I4/m) or monoclinic symmetry (I2/m) were observed to form in the compositional range 0 ≤ x ≤ 0.4. Structural models for the compositions, x = 0, 0.15, and 0.25 were developed from Rietveld analysis of powder diffraction data. Refined anisotropic displacement parameters (βij) for the Ba and Cs ions in the hollandite tunnels indicate local disorder of Ba/Cs along the tunnel direction. In addition, weak superlattice reflections were observed in X-ray and electron diffraction patterns that were due to the compositional modulation i.e., ordering of ions and vacancies along tunnel direction. Our overall observations suggest the phase-pure hollandites studied assumed supercell structures with ordered tunnel cations, which in turn have positional disorder in individual supercells.

Measurement of cesium emissions during the vitrification of simulated high level radioactive waste

International Nuclear Information System (INIS)

Zamecnik, J.R.; Miller, D.H.; Carter, J.T.

1992-01-01

In the Defense Waste Processing Facility at the Savannah River Site, it is desired to eliminate a startup test that would involve adding small amounts of radioactive cesium-137 to simulated high-level waste. In order to eliminate this test, a reliable method for measuring non-radioactive cesium in the offgas system from the glass melter is required. From a pilot scale melter system, offgas particulate samples were taken on filter paper media and analyzed by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). The ICPMS method proved to be sufficiently sensitive to measure cesium quantities as low as 0.135 μg, with the sensitivity being limited by the background cesium present in the filter paper. Typical particulate loadings ranged from 800 μg of cesium. This sensitivity allowed determination of cesium decontamination factors for four of the five major components of the offgas system. The decontamination factors measured experimentally compared favorably with the process design basis values

HIGH ASPECT RATIO ION EXCHANGE RESIN BED - HYDRAULIC RESULTS FOR SPERICAL RESIN BEADS

International Nuclear Information System (INIS)

Duignan, M; Charles Nash, C; Timothy Punch, T

2007-01-01

A principal role of the DOE Savannah River Site is to safely dispose of a large volume of liquid nuclear waste held in many storage tanks. An in-tank ion exchange unit is being considered for cesium removal to accelerate waste processing. This unit is planned to have a relatively high bed height to diameter ratio (10:1). Complicating the design is the need to cool the ion exchange media; therefore, the ion exchange column will have a central cooling core making the flow path annular. To separate cesium from waste the media being considered is made of resorcinol formaldehyde resin deposited on spherical plastic beads and is a substitute for a previously tested resin made of crystalline silicotitanate. This spherical media not only has an advantage of being mechanically robust, but, unlike its predecessor, it is also reusable, that is, loaded cesium can be removed through elution and regeneration. Resin regeneration leads to more efficient operation and less spent resin waste, but its hydraulic performance in the planned ion exchange column was unknown. Moreover, the recycling process of this spherical resorcinol formaldehyde causes its volume to significantly shrink and swell. To determine the spherical media's hydraulic demand a linearly scaled column was designed and tested. The waste simulant used was prototypic of the wastes' viscosity and density. This paper discusses the hydraulic performance of the media that will be used to assist in the design of a full-scale unit

Microbial accumulation of uranium, radium, and cesium

International Nuclear Information System (INIS)

Strandberg, G.W.; Shumate, S.E. II; Parrott, J.R. Jr.; North, S.E.

1981-05-01

Diverse microbial species varied considerably in their ability to accumulate uranium, cesium, and radium. Mechanistic differences in uranium uptake by Saccharomyces cerevisiae and Pseudomonas aeruginosa were indicated. S. serevisiae exhibited a slow (hours) surface accumulation of uranium which was subject to environmental factors, while P. aeruginosa accumulated uranium rapidly (minutes) as dense intracellular deposits and did not appear to be affected by environmental parameters. Metabolism was not required for uranium uptake by either organism. Cesium and radium were concentrated to a considerably lesser extent than uranium by the several species tested

Adsorption of Radioactive Cesium to Illite-Sericite Mixed Clays

Science.gov (United States)

Hwang, J. H.; Choung, S.; Park, C. S.; Jeon, S.; Han, J. H.; Han, W. S.

2016-12-01

Once radioactive cesium is released into aquatic environments through nuclear accidents such as Chernobyl and Fukushima, it is harmful to human and ecological system for a long time (t1/2 = 30.2 years) because of its chemical toxicity and γ-radiation. Sorption mechanism is mainly applied to remove the cesium from aquatic environments. Illite is one of effective sorbent, considering economical cost for remediation. Although natural illite is typically produced as a mixture with sericite formed by phyllic alteration in hydrothermal ore deposits, the effects of illite-sericite mixed clays on cesium sorption was rarely studied. This study evaluated the sorption properties of cesium to natural illite collected at Yeongdong in Korea as the world-largest illite producing areas (termed "Yeongdong illite"). The illite samples were analyzed by XRF, XRD, FT-IR and SEM-EDX to determine mineralogy, chemical composition, and morphological characteristics, and used for batch sorption experiments. Most of "Yeongdong illite" samples predominantly consist of sericite, quartz, albite, plagioclase feldspar and with minor illite. Cesium sorption distribution coefficients (Kd,Cs) of various "Yeongdong illite" samples ranged from 500 to 4000 L/kg at low aqueous concentration (Cw 10-7 M). Considering Kd,Cs values were 400 and 6000 using reference sericite and illite materials, respectively, in this study, these results suggested that high contents of sericite significantly affect the decrease of sorption capabilities for radiocesium by natural illite (i.e., illite-sericite mixed clay).

Chemistry of radio-frequency source of negative hydrogen ions; Chemia radio-frekvencneho zdroja negativnych ionov vodika

Energy Technology Data Exchange (ETDEWEB)

Skoviera, J.; Cernusak, I. [Univerzita Komenskeho, Prirodovedecka fakulta, Katedra fyzikalnej a teoretickej chemie, 84215 Bratislava (Slovakia)

2013-04-16

International Thermonuclear Experimental Reactor (ITER) is a prototype of nuclear fusion reactor Tokamak currently build in Cadarache. It will use as one of primary plasma heating components a radiofrequency driven negative ion source of deuterium. The purpose of cesium evaporated in the part of this ion source is to react with free electrons which can incidentally destroy generated hydrogen ions and are co-extracted with the hydrogen beam. Goal of this work is to investigate majority of processes which might have impact on hydrogen anion in either formative or destructive way associated with cesium. Generally the caesium dynamics is very complex in such sources and the interplay of the individual contributions and their control to establish optimum caesium coverage of the plasma grid is still an open issue. (authors)

Ion source techniques for high-speed processing of material surface by ion beams

International Nuclear Information System (INIS)

Ishikawa, Junzo

1990-01-01

The present paper discusses some key or candidate techniques for future ion source development and such ion sources developed by the author. Several types of microwave ion sources for producing low charge state ions have been developed in Japan. When a microwave plasma cathode developed by the author is adapted to a Kaufman type ion source, the electron emission currents are found to be 2.5 A for argon gas and 0.5-0.9 A for oxygen gas. An alternative ionization method for metal atoms is strongly required for high-speed processing of material surface by metal-ion beams. Detailed discussion is made of collisional ionization of vaporized atoms, and negative-ion production (secondary negative-ion emission by sputtering). An impregnated electrode type liquid-metal ion source developed by the author, which has a porous tip structure, is described. The negative-ion production efficiency is quite high. The report also presents a neutral and ionized alkaline-metal bombardment type heavy negative-ion source, which consists of a cesium plasma ion source, suppressor, target electrode, negative-ion extraction electrode, and einzel lens. (N.K.)

Dosage of cesium 137 in radioactive wastes by the application of sodium tetraphenylborate; Dosage du cesium 137 dans les effluents radioactifs par le tetraphenylborate de sodium

Energy Technology Data Exchange (ETDEWEB)

Testemale, G; Girault, J [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1967-07-01

A simple technique of the dosage of {sup 137}Cs has been developed. The technique consists in the formation of cesium tetraphenyl borate, followed by a double extraction with isoamyl acetate, and washing of the organic phase. The counting of known parts of the cesium solution assaying of its purity by {gamma} spectrometry enable the determination of the {sup 137}Cs. The yield is about 98 per cent. (authors) [French] Une technique simple du dosage du {sup 137}Cs a ete mise au point. Elle consiste en une double extraction du tetraphenylborate de cesium forme par l'acetate d'isoamyle suivie d'un lavage de la phase organique. Des comptages sur des parties aliquotes de la solution de cesium et un controle de purete par spectrometrie {gamma} permettent la determination de cet element. Rendement: environ 98 pour cent. (auteurs)

Heavy ion fusion year-end report, April 1, 1983-September 30, 1983

International Nuclear Information System (INIS)

1983-11-01

Some highlights of the program during this reporting period are as follows: (1) First results with the completed apparatus of the Single Beam Transport Experiment (SBTE) have shown the stable propagation of a space-charge-dominated cesium-ion beam through 41 periods of an AG focussing lattice. The space-charge effects were large enough to depress the betatron phase advance per cell from sigma 0 = 60 0 to sigma = 12 0 . (2) Understanding of the reflection stabilization of longitudinal instability in a high-current beam bunch has been improved by analytical and computational studies. (3) Conceptual design studies of a multiple-beam ion induction linac suitable for the High Temperature Experiment have progressed to the stage where a first reference design (sodium, 125 MeV, 30 μC, 16 beams) is available. (4) The Long-Pulse Induction Accelerating Unit, first used to accelerate a cesium-ion beam in February 1983, has been undergoing modification in the low-level trigger circuitry to allow more precisely controlled waveform synthesis

Removal of radioactive cesium from soil by ammonium citrate solution and ionic liquid

International Nuclear Information System (INIS)

Ishiwata, Shunji; Kitakouji, Manabu; Taga, Atsushi; Ogata, Fumihiko; Ouchi, Hidekazu; Yamanishi, Hirokuni; Inagaki, Masayo

2015-01-01

Radioactive cesium has strongly bound soil as time proceeded, which could not be cleaved in mild condition. We have found that serial treatment of ammonium citrate solution and ionic liquid removed radioactive cesium from soil effectively. The sequence of the treatment is crucial, since inverse serial treatment or mixture of two kinds of solution did not show such an effect, which suggested that ammonium citrate unlocked trapped cesium in soil and ionic liquid solved it. We also found that repeating serial treatment and prolonged treatment time additively removed cesium from soil. (author)

Cesium-plasma-conductivity enhancement in the advanced thermionic energy converter. Final report

International Nuclear Information System (INIS)

Manikopoulos, C.N.

Two methods of plasma conductivity enhancement in a cesium vapor thermionic energy converter have been studied. The first involved resonance photoabsorption of several cesium lines and the second utilized cesium plasma sustenance by application of microwave power. An extensive study of ionization processes in a cesium discharge in the presence of resonance ionization was made. Calculations were made of expected percentage excitation levels for several cesium resonance transitions for different values of neutral density and temperature as well as incident radiation power levels. The results of some of these computations were tabulated. Several ionization schemes were considered. A number of cesium transitions were investigated in the range of 799 to 870 nanometers for four different cesium reservoir temperatures, 467, 511, 550 and 591 K. The related absorption coefficients of the radiation lines in the plasma were deduced and tabulated. The resulting plasma conductivity increase was recorded and the associated ionization enhancement was deduced. A microwave cavity was built where the emitter and collector of a simple thermionic converter made up two of the cavity walls and resonant microwave power was externally applied. The I-V characteristics of the thermionic converter were studied under several microwave power levels in the range of 0 to 2 watts. Significant shifts to higher currents were observed as the microwave power levels were raised. In conclusion, both methods show promise as auxiliary ionization mechanisms for the thermionic energy converter, especially at low emitter temperatures

Pilot unit for cesium-137 separation

International Nuclear Information System (INIS)

Raggenbass, A.; Quesney, M.; Fradin, J.; Dufrene, J.

1958-01-01

Users of radiation are becoming increasingly interested in cesium-137. At the same time the starting up of the industrial plant at Marcoule will make available in the near future large stocks of fission products which should be made use of as quickly as possible. The installation described is a pilot plant for cesium-137 production which should make it possible: - to verify the chemical method on actual solutions of fission products, by treating about 100 curies of 137 Cs by operation, - to obtain technical information on the chemical equipment (tele-commands, corrosion, maintenance, etc...), - to obtain 137 Cs in sufficient quantity to perfect the technique of the manufacture of sealed sources. (author) [fr

Cesium 137 in oils and plants from Guatemala

International Nuclear Information System (INIS)

Ayala, R.E.; Perez, J.F.

1993-01-01

Since 1990 the project of radioactive and environmental contamination started in Guatemala. Studies about the radioactive contamination levels are made within the framework of this project. Cesium-137 has been an interest radionuclide, because it is a fission product released to the environment by the use of nuclear weapons and nuclear power plants accidents. The sampling consisted in collection of soil and grass in 20 provinces of Guatemala, one point by province, and it was made in 1990. The cesium-137 concentration in the samples, was determined by gamma spectrometry, using an hyper pure germanium detector. The results show the presence of radioactive contamination in soil and grass due to cesium-137, at levels that might be considered as normal. The levels found are not harmful for human health, and its importance is the fact that can be used as reference levels for the environmental radioactivity monitoring in Guatemala

Cesium uptake capacity of simulated ferrocyanide tank waste. Interim report FY 1994, Ferrocyanide Safety Project

International Nuclear Information System (INIS)

Burgeson, I.E.; Bryan, S.A.; Burger, L.E.

1994-09-01

The objective of this project is to determine the capacity for 137 CS uptake by mixed metal ferrocyanides present in Hanford waste tanks, and to assess the potential for aggregation of these 137 CS exchanged materials to form tank ''hot-spots.'' This research, performed at the Pacific Northwest Laboratory (PNL) for the Westinghouse Hanford Company (WHC), stems from concerns of possible localized radiolytic heating within the tanks. If radioactive cesium is exchanged and concentrated by the remaining nickel ferrocyanide present in the tanks, this heating could cause temperatures to rise above the safety limits specified for the ferrocyanide tanks. For the purposes of this study, two simulants, In-Farm-2 and U-Plant-2, were chosen to represent the wastes generated by the scavenging processes. These simulants were formulated using protocols from the original cesium scavenging campaign. Later additions of cesium-rich wastes from various processes also were considered. The simulants were prepared and centrifuged to obtain a moist ferrocyanide sludge. The centrifuged sludges were treated with the original supernate spiked with a known amount of cesium nitrate. After analysis by flame atomic absorption spectrometry, distribution coefficients (K d ) were calculated. The capacity of solid waste simulants to exchange radioactive cesium from solution was examined. Initial results showed that the greater the molar ratio of cesium to cesium nickel ferrocyanide, the less effective the exchange of cesium from solution. The theoretical capacity of 2 mol cesium per mol of nickel ferrocyanide was not observed. The maximum capacity under experimental conditions was 0.35 mol cesium per mol nickel ferrocyanide. Future work on this project will examine the layering tendency of the cesium nickel ferrocyanide species

Experimental study on cesium immobilization in struvite structures

International Nuclear Information System (INIS)

Wagh, Arun S.; Sayenko, S.Y.; Shkuropatenko, V.A.; Tarasov, R.V.; Dykiy, M.P.; Svitlychniy, Y.O.; Virych, V.D.; Ulybkina, E.A.

2016-01-01

Graphical abstract: X-ray diffraction patterns of Ceramicrete forms, green representing struvite-K, and red, struvite-(K,Cs) with 10 wt.% CsCl in it. Cs substitutes partially for K, which immobilizes Cs at room temperature by the acid–base reaction. - Highlights: • Struvite structure of Ceramicrete is an excellent host of radioactive cesium. • The volatility problem of cesium can be avoided by this method. • This method can be used to produce cesium waste forms in ambient conditions. • It can also be used to pretreat cesium in glass vitrification technology. • It also provides a method to produce safe sealed radioactive sources of cesium. - Abstract: Ceramicrete, a chemically bonded phosphate ceramic, was developed for nuclear waste immobilization and nuclear radiation shielding. Ceramicrete products are fabricated by an acid–base reaction between magnesium oxide and mono potassium phosphate that has a struvite-K mineral structure. In this study, we demonstrate that this crystalline structure is ideal for incorporating radioactive Cs into a Ceramicrete matrix. This is accomplished by partially replacing K by Cs in the struvite-K structure, thus forming struvite-(K, Cs) mineral. X-ray diffraction and thermo-gravimetric analyses are used to confirm such a replacement. The resulting product is non-leachable and stable at high temperatures, and hence it is an ideal matrix for immobilizing Cs found in high-activity nuclear waste streams. The product can also be used for immobilizing secondary waste streams generated during glass vitrification of spent fuel, or the method described in this article can be used as a pretreatment method during glass vitrification of high level radioactive waste streams. Furthermore, it suggests a method of producing safe commercial radioactive Cs sources.

Experimental study on cesium immobilization in struvite structures

Energy Technology Data Exchange (ETDEWEB)

Wagh, Arun S., E-mail: asw@anl.gov [Environmental Science Division, Argonne National Laboratory, 9700 S. Cass Avenue, IL 60439 (United States); Sayenko, S.Y.; Shkuropatenko, V.A.; Tarasov, R.V.; Dykiy, M.P.; Svitlychniy, Y.O.; Virych, V.D.; Ulybkina, E.A. [National Science Center, Kharkov Institute of Physics and Technology, Kharkov (Ukraine)

2016-01-25

Graphical abstract: X-ray diffraction patterns of Ceramicrete forms, green representing struvite-K, and red, struvite-(K,Cs) with 10 wt.% CsCl in it. Cs substitutes partially for K, which immobilizes Cs at room temperature by the acid–base reaction. - Highlights: • Struvite structure of Ceramicrete is an excellent host of radioactive cesium. • The volatility problem of cesium can be avoided by this method. • This method can be used to produce cesium waste forms in ambient conditions. • It can also be used to pretreat cesium in glass vitrification technology. • It also provides a method to produce safe sealed radioactive sources of cesium. - Abstract: Ceramicrete, a chemically bonded phosphate ceramic, was developed for nuclear waste immobilization and nuclear radiation shielding. Ceramicrete products are fabricated by an acid–base reaction between magnesium oxide and mono potassium phosphate that has a struvite-K mineral structure. In this study, we demonstrate that this crystalline structure is ideal for incorporating radioactive Cs into a Ceramicrete matrix. This is accomplished by partially replacing K by Cs in the struvite-K structure, thus forming struvite-(K, Cs) mineral. X-ray diffraction and thermo-gravimetric analyses are used to confirm such a replacement. The resulting product is non-leachable and stable at high temperatures, and hence it is an ideal matrix for immobilizing Cs found in high-activity nuclear waste streams. The product can also be used for immobilizing secondary waste streams generated during glass vitrification of spent fuel, or the method described in this article can be used as a pretreatment method during glass vitrification of high level radioactive waste streams. Furthermore, it suggests a method of producing safe commercial radioactive Cs sources.

Immobilization of Co{sup 2+} and Cs{sup +} in zeolites by thermal treatment and by combustion; Inmovilizacion de Co{sup 2+} y Cs{sup +} en zeolitas por tratamiento termico y por combustion

Energy Technology Data Exchange (ETDEWEB)

Rodriguez T, R.; Bulbulian G, S. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: rosarodtre@yahoo.com

2005-07-01

The radioactive waste, either those that take place in the {sup 235}U fission or those that are used in the radiochemical laboratories, are dangerous for the human being and for the one environment. The liquid radioactive wastes are of those that present bigger problem. It has intended to retain by the ion exchange method the radioactive ions of the liquids using, for example, zeolites. In this work so much synthetic zeolites was used (A and X) like a natural zeolite (clinoptilolite). Its were put in contact with cobalt or cesium solutions to simulate radioactive solutions. A part of the zeolite cations were exchanged with cobalt or cesium cations, eliminating them by this way of the solution. However, in extreme conditions these cations can be leached of the solids. To immobilize the cobalt or cesium cations in the zeolites net its are usually carried out thermal treatments to such temperatures that the structure is destroyed and that the contaminating ions are trapped in a solid often vitreous. The exchanged zeolites with cobalt or cesium, on one hand, its were thermally treated to different temperatures during three hours and by the other one, according to the treatment method by combustion, to different temperatures during five minutes in presence of urea, later its were put in contact with a solution of NaCl to measure the leaching of the interest cations. These solutions were analyzed by neutron activation. In general it was found that as the treatment temperature increases (in both methods) the so much immobility of the cesium like of the cobalt it increases. The grade of crystallinity of the samples before and after the treatments it was determined by X-ray diffraction. (Author)

Immobilization of Co2+ and Cs+ in zeolites by thermal treatment and by combustion

International Nuclear Information System (INIS)

Rodriguez T, R.; Bulbulian G, S.

2005-01-01

The radioactive waste, either those that take place in the 235 U fission or those that are used in the radiochemical laboratories, are dangerous for the human being and for the one environment. The liquid radioactive wastes are of those that present bigger problem. It has intended to retain by the ion exchange method the radioactive ions of the liquids using, for example, zeolites. In this work so much synthetic zeolites was used (A and X) like a natural zeolite (clinoptilolite). Its were put in contact with cobalt or cesium solutions to simulate radioactive solutions. A part of the zeolite cations were exchanged with cobalt or cesium cations, eliminating them by this way of the solution. However, in extreme conditions these cations can be leached of the solids. To immobilize the cobalt or cesium cations in the zeolites net its are usually carried out thermal treatments to such temperatures that the structure is destroyed and that the contaminating ions are trapped in a solid often vitreous. The exchanged zeolites with cobalt or cesium, on one hand, its were thermally treated to different temperatures during three hours and by the other one, according to the treatment method by combustion, to different temperatures during five minutes in presence of urea, later its were put in contact with a solution of NaCl to measure the leaching of the interest cations. These solutions were analyzed by neutron activation. In general it was found that as the treatment temperature increases (in both methods) the so much immobility of the cesium like of the cobalt it increases. The grade of crystallinity of the samples before and after the treatments it was determined by X-ray diffraction. (Author)

Structure of cesium loaded iron phosphate glasses: An infrared and Raman spectroscopy study

International Nuclear Information System (INIS)

Joseph, Kitheri; Premila, M.; Amarendra, G.; Govindan Kutty, K.V.; Sundar, C.S.; Vasudeva Rao, P.R.

2012-01-01

The structure of cesium loaded iron phosphate glasses (IPG) was investigated using infrared and Raman spectroscopy. The spectra of the cesium doped samples revealed a structural modification of the parent glass owing to the incorporation of cesium. The structural changes could be correlated with the variation observed in the glass transition temperature of these glasses. Increased Cs-mediated cationic cross linking appears to be the reason for the initial rise in glass transition temperature up to 21 mol% Cs 2 O in IPG; while, breakdown of the phosphate network with increasing cesium content, brings down the glass transition temperature.

Generation of CsI cluster ions for mass calibration in matrix-assisted laser desorption/ionization mass spectrometry

NARCIS (Netherlands)

Lou, X.; Dongen, van J.L.J.; Meijer, E.W.

2010-01-01

A simple method was developed for the generation of cesium iodide (CsI) cluster ions up to m/z over 20,000 in matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS). Calibration ions in both positive and negative ion modes can readily be generated from a single MALDI spot of CsI(3)

Industrial treatment of solutions of fission products. Separation of caesium-137; Traitement industriel de solutions de produits de fission. Separation du cesium-137

Energy Technology Data Exchange (ETDEWEB)

Fisher, C; Raggenbass, A [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1959-07-01

sources solides a partir du melange brut, sans separation; b) separation d'un ou plusieurs produits de fission determines a partir desquels sont confectionnees les sources. L'examen de la composition radioactive du melange de produits de fission resultant de l'exploitation des reacteurs de Marcoule (G1, G2 et G3) montre que le cesium-137 represente a lui seul 30 pour cent de l'energie {gamma} disponible a la sortie de l'usine plutonium, 70 pour cent deux ans apres et pratiquement 100 pour cent au bout de 5 ans. Il n'y a donc qu'un interet minime a entreprendre la confection de sources avec le melange de produits de fission, la separation du cesium ne representant pas un travail plus complique et conduisant a un produit dont les possibilites d'utilisation sont plus nombreuses. Nous avons envisage la separation du cesium-137 par une methode derivee de la methode connue basee sur la precipitation du cesium par l'acide phosphotungstique. Dans les methodes publiees, le phosphotungstate est completement dissous et le cesium est extrait de la solution par echange de cations ou par elimination des ions phosphates et tungstates sur une resine echangeuse d'anions. Nous avons etudie la transformation du phosphotungstate de cesium en phosphate et tungstate de baryum par emploi de l'hydroxyde de baryum qui remet le cesium en solution en hydroxyde. Les avantages sont les suivants: - decontamination plus poussee du cesium-137, sans purification supplementaire; - possibilite de transformation directe en sulfate de cesium; - simplification generale du mode operatoire, et par consequent de l'installation. (auteur)

Industrial treatment of solutions of fission products. Separation of caesium-137; Traitement industriel de solutions de produits de fission. Separation du cesium-137

Energy Technology Data Exchange (ETDEWEB)

Fisher, C.; Raggenbass, A. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1959-07-01

confection de sources solides a partir du melange brut, sans separation; b) separation d'un ou plusieurs produits de fission determines a partir desquels sont confectionnees les sources. L'examen de la composition radioactive du melange de produits de fission resultant de l'exploitation des reacteurs de Marcoule (G1, G2 et G3) montre que le cesium-137 represente a lui seul 30 pour cent de l'energie {gamma} disponible a la sortie de l'usine plutonium, 70 pour cent deux ans apres et pratiquement 100 pour cent au bout de 5 ans. Il n'y a donc qu'un interet minime a entreprendre la confection de sources avec le melange de produits de fission, la separation du cesium ne representant pas un travail plus complique et conduisant a un produit dont les possibilites d'utilisation sont plus nombreuses. Nous avons envisage la separation du cesium-137 par une methode derivee de la methode connue basee sur la precipitation du cesium par l'acide phosphotungstique. Dans les methodes publiees, le phosphotungstate est completement dissous et le cesium est extrait de la solution par echange de cations ou par elimination des ions phosphates et tungstates sur une resine echangeuse d'anions. Nous avons etudie la transformation du phosphotungstate de cesium en phosphate et tungstate de baryum par emploi de l'hydroxyde de baryum qui remet le cesium en solution en hydroxyde. Les avantages sont les suivants: - decontamination plus poussee du cesium-137, sans purification supplementaire; - possibilite de transformation directe en sulfate de cesium; - simplification generale du mode operatoire, et par consequent de l'installation. (auteur)

Accumulation of strontium 90 and cesium 137 in some hydrobionts

International Nuclear Information System (INIS)

Boyadzhiev, A.; Keslev, D.; Kerteva, A.; Novakova, E.

1974-01-01

Factors responsible for the accumulation of strontium 90 and cesium 137 in some plant organisms, characteristic for fishes in Bulgarian fresh-water reservoirs and in Black Seawater, were examined. The investigated samples were taken during spring, summer and autumn-winter seasons 1967/1968. Each sample burnt to ashes at 450 0 C was examined for strontium 90 and cesium 137 content as well as stable isotopes of calcuim and potassium. Accumulation factors for strontium 90 and cesium 137 were significantly higher in freshwater hydrobionts than in seawater hydrobionts. This could be explained by variations in the concentration of stable isotopes of calcium and potassium from freshwater reservoirs and from seawater. Potassium and calcium concentrations were relatively constant in seawater while in freshwater they were significantly variable. Accumulation factors for these radionuclides increased according to the amount of rain and the altitude above sea level. Strontium 90 was deposited mostly in fins, less in scales and least in the meat of fishes; cesium 137 was mainly deposited in the meat and less in the other parts of fishes. The highest accumulation factors for strontium 90 were determined in fishes and for cesium 137 in plant organisms. The most convenient plant and fish species for tracing radioactive contamination of freshwater reservoirs and in the Black Sea were indicated. (A.B.)

The molar enthalpies of solution and vapour pressures of saturated aqueous solutions of some cesium salts

International Nuclear Information System (INIS)

Apelblat, Alexander; Korin, Eli

2006-01-01

Vapour pressures of water over saturated solutions of cesium chloride, cesium bromide, cesium nitrate, cesium sulfate, cesium formate, and cesium oxalate were determined as a function of temperature. These vapour pressures were used to evaluate the water activities, osmotic coefficients and molar enthalpies of vapourization. Molar enthalpies of solution of cesium chloride, Δ sol H m (T = 295.73 K; m = 0.0622 mol . kg -1 ) = (17.83 ± 0.50) kJ . mol -1 ; cesium bromide, Δ sol H m (T = 293.99 K; m = 0.0238 mol . kg -1 ) = (26.91 ± 0.59) kJ . mol -1 ; cesium nitrate, Δ sol H m (T = 294.68 K; m = 0.0258 mol . kg -1 ) = (37.1 ± 2.3) kJ . mol -1 ; cesium sulfate, Δ sol H m (T = 296.43 K; m = 0.0284 mol . kg -1 ) (16.94 ± 0.43) kJ . mol -1 ; cesium formate, Δ sol H m (T = 295.64 K; m = 0.0283 mol . kg -1 ) = (11.10 ± 0.26) kJ . mol -1 and Δ sol H m (T = 292.64 K; m = 0.0577 mol . kg -1 ) = (11.56 ± 0.56) kJ . mol -1 ; and cesium oxalate, Δ sol H m (T = 291.34 K; m = 0.0143 mol . kg -1 ) = (22.07 ± 0.16) kJ . mol -1 were determined calorimetrically. The purity of the chemicals was generally greater than 0.99 mass fraction, except for HCOOCs and (COOCs) 2 where purities were approximately 0.95 and 0.97 mass fraction, respectively. The uncertainties are one standard deviations

Surface generation of negative hydrogen ion beams

International Nuclear Information System (INIS)

Bommel, P.J.M. van.

1984-01-01

This thesis describes investigations on negative hydrogen ion sources at the ampere level. Formation of H - ions occurs when positive hydrogen ions capture two electrons at metal surfaces. The negative ionization probability of hydrogen at metal surfaces increases strongly with decreasing work function of the surface. The converters used in this study are covered with cesium. Usually there are 'surface plasma sources' in which the hydrogen source plasma interacts with a converter. In this thesis the author concentrates upon investigating a new concept that has converters outside the plasma. In this approach a positive hydrogen ion beam is extracted from the plasma and is subsequently reflected from a low work function converter surface. (Auth.)

Functions and requirements for a cesium demonstration unit

International Nuclear Information System (INIS)

Howden, G.F.

1994-04-01

Westinghouse Hanford Company is investigating alternative means to pretreat the wastes in the Hanford radioactive waste storage tanks. Alternatives include (but are not limited to) in-tank pretreatment, use of above ground transportable compact processing units (CPU) located adjacent to a tank farm, and fixed processing facilities. This document provides the functions and requirements for a CPU to remove cesium from tank waste as a demonstration of the CPU concept. It is therefore identified as the Cesium Demonstration Unit CDU

Development of Electrically Switched Ion Exchange Process for Selective Ion Separations

International Nuclear Information System (INIS)

Rassat, Scot D.; Sukamto, Johanes H.; Orth, Rick J.; Lilga, Michael A.; Hallen, Richard T.

1999-01-01

The electrically switched ion exchange (ESIX) process, being developed at Pacific Northwest National Laboratory, provides an alternative separation method to selectively remove ions from process and waste streams. In the ESIX process, in which an electroactive ion exchange film is deposited onto a high surface area electrode, uptake and elution are controlled directly by modulating the electrochemical potential of the film. This paper addresses engineering issues necessary to fully develop ESIX for specific industrial alkali cation separation challenges. The cycling and chemical stability and alkali cation selectivity of nickel hexacyanoferrate (NiHCF) electroactive films were investigated. The selectivity of NiHCF was determined using cyclic voltammetry and a quartz crystal microbalance to quantify ion uptake in the film. Separation factors indicated a high selectivity for cesium and a moderate selectivity for potassium in high sodium content solutions. A NiHCF film with improved redox cycling and chemical stability in a simulated pulp mill process stream, a targeted application for ESIX, was also prepared and tested

Solvation of ions in the gas-phase: a molecular dynamics simulation

Science.gov (United States)

Cabarcos, Orlando M.; Lisy, James M.

1996-07-01

Molecular dynamics simulations have been performed on the collision between a cesium ion and a cluster of twenty methanol molecules. This process, generating a solvated ion, was studied over a range (1 to 25 eV) of eight collision energies. Preliminary analysis of this gas phase solvation has included the distribution of final ion cluster sizes, fragmentation patterns, solvation timescales and energetics. Two distinct patterns have emerged: a ballistic penetration of the neutral cluster at the higher collision energies and an evaporative evolution of the cluster ion at lower collision energies.

Nonlinear damage effect in graphene synthesis by C-cluster ion implantation

International Nuclear Information System (INIS)

Zhang Rui; Zhang Zaodi; Wang Zesong; Wang Shixu; Wang Wei; Fu Dejun; Liu Jiarui

2012-01-01

We present few-layer graphene synthesis by negative carbon cluster ion implantation with C 1 , C 2 , and C 4 at energies below 20 keV. The small C-clusters were produced by a source of negative ion by cesium sputtering with medium beam current. We show that the nonlinear effect in cluster-induced damage is favorable for graphene precipitation compared with monomer carbon ions. The nonlinear damage effect in cluster ion implantation shows positive impact on disorder reduction, film uniformity, and the surface smoothness in graphene synthesis.

Magnetic composite beads for sorption of cesium ions from aqueous streams

International Nuclear Information System (INIS)

Shinde, Rakesh N.; Pandey, A.K.; Acharya, R.; Rajurkar, N.S.

2014-01-01

Magnetic separation of metal ions is one of the promising methods due to simple, fast, efficient and cost effective technology. Highly selective magnetic sorbents can be designed by immobilizing functional groups in magnetic carrier which binds to the target specific ions. In the present work chitosan-(3-aminopropyl) triethoxysilane (APTS)- copperferrocyanide (CFC) composite beads have been synthesized for sorption of 137 Cs ions from aqueous streams. Physical characterization of the best resulted polymer beads was carried out by SEM-EDX and VSM technique. Sorption of Cs ions in the various magnetic polymer beads were studied in different aqueous condition by 137 Cs (662 KeV) radiotracer assay

Cesium-137 accumulation in higher plants before and after Chernobyl

International Nuclear Information System (INIS)

Sawidis, T.; Drossos, E.; Papastefanou, C.; Heinrick, G.

1990-01-01

Cesium-137 concentrations in plant species of three biotypes of northern Greece, differing in location as well as in vegetation, are reported following the Chernobyl reactor accident. The cesium uptake by plants was due to the foliar deposition rather than the root uptake. The highest level of cesium in plants was found in Ranunculus sardous, a pubescent plant. The 137 Cs concentration was about 22kBq kg -1 d.w. A high level of cesium was also found in Salix alba ( 137 Cs: 19.6 kBq kg -1 d.w.), a deciduous tree showing that hairy leaves or leaves having rough and large surfaces can absorb greater amounts of radioactivity (surface effect). A comparison is also made between the results of measurements of the present study and the results of measurements of some herbarium plants collected one year before the accident as well as the results of measurements of some new plants grown and collected one year after the accident resulting in a natural removal rate of 137 Cs in plants varying from 14 to 130 days

Cesium powder and pellets inner container decontamination method determination

International Nuclear Information System (INIS)

Ferrell, P.C.

1998-01-01

The cesium powder and pellets inner container is to be performance tested per the criteria specified in Section 4.0 of HNF-2399, ''Design, Fabrication, and Assembly Criteria for Cesium Powder and Pellet Inner Container.'' The test criteria specifies that the inner container be water tight during decontamination of the exterior surface. Three prototypes will be immersed into a pool of water to simulate a water decontamination process

Improvement of cesium retention in uranium dioxide by additional phases; Amelioration de la retention du cesium dans le dioxyde d`uranium au moyen de phases exogenes

Energy Technology Data Exchange (ETDEWEB)

Gamaury Dubois, S

1995-09-19

The objective of this study is to improve the cesium retention in nuclear fuel. A bibliographic survey indicates that cesium is rapidly released from uranium dioxide in an accident condition. At temperatures higher than 1500 deg C or in oxidising conditions, our experiments show the difficulty of maintaining cesium inside simulated fuel. Two ternary systems are potentially interesting for the retention of cesium and to reduce the kinetics of release from the fuel: Cs{sub 2}O-Al{sub 2}O{sub 3}-SiO{sub 2} et Cs{sub 2}O-ZrO{sub 2}-SO{sub 2}. The compounds CsAISi{sub 2}O{sub 6} and Cs{sub 2}ZrSi{sub 6}O{sub 15} were studied from 1200 deg C to 2000 deg C by thermogravimetric analysis. The volumetric diffusion coefficients of cesium in these structures, in solid state as well as in liquid one, were measured. A fuel was sintered with (Al{sub 2}O{sub 3} + SiO{sub 2}) or (ZrO{sub 2} + SiO{sub 2}) and the intergranular phase was characterized. In the presence of (Al{sub 2}O{sub 3} + SiO{sub 2}), the sintering is realized at 1610 deg C in H{sub 2}. It is a liquid phase sintering. On the other end, with (ZrO{sub 2} + SiO{sub 2}), the sintering is a low temperature one in oxidising atmosphere. Finally, cesium containing simulated fuels were produced with these additives. According to the effective diffusion coefficients that were measured, the additives improved the retention of cesium. We have predicted the improvement that could be hoped for in a nuclear reactor, depending on the dispersion of the intergranular additives, the temperature and the degree of oxidation of the UO{sub 2+x}. We wait for a factor of 2 for x=0 and more than 8 for x=0.05, up to 2000 deg C. (author). 148 refs., 122 figs., 34 tabs.

Removal of cesium from red deer meat

International Nuclear Information System (INIS)

Jandl, J.; Novosad, J.; Francova, J.; Prochazka, H.

1989-01-01

The effect was studied of marinading on the reduction of cesium radionuclide activity in red deer meat contaminated by ingestion of feed containing 134 Cs+ 137 Cs from radioactive fallout following the Chernobyl accident. Two types of marinade were studied, viz., a vinegar infusion and a vinegar infusion with an addition of vegetables and spices. The meat was chopped to cubes of about 1.5 cm in size and the marinading process took place at temperatures of 5 and 11 degC. The drop of cesium content in the meat was determined by gamma spectrometry at given time intervals. The replacement of the marinade and the duration of the process were found to maximally affect efficiency. If the solution was not replaced, about 80% of cesium radionuclides were removed after seven hours of marinading. With one replacement of the infusion the drop in 134 Cs+ 137 Cs radioactivity amounted to up to 90% after seven hours of marinading. No effects were shown of vegetable additions to the vinegar infusion and of the change in temperature from 5 to 11 degC on the efficiency of the process. (author). 3 tabs., 6 refs

Multi-ampere heavy ion injector for linear induction accelerators using periodic electrostatic focusing

International Nuclear Information System (INIS)

Herrmannsfeldt, W.B.

1978-10-01

Two configurations for ion source and drift-tube-linac combinations that could provide the energy and intensity of accelerated ions needed for the HIF applications are described. The focusing for the systems is provided by a periodic structure of rectangular electrostatic lenses. Scaling rules and extensions of the ideas will be briefly described. Example systems are described that could provide 150 μC of uranium or cesium ions at 12 MeV

Biological effects of cesium-137 injected in beagle dogs of different ages

International Nuclear Information System (INIS)

Nikula, K.J.; Muggenburg, B.A.; Griffith, W.C.

1995-01-01

The toxicity of cesium-137 ( 137 Cs) in the Beagle dog was investigated at the Argonne National Laboratory (ANL) as part of a program to evaluate the biological effects of internally deposited radionuclides. The toxicity and health effects of 137 Cs are important to understand because 137 Cs is produced in large amounts in light-water nuclear reactors. Large quantities of cesium radioisotopes have entered the human food chain as a result of atmospheric nuclear weapons test, and additional cesium radioisotopes were released during the Chernobyl accident. Although the final analyses are not complete, three findings are significant: older dogs dies significantly earlier than juvenile and young adult dogs; greater occurrence of sarcomas in the cesium-137 injected dogs; the major nonneoplastic effect in dogs surviving beyond 52 d appears to be testicular atrophy

Rocksalt or cesium chloride: Investigating the relative stability of the cesium halide structures with random phase approximation based methods

Science.gov (United States)

Nepal, Niraj K.; Ruzsinszky, Adrienn; Bates, Jefferson E.

2018-03-01

The ground state structural and energetic properties for rocksalt and cesium chloride phases of the cesium halides were explored using the random phase approximation (RPA) and beyond-RPA methods to benchmark the nonempirical SCAN meta-GGA and its empirical dispersion corrections. The importance of nonadditivity and higher-order multipole moments of dispersion in these systems is discussed. RPA generally predicts the equilibrium volume for these halides within 2.4% of the experimental value, while beyond-RPA methods utilizing the renormalized adiabatic LDA (rALDA) exchange-correlation kernel are typically within 1.8%. The zero-point vibrational energy is small and shows that the stability of these halides is purely due to electronic correlation effects. The rAPBE kernel as a correction to RPA overestimates the equilibrium volume and could not predict the correct phase ordering in the case of cesium chloride, while the rALDA kernel consistently predicted results in agreement with the experiment for all of the halides. However, due to its reasonable accuracy with lower computational cost, SCAN+rVV10 proved to be a good alternative to the RPA-like methods for describing the properties of these ionic solids.

Hybrid micro-particles as a magnetically-guidable decontaminant for cesium-eluted ash slurry

Science.gov (United States)

Namiki, Yoshihisa; Ueyama, Toshihiko; Yoshida, Takayuki; Watanabe, Ryoei; Koido, Shigeo; Namiki, Tamami

2014-09-01

Decontamination of the radioactive cesium that is widely dispersed owing to a nuclear power station accident and concentrated in fly ash requires an effective elimination system. Radioactive fly ash contains large amounts of water-soluble cesium that can cause severe secondary contamination and represents a serious health risk, yet its complete removal is complicated and difficult. Here it is shown that a new fine-powder formulation can be magnetically guided to eliminate cesium after being mixed with the ash slurry. This formulation, termed MagCE, consists of a ferromagnetic porous structure and alkaline- and salt-resistant nickel ferrocyanide. It has potent cesium-adsorption- and magnetic-separation-properties. Because of its resistance against physical and chemical attack such as with ash particles, as well as with the high pH and salt concentration of the ash slurry, MagCE simplifies the decontamination process without the need of the continued presence of the hazardous water-soluble cesium in the treated ash.

Test procedures and instructions for Hanford complexant concentrate supernatant cesium removal using CST

Energy Technology Data Exchange (ETDEWEB)

Hendrickson, D.W.

1997-01-08

This document provides specific test procedures and instructions to implement the test plan for the preparation and conduct of a cesium removal test, using Hanford Complexant Concentrate supernatant liquor from tank 241-AN-107, in a bench-scale column. The cesium sorbent to be tested is crystalline silicotitanate. The test plan for which this provides instructions is WHC-SD-RE-TP-023, Hanford Complexant Concentrate Supernatant Cesium Removal Test Plan.

Gaz Phase IR and UV Spectroscopy of Neutral Contact Ion Pairs

Science.gov (United States)

Habka, Sana; Brenner, Valerie; Mons, Michel; Gloaguen, Eric

2016-06-01

Cations and anions, in solution, tend to pair up forming ion pairs. They play a crucial role in many fundamental processes in ion-concentrated solutions and living organisms. Despite their importance and vast applications in physics, chemistry and biochemistry, they remain difficult to characterize namely because of the coexistence of several types of pairing in solution. However, an interesting alternative consists in applying highly selective gas phase spectroscopy which can offer new insights on these neutral ion pairs. Our study consists in characterizing contact ion pairs (CIPs) in isolated model systems (M+, Ph-(CH2)n-COO- with M=Li, Na, K, Rb, Cs, and n=1-3), to determine their spectral signatures and compare them to ion pairs in solution. We have used laser desorption to vaporize a solid tablet containing the desired salt. Structural information for each system was obtained by mass-selective, UV and IR laser spectroscopy combined with high level quantum chemistry calculations1. Evidence of the presence of neutral CIPs was found by scanning the π-π* transition of the phenyl ring using resonant two-photon ionization (R2PI). Then, conformational selective IR/UV double resonance spectra were recorded in the CO2- stretch region for each conformation detected. The good agreement between theoretical data obtained at the BSSE-corrected-fullCCSD(T)/dhf-TZVPP//B97-D3/dhf-TZVPP level and experimental IR spectra led us to assign the 3D structure for each ion pair formed. Spectral signatures of (M+, Ph-CH2-COO-) pairs, were assigned to a bidentate CIPs between the alkali cation and the carboxylate group. In the case of (Li+, Ph-(CH2)3-COO-) pairs, the presence of a flexible side chain promotes a cation-π interaction leading to a tridentate O-O-π structure with its unique IR and UV signatures. IR spectra obtained on isolated CIPs were found very much alike the ones published on lithium and sodium acetate in solution2. However, in the case of sodium acetate, solution

Investigations of the sorption of cesium from acid solutions by various inorganic sorbents

International Nuclear Information System (INIS)

Suess, M.; Pfrepper, G.

1981-01-01

Studies have been made to investigate the suitability of various inorganic sorbents for separating and obtaining cesium from acid solutions. In greater details, the distribution coefficients of cesium from nitric acid and ammonium nitrate solution were determined. To determine the saturation capacities it was necessary to plot the isotherms of adsorption from 0.5 N and 3.1 N nitric acid. Experimental sorption from a model solution, of which the composition was equal to that of the liquid Purex waste, enabled the suitability of the various exchangers for obtaining cesium from fission product solutions to be determined. From the results obtained it is apparent that ammonium phosphomolybdate is best suited for obtaining cesium from acid fission product solutions. (orig.)

High brightness K+ ion source for heavy ion fusion linear induction accelerators

International Nuclear Information System (INIS)

Henestroza, E.; Eylon, S.; Chupp, W.; Rutkowski, H.

1992-01-01

Low emittance, high current, singly charged potassium thermionic ion sources are being developed for the Induction Linac System Experiment injector, ILSE. The ILSE, now in study at LBL, will address the physics issues of particle beams in a heavy ion fusion driver scenario. The K + ion beam considered is emitted thermionically into a diode gap from alumino-silicate layers (zeolite) coated on a porous tungsten cup. The Single Beam Transport Experiment (SBTE) 120keV cesium source was redesigned and modified with the aid of an ion optics and gun design program (EGUN) to enable the evaluation of the K + source performance at high extraction currents of about 80mA from a one inch diameter source. The authors report on the source fabrication technique and performance, including total current and current density profile measurements using Faraday cups, phase space distributions using the double slit scanning technique, and source emitting surface temperature dependence on heating power using a wire pyrometer

Actual situation of concentration and inventory of radioactive cesium in Matsukawaura Lagoon sediment, Fukushima Prefecture

International Nuclear Information System (INIS)

Arita, Koichi; Yabe, Tohru; Hayashi, Seiji

2014-01-01

In order to qualitatively evaluate the current status of inventory of radioactive cesium in Matsukawaura Lagoon, profiles of radioactive cesium concentration in sediment cores and sediment characteristics were measured at 36 points. It was shown that sediment characteristics were different even at high concentration of radioactive cesium to the same extent. As a result, the inventory of radioactive cesium were also different. Even at high concentration of radioactive cesium, inventory in southwestern high mud content rate was less than the western. The total inventory of down to 20 cm of sediment throughout Matsukawaura Lagoon was estimated to be about 220 GBq, that more than 80% distributed to 15 cm shallower than has been revealed. (author)

High-capacity, selective solid sequestrants for innovative chemical separation: Inorganic ion exchange approach

International Nuclear Information System (INIS)

Bray, L.

1995-01-01

The approach of this task is to develop high-capacity, selective solid inorganic ion exchangers for the recovery of cesium and strontium from nuclear alkaline and acid wastes. To achieve this goal, Pacific Northwest Laboratories (PNL) is collaborating with industry and university participants to develop high capacity, selective, solid ion exchangers for the removal of specific contaminants from nuclear waste streams

A novel role for methyl cysteinate, a cysteine derivative, in cesium accumulation in Arabidopsis thaliana

DEFF Research Database (Denmark)

Adams, Eri; Miyazaki, Takae; Hayaishi-Satoh, Aya

2017-01-01

Phytoaccumulation is a technique to extract metals from soil utilising ability of plants. Cesium is a valuable metal while radioactive isotopes of cesium can be hazardous. In order to establish a more efficient phytoaccumulation system, small molecules which promote plants to accumulate cesium we...

Efficiency of fly ash belite cement and zeolite matrices for immobilizing cesium

International Nuclear Information System (INIS)

Goni, S.; Guerrero, A.; Lorenzo, M.P.

2006-01-01

The efficiency of innovative matrices for immobilizing cesium is presented in this work. The matrix formulation included the use of fly ash belite cement (FABC-2-W) and gismondine-type Na-P1 zeolite, both of which are synthesized from fly ash of coal combustion. The efficiency for immobilizing cesium is evaluated from the leaching test ANSI/ANS 16.1-1986 at the temperature of 40 deg. C, from which the apparent diffusion coefficient of cesium is obtained. Matrices with 100% of FABC-2-W are used as a reference. The integrity of matrices is evaluated by porosity and pore-size distribution from mercury intrusion porosimetry, X-ray diffraction and nitrogen adsorption analyses. Both matrices can be classified as good solidify systems for cesium, specially the FABC-2-W/zeolite matrix in which the replacement of 50% of belite cement by the gismondine-type Na-P1 zeolite caused a decrease of two orders of magnitude of cesium mean Effective Diffusion Coefficient (D e ) (2.8e-09 cm 2 /s versus 2.2e-07 cm 2 /s, for FABC-2-W/zeolite and FABC-2-W matrices, respectively)

Biological effects of cesium-137 injected in beagle dogs of different ages

Energy Technology Data Exchange (ETDEWEB)

Nikula, K.J.; Muggenburg, B.A.; Griffith, W.C. [and others

1995-12-01

The toxicity of cesium-137 ({sup 137}Cs) in the Beagle dog was investigated at the Argonne National Laboratory (ANL) as part of a program to evaluate the biological effects of internally deposited radionuclides. The toxicity and health effects of {sup 137}Cs are important to understand because {sup 137}Cs is produced in large amounts in light-water nuclear reactors. Large quantities of cesium radioisotopes have entered the human food chain as a result of atmospheric nuclear weapons test, and additional cesium radioisotopes were released during the Chernobyl accident. Although the final analyses are not complete, three findings are significant: older dogs dies significantly earlier than juvenile and young adult dogs; greater occurrence of sarcomas in the cesium-137 injected dogs; the major nonneoplastic effect in dogs surviving beyond 52 d appears to be testicular atrophy.

Incineration of ion-exchange resins

International Nuclear Information System (INIS)

Valkiainen, M.; Nykyri, M.

1985-01-01

Incineration of ion-exchange resins in a fluidized bed was studied on a pilot plant scale at the Technical Research Centre of Finland. Both granular and powdered resins were incinerated in dry and slurry form. Different bed materials were used in order to trap as much cesium and cobalt (inactive tracers) as possible in the bed. Also the sintering of the bed materials was studied in the presence of sodium. When immobilized with cement the volume of ash-concrete is 4 to 22% of the concrete of equal compressive strength acquired by direct solidification. Two examples of multi-purpose equipment capable of incinerating ion-exchange resins are presented. (orig.)

The determination of cesium and rubidium in highly radioactive waste liquid

International Nuclear Information System (INIS)

Wei Songsheng

1991-01-01

Cesium and rubidium in high-level waste liquid were determined by atomic absorption spectrometry with the instrument modified for analyzing radioactive samples. The results show that the method is effective and safe. The error of the method is less than +- 3%, and it has been used in the production of cesium

Lanthanide doped strontium-barium cesium halide scintillators

Science.gov (United States)

Bizarri, Gregory; Bourret-Courchesne, Edith; Derenzo, Stephen E.; Borade, Ramesh B.; Gundiah, Gautam; Yan, Zewu; Hanrahan, Stephen M.; Chaudhry, Anurag; Canning, Andrew

2015-06-09

The present invention provides for a composition comprising an inorganic scintillator comprising an optionally lanthanide-doped strontium-barium, optionally cesium, halide, useful for detecting nuclear material.

Mineral-deposit model for lithium-cesium-tantalum pegmatites

Science.gov (United States)

Bradley, Dwight C.; McCauley, Andrew D.; Stillings, Lisa L.

2017-06-20

Lithium-cesium-tantalum (LCT) pegmatites comprise a compositionally defined subset of granitic pegmatites. The major minerals are quartz, potassium feldspar, albite, and muscovite; typical accessory minerals include biotite, garnet, tourmaline, and apatite. The principal lithium ore minerals are spodumene, petalite, and lepidolite; cesium mostly comes from pollucite; and tantalum mostly comes from columbite-tantalite. Tin ore as cassiterite and beryllium ore as beryl also occur in LCT pegmatites, as do a number of gemstones and high-value museum specimens of rare minerals. Individual crystals in LCT pegmatites can be enormous: the largest spodumene was 14 meters long, the largest beryl was 18 meters long, and the largest potassium feldspar was 49 meters long.Lithium-cesium-tantalum pegmatites account for about one-fourth of the world’s lithium production, most of the tantalum production, and all of the cesium production. Giant deposits include Tanco in Canada, Greenbushes in Australia, and Bikita in Zimbabwe. The largest lithium pegmatite in the United States, at King’s Mountain, North Carolina, is no longer being mined although large reserves of lithium remain. Depending on size and attitude of the pegmatite, a variety of mining techniques are used, including artisanal surface mining, open-pit surface mining, small underground workings, and large underground operations using room-and-pillar design. In favorable circumstances, what would otherwise be gangue minerals (quartz, potassium feldspar, albite, and muscovite) can be mined along with lithium and (or) tantalum as coproducts.Most LCT pegmatites are hosted in metamorphosed supracrustal rocks in the upper greenschist to lower amphibolite facies. Lithium-cesium-tantalum pegmatite intrusions generally are emplaced late during orogeny, with emplacement being controlled by pre-existing structures. Typically, they crop out near evolved, peraluminous granites and leucogranites from which they are inferred to be

Cesium-137 in Norwegian milk 1960-1976

International Nuclear Information System (INIS)

Hvinden, T.

1977-03-01

Cesium-137 in milk has been measured at 11 sampling sites in Norway since 1960. The results show seasonal variations, normally with a peak during summer, and variations from district to district, depending upon farming and precipitation conditions. The concentration of cesium-137, averaged over the 11 sampling sites, reached a maximum of 0.44 nanocurie/litre in 1964, decreasing to 0.05 in 1975 and 1976. The range of variations within the 11 sites is of the order of 10. At other sites, with high precipitation and low grazing field qualities, the concentration has been found to be higher than at the 11 sites, giving a range of variations of more than 100. (Auth.)

Cesium titanium silicate and method of making

Science.gov (United States)

Balmer, Mari L.

1997-01-01

The invention is the new material, a ternary compound of cesium, silica, and titania, together with a method of making the ternary compound, cesium titanium silicate pollucite. More specifically, the invention is Cs.sub.2 Ti.sub.2 Si.sub.4 O.sub.13 pollucite which is a new crystalline phase representing a novel class of Ti-containing zeolites. Compositions contain relatively high Cs.sub.2 O and TiO.sub.2 loadings and are durable glass and ceramic materials. The amount of TiO.sub.2 and Cs.sub.2 that can be incorporated into these glasses and crystalline ceramics far exceeds the limits set for the borosilicate high level waste glass.

Modelling the transport of radioactive cesium released from the Fukushima Dai-ichi NPP with sediments through the hydrologic system

Science.gov (United States)

Kinouchi, T.; Omata, T.; Wei, L.; Liu, T.; Araya, M.

2013-12-01

Due to the accident of the Fukushima Dai-ichi Nuclear Power Plant on March 2011, a huge amount of radionuclides including Cesium-134 and Cesium-137 was deposited over the main island of Japan and the Pacific Ocean, resulting in further transfer and diffusion of Cesium through the atmospheric flow, watershed hydrological processes, and terrestrial ecosystem. Particularly, for the transfer of Cesium-134 and Cesium-137, sediments eroded and transported by the rainfall-runoff processes play an important role as Cesium tends to be strongly adsorbed to soil particles such as clay and silt. In this study, we focus on the transport of sediment and adsorbed Cesium in the watershed-scale hydrologic system to predict the long-term change of distribution of Cesium and its discharge to rivers and ocean. We coupled a physically-based distributed hydrological model with the modules of erosion and transport of sediments and adsorbed Cesium, and applied the coupled model to the Abukuma River watershed, which is located over the area of higher deposition of Cesium. In the model, complex land use and land cover distributions, and the effect of human activities such as irrigation, dam control and urban drainage system are taken into accounts. Simulation was conducted for the period of March 2011 until August 2012, with initial spatial distribution of Cesium-134 and Cesium-137 obtained by the airborne survey. Simulated flow rates and sediment concentrations agreed well with observed, and found that since the accident, two major storms in July and September 2011 transported about 50% of total sediments transported during the simulated periods. Cesium concentration in the sediment was reproduced well except for the difference in the initial periods. This difference is attributable to the uncertainty arisen from the initial distribution of Cesium in the soil and the transfer of Cesium from the forest canopy.

Contact parameters in two dimensions for general three-body systems

DEFF Research Database (Denmark)

F. Bellotti, F.; Frederico, T.; T. Yamashita, M.

2014-01-01

a subsystem is composed of two identical non-interacting particles. We also show that the three-body contact parameter is negligible in the case of one non-interacting subsystem compared to the situation where all subsystem are bound. As example, we present results for mixtures of Lithium with two Cesium......We study the two dimensional three-body problem in the general case of three distinguishable particles interacting through zero-range potentials. The Faddeev decomposition is used to write the momentum-space wave function. We show that the large-momentum asymptotic spectator function has the same...... to obtain two- and three-body contact parameters. We specialize from the general cases to examples of two identical, interacting or non-interacting, particles. We find that the two-body contact parameter is not a universal constant in the general case and show that the universality is recovered when...

The diffusivity of cesium, strontium, carbon and nickel in concrete and mixtures of sodium bentonite and crushed rock

International Nuclear Information System (INIS)

Muurinen, A.; Penttilae-Hiltunen, P.; Rantanen, J.

1986-07-01

The engineering barriers suggested to be used for the disposal of low and intermediate level wastes in Finland are concrete and crushed rock or mixtures of crushed rock and bentonite. In the repository the barriers are saturated by groundwater and radionuclides may be released by diffusion through the barries. For safety analysis, the mechanisms by which the nuclides migrate and corresponding parameters should be known. In this study diffusion measurements on different types of concrete and mixtures of sodium bentonite and crushed rock were carried out. Radioactive isotopes of cesium, strontium, carbon and nickel were used as tracers. The apparent diffusivities (Dsub(a)) were evaluated on the basis of the measurements. The apparent diffusivity of cesium in concretes was 10 -14 ...10 -15 m 2 /s. Strontium was mainly sorbed on cement where it diffuses slowly. Part of strontium propably penetrates in the rock ballast by diffusion. The diffusivities of carbon and nickel in the concrete was low. The upper limit was evaluated to be Dsub(a) -14 m 2 /s. The diffusivity of cesium in the mixtures of crushed rock and bentonite varies between 0.5x10 -12 and 7x10 -12 m 2 /s. Cesium was mainly sorbed on the rock. The diffusivity of strontium was 2x10 -11 ...2x10 -12 m 2 /s. Strontium was mainly sorbed on bentonite. The diffusion of the sorbed ions (surface diffusion) seems to be a additional migration mechanism in the case of cesium and strontium in the mixture of bentonite and crushed rock. The diffusivity of carbon in the mixtures of crushed rock and bentonite was 6x10 -11 ...4x10 -12 m 2 /s. No sorption was found in the case of carbon. The measured Dsub(a) of nickel in the mixtures of crushed rock and bentonite was 4x10 -14 ...2x10 -15 m 2 /s. The experimental arrangement was not, however, in the stationary state and the more correct values would propably be 10 -13 ...10 -14 m 2 /s. No surface diffusion was found in the case of nickel. (author)

Fabrication, characterization and radiation damage stability of hollandite based ceramics devoted to radioactive immobilisation; Synthese, caracterisation et etude du comportement sous irradiation electronique de matrices de type hollandite destinees au confinement du cesium radioactif

Energy Technology Data Exchange (ETDEWEB)

Aubin-Chevaldonnet, V. [CEA Valrho, Dir. de l' Energie Nucleaire (DEN/DETCD/SCDV), Dept. d' Etudes du Traitement et du Conditionnement des Dechets, Service de Conditionnement des Dechets et Vitrification, 30 - Marcoule (France)

2004-11-01

Research on treating specifically the long-lived and high level nuclear wastes, notably cesium, is currently carried out in France. Cesium immobilization in host matrices of high chemical durability constitutes the favoured option. Hollandite matrix is a good candidate because of its high cesium incorporation ability and its excellent chemical stability. During this study, different compositions of hollandite ceramics Ba{sub x}Cs{sub y}C{sub z}Ti{sub 8-z}O{sub 16} (C = Al{sup 3+}, Cr{sup 3+}, Ga{sup 3+}, Fe{sup 3+}, Mg{sup 2+}, Sc{sup 3+}), synthesized by oxide route, were characterized in terms of structure, microstructure and physical and chemical properties. Iron ions seems to be the most suitable of the studied C cations to get high-performance hollandites. The stability of these ceramics under external electron irradiation, simulating the {beta} particles emitted by radioactive cesium, were also estimated, at the macroscopic and atomic scale. The point defects creation and their thermal stability were followed by electron paramagnetic resonance. (author)

Upgradations and operational experience of MC-SNICS ion source for 15 UD pelletron at I.U.A.C., New Delhi

International Nuclear Information System (INIS)

Chopra, S.; Pranav, Kr.; Pawar, N.S.

2006-01-01

The multi-cathode sputter negative ion by cesium sputtering source is widely used as a negative ion source in many pelletron accelerators especially those with AMS facility. After installation and testing of this ion source, further modifications were planned, designed and implemented for cathode wheel bi-directional movement and remote controlled changing of cathodes

Mobility of radioactive cesium in soil originated from the Fukushima Daiichi nuclear disaster. Application of extraction experiments

International Nuclear Information System (INIS)

Yoshikazu Kikawada; Takao Oi; Katsumi Hirose; Masaaki Hirose; Atsushi Tsukamoto; Ko Nakamachi; Teruyuki Honda; Hiroaki Takahashi

2015-01-01

Extraction experiments on soil radioactively contaminated by the Fukushima Daiichi Nuclear Power Plant accident were conducted by using a variety of extractants to acquire knowledge on the mobility of radioactive cesium in soil. The experimental results revealed that cesium is tightly bound with soil particles and that radioactive cesium newly deposited on soil due to the accident had apparently a higher mobility than stable cesium commonly existing in soil. The results suggested that radioactive cesium deposited on soil hardly migrates via aqueous processes, although chemical and mineralogical conditions of soil affect their mobility. (author)

Efficient non-linear two-photon effects from the Cesium 6D manifold

Science.gov (United States)

Haluska, Nathan D.; Perram, Glen P.; Rice, Christopher A.

2018-02-01

We report several non-linear process that occur when two-photon pumping the cesium 6D states. Cesium vapor possess some of the largest two-photon pump cross sections in nature. Pumping these cross sections leads to strong amplified spontaneous emission that we observe on over 17 lasing lines. These new fields are strong enough to couple with the pump to create additional tunable lines. We use a heat pipe with cesium densities of 1014 to 1016 cm-3 and 0 to 5 Torr of helium buffer gas. The cesium 6D States are interrogated by both high energy pulses and low power CW sources. We observe four-wave mixing, six-wave mixing, potential two-photon lasing, other unknown nonlinear processes, and the persistence of some processes at low thresholds. This system is also uniquely qualified to support two-photon lasing under the proper conditions.

Immobilization of aqueous radioactive cesium wastes by conversion to aluminosilicate minerals

International Nuclear Information System (INIS)

Barney, G.S.

1975-05-01

Radioactive cesium (primarily 137 Cs) is a major toxic constituent of liquid wastes from nuclear fuel processing plants. Because of the long half-life, highly penetrating radiation, and mobility of 137 Cs, it is necessary to convert wastes containing this radioisotope into a solid form which will prevent movement to the biosphere during long-term storage. A method for converting cesium wastes to solid, highly insoluble, thermally stable aluminosilicate minerals is described. Aluminum silicate clays (bentonite, kaolin, or pyrophyllite) or hydrous aluminosilicate gels are reacted with basic waste solutions to form pollucite, cesium zeolite (Cs-D), Cs-F, cancrinite, or nepheline. Cesium is trapped in the aluminosilicate crystal lattice of the mineral and is permanently immobilized. The identity of the mineral product is dependent on the waste composition and the SiO 2 /Al 2 O 3 ratio of the clay or gel. The stoichiometry and kinetics of mineral formation reactions are described. The products are evaluated with respect to leachability, thermal stability, and crystal morphology. (U.S.)

Radioactive cesium content in selected food products. Pt. 2. Radioactive cesium in daily food rations of selected population groups

International Nuclear Information System (INIS)

Skibniewska, K.; Smoczynski, S.S.; Wisniewska, I.

1993-01-01

The content of radioactive cesium isotopes emitting beta radiation was studied in daily food rations analysed in diets of working-class and non-working-class families from food products from the regions of Olsztyn, Poznan, Lublin, Warsaw and Wroclaw in 1987 and 1988. In 1987 the highest level of radioactive cesium was found in the food rations in Olsztyn, and lowest in the rations in Poznan (3.32 and 0.65 Bq/kg respectively). In 1988 higher radiocesium content was found in rations composed according to the data on the diet consumed daily in non-working-class families. In that case the highest content was in the daily food rations composed in Warsaw - 2.35 Bq/kg and lowest in Poznan - 1.19 Bq/kg in the daily food rations of working-class families about one half of that value was found. The calculated means values of both analysed rations were: 1.35 for Olsztyn, 0.89 for Poznan, and 1.86 Bq/kg for Warsaw. The calculated mean value of the contamination with radioactive cesium was in 1988 0.93 Bq/kg for the rations in working-class families (in 1987 it was 1.80 Bq/kg). (author). 15 refs, 1 tab

Enhanced electrochemical etching of ion irradiated silicon by localized amorphization

Energy Technology Data Exchange (ETDEWEB)

Dang, Z. Y.; Breese, M. B. H. [Centre for Ion Beam Applications (CIBA), Department of Physics, National University of Singapore Singapore 117542 (Singapore); Lin, Y.; Tok, E. S. [Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore); Vittone, E. [Physics Department, NIS Excellence Centre and CNISM, University of Torino, via Pietro Giuria 1, 10125 Torino (Italy)

2014-05-12

A tailored distribution of ion induced defects in p-type silicon allows subsequent electrochemical anodization to be modified in various ways. Here we describe how a low level of lattice amorphization induced by ion irradiation influences anodization. First, it superposes a chemical etching effect, which is observable at high fluences as a reduced height of a micromachined component. Second, at lower fluences, it greatly enhances electrochemical anodization by allowing a hole diffusion current to flow to the exposed surface. We present an anodization model, which explains all observed effects produced by light ions such as helium and heavy ions such as cesium over a wide range of fluences and irradiation geometries.

Interim salt disposition program macrobatch 6 tank 21H qualification monosodium titanate and cesium mass transfer tests

Energy Technology Data Exchange (ETDEWEB)

Washington, A. L. II; Peters, T. B.; Fink, S. D.

2013-02-25

Savannah River National Laboratory (SRNL) performed experiments on qualification material for use in the Interim Salt Disposition Program (ISDP) Batch 6 processing. This qualification material was a set of six samples from Tank 21H in October 2012. This sample was used as a real waste demonstration of the Actinide Removal Process (ARP) and the Extraction-Scrub-Strip (ESS) tests process. The Tank 21H sample was contacted with a reduced amount (0.2 g/L) of MST and characterized for strontium and actinide removal at 0 and 8 hour time intervals in this salt batch. {sup 237}Np and {sup 243}Am were both observed to be below detection limits in the source material, and so these results are not reported in this report. The plutonium and uranium samples had decontamination factor (DF) values that were on par or slightly better than we expected from Batch 5. The strontium DF values are slightly lower than expected but still in an acceptable range. The Extraction, Scrub, and Strip (ESS) testing demonstrated cesium removal, stripping and scrubbing within the acceptable range. Overall, the testing indicated that cesium removal is comparable to prior batches at MCU.

Ionic properties of non-aqueous liquid and PVDF-based gel electrolytes containing a cesium thiolate/disulfide redox couple

International Nuclear Information System (INIS)

Renard, Ingrid; Li Hongmei; Marsan, Benoit

2003-01-01

Liquid electrolytes containing a cesium thiolate/disulfide redox couple, prepared from 5-mercapto-1-methyltetrazole cesium salt (CsT) and di-5-(1-methyltetrazole)disulfide (T 2 ) dissolved in several aprotic solvents and solvent mixtures, have been studied using various techniques. FTIR spectroscopy reveals that relatively strong interactions occur between the reduced species T - and DMSO or DMF while Cs + ions are very weakly coordinated to the S=O or C=O bond. It is shown that the electrolyte consisting of 1.55 mol kg -1 CsT in the solvent mixture DMSO/DMF (40/60%) exhibits the highest conductivity (1.1x10 -2 and 2.3x10 -2 S cm -1 at 23 and 80 deg. C, respectively), and that the presence of the oxidized species T 2 does not affect significantly its electrical properties up to a CsT:T 2 molar ratio of 5:1. Conductivity values as a function of salt concentration are discussed in terms of the effective number of charge carriers, taking into account the level of ionic association, and of the ionic mobility. Optically transparent gel electrolytes have been prepared by incorporation of the optimal liquid electrolyte into various amounts of poly(vinylidene fluoride) (PVDF). It is shown that ionic mobility is not much affected by the polymer concentration, suggesting that migration of ions occurs mainly through the solvent mixture surrounded by the PVDF matrix

Removal of cesium from simulated liquid waste with countercurrent two-stage adsorption followed by microfiltration

Energy Technology Data Exchange (ETDEWEB)

Han, Fei; Zhang, Guang-Hui [School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072 (China); Gu, Ping, E-mail: guping@tju.edu.cn [School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072 (China)

2012-07-30

Highlights: Black-Right-Pointing-Pointer The adsorption isotherm of cesium by copper ferrocyanide followed a Freundlich model. Black-Right-Pointing-Pointer Decontamination factor of cesium was higher in lab-scale test than that in jar test. Black-Right-Pointing-Pointer A countercurrent two-stage adsorption-microfiltration process was achieved. Black-Right-Pointing-Pointer Cesium concentration in the effluent could be calculated. Black-Right-Pointing-Pointer It is a new cesium removal process with a higher decontamination factor. - Abstract: Copper ferrocyanide (CuFC) was used as an adsorbent to remove cesium. Jar test results showed that the adsorption capacity of CuFC was better than that of potassium zinc hexacyanoferrate. Lab-scale tests were performed by an adsorption-microfiltration process, and the mean decontamination factor (DF) was 463 when the initial cesium concentration was 101.3 {mu}g/L, the dosage of CuFC was 40 mg/L and the adsorption time was 20 min. The cesium concentration in the effluent continuously decreased with the operation time, which indicated that the used adsorbent retained its adsorption capacity. To use this capacity, experiments on a countercurrent two-stage adsorption (CTA)-microfiltration (MF) process were carried out with CuFC adsorption combined with membrane separation. A calculation method for determining the cesium concentration in the effluent was given, and batch tests in a pressure cup were performed to verify the calculated method. The results showed that the experimental values fitted well with the calculated values in the CTA-MF process. The mean DF was 1123 when the dilution factor was 0.4, the initial cesium concentration was 98.75 {mu}g/L and the dosage of CuFC and adsorption time were the same as those used in the lab-scale test. The DF obtained by CTA-MF process was more than three times higher than the single-stage adsorption in the jar test.

Electrically switched cesium ion exchange. FY 1996 annual report

International Nuclear Information System (INIS)

Lilga, M.A.; Orth, R.J.; Sukamto, J.P.H.; Schwartz, D.T.; Haight, S.M.; Genders, D.

1996-12-01

An electrochemical method for metal ion separations, called Electrically Switched Ion Exchange, is described. Direct oxidation and reduction of an electroactive film attached to an electrode surface is used to load and unload the film with alkali metal cations. The electroactive films under investigation are Ni hexacyanoferrates, which are deposited on the surface by applying an anodic potential to a Ni electrode in a solution containing the ferricyanide anion. Reported film preparation procedures were modified to produce films with improved capacity and stability. Electrochemical behavior of the derivatized electrodes were investigated using cyclic voltammetry and chronocoulometry. The films show selectivity for Cs in concentrated sodium solutions. Raman spectroscopy was used to monitor changes in oxidation state of the film and imaging experiments have demonstrated that the redox reactions are spatially homogenous across the film. Requirements for a bench scale unit were identified

Cement materials for cesium and iodine confinement

International Nuclear Information System (INIS)

Nicolas, G.; Lequeux, N.; Boch, P.; Prene, S.

2001-01-01

The following topics were dealt with: radioactive waste storage, cement materials reacting with radioactive cesium and iodine, chemical barrier formation against radioactive pollution, ceramization, long term stability, XRD, PIXE analysis

Web-Based Geospatial Visualization of GPM Data with CesiumJS

Science.gov (United States)

Lammers, Matt

2018-01-01

Advancements in the capabilities of JavaScript frameworks and web browsing technology have made online visualization of large geospatial datasets such as those coming from precipitation satellites viable. These data benefit from being visualized on and above a three-dimensional surface. The open-source JavaScript framework CesiumJS (http://cesiumjs.org), developed by Analytical Graphics, Inc., leverages the WebGL protocol to do just that. This presentation will describe how CesiumJS has been used in three-dimensional visualization products developed as part of the NASA Precipitation Processing System (PPS) STORM data-order website. Existing methods of interacting with Global Precipitation Measurement (GPM) Mission data primarily focus on two-dimensional static images, whether displaying vertical slices or horizontal surface/height-level maps. These methods limit interactivity with the robust three-dimensional data coming from the GPM core satellite. Integrating the data with CesiumJS in a web-based user interface has allowed us to create the following products. We have linked with the data-order interface an on-the-fly visualization tool for any GPM/partner satellite orbit. A version of this tool also focuses on high-impact weather events. It enables viewing of combined radar and microwave-derived precipitation data on mobile devices and in a way that can be embedded into other websites. We also have used CesiumJS to visualize a method of integrating gridded precipitation data with modeled wind speeds that animates over time. Emphasis in the presentation will be placed on how a variety of technical methods were used to create these tools, and how the flexibility of the CesiumJS framework facilitates creative approaches to interact with the data.

Using of synthetic Zeolites in the treatment of low-level liquid radioactive waste

International Nuclear Information System (INIS)

Ganjizadeh, M.; Bayat, I.; Sadatipoor, M.T.; Yavari, I.

2002-01-01

The removal of Cesium-137 from low active waste solution from research reactors by ion exchange using synthetic zeolites 4 A and A R-1 has been investigated by using batch and column technique. In batch tests we have studied the distribution coefficient (k d ) of Cesium-137 on the zeolites as a function of P H, Sodium concentration, contact time, and particle size of zeolites. The decontamination factor determined in column test. The accuracy of the method is investigated by comparing results obtained by this method here with results obtained by other techniques

An Experimental Study of the Fluorescence Spectrum of Cesium Atoms in the Presence of a Buffer Gas

Science.gov (United States)

Davydov, V. G.; Kulyasov, V. N.

2018-01-01

A direct experiment is performed to determine the quantum efficiency of a cesium fluorescence filter. The fluorescence spectra of cesium atoms are recorded under excitation of the upper states of the second resonance doublet with a Bell-Bloom cesium lamp. Introduction of different noble gases into the cell with cesium leads to the appearance of additional fluorescence photons. It is found that a fluorescence filter based on atomic cesium vapor with addition of helium in the working cell has the highest efficiency and response rate of all known fluorescence filters based on alkali-metal atomic vapors.

Historical Cost Curves for Hydrogen Masers and Cesium Beam Frequency and Timing Standards

Science.gov (United States)

Remer, D. S.; Moore, R. C.

1985-01-01

Historical cost curves were developed for hydrogen masers and cesium beam standards used for frequency and timing calibration in the Deep Space Network. These curves may be used to calculate the cost of future hydrogen masers or cesium beam standards in either future or current dollars. The cesium beam standards are decreasing in cost by about 2.3% per year since 1966, and hydrogen masers are decreasing by about 0.8% per year since 1978 relative to the National Aeronautics and Space Administration inflation index.

Effects of mineralogy on sorption of strontium and cesium onto Calico Hills Tuff

International Nuclear Information System (INIS)

Meyer, R.E.; Arnold, W.D.; Case, F.I.; O'Kelley, G.D.; Land, J.F.

1990-04-01

The sorption properties of tuff formations at the proposed site for the high-level nuclear waste repository at Yucca Mountain, Nevada, have been extensively studied. Sorption and desorption measurements were made of strontium and cesium onto clinoptilolite and Calico Hills Tuff. The object was to see whether there was a correlation between sorption of strontium and cesium onto Calico Hills Tuff and the sorption of strontium and cesium onto clinoptilolite based on the content of clinoptilolite in the Calico Hills Tuff. 13 refs., 10 figs., 6 tabs

Cesium-137 in biota from the Bothnian sea after the Chernobyl accident

International Nuclear Information System (INIS)

Notter, M.

1990-01-01

The Chernobyl fallout in April 1986 hit the Swedish Bothnian Sea coast to a relatively large extent. Extended sampling programs to follow uptake and mobilization of Cs-137 at different trophic levels in the aquatic environment started immediately after the accident. Water, sediment, algae, fish and food organisms for fish have regularly been sampled during 1986 and 1988. The highest cesium concentration (3400 Bq/m 3 ) in water from the Bothnian sea was detected in May-July 1986. Since September 1986 the cesium concentration has been decreasing and was about 500 Bq/m 3 in March-June 1987. During the same period, green algae (Cladophora), from early top values at 17000 Bq/kg d.w., have rapidly decreased to about 200 Bq/kg d.w. Of the investigated food organisms, fish-spawn rapidly got high values (3000 Bq/kg d.w.) of cesium. There is also reason to believe that this was the case for plankton. The cesium concentration on the other food organisms was lower, about (500-1200 Bq/kg d.w.). The decrease was fast and already during August 1986 they had relatively low concentrations (less than 500 Bq/kg d.w.). The cesium metabolism was rapid in species that feed on plankton and filtered material from the pelagial, such as mussles and herring. The maximum concentration was reached (1000-1500 Bq/kg d.w.) in September 1986. Fish species with algae in the nutrient chain (e.g. roach) reached concentrations of about 1000 Bq/kg d.w. and the decrease is slower. The accessible cesium for prey fish became relatively good depending on the high concentrations in fish-spawn. The maximum value for the cesium concentration in perch and pike was 2000-3000 Bq/kg d.w. and the decrease is slow. From the results from late 1988 the concentration factor (CF) has been calculated for several fish species in brackish water

Experimental Evaluation of a Negative Ion Source for a Heavy Ion Fusion Negative Ion Driver

International Nuclear Information System (INIS)

Grisham, L.R.; Hahto, S.K.; Hahto, S.T.; Kwan, J.W.; Leung, K.N.

2004-01-01

Negative halogen ions have recently been proposed as a possible alternative to positive ions for heavy ion fusion drivers because electron accumulation would not be a problem in the accelerator, and if desired, the beams could be photo-detached to neutrals. To test the ability to make suitable quality beams, an experiment was conducted at Lawrence Berkeley National Laboratory using chlorine in an RF-driven ion source. Without introducing any cesium (which is required to enhance negative ion production in hydrogen ion sources) a negative chlorine current density of 45 mA/cm 2 was obtained under the same conditions that gave 57 45 mA/cm 2 of positive chlorine, suggesting the presence of nearly as many negative ions as positive ions in the plasma near the extraction plane. The negative ion spectrum was 99.5% atomic chlorine ions, with only 0.5% molecular chlorine, and essentially no impurities. Although this experiment did not incorporate the type of electron suppression technology that i s used in negative hydrogen beam extraction, the ratio of co-extracted electrons to Cl - was as low as 7 to 1, many times lower than the ratio of their mobilities, suggesting that few electrons are present in the near-extractor plasma. This, along with the near-equivalence of the positive and negative ion currents, suggests that the plasma in this region was mostly an ion-ion plasma. The negative chlorine current density was relatively insensitive to pressure, and scaled linearly with RF power. If this linear scaling continues to hold at higher RF powers, it should permit current densities of 100 45 mA/cm 2 , sufficient for present heavy ion fusion injector concepts. The effective ion temperatures of the positive and negative ions appeared to be similar and relatively low for a plasma source